Effect of Pilot Solenoid Valve Throat Diameter on Dynamic Response Time in Main Steam Valve Set

Abstract

The Main Steam Valve Set (MSVS) is set at the outlet of the steam generator in the secondary circuit of the Nuclear Power Plant, which plays a key role in overpressure protection of the steam generator. In actual working conditions, the response time of the MSVS is generally longer than the specified time due to the substandard flow coefficient of the pilot valve, which is directly connected to the upper chamber of main valve. In this paper, the flow characteristics of solenoid valve under different throat diameters and opening degrees is analyzed by. The result shows that the velocity and pressure of the flow field in the solenoid valve have an obvious change when the opening degree change from 25% to 50%. But after that, they stay unchanged approximately as the opening degree increases. Also, the outlet mass flow increases fast during the first 50% opening degree. The outlet mass flow when ds is 32 mm is higher than that when ds is 28mm. But when ds is 36 mm, the mass flow has no obvious change. Because the mass flow has a direct effect on response time, the research has a reference for the structural design of the solenoid valve in the MSVS, and ensure the safety of Nuclear Power Plants.