Study On The CFD Based Simulation And Optimization For Process Valves

Nowadays valves are used in more and more complex environments,and higher valve performance and reliability are in increasing demand.Advanced technologies to assist valve design becomes more and more necessary.Computational fluid dynamics(CFD)enables accurate display the detailed interaction between valve structure and the inside flow field,and provides important information for the valve designers.Therefore,CFD based simulation has attracted more and more attention in the valve industry.In this paper,the CFD methods to predict the flow capacity and hydrodynamic performance of valves were studied,and a series of experiments were also conducted to validate the methods.The detailed contents of this paper includes:(1)Grid-adaption technology based CFD method was used to study on valve flow field.In this part,gradient adaption and Y plus adaption technology were used to refine original mesh,and the results shown that it can effectively improve the simulation accuracy and reduce the difficulty of artificial mesh refinement.(2)According to Darcy-Weisbach formula,pipe-induced pressure drop(?Pp)and overall pressure drop(?Po)can be calculated by one numerical fluid model,and then Kv can be calculated by the valve flow coefficient formula.A series of experiment studies were performed,demonstrating the presented method can accurately predict flow coefficient for various types of valves,and thus has great potential to be widely used in the valve industry.In addition,the structure of two kinds of DN500 eccentric butterfly valve and one kind of DN100 diaphragm valve were optimized to improve the flow capacity.(3)A parametric platform was developed for valve flow field simulation.The parameters of meshing and solving process can be reset automatically through this platform,and then the fluid model would be meshed and simulated according to new parameters.Two kinds of valves were performed with this platform,demonstrating it can accurately predict flow coefficient,and thus reduce repetitive manual operation,promote CFD technology to be widely used in valve industry.(4)User-defined functions and sliding mesh technology were used to perform on dynamic simulation of rotation type valve.In this part,opening and closing hydrodynamic torque of a DN500 butterfly valve were measured by simulation method according to different rotation speed of disc,and the reliability of results were verified by empirical formula.The results shown that the tendency of hydrodynamic torque obtained by two methods agreed well with each other.The simulation method presented by this paper can provide richer data and was more conducive to guiding the structural design of the valve.