单级双吸双层蜗壳离心泵变工况运行特性研究

Study on the Variable Operation Characteristics of Single Stage Double Suction Double Volute Centrifugal Pump

为研究双层蜗壳离心泵变工况运行时的泵内流动特性,应用计算流体动力学技术对模型泵内部的流场进行数值模拟,并对设计工况和非设计工况下的压力等值线图和速度等值线图进行分析。结果表明,设计工况下泵内压力速度分布较均匀,流动轴对称性较好;小流量工况下靠近隔舌附近和蜗壳隔板始端附近叶轮内的压力和速度分布不均匀性增加,轴对称性变差;大流量工况下,叶轮内和叶轮周围蜗壳内流动对称性相对于小流量工况下的情况好,但隔板外侧压力和速度分布不均匀,会使流动损失增大。

In order to study the internal flow characteristics of the double volute centrifugal pump under variable operating conditions, the computational fluid dynamics method was applied to simulate the internal flow of the model pump, the pressure contours and velocity contours of the design and off-design conditions were analyzed. The results show that uniform pressure and velocity distribution and the fine axial symmetry of pressure and velocity distribution in the pump under the design condition. The pressure and velocity in the impeller near the tongue and the beginning of the volute partition are unevenly distributed and the inferior axisymmetry under the small flow condition. In large flow condition, the flow symmetry in and around the impeller is significant compared with the small flow condition however the uneven pressure and velocity distribution on the outside of the partition will cause the higher flow loss.