流量与环量对低扬程泵装置流道水头损失的交叉影响  

Cross Influence of Discharge and Circulation on Head Loss of the Conduit of Pump System With Low Head

作　　者：陆伟刚[1] 董雷[1] 王兆飞[1] 陆林广[1] 

机构地区：[1]扬州大学水利科学与工程学院,江苏扬州225009

出　　处：《应用数学和力学》2012年第12期1431-1441,共11页Applied Mathematics and Mechanics

摘　　要：流道水头损失与流量及环量之间的关系,是低扬程泵装置水力设计理论中对提高其水力性能的研究具有较大影响的重要问题.低扬程泵装置水泵导叶出口水流所具有的速度环量使上述关系变得复杂起来,需全面认识.研究结果表明:在无环量的条件下,进、出水流道水头损失与流量平方成正比;在Reynolds数达到阻力平方区要求的条件下,在一定转速范围内,对于不同转速下运行时的相似工况,流道水头损失与流量平方成正比,表现为泵装置效率保持不变;低扬程泵装置中设计流量时的出水流道水头损失决定于导叶出口水流的速度环量,两者之间的关系为一开口向上的曲线,存在最优环量;在低扬程泵装置变工况运行的条件下,出水流道水头损失受流量和环量的交叉影响,在水泵正常运行工况范围内,流道水头损失与流量之间呈现出接近于线性的关系,其机理有待进一步深入研究.The relationship between head losses and discharge and circulation for the conduit of a pump system with low head is an important problem having obvious influence on the im- provement for its hydraulic performance. The velocity circulation from the pump guide vane makes the relationship more complicated, which has to be understood comprehensively. The research results indicate that under the condition of zero circulation, the head loss of inlet and outlet conduit is in proportion to the square of discharge; under the condition for Re number to be satisfied with the resistant square area, the conduit loss is in proportion to the square of dis- charge for the similar working points with different speeds in a certain rotational speed range, which indicates the pump system efficiency constantly; the outlet conduit loss of design dis- charge for a pump system with low head depends on the velocity circulation from the guide vane exit, and the relationship between the loss and the circulation is an open curve with up di- rection which means there is an optimal circulation for the loss; under the condition of various working points for a pump system with low head, the head loss of the outlet conduit is under the cross influence of both the discharge and circulation, as a result the relationship between the head loss and discharge is almost the linear, the mechanism of which needs to be further studied.

关 键 词：流量 环量 低扬程 泵装置 流道 水头损失 

分 类 号：TV136.2[水利工程—水力学及河流动力学] TV675