Flow Field Analysis And Structural Optimization Of Nuclear Power Check Valve

As one of the clean and efficient energy sources,nuclear energy can effectively alleviate the world’s energy shortage.As an important part of nuclear power system,nuclear power check valve is related to the safe operation of nuclear power system,so it is very important to the rationality and safety of nuclear power check valve structure design.Therefore,it is of great reference significance and application value to study the operation performance of nuclear power check valve.This paper takes the nuclear power check valve as the research object,and deeply analyzes its internal flow characteristics and structural characteristics.Firstly,the internal flow characteristics of the nuclear power check valve are numerically simulated,and the pressure distribution cloud diagram and velocity distribution cloud diagram of the flow field in the valve under diff erent openings are obtained.Secondly,the strain of the structure under different opening degrees is obtained by coupling with the finite element module.Finally,the structure is optimized and the optimization results are verified by numerical simulation.The specific research contents are as follows :(1)The application background of nuclear power check valve and the research status of check valve at home and abroad are reviewed.The three-dimensional model of nuclear power check valve is constructed,a nd the best scheme of a series of pre-processing of the model before numerical simulation is found and verified.(2)The internal flow of the check valve is numerically simulated by computational fluid dynamics software combined with dynamic mesh technolog y.The pressure distribution,velocity vector distribution and turbulent kinetic energy distribution of the flow field in the check valve are obtained under steady and dynamic conditions,respectively.The results show that with the increase of valve opening,the high-speed flow area and high-pressure area in the check valve are expanding,but the peak velocity and pressure peak are decreasing,and the flow gradually tends to be stable.(3)Through the finite element analysis software,the structural charac teristics of the key components in the check valve structure are analyzed,and the internal flow data of the check valve are loaded on the check valve structure.The mechanical behavior of the check valve components under different opening conditions is simulated,and the stress distribution and deformation of the key components of the check valve are analyzed.The results show that the stress distribution of the check valve structure is mainly concentrated in the rocker arm and the lower end of the valve disc,resulting in the bending deformation of the rocker arm in the direction of flow.(4)By analyzing the simulation results,the influence of the check valve structure on the flow performance of the valve is studied,and a scheme to improve the performance of the check valve is proposed.The structure of the nuclear power check valve is optimized and improved.The optimized check valve is reconstructed into a three-dimensional model,and the numerical calculation of the flow field distribution law and the finite element analysis of the structure are carried out again.The optimized simulation results are compared with those before optimization to achieve the purpose of improving the flow performance of the check valve.The results show that under the same conditions,the internal flow characteristics of the optimized check valve are improved compared with those before optimization.The flow resistance coefficient in the valve is reduced,and the peak velocity is reduced.The stress and strain of the disc and rocker arm structure are less than those before optimization.In general,the optimized check valve has better flow performance and safety performance.