Axial Flow Check Valve Is Closed When The Transient Dynamic Analysis

There are many advantages for axial flow check valve, such as small local resistance coefficient, low noise level, low water hammer pressure, good flow ability and high response speed and so on, so it is wildly used in the oil and gas pipeline, the outlet of pump and compressor. The opening and close of axial flow check valve is a dynamic process. In this process, the motion instantaneous velocity of valve clack and the pressure distribution of medium on the surface of it affect the work performance of check valve. Doing dynamic analysis is necessary to ensure the check valve work normally and have a long service life. It will consume a lot of human and material resources as well as increase the production cost in the traditional test method. So we need to hunt for new analysis methods to analyze the running state of check valve. At present, numerical simulation has already been used on the static and dynamic analysis of flow field. So the numerical simulation calculation can analyze its motion state accurately and effectively.It took the axial flow check valve for example to do some numerical simulation calculations and test analysis about steady state characteristics of different valve opening degree to demonstrate the feasibility of numerical simulation. And it used moving-grid technology to analyze the motion law and force condition of valve clack when check valve was closed. After that, it used the transient dynamics to analyze the impact action on the valve seat from the valve clack when the valve was closed completely. The research contents in this paper were listed below:(1)It used the numerical simulation to analyze the steady-state flow characteristics under the ten valve opening degrees of axial flow check valve. It drawed the curve flow characteristics and local resistance coefficient based on the analysis results. It used the test method to analyze the local resistance coefficient of check valve under the different speed and the pressure drop of the inlet and outlet, and did a comparison between the text results and the stimulation results to prove the stimulation was reasonable and reliable for the flow characteristics analysis about check valve.(2) According to the motion equation of valve clack, it compiled UDF program and used moving-grid technology to analyze the dynamic characteristics of closingprocess of axial flow check valve to derived the change situation of pressure and speed cloud picture under the each time and analyze their change reason. At same time, it derived the relation between the velocity, acceleration and the time as well as the impact acceleration of valve clack when the valve was closed. Based on the quality of valve clack, it calculated the impact force to the seal surface of valve body from valve clack when it was closed. The closing process dynamic analysis of check valve provided data support for the shock response analysis.(3)According to the change law of this impact force, it used the transient dynamics to analyze the impact stress of valve body and valve clack. The stress reached the peak when the impact load was maximum value, and with the increase of time, it attenuated rapidly.