Numerical simulation of water hammer characteristics in the closing process of electric globe valve based on CFD

The electric globe valve is an important control element in the automatic water injection drainage system. The system requires the closing time of the electric globe valve to be less than 1s. However, the rapid closing of the globe valve may cause the water hammer phenomenon in the pipeline, which will lead to large mechanical vibration noise in the pipeline. Most of the traditional research only focuses on pipeline systems and carry out one-dimensional calculation based on the method of characteristic, while ignoring the influence of the two-dimensional characteristic of fluid flow and the internal flow structure of the valve on the water hammer phenomenon. In this paper, CFD technology and Fluent software are used to build the flow field simulation model of the electric globe valve, and the dynamic flow field simulation of the closing process of the electric globe valve is completed. The influence of inlet pressure, valve closing velocity, and valve closing motion law on the water hammer effect is obtained. The results show that the pressure pulsation amplitude caused by rapid valve closing can be effectively reduced by reducing the inlet pressure when the valve closing velocity is constant. When the inlet pressure and the valve closing velocity are constant, the maximum water hammer pressure can be effectively reduced by reducing the valve closing velocity. When the valve is closed for a certain time, the fast at first and then slow closing motion law can effectively reduce the maximum water hammer pressure. The research results can provide a reference for the design of the control law of the valve closing process in automatic injection drainage systems.