Research On The Effects Of Valve Core’s Geometrical Parameters On Flow Characteristics In Pilot Control Globe Valve

The pilot-control globe valve adopts the strategy of using smaller pilot valve to control the bigger globe valve.Controlling smaller pilot valve can change pressure difference between the upper and lower surfaces of valve core.Compared with the traditional globe valves,the pilot-control globe valve has smaller-scale structure,lower energy consumption and faster response speed.In this paper,a pilot control angle globe valve is proposed and its 3D model is established.Firstly,the validity of numerical simulation is verified by experiments.Secondly,the CFD method is used to conduct steady analysis to find out the effects of valve core’s geometrical parameters and working condition on flow characteristics in three kinds of pilot control globe valves,which is adapted to the horizontal,vertical and angle pipelines.Lastly,the dynamic analysis of the effects of valve core’s geometrical parameters on opening process of pilot control angle globe valve is carried out by using dynamic grid method.The main research contents are listed as follows:(1)The steady-state analysis on three kinds of pilot-control globe valve with different valve core’s geometrical parameters under different working conditions are conducted.The effects of valve core’s geometrical parameters and different working conditions on flow field distribution in valve and the pressure difference between the upper and lower surfaces of the valve core are analyzed.The engineering estimation formula of the pressure difference between the upper and lower surfaces of the valve core is summarized.Besides,the effect of valve core’s geometrical parameters on pressure distribution on the lower surface of the valve core in pilot control globe valve for horizontal pipelines is analyzed.The valve core’s geometrical parameters include the diameter of valve core,the diameter of orifice on valve core,the number of orifices on valve core and the distance between these holes.Different conditions include velocity of inletflow and valve opening.(2)The motion equation and force equation of the valve core are established.The UDF program is written based on these equations to simulate the opening process of the pilot control angle globe valve.The flow field and the valve core displacement,the force and the velocity of the valve core are studied through dynamic simulation of the pilot control angle globe valve with different valve core’s geometrical parameters.Which can help us have a comprehensive and clear understanding on the opening process of the valve.This study can provide important academic and scientific values for the optimal design and engineering application of the pilot valve.