Pressure Losses Analysis in Two High-Pressure Steam Turbine Control Valves Situated in One Valve Chamber

Abstract Steam turbines belong to the most important systems in power conversion. In order to control their power output at steady state base load or part load conditions, the use of control valves is a widely used method. The flow in a pair of high-pressure steam turbine control valves which are situated in one valve chamber is analyzed in this paper from the pressure losses point of view. The experiments were carried out on a valve model installed in a wind tunnel for high speeds in the Aerodynamic laboratory of the Institute of Thermomechanics of the Czech Academy of Sciences. The flow at different valve cone lifts in both control valves was investigated and results were generalized in the form of so-called valve characteristics. Investigations were carried out on the model with control valve strainers and without them. In order to further understand the reasons of detected pressure loss differences, the numerical simulations were carried out in the Doosan Skoda Power Company using ANSYS software tools. The comparison of results shows which cases of the valve setup are preferable with regard to pressure losses and thus efficiency. Furthermore, an existing pressure loss prediction model for valve pressure loss estimation for each investigated case was updated. This model helps to better design the valve geometry in order to increase overall turbine efficiency.