Chapter 4 Rev 1-1

4

DESCRIPTION OF OPERATING SEQUENCES

Chapter: 4 Title: Description of operating sequences

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4

DESCRIPTION OF OPERATING SEQUENCES

1

4.1

Introduction

5

4.2

Starting the gas turbine

6

4.2.1.1 4.2.1.2 4.2.1.3 4.2.1.4 4.2.1.5 4.2.1.6

Checks prior to start Turbogenerator set Air filter system Oil cooler Electrical supply Exhaust gas system Time intervals between repeated start-ups

6

4.2.2.1 4.2.2.2 4.2.2.3 4.2.2.4 4.2.2.5

Switching on the control system Presettings Switching on the system Check and Reset of the pending alarms Mode selection: local , remote Ready for start

10

4.2.3.1 4.2.3.2 4.2.3.3

Local start-up procedure, gas fuel Fuel selection Starting the turbine Start-up sequence gas fuel mode

13

4.2.4.1 4.2.4.2 4.2.4.3 4.2.4.4 4.2.4.5 4.2.4.6 4.2.4.7 4.2.4.8 4.2.4.9 4.2.4.10 4.2.4.11

Local start-up procedure, liquid fuel Fuel selection Starting the turbine Start-up sequence liquid fuel mode Pre-lubrication Cranking Low pressure liquid fuel pump check Exhaust gas duct purge Ignition Acceleration to 66% nominal speed Acceleration to nominal speed and warm-up Ready to load

18

Synchronization

24

Synchronization with the busbar Automatic synchronization Manual synchronization Busbar synchronization sequence

26

4.3.2

Synchronization test

29

4.3.3

Direct insertion of the generator circuit breaker

30

4.4

Operating modes and load charging

31

4.4.1

Power mode operation

32

4.4.2

Frequency mode operation

33

4.2.1

4.2.2

4.2.3

4.2.4

4.3 4.3.1

4.3.1.1 4.3.1.2 4.3.1.3

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6 7 7 7 8 9 10 11 12 12 12 13 13 14 18 18 19 19 20 20 20 22 22 23 23

26 26 27

4.4.2.1

Load charging – Isle mode operation

33

4.5

Gas turbine operation

35

4.5.1

Functional test during operation

35

Generator settings and adjustment during operation Adjustment of active power Adjustment of turbine speed (generator frequency) Adjustment of the generator power factor (Cosϕ) Adjustment of the generator voltage

35

Turbine stopping

37

4.6.1.1

Local shut-down in isle operation Local shut-down in isle operation:

37

4.6.2.1

Emergency shut-down (manual push button) Emergency stop sequence:

39

4.7

Safety procedure for fire alarm

41

4.7.1

Fire system’s equipment

41

4.7.2.1 4.7.2.2 4.7.2.3 4.7.2.4 4.7.2.5

Fire system operation Container door Operational logic of the automatic detection Fire monitoring and extinguishing system failure Fire warning Fire alarm

42

4.7.3.1 4.7.3.2 4.7.3.3

Operator container inspection and action No fire within the container A small fire is detected in the container An important fire is detected in the container

48

4.7.4

Precaution during maintenance works

51

4.7.5

Re-establishment of the unit after the discharge of extinguishing agents

51

4.8

Safety procedure for gas alarm

52

4.8.1

Description of the gas monitor system

52

4.8.2

Gas monitor system failure

53

4.8.3

Gas leakage warning

54

4.8.4

Gas leakage alarm

55

4.9

Turning and postlubrication

56

Turning and postlubrication sequence Post-lubrication End of the postlubrication sequence

56

4.10

Turbogenerator alarms

58

4.10.1

General Description

58

4.5.2

4.5.2.1 4.5.2.2 4.5.2.3 4.5.2.4

4.6 4.6.1 4.6.2

4.7.2

4.7.3

4.9.1

4.9.1.1 4.9.1.2

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35 36 36 36

37 39

43 43 44 45 46 48 49 50

56 57

4.10.2

E-xxx Error

59

4.10.3

W-xxx Warning

59

4.10.4

A-xxx Alarm with Normal Turbine Stop

59

4.10.5

S-xxx Alarm with Quick Shutdown

59

4.11

Taking the Plant out of Operation (weeks)

60

4.12

Plant Shutdown (months)

61

4.13

Crank

62

Start of the cranking process: Pre-ventilation Emergency lubrication pump test Pre-lubrication Cranking Washing release End of cranking

62

Compressor washing

65

4.14.1.1 4.14.1.2 4.14.1.3 4.14.1.4 4.14.1.5 4.14.1.6 4.14.1.7

Off-line compressor washing Pre-ventilation Emergency lubrication pump test Pre-lubrication Cranking Washing release To start the washing process: End of cranking

65

4.14.2.1 4.14.2.2

On-line compressor washing To start the washing process: To terminate the washing process:

69

4.15

Remote Control

70

4.15.1

Remote Controlled Start-up Procedure

71

4.15.2

Remote Controlled Synchronization Procedure

71

4.15.3

Remote Controlled Stopping Procedure

71

4.16

Operational Malfunctions

72

4.16.1

Compressor Surging

72

4.16.2

Generator Overheating and Vibration

72

4.13.1

4.13.1.1 4.13.1.2 4.13.1.3 4.13.1.4 4.13.1.5 4.13.1.6

4.14 4.14.1

4.14.2

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65 66 66 66 66 67 68 69 69

4.1

Introduction This chapter describes the various measures and steps, which are required for the operation of the gas turbine generator plant. The operator must strictly observe the instructions and information contained in this chapter in order to achieve the optimum operational reliability of the plant. The instructions include the checks to be carried out, the operating sequences and specify the most important messages displayed. Special situations are indicated in the individual operating steps by the terms NOTE, CAUTION and WARNING. It is imperative that these instructions are observed. WARNING Indicates a measure, procedure, condition or safety measure that, if ignored, may lead to injury or loss of life. CAUTION Indicates a measure that, if ignored, may lead to damage or destruction of the plant. NOTE Indicates information, which is essential for understanding respectively observance of a measure, procedure, condition or description.

In addition, remarks on Chapter “Safety” must be observed. The descriptions of the operating sequences in this chapter include sequences and functions, which correspond to a fully equipped standard plant. Project-specific adaptations are therefore not considered.

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4.2

Starting the gas turbine

4.2.1

Checks prior to start The checks specified below must be carried out before any start of the gas turbine plant. All these pre-start checks make it possible to detect any unusual conditions, which might impair the correct function and thus the operating performance of the plant. In general these checks should also be carried out - daily - in the normal operation of the gas turbine plant. The checks to be carried out cover several different systems. WARNING The following subsections should be gone through point by point before each start, and the turbine should only be started once it has been established that the whole plant is in a fault-free condition.

4.2.1.1

Turbogenerator set •

• • • • • • • • • • • • • •

Check the interior of the container and t he immediate environment. Examine all auxiliary equipments for the p resence of a ny combustible objects or fo reign bodies, which are not required for the operation of the gas turbine. Check that the entire plant is correctly mounted and installed. Check that all the co nnection valves to t he measuring and protection equipments are correctly opened. Check that the hand valves of the lube oil pumps, if any, are widely opened. Check that both drain and vent hand valves, if any, are closed. Open the manual fuel-stop valves. Check the pressure of the plant fuel supply for the selected fuel. Check the pressure of the instrument air supply. Open the valves of the water cooling system, if applicable. Check the connection of both the DC-operated emergency lubrication pump and of the other lube oil pumps, if any, and ensure the correct operation. Check all lines and connections for leaks. All leaks must be corrected. Check the oi l level; the oil tank m ust be filled to the permissible maximu m level (see maintenance instructions). Check that the oil tank he ater is functioning correctly; the temperature must be sufficient to start the gas turbine; the type of oil used determines the lowest permissible temperature. Check that the man ual oil filter cha nge-over valve is corre ctly positioned; check the d rain and venting valves of the twin filter. All doors of the package must be closed during operation.

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4.2.1.2

Air filter system • •

4.2.1.3

Oil cooler • • •

4.2.1.4

Check that al l the filters of the turbine combustion air system and the pocket filters of the container cooling air system are correctly installed. Check if there is any blocking or damage in the filter system.

Check for leaks in the cooler or the supply pipes. All leaks must be corrected. Check that the cooler is clean and completely free of blocking, which can have an adverse effect on efficiency. In the event of extreme o perating conditions or very low tempe ratures, it is necessary to check for frozen areas along the piping lines outside the container and in the oil cooler.

Electrical supply • • • •

Check that t he battery charger is working properly, check all the conn ections of the distribution system; check the battery conditions and the wiring. Check that all circuit bre akers and automatic miniature circuit breakers in the supply an d control cabinet are connected. Check that all AC/DC main and auxiliary supplies in the control cabinet are connected. Check that the fire and gas monitoring systems are functioning correctly. NOTE

The 400 V AC supply must be kept constant during the starting and the operation of the gas turbine, so that the correct function of the lubricating oil pump can be guaranteed. Any interruption in the power supply causes the start to be aborted or the shutdown of the turbine generator plant.

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4.2.1.5

Exhaust gas system Dangerous explosive conditions can occur if: Fuel or other combustible materials reach the gas turbine exhaust gas system • The ambient air and tem perature conditions reach the flammability threshol ds for the se substances (flash point) Fuel can become trapped in the exhaust gas system before the turbine is started or after it is stopped, if for instance the burner flame goes out or ignition fails. •

The following instructions are to be observed regularly and strictly: • • •

•

•

Check that the turbine exhaust gas system is completely unobstructed. Check that the waste heat boiler control system as well as the bypass system for discharge into the atmosphere (if available) are correctly connected and are working properly. Check that a ll valves o r dampers of the ga s turbine exhaust gas syste m are co rrectly mounted. It is ab solutely essential to check that these elements are functioning correctly. The exhaust gas ducts must in all cases be unobstructed during starting and continuous operation. Exhaust gas recovery systems are often equipped with bypass dampers to control the gas supply to the system. If a bypass damper is mounted, check that it is fun ctioning correctly; make sure that it is able, when the ga s turbine is started, to divert the entire exhaust g as flow into the atmosphere. Check that the fuel quality compli es permanently with the specifications for the gas turbine. A deviation f rom the fuel specification may l ead to a malfu nction of the fu el regulation system. CAUTION

Before starting the gas turbine make sure that the exhaust gas system has been completely freed of non-burned fuel or other combustible materials by means of purging.

The purging of the exhaust gas system with air is carried out automatically during the running up of the turbine. The operator must, however, regularly check that this purging process is taking place correctly (check duration and sequence). The purging process of the exhaust gas system takes place with the airflow delivered by the compressor of the gas turbine while turning with the starting motor system, without ignition. The total duration and the sequence of the purging process must be determined in accordance with local regulations and the purge volume. To start the purging process the gas turbine control system sends a signal to the boiler only if the turbine is turning without ignition. Upon completion of the purging process, the waste heat boiler control system triggers the ignition of the gas turbine with a corresponding signal. CAUTION The activation and control of the exhaust gas system purging process is the responsibility of the waste heat boiler control system, which functions separately from the gas turbine control.

If the purging process exceeds the programmed maximum duration, i.e. usually 5 minutes, the gas turbine is stopped and an alarm is released.

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4.2.1.6

Time intervals between repeated start-ups After a turbine shutdown it is possible to proceed with another start-up, two minutes after the turbine has decelerated below 5% speed. The start permission is given on the screen. In case of shutdown due to an alarm, do not proceed with the next attempt to start-up unless the problem is fixed. ATTENTION After three repeated start-up failures, a deep troubleshooting is necessary. Further start-up attempts without having removed the fault may damage part of the plant.

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4.2.2

Switching on the control system Check the self-initialization of the control system: • •

at first, switch on th e PC at its main switch on the rack and wait until the PC has booted up and configured the I/O bus modules. as soon as a steady condition occurs, switch on the failsafe miniature controller at the main switch. WARNING

When the control system is switched off, the gas and fire monitoring systems are not fully effective. With the safety system switched on, gas is detected and displayed visually, but the package ventilation is not active, which means that any escaped gas is not discharged. With the safety system switched on, fire is detected and the CO2 flooding initiated, but the container ventilation dampers remain closed, which means that a dangerous overpressure can build up in the container.

4.2.2.1

Presettings If you have not already done so, you should position the following three windows on the user video in such a way as to enable the most ergonomic input and display: • • •

Main Commands window Active Alarms window Information window

The “Main Commands” window is opened with a submenu option of the main “Commands” menu. The Active Alarms and Information windows are to be found under the “Monitoring” menu item.

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4.2.2.2

Switching on the system The “Main Commands” window is opened with a submenu option of the main “Commands” menu. The information window displays «SYSTEM OFF». Pushing the button System on activates the control system.

Prior to energize the electrical equipments, a 30s ventilation is carried out in order to remove possible gas leak inside the container. If , during the ventilation, the inlet or outlet air shutters do not open, there is a shut-down and the control system wait a reset signal. The information window displays «SYSTEM INITIALIZATION» and «ENCLOSURE PURGE». Once the container purge ventilation is over, the control system displays «SYSTEM INITIALIZATION» «POWER SUPPLY ON». And then the system asks the alarm reset. Window displays «START DISABLED» «RESET ALARM REQUIRED». Without any active alarm , the control system is in mode stand by, with the display «READY TO START» waiting the command «START».

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4.2.2.3

Check and Reset of the pending alarms The “Pending alarms” window lists all the currently recorded alarms. Pushing the button Reset resets all the alarms. If an alarm that represents a shutdown condition is still active, the plant cannot be started. In this case it is necessary first to remove the cause of the alarm. The information window displays «RESET ALARM REQUIRED». As soon as the plant is fault-free, the control system switches to the ready state.

4.2.2.4

Mode selection: local , remote Pushing the Local button tells the control system that the machine is to be controlled “locally“.

I.e. only commands that are entered via the “touch-screen” will be accepted. If the machine is being operated by remote control, the “remote control” signal (in the client module) is activated.

4.2.2.5

Ready for start The turbine has carried out all internal resets and is ready to start. The “ready to start” signal (in the client module) is activated.

The information window displays «READY TO START».

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4.2.3

Local start-up procedure, gas fuel The “Main Commands” window is required for the control. The “Main Commands” window is a submenu option of the main “Commands” menu.

4.2.3.1

Fuel selection Pushing the button Gas informs the control system that the start is to be with natural gas. The button is shown to be activated, which allows you to see at any time which fuel is being used. If the machine is being operated with gas fuel, the “gas fuel operation” signal (in the client module) is activated. (N.B.: On machines that are operated only with gas, the fuel selection is not mentioned)

4.2.3.2

Starting the turbine Pushing the button Start starts the machine. The start-up sequence runs fully automatically.

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4.2.3.3

Start-up sequence gas fuel mode Pre-ventilation To discharge any concentration of gas present in the container, the container inlet and exhaust fans are switched on and the container ventilated for 30 s.

•

The container heaters are switched off. The “start-up sequence” signal (in the client module) is activated and the “ready to start” signal deactivated. The information window displays «START SEQUENCE» and

•

«ENCLOSURE PURGE». Emergency lubrication pump test The emergency lube oil pump system undergoes a functional test.

•

The information window displays «START SEQUENCE»

and

«EMERGENCY OIL PUMP CHECK». Verification that the pump is off and that the signals coming from the pressure switches are low, during 10-15 seconds. • Switching-on the pump for 10-15 s and verification that the pressure switches activate. • Switching-off the pump and check that the pressure switches return to their initial condition. The start sequence will be interrupted in case that the emergency lubrication pump test is not successful. •

4.2.3.3.1.

Pre-lubrication For the pre-lubrication the control system switches on the pre/post pump. After that waiting time of 30 seconds the pre-lubrication oil pressure is checked during 30 additional seconds. If the oil pressure has reached its minimum value, the pre-lubrication is continued for further 4 minutes. The information window displays «START SEQUENCE»

and only during the check

«LUBE OIL PRESSURE CHECK» and then for 4 minutes «START SEQUENCE» «PRE LUBE SEQUENCE».

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4.2.3.3.2.

Cranking If the oil temperature is above 17°C, the electric starting motor system is switched on. The information window displays «START SEQUENCE»

and

«CRANKING» «ACCELERATION TO CRANK SPEED» The turbine receives torque and begins to turn. To start the exhaust gas duct ventilation the “boiler purge” signal (in the client module) is activated. •

4.2.3.3.3.

T60 turbines have to reach the 16% speed within 45 s, otherwise a shutdown takes place.

Gas valve tightness check There follows a gas valve tightness sequence which checks for any leakage in the closing of the gas stop valves. The venting valve between the primary and secondary gas stop valve is closed for 20 seconds. If pressure increases, the primary stop valve is opened for 3 s and then closed again. The gas pipe between the two stop valves is now under pressure, which must be maintained for 20s. If the pressure is maintained, the secondary stop valve is considered to be closing tightly. The gas vent valve is opened for 5 s to discharge the enclosed volume of gas to atmosphere. Now it is checked for 20 s whether there is any rise in pressure in the gas pipe between the stop valves. If no rise in pressure occurs, the primary stop valve is considered to be closing tightly. The information window displays «START SEQUENCE» «CRANKING»

and

and

«GAS VALVE CHECK SEQUENCE».

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4.2.3.3.4.

Exhaust gas duct purge In accordance with local regulations the exhaust gas duct is purged with the air produced by the turbine. The information window displays «START SEQUENCE»

and

«CRANKING»

and

«EXHAUST AND HEAT RECOVERY SYSTEM PURGE». When crank speed (in the starting sequence) is reached, a signal is sent to boiler to start purge, and the control system now waits for an ignition release signal back from the boiler. The time monitoring of the exhaust gas duct purge is carried out by the boiler control system. After 4 minutes boiler purge the information window displays «START SEQUENCE»

and

«CRANKING»

and

«WAIT FOR HEAT RECOVERY SYSTEM READY». If no ignition release has been given after 5 min. from the purge begin, an alarm is generated.

4.2.3.3.5.

Ignition As soon as the ignition release signal is received from the waste heat boiler, the two gas stop valves and the ignition gas valve are opened, and the spark plug is excited. The main gas regulation valve (and the pilot gas regulation valve on SoLoNOx machines) are at an opening suitable for the ignition. The operating hours counter is started. During the start-up phase the ignition time of the turbine is monitored by the safety system. The spark plug is excited and within 10 s, the turbine temperature (T5) has to reach 204°C, if not there is a start failure After a successful ignition the spark plug is switched off and the ignition gas valve is closed. The information window displays «START SEQUENCE»

and

«IGNITION».

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4.2.3.3.6.

Acceleration to nominal speed The control system regulates the fuel supply in such a way that the 66% speed threshold is reached with an almost constant acceleration. If the T60 turbine does not reach this speed within 180 s, a shutdown takes place. At 66% speed the turbine is self-powering and able to accelerate without the help of the starting system. The starting system is deactivated. The information window displays «ACCELERATION SEQUENCE»

and

«ACCELERATION TO 66%». The turbine speeds up from de 66% to 90%. The 90% speed has to be reached within 140 seconds. Window display «ACCELERATION SEQUENCE»

and

«ACCELERATION TO 90%» At 90% speed, the generator excitation is switched on, the minimal voltage protection of the generator is activated and the start counter increased by 1. The turbine now accelerates to 100% nominal speed. The information window display «ACCELERATION SEQUENCE»

and

«ADJUSTING RATED SPEED». The warm-up starts at this step and lasts 30 seconds with the window display «WARMING UP SEQUENCE»

and

«ADJUSTING RATED SPEED» After that, the turbine is ready for load. Ready to load At the end of the start-up the turbine is ready for synchronization and the window display is: «READY TO LOAD»

and

«SYNCHRO ALLOWED». The “ready for load” signal (in the client module) is now activated.

Verify that the generator voltage is at nominal level.

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4.2.4

Local start-up procedure, liquid fuel

4.2.4.1

Fuel selection Pushing the button Liquid informs the control system that the start is to be with liquid fuel. The button is shown to be activated, which allows you to see at any time which fuel is being used. If the machine is being operated with liquid fuel, the “liquid fuel operation” signal (in the client module) is activated.

4.2.4.2

Starting the turbine Pushing the button Start starts the machine. The start-up sequence runs fully automatically.

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4.2.4.3

Start-up sequence liquid fuel mode Pre-ventilation To discharge any concentration of gas present in the container, the container inlet and exhaust fans are switched on and the container ventilated for 30 s.

•

The container heaters are switched off. The “start-up sequence” signal (in the client module) is activated and the “ready to start” signal deactivated. The information window displays «START SEQUENCE»

and

«ENCLOSURE PURGE». Emergency lubrication pump test The emergency lube oil pump system undergoes a functional test.

•

The information window displays «START SEQUENCE»

and

«EMERGENCY OIL PUMP CHECK». Verification that the pump is off and that the signals coming from the pressure switches are low, during 10-15 seconds. • Switching-on the pump for 10-15 s and verification that the pressure switches activate. • Switching-off the pump and check that the pressure switches return to their initial condition. The start sequence will be interrupted in case that the emergency lubrication pump test is not successful. •

4.2.4.4

Pre-lubrication For the pre-lubrication, •

The control system switches on the DC pre- and post-lubrication pump

After that waiting time the pre-lubrication oil pressure is checked during 30 additional seconds. If the oil pressure has reached its minimum value, the pre-lubrication is continued for further 4 minutes. The information window displays «START SEQUENCE»

and only during the check

«LUBE OIL PRESSURE CHECK» and then for 4 minutes «START SEQUENCE» «PRE LUBE SEQUENCE».

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4.2.4.5

Cranking If the oil temperature is above 17°C, the electric starting motor system is switched on. The information window displays «START SEQUENCE»

and

«CRANKING» «ACCELERATION TO CRANK SPEED» The turbine receives torque and begins to turn. To start the exhaust gas duct ventilation the “boiler purge” signal (in the client module) is activated. •

4.2.4.6

T60 turbines have to reach the 16% speed within 45 s, otherwise a shutdown takes place.

Low pressure liquid fuel pump check All the liquid fuel valves are closed. The control system verifies that the low pressure liquid fuel transfer pump is working by checking the suction pressure at the inlet of the liquid fuel high pressure pump. The information window displays «START SEQUENCE» «CRANKING»

and

and

«LIQUID LOW PRESSURE PUMP CHECK».

4.2.4.7

Exhaust gas duct purge In accordance with local regulations the exhaust gas duct is purged with air. The information window displays «START SEQUENCE» «CRANKING»

and

and

«EXHAUST AND HEAT RECOVERY SYSTEM PURGE». When crank speed (in the starting sequence) is reached, a signal is sent to boiler to start purge, and the control system now waits for an ignition release signal back from the boiler. The time monitoring of the exhaust gas duct purge is carried out by the boiler control system. After 4 minutes boiler purge the information window displays «START SEQUENCE» «CRANKING»

and

and

«WAIT FOR HEAT RECOVERY SYSTEM READY».

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If no ignition release has been given after 5 min. from the purge begin, an alarm is generated.

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4.2.4.8

Ignition As soon as the ignition release signal is received from the waste heat boiler, the two liquid fuel stop valves, the atomization air valve and the liquid fuel ignition valve are opened, and the spark plug is excited. The main liquid fuel pump (and the pilot pump on SoLoNOx machines) are at controlled speed suitable for the ignition. The operating hours counter is started. During the start-up phase the ignition time of the turbine is monitored by the safety system. The spark plug is excited and within 25 s, the turbine temperature (T5) has to reach 204°C, if not there is a start failure After a successful ignition the spark plug is switched off and the liquid fuel ignition gas valve is closed. The information window displays «START SEQUENCE»

and

«IGNITION».

4.2.4.9

Acceleration to 66% nominal speed The control system regulates the fuel supply in such a way that the 66% speed threshold is reached with an almost constant acceleration. If the T60 turbines do not reach this speed within 180 s, a shutdown takes place. At 66% speed the turbine is self-powering and able to accelerate without the help of the starting system. The starting system is deactivated.

•

The information window displays «ACCELERATION SEQUENCE»

and

«ACCELERATION TO 66%».

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4.2.4.10

Acceleration to nominal speed and warm-up The turbine speeds up from de 66% to 90%. The 90% speed has to be reached within 140 seconds. Window display «ACCELERATION SEQUENCE»

and

«ACCELERATION TO 90%» At 90% speed , the generator excitation is switched on, the minimal voltage protection of the generator is activated and the start counter increased by 1. The turbine now accelerates to 100% nominal speed. The information window displays «ACCELERATION SEQUENCE»

and

«ADJUSTING RATED SPEED». The warm-up starts at this step and lasts 30 seconds with the window display «WARMING UP SEQUENCE»

and

«ADJUSTING RATED SPEED» After that, the turbine is ready for load.

4.2.4.11

Ready to load At the end of the start-up the turbine is ready for synchronization and the window display is: «READY TO LOAD»

and

«SYNCHRO ALLOWED». If the turbine has reached its nominal speed, the “ready for load” signal (in the client module) is activated.

Verify that the generator voltage is at nominal level.

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4.3

Synchronization This chapter deals with the various sequences for synchronization and direct insertion of the generator circuit breaker. CAUTION In the case of maintenance work, interventions or corrections to the gas turbine synchronization system , that means to the voltage measurement system or to the position signals of the circuit breakers , it must be ensured that the system is fully tested again before a synchronization is carried out.

When the turbine is running at its nominal speed, the three following possibilities exist: • •

The busbar voltage before the generator circuit breaker is present; in this case synchronization with the busbar can be carried out. The busbar voltage before the generator circuit breaker is not present after a cold start; in this case a direct insertion of the generator with the circuit breaker is possible. In praxis, the direct insertion operation is carried out very seldom. CAUTION The mentioned possibilities can be started manually or automatically. It is important to be clear about the mode of synchronization before starting the turbine: with manual or automatic initialization. The “Generator Commands” window should therefore be called up before each start and the appropriate presettings implemented.

The “Generator Commands” window is available for the desired synchronization mode selection as a submenu option of the main “Commands” menu. This menu allows you to carry out all the operations and pre-set, which are directly related to the synchronization.

General description of the MV plant: a) General: The basis of this study is the single line nr. The Turbomach generator (GT) and one gas engine (GE) 2.928MW are present on the plant. No grid connection is foreseen. Breakers: - Generator breaker of GT: GEN-CB, - Generator breaker of GE: GE-GEN-CB Voltage transformers (VT’s): - VT before generator breaker: Ugen, - VT on the busbar: Ubusbar, For the gas turbine (GT) it is foreseen to have island mode alone or with the GE. Island mode alone means: gen-CB closed AND GE-GEN-CB open. Island mode with GE means: gen-CB closed AND GE-GEN-CB closed.

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The GT will synchronise on the GEN-CB. No other synchronisation points are foreseen. b) GT regulation mode for the GT operating alone: The GT regulates in frequency mode all the time. If the GT i s alone then the internal consumption in the fa ctory must be kept lower th an the maximum power of the GT (client responsibility). c) GT regulation mode for the GT operating with the GE: If the GT is running in parallel with the GE, then it must b e decided how the load would be shared between the two generators. Therefore the following information is required from the GE: TBM needs to know, in which condition the GT is running. Therefore the following signals must be foreseen for: information GEN-CB open/closed, information GE-GEN-CB open/closed, d) GT start up from black If the plant is in black (me aning that both GT and GE are out of operation ), all the factory load s must be disconnected. The client must start the black start diesel generator in order to feed the GT with 415V. After the start sequence the G T can close the gen-CB directly since the busbar voltage is not present. At this moment the GT is operating alone in island mode. e) Normal synchronisation: If the GE is in operation a nd the GT is started, then there is voltage on the b usbar (Ubusbar present) and the GT synchronises on it through the GEN-CB. After this sequence the GT is operating in island mode with the GE. f) GE shut down: When both GT and GE a re operating, if the GE shut down and the internal consumption in the factory is bigger than the maximum GT power, t hen the clie nt must di sconnect some load, in order to reduce the internal consumption below the maximum GT power. Attention: this load disconnection must happen very quickly in order to avoid the trip of the GT due to under frequency (meaning complete plant black out).!!! The same must be done if the GT shut down and the GE remains alone in operation.

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4.3.1

Synchronization with the busbar If the plant is ready to load and the busbar voltage is present; the gas turbine can be connected to the busbar with the generator circuit breaker through the synchrosequence. In both modes, manual or automatic, the voltage, frequency and phase matching are performed automatically.

4.3.1.1

Automatic synchronization The automatic synchronization begins immediately, without the action of the operator, if is active in the Generator Commands window. Synchro auto There follows the fully automatic synchronization sequence.

4.3.1.2

Manual synchronization Manual synchronization takes place if the button has been preset in the Generator Commands window. Synchro manu The synchronization sequence can now be initiated manually by means of the button. Synchro start There follows the synchronization sequence. To interrupt the synchronization sequence press the button

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4.3.1.3

Busbar synchronization sequence

4.3.1.3.1.

Synchronization conditions The busbar voltage must be present. The generator circuit breaker must be open. The information window displays «READY TO LOAD»

and

«SYNCHRO SEQUENCE».

4.3.1.3.2.

Voltage connection All synchronization equipment is supplied with voltage. The synchronization instruments display the voltage and frequency differences between the AC generator and the busbar.

4.3.1.3.3.

Voltage and frequency regulation In this phase the synchronization system compares the frequency and the phase angle of the generator and busbar voltages and sends a correction signal to the control system, which adapts the turbine speed accordingly. In this way the voltage regulator adapts automatically the generator voltage.

4.3.1.3.4.

Synchronization pulses If voltage, frequency and phase angle lie within the tolerance range and remain constant for a defined period, the synchronization system sends a synchronization pulse. The system remains active, in order to send several pulses. Before permitting the closure of the generator circuit breaker, the control system tests whether the entire synchronization channel is working normally. For this purpose a sequence of 3 pulses is carried out:

Pulse 1

The first pulse is tested to make sure that the synchronization equipment is sending a correct pulse. The maximum permissible time interval between two pulses is 120 seconds. If this time is exceeded, the synchronization is aborted.

Pulse 2

The second pulse enables the connection of the undervoltage coil of the generator circuit breaker.

Pulse 3

The third pulse is transmitted directly to the generator circuit breaker, allowing it to close.

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4.3.1.3.5.

Insertion of generator circuit breaker The generator circuit breaker must close within 2 seconds of the third pulse. The acknowledgement is sent directly from the generator circuit breaker position switch. If this time is exceeded, the synchronization is again aborted.

4.3.1.3.6.

End of synchronization The command to close the generator circuit breaker represents the end of the synchronization sequence. The machine is now on the busbar delivering power to the factory. The information window displays «ON LOAD»

4.3.1.3.7.

Synchronization alarms As indicated above, the synchronization is interrupted if: • •

The time interval between two pulses exceeds 120 seconds. The generator circuit breaker does not close within 2 seconds of the third pulse.

After the synchro abortion, the information window displays «READY TO LOAD»

and

«RESET ALARM REQUIRED».

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4.3.2

Synchronization test For maintenance and commissioning, a test function is available, for busbar or back synchronization. Precondition is the selection of the manual synchronization. If the button is activated, Synchro test on the synchronization sequence is started; the closing command of the generator circuit breaker is, however, locked. This function is deactivated with the button. Synchro test off

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4.3.3

Direct insertion of the generator circuit breaker This is a very seldom situation, where the voltage after the generator circuit breaker is absent: there is no voltage or frequency to match and therefore no need to synchronize prior to close the generator circuit breaker. If the Gen CB insertion button has been preset, the circuit breaker closes automatically, as soon as the «READY TO LOAD » message is received. If the Gen CB insertion manu button has been preset, after the «READY TO LOAD» message the system waits the circuit breaker manual close command. The button Gen CB close can then be used to send the close command The Gen CB open button can be used to open the generator circuit breaker at any time independently from any regulation.

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4.4

Operating modes and load charging When the synchronization sequence has been executed successfully, the generator circuit breaker is closed, the gas turbine generator set is connected with the busbar and it is possible to increase the electrical load. Depending on the operator decision, the plant offers several operating possibilities: Power mode The information window displays

•

«ON LOAD»

and

«PARALLEL MODE». Activation of active power adjustment. Activation of power factor (cos ϕ) adjustment. Frequency mode The information window displays

•

«ON LOAD»

and

«ISLE MODE». Activation of speed adjustment. Activation of voltage adjustment.

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4.4.1

Power mode operation When the operator select the active power regulation mode, the gas turbine generator set can supply active power (kW) and reactive power (kVAR). The ratio (cos phi) can be predefined. The control system adapts the power supplied by the gas turbine to the value preset by the operator, while the generator output is continuously measured and compared with the set point. The power adaptation is carried out in accordance with the increase or decrease in load at a constant rate until the desired value is achieved. When maximum power is required, the control system limits turbine temperature (T5) to its maximum permissible value and thus ensures maximum power output under the current ambient conditions. In case of a load change, the generator voltage regulator keeps the generator power factor constant at the preset value. NOTE In order to ensure stable operating conditions in power mode operation, the gas turbine should be operated with at least 10% of its nominal power.

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4.4.2

Frequency mode operation When the operator select the frequency regulation mode, the turbine generator plant must supply and keep constant its own speed or generator frequency (Hz) and voltage (V) for a load. The gas turbine control system adjusts the speed to a value predefined (50Hz). The voltage regulator keeps constant the voltage supplied by the generator.

4.4.2.1

Load charging – Isle mode operation The load on the busbar is determined by the plant load connected to the busbar itself and cannot be changed or adjusted by the turbine generator plant. In isle mode of operation, the operator must connect the loads gradually, in order to avoid overloading the turbine generator plant and to prevent rejection of the loads which are already connected. The connection of a higher load produces severe frequency and voltage fluctuations and , under certain circumstances, the cut of the loads already connected. The type of load with which the gas turbine is charged also has an effect on these fluctuations: with a strongly ohmic load there are more pronounced fluctuations in speed than with a more inductive load. As a guideline one may consider that the load can be connected in increments of 1 MW. The maximum power for the gas turbine in isle mode of operation must be limited in relation to the anticipated load fluctuations. At the same time the decrease in load as a result of the rise in ambient temperature at the transition between night and day should also be considered. The generally recommended operational value is no more than 90% of maximum power. Manual opening of the generator circuit breaker in isle mode operation In isle mode of operation the operator has the option of manually disconnecting the generator circuit breaker. In isle operation the operator has two possibilities for manually disconnecting the generator circuit breaker. Press the red button on the front panel next to the “touch-screen”. For safety reasons this button is located under a transparent protective cover. In the “Generator Commands” menu, press the button. Gen CB open

NOTE The opening button for the Generator Circuit Breaker is effective any time. CAUTION

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Before opening the generator circuit breaker in isle mode of operation it should be ensured that the required power can be supplied by another plant. If this is not the case, the power supply is completely disconnected, which leads to the blackout of the entire plant.

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4.5

Gas turbine operation

4.5.1

Functional test during operation Upon completion of the start-up sequence and after power stabilization, the turbine generator plant works in continuous operation and supplies the required energy. During this operating time the control system checks the operating conditions of the gas turbine, the generator and all associated equipments and ensures that these conditions lie within the tolerance range. If an operating condition changes, the control system reacts automatically in order to adapt the plant to the new situation. If a parameter exceeds the specified permissible range, the system informs the operator of this by means of an alarm signal. The operator must, however, in any case, regularly check that all the components of the plant are functioning correctly, in order to be able to introduce the necessary corrective measures as soon as possible. The checking procedures are in “Maintenance” section.

4.5.2

Generator settings and adjustment during operation This section deals with the various settings and adjustment functions, which are to be carried out during the operation of the turbine generator plant.

4.5.2.1

Adjustment of active power The active power produced by the generator can be set to the desired value by means of the appropriate function of the local control system (“touch-screen”) or by the corresponding function of the remote control system. The new set point can be entered at any time; the adjustment of active power is, however, only effective if the operator has selected the power mode operation. The actual value of generated power may be lower than the required power, as the power can be limited by other factors, for example by the maximal permissible temperature T5. For entering the desired setting, the “Active Power Setpoint” window is available as a submenu option of the main “Setpoints” menu. The power set point is entered using the “touch-screen“.

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4.5.2.2

Adjustment of turbine speed (generator frequency) The turbine speed (and thus the frequency supplied by the generator) can be set to the desired value by means of the appropriate function of the local control system (“touchscreen“) or by the corresponding function of the remote control system. The new set value can be entered at any time; the adjustment of speed is, however, only effective if the plant is working in isle mode of operation (frequency mode). For entering the desired setting, the “Speed Setpoint” window is available as a submenu option of the main “Setpoints” menu. The speed set point is entered using the “touch-screen“. The permissible adjustment range is between 95% and 105%. The standard set point is 100%, which corresponds to a Generator frequency of 50 Hz.

4.5.2.3

Adjustment of the generator power factor (Cosϕ) The reactive power supplied by the generator is determined by the generator power factor (cos φ). This setting is only effective in operation with the generator circuit breaker closed and in power mode operation. In this operating mode the generator voltage regulator keeps the power factor constant at the preset value. The set point is defined upon commissioning of the generator in accordance with the client's instructions. The power factor values usually are between 0.9 and 0.8. To correct the set value, please consult Turbomach.

4.5.2.4

Adjustment of the generator voltage The adjustment of generator voltage is controlled by the generator voltage regulator. This adjustment is only possible in operation with the generator circuit breaker open and in isle mode of operation. The set value is defined upon commissioning of the generator in accordance with the client's instructions and is normally identical to the nominal voltage of the plant. To correct the set value, please consult Turbomach. For plants in which several generators are connected to the same load busbar, it is important that the set voltage value remains unchanged. In isle mode of operation the adjustment of generator voltage takes place upon commissioning of the plant. A static value is defined which in isle mode of operation guarantees the most even possible distribution of reactive power to the individual plants. CAUTION In isle mode of operation a modification of the generator voltage parameter may lead to uncontrolled fluctuations of reactive power and current, which may result in damage.

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4.6

Turbine stopping

4.6.1

Local shut-down in isle operation In isle operation, the power control of the turbine can not change the produced power. Therefore it is impossible to de-load the turbine and the generator circuit breaker opens and rejects the whole load instantly. NOTE The opening button for the Generator Circuit Breaker is effective any time. CAUTION Before opening the generator circuit breaker in isle mode of operation it should be ensured that the required power can be supplied by another plant. If this is not the case, the power supply is completely disconnected, which leads to the blackout of the entire plant.

4.6.1.1

Local shut-down in isle operation:

4.6.1.1.1.

Open circuit breaker No de-loading is possible. Immediate opening of the generator circuit breaker. If the generator circuit breaker does not open, an alarm is generated.

4.6.1.1.2.

Cooling Provided that the turbine receives AC supply ,a cool down sequence of 10 minutes duration begins. The information window displays «STOP SEQUENCE» «COOLDOWN»

and

and

«<START> Permitted when no Alarm (AL) pending». If no alarm is active the machine can be switched back to the «READY TO LOAD» mode at this point by pressing the Start button and synchronized again with the appropriate standard sequences.

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4.6.1.1.3.

Deceleration When the cooling time has elapsed, all fuel valves close and the gas turbine reduces its speed. The information window displays «STOP SEQUENCE»

and

«DECELERATION». When the gas turbine has reached 10% of nominal speed or 10 minutes have elapsed, the deceleration step is ended. Depending on the configuration of the control program, the turbine can carry out at first a turning sequence at low speed for 2 hours and then the postlubrication sequence or the turbine can at once carry out the postlubrication directly.

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4.6.2

Emergency shut-down (manual push button) A shutdown (emergency stop) of the gas turbine can be initiated at any time with the EMERGENCY SHUTDOWN buttons. These are located: • • •

On the outside wall of the turbine container Next to the “touch-screen” on the control panel In other plant specific places, if any. CAUTION An immediate shutdown can be initiated with the EMERGENCY SHUTDOWN buttons. These buttons may only be used to shut down the gas turbine in the event of a clearly signalled danger or in an emergency.

An immediate shutdown of the systems is also required in the event of a danger to the gas turbine or other plant sections. This shutdown takes place automatically if a S xxx error (Shutdown) occurs. This type of error is displayed visually on the main interface of the control program and can be consulted in the “Pending alarms” window. Such an error may be generated both by the control system and by the safety system.

4.6.2.1

Emergency stop sequence:

4.6.2.1.1.

Closing fuel stop valves and opening circuit breaker The fuel stop valves are closed independently by the safety system and by the control system. The circuit breaker is opened under the currently driven load. The information window displays «STOP SEQUENCE».

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4.6.2.1.2.

Deceleration As the fuel supply is off, the machine decelerates. The information window displays «STOP SEQUENCE»

and

«DECELERATION». When the gas turbine has reached 10% of nominal speed or 10 minutes have elapsed, the deceleration step is ended. If the AC power supply is missing, the DC lube oil pump starts .The lube oil pump is powered by batteries with a capacity of about 4 hours service. The pump is designed to supply a minimal flow of oil, in order to cool the white metal of the bearings located in the hot parts of the turbine. If the AC power supply is active, the stop sequence proceeds as usual: depending on the configuration of the control program, the turbine can carry out at first a turning sequence at low speed for 2 hours and then the postlubrication sequence or the turbine can at once carry out the postlubrication directly. NOTE In order to restore the system, after an emergency shutdown caused by the push button, clear the pending alarms and reset the emergency switch in its normal position by turning the switch head in the arrow direction.

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4.7

Safety procedure for fire alarm An automatic, electronically controlled fire detection system for the turbogenerator enclosure protection is provided. The system is monitored and operated from the fire monitor unit, and is equipped with CO2 extinguishing system. The installation is designed, executed and certified in accordance with local regulations. The fire monitoring and extinguishing system detects flames inside the package and, after a pre-set time delay, releases extinguishing agent (CO2), which will fill the enclosure. WARNING Carbon dioxide CO2 is a colorless, odorless gas (unless, for safety reason, lemon odor is added). The discharge of carbon dioxide creates serious hazard to personnel, such as serious suffocation and reduced visibility during and after the discharging period. CAUTION The fire monitor system is an independent control device, however the system is directly connected with the turbine control system for the alarm transmission and safety sequence.

4.7.1

Fire system’s equipment The fire monitoring and extinguishing system consists of following main components: • • •

a fire monitor unit consisting of : electronic control and monitoring unit with 220VAC supply, 24VDC internal battery and manual fire alarm button on the front panel in the container: infrared ray detectors RT0210 and RT0220 outside the container: manual release push-button SB0302, alongside the enclosure warning horn and flashing light signals HAL0305, above the inspection door a CO2 bottles set B0312 with sufficient filling for one extinguishing action weight switches for CO 2 bottle leakage monitoring WS0312 extinguishing agent release solenoid valve MV0313 distribution piping, and spray nozzles. CAUTION The CO2 cylinder set, is designed for one fire fighting action only. It must be refilled again to restore the fire fighting functionality.

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4.7.2

Fire system operation The fire fighting system is designed to detect and extinguish a fire propagating in the enclosure. Fires, such as fuel fires or lube oil fires, are quickly extinguished by flooding the area with an inert gas. Discharging a high concentration of CO2 into the container creates the inert atmosphere. To accomplish this, the enclosure ventilation system is shutdown, the ventilation shutters are closed and the extinguishing agent is discharged into the enclosure. The fire detection system is equipped with its own emergency power supply and remains active even in the event of 220 VAC supply failure. Once armed, normal system activation is controlled by the fire detection system; the extinguishing agent can also be released any time by pressing the push button in case of an emergency. A manual fire alarm button is mounted outside the container. To operate, break the glass and press the button. In order to reset the button, replace the glass cover. The infrared flame detectors monitor the possible flame inside the enclosure. The infrared flame detector, with highly sensitive element reacts rapidly to all flaming fire in which carbonaceous materials are burnt, such as wood, plastic, alcohol, natural gas, petroleum products etc. A pyro-electric sensor evaluates a specific wavelength of the hot carbon dioxide emitted by the flame. The detector achieves high immunity to deceptive phenomena by means of a second pyro-electric sensor, which operates on another wavelength. Signal from both sensors are correlated which enables clear differentiation between flame radiation and deceptive phenomena. Thus the detector is widely insensitive to artificial light, sunlight, and all kinds of heat, ultraviolet, x-ray, and gamma radiation. As soon as a detector responds the control unit actuates a preventive warning signal. Acoustic and lighting warning panel is provided outside the enclosure above the maintenance door for operator's alerting. When both detectors respond simultaneously, or if a button is pressed, the control unit gives the extinguishing command. After a delay, a valve is actuated to release the extinguishing agent. The main discharge valve is installed on the pilot bottle, charged with nitrogen , which produces,when energised, the cascade opening of all the cylinder discharge valves of the set. For personnel safety reason, an odorant stored in a bottle, connected to the piping and actuated by the discharge pressure, may be mixed with the odourless CO2, while discharging into the enclosure. The discharged CO2 is flushed to the protected area through spray nozzles. The spray nozzles are designed to distribute the gas smoothly and evenly on the enclosure. The nozzles are sized for discharging the whole extinguishing agent in about 60 seconds. In the event of loss of extinguishing agent, the weight switch of the leaking cylinder in question transmits an alarm signal to the fire detection system.

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4.7.2.1

Container door The door, located at the longitudinal side of the container, is provided with limit switch that locks the discharge of the extinguishing agent if the door is open. Personnel working inside the container have to keep the door open while working or to lock the extinguishing agent release with the special function button on the fire monitor control panel to avoid the possible release of the extinction during maintenance. CAUTION Under normal operating conditions, if no personnel is working inside the container, the door must be kept closed in order to permit the action of the extinguishing system.

4.7.2.2

Operational logic of the automatic detection The fire monitoring system provides the following main alarms:

System fault

Indicates a fault of the monitoring system or parts of it. The control system signals it as system error (ER). This alarm doesn’t cause any automatic action.

Fire pre-alarm

Indicates that one automatic fire sensor detects a fire. The control system signals it as system warning (WR).

Fire alarm

Indicates that two sensors detect a fire, or The manual fire release buttons are actuated. The control system signals it as alarm (SD). The signals of the automatic detectors, equipped with infrared sensors, are processed by the following logic:

First detector

second detector

OK

OK none

not OK

OK

fault

OK

not OK

fault

not OK

not OK

fault

not OK

fire detected

fault, pre-alarm, fire alarm

fire detected

not OK

fault, pre-alarm, fire alarm

fire detected

OK

pre-alarm

OK

fire detected

pre-alarm

fire detected

fire detected

pre-alarm, fire alarm

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Alarm signal

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4.7.2.3

Fire monitoring and extinguishing system failure Monitoring or extinguishing system defects, such as sensor failure, line interruption, measurement unit failures or supply failure, activates this alarm. WARNING In case of failure indication, part of or the whole system is out of service. It’s the operator’s responsibility to re-establish as soon as possible nominal operating conditions and to take all the necessary precautions to assure a safe unit operation. CAUTION The fire system is primarily a safety device to protect personnel and equipment. It must be ALWAYS READY. The system will provide safe and continuos monitoring of hazardous areas only with proper installation, calibration and maintenance.

Functional system failure sequence • • • •

A defect in the monitoring system or parts of it is detected. The alarm in the fire monitor is activated. The control system signals it as system error (ER). This alarm doesn’t cause any automatic action.

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4.7.2.4

Fire warning This alarm is activated when one out of two automatic fire sensors detects a fire. The alarm is announced by a continuous sound emitted by the beeper present in the enclosure and by a warning signal in the main control system. Indication given by light diodes is also visible on the front panel of the fire detection monitoring system WARNING IMMEDIATE operator intervention is mandatory in case of a fire detection warning, in order to verify the actual situation of the installation and take all necessary precautions to assure safety to avoid damage escalation. WARNING With the activation of the fire warning, the operator must proceed immediately to the turbine area and verify the situation in the enclosure. The operator must be equipped with appropriate portable extinguishing device. WARNING Extreme cautions must be taken when proceeding with enclosure inspection. CAUTION The main enclosure door (with handle) is equipped with a position switch; once opened automatic extinguishing is blocked in order to protect the personnel in the enclosure. For this reason, during normal condition main door must remain closed.

Functional fire warning sequence • • •

A fire pre-alarm is detected. The alarm in the fire monitor is activated. The control system signals it as system warning (WR). This alarm doesn’t cause any automatic action.

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4.7.2.5

Fire alarm This alarm is activated when both automatic sensors detect a fire. Activation is also possible via manual push buttons installed on the enclosure and at the front panel of the fire detection monitoring system. The alarm is announced by an intermittent sound emitted by the beeper present outside the enclosure and by an alarm signal in the main control system. Indication given by light diodes is also visible on the front panel of the fire detection monitoring system The gas turbine unit is instantly shut down, in parallel the extinguishing sequence is activated. CAUTION The extinguishing command may not be executed if a system failure was present before the fire alarm was issued. WARNING A fire detection alarm condition indicates a potential danger for fire development in all turbine area. It is in the operator’s responsibility to ensure safety to all personnel and equipment to avoid escalation of damages. CAUTION Do not push any of the reset push button before the fire has been completely extinguished. Nonobservance of this rule could cause interruption of the extinguishing sequence with inherent damages. WARNING With the activation of the fire alarm, the operator must proceed to the turbine area and verify immediately the situation in the enclosure. The operator must be equipped with appropriate portable extinguishing device. WARNING Extreme cautions must be taken when proceeding with enclosure inspection. CAUTION The main enclosure door (with handle) is equipped with a position switch; once opened automatic extinguishing is blocked in order to protect the personnel in the enclosure. For this reason, during normal condition main door must remain closed. WARNING When the extinguishing gas (CO2) has been discharged, the air concentration in the enclosure is extremely reduced; it’s highly dangerous to enter the enclosure without appropriate precautions, life danger persists. Do not enter the enclosure before ventilating sufficiently and after having checked oxygen concentration in the enclosure.

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4.7.2.5.1.

Fire alarm sequence • •

•

• •

• • • • • • •

A fire alarm is detecte d. The intermittent alarm in the enclosure is activated. Inherent safety sequence is activated by the control system. Immediate shutdown of the turbine is commanded. All main fuel shutoff valves are closed and the vent valves opened. Enclosure fans are switched off. Enclosure air shutters remain open during 45 seconds. The safety system is warned. Timer for a delay of norma lly 30 second s for the CO 2 discharge in the encl osure starts. During this waiting period it’s possible to block the discharge with the corresponding switch installed on the fire monitor. The turbine decelerates. The operator has to i ntervene IMMEDIATELY in o rder to verify the real situation of th e installation and to take th e necessary precautions to guarantee safety. Actions such as the following are at the operators responsibility: Evacuate all personnel in the turbine area proximity Close all external manual fuel & pressure air supply shut-off valves. Follow the safety prescription as per safety specifications. Once the 30 seconds timer expires, CO2 discharge is activated. Approxim ately 60 seconds are required to empty the CO2 bottles. 15 seconds after the CO2 discharge start, air shutters are commanded to closed position. Such sequence is to enhance air evacuation, since CO2 has a greater specific gravity. Once the CO2 is completely discharged, beeper tone changes from intermittent to continuos. In the mean time, the tu rbine shaft will de celerate to stand still if it was runnin g. The lubrication system remains in service.

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4.7.3

Operator container inspection and action With the activation of fire alarms, the operator must go to the turbine area and verify immediately the situation in the enclosure. The operator must be equipped with appropriate portable extinguishing gear. WARNING Extreme cautions must be taken when proceeding with enclosure inspection. CAUTION The main enclosure door (with handle) is equipped with a position switch; once opened automatic extinguishing is blocked in order to protect the personnel in the enclosure. For this reason, during normal condition main door must remain closed.

4.7.3.1

No fire within the container In case the inspection did not reveal the presence of a developing fire, proceed as follows: • • • • •

If possible, block the extinction with the corresponding switch on the fire control panel otherwise proceed on chapter re-establishment. If the situation is under control, cancel the present alarms on the fire control unit as well as on the main control system. After resetting the alarms, enclosure air gates are opened and the ventilation is automatically activated. Restart the engine. Observe long enough the enclosure to verify if there is a m alfunction in the fire monitoring system or a real fire danger.

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4.7.3.2

A small fire is detected in the container In case the enclosure inspection reveals the presence of a minor entity fire, proceed as follow: • • • • • • •

Make sure that nobody is inside or in proximity of the encl osure, if necessary evacuate the person(s). Be sure that the fire can be controlled by means of a portable extinguisher. Extinguish the fire with the portable extinguisher. Once the fire is surely extinguished, block the automatic fire e xtinguishing from the fi re monitor panel. Evaluate cause and damage entity. Once the cause has been identified a ssure the event cannot be repeated. If this is not possible stop immediately operation. Proceed with disconnection and repair of parts, if possible. WARNING Avoid repair of functional parts when powered or under pressure, non-observance could cause personal injuries.

• •

If necessary, stop the turbine and rep air, otherwise cancel the alarm s and continue with operation. Inspect periodically the development area for sufficient time. WARNING In case of doubt, close the inspection doors and push without hesitation the manual extinguishing switch in the enclosure area. Proceed as for important fires.

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4.7.3.3

An important fire is detected in the container In case the enclosure inspection reveals the presence of a major entity fire, proceed as follow: • • • • •

Make sure that nobody is inside or in proximity of the encl osure, if necessary evacuate the person(s). The fire cannot be manually controlled. Close the enclosure inspection doors. Actuate immediately the manual fire release button near the package or on the control panel in the control cubicle room. Call the intern or extern fire-fighters department. WARNING

In case of fire within the enclosure, fuels, lubrication and compressed air are an additional source that could increase the damage potential. Therefore it is mandatory to cut the medium supply from the external as soon as possible. The operator must immediately evaluate the situation and interrupt outer danger sources. • • • •

The turbo generator will shutdown. Close all the external manual liquid and gas fuel supply valves as well as the compressed air supply. If the oil spill is feeding the fire, for safety reasons, power-off lubri cation oil pumps a re required. The pumps must be switched off manually. The AC pre-post lube oil pumps can be disconnected by me ans of the corresponding automatic fuse. Once the AC pumps are off, t he emergency oil pump will automatically run because of p ressure drop. To swit ch off the emerge ncy oil pump use the ma nual switch installed in the supply panel. CAUTION Lubrication cut-off is an action fully under operator’s responsibility. Even if the turbine shaft is in standstill such action can lead to considerable damages, It is therefore mandatory to contact Turbomach SA before any further actions are taken.

• • •

Disconnect all enclosure equipment power supply. Because of t he potential high risk of a back-draft, and the pres ence of CO2 within the enclosure, the enclosure doors MUST NOT be opened. Continue as explained under chapter re-establishment WARNING Carbon dioxide (CO2) is a colorless, odorless (for safety reason, lemon odor is added), electrically non-conductive inert gas and is 1,5 times heavier than air. The discharge of carbon dioxide in fire extinguishing concentration creates serious hazard to persons, such as serious suffocation, which can be deadly, or reduce visibility in the protected area. Do not enter the enclosure before thorough ventilation and after having checked that the atmosphere in the enclosure contains enough oxygen.

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4.7.4

Precaution during maintenance works During welding works inside the container, desactivate the fire detection and fire extinction system in order to avoid any useless discharge of extinguishing agents. WARNING While the extinction system is out of service, it is necessary to install a portable extinguisher, with sufficient capacity, close to the zone where the welding works are carried out.

4.7.5

Re-establishment of the unit after the discharge of extinguishing agents WARNING When the extinguishing gas (CO2) has been discharged, the air concentration in the enclosure is extremely reduced; it’s highly dangerous to enter the enclosure without appropriate precautions, life danger persists. Do not enter the enclosure before sufficient ventilation and after having checked oxygen concentration in the enclosure. WARNING Because of its physical composition CO2 is heavier then air, therefore CO2 has the tendency to stay on the ground. • •

• • • • • •

When the fire is extinguished and qualified personnel have the situation under control, CO 2 evacuation is mandatory. Open of all doors and inspection panels. By means of compressed air flush en closure bottom and eve ntually cable trays, se ctions, rooms, etc. below the en closure level that could have been potentially contaminated by enclosure leaks. Before undertaking any activity related to the en closure be sure that all CO 2 is now properly evacuated. Cancel the present alarms on the fire control unit as well as on the main control system. Disconnect the in stallation parts, which could be damaged. If necessa ry, proceed with repairs. Refill the bottles with new Extinguishing agent. In case co ndition at the above point cannot be respected, due e.g. logistic rea sons, operators are responsible for supervision and operation. Inspect all t he gas turbine generator set for fire damages . After a CO 2-discharge the situation has to be carefully evaluated prior to restart.

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4.8

Safety procedure for gas alarm

4.8.1

Description of the gas monitor system The unit is equipped with a gas leakage monitoring system that covers the enclosure internal area. The gas detection system is designed to continuously monitor the explosive level of the atmosphere within the enclosure The system consists of a gas sensors assembly installed in the container. The detection sensors are connected to the safety back-up PLC (Process Logic Controller) which provides the monitoring. The safety system triggers the system fault, warning and alarm signals. The processed value is in percent of the LEL (lower explosion limit) : typically 10% of LEL for warning and 20% of LEL for alarm The 100% LEL indication means the gas has reached a concentration where the gas/air mixture become sufficient to produce an explosion (= 5% vol. CH4 in air). If the gas concentration in the container increases the pre-selected levels, visual warnings, alarms, and safety sequence, including turbine shutdown, are initiated to protect personnel and equipment. In case the concentration of gas exceeds 20% LEL the turbine will be shut down. WARNING In case of gas leakage detection alarm an explosion risk persists. Before resetting the system be sure that the gas is evacuated. To avoid personnel injuries, the system can only be restored once this condition is achieved.

The gas leakage monitoring system gives the following alarms ,which are displayed by the control system: Gas detection failure

Indicates system or part of it out of service. A system fault message is issued (SD). The unit shut down, a dedicated safety sequence is activated.

Gas detection warning

Indicates a gas concentration in the package above 10% LEL and below 20 % LEL. The control system signals this as a warning (WR).

Gas alarm

Indicates a gas concentration in the package above 20 % LEL. The control system signals this as alarm (SD). The unit shut down, a dedicated safety sequence is activated.

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4.8.2

Gas monitor system failure Monitoring system failure such as sensor failure, line interruption, measurement unit breakdown or supply failure, activates this alarm. Due to the high danger of the gas leakage within the enclosure, the monitoring is performed by the safety back-up PLC, working in the context of a redundancy control. For this reason in case of one channel failure a shutdown for discrepancy is activated. WARNING In case of failure indication, part of or the whole system is out of service. It’s operator’s responsibility to re-establish the correct system operation and take all necessary precautions to grant a safe operation of the plant. CAUTION The gas detection system is primarily a safety device for the protection of personnel and equipment It must always be ready The system will provide safe and continuous monitoring of hazardous areas only with proper installation, calibration and maintenance.

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4.8.3

Gas leakage warning This alarm is activated when the gas concentration in the enclosure exceeds the limit of the first threshold (> 10 % LEL). Warning (WR) will be commanded. Fans and air gates will be activated, if not already activated, to ensure gas evacuation. WARNING If a gas leakage warning appears on the screen check the gas concentration in the container using a hand-held gas detector: if the gas detector confirms the presence of gas or the leakage location is detected shutdown immediately the gas turbine and close the main shutoff hand valve on the gas line to the turbine.

Find here below recommended procedure to follow in case of gas leakage leading to a warning: •

• • • •

When this alarm is activated, concentration inspection by means of a portable instrument must be exe cuted. Inspection must co ver all in ternal fuel suppl y lines, starting from inlet flange till fuel injector’s connection ports. Once leak source has been identified, turbine must be stopped and external manual shut off valve closed. Once all valves are closed, all e nclosure maintenance doors can be opened to imp rove evacuation of gas residues. If the concentration is high or the escaped gas cannot be contained, all electrical supplies in the enclosure must be powered off. If the situation is under control or the gas leakage repaired, cancel the present alarms and restart the installation, keep the unit under visual control for a sufficient period.

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4.8.4

Gas leakage alarm This alarm is activated when the gas concentration in the enclosure exceeds the limit of the second threshold (> 20 % LEL). A shutdown signal (SD) is given. Enclosure fans and air gates are automatically activated to evacuate the detected gas. WARNING In case of gas leakage an explosion risk persists, therefore all personnel in the area must be evacuated and the enclosure must be closed to allow proper ventilation. In a second time, but as soon as possible, authorized and skilled personnel must intervene to find the source of the leak and take the necessary actions. Inspection personnel must be equipped with appropriate protection.

Find here below recommended procedure to follow in case of gas leakage leading to an alarm: Gas leakage above al arm threshold is detected. The safety back-up circuit is a ctivated (hardware-backup). Inherent safety sequence is activated by the control system. • Immediate shut-down of the turbin e is comma nded. All main fu el shut-off fuel valves are closed and vent valves opened. Enclosure fans are switched on if not already on. Enclosure air gates are commanded to open if not already open • Power supply to all non-explosion proof equipment in th e enclosure is switched off, exceptions are made for all explosion proof equipment (fire sensors, gas sensors, lighting) and the components necessary for the safety back-up circuit. • The turbine decelerates. • The operator has to i ntervene IMMEDIATELY in o rder to verify the real situation of th e installation and to take the necessary precautions to guarantee safety. Following actions are at operators responsibility: Evacuate all personnel in turbine area proximity. •

Close all external manual fuel shut-off valves. Follow the safety prescription as per safety specifications. • •

• •

• •

The lubrication system remains in service since it is ex proof. Verify immediately the gas concentration in the enclosure. Inspection must be done by using a portable equipment and must cover all th e gas fuel lin e, from inlet fla nge to i njector connections. Once all valves are closed, all e nclosure maintenance doors can be opened to imp rove evacuation of gas residues. If the concentration is high or the gas escape cannot be contained, all the electrical supplies in the enclosure must be powered off and action that could lead to ga s ignition must be avoided (welding, grinding, smoking,). If the situation is under control or gas leakage is repaired, reset alarms on the gas control unit and on the main control system. Once the unit is resta rted, it is a dvisable to proceed with regular concentration measurements and visual inspections for a reasonable time.

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4.9

Turning and postlubrication In order to equalize the temperature drops of the turbine hot parts, the turbine may undergo a low speed turning sequence for 2 hours: it depends on the control program configuration, whether the turning sequence is carried out or not. After the deceleration and the turning sequence, if any, the post-lubrication cycle, for the duration of which the lubricating system remains in operation, ensures the correct lubrication and cooling of the turbine bearings. If the bearings are not cooled, the heat released by the hot parts may damage them. For this reason a post-lubrication cycle lasting 1 hour is mandatory, in order to guarantee the correct cooling of the bearings and the correct operation of the plant. CAUTION A post-lubrication cycle lasting 4 hours is mandatory for the correct operation of the gas turbine. In the event of lubrication failure during the post-lubrication phase please consult Turbomach before attempting a restart. In the event of a lubrication failure for more than 20 minutes the gas turbine must be overhauled.

4.9.1

Turning and postlubrication sequence Depending on the control configuration: 2 hours low speed turning As soon as the turbine slows down at 10% speed or 10 minutes after shutdown, the starting motor system lets rotate the turbine at low speed for 2 hours. Then the starting motor stops and the post-lubrication sequence proceeds. Window displays «STOP SEQUENCE»

and

«TURNING SEQUENCE».

4.9.1.1

Post-lubrication The post-lubrication sequence lasts 1 hour. The information window displays «STOP SEQUENCE»

and

«POST LUBE SEQUENCE». During the post-lubrication phase it is still possible to start the gas turbine by pressing Start Or turn the turbine in crank operation. (See chapter on Maintenance) CAUTION It is not permissible to accelerate the cooling of the gas turbine using the crank procedure

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4.9.1.2

End of the postlubrication sequence After postlubricationcycle, the control system returns to the standby position.

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4.10

Turbogenerator alarms

4.10.1

General Description The gas turbine generator plant is equipped with all the safety equipments required to ensure the correct functioning and reliable continuous operation of all its components. In the event of a complete or partial failure of a component, unusual events, malfunctions or in other cases, the messages displayed on the “touch-screen” enable the operator to carry out troubleshooting and malfunction analysis. Although the automatic control system is very reliable, a constant monitoring of the various situations by the operator remains the best way of achieving safe and effective long-term operation. All displays which can provide detailed information on operating sequences should be checked as part of regular inspections at the plant. If the operator detects an unusual situation, the cause of the malfunction or deviation should be investigated and clearly determined before the operating sequences are continued, in order to avoid any greater damage to the plant or personal injury. It should not be waited until the automatic control system reacts; if the operator detects errors or deviations, he must take the necessary corrective measures to prevent or to limit any possible damage. The various alarm displays ,are generated by the control system, are shown below.

E-xxx

Error

Error condition

W-xxx

Warning

Warning indicator

A-xxx

Shutdown

Alarm with normal turbine shutdown (shutdown with cooling phase)

S-xxx

Shutdown

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Alarm with quick shutdown

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4.10.2

E-xxx

Error

The error signal indicates a problem in connection with measuring, signal transmission or value recording. In most cases this alarm does not stop or shutdown the gas turbine generator set. Communication problems arise as a result of faults in the communication lines to other systems, e.g. in the serial RS485 connections which link the control system with the multi-transducer. Value recording problems are caused by faults in the analogue transducers. In the event of an E xxx "error" alarm, the measurement channel in question is usually deactivated and the respective alarms or functions are no longer available. In the event of an E xxx "error" alarm the operator must use his own judgement to decide what measures are required to ensure the reliable operation of the plant. The operator is also responsible for constantly checking the deactivated signals with the aid of other control parameters in order to prevent possible damage to the system.

4.10.3

W-xxx

Warning

A warning signal indicates a sequence error or a warning condition in the various systems. Malfunctions in the course of the various functional sequences of the program, which are generally caused by defects in the systems involved, produce a sequence error. A warning is triggered by protective equipment which displays an unusual condition in a particular section of the plant. At this stage the situation is not (yet) critical for the safety of the plant; the operator must, however, immediately take suitable countermeasures to prevent the situation getting any worse, leading to more serious malfunctions or a shutdown of the plant.

4.10.4

A-xxx

Alarm with Normal Turbine Stop

An alarm message with normal turbine shutdown indicates an error situation which may lead to damage to the gas turbine, but which does not demand a quick shutdown. The shutdown caused by an A-xxxx is equivalent to manual stopping with the STOP button. The remaining sequence therefore corresponds to the stopping sequence described in corresponding section

4.10.5

S-xxx

Alarm with Quick Shutdown

A quick shutdown signal indicates an immediate danger to the gas turbine or other plant sections and demands an immediate shutdown of the system. The shutdown is equivalent to the emergency stop. During the gas turbine post-lubrication phase the plant may be restarted at any time. It is, however, necessary to determine the causes of the stopping or shutdown of the turbine. This is to be mentioned in the plant operation report and all damages or errors are to be corrected immediately.

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4.11

Taking the Plant out of Operation (weeks) If the plant is not going to be operated for a period of time, e.g. for a weekend or for one or more weeks, the plant may be taken out of operation. CAUTION Before the plant is taken out of operation the gas turbine must be in the “ready to start” state, i.e. the post-lubrication phase must have been completed. CAUTION In principle the machine remains in ready to start conditions during this period and the machine state is monitored even at standstill.

The following points are to be observed in this connection: The turbine control system is active. In the “Main Commands” menu the System on button is activated. The information window displays «SYSTEM ON». The safety system is active. The main current supply (AC main switch in the supply cabinet) is active, in order to ensure the power supply, e.g. to the container heater, or to keep the batteries at their optimum charge state via the battery charger. The gas detection system within the turbine enclosure is active. In the event of a gas leakage alarm the enclosure ventilation is immediately switched on and the heaters are switched off.

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4.12

Plant Shutdown (months) CAUTION Before the plant is shut down the gas turbine must be in the “ready to start” state, i.e. the postlubrication phase must have been completed.

Even for long periods of standstill it is advisable to proceed like for short periods of standstill and to leave the turbine in «READY TO START» conditions, in order to: • • • • • • •

have the lube oil tank heat er switched on, to keep the oil at a sufficient tempe rature for the next start. have the generator heater on , to prevent condensation forming within the generator. have the container heaters (if installed) on , to prevent condensation or freezing. have the battery charger active , to keep the batteries full charged. monitor possible gas leakage inside the container. monitor possible fire. let the air conditioning work and regulate the humidity and temperature in the control room.

If a plant is taken out of operation for a long period, the turbine must be turned at regular intervals. The turbine should be briefly brought up to its starting speed using the start-up system, that means by activating the crank sequence. This process should be carried out every 14 days; the turbine can subsequently remain out of service for a further 14 days. If the turbine is installed in an especially aggressive environment, e.g. in proximity to the sea or in a location with severe industrial pollution, this process should be carried out several times a week (at least once a week). The generator is particularly sensitive if put out of operation for an extended period. It is recommended that the operator carefully read through the instructions in the manual of the (delivered) generator and follow the manufacturer’s advice right down to the last detail.

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4.13

Crank The gas turbine crank mode enables the turbine to be brought up to a sufficient speed for compressor washing. In this case only the turbine start-up system is activated, without any fuel supply or ignition taking place. CAUTION It is not allowed to use the CRANK sequence for a quick cooling of the gas turbine. Instructions on gas turbine washing are in the «Maintenance» chapter.

The turbine can only be operated if the plant is in the «READY TO START»

or

«STOP SEQUENCE»

and

«POST LUBE SEQUENCE». The machine must be in local control mode.

4.13.1

Start of the cranking process: The cranking process is initiated in the “Main Commands” menu with the button. Crank The information window displays «CRANK SEQUENCE».

4.13.1.1

Pre-ventilation This sequence is identical to that one of the start procedure. The information window displays «CRANK SEQUENCE»

and

«ENCLOSURE PURGE». If the turbine is in postlubrication sequence, the preventilation is not carried out.

4.13.1.2

Emergency lubrication pump test This sequence is identical to that one of the start procedure. The information window displays «CRANK SEQUENCE»

and

«EMERGENCY OIL PUMP CHECK». If the turbine is in postlubrication sequence, the emergency lubrication pump test is not carried out.

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4.13.1.3

Pre-lubrication This sequence is identical to that one of the start procedure. The information window displays «START SEQUENCE»

and only during the check

«LUBE OIL PRESSURE CHECK» and then «START SEQUENCE» «PRE LUBE SEQUENCE». If the turbine is in postlubrication sequence, the prelube sequence is not carried out.

4.13.1.4

Cranking This sequence is identical to that one of the start procedure. The information window displays «CRANK SEQUENCE»

and

«CRANKING» «ACCELERATION TO CRANK SPEED» The turbine receives torque and begins to turn. •

4.13.1.5

T60 turbines have to reach the 16% speed within 45 s, otherwise a shutdown takes place.

Washing release Even if there is no intention to wash the compressor, a message is issued indicating that washing with water is permitted at this time: «CRANK SEQUENCE»

and

«WATER WASH ALLOWED» The Operator terminates the cranking sequence.

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4.13.1.6

End of cranking The cranking process is stopped in the “Main Commands” menu, with the button. Stop The information window displays «STOP SEQUENCE». The start-up system is switched off, and the turbine reduces its speed. The turbine switches to the normal stopping sequence consisting of deceleration, turning ,if any, and postlubrication

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4.14

Compressor washing To restore the full efficiency of the gas turbine, which may be deteriorated by dirt in the compressor, compressor washing should be carried out at regular intervals. There are two washing processes: • •

Gas turbine cold washing by turning the gas turbine without combustion ("offline" washing). Gas turbine washing during operation and under load ("online" washing). CAUTION When washing the gas turbine the instructions in the "Maintenance" chapter are to be followed exactly.

4.14.1

Off-line compressor washing This section only describes the operating sequences for the activation of gas turbine washing. For the execution of the complete gas turbine washing the operator must follow the instructions contained in chapter "Maintenance" exactly. CAUTION Before the start of gas turbine washing at least 8 (eight) hours must have elapsed since the plant was shut down; the average exhaust gas temperature (T5) must be less than 65°C. • •

Prepare the washing process, according to maintenance instructions. Start of the cranking process

Because of the standstill for the cool down and the preparation works to be done prior to wash the compressor , the turbine is usually is in stand-by «READY TO START» and no postlube sequence is ongoing. The cranking process is initiated in the “Main Commands” menu with the button. Crank The information window displays «CRANK SEQUENCE».

4.14.1.1

Pre-ventilation This sequence is identical to that one of the start procedure. The information window displays «CRANK SEQUENCE»

and

«ENCLOSURE PURGE».

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4.14.1.2

Emergency lubrication pump test This sequence is identical to that one of the start procedure. The information window displays «CRANK SEQUENCE»

and

«EMERGENCY OIL PUMP CHECK».

4.14.1.3

Pre-lubrication This sequence is identical to that one of the start procedure. The information window displays «CRANK SEQUENCE»

and only during the check

«LUBE OIL PRESSURE CHECK» and then «CRANK SEQUENCE» «PRE LUBE SEQUENCE».

4.14.1.4

Cranking This sequence is identical to that one of the start procedure. The information window displays «CRANK SEQUENCE»

and

«CRANKING» «ACCELERATION TO CRANK SPEED» The turbine receives torque and begins to turn. •

4.14.1.5

T60 turbines have to reach the 16% speed within 45 s, otherwise a shutdown takes place.

Washing release A message is issued indicating that washing with water is permissible at this time: «CRANK SEQUENCE»

and

«WATER WASH ALLOWED».

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4.14.1.6

To start the washing process: The washing process is initiated in the “Maintenance Commands” menu with the button. Water wash on The control system checks the external temperature. If the external temperature is lower than 7°C the operator is first asked whether washing should nonetheless take place (antifreeze required) and following message may be issued: «CRANK SEQUENCE»

and

«WATER WASH ALLOWED»

and

«AIR TEMP. LOW – ADD ANTIFREEZE AGENT TO WATER!». This decision – to carry out washing or not – is taken by the operator on his own responsibility. The operator has two minutes time to decide. The choice is logged in the control system. Following message appears: «CRANK SEQUENCE»

and

«WATER WASH IN PROGRESS» At this moment follow the procedure described in the chapter “Maintenance“: washing with the lance. To terminate the washing process: The washing process is terminated either automatically by means of the pressure switch PS1545 indicating that the tank is emptied or manually by the operator in the “ Maintenance Commands ” menu with the button. Water wash off The information window displays «CRANK SEQUENCE». The turbine keeps on running in the CRANK mode. The gas turbine can be stopped by terminating the cranking sequence.

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4.14.1.7

End of cranking The cranking process is stopped in the “Main Commands” menu, with the button. Stop The information window displays «STOP SEQUENCE». The start-up system is switched off, and the turbine reduces its speed. The turbine switches to the normal stopping sequence consisting of deceleration, turning ,if any, and postlubrication

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4.14.2

On-line compressor washing This section only describes the operating sequences for the activation of gas turbine washing. For the execution of the complete gas turbine washing the operator must follow the instructions contained in chapter "Maintenance". • •

Prepare the washing process, according to maintenance instructions. Washing release

The turbine is in operation at nominal speed, better with load: see chapter "Maintenance".

4.14.2.1

To start the washing process: The washing process is initiated in the “ Maintenance Commands ” menu with the button. Water wash on The control system checks the external temperature. If the external temperature is lower than 7°C it’s impossible to carry out the on-line washing. Beside the corresponding service message (ready to charge or in operation) following message appears: «WATER WASH IN PROGRESS» The sequence is manually ended by the operator.

4.14.2.2

To terminate the washing process: If the washing sequence is still running, the washing process may be terminated in the “Maintenance Commands ” menu with the button. Water wash off

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4.15

Remote Control In accordance with the planned system for the project, it is possible to remotely control the gas turbine using remote turbine supervision systems or a master computer via a serial connection. In both cases the gas turbine control cabinet must be correctly configured so that the remote control can be activated. Check that the control selection is set to “Remote“. If this is not t he case, you mus t first push the button to inform th e control system that the machine is to be controlled “remotely“.

• •

Remote The button is shown to be activated, which allows you to see at any time whether the machine is being controlled “locally” or “remotely”. In “Remote” mode only commands are accepted which are given by the remote control PC via serial interface or • the upper-level control system by means of hardware wiring. As with the local start-up procedure, all active alarms can be reset. •

Pushing the button resets all the alarms. Reset The information window displays «RESET ALARM REQUIRED». If an alarm that represents a shutdown condition is still active, the plant cannot be started. In this case it is necessary first to remove the cause of the alarm. If the plant is fault-free, the control system switches to the ready state. In normal cases the following functions can be controlled by remote control: 1. START

Gas turbine Start

2. STOP

Gas turbine Stop

3. QUIET

Acknowledge and cancel acoustic alarms

4. RESET

Reset alarms

5. GAS

Select operation with gas fuel

6. LIQUID

Select operation with liquid fuel The following functions are only available via the serial connection:

7. SYNC_ENB

Start synchronization

8. SYNC_BRK

Abort synchronization

9. SET kW

Change the set point for active power

10. SET Speed

Change the set point for turbine speed

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4.15.1

Remote Controlled Start-up Procedure Once activation has taken place the start-up sequence runs fully automatically, as described in the local start-up sequence. • •

4.15.2

Select fuel Initiate start

Remote Controlled Synchronization Procedure The synchronization procedure runs corresponding local synchronization.

fully

automatically,

as

described

in

the

In remote control mode, as in local mode it is possible to initiate the synchronization sequences with the corresponding commands. • • • • •

4.15.3

Automatic or manual synchro Start and stop synchro Select/deselect generator CB auto. Close and open generator circuit breaker Synchro test on and off

Remote Controlled Stopping Procedure Once activation has taken place the stopping sequence runs fully automatically, as described in the corresponding section on local stopping the plant.

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4.16

Operational Malfunctions Certain conditions represent deviations from normal turbine operation. If the following malfunction symptoms are detected, corrective measures must be taken.

4.16.1

Compressor Surging On all turbines a surging of the turbine compressor can occur under certain conditions. Transient conditions in the fuel or air systems can lead to turbine surging, which is identified by the noises and conditions described below: Surging in the lower speed range can be recognized by the fact that the turbine does not accelerate, that exhaust gas temperatures are higher than usual and that a rattling or fluttering noise can be heard. Surging in the upper speed range can be recognized by loud rumbling and/or bangs as well as the incapacity of the turbine to accelerate to its rated speed. If surging occurs, the turbine should be immediately shut down, in order to prevent a rapid and harmful rise in temperature. When the turbine has come to a standstill, a restart can be attempted in the usual manner. If surging reoccurs, specific troubleshooting should be carried out.

4.16.2

Generator Overheating and Vibration Under certain conditions generator overloading may occur. The normal temperature rise in the generator windings is specified in the generator manual. Always check the winding temperatures. Overheating may be caused by conditions such as high ambient temperatures, insufficient circulation of air as a result of unsuitable or obstructed air cooling, overloading, excessive field current, contaminated or insufficient supply of lubricating oil and worn bearings. If the excessive temperature persists, the plant must be shut down and the cause determined. An increase in generator vibration during operation must always be investigated. Check the generator for misalignment, warping of the shafts, friction between fixed and rotating parts etc.

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