Thermal performance of a novel porous crack composite wick heat pipe

• This research developed a novel porous crack composite wick heat pipe.
• Phase change flattening process was proposed to fabricate composite heat pipe.
• The composite wick structure was characterized.
• Heat transfer limit and thermal resistance were investigated by theoretically and experimentally.

A novel porous crack composite wick flattened heat pipe (PCHP) has been developed for electronic device cooling. PCHP was fabricated from grooved–sintered wick cylindrical heat pipe (GSHP) by phase change flattening technology. The composite wick was composed of porous sintered powder structure and axial micro-crack channels. The crack channels of composite wick were characterized and the calculation models of thermal resistance and capillary limit of PCHP were built. An experimental setup was used to test thermal resistance and heat transfer limit. The results showed that the parameters affecting thermal resistance from the most significant to the least one were wick thickness, powder diameter, flattened height, and tear number. The optimal wick thickness of PCHP for the maximum heat transfer limit was about 0.45 mm at flattened height of 3 mm. Heat transfer limit of PCHP increased with powder diameter while decrease of powder diameter could enhance anti-gravity ability of PCHP. Heat transfer limit of PCHP increased with flattened height. The effect of tear number on thermal resistance and heat transfer limit of PCHP could be neglected.