导流环结构对汽轮机排汽缸气动性能的影响  

Effect of Guide Structure on Aerodynamic Performance of Exhaust Hood in Steam Turbine

作　　者：曹丽华[1] 周凯 陈美端 李勇[1] CAO Li-hua;ZHOU Kai;CHEN Mei-duan;LI Yong(School of Energy and Power Engineering,Northeast Electric Power University,Jilin 132012,China;Huaneng Qinbei Power Generation Company Limited, Jiyuan 454000,China)

机构地区：[1]东北电力大学能源与动力工程学院,吉林132012 [2]华能沁北发电有限责任公司,济源454000

出　　处：《汽轮机技术》2018年第1期1-5,共5页Turbine Technology

基　　金：国家自然科学基金资助项目(51576036)

摘　　要：以某600MW汽轮机为研究对象,应用计算流体力学软件CFX对低压缸末级和排汽缸的耦合模型进行了数值模拟,分析了导流环的起始扩散角、直径以及轴向长度对排汽缸气动性能的影响。结果表明:随着导流环起始扩散角的增加,排汽缸的气动性能得到改善,但当增加到30°时,在扩压器内会产生流动分离,其最佳值为25°;导流环的直径和轴向长度过大或过小均不利于排汽缸的气动性能,其中直径最佳值为5000mm,轴向长度最佳值为900mm。选取3个变量最佳值作为导流环的优化方案,与优化前排汽缸的气动性能进行对比,排汽缸出口的静压恢复系数提高了7.2%,总压损失系数降低了8.4%,气动性能有了明显的改善。A combined numerical simulation was conducted to couple fluid flow between exhaust hood and last-stage blades of a600MW steam turbine using the computational fluid dynamics software CFX.The influence of the initial diffusion angle,the diameter and the axial length of the guide on the aerodynamic performance of the exhaust hood was studied.The results indicate that the aerodynamic performance of the exhaust hood has been improved with the increase of the initial diffusion angle.There is a flow separation in diffuser when the initial angle increases to30°.The most appropriate value is25°.It is not conducive to the aerodynamic performance of the exhaust hood that the diameter and the axial length of the guide are too large or too small.The most appropriate value of the diameter and the axial length of the guide are5000mm and900mm,respectively.The most appropriate value of the three variables was selected as the modification scheme of the guide.Comparing with the aerodynamic performance of the exhaust hood before reformation,the static pressure recovery coefficient of the outlet of the exhaust hood increases by7.2%,as well as the total pressure loss coefficient of the outlet of the exhaust hood reduces by8.4%.The aerodynamic performance is improved obviously.

关 键 词：汽轮机 排汽缸 导流环 气动性能 

分 类 号：TK263.1[动力工程及工程热物理—动力机械及工程]