Steady state model of a micro loop heat pipe

Loop Heat Pipes (LHP) have been demonstrated to be able to passively transport orders of magnitude more heat than conventional heat pipes, and offer other functional and performance advantages that have popularized its use in the aerospace industry. Developments at the NASA Glenn Research Center and the University of Cincinnati have produced micro-machining techniques for silicon that will be used to manufacture microchip scale LHP (/spl mu/LHP) with application potential for cooling of individual chips as an integrated package. To aid in its design and to ascertain its performance potential, a proven steady state analytical model developed by TTH Research for a large ammonia LHP was modified and further developed for microchip scale analysis with water working fluid. Without accounting for heat spreading efficiency across the evaporator wick surface, results show that the loop could accommodate more than 600 W/cm/sup 2/ of heat load. However, its operating (fluid) temperature was limited to >90/spl deg/C, even at moderate heat loads, regardless of condenser sink temperature, which could have adverse implications in terms of life and reliability of the component being cooled.