Study On The Pressure Stability Characteristics And High Precision Test System Development Of High/Micro-Flow Pressure Reducing Valve

Pneumatic pressure reducing valve is the most commonly used decompression and voltage stabilizer,and widely used in various occasions.The micro-flow pressure reducing valve is characterized by high precision of pressure and flow control and is the key component of the micro-satellite execution system.It can provide micro-flow(0～100 mg/s)and stable pressure for the execution system.Therefore,the work reliability of the micro-satellite can be directly affected by the performance of micro-flow pressure reducing valve.At present,the ability to accurately test the performance of micro-flow pressure reducing valve is lack in our country.The high-flow pressure reducing valve has been widely used in machining pneumatic control system due to its high-flow output characteristics.In this paper,to realize the precise test of the performance of high/micro-flow diaphragm pressure reducing valve,the corresponding test equipment and scheme were developed based on the micro-flow pressure reducing valve in a company and KHF high-flow pressure reducing valve in the self-development blasting equipment.The test method for the performance of the pressure reducing valve was summarized,and the existing problems of the test equipment were revealed.The basic structure and pressure reducing principle of KPR and KHF diaphragm pressure reducing valve were introduced.The first order differential equation of each chamber,the force balance equation of the valve core and the mathematical model of flow equation of the diaphragm pressure reducing valve were established,and the characteristic parameters of pneumatic pressure reducing valve were described.The flow and pressure and other characteristics of high/micro-flow pressure reducing valve were researched using AMESim software,and research showed that the pressure and flow characteristics of the high/micro-flow pressure reducing valve were relatively stable under the ideal condition,which provides theoretical basis for testing target of the test system.The flow change mechanism of the high/micro-flow pressure reducing valve was studied using Fluent software,it is found that with increasing of the opening of the valve port,the pressure distribution was increased gradually after the gas flows through the valve port,and the velocity distribution was more uniform,but the decompression capacity was decreased.In addition,the pressure was gradually increasing from the outer edge of the fluid along the valve core,while the velocity showed the trend of decreasing first and then decreasing.The design principles of the test system were formulated,and the composition and function of the test system were analyzed according to the test requirements of high precision and portable test.The gas path connection scheme of the test system was designed,and the overall structural design of the test equipment was completed.The 3D model design of the hardware of test system was completed using SolidWorks,and the key components of the system were selected reasonably.The man-machine interface design of the test system was completed using LabVIEW software,and the dynamic test,data acquisition,data storage,precision control and other important modules of the system software were developed.The reliability of the test system was verified by theoretical calculation.Finally,the performance testing of high/micro-flow pressure reducing valve were finished using test system.Experimental results showed that the pressure fluctuation of the micro-flow pressure reducing valve was within 0.8%,which indicated that it had higher pressure and flow characteristics.The pressure fluctuation of the high-flow pressure reducing valve was within 3.0%,which fully met the requirements of the tool blasting passivation.The experimental results also showed that the accuracy of the developed test system was within 0.5%,which verified the high precision and applicability of the test system.