汽轮机末级湿蒸汽凝结流动模型差异性研究

以汽轮机末级叶片为研究对象，采用计算流体力学方法对单流道几何模型进行数值计算，研究了湿蒸汽平衡与非平衡凝结流动模型之间的特性差异，并基于非平衡凝结探讨表面张力修正系数(NBTF)在定常分析中对湿蒸汽参数的影响。结果表明：非平衡凝结模型主要影响液滴数目及颗粒直径，速度场分布与平衡凝结模型有较大差异；基于非平衡凝结模型对表面张力进行修正的模型会降低级内热力学损失，总-静效率比未修正表面张力的原型增加0.16%,相较平衡凝结模型降低3.26%;在主频下，修正模型动叶所受轴向激励力相较于平衡凝结模型减少52.76%,切向激励力减少57.12%,但轴向力与切向力载荷均方根值分别增加1.59%和0.21%。

Study on Difference of Condensation Flow Model of Last Stage Wet Steam in Steam Turbine

Taking the last stage blade of steam turbine as research object,the geometric model of single channel was numerically calculated by computational fluid dynamics (CFD) method,and the characteristic differences between the equilibrium and non equilibrium condensation flow models of wet steam were studied.Based on non equilibrium condensation,the influence of surface tension correction coefficient on wet steam parameters in steady analysis was discussed.The results show that the non equilibrium condensation model mainly affects the number of droplets and the size of particle diameter,and the distribution of velocity field is quite different from that of equilibrium condensation model.The modified model for surface tension based on non equilibrium condensation will reduce the thermodynamic loss in the stage,and the total static efficiency will increase by 0.16% compared