Research On Dynamic Characteristics Of Nuclear Safety Valve Based On Fluid-Solid Polymerization

As a clean and safe new energy source,nuclear power is currently the most likely energy source to replace fossil fuels.Nuclear valve leakage caused serious accidents,which seriously endangered human life and health and brought huge disaster to the earth.For nuclear-grade valves,it is difficult to experimentally measure the numerical distribution of the pressure field,velocity field,and temperature field inside the valve body.Analyzing the dynamic characteristics of the safety valve is of great significance for the long-term stable and effective operation of the valve.Aiming at the above problems and current situation,this paper takes nuclear safety valve as the research object,and adopts a combination of theoretical analysis,numerical simulation and experimental verification to systematically analyze the dynamic characteristics of safety valve opening and closing,including the research of fluid-solid coupling of safety valve,safety Research on valve opening and closing sealing characteristics,analysis and test verification of seismic characteristics of safety valves.Firstly,the dynamic characteristics of opening and closing of the safety valve under fluid-solid coupling are studied.Explore the effect of the safety valve fluid on the solids,establish a fluid-solid coupling model and a valve fluid-solid coupling control equation,and simulate the fluid in the valve body to obtain the temperature,velocity,and pressure clouds at different openings of the fluid.The finite element analysis coupling module obtains the deformation cloud diagram and strain cloud diagram of the valve body at different opening degrees,which provides a theoretical basis for studying the dynamic characteristics of the safety valve under the fluid-solid coupling effect.Secondly,the sealing characteristics of the safety valve during opening and closing are analyzed.First,perform theoretical analysis on the sealing characteristics of the safety valve under operating conditions,then research and experimentally verify whether the lateral offset force caused by the preload force of the three models affects the sealing characteristics of the safety valve.Finally,the valve disc,valve seat,and valve are established.The rod model was analyzed by contact deformation,and the deformation and strain clouds under different pressures were obtained.The contact surface deformation law was obtained,which provided a theoretical basis for the analysis of the preload force of the safety valve spring.Finally,based on the above analysis and research,a safety valve seismic test bench based on modal theory was built.To verify whether the safety valve meets the requirements of anti-vibration,use a simplified method to build a model of the safety valve,add the mass of the spring,the upper spring seat and the lower spring seat to the adjusting screw,perform a simulation analysis on the safety valve,and then combine the test to verify the simulation analysis.The theoretical calculation of the natural frequencies of the spring,the upper spring seat,and the lower spring seat,and the simulation analysis to verify the correctness of the theoretical calculation.