Dynamic Performance of Spring-Loaded Pressure Relief Valve for High Temperature and High Pressure Steam

In this study, the complete dynamic performance of the high temperature and high pressure steam pressure relief valve (HTHP PRV) from pop up to reseating was simulated by CFD software which combined with moving mesh capabilities and multiple domains. An experimental setup was established for the testing of HTHP PRV in accordance with the standard of ASME PTC 25. The dynamic performance of HTHP PRV was recorded accurately. For the transient simulation of HTHP PRV, a domain with opening boundaries connected to the outlet of PRV was proposed to avoid the direct definition of the pressure at the PRV outlet and handle the critical flow. It also can describe the surrounding flow field and help us to understand the influence of the PRV discharge on the environment better. The simulation results were verified by experimental ones. The resultant force on the disk and the lift were monitored and analyzed. A detailed contour of the compressible steam flowing through the HTHP PRV was obtained, including small scale flow features in the back pressure chamber. The effect of the adjusting sleeve on the dynamic performance of HTHP PRV was also investigated in details. The blowdown increases linearly by 0.163% with the adjusting sleeve moves by each millimeter in the direction of departing from the disk. This study sheds a light of understanding of the dynamic characteristics of HTHP PRV.