Abstract: The circulating cooling water pump in a nuclear power plant operates in a high temperature environment， and the pump bearing receives a large amount of heat load， so the work reliability is of great importance. To reduce the bearing’s working temperature and ensure its safe operation， a cooling device should be installed in the pump system. The structure of the bearing’s axial flow cooling fan in the pump was proposed， and the optimum design method of the bearing’s axial flow cooling fan in the pump was established. For the fan blades， the optimized calculation using BFGS algorithm was proceeded. A simulation verification of the system was proposed by using FLUENT， whose results showed that the design method is suitable for the bearing’s axial flow cooling fan design in circulating cooling water pumps in a nuclear power plant.

Key words: nuclear pump, bearing cooling, fan structure, BFGS method, flow field analysis