摘要
采用数值模拟方法对汽轮机末级-排汽缸-凝汽器喉部的三维耦合流动规律进行了研究.讨论了末级-排汽缸、排汽缸-凝汽器喉部、末级-排汽缸-凝汽器喉部耦合模型,及单独排汽缸模型时的气动性能和流场分布的差异.计算结果表明:扩压管内分离涡的存在会减弱其扩压能力;耦合末级时扩压管入口速度沿叶高方向逐渐变化,更符合扩压管的设计,使扩压管内分离涡变小;耦合凝汽器喉部时除引入喉部的能量损失外,还会增加上游各部分的能量损失,并增加出口流场不均匀度;蜗壳内由于大尺度通道涡的存在,造成的能量损失约占总损失的60%;排汽通道扩压能力则主要集中在扩压管,约占整体扩压能力的90%.所得结果可为排汽通道的优化设计提供参考.
Three-dimensional coupled flow pattern of steam turbine last stage, exhaust hood, and condenser throat is studied by the numerical simulation method. The differences of the steam proper- ties and flow field distribution of the coupled model of last stage and exhaust hood, exhaust hood and condenser throat, last stage and exhaust hood-condenser throat, and the single exhaust hood model are discussed. The results show that the separation vortex in the diffuser pipe causes the decrease in the pressure recovery capability; when coupled with last stage, the velocity of diffuser pipe inlet changes along the blade height, which is more close to the design condition of the diffuser pipe, re- suiting in the decrease in the separation vortex; when coupled with condenser throat, there is energy loss increase in the throat as well as in each part of upstream passage, and it also causes the increase in the unevenness in the outlet; the volute shares 60% of total energy loss due to the passage vortex; the pressure recovery capability is mainly in diffuser pipe, which shares 90% of total capability. The results can guide the optimal design of exhaust passage.
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2015年第4期701-706,共6页
Journal of Southeast University：Natural Science Edition
基金
国家自然科学基金资助项目(51176031)
关键词
排汽通道
末级
数值模拟
耦合
exhaust passage
last stage
numerical simulation
coupling
