Analysis on closing characteristics of ultra-high pressure emergency relief valve in polyethylene plant

The emergency pressure relief valve is key equipment in the high-pressure polyethylene production unit LDPE/EVA, and its localization process faces major challenges. At present, the domestically developed pressure relief valves are mainly concentrated in the medium- and low-pressure fields, and the emergency pressure relief valves for ultra-high pressure conditions still rely on imported products. In order to achieve a breakthrough in the localization of this equipment, the key is to improve the stability of the flow field inside the valve, thereby ensuring the standardization of the opening and closing time and extending the service life of the components inside the valve. This paper adopts the method of numerical simulation by setting multiple sets of valve stem motion equations, and comparing and analyzing the static pressure changes before and after the valve, a systematic study is carried out on the internal flow field characteristics of the emergency pressure relief valve and the valve stem closing dynamics, and finally the optimal opening and closing speed optimization of the pressure relief valve is achieved.