涡轮动叶叶顶间隙导致工质泄漏,使得叶栅流动损失增加。为了减少叶栅流动损失并提升涡轮效率,本文以1.5级Lisa涡轮为研究对象,采用正交优化的方法,通过数值模拟的手段探究了动叶叶顶凹槽耦合射流结构的流动特性,分析了此叶顶结构对于泄漏流的控制机理以及其对涡轮效率的影响。最终得到一种最优的涡轮动叶叶顶凹槽耦合侧壁射流结构,即在动叶叶顶设置凹槽,并在压力侧(PS)侧壁上开设等间距射流孔。研究结果表明,相比传统凹槽耦合展向射流方法,凹槽耦合侧壁射流所需的总射流量降低90%,泄漏流量降低3.9%,且涡轮效率增幅相比其他传统控制方式提升显著,相较于原始涡轮效率提升1.55%。

The tip clearance of the turbine blade leads to the leakage of the working fluid, which increases the flow loss of the cascade. In order to reduce the cascade flow loss and improve the turbine efficiency, this paper takes the 1.5-stage Lisa turbine as the research object, and uses the orthogonal optimization method to explore the flow characteristics of the blade tip groove coupling jet structure by means of numerical simulation. The control mechanism of the tip structure on the leakage flow and its influence on the turbine efficiency are analyzed. Finally, an optimal turbine rotor blade tip groove coupling side wall jet structure is obtained, that is, a groove is set at the rotor blade tip and an equal spacing jet hole is opened on the pressure side ( PS ) side wall. The results show that compared with the traditional groove coupling spanwise jet method, the total jet flow required for the groove coupling side wall jet is reduced by 90 %, the leakage flow is reduced by 3.9 %, and the turbine efficiency is increased compared with other traditional control methods. Significantly, compared with the original turbine efficiency increased by 1.55 %.

上海市科学技术委员会项目,利用压缩蒸汽储能实现火电机组灵活性调峰的方法(No.22010503100)