考虑湿蒸汽行为的汽轮机排汽缸内流动的三维数值研究  

3D Numerical Analysis of Wet Steam Flow in Exhaust Hoods of Steam Turbines

作　　者：曹丽华[1] 刘佳[1] 李勇[1] 陈洋[1] 周云龙[1] 

机构地区：[1]东北电力大学能源与动力工程学院,吉林省吉林市132012

出　　处：《中国电机工程学报》2012年第29期79-86,I0012,共9页Proceedings of the CSEE

基　　金：吉林市科技发展计划资助项目(201030003)~~

摘　　要：为了更清晰地认识湿蒸汽在汽轮机排汽缸中的流动情况,采用相变模型、k-ε模型结合湿蒸汽流动方程,通过density-based耦合求解的方法,在不同来流条件下对排汽缸进行三维数值模拟。结果表明:随着排汽缸进汽湿度、进汽角度及旋流强度的增加,排汽缸的总压损失系数逐渐降低,而静压恢复系数则呈上升的趋势。排汽缸内部流场各个区域的湿度分布并不相同,其变化规律与压力的分布相同。导流环壁面上的低压槽随进汽角度及旋流强度的增加而变化。因此,不同的湿度条件、进汽角度、旋流强度对排汽缸的性能有很大的影响。研究更能反映排汽缸内部的真实流动情况,可为排汽缸的优化设计和改造提供一定的参考。In order to study the real flow condition of wet steam in the exhaust hood of steam turbine, the flow field of the exhaust hood was three dimensional numerical simulated at different inlet condition, by method of combining phase change model, κ-ε turbulence model and wet steam flow equations with the same density-based solver algorithms. The calculation results show that the total pressure loss coefficient of the exhaust hood decreases gradually and the static pressure recovery coefficient of the exhaust hood increases gradually when the inlet wetness, angle and swirl strength increases. The distribution of wetness is different at different region of flow field in the exhaust hood, and the change rule is the same with the pressure. The low pressure position of flow guide wall changes with the inlet angle and swirl strength increasing. So, the different inlet wetness, angle and swirl strength have a great influence on the performance of exhaust hood. The more real flow information of exhaust hood has been derived, and the studying results provide some references for the further design or for reconstruction of exhaust hood.

关 键 词：汽轮机 排汽缸 湿蒸汽 相变模型 数值模拟 

分 类 号：TK263[动力工程及工程热物理—动力机械及工程]