【作者】 曲文波；

【导师】 韩万金； 李宇峰；

【作者基本信息】 哈尔滨工业大学 ， 动力工程（专业学位）， 2021， 硕士

【摘要】 研制大功率蒸汽轮机,是实现节约能源的必然趋势。为了降低通流部分的级数和提高相对内效率,汽轮机叶片常常采用大焓降倾斜叶片。哈汽公司工程科技人员设计了新型大功率汽轮机组大焓降正倾斜叶片,为验证其气动性能指标,对新型大功率汽轮机中压级的静子叶型和叶栅进行了风洞吹风试验。中压7级静叶按前缘和尾缘计算径高比均为12.2,该叶片为短叶片,并采用尾缘积迭。其积迭线为仅随y坐标变化的周向负倾斜直线,叶顶最大前掠12%轴向弦长;内外子午流道分别为扩张角10度和11度的圆锥面。对该级静叶栅根、中、顶三个跨叶片截面叶型,采用等截面直列叶栅,分别试验测量了这3种叶型的变攻角特性、变安装角特性、变节距特性和变马赫数特性。同时,采用扇形叶栅作为7级静叶栅的实验模型,测量了气动参数沿叶高和节距的分布,考核其性能指标是否达到设计要求。试验结果表明:中压7级叶栅均采用的是先进的后部加载叶型,该叶型具有流线形“鱼头”前缘、高强度的叶身和薄的出口边,较为显著地降低了对进气攻角的敏感性。叶型安装角和相对节距(简称节距)的设计值都十分接近最佳值,叶型损失随安装角和相对节距的变化曲线曲率较小,同时叶型损失伴随马赫数的增加平缓下降。该静叶栅的几何成型改善了绕流工质的三维结构,沿叶高的气动参数分布比较均匀,特别是在短叶片大折转角叶栅中的主要流动损失源,即端壁二次流动损失,得到有效控制,沿叶高的节距平均总压损失系数曲线基本呈一直线连接两个近于相等较小凸起。本试验证明7级静叶片的气动性能超过了预期的设计指标。更多还原

【Abstract】 The development of high-power steam turbine is the inevitable trend of energy saving.In order to reduce the number of stages of flow passage and improve the relative internal efficiency,the steam turbine blades are often used with large sloping inclined blades.The engineering and technical personnel of Harbin Automobile Co.,Ltd.have designed the high enthalpy drop positive inclined blade of new type high power steam turbine unit.In order to verify its aerodynamic performance index,wind tunnel tests were carried out on stator profile and cascade of medium pressure stage of new high-power steam turbine.The medium-pressure 7-stage vane has a diameter-to-height ratio of 12.2according to the leading edge and the trailing edge.The blade is a short blade and is covered by a trailing edge.The stacking line is a circumferential negative oblique straight line which only changes with the y coordinate,and the maximum tip forward of the tip is 12% axial chord length;the inner and outer meridional flow paths are respectively a conical surface with an expansion angle of 10 degrees and 11 degrees.For the three-span blade cross-section of the stationary blade cascade,the cross-section in-line cascade is used to test the variation angle characteristics,variable installation angle characteristics,variable pitch characteristics of the three types of blade types.Change the Mach number property.At the same time,the fan-shaped cascade is used as the experimental model of the 7-stage static cascade.The distribution of aerodynamic parameters along the leaf height and pitch is measured,and whether the performance index meets the design requirements is evaluated.The test results show that the medium-pressure 7-stage cascade adopts the advanced rear loading blade type,which has a streamlined "fish head" leading edge,a high-strength blade body and a thin outlet edge,which is more remarkable.The sensitivity to the inlet angle of attack is significantly reduced.The design values of the blade mounting angle and the relative pitch(referred to as the pitch)are very close to the optimal value,and the curvature loss of the blade shape with the installation angle and the relative pitch is small,and the loss of the blade type is accompanied by the increase of the Mach number decline.The geometrical shape of the stationary blade cascade improves the three-dimensional structure of the flow-through working medium,and the aerodynamic parameter distribution along the blade height is relatively uniform,especially the main flow loss source in the short-blade large-turn corner blade cascade,that is,the secondary wall secondary flow The loss is effectively controlled,and the average pressure loss coefficient curve along the leaf height is substantially in line with two nearly equal small protrusions.This test proves that the aerodynamic performance of the 7-stage stationary vane exceeds the expected design specifications.更多还原