电动机前置和电动机后置潜水贯流泵装置水力性能比较

为了推动潜水贯流泵装置在低扬程泵站中的应用,提出了电动机前置的新型潜水贯流泵装置型式.基于某大型潜水贯流泵站的设计参数,分别设计了电动机前置和电动机后置2种型式的潜水贯流泵装置方案,采用数值模拟方法对这2种型式潜水贯流泵装置的三维流场分别进行数值计算和分析,预测泵装置的扬程和效率,并比较其水力性能和结构特点.结果表明:这2种型式潜水贯流泵装置的进水流道内水流收缩都平缓均匀、流线层次分明,电动机前置方案出水流道内水流扩散平缓且无旋涡或其他不良流态,电动机后置方案出水流道内主流偏向流道扩散段右下侧并在左上侧产生旋涡;电动机前置方案的流道水头损失小、泵装置效率高,水力性能优于电动机后置方案;电动机前置方案的潜水电动机密封更可靠、电动机支撑结构更合理、水泵导叶体的水力设计更成熟.潜水贯流泵装置应优先采用电动机前置方案.

Comparison of hydraulic performance between submersible tubular pump device with motor front and rear arrangements

In order to make the submersible tubular pump device get better and more application in the pumping station with low head,a new type of motor front arrangement for submersible tubular pump device was put forward.Based on the design parameters of a large-scale submersible tubular pumping station,two types of submersible tubular pump systems which are submersible tubular pump devices with motor front and rear arrangement were designed respectively.The three-dimensional flow fields in the two types of submersible tubular pump devices were calculated and analyzed respectively with the method of numerical simulation.The head and efficiency of pump devices were predicted,and the hydraulic performances and structural characteristics of the two types of submersible tubular pump devices were compared.The results show that the water flow contracts gently and evenly with distinct flow lines in the inlet conduits of the two types of submersible tubular pump devices.The water flow diffuses gently without vortex or other bad flow pattern in the outlet conduit of the motor front arrangement scheme.The main flow is inclined to the lower right side and vortex exists on the upper left side of the conduit diffusion section in the outlet conduit of the motor rear arrangement scheme.The conduit head loss of the motor front arrangement scheme is small and the pump device efficiency is high;the hydraulic performance of the motor front arrangement scheme is better than that of the motor rear arrangement scheme.The motor seal of the motor front arrangement scheme is more reliable,the motor supporting structure is more reasonable and the hydraulic design of the guide vane of the pump is more mature.Therefore,the scheme of submersible tubular pump device with motor front arrangement should be gi-ven priority to the scheme of motor rear arrangement.