Trip transient analysis on the main feedwater pump of HPR1000

In PWR, the main feedwater pump is one of the main equipment in the secondary side which has an important impact on the safe and stable operation of the entire power plant, and then directly affecting the output and availability of the unit. Based on the system manual and equipment data of a HPR1000 nuclear power unit, a mathematical model including the deaerator system and main feedwater pump system was established on the APROS platform. Through transient simulation and calculations of the main feedwater pump trip, it was shown that the load reduced to 50% FP quickly when backup pump for the tripping main feedwater pump did not start, and which can avoid reactor shutdown caused by low steam generator water level, whereas the three initial conditions of unit are 90% FP, 80% FP, and 70% FP. The comparison of debugging test data and the simulation data of a feedwater pump tripping under an initial load of 70% FP shows that the data is in good agreement, and the error between the experimental data and the simulation data for initial and final values of the deaerator pressure is within 1.5%. The flowrate error between the debugging test data and the simulation data of the tripping pump is about 8.1%, and the maximum flowrate error between the debugging test data and the simulation data for the normal operation pump overspeed operation is about 2‰, and the flowrate error between the debugging test data and the simulation data after stabilizing at 50% FP is about 10.1%. The mathematical model established in this paper can effectively predict the changes in deaerator pressure and liquid level, feedwater pump flowrate under transient conditions of a single feedwater pump failure and trips. The modeling method for the main feedwater pump, deaerator, and other systems and equipment used in this paper, as well as the boundary condition assumptions for calculating the operating conditions, can provide reference for the design of the subsequent HPR1000 nuclear power unit.