An Experimental Study of Unsteady Transonic Flow in a Steam Control Valve with Simple Model

Abstract

A steam control valve is used to control the steam flow from a steam generator to a turbine in power plants. The flow field in the steam control valve is usually complicated and transonic. A flow-induced vibration can occur in the valve and may cause unexpected shutdown of the plant. An experimental study is conducted to clarify the characteristics of the flow in the steam control valve. In the present study, scale effects on the condition of occurrence of various flow patterns are investigated. Experimental results show various flow patterns including new patterns which have not been reported. Additionally, even under the same operation condition, different flow patterns are observed under a certain range of condition. This effect is found to be comparable with the scale effect.