Experimental Optimization of Jet Self-Priming Centrifugal Pump Based on Orthogonal Design and Grey-Correlational Method

The novel jet self-priming centrifugal pump, as important modern irrigation equipment, is widely used in large-scale irrigation, mine drainage and so on. In order to improve the profile streamline of blade, the inlet shape of impeller was designed as distorted and the outlet shape as cylindrical, which can not only improve the pump efficiency, but also shorten the self-priming time. Further, the novel jet self-priming system was proposed, by employing the jet nozzle and check valve to improve the velocity of self-priming. Meanwhile, nine different structure jet nozzles were designed based on the orthogonal design method, and the relevant self-priming experiments were performed on I level accuracy test bench in Jiangsu University. According to the grey-correlational analysis, the influence of the nozzle geometry parameters on the self-priming performance was obtained. The relationship between self-priming time and self-priming height was discussed. The test results showed that the hydraulic design of jet self-priming centrifugal pump was reasonable; all indicators met the Chinese national standard; the head reached 21.04 m and efficiency was 72.8% under the design flow condition. What is more, the self-priming performance was obviously improved by adjusting the geometrical parameters of nozzle. When the height of the self-priming process was 5.3 m, the self-priming time reached 62 s, which was much shorter than the national standard. Therefore, this research could provide reference for designing the structure of jet self-priming centrifugal pump.