汽轮机高压主汽联合气阀优化设计

Optimised Design of High Pressure Main Steam Combined Valve for Steam Turbine

为了解决某型汽轮机高压主汽联合气阀压力损失较高的问题,采用ANSYS CFX软件进行不同工况的稳态计算流体力学数值模拟,探究汽轮机高压主汽联合气阀压力损失优化方法。对比分析了改变主汽阀偏心距、调整调节阀出口结构、增大高压主汽联合气阀总体尺寸以及优化调节阀型线等多种优化方案对高压主汽联合气阀压损的影响并对优化效果最佳的方案进行瞬态计算,获得流体作用于阀杆的动态激振力。结果表明:对调节阀偏心距与型线同时进行优化改进,可将压损降低0.1183%,相较于改变主汽阀偏心距等方式,优化效果最佳,符合优化目标,且此方案下的激振力频率相对于公频和阀杆固有频率的避开率都在10%以上,满足设计要求。

To solve the problem of high pressure loss of a certain type of high pressure main steam combined valve,this paper used ANSYS CFX software to carry out steady-state computational fluid dynamics simulation of different working conditions,and to explore the optimization methods for pressure loss in the high pressure main steam combined valve.A comparative analysis was conducted to investigate the impact of various optimization schemes,including modifying the eccentricity of the main steam valve,adjusting the outlet structure of the control valve,enlarging the overall dimensions of the high pressure main steam combined valve and optimizing the control valve profile,on the pressure loss of the high pressure main steam combined valve.Additionally,transient computations were performed for the optimal scheme to ob-tain the dynamic excitation force of the fluid acting on the valve stem.The study result shows that optimizing and improving the eccentricity and profile of the control valve simultaneously can reduce the pressure loss by 0.1183%,and the optimisation effect is the best compared with other methods such as altering the eccentricity of the main steam valve,meeting the optimisation objectives.Furthermore,under this scheme,the frequency avoidance rate of the excitation force is more than 10%relative to the common frequency and the intrinsic frequency of the valve stem,meeting the design requirements.