汽轮机低压级叶栅尾缘波系与蒸汽自发凝结的交互作用  

Interaction Between Wet Steam Condensation Flow and Shock Wave in LP Stage of Steam Turbine

作　　者：陈桐 谢诞梅 熊扬恒 张恒良 

机构地区：[1]水力机械过渡过程教育部重点实验室(武汉大学),湖北省武汉市430072

出　　处：《中国电机工程学报》2017年第21期6381-6389,共9页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51376140)~~

摘　　要：采用数值模拟的方法研究了渐缩叶栅及缩放叶栅在变工况跨音速状态下尾缘波系的演变规律及其与湿蒸汽非平衡自发凝结相变间的内在联系。研究发现两类叶栅尾缘在跨音速工况下放射出的膨胀波系对于蒸汽自发凝结过程有显著影响。对于渐缩叶栅,随背压降低,渐强的尾缘膨胀波促进了成核过程,凝结产生的液态水质量分数升高;对于缩放叶栅,发生在喉部下游的蒸汽自发凝结显著的削弱了尾缘再附激波强度,当背压降低,膨胀波系强度增强,使得液滴生长速率加快,导致液相质量分数的升高。Focusing on the common two kinds of cascade in the LP stage of the high capacity power unit, convergent blade passage and convergent-divergent blade passage, the evolution of trailing edge flow structures under transonic conditions was studied with numerical simulation. Furthermore, the interaction between wet steam two-phase non-equilibrium condensation flow and shock wave was also studied. The significant influence of expansion wave system on the spontaneous condensation process was also found. For the convergent blade passage, with the reduction of back pressure, nucleation was enhanced by the expansion wave. For the convergent-divergentblade passage, with the reduction of back pressure, droplet growth was accelerated by the expansion wave, which both leaded to the rise of liquid phase mass fraction.

关 键 词：汽轮机 低压级 尾缘波系 凝结流动 数值模拟 

分 类 号：TK261[动力工程及工程热物理—动力机械及工程]