CPR1000机组真空泵振动超标原因分析与处理

Cause Analysis and Treatment of the Vacuum Pumps’Over-vibration of CPR1000 Nuclear Power Plant

国内某核电厂1~4号机抽真空初期均存在真空泵振动超标现象,振动一度达到10 mm/s以上,严重影响真空泵的正常运行。对比发现,凝汽器容量大、抽真空初期抽气量超标是导致真空泵振动大的主要原因。为解决振动超标问题,本研究采用流体力学方法,针对真空建立初始阶段的抽真空管路建立模型并进行分析计算,得到了真空泵最小抽气量对应抽气隔离阀的开度。现场通过调节抽气隔离阀开度,降低真空泵抽气量,保证了真空建立阶段真空泵组在正常情况下运行,从而保证了机组和设备安全。

The phenomenon of vacuum pumps’vibration beyond the standard limit took place in Unit 1 to 4 of a nuclear power plant.The vibration once exceeded 10 mm/s,which seriously affected the running of the vacuum pumps.By comparison,we can find the main reason that caused over-vibration is the larger capacity and the larger amount of exhaust.To solve this problem,the research focus on the initial phase of vacuum pumping,using fluid mechanics method to build model and calculate.The research got the extraction isolation valves’opening while the vacuum pump pumping capacity is smallest.The tester adjusted the opening of the isolation valve to lower vacuum pumps’suction,which ensured the normal operation of vacuum pumps and the safety of unit and equipment.