喷灌泵自吸过程瞬态水力特性的试验研究  

Experimental Research on the Transient Hydraulic Performance of Irrigation Pumps during the Self-priming Period

作　　者：王涛[1] 徐志强[1] 

机构地区：[1]中国水产科学研究院渔业机械仪器研究所,上海200092

出　　处：《中国农村水利水电》2014年第5期57-60,共4页China Rural Water and Hydropower

摘　　要：喷灌泵自吸过程是一复杂的气液两相流动过程,自吸过程的瞬态参数与自吸性能的优劣密切相关.在自吸泵外特性试验台基础上,利用NI虚拟仪器、LabVIEW编程平台搭建了泵内部流态特性瞬态数据测试系统,对65ZB-40型喷灌泵自吸过程进行了试验研究,测量了泵在不同安装高度下自吸瞬态过程中关键监测点参数的变化,并建立了瞬时转速、压力、流量、扬程、功率及效率与自吸时间的关系,分析了喷灌泵自吸过程内特性参数的变化趋势,并探讨了泵自吸过程时内特性与外特性之间的联系.结果显示,在6个不同自吸高度条件下,各关键监测点的压力变化趋势基本一致.泵进口及叶轮进口处真空度随自吸泵安装高度增加而增加.回流孔处在自吸初期为负压状态,但末期压力迅速上升至400 kPa左右,说明外混式自吸泵回流孔处为气液混合的主要区域.泵出口处压力值在自吸过程中基本上维持在1～2kPa之间,但在自吸即将完成时压力值迅速增至400 kPa附近.流量、扬程、轴功率、输出功率及转速也均在自吸即将完成时有一个显著的变化,表现出明显的瞬态效应,在自吸完成后效率达到最高值.试验结果与自吸机理基本吻合.The self-priming process of irrigation pumps is a complex gas-liquid two-phase flow process, with the transient parameters closely related to the self-priming performance of pumps. In order to study the relationship between inner transient flow and explicit transient performances during the self-priming period, a self-priming pump typed 65ZB-40 is tested with the NI virtual instrument and LabVIEW used. Through the rapid test and data acquisition system, not only the transient parameters are obtained, but also the transient performances of the pump during self-priming period under different installation heights are tested. The relationships be- tween the instantaneous rotational speed, the pressure, the flow rate, the head, the power, the efficiency and the self-priming time is established. The results show that the pressure variation tendencies at each monitoring point are similar under 6 different self- priming heights. The vacuum degrees at the pump inlet and at the impeller inlet increase with the self-priming heights. The pressure is negative at the reflux hole in the initial self-priming period, but the pressure roars to about 400kpa in the final stage, which indi- cates that the reflux hole is the main region where the gas liquid mix for the external-mixture self-priming pump. The pressure at the pump inlet is generally about 1-2kpa, but it develops to almost 400kpa when self-priming is finished. The flow rate, the head, the shaft power, the output power and the rotational speed also change obviously at the end of self-priming. The efficiency arrives at its peak when self-priming is finished. The transient effects are obvious during the self-priming period. The experiment results are ana- lyzed and compared with explicit transient hydraulic performances, and the experiment results are in agreement with the theoretical calculations.

关 键 词：自吸喷灌泵 自吸过程 试验 水力性能 

分 类 号：TH311[机械工程—机械制造及自动化]