Multi-Objective Optimization of Efficiency and Pressure Fluctuation for Vertical Inline Pump

Abstract

Abstract Vertical inline pump is a single-stage single-suction centrifugal pump. In order to save the installation space, there is a bent pipe before the impeller. In this paper, to achieve efficient and stable operation of the pump, a multi-objective optimization of efficiency and pressure fluctuation on the inlet pipe of vertical inline pump was proposed based on Latin Hypercube Sampling. The geometric shape of an inlet pipe is controlled by the mid curve and the shape of cross section. The fifth-order Bezier curve was adopted to fit the mid curve and a round cross section was set. Totally 7 design parameters of the inlet pipe were selected as design variables, and the pump efficiency and the pressure fluctuation amplitude at the tongue were set as the optimization objectives. 36 groups of sample points were obtained from Latin hypercube sampling (LHS). The results showed that at design flow rate, the efficiency increased from 77.60% to 79.33%. Comparing with prototype, the pressure fluctuation amplitudes of main frequency at two monitoring points were decreased by 0.89% and 9.15%. It was observed that the profile of inlet pipe has an obvious influence on the pump performance and unsteady flow characteristics. Therefore, the profile of inlet pipe will be the key component for the optimization of vertical inline pump, and this study can provide theoretical guidance for researching the hydraulic efficiency and unsteady pressure fluctuation.