Analysis of losses in steam turbine control valves

The paper deals with a flow in control valves of steam turbines and in classical diffusers. The effect of the cone lift and the change of the flow cross-section on the energy losses is investigated. Total loss coefficients for a valve with a strainer and a valve without a strainer are evaluated along with the losses for the operating characteristics of the turbine. The effect of a flow dissipation and a disordered unsteady velocity flow field in the valve on the increase in the loss coefficient for a given angle of diffuser opening is considered.