导叶时序效应对液力透平性能影响的研究

Research on the Effect of Guide Vane Clocking Effects on Hydraulic Turbine Performance

液力透平的能量回收特性及压力脉动特性直接影响到装置是否能够高效、稳定运行。为了提高液力透平的运行稳定性,探究多级透平导叶与环形蜗壳进口的相对位置(时序效应)对其外特性和压力脉动的影响,建立了导叶在一个栅距内4种不同时序位置的透平模型,为了简化计算模型,取多级液力透平的首级叶轮进行数值模拟计算,对比分析了不同方案下该透平的能量回收特性及压力脉动特性。结果表明:当透平导叶A叶片的时序位置θ为110°时,透平在额定流量时的能量回收效率最高;当导叶A叶片的时序位置θ为90°时,透平蜗壳和导叶内的压力脉动能量幅值最大,导叶A叶片的时序位置θ为110°时,透平的压力脉动幅值最小;因此,透平蜗壳进口周向中心面位于两片导叶的中间位置以获得更好的外特性,并使得其内部压力脉动幅值更小。

The energy recovery characteristics and pressure pulsation characteristics of the hydraulic turbine directly affects whether the device can operate efficiently and stably. In order to improve the operating stability of the hydraulic turbine,the influence of the relative position( clocking effect) of the multi-stage turbine guide vane and the inlet of the annular volute on its external characteristics and pressure pulsation are explored. In this paper,turbine model with four different clocking positions for a guide vane within a pitch are established. In order to simplify the calculation model,the first stage impeller of a multi-stage hydraulic turbine is used for numerical simulation calculations,andthe energy recovery characteristics and pressure pulsation characteristics of the turbine under different schemes are compared. The results show that when the clocking position θ of turbine blade A is 110°,the turbine has the highest energy recovery efficiency at the rated flow rate. When the clocking position θ of the guide vane A blade is 90°,the turbine volute and the pressure pulsation energy amplitude in the guide vane is the largest,and when the clocking position θ of the vane A vane is 110°,the pressure pulsation amplitude of the turbine is the smallest. Therefore,it is recommended that the center of the inlet of the turbine scroll be located in the two guide vanes middle position to get better external characteristics and make its internal pressure pulsation amplitude smaller.