大型汽轮发电机转轴残余应力的检测

发布时间：2018-12-18 17:49

【摘要】：转子是大型汽轮发电机的核心部件,在其生命周期中一直进行着高速旋转,主要组成部分包括转轴、线圈绕组、辅助性环类件等,其中转轴是转子最为重要的载体,因此转轴的力学性能决定了转子的使用寿命及运行情况。由于转轴属于大型锻造件,在其制造的过程中不可避免的会引入残余应力,而残余应力恰恰是力学性能中的重要组成部分。目前国内大型汽轮发电机转轴残余应力的检测方法主要是切环法,而国外制造厂商则普遍采用环芯法,随着我国与国外同行日益密切的技术商务合作和自身制造能力的提升,近年来国内制造厂商也逐步引进了环芯法,因此目前国内处于两种检测方法并行的情形。作者所在的汽轮发电机制造工厂也在近几年引进了环芯法,但在实际检测中发现针对发电机转轴的残余应力检测,环芯法检测数据要略高于切环法的检测数据。通过从两种方法的理论基础及具体实践的比较发现,从原理上环芯法所检测的转轴切向与轴向的残余应力要比切环法所检测的转轴径向的残余应力更具有工程实用价值,而且环芯法的检测深度及应变系数的确定相比切环法要更加的科学;从具体实践上,环芯法的应变检测精度为1μm/m要高于切环法的10μm/m,而且环芯法的检测所占试料区更小、不需占用行车和大型机床使得检测成本更加的低廉,同时环芯法每个检测点30min的检测时间要比切环法约12h的检测时间更加高效。因此在今后对汽轮发电机转轴的残余应力进行检测时,建议使用环芯法替代切环法,以获得更好的综合效益,同时鉴于两种方法存在的差异,应在相应行业标准中对两种检测方法进行区分。
[Abstract]:Rotor is the core component of large turbogenerator, and it has been rotating at high speed in its life cycle. The main components include rotating shaft, coil winding, auxiliary ring and so on, among which the rotor shaft is the most important carrier. Therefore, the mechanical properties of the shaft determine the service life and operation of the rotor. As the shaft belongs to a large forging part, it is inevitable to introduce residual stress in the manufacturing process, and residual stress is an important part of mechanical properties. At present, the method of measuring residual stress of rotating shaft of large turbogenerator in China is mainly annular method, while foreign manufacturers generally adopt annular core method. With the increasing technical and commercial cooperation between our country and foreign counterparts and the improvement of its own manufacturing capability, In recent years, domestic manufacturers have gradually introduced the ring core method, so at present the two detection methods are in parallel in our country. In recent years, the ring core method has been introduced into the turbo generator manufacturing factory, but it is found in practice that the ring core method is a little higher than the tangent method in detecting the residual stress of the generator shaft. By comparing the theoretical basis and practical practice of the two methods, it is found that, in principle, the tangential and axial residual stresses detected by the annular core method have more practical engineering value than the radial residual stresses of the rotary axis measured by the tangential method. And the determination of the detection depth and strain coefficient of the ring core method is more scientific than that of the tangential method. In practice, the precision of strain detection by the annular core method is 1 渭 m / m higher than that of the annular method by 10 渭 m / m, and the testing area of the annular core method is smaller than that of the annular core method, and the testing cost is much lower without the need of driving and large machine tools. At the same time, the detection time of 30min at each detection point is more efficient than that of the annular method for about 12 hours. Therefore, it is suggested that the annular core method should be used instead of the annular method in order to obtain better comprehensive benefits when the residual stress of the rotating shaft of turbogenerator is measured in the future, and in view of the differences between the two methods, The two detection methods should be distinguished in the corresponding industry standards.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM311

【参考文献】