Steam Hammer Calculation and Study of Nuclear Island Main Steam Pipe Network

Abstract

The aim of this study was to study the steam hammer by fast closing of the main steam isolation valve of the nuclear island main steam pipe network in some nuclear power plant, establish the model using “PIPENET” software and calculate the most steam hammer load and the occurrence time in different pipes. The results show that the most steam hammer loads appear when closing the valve and the steam hammer load after the main steam isolation valve is larger than the one before the valve, because of the relief device set before the valve. Meanwhile, the flowrate of the relief device that has lower opening set point and nearer the main steam isolation valve is bigger. Further, only setting one train steam dump piping and only reducing the capacity of steam dump valves have complex steam hammer influence, and the steam hammer influence of the former is about ten times of the latter. All above can be used for system piping design, stress calculation of pipe, and optimizing piping layout, which has great significance for improving the safety of main steam system and nuclear power plants.