大型贯流式泵站快速门加速启动过渡过程

为研究大型贯流式泵站机组闸门加速启动过程中的外特性参数变化及流态变化,对灯泡贯流泵机组进行三维建模,采用Fluent软件中的UDF来控制闸门的启动过程,使用铺层法动网格技术来控制闸门处网格生成与消灭,并设定S-A模型作为湍流模型,对灯泡贯流泵机组启动过程进行瞬态数值模拟.计算结果表明:当贯流泵机组快速门以10倍设计速度启动时,机组的转速与流量将以更快的速度达到额定转速与额定流量,同时瞬间最大倒灌流量相比未加速启动时增加了30%.当贯流泵机组处于倒流状态时,靠近轮毂处叶轮叶道压力面的压强呈现出从叶轮进水边向出水边逐渐递增的分布规律.当机组处于零流量的临界状态时,混乱的流态导致压力集中及脱流现象加重,叶轮进水边负压区范围扩大且程度加深.

Accelerated starting transition process of rapid gate in large tubular pumping station

In order to study the change of external characteristic parameters and flow pattern during the acceleration start-up of large tubular pumping units, a three-dimensional model of bulb tubular pumping units was built, UDF in Fluent software was used to control the start-up process of the gates, and dynamic grid technology of laying method was used to control the generation and elimination of grid at the gates. Setting S-A model as turbulence model, the transient numerical simulation of the whole flow channel for the start-up process of bulb tubular pump unit was carried out. The calculation results show that when the fast gate of tubular pump unit starts at 10 times the rated speed, the speed and flow rate of the unit will reach the rated speed and flow rate faster, and the instantaneous maximum back-flow rate will increase by 30% compared with that of the non-accelerated start-up. When the tubular pump unit is in the backward flow state, the pressure on the impeller blade passage near the hub pre-sents a gradually increasing distribution law from the impeller inlet side to the outlet side. When the unit is in the critical state of zero flow rate, the chaotic flow leads to further aggravation of pressure concentration and flow separation phenomenon, and the negative pressure area at the inlet edge of impeller is wi-dened and deepened.