离心泵做透平的叶片弯曲形状分析  

Analysis on Blades Curved Shape of Centrifugal Pump as Turbine

作　　者：杨孙圣[1] 张慧 孔繁余[1] 许荣军 

机构地区：[1]江苏大学流体机械及工程技术中心,江苏镇江212013 [2]镇江市自来水公司,江苏镇江212013 [3]南京蓝深制泵集团股份有限公司,南京211500

出　　处：《上海交通大学学报》2016年第9期1467-1472,1479,共7页Journal of Shanghai Jiaotong University

基　　金：国家自然科学基金资助项目(51209106);江苏省青年自然科学基金(BK20130517);江苏大学引进人才项目(13JDG081)

摘　　要：为提高液力透平的效率,设计了前弯和后弯2种叶片弯曲形式的叶轮,利用实验、理论和数值计算相结合的方法对离心泵做透平的水力性能进行了研究.分别对后弯式叶轮泵工况、透平工况和前弯式叶轮液力透平工况3种情况的水力性能进行了分析,得到泵工况和2种液力透平工况下外特性曲线的差别,并分析了液力透平各过流部件内部功率损失分布.研究结果表明:泵作透平的外特性曲线与泵的不同,Q-H曲线随流量增加而逐渐增加;2种叶轮形式的液力透平对比中,前弯形叶轮在最高效率点的流量、扬程、轴功率和效率分别比后弯形叶轮高;前弯形叶轮高效点以及高效点之后的流量效率曲线高于后弯形叶轮的流量效率曲线,流量扬程曲线低于后弯形叶轮的流量扬程曲线,2种形式的叶轮轴功率相差不大.液力透平各过流部件功率损失分布表明,前弯形叶轮内部的功率损失的减小是液力透平效率提高的主要原因;对比2种叶片弯曲形状液力透平的流量和扬程系数可知,前弯式叶轮的流量系数和扬程系数均大于同尺寸后弯式叶轮的,因此前弯叶轮更适合于液力透平工况运行.To improve the efficiency of hydraulic turbine, backward and forward-swept impellers were designed. Experimental, theoretical and numerical methods were combined to study the hydraulic performance of backward and forward impellers. Experiment and numerical analyses were conducted on three conditions, including pump and turbine of the back ward-swept impeller and turbine condition of the forward- swept impeller. The performance difference of these two impellers was found by adopting the computational fluid dynamic software ANSYS CFX. The power loss distribution of each part of the hydraulic turbine was analyzed. The experimental research of these impellers was conducted. The results show that the characteristic performance of the turbine condition is different from that of the pump condition, and the head increases with the flow rate increasing. The turbine condition is more suitable for mass flow rate operation. Compared with the backward-swept impeller, the flow rate, head, shaft power and efficiency at the best efficiency point （BEP） of the forward-swept impeller are increased. After BEP, the r/-Q curve of the impeller with forward-swept shape is higher and the H-Q curve is lower than that of backward-swept shape. The variation of the shaft power of these two impellers is small. The power loss within each part shows that it is the decrease of hydraulic loss within the impeller that causes the increase of the efficiency of the turbine. Compared with the coefficient of flow capacity and head in the two swept impellers, the for- ward-swept impeller is more suitable for turbine mode.

关 键 词：离心泵做透平 前弯形叶轮 后弯形叶轮 

分 类 号：TH322[机械工程—机械制造及自动化]