Pump Selection and Performance Prediction for the Technical Innovation of an Axial-Flow Pump Station

摘要

Axial-flow pumps are widely used in every sector of China. After many years of operation, the aging of mechanical and electrical facilities poses threats to their steady and safe operation. Taking the technical innovation of an axial-flow pump station as an example, the study is focused on the pump selection and performance prediction. The pump similarity law and specific speed were applied to guide the pump selection based on the designed head and discharge. The performances of pump models were compared and it is suggested for the technical innovation that when the selected model pump is adopted, the impeller diameter is kept at 3100 mm and the rotational speed is reduced from 150r/min to 136.4r/min to improve its cavitation performance. A three-dimensional pumping system model was established by using software Pro/E and CFD analyses were conducted to predict the hydraulic performance of the pumping system for the evaluation of technical innovation. It is shown through the comparison of computed results with model test results that the designed flow rate corresponding to the designed head can be fully satisfied with the selected pump and stronger pumping capacity can be prospected at the designed and mean lifting head. The pumping system model tests, in comparison between the original and the selected model pump, indicate that when the innovated pump station operates under characteristic heads, the pumping system efficiency can be raised by more than 3 percentages, and the cavitation allowance can be decreased by 0.90m; thus, better engineering and economic benefits can be prospected through the technical innovation.