Study On The Jetted Self-Priming Centrifugal Pump

The jetted self-priming centrifugal pump is a new type of self-priming pump product, which is invented by our research group. By adding a self-circle jetted ware system at the inlet of centrifugal pump, and adopting the bowl type of valve self-motion closing system in the circumfluence hole, the self-priming function of the pump is reliazed according to the water-jetting suction. Compared with the traditional self-priming centrifugal pump, it has many advantages, such as simple and novelty structure, small volume, light weight and easy operation; and it is widely adopted in the field of agricultural saving-water irrigation.Based on the problems of complex structure, long self-priming time and low pump efficiency, which existed in the traditional self-priming centrifugal pumps, the inner flow of the jetted self-priming centrifugal pump is investigated systematically by combining theoretical analysis,experimental researches and numerical simulation. The main points of my work are listed as following:1．The structure, the basic characteristics and the working principle of the jetted self-priming centrifugal pump are systematically introduced. And based on present design formula for pump hydraulic model and combined the characteristics of the pump, the principle and mechanism of design are discussed deeply, the hydraulic design of the impeller, guild vanes and volute are done and revised.2．For the first time, the shell theory in material mechanics is used in the bowl-type valve of self-motion closing system, to deduce the fomula for the axial displacement and calculate its value theoretically. Numerical simulation for the structure analysis is done in the software of ANSYS, by dividing the valve to three parts, the axial displacement are gained respectively. The calculated results show that the bowl valve can be compressed entirely, for the axial maximal displacement 22．76 mm is bigger than the designed clearance 10 mm.3．The 3-D model of the pump and self-priming set are constructed in the software of Pro/ENGINEER, and in the software of GAMBIT, the mixed structure grid generation technique is used to mesh the internal flow area of the inlet of jetted self-priming pump, grid density is controlled by the distribution functions P, Q, R.4．Computational Fluid Dynamics (CFD) technique is applied to simulate the flow law for the S type inlet passage in 50SPG15-28Q pump. According to the rules of the distribution of velocity, pressure and turbulence kenetic in the middle flow section, the nozzle with diameter of 10 mm has well entrainment function in the S type inlet passage, and that is well self-priming capability.