|
|
|
| Influence of impeller inlet diameter on multiphase flow performance of sewage pump |
| ZHANG Yanlu1, XU Yunfeng1,2, WANG Zhen2, YANG Chen2, XU Bin1,2* |
| 1. National Research Center of Pumps, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2. Lanshen Group Co., Ltd., Nanjing, Jiangsu 211500, China |
|
|
|
|
Abstract To study the effect of impeller inlet diameter on the multiphase flow performance of sewage pump, three double-blade impellers with different inlet diameters(100, 120, 140 mm)were employed as the research object. The mixture multiphase model, Rayleigh-Plesset cavitation model and Gidaspow drag model were used to conduct steady numerical calculation of solid-liquid-gas three-phase flow in the pump, and the hydraulic characteristics of the sewage pump also be predicted. The research results show that increasing the diameter of the impeller inlet will cause the high-efficiency area of the sewage pump to shift to a small flow rate, but it will help to suppress the degradation of the hydraulic characteristics under the condition of multiphase flow. The efficiency of multiphase flow in the pump with impeller diameter of 100 mm is 10.27% lower than that of single-phase flow, while the efficiency of multiphase flow in the pump with impeller diameter of 120 mm and the pump with impeller diameter of 140 mm are 6.54% and 8.20% lower than that of single-phase flow, respectively. This indicates that increasing the impeller inlet diameter can significantly improve the anti-cavitation characteristics of the pump, and the critical net positive suction head of the sewage pump corresponding to the three impeller diameters are 4.03, 2.06 and 1.95 m, respectively. The flow blockage effect caused by cavitation can be effectively mitigated. Solid particles with high flow velocity are monitored in the pump with an inlet diameter of 100 mm, and the solid phase volume distribution on the impeller surface decreases with the increase of inlet diameter, and the solid phase flow velocity in the pump also decreases. The research shows that appropriately increasing the diameter of the impeller inlet is helpful to improve the multiphase flow performance of the sewage pump.
|
|
Received: 29 November 2021
|
|
|
|
|
|
|
