Design of cooling system for underwater motor based on phase-change heat transfer

This paper deals with the considerations associated with the design of cooling system for high-power-density underwater brushless DC motor (UBLDCM) based on phase-change heat transfer. The considerations discussed are described by the cooling system design of an actual 80-kW motor, which runs at speeds of 2400rpm with a rated power density of 2.0kW/kg for an underwater drive device. Using the phase-change heat transfer technology which makes the motor rated temperature reduce to 50%~75% of the motors under traditional cooling methods, the cooling structure is identified as an important and sensitive parameter in the design of high-power-density UBLDCM.