导叶叶片厚度对核主泵性能的影响

Effect of guide vane thickness on performance of nuclear main pump

为了研究导叶叶片厚度对核主泵性能的影响,在核主泵其他参数均不变的前提下只改变导叶叶片的厚度,通过数值方法预测了五种不同导叶叶片厚度下核主泵的水力性能.结果表明:设计工况下,导叶叶片均匀减薄0.5倍时,导叶间的排挤减小,但导叶的导流能力以及能量转化能力下降,最终使得核主泵的扬程、效率降低;导叶叶片前1/2段均匀加厚1.5倍时,较其他四种方案,其流场分布最为均匀,导叶内的流动损失也最小,模型泵的扬程、效率最高.在满足导叶叶片结构强度的前提下,可根据导叶流道的不同位置结合其不同流动状态对叶片进行非均匀加厚,以减小流道内的水力损失并最大程度地将动能转化为压能,从而提高核主泵的内外特性.

In order to research the effect of guide vane thickness on performance of nuclear main pump, the hydraulic performance of nuclear main pump with five thicknesses of guide vanes is predicted by means of numerical approach on the premise that all geometric parameters of the pump but its guide vane thickness are unchanged. The result shows that on the designed working condition and when the guide vane thickness is uniformly reduced by half, the flow-squeeze by the guide vane will be reduced, but its flow-guidance ability and the capacity of energy conversion will decline, making the head and efficiency of the pump to fall eventually. Compared with other four options, when the front half part of the guide vane is thickened by 1.5 times, its flow field distribution will be most uniform and the flow losses the least, so that the head and efficiency of the modeled pump will be the highest. On the premise that the guide vane structure meets the demand of its structural strength, the guide vane can be thickened nonuniformly according to the difference of position on guide vane passage and flow condition in there in order to reduce the hydraulic loss in guide vane passage and convert the kinetic energy into pressure energy to the full extent, so that the internal and external characteristics of the pump will be improved consequently.