Research Of Quick Switching 3-way Valve Of PVTt Gas Flow Standard Device

The pVTt gas flow standard device has applied extensivly in the gas flow field.Its prominent characteristics are simple structure and high precision.At first,the pVTt gas flow was without buffer container,but now it has.So the research on the performance of the swithching valve is imminent.The paper is a research on the quick swithching 3-way valve of the pVTt gas flow standard device.The main work is as follows:(1)Summarize the pVTt gas flow standard device,including the composition,the working principle and characteristics.Introduce the characteristics and the status of 3-way valve at home and abroad at the same time.Finally,discuss the important role of the 3-way valve in the pVTt device to explain the significance of the research.(2)According to the design index,design the quick switching 3-way valve,determine the system parameters and analyse the working principle and process.Finally,select the components of the 3-way valve using the mechanical and kinematics formulas.(3)Analyse each part of the quick switching 3-way valve and establish the mathematical model of two switching states.Built the simulation models in Matlab/Simulink.Analysis and summarise the main fators influencing its dynamic performance.(4)Use ANSYS to simulate the use of 3-way valve in pVTt device.On the basis of independent verification of the grid,study the influence of 3-way valve switching on critical flow in pVTt device using moving grid.The analysis results show that the switching of the valve has no effect on the critical flow in the pVTt device,indicate the design of 3-way is feasible in practical application and validate the cushion of the buffer tank.(5)At last,test one important index of the 3-way valve,that is air tightness test.The experimental results show that the tightness of the 3-way valve is good.Then the switching time of the 3-way valve is tested.The result is about 55 ms and it meets the design requirements.