Tu Shan,Sun Bi,Mao Jingru
(School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China)
Abstract:For a commonly used control valve in steam turbine of GX1 type, some measurement points are installed in key positions of the valve such as valve seat throat, valve seat diffuser and so on. Some mini-sensors of pressure with the collection system that have high frequencies and dynamic performances are employed successfully. The collection and measurement for many working conditions are carried out. The numerical simulation is to calculate the three dimensional, compressible and turbulent flow in steam turbine control valve by finite difference method. The complicated flow characteristics in control valve are studied by theoretical analysis, experimental investigation and numerical simulation. The results show that under the conditions of middle and small pressure ratio, the flow patterns in control valve are repeatly changed and the flow field is extremely nonuniform near the valve throat and unstable. The energy loss is mainly occurred near the valve throat, moreover the unsteady flow may induce its oscillation.
Keywords:control valve£»flow characteristics£»experimental investigation£»numerical simulation