Turbine Traning Manual

Cakerawala Platform Taurus 60 Generator Training Manual

SECTION 1 - INTRODUCTION TO CAKERAWALA GAS TURBINES Turbines & Origins There are many different types of turbines in use in the world today. Some forms are old, like the Waterwheel (hydraulic turbine) and Windmill. Others are of more recent origin, Steam Turbines date from the 19th century while Gas Turbines date from the 20th century. Gas Turbines were originally conceived as a means of aircraft propulsion and were not developed for industrial use until 1947. Since then they have undergone significant changes in design to become more powerful and efficient and capable of operation in a wide variety of environments and applications.

Operating Principles All turbines are basically engines that convert the energy of a moving stream of fluid (liquid / water, steam or gas) into mechanical energy. The essential element of all turbines is a shaft with blades or buckets arranged radially around the shaft in such a fashion that the fluid stream imparts a force to the blades or buckets to cause the shaft to rotate. The rotational torque imparted to the shaft is then used to provide useable power; Examples : Waterwheel – mechanical drive (corn mill) ,hydro-electric generator. Windmill – mechanical drive (water pump), generator. Steam Turbine – numerous including mechanical drives and generators. Turbo-charger – compressor driver. Note: The rotating shaft on a Turbo-jet (aircraft engine) drives a compressor and other auxiliary drives and uses the exhaust gases to provide thrust to ‘push’ the aircraft forward.

Why Gas Turbine? There are numerous variants to the basic operating concept of an ‘engine that converts the energy of a moving fluid stream into mechanical energy’. What is common to all Gas Turbines is the ‘Driving fluid’ which is Gas. An aircraft Turbo-jet may use liquid fuel, but it is still a Gas Turbine because it is ‘driven’ by gas, just as the Turbo-charger is driven by the exhaust gas of a reciprocating engine and an Expander / Compressor is driven by the gas of the process it is operating on.

Solar Taurus 60 under construction

Industrial Gas Turbine – Principle of Operation There are numerous designs and configurations of Industrial Gas Turbines, but they all operate in essentially the same basic manner. They are heat engines and use the expanding gases of combustion to drive the turbine shaft. They operate under what is called the Brayton Cycle. Unlike the reciprocating Internal Combustion engine which also uses the expanding combustion gases to drive it’s pistons and operates under the Otto Cycle; the Gas Turbine has continuous combustion to provide continuous torque to the turbine shaft. They do not need a flywheel to dampen the intermittent cylinder combustion of the Internal Combustion engine and do not develop the high internal pressures encountered in the cylinders of a reciprocating engine.

The Brayton Cycle Brayton Cycle

In order to begin and then sustain combustion, an oxidizer (oxygen) must be combined with the fuel and ignited. Free air contains nearly 21% oxygen and like the internal combustion engine, this is used air, the remaind by being drawn in and compressed, (compression Brayton Cycle 1>2). It is then mixed with the fuel and ignited and combustion occurs, (Brayton Cycle 2>3). The combustion gases expand rapidly, (expansion, Brayton Cycle 3>7) and drive the turbine shaft. The expanding gases are then allowed to exhaust to atmosphere (Brayton Cycle 7>1) where the remainder of their heat energy is dissipated (the temperature falls). Note from diagram (A) that pressure only increases from 1>2 where it is at a maximum and is designed so that there is no increase in pressure at combustion. The points in the diagrams (1,2,3,7) are ‘Engine Data Points’ commonly used to indicate particular locations throughout the engine gas path (refer to diagram on page 1.3).

This is the basis on which all Industrial Gas Turbines operate and will be more fully explained in the modules that follow. At this stage it is worth noting that although only about ¼ of the air that is drawn into the engine is used for combustion, the bulk of the remainder is used for cooling and this still contributes to expansion. About 2/3 of the total power developed is used to compress air, the remainder is used to drive ‘loads’. Most machines are as described and are referred to as ‘Open Cycle’ units. However, some using “Recuperators”, while others use Waste Heat Recovery Units to ‘extract’ heat from the exhaust to be used elsewhere, for example to raise steam.

Principle to Practice As the thermodynamic principle on which Gas Turbines operate has been mentioned, how this is achieved in practice can now be considered. On Cakerawala, “Solar Taurus 60 Generator” sets are installed. While other manufacturers use different arrangements these machines are typical of the most common internal mechanical arrangements generally used. The Taurus 60generator sets are referred to as a “Single Shaft” arrangement. The “Single Shaft” configuration is the least complicated arrangement and will be considered first. T3 P3

Data Points T1, etc T1 P1

T5 P5

T2 P2

Typical Single Shaft Cold End Drive Data Points

Typical Single Shaft (Cold End Drive) The drawing above shows the engine internal arrangement and the “Data Points” in the gas path. Air from the atmosphere is drawn in through the Air Inlet (T1, P1) by the Compressor Rotor Assembly, which is mounted on a common shaft connected to the Turbine Rotor Assembly at the RH end and the Engine Output Shaft at the LH end. As the Engine Output Shaft is at the cooler Air Inlet end and not at the hotter Turbine Exhaust end it is referred to as “Cold End Drive”. The compressed air leaves the compressor and enters the Diffuser (T2,P2) where it’s pressure(P2) is greatest and the temperature (T2) has also increased about 260C [@ 500F] above T1. Fuel Gas from the Fuel Gas Manifold is mixed with air from the Air Manifold and injected into the Combustion Chamber through Fuel Injectors where it is burnt after having been initially ignited by the Igniter Torch at the ‘start’. Combustion causes the temperature to increase to about 2800F and the volume to also increase greatly. The Combustion Chamber is constructed to allow cooler air to enter and direct the hot gases away from the Combustion Chamber liners (to minimise heat damage and to cool the hot gas) and into the Turbine assembly without increasing the pressure. The temperature at the inlet of the Turbine (T3) sometimes referred to as “TRIT” (Turbine Rotor Inlet Temperature) is generally not monitored, but the temperature at the inlet of the last stage (T5) invariably is and can be used as an indication of the heat energy in the engine. After exiting the turbine section the gases are directed away to atmosphere through the Turbine Exhaust (T7) and any external ducting.

T7 P7

Cakerawala Solar Turbo-Machinery The following machine packages installed on Cakerawala Platform:GQ 7500 Solar Taurus 60 Generator – Natural Gas Fuel / Liquid Fuel GQ 7520 Solar Taurus 60 Generator – Natural Gas Fuel / Liquid Fuel GQ 7540 Solar Taurus 60 Generator – Natural Gas Fuel GQ 7560 Solar Taurus 60 Generator – Natural Gas Fuel These engines are designed to operate with high CO2 content These engines were mentioned earlier (Page 1.3) and will now be described in more detail, with material largely quoted from the Solar Manuals available on site.

SAFETY Industrial Gas Turbines are high speed rotating heat engines which can present many potential hazards and caution must be exercised at all times, not only when in the vicinity of the Turbine package, but also when operating remotely. The following WARNING should be understood and heeded at all times. Appendix A of these notes contains the Solar Operations Manual Safety Guides which must be understood and should be used as a guide to the safe operation and maintenance of the packages.

WARNING 1. Operation of the unit may be performed only when conditions indicate it is safe to proceed. Dangerously explosive accumulations of natural gas, fuel fumes, oil tank vent leakage, or solvent fumes must be avoided at all times. This is done by proper ventilation, elimination of leaks, and by confining the use of solvents to appropriate maintenance facilities. 2. Appropriate hearing and eye protection must be used by operating and maintenance personnel in the vicinity of the operating machine. 3. Turn off electrical power. Tag control devices to prevent electrical shock and starting of unit while unit is shut down. 4. Allow sufficient time for piping and system components to cool. Components can become extremely hot and cause burns if touched with unprotected hands. 5. Do not allow fluids to come in contact with hot surfaces. Fluids discharged from lines or fittings may be flammable and could cause a fire hazard. 6. Depressurize system before loosening line fittings or removing components. High pressure lines or jetstreams can cause serious injury.

TURBINE PACKAGE INSPECTION ‘ON-LINE’ YOU MUST HAVE A PERMIT TO WORK ON ANY PART OF THE TURBINE PACKAGE

Before Opening Package Doors 1. Contact control room operator for permission to enter and to disarm fire system. 2. Disarm fire system. If fire system is not disarmed it may discharge 3. Take care when opening package doors. Inside package is pressurised and doors will open hard and fast 4. Carry out inspection Closing Package Doors 1. Take care. They are hard to close against the inside pressure and may require help to close. 2. Relock doors. 3. Rearm fire system. 4. Contact control room operator and notify you have finished inspection, fire system is re-armed and doors are locked.

NOTE - ORIENTATION Directional references on the unit (right side, left side, forward, and aft) are established by viewing the unit facing the engine exhaust (aft) end and looking forward.

AFT

Orientation Diagram

LEFT

RIGHT

FORWARD

Taurus 60 GAS TURBINE-DRIVEN GENERATOR SET

General Package Description The Taurus 60 Gas Turbine-Driven Generator Set consists of an axial-flow turbine engine, a generator, and gear unit. These elements are installed in-line on a steel base frame, a structural weldment with beam sections and cross members forming a rigid foundation. Machined mounting surfaces on the base facilitate alignment of major components. The gear unit input shaft is connected with the engine compressor rotor nose cone hub with a splined sleeve coupling. A mating flange bolted to the engine air inlet housing attaches the assemblies. The generator input shaft is aligned with the gear unit output shaft, and the shafts are connected with a flexible shear coupling in a protective cover.

Components The generator set’s accessories include the start, fuel, electrical control, lube oil, pneumatically controlled air systems, and a governor.

MAJOR COMPONENTS AND SYSTEM

Taurus 60 Gas Turbine Generator Set

Air Inlet Assembly

Exhaust Assembly

Generator

Turbine Engine

Starter Motor

Package Base Frame

Taurus 60 Gas Turbine Engine

Air Inlet

Compressor Assembly

Combustor Assembly

Fuel Injectors

Compressor Diffuser

Gas Fuel Manifolds Lube Oil Filters

The turbine engine is the package power plant. Air is drawn into the compressor section through the air inlet and is compressed. Fuel is added to the compressed air in the combustor and is ignited. After combustion, hot gases expand through turbine nozzles and drive the turbine rotor. The turbine drives the engine compressor, accessories, and generator. Air and combustion gases are discharged to the atmosphere through the exhaust system. Major components include air inlet, engine compressor, compressor diffuser, combustor, turbines, exhaust diffuser and exhaust collector.

Generator The genator, the driven equipment, transforms Mechanical energy to electrical energy. The Generator is bolted to the raised mounting pads on The base, in alignment with the gear unit. The Standard generator set has a two-bearing, revolving field-type, three-phase, ac generator, of dripproof construction, with damper windings and a direct- connected brushless exciter,controlled by a Voltage Regulator (AVR).

Electrical Generator Coupling Guard

Drive End Non-Drive End

Voltage Regulator

Gear Unit The two-stage, epicyclic gear unit transmits power from turbine engine to the electrical generator and also drives the main lube oil pump. The unit will sustain momentary overloads of up to approximately eight times normal operating torque. The lube oil system lubricates bearings and the gear train. The engine air system pressurizes the bearing oil seals

Start System The start system includes starter and control devices. The starter rotates the engine to selfsustaining speed, where the starter shuts down, the starter clutch overruns, and the engine accelerates under its own power to loading speed.

Starter Motor

Fuel System The fuel system regulates fuel flow. The dual fuel systemis a combination gas fuel and liquid (diesel) fuel system.Specially designed components, mechanical linkages, solenoid-operated valves and other devices combine the gas fuel system and the liquid fuel system into a single intergrated system.

Primary Gas Fuel Valve

Secondary Gas Fuel Control Valve

Gas Fuel Valves Electronic Gas Fuel Control Valve

Lube Oil System Supplied from the base frame reservoir, the lube oil system circulates pressurized oil to hydraulic subsystems and to the turbine engine, gear unit and starter motor to gear unit drive connection. An oil cooler and a thermostatic oil control valve maintain oil temperature. Oil Reservoir

Filler Cap

Lube Oil Filters

Electrical System The 24 Vdc electrical control system monitors the engine and generator and controls normal and emergency (malfunction) shutdowns. In operation, the electrical control system protects the engine and driven equipment from damage from hazards such as overspeed, high engine temperature and vibration levels, low lube oil pressure, excessive oil temperature and generator over or undervoltages and high winding temperature.

Turbotronics Display

The control system wiring is routed via control and monitoring junction boxes on the package skid to the “Turbotronics” panel located in the MCC. Display of engine and generator operational conditions is available on the“Turbotronics” panel , along with indicator lights and pushbutton and other switches to display and control operational status. A gauge panel is also installed on the engine package to show some engine operating conditions.

Taurus 60 Single Shaft Turbine Sectional View

Bleed Valve

Injector Gas Ring Air Inlet

Exhaust Power Turbine Gas Producer Combustor Compressor Accessory Gearbox

SAFETY WARNING 1. Operation of the unit may be performed only when conditions indicate it is safe to proceed. 2. Dangerously explosive accumulations of natural gas, fuel fumes, oil tank vent leakage, or solvent fumes must be avoided at all times. This is done by proper ventilation, elimination of leaks, and by confining the use of solvents to appropriate maintenance facilities. 3. Appropriate hearing and eye protection must be used by operating and maintenance personnel in the vicinity of the operating machine. 4. Turn off electrical power. Tag control devices to prevent electrical shock and starting of unit while unit is shut down. 5. Allow sufficient time for piping and system components to cool. Components can become extremely hot and cause burns if touched with unprotected hands. 6. Do not allow fluids to come in contact with hot surfaces. Fluids discharged from lines or fittings may be flammable and could cause a fire hazard. 7. Depressurize system before loosening line fittings or removing components. High pressure lines or jetstreams can cause serious injury.

Turbine inspection-On Line Before opening Turbine package doors. 1. Contact control room operator for permission to enter and to disarm fire system. 2. Disarm fire system. If fire system is not disarmed it may discharge 3. Take care when opening package doors. Inside package is pressurised and doors will open hard and fast 4. Carry out inspection Closing turbine package doors. 1. 2. 3. 4.

Take care. They are hard to close against the inside pressure and may require help to close. Rearm fire system Relock door Contact control room operator and tell you have finished inspection, fire system is rearmed and doors are locked.

YOU MUST HAVE A PERMIT TO WORK ON THE TURBINE PACKAGE

SECTION 2 - CAKERAWALA GAS TURBINE START SYSTEMS Taurus 60 START SYSTEM GENERAL DESCRIPTION When the start/crank cycle is initiated, a timed prelube sequence is activated. As the prelube cycle times out, the control system directs power to Variable Frequency Drive (VFD430) which provides starting power to Starter Motor (B330). Initially, variable frequency drive VFD430 provides a low frequency ac voltage to motor B330 to begin rotation. The frequency and voltage to motor B330 are then ramped up to accelerate the engine to purging speed. Correct engine purging speed is maintained by a programmed fixed current limit to motor B330. At the same time, the fuel valves are opened, light-off is attempted, and the control system increases motor velocity, causing motor B330 to start ramping from purge speed to starter dropout speed. As the engine reaches dropout speed, variable frequency drive VFD430 is de-energized by the control system, cutting power to motor B330, and the motor clutch is disengaged. The ac direct start system provides the starting power for the engine. The start system includes the following: • Starter motor • Radio Interference Filter • Monitoring Relay • Variable frequency drive Starter Motor Starter Motor (B330), installed a mounting flange on the front the accessory drive pad, is a squirrel cage induction, 15minute inverter duty, polyphase-type motor. The motor provides high breakaway torque, and will accelerate the engine from standstill to starter dropout speed. The motor power is provided by Variable Frequency Drive (VFD430) and the motor is protected from thermal overload by Monitoring Relay (RT230). The motor also incorporates a space heater.

on of

Starter Motor

Radio Interference Filter Radio Interference Filter (RFI430), located in the input cabling to Variable Frequency Drive (VFD430), prevents radio interference from affecting the operation of variable frequency drive VFD430. Monitoring Relay Monitoring Relay (RT230), monitors thermistors installed in the Starter Motor (B330) to provide thermal overload protection for the motor.

Variable Frequency Drive

Starter Motor VSD Variable Frequency Drive (VFD430) is a general purpose, variable speed, ac controller. Installed offskid, the variable frequency drive incorporates a keypad/display which can be used to program, through software, configuration adjustments.

FUNCTIONAL DESCRIPTION Starting Sequence The starting sequence is initiated by pressing the start button. Upon pressing the start button, the fuel gas valve and pre lube pressure checks are conducted. Along with this the enclosure pressurization and fan operation is also checked. STARTING Light (DS114) begins flashing. Fuel system valve check sequence begins. Post lubricating backup pump is tested for operation, post lubricating oil pump is started, and prelubrication begins. Enclosure ventilation fan is energized.

VALVE CHECK SEQUENCE Before the engine cranks during the start cycle, the fuel system performs a valve check sequence. If Gas Fuel Pressure Switches (S341-1, S341-2) sense fuel pressure, Gas Fuel Vent Shutoff Valves (V2P941, V2P941-1) are opened to vent gas from the supply line. If pressure drops below the set point, the vent valves are closed, and the valve check sequence proceeds. Primary shutoff valves V2P931 and V2P931-1 open and admit fuel to pressure switches S342-2, S342-3, and secondary shutoff valves V2P932 and V2P932-1. Pressure switches S342-2 and S342-3 signal increasing pressure. This verifies the opening of shutoff valves V2P931 and V2P931-1, and enables the start sequence to proceed. Five seconds after being opened, primary shutoff valves V2P931 and V2P931-1 close. If pressure drops, secondary shutoff valve V2P932 or V2P932-1 are leaking. After the prelube cycle, shutoff valves V2P932 and V2P932-1 open. With shutoff valves V2P931 and V2P931-1 closed, trapped gas is allowed to escape into the fuel system. Pressure drops indicating that shutoff valves V2P931 and V2P931-1 are fully closed and that shutoff valves V2P932 and V2P932-1 are open. If pressure fails to drop, a gas fuel valve fail malfunction indication and an engine shutdown are initiated 15 seconds after prelube is complete.

Lube Oil Pump Checks When the start cycle begins, the control system tests Postlube Backup Lube Oil Pump (P903). If pump P903 pressure reaches 4 psi (27.6 kPa), the control system deactivates pump P903 and then activates Pre/Post Lube Oil Pump (P902). If pump P902 pressure reaches 6 psi (41.3 kPa), the control system allows the engine prelube cycle to begin.

PRELUBE CYCLE After the lube oil pump checks are completed, the prelube time out timer (60 seconds) is started. The prelube time out timer is the allowable time for pump P902 to complete the prelube cycle. When the lube oil pressure is greater than the prelube low pressure limit of 6 psi (41.3 kPa), the prelube timer (30 seconds) is started. The engine must be prelubed at a pressure above 6 psi (41.3 kPa) continuously for the duration of the prelube timer (30 seconds). This prelube must occur within the time of the prelube time out timer (60 seconds). If the prelube timer times out before the prelube is done, the start is aborted and a prelube failed fast stop non-lockout alarm is annunciated on the control console.

Taurus 60 Generator Set - Start Sequence Diagram Speed Ngp

CURVE LEGEND : = Ngp NOTE : Annunciations are shown in RED font. Generators at idle and ready to load, bleed valve open

100 90

Guide Valve Fully Open

80

Generator Excitation Starter Motor Drop Out Speed

65

START RAMP Engine purge Timer

300 30 Sec

10

20 - 25

T5 Set Point change (50% Ngp) MIN. FUEL

0 T5 < 400F+ > 10 seconds = IGNITION FAILURE

Pre-start permissives 1 Fuel Valve Checks 2 Lube Oil Pump Checks 3 Prelube 4 Waste Heat Recovery Pre-start package checks - Safe to start and no alarms or inhibits = READY

Combustion starts T5> 400F