Heat pipes are important cooling devices that are widely used to transfer high heat loads with low temperature differences. In this paper, thermal performance of a novel type of sintered-wick heat pipe, namely, partly sintered-wick heat pipe, was investigated. The heat pipe was filled with degassed water and acetone, as working fluids, and effects of filling ratio, orientation, and heat inputs were tested. Moreover, conditions at which dry-out occurred were presented. The results showed that the best filling ratio for both working fluids is about 20%. The heat pipe filled with water has better thermal performance than that filled with acetone; thus, the thermal resistances of the 20% water-filled heat pipe are approximately 7%, 27%, and 75% lower than those of the 20% acetone-filled one in the vertical, horizontal, and reverse-vertical modes, respectively. This novel type of sintered wick heat pipe has good thermal performance in the horizontal mode and can be used in no-gravity conditions, i.e. space applications.
