汽轮机斜切喷嘴内部流动仿真分析  

Simulation Analysis of Internal Flow in Oblique Cutting Nozzle of Steam Turbine

作　　者：孟召军[1] 杨子健 王子聪 孟书宇 杨小龙 梁策 艾涔 MENG Zhao-jun;YANG Zi-jian;WANG Zi-cong;MENG Shu-yu;YANG Xiao-long;LIANG Ce;AI Cen(Shenyang Institute of Engineering,Shenyang 110136,China;Liaoning Datang International Shendong Thermal Power Co.,Ltd.,Shenyang 110000,China;China Railway 19th Bureau 13th Engineering Company,Shenyang 110136,China)

机构地区：[1]沈阳工程学院,沈阳110136 [2]辽宁大唐国际沈东热电有限责任公司,沈阳110000 [3]中铁十九局第十三工程公司,沈阳110136

出　　处：《汽轮机技术》2023年第3期173-175,182,共4页Turbine Technology

基　　金：辽宁省教育厅项目(JL-1904)。

摘　　要：在现有大型多级汽轮机中,由于汽轮机级的喷嘴叶栅为环形布置,喷嘴出口部分出现斜切部分,为了分析斜切部分对汽轮机级效率的影响,建立了某300MW汽轮机中压缸第一级的三维模型,对其流量在临界与亚临界两种工况下的流动设定了边界条件并进行了有限元仿真分析,分析结果表明,临界工况下级的喷嘴斜切部分速度能达到超音速,整个喷嘴部分一直起到加速作用,亚临界工况下级的喷嘴斜切部分出现了降速现象,速度降低了约8.5%,临界工况下比亚临界工况下喷嘴效率要高1.85%。两种工况下,喷嘴斜切部分汽流都会发生偏转,这也是引起级损失的原因。为了减少亚临界工况下汽轮机级内损失,设计一种无斜切喷嘴级的结构将是提高汽轮机级效率的有效方法。In the existing large-scale multi-stage steam turbine,because the nozzle cascade of the steam turbine stage is arranged in a ring shape,the nozzle outlet part has a beveled part.In order to analyze the influence of the beveled part on the efficiency of the steam turbine stage,a three-dimensional model of the first stage of the intermediate pressure cylinder of a 300MW steam turbine is established,the boundary conditions of its flow under critical and subcritical conditions are set,and the finite element simulation analysis is carried out.The analysis results show that,Under critical condition,the speed of the nozzle bevel part can reach supersonic speed,and the whole nozzle part has been accelerating.Under subcritical condition,the speed of the nozzle bevel part decreases by about 8.5%,and the nozzle efficiency under critical condition is 1.85%higher than that under critical condition.Under two working conditions,the steam flow in the oblique cutting part of the nozzle will deflect,which is also the cause of stage loss.In order to reduce the loss in the steam turbine stage under subcritical conditions,it is an effective way to improve the efficiency of the steam turbine stage by designing a structure without oblique cutting nozzle stage.

关 键 词：亚临界流动 斜切部分 损失 

分 类 号：TK263.2[动力工程及工程热物理—动力机械及工程]