大型汽轮机汽流激振研究现状及展望

The Status Quo and Prospect Concerning a Study on Steam Flow Excitations in Large-sized Steam Turbines

分析和总结了大型汽轮机汽流激振的产生机理及特征,对国内外汽流激振研究概况作了介绍,并重点对效率系数β的取值进行了介绍和分析,认为β值与偏心、叶顶间隙、叶距、叶片进出口相对汽流角及升力系数等诸多因素相关,且取值跨度较大。从加大转子刚度、增大系统阻尼和减小汽流激振力等方面对汽轮机汽流激振的预防及消除措施进行了总结,最后从效率系数β的取值、非线性动力学问题的求解、汽封的形式、叶片激振力的优化及轴系稳定性等5个方面对大型汽轮机汽流激振的研究存在的问题及今后的研究方向做了展望。

The generation mechanism and characteristics of steam flow excitations in large-sized steam turbines are analyzed and summarized along with an overview of the general situation of the research on steam flow excitations both at home and abroad. Special emphasis is laid on an analysis concerning the selection of efficiency coefficient β.It is believed that the efficiency coefficient β depends on such factors as eccentricity, blade tip clearance, blade spacing, blade inlet and outlet relative steam-flow angle and lift force factor etc. and can take a wide range of values for selection. Measures taken for preventing and eliminating steam flow excitations in steam turbines are summed up from the perspective of increasing rotor rigidity, increasing system damping and decreasing steam flow excitation force etc. Finally, the problems existing in the study of steam flow excitations in large-sized steam turbines are discussed and a forecast of the future research trend is given from the standpoint of selecting the efficiency coefficient β,types of packing rings, solving non-linear dynamics problems, optimizing blade excitation forces and ensuring the stability of the shaft system etc. altogether five aspects.