Comparative Study on Hydraulic Performance of Single-Suction Centrifugal Pump and Double-Suction Centrifugal Pump

In engineering applications, design and manufacture of double-suction impeller are on the basis of single-suction impeller. However, there is a lack of clear view on the differences of hydraulic performance between single-suction centrifugal pump and double-suction centrifugal pump which has the same blades. In this paper, a single-suction centrifugal pump and double-suction centrifugal pump with the same blades are investigated respectively, and their hydraulic performances have been compared in terms of external characteristics, flow pattern, pressure fluctuation and cavitation characteristics. In operating range of 0.6Q₀∼1.1Q₀, results show that the efficiency of double-suction pump is 4.14% higher than that of single-suction pump stably, and the head of single suction pump is 3.5% higher than that of double-suction pump stably. Single-suction impeller and double-suction impeller have similar jet-wake structure in impeller outlet, but the amplitude of velocity of single suction impeller changes more sharply. In the vicinity of rated condition, the amplitude of pressure fluctuation of double suction pump is about half that of the single suction pump, and the cavitation performance of double suction pump and single suction pump are basically the same. These quantitative results show that pressure fluctuation characteristics and cavitation performance of single-suction pump and double-suction pump with the same blades have little difference in the vicinity of rated condition. Compared with single-suction pump, the head of double-suction pump has declined, while the efficiency has improved remarkably. The research results have significant guidance on excavating the potential of excellent hydraulic models and guiding the design of double-inlet multistage double-suction centrifugal pump.