Effects of distance between impeller and guide vane on losses in a low head pump by entropy production analysis
Effects of distance between impeller and guide vane on losses in a low head pump by entropy production analysis
复制标题
通过熵产分析研究叶轮与导叶之间的距离对低扬程泵损失的影响
DOI：
10.1177/1687814016679568
复制
发表时间：
2016-11-01
影响因子：
2.1
通讯作者：
Chen, Jia
中科院分区：
文献类型：
--
作者：
Pei, Ji;Meng, Fan;Chen, Jia
低扬程泵广泛应用于许多重要的水利工程中，以排水和灌溉为目的。一种新型的低扬程泵——双向轴列式泵，由s形叶轮、直导叶片、进口段和出口段组成。从实际工程中得知，双向轴列泵叶轮与导叶之间的距离对泵的性能影响很大；然而，由于其独特的叶轮和导叶结构，两者之间的距离不能轻易地由一般经验公式确定。因此，本研究对正、负旋转条件下6个导叶位置进行了三维非定常数值模拟，并通过实验验证了结果的准确性。采用基于数值结果的熵产法评估了距离对内部流动损失分布和总功率损失的影响，从而更好地理解了水力损失机理。结果表明：在正旋转工况下，双向轴列泵叶轮与导叶之间的距离会影响泵的效率，其中湍流耗散是主要损失；该研究可为提高低扬程泵的水力效率提供理论指导。
The low head pump is widely used in many important water conservation projects for drainage and irrigation purposes. A new type of low head pump, the bidirectional shaft tubular pump, consists of an S-shaped impeller, a straight-guide vane, an inlet section, and an outlet section. As known from the practical project, the distance between the impeller and guide vane of the bidirectional shaft tubular pump greatly affects a pump’s performance; however, because of its unique impeller and guide vane structure, the distance between the two cannot be easily determined by general empirical formulas. Therefore, in this research, three-dimensional unsteady numerical simulations were performed for six guide vane positions under positive and negative rotation conditions, and the accuracy of the results was experimentally verified. The entropy production method based on numerical results was used to evaluate the effect of the distance on the internal flow-loss distribution and overall power loss, and as a result, a better understanding of the hydraulic loss mechanisms was obtained. The results show that the distance between the impeller and guide vane of a bidirectional shaft tubular pump can affect the pump’s efficiency under a positive rotation condition, and turbulence dissipation is the dominant loss. This study can provide theoretical guidance to improve the hydraulic efficiency of low head pumps.