Investigation of the split vane impeller on the gas–liquid performance and energy loss mechanism in a centrifugal pump

Centrifugal pumps are an important part of nuclear power plants, but their hydraulic performance deteriorates under gas–liquid conditions. In this paper, a split vane impeller was designed to improve the gas–liquid pressurization of the pump. The effect of the split vane impeller on the hydraulic characteristics of the pump was investigated, and the energy loss in the impeller was analyzed based on the entropy production theory. The gas accumulates at the inlet of the inner flow channel and at the suction surface of the outer vane in the split vane impeller. The split vane impeller can effectively delay the deterioration of the centrifugal pump's gas–liquid pressurization. The main cause of energy loss in the impeller is the gas vortex. In the original impeller, the energy loss occurs mainly in the latter half of the impeller channel near the shroud. In the split vane impeller, the energy loss occurs mainly near the pressure surface at the trailing edge of the inner vane and at the outer vane suction surface. The split vane impeller by separating and offsetting the inner and outer vanes can effectively inhibit gas accumulation, thus improving the gas–liquid performance and energy loss of the pump.