Research On Dynamic Characteristics Of High Pressure And Large Flow Relief Valve

Pilot relief valve is a key control element in hydraulic system,which plays a role of pressure limiting protection in hydraulic system.Dynamic characteristic is an important performance index of relief valve.Studying its dynamic performance is helpful to optimize the structural parameters of valve,and it is of great significance to optimize the design of the same type relief valve and improve the reliability of hydraulic system.In this paper,a certain type of high pressure and large flow relief valve is taken as the research object,and through theoretical analysis,simulation and experimental research,the influence law of key structural parameters of the valve on dynamic characteristics is analyzed and optimized.The main research contents are as follows:Firstly,the theoretical analysis of the high pressure and large flow relief valve is carried out from the aspects of its function,working principle and structural characteristics,and the mathematical model of dynamic characteristics and AMESim simulation model are established,and the accuracy of the simulation model is verified.Secondly,the single factor dynamic characteristics simulation analysis is carried out by taking several key structural parameters such as orifice diameter,half angle of valve core cone and so on as dependent variables,and the variation law of the influence of each parameter on the dynamic characteristics of relief valve is obtained.The simulation results show that the orifice diameter of main valve core,half angle of main valve and pilot valve core cone have significant influence on the dynamic performance of high pressure and large flow relief valve.Multi-factor response surface analysis is carried out by using Design expert software,and the optimization scheme of dynamic characteristics is put forward.Then,the flow field of relief valve is simulated by Fluent fluid dynamics software.The simulation results show that the cone-shaped valve port of the main valve is prone to cavitation and cavitation.The effects of boundary conditions or structural parameters such as inlet and outlet pressure of relief valve,cone half angle of main valve core and transition fillet of valve core on valve cavitation and noise are analyzed in turn,and the performance of relief valve is optimized comprehensively.Finally,the dynamic characteristics of the original test prototype and the optimized test prototype of the high pressure and large flow relief valve are tested respectively,and the dynamic response curves of the two are compared.The test results show that the pressure overshoot rate of the optimized test prototype is effectively reduced by 16.55%compared with the original test prototype,thus verifying the feasibility and effectiveness of the optimized scheme.