基于反问题设计的离心泵叶轮泥沙磨损特性优化研究

离心泵被广泛应用于我国黄河沿岸的提灌泵站中。黄河水中的泥沙对离心泵造成的泥沙磨损问题严重影响离心泵的安全高效运行。反问题设计是离心泵叶轮优化设计的常用方法，但作为其关键设计参数的叶片载荷加载方式对离心泵磨损性能的影响尚不清楚。针对叶片载荷加载方式对离心泵叶轮泥沙磨损特性影响的问题，采用固液两相流数值计算的方法，研究了前盖板前加载后盖板后加载、前后盖板均偏中加载以及前后盖板均偏后加载3种不同叶片载荷加载方式对离心泵水力性能、叶轮磨损特性和固液两相流流场特性的影响。结果表明：相比于其它方案，前后盖板均偏中加载方案得到的离心泵具有较优的水力性能。在各工况下，相比于原叶轮，前后盖板均偏中加载方案的叶片最大磨损率减小25%~73%，小流量工况下可减小73%，大流量工况下可减小25%，明显提高了叶片的磨损性能。相比于原叶轮，3种优化方案在前盖板背面流线上的压力分布更均匀光顺;在小流量工况下，前后盖板均偏中加载方案和前后盖板均偏后加载方案叶片表面的固相体积分数较小，各种方案得到的叶片表面的速度分布基本相同;在额定流量工况下，原叶轮的叶片表面体积分数较小，前后盖板均偏中加载方案和前后盖板均偏后加载方案的叶片工作面固相速度大的区域相对较小，固相速度也有所减小。因此，前后盖板均偏中加载方案具有较优的水力性能和磨损特性，可为离心泵叶轮磨损特性的优化提供参考。

Study on optimization of sediment erosion performance for centrifugal pump impeller based on inverse design method

The centrifugal pump is widely used in pump station along the Yellow River in China.The erosion problem of centrifugal pump caused by the sediment in the Yellow River seriously affects the safe and efficient operation of the centrifugal pump.The inverse design is a popular method to improve the performance of centrifugal pump, but the effect of blade loading mode as a key design parameter on erosion performance is still unclear.In this paper, in order to solve the problem of the influence of blade loading mode on the sediment erosion characteristics of centrifugal pump impeller, the effects of three different blade loading modes which are load-front for shroud and load-back for hub, load-middle both for shroud and hub, load-back both for shroud and hub on the hydraulic performance of centrifugal pump, the erosion characteristics of impeller and the flow field characteristics of solid-liquid two-phase flow are studied by using the numerical calculation method of solid-liquid two-phase flow.The results show that the hydraulic performance of the centrifugal pump obtained by scheme of load-middle both for shroud and hub is better compared with other schemes.Under various operation conditions, the maximum erosion rate of the blade obtained by scheme of load-middle both for shroud and hub is reduced by 25%~73%.It can be reduced by 73% under small flow condition and 25% under large flow condition.The erosion performance of the blade from scheme 2 is significantly improved.Compared with the original impeller, the pressure distributions of the three optimization schemes on the suction surface streamlines of the shroud are more uniform and smooth.Under the condition of low flow rate, the solid volume fractions on the blade surfaces of load-middle both for shroud and hub, load-back both for shroud and hub are small.The velocity distributions on the blade surfaces of all schemes are basically the same.Under the rated flow condition, the solid volume fraction on blade surface of the original impeller is small.The regions with high solid velocity on the blade surfaces of load-middle both for shroud and hub, load-back both for shroud and hub are relatively small, and the solid velocities are also decreased.Therefore, the hydraulic performance and erosion characteristic of scheme of load-middle both for shroud and hub are better, which can be provided as a reference to optimize the erosion characteristic of the centrifugal pump.