湿蒸汽条件下空心静叶缝隙抽吸性能的试验研究  

Experimental Research on Water Removal Performance of Hollow Stator Blade in Wet Steam Flow

作　　者：李亮[1] 薛太旭 刘启凡[1] 吴晓明 杨建道[1,2] 

机构地区：[1]西安交通大学叶轮机械研究所,西安710049 [2]上海汽轮机厂有限公司,上海200240

出　　处：《西安交通大学学报》2014年第11期1-7,共7页Journal of Xi'an Jiaotong University

摘　　要：为获得湿蒸汽流动条件下空心静叶缝隙除湿结构的设计依据,利用湿蒸汽试验平台、在与实际空心静叶工作湿度一致的条件下,对8组不同缝隙位置、形状和宽度的空心静叶进行了缝隙抽吸水膜性能的试验研究。结果表明:缝隙抽吸水膜的特性受到气流马赫数和抽吸差压的综合作用,当抽吸差压增大到一定程度时,缝隙尖角处发生水膜汽化是导致抽吸性能下降的重要因素;吸力面缝隙位置从0.24倍叶宽变化到0.42倍叶宽时,缝隙抽吸的水量持续增加;与平直缝隙相比,带台阶过渡的缝隙抽吸性能未提高,反而在马赫数大于0.7时出现显著下降,原因是引起水膜汽化的尖角数目增加;带圆角过渡的缝隙能有效消除水膜汽化,提高缝隙抽吸水膜的性能;0.35mm宽度的缝隙易于使水膜跨过缝隙,2mm宽度的缝隙不能形成有效的抽吸差压,且均导致缝隙抽吸性能降低;0.7mm和1mm宽度的缝隙均具有良好的抽吸性能,1mm宽度的缝隙受水膜汽化的影响更小。Aiming at providing guidelines for design of suction slots of hollow stator blade under wet steam flow condition, experiments were implemented on a wet steam test rig with eight hollow stator blades to investigate the water removal performance by varying the position, shape and width of suction slots. The wetness fraction at the inlet section of the test cascade was consistent with the real running condition. It is shown that the amount of removed water is affected by the main flow Mach number and suction pressure difference. When suction pressure difference increases to a moderate value, vaporization of water film occurs and acts as an additional important factor leading to degraded water removal performance. With the position of suction surface slot moving from 0. 24 to 0.42 of axial chord, the amount of removed water is continuously increased. Compared with the straight slot, the step-shaped slot cannot improve water removal performance. On the contrary, it results in poor performance when the Mach number is beyond 0.7 due to increased number of sharp corners, which leads to water vaporization. A suction slot with arc-shaped inlet is able to eliminate vaporization of water film and improve water removal performance. A suction slot of 0.35 mm width is apt to allow water film across, a suction slot of 2 mm width cannot form an effective suction pressure difference, andboth lead to degraded water removal performance. Suction slots of 0. 7 mm and 1 mm width have good water removal performance, but the later is more slightly influenced by water vaporization.

关 键 词：湿蒸汽 空心静叶 缝隙 抽吸性能 试验研究 

分 类 号：TK262[动力工程及工程热物理—动力机械及工程]