Abstract:To study the variation of internal flow in self-priming process of the self-priming centrifugal pump, a flow visualizable transparent self-priming centrifugal pump prototype was designed. The pressure, flow rate and rotational speed, etc., were recorded in the self-priming process of the pump with Labview virtual instrument in time domain, and the influence of rotational speed on the outlet pressure and self-priming time of the pump was investigated. Meanwhile, the air-water two-phase flow patterns in the key components of the pump were shot with a high-speed camera at various stages of the self-priming process, and transient variations of the two-phase flow in the pump were analyzed. The results show that the self-priming process of the pump can be divided into three stages in terms of the variations of pressure and flow rate with time, i.e., start-up, stable and sudden change stages. This feature can also be observed in the outlet pressure profiles at different rotating speeds. In the stable self-priming stage, the faster the impeller rotating speed, the larger the fluctuation amplitude in the outlet pressure, the higher the final stable pressure and the shorter the self-priming time. Bubble splitting phenomenon exists in the volute and impeller during the self-priming process. Firstly, a single large bubble is gradually elongated into a bubble in dumbbell shape. Then the connecting channel in the middle of the bubble disappears and the bubble is split into two small ones to promote air separation and complete the self-priming process.
[1]罗金耀. 节水灌溉理论与技术[M\]. 武汉:武汉大学出版社,2003.[2]张塬东, 张琼,吴大转,等.立式双级自吸泵水力性能分析及内部结构改进[J\].流体机械,2016,44(12):33-39.ZHANG Yuandong,ZHANG Qiong,WU Dazhuan,et al. Improvement design of a vertical doublestage selfpriming pump[J\]. Fluid machinery, 2016,44(12):33-39. (in Chinese)[3]袁寿其,李红,施卫东. 新型喷灌设备设计理论与技术[M\]. 北京:机械工业出版社,2011.[4]沙毅.旋涡泵内部流动分析及水力设计[J\].流体机械,2016,44(12):29-32,53.SHA Yi. Interior flow analysis and hydraulic design method of vortex pump[J\]. Fluid machinery, 2016,44(12):29-32,53. (in Chinese)[5]刘建瑞,苏起钦. 自吸泵气液两相流数值模拟分析[J\]. 农业机械学报,2009,40(9):73-76.LIU Jianrui, SU Qiqin, et al. Numerical simulation on gas-liquid twophase flow in selfpriming pump [J\]. Transactions of the Chinese Society for Agricultural Machinery,2009,40(9):73-76. (in Chinese)[6]姜波. 自吸离心泵气液两相流动的可视化研究[D\]. 镇江:江苏大学,2015.[7]潘中永,张大庆,李彦军,等. 喷灌与滴灌两用自吸泵设计与分析[J\]. 华中科技大学学报(自然科学版),2014,42(3):122-126.PAN Zhongyong,ZHANG Daqing,LI Yanjun, et al. Design and analyses of sprinkler irrigation and drip irrigation dualuse selfpriming pump [J\]. Journal of Huazhong University of Science and Technology (natural science edition),2014,42(3):122-126. (in Chinese)[8]SHKOLNIKOV V,RAMUNAS J,SANTIAGO J G. 〖JP2〗A selfpriming, roller-free,miniature,peristaltic pump ope〖JP〗rable with a single,reciprocating actuator [J\]. Sensors and actuators a physical,2010,160(1-2):141-146. [9]王尧耀.自吸泵自吸性能的影响因素[J\]. 湖南农机,2014,41(7): 95-96.WANG Yaoyao. The influence factors of selfpriming pump selfpriming performance [J\]. Hunan agricultural machinery,2014,41(7): 95-96. (in Chinese)[10]王涛,徐志强. 喷灌泵自吸过程瞬态水力特性的试验研究[J\]. 中国农村水利水电,2014(5): 57-60.WANG Tao, XU Zhiqiang. Experimental research on the transient hydraulic performance of irrigation pumps during the selfpriming period [J\]. China rural water and hydropower,2014(5): 57-60. (in Chinese)[11]MINOV S V,COINTAULT F,VANGEYTE J,et al. Development of highspeed image acquisition systems for spray characterization based on singledroplet experiments[J\]. Transactions of the ASABE,2015,58(1):27-37.〓[12]张金亚,蔡淑杰,朱宏武,强睿. 螺旋轴流泵内气液两相流型可视化研究[J\].工程热物理学报,2015,36(9): 1937-1941.ZHANG Jinya,CAI Shujie,ZHU Hongwu, QIANG Rui. Experimental study of gas-liquid twophase flow pattern in a helicoaxial multiphase pump by visualization [J\]. Journal of engineering thermophysics, 2015, 36(9): 1937-1941. (in Chinese)