配汽方式对汽轮机末级变工况的影响  

Effect of Steam Distribution Modes on Performance of Last Stage in Steam Turbine

作　　者：高怡秋[1] 李一兴[1] 周振东[1] 

机构地区：[1]中国船舶重工集团公司第704研究所,上海200031

出　　处：《核动力工程》2013年第2期114-117,共4页Nuclear Power Engineering

摘　　要：针对汽轮机末级低负荷工况的级功率大幅下降、动叶出口脱流现象,进行末级全工况计算,得到不同容积流量下的脱流高度。在通流保持不变的情况下,对喷嘴配汽和节流配汽方式下的汽轮机进行变工况计算。结果表明,脱流区域和脱流高度随容积流量的减小而急剧增加;节流配汽在低负荷工况下会增加汽轮机的汽耗率,提高压力级的焓降,同时减小由于蒸汽参数改变带来的功率分配变化;相同负荷下,节流配汽会增大末级的容积流量,并相应降低动叶出口的脱流高度,有助于改善低负荷工况下末级的流动,推迟零功率工况的出现。Considering that the power level drops significantly and steam flow separates from the outlet of rotor blades in the last stage of steam turbine at low load conditions, the last stage in whole working conditions was calculated and the height of flow separation in different volume flow was obtained. Different conditions of turbine under the same flow path with nozzle governing and throttle governing were calculated respectively. The results show that the flow separation bubble and separation height increased dramatically when volume flow decreased; the throttle governing at low load conditions increased the steam rate of turbine and the enthalpy drop of pressure stage, while reduced the changes of power distribution under the influence of steam parameters changing; in the same load, the throttle governing increased the volume flow in last stage, and reduced the separation height of rotor blades accordingly; it was propitious to improve the flow of the last stage at low load conditions, and postpone the emergence of zero power conditions.

关 键 词：节流配汽 末级叶片 低负荷工况 容积流量 脱流高度 零功率工况 

分 类 号：TK262[动力工程及工程热物理—动力机械及工程]