Influence of sudden expansion of pipelines after valve on flow resistance characteristics of control valve
In order to accurately describe the flow resistance characteristics of control valve under the condition of non-uniform flow after use of sudden expansion pipeline behind the valve,physical model tests and theoretical analysis methods were adopted for typical control valves(VAG plunger valve and fixed cone valve).Based on the flow field structure in the sudden expansion pipeline behind the valve and the pressure characteristics of the test section,the influence of sudden expansion behind the valve on the flow resistance characteristics of typical flow control and pressure regulating valves were studied.The results show that the flow resistance characteristics of different valve types are different when the same sudden expansion body is used.The influence of the valve type is mainly reflected in the change of the inflow and outflow conditions of the sudden expansion body.On the basis of the standard formula and considering the influence of the valve outflow flow field structure(sudden expansion body inflow condition)and the influence of the water flow pulsation(sudden expansion body outflow condition),the quantitative relationship between the sudden expansion ratio and the valve flow coefficient was obtained.The maximum difference between the calculated value of the standard and the experimental value was about 8%,and the maximum difference between the calculated value of the optimized formula and the experimental value was about 1%,indicating that the calculation accuracy of the improved flow resistance coefficient formula was improved somewhat compared with the standard formula.The results can be used as reference for pipeline design of high pressure differential and large flow and pressure regulating system.
control valvesudden expansionflow coefficientflow field structurevena contracta
万方数据
维普
