汽轮机末级湿蒸汽凝结流动模型差异性研究  

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

作　　者：吴涛[1] 杨爱玲[1] 陈二云[1] 彭姝璇 WU Tao;YANG Ai-ling;CHEN Er-yun;PENG Shu-xuan(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai,China,Post Code:200093;Nanjing Institute of Future Energy System,Nanjing,China,Post Code:210000)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093 [2]中科南京未来能源系统研究院,江苏南京210000

出　　处：《热能动力工程》2023年第3期31-40,共10页Journal of Engineering for Thermal Energy and Power

基　　金：国家自然科学基金(51106099,50976072)。

摘　　要：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%。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 to the prototype without surface tension correction and decrease by 3.26% compared with the equilibrium condensation model.Under the dominant frequency,compared with the equilibrium condensation model,the modified model reduces the axial excitation force and tangential excitation force by 52.76% and 57.12% respectively,but the root mean square values of axial force and tangential force loads on the moving blade increase by 1.59% and 0.21% respectively.

关 键 词：湿蒸汽 平衡凝结 非平衡凝结 表面张力修正系数 非定常流动特性 

分 类 号：TK261[动力工程及工程热物理—动力机械及工程]