Study Gas-liquid Transient Flow Opening And Closing Characteristics On One-way Ball Valve

Reciprocating oil-gas multiphase pump is a new type of equipment to transport multiphase flow since its high discharge pressure,stroing oil-gas mixing functioo,high compression radio,high efficiency and so on.It is recognized as the sophisticated equipment of land and submarine oil-gas transportation.However,the design theory of reciprocating oil-gas multiphase pump is very difficult.One-way ball valve is the key component of reciprocating oil-gas multiphase pump,its working characteristic directly affects the performance and working reliability of reciprocating oil-gas multiphase pump.At present,scholars have made some experiments and simulations,most of them are single phase fluid,lest of them involves gas-liquid two phase fluid in one-way ball valve.In this paper,one-way ball valve in the 3DP—60/3.0 reciprocating oil-gas multiphase pump is used as the research object,the numerical simulation is carried out in terms of inlet flow rate,the valve ball opening and the medium gas rate to reveal influence on pressure field,velocity field and distribution of gas liquid two phase.In the meantime,pressure of inlet and outlet were measured by doing experiment on the ball valve to confirm the accuracy of numerical simulation.Impacting on motion of the valve core of the inlet flow rate,medium gas rate,spring stiffness coefficient,valve core material was study by using dynamic simulation.The main work and results are as follows:1.Geometric model of the one-way ball valve is set up.Simulation is made in different condition of inlet flow rate,the valve ball opening and the medium gas rate by using Fluent.In the meantime,pressure of inlet and outlet were measured by doing experiment on the ball valve to confirm the accuracy of numerical simulation.2.Analysis the result of numerical simulation in steady state,we can find that with the increasing of inlet flow rate,the differential pressure of imports and exports increase uniformly,Vortex intensity of ball tail increase,gas phase increase inside the vortex,oil and gas separation phenomenon is gradually obvious.With the increase of the valve ball opening,the differential pressure of imports and exports decrease gradually,gas-liquid two phase gradually distributes uniform,the mixing degree of oil and gas is good.It is benefit to make oil-gas transportation.3.Using UDF program to get the dynamic mesh update method which can control the movement of valve,analysis influence of transient characteristics of inlet flow rate,medium gas rate on one-way ball valve by using Fluent.And the movement speed of valve core,the maximum displacement and the internal flow field are obtained.4.The influence of spring stiffness coefficient and valve core material on different transient characteristics of the ball valve is analyzed.When ball valve is designed,the basic principles should be considered that when spring stiffness coefficient is chosen,spring stiffness coefficient should be not too small which can ensure reliability of lift limiter and working time of reciprocating oil-gas multiphase pump,and should not be too large which can ensure the enough valve ball opening height of reciprocating oil-gas multiphase pump normal working...