Research on Primary Vacuum System Based on Ejector

In order to solve the problem that when the reactor coolant pump of the reactor coolant system discharges dynamically or jointly, the auxiliary thrust bearing of the reactor coolant pump burns out due to the rapid pressure drop of the main system and the instantaneous sharp increase of the auxiliary thrust bearing load of the reactor coolant pump, according to the operation process of water filling and discharge of the main system of the unit, an additional vacuum system is proposed to meet the low water filling and discharge requirements of the main system after overhaul. The simulation results show that the primary circuit pressure can be pumped to 0.015 MPa(a) within 70 minutes and 0.01 MPa(a) within 90 minutes after the vacuum system is put into operation. A nuclear power plant carried out the promotion and trial of the vacuum pumping system in the subsequent overhaul. The results showed that the gas content of the primary loop of the nuclear plant was qualified at one time, and the major hidden danger of burning the auxiliary thrust bearing of the reactor coolant pump after start-up was successfully avoided. The reliability of the reactor coolant pump was significantly improved, and at the same time, the critical path of overhaul was saved for more than 10 h.