Experimental and numerical study on loss characteristics of main steam valve strainer in steam turbine

Abstract

In this paper, a kind of filter screen with special structure used in steam turbine’s main stop valve is simplified, and the three-dimensional modeling software is applied to build the filter screen test rig. The loss characteristics of it are investigated by using the method of wind tunnel test. Through the correlation analysis, a simple expression that reflects the total pressure loss of the strainer is obtained. The grid division and numerical simulation are performed on the minimum repeating unit (single crystal cell) which is taken from the whole strainer model and we compare the simulation results with the test data. Then the whole filter screen is simplified into a model of porous media and the feasibility is verified. The experimental results show that the loss coefficient of the strainer with different wind speed changes in a very small range under the same flow deflection angle. At the same wind speed, strainer loss coefficient will rise with the increasing angle, and when the angle varies from 0° to 25°, the increase amplitude of the loss coefficient is small; while it is great when the angel changes from 25° to 65°. Besides, the circumferential rotation angle of the strainer has little effect on its own drag performance. Through the numerical simulation of the single crystal cell of the strainer, its resistance characteristics can be qualitatively obtained. But there are still some deviations between the calculating results and the test data. While the value and variation of the loss coefficients obtained by using the porous media model for numerical simulation are almost identical to experimental data, indicating that the porous media model can better reflect the loss characteristics of real strainer.