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Turbine Package Operators Manual

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Chapter 1 Turbine Package System Overview

Engine Core Assembly ...................................................................................................................5 General Description...................................................................................................................................5 Air Inlet Casing...........................................................................................................................................5 Compressor Inlet Bearing Housing Assembly........................................................................................5 Compressor Stator Casings......................................................................................................................5 Center Casing and Bearing Housing Assembly......................................................................................6 Combustion System ..................................................................................................................................6 Compressor Turbine Outer Casing ..........................................................................................................6 Compressor Turbine Nozzle Assembly Stage 1 and Duct .....................................................................6 Turbine Rotor Assemblies ........................................................................................................................6 Power Turbine Outer Casing and Interduct Assembly ...........................................................................7 Power Turbine Bearing Housing ..............................................................................................................7 Exhaust Diffuser ........................................................................................................................................7 Auxiliary Gearbox ......................................................................................................................................7 Cooling and Sealing Air System...............................................................................................................7 Turbine Instrumentation............................................................................................................................8

Temperature Monitoring ........................................................................................................................................... 8 Speed monitoring ..................................................................................................................................................... 8 Vibration Monitoring ................................................................................................................................................. 8 Pressure Monitoring ................................................................................................................................................. 8

Turbine Core Auxiliary Equipment ...........................................................................................................9 Variable Guide Vane (VGV) Actuator....................................................................................................................... 9 Interstage Bleed Valve ............................................................................................................................................. 9 P2 Blow-off Valves ................................................................................................................................................... 9 Waterwash Nozzles.................................................................................................................................................. 9

Auxiliary Gearbox ....................................................................................................................................10 Lubricating Oil System .................................................................................................................11

General Description.................................................................................................................................11 Lubricating Oil Tank ............................................................................................................................................... 11 Lubricating Oil Pumps ............................................................................................................................................ 11 Temperature Control Valve .................................................................................................................................... 12 Pressure Control Valve .......................................................................................................................................... 12 Lubricating Oil Filters.............................................................................................................................................. 12 Oil Cooler Circuit .................................................................................................................................................... 12


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Oil Mist Eliminator .................................................................................................................................................. 12 Lubricating Oil Tank Breather System Flame Trap (if applicable).......................................................................... 12 Secondary Breather Flame Traps (if applicable).................................................................................................... 12

Instrumentation........................................................................................................................................12 Temperature Monitoring ......................................................................................................................................... 13 Pressure Monitoring ............................................................................................................................................... 13 Lubricating Oil Tank Level Monitoring .................................................................................................................... 13

Lubricating Oil System Requirements ...................................................................................................13 Fuel System...................................................................................................................................15

General Description.................................................................................................................................15 Gas Fuel System Components ...............................................................................................................15

Off-Skid Block and Vent Valve ............................................................................................................................... 15 Demister or Filter/Coalescer (if applicable) ............................................................................................................ 16 Pipeline Trace Heating (if applicable)..................................................................................................................... 16 Fuel Strainer........................................................................................................................................................... 16 Block Valves........................................................................................................................................................... 16 Vent Valve .............................................................................................................................................................. 16 Fuel Control Valve/Actuator Assemblies ................................................................................................................ 16 Electronic Control Unit (ECU)................................................................................................................................. 17 Fuel Burners........................................................................................................................................................... 17 Igniter ..................................................................................................................................................................... 17

Instrumentation........................................................................................................................................17 Position Monitoring................................................................................................................................................. 17 Pressure Monitoring ............................................................................................................................................... 17 Temperature Monitoring ......................................................................................................................................... 18 Burner Instrumentation........................................................................................................................................... 18

Fuel System Requirements .....................................................................................................................18 Air Distribution System ................................................................................................................19

Air Distribution System Components ....................................................................................................19 Instrument Air Manual Shut-Off Valve and Filter Assembly ................................................................................... 19 Gas Fuel Module .................................................................................................................................................... 19 Off-Skid Gas Fuel Block and Vent Valve Assembly ............................................................................................... 19 Lubricating Oil Module............................................................................................................................................ 19 P2 Blow-Off Valve Air Manifold .............................................................................................................................. 20 Engine Auxiliary Module......................................................................................................................................... 20 Combustion Air Filter System................................................................................................................................. 20

Ignition System .............................................................................................................................21 Introduction ..............................................................................................................................................21 General Description.................................................................................................................................21 High Energy Spark Generator.................................................................................................................21

Starting System.............................................................................................................................23 General Description.................................................................................................................................23

AC Electric Drive Motor .......................................................................................................................................... 23 Hydraulic Pump Assembly ..................................................................................................................................... 23 Hydraulic Motor Assembly...................................................................................................................................... 23

Turbine Package Operators Manual Chapter 1

Turbine Package System Overview

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Hydraulic Pump Boost Flow Oil Filter..................................................................................................................... 24 Starter Clutch ......................................................................................................................................................... 24

Turbine Underbase, Enclosure and Air Supply/Exhaust Systems............................................25 Introduction ..............................................................................................................................................25 Underbase ................................................................................................................................................25 Turbine Acoustic Enclosure ...................................................................................................................25 Ventilation System...................................................................................................................................25

Dampers................................................................................................................................................................. 26 Ventilation Inlet and Outlet Silencers ..................................................................................................................... 26 Ventilation Inlet Filter – Inertial Type (if applicable)................................................................................................ 26 Ventilation Inlet Filter – Marine Type (if applicable) ............................................................................................... 26 Negative Pressure Ventilation Fan(s) (if applicable) .............................................................................................. 26 Positive Pressure Ventilation Fan(s) (if applicable)................................................................................................ 26 Instrumentation....................................................................................................................................................... 26

Combustion Air System ..........................................................................................................................27 Air Inlet Filter - Marine Type (if applicable)............................................................................................................ 27 Air Intake Filter - Pulse Type (if applicable)............................................................................................................ 27 Air Intake Silencer .................................................................................................................................................. 27 Acoustic Lagging.................................................................................................................................................... 28 Instrumentation....................................................................................................................................................... 28

Exhaust System .......................................................................................................................................28 Exhaust Silencer .................................................................................................................................................... 28 Acoustic and Thermal Lagging............................................................................................................................... 28 Instrumentation....................................................................................................................................................... 28

Fire & Gas Protection System......................................................................................................29 General Description.................................................................................................................................29 System Control and Operation ...............................................................................................................29 System Components ...............................................................................................................................29

Heat Detectors ....................................................................................................................................................... 29 Infra Red (IR) Flame Detectors .............................................................................................................................. 30 Gas Detectors ........................................................................................................................................................ 30 Ventilation Dampers............................................................................................................................................... 31 Extinguishant Bottles.............................................................................................................................................. 31

Instrumentation........................................................................................................................................31 Pressure Monitoring ............................................................................................................................................... 31 Position Monitoring................................................................................................................................................. 32

Gearbox and Generator ................................................................................................................33 Gearbox ....................................................................................................................................................33 Generator..................................................................................................................................................33

Cooling System ...................................................................................................................................................... 33 Generator Bearing Lubrication ............................................................................................................................... 33 Vibration Monitoring ............................................................................................................................................... 34 Generator Winding Temperature Monitoring.......................................................................................................... 34 Anti-condensation Heating ..................................................................................................................................... 34


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Electrical Operation .................................................................................................................................34 Generator Control System ......................................................................................................................34

General Description................................................................................................................................................ 34 Operation................................................................................................................................................................ 34

Control Panels and Electrical Equipment Cabinets ...................................................................35 Introduction ..............................................................................................................................................35 Unit Control System ................................................................................................................................35

General Description................................................................................................................................................ 36 Human / Machine Interface (HMI) .......................................................................................................................... 36 Generator Monitoring & Control ............................................................................................................................. 37

Generator Control Panel (GCP) ..............................................................................................................37 Description ............................................................................................................................................................. 37

Batteries & Battery Charging System ....................................................................................................38 Battery Charger & System Controller ..................................................................................................................... 38 24 Volt Batteries ..................................................................................................................................................... 38 24 Volt DC Battery Charger.................................................................................................................................... 38



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Engine Core Assembly The SGT-400 is a twin shaft, simple open cycle; non-regenerative industrial gas turbine designed for both power generation and mechanical drive applications. The core engine consists of a radial inlet casing through which air enters the eleven stage axial compressor for compression prior to entry to the combustion system.

General Description The combustion system employs reverse flow combustion chambers to mix, burn and expand the air fuel mixture to drive the twin shaft turbine and exit through the exhaust diffuser.

The integrated compressor and compressor turbine assembly, and separate power turbine rotor assembly, are supported and located by journal and thrust bearings in the inlet, compressor turbine and power turbine bearing housings respectively.

An auxiliary gearbox provides ancillary drives for the main lubricating oil pump, the liquid fuel pump (if fitted), and to provide drive to the turbine from the starting system.

Refer to the SECTIONAL ARRANGEMENT – SGT-400 (MW-1-1) located in this Manual Volume.

Air Inlet Casing The Air Inlet Casing is secured to the Inlet Bearing Housing both designed and shaped to provide a smooth path for the incoming air to the compressor. An inlet screen and a flexible joint, which accommodates relative movements due to thermal expansion, are fitted to the rectangular casing entry point to which external ducting is connected.

Compressor Inlet Bearing Housing Assembly The Compressor Inlet Bearing Housing Assembly, which is mounted on the turbine/auxiliary gearbox support casing, provides support for the Air Inlet Casing and Low Pressure (LP) Compressor Stator casing. Provision is made, at the bottom of the casing, for the attachment of the front gas generator support assembly. A tilting pad journal and thrust bearing assembly within the housing supports and locates the inlet end of the gas generator rotor.

Compressor Stator Casings The Compressor Stator Casings consist of an LP Compressor Stator casing and a High Pressure (HP) Compressor Stator casing.

The LP Compressor Stator casing is split along its centerline, bolted at its forward face to the Compressor Inlet Bearing Housing assembly, and has a spigot bolted to the center casing at the rear end. Boroscope access holes are provided in the top half casing to enable examination of the compressor stator and rotor blades.

Variable geometry inlet guide vanes form the first row of stator vanes, with the subsequent four rows being variable geometry compressor stator blades, which assist starting and prevention of compressor surge. An externally mounted operating mechanism controls the movement of the vanes. The remaining LP stator blades are retained by dovetail grooves in the casing.


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The HP compressor stator casing is in the form of an insert split along its horizontal centerline and located in the pressure casing back plate. The HP compressor stator blades being retained by dovetail grooves in the insert.

Center Casing and Bearing Housing Assembly The Center Casing and Bearing Housing Assembly provide support for the hot end of the gas generator assembly, including the combustion system and the Compressor Turbine (CT) Outer Casing. A tilting pad journal bearing provides support for the exit end of the gas generator rotor.

Combustion System The Combustion System comprises six tubular combustion chambers symmetrically positioned on the forward face of the Center Casing and Bearing Housing Assembly.

The system is of axial reverse flow design; air leaving the compressor exit nozzle is reversed and enters the head of the combustion chambers via a swirler plate, which imparts a rapid swirling motion to the flow to ensure complete mixing of fuel and air.

Compressor Turbine Outer Casing The CT Outer Casing provides the interface between the Center Casing and Bearing Housing Assembly and the Power Turbine (PT) Outer Casing and Interduct Assembly. Provisions are made, at the bottom of the casing, for the attachment of the rear gas generator support assemblies. Boroscope access holes are provided in the top of the casing to enable examination of the CT stator and rotor blades.

Compressor Turbine Nozzle Assembly Stage 1 and Duct Within the Compressor Turbine Nozzle Assembly Stage 1 and Duct are housed the CT1 nozzle segments, the combustion chamber transition ducts and the CT 2 nozzle assembly. Also, with the CT2 nozzle segments is the CT 2 retaining shroud, which carries a seal ring between the CT Nozzle Assembly Stage 1 and Duct and the PT Outer Casing and Interduct Assembly.

Turbine Rotor Assemblies The turbine rotor assemblies are comprised of two separate assemblies, the CT Rotor Assembly, and the PT Rotor Assembly.

The Compressor Rotor is a single spool 11 stage axial design made up of a series of discs carrying dovetail rooted compressor blades, located together with Hirth couplings at the outside diameter and held together with a single central tension stud bolt. Overhung from the Compressor rotor and secured to it with a central tension stud bolt is the CT, which is of a two-stage design. It consists of two rotor discs located on the Compressor spool by means of a central tension stud and Hirth couplings and carrying fir tree rooted turbine blades.

The Power Turbine is of two-stage axial design, consisting of two-rotor disc located with Hirth couplings and carrying fir tree rooted turbine blades. The PT rotor is bolted to a solid output shaft by means of a tension bolt.



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Power Turbine Outer Casing and Interduct Assembly The Power Turbine Outer Casing and Interduct Assembly are attached to the CT Center Casing and Bearing Housing and the Spoke Frame Assembly. It provides the mounting for the PT1 Stator assemblies with the Exhaust Diffuser bolted to the Spoke Frame Assembly/PT Support Assembly.

Power Turbine Bearing Housing The exhaust diffuser and support assembly from the outer casing rigidly support the Power Turbine Bearing Housing. The power turbine exit rotor shaft is supported in two tilting pad journal bearings and provided with main and reverse thrust bearings.

Exhaust Diffuser The lagged Exhaust Diffuser, mounted from the turbine pressure casing provides diffusion of the exhaust gases for the exhaust ducting system.

Auxiliary Gearbox The auxiliary Gearbox is mounted via an adapter ring directly off the gas generator inlet bearing housing and driven from the gas generator shaft. It contains the necessary auxiliary drives for the hydraulic starter motor and its associated clutch, and the main lubricating oil pump.

Cooling and Sealing Air System Compressor air is used for sealing at labyrinth seals and cooling of high temperature components. Refer to the COOLING AND SEALING AIR SYSTEM DIAGRAM – SGT-400 (MW-2-1) located in this Manual Volume. Medium pressure air, taken from the bleed band at the seventh stage of the compressor, is used to:

• Pressurize the inlet labyrinth seal.

• Pressurize the labyrinth seals located either side of the compressor turbine journal bearing to prevent stage ten high-pressure air entering the bearing housing.

• Pressurize the labyrinth seals of the PT and cool the turbine discs.

Stage ten high-pressure bleed air taken from before the compressor exit guide vane is used to:

• Balance the medium pressure air used to pressurize the labyrinth seals at the compressor journal bearing.

• Cool the turbine rotor discs and the interstage diaphragm.

Compressor exit air is used to:

• Cool the CT1 and CT2 nozzle assemblies via holes in the nozzle inner and outer carrier rings into the cooling tube of each nozzle followed by discharge into the gas stream by trailing edge slots.

• Cool the CT1 and CT2 rotor blades via their triple pass convection system prior to being ejected into the gas stream.

Used medium pressure air is vented to atmosphere through the secondary breather system. Used stage ten high-pressure air is vented into the exhaust system through the primary breather system.


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Turbine Instrumentation Instrumentation is provided to monitor the turbine parameters and provide warning and trip control functions.

Refer to the Turbine Instrumentation schematic diagram located in this Manual Volume.

Temperature Monitoring Temperature detectors (RTD1 and RTD48) mounted in the air inlet casing, and thermocouples (TC1 to TC13 inclusive), mounted in the gas generator exhaust outlet, monitor compressor turbine operating temperature and temperature deviation. Additionally the output thermocouples monitor combustion condition and will shut the turbine down in the event of flame out in one of the combustion chambers. A further two thermocouples (TC101 and TC102) are mounted in the exhaust ducting, downstream of the exhaust diffuser, as part of the turbine gas path instrumentation for turbine control.

Thermocouples (TC17 and TC18), mounted in the Center Casing and Bearing Housing Assembly, measure the compressor exit temperature.

Thermocouples (TC21 to TC28, and TC91, TC92, TC96 and TC227) positioned in the appropriate bearings, measure journal and thrust bearing temperatures.

Speed monitoring Speed probes (SD20 to SD23) are used for speed detection and overspeed protection in the gas generator, and speed probes (SD24 to SD27) are used for speed control indication and overspeed protection in the power turbine. Probes monitor from the gas generator rotor shaft and power turbine rotor shaft.

Vibration Monitoring X-Y non–contacting vibration probes (UD10X1 UD10Y1, UD11X1, UD11Y1, UD12X1, UD12Y1 and UD13X1 UD13Y1) are provided adjacent to each rotor journal bearings, within the gas generator and power turbine, to monitor radial vibration. Probes (UD10X2 UD10Y2, UD11X2 UD11Y2, UD12X2 UD12Y2, UD13X2 and UD13Y2) are fitted as non–active spares.

Axial vibration detection probes (ZD10T1 and ZD10T2) are provided at the gas generator input end thrust bearings.

Keyphasors (ND10K1 and ND12K1) are provided at the gas generator input end bearing and power turbine output end bearing respectively, (ND10K2 and ND12K2) are fitted as non-active spares.

Pressure Monitoring Pressure transmitters are provided to facilitate engine control as follows:

• Air inlet pressure (PT7).

• Turbine compressor discharge pressure (PT8).

• Interduct static pressure (PT258).



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Turbine Core Auxiliary Equipment

Variable Guide Vane (VGV) Actuator The purpose of the variable guide vane (VGV) system is to vary the flow through the gas generator to optimize starting and running conditions. This is achieved by altering the angles at which the inlet guide vanes and the first three stages of compressor blades are presented to the airflow. The position of the blades is altered by the operation of the mechanically linked VGV actuator.

The electrical VGV actuator (ZZ8) consists of an actuator and servo positioner assembly. The assembly is mounted on the turbine to vary the position of the inlet guide vanes and the first, second, third and fourth stages of compressor stator blades.

The actuator position is controlled by the servo positioner, which reacts to drive signals (ZC4) from the unit control panel. The unit control panel monitors the position of the VGS blades/inlet guide vanes using a proportional feedback signal (ZT9) from the VGS actuator.

Interstage Bleed Valve To prevent gas generator surge during starting, it is necessary to reduce the compressor delivery air pressure. This is achieved by the use of the interstage bleed valve, mounted on the upper low-pressure compressor stator casing.

During the turbine starting sequence, as the compressor speed increases, control air is bled from the delivery stage of the compressor and routed through a pilot valve (XV60) onto the piston of the interstage bleed valve (XV59). As the air pressure increases, the piston is pushed to its full extent of travel, thus closing off the air being vented to atmosphere.

Operation of the pilot valve is achieved by instrument air controlled by a solenoid mounted in the instrument air pipeline.

P2 Blow-off Valves Blow-off valves (XV267 and XV268) are mounted on the port and starboard sides of the turbine to modulate engine compressor air during starting and to enable a rapid discharge of air during engine over-speed conditions.

This is achieved by bypassing engine air from upstream of the power turbine through the blow-off valves into the exhaust diffuser.

The blow-off valves are operated by solenoid valves (port - SOL625, SOL627 and starboard - SOL626, SOL628). The solenoids direct P2 air to either side of the valve actuators (XV267 and XV268). The solenoid valves are operated by a drive signal (ZC43, ZC44) from the unit control panel. The unit control panel monitors the position of the P2 blow-off valves using a proportional feedback signal (ZT141, ZT142) from the P2 blow-off valve butterfly spindles.

Waterwash Nozzles Waterwash nozzles are mounted in the engine air inlet to facilitate the supply of wash and rinse fluids into the turbine during engine hot and cold wash operations. A last chance filter (XF27) ensures filtration of the wash/rinse fluids.


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Auxiliary Gearbox The auxiliary gearbox is mounted via an adaptor ring directly off the gas generator inlet bearing housing and driven from the gas generator shaft. It contains the necessary auxiliary drives for the hydraulic starter motor and its associated clutch, and the main lubricating oil pump.



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Lubricating Oil System Mineral lubricating oil is used to lubricate and cool the turbine journal and thrust bearings, the generator bearings and the gearbox bearings, gears and splines. The oil is also used as a hydraulic oil to operate the hydraulic starting system when starting the turbine.

General Description The oil is delivered from an on-skid lubricating oil tank and circulated throughout the lubricating system under normal running conditions by a main oil pump. The system includes a temperature control valve, pressure control valve, filter, instrumentation and associated piping to provide the correct delivery conditions.

The used oil is returned to the tank by gravity drainage to create a continuously circulating system.

Heat is removed from the oil by an oil cooler circuit, which is controlled by the temperature control valve.

A lubricating oil tank breather system is provided to vent to atmosphere oil fumes that are generated whilst the turbine is running.

A schematic diagram of the lubricating oil system is located in this Manual Volume.

Lubricating Oil Tank The lubricating oil tank is integrated into the underbase fabrication and is provided with internal baffles to aid circulation and maximize removal of entrapped air. Covers are provided to facilitate cleaning of the interior if contamination occurs.

The tank is fitted with immersion heater(s) to maintain the correct pre-start oil temperature. Integral thermal protection is provided.

Flip lid filler point(s) with integral strainers are provided for filling and replenishment.

Level gauge(s) provide visual indication of the oil level within the oil tank.

Lubricating Oil Pumps Three lubricating oil pumps are provided:

• The main pump (XP1) which is mounted on, and driven by the auxiliary gearbox, provides lubrication during normal running.

• The auxiliary pump (XP2), which is submerged in the lubricating oil tank and driven by an AC motor, provides lubrication during turbine start, run up and post shutdown.

• The emergency pump (XP3) which is submerged in the lubricating oil tank and driven by a DC motor, provides essential lubrication to the turbine hot bearing in the event of the auxiliary pump or AC power failure, during or after shutdown.

Circulation between the three pumps is controlled by non-return valves, located in each pump delivery system.

Each pump is provided with a pressure relief valve to guard against over-pressurization.

A strainer is provided at each pump suction inlet.


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Temperature Control Valve A temperature control valve (XV428) operates at a set value to divert lubricating oil through the oil cooler (TH1) as necessary to maintain the temperature of the oil at the optimum level.

Pressure Control Valve Pressure control valve (PCV1) maintains a constant oil pressure to the bearings during turbine running. The excess oil is spilled back through the valve to the lubricating oil tank.

Lubricating Oil Filters Two filters are provided:

• The main filter(s) (XF2 and XF3), which are installed downstream of the pressure control valve, filters the main line flow of lubricating oil from the main and auxiliary pumps.

• The lubricating oil flow from the DC motor driven emergency pump, which is separate from the main line flow, is filtered by an emergency filter (XF4).

Oil Cooler Circuit An oil cooler circuit incorporating an air blast oil cooler (TH1) is used to dissipate heat from the lubricating oil prior to its entry into the main supply line. Flow to the cooler circuit is controlled by the temperature control valve (XV428).

Non-return valves (XV26 and XV27) are fitted in the supply and return lines to prevent the lubricating oil draining back to the tank when the turbine is shutdown.

Oil Mist Eliminator An oil mist eliminator (XF7) is provided in the lubricating oil tank breather system to reduce the amount of oil mist being exhausted to atmosphere.

Lubricating Oil Tank Breather System Flame Trap (if applicable) The breather system contains a flame trap to prevent the ignition of any oil mist, which may cause a subsequent explosion in the lubricating oil tank.

Secondary Breather Flame Traps (if applicable) Flame traps are fitted in the compressor turbine and power turbine secondary breather systems to prevent the ignition of any oil mist which may cause a subsequent explosion in the breather passages.

Instrumentation Instrumentation is provided to monitor the lubricating oil system parameters, provide warning and trip control functions.

Refer to the Lubricating Oil System schematic diagram located in this Manual Volume.



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Temperature Monitoring A resistance temperature detector (TT7) mounted in the lubricating oil supply tank monitors the tank oil temperature and provides a permissive signal for tank immersion heater(s) control. The information is also used to inhibit a start until the tank oil temperature is above a set value.

The temperature of the lubricating oil is measured by instrumentation mounted in the manifold block by resistance temperature detectors (TT66A and TT66B) provide high oil temperature warning and shutdown.

Pressure Monitoring A pressure transmitters (PT6A, PT6B and PT6C (if fitted)) are mounted in the compressor turbine supply line to provide lubricating oil pressure low/high warning and emergency lubricating oil pump control signals.

The pressure drop across the main lubricating oil filter assembly is monitored by a pressure differential transmitter (PDT8) to provide a warning of deteriorating element condition.

Each main lubricating oil filter housing (XF2, XF3) and the emergency oil filter housing (XF4) is fitted with a pop up indicator button to provide a visual indication of filter blockage.

Lubricating Oil Tank Level Monitoring A level transmitter (LT1) is used to monitor the level of the oil in the lubricating oil tank. The information provided is used to inhibit starts if the oil level is below a set value during the gas turbine starting process and to annunciate a warning or shutdown if the oil level falls below a set value during normal gas turbine operation.

The level switch is also used to inhibit the operation of the immersion heater(s) if the level of the oil in the tank is below a pre-determined level.

Lubricating Oil System Requirements In normal conditions, the turbine is designed to run on mineral oil to ISO/VG46 in accordance with company Fluids Specification 65/0027, which is located in this Manual Volume. Where, due to prevailing ambient conditions or driven machinery requirements, it is necessary to use a heavier or lighter viscosity grade of oil, ISO/VG68 or ISO/VG32 may be used respectively. However, the company must be consulted before the use of these alternative oils.

Caution: It is important to use the correct type of lubricating oil. The use of oil with insufficient or incorrect additives will cause oil performance to deteriorate.


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Fuel System The fuel system is designed to deliver fuel to the combustion system at the correct pressure and flow required for the applicable power demand.

General Description The schematic diagrams of the Fuel System can be found in this Manual Volume.

The fuel system comprises:

Off-skid Components

• block and vent valve assembly (XV30, XV31)

• demister (if applicable)

• filter/coalescer (if applicable)

On-skid components

• gas fuel supply strainer (XF94)

• two block valves (XV6, XV7)

• vent valve (XV212)

• main fuel control valve/actuator assembly (XV150, XM26)

• pilot fuel control valve/actuator assembly (XV149, XM27)

• electronic control unit

• system monitoring and control instrumentation

• pipeline trace heating (if applicable).

Gas Fuel System Components

Off-Skid Block and Vent Valve The block and vent valve assembly is located in the customers gas supply line. The assembly comprises of a block valve (XV30) and a vent valve (XV31). Both valves are controlled by pneumatically operated rotary actuators. Air is directed to the actuators by solenoid valves (SOL12 and SOL11) respectively. When the situation demands, the block valve closes to prevent gas entering the on-skid fuel system and the vent valve opens to vent the interconnecting pipework.

The block valve is spring loaded to fail in the ‘closed’ position. The vent valve is spring loaded to fail in the ‘open’ position.


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Demister or Filter/Coalescer (if applicable) The off-skid demister or filter/coalescer is used to remove liquids and particulates from the gas fuel.

The gas enters the filter/colaescer at the inlet pipe and passes through a special filter element into the top chamber, from where it leaves the filter/colaescer in a clean dry condition via the outlet pipe.

Pipeline Trace Heating (if applicable) The gas fuel pipelines are trace heated to prevent the formation of condensation in the gas system.

Fuel Strainer A 76-micron fuel strainer (XF94) is located in the fuel pipework downstream of the skid edge to protect the burner orifices from blockage and contamination.

Block Valves The primary (XV7) and secondary (XV6) block valves provide isolation of the on–skid fuel system from the gas supply. They are controlled by integral actuators, which are operated by instrument air and spring pressure. The instrument air supply to the actuators is controlled by pilot solenoids (SOL5 and SOL110).

The block valves are designed to fail in the closed position.

Vent Valve The vent valve (XV212) provides for venting of the gas fuel pipework between the two block valves on turbine shutdown. The valve is controlled by an integral actuator operated by instrument air and spring pressure. The instrument air supply to the actuator is controlled by a pilot solenoid (SOL470).

The vent valve is designed to fail in the open position.

Fuel Control Valve/Actuator Assemblies The main and pilot fuel control valves (XV150 and XV149) are of the rotary ball valve type and operated through a zero backlash coupling by electrically operated rotary actuators (XM26 and XM27). Each valve/actuator assembly is firmly mounted and connected into the fuel system. The valves are calibrated and set up to meter the fuel flow to the burners under the control of an electronic control unit. Integral position transmitters (ZT12 and ZT103) monitor the position of the control valve actuators.



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Electronic Control Unit (ECU) The ECU is an integral part of the fuel system and interfaces with the fuel control valve actuator and the turbine governor to provide accurate fuel control, utilizing a high-speed microprocessor at its heart.

The ECU constantly receives fuel condition input signals, and uses this information to calculate the correct position of the fuel valve according to the flow rates demanded by the turbine governor. The ECU also provides feedback of valve position and fault conditions to the turbine control system.

Fuel Burners The burners incorporate main and pilot gas ports to introduce the correct proportion of fuel for the combustion process during starting and turbine operation.

Igniter An igniter (IG1 to IG6) is incorporated in each burner to provide a heat source to the fuel during engine starting. The units are connected by high-tension leads to a high-energy spark generator.

Instrumentation Instrumentation is provided to monitor the fuel system parameters and provide warning and protective control functions if unsafe or damaging conditions are detected.

Position Monitoring Position switches (ZS12 and ZS45) monitors the open/closed position of the off-skid block valve and switches (ZS44 and ZS11) monitor the open/closed position of the off-skid vent valve.

Position switches (ZS178 and ZS5) monitor the open/closed position of the primary on-skid block valve, switches (ZS207 and ZS208) monitor the open/closed position of the secondary on-skid block valve and switches (ZS742 and ZS743) monitor the open/closed position of the vent valve.

The switches initiate a start inhibit signal if the any of the valves are wrongly positioned prior to start.

Pressure Monitoring Pressure transmitters (PT2 and PT181) monitor the gas supply pressure at the input and the demand pressure at the output of the main gas fuel control valve respectively. The pressure differential across the valve is used in conjunction with the valve feedback position to calculate the approximate percentage fuel flow through the valve.

Pressure transmitters (PT220 and PT182) monitor the gas supply pressure at the input and the demand pressure at the output of the pilot gas fuel control valve respectively. The pressure differential across the valve is used in conjunction with the valve feedback position to calculate the approximate percentage fuel flow through the valve.

Dynamic air pressure through the center casing is monitored by a pressure transmitter (PT200).


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Temperature Monitoring A temperature transmitter (TT6) monitors the gas fuel supply temperature upstream of the gas fuel control valve(s). The transmitter relays temperature information to the ECU and programmable controller and provides low and high temperature shutdown signals.

Burner Instrumentation Six temperature sensors (TC255–TC260) mounted in each of the burner assemblies continuously monitor burner operation and provide operational data to the turbine control system.

Fuel System Requirements Refer to the SIEMENS Fluids Specification 65/0027, which is located in this Manual Volume, for more specific information on fuel requirements.



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Air Distribution System Instrument air is supplied to the package to assist in the operation and control of the gas fuel module valves, the off-skid gas fuel block and vent valves, the lubricating oil module valves, the P2 blow-off valves during starting and stopping, the interstage bleed valve, the combustion air filter pulse cleaning system, the enclosure vent dampers, the auto drain system and the turbine seals. P2 air from the turbine core is used to operate and control the P2 blow-off valves during normal turbine operation.

The air distribution system delivers the air through a system of pipework and manifolds to the various components.

Refer to the SIEMENS Fluid Specification 65/0027, which is located in this Manual Volume, for specific information on the instrument air quality requirements.

Instrumentation The pressure transmitter (PT185) monitors the instrument air supply pressure. The pressure transmitter initiates high and low pressure warning and shutdown signals.

Air Distribution System Components

Instrument Air Manual Shut-Off Valve and Filter Assembly A manual shut-off valve (HV220) and filter (XF102) assembly is located in the instrument air supply pipework. The shut-off valve facilitates manually isolation of the system for maintenance purposes. The filter provides filtration of the instrument air supply to remove particles above 5 microns.

Gas Fuel Module Instrument air is supplied to the gas fuel module to provide actuation for the primary and secondary block valves (XV7, XV6), and for the vent valve (XV212). The air is directed by the valve solenoids (SOL5, SOL110, SOL470) to the actuators, which position the valves as required for engine operation.

Off-Skid Gas Fuel Block and Vent Valve Assembly Instrument air is supplied to the block valve (XV30) solenoid (SOL12) and the vent valve (XV31) solenoid (SOL11) of the off-skid gas fuel block and vent valve. The air is directed by the solenoids to actuators, which position the valves as required for engine operation.

Lubricating Oil Module Instrument air is supplied to the lubricating oil module to provide control air for the lubricating oil supply pressure control valve (PCV1) and the temperature control valve (XV428) position indication.


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P2 Blow-Off Valve Air Manifold Instrument air is supplied to the P2 blow-off valves via the air manifold during engine start and shutdown. The P2 blow-off valve system is protected from excessive pressure by a pressure relief valve (PSV159).

P2 air for the P2 blow-off valves is supplied from the engine through a filter (XV187) and pressure control valve (PCV150) during normal engine operation.

A non-return valve (XV430) prevents P2 air from entering the main instrument air system during normal engine operation.

Engine Auxiliary Module Instrument air is supplied via process airlines to the engine auxiliary module for pressurization of the engine seals and to the instrument air manifold.

Combustion Air Filter System Instrument air is supplied as required to the combustion air filter for operation of the pulse clean system (if applicable).



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Ignition System Introduction During the start up cycle, a high-energy pulse spark from the ignition system is used to ignite the combustion chamber air/fuel mixture.

General Description The ignition system consists of a high-energy spark generator mounted in the underbase, with each combustor flame tube having its own igniter assembly (IG1 to IG6), which is permanently fixed. The units are connected with high-tension leads enclosed in an armored conduit.

High Energy Spark Generator The high-energy spark generator is a capacitor discharge system encapsulated within a steel enclosure with appropriate supply and high-tension terminations.


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Starting System The turbine is started with a hydraulic transmission system driving through an overrunning clutch assembly on the auxiliary gearbox. The turbine rotor is accelerated to a speed at which fuel may be introduced into the combustion system and ignited to provide self-sustained acceleration, up to the normal operating speed.

General Description The hydraulic start system comprises of an AC motor driven hydrostatic pump and boost pump mounted on the turbine underbase to drive the gearbox mounted hydrostatic starter motor. The hydraulic starter motor connects through a high-speed overrunning clutch and associated gearing in the gearbox to the turbine rotor assembly.

The pump and motor displacements are controlled to provide the correct system acceleration.

On achieving a successful turbine start and at a pre-set speed, power to the AC motor is removed and the system deactivated.

Turbine lubricating oil is used for the closed loop hydraulic circuit. Make-up oil is drawn from the lubricating oil tank to provide cooling.

During the hydraulic starter motor run up, the position of the variable geometry inlet guide vanes and stator blades are adjusted by the variable geometry stator actuator to optimize aerodynamic conditions for the starting cycle.

Prior to ignition, the turbine compressor interstage bleed valve is used to bleed compressor air to atmosphere to reduce the start-up power requirements and prevent compressor surge.

The Schematic Diagram of the Starting System is located in this Manual Volume.

AC Electric Drive Motor The AC electric drive motor (XM3) for the start system is an induction motor with anti-condensation heaters and thermistors for monitoring the motor winding temperatures. The thermistors relay temperature information to the programmable controller and provide start inhibit, and high temperature warning and shutdown signals.

Hydraulic Pump Assembly The hydraulic pump assembly (XP5, XP9) is a variable displacement, axial piston type with pre-set pressure cut-off control. The varying current signal from the unit control panel adjusts the pump displacement to achieve the required control rate.

Hydraulic Motor Assembly The variable displacement hydraulic starter motor (XM91) is fitted with a pre-set high-pressure related volume control. This control will decrease the motor displacement thereby increasing turbine speed as the motor differential pressure reduces.


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Hydraulic Pump Boost Flow Oil Filter A high-pressure filter (XF14) and bypass valve assembly (XV185) filters the oil to the hydraulic pump. The filter housing is fitted with a pop up indicator button to provide a visual indication of filter blockage.

Starter Clutch The hydraulic motor is mounted to the auxiliary gearbox through a high-speed overrunning clutch. During start up, the motor/clutch has a positively engaged connection to the auxiliary gearbox. The hydraulic motor runs the turbine up to its ignition speed. Upon ignition, the turbine speed increases further which causes the clutch to disengage. The design of the starter clutch enables re-engagement on run down, without having to fully stop the turbine before attempting a restart.



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Turbine Underbase, Enclosure and Air Supply/Exhaust Systems Introduction The underbase forms a structure for mounting the turbine, auxiliary gearbox and associated systems.

An acoustic enclosure is provided over the turbine, interfacing with the underbase, to reduce noise levels from the machinery to an acceptable level.

A ventilation system is used to purge the turbine enclosure prior to a start, to cool the turbine during running and for a period following shutdown, and to ventilate the enclosure should a gas leak occur. The ventilation air is discharged from the enclosure through the ventilation outlet.

The intake system filters and ducts combustion air to the turbine inlet casing and incorporates a silencer to reduce noise emissions from the turbine intake.

The exhaust system ducts the exhaust gases from the turbine to atmosphere and incorporates a silencer to reduce noise emissions

A schematic diagram of the ventilation and combustion air systems is located in this Manual Volume.

Underbase A single piece underbase of fabricated steel construction, which incorporates an integral lubricating oil tank, provides mounting points for the main turbine/gearbox support and the turbine combustion casing support. Torque reactions from the turbine/gearbox are transmitted from the fabrication to the foundations through the multiple mounting pads and foundation bolting.

The underbase incorporates mounting features/points for all the turbine support systems. System supply, vent, and drain connections are integrated into the main side members of the fabrication. The underbase also incorporates integral plating on the underside of the fabrication, which forms a spillage collection feature for any system leakage.

Turbine Acoustic Enclosure The turbine acoustic enclosure comprises a load bearing framework, with removable paneling and hinged doors, mounted on the turbine underbase. Sound attenuation is achieved by a combination of material thickness, acoustic infill and, if required, the provision of an acoustic skirt.

Ventilation System The ventilation system draws air from the atmosphere and directs it through ducting and system components before discharging it back to atmosphere in a safe area.


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Dampers Control system activated dampers are located at the enclosure ventilation inlet and outlet openings, which close when a fire is detected to retain the fire extinguishant. The dampers are also closed when the unit is in standby mode.

Ventilation Inlet and Outlet Silencers Silencers are provided to reduce noise emissions through the ventilation ducting from the gas turbine and the ventilation fan(s).

Ventilation Inlet Filter – Inertial Type (if applicable) An inertial type ventilation filter (XF33) is provided at the inlet to the ventilation system.

An AC driven bleed fan (XM42) is used to remove contaminants from the inertial panels.

Ventilation Inlet Filter – Marine Type (if applicable) A multi stage marine type ventilation filter (XF33) is provided at the inlet to the ventilation system.

The first stage of the filter consists of an optional selection of either; a weather louver, vane separator, vane separator with hood or a weather hood and bird screen, dependant upon the specific site conditions.

The main filter section comprises of a coalescer filter panel.

The final stage consists of a vane separator.

Negative Pressure Ventilation Fan(s) (if applicable) Motor driven fan(s) (XM6 and if applicable XM7) are mounted in the ventilation outlet duct to provide a flow of air through the enclosure. The system is designed to give a negative pressure within the acoustic enclosure.

Positive Pressure Ventilation Fan(s) (if applicable) Motor driven fan(s) (XM59 and if applicable XM37) are mounted in the ventilation inlet duct to provide a flow of air through the enclosure. The system is designed to give a positive pressure within the acoustic enclosure.

Instrumentation

Filter Differential Pressure Monitoring (if applicable) The ventilation intake filter pressure drop is monitored by a differential pressure transmitter (PDT27) which provides warning signals to the unit control panel.

Enclosure Differential Pressure Monitoring The enclosure pressure is monitored by a differential pressure transmitter (PDT138) which provides shutdown signals to the unit control panel.



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Combustion Air System

Air Inlet Filter - Marine Type (if applicable) The combustion air intake filter (XF34) is of the high velocity, high efficiency multi-stage type consisting of five stages.

The first stage of the filter consists of a weather hood and bird screen.

The second stage consists of a spin tube module and extractor assembly. The spin tube module consists of a bank of spin tubes mounted in a frame. Air entering the inlet tube strikes a fixed spinner that imparts a whirl effect, which develops a high radial velocity to the air stream. The inertial action forces heavy contaminants in the airflow to the periphery of the tube, separating them from the airflow. Purified air exits through a central discharge tube whilst contaminants are carried by the secondary discharge stream into a bleed duct system. The bleed duct system comprises a small transition section that leads to a short case axial flow fan. The fan pulls the contaminant-laden air through the bleed duct to the outside of the filtration system.

The main filter section is a high efficiency bag type filter with an optional pre–filter bag fitted directly in front of the main filter bags to prolong their life by removing heavy contamination.

The final stage consists of a vane separator for the inertial interception and removal of bulk water caused by high humidity, rainfall or sea spray.

The filter housing is provided with a side or front access door for servicing of filter elements and gas detectors (when fitted).

Where anti-icing is required a heat exchanger is mounted onto the front of the filter and provided with hot exhaust gases ducted from the exhaust system.

For further information, refer to the Maintenance Manual.

Air Intake Filter - Pulse Type (if applicable) The combustion air intake filter (XF34) is of the high efficiency, single stage, pulse clean type.

The filter comprises of a matrix of cylindrical filter elements, which are cleaned by means of a reversed pulse of compressed air.

Pulsing occurs automatically when a preset pressure differential is reached; it can also be initiated manually or via a timer to over-ride the differential pressure control signal. An additional timer is included to over-ride the control system to inhibit the pulse at preset times e.g. late at night.

Compressed air headers and blow tubes deliver a solenoid valve (SOL361) controlled pulse of air that clears dust cake and any ice build up from the outside surface of the elements.

A pulse clean scavenge fan XM19 is fitted to assist removal of debris from the filter (if applicable to this application).

For further information, refer to the vendor documentation in Volume V – Vendor Information Manual.

Air Intake Silencer A silencer is provided to reduce noise emissions from the turbine intake.


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Acoustic Lagging To meet site noise emission requirements, the intake system may be acoustically lagged up to and including the air intake silencer. As a minimum, the lagging will have sufficient physical properties to meet the package noise level requirements.

Instrumentation The air intake filter pressure drop is monitored by a differential pressure transmitter (PDT1) which gives warning and shutdown signals to the unit control panel.

Exhaust System

Exhaust Silencer An exhaust silencer reduces noise emissions from the turbine exhaust.

Acoustic and Thermal Lagging To meet site requirements, the exhaust system may be acoustically and thermally lagged downstream of the acoustic enclosure, up to the silencer or waste heat recovery unit (where applicable) excluding flexible joints. As a minimum, the lagging is sufficient to ensure the outer surface of the cladding is restricted to 55ºC for metallic cladding or 65ºC for non-metallic cladding. This will ensure:

• Heat is kept within the duct for overall system efficiency.

• Acoustic attenuation.

• Protection of personnel.

Instrumentation A pressure differential transmitter (PDT133) situated in the exhaust duct provides indication of exhaust gas backpressure (if applicable).



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Fire & Gas Protection System The turbine acoustic enclosure is provided with a fire and gas monitoring system and a fire extinguishant system to protect the installation should a gas leak or fire be detected. A schematic diagram of the Fire System is located this Manual Volume.

General Description The system comprises gas detectors, infrared flame detectors and heat detectors mounted in the turbine enclosure. Fire extinguishant cylinders are mounted external to the enclosure with an associated release mechanism, which delivers the extinguishant through pipework to nozzles located inside the enclosure. The system is automatically controlled by the fire and gas monitoring module located within the unit control panel. A manual extinguishant release button, on the turbine extinguishant release control panel located on the unit control panel, enables manual operation of the system. Audible and visual alarm units are fitted to the turbine enclosure roof.

Ventilation dampers, which are situated in the enclosure ventilation inlet and outlet ducts, are used to prevent the loss of extinguishant to atmosphere if a fire occurs.

System Control and Operation A twin shot system provides initial and reserve extinguishant charges. If a fire is detected either via the heat detector(s) or via infrared flame detectors then the turbine, all AC power supplies and fuel is shut down and isolated. After a short time delay, the initial charge of extinguishant is released and the DC motor driven emergency lubricating oil pump automatically starts.

If the extinguishant release is not detected by the in-line pressure switch, the reserve shot will be released. After a successful release is detected, then any further automatic releases are inhibited for 20 minutes. The emergency lubricating oil pump will continue to run.

Note: If a fire is considered to be due to a lubricating oil leak and being potentially fed by the emergency lubricating oil pump, then it is the responsibility of the operator to decide whether to switch off the pump or allow it to continue running.

The CO2 extinguisher cylinders must be isolated from the engine package during maintenance. A signal from the isolation valve inhibits a gas turbine start attempt when the valve is in the isolated position.

System Components

Heat Detectors Heat detectors (TD2A (TD2B, TD13, TD21 - optional)) are mounted in the turbine enclosure. If a heat detector detects a fire, a fire shutdown will immediately be initiated, and the fire extinguishant released after a predetermined time delay.


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Infra Red (IR) Flame Detectors IR flame detectors (YD5, YD7, and YD8) are provided, suitably located to detect a fire at any location within the enclosure.

If a detector detects a fire, a turbine shutdown will be initiated and the initial fire extinguishant charge will be released.

Fault conditions in the infrared detection system are monitored. If a fault is detected in a detector, a fault warning will be annunciated; if the fault is not rectified within 15 minutes the turbine will be shutdown (not a fire shutdown).

Gas Detectors

Enclosure ventilation outlet Two gas detectors (GD1, GD2) are provided, suitably located to detect gas exiting the enclosure vent outlet.

The detection of gas by any single gas detector in an area will provide fault and low/high alarm level signals. Operation of the low-level alarm will give an audible warning. Operation of the high-level alarm will initiate a turbine shutdown, but keep the turbine enclosure ventilation fan(s) running.

Enclosure ventilation inlet (if applicable) Two gas detectors (GD3, GD4) are provided, suitably located to detect gas entering the enclosure vent inlet.

The detection of gas by any single gas detector will provide fault and low/high alarm level signals. Operation of the low-level alarm will give an audible warning. Operation of the high-level alarm will initiate a turbine and turbine enclosure ventilation fan shutdown.

Combustion air inlet (if applicable) Two gas detectors (GD6, GD11) are provided, suitably located to detect gas entering the combustion air inlet.

The detection of gas by any single gas detector will provide fault and low/high alarm level signals. Operation of the low-level alarm will give an audible warning. Operation of the high-level alarm will initiate a turbine shutdown, but keep the turbine enclosure ventilation fan(s) running.

General If gas is detected at ‘warning’ level then a warning will be annunciated followed 15 minutes later by a turbine shutdown.

Prior to engine start, if gas is detected at the warning level, purging of the enclosure will take place and a subsequent recheck. If gas continues to be present at the warning level the start attempt will be aborted after 15 minutes. If gas is detected at the ‘shutdown’ level, purging of the enclosure will take place, followed by a subsequent recheck. If gas continues to be present at the ‘shutdown’ level, a start will not be permitted and should not be attempted.



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Ventilation Dampers Dampers (YV1 and YV2), located in the enclosure vent inlet and outlet respectively, are automatically opened during turbine operation by instrument air pressure. When the turbine is shutdown, the controlling solenoids (SOL162 and SOL161) are de-energized and the dampers will close under spring pressure. In the event of a fire, the dampers will therefore be closed to retain the fire extinguishant.

Extinguishant Bottles Four fire extinguishant bottles, two initial (XX16 and XX17) and two reserve (XX19 and XX20), are positioned on a skid outside the turbine acoustic enclosure with connecting pipework to nozzles within the enclosure. The bottles are suspended from automatic bottle weighing devices, if either of the initial or reserve bottles indicates low contents a warning is annunciated on the turbine control module. If BOTH sets of bottles indicate low contents then a warning will be annunciated followed 15 minutes later by a turbine shutdown.

The fire extinguishant is released by either a signal from the turbine control module or by manual actuation from the breakglass units located on corners of the turbine enclosure package (optional) and one located on the turbine control module. The bottles give the capacity for an initial automatic or manual release of extinguishant followed by the option of another automatic or manual reserve release. Both sets of bottles may be manually fired by operating the manual lever actuator located on top of the bottles.

A valve is provided adjacent to the extinguishant bottle skid for manual isolation. The valve is fitted with limit switches to indicate when the valve is fully open or closed. When the valve is closed the enclosure vent system trip is inhibited.

An integral safety feature of the extinguishant bottle skid is the provision of five bursting discs to safeguard against system overpressure. The discs are positioned on the ‘initial’ first bottle (PSE4), ‘initial’ second bottle (PSE5), ‘reserve’ first bottle (PSE6), ‘reserve’ second bottle (PSE7) and upstream of the manual shut off valve (PSE3).

Instrumentation

Pressure Monitoring Pressure monitoring is provided as follows:

Fire Extinguishant Bottles Pressure switches (PS8 and PS73) provide the unit control panel with a C02 Gas Gone warning for both Initial and Reserve cylinders respectively.


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Position Monitoring Valve position monitoring is provided as follows:

Ventilation Dampers Position switches (ZS16 and ZS17) monitor the enclosure ventilation dampers to ensure they are in the Open position. Position switches (ZS76 and ZS99) indicate when the enclosure ventilation dampers are in the Closed position.

Isolation Valve Position switches (ZS384 and ZS235) monitor the C02 Isolation valve in the Open and Closed positions respectively.

Fire Extinguishant Bottles Position Switches (ZS749 and ZS748) monitor the ’Initial’ C02 second bottle and first bottle low contents respectively.

Position Switches (ZS751 and ZS750) monitor the ’Reserve’ C02 second bottle and first bottle low contents respectively.



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Gearbox and Generator Gearbox The main gearbox located between the gas turbine and the generator provides speed reduction of the turbine output shaft to that suitable for operation of the generator.

The gear unit is a single reduction parallel shaft speed reducer with vertical offset. Lubrication of the gear units and bearings is provided by the gas turbine lubricating oil system. The gear unit is foot mounted on to the underbase.

Gearcase-mounted accelerometers provide indication of excess vibration.

The information contained within this section provides an overview of a typical gearbox and associated equipment. For specific manufacturer information, refer to the Driven Unit Manual.

Generator The generator is of salient-pole construction with brushless excitation, and a permanent magnet generator (PMG) for automatic voltage regulator (AVR) power supply. The design incorporates accessibility to facilitate commissioning, operation, inspection and maintenance.

All the component items of the generator are fixed to the base frame, which is the main structural member. It carries the end brackets and bearings, the stator corepack and the cooler, which is mounted on top. The exciter and PMG stators are fixed to a bracket mounted on the end bracket at the non-drive end (NDE). Terminals are mounted off the frame, either all on one side or lines one side and neutrals on the other, as required.

The information contained within this section provides an overview of a typical generator and associated equipment. For specific manufacturer information, refer to the Driven Unit Manual.

Cooling System A fan, mounted on the generator rotor shaft, provides circulation of cooling air to the electrical windings of the rotor and stator. This circulating cooling air inside the machine is sealed in and is cooled by passing it through an air cooled heat exchanger mounted on the top of the generator.

The air flow to the heat exchanger is induced by fans mounted in the air inlet.

A pressure differential switch monitors air flow to the heat exchanger.

The temperature of cooling air to the generator windings is monitored by resistance temperature detectors.

Generator Bearing Lubrication The generator bearings are supplied with lubricating oil from the turbine lubricating oil system.

One resistance temperature detector is fitted to each bearing housing. This monitors bearing temperature and provides warning and turbine shutdown functions if the temperature levels reach predetermined levels.


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Vibration Monitoring The generator is monitored for vibration by accelerometers located at the drive end and non-drive end bearings. The accelerometers provide warning and turbine shutdown functions if vibration levels reach predetermined levels.

Generator Winding Temperature Monitoring Resistance Temperature Detectors (RTD's) are fitted on the stator windings to monitor temperature and to provide warning and turbine shutdown functions if the temperature levels reach predetermined levels.

Anti-condensation Heating Anti-condensation heaters are located to protect the generator windings and generator exciter.

Electrical Operation The AC generator converts mechanical energy into electrical energy by electro-magnetic induction. To produce a voltage, there must be a relative motion between the armature windings of the stator and the field windings of the rotor. The motion is produced by the action of the gas turbine engine turning the rotor via the gearbox.

An automatic voltage regulator (AVR) provides and controls the DC power for the excitation of the generator.

A power factor/VAr control circuit enables the generator to operate at constant power factor or constant VAr’s when in parallel with other generators or with the public supply.

The overcurrent limit circuit protects the AVR and generator excitation system against overloads by limiting the maximum excitation output from the AVR.

An excitation fault detector is used to detect the malfunction of a generator caused by faulty excitation.

Generator Control System The generator control system protects and monitors the operation of the generator.

General Description As required, the generator control system consists of various metering, indication, control, protection, and synchronizing devices and instrumentation as well as the panel switches that enable generator functions.

Operation Control of the generator is achieved through a generator control panel (GCP). Links exist between the GCP and the turbine control system to enable emergency stop, raise, and lower command signals.



Control Panels and Electrical Equipment Cabinets Introduction This section describes details of the control panels and electrical equipment associated with the turbine package.

Unit Control System The unit control system provides control signals and monitoring for all the turbine systems and associated instrumentation to allow safe starting, normal running and shutdown of the gas turbine.

The system, which is microprocessor-based, provides control and monitoring which includes:

• Turbine sequencing and protection,

• Fault monitoring,

• Annunciation,

• Gas turbine speed control and temperature monitoring,

• Back up protection for safety related functions,

• Driven unit monitoring,

• Fire and gas monitoring.

Figure 1-1 Unit Control Panel (UCP) (onskid)

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Figure 1-2 Operator Panel

General Description The on-package control system comprises a main controls housing mounted on the outside of the turbine enclosure together with networked I/O nodes mounted inside the turbine package distributed around the engine. A driven unit node is located on the driven unit end of the package. Some modules are mounted off the package, such as the motor control center (MCC) and battery system. The main operator interface is a remote desktop personal computer (PC) or a touchscreen display mounted on a free standing controls cubicle.

Human / Machine Interface (HMI) The human / machine interface is provided for unit operation, control data and status information. The displays are selected by using a mouse to make selections via a menu system.

The Human / Machine Interface (HMI) includes on screen data trending facilities. Screens display the information in various formats, including pictorial and tabular, and can incorporate live data and animation. All text on the HMI is in the native language.

A typical selection of main menu functions available on the display is listed below:

1. Unit Operation – This is the main page from which control of turbine and driven unit can be performed. The mimic also shows summary data for the unit.

2. Auxiliaries – This shows turbine auxiliaries such as the seal air system and drains tank.

3. Core Instruments – Shows bearing temperature and vibration data.

4. Core Temperature – The temperature of the turbine core as measured by a thermocouple ring is shown here.

5. Fire and Gas – Summary of data from the fire and gas systems.

6. Fuel – An overview of the fuel system is shown on this mimic. Where multiple fuels are available to the turbine, the individual systems are also selectable.



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7. Gas Path – The temperature and pressure of air flowing through the turbine is displayed on this mimic.

8. Turbine Governor – This shows the state of the turbine fuel governor and allows selection of all governing modes.

9. Lubrication Oil –Shows the lubrication oil system for the turbine and driven unit, indicating which oil pumps are running and giving oil pressure and temperature.

10. Turbine Log – This page shows key data for the turbine which can be interpreted by experienced personnel.

11. Ventilation – Includes the enclosure ventilation fans, flow detection and related items such as inlet filters and enclosure dampers.

12. Driven Unit – A group of mimics provide access to driven unit control and monitoring.

Generator Monitoring & Control The control system provides a mixture of digital and analogue I/O for the generator sequencing / monitoring and alarm protection. The exact configuration is dependent on the generator instrumentation and electrical interface, but would typically include:

• Monitoring of the Shutdown Sequencing and Protection relays,

• Generator Control Panel Speed Control and synchronizing unit interface,

• Instrument Fault Monitoring,

• Message Annunciation,

• Generator Winding and Bearing Temperature Monitoring and Protection,

• Generator Cooling Control and Monitoring,

• Vibration Monitoring of the generator non-driven and drive end seismic probes.

Generator Control Panel (GCP) Normal control of the generator is achieved from the HMI via a generator control panel (GCP). Links exist between the GCP and the turbine control system to enable emergency stop and raise/lower command signals.

The generator control panel also protects and monitors the operation of the generator.

Description The GCP consists of a cubicle housing various metering, indication, control, protection, and synchronizing devices and instrumentation as well as the panel switches which enable the generator functions.

Access into the cubicle can be gained through a front mounted door. Opening the door will activate a light within the cubicle.

For more specific details of the GCP refer to the ACTEMIUM literature contained in the Vendor Information Manual.


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Batteries & Battery Charging System The DC supply is provided by 24 volt batteries and a battery charger. The supply is directed through a DC distribution plate to the package systems.

The battery system is designed to have the capacity to run the DC motor driven emergency lubricating oil pump for three hours in the case of a mains failure.

Battery Charger & System Controller The battery charger is housed in a freestanding steel enclosure, which also contains the batteries, DC-DC converters, and a system controller. The system controller allows the user to configure, monitor and control the entire DC power system from a touch screen display. In addition to local indicators and alarms, the system controller also has Ethernet communication capabilities.

24 Volt Batteries 24 volt NiCad battery, plastic cased, consisting of 20 cells having a nominal capacity of 550Ah. The cells are designed for optimal operating in an ambient of 25ºC.

The cells are mounted on a battery rack.

24 Volt DC Battery Charger The 24 volt battery charger is housed in a freestanding steel cubicle.

The equipment comprises a 24V 3k1W Rectifier module, a CXCR Controller, 24V battery and associated protective devices. The rectifier will support any standby load and recharge the associated battery.

Local indicators and alarms provide indication of voltage/current, charge/charge failure, and mains supply.

Contacts are also included to provide remote indication of mains and charger failure.

For more specific details of the Batteries and Battery Charger refer to the Alpha-Argus literature contained in the Vendor Information Manual.

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