低扬程立式泵进水流道基本流态及水力性能的比较

Comparison of Basic Flow Pattern and Hydraulic Performance in Suction Boxes of Low Lift Vertical Axial-Flow Pumps

采用数值计算和模型试验的方法分别研究了低扬程立式泵装置常用的肘形、钟形和簸箕形等三种形式进水流道的基本流态,给出了表达这三种形式进水流道水力性能的主要指标。结果表明:三种形式进水流道都可为水泵叶轮室进口提供良好的进水流态,但流道水力损失差别较大;肘形进水流道流态简单、水力损失小,钟形和簸箕形进水流道的流态较复杂、水力损失较大;对于年运行时数较多的大型泵站,宜优先选用水力性能最好的肘形进水流道。

Basic flow patterns in 3 types of suction boxes are studied respectively by both numerical calculation and model test, and the essential hydraulic indexes are listed. The boxes, including elbow inlet, bell-like inlet and dustpan like inlet, are usually applied for vertical pump of low head. The results make it clear that all of them can offer favorable flow pattern to the impeller-inlet; the flow pattern in the elbow inlet is simpler and its hydraulic loss is lower, the flow patterns in the bell like and dustpan-like inlet are more complex and their hydraulic loss is larger. Consequently, elbow inlet, with the best hydraulic performance, should be preferentially chosen for a large pump station with long runtime.