RESEARCH ON HYDRAULIC STRUCTURE OF LOW PRESSURE PULSATIONS DOUBLE-SUCTION PUMPS BASED ON UNSTEADY FLOW NUMERICAL SIMULATION

Low pressure pulsations double-suction pumps, which can reduce the pump outlet pressure pulsations, are widely used in paper-making technique processes. To design the proper geometric sizes and improve the inner flow will reduce the outlet pressure pulsations. From the aspect of the pump hydraulic design, several optimized projects to lower the pressure pulsations are proposed, such as optimizing the arrangement of blades, changing the shape of the blades, changing the size of base circle and the shape of tongue of the volute, etc. The unsteady flows in different time and different impeller positions in every project have been simulated using the CFD software. The outlet pressure distribution is caught and described as the 2-D graphs of pressure pulsations versus time by EXCEL and MATLAB. By comparing the results of all optimized schemes, it has been shown that the stagger arrangement of blades, the increased diameter of base circle, the ladder tongue of volute, more blades of impeller all can reduce the outlet pressure pulsations of centrifugal pump.