The application of heat pipes to cooling rotating electrical machines

A heat pipe is a closed system (normally tubular) containing: a material which is able to undergo a phase change, thus absorbing heat at one point within the system and redepositing it at any other point within the system which is at a lower temperature; and some means of returning the working material to the starting point so that a continuous cycle can be maintained. The author examines the possible application of heat pipes to electrical machines. The author discusses heat pipe operation including choice of working fluid and thermal resistance. The thermal characterisation of heat pipes is also discussed