Heikichi Kuwahara

Enhancement of a two-phase thermosyphon for cooling high heat flux power devices

The purpose of this study is the enhancement of cooling of high heat flux power devices such as a thyristor by a thermosyphon system. The thermosyphon uses boiling and condensation of an inert dielectric fluorocarbon (FC-72). Boiling occurs from a multiple chimney heat transfer structure. A boiling chamber is connected to the condenser by a double tube, with the inner tube carrying the condensed liquid and the outer annulus carrying vapor. Using the experimental model of a thermosyphon, heat flux capacity is enhanced by increasing the flow tube height H/sub 0/, boiling chamber height H/sub h/, and condenser liquid level H/sub l/. High heat flux capacity is achieved with H/sub 0/>8 cm, H/sub h/>10 cm, and H/sub l/>H/sub 0/, using the chimney heat transfer structure with a channel width of 3 mm. The thermosyphon system is able to cool a maximum heat flux of 3 kW per device. >