两种叶轮型式潜水排污泵的内流特征与通过能力

为了比较具有不同叶轮型式的2台潜水排污泵的通过性能,采用计算流体动力学方法和SST湍流模型,分别选用清水和固液两相流体为液体介质,模拟双流道污水泵与双叶片污水泵在3种不同流量工况(0.8Q,1.0Q,1.2Q)下的流动特征.对比2台污水泵在输送清水与固液两相流体时的流动参数分布,并对输送这2种介质时的固体颗粒速度和固相颗粒体积分数分布进行分析.结果表明:与双叶片污水泵相比,双流道污水泵内的流动参数分布更加均匀.双流道污水泵叶轮进口存在1个大尺度旋涡,在一定程度上提高了双流道污水泵的通过能力.对比双流道污水泵与双叶片污水泵内固相颗粒分布规律,发现双流道污水泵内固体颗粒的速度更快,局部固体颗粒聚集程度较小,因而双流道污水泵的通过能力强于双叶片污水泵.

Inflow characteristic and transport capability of two submersible sewage pumps with different impellers

The transport capability of two submersible sewage pumps, equipped respectively with a dual-channel and a double-blade impeller, was comparatively investigated. The computational fluid dynamics(CFD)technique and the shear stress transport(SST)turbulence model were used in combination to simulate flows in the two pumps. Pure water and solid-liquid two-phase fluid were selected as two working mediums. Three flow-rate conditions of 0.8Q, 1.0Q and 1.2Q were considered. Flow parameter distributions were compared between the two pumps as the two mediums were transported respectively. Emphasis was placed on the distributions of solid particle velocity and solid-phase volume fraction as the solid-liquid two-phase fluid was transported. The results show that the flow parameter distributions in the dual-channel sewage pump are more uniform than than those of double-blade se-wage pump. The dual-channel sewage pump is featured by a large-scale vortex at the impeller inlet which enhances its transport capability. Compared with the rule of solid particle distribution between the dual-channel and double-blade sewage pumps, it is found that in the dual-channel pump, the solid particle velocity is high and the local accumulation of solid particle is mitigated, thus signifying higher transport capability relative to its counterpart.