叶片交错布置对双吸泵空化性能的影响分析  

Effects of Staggered Blades on Cavitation Characteristics of Double-suction Centrifugal Pump

作　　者：韩伟[1,2] 郑昊 王丽琼 张振中 苏敏 

机构地区：[1]兰州理工大学能源与动力工程学院,兰州730050 [2]甘肃省流体机械重点实验室,兰州730050 [3]山东双轮股份有限公司,威海264203 [4]兰州理工大学电气工程与信息工程学院,兰州730050

出　　处：《农业机械学报》2017年第12期124-131,140,共9页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金项目(51209113)

摘　　要：为研究叶片交错布置对双吸离心泵空化性能的影响,选用RNG k-ε湍流模型和基于Rayleigh-Plesset方程的空化模型,考虑泵腔和工艺圆角的影响,分别对叶片交错角为0°、10°、15°、20°、30°的5组角度在设计工况下进行了全流场空化流动模拟和性能试验。为突出研究结论的共性,引入交错度的定义,并分析了不同交错度下叶轮中间流面的空泡分布、扬程和叶轮扭矩变化,同时验证了所选数值计算模型的准确性;从数值分析中得到,选择合理的交错度可以有效提高双吸离心泵的抗空化性能。不同交错度下叶轮所受扭矩急剧下降时对应的有效空化余量均不同,当交错度为1时,叶轮所受扭矩在未空化时较为稳定且在空化时损失较少;当有效空化余量小于临界空化余量时,双吸离心泵叶轮流道内低于当地空化压力的区域,交错度为1时相对最少,即空泡占据流道过流面积最少,此时双吸叶轮的空化特性也相对较好。In order to identify effects of staggered blades on cavitation characteristics of double-suction centrifugal pump,considering the influence of the shrouds of pump and fillet,the blades of both sides of the impeller were separated circumferentially at 0°,10°,15°,20° and 30° staggered angles,respectively.RNG k-ε turbulence model and Rayleigh-Plesset equation were applied to simulate cavitation characteristics and performance test under design conditions. In order to highlight the generality of the research conclusion,the definition of staggered degree was introduced and the vapor volume fraction on the middle stream surface of impeller and head and the variation of the impeller torque at different staggered degrees were analyzed. Compared with experimental values,the results indicated that the prediction results were accurate to some extent; it can be seen that the selection of reasonable staggered degree can improve the performance of anti-cavitation. At different staggered degrees,the corresponding net positive suction head values were different when the impeller torque was subjected to a sharp decrease,when the staggered degree was at 1,the impeller torque was stable in cavitation and relatively less in cavitation; when net positive suction head was under critical net positive suction head,the region of static pressure was lower than the local cavitation pressure at the double-suction centrifugal pump impeller channel and the vapor occupied the least flow area at the flow channel,staggered degree at 1 was the least. Therefore,the cavitation characteristics were relatively good when the staggered degree was at 1 to provide a theoretical basis for improving the cavitation characteristics and the safe operation of doublesuction centrifugal pump.

关 键 词：双吸离心泵 交错叶片 空化 数值模拟 

分 类 号：TH311[机械工程—机械制造及自动化]