Important Safety Information In handling marine auxiliary boiler HB-T type (hereinafter called this boiler), read and fully understand this manual and follow instruction that is contained in this manual.
This boiler contains hot parts that may cause burn, high-pressure parts that may cause injury due to pressure break, moving parts in which a part of body may get caught, and high-voltage parts that may cause electrical shock. Improper handling of these parts may cause accident involving death, fire, or other disasters.
This boiler can be operated in automatic operation mode (normal mode) and manual operation mode for emergency. In manual operation mode, fire or burn due to backfire (*) may be caused unless boiler is handled properly. Use manual operation mode only in emergency.
To ensure safety of operation and maintenance of this boiler, it is essential to know possible causes of disasters in advance. We cannot predict all potential dangers, but present dangers involved in handling of boiler in this manual to the best of our knowledge. Following warnings or instructions that are contained in this manual better ensures safety of work. In this manual, harm and damage are categorized into following three levels. These are attached on this boiler as warning labels (*) and also described in this manual.
DANGER WARNING CAUTION
Indicates any condition or practice that, if not observed, causes imminent danger of death or serious injury to user.
Indicates any condition or practice that, if not observed, may cause death or serious injury to user.
Indicates any condition or practice that, if not observed, may cause minor injury to user or property damage.
If failed components are found, contact MIURA offices and replace them with genuine parts. Using different model part may reduce safety of boiler. Remodeling this boiler without consultation with MIURA or repairing it in way that is not specified in this manual may seriously affect safety of boiler. Do not remodel or repair boiler on your own.
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Introduction This manual describes procedures for handling this boiler for proper operation. Precautions relating to operating method and safety indicated in this manual from damages to measures only relate to usage for specified purposes. Do not use boiler by methods that are not mentioned in this manual. Be aware that MIURA cannot be held responsible if boiler is used by methods that are not mentioned in this manual.
Before using this boiler, those who use it for the first time as well as those familiar with handling of it must read this manual thoroughly and understand proper method of handling it. Keep this manual in place so that it can be consulted whenever there is any uncertainty about this boiler. In addition to this manual, following booklets are provided as information that is needed to use this boiler. Before using boiler, thoroughly read these booklets in addition to this manual. [1] Final Drawing:······ Final drawing is documents containing all specifications for customer. Look over and understand final drawing before use. Refer to this document for information that depends on capacity or options. [2] Procedure: ·········· Manual for Installation: Procedure manual for installation contains information on installation of this boiler and incidental parts. Install this boiler according to this procedure manual (This procedure manual is contained in final drawings). [3] Instruction manuals for incidental equipment: Handle incidental equipment according to respective instruction manuals. [4] Manual for Water ·· Treatment: Manual for water treatment describes procedure of water treatment that is needed to use this boiler. Understand content of manual, and handle chemicals and carry out water treatment work according to instructions that are contained in this manual.
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[Graphical symbols] Graphical symbols used in this manual have following meanings: Indicates certain behavior is prohibited. Prohibition
Indicates touching certain area may cause personal injury. Do Not Touch
Indicates handling with wet hands may cause electrical shock.
Do Not Touch with Wet Hands
Provides instruction to be followed (action to be taken). Instruction
Indicates ground wires must be connected.
Connect Ground Wire
Indicates a precaution to be remembered. Caution
Indicates potential danger of injury from heat under certain conditions. Caution: Hot
Note
Provides precaution to prevent boiler failure, point to be remembered for effective operation, or other useful information. Indicates related page(s).
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Term Definitions Terms that are used in this manual are defined as follows. These terms are marked with asterisk (*) in manual. Term H.F.O.
Description Abbreviation of fuel oil. Fuel used with main burner. When this boiler is used in Japan, term refers to heavy oil C.
M.D.O.
Abbreviation of marine diesel oil. When this boiler is used in Japan, term refers to heavy oil A. Fuel used with pilot burner.
Flammable
Substance with low ignition temperature that is fire hazard (A handling place
Dangerous
for flammable dangerous substance refers to place where such a substance
Substance
is stored).
Wind Box
Wind box in which burner is installed. It controls air flow from fan.
Oil Air Separator
Container that is designed to separate components evaporated from fuel oil or air retaining in fuel oil circulation line or other gas phases from liquid phases. Oil air separator is installed on inlet side of fuel oil pump.
Air Supply Fan
Air supply system designed to bring air into furnace.
Warning Label
Label to call attention to operating precaution.
Ventilation (draft)
Phenomenon that exhaust gas with higher temperature and smaller specific gravity than surrounding air rises toward outlet of funnel.
Differential
Differential means control width that is set with controller. It is control width between when contact of controller is turned off (on) and when it is turned on (off) again.
Ignition Transformer
High voltage supply system designed to generate sparks for igniting pilot burner or main burner.
F.O. Heater
Heater that is designed to heat fuel to suitable temperature to be atomized by burner. This heater is included as standard when H.F.O. is used as main fuel.
Pilot Flame
Fire source for igniting main burner when H.F.O. is used as main fuel. Pilot flame is formed by igniting pilot burner.
Backfire
Phenomenon that fire source is generated in furnace under poorly ventilated conditions before combustion is started or when combustion is stopped, and combustible gas mixture in furnace is ignited to cause explosion.
Flame eye
Sensor that is designed to detect flame in furnace.
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Term Pre purge Post purge Main fuel
Description Pre-purge is ventilating combustion chamber of boiler before combustion. Post-purge is ventilating combustion chamber of boiler when combustion is stopped. Fuel used with main burner.
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CONTENTS
Important Safety Information .............................................................. i Introduction........................................................................................ ii Term Definitions................................................................................ iv CHAPTER 1: SAFETY.........................................................................1 1. Safety Regulations ........................................................................1 2. Knowledge and Skill Required for Safe Handling .........................1 3. Protective Equipment ....................................................................1 4. Prohibition of Remodeling without Permission..............................1 5. Use of Specified Fuels ..................................................................2 6. Warning Labels (*) on Products......................................................2 7. Precautions for Safe Handling ......................................................3 7.1 Safety Precautions in Installation ................................................................................3 7.2 Safety Precautions in Pre-operation Inspection and Preparation ................................4 7.3 Safety Precautions in Operating Boiler........................................................................5 7.4 Safety Precautions in Bringing Boiler to Emergency Stop...........................................7 7.5 Safety Precautions in Inspections and Maintenance ...................................................7 7.6 Safety Precautions in Replacing Parts ........................................................................9 7.7 Safety Precautions in Working on Failures..................................................................9 7.8 Safety Precautions in Storage Work..........................................................................10
2. Water and Steam Supply Flow.................................................... 12 2.1 Water and Steam Pipe System ................................................................................. 12
CHAPTER 3: BASIC OPERATION.................................................... 22 1. Details of Control Panel and Display .......................................... 22 1.1 Details of Control Panel and Display......................................................................... 22 1.2 Details of Manual Combustion Switch (Automatic / Manual Shift Switch) ................. 23 1.3 Details of Alarm Display ............................................................................................ 23
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CHAPTER 4: OPERATION................................................................24 1. Inspection and Preparation before Operation .............................24 1.1 Inspection and Preparation of Boiler and Peripheral Equipment ...............................24 1.2 Inspection of Boiler Body and Accessories................................................................25 1.3 Inspection and Preparation of Feed Water System ...................................................26 1.3.1 Inspection Items........................................................................................26 1.3.2 Flushing of Pipes ......................................................................................27 1.3.3 Air Vent .....................................................................................................27 1.4 Inspection and Preparation of Fuel System...............................................................28 1.4.1 Preliminary Inspection...............................................................................28 1.4.2 Air Vent .....................................................................................................29 1.5 Inspection and Preparation of Burner........................................................................29 1.6 Inspection and Preparation of Electrical System .......................................................30 1.7 Inspection and Preparation of Steam System ...........................................................30
2. Automatic Operation (Normal Operation) ....................................31 2.1 Checking of Control Panel Switches .........................................................................31 2.2 Feeding Water to Boiler.............................................................................................31 2.3 Feeding Water to Boiler by Differential Transmitter ...................................................32 2.3.1 Feeding Water to Differential Transmitter..................................................32 2.4 Starting Combustion with M.D.O.(*)............................................................................34 2.4.1 Combustion with Air Atomization...............................................................34 2.4.2 Control and Checking during Operation (Combustion with Air Atomization)..............................................................................................35 2.4.3 Combustion with Steam Atomization ........................................................35 2.4.4 Control and Checking during Operation (Combustion with Steam Atomization) .............................................................................................35 2.5 Combustion Stop.......................................................................................................36 2.6 Shift from M.D.O. to H.F.O. .......................................................................................36 2.7 Shift from H.F.O. to M.D.O. .......................................................................................37
3. Emergency Operation .................................................................38 3.1 Emergency Combustion Operation ...........................................................................38 3.2 Control and Checking during Operation ....................................................................38 3.3 Restoration to Normal Combustion and Checking of Combustion ...........................38
CHAPTER 5: INSPECTION AND MAINTENANCE ........................... 46 1. List of Inspection Items and Inspection Frequencies .................. 46 1.1 Regular Inspection and Maintenance........................................................................ 47 1.2 Safety Valve .............................................................................................................. 49 1.2.1Internal Structure of Safety Valve .............................................................. 49 1.2.2 Adjustment of Safety Valve....................................................................... 50 1.3 Other Important Inspection Items .............................................................................. 50
2. Daily Inspection and Maintenance .............................................. 51 3. Weekly Inspection and Maintenance .......................................... 52 3.1 Main Burner .............................................................................................................. 52 3.1.1 Overview................................................................................................... 52 3.1.2 Disassembly and Adjustment.................................................................... 52 3.2 Nozzle Tip ................................................................................................................. 53 3.3 Pilot Burner ............................................................................................................... 54 3.3.1 Overview................................................................................................... 54 3.3.2 Disassembly and Adjustment.................................................................... 55 ix
4. Monthly Inspection and Maintenance..........................................55 4.1 Fan ............................................................................................................................55 4.1.1 Overview...................................................................................................55 4.1.2 Regular Maintenance................................................................................56 4.2 Suction Damper (Attachment of Blower) ...................................................................57 4.2.1 Overview...................................................................................................57 4.2.2 Inspection .................................................................................................57 4.2.3 Measures on Failures (Fixing Fully Open State).......................................58 4.3 Fuel Flexible Tube .....................................................................................................59 4.4 Oil Flow Control Valve, Air Flow Controller, and Damper ..........................................59 4.4.1 Overview ...................................................................................................59 4.4.2 Inspection..................................................................................................60 4.5 Control Motor ............................................................................................................61 4.5.1 Overview...................................................................................................61 4.5.2 Inspection .................................................................................................61 4.6 Flame Eye (*)..............................................................................................................62 4.6.1 Overview...................................................................................................62 4.6.2 Inspection and Cleaning ...........................................................................62 4.7 Strainer for Fuel.........................................................................................................63 4.7.1 T-type Auto-cleaner...................................................................................63 4.7.2 Y-type Strainer ..........................................................................................64 4.7.3 Double Strainer.........................................................................................64 4.8 Fuel Oil Pump............................................................................................................66 4.8.1 GFS Type (for Pilot Burner) ......................................................................66 4.8.2 Main Fuel Oil Pump ..................................................................................67 4.8.3 Procedure of Fuel Oil Pump Discharge Pressure Setting .........................67 4.8.4 Circulation Relief Valve .............................................................................69
5. Quarterly Inspection and Maintenance .......................................70 5.1 Inspection and Blow of Boiler Water..........................................................................70 5.2 Equipment around Burner .........................................................................................70 5.2.1 Solenoid Valve ..........................................................................................70 5.2.1-1 Solenoid Valve for Pilot Burner...........................................................71 5.2.1-2 Solenoid Valve for Pneumatic Fuel Shutoff Valve ..............................71 5.2.1-3 Solenoid Valve for Atomized Air .........................................................72 5.2.1-4 Solenoid Valve for Atomized Steam ...................................................73
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5.2.2 Other Equipment ...................................................................................... 74 5.2.2-1 Pneumatic Fuel Shutoff Valve ............................................................ 74 5.2.2-2 Filter Regulator .................................................................................. 75 5.2.2-3 Pressure Reducing Valve................................................................... 76 5.2.2-4 Seal Pot ............................................................................................. 77 5.2.2-5 Equalizing Valve................................................................................. 78 5.3 Fuel Oil Thermostat (for Fuel Oil Heater) .................................................................. 79 5.3.1 Dial Type................................................................................................... 79 5.3.2 RT Type .................................................................................................... 80 5.3.3 Heavy Oil Heating Temperature................................................................ 81 5.4 Pressure Switch (for Steam, Atomized Fluid, and Fuel Oil)....................................... 82 5.4.1 Steam Pressure Switch ............................................................................ 82 5.4.2 Atomized Fluid Pressure Switch ............................................................... 83 5.4.3 Fuel Oil Pressure Switch .......................................................................... 83 5.4.4 Pressure Switch Adjustment Procedure.................................................... 84 5.5 Differential Transmitter .............................................................................................. 85 5.6 Flow Control Valve .................................................................................................... 86 5.7 Operation Check of Each Safety System .................................................................. 87 5.7.1 Ignition Failure Alarm ................................................................................ 87 5.7.2 Fan Abnormal Stop Alarm......................................................................... 87 5.7.3 Flame-out Alarm ....................................................................................... 88 5.7.4 Abnormal Fire Alarm ................................................................................. 88 5.7.5 Low Oil Pressure Alarm ............................................................................ 88 5.7.6 Low Oil Temperature Alarm ...................................................................... 89 5.7.7 High Oil Temperature Alarm...................................................................... 89 5.7.8 Exhaust Gas High Temperature Alarm...................................................... 90 5.7.9 High Steam Pressure Alarm ..................................................................... 90 5.7.10 Low Steam Pressure Alarm .................................................................... 91 5.7.11 Low Water Level Alarm ........................................................................... 91 5.7.12 Low Low Water Level Alarm ................................................................... 91 5.7.13 Power-off Alarm ...................................................................................... 91 5.7.14 Sequencer Error Alarm ........................................................................... 91 5.7.15 Low Atomized Steam Pressure Alarm..................................................... 92 5.7.16 Low Atomized Air Pressure Alarm........................................................... 92 5.7.17 Damper Control Alarm ............................................................................ 92 5.7.18 Operation Check by differential transmitter（Low Water Level, Low Low Water Level, High Water Level） .......................................................... 92 5.7.19 Suction Damper Error Alarm................................................................... 94
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6. Yearly Inspection and Maintenance ............................................95 6.1 Fuel Oil Heater ..........................................................................................................95 6.1.1 Combined Use of Electricity and Steam....................................................95 6.1.2 Solenoid Valve for Steam Heater..............................................................96 6.2 Water Level Gauge and Water Level Detecting Rod .................................................97 6.3 Flame Detector (FS-901)...........................................................................................98
7. Inspection and Maintenance on Vessel Docking.......................100 7.1 Soot Cleaning of Furnace........................................................................................100
8. Parts Information about Replacement.......................................101 8.1 Ignition Transformer (*) .............................................................................................101 8.2 Sequencer (Programmable Controller)....................................................................102 8.2.1 Description of Component Unit of CJ2M.................................................102 8.2.2 Function of Display .................................................................................105 8.2.3 Errors and Countermeasures..................................................................106 8.3 Steam Pressure Regulator ......................................................................................107 8.4 Fuel Oil Temperature Controller ..............................................................................108 8.4.1 Name and Function ................................................................................108 8.4.2 Setting Procedure ...................................................................................108 8.5 Water Level Detector (LM1-200) .............................................................................109 8.6 Water Level Indicator...............................................................................................110
CHAPTER 6: TROUBLE SHOOTING.............................................. 111 1. Feed Water System................................................................................................... 111 2. Fuel System .............................................................................................................. 114 3. Combustion System .................................................................................................. 116 4. Control System..........................................................................................................122 5. Trouble Shooting for Boiler Body...............................................................................123 6. Repairing Damaged Water Tubes .............................................................................124 6.1 Insertion of Stoppers from Inside of Water Drum.................................................124 6.2 Stopper Welding from Combustion Chamber ......................................................125
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CHAPTER 7: STORAGE ................................................................. 126 1. Maintenance When Boiler is Shut Down for a Long Time......... 126 2. Movement or Resale ................................................................. 126 3. Export........................................................................................ 126
CHAPTER 9: GUARANTEE ............................................................ 128 1. Description of Guarantee .......................................................... 128 2. Contact Information for Inquiries about Products and Instruction Manual....................................................................................... 128 3. Sale of Instruction Manual......................................................... 128 4. Sale of Parts.............................................................................. 128
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CHAPTER 1: SAFETY
1. Safety Regulations In sailing in the high seas, observe the Rules and Regulations for the Classification of Ships, the SOLAS Convention, the MARPOL Convention, and other international conventions. Also observe regulations in way ports or the country in which vessel is registered and other applicable regulations.
2. Knowledge and Skill Required for Safe Handling Handling of this boiler includes operating boiler, operating controller for controlling operation of boiler, and maintaining them. Before carrying out work, fully understand this manual. People who satisfy all of following requirements are qualified to handle this boiler. They are called operators.
[Requirements to be satisfied by operators] Those who have received explanation of handling from our service staff during trial operation or those who have received explanation of handling directly from them Those who have thoroughly read instruction manual for this boiler and have full understanding of content Those who have been permitted to handle this boiler by chief engineer Appoint chief operator from among operators.
3. Protective Equipment Do not forget to wear helmet, protection eyewear, safety shoes, safety belts, leather gloves, protective masks, or other appropriate protective equipment when working on device.
4. Prohibition of Remodeling without Permission Remodeling this boiler without consultation with MIURA or repairing it in a way not specified in this manual may seriously affect safety of boiler. Do not remodel or repair boiler on your own.
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5. Use of Specified Fuels Do not use fuel that is not specified with this boiler. Failure to observe this instruction may seriously affect safety of boiler.
6. Warning Labels (*) on Products For safe use of boiler, warning labels are attached on locations where attention to operating precaution is called for. If warning label comes off or tears, replace it with new warning label. For more details about warning labels, contact MIURA offices.
Scald Warning Label:······················ Attached near parts with hazard of scalding or hot parts (Parts with surface temperature of over 60°C). Do not touch surface around this warning label.
Catch Warning Label: ····················· Attached on rotating parts with gaps in structure that could catch fingers (Fingers might get trapped). Do not get close to area near warning label before parts are operated or when they are in operation.
Electric Shock Warning Label:·········· Attached on or around electric equipment that cannot be insulated (or covered) completely. To prevent electrical shock or electric leakage, prevent objects or body from coming in contact with such
Damage Warning Label: ················· Attached on water gauge glass as there is possibility of damage by aged deterioration when it is used for long periods. When deterioration, cracks, or other problems are found, promptly replace part.
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7. Precautions for Safe Handling 7.1 Safety Precautions in Installation In carrying out installation work, observe following safety precautions:
WARNING Secure ventilation (draft) (*) in funnel (exhaust stack) and ensure that exhaust from outlet does not have harmful influence on surrounding environment. (Refer to “1. Safety Regulations.”) In engine room, secure adequate area for air inlet, exhaust outlet, and air supply fan (*). If these are not installed and managed properly, carbon monoxide poisoning due to exhaust gas may be caused. Ensure that ventilation fan, air inlet, and exhaust outlet are installed in engine room. Insufficient air supply or exhaust ventilation may cause carbon monoxide poisoning due to exhaust gas or explosion. Ensure that boiler is not installed in handling place for flammable dangerous substance Instruction
(*)
.Install it on floor made of noncombustible material. Ensure that boiler is more than 45 cm
away from flammable materials. They may ignite due to hot part of boiler to cause fire, resulting in accident involving death. Ignition due to hot part may cause fire. If exhaust stack or steam piping is passed through wall that is made of flammable material, use noncombustible material for fire protection. Water discharged from boiler is extremely hot and may cause burn. Ensure that drainage piping is fixed to prevent it from being forced to move by discharged water and that the end of piping is released into safe place. Connect power supply using cables with specified diameters. Use special wiring breaker. Failure to observe this instruction may cause electrical shock, burn, or other serious accidents. Wiring breaker Breaker capacity
Connect Ground Wire
Wiring
3
Wiring breaker
7.2 Safety Precautions in Pre-operation Inspection and Preparation (Excerpt from page 24-) In pre-operation inspection and preparation, observe following safety precautions:
WARNING Keep flammable materials away from boiler. They may ignite due to hot part of boiler to cause fire, resulting in accident involving death. Prohibition
Do not put flammable materials in control box. They may ignite to cause fire, resulting in accident involving death. If you touch coupling of pump that is spinning rapidly, you may get caught in it. Do not touch
Do Not Touch
coupling of pump during pump operation. Do not operate breaker of main power supply and equipment in control panel with wet hands.
Do Not Touch with Wet Hands
Failure to observe this instruction may cause electrical shock due to high voltage, resulting in injury or death. Check that funnel (exhaust stack) is properly constructed. Gaps, faulty construction, blocked outlet of funnel (exhaust stack), or other problems may cause carbon monoxide poisoning due to exhaust gas or fire. Check for water or oil leaks around boiler related equipment. Switching on or off wet equipment may cause electrical shock or fire from short circuit. Run ventilation (air supply and exhaust equipment) in engine room and check that air vent is not blocked off.
Instruction
If air vent is blocked off, carbon monoxide poisoning due to exhaust gas or explosion may be caused. If you touch hot piping of feed water system, you may suffer burn. Wear protective equipment while working with it. If insulation of piping deteriorates or falls off, repair it. If fuel oil leaks out of system, it may ignite to cause fire, resulting in accident involving death. Check connections of piping and air vent valve for leaks. Dispose of fuel oil leakage and waste cloth used to wipe off oil immediately in an appropriate manner. If you touch hot piping of cascade tank, you may suffer burn. Do not touch tank. Wear protective equipment while working around tank.
Caution: Hot
If you touch hot fuel piping, you may suffer burn. Do not touch fuel piping directly.
CAUTION If fuel oil spill occurs, it may have adverse influence on marine ecosystem. Take measures Instruction
to prevent fuel oil spill and establish method for coping with spillage in advance. 4
7.3 Safety Precautions in Operating Boiler (Excerpt from page 31-) In operating boiler, observe following safety precautions:
WARNING If automatic operation is hindered by parts damage or another reason, remove cause of problem and start automatic operation again. This boiler has manual operation circuit for emergency operation when automatic operation is hindered. Operating error in manual operation mode, in which some safety systems are disabled, may cause accident involving death. Do not use manual operation mode except in emergency. If manual operation circuit must be used for unavoidable reason, follow instructions in this manual. Cases in which automatic operation cannot be continued are as follow: Failure of instrumentation Prohibition
Sequencer trouble Sensor trouble, interlock by abnormality detection In manual operation mode, backfire (*) or other accidents involving death by ignition error or fire by empty heating may be caused. Do not use manual operation mode except in emergency. If manual operation circuit must be used for unavoidable reason, follow instructions in this manual. During manual combustion operation, do not shift fuel (M.D.O. (*) ↔ H.F.O. (*)).Failure to observe this instruction may cause backfire or other accidents involving death. Do not operate breaker of main power supply and equipment in control panel with wet hands.
Do Not Touch with Wet Hands
Failure to observe this instruction may cause electrical shock due to high voltage, resulting in injury or death. If water or steam leaks out of system, burn, blindness, or accidents involving death may be caused. During operation and after operation stop, check connections of piping and air vent valve for leaks. If you touch hot piping of water and steam systems, you may suffer burn. Wear protective equipment while working with it. If insulation of piping deteriorates or falls off, repair it. If fuel oil leaks out of system, it may ignite to cause fire, resulting in accident involving death.
Instruction
Check connections of piping and air vent valve for leaks. Dispose of fuel oil leakage and waste cloth used to wipe off oil immediately in an appropriate manner. Surface temperature of upper part of boiler exceeds 60°C and may cause burn if surface is touched. When working with upper part of boiler, wear gloves and other protective equipment to prevent direct contact. 5
WARNING Perform purge operation sufficiently before ignition and when combustion is stopped. Insufficient purge operation may cause backfire(*) or other accidents involving death. Pre-purge (*) (before ignition): 20 seconds or longer * Post-purge (*) (when combustion is stopped): 60 seconds or longer * Instruction
*In manual operation mode, ignition is not started until sufficient pre-purge lamp is lit after 20-second or longer pre-purge. Switch fuel when boiler is in automatic operation mode. Operating error in manual operation mode may cause backfire or other accidents involving death. In manual operation mode, following interlock functions of safety system are disabled. Improper operation may cause accidents involving death. Be careful with operating boiler in manual operation mode.
Interlock functions disabled when manual combustion circuit is used: Fuel oil pressure low (fuel) Fuel oil temperature high (fuel) Fuel oil temperature low (fuel) Steam pressure high Caution
Steam pressure low Abnormal fire These interlock functions work only when all functions are working properly. When there are problems with sensors or other parts, interlock functions may not work properly. In feed water control by differential transmitter, feed water pump control does not operate properly when feeding water and adjustment of differential transmitter is not completed. Boiler becomes fill with water and high water level, it may cause hot water blow out from safety valve during boiler combustion. If you touch hot piping of cascade tank, you may suffer burn. Do not touch tank. Wear protective equipment while working around tank.
Caution: Hot
If you touch hot fuel piping, you may suffer burn. Do not touch fuel piping directly.
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7.4 Safety Precautions in Bringing Boiler to Emergency Stop (Excerpt from page 44-) In bringing boiler to emergency stop, observe following safety precautions:
DANGER Emergency stop is operation that gives top priority to stopping boiler immediately in emergency. If breakers are turned off inadvertently, feed water and circulation pumps may be stopped to cause soot fire, explosions in furnace, or other accidents. Do not use this function except in emergency. Emergency stop is operation that gives top priority to stopping boiler immediately in emergency. Emergency stop skips safety checks for ongoing operation and may cause Caution
unexpected accident or failure. Use this function only when there is unavoidable reason for bringing boiler to emergency stop. Users must judge when and how boiler should be brought to emergency stop because it depends on situation. When resuming operation after emergency stop, ensure that switches are turned on or off to stop all ancillary equipment before turning power on.
Otherwise, equipment may start to
work unexpectedly to cause accidents.
7.5 Safety Precautions in Inspections and Maintenance (Excerpt from page 46-) In inspections and maintenance, observe following safety precautions:
DANGER Inspect fan once a month. Failure to inspect fan may cause it to break or fly apart due to Instruction
deterioration of impeller or external force, resulting in injury or death.
WARNING Improper adjustment of blow off pressure of safety valve may damage boiler body. As a rule, do not adjust blow off pressure of safety valve. Prohibition
Remodeling of safety valve may damage boiler body. As a rule, do not remodel safety valve. If steam leak from safety valve is found, replace part and repair it immediately. When steam leak is left, function of safety valve is decreased and there is possibility of leading to serious accident
Instruction
Complete purge by fan before burner opening and inspection to make combustion chamber cold and ventilate. Stop fuel oil pump and close main fuel valve of main and pilot burners. Wipe away fuel oil from burner nozzle and flexible tubes immediately and dispose of it properly. 7
WARNING Before moving impeller by hand, turn off main power supply. If impeller is rotated accidentally during maintenance, physical injury may be caused. Inspect suction damper once a month. Failure to inspect suction damper may cause damage of part and malfunction due to looseness of part, resulting in injury or death. Do not give impact to boiler fuel pipe or bend any part of it. Failure to observe this instruction may cause fuel oil leak, resulting in fire. Equipment has been brought into optimum state in trial operation. Do not make changes to state after trial operation. Failure to observe this instruction may cause poor combustion, backfire (*), or other accidents. If changes are made for unavoidable reasons, contact MIURA Instruction
offices and ask for instructions. In order to prevent serious accident, check solenoid valves and valve seats for oil leaks after cleaning, inspecting, or replacing. Before inspection or adjustment, check that there is no internal pressure present. Compressed air or steam may blow out, causing burn or laceration. Equalizing valve has been set at optimum pressure in trial operation, and it is prohibited to change setting as a rule. Failure to observe this instruction may cause poor combustion, backfire (*), or other accidents. If changes are made, contact MIURA offices and ask for instructions. Surface temperature of the top of boiler exceeds 60°C and may cause burn if surface is touched. Take extra care in daily inspection work. Blow valve and sample water (blow water) are hot. When carrying out inspection and maintenance work, wear protective equipment to prevent burn. During inspection work, hot steam may blow out to cause burn. Be careful when operating
Caution
valves. Before wiring work, be sure to turn control panel power off. Failure to observe this instruction may cause electrical shock due to high voltage, resulting in injury or death. Do not pull out lead wire with wet hands. Failure to observe this instruction may cause electrical shock due to high voltage, resulting in injury or death.
CAUTION When cleaning strainer or performing other work using oil, wear protective equipment to protect eyes and body from splashes of oil. This adjustment is also needed when fuel oil pump is replaced. Adjust pressure regulating Instruction
valve in burner piping unit after discharge pressure of fuel oil pump is adjusted. Fuel oil pump is deteriorated over time and its performance is gradually declined.
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CAUTION Improper spray volume, spray angle, and spray form cause poor combustion and sometimes Caution
cause backfire. Use only genuine parts.
7.6 Safety Precautions in Replacing Parts (Excerpt from page 101-) In replacing parts, observe following safety precautions:
WARNING Ignition transformer (*) conducts high voltage. Touching live wiring may cause electrical shock. Turn power off before working with ignition transformer. Instruction
Do not make changes to state after trial operation. Failure to observe this instruction may cause poor combustion, backfire (*), or other accidents.
CAUTION Improper setting of water level may damage boiler body. Do not change setting from trial operation. Instruction
Do not change internal parameters. Improper setting of water level may damage boiler body.
7.7 Safety Precautions in Working on Failures (Excerpt from page 111-) In working on failures, observe following safety precautions:
WARNING Stopper treatment and furnace building with refractory is temporary treatment. Do not operate for a long time; otherwise, there is possibility of serious accident. Contact each classification in advance and replace water tubes (or body) immediately at periodical inspection. Contact with MIURA offices about replacement of water tubes (or body). Instruction
Before inspecting interior, stop main engine. Purge with the bottom blow and fan, and cool both the inside of drum and combustion chamber. Then make sure that pressure inside the drum is 0 MPa. Also, make sure ventilation is provided by air duct and/or the ventilator fan during inspection.
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CAUTION Before working on water tube leaks, check water tubes and burner funnel that may be touched are fully cooled. Otherwise, you may suffer from burn. For more information, Caution: Hot
contact with MIURA offices.
7.8 Safety Precautions in Storage Work (Excerpt from page 126-) In storage work, observe following safety precautions:
WARNING Do not perform installation work and connection of incidental equipment unless it is specified. Prohibition
Failure to observe this instruction may cause physical injury.
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CHAPTER 2: OVERVIEW
1. Features of Product 1.1 Functions and Operating Principle 1.1.1 Functions This boiler burns fuel oil and collects resultant heat to provide high-temperature, high-pressure steam.
1.1.2 Operating Principle Feed water is pressurized by feed water pump and supplied to upper drum. Water that is fed to upper drum is loaded into boiler body (upper drum, water tubes, and lower drum). Heat to generate steam comes from combustion heat by burner. Fuel oil heated and pressurized by fuel oil pump unit to right temperature and pressure, respectively, is supplied to burner. Boiler employs two-fluid burner that uses atomized fluid (steam or compressed air) to atomize fuel oil and combines atomized particles with air supplied by fan to cause combustion. Water in water tubes is heated by combustion heat from burner into gas-liquid phase, which rises to upper drum. Liquid phase in water tubes without thermal load drops down to lower drum. This series of actions causes natural circulation inside boiler body and allows heat recovery. Steam generated in drum is subjected to steam separation to obtain saturated steam, which is supplied to load side through main steam valve.
1.2 Product Components This boiler consists of boiler body and following units: Boiler body Feed water pump (including feed water strainer and valves) Fuel oil pump unit Control panel Fan *This is standard configuration. For details about configuration of product that is delivered, refer to final drawing. 11
2. Water and Steam Supply Flow Typical flow for this boiler is described here. Actual flow may be different from flow described here, depending on specifications. Check pipe system diagram in final drawing before use.
2.1 Water and Steam Pipe System Water in system is supplied to boiler body by feed water pump. Water sent to boiler is heated by combustion heat into high-temperature, high-pressure steam. Generated steam is supplied to load side and used as a heat source.
Figure 2-1 Water and Steam Pipe System Diagram (Example)
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3. Fuel Supply Flow Typical flow for fuel pipe system of this boiler is described here. Actual flow may be different from flow described here, depending on specification. For details about flow for product that is delivered, refer to pipe system diagram in final drawing.
3.1 Fuel Pipe System
F.O. TANK F.O. TANK
D.O. TANK D.O. TANK
Figure 2-2 Fuel Pipe System Diagram (H.F.O.(*)) a) All solenoid valves (SV-1 to SV-4) are closed when operation is stopped. When operation is started and main fuel (*) oil pump (M-2) is brought into operation, fuel oil is circulated throughout fuel pipe system leading back to oil air separator (*) via circulation relief valve (RV) and is heated by heater. b) When H.F.O. is heated and pre-purge (*) is performed, solenoid valve for atomized fluid (SV-2) is opened. When pre-purge is completed, pilot fuel oil pump (M-4), ignition transformer(*), and solenoid valve for pilot burner (SV-1) are started to form pilot flame(*). c) When flame eye (*) detects pilot flame, solenoid valve for air-driven valve (SV-3) is started to open air-driven valve (AC-1), allowing main burner and pilot burner to form mixed flame. After mixed flame is formed, solenoid valve for pilot burner (SV-1) is shut off to put out pilot flame, and flame from main burner is formed. d) While combustion is continued, pressurized fuel oil is still circulated throughout fuel pipe system via circulation relief valve (RV) to keep fuel oil temperature and oil pressure stable. 13
4. Basic Specifications Table 2-1 lists specifications of different types of boilers and different capacities. Specifications may be different from those listed here, depending on special order requirements. For detailed specifications of product that is delivered, refer to list of principle items on final drawing. Table 2-1 Basic Specifications of HB-T Type Boiler HB-08T
Model Max. Design Press. Heating Surface Area Actual Evaporation Water 60°C Steam 0.69 MPa
Net Heat Output
HB-12T
MPa
HB-15T
HB-18T
HB-20T
1.0
m2
104
115.5
131.6
kg/h
8,000
10,000
12,000
15,000
18,000
20,000
kW
5,580
6,980
8,380
10,470
12,570
13,970
kcal/ h
4,806,800
6,008,500
7,210,200
9,012,750
10,815,300
12,017,000
-
Fuel Oil
HB-10T
184.2
224.6
Heavy Fuel Oil: Up To 380 cSt (at 50 °C)
kg/h
578
722
866
1,082
1,299
1,444
Installed Electric Capacity
kW
62.5
65.5
77.5
96
121
124.5
Type
-
Steam Atomizing Type
-
High Voltage Spark System
-
Flame Eye Type
Ignition System Flame Detector Capacity
m3/h
Pressure
MPa
Motor
1.41
2.4 1.5
kW
2.2
3.7
m3/min
160
200
240
300
Motor
kW
30
37
45
55
-
Type
kW
17
Capacity
m3/h
12
Pressure
MPa
0.98
Electric Power
Motor
Control System
360
395 75
Electric Heater With Steam
F.O. Heater
Capacity
Feed Water Pump
Fan
F.O. Pump
Burner
Fuel Consumption
kW
13
17 14
20
25
18
22
23
1.08 11
-
15
18.5
Proportional Control
Boiler Weight(Dry)
kg
14,200
17,300
18,000
21,600
23,500
Normal Weight of Boiler Water
kg
5,020
6,650
6,890
8,200
9,170
Note 1: Power supply is 60Hz, 3 AC 220V or 440V. Note 2: H.F.O.(*) with low calorific value of 41,000 kJ/kg (9,800 kcal/kg) is used. 14
5. Part Names and Functions Part names and functions are described here. Appearance and layout depend on type and capacity. For details of product that is delivered, refer to final drawing. (1) Main steam valve Valve to supply steam to load side (2) Burner Equipment to burn fuel and to generate heat source (3) Water level gauge Equipment that indicates water level of boiler (4) Boiler water sampling valve Valve to sample boiler water (5) Manhole (upper) This manhole is used to inspect and clean boiler and water tubes. (6) Surface blow valve Valve to discharge concentrated boiler water around evaporation surface (7) Funnel flange Outlet of exhaust gas generated by combustion of heavy oil (leading to funnel) (8) Fan * 1 Equipment to send burner air for combustion (9) Control panel * 1 Equipment to operate boiler (10) Fuel oil pump unit * 1 Equipment to pressurize and heat fuel and send it to burner (11) Manhole (lower) Same as (5) (12) Bottom blow valve Valve to discharge concentrated boiler water (including sludge) (13) Steam pressure gauge unit *2 Unit of boiler pressure gauge and pressure switches for combustion control
5.1 Boiler Body
Figure 2-3 External View of Boiler
No
Part name
No
1
Main steam valve
8
Fan
2
Burner
9
Control panel
3
Water level gauge
10
Fuel oil pump unit
11
Manhole (lower)
12
Bottom blow valve
4 5 6 7
Boiler water sampling valve Manhole (upper) Surface blow valve
13
Part name
*1: Equipment installed separately from boiler. Installed into a unit here just for simplicity of illustration. *2: Equipment installed separately from boiler for standard specifications. Depending on specifications, it can be provided as part of boiler.
Steam pressure gauge unit
Funnel flange
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5.2 Burner and Burner Piping Structure
Figure 2-5 Structural Diagram of Burner Piping
Figure 2-4 Structural Diagram of Burner
1
Oil flow control valve
11
Atomized steam valve
2
Pneumatic fuel shutoff valve
12
Pressure reducing valve
3
Circulation relief valve
13
Solenoid valve for atomized steam
4
Emergency fuel switch valve (main)
14
Seal pot
5
Emergency fuel switch valve (pilot)
15
Equalizing valve
6
Solenoid valve for pilot burner
16
Cock for equalizing valve oil detection
7
Filter regulator
17
Main burner ASSY
8
Solenoid valve for fuel shutoff valve
18
Main baffle plate
9
Atomized air valve
19
Pilot burner ASSY
10
Solenoid valve for atomized air
20
Inner cylinder
16
5.3 Internal Structure of Boiler Body Burner Wind box
Stay Upper drum Heat insulator Expansion ring Inner casing Water tube
Castable Outer casing
Funnel flange
Lower drum
Figure 2-6 Internal Structure of Boiler Body
Combustion chamber
Funnel
Figure 2-7 Water Tube Arrangement
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Boiler consists of doughnut shaped upper drum and lower drum that are connected through water tubes. Water tubes with narrow ends are arranged as shown Figure 2-7. Combustion gas flows in two directions as shown by arrows and meets again at exit to be discharged from funnel. While water in innermost water tubes is subjected to flame, other water tubes are subjected to combustion gas that passes through them. This allows efficient transfer of heat to water. Casing consists of welded inner casing and outer casing. Heat insulating material is placed between water tubes and inner and outer casing to restrict radiation of heat. Inner lower part of furnace and narrow end part of water tubes are insulated with castable to prevent short path of combustion gas. Upper and lower drums have manhole to check inside. Check condition of scaling, corrosion, pitching on tubes, and reflect results in boiler water treatment (For more details, refer to Manual for Water Treatment). At furnace inspection, check for soot adherence, peeling of castable, fuel leakage on furnace bottom, traces of water leakage and accumulations of unburnable materials.
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6. Boiler Automatic Operation by Sequencer 6.1 Overview Sequence control is automatic control that completes each control step following procedure that is provided in advance. This boiler starts fuel oil pump and fan operation, and after pre purge is completed sufficiently, ignition device is started; after fuel valve is opened to ignite burner, start-stop of burner is controlled by steam pressure switch. These steps are carried out automatically.
6.2 Flowchart Figure 2-8 shows flowchart of basic operation of boiler; actual flow may be different depending on specifications.
Fuel oil SWONON 燃焼SW
ボイラ運転 Boiler operation （燃焼モード） (Combustion mode) 表示灯点灯 Indicator lump on NO
When alarm is started, reset after combustion intercepted.
Combustion 燃焼要求あり is requested. YES
送風機運転 Fan operation
Ignition 点火トランス作動 transformer on
プ レ パ ー ｜ ジ 20 秒
Pre-purge (20 sec.)
警 報 発 生 時 燃 焼 遮 断 後 リ セ ッ ト 操 作 へ
リセット操作 Reset
Pilot solenoid valve パイロット電磁弁開 open
Flame 炎センサ censor 炎検出 Flame Detector
NO
Misfire alarm 不着火警報報知 Ignition transformer off 点火トランス停止 Pilot solenoid valve close パイロット電磁弁閉 Boiler operation lamp off ボイラ運転表示灯消灯
YES
Combustion lamp 燃焼表示灯点灯 on
(A) イ
(B) ロ Figure 2-8 Flowchart of Basic Operation
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(A) イ
(B) ロ
When alarm is started, reset after combustion intercepted.
Combustion solenoid 燃焼電磁弁開 valve open
Ignition transformer 点火トランス停止 stopped. パイロット電磁弁閉
Pilot solenoid valve close.
警 報 発 生 時 燃 焼 遮 断 後 リ セ ッ ト 操 作 へ
Proportional control combustion 比例燃焼 (Low combustion is continued for 30 （状態移行初期30秒間 seconds after combustion is は低負荷燃焼を継続） entered.)
YES
Combustion 燃焼要求ありis requested.
NO
Solenoid valve close. 電磁弁閉 Combustion lamp off 燃焼表示灯消灯
Post-purge 35S ポストパージ35秒 Fan stopped 送風機停止
Figure 2-8 Flowchart of Basic Operation (Continued)
Note When alarm lamp related to burner interlock lights up, automatic recovery does not take place. Be sure to perform reset operation.
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6.3 Operation Explanation of Steam Pressure Control 6.3.1 Proportional Control Steam pressure regulator installed on control panel controls boiler burner and adjusts steam pressure.
Sample settings of steam pressure regulator
Boiler steam pressure Higher pressure limit
Normal working pressure Lower pressure limit
Time
a) For 30 seconds after ignition, low combustion (20% load) is kept not to put boiler under heavy load. 30 seconds later, boiler is held under proportional control so that normal working pressure can be kept in response to changes in steam pressure. b)
When steam consumption is lowered and boiler steam pressure is increased to reach higher pressure limit, burner is stopped and post-purge(*) is performed.
c)
When boiler steam pressure is decreased to lower pressure limit, combustion is started again under proportional control so that normal working pressure is kept.
*1:
At start of operation, atomized air is used (with M.D.O.(*)) to increase boiler steam pressure to 0.7 MPa. Refer to page 34 “2.4 Starting Combustion with M.D.O” in Chapter 4.
Note When air is used as atomized fluid, only M.D.O. can be used as fuel, and proportional control cannot be used. (Forced low fire)
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CHAPTER 3: BASIC OPERATION 1.Details of Control Panel and Display Layout and functions of control panel and display are described here. Actual layout and functions may be different from those described here, depending on specifications. For details about layout of control panel and display, refer to external view of control panel in final drawings.
1.1 Details of Control Panel and Display Water level indicator
Control equipment for opens and closes flow control valve depending on signal from differential transmitter.
Alarm display
Ammeter (fan)
Alarm lamps blink or light up to warn of failures. Ammeter (fan)
It indicates current value of fan. Steam pressure regulator Control equipment for proportional combustion control based on boiler steam pressure.
It indicates current value of fan.
Boiler operation (COM MODE) lamp
Atomized fluid selection switch
Lamp is on when combustion switch is on. Combustion lamp
This switch can be used to switch atomized fluid between air and steam.
Buzzer stop switch
Lamp is on when combustion is continued.
When alarm is started, this switch can be pressed to stop buzzer.
Combustion switch
Alarm reset switch This switch can be pressed to reset alarm.
Pressing this switch allows boiler to start combustion. Combustion stop switch
Fuel heater switch
Pressing this switch allows boiler to stop combustion.
This switch can be used to switch by fuel oil type.When it is switched to A, fuel heater is stopped.When it is switched to C, low oil temperature alarm function is enabled.When it is switched to A, fuel heater is stopped.
Booster pump operation lamp
Lamp test switch
This lamp lights up when booster pump is in operation. Booster pump operation switch
This switch can be used to check lamps on display. When switch is pressed, all the indicator lamps are lit.
Turning this switch on starts booster pump.
Fuel oil pump selection switch This switch can be used to switch main fuel oil pump between No. 1 and No. 2.
Manual combustion control part Combustion changeover switch Manual combustion switch
This switch can be used during manual combustion to switch between low combustion and proportional combustion control.
Auxiliary equipment is started operation by cam switch turning.The ignition transformer is not started until pre-purge time elapses. For automatic combustion, set cam at AUTO.
Pre-purge completion lamp This lamp lights up when operation time of fan exceeds set time in manual operation. When sufficient pre-purge lamp lights up, ignition transformer for manual operation is started.
Figure 3-1 Layout and Functions of Control Panel and Display
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1.2 Details of Manual Combustion Switch (Automatic / Manual Shift Switch) Ignition transformer (pilot burner) is started. It is not started until operation time of fan exceeds pre-purge time. If switch is shifted to IGNITION position before pre-purge time elapses, ignition transformer (pilot burner) remains stopped.
Ignition transformer (pilot burner) is stopped. Combustion with main burner alone is continued. When combustion lamp is off, close combustion solenoid valve. When combustion lamp is turned off, immediately shift switch back to FAN RUNNING position and perform purge for 60 seconds or longer. Starting combustion without sufficient purge may cause fire or an explosion.
All equipment is stopped. Some self-diagnosis functions are also stopped. Shifting switch to this position enables with ON. Fuel oil pump and fuel oil heater are started. (When selecting C. A/C) Some self-diagnosis functions are enabled.
Figure 3-2 Manual Combustion Switch
Note Do not use manual combustion switch except emergency.
1.3 Details of Alarm Display
Circles (O) in the figure represent (red) indicator lamps.
Figure 3-3 Details of Alarm Display
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CHAPTER 4: OPERATION
1. Inspection and Preparation before Operation 1.1 Inspection and Preparation of Boiler and Peripheral Equipment Before starting operation, check followings:
WARNING Keep flammable materials away from boiler. They may ignite due to hot part of boiler to cause fire, resulting in accident involving death. Prohibition
Do not put flammable materials in control box. They may ignite to cause fire, resulting in accident involving death. Check that funnel (exhaust stack) is properly constructed. Gaps, faulty construction, blocked outlet of funnel (exhaust stack), or other problems may cause carbon monoxide poisoning due to exhaust gas or fire. Check for water or oil leaks around boiler related equipment. Switching on or off wet equipment may cause electrical shock or fire from a short circuit.
Instruction
Run ventilation (air supply and exhaust equipment) in engine room and check that air vent is not blocked off. If air vent is blocked off, carbon monoxide poisoning due to exhaust gas or explosion may be caused.
a) Check that funnel (exhaust stack) has been properly constructed. If problem is found with funnel, do not operate boiler. Restore funnel (exhaust stack) to normal state. b) Check for water or oil leaks around boiler. If leak is found, do not operate boiler. Turn off breaker of main power supply. Remove cause of leak and dry the area completely. c) Check where air inlet of engine room is and check that ventilation (air supply and exhaust equipment) is working. If engine room does not have air inlet, provide air inlet. If air supply and exhaust equipment is stopped, bring it into operation.
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d) Check that there are no flammable materials around boiler. If flammable materials are found, remove them to safe place where flame is not used. Improper storage of cloth stained with fuel or oil may cause it to ignite spontaneously. Handle such materials carefully and dispose of them properly. Wipe up spilt oil immediately. e) Check where fire extinguishing system and first-aid kit are placed. If these are not available, put them in place. f) Check that contact numbers in case of fire or accident and how to handle such emergencies have been established. g) Check that there are no obstacles around boiler and in walkways. If obstacles are found, put them back in place. h) Check that air pressure in engine room is positive. If air pressure in engine room is negative, install additional ventilator.
1.2 Inspection of Boiler Body and Accessories a) Check equipment, inspection holes, covers, valves, and connections for water leaks. If leak is found, fasten part or install it again to make it watertight. b) Check that valves are opened and closed properly. Check that outlet and inlet valves are opened. Check that air vent valve is closed. c) Check that drain pipe of safety valve is installed in safe place. Check that wiring for operation of safety valves’ lever is operated normally. d) Check that water level gauge glass is not stained and not damaged.
e) Check that needles of pressure gauges work properly. When pumps are stopped, they are under head pressure only. For details about inspection items, refer to page 47 “1.1 Regular Inspection and Maintenance” in Chapter 5.
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1.3 Inspection and Preparation of Feed Water System
WARNING If you touch coupling of pump, which is spinning rapidly, you may get caught in it. Do not Do Not Touch
touch coupling of pump during pump operation. If you touch hot piping of feed water system, you may suffer burn. Wear protective
Instruction
equipment while working with it. If insulation of piping deteriorates or falls off, repair it. If you touch hot piping of cascade tank, you may suffer burn. Do not touch tank. Wear
Caution: Hot
protective equipment while working around tank.
1.3.1 Inspection Items a) Check that cascade tank contains sufficient amount of water. b) Check that feed water is clean. c) Check that oil has not gotten into feed water (Use observation measure to check that oil has not gotten into feed water). d) Check that automatic feed water valve (ball tap) works properly. e) Check that valves on feed water line are opened and closed properly. Check that all valves on feed water line of feed water pump in use are opened. (Check that opening instruction of flow control valve is proper.) Check that feed water pump in use matches switch number in control panel. f) Check pipes for clogging, air inclusion, leaks, or loose connections. g) Check that strainer on suction side is not clogged. h) Check that seal of feed water pump has no leaks. i) Check that needles of pressure gauge and compound gauge work properly. j) Check chloride ion concentration of water in cascade tank (once a week). For more details, refer to Manual for Water Treatment.
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1.3.2 Flushing of Pipes Note Following preparation procedure is needed when boiler is used for the first time or when pipe system is repaired. There may remain in pipes welding chips, rust or other foreign matters that may have bad influence on feed water. Before feeding water, flush pipes with treated water or pressurized gas as needed. Whether flushing is needed or not depends on how pipes have been constructed. Before flushing pipes, consult with constructor about procedure and safety precautions.
1.3.3 Air Vent Note Following preparation procedure is needed when boiler is used for the first time or when pipe system is repaired. Let out air of pipes on suction side. Air remaining in pipes may cause cavitation, resulting in damage of pump. Prepare for operation of feed water pump according to instruction manual for feed water pump.
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1.4 Inspection and Preparation of Fuel System
WARNING If fuel oil leaks out of system, it may ignite to cause fire, resulting in accident involving death. Check connections of piping and air vent valve for leaks. Dispose of fuel oil leakage Instruction
and waste cloth used to wipe off oil immediately in an appropriate manner. If you touch hot fuel piping, you may suffer burn. Do not touch fuel piping directly.
Caution: Hot
CAUTION If fuel oil spill occurs, it may have adverse influence on marine ecosystem. Take measures Instruction
to prevent fuel oil spill and establish method for coping with spillage in advance.
1.4.1 Preliminary Inspection a) Check that F.O. service tank contains specified fuel. b) Check that F.O. service tank is heated moderately. When H.F.O. (*) is used, heat it so that temperature reaches over 65°C at main fuel pump inlet. c) Discharge drainage from F.O. service tank. d) Check valves open-close condition on fuel piping between F.O. service tank and boiler. Open all valves on supply line. Close all air vent valves. e) Check that there are no pipes clogging, loose connections, or fuel leaks. Especially, check the top of boiler carefully because burner is often removed for inspections. f) Check that pipe system has no place where air tends to build up. g) Check fuel strainer has no clogging. h) Check that fuel is supplied properly from service tanks to fuel oil pump. If problems are found or fuel is not supplied properly, check whether or not booster pump is working properly. i) Check that needles of pressure gauges and thermometers are working properly.
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1.4.2 Air Vent a) Open valves of fuel system. b) Open strainer air vent valve to remove air. c) Close air vent valve after removing air. Remove air for both main and pilot.
To F.O. Tank or D.O. Tank
d) Close valve V-1 in Figure 4-1.Check that drain valve V-2 is closed. e) Shift manual combustion switch to AUTO COMB.
Oil air separator
From burner
position. Main fuel oil pump starts running. Check that main fuel oil pump motor is running in right direction with no abnormal noise. f) Open drain valve V-2 and remove air sufficiently. g) Check fuel system for leaks. If leak is found, immediately stop fuel oil pump to stop
Figure 4-1 Valves around Oil Air Separator (*)
leak. h) Check in fuel oil temperature controller that fuel is heated to right temperature. Refer to page 108 “8.4 Fuel Oil Temperature Controller” in Chapter 5.
1.5 Inspection and Preparation of Burner a) Check that ignition rod is clean and parts size is normal. b) Check that pilot nozzle tip and main burner nozzle are not clogged. c) Check that flame eye (*) and glass are clean. d) Check that lead wire is installed properly between ignition transformer (*) and ignition rod. e) Check that screws, levers, lock nuts, and other parts of damper are not loosened. f) Check that equipment around burner is installed properly. g) Check that there is no fallen object (insulation materials, castable, etc.) in furnace. h) Check furnace for boiler water or traces of fuel oil leaks. i) Check that inner cylinder is not damaged. j)) Check generating tubes for heavy soil, wastage, or pinholes. k) Check that atomized air pressure is between 0.6 MPa and 0.9 MPa.
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1.6 Inspection and Preparation of Electrical System
WARNING Do not operate breaker of main power supply and equipment in control panel with wet hands. Do Not Touch with Wet Hands
Failure to observe this instruction may cause electrical shock due to high voltage, resulting in injury or death.
a) Check that motors of fun, feed water pump, fuel oil pump, and other equipment run properly in right direction. b) Check that thermostats (exhaust gas, fuel oil heater (*), etc.), fuel oil temperature controller, and pressure switch are set properly (Check setting values in list of principle items in final drawings). c) Check that control panel is not damaged and that each equipment is installed properly. d) Check for broken wires, loose screws, or damaged lamps or switches. e) Check that power supply is as specified in list of principle items in final drawings. f) Check external wiring of each equipment for broken wires or other problems.
1.7 Inspection and Preparation of Steam System a) Check that valves on boiler and on steam piping are opened and closed properly. b) Check that valves on boiler and on piping are installed properly. If loose connections or other problems are found, retighten that part or install it again to bring it back to normal condition. c) Check that outboard valve for boiler water blow is closed. d) Check that cooling water is circulating throughout drain cooler. e) Check that excess steam dump valve is installed and set to specified pressure.
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2. Automatic Operation (Normal Operation)
WARNING Do not operate breaker of main power supply and equipment in control panel with wet hands. Do Not Touch with Wet Hands
Failure to observe this instruction may cause electrical shock due to high voltage, resulting in injury or death. If water or steam leaks out of system, burn, blindness, or accidents involving death may be caused. During operation and after stop, check connections of piping and air vent valve for leaks. If you touch hot piping of water and steam system, you may suffer burn. Wear protective equipment while working with it. If insulation of piping deteriorates or falls off, repair it. If fuel oil leaks out of system, it may ignite to cause fire, resulting in accident involving death. Check connections of piping and air vent valve for leaks. Dispose of fuel oil leakage
Instruction
and waste cloth used to wipe off oil immediately in an appropriate manner. Surface temperature of upper part of boiler exceeds 60°C and may cause burn if surface is touched. When working with upper part of boiler, wear gloves and other protective equipment to prevent direct contact. Switch fuel when boiler is in automatic operation mode. Operating error in manual operation mode may cause backfire(*) or other accidents involving death. If you touch hot piping of cascade tank, you may suffer burn. Do not touch tank. Wear protective equipment while working around tank.
Caution: Hot
If you touch hot fuel piping, you may suffer burn. Do not touch fuel piping directly.
2.1 Checking of Control Panel Switches Check that all switches on control panel are set at OFF position. If switch is not set at OFF, shift it to OFF position.
2.2 Feeding Water to Boiler Before starting burner, feed water to boiler according to following procedure: a) Open all valves from cascade tank to boiler. b) Turn on boiler power supply. c) Set feed water shift switch to AUTO and select pump to operate by feed water pump shift switch. d) Turn on feed water pump start switch. Operation indicator lamp of feed water pump lights up. Buzzer of low low water level sounds. Press buzzer stop switch. Check feed water pump and motor for abnormal noise or abnormal heating. 31
e) Check compound and pressure gauges on inlet and outlet of feed water pump. f) Check in water level gauge that water supply is stopped at right level. Check that water level gauge is cleaned and easy to read. If it is dirty and difficult to read, clean it. g) Check pipe system for water leaks. h) Press alarm reset switch and check that low low water level lamp is turned off.
2.3 Feeding Water to Boiler by Differential Transmitter
CAUTION In feed water control by differential transmitter, feed water pump control does not operate properly when feeding water and adjustment of differential transmitter is not completed. Caution
Boiler becomes fill with water and high water level, it may cause hot water blow out from safety valve during boiler combustion.
Note Supply water to differential transmitter when pressure of boiler body is atmospheric pressure and temperature of water is normal. Feeding water to differential transmitter under high temperature and high pressure may cause damage of differential transmitter. Set feed water shift switch to AUTO after feeding water to piping of differential transmitter and close bypass valve of manifold valve. In case that feed water pump is operated before adjustment, feed water pump is not stopped until high water level. Stop feed water pump manually.
2.3.1 Feeding Water to Differential Transmitter Before feeding water to differential transmitter, flush pipes. Recommend procedure is described below. Start operation when close all valve and plug.
a）Check that all manifold valve of differential transmitter is closed. Feed water to boiler manually to upper level of root valve for low pressure side (position above middle of water level gauge) Open root valve for low pressure and drain valve of low pressure side piping when water is accumulated. Blow low pressure side piping until drain water is not dirty. b）When drain water is not dirty, open all manifold valves, and close drain valve of low pressure side. Open drain valve of high pressure side piping. Take off plug of air vent valve of seal pot, and open air vent valve. Blow high pressure side piping.
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c）When drain water is not dirty, close manifold valve (bypass valve). Supply water from air vent valve of seal pot. Or feed water to seal pot after raising water level of boiler and opening root valve for high pressure side. Continue to blow high pressure side piping. Note Select feed water from air vent valve of seal pot in case it can’t blow from high water level to return to normal water level.
d）When drain water is not dirty, close drain valve of high pressure side pipng. e）Accumulate water to air vent valve of seal pot. Open root valve for high pressure side in case of feed water to boiler from air vent valve. Stop supplying water and close air vent valve and install plug. Close air vent valve and install plug in case that feed water from boiler. And blow to boiler normal water level. f）Feeding water of differential transmitter is completed in above procedure.
Figure 4-2 Reference piping layout of differential transmitter(Remote level gauge）
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2.4 Starting Combustion with M.D.O. (*) Note When H.F.O (*) is used as main fuel (*), switch main fuel to M.D.O. in advance for cold start. If H.F.O is used in cold start, poor combustion or failure of fuel oil pump may be caused. Similarly, before stop operation, switch to M.D.O. in advance if it is expected that fuel oil pump will not be used for a long period of time.
2.4.1 Combustion with Air Atomization a) Close air vent valve of oil air separator (*). b) Open and close return lines of booster pump leading to D.O. tank and to F.O. tank, respectively. c) Open D.O. tank valve and close F.O. tank valve. d) Open outlet and inlet valves of booster pump and start booster pump. As for use of booster pump with M.D.O. combustion, follow rules of vessel. e) Open compressed air valve and check that pressure is between 0.6 MPa and 0.9 MPa. f) Shift fuel oil heater (*) switch to A position. g) Shift atomized fluid selection switch to AIR position. h) Close main steam valve and atomized steam valve and open atomized air valve. i) Open emergency fuel switch valve on main side and close emergency fuel switch valve on pilot side. j) Check that filter regulator pressure is set at 0.4 MPa. k) Select pump to be used by fuel oil pump selection switch. Check that outlet and inlet valves of fuel oil pump to be used are opened and closed properly. l) Shift manual combustion switch on AUTO COMB. position. m) Press combustion switch. After fan starts running and pre-purge (*) is completed, combustion operation is started. Several seconds later, combustion is started and combustion lamp lights up. Check fuel oil pump and fan for abnormal noise.
34
2.4.2 Control and Checking during Operation (Combustion with Air Atomization) After combustion is started, check that boiler is in normal operation. Check that fuel flow amount, fuel oil pump discharge pressure, damper opening, and current are not different substantially from those recorded on trial operation report. Check that color, expansion, and stability of flame are the same as usual. Check color of smoke (black) and check for any gas leakage from its path. Check for vibration or abnormal noise. If any problem is found, stop combustion and remove cause of problem. Check fuel pipe system for fuel leaks. Check that needles of pressure gauges do not jump. 2.4.3 Combustion with Steam Atomization a) Check that boiler steam pressure is 0.7 MPa or above.If it is below 0.7 MPa, increase steam pressure by combustion with air atomization. b) Close atomized air valve and open atomized steam valve and valve on boiler body for atomized steam. c) Shift atomized fluid selection switch to STEAM position. d) Check that main steam valve is closed. e) Check that emergency fuel switch valve on main side is opened and emergency fuel switch valve on pilot side is closed. f) Check that filter regulator pressure is set at 0.4 MPa. g) Select pump to be used by fuel oil pump selection switch. Check that outlet and inlet valves of fuel oil pump to be used are opened and closed properly. h) Check that manual combustion switch is set at AUTO.COMB. i) Press combustion switch. After fan starts running and pre-purge (*) is completed, combustion operation is started. Several seconds later, combustion is started and combustion lamp lights up. Check fuel oil pump and fan for abnormal noise. Check that after about 30-second low combustion, proportional control combustion based on steam pressure is started. 2.4.4 Control and Checking during Operation (Combustion with Steam Atomization) a) Check that boiler is in normal operation. Refer to “2.4.2 Control and Checking during Operation (Combustion with Air Atomization)” in Chapter 4. b) Check that when steam pressure increases and reaches max. design pressure, combustion is automatically stopped. Main fuel oil pump is stopped. After about 35-second post-purge (*), fun stops running. 35
c) Open main steam valve gradually to send air to steam system. Check steam system for leaks.
2.5 Combustion Stop Press combustion stop switch. Main fuel oil pump is stopped. (When H.F.O.(*) is used, it continues to operate.) After about 35-second post-purge (*), fun stops running. ○ Blow of boiler through surface, bottom and of water level gauge ○ Closing valves of feed water system and fuel system
Note When switching fuel from M.D.O.(*) to H.F.O., check that boiler steam pressure is 0.7 MPa or above, and then close mail steam valve and stop combustion.
2.6 Shift from M.D.O. to H.F.O. a) Operate boiler with M.D.O. properly. b) Heat F.O. service tank to proper temperature (between 80°C and 90°C). Heat tank so that temperature reaches over 65°C at main fuel oil pump inlet. c) According to procedure in 2.4, stop boiler and F.O. booster pump. d) Open and close return lines of booster pump leading to F.O. tank and to D.O. tank, respectively. e) Open F.O. tank valve and close D.O. tank valve. f) Run booster pump. Check that heated H.F.O. is flowing through return lines of booster pump. g) Shift manual combustion switch to AUTO.COMB position. h) Press combustion switch. Main fuel oil pump is started. After fan starts running and pre-purge (*) is completed, combustion operation is started. Several seconds later, combustion is started and combustion lamp lights up. Check fuel oil pump and fan for abnormal noise. Check that after about 30-second low combustion, proportional control combustion based on steam pressure is started. i) Shift fuel oil heater (*) switch to A/C position. Note When fuel oil heater switch is shifted to A/C position, fuel oil heater is turned on with low oil temperature alarm function disabled. 36
j) Adjust opening of air vent valve of oil air separator (*). Adjust opening according to combustion state. k) Open steam trace valve of boiler fuel oil pipe. l) When indication of fuel oil heater (*) temperature controller reaches setting value (refer to page 78 “5.3.3 Heavy Oil Heating Temperature” in Chapter 5.), and pressure is settled, slightly open drain valve on fuel return line of oil air separator and visually check that oil has been fully replaced. m) Shift fuel oil heater switch from A/C position to C position. Low oil temperature alarm function is enabled. n) Check that boiler is in normal operation. Refer to page 35 “2.4.2 Control and Checking during Operation (Combustion with Air Atomization)” in Chapter 4. Note If fuel is heated before M.D.O.(*) is fully replaced with H.F.O.(*), fuel is vaporized to cause cavitation in fuel oil pump. If abnormal noise or rapid change of pressure gauge value is observed, immediately shift fuel oil heater switch to A position (turn off fuel oil heater) and check again that M.D.O. has been fully replaced with H.F.O.
2.7 Shift from H.F.O. to M.D.O. a) Operate boiler with H.F.O. properly. b) Open M.D.O supply valve, and close H.F.O. supply valve quickly. c) Close steam trace valve on boiler fuel oil pipe. d) Shift fuel oil heater switch to A position. e) Check that fuel oil heater outlet temperature is decreased and pressure is stable. f) Fully close air vent valve of oil air separator. g) Slightly open drain valve on fuel return line of oil air separator and visually check that oil has been fully replaced. h) Open and close return lines of relief valve of F.O. booster pump leading to D.O. tank and to F.O. tank, respectively. i) Check that boiler is in normal operation. Refer to page 35 “2.4.2 Control and Checking during Operation (Combustion with Air Atomization)” in Chapter 5. Note Switch fuel to M.D.O. when boiler is shut down for a long period. Low temperature F.O. may damage fuel oil pump, mechanical seal, solenoid valves and fuel oil heater.
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3. Emergency Operation Emergency operation is function that restarts boiler quickly when low atomized steam pressure alarm is issued or when boiler steam pressure is temporarily decreased during combustion with H.F.O.(*). This function switches atomized fluid to air, circulates H.F.O. in fuel piping, and temporarily causes main burner to burn M.D.O.(*) in pilot burner line. This is emergency operation, and cannot be used in other situations.
3.1 Emergency Combustion Operation a) Press combustion stop button and check that combustion is stopped. Main fuel oil pump continues to operate. After about 35-second post-purge (*), fun stops running. b) Close main steam valve, atomized steam valve, and valve on boiler body for atomized steam and open atomized air valve. c) Open compressed air valve and check that pressure is between 0.6 MPa and 0.9 MPa. d) Check that filter regulator pressure is set at 0.4 MPa. e) Shift atomized fluid selection switch to AIR position. f) Close emergency fuel switch valve on main side and open emergency fuel switch valve on pilot side. g) Check that manual combustion switch is set at AUTO.COMB. h) Press combustion switch. After fan starts running and pre-purge (*) is completed, combustion operation is started. Several seconds later, combustion is started and combustion lamp lights up. Check fuel oil pump and fan for abnormal noise.
3.2 Control and Checking during Operation Check that boiler is in normal operation. Refer to page 35 “2.4.2 Control and Checking during Operation (Combustion with Air Atomization)” in Chapter 4.
3.3 Restoration to Normal Combustion and Checking of Combustion a) Check that boiler steam pressure is 0.7 MPa or above.
If it is below 0.7 MPa, increase steam pressure by emergency combustion.
b) Close atomized air valve and open atomized steam valve and valve on boiler body for atomized steam c) Shift atomized fluid selection switch to STEAM position.
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d) Check that main steam valve is closed. e) Open emergency fuel switch valve on main side and close emergency fuel switch valve on pilot side. f) Press combustion switch. After fan starts running and pre-purge is completed, combustion operation is started. Several seconds later, combustion is started and combustion lamp lights up. Check fuel oil pump and fan for abnormal noise. Check that after about 30-second low combustion, proportional control combustion based on steam pressure is started. g) Check that boiler is in normal operation. Refer to page 35 “2.4.2 Control and Checking during Operation (Combustion with Air Atomization)” in Chapter 4.
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4. Manual Operation (Use Only in Emergency)
WARNING If automatic operation is hindered by parts damage or another reason, remove cause of problem and start automatic operation again. This boiler has manual operation circuit for emergency operation when automatic operation is hindered. Operating error in manual operation mode, in which some safety systems are disabled, may cause accident involving death. Do not use manual operation mode except in emergency. If manual operation circuit must be used for unavoidable reason, follow instructions in this manual. Cases in which automatic operation cannot be continued are as follow: Failure of instrumentation Prohibition
Sequencer trouble Sensor trouble, interlock by abnormality detection In manual operation mode, backfire (*) or other accidents involving death by ignition error or fire by empty heating may be caused. Do not use manual operation mode except in emergency. If manual operation circuit must be used for unavoidable reason, follow instructions in this manual. During manual combustion operation, do not shift fuel (M.D.O.(*) ↔ H.F.O.(*)).Failure to observe this instruction may cause backfire or other accidents involving death. Perform purge operation sufficiently before ignition and when combustion is stopped. Insufficient purge operation may cause backfire or other accidents involving death. Pre-purge (*) (before ignition): 20 seconds or longer *
Instruction
Post-purge (*) (when combustion is stopped): 60 seconds or longer. * In manual operation mode, ignition is not started until sufficient pre-purge lamp is lit after 20-second or longer pre-purge.
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WARNING In manual operation mode, following interlock functions of safety system are disabled. Improper operation may cause accidents involving death. Be careful with operating boiler in manual operation mode.
Interlock functions disabled when manual combustion circuit is used: Fuel oil pressure low (fuel) Fuel oil temperature high (fuel) Caution
Fuel oil temperature low (fuel) Steam pressure high Steam pressure low Abnormal fire These interlock functions work only when all functions are working properly. When there are problems with sensors or other parts, interlock functions may not work properly.
There are two circuits for manual operation: one for manual feed water pump operation and another for manual combustion operation.
4.1 Starting/Stopping Manual Feed Water Pump Operation Note When feeding water manually, do not leave boiler. Proportional control from differential pressure is operated, but high level alarm is disabled.
4.1.1 Starting Manual Operation a) Turn on breaker of main power supply. Power lamp lights up. b) Select pump to be operated by feed water pump shift switch. Check that outlet and inlet valves of feed water pump to be used are opened and closed properly. c) Set feed water shift switch to MANU. Feed water pump is started. 4.1.2 Stopping Manual Operation Set feed water shift switch to OFF. Feed water pump is stopped. 41
4.2 Manual Combustion Note When manual combustion is performed, do not leave boiler. If there is any problem, it is not controlled automatically. Enter manual operation by shifting manual combustion switch in order. Manual combustion switch can be set to the following positions: [OFF], [F.O. PUMP/HEATER], [FAN RUNNING], [IGNITION] (ignition (pilot burner)),[ PRI.COMB.] (preliminary combustion (double combustion with pilot burner and main burner), [COMB.] (combustion (single combustion with main burner). These positions are arranged in this order. Boiler also has combustion changeover switch that can be used to switch between low combustion and proportional control combustion. Because individual operation of each equipment is not allowed for safety reasons, turn cam switch in order to check operation. Procedure for starting combustion with air atomization using M.D.O. (*) as main fuel (*) is described below: a) Check that manual combustion switch is set at [OFF]. b) Check that combustion changeover switch is set at [LOW] (low combustion). c) Follow steps a) to k) in 2.4.1. Refer to page 34 “2.4.1 Combustion with Air Atomization” in Chapter 4. d) Shift manual combustion switch to [F.O. PUMP/HEATER]. Main fuel oil pump is started. Check that fuel is circulating properly (Check oil pressure gauge). e) Shift manual combustion switch to [FAN RUNNING]. Fan is started. Check for abnormal noise. f) Check that pre-purge (*) completion lamp lights up. Combustion can be started when pre-purge completion lamp lights up. g) Shift manual combustion switch to [IGNITION]. Ignition rod sparks and pilot burner ignites. Check through sight glass that pilot burner is burning. Note If pilot burner is not burning, immediately shift manual combustion switch back to [FAN RUNNING] and repeat f) and subsequent steps in 4.2. 42
h) Shift manual combustion switch to [PRI.COMB.]. Double combustion with pilot burner and main burner is started. Check through sight glass that it is burning. Note If main burner is not burning, immediately shift manual combustion switch back to [FAN RUNNING] and repeat f) and subsequent steps in 4.2.
i) Shift manual combustion switch to [COMB.] position. Pilot burner is put out, and combustion is continued with main burner alone. Check through sight glass that it is burning. Note If main burner is not burning, immediately shift manual combustion switch back to [FAN RUNNING] and repeat f) and subsequent steps in 4.2.
j) When combustion changeover switch is shifted to [AUTO.] (proportional control combustion) during combustion with steam atomization, proportional control combustion is started.
4.3 Manual Combustion Stop a) Shift manual combustion switch from [COMB.] to [FAN RUNNING]. Combustion is stopped. Only fan continues to operate. Keep switch at [FAN RUNNING] for 60 seconds or longer for post-purge (*). b) Shift manual combustion switch to [OFF]. Fan and main fuel oil pump are stopped.
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5. Emergency Stop
DANGER Emergency stop is operation that gives top priority to stopping boiler immediately in emergency. If breakers are turned off inadvertently, feed water and circulating water pumps may be stopped to cause soot fire or furnace explosion. Do not use this function except in emergency. Emergency stop is operation that gives top priority to stopping boiler immediately in emergency. Emergency stop skips safety checks for ongoing operation and may cause Caution
unexpected accident or failure. Use this function only when there is unavoidable reason for bringing boiler to emergency stop. Users must judge when and how boiler should be brought to emergency stop because it depends on situation. When resuming operation after emergency stop, ensure that switches are turned on or off to stop all ancillary equipment before turning power on. Otherwise, equipment may start to work unexpectedly to cause accidents.
Procedure of boiler emergency stop because of accident or other necessity to stop boiler urgently is described here.
5.1 Emergency Stop of Combustion System 5.1.1 Cases in which Emergency Stop is Required Fuel oil leaks Considerably poor combustion Abnormal noise from fan or fuel oil pump Exhaust gas leaks When part of body or object gets caught in rotating parts of fan or fuel oil pump, etc. 5.1.2 Stop Procedure a) Shift manual combustion switch to OFF position. Fuel oil pump and fan are stopped, and combustion is stopped. b) Close main fuel valve.
5.2 Emergency Stop of Entire Boiler 5.2.1 Cases in which Emergency Stop of Entire Boiler is Required Fire When all running equipment should be stopped immediately, etc. 5.2.2 Stop Procedure Stop power supply to boiler or turn off power supply breaker in control panel. All equipment is stopped. 44
6. Cold Start When boiler water becomes completely cold and especially when trial operation is started or new boiler is brought into operation, start boiler with followings in mind: For cold start, it needs to take enough time until steam pressure is raised to 0.1 MPa because each part of boiler is completely cold. Note Do not raise steam pressure rapidly.
a)
Raise steam pressure gradually to 0.1 MPa by repeating 1 minute combustion and 4 minute purge. Keep steam pressure at 0.1 MPa for 10 minutes. While steam pressure is between 0.1 MPa and 0.2 MPa, repeat 2 minute combustion and 3 minute purge to raise pressure.
b)
When steam pressure reaches around 0.2 MPa, stop boiler. Retighten bolts and nuts around fastening parts and connections of valves on body, manhole packing and water level gauge.
c)
Blow water level gauge to make it easy to check.
d)
Blow boiler water and purify water. Make boiler water purify.
e)
After steps a) to d) are finished, turn on combustion switch to start combustion again.
f)
When steam pressure is increased to maximum pressure for general use, check for steam leaks.
g)
Open main steam valve and start automatic operation.
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CHAPTER 5: INSPECTION AND MAINTENANCE 1.
List of Inspection Items and Inspection Frequencies
WARNING Surface temperature of the top of boiler exceeds 60°C and may cause burn if surface is Caution
touched. Take extra care in daily inspection work.
CAUTION When cleaning strainer or performing other work using oil, wear protective equipment to Instruction
protect eyes and body from splashes of oil.
In order to prevent accidents, carry out inspection and cleaning listed below regularly. (Some items should be inspected depends on system.) List shows standard inspection frequencies. More frequent inspections may be required, depending on use conditions or environments. Carry out inspections with appropriate frequency on your own responsibility. Note When carrying out inspections, put sign on boiler stating that it is under inspection.
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1.1 Regular Inspection and Maintenance Every day ● ● ●
Inspection/maintenance item Check of ventilation Check of surroundings for flammable materials Check of funnel (exhaust pipe) Check of feed water pump for leaks or abnormal noise and check of pressure gauge Retightening of valves, gland, and flanges (only when signs of leaks are found) Drainage of fuel service tank Blow of water level gauge Inspection and adjustment of drive part of dampers
P 97
Every year
P 59
● ● ●
Hardness check of water softener Cleaning of fuel strainer
P 63 - 65
(●)
(●) (●) ●
Maintenance of burner body (Baffle plate, rectifier grid, etc.)
P 52 - 55
●
Inspection of burner nozzle Inspection of ignition rod for cracks and adjustment (*) Inspection of wind box Inspection of fan
P 52 - 55
● ● ●
P 55
●
Inspection of link of blower suction damper
P 57
●
Measurement of insulation resistance of each motor
P 56
●
Inspection of flexible tube Inspection of oil flow control valve, air flow controller and damper Inspection of control motor (*) Inspection of dirt on flame eye /glass. Inspection and adjustment of discharge pressure of fuel oil pump Inspection and adjustment of circulation relief valve Visual inspection of wiring Inspection of motor ball bearings Inspection and cleaning of dirt on feed water strainer Drainage of cascade tank Inspection of drive valve for burner control Inspection and adjustment of fuel oil thermostat Inspection and adjustment of pressure switch Operation check of each safety system Operation test of exhaust gas thermostat Check of main burner assembly for fuel oil leaks Inspection and adjustment of coupling for fuel oil pump Inspection of inner cylinder of burner
P 59
●
P59,60
●
P 61 P 62
● ●
P 66-68
●
P 69
● ● ● ● ●
P 56
P 70~ P79,80 P 82 - 84 P 87~ P 90
● ● ● ● ● ● ● ●
P 57
●
P 97 - 98
●
P 85
● ●
Greasing of bearing of blower suction damper Cleaning of water level detecting rods and holder and check of continuity and insulation Inspection of differential transmitter Inspection of flow control valve Cleaning and inspection of fuel oil heater Inspection of feed water check valve Voltage check of flame detector
Every 3 months
●
(●)
Blow of boiler through surface and bottom
Every month
●
Manual for WaterTreatment Manual for WaterTreatment Manual for WaterTreatment
Sampling of boiler water
Every week
P 86 P 95 P 99
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● ● ●
When docked
Every day
Inspection/maintenance item Inspection of inside of boiler Inspection of combustion chamber and cleaning of furnace with water to remove soot Inspection and cleaning of inside of fuel service tank
Every week
Every month
Every 3 months
Every year
When docked
● P 100
● ●
Inspection of inside of chimney
●
Inspection of valve on boiler
●
Cleaning of inside of cascade tank
●
Inner inspection and maintenance of differential transmitter
●
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1.2 Safety Valve
WARNING Improper adjustment of blow off pressure of safety valve may damage boiler body. As a rule, do not adjust blow off pressure of safety valve. Prohibition
Remodeling of safety valve may damage boiler body. As a rule, do not remodel safety valve. If steam leak from safety valve is found, replace part and repair it immediately. When steam leak is left, function of safety valve is decreased and there is possibility of
Instruction
leading to serious accident
Safety valve is safety device that is installed to prevent boiler steam pressure from exceeding maximum allowable working pressure; full-bore safety valve is used for this boiler. Normally, safety valve does not operate because steam pressure switch works. When pressure switch does not work for some reason and combustion is continued to cause abnormal steam pressure increase or rapid pressure increase is caused by rapid load change, safety valve protects boiler by blowing steam off and lowering steam pressure. As a rule, two or more safety valves are installed and they are selected so that total blow off level exceeds the maximum evaporation level of boiler for safety. Boiler safety valve is set at presence of inspector, so as to blow off at strictly limited pressure; nobody is allowed to make attempt of further adjustment on board. However, only in case of emergency, such as when safety valve leaks, some countermeasures, such as opening or adjusting valve, can be taken at discretion of chief engineer. In that case, adjust blow off pressure of safety valve according to procedure that is described in next page. 1.2.1 Internal Structure of Safety Valve <50A or less>
No. 1
Valve casing
2
Valve seat
3
Valve body
4
Adjustment ring
5
Valve cylinder
6
Lift control bush
7
Spring
8
Valve stem
9
Adjusting bolt and nut
10
Cap
11
Valve lift lever
Figure 5-1 Internal Structure of Safety Valve : 50A or less 49
Part name
＜65A or more＞
No.
Nut Stud bolt
Part name
1
Valve casing
2
Valve seat
3
Lower ring
4
Set bolt
5
Valve body
6
Upper ring
7
Guide
8
Valve stem
9
Adjusting bolt and nut
10
Cap
11
Valve lift lever
12
Spring
Figure 5-1 Internal Structure of Safety Valve : 65A or more 1.2.2 Adjustment Procedure of Safety Valve a) Unlock key on shaft of valve lift lever (11), pull out shaft, and remove lift lever. b) Remove cap (10) by loosening setting bolt. c) Loosen nut (9) of adjusting bolt and activate safety valve. ● Switch to manual operation of boiler and check that steam goes up and blow off pressure of safety valve. d) Turn adjusting bolt (9) to left if blow off pressure is higher than pressure limit and to right if it is lower than that, so that it blows off at limited pressure. e) After adjustment, fasten adjusting nut (9) tightly to fix it securely. f) Put cap back in place, set valve lift lever, and lock and fix key.
1.3 Other Important Inspection Items The procedure for water treatment is described in Manual for Water Treatment. Most of boiler accidents come from faulty water treatment; read and understand instruction manual thoroughly for water treatment. Manual also describes procedure of long-term boiler shutdown. Refer to "Manual for Water Treatment". Note If boiler that is designed 60 Hz power supply inside of vessel is docked and operated in 50 Hz land power supply, each motor capacity for 60 Hz is decreased and cases lack of combustible air, insufficient fuel flow rate. Be sure to use power supply on vessel. If boiler that is designed 50 Hz power supply is operated in 60 Hz land power supply, motor is burned and magnetic contactor is tripped. 50
2. Daily Inspection and Maintenance Peripheral equipment depends on system. Use equipment properly according to instruction manual. Put instruction manuals together with this manual in place so that they can be read whenever they are needed. For details about inspections of equipment around boiler before operation and monitoring for problems during operation, refer to “1. Inspections and Preparation Before Operation,” "2.4.2 Control and Checking during Operation (Combustion with Air Atomization),” and "2.4.4 Control and Checking during Operation (Combustion with Steam Atomization" in Chapter 4. Refer to page 24 “1. Inspections and Preparation Before Operation” in Chapter 4. Refer to page 35 “2.4.2 Control and Checking during Operation (Combustion with Air Atomization)” in Chapter 4. Refer to page 35 “2.4.4 Control and Checking during Operation (Combustion with Steam Atomization)” in Chapter 4.
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3. Weekly Inspection and Maintenance 3.1 Main Burner
WARNING Instruction
Complete purge by fan before burner opening and inspection to make combustion chamber cold and ventilate. Stop fuel oil pump and close main fuel valve of main and pilot burners. Wipe away fuel oil from burner nozzle and flexible tubes immediately and dispose of it properly.
3.1.1 Overview Main burner consists of main burner body with burner nozzle and guide pipe with baffle plate. In burner nozzle, fuel oil sent by fuel oil pump is mixed with fluid for atomization (air or steam). The mixture is squirted out of cap end and atomized. Burner nozzle consists of cap, mixer, nozzle, check valve, and ferrule. Fuel oil sent from center of burner nozzle and fluid for atomization supplied from circumference are squirted out of nozzle, mixed in mixer, and then atomized through opening in cap. Check valve is installed before nozzle to prevent oil dripping when combustion is stopped. Clean main burner on a weekly basis.
3.1.2 Disassembly and Adjustment < Main burner> a) Loosen 2 hexagon socket set bolts on top of guide pipe and pull out burner gun. b) Remove burner nozzle from main burner in ferrule position. c) Disassemble burner nozzle into cap, mixer, nozzle, check valve, and ferrule. ● When disassembling it, pull out lock screws completely. Failure to pull out lock screws may damage burner nozzle. d) Wash these components with light oil, clean them with air, and assemble them by following disassembly steps in reverse.
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a) Remove nut on upper plate and pull out guide pipe. b) Remove baffle plate, wash these components with light oil, clean them with air, and assemble them by following disassembly steps in reverse.
Fuel oil inlet x3 Atomized fluid inlet
x3
x3
D.O. inlet Atomized fluid
Fluid oil
Enlarged View of Section A
No.
Figure 5-3 Structure of Burner
Part name
1
Guide pipe
2
Main burner
3
Pilot burner
4
Cap
5
Mixer
6
Nozzle
7
Check valve
8
Ferrule
9
Lock screw
10
Upper plate
3.2 Nozzle Tip
CAUTION Improper spray volume, spray angle, and spray form cause poor combustion and sometimes Caution
cause backfire (*). Use only genuine parts.
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3.3 Pilot Burner 3.3.1 Overview This burner comes with pilot burner designed for use with M.D.O.(*). Pilot burner consists of baffle plate, nozzle tip, nozzle holder, check valve, ignition rod, and nozzle pipe. Oil entering nozzle tip of pilot burner goes through strainer and trench of distributor and enters evolution room. Conical evolution room has orifice in its end. Oil increases its speed while swirling in evolution room, passes through orifice, and then is sprayed to combustion chamber. Nozzle tip is made of hard material as high-pressure, high-speed oil wears away orifice and other parts. Replace it on a yearly basis.
No.
Part name
1
Baffle plate
2
Nozzle tip
3
Nozzle holder
4
Check valve
5
Ignition rod
6
Nozzle pipe
Figure 5-4 Structure of Pilot Burner
Body
Distributor Figure 5-5 Nozzle Tip of Pilot Burner 54
Strainer
3.3.2 Disassembly and Adjustment a) Remove bolt on pilot burner and pull out pilot burner. b) Remove nozzle tip, baffle plate, and ignition rod from pilot burner. c) Disassemble nozzle tip into strainer, distributor, and strainer, wash these parts and baffle plate with light oil, and clean them with air. d) Remove soot out of ignition rod with brush. e) After cleaning these parts, adjust their dimensions with reference to pilot burner dimensions shown in Figure 5-3 and burner dimensions measured in trial operation, and assemble them.
4. Monthly Inspection and Maintenance 4.1 Fan
DANGER Inspect fan once a month. Failure to inspect fan may cause it to break or fly apart due to Instruction
deterioration of impeller or external force, resulting in injury or death.
WARNING Before moving impeller by hand, turn off main power supply. If impeller is rotated accidentally Instruction
during maintenance, physical injury may be caused.
4.1.1 Overview Fan, which forces air into boiler, secures wind pressure and wind flow by rotating impeller by motor. This boiler has fan with high wind pressure and high revolution speed because combustion gas speed is high for efficient heat exchange with combustion gas. Attention and care are required to prevent foreign particles from clogging wire mesh of suction. When there is significant vibration even after impeller is cleaned, bearing replacement or impeller adjustment is required.
55
4.1.2 Regular Maintenance a) Inspect fan once a month. b) Check for vibration, strange noises, and abnormal bearing temperature increase during operation. When fan is not in operation, turn off power supply, and move impeller by hand to check for problems. ● Conduct insulation test once a month, after long-term shutdown, and when it is necessary. If insulation resistance is below 1 MΩ, replace motor or unship and repair it. ● Motor bearing requires grease injection. Grease motor bearing regularly according to notes on greasing on motor. Greasing is not needed for HB-08T type because grease is sealed in bearing.
① HB-10T, 12T
② HB-15T, 18T, 20T Figure 5-6 Bearing Grease Inlet
Greasing is not needed because grease is sealed in bearing.
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4.2 Suction Damper (Attachment of Blower)
WARNING Inspect suction damper once a month. Failure to inspect suction damper may cause damage Instruction
of part and malfunction due to looseness of part, resulting in injury or death.
4.2.1 Overview Suction damper opens fully when combustion is started and it closes fully after post purge(*) of combustion stop for restraining heat loss due to blowing of continuous-running fan motor. 3 damper plates are connected to motor with damper arm. They open and close in interlock with rotation of motor. Limit switch is installed on damper arm part to check that damper opens fully during combustion. Oscillation and external force apply to damper continually, so pay attention to looseness of part etc.
Motor wiring hole
Motor Damper body
Wiring fixing base×3
Motor arm
Limit Switch Wiring hole
Link block
Damper arm
Figure 5-7 Suction Damper
4.2.2 Inspection a) Confirm that there is no looseness of fastening part once a month. (Link block, damper arm and damper plate) b) Grease bearing of damper shaft once every three months. ・Required grease is alvania grease S3 (SHOWA SHELL SEKIYU K. K.). Greasing amount is 1.4g. c) Confirm that there is no looseness of fixed screw and wiring once a month. ・This boiler doesn’t shift to automatic combustion if motor is damaged.
57
4.2.3 Measures on Failures (Fixing Fully Open State) In case that damper doesn’t fully open automatically due to malfunction of motor, this boiler doesn’t shift to automatic combustion, so damper needs to be fixed in open state forcibly. Follow the following instructions for fixing damper. a) Remove link block of tip part of motor arm A. b) Pull up connecting rod until damper opens fully. Confirm that damper arm touches limit switch in that position. c) Let removed link block through connecting rod and fix motor arm B and connecting rod firmly. d) Confirm that damper is fixed in open state. Motor arm B
Motor arm A Link block Connecting rod ucture of Safety
Figure 5-8 Diagram of fixed position of open state (Left: Fully closed, Right: Fully open)
58
4.3 Fuel Flexible Tube
WARNING Do not give impact to boiler fuel pipe or bend any part of it. Instruction
Failure to observe this instruction may cause fuel oil leak, resulting in fire.
Flexible tube on burner is used at high temperature and high pressure. Generally, it needs to be replaced once every 1 or 2 years.
4.4 Oil Flow Control Valve, Air Flow Controller, and Damper
WARNING Equipment has been brought into optimum state in trial operation. Do not make changes to state after trial operation. Failure to observe this instruction may cause poor combustion, Instruction
backfire (*), or other accidents. If changes are made for unavoidable reasons, contact MIURA offices and ask for instructions.
4.4.1 Overview Fuel oil flow rate and air flow rate are adjusted by oil flow control valve, air flow controller, and damper. Oil flow control valve changes its opening to adjust fuel oil flow rate. By rotating control motor on oil flow control valve shaft, slot in shaft is rotated to change inner opening. Air flow controller attunes throttling characteristics of oil flow control valve to air flow throttling characteristics of damper. It has leaf spring bent into a fan-like shape, along which damper drive arm moves. This leaf spring has 8 adjustment bolts, with which spring's shape can be changed to adjust air flow throttling characteristics of damper. This mechanism adjusts air flow to optimum rate for combustion levels at different combustion loads. Damper is subject to continuous vibration and external force and must be checked for loose parts.
59
4.4.2 Inspection Loose parts of damper cause changes in damper opening. Check damper drive arm and leaf spring for loose lock screws on a monthly basis. If loose parts are found, retighten them or apply grease. Coupling is connects motor and air flow controller shaft by tightening lock screw. Inspect looseness of lock screw once a month because it can not control combustion normally when lock screw is loosened. If loose parts are found, retighten them additionally and check that control motor opening and air flow control valve opening have not deviated from position in trial operation. Air flow controller Leaf spring adjusting bolt
Air flow controller
Leaf spring
Coupling
Lock screw
Control valve
Control motor
opening instruction plate Damper drive arm Oil flow control
Lock nut
valve Damper drive arm
Air flow controller Leaf spring adjusting bolt
Damper 図 5-6 燃焼調整ダンパ Damper drive arm Lock nut Coupling
Control motor opening
Lock screw
Coupling
Figure 5-9 Oil Flow Control Valve and Air Flow Controller
60
4.5 Control Motor 4.5.1 Overview Control motor controls oil flow control valve and damper to realize proper combustion conditions for different pressure conditions according to signals from steam pressure regulator. It also has cam switches in it, which notify control panel of damper position. Because it repeats opening and closing constantly during combustion control, parts of control motor inside are consumed gradually. Generally, it needs to be replaced at every docking.
Figure 5-10 Control Motor
4.5.2 Inspection If control motor is failed, it cannot be burned normally. Inspect fixed screw and wiring for looseness every month.
61
4.6 Flame Eye (*)
1
Flame eye
2
Flame eye fitting box
3
Flame eye fitting stand
4
Protection glass
5
Packing (2 pcs.)
Figure 5-11 Flame Eye
4.6.1 Overview Flame eye is a device that detects flame during combustion and gives instruction to combustion circuit. It monitors flame by using photosensitive characteristic of CdS (cadmium sulfide cell) (Normally, when resistance of 100 kΩ catches flame, it drops under 500 Ω). If flame eye is damaged or protection glass is blackened with soot, it cannot detect flame and stops burner and brings it to the same state as when ignition failure or flame-out occurs.
4.6.2 Inspection and Cleaning Ignite burner with burner switch and look in furnace through sight window. If flame dies out about 3 or 4 seconds after burner is ignited, flame eye or flame detector may be out of order or protection glass soiled. Inspect and clean protection glass on a monthly basis. Refer to page 99 “6.3 Flame Detector (FS-901) ” in Chapter 5.
62
4.7 Strainer for Fuel 4.7.1 T-type Auto-cleaner T-type auto cleaner removes dust and other impurities from fuel to prevent them from entering and damaging fuel oil pump, solenoid valves, or burner nozzle. It is installed on suction side of fuel oil pump. Element of auto cleaner can be cleaned during operation. To prevent it from being clogged, turn handle and clean it at least once a day. Drain all water and sludge from strainer once a month.
1 2 3 4 5 6 7 8
Cleaner cover Oil tank Handle Main shaft Gland O ring Ring Packing
9 10 11 12 13 14 15 16
Air vent plug Packing Upper end Lower end Fixing plate Packing Filter plate Scrapper plate
Figure 5-12 Oil Strainer 63
17 18 19 20 21 22 23
Square rod Round rod Drain plug Packing Washer Nut Cap nut
a) Draining strainer Close main valve of fuel service tank, loosen drain plug (19) in lower part of strainer, and drain water and impurities from strainer. b) Disassembling and cleaning ● Check main valve of oil tank is closed. ● After draining of strainer, remove bolt on the upper part of oil strainer to remove cup. ● Clean dust off plate filter with oil. ● Assemble strainer in reverse order. c) Air vent ● Open main valve of oil tank and slightly loosen air vent plug (9) on the upper part of auto cleaner. ● When air is removed and oil starts to come out of loosened screw, fasten screw. 4.7.2 Y-type Strainer Y-type strainers are installed on outlet of fuel oil heater (*) and inlet of burner. Remove foreign materials that are contained in fuel oil to prevent solenoid valves and other parts from being damaged. ● Cleaning Open and clean Y-type strainer and inspect element for deformation or damage about once every 3 months; frequency depends on property of fuel oil. Replace a deformed element with new one.
1 Body 2 Cover 4.7.3 Double Strainer 3 Upper cock cover 4 Lower cock cover 5 Cock plug 6 Cock switch handle 7 Cock lift handle 8 Spindle 9 Cover retainer 10 Fastening bolt 11 Ring 12 Packing retainer 13 Filter tube handle 14 Filter tube 15 Filter rope 16 Drain plug 17 Air vent plug 18 O ring 19 O ring 20 O ring 21 O ring 22 Gasket Figure 5-13 Double Strainer 23 Gasket Double strainer removes dust, sand, and other impurities from fuel that is used with boiler to prevent them from entering and damaging fuel oil pump, solenoid valves, or burner nozzle. Double strainer is installed on suction side of fuel oil pump. 64
a) Close line valve first. b) Pull up cock lift handle (7), give it two turns counterclockwise when viewed in Figure 5-13, and pull up cock plug (5). c) Turn cock plug (5) in desired direction by using cock switch handle (6).
Figur Figure (a)
● If cock switch handle (6) is turned rightward (refer to Figure (a)), strainer B is used. ● If cock switch handle (6) is turned leftward (refer to Figure (b)), strainer A is used. d) Pull up cock lever (7) and turn it clockwise to allow cock plug (5) to adhere closely to body (1). e) Fully open line valve gradually. f) When oil passes through strainer A or B, air is
Figure Figure (b)
accumulated in upper part of body (1). Loosen air vent plug (17), and close it after checking that oil comes out
Figure 5-14 Double Strainer
slightly.
Screen Switching
Disassemble and clean strainer that is not used according to following procedure: a) Check that screen that is disassembled is not used. b) Loosen drain plug (16) and air vent plug (17) to drain oil. c) Loosen fastening bolt (10) and remove cover retainer (9) and cover (2) after oil is completely discharged. d) Take out screen (14) by using screen handle (13). e) Clean screen filter (15). f) Assemble strainer in reverse order. Set screen (14) in strainer body. g) Close drain plug (16) and air vent plug (17). h) Fully open line valve gradually, and close air vent plug when oil comes out from air vent plug (17) that fills stop side with oil.
65
4.8 Fuel Oil Pump 4.8.1 GD Type (for Pilot Burner) This boiler uses GD type pilot pump. This pump is connected to motor through a coupling and runs at a speed of about 3500 rpm to send fuel to pilot burner nozzle though solenoid valve.
Figure 5-15 Rotors of Fuel Oil Pump (Trochoid System) Fuel oil pump employs trochoid system as shown above and it generates high pressure by rotation of inner and outer rotors. Rotor has profile as shown above and inner and outer rotors rotate in light contact with each other and tooth surface slippage is quite limited. Almost no noise is generated because oil is not contained. However, inspect fuel oil pumps and adjust discharge pressure once a month. Refer to page 67 “4.8.3 Procedure of Fuel Oil Pump Discharge Pressure Setting” in Chapter 5.
Return opening Pressure regulating valve Note: Do not disassemble rotors and other major parts for repair. It cannot be repaired disassembled pump that is not covered by guarantee.
Discharge opening
Suction opening
Figure 5-16 GD Type < Adjustment> ● Adjust pressure by using pressure regulating valve. ● Turning it to right increases pressure, and turning it to left decreases pressure. Note Pump rotates clockwise when viewed from the end of pump shaft.
< Inspection and maintenance> Check cover and oil seals for leaks on a daily basis. ● It does not contain strainer. In case of trouble, do not disassemble unit, and unship and have it repaired.
66
4.8.2 Main Fuel Oil Pump This pump is connected to motor through a coupling and sends fuel to burner nozzle though fuel oil heater (*), oil flow control valve, and fuel shutoff valve. Prepare for operation of main fuel oil pump according to instruction manual for screw pump.
4.8.3 Procedure of Fuel Oil Pump Discharge Pressure Setting
CAUTION This adjustment is also needed when fuel oil pump is replaced. Adjust pressure regulating valve in burner piping unit after discharge pressure of fuel oil pump is adjusted. Fuel oil Instruction
pump is deteriorated over time and its performance is gradually declined.
If fuel oil pump is used for many years without adjustment, it deteriorates and becomes worn and causes decreases in oil pressure. In order to maintain proper oil temperature and circulation level, check and adjust discharge pressure of fuel oil pump once a month according to following procedure. If oil pressure is adjusted with M.D.O. (*), adjust it again when fuel oil is switched to H.F.O. (*). Note Ensure that safety valve pressure setting of fuel oil heater is not exceeded. a) Stop combustion and run fuel oil pump. b) Slowly close fuel return pipe valve (1) shown in Figure 5-17. ● Pressure indicated in fuel oil pump discharge pressure gauge (2) is increased slowly. c) Adjust pressure indicated in fuel oil pump discharge pressure gauge (2) to value set in trial operation by using pressure regulating valve (3) of fuel oil pump unit. d) Slowly open fuel return pipe valve (1). Pressure indicated in fuel oil pump discharge pressure gauge (2) is decreased slowly. e) Open discharge valve (4), check that fuel oil is circulating, and close it.
(1) Remove adjustment screw cover of fuel pressure regulating valve and loosen lock nut. (2) Turn adjustment screw of fuel pressure regulating valve to adjust pressure. ● Turn screw clockwise to increase pressure. ● Turn screw counterclockwise to decrease pressure. (3) Check indicated pressure and tighten lock nut. (4) Install adjustment screw cover.
68
4.8.4 Circulation Relief Valve Fuel oil is pressurized by fuel oil pump and heated by fuel oil heater, and its pressure is adjusted properly by circulation relief valve on top of boiler. Part of fuel oil circulates throughout system and heats fuel return pipes during combustion, keeping fuel at constant temperature. Circulation relief valve is important part that controls combustion level and temperature of combustion system. Inspect this valve and adjust pressure once a month. Circulation relief valve is adjusted to optimum pressure in trial operation. a) Check that inlet pressure of adjusting flow valve when H.F.O. (*) is circulating is pressure set in trial operation. b) Check that lock nut is not loosened. ● If lock nut is loosened, retighten it. If pressure gauge indicates pressure set in trial operation, combustion level does not need to be adjusted. If pressure gauge does not indicate pressure set in trial operation, adjust combustion level. a) Adjust fuel oil pump discharge pressure according to procedure in 4.8.3. b) Adjust circulation relief valve according to 3) in 4.8.3. Refer to page 67 “4.8.3 Procedure of Fuel Oil Pump Discharge Pressure Setting” in Chapter 5.
List of standard pressure settings (reference) HB-08T
HB-10T
HB-12T
HB-15T
HB-18T
HB-20T
M.D.O.（＊）［MPa］
0.8
0.8
0.9
1.1
1.2
1.2
［MPa］
1.0
1.0
1.1
1.3
1.4
1.4
H.F.O.
Figure 5-18 Circulation Relief Valve
69
No. 1 2 3 4 5 6 7 8 9 10 13 14 15 16 17
Part name Relief valve body Relief valve plunger Spring retaining nut Spring strike plate Relief spring Relief valve cap Pressure adjusting bolt Hexagon nut O ring O ring Relief valve packing Relief valve stand Packing Hexagon bolt Spring washer
5. Quarterly Inspection and Maintenance 5.1 Inspection and Blow of Boiler Water
WARNING Blow valve and sample water (blow water) are hot. Wear protective equipment while working Caution
with them to prevent burn.
Treat and blow boiler water regularly according to Manual for Water Treatment.
5.2 Equipment around Burner 5.2.1 Solenoid Valve
WARNING In order to prevent serious accident, check solenoid valves and valve seats for oil leaks after Instruction
cleaning, inspecting, or replacing.
Solenoid valve opens and closes by electric activation and non-activation to control supply of fuel oil to burner nozzle and other control equipment. If seat of any of solenoid valves is clogged due to foreign particles on seat, oil leak into combustion chamber, ignition failure, or other combustion related problems may be caused. Visually check flow meter when combustion is stopped or check for oil leaks in bottom of furnace on quarterly basis. In disassembling device, be careful not to lose internal parts. When replacing valve, check flow direction.
70
5.2.1-1 Solenoid Valve for Pilot Burner This solenoid valve is used to control fuel used with pilot burner. It is opened when activated and two valves are used for combustion. When pre-purge (*) is completed, this solenoid valve is activated and opened.
No. A1 A2 A3 A4 A5 A6 A7 A8 A13 N 1 2 3
Part name Tube & base ASSY O ring Top plate Spring washer Coil O ring Base nut O ring Terminal box Neon lamp Plunger ASSY O ring Spring
Figure 5-19 YS301 Type
5.2.1-2 Solenoid Valve for Pneumatic Fuel Shutoff Valve This solenoid valve controls air that drives pneumatic fuel shutoff valve. It uses compressed air in line for atomized air to drive main fuel shutoff valve. When it detects flame of pilot burner, it is opened to start air supply to pneumatic fuel shutoff valve. This solenoid valve is installed in each of air supply lines leading to 2 main fuel shutoff valves.
Lead wire Solenoid Spring Movable element
Poppet set screw V seal Poppet shaft Body
Figure 5-20 062E1 Type 71
5.2.1-3 Solenoid Valve for Atomized Air This solenoid valve is used to control atomized air. A single solenoid valve for atomized air is installed in atomized air line and is opened when activated. When "AIR" is selected as atomized fluid, it is opened following detection of flame of pilot burner to supply atomized air to main burner and atomize fuel.
O-ring Coil Bracket (Option)
Nut Washer A
Bolt
Washer B Bonnet Diaphragm ASSY
Lock washer Name plate Housing
Base nut O-ring
Spring washer Tube ASSY
Spring
O-ring
Plunger ASSY
Body
Figure 5-21 YS211 Type
72
5.2.1-4 Solenoid Valve for Atomized Steam This solenoid valve is used to control atomized steam. A single solenoid valve for atomized steam is installed in atomized steam line and is opened when activated. When "STEAM" is selected as atomized fluid, it is opened following detection of flame of pilot burner to supply atomized steam to main burner and atomize fuel.
Part name Valve casing Cover Spring pin Pipe Valve body Valve disk Valve body washer Connecting spring Piston ring Pilot ring Pilot disk Spring retainer Plunger Pin Valve body spring Gasket O ring Coil O ring Pilot spring
5.2.2 Other Equipment
WARNING In order to prevent serious accident, check solenoid valves and valve seats for oil leaks after cleaning, inspecting, or replacing. Instruction
Before inspection or adjustment, check that there is no internal pressure present. Compressed air or steam may blow out, causing burn or laceration.
If seat of any equipment is clogged due to foreign particles on seat, oil leak into combustion chamber, ignition failure, or other combustion related problems may be caused. Visually check flow meter when combustion is stopped or check for oil leaks in bottom of furnace on a quarterly basis, along with carrying out inspection specified in each section. 5.2.2-1 Pneumatic Fuel Shutoff Valve This is pneumatic actuator used to control fuel oil supplied to main burner. Two pneumatic fuel shutoff valves are installed in main fuel oil (*) line and actuated by compressed air. This valve is closed under no pressure and opened to start fuel oil supply to main burner when it detects compressed air from filter regulator or solenoid valve for fuel shutoff valve. Carry out following inspections while boiler is in operation: Check positions of valve when it is fully opened and fully closed. Check valve and pneumatic pipe connections for leaks. Check valve and pneumatic pipe for abnormal noise. Check for vibration when it is actuated. Check for loose bolts or nuts.
Part name Valve casing Cover Valve stem Ball Packing retainer Packing retainer ring Packing Gasket Packing washer Ball seat Nut for cover bolt Nut for packing retainer Nut Cover bolt Packing retainer bolt Thrust washer Stem bearing Connector Bracket Bolt Pneumatic actuator Set bolt Spring & pin Spring Spring washer Spacer
5.2.2-2 Filter Regulator Filter regulator is used to reduce pressure of compressed air supplied to solenoid valve for fuel shutoff valve and to remove sludge. Installed in inlet of atomized air line, filter regulator reduces pressure of air supplied to fuel shutoff valve to 0.4 MPa as well as removes dust in air with inner filter to prevent solenoid valve for fuel shutoff valve from including dust. a) Check that pressure is set at 0.4 MPa. b) Drain filter regulator. If drain level exceeds upper limit, drain filter regulator in shorter intervals than inspection. c) Check plastic bowl in filter regulator for cracks, scratches, or deterioration. Pressure adjusting knob
Pull pressure adjusting knob a notch to unlock it. Turning pressure adjusting knob in "H" direction shown in upper surface increases secondary pressure, and turning it in "L" direction decreases secondary pressure. After adjusting secondary pressure, push pressure adjusting
Figure 5-24 Detailed View of Pressure Adjusting Knob
knob a notch to lock it.
Turn cock in "O" direction to drain filter regulator and in "S" direction to stop draining it
Figure 5-25 Detailed View of Drain Outlet
Stop compressed air flow, check that there is no pressure present in product, and then remove bowl. a) Turn bowl and bowl guard by about 45° until they are stopped while pushing them up (Figures [1] and [2]). By pulling bowl and bowl guard out downward, they can be removed (Figures [2] and [3]). b) Assemble them in reverse order (Turn them until they are stopped). c) Before letting compressed air in, check that marks of bowl guard and body meet each other in point A (Figure [1]).
[1]
[2]
[3]
Body
Bowl guard
75
Figure 5-26 Procedure for Removing Bowl Guard
5.2.2-3 Pressure Reducing Valve This valve reduces pressure of steam for atomization supplied by boiler. It adjusts secondary steam pressure to 0.5 MPa. a) Check that lock nut of adjusting screw (9) is not loosened. b) Check secondary pressure. Check secondary pressure when primary pressure is 0.6 MPa or above. c) Check for abnormal noise. d) Check for steam leaks. If secondary pressure cannot be adjusted to 0.5 MPa, adjust it by steps below: a) Check that atomized steam can be supplied and run fan in manual operation mode. After a while, solenoid valve for atomized steam is opened. Refer to page 40 “4. Manual Operation” in Chapter 4. b) Loosen lock nut of adjusting screw (9). Turn adjusting screw to adjust pressure to 0.5 MPa while checking atomized steam pressure gauge. Turn screw clockwise to increase pressure. Turn screw counterclockwise to decrease pressure. c) After adjusting pressure, tighten lock nut. No. 1
Body
5
Diaphragm
8
Adjusting spring
9
Adjusting screw
11
Main valve
12
Valve seat
13
Main valve spring
14
Piston
15
Cylinder
19
Pilot valve body
20
Pilot valve seat
28
Strainer
42 43 44
Figure 5-27 GP Type
76
Part name
Primary communicating port Secondary pressure detection port Diaphragm chamber
5.2.2-4 Seal Pot This is a pot filled with ethylene glycol. Ethylene glycol is a liquid used to transmit fuel atomizing pressure to equalizing valve. If seal pot does not contain a sufficient amount of ethylene glycol, atomized steam pressure is not set properly to cause poor combustion. Follow steps below to check ethylene glycol level and fill seal pot with this liquid. Use ethylene glycol that meets following specifications: Purity: 99.5% or above Density (20°C): 1.12 to 1.15 g/ml Water content: 0.2% or above a) Close cock for equalizing valve oil detection connected to fuel piping. b) Remove air vent plug on top of seal pot and open cock. c) Loosen air vent plug of equalizing valve body, check that ethylene glycol comes out, and then tighten it. d) Pour ethylene glycol until it comes out of air vent cock on top of seal pot.
Ethylene glycol comes out soon if there is no vent.
e) Close air vent cock. f) Open cock for equalizing valve oil detection connected to fuel piping. g) Put air vent plug back in place.
Air vent cock and plug
Seal pot
Cock for equalizing valve oil detection Air vent plug on equalizing valve body
77
5.2.2-5 Equalizing Valve
WARNING Equalizing valve has been set at optimum pressure in trial operation, and it is prohibited to change setting as a rule. Failure to observe this instruction may cause poor combustion, Instruction
backfire (*), or other accidents. If changes are made, contact MIURA offices and ask for instructions.
Equalizing valve adjusts atomized steam flow rate appropriately for different combustion levels. It also detects fuel oil pressure and keeps difference from steam pressure constant. Reference differential pressure settings for different models at combustion load of 20% (low combustion) are (Reference value)
shown below:
Model HB-08T HB-10T HB-12T HB-15T HB-18T HB-20T Differential pressure setting of atomized MPa 0.05 0.08 steam equalizing valve Differential pressure setting of atomized steam equalizing valve = (steam) pressure at exit of equalizing valve - (fuel) pressure at exit of shutoff valve (MPa) a) Check secondary pressure of equalizing valve at combustion load of 20%. Confirm that primary steam pressure of equalizing valve is around 0.5 MPa. b) Check for abnormal noise. c) Check for steam leaks.
If difference between secondary pressure and fuel
Figure 5-28 Inter structure of equalizing valve RCV Type
pressure at combustion load of 20% has deviated from 1
Body
16
Spring
2
Lower cover
17
Gasket
3
Valve Sheet (upper)
18
Bellows unit
4
Valve Sheet(lower)
19
Packing
5
Spring Sheet(upper)
20
Plug
b) Remove cap (13) .
6
Stud bolt
21
Air vent plug
c) Turn adjusting screw (11) to adjust secondary pressure.
7
Lower cover gasket
22
Hexagon bolt
8
Adjusting screw guide
23
Spring washer
Turn screw clockwise to increase pressure.
9
Valve Stem
24
Hexagon nut
Turn screw counterclockwise to decrease pressure.
10
Lower cover
25
Hard lock
value set in trial operation, adjust it by following steps below: a) Ensure that combustion is taking place at load of 20%.
d) After adjusting pressure, put cap (13) back in place.
78
11
Adjusting screw
26
Plate spring washer
12
Packing retainer
27
Gland packing
13
Cap
28
Spring Sheet（lower）
14
Upper cover gasket
15
Setting spring
5.3 Fuel Oil Thermostat (for Fuel Oil Heater) Carry out operation test of each alarm once every three months. Check that temperature at which alarm is activated is almost the same as dial setting. Temperature setting of thermostat for low and high temperature alarm depends on viscosity of fuel. Refer to temperature chart. Refer to page 81 “5.3.3 Heavy Oil Heating Temperature” in Chapter 5.
5.3.1 Dial Type Thermostat for fuel oil senses temperature and turns electrical switch on or off. It uses fluid with high expansion coefficient in thermo sensor. When it senses temperature, fluid is expanded and pressure inflates diaphragm of body inside to activate lever for opening electrical contact. When diaphragm is deflated, electrical contact is closed.
< Adjustment> As shown in below figure, thermostat is dial type. After loosening dial set fittings, set dial to given temperature and fasten it with set fittings. Set thermostat for heater protection at 180°C (Unchangeable).
EGO thermostat specification
Thermostat for heater protection
Thermostat for high temperature alarm
Thermostat for low temperature alarm
Figure 5-29 Fuel Oil Thermostat (Dial Type)
79
5.3.2 RT Type Note Some boiler use thermostat of RT type depending on specification. < Adjusting operation temperature> Adjust temperature by setting knob with reference to value on setting scale plate. Set differential (*) to the minimum.
5.3.3 Heavy Oil Heating Temperature For effective combustion ability, keep viscosity of fuel oil in nozzle section at 12 cSt or less. For proper fuel oil heating temperature for different viscosity standards of fuel oil, refer to following chart. Table 5-2 Temperature Setting for Viscosity (Example) Redwood No.1Sec./100゜F
1500sec.
Kinematic Viscosity（cSt）at 50℃
IF-180
（IF）Residual Fuels, cSt/50℃
180cSt
Kinematic Viscosity（cSt）at 100℃
25cSt
CIMAC and ISO Fuels, cSt/100℃
2500sec. （280cSt）
－
CIMAC/RM-25
3500sec. IF-380 380cSt 35cSt CIMAC/RM-35
Fuel oil heating temperature (Setting temperature of temperature
～125°C
130°C
135～140°C
controller)
Table 5-3 Heavy Oil Heating Temperature Chart
When 300cSt (at 50°C)
81
5.4 Pressure Switch (for Steam, Atomized Fluid, and Fuel Oil)
WARNING During inspection work, hot steam may blow out to cause burn. Be careful with operating valves. Caution
Before wiring work, be sure to turn control panel power off. Failure to observe this instruction may cause electrical shock due to high voltage, resulting in injury or death.
Note Inspect pressure switches and check their operation once every 3 months according to steps below: 5.4.1 Steam Pressure Switch Steam pressure switch is used to issue alarms. Contact of pressure switch for low pressure alarm is opened to issue alarm when steam pressure falls below set pressure. Contact of pressure switch for high pressure alarm is opened to issue alarm and stop combustion when steam pressure exceeds set pressure.
Check connections for steam leaks. Carry out inspections with reference to Sections 5.7.9 and 5.7.10 in "5.7 Operation Check of Each Safety System" in Chapter 5. Refer to page 90 “5.7.9 High Steam Pressure Alarm” and page 91 "5.7.10 Low Steam Pressure Alarm" in Chapter 5.
Figure 5-31 Steam Pressure Switch and Pressure Gauge
82
5.4.2 Atomized Fluid Pressure Switch Atomized fluid pressure switch is used to issue low atomized fluid pressure alarm. When atomized fluid pressure falls below set pressure, contact is opened to issue alarm and stop combustion. Check connections for steam leaks. Carry out inspections with reference to Sections 5.7.15 and 5.7.16 in "5.7 Operation Check of Each Safety System" in Chapter 5. Refer to page 92 “5.7.15 Low Atomized Steam Pressure Alarm” and "5.7.16 Low Atomized Air Pressure Alarm" in Chapter 5.
5.4.3 Fuel Oil Pressure Switch This pressure switch is used to issue alarm when fuel oil pressure drops for some reason during combustion. Note Some boilers use fuel oil pressure switch of RT type, depending on specifications (Standard boilers use SNS-P type). Check connections for steam leaks. Carry out inspections with reference to Sections 5.7.5 in "5.7 Operation Check of Each Safety System" in Chapter 5. Refer to page 88 “5.7.5 Low Oil Pressure Alarm” in Chapter 5.
Figure 5-33 Fuel Oil Pressure Switch 83
5.4.4 Pressure Switch Adjustment Procedure Note Do not adjust working position adjustment screw. Adjusting screw may cause trouble. a) Turn pressure regulating screw counterclockwise. (pressure regulating spring is compressed) Contact pressure goes up as shown on gauge. b) When contact pressure goes up, disconnection pressure goes up, logically. < Adjusting differential (*)> Set differential for pressure switch that is used for alarm to the minimum by turning differential pressure regulating screw counterclockwise.
5.5 Differential Transmitter Differential transmitter detects differential pressure occurred by boiler water level and sends electric signal accordingly differential pressure to water level indicator inside of boiler control panel . a）Confirm that there is no difference between water level indicator display and water level gauge display. ・In case difference is big, perform zero adjustment by normal water level at zero adjustment trimmer of side of differential transmitter. b）Check for water leakage. a）Adjust water level to normal water level while checking water level of water level gauge. b）Adjust zero while pushing adjustment trimmer and turn trimmer. c）Confirm water level indicator displays 0mm, for normal water level of water level gauge.
Note Adjust normal water level during combustion at pressure for general use. Display of water level gauge and water level indicator occur error due to steam pressure and operation condition. And, display of water level gauge and water level meter occur error during combustion stop, because water level ware adjusted to normal level during combustion at pressure for general use at the time boiler is delivered. Manifold valve
Zero adjustment trimmer
Figure 5-35
Differential transmitter
85
5.6 Flow Control Valve Flow control valve opens and closes by electric signal from water level indicator, and controls amount of feed water with target of normal water level.（Feed water pump is always in operation.） a）Check for water leaks. b）Confirm opening indication and operation time is in normal range. c）Check for abnormal noise. d）Check there is no water or dew condensation inside of controller.
No
Part name
Material
Body Cap Ball Temper
Sheet Temper
Stellite
Stem Packing Bracket Connector Electric operate machine
Direction of flow
Figure 5-36 Flow control valve
86
Temper
Quantity
5.7 Operation Check of Each Safety System
WARNING Do not pull out lead wire with wet hands. Failure to observe this instruction may cause Caution
electrical shock due to high voltage, resulting in injury or death.
5.7.1 Ignition Failure Alarm a) Before igniting burner, remove flame eye (*) on the top surface of wind box (*) and put your hand over tip. b) Press combustion switch. Ignition is attempted after pre-purge (*); however, flame eye does not detect flame and determines that there is something wrong. c) Check that audio and visual alarms are issued. Check that combustion is stopped. d) Press buzzer stop switch. Audio alarm is stopped. Alarm lamp does not turn off and comes to remain on. e) Put flame eye back in place. Alarm lamp does not turn off but remains on. f) Press alarm reset switch. Alarm lamp turns off and alarm is reset. 5.7.2 Fan Abnormal Stop Alarm a) Trip fan thermal relay during combustion. b) Check that audio and visual alarms are issued. Check that combustion is stopped. c) Press buzzer stop switch. Audio alarm is stopped. Alarm lamp does not turn off and comes to remain on. d) Reset fan thermal relay. Alarm lamp does not turn off but remains on. e) Press alarm reset switch. Alarm lamp turns off and alarm is reset.
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5.7.3 Flame-out Alarm a) Remove flame eye (*) during combustion, and put your hand over tip. b) Check that audio and visual alarms are issued. •
Check that combustion is stopped.
c) Press buzzer stop switch. •
Audio alarm is stopped.
•
Alarm lamp does not turn off and comes to remain on.
d) Put flame eye back in place. •
Alarm lamp does not turn off but remains on.
e) Press alarm reset switch. •
Alarm lamp turns off and alarm is reset.
5.7.4 Abnormal Flame Alarm a) Remove flame eye during post-purge (*), and illuminate flame eye. b) Check that audio and visual alarms are issued. •
Check that post-purge is continued.
c) Press buzzer stop switch. •
Audio alarm is stopped.
•
Alarm lamp does not turn off and comes to remain on.
d) Put flame eye back in place. •
Check that post-purge is stopped 35 seconds after flame eye is put back in place.
•
Alarm lamp does not turn off but remains on.
e) Press alarm reset switch. •
Alarm lamp turns off and alarm is reset.
5.7.5 Low Oil Pressure Alarm a) Press combustion switch. b) Lower flow rate of fuel oil by adjusting fuel oil pump outlet valve or pump oil pressure. c) Check that audio and visual alarms are issued. There should be 2-second delay before they are issued. •
Check that combustion is stopped.
d) Press buzzer stop switch. •
Audio alarm is stopped.
•
Alarm lamp does not turn off and comes to remain on.
e) Press alarm reset switch. •
Alarm lamp turns off and alarm is reset.
f) Adjust flow rate of fuel oil.
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5.7.6 Low Oil Temperature Alarm a) Switch fuel to M.D.O. (*).Shift fuel oil heater (*) switch to A. •
Check that fuel oil heater is stopped, and fuel oil is no longer heated.
b) Shift manual combustion switch to AUTO position, and press combustion switch. c) Shift fuel oil heater switch to C position. d) Check that audio and visual alarms are issued. •
Check that combustion is stopped.
e) Press buzzer stop switch. •
Audio alarm is stopped.
•
Alarm lamp does not turn off and comes to remain on.
f) Shift fuel oil heater switch to A position. •
Check that fuel oil pump is stopped.
•
Alarm lamp does not turn off but remains on.
g) Press alarm reset switch. •
Alarm lamp turns off and alarm is reset.
h) Switch fuel to H.F.O. (*). Shift fuel oil heater switch to C position. 5.7.7 High Oil Temperature Alarm a) Lower setting of thermostat for high oil temperature during combustion. b) Check that audio and visual alarms are issued. When fuel oil heater is not working, there should be 10-second delay before they are issued. There is no such delay if fuel oil heater is in operation. •
Check that combustion is continued.
c) Press buzzer stop switch. •
Audio alarm is stopped.
•
Alarm lamp does not turn off and comes to remain on.
d) Reset thermostat for high oil temperature to value in list of principle items. •
Alarm lamp turns off.
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5.7.8 Exhaust Gas High Temperature Alarm Boiler flue has thermostat to measure temperature of exhaust gas. If there is abnormal temperature, alarm is started and operation is stopped electrically. At the time thermostat is delivered from factory, it is set at 450°C (Unchangeable). If thermostat is activated to stop boiler during operation, measure gas temperature with thermometer, and determine whether problem is due to failure of thermostat or temperature is actually increasing. If temperature of exhaust gas exceeds 450°C, there is high possibility that there is some sort of malfunction in combustion chamber. Open furnace, and check for fallen refractory materials, or other causes. If there is malfunction, immediately take corrective action. Figure 5-37 Exhaust Gas Thermostat
If incomplete combustion continues for a long time, soot may be accumulated on heating pipes to increase temperature of exhaust gas. Pay constant attention to furnace to keep complete combustion.
a) Lower setting of thermostat by turning dial during combustion. b) Check that audio and visual alarms are issued. 5.7.9 High Steam Pressure Alarm a) Turn off main power supply of control panel. b) Disconnect wiring from back surface of pressure regulator (see right figure). c) Turn on main power supply of control panel and start combustion. •
Boiler continues combustion at pressure above set pressure.
•
Check that pressure switch (for high steam pressure) is activated when set pressure is reached and combustion is stopped following issuance of alarm.
d) Turn off main power supply of control panel and connect wiring disconnected above. e) Open main steam valve to make boiler pressure fall within normal working pressure range. Disconnect wiring of Y434 or Y515. Figure 5-38 Back Surface 90
of Pressure Regulator
5.7.10 Low Steam Pressure Alarm a) Increase boiler pressure to normal working pressure. b) Close steam pressure gauge valve. c) Check that test cock is closed and remove plug. d) Open test cock gradually. Note Hot, high-temperature steam blows out. Be careful not to get burned. •
Check that pressure gauge reading decreases and that pressure switch is activated when set value of pressure switch is reached. Combustion is not stopped.
e) Close test cock, put plug back in place, and open steam pressure gauge valve. 5.7.11 Low Water Level Alarm a) Close upper and lower water level gauge valves. b) Open water level gauge drain valve slightly. •
Check that boiler water is discharged from inside water level gauge and that low water level alarm is issued.
•
Combustion is not stopped.
c) Close water level gauge drain valve and open upper and lower water level gauge valves. 5.7.12 Low Low Water Level Alarm a) Perform steps a) and b) in 5.7.11. •
Check that boiler water is discharged from inside water level gauge and that combustion is stopped following issuance of low low water level alarm.
b) Close water level gauge drain valve and open upper and lower water level gauge valves. 5.7.13 Power-off Alarm a) Turn power off during combustion. •
Check that burner is stopped.
b) Turn power on. 5.7.14 Sequencer Error Alarm • When malfunction of sequencer is detected, lamp lights up as visual alarm. Note To allow sequencer operating normally to malfunction intentionally, special equipment must be used. For more details, contact MIURA offices.
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5.7.15 Low Atomized Steam Pressure Alarm a) Switch atomized fuel to "STEAM" and bring boiler into automatic combustion. b) Close atomized steam valve. •
Check that pressure gauge reading decreases and that pressure switch is activated to stop combustion when set value of pressure switch is reached.
c) Open atomized steam valve. 5.7.16 Low Atomized Air Pressure Alarm a) Switch atomized fuel to "AIR" and bring boiler into automatic combustion. b) Close atomized air valve. •
Check that pressure gauge reading decreases and that pressure switch is activated to stop combustion when set value of pressure switch is reached.
c) Open atomized air valve. 5.7.17 Damper Control Alarm a）Turn off main power supply of control panel. b）Disconnect wiring of external wiring terminal ”23” on control panel. c）Turn on main power supply of control panel and start combustion. d）Check that audio and visual alarm are issued within 90 seconds after combustion is started. e）Press stop buzzer switch. •
Audio alarm is stopped.
•
Blinking alarm lamp does not turn off and comes to remain on.
f）Press combustion stop switch. •
Alarm is reset.
g）Turn off main power supply of control panel and connect wiring disconnected above. 5.7.18 Operation Check by differential transmitter（Low Water Level, Low Low Water Level, High Water Level） Adjust water level of water level gauge to proper level and close upper and lower water level gauge valves on water level gauges of water level electrode to check differential transmitter. Check water level by water level indicator. Check water level control and adjust water level to proper, before check open upper and lower water level gauge valves on water level gauges. Note •
Perform operations after ensure that boiler combustion is stopped.
•
Water level alarm detects at each water level electrode and differential transmitter. Checking water level control by differential transmitter is described here. For details about checking water level control by water level electrode, refer to “5.7.11 Low Water Level Alarm” and “5.7.12 Low Low Water Level Alarm” in Chapter 5. Refer to page 91 “5.7.11 Low Water Level Alarm” in Chapter 5. Refer to page 91 “5.7.12 Low Low Water Level Alarm” in Chapter 5.
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＜Low Water Level Alarm＞ a）Set feed water pump shift switch to OFF, open bottom blow valve slowly. Check that water level is lowered to low water level. When water level is lowered to low water level, close bottom blow valve. b）Check that audio and visual alarms are issued. There should be 10-second delay before they are issued. c）Press stop buzzer switch.
Audio alarm is stopped. Blinking alarm lamp does not turn off and comes to remain on.
d）Select pump for operation by feed water pump shift switch. Operation indicator lamp of feed water pump is lightened. Feed water to boiler uppered to low water level, set feed water pump shift switch to OFF. Alarm lamp turns off. ＜Low Low Water Level Alarm＞ a）Set feed water pump shift switch to OFF, open bottom blow valve slowly. Check that water level is lowered to low low water level limit. When water level is lowered to low low water level limit, close bottom blow valve. b）Check that audio and visual alarms are issued. c）Press stop buzzer switch Audio alarm is stopped. Blinking alarm lamp does not turn off and comes to remain on. d）Select pump for operation by feed water pump shift switch. Operation indicator lamp of feed water pump is lightened. Alarm lamp does not turn off but remains on when water level rises over low low water level. e）Press alarm reset switch.
Alarm lamp turns off and alarm is reset.
＜High Water Level Alarm＞ a）Set feed water shift pump to MANU and select pump for operation by feed water pump shift switch. Operation indicator lamp of feed water pump is lightened. Ensure that water level does not reach upper limit. b）When water level is uppered to high water level, set feed water pump shift switch to OFF. c）Check that audio and visual alarms are issued. There should be 30-second delay before they are issued. d）Press stop buzzer switch Audio alarm is stopped. Blinking alarm lamp does not turn off and comes to remain on. e）Open bottom blow valve slowly. When water level is lowered to high water level, alarm lamp turns off.
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5.7.19 Suction Damper Error Alarm a）Turn off main power supply of control panel. b）Disconnect wiring of external wiring terminal ”49” on control panel. c）Turn on main power supply of control panel and start combustion. d）Check that audio and visual alarm are issued in 50 seconds after combustion is started. e）Press stop buzzer switch. Audio alarm is stopped. Blinking alarm lamp does not turn off and comes to remain on. f）Press alarm reset switch. Alarm lamp turns off and alarm is reset. g）Turn off main power supply of control panel and connect wiring disconnected above.
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6. Yearly Inspection and Maintenance 6.1 Fuel Oil Heater (*) 6.1.1 Combined Use of Electricity and Steam Heater that uses both electricity and steam as shown in figure below is used to heat heavy oil to proper temperature. F.O. outlet
Steam inlet Safety valve
Drain Steam outlet F.O. inlet
Drain
Figure 5-39 Fuel Oil Heater (Electricity/Steam)
Electric heater contains nichrome wire coil with high thermal conductivity as heating element in the center of pipe, and is filled with special fused powder with excellent electric insulation at high temperature. To save electric capacity, heater body is heated by steam from outside. Thus, electric heater is combined with steam. Both steam and electric heater are controlled by opening or closing steam solenoid valve with fuel oil temperature controller. If sludge adheres to heater, poor combustion or abnormal heating may be caused due to unstable control. Clean inside of heater on a yearly basis. Electric heater as shown in figure is used as standard to heat heavy oil used as fuel to proper temperature. Heater is installed on outlet side of oil pump and oil temperature is regulated by temperature controller. Fuel oil heater contains nichrome wire coil as heating element in the center of pipe for high conductivity, and is filled with special powder that has excellent electric insulation at high temperature; these materials are solidified under high pressure. Long-term use of fuel oil heater causes accumulation of oily sludge in heater, which may lower heating temperature or damage element due to insulation failure. Open and clean fuel oil heater on a yearly basis. In addition, raise discharge pressure of fuel oil pump and check operation of safety valve. Note
Sludge remaining after cleaning may cause leaks from solenoid valves. Remove it completely by flushing or by another method. 95
6.1.2 Solenoid Valve for Steam Heater
1
Core assembly (fixed iron core)
2
Coil
3
Plunger spring
4
Plunger
5
Tension spring
6
Stuffing
7
Main valve assembly
8
Body
Figure 5-40 Solenoid Valve for Steam Heater
< Inspection and maintenance> Check valve and seat for scratches, check for coil burnout, and clean them regularly. In disassembling device, be careful not to lose internal parts. When replacing valve, check flow direction.
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6.2 Water Level Gauge and Water Level Detecting Rod Note Replace water level gauge glass once a year. If it is not replaced, it may be deteriorated with time and damaged to cause hot water or steam to blow out from damaged part and cause a burn.
Water level gauge is integrated with water level detecting rod as shown below:
Boiler body
Upper water level gauge valve
Upper water level detecting rod connecting pipe
Lower water level gauge valve Lower water level detecting rod connecting pipe
Section view along line A-A
1
Water level gauge column
7
Hexagon nut
2
Water level gauge glass seat
8
Spring washer
3
Water level gauge glass holder
9
Plain washer
4
Water level gauge glass
10
Connecting pipe
5
Water level gauge glass packing
11
Water level gauge cover
6
Hexagon bolt
12
Water level gauge drain valve
Figure 5-41 Water Level Gauge and Water Level Detecting Rod Water level detecting rod is installed on the top and bottom of steam drum (on steam side and water side) with valves. Rod contains water level gauge glass to serve as both water level gauge and water level detecting rod. Water level gauge is important device for safety to check if prescribed water level is kept in boiler. As glass of water level gauge must be kept clean, clean it by blowing water level gauge at least once a day. Reflective gauge glass is used for water level gauge, and size depends on rules of vessel classification. 97
Aside from water level gauge, which is designed to visually check water level, water gauge column has four (or five) water level detecting rods (3) with different lengths, which electrically detect water level and put out signal to automatically start/stop feed water pump or to automatically stop burner when low low level is detected. Stainless detecting rod is screwed in electrode holder and further tightened with set screws. As water level detecting rod may get dirty with concentrated boiler water and cause malfunction, pull water level detecting rods out and clean them at least once every three months.
1
Electrode holder
2
Water gauge column
3
Water level detecting rod
4
Drain valve flange
Figure 5-42 Water Level Detecting Rods a) Continuity and insulation check of electrode holder. •
Check continuity and insulation of electrode holder every three months.
•
Replace electrode holder periodically (once every 2 years) as aged deterioration causes insulation and continuity failure. a to ○ Continuity check ○ c : 0Ω Insulation check ○ a to ○ b : 0.1 MΩ or above
b) If continuity or insulation failure is found, replace electrode holder.
Blow water level gauge once a day. a) Close upper water level gauge valve and open water level gauge drain valve. •
Boiler water is discharged from inside water level gauge, and lower water gauge column connecting pipe is cleaned.
b) Close water level gauge drain valve and lower water level gauge valve, and open upper water level gauge valve. c) Open water level gauge drain valve. •
Steam is discharged, and upper water gauge column connecting pipe and inside of water gauge column are cleaned.
d) Close water level gauge drain valve and open lower water level gauge valve. 98
6.3 Flame Detector (FS-901) Flame detector is auxiliary relay that is installed to detect burner flame and output electric signal.
Figure 5-43 Flame Detector Check on a yearly basis that voltage between terminals [3] and [4] of flame detector during combustion does not exceed 2.5 V. If voltage exceeds 2.5 V, check whether or not flame eye (*) glass and light sensitive surface of flame eye are dirty. If they are dirty, clean them. Refer to page 62 “4.5 Flame Eye” in Chapter 5.
If voltage exceeds 2.5 V even after cleaning, there is possibility of failure of flame eye or flame detector. In that case, replace flame eye with a spare one. If voltage exceeds 2.5 V again, there is high possibility of failure of flame detector. In that case, replace flame detector.
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7. Inspection and Maintenance on Vessel Docking 7.1 Soot Cleaning of Furnace a) Remove burner from boiler. b) Open inspection opening of funnel. c) Visually inspect inside of combustion chamber and check conditions of castable and whether or not inside is blackened by soot. d) Clean combustion chamber with high-pressure water cleaner. Also clean boiler body from inspection opening of funnel. Refer to page 15 “5.1 Boiler Body” in Chapter 2. e) Suck out cleaning solution in bottom of furnace with pump.
Note Dispose of wastewater after cleaning, which has a low pH of around 1, properly. MIURA cleans furnace to remove soot. For more details, contact MIURA offices.
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8. Parts Information about Replacement 8.1 Ignition Transformer (*)
WARNING Ignition transformer conducts high voltage. Touching live wiring may cause electrical shock. Instruction
Turn power off before working with ignition transformer.
Figure 5-44 Ignition Transformer Ignition transformer is important device for creating sparks from ignition rod by converting voltage of 100 V on primary side to a high voltage of 10 KV. Primary voltage of transformer can be 100 V or 200 Wiring is different depending on primary voltage.
Control voltage 100V
Control voltage 200V
Figure 5-45 Ignition Transformer Wiring Diagram Note Avoid insulating ignition transformer from boiler by rubber or other materials. Otherwise, it cannot be earthed and may be burned. 101
8.2 Sequencer (Programmable Controller) 8.2.1 Description of Component Unit of CJ2M
Input unit
Output unit
CPU
Figure 5-46 External View of the Sequencer Unit
Slider Fix adjacent units Battery storage cover When cover is opened, there are battery and front dip switch. Memory cassette is also installed inside of cover.
LED display
Connector Connect between adjacent units.
Memory card cover There is memory card in cover.
Figure 5-47 Name of Part of CPU Unit
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＜Dip Switch＞ Shows standard condition of dip switch Condition of dip switch 1
OFF
2
ON
3
OFF
4
OFF
5
OFF
6
OFF
7
OFF
8
OFF
Figure 5-48 Dip switch
＜How to install memory card＞
・Pull the top of memory card to remove.
・Insert memory card back with label is on left side. Label
Figure 5-49
Installing/Removing of Memory Card
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Battery is built in CPU unit. Following data is backed up by battery.
I/O memory (including PC system configuration)
Clock data (when memory cassette with clock function is installed)
Battery lasts for 5 years in 25°C ambient temperature. When battery runs out, front ERR/ALM LED flashes. It must be replaced with new battery. Contact with MIURA offices.
Replace battery according to following steps. a)
Turn off boiler power. If power is off, turn on power once and leave it at least for 5 minutes.
b)
Pull out connector of battery in battery storage cover and replace battery with new one.
Once old battery is removed, install new battery within 5 minutes. If power is not supplied to CPU for 5 minutes or more, stored data may be lost.
Figure 5-50 Replacement of Battery
Operation switch, pressure switch on detector and thermostat are connected to work as joint.
