考虑气动和湿汽损失综合影响的低压多级透平优化
Optimization for Low？？Pressure Multi？？Stage Turbine Considering Influences of Aerodynamic Losses and Wetness Losses

针对叶轮机械多级透平优化的问题,在考虑湿蒸汽透平中气动损失和湿汽损失的综合影响的基础上,采用响应面方法对某300 MW汽轮机低压缸末三级透平进行了优化。优化变量为末三级静叶的安装角和型线沿叶高的积叠规律,安装角优化通过改变多级透平级之间的压力平衡,来改变湿蒸汽透平级内过冷度的分布,降低非平衡热力学损失和水滴的直径,使得末三级的湿汽损失减小了20.71％,由此获得了通过调整低压透平静叶安装角从而减小湿汽损失的方法。静叶积叠规律的优化中通过改善反动度沿叶高的分布、减小叶根边界层分离和降低二次流损失提高了气动效率,同时引起级内过冷度和出口流速沿叶高变化,使一次水滴和二次水滴的直径减小,导致气动损失降低了0.52％,湿汽损失进一步降低了9.48％。该结果可为多级透平优化提供参考。
The last three stages of a low？？pressure steam turbine are optimized with the response surface method simultaneously considering the influences of aerodynamic losses and wetness losses. The stagger angles and stacking lines of the last three stages are chosen as the design variables. Adjusting the stagger angles, the pressure distribution, consequently the supercooling distribution, among the multi？？stage turbine are changed. As a result, both the non？？equilibrium thermodynamic loss and the water droplet diameter are reduced. The wetness losses in the last three stages decrease by 20.71％. The strategy for adjusting stagger angles to reduce the wetness losses is concluded. The optimization of stacking lines improves the radial reaction distribution, reduces the boundary layer separation and secondary losses to heighten aerodynamic effects. Meanwhile the optimization of stacking lines also leads to changes of supercooling and outlet velocity in a turbine stage resulting in decrease in the primary and secondary water droplet sizes. The aerodynamic loss is reduced by 0.52％, and the wetness loss is further reduced by 9.48％