File No.5 - Gt Operating Manual

SPIC – GT Operating Manual

CONTENTS

S No PARTICULARS PAGE NO

1 GENERAL DESCRIPTION 2

2 EQUIPMENT SPECIFICATION 3

3 ENGINE SYSTEM 5

4 FUEL SYSTEM 9

5 LUBRICATION SYSTEM 10

6 COOLING AIR SYSTEM 11

7 CONTROL SYSTEM 11

8 STARTING AND STOPPING 12

9 TRIPS AND ALARMS SYSTEM 15

10 TROUBLE SHOOTING 16

11 DRAWINGS 6 Sheets

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1.0 GENERAL DESCRIPTION

Gas Turbine manufactured by Ruston Gas Turbine Limited, England

(Model: TB 5000) is a power generating system with a capacity of 2.5

MW. GT is dual fuel power turbine that can be operated by both

liquid (Kerosene and Diesel) and gas fuel. Generator manufactured

by Meidem Sha Electric Company, Japan is coupled with power

turbine by a gearbox. Air admitted to the two-stage power turbine

after compression in 12 stages of the compressor turbine

(compression pressure ratio: 6.89). Around 76.1 T/hr. of air is moved

by power turbine to produce power of 2.5 MW in the generator. Gas

turbine has thermal efficiency of about 25%. The exhaust gas of gas

turbine is either utilised for superheating the saturated steam from

SA Plant or can be diverted to the atmosphere through chimney.

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2.0 EQUIPMENT SPECIFICATION

2.1.1 ENGINE DATA

2.1.1 Operating Temperature:

Nominal Continuous Operating Temperature : T. op 480oC Maximum Continuous Operating Temperature: T. op 5100C

2.1.2 Speed:

Gas Generator – At Normal Rating : 10000 rpmPower Turbine : 7940 rpmGenerator Speed : 1500 rpm

2.2 FUEL SYSTEM:

2.2.1 Fuel Transfer Pump

Capacity : 1.8 M3/hr.Discharge Pressure : 2.0 Ksc (g)Speed : 930 rpmDrive : 440V x 50 HZ x3PhasePower : 1.5 KW

2.2.2 Main Fuel Pump

Capacity : 50 Lit/Min.Discharge Pressure : 125 Ksc (g)Speed : 1470 rpmDrive : 440V x 50 HZx3PhasePower (Motor) : 20 KW

2.2.3 Fuel Specification

Fuel : Superior Kerosene OilFlash Point : 35o CSmoke Point : 22 mmTotal sulfur : 0.2 % w/wAcidity : NILChar Value : 20 mg/Kg of SKOBloom on glass chimney : Grey

2.3 LUBRICATION SYSTEM:

Lube Oil : SP 46 Type : Forced lubrication

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2.3.1 Main Lube Oil Pump

Capacity : 410 Lit/Min.Discharge Pressure : 7 Ksc (g)Drive : Turbine

2.3.2 Auxiliary Lube Oil Pump

Capacity : 393 Lit/Min.Discharge Pressure : 7.0 Ksc (g)Speed : 1440 rpmDrive : 440V x 50 HZx 3PhasePower : 15 KW

2.3.3 Emergency Lube Oil Pump

Capacity : 13.7 Lit/Min.Discharge Pressure : 3.0 Ksc (g)Speed : 1600 rpmDrive : 24V DCPower : 0.37 KW

2.3.4 Lube Oil Cooler Fan

Drive : 440V AC x 50HZx 3Ph.Power : 5.5 KWRated Current : 9.6 Amps

2.4 GENERATOR DETAILS

Manufacturer : Meidem Sha, JapanType : Brushless ExciterVoltage : 11000 VoltsFrequency : 50 HZSpeed : 1500 rpmNo of Poles : 4Power Factor : 0.8Exciter Voltage : 201 Volts.Field Current : 150 Amps

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3.0 ENGINE

The engine is a twin shaft unit and consists of two main sections:1. Gas Generator2. Power Turbine

3.1 GAS GENERATOR

The gas generator section comprises the air inlet casing, compressor stator casing, compressor turbine stator casing, centre casing, combustion chambers and rotor assembly.

3.1.1 Air Inlet Casing

The air inlet casing assembly comprises an external casing rectangular in shape and a circular internal casing, which incorporates the compressor rotor front bearing housing and also carries the twenty six radially disposed variable inlet guide vanes. This casing is called the Bearing support member and is designed and shaped to provide a smooth and uninterrupted path to the compressor for incoming air.

3.1.2 Variable Inlet Guide Vanes

The engine is equipped with air inlet guide vanes, the angles of which are variable according to engine conditions.

The vanes are moved to either one of two positions by an automatic self-contained system comprising valves, cylinders and levers pneumatically operated by air pressure taken from the engine compressor.

The initial position of the inlet guide vanes gives a reduced mass airflow to aid start conditions and engine handling up to approximately one third of full load.

Upon the engine reaching approximately one third of full load, an air relay valve, actuated by air pressure taken from the compressor delivery stage, automatically operates a spool valve, allowing air from stage 10 of the compressor to enter a “Belloframe” cylinder, which in turn, through levers and linkage, moves the inlet guide vanes into their normal running position, giving maximum air mass flow to the gas generator, resulting in a reduced maximum temperature (T.Max) at full load.

Upon the engine load falling below approximately one third of full load, the procedure is reversed and the inlet guide vanes revert to their original engine starting position.

3.1.3 Compressor Stator Casing Assembly

The compressor stator casing comprises a top and bottom half. The stator casing carries twelve stages of stator blades and one stage of exit guide vanes. Stator stages numbers one and two contain thirty nine blades and thirty nine spacers in each stage, i.e. assembly is blade and spacer alternately, stages three to five inclusive each have fifty one blades and fifty one spacers, stages six to eight inclusive have sixty blades and stages nine to twelve and the single stage of exit guide vanes each contain sixty eight blades. All stages from six onward are assembled without spacers.

3.1.4 Centre Casing Assembly

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Centre casing is split along its horizontal axis, to carry the four combustion chambers.

The bottom of the compressor centre bearing and labyrinth seal housing is integral with the bottom half of the centre casing and oil ways are drilled in the bearing housing support structure to provide a lubricating oil feed and drain.

3.1.5 Quadrant Support Casing

At their “exit” ends the four quadrants are connected together to form an annulus into which the sixty four first stage stator blades are fitted, thus forming the first stage stator quadrant assembly.

The compressor turbine second stage stator ring assembly consists of sixteen segments, which form an outer ring. Sixty four stator blades dovetailed into segments and the diaphragm, which carries the outer member of the stator shroud seal and to which the inner ends or “platforms” of the stator blades are secured by parallel pins.

3.1.6 Interduct Casing

The interduct casing joins the gas generator section of the engine to the power turbine section. A ring welded to the inner face of the casing, forms the outer skin of the duct, which transfers the hot gases from the compressor turbine outlet to the power turbine inlet.

3.1.7 Turbine Stator Casing

Turbine stator casing consists of power turbine first and second stage stator assembly.

The power turbine first stage stator assembly consists of sixteen segments. A dovetail groove is machined in their inner faces to accept the sixty four first stage stator blades. The “platforms” or inner ends of the blades are drilled and secured to the periphery of the diaphragm. The centre of the diaphragm is blanked off by a disc called a turbine sealing plate which completely separates the gas generator side of the engine from the power turbine, except that the hot gases are permitted to pass from one to the other through the interduct.

The power turbine second stage stator assembly is located in the forward end of the power turbine stator support casing. The second stage stator contains the same number of blades as the first stage except that the turbine sealing plate is replaced by a stator shroud seal.

3.1.8 Gas Generator Rotor Assembly

The gas generator rotor assembly comprises a twelve stage compressor rotor and a two stage compressor turbine with their relative seals on a common shaft.

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The number of blades in each stage is as follows:

Stage numbers 1 and 2 – thirty seven blades and thirty seven spacers, i.e. blade and spacer alternately, stage numbers 3 to 5 – forty nine blades, stage numbers 6 to 8 and 9 to 12 – fifty nine blades and sixty nine blades respectively. To prevent the blades from moving circumferentially in their grooves, four equally spaced blades in each stage are located by means of dowels, inserted between the rotor discs on assembly.

The compressor turbine rotor consists of two discs, which are accurately located relative to the stubshaft and each other by means of “Hirth Couplings”.

3.2 THE POWER TURBINE

The power turbine comprises the power turbine stator assembly, exhaust collector assembly and power turbine rotor assembly from which the drive is transmitted to the gearbox and driven machinery through a gear type sleeve coupling.

3.2.1 Power Turbine Rotor Assembly

The power turbine rotor assembly consists of two rotor discs attached to a common shaft. Each of the two rotor discs carries seventy five blades. The power turbine output shaft is machined to include the inner member of the power turbine bearing housing labyrinth seal, front and rear bearing journals, a seating for the oil sealing ring and flange for the thrust bearing.

3.3 GEARBOX

Common to all gearbox configurations is a gear train, driven by the gearbox shaft, which provides a drive of 1500 rpm for the auxiliary gearbox. This in turn drives the main lubricating oil pump. A speed sensing probe is positioned close to the teeth of the driving gear on the gearbox shaft, for the purpose of providing a power turbine speed signal to the governor.

3.4 COMBUSTION CHAMBERS

Four separate combustion chambers are employed; they are of the reverse flow type equally spaced on the forward face of the pressure casing and inclined at an angle to the axis of the engine.

The outer end is closed by the end cone and back plate. The sight window and igniter are mounted on the end cone and the back plate carries the burner assembly and the gas and distillate fuel connections.

The flame tube is centrally disposed, forming an annular passage to allow air to flow from the compressor to the head of the combustion chamber.

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Attached to the back plate are the swirler and the diffuser. The purpose of the former is to produce a vortex flow around the tip of the burner. In order to maintain stable conbustion conditions and the diffuser, which has a series of radially disposed slots and louvres, creates a turbulance within the flame tube to give complete combustion of the fuel and an even temperature to the gas stream passing to the turbine.

The outer end of the flame tube allow the passage of air to the swirler and the diffuser and a series of smaller holes further down the wall provides for a supply of air to flow directly into the tube to cool the skin.

3.5 FRAME ASSEMBLY

The frame is manufactured as a single unit to carry the engine and gearbox. Housed within the frame is the lubricated oil tank.

The front engine support is mounted on two pads at the forward end of the engine; it is in the form of a double trunnion thus permitting free axial expansion or contraction, which takes place due to changes in temperature. Two support feet, which are integral with the frame, carry the engine at the gearbox end. Three drainpipe assemblies carry oil back to the tank from the front bearing assembly, the centre bearing and the gearbox / power turbine bearing assembly.

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4.0 FUEL SYSTEM

The engine is fitted with a duplex fuel system so that either gas or liquid fuel may be used. The changeover from one fuel to the other is automatic in operation and is initiated by pressing the appropriate push button.

4.1 LIQUID FUEL

Liquid fuel is supplied to fuel pump through a firesafe shut-off ball valve and a duplex filter. A pressure switch provides a warning if the pump inlet pressure falls below 0.2109. The pump output pressure is controlled at 126.5 Ksc by a relief valve, which relieves excess pressure to the inlet side of the pump. Fuel flows to the burners through a high pressure filter, a liquid fuel valve, solenoid fuel valve, diversion valve and a duplex pressurising valve. A tapping is taken from the pressurising valve to a pressure gauge, which indicates fuel pressure at the burners.

The duplex fuel filter has facilities for changing its renewable elements whilst the engine is running. A differential pressure device, mounted on a panel on the underbase, indicates when the element requires replacing.

The liquid fuel valve incorporates a throttle valve, an excess fuel spill valve and two constant pressure drop valves. The operating principle is that of a fixed pressure drop being set up across a variable throttle slot, so that a linear relationship is obtained when an area is increased. The excess fuel spill valve passes excess fuel flow back to the main pump inlet.

If liquid fuel is selected, the solenoid operated fuel valve is used to open the supply line to the burners at the correct point in the starting cycle. It also shuts off the supply of shutdown, or on changeover to gas fuel. A microswitch operates with a valve and is used in conjunction with the control logic to shut down the engine in the event of both liquid fuel and gas fuel solenoid valves being open at the same time. When the solenoid valve is closed the fuel is by-passed directly back to the pump inlet.

Fuel is supplied to the burners through a pressure setting valve and adaptor block. The pressure setting valve provides pilot flow for light-up and increased main flow for running. The adaptor block, fitted to the top of each burner, directs the appropriate fuel flow to the burner.

The igniters, which are in operation for only a short period of time during the starting cycle, are used to light the main burners. Gas is fed to the igniters through a filter, solenoid operated valve, main line restrictor and a restrictor in each combustion chamber line.

The gas pressure supply to the starter engagement cylinder is through a solenoid-operated valve, which opens at the appropriate point in the starting sequence. This forces the starter engagement piston forward, engaging the starter with the gas generator rotor.

In the fully engaged position, the engagement piston uncovers a port in its cylinder wall, admitting gas to a pressure switch, the contacts of which change over, energising the electric starter motor. When the engine is self-sustaining, the solenoid valve is deenergised, shutting off the gas supply to the engagement piston and pressure switch. The electric starter motor is thus de-energised and the piston retracts, disengaging the starter motor from the gas generator.

5.0 LUBRICATION SYSTEM

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The lubricating oil storage tank is a fabricated structure housed within the engine underbase. The tank, which has a capacity of approximately 1364 Litres, is equipped with the following.

Visual Oil Level Indicator Thermostatically controlled heaters, to maintain the temperature of the

oil in the tank above 4.4 Deg.C (40 Deg.F)

Oil is supplied to the engine and driven unit bearings by an engine-driven main pump during normal running and by an A.C motor driven auxiliary pump during the starting, slow speed running, stopping and cooling periods. A D.C. motor driven emergency pump is also installed to provide lubrication and cooling of the ‘hot bearings’ in the event of failure of the A.C auxiliary lube oil pump during the cooling period.

When the main pump is in use, oil is drawn from the tank, through a non-return valve, to the pump inlet and delivered to the bearings through the oil cooler and filter. The main pump incorporates a 1.0 Ksc(g) relief valve. Oil flow by-passes the oil cooler through a thermostatic diversion valve until the oil temperature reaches 40.6oC, when the valve commences to open to the cooler connection, accepting some oil flow from the latter. When the lubricating oil temperature reaches 48.6oC the diversion valve is fully open to the cooler connection and closed to the bypass line accepting only the oil passing through the oil cooler. On leaving the oil cooler / thermostatic diversion valve, the oil enters the manifold block to which are connected the lube oil filter and its differential pressure indicator, a temperature gauge and a dual temperature switch. The switches operate to provide warning and shutdown signals should the lubricating oil temperature rise above 66oC and 74oC respectively. Within the manifold block, a tapping is taken from the main delivery line, between the cooler and the filter, to the main pressure setting valve, which controls the system pressure at 3.5 Ksc by spilling excess oil directly back to the tank.

After passing through the filter, the oil supply is divided into four main feeds:

1. Direct to the compressor journal bearing, compressor thrust bearing, power turbine rear bearing, power turbine thrust bearing and the auxiliary gearbox.

2. Through a non-return valve to the ‘hot bearings’ comprising the compressor turbine centre section bearing and the power turbine front bearing.

3. Direct to the main gearbox.4. Direct to the driven unit.

When the auxiliary pump is in use it draws oil from the tank and delivers it, through a non-return valve, to the outlet line from the main pump. A pipeline connects the auxiliary pump outlet with the main pump inlet in order to prime the main pump during the starting period. A 70 Ksc non-return valve is fitted in a line connecting the auxiliary pump outlet and inlet to act as a relief valve.

When the D.C motor driven emergency pump is in use it draws oil from the tank and delivers it through a filter and non-return valve to the ‘hot bearings’ supply line. Incorporated in the pump is a 30 lb/in2 (2.07 bar) relief valve. Oil is prevented from passing to the rest of the oil system by a non-return valve within the manifold block in the normal supply line to the ‘hot bearings’.

6.0 COOLING AIR SYSTEM

The turbine discs and other high temperature components at the hot end of the engine are cooled by air tapped from the compressor, this air is also used for labyrinth pressurisation and sealing.

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High pressure feed is used for the compressor turbine and medium pressure for the power turbine and compressor inlet labyrinth seals.

The medium pressure air is taken from between the sixth and seventh stator stages into an annulus in the stator casing and piped to the power turbine support housing. A passage formed in the housing conveys the air to the labyrinth seal, where its flow prevents ingress of oil or hot gases and its discharge at the rear face of the turbines cools the rotor disc before spilling into the gas stream and main engine breather.

Air is tapped off after the last stage of the compressor rotor through radial holes filling the cavity in the intermediate shaft, stub shaft and the bore of the compressor turbine rotors.

7.0 CONTROL SYSTEM

The control system has following main functions:

A solid stage logic system accepts signals from the engine and driven equipment during starting and stopping and automatically sequences and times the engine controls. Reed relays are used in the remote annunciation circuits.

A Rustronic electronic governor controls the gas generator and power turbine speeds during starting and running.

A Delta thermocouple temperature monitor indicates exhaust gas temperature and provides signals to the logic system.

For fault protection, the logic system gives audible and visual warning on non-critical faults and shuts down the engine automatically in the event of critical faults.

An electro-mechanical emergency stop system is provided as a back up to the logic system.

The governor is solid state electronic type, that provides following:

Limiting Control Normal Control Output Signals

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7.1 Limiting Control

The governor will limit the fuel input for (a) starting (b) load acceptance (c) maximum power and (d) maximum temperature. During the starting cycle the governor start limiting schedule allows the fuel valve to open slowly, with respect to time, and thus allows the gas generator to accelerate. The gas generator eventually runs fast enough to cause the power turbine to rotate. The power turbine increases in speed to approximately demanded speed at which point normal governing takes place.

7.2 Normal Control

When the power turbine reaches governed speed, normal engine governing takes place, i.e. the fuel flow is regulated by the governor to achieve a steady constant speed. The speed can be adjusted in the following manner, (a) by using the manual raise / lower push buttons on chassis 3 (b) by remote speed control contacts. The location of control is selected by the ‘local / remote’ switch.

7.3 Output Signals

Indication of gas generator speed and output shaft speed is provided and speed switches provide signals for control of pumps, valves, circuit breakers, etc. Some of these switch levels are site adjustable.

8.0 STARTING AND STOPPING

8.1 PRELIMINARY CHECKS

a) Check that the oil level in the frame tank is to the ‘Standing’ level mark on the oil level indicator.

b) Check that the slam-shut valve in the gas fuel system is correctly reset, i.e. with the slot in the squared head of the reset plunger horizontal and the reset plunger capable of being pushed in ¼ inch. (6.35 mm) approximately (with no gas pressure in the line).

c) Open the necessary valves in the main fuel and igniter supply lines and check that the correct pressures are obtained.

d) Ensure the manual fuel valves in both fuel systems are open.e) Check that the turbine liquid fuel supply is adequate.f) Check that the A.C supply is established to the motor control centre and

switched ‘ON’.g) Check that the A.C motor selector switches at the motor control centre

are set to ‘Auto’.h) Check that the D.C emergency lube oil pump motor switch is set to

‘Auto’.i) Ensure the fire and gas detection equipment is switched ‘ON’.j) Close the manual isolators in the control and auxiliary circuits, D.C

circuit breakers CB1 and CB2, and A.C. circuit breaker.k) On closing the D.C circuit breakers power is connected to some of the

turbine control circuits. A few of the fault warning and shutdown lights will commence flashing. Press the ‘Accept’ button to change the flashing lights to steady.

l) Turn the ‘local / remote’ switch to the required position.

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m) Switch on the hood ventilation fan. After a pre-set purge period power is connected to the remainder of the turbine control circuits and the igniter circuits. After approximately 15 seconds the ‘Reset’ button may be pressed to set the fault shutdown circuits. All the fault indication lights should be extinguished and the ‘Ready to Run’ light illuminated.

8.2 STARTING SEQUENCE

Press the start button. The start memory is set, the ‘Ready to Run’ light will start flashing and the ‘A.C Lube oil Pump on’ light will be illuminised. The start memory then starts the following items:

The A.C auxiliary lube oil pump. A digital timer circuit, which gives a number of timed outputs during the

start sequence. The liquid fuel pump A.C motor if liquid is selected. The air filter motor.

When the digital timer reaches 16 seconds, the starter motor is engaged providing that pre-lube oil pressure is present and the fuel valves are at ‘minimum set point’.

The gas generator speed starts to rise, and to 18% speed a governor signal prepares the igniters and pilot gas fuel circuit; when the digital timer reaches 40 seconds the igniters and pilot gas fuel are turned on.

When four pilot flames are seen by the flame detection equipment, a ‘Four Flames On’ signal opens the main fuel valve and the main burners light up. When the digital timer reaches 64 seconds the ignition and pilot gas fuel is turned off.

The power developed due to the fuel input to the gas generator assists the starter to accelerate the gas generator further. At 28% speed the governor starts to open the fuel valves from their ‘light-up’ position, increasing the fuel valve angle linearly with time. At 48% speed a signal disengages the starter motor.

As the gas generator exit gas flow increases the power turbine starts to rotate, and when it has accelerated up to a speed of 45%, the governor provides signals to de-inhibit the 'Lube Oil Pressure Low’ fault protection circuit, inhibit the ‘Start Failed’ shutdown circuit, energise the hours run counter, reset the digital timer, de-inhibit the ‘Exhaust Temperature Deviation High’ circuit, de-inhibit the vibration protection circuit, de-energise the start seconds counter, extinguish the flashing ‘Ready to Run’ light and illuminate the ‘Turbine Running’ lamp. A ‘Ramp-Up’ signal is also provided. At 90% speed a further governor signal de-energises the auxiliary lube oil pump motor.

When the turbine reaches approximately 1/3 full load the inlet guide vanes change over to the run position. This operation is automatically carried out by the inlet guide vane pneumatic system.

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8.3 NORMAL STOPPING

Pressing the stop button causes a normal shutdown to take place. Alternatively one of the ‘Emergency Stop’ buttons may be used, if the need arises, to initiate an immediate shutdown. When a stop signal is sent to the stop memory allowing the stop circuits to operate, the following functions automatically take place:

The fault annunciation is locked out. The main fuel valve of the fuel being supplied to the engine is closed. The sequence logic is reset. The generator circuit breaker is tripped and after a short delay the

generator excitation is tripped.

As the speed falls below 90% the A.C motor driven lubricating oil pump is started. When the gas generator speed falls to below 200 rpm, a signal resets the stop memory. When the engine cools to below 130 Deg.C, an ‘engine cold’ signal stops the Ac motors of the auxiliary lube oil pump, air filter and air blast oil cooler, provided that the gas generator has topped.

The AC and DC isolators must not be opened until the AC auxiliary motor stops running.

If the engine is not being restarted immediately, then both manual fuel shut off valves should be closed.

8.4 EMERGENCY STOPPING

Emergency stopping is initiated automatically if the 24V power supply fails or manually by pressing one of the emergency stop push buttons. In each case the emergency stop relay is de-energised and its contacts operate to shut off the fuel supply to the engine. This is done by closing the main gas fuel valve when running on gas and by closing the main liquid fuel valve and stopping the liquid fuel pump when running on liquid fuel. A slam-shut valve in the gas supply line is closed irrespective of which fuel the engine is being run on. A signal is provided initiating ‘Emergency Stop’ shutdown annunciation.

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9.0 TRIPS AND ALARMS SYSTEM

9.1 TRIPS

Gas Temperature Trips

Exhaust Temperature High:

a. Rising Power Turbine Exit Temperature: 600 oC

b. Thermocouple Deviation Temperature : > 60 oC

Over Speed Trip : 110 % of output shaft speed

Lube oil pressure Low : 2.5 Ksc (g)

Lube oil high Temperature : 74 oC

9.2 ALARMS

Operating Temperature High Warning : 510 oC

Engine Hot Signal : 130 oC

Lube Oil High Temperature : 66 oC

Any gas temperature differ from average temperature : 60 oC

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10.0 TROUBLESHOOTING

In this section a number of faults and their possible causes and remedies are tabulated. This list can not however be considered comprehensive and should be used as a guide only. A commonsense and methodical approach to fault finding should be adopted, eliminating obvious causes first before interfering with involved circuitry and controls.

In use, the solid stage control system has proved extremely reliable and the majority of defects arising during running have been external to the control module. If fault finding has to be carried out on any of the control module circuits it is most importing that only personnel competent to carry out such work be used and that they should be conversant with the procedure listed in sections TB-6G2, 3 and 4.

PRECAUTIONS

1. Ensure that the main supply shut off valves in the fuel, igniter and gas/ air starting systems are closed when investigating faults in these systems. It is also important that the fuel demister is vented by opening the drain cock on its base before disconnecting any gas fuel pipelines.

2. Ensure that there are no naked flames or live circuits in the vicinity when opening gas pipelines.

3. Ensure that the control module is electrically isolated when using a megager (insulation tester) in its vicinity.

4. Do not attempt to run the engine without a fully serviceable and calibrated high exhaust gas temperature protection facility.

5. Many of the fault protection sensing switches are connected to a 100V D.C power supply. Exercise great care when dealing with these circuits.

6. Do not use a soldering iron larger than 25 W when working on solid state circuits. It is also recommended that a de-soldering tool be used when removing components from printed circuit boards.

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SECTION A – PRESTART FAULTS

S No FAULTS POSSIBLE CAUSES REMEDIES LOCATION1 ‘D.C On’ lamp does not light

when D.C isolator set to ON and Circuit breaker closed

A. Ament lamps loose or faulty.

B. 24V fuse link (F1) ruptured in Chassis 2.

Tighten or renew lamps

Determine Cause, renew fuse

Chassis 2

Chassis

2 ‘A.C On’ lamp does not light when A.C power available.

A. Filament lamps loose or fault

B. A.C control fuse link ruptured.

C. 24V mains transformer faulty.

Tighten or renew lamps.

Determine cause, renew fuse.

Check transformer input / output A.C voltage.

Chassis 2

Chassis 6

Chassis 6

3 ‘Ready to Run’ lamp not lit after ‘Reset’ button pressed

A. Annunciator trip displayed.

B. Filament lamps loose or faulty

C. Chassis 3 fuse-link ruptured.

D. False ‘gas generator above 200 rpm’ signal from governor to logic.

E. Starter motor tempera-ture switches open.

F. Inlet guide vanes not fully closed (MS21 open)

Push reset button. If unable to ‘Reset’ investigate fault displayed.Tighten or change lamps.


Check pin U11 card 1, chassis 3 is at logic 0. If not, check on C.T. speed module front panel, chassis 4, that lamps Cl (Probe O.K) and C6 (gas generator below C.T. speed 3) are illuminated. If lamp Cl not illuminated change probe. If lamp C6 not illuminated change C.T. module. If both lamps C1 and C6 are illuminated check wiring between chassis 4 and chassis 3 logic circuits.

Allow starter motor to cool for 1 hour. Check 100 V D.C supply to switches and switch operation.Check inlet guide vanes are fully closed. Check 100V D.C to MS21, check operation of microswitch and inlet guide vanes.

Chassis 3

Chassis 2Chassis 3

Chassis 3Chassis 4

Starter motor

Engine

SECTION B – STARTING FAULTS

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S No FAULTS POSSIBLE CAUSES REMEDIES LOCATION1 ‘Ready to Run’ lamp does not

flash when start button pushed.A. Faulty push-button or circuit.B. Faulty CardC. No flashing signal.

Check push-button and wiring.

Change card 1.Check flashing signal at output 307 change card 3 of necessary

Chassis 3

Chassis 3Chassis 3

2 ‘Start Failed’ shutdown 16 seconds after pushing start button

A. Lubricating oil system not primed.

B. A.C auxiliary lubricating oil pump or circuit faulty.

C. Fuel valve actuator stepper motor not activated

D. No “fuel valve at minimum set point” signal within 16 seconds.

E. Fuel valve not at ‘minimum set point’ within 16 seconds.

Run A.C lubricating oi pump for a few minutes before starting up.Bleed system if necessaryCheck lubricating oil pump motor starter supply and circuits. Check 100V D.C supply to pre-lub oil pressure switches. Check pressure switches, temperature switches and oil level.

Carry out checks listed in TB-64GB applicable to fuel valve actuator and electronic module.Check 100 V D.C supply to actuator electronic module.

On P.T speed module front panel chassis 4 check that lamp D1 (Probe O.K) is illuminated and lamp D2 (Probe Failed) is extinguished. (Probe failure will close the fuel valve and also illuminate the ‘Governor Failed’ lamp on the annunciator panel). If problem O.K change the LIMITER module. If fault still present, change the CONTROL module.

M.C.C

M.C.CD.CCabinetLub OilModule

Fuel Valve Module Fuel Valve Module

Chassis 4

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S No FAULTS POSSIBLE CAUSES REMEDIES LOCATION3 ‘Start Failed’ shutdown 40

seconds after pushing start button

A. Insufficient igniter gas pressure.

B. Solenoid 2 inoperative.

C. Pressure switch PS9 fails to close.

D. Sticking starter engagement piston.

E. Starter motor not opera-ting correctly.

F. False ‘gas generator speed above 48%’ signal from governer

G. No ‘gas generator speed above 18%’ signal from governor.

H. Gas Generator does not accelerate.

Check supply on. Check pressure.

Check 24V D.C supply to solenoid. Check solenoid not seized. Check control signal to solenoid.Check operation of pressure switch PS9 and gas line for leaks. Check that starter engagement piston has moved fully forward allowing gas pressure to the pressure switch.Turn off starting gas supply and check with external supply to engagement cylinder.Check that the starter motor contactor selector is set to ‘auto’ and that the motor winding temperature switches are closed. Check starter motor connections and circuits.Check that the signal on pin U12, card 1, chassis 3 changes from 0 to 1 at 48% speed. Check that lamp C5 (above C.T speed 2) is extinguished until 48% gas generator speed is reached. If not, change the C.T speed module. Otherwise, the fault lies within the logic circuits, chassis 3, or associated wiring.Check that during the start sequence, the signal on pin U22 card 1, chassis 3, changes to 1 before 40 seconds has elapsed. If not, check on C.T speed module front panel chassis 4, that lamp Cl (Probe O.K) is illuminated and that lamp C2 (Probe failed) is extinguished. If lamp indications are correct, check that lamp C4 9above C.T speed 1) is illuminated above 18% gas generator sped. If lamp C4 remains extinguished above that speed, change the C.T. speed module. If lamp lights satisfactorily, the fault lies within the logic circuits, chassis 3 or associated wiring.Check that starter motor is in the correct operating mode, i.e. 4 pole operation.

Igniter Gas bot-tle supplyD.C Cabinet

Engine

Starter motor

M.C.C Starter motor D.C cabinet.

Chassis 3

Chassis 3

Chassis 4

Starter Motor

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S No FAULTS POSSIBLE CAUSES REMEDIES LOCATION4. No light up on igniter gas A. Insufficient or no gas

pressure.

B. Igniter units fuse links ruptured.

C. Sol. 1 not energising

D. Spark plug/plugs not working

E. Wipac igniter unit / units failed.

F. Igniter blocks incorrectly fitted.

G. Incorrect gas flow from gas connection.

Check shut off valve is open. Check bottle pressure – this is critical and should be 80-100 lb/in2. Check pipelines for leaks and correct restrictor fitted. Check system filter.


Check 24 V D.C supply to solenoid.Check control signal to solenoid.Check seized solenoid valve.Clean or renew spark plugs. Check H.T cables for damp and short circuit.Check supply to igniter units.Check igniter units relay. Replace igniter units if necessary.

Check that blocks are fitted so that spark plug is downstream in direction of swirl.

Orifice plates, either individually or in sets, may be removed to achieve reliable ignition.

Igniter System

D.C contactor Box

D.C Cabinet

Combustion Chamber

D.C Cabinet

Combustion Chamber

Combustion Chamber

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S No FAULTS POSSIBLE CAUSES REMEDIES LOCATION5 ‘Flame Failed’ shutdown 64

seconds after pushing start button (with liquid fuel selected).

A. Start up fault No.4

B. Insufficient fuel supply.

C. Fuel pump inoperative.

D. Main liquid fuel valve solenoid So1.8 not energising.

E. Flame detector circuits faulty.

F. Incorrect light up pressure

G. Duplex burner pressurising valve not operating correctly due to valve not seating.

Check fuel filter not blocked.

Check A.C power supply to main pump motor and circuit. Check that signal on pin L9 card 1, chassis 3 is at ‘0’. If not determine cause and rectify.

Check 24V D.C supply to solenoid. Check control signal to solenoid.Check seized solenoid valve.

Check circuits and viewing heads, carry out flame failure test procedure (TB-6G2C). Check viewing heads for cleanliness and alignment with viewing holes inside combustion chamber.Check supply pressure of 1800 lb/in2 (125 bar) is indicated. If not, check drive shaft and coupling. Check light up pressure.

Observe ‘light up’ pressure. If gauge reading fluctuates unduly remove pressurising valve and bench test with burner. If fuel issue from burner ‘pilot’ orifice not atomising at ‘light up’ pressure figure, and/or fuel issuing from ‘main’ burner orifices, change pressurising valve.

Fuel pipelines.

DistributionPanels

D.C CabinetFuel pipelines

Chassis 1

Combustion ChamberFuel Pump

Combustion Chamber

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S No FAULTS POSSIBLE CAUSES REMEDIES LOCATION6 ‘Flame failed’ shutdown 64

seconds after pushing start button (with gas fuel selected).

A. Start up fault No.4

B. In correct main gas fuel light up pressure.

C. Gas fuel slam-shut valve closed.

D. Main gas fuel valve solenoid So1.5 energising.

E. Flame detector circuits faulty.

F. Flame detector not ‘seeing’ flame.

Check supply pressure and light-up presure.

Reset

Check 24V D.C supply tosolenoid.

Check control signal to slenoid.Check seized solenoid.Check circuits and viewing heads, carry out relevant test procedure in Section TB-6G2.Check viewing heads for cleanliness and alignment with viewing holes inside combustion chamber.

Fuel Valve

Fuel Pipeline

D.C Cabinet

Fuel PipelineChassis 1

Combustion Chamber


A. Fuel valve does not move to light up angle when start button pushed.

B. Starter motor fails to change to 2 poles operation.

Check that fuel valve is moving to correct light up angle when starting sequence is initiated. If not, carry out item 2c and 2e, Section B. If yes, check that gas generator speed is indicated during starting. If not, change C.T module. If yes, change LIMITER module.

Check undercurrent relay for correct operation.

Fuel Valve Module

M.C.C starter motor

8 ‘Start Failed’ shutdown 96 seconds after pressing start button

No ‘gas generator speed above 48% signal from governor.

Check on C.T speed module front panel, chassis 4, that lamp Cl (Probe O.K) is illuminated and that lamp C2 (Probe failed) is extinguished. If lamp indications are correct, check that lamp C5 (above C.T speed 2) is illuminated above “48% gas generator speed”. If not, change C.T speed module. If lamp C5 is illuminated at the correct speed, the fault lies within the logic circuits, chassis 3 or associated wiring.

Chassis 4

Chassis 3

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S No FAULTS POSSIBLE CAUSES REMEDIES9

9.1

Gas Generator surges during start up.

Blow off valves closing too early.

Inlet guide vanes seized or incorrect operation

A. Valves seized in closed position broken springs in interstage bleed valves.

B. Check that inlet guide vanes operate correctly as described in section T6D-7

Compressor Casing

Compressor Casing.

10 Engine accelerates but does not reach full set speed

A. Load acceptance schedule operating, lamp E14 lit.

B. Engine running on ‘Engine Temperature Rise’ limit.

Check for correct fuel supply pressure.

Check by increased ‘Engine Temperature Rise’ set point adjuster on LIMITER module (not beyond the maximum allowable limit). NOTE: If running on ‘Engine Temperature Rise’ limit, lamp E13 on front panel of LIMITER module will be illuminated.

11 Engine speed reduces by more than expected amount when load is applied.

A. Lack of power

B. Engine running on ‘Engine Temperature Rise’ limit.

C. Engine running on ‘Power Limit”

See item 1, Section C.

Increase set point if necessary (not beyond maximum allowable limit).

Check correct fuel supply pressure.

Chassis 4

12 Engine overheats during starting.

A. Fuel valve opening too fast.

B. Fuel valve opening delayed.C. Blow-off valves not closing.D. Undetected stall of

compressor.E. Incorrect operation of inlet

guide vanes.

Check fuel valve opening rate against, rate quoted in governor schematic drawing in Section 8. If incorrect, change LIMITER module.See item 3, Section C.Check for seized valves and leaking control pipelines.Reduce light up pressure.

Check operation as described in Section T67D-7.

Chassis 4

Centre casing

Compressor casing

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S No FAULTS POSSIBLE CAUSES REMEDIES13 ‘Lub Oil Pressure Low’ shutdown

when output shaft speed above 45%.

A. Lubricating oil pressure switch circuits faulty.

B. Lubricating oil pressure switches incorrectly set.

C. Lubricating oil pressure switches faulty.

D. Low lubricating oil pressure

Check 100V D.C supply to pressure switch PS4. Check logic circuits in Chassis 3 (see relevant part of Section TB-6G2C)/Check setting.

Renew

Check relief valves, pressure setting valves, N.R.V.s, aux. Pump check valve and main oil pump drive.

D.C Cabient

Lub Oil Module

Lub Oil Module.

14 ‘Lub Oil Pressure Low’ shutdown when output shaft speed below 45% speed.

Incorrect output shaft speed signal from governor

Check that lamp D4 on P.T speed module front panel, chassis 4, is not extinguished before 45% output shaft speed is reached. If lamp D4 is extinguished before that speed, then change the P.T. speed module.

Chassis 4


A. Output shaft not accelerating to 45% speed within 160 seconds.

B. No ‘Turbine above 45% speed, signal from governor

Check fuel valve opening rate, change the LIMITER module.

Check ‘Turbine Running’ lamp comes on at 45% speed. If not, check that lamp D6 on P.T. speed module front panel is illuminated at 45% output shaft speed. If lamp is illuminated check for logic 1 at 3U27. If signal is logic 0, change P.T. speed module.

Fuel valve Module.Chassis 4Chassis 2Chassis 4

16 Output shaft runs at minimum sped.

‘Raise Speed’ signal ineffective (manual)

Permanent ‘Lower Speed’ signal

With ‘Raise Speed’ button pressed, check test point A3 on speed DEMAND module. If 0 check logic circuits Chassis 3.Check test point A4 on speed DEMAND module, Chassis 4. If 1, check chassis 3 logic circuits.

Chassis 3Chassis 4

Chassis 4Chassis 3

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SECTION C – RUNNING FAULS

S No FAULTS POSSIBLE CAUSES REMEDIES LOCATION1 Lack of power A. Faulty instrumentation giving

apparent loss of power.

B. Compressor air inlet fouled

C. Low fuel supply pressure.

D. Low burner pressure.

E. Fouled compressor.

F. Inlet guide vanes fail to open.

Check and calibrate the exhaust temperature thermocouples and output shaft speed indicators.

Check and clean air inlet filter.

Check supply pressure; fuel filter.

Check fuel supply pressure as item C above; check burners for blockage; check fuel valve for sticking or blockage; check actuator for correct operation

Clean compressor using solids injection cleaning equipment. After each cleaning operation the inlet guide vanes pneumatic system should be blown through with low pressure air to remove any cleaning material which may have accumulated.

Check operation of guide vanes, check air supply lines for damage and leaks, check valves operating correctly. Check mechanism for freedom of movement.

Chassis 5Chassis 4

Air Inlet Filter

Fuel Line

Fuel valve

Compressor

Engine

2 Output shaft speed not governed.

A. Fuel valve seized

B. Fuel valve actuator faulty

Check valve freedom of movement and rectify if necessary.

Check wiring to actuator stepper motor.

Fuel valve Module

Fuel valve Module

3 Poor governing of output shaft speed.

A. Fuel valve sticking.

B. Fuel valve actuator sticking.C. Engine being governed by

‘Engine Temperature Rise’ Control.

Check valve freedom of movement and rectify if necessary.Check wiring to actuator stepper motor.Check ‘Engine Temperature Rise’ limit setting. If temperature limiting is taking place (lamp E13 on LIMITER module front panel illuminated) below ‘Engine Temperature Rise’ setting, change the limiter module.

Fuel valve moduleFuel valve moduleChassis 4

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S No FAULTS POSSIBLE CAUSES REMEDIES LOCATION4 Engine shutdown A. Shutdown due to

annunciation trip.

B. D.C electrical power supply failure.

C. Main fuel valve solenoid failed.

D. Emergency relay deenergised.

Check annunciator panel and rectify fault displayed.

Check power supply fuses in control cabinet.

Check valve operation. Check power supplies to solenoid and control circuits.

Check power supply to relay and operation. Check emergency stop buttons for open circuit.

Chassis 2

Control cabinet

Skid/ Cabinet

Chassis 6

5 A.C aux. Lub oil pump inoperative below 90% output shaft speed.

A. See item 2b of Section B.

B. Faulty speed signal from governor

Check that lamp D5 on P.T speed module front panel is extinguished below 90% output shaft speed. If lamp is illuminated, check lamp D1 (probe OK) is illuminated and lamp D2 (probe failed) is extinguished. If not change probe. If indications at D1 and D2 are correct, change the P.T. speed module. If lamp D5 is extinghished, fault lies within chassis 3, logic circuits or associated wiring.’

Chassis 4Chassis 3

6 Engine does not shutdown on Emergency stop

Faulty emergency stop relay. To stop engine select D.C lub oil pump to ‘On’ and turn off the fuel supply. Check and rectify relay and circuits.

D.C Cabinet Chassis 6

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SECTION D – POST RUNNING FAULTS

S No FAULTS POSSIBLE CAUSES REMEDIES LOCATION1 A.C Aux lub oil pump does not

run when engine is hot.A. See item 2b of Section B.

B. ‘Engine Hot’ signal faulty.Check ‘Engine Hot’ signal and circuits. Chassis 5

2 No oil pressure at hot bearings. A. D.C emergency lub oil pump faulty.

B. N.R.V on manifold leaking.

Check pressure at pump outlet. (pressure tapping 14C).

Check pressure at pressure tapping 14F. Service or change N.R.V

D.C lub oil pump

Feed pipe to hot bearings.

3 D.C emergency lub oil pump does not run if A.C pump fails.

A. D.C contactor failed.

B. ‘Engine Hot’ signal faulty.

C. Pressure switch PS1 and/ or 2 inoperative.

D. Pump drive sheared.

E. No signal from logic circuits.

Check contactor and control circuits.

Check ‘Engine Hot’ signal and circuits.

Check switches and circuits.

Rectify as necessary.

Check logic circuits.

D.C contactor box Chassis 5

Lube oil Module

Lub oil Module

Chassis 3

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File No.5 - Gt Operating Manual

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Transcript of File No.5 - Gt Operating Manual