运用现代CAE工具开发大容量汽轮机的关键部件——末级长叶片

Developing the Long Rotating Blade for Large Scale Steam Turbines with Modern CAE Software

末级长叶片是汽轮机机组的关键部件之一。汽轮机的效率和末级叶片的排汽面积(叶片高度)息息相关。近年来伴随着高参数汽轮机以及半转速大容量汽轮机在国内的推广应用,一系列长度为1 000 mm以上的全速长叶片以及1 600 mm至1 900 mm等级的半速长叶片的开发都被提上了议事日程,其中1 710 mm叶片是一个已经实际开发成功的产品。以其为例对长叶片开发所涉及的方法,包括一些针对长叶片的新思路,进行阐述,重点对采用现代CAE工具开发长叶片的过程进行了论述。通过比较不同方法得到的计算结果以及试验结果,证明当前将商业CAE程序应用到长叶片的工程研发领域,可以同时满足精度和效率的要求。

The last stage long rotating blade is one of the key components in a steam turbine unit.Recently,a series of half-speed last stage rotating blades which range from 1 600 mm to 1 900 mm length and full-speed blades beyond 1 000 mm are proposed in order to meet the high economic and security requirements of the power plants,among which the 1 710 mm long blade is an important application using mostly domestic technology.It is presented to describe the progress of creating a long rotating blade using CAE software for a large scale steam turbine.After the strategy of how to determine the appropriate height of the last stage rotating blade for the steam turbine is set up,the quasi/full-3D flow field of the last three stages in LP casing is calculated.Furthermore,a sophisticated blade structure design and CAE analyzing system for a long blade are introduced to obtain the detail dimension of the blade.Commercial FEA software,such as ABAQUS,is employed to ensure the good reliability of the blade during service period.Finally,in terms of the experiment process,the whole pre-design CAE phase of the extra-long turbine blade is examined and verified.