Transient And Optimization Analysis On Opening Characteristic Of Butterfly Check Valve

Due to its simple structure,small size and easy installation,the disc check valve has been widely used in agriculture,nuclear energy,metallurgy,petrochemical and other fields.Especially in the nuclear power plant system,not only does the check valve require high performance and is not easily damaged,it also needs to operate smoothly under very small flow rates.Therefore,in-depth study of the operation status of the check valve has certain academic significance and application value.Firstly,according to the definition of the standard size flow rate,through comparison of the flow coefficient and the typical butterfly valve opening diagram given in the practical valve design manual with the simulation data,a set of simulation models suitable for the butterfly check valve is determined.Secondly,using steady-state numerical simulation method,the simulation calculation and visualization of the internal flow field of the check valve at fixed opening of 10°,45°,and 90° were studied.The velocity field,pressure field and turbulent kinetic energy distribution diagram in the check valve flow passage are given.Analysis shows that the medium easily passes through the valve when the flow separation area,so that the effective flow area is reduced,the flow rate increases,and the vortex area,resulting in energy dissipation and other issues.Thirdly,using the dynamic technology and user defined function of FLUENT,the CFD simulation of the valve opening process was performed under the boundary conditions of different inlet flow rates,and the opening characteristics of the check valve flap were studied.The internal flow field at the time of valve opening of 10°,45°,and 90° was also selected for analysis.The results showed that the valve flaps were oscillating during different operating conditions and were difficult to maintain in the fully open state.The vortex structure at the lower end of the valve flap is the main reason for the energy consumption of the check valve and the noise.Finally,according to the problems reflected by the above numerical simulation results of the check valve,the structure of the check valve is optimized.The results show that: When the medium passes through the optimized check valve,the flow stability is improved,the vortex area is reduced,the noise is reduced,the valve flap does not have oscillation,etc.and the valve effect in checking back flows is also improved when the media is reverse.