Gas Turbine Auxiliaries Systems. An introduction to gas turbine auxiliary systems. Lubrication systems, exhaust systems, air inlet systems, etc.

An introduction to gas turbine auxiliary systems. Lubrication systems, exhaust systems, air inlet systems, etc.

1. Iván de Lorenzo
December 2004
•Lube Oil
•Oil VapourSeparator
•Hydraulic Oil
•Control Oil
•Cooling Water
•Variable Inlet Guide Vanes
•Starting System
•Fuel Gas
•Cooling & Sealing Air
•Air Inlet & Exhaust
•Control Devices
•Ventilation
•Fire & Gas Protection
•Water Wash
•Seal Gas

2. Iván de Lorenzo
December 2004
•Provides filtered oilat the proper temperature and pressurefor satisfactory
operation of the turbine and its associated equipment.
•Provides lubricationand absorbs the heatrejected by the three turbine bearings,
compressor and starter motor bearings and the accessory gear and starting system
bearings.
• Additionally, the oil is
used as the torque
converter transmission
fluidas well as the fluid
supply for the hydraulic
control oiland safety
trip oilsystems.

3. Iván de Lorenzo
December 2004
•9500 liter tankfabricated as an integral part of the accessory compartment base. An
additional 2270 liters are contained in the tanks in the turbine base.
•High and Low Lube Oil Tank Level Alarm Switches
– Initiate alarms when lube oil tank level is too high or too low
L: 45%H: 55%
•High and Low Lube Oil Tank Pressure Alarm Switches
– Initiate alarms when lube oil tank pressure is too high or too low
L: 3 mbarH: 4.2 mbar
•Lube Oil Tank Heater On/Off Switch
– Senses oil temperature, controlling tank heaters
to maintain desired oil viscosity
ON: 25°C OFF: 30°C
•Lube Oil Tank Temperature Switch
– Will not permit turbine start-up if lube oil
temperature below 20°C
•Lube Oil Tank Immersion Heaters ( x 2 )
– Rated at 10 kW, maintain lube oil at proper
viscosity for turbine start-up
– Overload indication at temperature H: 80°C
Immersion Heater

4. Iván de Lorenzo
December 2004
•PG 1 Main Lube Oil Pump Output Pressure
•PG 2Aux. Lube Oil Pump Output Pressure
•PG 3Emergency Lube Oil Pump Output
Pressure
•PG 4Lube Oil Header Pressure
•PG 5Turbine Header Pressure
•PG 20Lube Oil Tank Pressure
•PDG 1Lube Oil Filters Differential Pressure
•TG 1Lube Oil Tank Temperature
•TG 2Turbine Header Temperature

5. Iván de Lorenzo
December 2004
•Positive displacementpump. Driven by the
lower drive of the Accessory DriveGear
• Provides lube oil during normal operation
• Provided with:
–Main Lube Oil Pump Pressure Relief
Valve
• Limits pump discharge pressure to
7 barg
• Returns excess oil to Lube Oil Tank
–Orificed Check Valve
• Installed between the auxiliary
pump discharge and the main pump
discharge.
• Lubricates and primes the main
pump during start-up.

6. Iván de Lorenzo
December 2004
•Vertical induction motor
– 55 kW / 380 V / 3600 rpm
• Auxiliary Lube Oil Pump provides oil during
start-upand shutdown until 95% operating
speed, or whenever the main lube oil pump
does not provide adequate system pressure.
• Also circulates lube oil during stand-by
periods when oil heaters are operating.
• Auxiliary Pump Start Pressure Switch will
activate pump if discharge header pressure
drops belowL: 5 barg
• Auxiliary Lube Oil Pump running indication at
2.8 barg

7. Iván de Lorenzo
December 2004
•Vertical induction motor.
– 12.3 kW / 110 VDC
• Supplies lube oil during shutdown or
cool down when AC power is not
available. Also in the event that the
auxiliary pump is out of service in an
emergency shutdown.
• Low Lube Oil Pressure Emergency
Pump Start Switch turns on pump if
bearing header pressure drops
below L: 0.6 barg.
• Emergency Lube Oil pump running
indication at 0.7 barg
Lube Oil Pump

8. Iván de Lorenzo
December 2004
•Remove particulate matterfrom
lubricating oil.
• 1 in service, 1 stand-by.
•A transfer valveallows out-of-service
filter to be serviced without interrupting
lube oil flow.
• A differential pressure gauge provides
a visual indication of oil filter condition.
It will initiate an alarmif differential
pressure is above H: 1.5 bar.

9. Iván de Lorenzo
December 2004
•Cool lube oilby circulating water.
• Duplex, shell and tube type.
• Cooling water flow is regulated according
to oil temperature.
•Lube Oil Temperature Regulator valve:
– Controls rate of coolant flowto the
Lube Oil Heat Exchangers.
– It senses lube oil temperature in the
Lube Oil Header.
– It is set at 55°C.
•A transfer valvedirects lube oil flow
through either heat exchanger. It allows
maintenance to be performed on the out-
of-service heat exchanger.
Lube Oil In
Lube Oil Out
Cooling Water

10. Iván de Lorenzo
December 2004
• Maintains bearing header oil pressureat
1.72 barg.
•An orificein parallel to it ensures lube oil
is available if the va lve fails in the closed
position
• Also, header is provided with:
–High Temperature AlarmSwitch:
installed in bearing header, activates
an alarm when lube oil temperature
exceeds H: 72°C.
–High Temperature TripSwitches:
installed in bearing header, will trip the
turbine if oil temperature exceeds
HH: 79°C.
This valve is operated by fluid pressure

11. Iván de Lorenzo
December 2004
Oil lines to thrust and journal bearings are fitted with calibrat ed orifices which adapt a proper
pressure level. This level is in dicated by a local pressure gauge.
Turbine no. 1 bearing housing
• Lube Oil is delivered to:
– No. 1 Journal Bearing.
– Active and Inactive Thrust Bearings.
• No. 1 Bearing Lube Oil Drain Thermocouples are
located in bearing drains
(alarm if temp. above H: 107°C).
Turbine no. 2 and no. 3 bearing housing
• Oil is delivered to No. 2 and No. 3 Journal Bearings.
• Drain into deaeration tanks in the turbine base. This serves as a settling chamber for air to
escape.
• Thermocouples are located in the bearings drains (alarm if temperature above H: 107°C).

12. Iván de Lorenzo
December 2004
Lube oil flow in bearing
Lube Oil to compressors and starter/helper motor
• Lubricates shaft bearingsand provides a source for
jacking oil (see next page) .
•The jacking oil system is needed to inject oilat 52
or 58 barg in order to lift the helper motor shaftat
low shaft speed(from 0 to 500 rpm).
•Jacking oil systemconsists of the following:
– Main Jacking Oil Pump
– AC Main Jacking Oil Pump Motor
– Emergency Jacking Oil Pump
– DC Emergency Jacking Oil Pump Motor
– Main Jacking Oil Filter
– Emergency Jacking Oil Filter
Other systems consuming lube oil
• Control Oil, Hydraulic Oil and Starting System.

13. Iván de Lorenzo
December 2004
Lube Oil Header Pressure
L: 1.4 barg LL: 1 barg
Pressure on VSDS
motor shaft
H: 30 barg
JACKING OIL SYSTEM
Green piping:
lube oil
Pink piping:
oil vapour
Orange piping:
jacking oil
M
M~
PTPT
PGPG
AN200
MCL 1002
VSDS MOTOR
PGPG
PGPG
PGPG
PTPT
PGPG
TGTG
TGTG
TGTG
TGTG
TGTG
PGPG
COOL AIR HOT AIR
PTPT
PTPT
PTPT
PGPGPTPT
VENT TO SAFE AREA VENT TO SAFE AREA
PGPG
OIL SUPPLY HEADER
OIL VENT HEADER
OIL DRAIN HEADER
TGTG

14. Iván de Lorenzo
December 2004
•Heavy-duty filterdesigned to remove
any fine mist and oil droplets from air
in lube oil and cooling and sealing air
systems.
• Coalescing-type filter.
• Low pressure drop, long life and high
efficiency.
• Normal flow: 1700 Nm
3
/h
• This system is started at flame, after lube
oil pump startup.
• Also called Mist Eliminator.
Oil Vapour Separator schematic
Lube Oil
Vapour In
Lube Oil
Vapour Out

15. Iván de Lorenzo
December 2004
•Oil Vapour Separator AC Motors(one duty, one
stand-by):
– Drives Exhaust Fans(one duty, one stand-by).
– Maintains a slight negative pressure in the Lube
Oil Tank.
•Oil Vapour Separator Bypass Valve:
– Opens to bypass the Oil Vapour Separator if
motor fails.
– Prevents Lube Oil Tank from being pressurized.
•PG 6
– Pressure Gauge indicates pressure before vapour separator.
– Alarm is pressure over H: 10 mbar.
•PG 7
– Pressure Gauge indicates pressure after vapour separator.
AC Motors
Main Fan
Stand-by Fan

16. Iván de Lorenzo
December 2004
• This system provides the fluid powerrequired for operation of the control
devicesof the fuel systemsand VIGVs.
• Low pressure oil obtained from the lube oil header is the supply for this system.
• The primary pumpthat pumps oil from the lube syst em to the hydraulic supply
manifold is driven by a shaft of the accessory gear. Anauxiliaryelectric motor
driven hydraulic pump is also provided as the backupto the primary pump.

17. Iván de Lorenzo
December 2004
Main Hydraulic Supply Pump
– Driven by Accessory Drive Gear.
– Delivers high pressure control fluid ( 85 barg) to fuel and VIGV systems.
– Guarantees oil flow when the operating speed of the turbine > 95%.
Auxiliary Hydraulic Supply Pump
– Driven by an AC motor(15 kW).
– Delivers high pressure control fluid ( 72 barg), operating when the output
pressure of the Main Hydraulic Supply Pump is inadequate for turbine operation.
Positive
displacement, axial
piston pumps

18. Iván de Lorenzo
December 2004
• Both valves are provided with compensators
– They control the output pressureof the pumps.
• Air Bleed valves
–Vent any air present in the pump discharge line during start-up.
– Close when Hydraulic Oil System is pressurized.
• Check valves
– Prevent oil from the operating hydraulic supply pump from back flowing through
the idle pump circuit.
• Pressure relief valves
– Open at 90 barg(Main Hyd. Relief Valve) and 75 barg(Aux. Hyd. Relief Valve)
and return excess oil to drain.
– Protect the hydraulic pump circuits fr om over-pressurization if one of the
compensators fail.

19. Iván de Lorenzo
December 2004
• Hydraulic Supply Filters ( x2 )
–Prevent contaminantsfrom entering the control
devices of the fuel and IGV systems.
• Hydraulic Oil Accumulators ( x2 )
–Smooth out pressure fluctuationsin the Hydraulic
Supply Line.
– Provide a source of high pressure oilfor immediate
use if the hydraulic supply pump fails.
• PG 9 - Hydraulic Oil System Pressure Gauge
– Displays oil pressure within the Hydraulic Supply Line.
– Alarm and Aux. Pump Start-up at L: 72 barg.
• Hydraulic Supply Filter Differential Pressure Gauge
– Connected in parallel to Hydraulic Supply Filters.
– Provides a visual indication of oil filter condition.
Alarm at differential pressure of H: 5 barand higher.
Accumulator schematic

20. Iván de Lorenzo
December 2004
• The control oil system is theprimary protection interfacebetween the Master
Protection Circuitsand the devices which control fuel flow and VIGV position.
• The system contains devices which are electrically operated by Speedtronic signals and
others that are completely mechanical.
• Low pressure oil, taken from the lube oil system, becomes control oil after passing
through a piping orifice, whic h insures an adequate capacity for all tripping operations
without causing a starvation of the lube system when the trip oil system is activated.
• The devices that cause a turbine shutdown through the trip system do so by dumping
fluid pressurefrom the system through electrohydraulic dump solenoid valves. When oil
in the trip oil line is dumped, fuel stop valveand IGV closeby spring return action.
Control Oil System
schematic

21. Iván de Lorenzo
December 2004
•IGV Solenoid Valve
– Energized (closed) by the control system to establish trip oil pressure in VIGV system.
– De-energized (open) to dump trip oil and close the VIGVs.
•Gas Fuel Stop Valve Solenoid Valve
– Energized (closed) by the control system during Gas Fuel operation.
– De-energized (open) to dump trip oil and close the SRV.
•Over speed Trip Mechanism
– This totally mechanical device, located in the
accessory gear, is actuated automatically by the
over speed bolt if the turbi ne speed exceeds the bolt
setting (HH: 110% speed).
– Has a limit switch provided with alarm.
•PG 8: Pressure Indicator Control Oil
•Gas Fuel System Trip Oil Pressure Switches
– Provide feedback to the triple-redundant processors
of the turbine control and protection systems. Voting
trip and permissive to start. Setting: LL: 1.4 barg.

22. Iván de Lorenzo
December 2004
•Closed system. It absorbs heatfrom lube oil, flame
detectorsand turbine support legs.
•LUBE OIL SYSTEM:
– Lube Oil Temperature Regulator Valvecontrols rate of
coolant flow to Heat Exchangers.
– Heat Exchangers transfer heat from lube oil to the cooling
water to maintain lube oil at the proper temperature. Two,
one in operation and one in stand-by.
•FLAME DETECTORS:
–Have cooling jacketsto protect the flame detector
instrument.
•TURBINE SUPPORT LEGS:
– They are cooled to prevent vertical growthdue to thermal
expansion.
– Uncontrolled vertical growth can cause misalignment.
Flame Detector
Cooling Jacket

23. Iván de Lorenzo
December 2004
•Set of airfoil-shaped vanesmounted in the compressor inletdirectly ahead of the
first compressor stage.
• Actuation of the ring through a double-acting hydraulic cylinder, pivots the vanes
about their mounts and increases or decreases the effective inlet area of the
compressor, controlling airflowthrough the gas turbine compressor.
•Prevent compressor pulsationduring start-up and shutdown by reducing air flow
and maintaining a lower compressor pressure ratio, and optimize operationunder
varying weather and fuel conditions.

24. Iván de Lorenzo
December 2004
• Inlet Guide Vane Ring
– Encircles the compressor inlet
casing near the VIGVs.
– Actuated by a double-acting
hydraulic cylinder.
• IGV Hydraulic Cylinder Actuator
Assembly
– Consists mainly of a double-acting
hydraulic cylinder, hydraulic
manifold, servo valve, dump valve
and hydraulic supply filter.
– Controls the position of the
IGVs.
VIGV Operation

25. Iván de Lorenzo
December 2004
•IGV Servo Hydraulic Supply Filter
– Prevents contaminants from entering the servo valve.
– Provided with differential pressure indicator.
•IGV Servo Valve
– Supplies oil to the hydraulic cy linder that rotates the IGV ring.
•IGV Dump Valve
– When trip oil is at normal pressure, it a llows the IGV Servo Valve to control the
hydraulic cylinder.
– When trip oil is dumped, it bypasses the IGV Servo Valve and forces the hydraulic
cylinder to close the VIGVs.
•Hydraulic Cylinder
– Designed for high pressures and the peak shock pressures that could occur in the
gas turbine hydraulic system during transients.
•IGV LVDTs
– Provide an analog AC voltage feedback to the control system that represents
VIGV position.

26. Iván de Lorenzo
December 2004
Typical VIGV Schedule
•VIGVsareclosedfrom 0% to 85% speed.
•VIGVsopento minimum full speed angleat 85% speed.
• VIGVs remain at minimum full speed angle up to IGV Exhaust Temp Setpoint.
54
degrees
from open
to closed
position
80°
25.4°

27. Iván de Lorenzo
December 2004
• Before the gas turbine can be fired and started, it must be ro tated or cranked by accessory
equipment.
• This is accomplished by an electric motor, operating through a torque converter, when
the helper motor VSDS is not available.
• The starting system components also provide slow speed rotation of the turbine for cool-
down purposes after shut-down (turning gear).
•A starting clutchis provided.
• The starting system uses the
lube oil systemfor its
lubrication and working fluid.
The oil lubricates the gear box,
duo-concentric clutch and its
support bearings.
• The torque converter also uses
plant lube oil for its working
fluid. The charging pump feeds
oil to the torque converter.

28. Iván de Lorenzo
December 2004
•Qualities of Electric Starting Motors
– Simple design and construction.
– Reliable operation.
– Little maintenance required.
– Power requirements readily
available.
– Relatively expensive.
•6600 V
•935 kW
•Drives the impeller of the Torque
Converter at a constant speed:
3600 rpm
• Used when it is needed to
start the unit for
maintenancewhen load
coupling is removed.
• In this case, the turning gear
and the electric motor will
start the turbine.
• The motor will stop when
minimum operating speed is
reached.

29. Iván de Lorenzo
December 2004
• Produces the turning forcerequired to start and accelerate the gas turbine.
• The mechanical energy of the motor is converted into hydraulic energythrough the pump
wheel. In the turbine wheel the same hydraulic energy is converted back into mechanical
energy and transmitted to the gas turbine shaft.
• The assembly contains two gears, driver and driven.
–Step-up typeincreases the input speed to match the torque absorption characteristics
of the torque converter and provides optimum torque for turbine starting.
• The turbine wheel’s
speed is variableand can
be adjusted to match the
various operating points of
the gas turbine.

30. Iván de Lorenzo
December 2004
• A torque converter charging pumpis
provided as part of the assembly.
– Mounted to the input gear, boosts
oil pressure to 4.85-7.75 barg
suitable for the converter traction
circuit.
•A Fill/Drain solenoid valveenergizes
to fill the Torque Converter and de-
energizes to drain it.
• After the starting motor is de-energized,
a brake automatically engages and the
driven elements of the torque converter
are brought to rest.
Details of torque converter

31. Iván de Lorenzo
December 2004
• The S.S.S. (Synchro-Self-Shifting) clutch is a positive tooth type overrunning clutch
which is self-engagingwhen passing through synchronism.
• The duo-concentric clutch combines the turning gear and starting system
clutches.
• The dual clutch disengagesthe turbine shaft from the turning gear system when
the turbine speed becomes greater than the speed of the turning gear
system.
• Likewise, the clutch disengages the turbine shaft from the starting system when
the turbine speed becomes greater than the speed of the starting system.

32. Iván de Lorenzo
December 2004
•Provides the torquenecessary to:
–breakawayand rotate the turbine shaft prior to the startof the turbine.
– rotate the turbine shaft after shutdown –normal or emergency- to avoid rotor
deformation due to thermal gradients until the end of the cool down period.
• The AC motordriven turning gear provides a continuous output speedof 6 rpm.
• Consists of:
–worm gear assembly
–AC electric motor
• In the event of a loss of AC power an emergency DC motordrive is provided to
continue low speed operation, again to prevent rotor deformation until AC power
can be restored.
• The emergency motordrive will provide a continuous output speedof 0.25
rpm.

33. Iván de Lorenzo
December 2004
• Initially, with the turbine dr ive train shafts at rest, the turning gear systemprovides the
necessary breakaway torque to start the shaft turning slowly at 6 rpm.
• When the starting motoris energized, the power and torque are transmitted through the
input gear box, torque converterand clutchto accelerate the turbine shafts from
turning gear speed to ignition speed.
• If the starting attempt is successful, the starting system will cont inue to assist the turbine
to its self-sustained speed(approximately 2400 rpm) and then disengages and comes
to rest.
• If the starting attempt is unsuccessful, the turbine is shut down and starts to decelerate.
When the turbine speed drops to turning gear speed(6 rpm), the turning gear system
will automatically engage and rotate the turbine shaft slowly un til another start attempt is
initiated.
• After a normal turbine shut down, the turning gearsystem will engage and rotate the
drive train shafts slowly unt il the turbine completely cool s down to avoid shaft bending.

34. Iván de Lorenzo
December 2004

35. Iván de Lorenzo
December 2004

36. Iván de Lorenzo
December 2004
This system regulates the amount of
fuel directed to the nozzles to be burnt
together with high pressure air from
compressor discharge.
•DLN System (Dry Low NOx)
– Reduces emissions by having
a two zonecombustion
(primary / secondary).
– This system reduces the peak
flame temperature, thus
diminishing NOx emissions.
Peak flame temperature reduces with DLN combustor
•Fuel gas follows 3 paths:
–Primary fuel goes to
primary zone.
–Secondaryand transfer
fuels go to the secondary
zone.
Fuel Gas System schematic

37. Iván de Lorenzo
December 2004
Primary Fuel Nozzle
Secondary Fuel Nozzle
End Cover Assembly
Combustor external appearance

38. Iván de Lorenzo
December 2004
•Any condensatecoming with the fuel from the
fuel gas system of the plant has to be removed
before proceeding to the control valves.
• This is done in 2 fuel gas scrubbers(1 duty, 1
stand-by). Duty scrubber is selected in field by
means of manual valves.
• The level of the scrubbers is continuously
monitored by means of 2 level transmitters,
one for control and one for trip.
Control:L: 70 mm H
2
O
H: 210 mm H
2
O
Trip:HH: 70 mm H
2
O
• Both scrubbers are equipped with PRVset at 34
barg. Alarm at differential pressure H: 1.5 bar.
• When the level is above 60% of transmitter
range the drain valve is open. When below 40%
the drain valve closes again.
FUEL GAS
INLET
FUEL GAS
SCRUBBER
# 1
N2 PURGE
INLET
VENT
PG LT
LV
LY
PG
LG
LT
FUEL GAS
SCRUBBER
# 2
PG LTPG
LG
LT
LY
LV
FUEL GAS
OUTLET
HH
HH
H
L
H
L

39. Iván de Lorenzo
December 2004
• Fuel gas flow is controlled with the fuel gas stop/ratio valve, gas control valve, gas
splitter valveand the gas transfer valveassemblies.
• The stop/ratio valve (SRV)and the gas control valve (GCV)work in conjunction to
regulate the total fuel flow deliveredto the gas turbine.
• The gas splitter valve (GSV)and the gas transfer valve (GTV)are used to control
the distribution of the fuel flowto a multi-nozzle combustionsystem.
• The gas purge systemis used to protect the gas manifolds from a number of
undesirable effects.

40. Iván de Lorenzo
December 2004
• The stop/ratio valve (SRV) is a dual function valve: it serves as a stop valve and as a
pressure regulating valve. Its position is sensed by two LVDTs.
•Stop valve function:
– The valve is an integral part of the protection system.
– Actuation of the spring-loaded gas control valve is by a hydraulic cylinder
controlled by the electrohydraulic servovalve..
– A hydraulic trip relay dump valveis located between the electrohydraulic
servovalveand the hydraulic cylinder. It is operated by the control oil trip system.
– Normally, the dump valve is maintained in a position that allows the servovalve to
control the cylinder position. When the trip oil pressure is low(as in the case of
normal or emergency shutdown), the dump valve spring shifts a spool to a position
which dumps high pressure hydraulic oil in the stop/speed ratio valve actuating
cylinder to the lube oil reservoir.
– The closing spring, atop the valve plug, instantly shuts the valve, thereby shutting
off fuel gas flowto the turbine combustors.
•Speed ratio function:
– This valve holds a known fuel gas pressureahead of the gas control valve.
– Fuel gas pressure at the inlet to the gas control valve is a function of turbine speed.

41. Iván de Lorenzo
December 2004
• The gas control valve (GCV) controls
the desired fuel flowin response to
the command voltage FSR.
• The position of the gas control valve
plug is intended to be proportional to
FSRwhich represents the total
called-for fuel flow.
• The gas control valve stem position
is sensed by the output of two LVDTs.
• Actuation of the spring-loaded gas
control valve is by a hydraulic
cylindercontrolled by the
electrohydraulic servovalve.
• Gas flow is a function of valve inlet
pressure, P2, and valve area only.

42. Iván de Lorenzo
December 2004
• The gas splitter valve (GSV) divides the total fuel flowregulated by the gas control
valve between the primary and secondary fuel paths.
• The primary fuel pathsupplies a manifold which distributes fuel to the combustion
chamber primary nozzles.The secondaryside of the gas splitter valve supplies the
gas transfer valve with a fuel source.
• The GSV assembly is a three-way valveactuated by a hydraulic cylinder. When the
primary side of the GSV is closed by a fixed amount, the secondary side is opened
by the same amount and vice versa.
• The split between the primary and secondary fuel is determined by a control
algorithmin the Speedtronicsoftware
• Two redundant LVDTsare mounted on the gas splitter valve to provide valve
position feedback.

43. Iván de Lorenzo
December 2004
• The gas splitter valve (GTV) divides the gas fuel flowexiting the right hand side
of the three-way splitter valve between two separate flow paths called the
secondary fuel flowand the transfer fuel flow.
• Both flow paths supply gas fuel to unique manifoldswhich in turn supply various
combustion chamber fuel nozzles.
• The gas transfer valve assembly is a three-way valveactuated by a hydraulic
cylinder. When the primary side is closed by a fixed amount, the secondary side is
opened by the same amount and vice versa.
•Two LVDTsare mounted on the gas transfer valve to provide valve position
feedback for closed loop control.

44. Iván de Lorenzo
December 2004
• This system prevents hot combustion gasesfrom entering transfer fuel passages.
•Compressor Discharge Airis piped to the transfer gas manifold through the gas
fuel transfer nozzle purge valves.
• Inadequate purge flow will cause catastrophic fuel nozzle failure.
• During normal gas fuel operation the gas purge valvesare opened by energizing
solenoid valves20PG-3 and -4. The signal to energize them closes the gas vent
solenoid valveto prevent venting of the volume between the valves.
•Limit switchesand pressure
switch96PG-2 are used to
detect proper system
operation. 96PG-2 will initiate
analarmif pressure builds up
over H: 3.4 barg.
•An Air Filterand Pressure
Control Valvewill condition
the air so that it can be used to
pilot the purge valves.
Air Filter
PCV
Pressure switch
96PG-2
Solenoid valves 20PG-3 and -4
Gas Vent solenoid valve

45. Iván de Lorenzo
December 2004
•Gas Strainer: provided in gas supply lines to remove any foreign particles from the
gas fuel before it is admitted to the speed/ratio valve assembly.
•Pressure Switch:
– installed in the gas piping upstrea m from the gas stop/speed ratio valve.
– initiates an alarmwhenever the gas pressure is belowL: 19 bargor overH: 26
barg.
•Fuel Gas Pressure Transducers ( x3 ):sense pressure between SRV and GCV.
•Gas Fuel Vent Solenoid Valve:
–ventsthe volume between SRV and GCV when the solenoid is deenergized.
– insures that during the shutdown period fuel gas pressure will not build up
between SRV and GCV.
– will be closed and remain closed during gas fuel operation.
•Fuel Gas Temperature Sensor: alarm if gas temperature is over H: 62°C.
•Hydraulic Oil Filters:
– Gas Control Valve Filter - SRV Filter
– Gas Splitter Valve Filter - Transfer Valve Filter

46. Iván de Lorenzo
December 2004
•Pressure Gauges:
PG 12:Inlet Fuel GasPG 18:Secondary Line
PG 13:Intervalve Fuel GasPG 19:Transfer Line
PG 14:Fuel Gas to NozzlesDPG 26:SRV Filter Diff. Pressure
PG 15:Hydraulic Oil InletDPG 27:GCV Filter Diff. Pressure
PG 16:Transfer / Secondary LineDPG 28:GSV Filter Diff. Pressure
PG 17: Primary LineDPG 29:Transfer Valve Filter DP
Fuel Gas Valves overview

47. Iván de Lorenzo
December 2004
STOP/SPEED
RATIO
VALVE
XY XYXY
PDG
XV
L L L
XY
PG
PT
PT
PT
PT
L L L L
ZTZT
ZTZT
XV XV
L L L L L
L L
PDG
// // // // // ////
PCVPCV
//
// // // // // //// // // // // //
// // //// // //
// // //
//
// // //
GAS SPLITTER
VALVE
ASSEMBLY
TRANSFER
VALVE
ASSEMBLY
ZTZT
ZTZT
XV
PDG
GAS CONTROL
VALVE
PDG
VENT TO ATM. VENT TO ATM.
AT SAFE LOCATION AT SAFE LOCATION
PG
FROM
HYDRAULIC
OIL
L L
L L L
FROM CONTROL
OIL
XY XYXY
XY XYXY
XY XYXY
ZT
ZT
ZT
ZT XV
XV
PG PG
PDIPDIPDI
ZSO
ZSC
XY
PT
XY
// // // // // ////
ZSO
ZSC
PCV
PG
FROM FUEL GAS SCRUBBERS
FROM COOLING FROM COOLING
AND SEALING AIR AND SEALING AIR
FUEL NOZZLES
PRIMARY PRIMARY
SECONDARY SECONDARY
TRANSFER TRANSFER
XY
H
L
TETE
H
H

48. Iván de Lorenzo
December 2004
• In order to achieve a good mixing of fuel and air, the DLN system goes through a
series of modes of operation when starting the gas turbine.
•DLN System Modes of Operation:
-Primary Mode
After system has been purged with compressor discharge air, the
fuel gas is allowed to enter the primary nozzles. The whole
combustion chamber will be then full of gas and prepared for firing.
-Lean Lean Mode
After firing has been done and flame appears in the primary zone,
fuel gas is split into the pr imary (around 70% of flow) and
secondary nozzles (around 30%).
-Secondary Mode
The primary line is gradually closed and the secondary opened until
100% of fuel goes to secondary and the flame is transferred to
the secondary zone.
-Premix Mode
The primary line opens again while the secondary line closes. The
opening of the primary will be around 80-90% while the secondary
line will receive the rest 10-20% of the fuel. Flame will only be
present in the secondary zone.
• Aim: to sustain flame in the secondarywith the highest possible amount of gas
going to primary Ægood air-fuel mixing.
• With this system, the temperature in the combustion chamber will be reduced
significantly.

49. Iván de Lorenzo
December 2004

50. Iván de Lorenzo
December 2004

51. Iván de Lorenzo
December 2004
•Fuel supplymust be controlled in accordance with the demand of turbine speed load.
• This function is realized by receiving gas turbine speed and temperature signals, output
the fuel control signal by using load or speed control function,and then regulate the
amount of fuel supply.
• Output consists of 3 different systems:
–Start-up control
–Speed / Load control
–Temperature control
• Optimum signal in accordance with the operating conditions is selected from these three
system’s output to control the amount of fuel supply.
•Start-up control
Determines the fuel control signal at igniti on, warm-up and acceleration so that thermal
stress during gas turbine start-up becomes within the acceptable limit.

52. Iván de Lorenzo
December 2004
•Speed / Load control
Gas turbine speed is detected by magnetic pick-up which output pulse proportional to the
speed.
Fuel control signal is calculated by compar ing this signal with the speed set point.
•Temperature control
Gas turbine combustion temperature shall be controlled within a certain range.
Direct gas turbine temperature measurement is not recommended due to the extremely
high values and the un-uniform distribution of temperatures.
This is why combustion is controlled by measuring the exhaust gas temperature.
18 thermocouples measure this temperature and feedback to control system.
•Fuel gas control
Fuel control signal adjusts fuel gas flow through opening of gas control valve by hydraulic
cylinder. It also adjusts gas pressure through opening of stop/ratio valve.
Fuel gas adjusted in flow and pressure is injected to the combustion chambers

53. Iván de Lorenzo
December 2004
• This system provides the necessary air flow from the gas turbine compressorto
other parts of the gas turbine roto r and stator to prevent excessive temperature build-
upin these parts during normal operation and for sealingof the turbine bearings.
• The cooling and sealing functionsprovided by the system are the following:
- Cool internal turbine parts.
- Cool turbine outer shell.
- Cool exhaust frame.
- Seal turbine bearings.
- Prevent compressor pulsation.
- Provide air for air operated valves.
• This system consists of specially designed air passagesin the turbine casing, turbine
nozzles and rotating wheels, piping for the compressor extraction air and associated
components.
•Associated componentsused in the system include the Turbine Exhaust Frame
Cooling Blowers, Air Filter, Pres sure Gauge and Dirt Separator.

54. Iván de Lorenzo
December 2004
• The cooling and sealing air system utilizes air from the axial flow compressor,
extracted from several points, for sealing the bearings, cooling turbine internal parts
and to provide a clean air supply for air op erated control valves of other systems.
•Bearing sealing airis extracted from the compressor 5
th
stagewhen the turbine is in
normal running operation.
•Compressor bleed extractionis taken from the compressor 11
th
stageto provide
pulsation protection.
•Internal cooling airis extracted
from the discharge of the
compressorincluding the
internal flow of cooling air through
the centre of the turbine rotor
(16
th
stageinternal extraction),
and leakage air.
• Air used in cooling the turbine
external casingis ambient air
supplied by motor driven blowers.

55. Iván de Lorenzo
December 2004
• An opening in the Compressor Case diverts a portion of
the compressed air stream.
• Located at the 5th Stage Stator Bladelocation, the air is
used to cooland sealall three turbine bearings.
• The platforms of the 5th Stage Stator Blades are drilled
through. This allows the air to flow into the compressor
case passages to the pipe connection that supplies sealing
air to the bearings.
Opening in 5th stage
Bearing detail (sealing air shown
In light blue colour)

56. Iván de Lorenzo
December 2004
•Twocompressor bleed valves –butterflytype- are available:
– VA2-1 Upper Half
– VA2-2 Lower Half
•Fully openat startupand low speed operation.
• These valves reduce the air flowload on compressor stages downstream of the 11th
StageExtraction point.
•This reduces starting torqueand provides pulsation protectionand smooth loading
of the compressor as turbine rpms rise fr om startup to generator breaker closure.
• The valves are fully closed–by compressor discharge air- during normal turbine
operation.
•Compressor Bleed Valve Limit
Switch: provides a “ready-to-start”
permissive during turbine start-up.
•Compressor Bleed Solenoid
Valve: de-energized during start-up
and shutdown; energized at 95%
speed.
•Compressor Bleed Air Filter:
prevents contamination of solenoid
and bleed valves.

57. Iván de Lorenzo
December 2004
•16th stage aircools turbine buckets and wheelspaces. •Compressor HP Seal Leakagecools the
1st stage turbine wheel.
Detail of 1st stage bucket cooling

58. Iván de Lorenzo
December 2004
•Compressor discharge aircools 1
st
and 2
nd
turbine nozzles and several turbine
rotor parts.
• The temperatures in these areas are extremely high as they receive directly the hot
combustion gases from the combustion system.
• In addition, compressor discharge air is used as purge airfor the gas fuel system
and to clean the pulse-jet filter assembliesin the Inlet Filter House.

59. Iván de Lorenzo
December 2004
•Turbine Shell and Exhaust Frame blowers ( x2 )
cool the turbine shell and exhaust frame.
• Turbine Shell and Exhaust Frame blower motors
• Turbine Shell and Exhaust Frame blower check
valves: prevent the discharge of the operating
blower from backflowingthrough the failed blower
circuit.
• Turbine Shell and Exhaust Frame
blower discharge pressure
switches:
– initiate an alarm if blower discharge
pressure falls below L: 60 mbar.
– shut down the turbine in a normal
shutdown sequence if both blowers
fail LL: 60 mbar.

60. Iván de Lorenzo
December 2004
• The Air Inlet Systemmodifies the
atmospheric air entering the turbine
and filters out contaminants.
• Main parts:
– Inlet Filter House
– Inlet Ducting
– Inlet Plenum
• The Exhaust System cools and attenuatesthe hot exhaust gases created by the
turbine’s combustion process. The exhaust system also silencesthe exhaust noise and
transportsthe exhaust gases either to the atmosphereor to a Heat Recovery Unit.
• Main parts:
– Exhaust Plenum
– Exhaust Ducting
– Exhaust Stack

61. Iván de Lorenzo
December 2004
• The Inlet Filter Housefilters the
atmospheric air and directs it to
the inlet ducting.
• It is composed of numerous filtration modules,
which remove particulates from air. Elevated
intake minimizes pickup of dust near the
ground.
• The filter is a pulse-jet type. The 210 filter
assemblies are sequentially self-cleaned by
compressor discharge air.
• The Air Inlet Filter Self-Cleaning Sequencer
consists of electronic ci rcuits within the Air
Filter Control Box.
–Initiates pulse-cleaningwhen differential
pressure across the filters > 5.5 mbar.
–Stops pulse-cleaningwhen differential
pressure across the filters < 4.5 mbar.
Pulse-jet filters

62. Iván de Lorenzo
December 2004
• The air coming from the compressor discharge is filtered and pressure regulated to7
bargto supply the manifolds. A security valveis set at 8.5 bargafter the PCV.
•Pressureand temperature gaugesPG-13 and TG-13 indicate the condition of the air in
the supply manifolds.
•An Air Inlet Filter Excessive Pressure Drop Alarm Switchis located inside the Air
Filter Control Box, and activates an alarm when differential pressure H: 14.7 mbar.
•2 Air Inlet Filter Excessive Pressure Drop Switches, located inside the Air Filter
Control Box, initiate a controlled shutdown of the gas turbine when differential pressure
HH: 19.6 mbar. They protect the Inlet Ducting from implosion.
•Pressure gaugeDPG 3 indicates the total differential pressure in the air filter, and
pressure transmitter96AP-1 the atmospheric pressure.
• Additionally, three redundant air combustion inlet gas detectorsare provided, which
alarm at H: 25% LELand trip at HH: 60% LEL.

63. Iván de Lorenzo
December 2004
• The Air Inlet Ducting connects the Inlet Filt er House to the Inlet Plenum, directing the
filtered air to the compresso r inlet. Its main parts are:
• The Expansion Jointsprevent buckling
due to thermal expansion and dampen
vibrations.
• The Silencer Ducteliminates the
fundamental compressor tone and other
audible frequencies.
• The 90° Elbowchanges the inlet air stream
from horizontal to vertical flow.
• The Transition Ductdirects the inlet air
stream into the Inlet Plenum
• Finally, the Inlet Plenumdirects the filtered air in to the compressor bellmouth.

64. Iván de Lorenzo
December 2004
• The Exhaust Plenumis the first stage of the Exhaust Ducting. It directs exhaust gas flow
into the Exhaust Ducting.
• The Exhaust Ductingdelivers these
gases to the Exhaust Stack. Its main
parts are:
•Expansion Joint, that compensates
from thermal expansion.
•Transition Ducts, before and after
the Silencer Module, increasing and
decreasing the flow path.
•90° Elbow, provided with deflecting wall.
• Finally, the Exhaust Stackreleases exhaust gases to atmosphere. It has a platform for
emissions monitoring equipment. It has a round design.

65. Iván de Lorenzo
December 2004
• The turbine control devices are all of the control components, sensorsand transducers
used to monitor and control the operation of the flange-to-flan ge gas turbine. The devices
are located in the inlet and exhaust plenums and mounted on the gas turbine unit, with
functions including the following:
- temperature measurement - flame detection
- vibration detection -combustion ignition
- speed measurement
•Inlet Plenum
– The devices mounted in the forward wall of the inlet plenum are the compressor inlet
temperature thermocouplesand are used as an indication of the ambient temperature to the
compressor inlet.
•Exhaust Plenum
– The devices mounted in the exhaust plenum are the turbine exhaust control and protection
thermocouplesand the primary function is to provide turbi ne exhaust temperature
measurements 360° around all 10 combustors.
•Flange–to–Flange Gas Turbine
– The remaining devices mounted on the turbine itself.

66. Iván de Lorenzo
December 2004
•Bearing Vibration Detection
–
using velocity (seismic)type sensors
– Located in #1, #2 and #3 Bearing Housing
– The function of these devices is to monitor and protect the turbine rotor and bearings from
excessive vibration and damage.
•Turbine Shaft Speed Detection
–using magnetic type pickups
– Located in the Forward Compressor Stub Shaft
– The function of these devices is to provide a speed signal referen ce for the controls during start–
up, loading, and shutdown of the turbine unit.
•Temperature Detection
–
using precisionthermocouples
–Compressor discharge(exhaust thermocouples)
–Turbine Wheelspaces
– The function of these devices is to protect the turbine hot sectio n parts such as nozzles, buckets,
and wheels from damage due to excessive temperatures.
•Flame Detection
–
using ultraviolet radiationtype sensors
– Primary FD in combustors # 2, 3, 7, 8, Secondary FD in combustors # 1, 2, 8, 9
– The function of these devices is to indicate the presence of flame in the combustors. When flame
loss occurs in a combustion chamber, fuel shall be stopped immediately and unit will trip.
•Combustion Ignition
–
using devices such as spark plugsin combustors # 1 & 10
– Their functions are to light–off the combustors and establish combustion during turbine start–up.

67. Iván de Lorenzo
December 2004
VE 1: Vibration sensor (seismic) accessory gear
VE 2: Vibration sensor (seismic) accessory gear
VE 3, 4: Flame detector in comb. chamber #8
VE 6, 7: Flame detector in comb. chamber #7
VE 5: Vibration sensor (seismic)H: 12.5mm/s
VE 8: Vibration sensor (seismic)HH: 25 mm/s
SE 1, 2: Magnetic pick-ups turbine speed
PDT 1: Exhaust pressure transmitter H: 40 mbar
HH: 49 mbar
TE 1, 4: Axial compressor discharge temperature
TE 2: Turbine temp. wheel space 3rd stage after (outer)
TE 3: Turbine tunnel temperature alarm
TE 5: Turbine temp. wheel space 1st stage fwd (inner)
TE 6: Turbine temp. wheel space 1st stage after (outer)
TE 7: Turbine temp. wheel space 2nd stage fwd (outer)
TE 8: Turbine temp. wheel space 3rd stage fwd (outer)
TE 9: Turbine temp. wheel space 2nd stage after (outer)
TE 10: Turbine tunnel temperature alarm
TE 11: Turbine tunnel temperature alarm
H: 427°C
H: 260°C
H: 427°C
H: 510°C
H: 510°C
H: 482°C
H: 510°C
H: 260°C
H: 260°C

68. Iván de Lorenzo
December 2004
VE 1: Vibration sensor (seismic)
VE 2, 3: Flame detector in comb. chamber #3
VE 4: Vibration sensor (seismic)H: 12.5mm/s
HH: 25 mm/s
VE 5, 6: Flame detector in comb. chamber #4
VE 7: Vibration sensor (seismic)H: 12.5mm/s
HH: 25 mm/s
SE 1, 2, 3, 4: Magnetic pick-ups turbine speed
TE 1: Turbine temp. wheel space 3rd stage after (outer)
TE 2: Turbine temp. wheel space 2nd stage after (outer)
TE 3: Turbine temp. wheel space 3rd stage fwd (outer)
TE 4: Turbine temp. wheel space 2nd stage fwd (outer)
TE 5: Turbine temp. wheel space 1st stage after (outer)
TE 6: Turbine temp. wheel space 1st stage fwd (inner)
TE 7: Axial compressor discharge temperature
H: 427°C
H: 510°C
H: 482°C
H: 510°C
H: 510°C
H: 427°C

69. Iván de Lorenzo
December 2004
TE 1: Axial compressor inlet temperature
TE 2: Axial compressor inlet temperature
TE 3: Axial compressor inlet temperature
TE 4: Axial compressor inlet temperature
TE 5: Compressor temperature inlet flange
TE 6: Compressor temperature inlet flange
Exhaust thermocouples feed a software block that
generates control, alarm and trip functions.
The 18 thermocouples detect exhaust gas
temperature. Alarm is issued when fuel flow and
combustion and exhaust gas temperature
increase abnormally, and trip turbine for further
temperature increases.

70. Iván de Lorenzo
December 2004
•Bearing Vibration Monitoring
–using proximity (non–contacting)type position
sensors:
– #1 Bearing – radial (X and Y), axial and key phasor
– #2 Bearing – radial (X and Y)
– #3 Bearing – radial (X and Y)
•Bearing Metal Thermocouples
– The turbine journal and thrust bearings are equipped with thermocouples embedded
into the bearing metal with the function to monito r the temperatures during operation
and give an alarm indication if the metal te mperature is too high.
– The function of these devices is to protect the turb ine bearings and rotor journal
surfaces from overheating and failure.
•Bearing Drain Lube Oil Temperature Thermocouples
– The turbine unit bearings drains are equipped with thermocouples with the function to monitor the
lube oil temperatures during operation and give an alarm indication if the te mperature is too high.
– The function of these devices is to protect the turb ine bearings and rotor journal surfaces from
overheating and failure. The thermocouples are placed in the #1, #2 and #3 main journal bearing
drains.
•Turbine Performance Monitor
– The compressor inlet bellmouth area has pressure probes included as well as an RTD mounted to
monitor the compressor performance during turbine unit operation.
BEARING
PROTECTION
SYSTEM
TO
REDAS

71. Iván de Lorenzo
December 2004
Bearing Metal Temp.
Thrust Bearing #1
(inactive side)
H: 115 °C
Bearing Metal Temp.
Journal Bearing #1
H: 115 °C
Bearing Metal Temp.
Thrust Bearing #1
(active side)
H: 115 °C
Radial Probes
X and Y
Bearing #1
H: 150 micron
Bearing Metal Temp.
Thrust Bearing #1
(active side)
H: 115 °C
Bearing Metal Temp.
Thrust Bearing #1
(inactive side)
H: 115 °C
Bearing Metal Temp.
Journal Bearing #1
H: 115 °C
Bearing Metal Temp.
Journal Bearing #2
H: 115 °C
Bearing Metal Temp.
Journal Bearing #2
H: 115 °C
Radial Probes X and Y Bearing #2 H: 150 micron
Radial Probes
X and Y
Bearing #2
H: 150 micron
Bearing Metal Temp.
Journal Bearing #3
H: 115 °C
Bearing Metal Temp.
Journal Bearing #3
H: 115 °C
Radial Probes
X and Y
Bearing #3
H: 150 micron
Axial Displacement
Probes Bearing #1
H: ±600 micron
HH: ±800 micron
Key phasor Probe Bearing #1

72. Iván de Lorenzo
December 2004
Radial Vibration
Journal Bearings
H: 44 micron
HH: 66 micron
Radial Vibration
Journal Bearings
H: 44 micron
HH: 66 micron
Axial Vibration on
Compressor Shaft
H: 0.5 mm
HH: 0.7 mm
Axial Vibration on
Compressor Shaft
H: 0.5 mm
HH: 0.7 mm
Radial Vibration
Starter Motor Bearings
H: 80 micron
HH: 110 micron
RTD on Journal and
Thrust Bearings
H: 120 °C
HH: 130 °C
RTD on Journal and
Thrust Bearings
H: 120 °C
HH: 130 °C
RTD on Journal Bearings H: 120 °C HH: 130 °C
GAS TURBINE GAS TURBINE
MS 7001 EA MS 7001 EA
AN200
16-MJ01
MCL 1002
16-MJ02
VSDS MOTOR
16-MJ01-M
STARTER/HELPER MOTOR
FOR MR COMPRESSOR
COOL AIR HOT AIR
TETETETE
VXEVXE
VYEVYE
VYEVYE
VXEVXE
TETE
TETE
TETE
TETE
TETE
ZEZE
TETE
VXEVXE
VYEVYE
VYEVYE
TETE
TETE
TETE
TETE
VXEVXE
TETE
TETE
ZEZE
ZEZE
ZEZE
VYEVYE
VXEVXE
TETE
TETE
TETE
TETE
VYEVYE
VXEVXE
ZEZE
ZEZE
VSDS
MOTOR
EXCITER
TETE
TETE
RTD on Journal and
Thrust Bearings
H: 120 °C
HH: 130 °C
RTD on Journal and
Thrust Bearings
H: 120 °C
HH: 130 °C

73. Iván de Lorenzo
December 2004
RTD Starter Motor
Cooling Hot Air
H: 105 °C
HH: 110 °C
RTD Starter Motor
Cooling Cold Air
H: 65 °C
HH: 70 °C
Flow Indicator Air
Outlet from Cooler
VSDS Motor
Air Outlet from Cooler
VSDS Motor
RTD Starter Motor Winding Temperature
H: 130 °C
HH: 135 °C RTD Motor Exciter
Winding Temperature
H: 130 °C
HH: 135 °C
VSDS MOTOR
TGTG
TGTG
COOL AIR HOT AIR
TETE
TETE
TETE
TETE
TETE
TETETETETETETETETETETETETETETETE
TETE
TETE
TETETETETETETETETETETETE
TGTG
FIFI
ELECTRIC MOTOR
STATOR WINDING
TO MARK IV
TETE
TETETETETETETETETETE
TETETETETETE TETE
EXCITER STATOR
WINDING TO MARK
IV

74. Iván de Lorenzo
December 2004
• The ventilation system draws cool airinto the accessory, turbine, load coupling and
compressor compartments. It absorbs and exhausts the heat generated.
• This helps avoid componentfailuredue to overheating.
•Two ventilation fans(1 duty, 1 stand-by) create a negative pressureinside the
compartments. Ambient air enters the inlet dampersand heat is transferred to it. It is
then sent to atmosphere through the outlet dampers.
Inlet dampers open when
ventilation fan is off

75. Iván de Lorenzo
December 2004
• The ventilation fansare designed for continuous operation, but are not operated
after the gas turbine is shut down and the cool down timer has elapsed.
• They are driven by two AC motors
• The “non-duty” fanwill automatically start
in the following situations:
– Turbine or Compressor Compartment
temperature high alarm H: 85°C
– Gas detected in outlet air
• The fans will stopat the end of the cool downor whenever gas is detected in the
inlet filteror fire is detectedin the enclosure.
• Two redundant high temperature transmitters in both the turbine and compressor
compartments are provided, which trip the gas turbine at HH: 105°Csignal.
Details of ventilation fan

76. Iván de Lorenzo
December 2004
• Each of the three main enclosure compartments(accessory, turbine and
compressors) is protected against fire.
• Each compartment is equipped with two groupsof 3 heat rise detectors, working in “2
out of 3” logic.
–Fire Alarmsignal is generated if 1 dete ctor in 1 area is activated.
–Fire Trip conditionis generated if 2 detectors of 1 group are activated.
–Fire Trip conditionis also generated if 1 s ensor is activated in more than 1 group or zone.
• The settings for these detectors is HH: 162 °Cfor the accessory and compressors
compartment and HH: 316 °Cfor the turbine compartment.
• The compartments are also equipped with a parallel fire detection systembased on
UV detectorsalso working in “2 out of 3” logic.
• Fire trip condition will de termine the following events:
• Turbine shutdown
• Ventilation cutout
• Activation of fire lamps
• Activation of electric fire horns
• Activation of relays relevant to output of
Inergen cylinders

77. Iván de Lorenzo
December 2004
• The fire fighting system is provided with 24 cylindersdivided in 2 banksfilled with
Inergenthat discharge when fire is detected.
• The cylinders of each bank are divided in 3 groups: initial discharge, extended
discharge and turbine and coupling compartment discharge.
• All air outletsare also equipped with gas leakage detectors, also provided in turbine
compartmentand in air intake filters.
• 7 gas detection spots are equipped with groups of 3 gas detectors working in “2 out of
3” logic.
– Alarm signal will be generated at H: 20% LEL
– Trip signal will be generated at HH: 60% LEL
• In case of trip for gas detected in air intake filterÆventilation is cut-out.
• If gas is detectedwithin turbine enclosureor in the ventilation outletsÆauxiliary
ventilation fan is started.

78. Iván de Lorenzo
December 2004
• Gas turbine compressor is sucking a great amount of air. In case that dirt (dust, salt,
insects, hydrocarbon fumes) is included in the air, deposits may form on the compressor
blades. This reduces the amount of inlet air and compressor efficiency.
• The compressor water wash system restoresthe gas turbine’s operating efficiency by
removing the depositson the compressor blading.
• This is accomplished by injecting a solution of water and detergentinto the
compressor bellmouth, followed by a water rinse.
•Two typesof washing
•Off line: injects cleaning solution while the turbine is being
turned atcranking speed. It is the most effective means of
cleaning the compressor
•On line: injects cleaning solution while the turbine is
operating atfull speedand some% of load. It is used to
supplement off-line washing

79. Iván de Lorenzo
December 2004
• The detergent tankcontains the cleaning compound that may be used during a
compressor water wash.
• The detergent is mixed with demineralized water in the wash water tank, by means of
the wash water chemical drum pump, driven by an AC motor.
• The wash water is pushed through the system by means of instrument airsupply.

80. Iván de Lorenzo
December 2004
• The wash water tank is provided with one electric heater.
It has a start/stop temperature switchand an overload switch.
• The levelof the tank is controlled betwe en 400 and 500 litres by means of a water
supply servovalve.
Any level beyond L: 400 litresor H: 500 litreswill generate an alarmand a signal of
LL: 0 litreswill tripthe gas turbine.
The tank is provided with a level gauge.
• The pressureof the tank is set at 5.4 barg. A safety valve is set at 7.6 barg.
PG-24 is a gauge that shows the washing water tank pressure.
• The air inletto the tank is by 2 solenoid valves, one for on-line and the other for off-
line washing.

81. Iván de Lorenzo
December 2004

82. Iván de Lorenzo
December 2004
• The washing water is distributed via 2
different piping, one for on-line and the
other for off-line washing, by 2 injection
valves.
• The off-linecompressor washing is done
through 1 manifoldthat discharges in
the forward wall of the inlet plenum
• The on-line compressor washing is done
through 2 manifoldsthat discharge in
the forward wall of the inlet plenum and
in the aft wall of the inlet plenum.
• The false start drain valvesallow
unburned fuel to drain after an
unsuccessful start.
They allow wash water to drain during an
off-line compressorwater wash.
Wash water spray manifolds Wash water spray nozzles

83. Iván de Lorenzo
December 2004
• This system supplies filtered seal (buffer) gas to the mechanical and tertiary seals
assembled at the two ends of the compressor shaft.
• The purpose of the compressor shaft seals is to prevent the process gas from
escaping out of the machine.
• Both ends of the compressor have a pressure close to the suctionone that permits to
use two similar groups of sealing rings and the same seal gas pressure for both ends.
• This is done through the balancing gasthat equalizes the pressure at both ends.
• The dry gas seal system is composed of 3 different parts:
– The 1st has the scope to inject filtered buffer gasto the seals.
– The 2nd is designed to monitor the gas leakageand the good working of the seals.
– The 3rd has the scope to inject a purge gasfor a good separation between the seals area and
the lube oil area.
• Process gas from compressor medium discharge of MCL 1002 is used as buffer gas.
• Nitrogen is injected as purge gas taken from the plant network.

84. Iván de Lorenzo
December 2004
Inlet for
Seal Gas
Inlet for
Purge Gas
Inlet for
Purge Gas
1
ry
vent 2
ry
vent
Process
Gas
Side
Mating
Ring
Mating
Ring
Primary
Ring
Primary
Ring
1
st
stage 2
nd
stage
Tertiary Seal

85. Iván de Lorenzo
December 2004
• In order to prevent the process gas from escaping through the labyrinth seals,
chambers Aare pressurized.
•Filtered buffer gasis injected at a pressure higher that suction pressure.
• This is assured by a differential pressure control system (one for each compressor)
between the buffer gas (chamber A) and balancing gas.
Inlet for
Seal Gas
1
ry
vent
2
ry
vent
Purge
Gas
Purge
Gas
Process
Gas

86. Iván de Lorenzo
December 2004
• The seal gas that escapes from chambers A reaches the chambers Bfrom where it is
sent to flare by means of lines called “primary vent lines”
• These lines are provided with adjusting flow orifice valves. Theses orifice valves will
send an alarm signal in case of high differentia l pressure and trip the unit in case of
high-high differential pressure.
Inlet for
Seal Gas
1
ry
vent
2
ry
vent
Purge
Gas
Purge
Gas
Process
Gas

87. Iván de Lorenzo
December 2004
• The flushing gas is injected into 2 chambers at 2 different pressure levels. The flushing
or purge gasinjected into chamber Cis used to isolate the mechanical seal during
normal leakage values.
• The seal gas that manages to reach chambers Dis vented to atmosphere through a
piping system called “secondary vent”.
• The purge gasin chambers Eprevents any gas escaping from chambers D to go
through the 3
ry
seals and the oil vapour to become in contact the mechanical seals.
Inlet for
Seal Gas
1
ry
vent
2
ry
vent
Purge
Gas
Purge
Gas
Process
Gas

88. Iván de Lorenzo
December 2004

89. Iván de Lorenzo
December 2004
•Filtered gas supply (buffer gas)
Taken from a suitable intermediate stage or from an external source for start-up.
Filtered by double filter. Alarm at differential pressure: H: 1.5 bar
A differential pressure controlvalve controls filtered buff er gas in order to have a
constant flow injection on both seal s at each side of the compressor.
This PDCV sets the buffer gas pressure 3 barhigher than that of the balancing gas.
Alarm at low differential pressure: L: 2 bar
•Seal gas line to IGV
Part of the seal gas is tak en from downstream of the filters and is pressure controlled
to 3 bardifferential pressure to the IGV control valve.
Differential pressure alarm in seal gas line to IGV if: L: 0.2 bargH: 0.8 barg

90. Iván de Lorenzo
December 2004
•Seals leakage monitoring (primary vent)
The gas leakage from the primary seals goes through adjustable orifices, tuned to
maintain a pressure of 3 barga differential pressure of 400 mbarwith normal leakage
and under normal operating condition. Differential pressure gauges are installed in all
primary vent lines.
Downstream each orifice a flow indicating transmitteris installed. In ca se of high or low
flow through the primary vent, an alarm is activated. L: 10%H: 90%
The primary vent lines are connected to a header towards the flare.
Alarm at high pressure H: 1 bar
Should a high flare back pressure be detected, vent is switched to atmosphere.
If high pressureis detected, 2oo3 pressure transmitters activate a shutdown to prevent
damage to the mechanical seal. H: 4 bar HH: 5 bar
The monitoring of the 2
ry
seal’s good condition is done through the flow transmitters of the
primary vent lines. A low fl ow alarm means that the 2
ry
seal leakage is too high.
The secondary vent lines are connected to an atmosphere vent on safe location.

91. Iván de Lorenzo
December 2004
•Nitrogen injection (purge gas)
Nitrogen is injected as purge gas taken from the plant network.
Mechanical separation is performed by using carbon tertiary seals.
Purge gas for carbon tertiary seals need s always filtration. For this reason, a double filter
with transfer valve is installed. Filter condi tion is monitored by a differential pressure
gauge.
Purge gas is controlled by a pressure regulatorand injected on both sides of the
compressor. 2 pressure reducing valvesare installed downstream of the filters.
The first one –for intermediate chamber C- is set at 4 bargand the second one –for
tertiary seals- at 1 barg.
Both are provided of block valves and by -pass line with calibrated orifice set at 3 barg.
Pressure transmitters on header are installed for low-pressure alarmand 2oo3 very low-
pressure trip in order to save tertiary seals. L: 0.7 bar LL: 0.4 bar
In the flushing chamber drain line are installed automatic traps(LCV) to assure the lube
oil drain.

92. Iván de Lorenzo
December 2004
Flow valves
(orifices)
Pressure
Transmitters
A, B, C
PDIT
Pressure
Control
Valve
Seal gas
filter
Flowmeters
(on the back)
Pressure
gauges
Flow
valves
Pressure
Control
Valve
Nitrogen
Filters
Seal gas filter

93. Iván de Lorenzo
December 2004
1616--MJ01 MJ01
1616--MJ02 MJ02
BALANCING BALANCING
GASGAS
SEAL GAS SEAL GAS
BALANCING BALANCING
GASGAS
SEAL GAS SEAL GAS
SUCTION SUCTION
SIDE SIDE
DISCHARGE DISCHARGE
SIDE SIDE
FILTERS FILTERS
NN
2
INLET INLET
EXTERNAL SOURCE TO STARTUP EXTERNAL SOURCE TO STARTUP
SEAL GAS FROM COMPRESSOR MCL1002 MEDIUM STAGE SEAL GAS FROM COMPRESSOR MCL1002 MEDIUM STAGE
FILTERS FILTERS
22
ryry
VENT VENT
11
ryry
VENT VENT
TO FLARE TO FLARE
TO ATMOSPHERE TO ATMOSPHERE
SAFE LOCATION SAFE LOCATION
TO LUBE OIL TO LUBE OIL
DRAIN HEADER DRAIN HEADER
TO LUBE OIL TO LUBE OIL
DRAIN HEADER DRAIN HEADER
TO LUBE OIL TO LUBE OIL
DRAIN HEADER DRAIN HEADER
PCVPCV
PCVPCV
PGPG
PGPG
PGPG
SET AT SET AT
4 BARG. 4 BARG.
PDGPDG
PGPGPGPGPGPG
SET AT SET AT
1 BARG 1 BARG
PDCV PDCV
LCVLCVLCVLCV
FVFV
FVFV
FVFV
FVFV
PDCV PDCV
LCVLCVLCVLCV
PGPG PDIT PDIT
PDIT PDIT
PDCV PDCV
SEAL GAS TO IGV OF AN 200 SEAL GAS TO IGV OF AN 200
SEPARATION GAS SEPARATION GAS SEPARATION GAS SEPARATION GAS
PDGPDG
PDGPDG
PT (x 3) PT (x 3)
PDGPDGPDGPDG
PGPG PDIT PDIT
PT (x 3) PT (x 3) PT (x 3) PT (x 3)
PT (x 3) PT (x 3)
DISCHARGE DISCHARGE
SIDE SIDE
SUCTION SUCTION
SIDE SIDE
PT (x 3) PT (x 3)
22
ryry
VENT VENT
11
ryry
VENT VENT
Orange piping: seal gas
Blue piping: purge (separation) gas
Red piping: 1
ry
vent
Green piping: 2 ry
vent
Purple piping: Balancing gas
FITFITFIT FIT

94. Iván de Lorenzo
December 2004
Seal gas
Primary vent
Secondary vent
Lube oil inlet
Lube oil drain
Outer buffer gas drain
Lube oil vapour
Inner buffer gas injection
Outer buffer gas injection
I Oil inlet to journal bearing II Oil inlet to thrust bearing XXI Outer buffer gas drain XXII Seal gas injection XXIII Primary vent XXIV Inner buffer gas injection XXV Secondary vent XXVI Outer buffer gas injection
Front view of seal gas and lube oil piping for
coupling between comp. AN 200 and MCL 1002

95. Iván de Lorenzo
December 2004
Seal gas
Primary vent
Secondary vent
Lube oil inlet
Lube oil drain
Outer buffer gas drain
Lube oil vapour
Inner buffer gas injection
Outer buffer gas injection
Side view of seal gas and lube oil
piping for coupling between
compressors AN 200 and MCL 1002
AN 200MCL 1002