Abstract: The sodium pump in secondary circuit of fast reactor is one ofkey equipment of the most advanced fourth-generation nuclear power in the world at present. It is very important to improve pump efficiency under the conditions of safe operation. Hydraulic design of the pump was carried out bycombining one-dimensional design method with computional fluid dynamics(CFD) based on its performance requirements and dimensional limitation and the matching rules of the blade number of the pump impeller and guide vane were discussed. The results show that the maximum influences of blade number of guide vane on its efficiency and head are 4.01% and 9.75% of their designing values, respectively, when the blade number of the impeller is kept constant. The optimal matching ratio of the blade number of impeller and guide vane for each other under designing condition is 5∶8, or 6∶9, or 7∶11, namely, the pump hydraulic performance reaches its optimal value when the matching ratio is about 1∶1.5. Nevertheless, the matching ratio of blade number of impeller and guide vane is at 6∶11, the sodium pump gets the best hydraulic performance.

Key words: centrifugal pump, hemispherical pressure chamber, fast reactor, blade number, matching