资料编号：71.D151.35-08E03135MW TURBINEEMERGENCY TRIP SYSTEMSPECIFICATION135MW汽轮机组危急遮断系统说明书发布实施中华人民共和国上海汽轮机有限公司发布此资料系上海汽轮机有限公司专有资料，属本公司产权所有。
未经本公司书面同意，不准擅自资料编号：71.D151.35-08E03COMPILING DEPT.：编制部门：自控中心COMPILED BY：编制：陈建2005.5CHECKED BY：校对：王正明2005.5REVIEWED BY：审核：王正明2005.5APPROVED BY：审定：杨炯2005.5STANDARDIZED BY：标准化审查：COUNTERSIGN：会签：RATIFIED BY:批准：资料编号：71.D151.35-08E03共 1 页 第 1 页目 次1. GENERAL ............... . (1)2. EMERGENCY TRIP CONTROL BLOCK (1)3. TEST BLOCK (2)4. THRUST BEARING TRIP DEVICE (3)5. ELECTROLCAL OVERSPEED TRIP DEVICE ...............4 6. PRINCIPLE OF CONTROL LOGIC ...... . (4)6.1 TRIP LOGIC (4)6.2 TRIP CONTROL LOGIC (5)7. INTRODUCE OF ETS CABINET AND PANEL (6)7.1 POWER SUPPLY (6)7.2 PLC USING ANNOTATES (6)7.3 OPERATOR PANEL (7)8. TESTING (10)8.1 LOW BEARING OIL TEST (10)8.2 ELECTRICAL OVERSPEED TEST (11)8.3 MECHANICAL OVERSPEED TEST (11)9. NOTE. (12)1.GENERALThe emergency trip system monitors certain turbine parameters and closes all turbine steam inlet valves when the operating limits of these parameters are exceeded. The parameters monitored as follows:●Turbine over-speed●Low bearing oil pressure●Low condenser vacuum●Low EH fluid pressure●Thrust bearing wear●Vibration bearing●Differential expansion●Remote trips which accept additional external trip are also providedThe system utilizes a two-channel concept that permits on-line testing with continuous protection afforded during the test sequence.As illustrated in Figure 1, the system consists of an emergency trip control block with trip solenoid valves and status pressure switches, three test trip blocks with pressure switches and test solenoid valves, some of pickups of the turbine supervisory instrument (TSI), for example rotor position pickups etc., three speed pickups, a cabinet containing electrical and electronic hardware and a remotely mounted status and test panel.The sensing devices at the turbine transmit electrical signals to the trip cabinet where control logic in the programming logical controller determines when to trip the auto stop emergency trip header.2.EMERGENCY TRIP CONTROL BLOCKRefer to Figure 2 for a schematic of this block. The auto stop emergency trip header pressure is established when the auto stop trip solenoid valves (20/AST) are energized closed. The valves are arranged in two channels for testingpurposes. The odd numbered pair corresponds to channel 1 and the even numbered pair corresponds to channel 2. This convention is carried throughout the emergency trip system in designating all devices; e.g., channel 1 devices are odd-numbered, and channel 2 devices are even-numbered. Both valves in a channel will open to trip that channel. It can be seen from Figure 2 that both channels must trip before the auto stop trip header pressure collapses to close the turbine steam inlet valves. On-line testing can be accomplished by “tripping” one channel at a time.The 20/AST solenoid valves are externally piloted two-stage valves. Safe Fluid pressure is applied to the pilot piston to close the main valve. A 63/ASP pressure switch monitors the pressure of each channel. The pressure switch is used to determine the tripped or latched status of each channel and as an interlock to prevent testing one channel when the other channel is being tested.3.TEST BLOCKSThe test blocks for bearing oil pressure. EH Fluid Pressure and condenser vacuum are illustrated schematically in Figure 3.Each test block assembly consists of a steel test block, two pressure gauges, two shutoff valves, two solenoid valves, and three needle valves; each assembly is arranged into two channels. The assemblies, mounted on the governor pedestal, are connected to pressure switches mounted in a nearby terminal box. An orifice is provided in each channel so that the measured parameter is not affected during testing. An isolation valve on the supply side allows the test block assembly to be serviced without contaminating the rest of the system. Certain drilled passages are permanently plugged with pipe plugs in the bearing oil and condenser vacuum blocks; and with a straight threaded plug and O-ring in the EH fluid block. These plugs are permanent and should not be removed at any time. In order to replace any component on the block other thana pressure gauge, it will be necessary to first close the isolation valve and then bleed the medium from the block by opening the manual test valves. During replacement ensure that the appropriate cleaning, flushing fluid care and handing procedures, etc. are followed. The pressure switches and pressure gauges can be isolated from the system by closing the appropriate shutoff valves. These valves should not be closed until after the medium in the block has been relieved. Ensure that all shutoff valves are reopened prior to latching the auto stop.If the medium (pressure or vacuum) reaches a trip level, then the pressure switches would function and cause the auto-stop emergency trip header to trip. When testing, the medium is reduced to the trip level in that channel either locally through the hand test valves or remotely from the trip test panel via the test solenoid valves.4.THRUST BEARING TRIP DEVICEPosition pickups, which are part of the turbine supervisory instrument package, monitor movement of a disc mounted on the rotor near the thrust-bearing collar. Any axial movement of this collar will also be reflected in movement of the disc. Excessive movement of the disc is an indication of thrust bearing wear. Should excessive movement occur, relay contacts from the supervisory instrument modules close to effect a turbine trip.The pickups of another of TSI package, for example vibration bearing, differential expansion, etc., are similar with THRUST BEARING TRIP DEVICE. Their working principle is similar with it, too.5.ELECTRICAL OVERSPEED TRIP DEVICEThe electrical over-speed trip utilizes two out of three voting concept. It consists of three magnetic pickups mounted at the turning gear and three speedrelays mounted in the trip system cabinet. The output frequency of the pickup is proportional to the shaft speed. If the shaft speed exceeds the trip set point (110% speed), these contacts OST1, OST2, OS3 are closed. Contacts from this relay cause both auto stop channels to trip.6.PRINCIPLE OF CONTROL LOGIC6.1 Trip LogicReferring to Figure 5 and Emergency Trip System Schematic, solenoid valves 20-1/AST and 20-3/AST (channel 1) are kept energized by normally open contacts from trip relays 1A and 1B. Likewise 20-2/AST and 20-4/AST are kept energized by contacts from trip relays 2A and 2B (channel 2). The trip relays are energized as long as all of the contacts from the trip control relays (LP1, LBO1, LV1 etc.) are closed. There is one trip control relay contact for each trip function in each trip channel. If any turbine trip function reaches a trip level, the appropriate trip control relay contact(s) will drop out causing the trip relays to drop out de-energizing the 20/AST solenoid valves, thereby decaying the auto stop trip header pressure. When the trip condition clears, depressing the RESET TEST TRIPS push button on the emergency trip test panel can only energize the trip relays.6.2 Trip Control Logic6.2.1 Low Bearing Oil, Low Vacuum and Low EH Fluid PressureFigure 4 shows a simplified schematic diagram of the low bearing oil trip control relay logic. The contacts of pressure switches 63-1/LBO and 63-3/LBO (associated with channel 1) are closed during normal operation of turbine generator. Therefore, interposing relays 1X/LBO and 3X/LBO are normally energized. Relay contacts 1X/LBO and 3X/LBO in series with trip control relay LBO-1, are closed during normal operation, thereby energizing relay LBO-1,Channel 2 has identical components. LBO-2 is the trip control relay for channel 2.One side of the coils of relays LBO-1 and LBO-2 are interconnected through contacts of selector switches LBO1T and LBO2T. Contacts LBO1T and LBO2T are closed during normal operation. Therefore, the coils of relays LBO-1 and LBO-2 are in parallel. Relays LBO-1 and LBO-2 will be de-energized (causing a trip of auto stop channels 1 and 2) if at least one pressure switch contact in each channel opens, signifying low bearing oil pressure.Selector switch contact LBO1T is open only when the channel 1 low bearing oil pressure function is being tested. Opening contact LBO1T allows relay LBO-1 to be de-energized during test without de-energizing relay LBO-2.Similarly, selector switch contact LBO2T is open when the channel 2 low bearing oil pressure function is being tested.In the event that an actual low bearing oil pressure condition occurs, it will be sensed by all four pressure switches and both trip control relays LBO-1 and LBO-2 will be de-energized even though a test of one channel may be in progress.The trip control relay logic for low vacuum and low EH fluid pressure is identical to that for low bearing oil pressure.6.2.2 TRIPS FROM TSIThe function of contact from the TSI close upon excessive thrust bearing wears. This short out causes the AST solenoid valves to trip.6.2.3 PURCHASER‟S REMOTE TURBING TRIPThe function of contacts from the purchaser‟s remote turbine trip, such as the tripping signal of the generator fault, the stopping signal from MFT. Theseshort circuits cause the AST solenoid valves to trip.7. INTRODUCE OF ETS CABINET AND PANEL7.1 POWER SUPPLYTwo 220V AC power supplies come from the external, combined to from a signal 220V AC bus which supplies power to the RESET valve, the SV(R, L) and TV(R, L) TEST of DEH.One 220VdC power supplies come from the external, supplies power to the OPC solenoid valves (110VDC) , the electrical circuit include resistance to participate the voltage 110VDC.The 110V AC#1 power supply is changed separately through the transformer 220V AC#1 power supply, supply power of the first channel‟s valves, for example 20-1/AST and 20-3/AST; The 110V AC#2 power supply is similar, which is changed separately through the transformer 220V AC#2 power supply, supply power of the second channel‟s valves, such as 20-2/AST and 20-4/AST. Two 220V AC power supplies change a serial of 24 VDC bus through the blocks of switch-power, offer the power supply 24VDC of the PLC‟ s CPU, I/O modules and the speed box.7.2 PLC USING ANNOTATEThe whole control logic is in the PLC‟ s CPU, it is important to observe the PLC …s indicating states. When the hot standby PLC (M0, B0) are work on, the “RUN” lamp on the front panels of the PLC …s CPU are on, it is yellow.When the PLC (M0) is communication with the operator panel, the “MODBUS” and “MODBUS+” lamps on the front panels of the PLC (M0)…s CPU are on, they are flash.When the PLC (M0) is main state, the state lamp on the front panels of the module CHS of PLC (M0) is indicate “Primary”, the state lamp on the frontpanels of the module CHS of PLC (B0) is indicate “Standby”; Otherwise, the PLC (B0) is “Primary”, the PLC (M0) is “standby”.When the HOT STANDBY PLC backup batteries‟electromotive force is low, the “BAT LOW” light is on (red); the backup batteries need to be changed out. Don‟t close the switch which PLC responded power supply 220V AC When the condition is meet.Backup battery Type: 990XCP98000Used life: 10 years (account the period from the first used time)Used life: 450 days (progression out of power supply)Advice the user to pay attention to the indicating condition of “BAT LOW”lights, and used life of the backup battery, change out the old battery in time. Refer to MODICAN Quantum Hot Standby 840 USE 106 007.3 OPERATOR PANELThe operation of ETS‟ tripping functions and the condition of its components can be rapidly and systematically tested and verified from the operator panel. Short circuit or cut the contacts in the terminals U1 and U3 view the condition about the correspondence indicating lamps on the panel.7.3.1 POWER SUPPLYFirst of all, join two sources of power supply (220V AC, 8A) to the terminal U0 of the casket inside the ETS cabinet1)Close switch K1, join the first source of power supply (220V AC#1,8A),Quantum Hot Standby PLC‟s CPU (M0) is working; Close switch KF1, mearsure the voltage of power supply 110V AC between U7-2 and U7-3;otherwise, measure the voltage of power supply 0V AC between U7-2 and U7-3.2)Close switch K3, join the second source of power supply (220V AC#2,8A),Quantum Hot Standby PLC‟s CPU (B0) is working; Close switch KF1,mearsure the voltage of power supply 110V AC between U7-5 and U7-6;otherwise, measure the voltage of power supply 0V AC between U7-5and U7-6.3)Close switch KFN, start the fan; otherwise, stop the fan.4)Close switch K2, join the voltage of power supply 220V AC#1 to PS1 andPS3; Otherwise, PS1 and PS3 lose the power supply.5)Close switch K4, join the voltage of power supply 220V AC#2 to PS2 andPS4; Otherwise, PS2 and PS4 lose the power supply.6)Close switch K2 (or K4) and KF2, join the voltage of power supply24VDC to I/O POWER (Input signals). Otherwise, I/O POWER loses the power supply.7)Close switch K2 (or K4) and KF4, join the voltage of power supply 24VDCto BACK. Otherwise, BACK lose the power supply.8)Close switch K2 (or K4) and KF6, join the voltage of power supply 24VDCto operator panel. Otherwise, the panel loses the power supply.9)Close switch K2 (or K4) and KF8, join the voltage of power supply 24VDCto speed box. Otherwise, the speed box loses the power supply.7.3.2 MONITER FUNCTIONS1) LP (Low EH Fluid Pressure)Each of the 4 (1,2,3,4) monitor lamps is associated with a pressure switch where each number corresponds to the suffix number of the pressure switch designation (63-1/LP-lamp #1 etc.). When a lamp illuminates, it indicates that an associated switch is sensing at a pressure below the trip set point. This will occur during a trip, a test or upon failure of the switch.2) LBO (Low Bearing Oil Pressure)These monitor lamps function the same as the LP lamp except for the medium being monitored.3) LV (Low Condenser Vacuum)These monitor lamps function the same as the LP lamp except for the medium being monitored.4) Test and 63/ASP INDICATECH.1 TRIP and CH.2 TRIP lamps illuminate whenever Auto Stop Pilot Header pressure (63/ASP) is out of normal rang. When they are testing, the lamps illuminate the associated channel is in the test mode. They are controlled by contacts from pressure switches (63-1, 2/ASP). These lamps condition are as follows:TEST CH.1 TEST CH.2 CH.1TRIP CH.2 TRIP NORMAL OFF OFF OFF OFF TEST OF CHANNEL 1 ON OFF OFF OFF TEST TRIP OF CHANNEL 1 ON OFF TEST OF CHANNEL 2 OFF ON OFF OFF TEST TRIP OF CHANNEL 2 OFF ONTRIP OF BOTH CHANNELS OFF ON5) FIRST TRIP MEMORYWhen the system is latch through press a time the button “LATCH” on the desk or the buttons “TEST” + “TEST RESET” on the operator panel, “FIRST TRIP MEMERY” indicating of the cause about previous unit tripped erase. “MEM ALM” lamp is the indicating of the first trip memory.8. TESTING FUNCTIONSAll trip functions (LBO, LV, LP, OS, etc.) should be tested monthly and prior to each startup. Testing can be accomplished when on line. First channel 1 trip functions should be tested in sequence. Following which, Channel 2 trip functions should be tested. The testing sequence is as follows:At first, the situation of the emergency trip system is normal. The whole oil system is latch.8.1 LOW BEARING OIL TEST1) Press a time the buttons ”TEST”, ”CH. 1”and”LBO”, observe the lamps are on.2) Press a time the buttons ”ACTIVE”, observe the lamps is on, confirm the voltage is 220V AC between U2-36 and U2-31.The solenoid of Low bearing Oil Test (20-1/LBOT) is magnetized.3) The relative lamps are on when two bearing Oil pressure switches (63-1/LBO, 63-3/LBO) are off. The bearing Oil pressure in the first channel is vanished, The Low Trip solenoids (20-1/AST, 20-3/AST) are not magnetized, and the lamp “CH.1 TRIP” is on. After a few seconds, the voltage is vanished between U2-36 and U2-31. The solenoid of Low Bearing Oil Test (20-1/LBOT) isn‟t magnetized.4) Then the LBO pressure contacts are turn on. The relative lamps are off. Press a time the button “TEST ESC”, then press a time the button “TEST RESET”, and observe the indicating of the lamp “CH.1 TRIP”.When the lamp is off, measure the voltage 220V AC between U2-36and U2-34 (U2-35). The trip solenoids (20-1/AST, 20-3/AST) are magnetized, the test of CH.1 of LBO is finished.The test of CH.2 of LBO is similar with above sequence.Test of low EH oil pressure and low vacuum is similar with the test of low bearing oil pressure.8.2 ELECTRICAL OVER-SPEED TESTFirst, the system is reset. Speed –testing value is set above 3300RPM.1)Press a time the button “TEST” AND “SPEED 1”;2)Press a time the button “ACTIVE”, observe the lamp “OVER-SPEED 1”.3)The lamps “OVER-SPEED1” and “CH.1 TRIP” are on. The trip solenoids (20-1/AST, 20-3/AST) are not magnetized.4)After a few seconds, the lamp “OVER-SPEED 1” is off. Press a time the button “TEST ESC”, then press a time the button “TEST RESET”, and observe the indicating of the lamp “CH.1 TRIP”. Measure the voltage 220V AC between U2-36and U2-34 (U2-35). The trip solenoids (20-1/AST, 20-3/AST) are magnetized; the over-speed 1 test is finished.Over-speed 2 and over-speed 3 test: They test channel #2 trip (CH.2 TRIP) separately. The test steps are similar to the produce of SPEED #1 TEST.8.3 MECHANICAL OVER-SPEED TESTWhen the Over-speed Trip key-switch (or “Mechanical Test Switch”) is turned to the MECHANICAL OVER-SPEED position, the electrical over-speed channel is biased to a higher trip set point (112% SPEED). It should be left in the NORNAL position with the key removed and stored in a safe place. It should only be turned to the MECHANICAL OVER-SPEED position when the turbine is actually over-speeded to verify the operation of the mechanical over-speed trip channel.9. NOTE1)The button “test” is bit invert. Press a time, the lamp is on, press the othertime, the lamp is off, and the rest may be deduced by analogy.2)If there is some fault about DC POWER OR (AND) AC POWER of ETScabinet, the terminals U4-9 and U4-10 will be closed; Otherwise, it will be turn off.3)If there is some fault about pressure (LBO, LV, LP) of ETS, the terminalsU4-7 and U4-8 will be closed; Otherwise, it will be turn off.4)If there is some tripping signal of ETS, the terminals U4-1 and U4-2 (U4-3and U4-4, U4-5 and U4-6) will be closed; Otherwise, it will be turn off.5)If the unit is stop (the trip solenoids are de-energized), the terminals U4-11and U4-12 will be closed; Otherwise, it will be turn off.。
