Numerical Simulation of Pump-Stopping Water Hammer in Tertiary Circulating Water System of PWR Nuclear Power Plant

Based on the basic theory of water hammer,the mathematical models of boundary condition of each component of tertiary circulating water system of PWR nuclear power plant,including pump unit,pump discharge valve,condenser and siphon outlet sump,were developed in this paper.Also,the solving method for the functions,namely characteristic-line method,was introduced.Combining with the calculation example,the author pointed out that the close schedule of pump discharge valve had notable influence on the water hammer pressure,while the butterfly valve closed in two stages could reduce the water hammer pressure effectively,but its optimized closing schedule should be determined based on the numerical simulation of fluid transient.