低压汽轮机末级长叶片改型试验研究  

Experimental Study of a Retrofitted Long Blade Used in the Last Stage of a LP Steam Turbine

作　　者：康磊[1] 梁瑶 于剑锋[1] 王超[1] 

机构地区：[1]中国船舶重工集团公司第七O三研究所,黑龙江哈尔滨150078 [2]中国电力工程有限公司,北京100048

出　　处：《热能动力工程》2014年第5期483-491,592,共9页Journal of Engineering for Thermal Energy and Power

摘　　要：针对船用汽轮机的变工况、末几级湿度大的运行特性,对某汽轮机末级长叶片进行气动优化,并在环形叶栅试验台上对原型和改型两组叶栅进行了3个出口马赫数与5个冲角下的吹风试验。结果表明:随着栅后马赫数的增加,叶片吸力面最低压力点位置后移,叶栅前半段的降压段增长、顺压梯度增加,附面层变薄,降低了叶片的叶型损失;改型后的动叶外端壁二次流损失显著下降,而且提高了冲角的适应性;正、负冲角仅影响叶片前缘吸力面或压力面的静压分布,在任一马赫数下,冲角的绝对值的增加都引起叶栅损失的增加。In the light of such operation characteristics of marine steam turbines as off-design operating conditions and a big wetness in several stages before the last one,dynamically optimized was the long blades in the last stage of a steam turbine and air-blowing tests were performed of the prototype and retrofitted totaling two cascades on an annular cascade test rig at three mach numbers at the outlet and at five attack angles. It has been found that with an increase of the Mach number after the cascades,the location of the lowest pressure point on the suction surface of the blades will shift rearwards,the pressure dropping section in the front half section of the cascades will become longer,the pressure gradient along the pressure dropping direction increase,the boundary layer become thinner and the blade profile loss decrease. The secondary flow loss on the outside end wall of the rotating blades after the retrofitting will markedly drop and enhance the applicability to attack angles. The positive and negative attack angles will only affect the static pressure distribution on the suction surface or pressure surface at the leading edge of the blades. At any Mach number,any increase in the absolute attack angle will all lead to an increase of the loss in the cascades.

关 键 词：变工况 长叶片 扭叶片 风洞试验 总压损失系数 

分 类 号：TK262[动力工程及工程热物理—动力机械及工程]