The Dynamic Characteristics Of Simulation And Experimental Study On Opening And Closing Process Of Ball Valve

Ball valve is widely used in petroleum refining, chemical, pharmaceutical industries,because of its large flow capacity, good sealing performance, compact structure, etc. Usually theball is best for opening and closing directly. However, with the development of ball, the ball isalso used for throttling and regulating the flow. In the process of regulating the flow, thedynamic of ball will produce flow vortex or water hammer, etc, and it even can influence thepiping system which is connected with the valve. Therefore, the numerical simulation andexperimental research of dynamic process of ball valve opening and closing was done in thispaper. And the performance curve ball and internal flow field of dynamic process was analyzedto providing reference and basis for design and application of ball valve. The detailed contentsare as follows:(1)Three-dimensional modeling for the ball and internal flow field were completed by UG.Then the internal flow field model was meshed by GAMBIT. Based on the dynamiccharacteristics of experimental on opening and closing process of ball valve, the flow rate andinlet and outlet pressure under four different opening and closing time (18s、23s、34s and70s)andthe steady operating mode (the steady condition is considered as infinity opening and closingtime conditions) was obtained. And the experimental data of flow rate and inlet and outletpressure were fitted as the import and export of boundary condition to numerically simulate ofthe ball valve opening and closing process. The numerically simulate of the ball valve openingand closing process based on sliding grid technology.（2）The dynamic experimental data of flow rate and inlet and outlet pressure wereanalyzed to understand the performance of the ball valve in different opening and closing time.Comparative analysis of pressure differential and flow resistance coefficient of experiment andnumerical simulation results revealing the flow resistance characteristics of ball valve with thechanging rule of the opening and closing time and different between opening process andclosing process.(3) The interior flow field of three valve opening（20%、40%and70%）was analyzed. Andthe influence of the opening and closing time for opening and closing process was got. Meanwhile, the difference of pressure and velocity field between opening and closing processwere compared to reveal the otherness of ball valve opening and closing process.