Turbine Traning Manual

Cakerawala Platform Taurus 60 Generator Training Manual

SECTION 1 - INTRODUCTION TO CAKERAWALA GAS TURBINES Turbines & Origins There are many different types of turbines in use in the world today. Some forms are old, like the Waterwheel (hydraulic turbine) and Windmill. Others are of more recent origin, Steam Turbines date from the 19th century while Gas Turbines date from the 20th century. Gas Turbines were originally conceived as a means of aircraft propulsion and were not developed for industrial use until 1947. Since then they have undergone significant changes in design to become more powerful and efficient and capable of operation in a wide variety of environments and applications.

Operating Principles All turbines are basically engines that convert the energy of a moving stream of fluid (liquid / water, steam or gas) into mechanical energy. The essential element of all turbines is a shaft with blades or buckets arranged radially around the shaft in such a fashion that the fluid stream imparts a force to the blades or buckets to cause the shaft to rotate. The rotational torque imparted to the shaft is then used to provide useable power; Examples : Waterwheel – mechanical drive (corn mill) ,hydro-electric generator. Windmill – mechanical drive (water pump), generator. Steam Turbine – numerous including mechanical drives and generators. Turbo-charger – compressor driver. Note: The rotating shaft on a Turbo-jet (aircraft engine) drives a compressor and other auxiliary drives and uses the exhaust gases to provide thrust to ‘push’ the aircraft forward.

Why Gas Turbine? There are numerous variants to the basic operating concept of an ‘engine that converts the energy of a moving fluid stream into mechanical energy’. What is common to all Gas Turbines is the ‘Driving fluid’ which is Gas. An aircraft Turbo-jet may use liquid fuel, but it is still a Gas Turbine because it is ‘driven’ by gas, just as the Turbo-charger is driven by the exhaust gas of a reciprocating engine and an Expander / Compressor is driven by the gas of the process it is operating on.

Solar Taurus 60 under construction

Industrial Gas Turbine – Principle of Operation There are numerous designs and configurations of Industrial Gas Turbines, but they all operate in essentially the same basic manner. They are heat engines and use the expanding gases of combustion to drive the turbine shaft. They operate under what is called the Brayton Cycle. Unlike the reciprocating Internal Combustion engine which also uses the expanding combustion gases to drive it’s pistons and operates under the Otto Cycle; the Gas Turbine has continuous combustion to provide continuous torque to the turbine shaft. They do not need a flywheel to dampen the intermittent cylinder combustion of the Internal Combustion engine and do not develop the high internal pressures encountered in the cylinders of a reciprocating engine.

The Brayton Cycle Brayton Cycle

In order to begin and then sustain combustion, an oxidizer (oxygen) must be combined with the fuel and ignited. Free air contains nearly 21% oxygen and like the internal combustion engine, this is used air, the remaind by being drawn in and compressed, (compression Brayton Cycle 1>2). It is then mixed with the fuel and ignited and combustion occurs, (Brayton Cycle 2>3). The combustion gases expand rapidly, (expansion, Brayton Cycle 3>7) and drive the turbine shaft. The expanding gases are then allowed to exhaust to atmosphere (Brayton Cycle 7>1) where the remainder of their heat energy is dissipated (the temperature falls). Note from diagram (A) that pressure only increases from 1>2 where it is at a maximum and is designed so that there is no increase in pressure at combustion. The points in the diagrams (1,2,3,7) are ‘Engine Data Points’ commonly used to indicate particular locations throughout the engine gas path (refer to diagram on page 1.3).

This is the basis on which all Industrial Gas Turbines operate and will be more fully explained in the modules that follow. At this stage it is worth noting that although only about ¼ of the air that is drawn into the engine is used for combustion, the bulk of the remainder is used for cooling and this still contributes to expansion. About 2/3 of the total power developed is used to compress air, the remainder is used to drive ‘loads’. Most machines are as described and are referred to as ‘Open Cycle’ units. However, some using “Recuperators”, while others use Waste Heat Recovery Units to ‘extract’ heat from the exhaust to be used elsewhere, for example to raise steam.

Principle to Practice As the thermodynamic principle on which Gas Turbines operate has been mentioned, how this is achieved in practice can now be considered. On Cakerawala, “Solar Taurus 60 Generator” sets are installed. While other manufacturers use different arrangements these machines are typical of the most common internal mechanical arrangements generally used. The Taurus 60generator sets are referred to as a “Single Shaft” arrangement. The “Single Shaft” configuration is the least complicated arrangement and will be considered first. T3 P3

Data Points T1, etc T1 P1

T5 P5

T2 P2

Typical Single Shaft Cold End Drive Data Points

Typical Single Shaft (Cold End Drive) The drawing above shows the engine internal arrangement and the “Data Points” in the gas path. Air from the atmosphere is drawn in through the Air Inlet (T1, P1) by the Compressor Rotor Assembly, which is mounted on a common shaft connected to the Turbine Rotor Assembly at the RH end and the Engine Output Shaft at the LH end. As the Engine Output Shaft is at the cooler Air Inlet end and not at the hotter Turbine Exhaust end it is referred to as “Cold End Drive”. The compressed air leaves the compressor and enters the Diffuser (T2,P2) where it’s pressure(P2) is greatest and the temperature (T2) has also increased about 260C [@ 500F] above T1. Fuel Gas from the Fuel Gas Manifold is mixed with air from the Air Manifold and injected into the Combustion Chamber through Fuel Injectors where it is burnt after having been initially ignited by the Igniter Torch at the ‘start’. Combustion causes the temperature to increase to about 2800F and the volume to also increase greatly. The Combustion Chamber is constructed to allow cooler air to enter and direct the hot gases away from the Combustion Chamber liners (to minimise heat damage and to cool the hot gas) and into the Turbine assembly without increasing the pressure. The temperature at the inlet of the Turbine (T3) sometimes referred to as “TRIT” (Turbine Rotor Inlet Temperature) is generally not monitored, but the temperature at the inlet of the last stage (T5) invariably is and can be used as an indication of the heat energy in the engine. After exiting the turbine section the gases are directed away to atmosphere through the Turbine Exhaust (T7) and any external ducting.

T7 P7

Cakerawala Solar Turbo-Machinery The following machine packages installed on Cakerawala Platform:GQ 7500 Solar Taurus 60 Generator – Natural Gas Fuel / Liquid Fuel GQ 7520 Solar Taurus 60 Generator – Natural Gas Fuel / Liquid Fuel GQ 7540 Solar Taurus 60 Generator – Natural Gas Fuel GQ 7560 Solar Taurus 60 Generator – Natural Gas Fuel These engines are designed to operate with high CO2 content These engines were mentioned earlier (Page 1.3) and will now be described in more detail, with material largely quoted from the Solar Manuals available on site.

SAFETY Industrial Gas Turbines are high speed rotating heat engines which can present many potential hazards and caution must be exercised at all times, not only when in the vicinity of the Turbine package, but also when operating remotely. The following WARNING should be understood and heeded at all times. Appendix A of these notes contains the Solar Operations Manual Safety Guides which must be understood and should be used as a guide to the safe operation and maintenance of the packages.

WARNING 1. Operation of the unit may be performed only when conditions indicate it is safe to proceed. Dangerously explosive accumulations of natural gas, fuel fumes, oil tank vent leakage, or solvent fumes must be avoided at all times. This is done by proper ventilation, elimination of leaks, and by confining the use of solvents to appropriate maintenance facilities. 2. Appropriate hearing and eye protection must be used by operating and maintenance personnel in the vicinity of the operating machine. 3. Turn off electrical power. Tag control devices to prevent electrical shock and starting of unit while unit is shut down. 4. Allow sufficient time for piping and system components to cool. Components can become extremely hot and cause burns if touched with unprotected hands. 5. Do not allow fluids to come in contact with hot surfaces. Fluids discharged from lines or fittings may be flammable and could cause a fire hazard. 6. Depressurize system before loosening line fittings or removing components. High pressure lines or jetstreams can cause serious injury.

TURBINE PACKAGE INSPECTION ‘ON-LINE’ YOU MUST HAVE A PERMIT TO WORK ON ANY PART OF THE TURBINE PACKAGE

Before Opening Package Doors 1. Contact control room operator for permission to enter and to disarm fire system. 2. Disarm fire system. If fire system is not disarmed it may discharge 3. Take care when opening package doors. Inside package is pressurised and doors will open hard and fast 4. Carry out inspection Closing Package Doors 1. Take care. They are hard to close against the inside pressure and may require help to close. 2. Relock doors. 3. Rearm fire system. 4. Contact control room operator and notify you have finished inspection, fire system is re-armed and doors are locked.

NOTE - ORIENTATION Directional references on the unit (right side, left side, forward, and aft) are established by viewing the unit facing the engine exhaust (aft) end and looking forward.

AFT

Orientation Diagram

LEFT

RIGHT

FORWARD

Taurus 60 GAS TURBINE-DRIVEN GENERATOR SET

General Package Description The Taurus 60 Gas Turbine-Driven Generator Set consists of an axial-flow turbine engine, a generator, and gear unit. These elements are installed in-line on a steel base frame, a structural weldment with beam sections and cross members forming a rigid foundation. Machined mounting surfaces on the base facilitate alignment of major components. The gear unit input shaft is connected with the engine compressor rotor nose cone hub with a splined sleeve coupling. A mating flange bolted to the engine air inlet housing attaches the assemblies. The generator input shaft is aligned with the gear unit output shaft, and the shafts are connected with a flexible shear coupling in a protective cover.

Components The generator set’s accessories include the start, fuel, electrical control, lube oil, pneumatically controlled air systems, and a governor.

MAJOR COMPONENTS AND SYSTEM

Taurus 60 Gas Turbine Generator Set

Air Inlet Assembly

Exhaust Assembly

Generator

Turbine Engine

Starter Motor

Package Base Frame

Taurus 60 Gas Turbine Engine

Air Inlet

Compressor Assembly

Combustor Assembly

Fuel Injectors

Compressor Diffuser

Gas Fuel Manifolds Lube Oil Filters

The turbine engine is the package power plant. Air is drawn into the compressor section through the air inlet and is compressed. Fuel is added to the compressed air in the combustor and is ignited. After combustion, hot gases expand through turbine nozzles and drive the turbine rotor. The turbine drives the engine compressor, accessories, and generator. Air and combustion gases are discharged to the atmosphere through the exhaust system. Major components include air inlet, engine compressor, compressor diffuser, combustor, turbines, exhaust diffuser and exhaust collector.

Generator The genator, the driven equipment, transforms Mechanical energy to electrical energy. The Generator is bolted to the raised mounting pads on The base, in alignment with the gear unit. The Standard generator set has a two-bearing, revolving field-type, three-phase, ac generator, of dripproof construction, with damper windings and a direct- connected brushless exciter,controlled by a Voltage Regulator (AVR).

Electrical Generator Coupling Guard

Drive End Non-Drive End

Voltage Regulator

Gear Unit The two-stage, epicyclic gear unit transmits power from turbine engine to the electrical generator and also drives the main lube oil pump. The unit will sustain momentary overloads of up to approximately eight times normal operating torque. The lube oil system lubricates bearings and the gear train. The engine air system pressurizes the bearing oil seals

Start System The start system includes starter and control devices. The starter rotates the engine to selfsustaining speed, where the starter shuts down, the starter clutch overruns, and the engine accelerates under its own power to loading speed.

Starter Motor

Fuel System The fuel system regulates fuel flow. The dual fuel systemis a combination gas fuel and liquid (diesel) fuel system.Specially designed components, mechanical linkages, solenoid-operated valves and other devices combine the gas fuel system and the liquid fuel system into a single intergrated system.

Primary Gas Fuel Valve

Secondary Gas Fuel Control Valve

Gas Fuel Valves Electronic Gas Fuel Control Valve

Lube Oil System Supplied from the base frame reservoir, the lube oil system circulates pressurized oil to hydraulic subsystems and to the turbine engine, gear unit and starter motor to gear unit drive connection. An oil cooler and a thermostatic oil control valve maintain oil temperature. Oil Reservoir

Filler Cap

Lube Oil Filters

Electrical System The 24 Vdc electrical control system monitors the engine and generator and controls normal and emergency (malfunction) shutdowns. In operation, the electrical control system protects the engine and driven equipment from damage from hazards such as overspeed, high engine temperature and vibration levels, low lube oil pressure, excessive oil temperature and generator over or undervoltages and high winding temperature.

Turbotronics Display

The control system wiring is routed via control and monitoring junction boxes on the package skid to the “Turbotronics” panel located in the MCC. Display of engine and generator operational conditions is available on the“Turbotronics” panel , along with indicator lights and pushbutton and other switches to display and control operational status. A gauge panel is also installed on the engine package to show some engine operating conditions.

Taurus 60 Single Shaft Turbine Sectional View

Bleed Valve

Injector Gas Ring Air Inlet

Exhaust Power Turbine Gas Producer Combustor Compressor Accessory Gearbox

SAFETY WARNING 1. Operation of the unit may be performed only when conditions indicate it is safe to proceed. 2. Dangerously explosive accumulations of natural gas, fuel fumes, oil tank vent leakage, or solvent fumes must be avoided at all times. This is done by proper ventilation, elimination of leaks, and by confining the use of solvents to appropriate maintenance facilities. 3. Appropriate hearing and eye protection must be used by operating and maintenance personnel in the vicinity of the operating machine. 4. Turn off electrical power. Tag control devices to prevent electrical shock and starting of unit while unit is shut down. 5. Allow sufficient time for piping and system components to cool. Components can become extremely hot and cause burns if touched with unprotected hands. 6. Do not allow fluids to come in contact with hot surfaces. Fluids discharged from lines or fittings may be flammable and could cause a fire hazard. 7. Depressurize system before loosening line fittings or removing components. High pressure lines or jetstreams can cause serious injury.

Turbine inspection-On Line Before opening Turbine package doors. 1. Contact control room operator for permission to enter and to disarm fire system. 2. Disarm fire system. If fire system is not disarmed it may discharge 3. Take care when opening package doors. Inside package is pressurised and doors will open hard and fast 4. Carry out inspection Closing turbine package doors. 1. 2. 3. 4.

Take care. They are hard to close against the inside pressure and may require help to close. Rearm fire system Relock door Contact control room operator and tell you have finished inspection, fire system is rearmed and doors are locked.

YOU MUST HAVE A PERMIT TO WORK ON THE TURBINE PACKAGE

SECTION 2 - CAKERAWALA GAS TURBINE START SYSTEMS Taurus 60 START SYSTEM GENERAL DESCRIPTION When the start/crank cycle is initiated, a timed prelube sequence is activated. As the prelube cycle times out, the control system directs power to Variable Frequency Drive (VFD430) which provides starting power to Starter Motor (B330). Initially, variable frequency drive VFD430 provides a low frequency ac voltage to motor B330 to begin rotation. The frequency and voltage to motor B330 are then ramped up to accelerate the engine to purging speed. Correct engine purging speed is maintained by a programmed fixed current limit to motor B330. At the same time, the fuel valves are opened, light-off is attempted, and the control system increases motor velocity, causing motor B330 to start ramping from purge speed to starter dropout speed. As the engine reaches dropout speed, variable frequency drive VFD430 is de-energized by the control system, cutting power to motor B330, and the motor clutch is disengaged. The ac direct start system provides the starting power for the engine. The start system includes the following: • Starter motor • Radio Interference Filter • Monitoring Relay • Variable frequency drive Starter Motor Starter Motor (B330), installed a mounting flange on the front the accessory drive pad, is a squirrel cage induction, 15minute inverter duty, polyphase-type motor. The motor provides high breakaway torque, and will accelerate the engine from standstill to starter dropout speed. The motor power is provided by Variable Frequency Drive (VFD430) and the motor is protected from thermal overload by Monitoring Relay (RT230). The motor also incorporates a space heater.

on of

Starter Motor

Radio Interference Filter Radio Interference Filter (RFI430), located in the input cabling to Variable Frequency Drive (VFD430), prevents radio interference from affecting the operation of variable frequency drive VFD430. Monitoring Relay Monitoring Relay (RT230), monitors thermistors installed in the Starter Motor (B330) to provide thermal overload protection for the motor.

Variable Frequency Drive

Starter Motor VSD Variable Frequency Drive (VFD430) is a general purpose, variable speed, ac controller. Installed offskid, the variable frequency drive incorporates a keypad/display which can be used to program, through software, configuration adjustments.

FUNCTIONAL DESCRIPTION Starting Sequence The starting sequence is initiated by pressing the start button. Upon pressing the start button, the fuel gas valve and pre lube pressure checks are conducted. Along with this the enclosure pressurization and fan operation is also checked. STARTING Light (DS114) begins flashing. Fuel system valve check sequence begins. Post lubricating backup pump is tested for operation, post lubricating oil pump is started, and prelubrication begins. Enclosure ventilation fan is energized.

VALVE CHECK SEQUENCE Before the engine cranks during the start cycle, the fuel system performs a valve check sequence. If Gas Fuel Pressure Switches (S341-1, S341-2) sense fuel pressure, Gas Fuel Vent Shutoff Valves (V2P941, V2P941-1) are opened to vent gas from the supply line. If pressure drops below the set point, the vent valves are closed, and the valve check sequence proceeds. Primary shutoff valves V2P931 and V2P931-1 open and admit fuel to pressure switches S342-2, S342-3, and secondary shutoff valves V2P932 and V2P932-1. Pressure switches S342-2 and S342-3 signal increasing pressure. This verifies the opening of shutoff valves V2P931 and V2P931-1, and enables the start sequence to proceed. Five seconds after being opened, primary shutoff valves V2P931 and V2P931-1 close. If pressure drops, secondary shutoff valve V2P932 or V2P932-1 are leaking. After the prelube cycle, shutoff valves V2P932 and V2P932-1 open. With shutoff valves V2P931 and V2P931-1 closed, trapped gas is allowed to escape into the fuel system. Pressure drops indicating that shutoff valves V2P931 and V2P931-1 are fully closed and that shutoff valves V2P932 and V2P932-1 are open. If pressure fails to drop, a gas fuel valve fail malfunction indication and an engine shutdown are initiated 15 seconds after prelube is complete.

Lube Oil Pump Checks When the start cycle begins, the control system tests Postlube Backup Lube Oil Pump (P903). If pump P903 pressure reaches 4 psi (27.6 kPa), the control system deactivates pump P903 and then activates Pre/Post Lube Oil Pump (P902). If pump P902 pressure reaches 6 psi (41.3 kPa), the control system allows the engine prelube cycle to begin.

PRELUBE CYCLE After the lube oil pump checks are completed, the prelube time out timer (60 seconds) is started. The prelube time out timer is the allowable time for pump P902 to complete the prelube cycle. When the lube oil pressure is greater than the prelube low pressure limit of 6 psi (41.3 kPa), the prelube timer (30 seconds) is started. The engine must be prelubed at a pressure above 6 psi (41.3 kPa) continuously for the duration of the prelube timer (30 seconds). This prelube must occur within the time of the prelube time out timer (60 seconds). If the prelube timer times out before the prelube is done, the start is aborted and a prelube failed fast stop non-lockout alarm is annunciated on the control console.

Taurus 60 Generator Set - Start Sequence Diagram Speed Ngp

CURVE LEGEND : = Ngp NOTE : Annunciations are shown in RED font. Generators at idle and ready to load, bleed valve open

100 90

Guide Valve Fully Open

80

Generator Excitation Starter Motor Drop Out Speed

65

START RAMP Engine purge Timer

300 30 Sec

10

20 - 25

T5 Set Point change (50% Ngp) MIN. FUEL

0 T5 < 400F+ > 10 seconds = IGNITION FAILURE

Pre-start permissives 1 Fuel Valve Checks 2 Lube Oil Pump Checks 3 Prelube 4 Waste Heat Recovery Pre-start package checks - Safe to start and no alarms or inhibits = READY

Combustion starts T5> 400F <10 seconds = LIGHTOFF IGNITION READY TO LOAD command ON = Fuel valves + torch + ignition STARTING RUNNING

Press

Time

Taurus 60 Start Procedure 1. Perform prestart procedures. 2. Select gas fuel or liquid fuel by pressing GAS/LIQUID Switch/Light (S/DS141). NOTE For gas fuel, the [Gas Selected] indication on the OPERATION SUMMARY display screen will highlight. When gas fuel operation begins, the [Gas Active] indication on the OPERATION SUMMARY display screen will highlight. For liquid fuel, the [Liquid Selected] indication on the OPERATION SUMMARY display screen will highlight. When liquid fuel operation begins, the [Liquid Active] Indication on the PERATION SUMMARY display screen will highlight. 3. Press START Switch (S110) located on turbine control panel. a. STARTING Light (DS114) begins flashing and [Starting] is highlighted on OPERATION SUMMARY display screen. Backup lube oil pump is tested for operation and pre/post pump starts prelubrication cycle. Gas fuel system valve check sequence begins. Start system is energized. Enclosure vent fan is energized. b. Waste heat recovery diverter valve, will switch from closed mode to open mode to divert the exhaust gases to the waste heat recovery unit. When the diverter is open a permissive to start signal is sent to activate the purge timer. c. After the prelube cycle is complete, engine cranking begins. d. After the starter has cranked the engine to 15 percent speed, the purge timer is activated and provides 5 minutes of exhaust system purging via engine airflow. [Purge Crank] is highlighted on OPERATION SUMMARY display screen. e. After turbine purge timer times out, and diverter valve, controlled by customer-furnished devices, is switch from bypass (closed) mode to open mode to divert exhaust to waste heat recovery unit. [Ignition] is highlighted on OPERATION SUMMARY display screen. f. The engine continues to accelerate and engine temperature increases to 400 F˚ (204 C˚). [Light Off] is highlighted on OPERATION SUMMARY display screen, fuel ramp is activated, and ignition is deenergized. The ENGINE HOURS/START COUNTER Meter (M210) registers a successful start. g. Engine speed increases to starter dropout speed. Engine-driven lube oil pump pressure increases and pre/post pump stops. Start system is de-energized and starter clutch overruns, starter begins the cooldown cycle. Voltage regulator is energized. Vibration monitor is switched from offset to normal settings. The ENGINE HOURS/START COUNTER Meter (M210) begins to log engine operating hours. STARTING Light is extinguished and [Running] is highlighted on OPERATION SUMMARY display screen. h. At approximately 80 percent engine speed, the voltage regulator is energized. i. Engine speed increases to 90 percent. Speed-sensing circuit assumes fuel control by sending commands directly to fuel actuator. [Ready To Load] is highlighted on OPERATION SUMMARY display screen. 4. When load is applied, [On Load] is highlighted on OPERATION SUMMARY display screen. Main fuel actuator is positioned in such a way that maintains engine at its preselected operating speed setting.

SECTION 3 - CAKERAWALA GAS TURBINES LUBE OIL SYSTEMS TAURUS 60 LUBE OIL SYSTEM GENERAL DESCRIPTION The main purpose of the lube oil system is to deliver lube oil under pressure to the turbine bearings, driven equipment bearings, and gearbox (if installed) bearings, providing lubrication and cooling. The oil system also includes a servo oil system. The servo oil system supplies regulated, pressurized oil (hydraulic pressure) to numerous control actuators, providing the motive force needed to drive them. The systems utilize a common oil reservoir. Required cooling for the oil supply is provided by an oil cooler assembly which may be located remotely from the skid base or mounted directly on the skid base.

FUNCTIONAL DESCRIPTION General Lube Oil Flow The lube oil system provides oil delivered by Main Lube Oil Pump (P901) to the lube oil manifold. The oil is maintained at a nominal engine inlet pressure by Main Lube Oil Pressure Control Valve (PCV901). Oil pressure is also supplied to Guide Vane Control Actuator (L339) and bleeds valve actuator, causing the actuator piston to move in response to electrical signals from the control system. Temperature Control Valve (TCV901–1) will divert all of the oil from Air/Oil Cooler (HX901-1) until the oil temperature reaches a predetermined setting. Temperature control valve TCV901–1 then gradually transitions to supply oil to air/oil cooler HX901-1 in proportion to the oil temperature. From air/oil cooler HX901-1, the oil flows through Main Lube Oil Filters (FS901-1, FS901-2) to the oil supply manifold, then through various branch lines to points of lubrication. Oil to the reduction gear unit enters a port on the right-hand side of the housing. It flows through internal passages to a tubular oil transfer assembly, which directs the oil to the compressor rotor forward bearing. An oil jet, from a small tube in the oil transfer cap, lubricates the splined sleeve coupling on the compressor nose cone hub. Lubricating oil for remaining gears and bearings in the power train and accessory drive sections of the reduction gear unit is directed to their respective points through drilled passages in the gear unit housing and individual subassemblies. Oil is drained from the reduction gear unit housing by gravity to the oil reservoir. Oil supplied to a port on the compressor bearing support housing is delivered to compressor rotor aft journal and thrust bearings and, through internal passages, to the turbine rotor bearing. Oil from turbine rotor and compressor aft bearings drains by gravity to the lube oil reservoir through two drain outlets in the compressor bearing support housing.

Lube Oil Pump Checks When the start cycle begins, the control system tests Postlube Backup Lube Oil Pump (P903). If pump P903 pressure reaches 4 psi (27.6 kPa), the control system deactivates pump P903 and then activates Pre/Post Lube Oil Pump (P902). If pump P902 pressure reaches 6 psi (41.3 kPa), the control system allows the engine prelube cycle to begin.

PRELUBE CYCLE After the lube oil pump checks are completed, the prelube time out timer (60 seconds) is started. The prelube time out timer is the allowable time for pump P902 to complete the prelube cycle. When the lube oil pressure is greater than the prelube low pressure limit of 6 psi (41.3 kPa), the prelube timer (30 seconds) is started. The engine must be prelubed at a pressure above 6 psi (41.3 kPa) continuously for the duration of the prelube timer (30 seconds). This prelube must occur within the time of the prelube time out timer (60 seconds). If the prelube timer times out before the prelube is done, the start is aborted and a prelube failed fast stop non-lockout alarm is annunciated on the control console.

Engine Running After the prelube cycle is completed, pump P902 is de-energized when the engine is above starter dropout speed and the lube oil pressure is at or above 35 psi (241 kPa). At this point, engine-driven pump P901 begins providing lube oil pressure and continues to the steady state condition. After engine-driven pump P901 reaches the steady state condition, the lube oil schedule becomes active. During the steady state engine running condition, pump P902 is energized when: • •

The engine is below starter dropout speed and the lube oil pressure is at or below 25 psi (172.25 kPa) Engine speed of greater than 5% Ngp is detected.

Pump P902 will not be annunciated as failed during the steady state engine running condition when the lube oil pressure is less than the postlube low pressure shutdown limit, because pump P901 may be at fault.

Run Protection During steady state engine running, the control system provides run protection to the engine by energizing pump P903 anytime the lube oil pressure is below the lube oil pressure low alarm limit (41psi). When the lube oil pressure is no longer below the lube oil pressure low alarm limit pump P903 continues to run for 30 seconds and is then de-energized. The following 3 situations may arise: •

If the lube oil pressure continues to decrease below the lube oil pressure low alarm limit to the low lube oil pressure shutdown limit, a fast stop, lockout engine shutdown is initiated, and pump P903 contributes to protecting the engine bearings during the engine shutdown.

•

If the lube oil pressure continues to decrease below the lube oil pressure low alarm limit but stabilizes between the low lube oil pressure low alarm limit and the low lube oil pressure shutdown limit continuously for 5 seconds, a fast stop, non-lockout engine shutdown is initiated, and pump P903 contributes to protecting the engine bearings during the engine shutdown.

•

If the lube oil pressure increases above the lube oil pressure low alarm limit, and after 30 seconds or when pump P903 is de-energized, lube oil pressure once again decreases, an alarm is initiated and pump P903 is once again energized.

Postlube Backup Lube Oil Pump Checks During engine running, pump P903 operation is checked automatically. Pump P903 operation can also be checked manually.

AUTOMATIC POSTLUBE BACKUP LUBE OIL PUMP CHECK The operation of pump P903 is checked automatically each 24 hours. Every day at 12:00 Noon, a backup pump check is annunciated on the control console, indicating that a check of pump P903 has been initiated. Pump P903 is energized. When pump P903 has made enough pressure for Postlube Backup Lube Oil Pump Pressure Switch (S322-5) to remain closed for 90 seconds, pump P903 is deenergized and the backup pump check on the control console is extinguished. If pressure switch S322-5 is not closed within 30 seconds of pump P903 being energized, pump P903 is de-energized, the backup pump check on the control console is extinguished, and a backup pump check failed is annunciated on the control console.

MANUAL POSTLUBE BACKUP LUBE OIL PUMP CHECK Operation of pump P903 can be checked manually by selecting the backup pump check on the control console terminal. The sequence of events for manually checking the operation of pump P903 are the same as the automatic check above.

Postlube Cycle The postlube cycle begins when the rundown timer (6 minutes) has expired. Initially, pump P902 is de-energized to allow a check of pump P903 to take place. A 30 second pressure decay timer is started to allow the lube oil pressure to drop to 5 psi (34.4 kPa). If the pressure decay timer expires before the pressure drop occurs, the start is aborted and a backup lube oil pump fail alarm is annunciated on the control console. While the engine is in the postlube cycle, if pump P902 fails to keep the lube oil pressure above the postlube low lube oil pressure shutdown limit, a pump failure is annunciated on the control console. Pump P903 takes over the postlube and pump P902 is de-energized. However, pump P902 can be re-initiated to take over the postlube by acknowledging and resetting the alarm. During the time the lube oil pressure is less than the postlube low lube oil pressure shutdown limit, the postlube timer is frozen.

Postlube Scenarios The following are five distinct postlube scenarios which may be initiated: 1. POSTLUBE AFTER SHUTDOWNS BEFORE ENGINE TURNS If the prelube has been completed, but the starter motor has not yet been engaged, and the engine is stopped, the rundown timer is not triggered and postlube will not be initiated unless the engine was in postlube prior to the initiation of the failed start. In this case, the postlube will continue from the accumulated time from before the start was initiated.

2. POSTLUBE AFTER SHUTDOWNS FROM SPEEDS BELOW FIVE PERCENT If the starter motor has been engaged, but the engine is shut down before five percent Ngp, the rundown timer is reset so the engine is lubed for the duration of the rundown timer. Postlube will not be initiated unless the engine was in postlube prior to the initiation of the failed start. In this case, the postlube will continue from the accumulated time from before the start was initiated. 3. POSTLUBE AFTER SHUTDOWNS FROM SPEEDS ABOVE FIVE PERCENT AND BEFORE ENGINE LIGHTOFF If the engine is started and an engine shutdown is initiated after five percent Ngp, but before lightoff has been achieved, the engine is lubed for the time it takes the Ngp to drop below five percent plus the duration of the rundown timer. Postlube will not be initiated unless the engine was in postlube prior to the initiation of the failed start. In this case, the postlube will continue from the accumulated time from before the start was initiated. 4. POSTLUBE AFTER SHUTDOWNS WHEN LIGHTOFF HAS OCCURRED If the engine has achieved lightoff (defined as the T5 average temperature exceeding 400˚F [204.4˚C]), a full postlube is required. The full postlube lasts for 55 minutes, with the alarm and shutdown pressures as follows: •

Low Lube Oil Pressure Shutdown - 4 psi (27.6 kPa)

•

Low Lube Oil Pressure Alarm - 6 psi (41.3 kPa)

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High Lube Oil Pressure Alarm - 25 psi (172.25 kPa)

5. POSTLUBE IN THE EVENT OF FIRE If an engine shutdown is initiated due to a fire, the engine is lubed until the rundown timer (6 minutes) expires. The postlube is then automatically postponed for 20 minutes. However, the postlube can be initiated manually during this time period by acknowledging and resetting the alarm. After the 20 minutes has expired, a postlube is automatically initiated. If a postlube is not desired, the postlube can be stopped manually. If the engine has been without postlube for longer than 20 minutes, a BEARING INSPECTION MAY BE REQUIRED alarm is annunciated on the control console. Such an event would be cause for investigation of possible bearing damage.

Lube Oil Pressure Schedule The low lube oil pressure shutdown limit is 4 psi (27.6 kPa) and the low lube oil pressure alarm limit is 6 psi (41.3 kPa) between the completion of the prelube cycle and the starter dropout speed. Ten seconds after starter dropout speed has been achieved, if the pressure is below 41 psi (282.5 kPa), a LOW LUBE OIL PRESSURE alarm is annunciated on the control console. If the pressure is below 25 psi (172.25 kPa), a fast stop, non-lockout engine shutdown is initiated. There is no high lube oil pressure alarm . Pre/Post Lube Oil (below 65% NGP) Low Lube Oil Pressure Shutdown - 4 psi (27.6 kPa) Low Lube Oil Pressure Alarm - 6 psi (41.3 kPa) High Lube Oil Pressure Alarm - 25 psi (172.25 Normal Running (above 65%) Low Lube Oil Pressure Shutdown - 25 psi (172.25 kPa) Low Lube Oil Pressure Alarm - 41 psi (282.5 kPa)

Taurus 60 Generator Set: Pre-Lube, Start & Steady State Lube Oil Diagram

NOT TO SCALE TP380 (LOP) PUMP CHECKING ACTIVE – remains until Rundown Timer is DONE Pre-Post High Pressure Alarm Enabled

AL = 6 PSI SD = 4 PSI 60 sec.

AL = 41 PSI SD = 25 PSI 10 s STEADY STATE

41 PSI

AL

35 PSI 30 sec. 25 PSI

SD

6 PSI

4 PSI 3 PSI

Time START REQ. P202 START P202 STOP P203 START Main Pump Press. Pass PRELUBE TIMER ENGAGE STARTER PRELUBE TIMEOUT TIMER P203 STOP

LOW AL & SD Set Point Change DISENGAGE STARTER

LEGEND Lube Oil Header Pressure (TP380) High Pre - Post Alarm Low Alarm Low Shutdown

SECTION 4 - CAKERAWALA GAS TURBINES FUEL SYSTEMS TAURUS 60 FUEL SYSTEM GENERAL DESCRIPTION The fuel system, in conjunction with the electrical control system and the air system, schedules the fuel during acceleration and modulates fuel flow during operation. The system also provides overtemperature and overspeed topping control of fuel flow and includes automatic shutdown in the event of fuel component malfunction. The fuel system is designed to accommodate the high fuel flow of low Btu gas by incorporating two parallel gas fuel systems. These systems are duplicate systems. They operate in the same fashion. They are routed alongside one another, and they each contain the same primary and secondary pilot solenoid valves and gas fuel shutoff valves. NOTE The engine normally starts on gas fuel unless the liquid select switch is pressed before start. If the engine is shutdown while operating on liquid fuel, and the system control switch has not been moved to OFF position, a restart will be with liquid fuel unless the gas fuel system activate switch is pressed. At initiation of a gas fuel start, Liquid Fuel Purge Shutoff Solenoid Valve (L345-1) opens to drain liquid fuel from the fuel metering block and associated lines. The gas fuel system includes the following: • Gas fuel filtering • Pilot pressure for operation of solenoid-actuated pilot valves • Gas fuel metering and control The liquid fuel system includes the following: • Liquid fuel inlet fuel boost • Liquid fuel metering and delivery • Air assist (fuel atomizing air). Fuel transfer is possible only during normal operation, when engine speed is above 90 percent. Transfer is accomplished automatically if the operating fuel pressure drops below a preset value, or it may be initiated manually. When manual fuel transfer is initiated, the fuel pressure of the fuel subsystem, to which transfer is attempted, must be within prescribed limits. If the selected fuel system pressure is not within the prescribed limits, engine operation will continue on the operating fuel system until the selected system pressure becomes normal. Fuel transfer will then take place in the usual manner.An automatic fuel transfer may occur due to an operating fuel system pressure decrease. However, since an extremely rapid loss of fuel pressure may cause an engine flameout, the pressure drop must not be too large or sudden. Air assist is required for liquid fuel atomization during the start cycle. This supply must be clean, dry air regulated between 70 PSIG(482.6 kpa) and 250 PSIG (1712 kpa) at the package connection. Air usage per start is 30 SCFM (0.8 NM³/min) for 30 secsonds.

FUNCTIONAL DESCRIPTION Gas Fuel Operation Sequence of Operation Sequence of operation includes the following steps: • Valve check sequence • purge crank cycle • Ignition sequence • Acceleration sequence

VALVE CHECK SEQUENCE Before the engine cranks during the start cycle, the fuel system performs a valve check sequence. If Gas Fuel Pressure Switches (S341-1, S341-2) sense fuel pressure, Gas Fuel Vent Shutoff Valves (V2P941, V2P941-1) are opened to vent gas from the supply line. If pressure drops below the setpoint, the vent valves are closed, and the valve check sequence proceeds. Primary shutoff valves V2P931 and V2P931-1 open and admit fuel to pressure switches S342-2, S342-3, and secondary shutoff valves V2P932 and V2P932-1. Pressure switches S342-2 and S342-3 signal increasing pressure. This verifies the opening of shutoff valves V2P931 and V2P931-1, and enables the start sequence to proceed. Five seconds after being opened, primary shutoff valves V2P931 and V2P931-1 close. If pressure drops, secondary shutoff valve V2P932 or V2P932-1 are leaking. After the prelube cycle, shutoff valves V2P932 and V2P932-1 open. With shutoff valves V2P931 and V2P931-1 closed, trapped gas is allowed to escape into the fuel system. Pressure drops indicating that shutoff valves V2P931 and V2P931-1 are fully closed and that shutoff valves V2P932 and V2P932-1 are open. If pressure fails to drop, a gas fuel valve fail malfunction indication and an engine shutdown are initiated 15 seconds after prelube is complete.

PURGE CRANK CYCLE After the valve check sequence is completed, the purge crank cycle is initiated. The purge crank cycle removes combustibles from the entire engine exhaust system. The starter cranks the engine to 25 percent engine speed (Ngp) for a minimum of 5 minutes. The purge crank cycle is programmed according to package exhaust system volume.

IGNITION SEQUENCE After the purge crank is completed, Torch Gas Fuel Shutoff Valve (V2P940), Ignition Exciter (G340), and the fuel control ramp are energized. Shutoff valves V2P931, V2P931-1, V2P932, and V2P932-1 are opened and gas flows into the system. Fuel flows to the torch and is ignited by Igniter Plug (E340) in the presence of combustor air. The torch flame flares into the airflow inside the engine combustor liner. Gas fuel flows from the shutoff valves and is regulated by Gas Fuel Control Valves (EGF344, EGF344-1). Fuel passes through fuel injectors, spaced equally around the combustor, to mix with combustor air stream. Initially, fuel/air mixture is too lean for ignition. The fuel control ramp directs valves EGF344 and EGF344-1, to move toward a maximum open position. The control ramp enriches the fuel/air mixture and lightoff occurs smoothly.

ACCELERATION SEQUENCE Following lightoff, turbine temperature increases rapidly beyond 400_F (204_C). The lightoff ramp is completed, and the acceleration ramp is initiated. Ignition Exciter (G340) and shutoff valve V2P940 are de-energized and the torch extinguishes. Fuel control valves EGF344 and EGF344-1 are ramped open to gradually bring T5 temperature up to 800_F (427_C). At 35 percent gas producer speed (Ngp), fuel control valves EGF344 and EGF344-1 continue to ramp until T5 reaches 1200_F (654_C). From this point, the control system is switched over to engine speed (Ngp) control. At 65 percent engine speed (Ngp), the starter clutch overruns and the start system is de-energized. The engine continues to accelerate. At 70 percent engine speed (Ngp), Compressor Bleed Valve (PCV942) begins to close. Continuing to 80 percent engine speed (Ngp), the inlet guide vanes begin to move toward the maximum open position. As engine speed (Ngp) increases to 90 percent, the fuel supply rate from control valves EGF344 and EGF344-1 level off for 10 seconds to prevent T5 temperature from exceeding the shutdown limit. After the time delay, control valves EGF344 and EGF344-1 increase fuel supply until engine speed (Ngp) is 100 percent (synchronous idle). At synchronous idle, the guide vanes are fully open and bleed valve PCV942 is closed. The engine is now ready for load and the control system switches to generator load control. If the temperature shutdown timer fails to shut down the engine during an overtemperature condition and the turbine engine temperature reaches a higher maximum limit, the engine temperature T5 backup shutdown circuit will activate and initiate an immediate engine temperature T5 high malfunction indication and an engine shutdown.

Liquid Fuel Operation Liquid Fuel System Liquid fuel flows through a Filter Transfer Valve (VT933) to a single filter element of the duplex filter system, and Liquid Fuel Filter Differential Pressure Switch (S343). Filtered liquid fuel then flows to the Liquid Fuel High Pressure Pump (P931). Pump P931 is driven by the Main Liquid Fuel Pump Motor (B343). High pressure fuel from pump P931 flows through Liquid Fuel High Pressure Filter (FS936). Fuel from filter FS936 is metered to the engine fuel injectors by Liquid Fuel Control Valve (ELF344). Fuel is routed to the torch through Liquid Fuel Torch Shutoff Solenoid Valve (L348-1).

PURGING SEQUENCE At initiation of the start sequence, shutoff valve V2P945 is opened and the purge valve timer is started. Shutoff valve V2P945 remains open until the purge valve timer times out. At initiation of a liquid fuel start, the liquid fuel select switch is pressed. When the start switch is pressed, the air assist shutoff valve (L350-1) opens and Liquid Fuel Purge Shutoff Solenoid Valve (L345-1) opens to purge the fuel metering block and associated lines.

IGNITION SEQUENCE After the purge cycle is completed, solenoid valve L348-1 opens and Ignition Exciter (G340) is energized. Liquid fuel flows through solenoid valve L348-1 to the igniter torch, is atomized by torch air assist pressure, and is ignited by Igniter Plug (E340) in the presence of combustor air. Simultaneously, fuel from pump P931 flows through open Liquid Fuel Shutoff Valve (V2P939 and a torch fuel bias pressure valve VCS932 to the fuel injectors. Air from the air assist manifold enters the injectors and atomizes the fuel. The torch flame flares into the airflow inside the combustor liner and ignites the mixture from the fuel injectors when the mixture has enriched sufficiently to support combustion.

ACCELERATION SEQUENCE Following ignition, turbine temperature increases beyond a predetermined setpoint, ignition exciter G340 and solenoid valve L348-1 are de-energized, and the torch extinguishes. The control voltage to control valve ELF344 is slowly ramped open to increase the turbine engine temperature. When the engine temperature reaches the 1125° F (633°C) threshold, the ramp is halted. Increasing engine airflow reduces engine temperature. At 1110°F (599°C), the ramp resumes. At 66 percent engine speed, the start system is de-energized. Engine cranking ceases and fuel atomizing air is supplied by Pcd through the air blast and injector fittings. Pcd air continues to circulate through the air assist passages and manifold to keep them purged of liquid fuel. As engine speed increases, the liquid fuel control valve balances fuel with Pcd to maintain the acceleration schedule. As the engine attains 100 percent speed, control of control valve ELF344 is switched from the acceleration control system to the generator load system. Line synchronization module assumes fuel control by means of analog signals to control valve ELF344 to control engine speed. Engine temperature T5 setpoints, which are offset to other-than-normal values during the start sequence, are switched to the normal operation temperature setpoints at 66 percent speed. Should the turbine engine temperature exceed the temperature control setpoint at engine speeds above 65 percent, the engine temperature, T5 delayed shutdown alarm is indicated and, following the five-second time delay, an engine shutdown is initiated. The time delay is to allow for momentary overtemperature during load transients. If the temperature shutdown timer fails to shut down the engine during an overtemperature condition and the turbine engine temperature reaches a higher maximum limit, the engine temperature T5 backup shutdown circuit will activate and initiate an immediate engine temperature T5 high malfunction indication and an engine shutdown. If during normal operation the differential pressure across the duplex low pressure fuel filters should exceed a predetermined setting, pressure switch S343 will transfer and initiate a high fuel filter differential pressure alarm without causing an engine shutdown.

If the high pressure fuel pump inlet pressure should drop below a preset value, pressure switch S3872 will transfer. If the engine speed is above 15 percent, pressure switch S387-2 will initiate a sixsecond time delay followed by a low liquid fuel pressure malfunction and an engine shutdown. Upon engine shutdown (normal or malfunction), shutoff valve V2P945 opens. During run-down, the Pcd purges the fuel injector, torch nozzle, and the lines back through the purge valve to an external drain, until the purge valve timer times out, at which time spring pressure closes shutoff valve V2P945.

Air Assist (Fuel Atomizing) System Proper functioning of the liquid fuel system requires that liquid fuel be positively atomized upon injection into the combustor. During normal operation at operating engine speed, Pcd air flowing inside the combustor housing is directed through the injector fittings to atomize injected fuel. In the beginning of the start sequence, when Pcd air blast flow at the injector fittings is too low for proper atomization, air assist from an external source is required.

PURGING SEQUENCE At start, air assist is first directed to both Air Assist Shutoff Solenoid Valve (L350-1) and pilot solenoid valve L345-1. Shutoff valve V2P945 is opened and Pcd purges the fuel injectors and the lines back through shutoff valve V2P945. When purging is completed, internal springs close shutoff valve V2P945.

IGNITION SEQUENCE Air Assist Pressure Control Valve (PCV933) senses Pcd to control the air assist pressure at a fixed bias above Pcd. After passing through a check valve, the pressure-controlled air separates and flows in two different directions. One path flows to the igniter torch where the air flow is used to provide positive atomization of the liquid fuel at the torch during the start sequence only. The other path passes directly to the air assist manifold and out to the injectors.

ACCELERATION SEQUENCE At 66 percent engine speed, Pcd air is at a sufficient level for proper fuel atomization, and valve L3501 is de-energized. This cuts off air assist to pressure control valve PCV933. Fuel atomizing air is supplied solely by Pcd air through the air blast and injector fittings.

SHUTDOWN SEQUENCE During engine shutdown (normal or malfunction), shutoff valve V2P945 is opened. During run-down, the Pcd purges the fuel injector, torch nozzle, and the lines back through shutoff valve V2P945 to the purge tank, until engine speed decreases below 15 percent when internal springs close shutoff valve V2P945.

Fuel Transfer Fuel transfer is possible only during normal operation when engine speed is above 90 percent. Automatic transfer is accomplished from gas fuel to liquid fuel only. The transfer takes place when gas pressure drops below a preset value, or it may be initiated manually. When manual transfer is initiated, the pressure of the selected fuel system must be within prescribed limits. If the selected fuel system pressure is not within the prescribed limits, engine operation will continue on the operating fuel system until the selected system pressure becomes normal. Fuel transfer will then take place in the usual manner. An automatic fuel transfer to liquid fuel may occur due to a decrease in gas fuel pressure. However, since an extremely rapid loss of fuel pressure may cause an engine flameout, the pressure drop must not be too large or sudden.

COMPONENT DESCRIPTIONS DUAL FUEL Main Liquid Fuel Pump Motor Main Liquid Fuel Pump Motor (B343), connected to Liquid Fuel High Pressure Pump (P931) by a coupling, is a continuous-duty, squirrel-cage, polyphase electric motor. The motor is used to drive pump P931. The motor incorporates a space heater. Gas Fuel Control Valves Gas Fuel Control Valves (EGF344, EGF344-1), downstream of Gas Fuel Secondary Shutoff Valves (V2P932, V2P932-1), are electrical, closed-loop servo valve that controls the steady state flow of gas fuel to the engine. The electrical control signal is provided by an analog signal from the control system. As the valve piston moves to its commanded position, the feedback mechanism spring begins to develop an equal and opposite force. This feedback force will balance the electrically-generated force created by the input signal. As a result, movement of the valve piston will stop at a position proportional to the input signal current. For each input signal from the control unit, there is only one position of the valve piston at which the feedback spring force exactly balances the deflection force imposed on the armature by the torque motor coil. During the ignition sequence, beginning at the moment the torch is ignited, the valve is energized by an increasing signal from the control system. The valve gradually opens, enriching the fuel/air mixture until combustion is able to propagate smoothly from the torch. This action avoids a lightoff into surge. When the turbine temperature reaches 400°F (204°C), the valve is commanded to be ramped open at a predetermined rate.

Gas Fuel Control Valve

Simplified Fuel System

Liquid Fuel Control Valve Liquid Fuel Control Valve (ELF344), located downstream from Liquid Fuel High Pressure Filter (FS936), is an electrical, closed-loop servo valve that controls the steady state flow of liquid fuel to the engine. The electrical control signal is provided by an analog signal from the control system. As the valve piston moves to its commanded position, the feedback mechanism spring begins to develop an equal and opposite force. This feedback force will balance the electrically-generated force created by the input signal. As a result, movement of the valve piston will stop at a position proportional to the input signal current. For each input signal from the control unit, there is only one position of the valve piston at which the feedback spring force exactly balances the deflection force imposed on the armature by the torque motor coil. The fuel metering portion of the control valve meters fuel to the engine according to demand established by the control system. Excess fuel is returned to the fuel inlet by action of the differential pressure control valve. During the ignition sequence, beginning at the moment the torch is ignited, the valve is energized by an increasing signal from the control system. The valve gradually opens, enriching the fuel/air mixture until combustion is able to propagate smoothly from the torch. This action avoids a lightoff into surge. When the turbine temperature reaches 400°F (204°C), the valve is commanded to be ramped open at a predetermined rate. Gas Fuel Torch Assembly Fixed Orifice Gas Fuel Torch Assembly Fixed Orifice (F0931-1), located in the torch assembly, is a fixed orifice which restricts the flow of gas fuel to the torch assembly.

Liquid Fuel Torch Flow Fixed Orifice Liquid Fuel Torch Flow Fixed Orifice (F0934), located downstream from Torch Purge Check Valve (VCS933), is a fixed orifice which restricts the flow of purged liquid fuel to the purge tank. Liquid Fuel Torch Flow Fixed Orifice Liquid Fuel Torch Flow Fixed Orifice (F0936), located downstream from Torch Purge Check Valve (VCS933), is a fixed orifice which restricts the flow of liquid fuel to the torch assembly. Pilot Pressure Fixed Orifice Pilot Pressure Fixed Orifice (F0937), located downstream from Pilot Gas Pressure Control Valve (PCV931), is a fixed orifice which restricts the flow of pilot pressure to Gas Fuel Primary and Secondary Shutoff Pilot Solenoid Valves (L341-1, L342-1, L341-2, L342-2). Pcd Sensing Line Condensate Drain Fixed Orifice Compressor Discharge Pressure (Pcd) Sensing Line Condensate Drain Fixed Orifice (F0938-1), located in the condensate drain line, allows condensate to be drained to the drip pan. The condensate drain line is connected to the lowest point of the trap located in the tubing run between the Pcd sensing port and the low side of Gas Fuel Flow Scheduling Differential Pressure Transmitter (TPD344). Liquid Fuel Flow Fixed Orifice Liquid Fuel Flow Fixed Orifice (FO939-2), located in the liquid fuel flow divider manifold and upstream of the fuel injector assemblies, equalizes liquid fuel distribution to the fuel injector assemblies. The flow divider manifold has one fuel inlet port and numerous fixed orifices and outlet fittings, in parallel, which connect to each fuel injector assemblies. Flameout Time Delay Fixed Orifice Flameout Time Delay Fixed Orifice (F0940), mounted parallel to Flameout Indicator Differential Pressure Switch (S349), is a fixed orifice used to create a backpressure. This backpressure between the high side of the switch and orifice sets up differential pressure across the switch during sudden losses of Pcd. The calibrated volume trapped between fixed orifice F0940 and pressure switch 5349 acts as a timing circuit to match the sensitivity of the switch to the flameout characteristics of the engine. This relationship forms a flameout detection circuit. Fuel Injector Assembly Gas Fuel Flow Fixed Orifice Fuel Injector Assembly Gas Fuel Flow Fixed Orifice (FO941-1), located in the fuel injector assembly, is a fixed orifice which restricts the flow of gas fuel into the engine combustor. Fuel Injector Assembly Liquid Fuel Flow Fixed Orifice Fuel Injector Assembly Liquid Fuel Flow Fixed Orifice (F0941-2), located in the fuel injector assembly, is a fixed orifice which restricts the flow of liquid fuel into the engine combustor. Fuel Injector Assembly Air Assist Flow Fixed Orifice Fuel Injector Assembly Air Assist Flow Fixed Orifice (F0941-4), located in the fuel injector assembly, is a fixed orifice which restricts the flow of assist air into the engine combustor. Flow Limiter Fixed Orifice Flow Limiter Fixed Orifice (F0949), located downstream from the engine, is a fixed orifice which limits the flow of Pcd bleed air pressure. The Pcd bleed air pressure is used to seal the accessory gearbox output shaft labyrinth seal to stop oil leakage along the output shaft. Air Assist Strainer Air Assist Strainer (FS911-1), located downstream from the package air assist supply connection, is a metal bowl-type filter with a removable element. The strainer protects the air assist system from lineborne contaminants.

Pilot Gas Filter Pilot Gas Filter (FS932), located upstream of Pilot Gas Pressure Control Valve (PCV93 1), is a teetype filter with a removable element. The filter protects the pilot gas system from contaminants and liquids in the gas stream. Liquid Fuel Low Pressure Filters Liquid Fuel Low Pressure Filters (FS935-1, FS935-2), located upstream of Liquid Fuel High Pressure Pump (P931), are canister-type filters each containing two replaceable filter elements. The filters remove contaminants from the liquid fuel system. Fuel flow, as manually selected by positioning Filter Transfer Valve (VT933), may be directed through either filter. During operation, fuel flows through one filter at a time. Liquid Fuel Filter Differential Pressure Switch (5343) provides an electrical indication of a pressure drop across the filters. The switch transfers at a predetermined increasing differential pressure, indicating the need for a changeover of the filter element in service. Liquid Fuel High Pressure Filter Liquid Fuel High Pressure Filter (FS936), located downstream from Liquid Fuel High Pressure Pump (P931), is a tee-type filter with a differential pressure indicator and a removable element. The filter removes contaminants from the liquid fuel supply. On-Crank Water Wash Strainer On-Crank Water Wash Strainer (FS991-1) protects downstream water wash components from lineborne contaminants. On-Line Water Wash Strainer On-Line Water Wash Strainer (FS991-2) protects downstream water wash components from lineborne contaminants. Gas Fuel Coalescing/Filtration Module Gas Fuel Coalescing/Filtration Module (FSM932) is located offskid and upstream of Gas Fuel Primary Shutoff Valves (V2P931, V2P931-1). The module consists of Sump No. 1 Level Switch (S542-1), Sump No. 2 Level Switch (S542-2), Gas Fuel Coalescing/Filtration Module Differential Pressure Transmitter (TPD542), Gas Fuel Coalescing/Filtration Module Differential Pressure Gage (PD1954), and Gas Fuel Coalescing/Filtration Module Level Indicators (L1931-1, L1931-2). The module removes gross contaminants and water from the gas fuel supply. The sumps are drained manually by opening the drain hand valves. Bleed Valve Directional Control Solenoid Valve Bleed Valve Directional Control Solenoid Valve (L338), located upstream of Bleed Valve Pressure Control Valve (PCV942), is a four-way, solenoid-actuated, solenoid valve. The solenoid valve directs oil pressure to pressure control valve PCV942 which modulates the opening and closing of pressure control valve PCV942. Torch Gas Fuel Shutoff Pilot Solenoid Valve Torch Gas Fuel Shutoff Pilot Solenoid Valve (L340-1), located upstream of Torch Gas Fuel Shutoff Valve (V2P940), is a normally closed, three-way solenoid valve. When energized, the solenoid valve opens to allow pilot pressure to open shutoff valve V2P940. When de-energized, the solenoid valve closes to cut off pilot pressure, and internal spring pressure closes shutoff valve V2P940.

Gas Fuel Primary Shutoff Pilot Solenoid Valves Gas Fuel Primary Shutoff Pilot Solenoid Valves (L341-1, L341-2), upstream of Gas Fuel Primary Shutoff Valves (V2P931, V2P931-1), are normally closed, three-way solenoid valves. When energized, the solenoid valves open to allow pilot pressure to open shutoff valves V2P931 and V2P931-1. When de-energized, the solenoid valves close to cut off pilot pressure, and internal spring pressure closes shutoff valves V2P931 and V2P931-1.

24 Volts

0 Volts

De-Energized (OFF)

Energized (ON)

Gas Fuel Vent Shutoff Pilot Solenoid Valves Gas Fuel Vent Shutoff Pilot Solenoid Valves (L341-3, L341-4), upstream of Gas Fuel Vent Shutoff Valves (V2P941, V2P941-1), are normally closed, three-way solenoid valves. When energized, the solenoid valves open to allow pilot pressure to open shutoff valves V2P941 and V2P941-1. When deenergized, the solenoid valves close to cut off pilot pressure, and internal spring pressure closes shutoff valves V2P941 and V2P941-1. Gas Fuel Secondary Shutoff Pilot Solenoid Valves Gas Fuel Secondary Shutoff Pilot Solenoid Valves (L342-1, L342-2), upstream of Gas Fuel Secondary Shutoff Valves (V2P932, V2P932-1), are normally closed, three-way solenoid valves. When energized, the solenoid valves open to allow pilot pressure to open shutoff valves V2P932 and V2P932-1. When de-energized, the solenoid valves close to cut off pilot pressure, and internal spring pressure closes shutoff valves V2P932 and V2P932-1. Liquid Fuel Purge Shutoff Pilot Solenoid Valve Liquid Fuel Purge Shutoff Pilot Solenoid Valve (L345-1), located upstream of Liquid Fuel Purge Shutoff Valve (V2P945), is a normally closed, three-way solenoid valve. When energized, the solenoid valve opens to allow pilot pressure to open shutoff valve V2P945. When de-energized, the solenoid valve closes to cut off pilot pressure, and internal spring pressure closes shutoff valve V2P945. Liquid Fuel Torch Shutoff Solenoid Valve Liquid Fuel Torch Shutoff Solenoid Valve (L348-1), located upstream of the igniter torch assembly, is a normally closed, two-way solenoid valve. When energized, the solenoid valve opens to allow liquid fuel to the igniter torch assembly. When de-energized, the solenoid valve closes to cut off liquid fuel to the igniter torch assembly. The solenoid valve functions during the engine start sequence on liquid fuel only. Torch Air Assist Shutoff Solenoid Valve Torch Air Assist Shutoff Solenoid Valve (L348-2), located upstream of the igniter torch assembly, is a normally closed, two-way solenoid valve. When energized, the solenoid valve opens to allow assist air to the igniter torch assembly. When de-energized, the solenoid valve closes to cut off assist air to the igniter torch assembly. The solenoid valve functions during the engine start sequence on liquid fuel only.

Liquid Fuel Shutoff Pilot Solenoid Valve Liquid Fuel Shutoff Pilot Solenoid Valve (L349-1), located upstream of Liquid Fuel Quick Exhaust Pilot Valve (V2P939-1), is a normally closed, three-way solenoid valve. When energized, the solenoid valve opens to allow pilot pressure to open quick exhaust pilot valve V2P939-1. When de-energized, the solenoid valve closes to cut off pilot pressure, and internal spring pressure closes quick exhaust pilot valve V2P939-1. Air Assist Shutoff Pilot Solenoid Valve Air Assist Shutoff Pilot Solenoid Valve (L350-1), located upstream ofAirAssist Shutoff Valve (V2P9501), is a normally closed, three-way solenoid valve. When energized, the solenoid valve opens to allow pilot pressure to open shutoff valve V2P950-1. When de-energized, the solenoid valve closes to cut off pilot pressure, and internal spring pressure closes shutoff valve V2P950-1. On-Crank Cleaning Shutoff Valve On-Crank Cleaning Shutoff Valve (L390-1) is energized to allow on-crank cleaning solution to flow to the engine. When de-energized, the shutoff valve closes to cut off the flow of on-crank cleaning solution. On-Line Cleaning Shutoff Valve On-Line Cleaning Shutoff Valve (L390-2) is energized to allow on-crank cleaning solution to flow to the engine. When de-energized, the shutoff valve closes to cut off the flow of on-line cleaning solution. Gas Fuel Coalescing/Filtration Module Level Indicators Gas Fuel Coalescing/Filtration Module Level Indicators (L1931-1, LI931-2), are part of Gas Fuel Coalescing/Filtration Module (FSM932). The level indicators give a visual indication of the level of liquid accumulated in the coalescing sumps. Purge Tank Level Sight Glass Purge Tank Level Sight Glass (LG931), mounted on the front-right corner of the package skid, is a channel-type sight glass. The sight glass indicates the level of purged liquid fuel in Purge Tank (R931). Liquid Fuel High Pressure Pump Liquid Fuel High Pressure Pump (P931), located upstream of Liquid Fuel High Pressure Filter (FS936), is a gear-type, positive-displacement pump. The pump is driven by Main Liquid Fuel Pump Motor (B343). The high pressure pump raises system pressure to a level sufficient to allow metering and distribution of the fuel to the engine. Torch Gas Fuel Pressure Control Valve Torch Gas Fuel Pressure Control Valve (PCV930-1), upstream of Torch Gas Fuel Shutoff Valve (V2P940), is a pressure-reducing pressure control valve. The pressure control valve maintains a preset, optimum gas fuel pressure to the igniter torch. Torch Gas Fuel Fine Adjustment Pressure Control Valve Torch Gas Fuel Fine Adjustment Pressure Control Valve (PCV930-2), downstream from Torch Gas Fuel Shutoff Valve (V2P940), is a pressure-reducing pressure control valve. The pressure control valve maintains a preset, optimum gas fuel pressure to the igniter torch. Pilot Gas Pressure Control Valve Pilot Gas Pressure Control Valve (PCV931), downstream from Pilot Gas Filter (FS932), is a pressurereducing pressure control valve. The pressure control valve maintains a preset, optimum pilot pressure to the gas valve pilot operator system.

Air Assist Pressure Control Valve Air Assist Pressure Control Valve (PCV933), located downstream from Air Assist Shutoff Valve (V2P950-1), is a spring bias volume booster relay-type pressure control valve. The pressure control valve, sensing Pcd from a line tapped off the turbine rotor bearing support housing, maintains a preset, optimum air assist pressure to the igniter torch and the air assist manifold at a fixed bias above Pcd. Liquid Fuel Pressure Control Valve Liquid Fuel Pressure Control Valve (PCV938), located downstream from Liquid Fuel Control Valve (ELF344), is a spring-loaded, piston and sleeve-type pressure control valve. The pressure control valve maintains a preset, optimum liquid fuel pressure to the igniter torch and the fuel injector assemblies. Combustor Drain Pressure Control Valves Combustor Drain Pressure Control Valves (PCV941-1, PCV941-2), downstream from the engine combustor and exhaust collector in the condensate drain line, are normally open, in-line drain-type pressure control valves. The pressure control valves close during operation at a preset Pcd and prevent liquids from draining. At pressures less than this preset Pcd, the pressure control valves open, allowing accumulated liquids to drain to an onskid collection point. Bleed Valve Pressure Control Valve Bleed Valve Pressure Control Valve (PCV942), mounted directly on the engine, is an adjustable piston-type pressure control valve. The pressure control valve is controlled by engine compressor discharge pressure (Pcd) to reduce compressor backpressure during starting and part speed operation to avoid engine surge. Air Assist Pilot Pressure Control Valve Air Assist Pilot Pressure Control Valve (PCV952), located downstream from Air Assist Strainer (FS911-1), is a pressure reducing-type pressure regulator with an integral filter. The pressure control valve maintains a preset, optimum pilot pressure to the air assist pilot operator system. Gas Fuel Coalescing/Filtration Module Pressure Indicator Gas Fuel Coalescing/Filtration Module Pressure Indicator (PD1954), is part of Gas Fuel Coalescing/Filtration Module (FSM932). The pressure gage indicates the pressure across FSM932. Engine Compressor Discharge Pressure Gage Engine Compressor Discharge Pressure Gage (P1930), located downstream from the engine on the Pcd line, is a Bourdon tube, liquid filled-type pressure gage. The pressure gage indicates the engine Pcd. Instrument Isolation Hand Valve (VI931-3) is used to isolate the pressure gage from the system for calibration, testing, or replacement. Engine Gas Fuel Pressure Gage Engine Gas Fuel Pressure Gage (P1931), located downstream from the package gas fuel connection, is a Bourdon tube, liquid filled-type pressure gage. The pressure gage indicates the inlet gas fuel pressure. Instrument Isolation Hand Valve (VI931-1) is used to isolate the pressure gage from the system for calibration, testing, or replacement. Engine Liquid Fuel Pressure Gage Engine Liquid Fuel Pressure Gage (P1932), located downstream from Liquid Fuel Low Pressure Filters (FS935-1,FS935-2), is a Bourdon tube, liquid filled-type pressure gage. The pressure gage indicates liquid fuel pressure at the inlet side of Liquid Fuel High Pressure Pump (P931). Instrument Isolation Hand Valve (V1931-2) is used to isolate the pressure gage from the system for calibration, testing, or replacement.

Liquid Fuel Purge Tank Liquid Fuel Purge Tank (R931), located in the skid base at the engine aft end, is an aluminum reservoir. The tank holds accumulated liquids drained from the engine during normal operations. The tank should be drained regularly as indicated by Purge Tank Level Sight Gage (LG931). A Purge Tank Level Switch (S389) actuates an alarm indicating the purge tank is full if level reaches predetermined setpoint. The tank may be emptied by pumping or draining through the connection located on the skid base. This liquid is not reusable. Air Inlet Resistance Temperature Detector Air Inlet Resistance Temperature Detector (RTD) (RT339), in air inlet duct, is a resistance temperature detector. The resistance temperature detector senses air temperature at engine air inlet. Resistance within the RTD varies with the sensed temperature. The resistance is measured by the control system and is converted to an analog value in milliamps which is further used by the control system. High Gas Fuel Start Shutdown Pressure Switches High Gas Fuel Start Shutdown Pressure Switches (S341-1, S341-2), are located downstream from Gas Fuel Control Valves (EGF344, EGF344-1), are double-pole, double-throw, snap-acting-type pressure switches. The pressure switches monitor the output of control valves EGF344 and EGF344 during the ignition sequence. If the fuel control output pressure exceeds its calibration limits, a malfunction is displayed and the start sequence is aborted. Valve Check Differential Pressure Switches Valve Check Differential Pressure Switches (S342-2, S342-3), located upstream of Gas Fuel Secondary Shutoff Valves (V2P932, V2P932-1), are double-pole, double-throw, snap-acting-type pressure switches. The pressure switches work with Gas Fuel Primary Shutoff Valves (V2P931, V2P931-1) and shutoff valves (V2P932, V2P932-1) to make possible an automatic valve check sequence during the engine start cycle, or any time gas fuel is selected. Liquid Fuel Filter Differential Pressure Switch Liquid Fuel Filter Differential Pressure Switch (S343), located upstream of Filter Transfer Valve (VT933) and downstream from Liquid Fuel Low Pressure Filters (FS935-1, FS935-2), is a doublepole, double-throw, snap-acting-type pressure switch. The pressure switch provides an electrical indication of a pressure drop across the filters. The pressure switch transfers at a predetermined increasing differential pressure. Pump Check Pressure Switch Pump Check Pressure Switch (5344), located downstream from Liquid Fuel Control Valve (ELF344), is a double-pole, double-throw, snap-acting-type pressure switch. The pressure switch checks the function of Liquid Fuel High Pressure Pump (P931) prior to a fuel transfer. If sufficient pressure is being produced by pump P931, the pressure switch transfers and a transfer to liquid fuel is allowed. If not, the transfer is inhibited until sufficient pressure is being produced. Flameout Indicator Differential Pressure Switch Flameout Indicator Differential Pressure Switch (S349), mounted parallel to Flameout Time Delay Fixed Orifice (F0940), is a double-pole, double-throw, snap-acting-type pressure switch. Their relationship forms a flameout detection circuit. The pressure switch is used to initiate a malfunction shutdown whenever differential pressure across the pressure switch occurs due to sudden pressure losses of engine Pcd. A slow reduction in engine Pcd (as occurs in a load reduction) will not actuate the pressure switch (no flameout indicated). The pressure switch transfers when differential pressure exceeds the setting of the pressure switch. The pressure differential across the pressure switch happens because fixed orifice F0940 limits the rate at which the pressure in the calibrated volume on the high side of the switch can decay. The slow decay causes the pressure switch to stay energized from 1 to 5 seconds after a rapid loss of Pcd due to possible flameout.

During start pr operation above 65 percent speed, if the main fuel actuator exceeds 95 percent of its acceleration limit and engine Pcd drops by more than the stepping of the pressure switch in 0.25 seconds, the pressure switch is actuated, a flameout malfunction is annunciated, and the engine is shut down. This time/pressure relationship is a physical characteristic of a flameout. Liquid Fuel Low Pressure Shutdown Pressure Switch Liquid Fuel Low Pressure Shutdown Pressure Switch (5387-2), located downstream from Liquid Fuel Low Pressure Filters (FS935-1, FS935-2), is a double-pole, double-throw, snap-acting-type pressure switch. The pressure switch senses inlet fuel pressure to the high pressure fuel pump. The switch transfers to initiate engine shutdown if the liquid fuel pressure decreases below a predetermined setting. Sump Level Switches Sump Level Switches (S542-1, S542-2), are part of Gas Fuel Cpalescing/Filgragipn Module (FSM932). The switches provide electrical indication to the control system that the sumps require draining. Purge Tank Level Switch Purge Tank Level Switch (S389), located in Liquid Fuel Purge Tank (R931), is a single-pole, singlethrow one-float-type level switch. The level switch transfers when purge tank R931 level reaches a preset limit and an alarm is annunciated on the control console. Liquid Fuel Flow Transmitter Liquid Fuel Flow Transmitter (TF332), located downstream from Torch Bias Check Valve (VCS932), is a turbine-type flow transmitter. The flow transmitter senses fuel flow through the liquid fuel system and sends a signal, corresponding to a flow rate, to the control system for condition monitoring. Engine Compressor Discharge Pressure Transmitter Engine Compressor Discharge Pressure Transmitter (TP349), downstream from the engine on the Pcd line, is a microprocessor based electronic-type pressure transmitter. The pressure transmitter senses engine compressor discharge pressure and sends a corresponding signal to the control system for condition monitoring. Instrument Isolation Hand Valve (V1931-3) is used to isolate the transmitter from the system for calibration, testing, pr replacement. Gas Fuel Pressure Transmitter Gas Fuel Pressure Transmitter (TP386), downstream from the package gas fuel connection, is a small size, microprocessor based electronic-type pressure transmitter. The pressure transmitter senses gas fuel supply pressure as applied to Gas Fuel Primary Shutoff Valves (V2P931, V2P931-1) and sends a corresponding signal to the control system for monitoring. 3.3.62 Gas Fuel Flow Scheduling Differential Pressure Transmitter Gas Fuel Flow Scheduling Differential Pressure Transmitter (TPD344) senses the difference between gas fuel pressure to the engine and engine combustor pressure and sends a corresponding signal to the control system for controlling Gas Fuel Control Valves (EGF344, EGF344-1). Air Inlet Differential Pressure Transmitter Air Inlet Differential Pressure Transmitter (TPD358), downstream from the air inlet duct, is a solid state, electronic sensing-type differential pressure transmitter. The differential pressure transmitter senses the difference between ambient air pressure and the inlet duct air pressure and sends a corresponding signal to the control system for condition monitoring. Gas Fuel Coalescing Filter Differential Pressure Transmitter Gas Fuel Coalescing Filter Differential Pressure Transmitter (TPD542), offskid on Gas Fuel Coalescing/Filtration Module (FSM932), is a solid state, electronic sensing-type differential pressure transmitter. Connected across the inlet and outlet of the fuel module, the differential pressure transmitter senses the differential pressure between the inlet and outlet of Gas Fuel Coalescing/Filtration Module (FSM932) and sends a corresponding signal to the control system for monitoring.

Gas Fuel Primary Shutoff Valves Gas Fuel Primary Shutoff Valves (V2P931, V2P931-1), downstream from the package gas fuel connection, are normally closed, pneumatically operated, spring-return actuator, ball-type shutoff valves. When Gas Fuel Primary Shutoff Pilot Solenoid Valves (L341-1, L341-2) are energized, pilot pressure is applied to open the shutoff valves. When pilot solenoid valves L341-1 and L341-2 are deenergized, pilot pressure is vented and internal spring pressure closes the shutoff valves.

Gas Fuel Secondary Shutoff Valves Gas Fuel Secondary Shutoff Valves (V2P932, V2P932-1), downstream Primary fuel valve Gas Fuel Primary Shutoff Valves (V2P931, V2P931-1), are normally closed, two-way, pilot control-type shutoff valves. When Gas Fuel Secondary Shutoff Pilot Solenoid Valves (L342-1, L342-2) are energized, pilot pressure is applied to the shutoff valves. When pilot Secondary fuel valve solenoid valves L342-1 and L342-2 de-energized, pilot pressure is vented internal spring pressure closes the shutoff valves.

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Liquid Fuel Shutoff Valve Liquid Fuel Shutoff Valve (V2P939), located downstream from Liquid Fuel Control Valve (ELF344), is a normally closed, two-way, air operated, spring return, full-bore ball-type shutoff valve. When Liquid Fuel Shutoff Pilot Solenoid Valve (L349-1) is energized, pilot pressure opens Liquid Fuel Quick Exhaust Pilot Valve (V2P939-1), in-turn pilot pressure is applied to open the shutoff valve. When pilot solenoid valve L349-1 is de-energized, pilot pressure is vented and internal spring pressure closes quick exhaust pilot valve V2P939-1, in-turn pilot pressure is vented and internal spring pressure closes the shutoff valve. Liquid Fuel Quick Exhaust Pilot Valve Liquid Fuel Quick Exhaust Pilot Valve (V2P939-1), located upstream of Liquid Fuel Shutoff Valve (V2P939), is a normally closed, pneumatically-operated quick exhaust pilot valve. When Liquid Fuel Shutoff Pilot Solenoid Valve (L349-1) is energized, pilot pressure is applied to open the quick exhaust pilot valve, in-turn pilot pressure is applied to open shutoff valve V2P939. When pilot solenoid valve L349-1 is de-energized, pilot pressure is vented and internal spring pressure closes the quick exhaust pilot valve, in-turn pilot pressure is vented and internal spring pressure closes shutoff valve V2P939. Torch Gas Fuel Shutoff Valve Torch Gas Fuel Shutoff Valve (V2P940), located downstream from Torch Gas Fuel Shutoff Pilot Solenoid Valve (L340-1), is a normally closed, two-way pilot operated ball-type shutoff valve. When pilot solenoid valve L340-1 is energized, pilot pressure is applied to open the shutoff valve. When pilot solenoid valve L340-1 is de-energized, pilot pressure is vented and internal spring pressure closes the shutoff valve. Gas Fuel Vent Shutoff Valves Gas Fuel Vent Shutoff Valves (V2P941, V2P941-1), downstream from Gas Fuel Vent Shutoff Pilot Solenoid Valves (L341-3, L341-4), are normally closed, two-way, air operated, spring return, full-bore, ball-type shutoff valves. When pilot solenoid valves L341-3 and L341-4 are energized, pilot pressure is applied to open the shutoff valves. When pilot solenoid valves L341-3 and L341-4 are deenergized, pilot pressure is vented and internal spring pressure closes the shutoff valves. Liquid Fuel Purge Shutoff Valve Liquid Fuel Purge Shutoff Valve (V2P945), located downstream from Torch Bias Check Valve (VCS932), is a normally closed, two-way, pneumatically-operated ball-type shutoff valve. When Liquid Fuel Purge Shutoff Pilot Solenoid Valve (L345-1) is energized, pilot pressure opens the shutoff valve. When pilot solenoid valve L345-1 is de-energized, pilot pressure is vented and internal spring pressure closes shutoff valve. Air Assist Shutoff Valve Air Assist Shutoff Valve (V2P950-1), located upstream of Air Assist Pressure Control Valve (PCV933), is a normally closed, two-way, air operated, spring return, full-bore ball-type shutoff valve. When Air Assist Shutoff Pilot Solenoid Valve (L350-1) is energized, pilot pressure is applied to open the shutoff valve. When pilot solenoid valve L350-1 is de-energized, pilot pressure is vented and internal spring pressure closes the shutoff valve. On-Crank Auxiliary Cleaning Shutoff Hand Valve On-Crank Auxiliary Cleaning Shutoff Hand Valve (V2P990-1) is manually positioned to allow on-crank cleaning solution to flow to the hand wand. For more information, refer to Turbine Engine, Chapter 8. Air Inlet Duct Drain Check Valve Air Inlet Duct Drain Check Valve (VCH930), downstream from the air inlet duct in the drain line, is a swing-type check valve. The check valve opens at a preset cracking pressure to drain liquids from the air inlet duct. A preset backpressure is required to prevent leakage.

Air Assist Check Valve Air Assist Check Valve (VCH932), located downstream from Air Assist Pressure Control Valve (PCV933), is a swing-type check valve. The check valve prevents backflow of Pcd into the air assist system once the engine is running. Torch Bias Check Valve Torch Bias Check Valve (VCS932), located downstream from Liquid Fuel Shutoff Valve (V2P939), is an in-line spring-type check valve. The check valve produces a bias pressure to force liquid fuel flow to the torch at lightoff under regulated pressure. Once torch flow is shut off, it acts as a pressurizing valve in the main liquid fuel flow to the engine. Torch Purge Check Valve Torch Purge Check Valve (VCS933), located downstream from Liquid Fuel Torch Shutoff Solenoid Valve (L348-1), is an in-line spring-type check valve. The check valve prevents backflow to Liquid Fuel Shutoff Valve (V2P939) and, when solenoid valve L348-1 is de-energized, allows Pcd to purge the torch line through Liquid Fuel Torch Flow Fixed Orifice (F0934) to the purge tank. Torch Gas Fuel Check Valve Torch Gas Fuel Check Valve (VCS933-2), upstream from Torch Gas Fuel Shutoff Valve (V2P940), is a low pressure drop, in-line-type check valve. The check valve prevents backflow of torch gas fuel into the gas fuel system. Low Pressure Filter Check Valves Low Pressure Filter Check Valves (VCS939-1, VCS939-2), located downstream from Liquid Fuel Low Pressure Filters (FS935-1, FS935-2), are spring-loaded, in-line poppet-type check valves. The check valves prevent backflow of liquid fuel from the high pressure liquid fuel line, Low Pressure Filter Bypass Check Valve Low Pressure Filter Bypass Check Valve (VCS939-3), located downstream from Liquid Fuel Low Pressure Filters (FS935-1, FS935-2), is an in-line spring-type check valve. The check valve functions to bleed off excessive pressures in the liquid lines when the unit is shut down. The check valve also acts to lower excessive fuel pressure developed in a static fuel system after a hot shutdown. Liquid Fuel Bleed Hand Valve Liquid Fuel Bleed Hand Valve (VH931), located upstream of Liquid Fuel High Pressure Pump (P931), is a normally closed, needle-type hand valve. The hand valve includes a capped port which, with the cap removed and the hand valve open, will permit bleeding of air from the liquid fuel system inlet line when the external fuel supply is pressurized. Instrument Isolation Hand Valve Instrument Isolation Hand Valve (V1931-1), located upstream of Engine Gas Fuel Pressure Gage (P1931), is an instrumentation, needle-type hand valve. The hand valve is used to isolate pressure gage PI931 from the pressurized system for testing, calibration, or replacement. Instrument Isolation Hand Valve Instrument Isolation Hand Valve (V1931-2), located upstream of Engine Liquid Fuel Pressure Gage (P1932), is an instrumentation, needle-type hand valve. The hand valve is used to isolate pressure gage P1932 from the pressurized system for testing, calibration, or replacement. Instrument Isolation Hand Valve Instrument Isolation Hand Valve (V1931-3), upstream of Engine Compressor Discharge Pressure Transmitter (TP349), is an instrumentation, needle-type hand valve. The hand valve is used to isolate pressure transmitter TP349 from the pressurized system for testing, calibration, or replacement.

Pilot Relief Valve Pilot Relief Valve (VR931), downstream from Pilot Pressure Fixed Orifice (F0937), is an in-line-type relief valve. The relief valve limits the pilot system pressure in the event Pilot Gas Pressure Control Valve (PCV931) fails. Main Liquid Fuel Pump Relief Valve Main Liquid Fuel Pump Relief Valve (VR931-1), located across Liquid Fuel High Pressure Pump (P931), is an externally-adjustable, direct operated-type relief valve. The relief valve limits liquid fuel pressure downstream from pump P93 1. Air Assist Pilot Pressure Relief Valve Air Assist Pilot Pressure Relief Valve (VR952), located downstream from Air Assist Pilot Pressure Control Valve (PCV952), is an in-line-type relief valve. The relief valve limits the air assist pilot system pressure in the event of pressure control valve PCV952 failure. Filter Transfer Valve Filter Transfer Valve (VT933), located upstream of Liquid Fuel Low Pressure Filters (FS935-1, FS935-2), is a hand-operated, grounded stem, diverter style ball-type transfer valve. The transfer valve directs the fuel flow through either filter, permitting servicing of a filter without package shutdown. Igniter Torch The igniter torch is bolted to a mounting boss on the combustor housing. When the engine is started on gas fuel, gas fuel enters the torch through the gas fuel inlet port. Gas fuel is ignited by igniter plug E340, and the flame torches into the combustion chamber to initiate the propagation of the flame front as the fuel-to-air mixture enriches. Gas fuel and torch ignition are shutoff when turbine temperature reaches a preset value, and combustion is self-sustained. When the engine is started on liquid fuel, liquid fuel enters the torch through the liquid fuel inlet port. Liquid fuel is atomized by air assist pressure entering the air inlet port through piping from an external source. The mixture is ignited by igniter plug E340, and the flame torches into the combustion chamber to initiate the propagation of the flame front as the fuel-to-air mixture enriches. Liquid fuel, air assist, and torch ignition are shutoff when turbine temperature reaches a

Dual Fuel System Manifolds and Injectors The dual fuel system manifolds and injectors consist of a gas fuel manifold, gas fuel manifold-to-injector tube assemblies, an air assist (fuel atomizing) manifold, air assist manifold-to-injector tube assemblies, a liquid fuel flow divider manifold, liquid fuel manifold-to-injector tube assemblies, and fuel injectors. The gas manifold assembly is of tubular construction and is located around the forward end of the combustor housing. It is bolted to the turbine rotor bearing support housing by mounting brackets. The manifold includes a gas fuel inlet boss and outlet bosses for connecting the manifold-to-injector tube assemblies the fuel injectors. The tube assemblies direct gas fuel through the metering orifices to the fuel injectors. The liquid fuel flow divider manifold is bolted to a mounting bracket beneath the combustor housing. It includes an inlet fuel connection and outlet connections for the manifold-to-injector tube assemblies. The tube assemblies feed the liquid fuel to the fuel injectors. The air assist manifold is bolted to the turbine rotor bearing support housing, adjacent to the gas fuel manifold. The manifold-to-injector tube assemblies speed fuel atomizing air to the fuel injectors. During operation at operating speed, fuel atomizing air is supplied by Pcd. During engine starting, prior to Pcd build-up, fuel atomizing air is furnished from an external source by the air assist portion of the liquid fuel system. The dual fuel injectors are mounted in bosses around the periphery of the combustor housing. They are seated in the combustor liner and protrude into the combustion chamber. The air blast and injector fitting assemblies mix compressed air with gas or liquid fuel by allowing air to flow across the fuel injector nozzles into the combustor.

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SECTION 5 – CAKERAWALA GAS TURBINES AIR SYSTEMS Introduction The basic operating principles of Industrial Gas Turbines that these notes are considering were introduced in Section One “Introduction to Gas Turbines”. It was mentioned that a fundamental component of these engines is the Compressor, which compresses air for various uses in the engine, which include; Primary Air for Combustion and Secondary Air for Cooling, Sealing and Control . It was also mentioned that about 2/3 of the total power developed was used to drive the compressor and this should illustrate not only how important a component the compressor is, but also that it must be capable of operating satisfactorily over the entire speed range from start to full load. How this is achieved will be considered in this section after a view of the fundamentals of the air systems.

Principles Ambient air is drawn into the Compressor – data point T1, P1. Work is done by the Compressor to increase the pressure (and temperature) of the air and to decrease its actual volume – data point T2, P2, at the exit of the Compressor. As will be seen a further pressure increase then occurs in the Compressor Diffuser and the pressure here is monitored and is also used for control purposes. This pressure is known as “Pcd” From the Compressor Diffuser the air path is divided to supply Primary Air for combustion and Secondary Air for cooling and sealing (although some applications divert air from some of the compressor stages for sealing rather than use the higher Pcd pressure). ‘Spent’ Primary Air and air used for cooling then exits through the Turbine Section and through the Exhaust Assemblies to atmosphere. Air used for sealing should exit to atmosphere along with the oil in the bearing lube oil drains to the Lube Oil Reservoir and its vent. The following 3 diagrams show simplified points for temperature, pressure and basic principle of turbine operation.

Engine Temperature Station Schematic

Axial Flow Path

Axial Flow Compressor Axial Flow Compressors which are designed so that the flow of air is along the axis of the compressor shaft rather than radial to it, as in the Centrifugal type which is the other style sometimes used. An Axial Flow Compressor basically comprises two sections, a stationary casing and a rotor assembly which rotates inside the casing. The rotor assembly is constructed from a series of blades (“Rotor blades”) mounted radially on a shaft and arranged in rows, such that the effective area of each blade decreases from inlet to outlet. The casing bore also has a series of blades (“Stator blades”) mounted radial fashion and arranged in rows and like rotor blades the effective area of each blade decreases from inlet to outlet. The rotor is mounted inside the casing bore so that each of rotor blades is located next to a row of blades. A row of stator and adjacent rotor blades is called a”Stage”. The rotor is mounted on journal bearings at each end and thrust bearing

in a the row stator a

Velocity Up

Velocity Down, Pressure Up

Nozzle Effect

Principle of Operation The diagrams above illustrate the principle of operation of an Axial Flow Compressor. The Rotor Assembly is driven by the turbine shaft and the Rotor Blades impart energy to the air by increasing its velocity. The Rotor Blades are arranged to force the air into the Stator stage that follows, where the blades are arranged to offer an increasing path for the air that enters. This causes the air velocity to decrease with a corresponding increase in pressure (and temperature). This process is repeated throughout each compressor stage.

Compressor Diffuser The Compressor Diffuser is located at the exit of the Compressor. The process of energy conversion continues in the Compressor Diffuser. The picture below shows the Diffuser attached to the Compressor exit and the air path is again expanding. This results in the air velocity again decreasing with a corresponding increase in the air pressure (and temperature). The greater air pressure in the Diffuser is known as “Pcd” (Pressure, Compressor Discharge.)

Primary Air The air used for combustion is known as Primary Air and usually accounts for about 25% of the total air required. It is mixed with the fuel used and the resultant fuel air mixture will burn if the proportions are suitable .It should be noted here that the routing of Primary Air varies between engine designs.

Cooling Air (Secondary Air) The majority of the air used in the engine is used for cooling. Firstly air is allowed to enter the combustor to contain the ‘Fireball’ and prevent it contacting the combustion liners. Additional air ensures complete combustion and also further cools the hot combustion gases before they enter the turbine inlet (T3). Air will also be directed onto or in some cases into various parts of the hotter sections of the engine particularly the turbine nozzles, and the turbine blades. The diagrams on this page show examples of Primary and Secondary Air in the Combustor.

System Function The engine air system, in addition to its main function of supporting combustion, also pressurises oil seals, cools turbine rotor blades and nozzles, assist in obtaining smooth engine operation by preventing surge conditions at critical speeds, and supplies control air for operation of the fuel control system. Air system supply is compressor discharge air pressure (Pcd). The air system starts to function with the rotation of the engine compressor rotor which draws in ambient air. The air is compressed and directed through the diffuser to the combustion chamber where fuel is injected and the combustible mixture is burned. This action transforms the air into a hot gas, which expands through the turbine, creating mechanical energy. The gas is expelled to atmosphere through the exhaust collector. The entire turbine cooling air is returned to the main gas stream in the turbine section. The seal air that leaks past the labyrinth seals travels through the engine oil drain lines and is vented from the main lube oil tank.

Sealing Air The engine incorporates three airpressurized labyrinth seals to prevent leakage of lube oil from the bearings. Compressor discharge pressure is routed by external air lines through orifices to the compressor rotor forward oil seal. Compressor diffuser air is metered through internal passages to the compressor rotor aft oil seal and gas producer turbine oil seal.

Turbine Cooling Air A portion of air from the compressor diffuser is used for cooling. The cooling air has an inner and outer primary flow path. The inner path is split at the inner shroud. One path flows between inner shroud and the combustor liner dome along the inner plates and between the inner cone and inner support. Small holes that ring the inner plates and cone provide a flow path for cooling air into the combustion chamber. The other inner path flows through holes in the inner shroud near the aft end of the compressor diffuser housing and fills a void between the shroud and the gas producer bearing support housing. The cooling air then flows through the first-stage diaphragm and preswirler.

The first-stage gas producer turbine uses cooling air that leaves the preswirler and flows into a void created by the forward rim seal attached to the first-stage rotor disc. Holes in the rim seal direct cooling air under the rotor blade assembly. Each blade has a three-pass internal convection cooling circuit that passes all cooling air up the leading edge, down the midchord passage, and then up and out the trailing edge holes. The outer cooling air path is split at the insulated outer shroud assembly. One path is along the combustor liner dome, past the torch igniter nozzle and along the outer plate and between the outer cone and outer support. Small holes that ring the outer plate and cone provide a flow path for cooling air into the combustion chamber. The cooling air duct assembly creates three separate concentric passages that surround the No. 3 bearing housing. Cooling air for the duct assembly, combustor, rotor disc and blades is directed from the compressor diffuser and flows through the duct assembly to the preswirler. The cooling air from the preswirler cools the leading edge of the firststage turbine rotor disc and the first-stage rotor blades. Leakage from the aft compressor hub (eleventh-stage) is the cooling air that is directed under the duct assembly. This air cools the No. 3 compressor bearing support housing, gas producer center-bolt, and rotor disc. The air that flows through passages in the gas producer turbine shaft is directed to the gas producer turbine rotor discs and center-bolt. The cooling air path is split between the radial holes in the aft hub of the first-stage and secondstage disc and the center bolt. The cooling air path in the rotor disc is metered to the forward face of the rotor discs by a labyrinth seal in the hub of each interstage nozzle diaphragm. Cooling air supplied from the area surrounding the convector (outer liner) passes through the nozzle support housing screen and is directed by an annular duct to the first-stage turbine nozzle. Cooling air that enters the hollow first-stage nozzles passes through the outer impingement plate installed on each nozzle segment, and exits through a number of metering holes in the trailing edges of each firststage nozzle vane.

Bleed Air Valve The Bleed Air Valve is designed to prevent engine surge during starting and acceleration and possible flameout if the load decreases suddenly. In split shaft engine arrangements it also assists in avoiding PT over-speed. During starting and acceleration, the bleed valve is opened to allow compressor exit airflow to bypass the combustor and turbine and go directly into the exhaust plenum. Bypassing the flow reduces backpressure on the compressor and avoids surge. The bleed valve assembly is located on the combustor case assembly. The valve assembly consists of a rotary actuator, trunnion valve, and valve actuator bracket. The rotary actuator is a single-acting, hydraulic piston with rack and pinion mechanism supported by the valve actuator bracket. Pressurization of one port closes the valve, pressurization of the other port opens the valve.

Bleed Valve Actuator Assembly

The

trunnion valve body is mounted between flanges on the combustor case assembly and the bleed valve exhaust duct. The duct directs compressor discharge pressure to the turbine exhaust diffuser. A flange at the stem packing gland supports the valve on the actuator bracket. The end of the stem is machined with a keyway and fits into the bleed valve.

Inlet Guide Vanes On larger engines the compressor design for full load, generally results in the bleed valve being insufficient to bleed enough air to prevent surge. To overcome this, the compressor efficiency is altered to suit the engine speeds.

Guide Vane System The system responds to corrected gas producer speed to change the angle of the inlet guide vane and the first,second,and third stage vanes to aerodynamically match the low pressure stages of the compressor with the high pressure stages. This change of vane position varies the effective angle at which the air flows past the rotor blades. By changing the position of the variable vanes, the critical low pressure stages are automatically realigned to maintain satisfactory air flow and compressor performance during all operating speeds. The variable vane system consists of a single row of variable Inlet Guide Vanes (IGVs) and three rows of Variable Stator Vanes (VSVs), and is controlled using the following: • Guide Vane Actuator Cylinder (CYL901) • Guide Vane Actuator Directional Control Valve (L339) Lube oil pressure supplied to Guide Vane Actuator Directional Control Valve (L339) actuates the Guide Vane Actuator Cylinder (CYL901). When valve L339 is energized to open by a signal from a discrete output module, oil pressure is directed through a metering orifice. The orifice regulates the flow rate to limit the actuator movement to about 5 seconds. When valve L339 is de-energized, oil is directed to the closing port. The oil that is displaced from the actuator bypasses the metering orifice as it passes through a check valve allowing a faster closing rate of about 2 seconds. The variable vanes are opened as a function of Gas Producer Speed (Ngp) corrected to 59_F (15_C). When accelerating the variable vanes will open at 90% corrected Ngp. When decelerating, the variable vanes will close at 90% corrected Ngp.

Engine Compressor Assembly The engine compressor assembly is a twelve-stage, axial-flow-type compressor incorporating the compressor case assembly, compressor rotor assembly and variable vanes. The compressor rotor forward cone is supported by the No. 1 tiltpad bearing in the air inlet assembly. The compressor rotor aft hub assembly is supported by the No. 2 tilt-pad bearing in the compressor diffuser assembly. The labyrinth seal attached to the aft compressor hub assembly forms the rotating component of the thrust balance seal. The compressor rotor aft hub assembly is connected to the gas producer rotor assembly. The compressor forward cone is connected to the accessory drive gear train. There are four stages of variable vanes located in the forward end of the compressor case. They are aerodynamic vanes that have a long machined shaft with two parallel flats near the top and a short shaft at the bottom. Outer bushings in the compressor case provide a bearing surface for the long vane shaft. Inner ring sets support the inner bushings to provide a bearing surface for the short shaft and a stationary seal for the air path. The four stages of variable vanes are Inlet Guide Vanes (IGVs), zero-, first-, and second-stage Variable Stator Vanes (VSVs).

Compressor Diffuser Assembly The forward end of the compressor diffuser assembly is bolted to the aft end of the compressor case. The diffuser assembly supports the No. 2 and No. 3 bearing support housings and thrust balance diaphragm. The diffuser housing incorporates the oil inlet, two oil drain ports, compressor discharge pressure taps, turbine cooling air pressure tap, and borescope access. The No. 2 bearing support housing incorporates the No. 2 tilt-pad bearing, thrust bearing, thrust balance diaphragm and the stationary components of the thrust balance seal. The No. 2 bearing supports the aft end of the compressor rotor. The thrust bearing is adjacent to the No. 2 bearing and it is the fixed-ramp type. The No. 3 bearing support housing incorporates the No. 3 tilt-pad bearing and supports the turbine rotor shaft.

Combustor and Gas Producer Turbine Assembly The combustor and gas producer turbine assembly includes the combustor assembly, fuel manifold assemblies, fuel injectors, bleed valve assembly, T5 thermocouples, and the gas producer turbine assembly. The combustor assembly includes an outer housing which bolts to the aft flange of the compressor diffuser assembly. The annular-type combustor liner is supported in the combustor housing by six combustor support pins located between the 12 fuel injectors. The torch igniter assembly, used only at combustion lightoff, has its own interruptible fuel supply and igniter plug and also contains the forward combustor drain. The bleed valve mounts to a combustor housing flange and is electrically controlled and hydraulically actuated. The combustor housing has an insulation blanket aft of the fuel injectors. Borescope access is through six ports near the forward end of the combustor housing which is used to inspect fuel injectors, combustor liner, and turbine section. One borescope access port, near the aft end of the combustor housing, enters into the second-stage nozzle and is used to inspect the first-stage and second-stage turbine rotor blades and secondstage nozzles. The T5 thermocouple ports are used to inspect the second-stage and thirdstage turbine rotor blades and nozzles. The fuel manifold assemblies include fuel injectors, fuel manifolds for gas fuel, liquid fuel, air assist, or water, as applicable, and the interconnecting lines. The fuel injectors mount radially in the combustor housing with the injector tips fitted into the combustor dome. actuator.

T5 THERMOCOUPLES The T5 Thermocouples (TC1 through TC6) are mounted around the combustor aft housing. The thermocouples protrude into the turbine nozzle area, where they sense the temperature of the thirdstage turbine inlet (T5).

Turbine Rotor Assembly The turbine rotor assembly consists of the turbine rotor shaft and three disc assemblies. The discs and turbine rotor shaft engage each other by radial face splines which transmit torque and keep the discs concentric to the center of the shaft. Radial face splines allow the disc to thermally expand radially. The entire assembly is secured by a thermo-stretched throughbolt. The first-stage turbine rotor blades are cooled by compressor air and fed at a controlled rate through the first-stage turbine nozzle support assembly to an annular slot (preswirler) that discharges onto the rotating blade roots. The air makes two passes through an internal passage in each blade and is discharged from a third chamber through a series of passages in the trailing edge and tip.

Turbine Nozzle Assembly The turbine nozzle assembly consists of the nozzle support housing, first-stage, second-stage, and third-stage turbine nozzle assemblies. The mounting flange of the nozzle support housing is pinned to the aft flange of the combustor housing for alignment and is cantilevered forward. The nozzle support housing is compressed between the aft flange of the combustor housing and the forward flange of the exhaust diffuser for rigid support. The nozzle support housing contains one borescope port hole and six T5 thermocouple ports. The housing supports the screen assembly and three stages of turbine nozzles. The first-stage nozzle assembly contains the first-stage nozzle segments and first-stage diaphragm assembly, which includes the preswirler, and the nozzle clamp ring. The first-stage nozzle segments are secured to the first-stage diaphragm assembly by a nozzle clamp ring. Each first-stage nozzle segment contains two aerodynamic vane segments and inserts. The throat of the nozzle segment directs hot exhaust gasses toward the first-stage disc assembly. Cooling air, which enters each aerodynamic vane segment, is directed by flow control inserts to internally cool the leading edge and air foil surfaces, and is then discharged through the trailing edge. The second- and third-stage turbine nozzles segments are pinned to their respective diaphragm assemblies which form a seal against the second- and third-stage disc assemblies to direct cooling air and control the exhaust gas path.

Turbine Exhaust Diffuser and Bellows Assembly The turbine exhaust diffuser and bellows assembly includes an inner and outer diffusing wall, seven radial struts supporting the center cylinder, and a bellows connected to the outlet V-band clamp. This assembly is bolted to the combustor housing aft flange. It is provided with a liquid drain. A flexible bellows section is incorporated in the turbine exhaust diffuser assembly as a standard feature. This bellows is designed to accommodate the engine thermal growth and up to 0.5 in. (12.7 mm) of external thermal growth when optional equipment such as an exhaust silencer, a heat recovery system, or other special exhaust ducting is used.

Engine Support The turbine engine is cantilevered aft from the forward flange of the air inlet housing, which is bolted to the reduction drive assembly. Additional rear support is provided by a steel pedestal attached to the combustor housing aft flange. The pedestal base rests on a vibration isolating pad located on the steel base crossmember below the combustor housing. The vibration pad is provided with load springs, adjustment bolts, and spacers, that in addition to serving as a resilient rear mount, also permit vertical and horizontal adjustments of the engine for purposes of alignment.

SECTION 6 – Cakerawala Generators ABB Generator driven by Taurus 60 The main driven system components are the Gear Unit and Generator which are connected together with a coupling. The Gear Unit is also designed to drive accessories and to accommodate the Starter Motor.

Reduction Drive Assembly Since the required input speed of the generator is lower than the output speed of the turbine, a reduction drive assembly is necessary. The reduction drive assembly is an epicyclic, high-speed, star-gear design used to reduce the drive speed from the turbine engine to the generator. The reduction drive assembly is designed for an output speed of 1500 rpm for 50 Hz service. The reduction drive assembly is located between the engine and the generator. It is bolted directly to the air inlet housing and the oil tank to provide a rigid support. For this reason, the reduction drive assembly does not require alignment with the engine. The firm attachment of the housing provides support to the forward end of the turbine engine. The reduction drive assembly case consists of a large housing, attached to the air inlet housing, and a smaller output shaft case.

Mounted on the reduction drive assembly is a magnetic pickup which counts the speed of the gear teeth and transmits a signal to the speed monitor control box in the control panel. Another magnetic pickup device directs a signal to the governor to control turbine speed.

The reduction drive assembly gear train is a compound star arrangement with three equally spaced star clusters. The power flows through the input pinion (sun gear) (5) into three first-stage star gears (6), through three second-stage pinion gears (7), and to the second-stage ring gear (4) on the output shaft (9). The input pinion assembly (5) is supported at one end by a ramp bearing mounted on an adapter on the gear carrier. The other end is supported by the three first-stage star gears (6). Pinion thrust loads are taken by a tapered land thrust bearing. The gear clusters have two sleeve bearings mounted inside their bores. The journal bearing is stationary and is mounted in the carrier to support the gear clusters. The second-stage ring gear (4) is mounted on a hub with a loose fitting spline, which allows the ring to center itself on the output shaft (9) through a fixed spline. A sprag-type one-way clutch is mounted on the starter gear shaft. The starter drives through the clutch. When the starter disengages, the sprags lift off the shaft and the clutch overruns continuously.

Each of the first-stage meshes in the power train is cooled and lubricated by three sets of two oil jets directed toward the sun gear between each pair of meshes. Each pinion in the second-stage is cooled and lubricated by two jets on the inboard side. Centrifugal force drives this oil into the ring gear teeth. It is then flung out at the open end of the ring and through holes at the inner end. Additional oil jets cool and lubricate the accessory pinion gear mesh, the output ball bearing, and the one-way clutch on the starter shaft. All other accessory gear meshes and bearings are lubricated by air-oil mist generated in the housing by the high speed meshes. The hydrodynamic ramp bearing and thrust bearing on the input pinion assembly and the sleeve bearings on the countershafts are pressure-fed with oil. Pressurized oil is provided by the externally mounted main lube oil pump.

Accessory Drive Assembly In addition to reducing the speed of the output shaft (Reduction Drive) the gear unit also incorporates the gearing to accommodate Accessory Drives. The only engine-driven accessory used is the Lube Oil Pump (P901) which is mounted on a Drive Pad. The other Drive Pads are not used and are ‘blanked’ by metal plates. Main Lube Oil Pump The Starter Motor (M922) is mounted onto a Starter Drive Adaptor which is then bolted to the Starter Drive Pad. Both the Starter Motor and Lube Oil Pump engage with Spur Gears and then with another spur gear which is attached via splines to the output shaft. The Starter Motor can drive through this gear and the Lube Oil Pump can be driven by it.

Reduction/Accessory Drive Assembly

Generator

Starter Motor

Generator

Introduction Electricity generation was first developed in the 1800's using Faradays dynamo generator. Almost 200 years later we are still using the same basic principles to generate electricity, only on a much larger scale. Electricity can be made or generated by moving a wire (conductor) through a magnetic field.

Magnetism A bar magnet has a north and south pole. If it is placed under a sheet of paper and iron filings are sprinkled over the top of the paper, these iron filings will arrange themselves into a pattern of lines that link the north pole with the south pole of the magnet (diagram 1). These lines show the magnetic field around the magnet. Diagram 1 Making electricity If a coil of wire is moved within a magnetic field so that it passes through the magnetic field, electrons in the wire are made to move (as in diagram 2). When the coil of wire is connected into an electric circuit (at the terminals A and a) the electrons are under pressure to move in a certain direction and a current will flow. This electrical pressure is called voltage. The amount of pressure or voltage depends on the strength and position of the magnetic field relative to the coil, as well as the speed at which the coil is turning. As the amount of electricity changes so does its voltage. Diagram 2

Diagram 3.1

Diagram 3.2

Diagram 3.3

Diagram 4 In the diagrams above, the coil of wire is rotating in a clockwise direction. When the coil of wire is in the horizontal position (3.3), the voltage is greatest (diagram 4) because the coil is passing through the strongest part of the magnetic field. At this stage the current flows from 1 to 2 to 3 to 4, out through terminal A, through the globe and back into terminal a. When the coil of wire is in the vertical position (3.2), no electricity is produced because the coil does not cut the magnetic field, and no current flows. When the coil of wire is in the horizontal position again (3.3), the voltage is at its maximum (diagram 3.3), however the current flows in the opposite direction 4 to 3 to 2 to 1, out through terminal a, through the globe, and back into terminal A.The current produced changes direction every half turn (180 degrees). This is called alternating current or AC. The generators at large power stations produce nearly all the electricity we use in this way.

Power Stations Generators With large power station generators, the coils actually remain stationary, and the magnetic field rotates. This still produces the same effect as described above. The magnet rotates as the turbine to which it is attached rotates. When only one of the coils of wire is connected in the stationary part of the generator (known as the stator), the electricity circuit is said to be one phase (or one circuit). Diagram 5.1 shows what a rectangular coil or winding may look like. It is mounted inside the stator as in diagram 5.2 and has terminals A and a. When the magnet rotates the voltage is produced as shown in diagram 5.3.

Diagram 5.1

Diagram 5.2

Diagram 5.3

Diagram 5.4

Diagram 5.5 It is more cost efficient and technically better to connect three sets of coils in the stator. Diagram 5.4 shows how these coils are mounted. Each of these coils will be connected as separate electrical circuits. When the magnet rotates an identical voltage is produced in each coil and circuit, but each is staggered or delayed from one another (diagram 5.5). The electricity circuit is said to be three phase. Relative Motion between conductor and magnetic field (Condition 3 above), will result in a similar effect if the conductor is stationary and the magnetic field ‘moves’. In practice the generator output voltage and current will be high and require good connections between the ‘conductors’ and the load circuit cables to minimise resistance and losses and therefore the generation of heat. These results in the conductors being stationary and the magnetic field being rotated in practical generators. The following diagrams will examine the construction and operating principles of a typical generator. The turbine is called the prime mover and the shaft, magnet and copper windings make up the alternator. An alternator consists of a rotor and a stator. The rotor is directly connected to the prime mover and rotates as the prime mover turns. The rotor contains a magnet that, when turned, produces a moving or rotating magnetic field. The rotor is surrounded by a stationary casing called the stator, which contains the wound copper coils or windings. When the moving magnetic field passes by these windings, electricity is produced in them. By controlling the speed at which the rotor is turned, a steady flow of electricity is produced in the windings. These windings are connected to the electricity network. The structure of the alternator usually stays the same regardless of the type of energy being used to produce electricity. The prime mover can be a turbine driven by steam, water, wind or burning gases. The prime mover can also be an engine (like a car engine) that uses fuel to turn the generator.

Rotor Shaft

Gear Unit Gear Unit Bearing Gear Unit Output Shaft

Rotor Stator (Windings) Stator Casing

End Plate Exciter Exciter Field PMG PMG Field

Generator Base Fan (Fixed to Rotor) Drive End Bearing Rectifier End Plate (includes Bearing Housing) ND End Bearing

Coupling

Typical Generator arrangement

Cabling

Generator Output Cables (3Ф 50 Hz) Exciter Field (DC) Permanent Magnet Generator (AC 250-300Hz) Other control wiring (Metering, Temperature Sense)

The diagram above shows that the generator rotor shaft is supported by bearings at the Drive and Non-Drive ends and is rotated by the torque transmitted from the engine through the gear unit and coupling. Attached to the rotor shaft is a fan and the rotor which is located within the stator casing so that it aligns with the stator windings. Also attached to the rotor shaft are the rectifier, exciter armature and the PMG (Permanent Magnet Generator). There will be interconnecting conductors between the rotor, rectifier and the exciter armature, shown above as . The following descriptions have been taken from the Installation and Maintenance Manual.

Functional Discription During generator set operation, the three-phase ac power generated in the exciter armature is applied to the rectifier where it is converted to direct current power. The dc output from the rotating rectifier is then applied as field excitation current to the generator rotating field coils. It should be noted that, with this arrangement, the main generator field coils rotate and its armature is stationary, while the exciter field is stationary but its armature rotates with the main generator rotor shaft. As a result, a single rotating assembly, consisting of exciter armature, exciter rectifier, and main generator field coils is formed, greatly simplifying all electrical connections within the generator assembly. A sensing transformer supplies the bus potential signal to the regulator. The main generator output is controlled by the generator field current. The generator field current is in turn controlled by the brushless exciter circuit. The power transformer through the regulator, furnishes the excitation to the exciter field. Variations in bus potential, then, will be sensed and subsequently corrected by this circuit.

All ac generators require that direct current (excitation) be applied to the rotor windings (field coils) in order to set up the magnetic flux necessary for generator operation. Because the amount of dc current going into the field of the exciter will determine the output voltage of the exciter, the exciter output, being applied to the generator field, will therefore control the output voltage of the main generator. Upon proper voltage buildup, the generator accelerates to 100 percent speed and excitation and voltage control are assumed by the voltage regulator. A crosscurrent-compensating transformer provides the proper signals to the regulator to accommodate reactive loadsharing between multiple units in parallel.

COMPONENT DESCRIPTIONS Rotor The rotor is dynamically balanced so that the degree of dynamic imbalance provides minimum vibration. Efficient rotor fans move air through the generator and around the rotor for cooling. The rotors have layer-wound field windings, which are then cemented with a highstrength resin and baked. The rotor is in electrical and mechanical balance at all speeds, up to 125 percent of rated speed.

Stator The stator is built with high-grade silicon steel laminations, which are precision punched and individually insulated. Windings, form-wound in lined slots, are repeatedly treated with thermosetting synthetic varnish and baked for maximum moisture resistance, high dielectric strength, and high bonding qualities. The windings are also braced to withstand shock loads such as motor starting and short circuits. Space heaters can be supplied to minimize condensation during shutdowns.

Shaft The shaft diameter is sufficient to provide the stiffness necessary to preclude torsional problems.

Frame The frame is heavy-duty steel, fabricated with deep welds and internal reinforcing for extra rigidity and strength. Lifting lugs are provided.

Exciter Excitation current for the generator field coils is provided by a brushless rotating exciter unit with permanent magnet generator (PMG) pilot exciter. The generator is a synchronous, three-phase, alternating current generator with rotating field coils, and the exciter unit is mounted directly on the generator rotor shaft. The exciter unit consists of two basic parts, a small three-phase, ac generator with rotating armature, and a three-phase, full-wave, diode-type bridge rectifier portion that rotates together with the armature. The pilot exciter is a permanent magnet generator that rotates with the main generator rotor shaft. It feeds the exciter field windings with excitation current through the voltage regulator. Since the exciter unit itself also requires dc current for excitation of its own stationary field coils, this is furnished by a pilot exciter which is simply a PMG that is mounted on and rotates together with the main rotor shaft. It will be apparent that when starting the generator set, little or no direct current will be available for excitation of either the main generator or the exciter fields, were it not for the action of the PMG pilot exciter.

Permanent Magnet Generator Field Rotating Rectifier Assembly

Exciter Armature

Voltage regulator The control of the arrangement is undertaken by the Voltage Regulator. As most are able to control the generator automatically, they are known as Automatic Voltage Regulators, or “AVR s”. The schematic on the previous page shows that the AVR is powered by voltage from the PMG. On GT7300 & GT7400 power to the AVR will be available once K261 is energised (represented by “Contacts close at 65%NGP”). Power is basically available if no over-voltage condition exists and Ngp is > 80%. The AVR is set to allow the generator to generate voltage of an amplitude which is determined by the controls at the setup stage (Voltage Adjust Potentiometer in the schematic).This is achieved by the AVR controlling the amount of DC current sent to the exciter field windings. The actual generator output voltage is sensed by the AVR and this forms the ‘feedback’ for the AVR control algorithm to compare with the desired set voltage. If it is too high the field current output to the exciter field will be reduced. If it is too low the exciter field current will be increased. The output current is also sensed to allow load sharing with other generators to be achieved. Although the frequency of the generator output voltage is largely determined by the rotational speed of the rotor, which will be set and controlled by the prime mover, the frequency is also monitored by the AVR to alter the control voltage characteristics as the frequency changes. Additional protection is afforded by monitoring the current output to the exciter field for over current and also over voltage at the generator output as well as loss of sense voltage. Over temperature operation of the AVR will result in the AVR automatically turning itself off. The AVR will need to be set to control the generator output voltage by a control scheme which will differ if it is required to operate in parallel (load share) with other machines. If a generator is operating alone ISOCH should be set for Voltage Control mode on S260. If either generator is to be paralleled with other generators, DROOP mode should be selected for Voltage Control mode on S260-1. The speed (frequency) should in both cases be set to ISOCH on SPD ISOCH/SPD DROOP Switch (S/DS191).

Typical Electrical Schematic The following drawing shows the overall electrical arrangement of a typical generator and how the Voltage Regulator is used to monitor the output voltage and current and alter the exciter field current to suit the required generator output. As can be seen it is supplied with power from the Permanent Magnet Generator and sences generator output voltage and current and alters the exciter field current to suit.

Coupling The rotational torque to drive the generator is transmitted from the engine through the gear unit and then to the generator by connecting the gear unit output shaft to the generator rotor shaft with a coupling. The coupling is designed to allow transmission of power only within certain limits. Firstly, it is important to ensure that the alignment of the two shafts is within allowable limits of ‘runout’. This will ensure that not only is the coupling not exposed to excessive stress, but will ensure that the shaft bearings are not adversely loaded and that vibration will be minimised. Although the design will allow some mis-alignment to be accommodated and this is achieved by the use of ‘disc packs’, whatever method is used, must be in a suitable condition for use. ‘Disc packs’ are normally made from thin steel sheets with the appropriate profile and holes formed on each sheet. The sheets are then riveted together to form a laminated ‘spacer’, which is then installed in the coupling assembly, by bolts which pass through the rivets. Misalignment is accommodated by the sheets ‘flexing’ slightly. Care should therefore be taken to ensure that the ‘disc packs’ sheets are not excessively cracked and that they are clean. Ingress of dirt, etc between the sheets can cause abrasive wear and also possibly imbalance. Secondly, to protect the engine and gear unit as well as the generator from potentially damaging operating conditions, the coupling is also designed to ‘shear’ if subjected to excessive torsional forces. These could arise if the generator was subjected to a massive overload or more commonly, if the generator was attempted to be synchronised ‘Out of phase’ with the output bus. The shear elements (basically mechanical ‘fuses’) are usually specially machined bolts or pins which connect the coupling ‘halves’ together, but are designed to shear (break) if the load they are transmitting becomes too great. This then allows the engine to continue to drive the gear unit and the part of the coupling connected to the gear unit output shaft, but the generator will no longer be driven by the engine.

Flexible Coupling These couplings eliminate the need for lubrication. However, lube oil may be present in the shaft cover. Hubs are attached to the rotating equipment with splines and / or interference fit pilots. The flexing of the coupling is accommodated through the use of flexible disks in a plane perpendicular to the shaft centre line.

Typical Flexible Disk Coupling

SECTION 7 – Cakerawala Gas Turbine Turbotronic Control Ststem General Discription The Turbotronic™ Control System operates the turbomachinery package and its subsystems. The system generates electronic control signals to start, stop, load, and unload the turbomachinery, manually or automatically, from a local or remote location. Control system functions are: • • • •

Sequence Control Protect Display

This chapter describes control system operation.

Functional Discription The control system is microprocessor-based and customized for each application using a combination of input and output (I/O) modules. The system controls scanning, monitoring, and reception of data. Data is processed in the Programmable Logic Controller (PLC) and sent to output modules for transmittal to package control elements. The control panel is electrical switch-based, allows command input, and indicates status. The turbine package includes instrumentation to report operating conditions to the control system and control devices to receive control output from primary or backup control systems. Control elements are primarily electrical, electromechanical, and electrohydromechanical devices controlled by the PLC.

Sequence Sequencing functions control logic elements in the control system. Logic elements are (on/off, open/close, start/stop, yes/no) events associated with switches, solenoids, relays, and comparator devices. Sequencing monitors and senses events, and carries out computations to operate components in the system. Examples of sequencing elements include: • Start • Load • Stop • Postlube

Start Manual actions to start the turbomachinery are: • Arm the system • Reset malfunctions • Select operating mode • Initiate start After start is manually initiated, the system accomplishes the following: • Purge crank • Lightoff • Starter dropout • Lubrication check

Load The load function maintains operating speed, loads the generator and transfers to steady state control.[RUNNING] is highlighted on the operation summary screen. When the engine reaches 90 percent speed, the ready to load timer starts to time. When the ready to load timer times out, the READY-TO-LOAD light illuminates. When [READY TO LOAD] is displayed on the operation summary screen, the generator can be connected to the load bus by closing the generator circuit breaker. The circuit breaker can be closed to a dead bus or a hot bus. When a dead bus is sensed, the circuit may be manually closed. When a hot bus is sensed, the generator is synchronized to the load bus before closing the circuit breaker. The voltage is matched to minimize flow of circulating current between the generators. The frequency is matched to minimize initial loading and allow phase matching (synchronization). Phase is synchronized to allow safe closing of the circuit breaker. Closing the circuit breaker when the generator and load bus are out-of-phase can cause equipment damage, and is not permitted by the control system.

Synchronization Before the generator circuit breaker can be closed to the load or tie bus, the generator frequency, voltage, and phase must be synchronized to the bus. The operator can manually synchronize the generator to the load or tie bus, or the control system can automatically perform the synchronization process. This process includes matching of the generator and load or tie bus voltage, frequency, and phase. To synchronize automatically, AUTOMATIC SYNCHRONIZE INITIATE is selected. The auto synchronization fail timer starts timing and an AUTO SYNCH indication is displayed. The automatic synchronizer matches the generator frequency, voltage, and phase to the load or ties bus and closes the generator circuit breaker. When automatic synchronization is complete and the synchronization check relay monitor permissive is closed, the circuit breaker closes and connects the generator to the load bus. Indicators operate as described under dead bus. If the generator circuit breaker does not close before the auto synchronization fail timer times out, the generator circuit breaker lockout relay is activated. The automatic synchronization function is deenergized. The auto synch selection highlight is extinguished and the Auto Sync Fail alarm is annunciated on the display screen.

Stop Turbine shutdown can be manual or automatic with either a cooldown or fast stop.

Cooldown stop Unloads the generator by reducing engine operating speed to idle, and starts the cooldown timer (5 minitues). If a start is re-initiated during the cooldown stop, the shutdown is aborted. A start can be re-initiated during the cooldown period by pressing :- acknowledge, reset and start.

Fast stop Unloads the gas compressor, (or generator) closes the fuel shutoff valves and stops the turbine without a cooldown period

Manual shutdown Is initiated by either activating the stop switch or the emergency stop switch. The stop switch provides a cooldown stop and the emergency stop switch provides a fast stop. The gas compressor is unloaded once a stop is initiated. For a normal and/or station shutdown, compressor (or generator) load should be reduced before initiating a stop. When the gas compressor(or generator) is under a load and a malfunction occurs, the control system unloads the compressor(or generator) and shuts off fuel to the turbine. The control system provides both a cooldown stop (lockout or nonlockout) and a fast stop (lockout or nonlockout).

Emergency Stop The Emergency Shutdown (ESD) is initiated by detection of a fire, backup overspeed system failure, PLC failure, or the operator pressing the ESD switch. The ESD stop unloads the gas compressor (or generator), closes the fuel shutoff valves and stops the turbine without a cooldown period. Lube oil control for turbine rundown and postlube is controlled by the backup relay system. If an ESD stop has been initiated, the backup system must be reset with the BACKUP RESET keyswitch and by pressing the ACKNOWLEDGE and RESET switches prior to restart.

Postlube As the engine slows, the engine driven lube oil pump pressure decreases and the ac lube pump starts. If the ac lube oil pump fails to provide minimum pressure, the backup pump is started.

Control The control function monitors and regulates process variables such as speed, pressure, and temperature. The function controls transient response to load changes and controls actuators during start, stop, and load.

Fuel Control Turbine fuel flow control regulates pressure and fuel flow. Fuel flow is controlled by regulating the electronic fuel control valve. The fuel system establishes the fuel flow range by regulating fuel supply pressure and flow. Fuel pressure is regulated to a value greater than Pcd between maximum and minimum valve positions. The control system positions the electronic fuel control valve and regulates fuel flow to regulate engine speed, power, and T5 temperature during lightoff, acceleration, steady state, and transient load conditions.

Bleed Valve Bleed valve position control regulates Pcd by routing airflow to the exhaust, bypassing combustor and turbine. During start and acceleration, the bleed valve avoids engine surge. During start and acceleration, the bleed valve is opened to allow airflow to bypass combustor and turbine . An open bleed valve reduces turbine compressor back pressure and avoids engine surge, the bleed valve position is determined as a function of kilowatt load.

Guide Vane System Airflow through the turbine compressor is regulated by controlling angular position of variable geometry inlet guide vanes. Guide vanes maximize gas turbine compressor performance and avoid surge during start and acceleration. During start and acceleration, guide vane position is determined by engine speed.

Protect The protect function monitors operating conditions, compares to limits, identifies when a limit is exceeded, annunciates the fault, and initiates a stop if the fault is a shutdown-type malfunction. A backup relay system protects in the event of PLC failure, fire, power turbine overspeed, or a manual emergency stop.

Malfunction Alarm The alarm task detects when a condition changes from normal to a level of concern. It annunciates the problem to communicate that corrective action is required.

Malfunction Shutdown The shutdown task detects when a danger level is reached, or a major malfunction occurs. Shutdowns are one of four types:1. Cooldown Stop Nonlockout 2. Cooldown Stop Lockout 3. Fast Stop Nonlockout 4. Fast Stop Lockout

CN CL FN FL

Fast Stop Vs Cooldown Stop The cooldown stop unloads the gas compressor(or generator) and allows the engine to idle for a cooldown period of 10 minutes before shutting off fuel. A start can be re-initiated during the cooldown period by pressing :- acknowledge, reset and start. The malfunction fast stop immediately shuts off fuel and unloads the compressor(or generator). . A start can not be re-initiated

Lockout Vs Nonlockout Malfunctions The lockout malfunction inhibits control system operation. The control system cannot initiate a start until the malfunction is reset. Nonlockout malfunctions typically result from an operation disruption or an abnormal condition. Nonlockout malfunctions can be reset when conditions return to normal. Lockout-type malfunctions are generally more severe and require attention before the system can be restarted.

Cooldown Stop Nonlockout Cooldown stop nonlockouts include normal stops as well as stops responding to alarms not serious enough to cause immediate damage. Some of these conditions require corrective action before resuming operation. These conditions include reaching temperature and pressure limits with lube oil, air filter, gas compressor suction and discharge lines or a failure to load. A start can be re-initiated during the cooldown period by pressing :- acknowledge, reset and start.

Cooldown Stop lockout Cooldown stop lockouts respond to conditions that may not exceed shutdown levels but indicate a component has failed. Coold own stop locko ut malfu nctio ns includ e sens or (RTD , thermocouple, etc.) failure and a lube oil tank pressure or temperature limit being reached.

Fast Stop Nonlockout Fast stop nonlockouts respond to conditions that can cause damage if operation continues. The conditions are caused by a momentary disturbance in the system or an occasional sequencing related malfunction.

Fast Stop Lockout Fast stop lockouts respond to conditions that can cause serious damage if operation continues. Investigation for damage is required. Corrective action may be required before restart.

Backup Active Shutdown The backup active shutdown is enabled if there is a microprocessor failure, fire, backup overspeed, or manually initiated Emergency Shutdown (ESD). The system immediately shuts off fuel, opens yard valves to eliminate compressor load,(or unloads generator) and controls lubrication oil for engine roll down and post lube. After a backup active shutdown, the backup system must be reset with the BACKUP RESET keyswitch. The ACKNOWLEDGE and RESET switches must be pressed before the package can be restarted.

Microprocessor Fail When microprocessor failure is detected, a fast stop is initiated and backup control is activated.

Manual Emergency Stop The manual emergency stop is initiated by depressing the local, remote, or skid-mounted emergency stop switch. When the stop is initiated, the start/run latch in the microprocessor is reset and the fast stop latch in the backup control is set.

Fire Detected When fire is detected, the backup system immediately sets the fast stop latch in backup control and the shutdown sequence proceeds as with the manual emergency stop except enclosure fans, if present, are stopped, and lube continues for engine rolldown, is stopped for 20 minutes, and, if the PLC is functioning after the 20 minute hold, a postlube cycle is completed.

Turbine Backup Overspeed The turbine overspeed malfunction is sensed by the backup overspeed detection module. The magnetic pickup speed sensor is independent from primary control sensor. The backup overspeed monitor detects overspeed that indicates the normal control and protect systems are not operating. When overspeed is detected, the fast stop latch in the backup control is set and the stop sequence proceeds as with manual emergency stop.

Turbotronics Display The display function formats systems operating information, collects data, and provides the information to the operator through the display device. The display device allows the operator to monitor the operating conditions of the turbomachinery and perform limited turbine control functions. This display device may provide historical as well as current information. The display computer is an industrial personal computer (PC) with video display monitor and software. The computer has a rear power switch and a floppy disk drive. The monitor has a color display screen and two sealed-membrane keypads. The function keypad accesses display features listed on the MENU SELECTION screen. Display software is on floppy disks.

Display Control Keys Control keys are number/control and function keypads. The keypad enters data and controls cursor position on the screen. The function keypad activates display features.

Control Key The CTRL (Control) key, with the ENTER key, activates or deactivates display functions indicated with a blinking asterisk (*). With the PAGE DOWN key, the CTRL key prints the screen.

Cursor Controls Up, down, left, and right arrow keys move the cursor on the screen. On the MENU SELECTION screen, the green rectangle cursor highlights display feature blocks. In stripchart screens, the blue bar cursor moves up or down to highlight a listed variables. On the OPERATION SUMMARY screen, the cursor is a blinking asterisk.

Enter The ENTER key activates the current selection. On the MENU SELECTION screen, for example, after a display feature is selected (the block is highlighted), pressing ENTER causes the selected screen to appear. CTRL and ENTER keys activate the blinking asterisk function.

Escape The ESC (Escape) key recalls the MENU SELECTION screen. The key cancels any operation in progress.

Function Keys Function keys, F1 through F10, SHIFT F1 through SHIFT F10, CTRL F1 through CTRL F10, and ALT F1 through ALT F10, access MENU SELECTION display features. To change from one screen to another, the function key is pressed, without returning to MENU SELECTION. In lower level menu screens, function keys are used as prompted.

Number Keys Number keys select options for loading software, resetting passwords, initializing the history file, changing package constants (Kvals), initiating printing functions, and multi-package monitoring.

Home And End Keys The HOME key selects the first parameter on the first page of a display. The END key selects the last parameter on the last page of the display screen.

Page Up And Page Down Keys PAGE UP and PAGE DOWN keys allow observation of sections of multiscreen displays. PAGE DOWN, with the CTRL key, prints the displayed screen.

System Reboot To reboot the system, turn power OFF and ON using the power ON/OFF push-button on the rear of the computer. Reboot diagnoses and resets the system.

Display Screens Display screens can be viewed in the on-line or the optional playback mode. Refer to SYSTEM MANAGER display screen to access playback mode. The MENU SELECTION display screen contains the display screen selection blocks and will be the first screen displayed after power is supplied to the operator interface display computer. Follow the instructions provided on the message at the bottom of each screen for additional display feature selections or operating procedures.

line

The asterisk (*) preceding an entry on a display screen indicates that the feature can be activated, or controlled, by the operator. Position the cursor to the desired feature (asterisk blinking), hold down the CTRL key and simultaneously press ENTER to activate or stop the selected activity. After a momentary pause, observe the highlighted onscreen entry for confirmation.

On-line mode, some of the screens display real-time data being collected from the controller, and others display data stored in the computer. When powered-up, the system is placed in the on-line mode. Playback mode, the screens only display data stored in the computer. The background display tasks, such as alarm checking and data logging, continue to operate and real-time alarms are displayed at the top of the screens. The FIRST OUT ALARMS, STRIPCHART, and PROGRAM CONSTANTS display screens are not active in the playback mode. In the playback mode, the operator can interrogate and view data in the EVENTLOG, TRIGGER, ELAPSED TIME, and HISTORY databases. The screens that normally display stored data, in the on-line mode, are also used to select the database to be viewed.

Menu Selection Display Screen The MENU SELECTION display screen is displayed at power-up or when power to the display is interrupted by turning its power supply circuit breaker OFF and ON. The selection menu provides access to the display screens. Selections can be made directly from the MENU SELECTION display screen. To select a menu option, use the arrow keys on the number/control keypad to move the cursor to the desired option. Press the ENTER key to select the screen. Screens may also be selected by pressing the appropriate function key associated with the screen (for example, F1; hold down SHIFT key and simultaneously press F6; or hold down CTRL key and simultaneously press F9). To print any screen, hold down CTRL and simultaneously press PAGE DOWN.

TYPICAL MENU DISPLAY SCREEN

Operation Summary Display Screen The OPERATION SUMMARY display screen selected from the MENU SELECTION display screen by pressing the appropriate function key or by positioning the cursor to the OPERATION block with the up, down, left, or right arrow keys and pressing ENTER. Press the ESC (escape) key to return to the MENU SELECTION display screen. The OPERATION SUMMARY display screen is used by the operator to view overall system conditions, and is generally the screen left on the display during normal system operation. The conditions being monitored are highlighted on the screen. The data is presented in real time and is continually updated. An asterisk (*) next to a function indicates it is controlled by the operator at this screen. Use arrow keys to position the cursor at the function (asterisk blinks), hold down the CTRL key and simultaneously press ENTER to activate or stop the selected function. Wait a few seconds (2 to 3) for the function to activate. Observe the highlighted entry for confirmation

Generator Operation Summary Screen Typical Control Keys Press arrow keys. : Press CTRL/ENTER key : Press + (plus) key.:Press - (minus) key.:Press ESC key.:-

Moves cursor (asterisk) on the screen (on-line mode only). Activates/deactivates function next to which cursor (asterisk) is blinking(on-line mode only). Increments data by one record (playback mode only). Decrements data by one record (playback mode only). Returns to MENU SELECTION display screen

Temperature Summary Display Screen The TEMPERATURE SUMMARY display screen is selected from the MENU SELECTION display screen by pressing appropriate function key or by positioning the cursor to the TEMPERATURE block with the up, down, left, or right arrow keys and pressing ENTER. Press the ESC key to return to the MENU SELECTION display screen. The TEMPERATURE SUMMARY display screen displays all the temperatures being monitored on the unit. The Saturn 20 displays the T5 average. The lube system and bearing readings are indicated in actual temperatures.

TEMPERATURE SUMMARY

Vibration Summary Display Screens Vibration summary display screens are selected from the MENU SELECTION display screen by pressing appropriate function key or by positioning the cursor to the VIBRATION block with the up, down, left, or right arrow keys and pressing ENTER. Press the ESC key to return to the MENU SELECTION display screen. Vibration summary is displayed on two screens, the DRIVER VIBRATION SUMMARY display screen and the DRIVEN VIBRATION SUMMARY display screen.

Typical Driver Vibration Screen

Driver Vibration Summary Display Screen When VIBRATION is selected from the MENU SELECTION display screen, DRIVER VIBRATION SUMMARY is the first display screen for viewing. The DRIVER VIBRATION SUMMARY display screen shows the vibration readings and proximity probe gap voltages being monitored on the driving equipment. Use PAGE DOWN key to view DRIVEN VIBRATION SUMMARY display screen or press the ESC key to return to the MENU SELECTION display screen.

Generator Summary Display Screen The GENERATOR SUMMARY display screen is selected from the MENU SELECTION display screen by pressing appropriate function key or by positioning the cursor to the GENERATOR block with the up, down, left, or right arrow keys and pressing ENTER. Press the ESC key to return to the MENU SELECTION display screen.

GENERATOR SUMMARY PAGE

The GENERATOR SUMMARY display screen displays generator operating values. The displayed values include setpoint, alternator, bus, balance line, and power status.

Engine Performance - Gas Display Screen The ENGINE PERFORMANCE - GAS display screen (Figure 3.3.6) is selected from the MENU SELECTION display screen by pressing appropriate function key or by positioning the cursor to the ENGINE PERFORMANCE block with the up, down, left, or right arrow keys and pressing ENTER. Press the ESC (escape) key to return to the MENU SELECTION display screen. The ENGINE PERFORMANCE - GAS display screen displays engine performance curves, depicting theoretical values under given conditions, in contrast to current actual values under existing operating conditions. The important indications are in the trends between the theoretical and actual values. Refer to Installation and Maintenance Instructions, Turbine Engine Chapter, of this manual set for applicable engine performance calculations.

Alarms Display Screen The ALARMS display screen is selected from the MENU SELECTION display screen by pressing appropriate function key or by positioning the cursor to the ALARMS block with the up, down, left, or right arrow keys and pressing ENTER. Press the ESC (escape) key to return to the MENU SELECTION display screen. Acknowledged and unacknowledged alarm and shutdown codes are displayed on the ALARMS display screen. Any malfunctions detected will flash corresponding indication until the

TYPICAL ALARMS PAGE

ACKNOWLEDGE switch on the turbine control panel is pressed. As malfunctions are acknowledged, they will stop flashing and remain highlighted on the screen until cleared from the system and the RESET switch is pressed. In a single unit configuration, the first four malfunctions detected are displayed at the top of all screens until cleared. In a multi-unit configuration, one alarm is displayed per unit. The display screen is divided into four columns. At the left is the date, in the center is the time, and on the right is the alarm designation and description. If more alarms have occurred than will fit on one page, the additional alarms can be viewed by pressing the PAGE UP/PAGE DOWN keys on the number/control keypad. Noncritical alarms are shown in yellow. Critical alarms (shutdowns) are shown in red. Unacknowledged alarms blink in yellow highlights with black letters. Acknowledged alarms appear unblinking in reverse video (yellow letters on black background).

First Out Alarms Display Screen The FIRST OUT ALARMS display screen is selected from the MENU SELECTION display screen by pressing appropriate function key or by positioning the cursor to the FIRST OUT ALARMS block with the up, down, left, or right arrow keys and pressing ENTER. Press the ESC (escape) key to return to the MENU SELECTION display screen.

TYPICAL FIRST OUT ALARMS PAGE

The FIRST OUT ALARMS display screen shows only unacknowledged alarms in the order in which they occurred.

Meters Display Screen The METERS display screen can be selected from the MENU SELECTION display screen by pressing appropriate function key or by positioning the cursor to the METERS block with the up, down, left, or right arrow keys on the number/control keypad and pressing ENTER. Press the ESC (escape) key to return to the MENU SELECTION display screen.

TYPICAL METERS PAGE

The METERS display screen shows, in real time, all the monitored functions in a bar-graph format. Up to 33 meters are displayed on each page. When a transmitted value is under or over range, the color will change to blinking blue color to indicate this condition. Press the PAGE UP or PAGE DOWN to display more Meters.

Stripchart Display Screen The STRIPCHART display screen is selected from the MENU SELECTION display screen by pressing appropriate function key or by positioning the cursor to the STRIPCHART block with the up, down, left, or right arrow keys and pressing ENTER. Press the ESC (escape) key to return to the MENU SELECTION display screen. The STRIPCHART screen is a multiscreen display. The first screen displays the titles of the analog variables available for presentation in stripchart form.

TYPICAL STRIPCHART ANALOG TITLES AVAILABLE FOR DISPLAY

Use the following procedures to select and display variables in stripchart format. 1. Use PAGE UP/PAGE DOWN keys to view all available titles of analog variables. 2. Select any four variables to be displayed in stripchart format. 3. Use the arrow keys to move the highlighting bar up or down to each of the selected variables. 4. Press ENTER after each selection. 5. When all four variables are selected, press ENTER once again to view the stripcharts of the four selected variables, or press ESC to clear.

The second screen emulates a four-pen stripchart recorder to monitor the selected analog variables. The stripcharts displays raw, real time data.

TYPICAL STRIPCHART ANALOG PAGE

After viewing original stripcharts, to choose four different variables for display, return to the selection screen by pressing the ESC key at the stripchart screen. The system will return to the MENU SELECTION display screen. Choose the STRIPCHART display screen. When at the STRIPCHART display screen, displaying the titles of the analog variables, press the ESC key to clear the entries. Select four different variables as described in Steps 1 through 5. When done, press the ESC key to return to the MENU SELECTION display screen. The stripchart display screens are not available in playback mode.

Analog History Display Screen The ANALOG HISTORY display screen is selected from the MENU SELECTION display screen by pressing appropriate function key or by positioning the cursor to the ANALOG HISTORY block with the up, down, left, or right arrow keys and pressing ENTER. Press the ESC (escape) key to return to the MENU SELECTION display screen. The ANALOG HISTORY display screen is a multiscreen display. The first screen displays the titles of the analog variables available for presentation in stripchart form.

TYPICAL ANALOG TITLES AVAILABLE FOR DISPLAY INSTRIPCHART FORMAT

Use the following procedures to select and display variables in stripchart format. 1. Use PAGE UP/PAGE DOWN keys to view all available titles of analog variables. 2. Select any four variables to be displayed in stripchart format. 3. Use the arrow keys to move the highlighting bar up or down to each of the selected variables. 4. Press ENTER after each selection. 5. When all four variables are selected, press ENTER once again to view the stripcharts of the four selected variables, or press ESC to clear. 6. When the stripchart screen appears, the stripcharts will be blank. 7. Select the desired time interval for display. 8. Press the function key for desired time interval. Function keys F1 and F2 offer the fastest changing historical data available. 9. Function key F7 offers the slowest changing historical data available. 10. When the stripcharts reflect data, move the vertical line with the left and right arrow keys over the data to display the value and time for specific data points.

The second screen shows the data in stripchart form. The data is conditioned and historical rather than raw and real-time. The stripchart display also includes a bar graph and digital indicator that show the current value of the data point.

In the playback mode, when viewing Analog History data, the time interval in effect will remain the same as the time interval chosen in the Analog History option. If the operator is looking at the data in the minutes time-base, after exiting the option, the data shown is the minutes data from the History file, until another database or time interval is chosen. Moving the vertical line with the left and right arrow keys over the data, in playback mode, selects the ANALOG HISTORY database and record group that will also be viewed in other applicable screens. • Press the END key to move the view to the oldest data point displayed (last point displayed on left-most side). • Press the HOME key to move the data to the most recent data point displayed (last data point on the right-most side). • To display the same variables but at a different time interval. Press the function key for the desired new time interval. To choose four different variables, return to the selection screen by pressing the ESC key at the stripchart screen. The system will return to the MENU SELECTION display screen. • Choose the ANALOG HISTORY display screen. • When at the ANALOG HISTORY display screen, displaying the titles of the analog variables, press the ESC key to clear the entries. • Select four variables as described in Steps 1 through 6. When done, press the ESC key to return to the MENU SELECTION display screen.

Predictive Trend Display Screen The PREDICTIVE TREND display screen is selected from the MENU SELECTION display screen by pressing appropriate function key or by positioning the cursor to the PREDICTIVE TREND block with the up, down, left, or right arrow keys and pressing ENTER. Press the ESC (escape) key to return to the MENU SELECTION display screen. The PREDICTIVE TREND display screen is a multiscreen display. The first screen displays the titles of the analog variables available for presentation in stripchart form.

Use the following procedures to select and display variables in stripchart format. 1. Use PAGE UP/PAGE DOWN keys to view all available titles of analog variables 2. Select any four variables to be displayed in stripchart format. 3. Use the arrow keys to move the highlighting bar up or down to each of the selected variables. 4. Press ENTER after each selection. When all four variables are selected, press ENTER once again to view the stripcharts of the four selected variables, or press ESC to clear selections. The second screen shows the data in stripchart form. The predictive trend feature can be used to identify and schedule requirements for corrective or preventive maintenance. When the stripchart screen appears, the stripcharts will be blank. Select the desired time interval for display. Press the function key for desired time interval. Function keys F1 and F2 offer the fastest changing historical data available. Function key F7 offers the slowest changing historical data available. When the stripcharts reflect data, move the vertical line with the left and right arrow keys over the data to display the value and time for specific data points.

Moving the vertical line with the left and right arrow keys over the data, in playback mode, selects the ANALOG HISTORY database and record group that will also be viewed in other applicable screens. Press the END key to move the view to the oldest data point displayed (last point displayed on leftmost side). Press the HOME key to move the data to the most recent data point displayed (last data point on the right-most side). To display the same variables but at a different time interval, press the function key for the desired new time interval. To choose four different variables, return to the selection screen by pressing the ESC key at the stripchart screen. The system will return to the MENU SELECTION display screen. Choose the PREDICTIVE TREND display screen. When at the PREDICTIVE TREND display screen, displaying the titles of the analog variables, press the ESC key to clear the entries. Select four variables as described in Steps 1 through 6. When done, press the ESC key to return to the MENU SELECTION display screen. The predictive trend stripchart display screen is divided into two sections. The left side shows a plot using real-time package operation, the right side displays the predicted values of operation. A graphic plot is developed using data points collected during package operation. Data points are compressed by using an averaging period. The averaging period is based on designated time intervals from 1 second to 10 000 hours. The time interval for predictive trend is the same as analog history. The plot is developed by using intervals of time as data points. When the predicted curve, on the right side of the plot, is not on the screen, assume that the prediction is “off scale,” and reexamine the variable values. Alarm or shutdown values associated with the selected variables may be read by moving the cursor, with the arrow keys, from the left side of the graph to the right side. Alarm levels are shown in yellow and shutdown levels are shown in red. In playback mode, when viewing the predictive trend data, the time interval will remain the same as the time interval chosen in the predictive trend option. If the operator is exiting this option while looking at future data, the point of entry will be the latest, or center point displayed.

Elapsed Time Data Display Screen The ELAPSED TIME SELECT display screen is selected from the MENU SELECTION display screen by pressing appropriate function key or by positioning the cursor to the ELAPSED TIME DATA block with the up, down, left, or right arrow keys and pressing ENTER. Press the ESC (escape) key to return to the MENU SELECTION display screen. The elapsed time data is presented in a multiscreen display. The first screen, ELAPSED TIME SELECT, displays the titles of the analog variables available for presentation in stripchart form.

The second screen, ELAPSED TIME DATA, shows the data in stripchart form. This elapsed time data feature provides a file of analog data showing the actual conditions at specific intervals of time. This allows for plotting of the actual operating duty cycle of the equipment over long periods of time by showing start and stop events and operating power levels. Use the following procedures to select and display variables in stripchart format. 1. Use PAGE UP/PAGE DOWN keys to view all available titles of analog variables. 2. Select any four variables to be displayed in stripchart format. 3. Use the arrow keys to move the highlighting bar up or down to each of the selected variables. 4. Press ENTER after each selection. 5. When all four variables are selected, press ENTER once again to view the stripcharts of the four selected variables, or press ESC to clear. 6. When the stripchart screen appears, the stripcharts will be blank.

Select the desired elapsed time interval for display. Function keys F2 and F3 offer the fastest changing elapsed time data. Function key F6 offers the slowest changing elapsed time data. When the stripcharts reflect data, move the vertical line with the left and right arrow keys over the data to display the value and time for specific data points. When the plot is larger than the screen display, function keys F2 (left) and F6 (right) may be used to shift the screen viewing area.

Moving the vertical line with the left and right arrow keys over the data, in playback mode, selects the ELAPSED TIME database and record group that will also be viewed in other applicable screens. Press the END key to move the view to the oldest data point displayed (last point displayed on leftmost side). Press the HOME key to move the data to the most recent data point displayed (last data point on the right-most side). Press function key F4, NEWSTEP, to select a new time interval. The data shown on the stripchart is historical. When a new time interval is selected, the latest data available is displayed. To choose four different variables, return to the selection screen by pressing the ESC key at the stripchart screen. The system will return to the MENU SELECTION display screen. Choose the ELAPSED TIME SELECT display screen. When at the ELAPSED TIME SELECT display screen, displaying the titles of the analog variables, press the ESC key to clear the entries. Select four variables as described in Steps 1 through 6. When done, press the ESC key to return to the MENU SELECTION display screen. In playback mode, when viewing the elapsed time data, the time interval will remain the same as the time interval chosen in the elapsed time option.

Trigger Log Display Screen The TRIGGER LOG display screen is selected from the MENU SELECTION screen by pressing the appropriate function key or by positioning the cursor to the TRIGGER LOG block with the up, down, left, or right arrow keys and pressing ENTER. Press ESC key to return to MENU SELECTION display screen. The trigger log is a group of files containing data surrounding an event, or a “trigger.” This feature allows examination of data for up to four analog variables, chosen from a possible five, in a selected time span of system operation. Data are displayed in stripchart format and can be printed in tabular format. TRIGGER LOG has multiple screens. The first, shows titles of analog variables.

Use the following procedure to select and display analog variables and trigger files in stripchart format. 1. Use PAGE UP/PAGE DOWN keys to view available titles of analog variables. 2. Select four analog variables to be displayed or select the same analog variable four times to view the variable over more than one time frame. 3. Use arrow keys to move highlighting bar up or down to select analog variables. 4. Press ENTER after each selection. 5. When four analog variables are selected, press ENTER to view the trigger file, or press ESC to clear.

6. Use arrow keys to move the highlighting bar up or down to each of the trigger files. 7. Press ENTER after each selection. As each file is selected, the file name is displayed next to the analog variable on the lower portion of the screen. 8. When four files are selected, press ENTER, or press ESC to clear. When ENTER is pressed, the screen clears, the files are read, and data are displayed in stripchart format. 9. When the stripcharts show data, move the vertical line with the arrow keys over the data to display value and time for specific points.

The second, shows optional trigger files for selected analog variables.

The third screen, shows data in stripchart format .

Moving the vertical line with arrow keys over the data, in playback mode, selects the TRIGGER database and record group that will also be viewed in other applicable screens. Press the ESC key to return to the MENU SELECTION display screen.

Discrete Event Log Display Screen The DISCRETE EVENT LOG screen is selected from the MENU SELECTION screen by pressing the appropriate function key or by positioning the cursor to the DISCRETE EVENT LOG block with the arrow keys and pressing ENTER. Press ESC key to return to the MENU SELECTION screen. The DISCRETE EVENT LOG screen lists events that occurred in system operation. Each entry includes event date and time. This feature is useful in troubleshooting. A list of events may be printed as follows: 1. 2. 3. 4.

Use PAGE UP/PAGE DOWN keys to view all listed events. Press function key F9 (START) to mark start point. Press function key F8 (STOP) to mark stop point. Press function key F10 (PRINT) to print marked events.

While being viewed, the DISCRETE EVENT LOG display screen is not updated to display new events. To view the latest list of discrete events, press ESC key to return to MENU SELECTION screen and select the DISCRETE EVENT LOG screen as described above. Selecting DISCRETE EVENT LOG display screen, in playback mode, selects the EVENTLOG database that will be viewed in other applicable screens.

Save Data Files Display Screen The SAVE DATA FILES display screen is selected from the MENU SELECTION display screen by pressing the appropriate function key or by positioning the cursor to the SAVE DATA FILES block with the up, down, left, or right arrow keys and pressing ENTER. Press the ESC key to return to the MENU SELECTION display screen. This display screen enables the operator to download data from the system data files to a floppy disk.

Use the following procedures to download data onto a floppy disk. 1. Open floppy drive access door on the front panel below the number/control keypad. Insert floppy disk. 2. Press function keys F7 and F8 to scroll through and select the desired data file. 3. Press function key F9 to move cursor and activate the next box requiring input. 4. Press function key F10 to accept the selections. 5. If trigger log file was selected, a list of valid trigger files will appear. Use the up and down arrow keys to select the desired file, and press function key F10 once the desired file is highlighted. 6. Press function key F10 when all inputs have been selected. For elapsed time data, discrete event log, or trigger log files, a set of input boxes for entering the start and end time is displayed. Use F7, F8, and F9 to set inputs as desired. 7. The last prompt to appear is for the file name. Press F10 to accept the currently displayed file name. 8. The default directory to save the data file is C:\MAIN. To save the data directly to a floppy disk, either change the directory in the displayed file name to A:, or exit the display system to get to the DOS prompt and use the DOS copy command to copy the file from C:\MAIN to A:. 9. A status message is displayed to indicate the progress of the record downloading. 10. Pressing ESC will abort the save process, leaving a target file with incomplete data.

Program Constants Display Screen The PROGRAM CONSTANTS display screen is selected from the MENU SELECTION display screen by pressing appropriate function key or by positioning the cursor to the PROGRAM CONSTANTS block with the up, down, left, or right arrow keys and pressing ENTER. Press the ESC key to return to the MENU SELECTION display screen. The PROGRAM CONSTANTS display screen is a multipage display that lists various operating parameters (Kvals) that are programmed into the control system. At this screen, the operator may also modify the Kvals.

When this screen is displayed, a password is required to change any Kval. Use the following procedures to select and change Kvals. 1. Use the arrow keys to move highlight bar over the desired Kval. Press ENTER to select. The screen will prompt to enter password. 2. Use the number keys on the number/control keypad to enter four-digit password at screen prompt. 3. Press ENTER to accept password. 4. Enter new value (Kval) within allowable range. The allowed range is indicated in the “MIN” and “MAX” values displayed in the lower right corner of the screen. 5. Press ENTER within ten seconds or system returns to the select variable prompt. System displays: “Waiting for reply from PLC®” while system processes accepted new value. System displays: “Value out of range” when new value is not accepted. The program will not allow a Kval that exceeds the “MIN” or “MAX” operating range.

System Manager Display Screen The SYSTEM MANAGER display screen is selected from the MENU SELECTION display screen by pressing appropriate function key or by positioning the cursor to the SYSTEM MANAGER block with the up, down, left, or right arrow keys and pressing ENTER. Press the ESC key to return to the MENU SELECTION display screen. The system manager display controls access to display system functions which require restricted availability. The SYSTEM MANAGER display screen shows the menu of display system functions. When this screen is displayed, before any of the available functions may be selected, the correct password (a four-digit number) must be entered.

SYSTEM MANGER DISPLAY

Use the number/control keypad to enter the password and press ENTER. When the correct password has been entered, functions from the menu may be selected. Enter the function's corresponding number using the number/control keypad and pressing ENTER. The available display system functions are shown on the screen. The screen includes: Exit to DOS , Set New Password,Disable Printer, Purge Print Buffer, Playback Remote, and select Controller Maintance.

0.

EXIT TO DOS CAUTION

The EXIT TO DOS command should be entered only by operators familiar with operating systems. Menu item 0 (EXIT TO DOS) should be accessed by qualified maintenance personnel only. EXIT TO DOS function allows the operator to exit the display program and access DOS (disk operating system).

1. SET NEW PASSWORD SET NEW PASSWORD function allows the operator to change the four-digit password. The password limits access to terminal functions, such as SYSTEM MANAGER and PROGRAM CONSTANTS. A request for the entry of a number password will appear on the screen. Select four numbers as the new password, enter them on the number/control keypad and press the ENTER key. The screen will then request the reentry of the password with the message: “Verify New Password.” Reenter the new password and press ENTER again. When done, the display returns to the SYSTEM MANAGER menu selection. The factory programmed password is 1111. If the password has been forgotten, the factory default must be reinstalled. Refer to SOLAR SYSTEM OPERATORS GUIDE - SECTION 3.2.3

2. DISABLE PRINTER Selecting this option will either disable or enable the printer.

3. PURGE PRINTER BUFFER Selecting this option purges the printer buffer memory of all information stored there.

4. .PLAYBACK REMOTE The off-line playback mode allows the interrogation of previously saved data files on the operator interface display or other desktop PC as described below. Playback mode, the screens only display data stored in the computer. The background display tasks, such as alarm checking and data logging, continue to operate and real-time alarms are displayed at the top of the screens. The FIRST OUT ALARMS, STRIPCHART, and PROGRAM CONSTANTS display screens are not active in the playback mode. In the playback mode, the operator can interrogate and view data in the EVENTLOG, TRIGGER, ELAPSED TIME, and HISTORY databases. The screens that normally display stored data, in the on-line mode, are also used to select the database to be viewed.

DAILY LOG The DAILY LOG is selected from the MENU SELECTION display screen by pressing appropriate function key or by positioning the cursor to the DAILY LOG block with the up, down, left, or right arrow keys and pressing ENTER. This issues a command to print out the DAILY LOG. The DAILY LOG IS NOT A DISPLAY SCREEN. The DAILY LOG gives a print out of selected data for the last 24 hours and includes minimun,maximum and average readings for the selected data.

STATUS PRINT The STATUS PRINT is selected from the MENU SELECTION display screen by pressing appropriate function key or by positioning the cursor to the STATUS PRINT block with the up, down, left, or right arrow keys and pressing ENTER. This issues a command to print out the STATUS PRINT. The STATUS PRINT IS NOT A DISPLAY SCREEN. The STATUS PRINT gives a print out of selected data at the time of selection.