630MW机组汽轮机低压缸排汽通道流场数值模拟与优化  

Optimization Research on Exhaust Passage of Low Pressure Cylinder of 630MW Steam Turbine

作　　者：李敏杰 曹昊楠 徐钢[1] 张文韬 刘文毅[1] LI Min-jie;CAO Hao-nan;XU Gang;ZHANG Wen-tao;LIU Wen-yi(School of Energy Power and Mechanical Engineering,North China Electric Power University,Beijing 102206,China)

机构地区：[1]华北电力大学能源动力与机械工程学院,北京102206

出　　处：《汽轮机技术》2025年第1期6-12,共7页Turbine Technology

基　　金：国家自然科学基金创新研究群体项目(51821004)。

摘　　要：排汽通道流场的好坏是影响汽轮机排汽压力与凝汽器换热性能的重要原因。为优化排汽通道的气动性,以国内某630MW湿冷机组为研究对象,对机组汽轮机低压缸排汽通道开展流场数值模拟计算与分析,并设计提出利用导流装置改善排汽通道流场的优化方案。首先利用CFD仿真软件对排汽通道进行数值模拟,结合凝汽器热力计算与数值计算方法,利用MATLAB软件对凝汽器的换热系数、端差等参数进行计算;在此基础上,通过分析抽汽管道、低压加热器以及小汽机等各结构对流场的影响,在排汽通道中合适的位置安装导流装置,优化流场分布,从而使排汽通道出口流场的均匀性提高,排汽通道的总压损有所下降,凝汽器的换热性能得到改善。分析结果表明,安装本文提出的导流装置,案例机组排汽通道的总压损减小57.63Pa,排汽通道出口的速度均匀性系数增大18%;凝汽器换热系数增加486.91 W/(m·℃),端差减少1.59℃,凝汽器压力降低490Pa。The flow field of the exhaust channel is an important reason that affects the exhaust pressure of the steam turbine and the heat transfer performance of the condenser.In order to optimize the aerodynamic performance of the exhaust channel,a 630MW wet cooling unit in China is taken as the research object,the numerical simulation and analysis of the flow field of the exhaust channel of the low-pressure cylinder of the steam turbine of the unit,an optimization scheme for improving the flow field of the exhaust channel by using the diversion device is proposed.Firstly,the exhaust channel is numerically simulated by CFD simulation software,combined with the condenser thermal calculation and numerical calculation method,and the heat transfer coefficient and end difference of the condenser are calculated by MATLAB software.Based on the simulation results of the flow field outlet of the exhaust channel,by analyzing the influence of various structures such as steam extraction pipeline,low-pressure heater and the small steam turbine on the flow field,guide devicesare installed at a suitable position in the exhaust channel.the uniformity of the flow field at the outlet of the exhaust channel is improved,the total pressure loss of the exhaust channel is decreased,and the heat transfer performance of the condenser is improved.The results show that the total pressure loss of the exhaust channel after the installation of the diversion device is reduced by 57.63Pa,and the velocity uniformity coefficient of the exhaust channel outlet is increased by 18%.The heat transfer coefficient of the condenser is increased by 486.91W/(m·℃),the end difference is reduced by 1.59℃,and the condenser pressure is reduced by 490Pa.

关 键 词：排汽通道 导流装置 数值模拟 气动性 凝汽器换热性能 

分 类 号：TM621[电气工程—电力系统及自动化]