Research of 3D flow field of the water route of canned primary pump motors in nuclear power stations

The canned primary pump motor is an important part of a loop system of the nuclear island in nuclear power stations, while the flow states of the cooling water inside the canned motor directly affect the heat transfer within the motor. Consequently, a three dimensional model of flow field of the whole motor was established. Based on the finite volume method in the computational fluid dynamics theory, the velocity distribution in canned motor was calculated under boundary condition of the velocity inlet of primary water at the rated working point using the Ansys Fluent software. The axial and radial velocity distribution inside the canned motor was obtained by respectively analyzing the flow field of key parts of the canned motor. The results show that, near the rotating wall surface, the water with high velocity flow upward along the axial direction in the form of the spiral line. In the flywheel and the shielding clearance, the fluid velocity along the radial velocity gradient is larger. The research can provide the velocity magnitude and distribution in different locations for the followed temperature field investigation. (authors)