| Liquid ring pump is a kind of fluid machinery which is often used to pump gas.Because of its compact structure,isothermal compression,large extraction capacity and other characteristics,it is widely used in oil,coal,chemical,metallurgy and other fields.Especially in coal mine gas pumping,national defense wind tunnel,nuclear power system and other important areas of the country's demand for high-performance liquid ring pump.However,due to the axial clearance of the impeller,the leakage flow of gas-liquid two-phase presents a complex space-time structure under the action of the pressure difference between the working face and the back of the blade and the asymmetric pressure distribution in the pump body,and the leakage and the main flow interfere with each other,which has a serious impact on the performance of the pump.Therefore,in order to improve the leakage flow field structure of the axial tip clearance of the liquid ring pump and improve the hydraulic performance of the liquid ring pump,the study presents the structural design of the axial squealer tip of the liquid blade.Taking 2BE-203 A liquid ring pump as the research object,the numerical simulation method is used to analyze the leakage flow in the axial clearance of the impeller of the liquid ring pump and its interaction with the main flow.The comparative analysis of the leakage flow and its performance between the squealer tip and the flat top clearance shows that:1.Compared with the flat top gap structure,the vacuum value of the liquid ring pump with the squealer tip structure at the top of the blade is improved,and the efficiency is also greater than that of the flat gap structure.The squealer at the top of the blade can improve the hydraulic performance of the liquid ring pump.At the same time,it is found that with the increase of the inlet flow,the performance of the liquid ring pump increases more obviously.2.Under the condition of large flow rate,the axial tip clearance and flow field in the groove of the liquid ring pump are basically consistent with the flow distribution of the impeller on the vertical surface of the shaft,and the gas-liquid two-phase is basically separated.Under the condition of small flow rate,the gas-liquid interface becomes disordered and unclear gradually.3.The structure of the angle vortex at the front end of the gap pressure and the leakage vortex behind the suction surface are the same as that of the flat top gap.Due to the diffusion of the area of the squealer tip,the low-speed fluid in the squealer tip forms the groove vortex under the action of the jet leaking from the working face.The strength of the angle vortex in front of the axial tip pressure and the leakage vortex behind the suction surface of the liquid ring pump gradually increases from the rim to the hub,and the development of the channelvortex in the impeller is complex.To some extent,the strength of the angle vortex and the leakage vortex can be weakened by the squealer axial tip.4.Because of the buffer effect of the squealer,the leakage flow intensity,turbulence intensity and power loss in the gap and behind the suction surface of the blade are reduced to a certain extent compared with the flat top gap structure.Therefore,the squealer structure of the blade top can achieve the purpose of improving the suction vacuum and efficiency of the pump,so as to improve the hydraulic performance of the liquid ring pump.5.Along the circumference,the vorticity distribution of the transition area,the suction area and the exhaust area are different,and the leakage vorticity intensity of the axial tip clearance in the gas distribution area is significantly higher than that in the liquid distribution area. |
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