Experimental investigation of thermal performance characteristics of sintered copper wicked and grooved heat pipes: A comparative study

Heat pipes are most frequently used for thermal management solutions. Selection of right type of heat pipe for a specific scenario is utmost necessary for best outcomes. The purpose of this research is comparison of thermal performance characteristics of sintered copper wicked and grooved heat pipes, which are mostly used types of heat pipes. Distilled water filled heat pipes were tested through experimentation in gravity assisted position. Experimental outcomes have been compiled in terms of capillary pressure, operating temperature, thermal resistance and heat transfer coefficient. Capillary pressure is high in sintered heat pipes compared to grooved heat pipes irrespective of groove dimensions. Grooved heat pipes have lower operating temperature compared to sintered heat pipes at the same heat load. At 8 W, compared to sintered heat pipes, grooved heat pipes have 8.24% lower condenser surface temperature, 4.41% lower evaporator surface temperature and 7.79% lower saturation temperature. Thermal resistance of sintered heat pipe is much lower than grooved heat pipe. The maximum relative difference of 63.8% was observed at 8 W. Heat transfer coefficient of sintered heat pipe was observed double compared to grooved heat pipe at 8 W heat load. Thermal resistance and hence heat transfer coefficient of sintered heat pipe change almost in a linear manner with respect to heat load but unexpectedly turning point is observed in thermal resistance and heat transfer coefficient of grooved heat pipe. Grooved heat pipes attain equilibrium much earlier compared to sintered ones. Varying heat loads from 4 to 20 W causes variation in equilibrium establishment time from 7 to 4 min for grooved and from 10 to 7 min for sintered heat pipes.