Numerical Study Of Unsteady Flow Fieldwithin The Main Valve And Control Of A Ultra-supercritical Million Steam Turbine

In this paper, By commercial computational fluid dynamics (CFD) Fluent software, the steady and the unsteady steam flow field of the main Valve system of a certain million kilowatts Ultra Supercritical Steam turbine, being consist of by the main steam valve and the control valve, have been simulated. First of all, the main steam valve and the control valve fully open conditions, according to the characteristics of sliding pressure operation unit, calculated and analyzed under different load steady flow of steam, followed by simulation steady steam flow of the two kinds of conditions, the control valve fully open in the main steam valve opening under different positions; the main steam valve fully open in the control valve opening under different positions, mainly to understand the main steam valve and the control valve opening in the part load of the losses; Finally, in the main steam valve fully open conditions, By the use of Fluent The dynamic mesh technology, calculated and analyzed non-steady steam flow of the control valve quick closing from fully open to part open process. Calculation shows that: for stable operation, When the valve fully open, the main valve system'total pressure loss is about 1.23% of the inlet pressure, 57.52% of which is caused by the control valve, the Valve throttle losses at different valve positions are higher than the loss of the valve fully open, the final computations give out the control valve the dynamic curves quickly shut down, the control valve lift, flow, back pressure with valve closing time.