高效平面S形轴伸泵装置优化设计与模型试验

平面S形轴伸泵装置是低扬程泵站的重要装置,现有的平面S形轴伸泵装置效率较低,难以推广应用。对传统的S形弯管和流道进行优化设计,提出平面S形轴伸泵装置方案,通过CFD数值模拟计算,获得了全流道内部流场,显示了优良的流动特性,进水流道出口轴向流速均匀度达到99.2%以上。泵装置在高精度水力机械试验台进行试验,其性能在水泵叶片角2°下流量Q=244.21 L/s,扬程H=2.003 m,最高装置效率为78.35%。在叶片角-2°下,流量Q=232 L/s,扬程H=1.05 m,效率为68%,满足设计运行工况运行要求;叶片角-2°下最高效率点出现在Q=213.79 L/s、扬程H=1.74 m,效率为77.1%。泵装置最高运行扬程大于3 m,满足泵站最高扬程运行要求。模型泵装置试验的结果,验证了数值计算结果,二者在高效区一致。在叶片角度-4°、-2°、0°和2°,扬程1.7~2.0 m时,模型试验最高泵装置效率为77.1%~78.35%,达到实际工程应用的较高要求。高效平面S形轴伸泵装置在黄金坝闸站实际工程应用表明,泵机组运行平稳,性能良好。

Optimal Design and Model Test of High Performance S-shaped Shaft Extension Pump System

S-shaped shaft extension pump is an important device for low-lift pumping station. The efficiency of the existing S-shaped extension pump system can not satisfy the users, so it is difficult to be applied to the practice. Based on CFD numerical simulation, an optimization of the traditional S-shaped bend was made, a new S-shaped shaft extension pump scheme was proposed. A whole flow passage of the system was obtained. The results displayed excellent flow characteristics of the system and the axial velocity uniformity at outlet section of the suction passage at different flow rates was over 99.2%;the efficiency of the system was higher than 77.1% from the pump performance prediction which was approved by the model test. The model pump test was conducted in a high accuracy test standed for hydraulic machinery to validate the numerical results. Under the blade angle of -4°, -2°, 0° and 2°, the lifting heads were between 1.7m and 2.0m, and the maximum pumping efficiencies reached 77.1%~78.35%, which met the higher requirements for application in practice. The horizontal S-shaped shaft extension pump system was successfully applied to a pumping station of Gold-Dam water diversion project in Yangzhou City. The field test of pumping station showed that the hydraulic performances of the high efficient planar S-shaped shaft extension pump system for the prototype system and the performance results of the model system test were basically coincident. The pump units were running stably, and vibration and noise were small. The high efficient planar S-shaped shaft extension pump system had advantages in simple structure, compact layout, less occupation of land, large working space, convenient installation and maintenance. The operation cost of the pumping station would be low due to the hydraulic losses of the system were significantly reduced, especially for the long-running pumping station which had effects on energy saving and consumption reducing;and it was convenient to be used in small and medium sized pumping station to implement standardized construction.