Research on the Operation and Maintenance Optimization of Packing for Important Service Water Pumps in Nuclear Power Plants Based on Finite-Element Analysis

In order to solve the problems of high pressure in the shaft-seal water pipeline of the important service water system (SEC) pump and the packing structure design that does not meet the requirements of high-pressure shaft-seal water in a nuclear power plant, a finite-element simulation analysis method is used to conduct a systematic analysis from two aspects: the inlet pressure of the shaft-seal water and the packing structure design. A scheme is proposed to increase a customized pressure-reducing valve and a flowmeter in the shaft-seal water pipeline and modify the pump packing structure to improve the service life of the packing and reduce the consumption of shaft-seal water, thereby avoiding the generation of an unplanned shutdown maintenance window. This scheme has been proven to be practical through partial on-site practice, improving the safe and stable operation of the SEC, and can provide a general solution idea and solution for nuclear power plants with common problems.