Design And Characteristic Research Of Sliding Valve Type Gas Differential Pressure Compensator

Gas proportional flow control technology has been widely used in high-precision machinery in recent years.The proportional flow valve is the main component that realizes the stable adjustment of gas flow.Its output flow during operation will not only change with the size of the valve port,but also Follow the continuous change of the import and export pressure difference.In order to ensure that the proportional flow valve can accurately regulate its output flow by adjusting the opening of the valve port,it is necessary to ensure a constant pressure difference between the inlet and outlet of the throttle valve.This is also a problem that needs to be considered when designing a specific flow control system.The function of the differential pressure compensator is to maintain a constant differential pressure by adjusting the inlet or outlet pressure of the throttle valve.In the traditional sense,the pressure difference compensator of purely mechanical structure relies on springs for dynamic adjustment,and it extremely depends on the spring stiffness during adjustment.In view of the above situation,this paper designs a sliding valve type gas pressure difference compensator driven by a proportional electromagnet,which realizes the control of gas pressure through the electro-mechanical conversion of the proportional electromagnet.In order to study the relevant characteristics of the differential pressure compensator,the thesis uses a combination of theoretical analysis and the simulation of the flow field in the valve to study the characteristics of the valve port of the differential pressure compensator and the reasons and effects of the steady-state aerodynamic force,and then the differential pressure compensation The dynamic response characteristics of the device are simulated,and finally the differential pressure compensator is experimentally researched.The main research contents are summarized as follows:(1)Design the structure of the differential pressure compensator and analyze its working principle,study its valve port structure and analyze the change of the valve port flow area with the valve port opening with the help of Matlab,and then theoretically derive the spool subjected to Steady-state aerodynamic force,and finally established the dynamic response mathematical model of the differential pressure compensator based on certain assumptions.(2)Taking the U-shaped and K-shaped valve ports of the spool valve type differential pressure compensator as the research object,the flow field in the valve of the differential pressure compensator is numerically solved.Analyze the influence of different valve port opening degrees on the pressure,flow rate and mass flow of the two valve ports,and the change of steady-state aerodynamic force on the valve core.The results show that: the two valve ports can reflect the secondary pressure reduction characteristics during the adjustment process,and the pressure growth rate of the valve port outlet is gradually slowing down;the jet angle of the U-shaped valve port is getting smaller and smaller,and the jet of the K-shaped valve port is getting smaller and smaller.The angle change is small,and the jet effect is more obvious than that of the U-shaped valve port;the steady aerodynamic force of the slide valve spool where the two valve ports are located will hinder the opening of the valve port,and the steady-state aerodynamic force will increase during the opening process of the valve port.But the growth rate is gradually decreasing.(3)Designed the control scheme of the differential pressure compensator,studied its control method,established Simulink simulation model with the aid of the dynamic response mathematical model of the differential pressure compensator,analyzed the control characteristics of the differential pressure compensator under different input and output pressures,and studied the compensation of the structural parameters for the differential pressure The influence of the dynamic response characteristics of the compressor provides a theoretical basis for further optimizing the structure of the differential pressure compensator.Finally,build an experimental platform and test the prototype to verify the feasibility of the differential pressure compensator to compensate the pressure and maintain a constant differential pressure.