28954753 Combined Cycle Principles

Combined Cycle Cycle Power Plant  The  Th e Comb Co mbin ined ed Cycl Cy cle e Powe Po werr Plan Pl antt cons co nsis ists ts of two tw o gas ga s turb tu rbin ine e g e n e r a t o r u n i t s S i e me n s V 9 4 . 2 , t w o h e a t r e c o v e r y s t e a m generators, a steam turbine - generator complete with a condenser and condensate / feedwater system and all required auxiliaries. A gas turbine turbine that drives drives its own generato generator, r, exhaust into a special special boil boiler er call called ed a Heat Heat Reco Recove very ry Stea Steam m Gene Genera rato torr (HRS (HRSG) G) that that gener generate ates s steam steam for us use e in Steam Steam Turbin Turbine. e. One of the princi principal pal reasons for the popularity of the combined cycle power plants is their high thermal efficiency. Combined cycle plants with thermal efficienci efficiencies es as high as 52% have been built. built. Combined Combined cycle plants can can achi achiev eve e thes these e high high effi effici cien enci cies es beca becaus use e much much of the the heat heat exhaust from the gas turbine(s) is captured and used in the Rankine cycle portion of the plant. Refer figure. The heat from the exhaust gases would normally be lost to the atmosphere in an open cycle gas turbine. Steam from auxiliary steam boiler 

Left

Steam Turbine Cycle Rankine Cycle

Right

Gas Turbine Cycle Brayton Cycle

H P S to p V

H P S te

am

Steam Condenser 

C o n tr o l V

al

v e R ig h t

al

v e

Cooling

Gland Steam Condenser 

Condensate Extraction Pumps

 Block-3: Combined Cycle Gas Turbine, Compressor, HRSG & Steam Turbine

Another reason for the popularity of combined cycle plant is that it r e qu qu ir ir e s l es es s t i me me f o r t h he e ir ir c on on s tr tr u c ti ti o n a s c om omp ar are d t o a conven conventio tional nal steam steam power power plant plant of the same same outpu output. t. Altho Although ugh it takes longer time to build a combined cycle plant than a simple gas t u rb rb i ne ne p l an an tt.. Na tu tu r a l g as as i s t h e mo s t c om om mo n f u ue e l u s ed ed b y combined combined cycle gas turbine turbine power plants. At KAPCO KAPCO three three fuels are used i.e. Gas, HSD and Furnace Oil.  The  Th e mai n comp co mpon onen ents ts of a Comb Co mbin ined ed Cycl Cy cle e incl in clud ude e the th e foll fo llow owin ing: g: 

Gas Turbine

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Steam Turbine

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Diverter Damper Feedwater

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HRSG

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Condenser and Condensate

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P u mp s 

P u mp s

Cooling Tower etc et c

Introduction to GT V94.2 and ST  The  Th e two tw o gas ga s turb tu rbin ines es are ar e prov pr ovid ided ed to fire fi re natu na tura rall gas, ga s, high hi gh sp spee eed d diesel oil and furnace oil (heavy fuel oil).  The  Th e Siem Si emen ens s V9 V94. 4.2 2 gas ga s turb tu rbin ines es are ar e driv dr ivin ing g the th e air ai r cool co oled ed generato generators, rs, which have max. max. output output power of 170 MVA (144 MW at pf = 0.85). The gas turbines flue gasses are directly conveyed to the adjacent heat recovery boilers the energy of which is transferred to the feedwater loop.  The  Th e HP HP-s -sys yste tem m of the th e boil bo iler er is prod pr oduc ucin ing g the th e HP stea st eam. m. For Fo r this th is purpose it has to be supplied with the right amount of feedwater at any time during its operation: e.g. during start up, load variations etc. Additional it has to produce steam of a specific quality, which means of correct pressure and temperature which varies again with the different operation modes and load conditions. The HP-system gene genera rate tes s stea steam m at 60 bar bar / 53 530 0 °C from from the the ther therma mall ener energy gy contained in the GT exhaust gas.  The  Th e LP LP-s -sys yste tem m of the th e boil bo iler er is prod pr oduc ucin ing g the th e LP LP-s -ste team am.. For Fo r this th is purpose it has to be supplied with the right amount of feedwater at any time during its operation: e.g. during start up, load variations etc. The LP-steam in the range of 3-10 bar is used for condensate heating and for the feedwater deaeration in the deaerator.  The  Th e main ma in stea st eam m flow fl ows s to the th e stea st eam m turb tu rbin ine e whic wh ich h driv dr ives es the th e air ai r cooled generator of max. 175 MVA (150 MW at pf = 0.85). The steam turbine is designed as a single - shaft machine with separate separate HP and LP sect sectio ions ns.. The The HP sect sectio ion n is a sing single le flow flow cyli cylind nder er and and the the LP section is a double flow cylinder. Turbine bypass system is to dump t h e e xt xt ra ra s t e am am i n t h he e c on on d en en s er er d u urr i ng ng s t ar ar t u up p a nd nd s t e am am unloading conditions. Both the exhaust steam and the bypass steam are condensed by means of a water cooled box type condenser. Conden Condensat sate e pumps pumps take take su sucti ction on from from the the conden condenser ser hot hot well well and discharge through the gland steam condenser and the LP-preheater to the feedw feedwate aterr stor storage age tank. tank. One One conden condensat sate e storag storage e tank tank for controll controlling ing the water level is provided. provided. The condensat condensate e is further further deaerated in the feedwater tank to the specified oxygen content. LPfeedwater pumps feed the water from the storage tank to the drums of the the preh prehea eati ting ng sy syst stem em in the the HRSG HRSG's 's in orde orderr to preh prehea eatt the the feedwater in the feedwater storage tank. An auxiliary steam system  Prepared by: Fazal-ur-Rehman Fazal-ur-Rehman Babar Babar Cell: 92 322 6729767 

Siemens Gas Turbines Turbines V 94.2

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2

P u mp s 

P u mp s

Cooling Tower etc et c

Introduction to GT V94.2 and ST  The  Th e two tw o gas ga s turb tu rbin ines es are ar e prov pr ovid ided ed to fire fi re natu na tura rall gas, ga s, high hi gh sp spee eed d diesel oil and furnace oil (heavy fuel oil).  The  Th e Siem Si emen ens s V9 V94. 4.2 2 gas ga s turb tu rbin ines es are ar e driv dr ivin ing g the th e air ai r cool co oled ed generato generators, rs, which have max. max. output output power of 170 MVA (144 MW at pf = 0.85). The gas turbines flue gasses are directly conveyed to the adjacent heat recovery boilers the energy of which is transferred to the feedwater loop.  The  Th e HP HP-s -sys yste tem m of the th e boil bo iler er is prod pr oduc ucin ing g the th e HP stea st eam. m. For Fo r this th is purpose it has to be supplied with the right amount of feedwater at any time during its operation: e.g. during start up, load variations etc. Additional it has to produce steam of a specific quality, which means of correct pressure and temperature which varies again with the different operation modes and load conditions. The HP-system gene genera rate tes s stea steam m at 60 bar bar / 53 530 0 °C from from the the ther therma mall ener energy gy contained in the GT exhaust gas.  The  Th e LP LP-s -sys yste tem m of the th e boil bo iler er is prod pr oduc ucin ing g the th e LP LP-s -ste team am.. For Fo r this th is purpose it has to be supplied with the right amount of feedwater at any time during its operation: e.g. during start up, load variations etc. The LP-steam in the range of 3-10 bar is used for condensate heating and for the feedwater deaeration in the deaerator.  The  Th e main ma in stea st eam m flow fl ows s to the th e stea st eam m turb tu rbin ine e whic wh ich h driv dr ives es the th e air ai r cooled generator of max. 175 MVA (150 MW at pf = 0.85). The steam turbine is designed as a single - shaft machine with separate separate HP and LP sect sectio ions ns.. The The HP sect sectio ion n is a sing single le flow flow cyli cylind nder er and and the the LP section is a double flow cylinder. Turbine bypass system is to dump t h e e xt xt ra ra s t e am am i n t h he e c on on d en en s er er d u urr i ng ng s t ar ar t u up p a nd nd s t e am am unloading conditions. Both the exhaust steam and the bypass steam are condensed by means of a water cooled box type condenser. Conden Condensat sate e pumps pumps take take su sucti ction on from from the the conden condenser ser hot hot well well and discharge through the gland steam condenser and the LP-preheater to the feedw feedwate aterr stor storage age tank. tank. One One conden condensat sate e storag storage e tank tank for controll controlling ing the water level is provided. provided. The condensat condensate e is further further deaerated in the feedwater tank to the specified oxygen content. LPfeedwater pumps feed the water from the storage tank to the drums of the the preh prehea eati ting ng sy syst stem em in the the HRSG HRSG's 's in orde orderr to preh prehea eatt the the feedwater in the feedwater storage tank. An auxiliary steam system  Prepared by: Fazal-ur-Rehman Fazal-ur-Rehman Babar Babar Cell: 92 322 6729767 

Siemens Gas Turbines Turbines V 94.2

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supplies steam for the turbine gland sealing and for the feedwater tank heating during start up. HP-feedwater pumps deliver the feedwater into boiler drums of the stea steam m gene genera rato tors rs at the the desi design gn pres pressu sure re unde underr all all oper operat atin ing g conditions. The function of the circulating water system is to provide a h e a t si n k f o r t h e c o n d e n s e r a n d r e m o v e t h e h e a t t o t h e environment via the cooling tower. Further the system is connected with the closed cooling water system via the service cooling water system.  The  Th e task ta sk of the th e serv se rvic ice e cool co olin ing g wate wa terr sy syst stem em is to remov re mov e the th e heat he at absorbed by the closed cooling water system in cooling components of the gas turbine generator, the steam-, condensate- and feedwater cycle via the closed cooling water heat exchanger and to transfer this heat to the circulating water system. A wa te r trea tme nt pl a nt c o n s i s ts of a ma k e - u p wa te r demineralization plant, regeneration station with chemical storage tanks tanks and regene regenerat ration ion waste wastes s neutra neutraliz lizati ation on is instal installed led with with all necessary equipment for satisfactory operation of the CCPP. Furthe Furtherm rmor ore e a chlor chlorina inatio tion n plant plant for the main main circul circulati ating ng water water syst sy stem em and and for for the the fres fresh h wate waterr (Muz (Muzaf afar arga garh rh Cana Canal) l) sy syst stem em is installed.

 The figure 1.1 shows the electrical systems configuration of the CCPP in a simplified manner. Each gas turbine generator unit and the steam turbine generator unit are interconnected via its own main transformers to the 220 kV switchyard.  The gas turbine generator is capable of being fully automatically started by elec electr tric ical al ener energy gy fed fed from from the the main main grid grid via via 22 220/ 0/11 11 kV main main unit unit tran transf sfor orme merr and and the the unit unit auxi auxili liar ary y tran transf sfor orme mer. r. The The stea steam m turb turbin ine e generator unit can be started via the 11 kV switchgears either from unit 13 or from unit 14 which are connected by means of bus-coupler to the 11 kV switchgear of the steam turbine generator.  The auxiliary power system is designed to meet all plant auxiliaries and relate related d buildi buildings ngs servic service e requir requirem ement ents. s. Power Power for the auxili auxiliary ary power power syst sy stem ems s is fed fed fro from the the unit unit auxi auxili liar ary y tran ransfo sformer via via the the 11 kV switch switchgea gear. r. Low voltag voltage e auxili auxiliary ary trans transfor former mers s supply supply the 380 V unit unit switchgear as a 100% back-up. The second supply is interlocked from the first, so that an operation without interruption shall be possible.

 Prepared by: Fazal-ur-Rehman Fazal-ur-Rehman Babar Babar Cell: 92 322 6729767 

Siemens Gas Turbines Turbines V 94.2

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 The emergency diesel set has sufficient capacity for emergency supply of  the units, turning gears and emergency light. The capacity covered the gas turbine units as well as the steam turbine unit.  The DC system consists of a 220V DC and ± 24V DC system. The 220V DC system feed all power, control and protection equipment as required. The ± 24V DC system feed the I & C equipment and the protection equipment as required. The capacity of each battery charger is 100% of the power requirements of the whole plant extension. Each battery is designed to allow for normal operation as well as for safe shut-down of the plant in case of a total black-out.

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 Prepared by: Fazal-ur-Rehman Fazal-ur-Rehman Babar Babar Cell: 92 322 6729767 

Siemens Gas Turbines Turbines V 94.2

      0        2       Q        4       1       D

220 kV Feeder New Multan 4

220 kV Feeder New Multan 3

220 KV Bus Bar2

GS 011 GS 011 GS 010

D14Q D14Q 2 1 3 D 1 4 Q

GS 012

0 2 1

Generator Isolator

G S

0 2 0

G S

0 2 2

GS 011       Q  GS 011 GS 010

220KV Bus Bar-1

GS 010 GS 012

0 2 1

G S

Generator Isolator

Portable earths

T ra n

U n it

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fo rm e

14BAC01GS001 11KV Breaker

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r

T ra n s

fo rm e r

F re q u e n c y

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fo mr e

A u x

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14BBE 1

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fo mr e it

L V U n A u x

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11KV

1 3 B F 0 T 0 0

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11KV S p a er

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380V

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00BLE

380V

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T ra n s

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F re q u e n c y

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rt

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13BAC01GS001 11KV Breaker

1 3 M B 0J

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GT-13 14BFE

13BFE

380V

380V

00BME

 Prepared by: Fazal-ur-Rehman Babar 

380V

EDG behind CCR-3

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3.0

 The CCPP plant features a high level of automation with plant start up, operation and shut down being carried out by the TELEPERM ME control and data acquisition system. For the control system the total plant is divided into following five functional areas: 1. 2. 3.

4. 5.

0 2 2

G S

13BAC01GS002 11KV Isolator

G

GT-14

GS 012

13BAT0 1

13BBT0 1GT002

13BBE

D13Q 3 G

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fo rm e

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14BBT0 1GT002 G T 0 0 1

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Main Unit Tr. 11KV / 220KV

14BAT0 1

14BAC01GS002 11KV Isolator

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GS 012

GS 033

Main Unit Tr. 11KV / 220KV

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Gas Turbines Heat Recovery Boilers Water/Steam Cycles Steam Turbine Auxiliary Plant

 The I & C equipme nt associated with these functional areas is distributed throughout the plant and transmit the measured values and plant status information to local processing units contained within Power Control Centers. These PCC's are prefabricated units and enclosed in containers where also the plant related switchgear is arranged.  The Central Control is loc ated in the Control Room Building 15 UCA (CCR-3). Information transfer between the control room and the local plant is achieved via a duplicated data highway. Central redundant data acquisition and control processors are located in the control room building for alarm monitoring, logging and plant status display.  The interface between plant and operator is located in the both

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3.0

 The CCPP plant features a high level of automation with plant start up, operation and shut down being carried out by the TELEPERM ME control and data acquisition system. For the control system the total plant is divided into following five functional areas: 1. 2. 3.

4. 5.

Gas Turbines Heat Recovery Boilers Water/Steam Cycles Steam Turbine Auxiliary Plant

 The I & C equipme nt associated with these functional areas is distributed throughout the plant and transmit the measured values and plant status information to local processing units contained within Power Control Centers. These PCC's are prefabricated units and enclosed in containers where also the plant related switchgear is arranged.  The Central Control is loc ated in the Control Room Building 15 UCA (CCR-3). Information transfer between the control room and the local plant is achieved via a duplicated data highway. Central redundant data acquisition and control processors are located in the control room building for alarm monitoring, logging and plant status display.  The interface between plant and operator is located in the both central and local control rooms. From here, all plant control functions can be carried out during both normal and emergency situations. At Block-3, for the process automation of the CCPP, the TELEPERM ME process I & C system is used. Its functions are: acquisition and processing of process data, open and closed-loop control, calculation and optimizing as well as supervision, signaling, operation and monitoring of the process in interactive mode on the screen and using miniaturized control room equipment. 4.0

 The plant can be operated in a simple-cycle and a combined-cycle operation.

Simple-Cycle Operation  The procedure for startup of the gas turbine in simple-cycle operation is as follows: -

Diverter damper upstream of the steam generator closed, bypass path open Starting of gas turbine, purging of the turbine through bypass stack during runup to ignition speed Ignition of the gas turbine burners Runup to rated speed and loading of the gas turbine

Combined-Cycle Operation  Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15

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 Two procedures are possible for startup of the heat recovery steam generator (HRSG): -

Startup of the gas turbine as a function of output load control Startup of the gas turbine as a function of exhaust temperature control

 The gas turbine is started up as described in the simple-cycle operation, however, the gas turbine exhaust gas temperature is kept below < 350 °C. After the purging process (for 1 min), gas turbine output is increased to rated power. The rated temperature is achieved at about 60% gas turbine output. Startup of the HRSG is performed by opening the diverter damper upstream of the steam generator and thus simultaneously closing the bypass path. In the case of gas turbine startup under temperature control , the bypass path remains closed after the steam generator has been purged. The gas turbine load is controlled at the permissible temperature transients for the thick-walled components of the steam generator, piping and steam turbine. For gas turbine startup under load control, the diverter damper is set at an intermediate position after the steam generator has been purged such that the cross-section of the line to the steam generator is opened by about 20%. After expulsion of the water and when the level in the drums stabilizes and the steam temperature is almost equal to the gas turbine exhaust gas temperature, the diverter is opened in stages. Whenever a temperature change in the HRSG permits, a defined time pulse is released to open the diverter damper a stage further.  The main steam line is warmed up, in accordance with a specified mean warmup transient, for the leading item (strainer casing). Controlled warmup of the LP-steam line to the feedwater tank is not necessary owing to the reduced wall thickness.  The steam turbine is started up under speed control. As soon as the generator is synchronized with the grid system, the valve lift, which is limited by the Turbine Stress Evaluator (TSE), is increased by the startup control until the turbine assumes the full steam mass flow, the turbine bypass station closes and the initial pressure controller is activated.  The pressure in the LP-evaporator system is governed by the LPstartup station. If sufficient hot steam is extracted to the feedwater tank, the LP-startup station closes and lowers the response setpoint.

 The HRSG / Steam Turbine plant are capable of utilizing the exhaust gas from the gas turbines when operating over full range of  operating conditions up to base load according to Kot Addu site ambient temperatures from 1 °C to 50 °C (design temperature) and at relative humidity of up to 80 % (design ambient relative humidity for electrical and I & C equipment).  Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15

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 The mac hines are designed according to the following performance data: Ambient Temperature Relative Humidity Atmospheric Pressure

= 30°C, = 60 % = 0.996 bar.

 The electric output of Block-3 (GT-13, 14 & ST-15) is 406 MW (Net Power Output = 397 MW), 129 MW from each gas turbine and 148 MW from the steam turbine. The heat input amounts to 818 MJ/sec so that the overall net efficiency is 48.5 %.

Combined Cycle Components Some of the components are described here;

 The first major component of the combined cycle power plant is the gas turbine. Gas Turbine is a machine which runs with the action of flue gases on its turbine blades. Flue gases are produced by burning the fuel. When gas turbine exhausts directly to the atmosphere, it is said to be operating in "open cycle" mode. When a gas turbine exhausts into a heat recovery steam generator (HRSG) the resultant steam is used to operate a steam turbine, this operation is called “combined cycle”.

A model of gas turbine 13, 14 is shown. Unit 13, 14 gas turbines consist of a single body including 16 stage Compressor, 2 Combustion Chambers and 4 stage Turbine. The turbine rotor has two bearings one at the air inlet of compressor side and second in the turbine exhaust. The body is divided in various planes to facilitate inspection. Mechanical power generated in the turbine is used to drive both the compressor and the generator. The electric power is available at the generator terminals in 11KV.  The gas turbine uses air as working fluid which is drawn in through filters and sound absorbers, it is compressed in the compressor up to 10 bar. Compressed air is directed into the combustion chambers. Fuel is added and burnt in the combustion chamber, and the resultant flue gas is heated up to approx. 1050 °C for the turbine inlet. The hot gases are expanded to atmospheric pressure in the turbine and transfer their energy to the turbine blades, where its energy is used to drive the shaft. The compressor and turbine blades are arranged on a common shaft and connected to the generator via the intermediate shaft. The exhaust gases leave the turbine through the

 Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15

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exhaust diffuser for being discharged into the bypass stack or to the HRSG for combined cycle operation.

1.1Main Components of a Gas Turbine 1.1.1Intake Air Filters  These provide clean, filtered and dust free air to the compressor inlet.

1.1.2Compressor Air is drawn in and compressed when passing through rows of  rotating blades and stationary vanes. At the end of the compressor, before reaching the combustion chamber, the air is compressed to about 10 bar and has been heated to about 300°C by compression.

1.1.3Combustor / Combustion Chamber  The combustor or combustion chamber is the heart of the engine; here the combustible mixture of compressed air and fuel is burnt.  The hot gas output temperature becomes 1000°C to 1300°C; its volume becomes more than doubled by the temperature rise where as pressure remains constant.

1.1.4Turbine  The turbine section converts the thermal and kinetic energy of the combustion gases into rotational mechanical energy. Gas turbines like steam turbines have three or four stages of rotating and stationary blades. However; because gas turbines work with lower initial inlet pressures, they have fewer stages and less change in blade height from inlet to exhaust. Turbines normally consist of combination of impulse and reaction types. The gas turbine also differs from the steam turbine in; (1) the type of blading material used (2) the lower ratio of blade length to wheel diameter (3) less number of turbine stages Flue gases flow to the turbine with a very high velocity v of about 80 m/s (288 km/hr). It means it has high kinetic energy ½mv . T h e kinetic energy of flue gases is converted to mechanical energy when flue gas is expanded in the stages of turbine transferring its energy to the turbine rotor. The volume of flue gases is increased by expansion and thus temperature is decreased and at the exhaust it is about 500 °C. 2

 The turbine parts which are mec hanically stressed are at the same time subject to very high temperature, so that these parts are designed with special material and cooling paths are provided for cooling air to flow.

1.1.5Exhaust diffuser It diverts the de-energized (but still hot) flue gases into the ambience to complete the cycle. It is fitted with filter and silencer.

 Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15Prepared by: Fazl-ur-Rehman Babar 

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 The HRSG is basically a heat exchanger composed of a series of  economizer, evaporator and superheater sections. These sections are positioned from gas inlet to gas outlet to maximize heat recovery from the gas turbine exhaust gases. The heat recovered in the HRSG is used to supply steam to the steam turbine at the proper temperature and pressure. The exhaust gases temperature leaving turbines are in the range as given bellow: Un it No . 1 &2 3 &4 5 – 8 13 & 14

Exha us t te mpe ra ture St ea m fl ow rat e 500 °C to 550 °C 205 Tons/hour on 220 Tons/hour on 550 °C to 610 °C 210 Tons/hour 480 °C to 530 °C 150 Tons/hour on 160 Tons/hour on 530 °C to 550 °C 203 Tons/hour on 200 Tons/hour on

Gas FO Gas FO Gas FO

High temperature gas represents a source of heat energy, some of  which can be recovered thus the output and the efficiency of a combined cycle power plant is increased.  The function of a heat recovery steam generator (HRSG) is to recover the waste heat available in these exhaust gases and transfer that waste heat to water and steam. The heat is used to generate steam at high pressure and high temperature. The steam is then used to generate additional power in a steam turbine driven generator. The HRSG provides a link between the gas turbine and the steam turbine in a combined cycle plant. Therefore, the HRSG is a key component in combined cycle efficiency.

2.1 Main Components of an HRSG 2.1.1 Diverter Damper At outlet of the gas turbine, upstream the boiler, a diverter is provided which makes it possible to send the exhaust gas directly to the atmosphere, by means of a bypass stack or to heat the boiler by opening the path towards the HRSG. The diverter is provided with hydraulic actuators. The actuators have been sized to permit intermittent operation of the damper to a predetermined position, but not regulated control. The ‘close position’ is with the blade closed to HRSG and the open to bypass stack. The ‘open position’ is with the blade open to HRSG and the close to bypass stack.  The diverter damper is actuated through the various modes of  operation by an electrically controlled hydraulic system. This hydraulic system comprises an independent, self contained power unit connected electrically and hydraulically to the diverter blade.  The power unit consists of a weather proof enclosure containing a system of two motor pump units, one control valve assembly, a hand pump system and 3 hydraulic accumulators.  Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15

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2.1.2 Water & Steam Heaters  The water and steam are heated at different steps according to the flue gas temperature. These include HP Economizer, HP Evaporator, LP Evaporator and Superheater.

2.1.3 Drums HP drum and LP Drum or LP separator tank are installed to separate steam from water.

2.1.4Pumps  These pumps are installed for the circulation of water and they include HP Feedwater pumps or HP Evaporator recirculation pumps, LP Feedwater pumps or LP Evaporator recirculation pumps, HP Economizer recirculation pumps etc.

2.1.5 Soot Blowers  They clean soot deposits from the tubes on flue gas side of the Boiler.

 The Steam Turbine is a power unit which produces power from a continuous action of steam on its turbine blades, the steam being delivered to the turbine at a high pressure and exhausted to the condenser at a low pressure. Steam turbine converts the heat energy of superheated highpressure steam, coming from the boiler or HRSG, into rotational mechanical energy. The conversion of energy in the turbine occurs in two steps. •

First, the heat energy in the steam is converted into kinetic energy of a steam jet by nozzles (stationary blades).

•

Second, the steam jets blow on buckets or moving blades mounted on a rotor to produce a mechanical force and torque.

 The mechanical energy of the steam turbine is then used to drive a generator to produce electrical energy. The steam turbine generator is, by itself, a very simple machine with few moving parts. It is not unusual for a steam turbine-generator to operate continuously for more than a year without shutdown.

3.1 Main Components of a Steam Turbine 3.1.1 Turbine

 Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15

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 The turbine converts the thermal and kinetic energy of the steam into rotational mechanical energy. ST-15 Stage 1 Stage 2 has 26 stages of HP and 8+8 stages of  LP turbine and their sealing steam system. There are two types of turbine blades, Impulse and Reaction types. Normally, turbine consists of   combination of impulse and reaction types.

 Turbine Principle Steam enters the rotating channels with absolute velocity ‘c’ with reference to the fixed parts. When magnitude and direction of both velocities are known we get the relative velocity ‘w’ with reference to the rotating blades. Circumferential velocity ‘u’ at rotating blade tip can be calculated by the difference of ‘c’ and ‘w’. c absolute velocity w velocity in rotating channel = relative velocity

U1 = C1 – W1

u circumferential velocity

Guide wheel

Rotating wheel

Guide wheel

Indices 1 Inlet rotating wheel

Velocities in Steam Turbine Stages

U2 = C2 – W2 Impulse Type Turbine

 The basic idea of an impulse turbine is that a jet of steam from a fixed nozzle pushes against the rotor blades and impels them forward. The velocity of the steam is about twice as fast as the velocity of the blades. Only turbines utilizing fixed nozzles are classified as impulse turbines.

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Reaction Type Turbine A reaction turbine utilizes a jet of steam that flows from a nozzle on the rotor. Actually, the steam is directed into the moving blades by fixed blades designed to expand the steam. The result is a small increase in velocity over that of the moving blades. These blades form a wall of moving nozzles that further expand the steam. The steam flow is partially reversed by the moving blades, producing reaction on the blades. Since the pressure drop is small across each row of nozzles (blades), the speed is comparatively low. So more rows of moving blades are needed in a reaction turbine than in an impulse turbine.

3.1.2 Condenser and Vacuum Pumps It condenses steam when it finishes its work and exit from the turbine. Vacuum pump regularly runs to evacuate any air accumulation in the condenser.

3.1.3 Cooling Tower  This is provided to cool the close circulating water from the condenser. It removes the latent heat of steam and converts it into condensate.

3.1.4 Lube Oil system It supplies lubrication and cooling for all bearings like compressor, turbine, generator and supplies oil to the hydraulic oil system, torque convertor and turning gear.

3.1.5 Generator  The generator is connected to the gas turbine. Generator converts the mechanical output power of the gas turbine into electricity. When rotor rotates in the stator, there is a relative motion between conductor and rotor’s magnetic field. Voltage is induced by this relative motion into the three coils of stator winding. When north and south poles of rotor magnetic field pass before a stator winding then alternating currents of  sinusoidal (~) wave shape are produced. In this way three phase currents 132 KV  are produced by the three phases of stator winding as shown in figure.

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 The generator is air cooled in closed circuit. Generator output is at 11KV; it is stepped up by main transformer to 132 KV or 220 KV and sent to WAPDA via transmission lines.

2.1Gas Turbine (Joule-Brayton) Cycle  The thermodynamic cycle of a gas turbine is referred to as the JouleBrayton Cycle (or simply Brayton Cycle). The four processes of the Brayton Cycle are represented on a temperature-entropy (T-s) diagram shown in figure. Entropy is a property of substances that describes the availability of energy to do work. The T-s diagram is useful in analyzing thermodynamic cycles because it reveals the amount of heat required to make a process occur in a cycle. If a process can be represented as a curve on the T-s diagram, the area under the curve is the amount of heat required to make that process occur.

HEAT ADDED

er ut ar e p m e T

HEAT REJECTED

Four Processes of Gas Turbine Compression A-B Combustion B-C Expansion Each process in Heat Rejection D-A

Combustion Expansion (Turbine)

Compression

Brayton Cycle T-S Diagram

C-D the Brayton Cycle can be drawn on the T-s diagram.  The first process is the compression of Heat air in the compressor represented by the line A-B. As the air is compressed, its temperature and pressure increases and there is a corresponding increase in enthalpy. As work is done on the air, the air stores this energy in the form of temperature and pressure. The power (energy) to perform this work originates from the turbine, which is directly coupled to the gas turbine compressor through a common shaft.

 The second process is the addition of heat to the cycle at a constant pressure by burning of fuel represented by the line B-C. The temperature of the gas that results from the combustion increases considerably from the temperature of the air at the compressor outlet. Normally air temperature at the compressor outlet is 300°C and the flue gas temperature is increased up to 1000°C or 1300°C.  Prepared by: Fazal-ur-Rehman Babar

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 The third process is the expansion and cooling of the gas as it passes through the turbine, is represented by the line C-D. Here, the energy of the hot pressurised gas is used to perform work.  The final process in the Brayton cycle is the cooling of the hot gas that exhausts to the atmosphere represented by line D-A. The exhausted gas mixes with ambient air, thus decreasing in temperature. Amount of heat that is required to make Brayton cycle work is represented by the area under lines B-C. The area under the line D-A represents the fraction of heat that is rejected. The area between these two lines represents the heat that is converted to useful mechanical energy. The heat converted to useful mechanical energy is 20% to 25% of the total heat required to make the process work.

2.1.1Thermodynamics of Gas Turbine

Generator loss (0.8 %)

 The energy at the input is available as fuel (furnace oil or gas) and it represents chemical energy. At the output we have energy in the most valuable form as electrical energy. Electricity is easily transported, easily controlled and easily applied at all instances when energy is used. There are several steps when energy is converted from its chemical form to electrical form:

STEP 4

Compressor Mechanical loss (0.5 %) Air Exhaust Heat Energy (61 %)

STEP 2 &3

 Turbine mechanical loss (0.5 %)

Combustion Chamber Step 1: Chemical energy is converted radiation loss (2 %) STEP 1 to thermal energy (heat) in the form of a flow of hot "flue gases". Step 2: Heat e nergy i s transformed t o FUEL kinetic energy by increasing speed of flue gases in nozzles. Step 3: Flue gases act on rotor blades and rotate, in this way kinetic energy is converted to mechanical energy. Step 4: The mechanical energy is used to drive the generator rotor, and it is converted to electrical energy.

Energy Conversion Processes: Chemical Energy  Heat or Thermal Energy Mechanical Energy  Electrical Energy



Kinetic Energy



Now we look at first two steps more closely.

2.1.2Cyclic Process  These first two steps are only possible as parts of a thermod ynamic cyclic process because nature does not grant any gifts without being paid; i.e. we must come back to the initial conditions where we started. Such a cyclic process describes how the fluid changes its state during its flow through a given machine. State of the fluid can be

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described by a couple of parameters which are inter-dependent.  These parameters are: - Pressure - Temperature T - Entropy S

P

We use these parameters to draw "T-S diagrams" which apply to the actual fluid. For our present considerations we can use the T-S diagram for air which is applicable for flue gas, too. In the range of  cyclic processes we commonly use the laws for ideal gases which are valid here. By means of T–S diagrams - cyclic processes can be made apparent - cyclic processes can be evaluated how efficient they are - we learn how the machine has to be designed in which a given cyclic process takes place. In the following we apply these three uses to our gas turbine process:

2.1.3Gas Turbine Cycle of GT 1,2 & 13,14  The ideal gas turbine process normally applied named "Joule-Brayton - Cycle" is defined by two isentropic and two isobaric changes of state.

er ut ar e p m e T

°C 1000 Heat Input (Combustion)

It begins at ambient conditions and an isentropic compression of the fluid (air). It means that the change of state of the fluid is made at constant entropy, i.e. free of any friction and free of any heat transfer across the boundaries of the machine. At the end of this ideal compression, both pressure and temperature are increased but entropy remained the same. Now heat is added to the fluid by burning the fuel in the compressed fluid. Thus, entropy and Entropy temperature are increased but pressure 7 8 kJ remained the same. Hereafter the flue kg °K   Ideal Joule – Brayton Cycle gas is expanded during an isentropic change of pressure and temperature. The flue gas is now at ambient pressure again but at elevated entropy and elevated temperature. Expansion (Turbine)

800

Specific Power available at Coupling Flange

600

400

Evaluation of Energy 1 square is equivalent to 20 MW

200

100

0

Exhaust

Ambient Conditions

-100

In order to complete the cyclic process the flue gases are blown into the atmosphere and the energy content is dissipated, i.e. wasted. This is the price we must pay for having converted the energy from a lower to a higher value.

2.1.4Evaluate

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 The T-S diagram is handy for representing energy and heat per fluid mass unit. These values appear as areas; e.g. 1 square shown on the  T-S diagram is equivalent to 20 MW. It means, that if we know the mass-flow we can easily calculate - the power available at the coupling flange - the heat to be put in Flue gas mass flow: Unit 1, 2 426 Kg/sec

Unit 13, 14 471 Kg/sec

Unit 3, 4 322 Kg/sec

Unit 5-8 406 Kg/sec

2.2The Steam-Water (Rankine) Cycle  The Rankine Cycle used in conventional steam power plants can be represented on a T-h diagram. As with the Brayton Cycle, each line segment corresponds to a process in the cycle. A simple Rankine Cycle consists of only four components; the boiler (often called a steam generator), a turbine, a condenser and a boiler feed pump. Boiler is shown with a superheater, thus the steam entering the turbine is above saturation temperature. Super heater 3

HEAT ADDED

4

Steam  Turbin e

Super heater

5

 T Boiler

Boiler

2 Condenser

Steam  Turbin e

Boiler Feed Pump

1 Boiler Feed Pump

HEAT REJECTED

Figure: Rankine Cycle T-h diagram

Condenser

h

 The first process in Rankine Cycle (Line 1- 2) is the increase in pressure of condensate from condenser by the boiler feed pump. Increase in pressure occurs with a slight increase in enthalpy (h).  The second Rankine Cycle process (Line 2-3) is the addition of heat to wa te r e nt erin g th e b oi ler. Wi thi n th e b oi ler, t he wa ter i s transformed from a liquid to steam (a gas). The generation of steam is assumed to occur at a constant pressure. Additional energy is added to steam as it passes through the superheater (Line 3-4). Steam is then expanded and cooled as it passes through the turbine as represented by Line 4-5. Here, the energy of steam is used to perform work.  The last process in the Rankine Cycle is the condensation of steam that exhausts from the turbine, represented by line 5-1. During  Prepared by: Fazal-ur-Rehman Babar

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c ond ens at ion, c on si de ra bl e vaporization, is lost.

hea t,

c al le d

th e

la ten t

he at

of 

 The heat required to make the Rankine Cycle work is determined by the area under the lines between points 2 to 4; and the heat lost from the cycle is under the line between points 5 and 1. The area between the lines represents the heat that is converted to useful mechanical energy. The useful mechanical energy is only about ⅓ rd of the heat required to make the cycle work.  The efficiency of conventional steam power plants is about 30% to 35%. Actual steam power plants are considerably more complex than the simple cycle shown in Figure, because components such as Condensate pump, Feedwater tank, Economizer, LP & HP Feedwater heaters and Air preheater are added to improve efficiency. Typically only 85% to 90% of the heat energy input is absorbed in Boilers.  This mea ns that the boiler is only 85% to 90% efficient. Additional auxiliary equipment, such as fans and soot blowers, use part of the power produced usually around 5%.

2.2.1Act ual St eam - Wat er Cyc le / T-s di agr am  The T-s diagram (Fig 4.3) illustrates the thermodynamic conditions and parameters in the actual water- steam cycle. Clausius established entropy in mathematic formulas in order to determine transformability of heat energy. Later on Belpair found that principle of entropy can be presented by areas of transferable amounts of heat in the T-s diagram. If one follows the various stages of the water-steam cycle, they can be presented in the T-s diagram. The area below the curve depicts the supply or release of heat energy in order to reach a new condition. The temperature axis must then however be extended to the absolute "0 °K" point. In calculations temperatures are stated in Kelvin, which means the origin in the diagram is 0 °K (- 273.15 °C).  The region of wet steam can be easily recognized in the T-s diagram.  The hill, the left margin of which equals  x = 0, that is pure water, is remarkable. The right curve represents saturated steam ( x = 1). All points in between these margins depict wet steam with a certain share of water. One must be careful, because the diagram shows the specific entropy ‘s’ in units of kJ/kg/°K. So you should keep in your mind, that the shown values of entropy are good for 1 kg of the media at the given point.  This T-s diagram shows the turbine cycle all over the Plant i.e. Steam Turbine and HRSG. It starts with the condenser outlet to the feedwater tank. The area underneath this line is the amount of heat brought to the cycle from the LP evaporator into the feedwater tank by the LP steam.

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2

3

4

5

6

7

8

9

600

T [°C]

h [kJ/kg] v [m3/kg]  p [bar]

Outlet Superheater 

Values at Triple Point:  p = 0.006112 bar  T = 0.01 °C s = 0.00 kJ/kg/°K (arbitrary)

500

Values at Critical Point:  p = 221.2 bar (3206.2 psia) T = 374.15 °C (705.4 °F) v = 0.00317 m3/kg h = 2107.4 kJ/kg s = 4.4429 kJ/kg/°K 

400

400

(0.00 °C = 273.15 °K)

re ut ar e p m e T = T

300

300 HP-Drum Inlet

HP-Drum Outlet HP-Turbine Outlet

200

200

Feedwater  Tank 

100

100

Condenser  Outlet Condenser  Inlet 0 1

2

3

4

5

6

7

8

s [kJ/kg/°K]

9

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 The area underneath the line feedwater tank to HP drum inlet shows (theoretically) the amount of heat drawn from the exhaust gases by the economizer. The HP evaporator draws the heat underneath of the horizontal line in between HP drum inlet and HP drum outlet. The superheating is done nearly at the same pressure, but up to higher temperature. The steam condition becomes far away from the saturated condition, so the end of the turbine gets better conditions concerning the arising of water. Due to the heat transfer for superheating the enthalpy will rise too, gives the turbine a higher "capacity of work".  The arising heat underneath of the line "outlet superheater" to "condenser inlet" is the heat, Clausius was thinking of Conversion of  heat energy into mechanical energy causes a rising of the entropy, which is sometimes explained as an arising of losses. These losses in that connection are losses due to "intermolecular friction", not losses to the environment.  The amount of heat shown underneath the line "condenser inlet" to "condenser outlet" has to be given to the environment to condensate the steam of the turbine and to close the circuit. To calculate the real amount of heat, one has to multiply this value with the actual mass flow.

2.3The Combined Cycle Combined cycle is a power plant in which consists of a gas turbine, Boiler

Gas Turbine Cycle

Steam Turbin

ce Cycle

20

 The area underneath the line feedwater tank to HP drum inlet shows (theoretically) the amount of heat drawn from the exhaust gases by the economizer. The HP evaporator draws the heat underneath of the horizontal line in between HP drum inlet and HP drum outlet. The superheating is done nearly at the same pressure, but up to higher temperature. The steam condition becomes far away from the saturated condition, so the end of the turbine gets better conditions concerning the arising of water. Due to the heat transfer for superheating the enthalpy will rise too, gives the turbine a higher "capacity of work".  The arising heat underneath of the line "outlet superheater" to "condenser inlet" is the heat, Clausius was thinking of Conversion of  heat energy into mechanical energy causes a rising of the entropy, which is sometimes explained as an arising of losses. These losses in that connection are losses due to "intermolecular friction", not losses to the environment.  The amount of heat shown underneath the line "condenser inlet" to "condenser outlet" has to be given to the environment to condensate the steam of the turbine and to close the circuit. To calculate the real amount of heat, one has to multiply this value with the actual mass flow.

2.3The Combined Cycle Gas Turbine Cycle

Steam Turbin

Combined cycle is a power plant in ce Cycle which consists of a gas turbine, Boiler Heat and a Steam Turbine. In this cycle a Rejected gas turbine is connected to a steam turbine via a boiler. The steam turbine cycle makes use of much of the heat in the gas turbine exhaust gases.  Thermodynamically, the combined cycle can be represented by joining the high temperature Brayton cycle with the moderate pressure and temperature Rankine cycle. An Combined Cycle T-h Diagram example of a combined cycle showing the Brayton cycle (gas turbine) and the Rankine cycle (steam turbine) on a T-h diagram is shown in Figure.  The area enclosed by the Rankine cycle is within the area that represents the heat rejected from the Brayton cycle. Thus, the Rankine cycle area represents the heat energy that is converted to useful mechanical energy that would other-wise be rejected to the atmosphere. A large portion of the heat lost from the Brayton cycle is used in the Rankine cycle. A much greater fraction of the heat added to the cycle is actually converted to useful mechanical energy in the combined cycle than either the Brayton cycle or the Rankine cycle alone. The Rankine cycle parameters (pressure and temperature) are selected to match the temperature of the available gas turbine exhaust gases. Usually, the pressure and temperature used in the Rankine cycle portion of the combined cycle plant are much lower  Prepared by: Fazal-ur-Rehman Babar

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than those used in conventional Rankine cycle plants. The lower pressure and temperature are necessary because the gas turbine exhaust gas, while very hot, is not nearly as hot as the flue gas entering the convection pass of a conventional fuel fired boiler.  The challenge in joining the Brayton and Rankine cycles in a combined cycle plant is the degree of integration needed to maximize efficiency at an economic cost. The simple combined cycle can consist of a single gas turbine, HRSG, steam turbine, condenser and auxiliary systems. In addition, if the environmental regulations require, an emissions reduction system can be directly integrated within the HRSG.

1.

Its operation is simple, can be started quickly and can be put on load in very short time. For these reasons, gas turbine power plants are able to meet peak - load demand, such as at evening peak.

2.

They require lower capital investment and occupy less space.  The starting cost of the plant is lower than equivalent steam power plant.

3.

The time required for their construction is short. The plant does not require heavy foundation and a large building.

4.

The maintenance of the plant is easier and maintenance cost is lower.

5.

The lubrication of the plant is easy. In this plant lubrication is needed mainly in compressor bearing, turbine bearing and bearing of auxiliary equipment.

6.

The gas turbine power plant requires less water as compared to condensing steam power plant.

7.

Gas Turbine auxiliary consumption is very less and there are very little standby losses in the gas turbines as compared to a Steam Turbine.

8.

There is a great simplification of the gas turbine power plant over the steam turbine power plant due to less auxiliaries and a bse nce of boi le rs wi th the ir f eed wa te r e va pora tor a nd condensing system.

1.

Major part of the work developed in the turbine, about 60%, is used to drive the compressor. The remainder of the turbine work is available to produce power by driving a generator. Therefore network out put of the plant is lower.

2.

For it starting purpose starting motor is required.

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3.

Since the temperature of the parts in the combustion becomes too high, so services conditions become complicated even at moderates pressures. Similarly, the first stage turbine blades face high temperature flue gases, therefore these are made with special material and these are coated with high temperature material.

4.

On open cycle its thermal efficiency is low and it is about 34%. However in combined cycle mode the overall thermal efficiency is can be even higher than 45%.

a. Newton  The force required to give a mass of 1 Kg an acceleration of 1 m/sec 2 . b. Joule Work done is 1 joule when a force of 1 Newton moves a body by 1 meter. (1 joule = 1 Newton-meter). c. Watt   Power is the rate of doing work. One watt is the power or rate of  doing work when 1 joule of work is done in 1 second. (1 watt = 1  joule/sec). d. C alo rie  The calorie is the quantity of heat required to raise the temperature of one gram of water one degree centigrade (more accurately, from 15.5 to 16.5 °C).  The multiple is the kilocalorie, quantity of heat required to raise the temperature of 1000 grams of water one degree centigrade.  The "thermie" equal to 1000 kilocalories, is the quantity of heat required to raise the temperature of 1000 kilograms of water one degree centigrade e. BTU (British Thermal Unit) BTU is the quantity of heat required to raise the temperature of  1 pound (1lb) of water by one degree Fahrenheit (1°F) (more accurately, from 63.5 to 64.5° F). 1 BTU = 252 calories = 0.252 kilocalorie f. Calorific Value It is the heat evolved by burning a unit mass of fuel. For example 40,200 kJ of energy is released when one kg of Furnace Oil is burnt and 32,400 kJ of energy is released when 1 M3 of Gas is burnt. g. Fuel Equivalent  210 Ton Fuel Oil = 9.9 MMCF of Gas = 1 GWh h. Specific Heat 

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 The specific heat of a substance is the heat in calories required to raise the temperature of one gram of the substance one degree centigrade. In effect there are two sorts of specific heat: i. Cv - specific heat at constant volume, Quantity of heat required to raise the temperature of the mass unit of the gas, one degree centigrade, at constant volume.  j. Cp - specific heat at constant pressure, Quantity of heat required to raise the temperature of the mass unit of the gas, one degree centigrade, at constant pressure. Note: the ratio Cp/Cv generally is labeled γ  . Besides, it is important to note that in the processes that constitute the thermodynamic cycle of a gas turbine, Cp can be considered as constant. k. Latent Heat  It is the heat used to change the state of a substance e.g. change of state from water to steam at the same temperature in HP evaporator. Similarly it is the heat rejected (to cooling tower) in condenser when turbine exhaust steam at 40 °C is converted to water (condensate) at the same temperature. l. Entropy (S) It is the heat quantity evolved in a process when the temperature considered uniform during the process. S is expressed in calories per degree centigrade. m.Enthalpy (h) It is the heat supplied to the fluid at constant pressure. It is me asu re d i n k J/ kg . The f al l of e nt ha lpy is e qu iva le nt t o mechanical work output. n.

Net Power and Work Output (P, W) are those available at generator terminals.

o.

Power and Work at Turbine Flanges (Pf  , W  ) f  are those directly available from the sole engine, reduction gear, auxiliaries, etc.

before

 p.

Specific Power (Ps ) is the power output for each mass flow unit running the cycle.

q.

Specific Work (W s ) It is the work obtained from the mass unit running a cycle.

r.

Mechanical Efficiency ( η  m ) is the ratio between the work output at turbine flange and the internal work of the gas on the blades.

s.

Combustor Efficiency ( η  b )

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is the ratio between the heat actually supplied to the gas in the engine combustion system and the heat that a fully burned fuel should have released. t.

Overall Efficiency ( η  g ) is the ratio between the net power output and the product of  fuel flow multiplied by its lower heating value.

u. Heat Rate (HR) is the inverse of the Overall Efficiency. It is the heat in BTU or kJ required to generate 1 kW of energy. v.

Thermal Efficiency ( η  t ) η 

t

= 1 – 

where: rp = pressure ratio γ  = 1.4 (a constant for flue gas)

1 r  p(1– 1/γ  )

 This equation shows that thermal efficiency depends upon pressure ratio only which relates to the compressor. w. Exhaust Temp Calculation CPD T f  = T x × Patm

k

 This equation shows that thermal efficiency depends upon pressure ratio only which relates to the compressor.  x. Pressure Ratio It is the ratio of compressor discharge pressure to the inlet pressure; Pressure ratio r p =

P2 P1

 y. Work Ratio It is the ratio of Net work and Gross work; Work ratio =

a.

Net work Gross = work

work of expansion – work of  compression work of expansion

Coulomb (C) It is the quantity of charge of 6.02 × 10 23 electrons or protons.

 b.

 Ampere (A) It is the unit of current and it is equal to 1 coulomb charge flowing in 1 second. 1 Ampere = 1 Coulomb/sec.

c.

Volt (V)

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 The potential difference is 1 Volt if 1 Joule of work is done for moving 1 Coulomb of charge between two points. (1 V = 1 J/C). d.

Ohm (Ω) It is the resistance in which a dc current of 1 Ampere generates heat at the rate of 1 joule/second (1 watt).

e.

Watt (W) It is the unit of power (P). Between two points if the potential difference is 1 volt and current is flowing 1 Ampere then the electrical power is 1 watt. (P = V I). 1 kW = 1000 watt. Domestic electric energy meters measure electricity in kWh (1 Unit = 1 kWh), it means 1 Unit of electricity is consumed if an electric iron of 1000 watt work for 1 hour or if a bulb of 100 watt light for 10 hours.

Turbine It is a mechanical component in which the thermal energy of the working medium is converted to mechanical energy by kinetic action on a rotary element. Single shaft turbine Such turbine in which turbine and compressor are on one shaft is called single shaft turbine. Turbine stage It consists of a set of stationary nozzles and one row of moving blades which are mounted on one disc.  The flue gas expands through the stationary nozzles to a lower pressure, thus releasing kinetic energy which is absorbed by the moving blades. Turbi ne rotor blades or Bucket (GT 5-8) Aerofoil sections mounted on a rotor disc and proportioned to transfer energy from the flue gas volume to the turbine rotor. Turbine stationary blades or Nozzles (GT 5-8) or Diaphragm (GT 3,4) A stationary element of the turbine blades used to expand the flue gas and increase its velocity by reducing pressure and direct it against the rotating blades.  Axial compressor   The mechanical component through which the air pressure is increased. Compressor blades Aerofoil sections mounted on a disc and proportioned to press the air through each successive row of compressor stationary blades or diaphragms. Compressor stationary blades or diaphragms A stationary element containing a set of stator blades used to compress the air and direct it towards the rotating blades.  Prepared by: Fazal-ur-Rehman Babar

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Combustor basket   The mec hanical component of the combustion system in which the fuel is burnt to increase the temperature of the flue gas. Transition piece Mechanical component which directs the hot gases from combustor basket to the segmental opening leading to the turbine inlet. Fuel nozzle  The component of the combustion system which meters the fuel to the combustor basket with the proper dispersion pattern. Igniter   The component of the combustion system which at a predetermined point is energized to provide the spark for igniting the fuel in the combustor basket. Cross flame tube A mechanical interconnection between combustor baskets for the purpose of carrying the flame from a fired to an unfired combustor basket. Temperature control system Under any normal conditions of operation, it limits input fuel as necessary to prevent the temperatures in the turbine from exceeding allowable limits. Turbine temperature detector   That component of the control system which senses the temperature of the flue gases and provides the signal to limit the fuel input to the combustor baskets when maximum predetermined temperature is reached. Ignition speed  The speed of the compressor shaft at which ignition and fuel are applied. Self-sustaining speed  The minimum speed of the compressor shaft at which the turbine will continue to operate at no-load without cranking power. Idling speed:  The specified operating speed of the compressor shaft for noload operation. Rated speed  The speed of a designated shaft at which it runs on load. Trip speed  The speed at which the overspeed protective device operates. Cranking speed  The speed at which the turbine is rotated for washing. Starting power   The external power which is required to accelerate the compressor, its turbine, and any connected load to self sustaining speed in a specified time.  Journal- bearing

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 This bearing is used to support the rotating elements (shaft) and it maintains the radial position of the rotor with respect to the stator. Thrust bearing  This bearing supports the axial thrust of the rotor to the bearing housing and it maintains the axial position of the rotor with respect to the stator. Bearing housing An enclosure used to contain and support the shaft bearings and may be of the bracket or pedestal type. Interstage seals Mechanical device used to restrict the leakage of the air or flue gas between stages. Compressor bleed valve An open-close line used to blow off a portion of the air from a stage of compressor during a start-up or a shut down period. Rotor assembly   This is the rotating element of the gas turbine which includes all parts attached on the shaft and has provision for coupling. Discs or Wheels  They constitute the gas turbine shaft. On these discs the rotating blades are assembled. Wheel space or Disc Cavity  It is the space between rotor wheel and diaphragm of the stator blade. Here thermocouples are placed to measure the temperature. Shroud or Seal A shaped metallic strip next or connected to the blades in order to limit the leakages. Governing system; which includes but it is not limited to: • Speed governor on the load shaft with load setting device for manual operation at the machine and/or control panel • Check of turbine maximum over-temperature • Emergency over-speed governor on the load shaft. Speed governing system A system of control elements and devices for the control of the speed or power output of a gas turbine and includes a speed governor, speed changer, fuel control mechanism, and other devices and control elements required to actuate the fuel control valve. Speed governor   The primary speed-sensitive element which is directly responsive to speed and which positions or influences the action of other control elements. Fuel control mechanism  This mec hanism controls the flow of fuel to the gas turbine. Speed changer   Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15

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Used to change the setting of the speed governing system for the purpose of adjusting the speed and/or load of the gas turbine during operation. Control panel A c ompon ent on w hi ch a re moun te d t he d evi ce s us ed t o regulate and monitor the necessary functions for safe operation of the gas turbine. Controlling device One which automatically initiates action of a system which controls conditions during the normal operation of the gas turbine. External control device An element which is responsive to signals that are external to the gas turbine. It may be pneumatically, hydraulically or electrically actuated from the signal source and acts to control the energy input to the gas turbine. Protective device One which, alone or as part of a system, controls or signals in some predetermined manner, abnormal conditions which may occur during the operation of the unit or system to which it is connected. Warning device One which by visible or audible means, or both, indicates that an abnormal operating condition exists. Baseplate (bedplate) A structural metal frame for supporting the gas turbine and its auxiliaries as a unit. Inlet silencer   The elements system which decreases the sound power level transmitted by the air at the inlet of the compressor. Exhaust silencer   The elements system which decreases the sound power level transmitted by the flue gases leaving the gas turbine.  Auxiliary gear or Accessory drive Converts the gas turbine speed to the speed required by the auxiliary equipment.  Accessories Apparatus deemed necessary for the proper functioning and safety of operation of the gas turbine. Starting equipment 

 Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15

29

 The starting equipment shall be capable of bringing the gas turbine up through the normal starting cycle to self-sustaining speed. Turning gear   The turning gear rotates the gas turbine rotor at low speed prior to starting and immediately after shut-down to assure uniform temperature distribution in the rotor. Heat Recovery Steam Generator or Exhaust heat boiler  Used to recover and transfer heat from the flue gases leaving the gas turbine to generate steam or hot water. Lubricating system; Closed forced-feed system including the following: • Oil tank of sufficient capacity and oil piping •  Tank oil level indicator • Main oil pump-sized to supply oil requirements for the complete gas turbine unit during normal operation • Auxiliary and Emergency lube oil pumps with means for testing their operation • System for automatically activating emergency and auxiliary lube oil pump •  Temperature measuring device in the oil feeding man ifold • Lube oil coolers • Pressure gauge on oil feeding manifold • Relief valves Supervisory instrumentation;

Electro-pneumatic system for checking and monitoring of unit performances. It include • Master control switch for semi-automatic start and for stopping the gas turbine • Speed changer checking system • Re la y to p rovi de the ne ces sa ry f un cti ons of con trol a nd protective operations of the gas turbine • Starting and sequence indicating lights •  Temperature indicator for the turbine exhaust temperature • Speed indicator for output shaft • Loss of flame indication • Annunciator with audible alarm and individual malfunction indicators for overspeed, flameout, low lube pressure, high be ari ng oi l t emp era ture an d h ig h tu rb ine co ol in g wat er temperature • Pressure gauges for measuring lube oil manifold pressure, fuel pressure, overspeed oil pressure and control air pressure.

 Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15

30

Description Gas Turbine Model Manufacturer

Control Design Load Base Load rating according to IDC test in 1996 Base Load rating according to ADC test Starting time upto 3000 RPM Spining Reserve Auto Loading gradient App. net thermal efficiency Critical speed Turbine Turbine Stages Max. Turbine Inlet Temperature Turbine exhaust temp. at full load Heat rate (kJ/kWh)

Unit 1, 2

Unit 13, 14

Unit 3, 4

Unit 5-8

V-94.2 V-94.2 TG-50 Siemens (Germany) Siemens (Germany) FIAT M/s GIE (Italy) ISKAMATIC TELEPERM Conventional relay EA/EHF type; Fiat Hi Tech 114.75 MW 94 on GAS 110 / 107 on Gas 84 / 83 on GAS 91 on HSD 105 / 103 on HSD 83 / 84 on HSD 91 on FO 105 / 103 on FO 94 on GAS 110 / 107 on Gas 84 / 83 on GAS 91 on HSD 105 / 103 on HSD 83 / 84 on HSD 91 on FO 105 / 103 on FO 4 Minutes 4 Minutes 25 Minutes

MS 9001 E M/S ALSTOM France Mark IV Speedtronic control 97.1 MW 80/79/80/80 on Gas 76/76/77/76 HSD 76/76/77/76 on FO 80/79/80/80 on Gas 76/76/77/76 HSD 76/76/77/76 on FO 10 Minutes

20 MW 11 MW/minute upto base load 26 % (open cycle)

20 MW 11 MW/minute upto base load 29 % (open cycle) 1500 – 1850 rpm

2 MW, after 90 Sec 4 MW 6 MW/minute 8 MW/minute 25 % (open cycle)

27 % (open cycle)

4 1050 °C

4 1050 °C

4 1050 °C

3 1050 °C

500 to 530 °C

500 to 550 °C

550 to 610 °C

480 to 550 °C

11,200 on Gas 11,300 on HSD 11,600 on BFO 471 Kg/sec 8.73 on Gas 9.28 on HSD 8.55 on BFO

322 Kg/sec

406 Kg/sec

Flue gas mass flow 426 Kg/sec Fuel flow (kg/s)

Description Compressor Compressor Stages Discharge pressure varies acc to speed Compression Ratio Inlet guide vanes

Unit 1, 2

Unit 13, 14

Unit 3, 4

Unit 5-8

16 1-9 bar

16 1-9 bar

20 1-9 bar

17 1-9 bar  

9.11 Fixed

Bleed valves

№ 1.1 is electric operated, № 1.2 is air  operated and both

9.11 12 9.11 Variable,modulated Variable,modulated Variable,modulated at 34°, 57°, 84° № 1.1 and № 1.2 3, 4, close with comp are air operated, № 1, stage 6 close discharge air & and both are at above 2800 rpm. open with spring. stage 5, these close № 2, stage 12 close All close at 95%

 Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15

31

are at stage 5, these close above 2950rp. № 2 is air operated, at stage 10, close above 2300 rpm Starting System Starting Device

above 2940 rpm. above 2700 rpm. speed № 2 is air operated, № 3, stage 15 close at stage 10, close above 1900 rpm above 2280 rpm

S.F.C Max. startup rating 2900 kW Declutching Speed 2100 to 2300 RPM Combustion and Fuel System  No of Combustors 2 Fuel Nozzles/ 8 per combustion Burners chamber  Spark Plugs 1 for each nozzle

S.F.C 11KV – 1915 KW 6.6KV – 1000 KW Max. startup rating 2900 kW 2100 to 2300 RPM 1910 to 1980 RPM 1800 RPM

Description Unit 1, 2 Combustion and Fuel System Fuel oil control At return line, valve hydraulic control

Unit 13, 14

Unit 3, 4

Unit 5-8

At return line, hydraulic control

Air operated

Fuel oil pressure low Fuel oil pressure high Dosing pumps

6-7 bar

6-7 bar

VC 3 Fuel bypass valve and flow divider control the fuel oil flow 5-6 bar  

65 bar

65 bar

65-70 bar

65-70 bar  

2 pumps with low and high range

2 pumps with low and high range

2 pumps with low and high range

TRESSO-46

TRESSO-32

DTE-724

2 8 per combustion chamber  1 for each nozzle

18 Nozzles 1 per combustor

14 reverse flow 1 per combustor 

2, electrode type, spring-injected, self-retracting, located at burners 12 & 13. Flame detectors 2, one at each left 2, one at each left 4, ultra-violet type, 4, ultra-violet type, and right chambers and right chambers FD1,2 at nozzle 1, located at burners 3, FD3,4 at nozzle 18. 4, 5 & 11. Fuel pump 1, Electric motor   2, Electric motor  1, Electric motor  1, Accessory geardriven. Fixed driven. Fixed driven. Fixed driven, Fixed displacement, displacement, displacement, displacement, screw screw type pump screw type pump screw type pump type pump Flow divider Ram type Circular, free wheeling, 14 elements Fuel oil emergency Open by hydraulic Open by hydraulic Air operated Open by electrostop valve (ESV) control oil, close by control oil, close by hydraulic servo spring force spring force control oil, close by spring force

2 pumps with low and high range Lubrication System Lube Oil Grade TRESSO-46  Prepared by: Fazal-ur-Rehman Babar

2, located at  burners 12 & 13.

GT 13, 14 & ST 15

32

Total Oil Capacity 11.4 m3 Max. Oil Level

13.5 m3

10.5 m3

3,300 gallons or  12,540 litres

320 mm from top

320 mm from top 12.13 m 3 Min. Oil Level 440 mm (from top 440 mm from top of oil tank) 10.54 m 3 Main lube oil pump One AC motor   No. 1, AC motor  driven Press = 5 bar  driven Auxiliary lube oil 1, AC motor driven No. 2, AC motor   pump driven

2, AC motor driven Pressure = 4-5 bar  Any one can be selected as main and other standby Emergency lube oil 1, DC motor driven 1, DC motor driven 1, DC motor driven  pump Pressure = 1.2 bar  Pressure = 1.2 bar  Pressure = 1.2 bar  Jacking oil pump

1, AC motor driven 1, AC motor driven  Nil Pressure = 140 bar  Pressure = 140 bar  Bearings at Compressor, Turbine and Generator Rotor Quantities 2+2 2+2 2+2 Lubrication Pressure lubricated Pressure lubricated Pressure lubricated № 1 bearing MBD11, Journal MBD11, Journal Located at Turbine Located at Turbine Exhaust Exhaust Journal Active thrust Inactive thrust № 2 bearing

MBD12, Journal + Thrust, Located at Compressor air  Intake

Description № 3 bearing

MBD12, Journal + Thrust, Located at Compressor air  Intake

1, accessory gear  driven, Pressure 1,AC motor driven, vertical,submerged, centrifugal type DC motor driven, vertical,submerged, centrifugal type Nil

3+2 Pressure lubricated Located in inlet casing assembly, Active and inactive thrust Elliptical Tilting pad, self-equalizing Tilting pad, non-equalizing Located in compressor  discharge casing, Elliptical journal

Unit 1, 2 MKD11, Located at Generator on Compressor side № 4 bearing MKD12, Located at Generator on slipring side Hydraulic supply system Main hydraulic supply pump

Unit 13, 14 Unit 3, 4 MKD11, Located at Generator on Compressor side MKD12, Located at Generator on slipring side

Unit 5-8 Located in exhaust frame, Journal, tilting pad

-

Auxiliary hydraulic supply pump

-

Accessory gear   driven, variable  positive displacement, axial  piston AC motor driven 88HQ

Control oil system  Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15

33

Booster oil pump

1, AC motor driven 1, AC motor driven 2, AC motor driven Press = 8-9 bar 

Atomizing air system Main compressor no air atomizing fuel burn, pressure atomization Starting (booster) compressor 

no air atomizing fuel burn, pressure atomization -

Air pre-cooler

-

-

Data from Performance Section Fuel Calorific Values

-

Accessory gear  driven 51,000 rpm, centrifugal type Axial flow, positive displacement, belt driven by ACmotor  Water-to-Air heat exchanger 

 Net Complex Output (MW) in IDC 1996  Net Complex Output (MW) in ADC 2004 Maximum Generation in a Month (April 2004) Maximum Generation in one day Maximum Plant Load

Sui Gas : 32,400 kJ/m3, HSD : 36,300 kJ/Ltr   FO : 40,200 kJ/kg 1345 MW 1360 MW 789,665 MWh 35,667 MWh 1541 MW

Conversion 1 mm of Water Column 1 bar (= 1 M water column) 3412 BTU = 3600 kJ

2.81 mbar; 2.107 mm of Mercury 14.7 PSI = 100,000 Pascal 1 kWh

 Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15

34

Description Steam Turbines Make Type Rated Power  No. of Cylinders First Cylinder Stages Second Cylinder Stages HP steam inlet  pressure Temperature LP steam inlet pres Temperature Vacuum Turning Gears Make Drive

Turning Speed Condensers Make Type

Water passes Cooling Area Circulating water  flow Vacuum Total steam flow CW flow CW vel in tubes CW inlet temp Cond pres loss  No. of tubes Tube outer dia Tube thickness Tube Material

Unit 9, 10

Unit 11, 12

Unit 15

ABB, Germany DK 2056 112.2 MW 2

RATEAU, France VEGA 209 110 B 103.4 MW 1

SIEMENS, Germany 030-16, N30-2X5-B-9 148.6 MW 2

16 Reaction

12 HP, 5 LP

26 Reaction

7+7 reaction double flow 47.9 bar

40 bar

8+8 reaction double flow 57 bar  

495 °C 3.99 bar 190.6 °C 0.091 bar (a)

510.8 °C 0.091 bar (a)

528 °C 5.78 bar   221 °C 0.091 bar (a)

ABB, Germany AC motor driven reduction gear  43 rpm

FLENSER, France AC motor driven reduction gear  50 rpm

KWU, Germany 57 bar 

ABB, Germany Spring mounted surface condenser  2 8204 m 2

DELAS Rigid mounted surface condenser  2 8651 m2

0.091 bar (a) 110.551 Kg/sec 4681.6 Kg/sec 1.91 m/sec 29 °C 0.38 bar 13000 24 mm 1 mm CuZn28Sn X 2CrNiMo Corrosion prot for  Rubber Lined Water Box

 Prepared by: Fazal-ur-Rehman Babar

0.091 bar (a) 97.64 Kg/sec 4626 Kg/sec 1.95 m/sec 30 °C 0.46 bar 12532 24 mm 1 mm Admiralty Brass Stainless Steel Epoxy Paint

58 rpm

KWU Rigid mounted surface condenser  2 9982 m2 5.690 m 3/sec or  20,484 Ton/hr  0.091 bar (a) 128.04 Kg/sec 5650.1 Kg/sec 1.9 m/sec 28.5 °C 0.41 bar   16032 + 1236 23 mm 1 mm & 0.7 mm CuZn28Sn1F32 X 2CrNiMo N17135 Epoxy Paint

GT 13, 14 & ST 15

35

Description Unit 9, 10 Circulating Water Pumps Make TORISHIMA Type 1200-SPB Flow 9630 Ton/hr TDH 23.2 m  NPSH 5m Speed 325 rpm Power 920 KW

Unit 11, 12

Unit 15

KSB PHZ 900-990 8360 Ton/hr 17.2 m 3.5 m 590 rpm 462 KW

TORISHIMA SPV 1200 11320 Ton/hr   22.3 m 12.3 m 295 rpm 1000 KW

Cast Iron Carbon Steel Bronze GCu SN10

JIS FC 250 JIS S45C SCS1

FEX.36-3 422 96 33.4 1480 150

12QLQC 21/60/3 465 195 2.5 1480 316

A420CM Z15CN16-02 Z4CND13-412

ASTMA 48 CL.35 ASTMA 276-410 ASTMA 743CA6NM

INGERSOL DRESSER ERP100-200 175 6.7 7.8 2950 30.1

WORTHINGTON HED 39.24 20 0.884 2980 65

A216GrWCB A193GrB7 A473CA6NM

A216 GR WCB A276 – 410 A487 GR – CA6NM

 Material 

Casing Shaft Impeller

JIS FC25 JIS S45C SCS1

Condensate Pumps Type WKTA-200/2 Flow (t/h) 403.1 TDH (m) 75.6  NPSH (m) 3.3 Speed (rpm) 1480 Power (kw) 130 KW  Material 

Casing Shaft Impeller

JIS SCPM 2 JIS SUS42OL2 JIS SC51

LP Feedwater Pumps Make TORISHIMA Type RPK50-400 Flow (t/h) 30 Head (m) 190  NPSH (m) 1.9 Speed (rpm) 2945 Power (kw) 55  Material 

Casing Shaft Impeller

JIS SCS1 JIS SUS420J2 JIS SCS1

 Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15

36

Description

Unit 9, 10

HP Feedwater Pumps Make TORISHIMA Type HGC 4/8 Flow (t/h) 206.9 Head (m) 831.2  NPSH (m) 6 Speed (rpm) 2970 Power (kw) 671

Unit 11, 12

Unit 15

BYRON JACKSON

WORTHINGTON

183.5 675 6.51 2980

337 933 10.50 2980 1200

A743-CA-6MM A276-TP410 A743-CA-6MM

A 487 GR CABNM A 276 TY 410 A 487 GR CABNM

HIBON SHR215006H00.950

SIEMEN 2BE 1303-OZY4Z

0.39 bar 25.5 kg/h 42 kw

300 mm bar   30 Kg/hrs

0.083 bar 44

0.1 bar   100

108 Kg/h

67.5 Kg/h

 Material 

Casing Shaft Impeller

SFVE2 13CR SCS1T2

Vacuum Pumps Make SIEMEN Type 2BW4303-0=OML49 HOGGING OPERATION Suction Pressure 0.3 bar Design Flow 5200 m 3/h Rated Power 65 kw HOLDING OPERATION Suction Pressure 0.0326 bar Suction Temp. °C 40 Design vapor  mixture flow 37.3 Kg/h

 Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15

37

Description Type

Make Rated Out Put (MVA) Power Factor Rated Voltage (KV): Rated Current (A) Frequency (HZ) Speed (RPM) Over Speed Limit (RPM) Field Voltage (V) Field Current (A) Short Circuit Ratio Direct-Axis subtransient Reactance (Xd″ ) per unit Direct-Axis Transient Reactance (Xd′ )  per unit Direct-Axis Transient Open circuit time constant T’d (Sec) Direct-Axis Transient short circuit time constant T′ d (Sec) Rotor Resistance (ohm) Stator Resistance (ohm) Insulation Class Excitation system

Cold Air Temp °C

Unit 1,2 TLRI 108/41 KWU

Unit 3,4 SGTIC 243704

Unit 5-8 Unit 9,10 Unit 11,12 T 229-320 WX 21L- T-229-320 064LL ALSTHOM ABB ALSTHOM

Unit 13,14 TLRI 108/36 KWU

Unit 15 TLRI 108/41 KWU

135

87

125.95

132

121.647

170

175

0.85 10.5

0.85 11.0

0.85 11.5

0.85 11.0

0.85 11.5

0.85 11.0

0.85 11.0

7423 50 3000 3600

4567 50 3000 3600

6223 50 3000 3600

6928 50 3000 3600

6107 50 3000 3600

8923 50 3000 3600

9185 50 3000 3600

333 641 0.5 0.148

142 810 0.6 0.114

151 2110 0.51 0.195

236 1495 0.5 0.17

146 2011 0.58 0.175

432 946 0.502 0.183

432 865 0.534 0.176

0.242

0.145

0.275

0.26

0.252

0.304

0.286

13.3

11.6

6.56

7.4

7.2

11.34

10.8

0.27

0.04

0.40

0.04

0.25

1.56

1.62

0.3638 (at 20 °C) 0.00061 (at 20 °C) F SEMIPOL (Static)

0.175 0.0508 (at 75 °C) (at 20 °C) 0.0011 0.00107 (at75 °C) (at 20 °C) F F STATIC ROTA DUCT (Rotary) Brushless 50 50

0.1165 (at 20 °C) 0.00079 (at 20 °C) F STATIC

0.226 (at 20 °C) 0.001 (at 75 °C) F ROTA DUCT (Rotary) Brushless 36

0.3242 (at 20 °C) 0.00058 (at 20 °C) F SEMIPOL (Static)

0.3671 (at 20 °C) 0.00053 (at 20 °C) F SEMIPOL (Static)

40

40

55

 Prepared by: Fazal-ur-Rehman Babar

ERCOLE MARELLI

33.3

GT 13, 14 & ST 15

38

Description

Unit 9, 10

Unit 11, 12

Unit 15

220 KV CIRCUIT BREAKERS Make Nova Magrin Galiloo Italy GEC ALSTHOM Type SF6 / Air operated SF6 / Hydraulic oil operated Rated Voltage 145 KV 145 KV Rated current 2000 Amp 2000 Amp Rated breaking 40 (KA) 40 (KA) capacity BIL 1050 KV 1050 KV  No. of circuit 6 18  breaker  132 KV CIRCUIT BREAKERS Make Nova Magrin Galiloo Italy Type SF6/Air operated Rated Voltage 145 KV Rated current 1600 Amp Rated breaking 40 (KA) capacity BIL 650 KV  No. of circuit 17  breaker  11 KV CIRCUIT BREAKERS Description Unit 1,2 Make SIEMENS Germany Type Vacuum

Rated Voltage Rated current Rated breaking capacity  No. of circuit  breaker 

1050 KV 9

Nova Magrin Galiloo Italy SF6/Air operated 145 KV 3000 Amp 40 (KA) 650 KV 1

12 KV 1250 Amp 25 (KA)

Unit 5-8  Nova Magrin Marlin Galiloo Italy Gerin Air   SF6 Magnetic 12 KV 12 KV 1250 Amp 1250 Amp 25 (KA) 25 (KA)

26

24

 Prepared by: Fazal-ur-Rehman Babar

SIEMENS SF6 / Hydraulic oil operated 145 KV 2000 Amp 40 (KA)

Unit 3,4

42

Unit 9,10 AEG

Unit 11,12 Marlin Gerin SF6

Unit 13,14 SIEMENS ABB Vacuum

25 (KA)

12 KV 630 Amp 25 (KA)

12 KV 800 Amp 20 (KA)

40

36

48

Vacuum 12 KV

GT 13, 14 & ST 15

39

Description Make

Unit 1,2

Unit 3,4

TRAFO UNION

ANSALDO ALSTHOM TOSHIBA

Rated Power MVA Rated Voltage KV (LV/HV) Rated Frequency  No of Phases Rated Current (A) (LV/HV) Connection Symbol Type of Cooling

117.6/147 77/95.5 10.5/139 11.139

125 11.5/240

90/135 11/139

50 Hz 3

50 Hz 3

50 Hz 3

8083/611 YNd11

5012/396 YNd11

ONAN/ ONAF 55/50 On Load

Temp. Rise °C Winding/Oil Type of Tap Changer  Total No. of Taps Impedance % Connection (HV/LV)

Unit 5-8

Unit 9,10 Unit 11,12 Unit 13,14 Unit 15 ALSTHOM TRAFO UNION

TRAFO UNION

168 11 / 258

190 11 / 258

50 Hz 3

112/125 11.5 / 240.18 50 Hz 3

50 Hz 3

50 Hz 3

6276/300 YNd11

7090/561 YNd11

6276/300 YNd11

8819/422 YNd11

8083/661 Ynd11

ONAN/ ONAF 55/50

ONAN/ ONAF 55/50

ONAN/ ONAF 55/50

ONAN/ ONAF 55/50

ONAN/ ONAF 55/50

ONAN/ ONAF 55/50

On Load

Off Load On Load

Off Load

Off Load

Off Load

17 15 09 17 09 11 11 9.2/11.5 10.9 14.5 12.63 14 14 15.5 Star/Delta Star/Delta Star/Delta Star/Delta Star/Delta Star/Delta Star/Delta

Description Make

Unit 1,2 Unit 3,4 SIEMENS O.T.E

Type of cooling Rated power  (KVA) Frequency (Hz) Impedance % Rated voltage KV (HV/LV) Rated current (AMP) Vector group Total no. of taps Type of tap changer  Temp. rise oil/winding Connection (HV/LV) Weight of oil KG

ONAN 1000

Unit 5-8

ONAN 2500

Unit 9,10 Unit 11,12 Unit 13,14 ALSTHOM PEL ALSTHOM TRAFO UNION ONAN ONAN ONAN ONAN 1250 630 630 800KVA

ONAN 1250

50 5.47 11/0.4

50 8.38 11/0.415

50 5.5 11.5/0.4

50 5.98 11/0.4

52.5/ 1443.4 DYN11 5 Off Load

131.2/ 3478 DYN11 5 Off Load

6.56/1804 33.1/ 909.3 DYN11 DYN11 5 5 Off Load Off Load 50/55

50 4.09 11/0.4

50 4.21 % 11/400

50 5.8 % 11/400

Unit 15 SIEMENS

33.1/909.3 42/1155 DYN11 5 Off Load

65.6/ 1804.2 DYN1 DYN11 5 5 Off Load Off Load 55

Delta/Star  Delta/Star  Delta/Star  Delta/Star  Delta/Star  Delta/Star  Delta/Star  Δ/Ү Δ/Ү Δ/Ү Δ/Ү Δ/Ү Δ/Ү Δ/Ү 1035 1200 5100 600 385 1257

 Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15

40

Description Make

Unit 1,2 SIEMENS

Type of cooling  No. of phases Operation Rated power(KVA) Frequency Rated current HV/LV(A) Rated voltage HV/LV(B) Type of tap changer   No. of taps Vector group Temp. Rise at 50 C Winding/oil Impedance %

Description Type

Unit 1,2

Unit 3,4

Brushes.

Brushes

Make

Rated power (kw) Rated voltage (V) Rated Current (A) Converters / Blade Duty Class of Insulation Supply source

ON 3 Continuous 630 50 33.06/ 673.6 11000/940

Unit 3,4 STEMTRENTO ONAN 3 Continuous 450 50 23.6/927

Unit 9,10 MAY & CHRISTE AN 3 Continuous 800 50 42/1499.6

Unit 13,14 TRAFO UNION AN 3 Continuous 1660 50 87.1/1229

Unit 15 TRAFO UNION AN 3 Continuous 1025 50 53.5/845

11000/280

11000/380

11000/780

11000/700

Off Load

Off Load

Off Load

Off Load

Off Load

5 YD-5

5 YD-11

5 YD-5

3 YD5

3 YD-5

50/45 5.55

50/45 7.0

50/45 6.05

50 C 5.9

5.8

Unit 5-8 STATIC STATIC Rotating with Carbon with Carbon Diodes

Unit 9,10 Unit 11,12 Unit 13,14 Unit 15 STATIC Rotating STATIC STATIC Diodes

AEG

MAY & Christe

Ercole Telefuncon Marelli

Alsthom

215 342 658 6

115 142 810 3

319 151 2110 18

353 236 1495 3

Als AEG tho Telefuncon m 293.6 408 146 423 2011 946 18 6

Continuous

Continuous

Continuous

Continuous

Continuous

Continuous

AEG Telefuncon

366 423 865 6 Continuous

F F F F F F F Auxiliary Auxiliary Auxiliary Auxiliary Auxiliary Auxiliary Auxiliary

 Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15

41

Description Boiler output (T/H) Design Gauge Pressure (bar) Superheater outlet Pressure (bar) Superheater Steam Temp. (°C) Heating Surface Area LP Evaporator HP Economizer HP Evaporator HP Superheater Total heating Surface

(m2) (m2) (m2) (m2) (m2)

Unit 1,2 208 62 47.1 505

Unit 3,4 180.8 62 48 500

Unit 11,12 96.25 51 42 512

Unit 15 234 60.7 60.7 530

4345 18200 28220 5415 56180

10200 17950 22820 3212 54182

7439 13139 26014 9794 56386

9914 33909 34578 5693 84094

FEED WATER AND WATER FOR SPRAY ATTEMPERATOR

Description General requirements Conductivity PH-Value Oxygen Total Iron Total Copper Silica Carbon dioxide Hardness KMnO4 Consumption Oil

Unit at 25 °C µS/cm at 25 °C O2 mg/kg Fe mg/kg Cu mg/kg SiO2 mg/kg CO2 mg/kg mval/kg mg/kg mg/kg

Clear and Colorless 0.2 9 0.02 0.02 0.003 0.02 Not detectable Not detectable 5 0.3

Unit at 25 °C µS/cm at 25 °C SiO2 mg/kg PO4 mg/kg

150 9.5 – 10.5 5 61

BOILER WATER

Description Conductivity PH-Value Silica Phosphate

 Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15

42

Symbols used in System Diagrams are stipulated in DIN 2481. This standard provides the full scope of symbols which are used in power plant engineering. An excerpt of this standard containing most frequently used symbols in the system diagrams is filed here.

DIN Standard Valve Shut off valve general

Shut off through valve

Hand Operated

Fitting with constant setting action

Motor Operated

Fitting with safety function

Solenoid Operated

Non-return valve general

Non-return through-valve

Fluid Operated Non-return valve without spring

Non-return valve with spring

Piston Operated

Controlled non-return valve

Diaphragm Operated

Control valve Angle valve or ball valve

 Throttle valve adjustable

 Throttle valve with constant restriction

Check valve  Three way valve

Four way valve

Safety shut off  valve

Safety relief valve

Coupling general

Separator general Pressure reducing valve Gate valve or Main slide valve

Air Filter

Ball/cock valve

Liquid Filter

Strainer

3-way cock valve Cooling Tower general Butterfly valve

 Prepared by: Fazal-ur-Rehman Babar

GT 13, 14 & ST 15