(1) Unit operation mode:
Unit operation, the load of the unit is 300-600MW, the unit is coordinated input, the load control mode is AGC input, the circulating water pump 1A and 1B are running, and the circulating water contact door is closed.
2.Unit 1 is in operation, the load of the unit is 300-600MW, the unit is coordinated input, the load control mode is AGC input, the circulating water pump is running 1A, 1B is standby, and the 2nd circulating water contact door is closed.
2) Accident phenomenon:
1.Send 6kv auxiliary circulating water pump trip alarm;
2.The vacuum of the unit drops rapidly;
3.The temperature of the exhaust cylinder rises sharply;
3) Cause of the accident:
1.1A and 1B circulating water pumps were tripped;
2.The power supply of the plant was interrupted, and two circulating water pumps tripped;
3.The running cycle pump tripped, and the standby cycle pump did not start together;
4.Other reasons cause the circulating water pump to trip.
4) Accident handling
1.If the unit is running in mode 1, run 1a to handle the pump tripping:
a. Immediately check whether the 1C cycle pump is connected, if the outlet butterfly valve is automatically opened, the outlet pressure is normal, the motor coil temperature and bearing temperature are normal, and the load operation of the unit is maintained
b. If the standby pump is not connected, immediately start the 1C pump operation manually
c. Check that the butterfly valve at the outlet of the pump is closed in 1a, otherwise it is closed manually, and the pump in 1a is not reversedQuickly find and eliminate the cause of the tripping of the 1A circulating pump, and restore the backup of the 1A circulating pump
D. If the manual start of the 1C cycle pump is not successful, confirm that the 1A cycle pump has no electrical fault, and can grab a 1A cycle pump, if the rush is successful, maintain the load operation of the unit, quickly find and eliminate the reason why the 1C cycle pump cannot start, make it in a good standby state, and find the reason why the 1A cycle pump trips
e. If the 1A pump trips due to the loss of power in the 1A and 1b sections of the factory, and the No. 2 unit has the following pump, the butterfly valve at the outlet of the 1A pump should be checked and closed immediately, and the outlet pipeline of the 1A and 2B pumps should be opened to ensure that the water supply of the condenser of the No. 1 machine is normal, and the unit will be treated as an emergency shutdown
f. If the condenser of the unit has water cooling (contact opening), the high and low sides can be turned on during the shutdown process, and if the condenser has no circulating water, it is forbidden to open the high and low sides. It is forbidden to open the main machine and the small machine to drain the water.
2.The unit is operated in the case of mode 2: (expand the unit system, 1 and 2 circulating jellyfish pipe contact doors to maintain a certain opening).
a. The circulating water system is operated in the mode of "expanding the unit system", if a pump trips during operation, check whether the outlet butterfly valve of the tripping pump is closed, otherwise it is manually closedCheck whether the standby pump is connected to normal, if not, manually start the standby pump operation;Check the vacuum change of the adjacent unit, and adjust the opening of the outlet contact door of the pump according to the load carried by the unitFind out and eliminate the cause of the tripping of the circulating pump, and restore the tripped circulating pump as soon as possible.
b. If the circulating water system is operated in the mode of "expanding the unit system", if the 1A and 1B pumps are tripped, immediately check and close the butterfly valve of the pump outlet, open the outlet contact door of the pump, and the unit will be treated as an emergency shutdownThe other unit can appropriately reduce the load according to the vacuum situation, and at the same time, it should be checked that the standby pumps such as 2a and 2b should be connected, and pay attention to adjusting the opening of the contact door of the circulating jellyfish pipe of the 1 and 2 machines to prevent the water tower from being full of water and the water level deviation is too large.
c. If it is caused by the loss of power of the No. 1 unit plant, it will be treated as an emergency shutdown, and it is forbidden to open the high and low voltage bypass during the shutdown process, and close all the drains opened by the steam turbine interlock.
d. After the circulating water is interrupted, the circulating water is passed to the condenser again, and the condenser temperature must be reduced to below 50 before the condenser can be passed to the condenser again.
3.Report to the leaders of the department, the company's vice president of production, chief engineer, and the central duty officer, and notify the relevant maintenance personnel.
5) Measures to prevent the interruption of circulating water:
1.Before the circulating water pump is started, the static interlock protection test of the circulating water pump must be qualified.
2.Strengthen the maintenance of the circulating water system.
a. The cooling water of the circulating water pump is put into normal to ensure the pressure and flow
b. The lubricating oil quality of the motor bearing of the circulating water pump is qualified and the oil level is normal
c. The temperature measurement point of the motor winding is normal, and the temperature is within the specified range
d. The opening of the butterfly valve at the outlet of the circulating water pump is normal, and the limit indication is correct
e. The oil level of the butterfly valve oil tank at the outlet of the circulating water pump is normal, the oil quality is qualified, the oil pressure is normal, and the oil pump is standby
f. The water level of the pool in front of the circulating water pump is normal, there is no obvious drop before and after the filter screen, and the cleaning machine runs regularly
g. Strengthen monitoring on the operator's plate, circulating pump current, flow, motor winding temperature, bearing temperature;
h. Notify and contact the defect in time when defects are found.
3.When the single machine and single circulating water pump are running, the 1 and 2 circulating jellyfish pipes are connected to the electric door to keep all closed and the power is off, and the operation mode of the circulating water system should be selected in the "unit system" mode, so as to maintain the normal hot standby of another circulating pump, and do a good job of regular measurement insulation and switching.
4.If the adjacent units are in operation and are "two machines and three pumps", the operation mode of the circulating water system should be selected as "expanded unit system", and the standby circulating pump is in a good hot standby state.
5.The adjacent units are all in operation and are operated by "two machines and four pumps", and the operation of the fully open circulating water contact door can improve the operation flexibility and safety of the unit.
6.After the electric doors of the condenser circulating water inlet and outlet are fully opened, a "forbidden operation" is set to prevent misoperation and misclosing.
7.Strengthen the management of the circulating water pump room, pay attention to locking the door after the inspection, and prevent idle personnel from entering the circulating water pump room.