Influence of volute section form on hydraulic performance and pressure fluctuation in double suction centrifugal pump

Abstract

Double suction centrifugal pump has characteristics of large flow rate and high head. It is widely used in agricultural irrigation and water delivery and other projects. As the flow components, volute has a great influence on the hydraulic performance in double suction centrifugal pump. Based on the original circular section volute of the double suction centrifugal pump, the trapezoidal section volute and the horseshoe-shaped section volute were designed. By analyzing the influence of three different volutes on hydraulic performance and pressure fluctuation, it was obtained that the circular section volute had higher head in the low flow rate condition, and efficiency of the three were similar. In the design condition, the circular section volute had the highest efficiency, and head of the three were similar. The decline of the efficiency in the circular section volute was the smallest in large flow rate condition, and the head of the three were similar. Thus, the hydraulic performance of the circular section volute was better. For the pressure fluctuation in the design condition, the pressure fluctuation in the volute is mainly affected by the impeller rotation. The pressure fluctuation in the circular section volute was the biggest, especially at the tongue. The horseshoe-shaped section volute was the second. The pressure fluctuation in the volute of the trapezoidal section was the smallest. Therefore, the trapezoidal section volute is helpful to reduce the pressure fluctuation in the volute. The results of this research provide reference for designing double suction volute of centrifugal pump in engineering.