汽轮机静叶栅内平行通道除湿特性研究

Study on Dehumidification Characteristics of Parallel Channel in Turbine Stator Cascade

火电汽轮机低压级组和核电汽轮机/船用核动力汽轮机全级都处于湿蒸汽区,湿蒸汽凝结流动长期以来是影响汽轮机经济性和安全性的难题。针对White叶栅,在吸力面和压力面间设计了一个连接相邻的汽流通道的平行通道,采用双流体模型对原型叶栅和改型叶栅内湿蒸汽凝结特性和气动性能进行研究。以总压损失系数、湿汽损失为评价指标,研究了平行通道开设位置对叶栅性能的影响。研究表明:吸力面开设位置(D点)越靠近叶栅尾缘,改型叶栅除湿性能越好:压力面开设位置(C点)对改型叶栅除湿性能影响不大:C点和D点越靠近叶栅尾缘,总压损失系数越大。

The low pressure stage group of thermal power turbine and the whole stage of nuclear power turbine/marine nuclear power turbine are located in the wet steam area.The wet steam condensation flow has long been a difficult problem affecting the economy and safety of steam turbine.For the White cascade,a parallel channel connecting the adjacent steam flow channels was designed between the suction surface and the pressure surface.The two fluid model was used to study the wet steam condensation characteristics and aerodynamic performance in the cascade.Taking the total pressure loss coefficient and the wetness losses as the evaluation indexes,the effects of the opening position of the parallel channel on the cascade performance were studied.The results show that the dehumidification performance of the modified cascade is better when the suction surface(D point)is closer to the trailing edge of the cascade;the pressure surface(C point)has little effect on the dehumidification performance of the modified cascade;the total pressure loss coefficient increases when the C and D points are closer to the trailing edge of the cascade.