Experimental study on the heat transfer performance of a gallium heat sink

Phase change thermal storage technology has received considerable attention in the thermal management of electronic devices. Unfortunately, the efficiency using paraffin is too low to meet the heat dissipation requirements of high power devices. In this work, gallium is selected as the phase change material, and the melting mechanism of gallium heat sink in spatial distributions is examined by experiment. Results show that the heat transfer efficiency of regions in the Y-cross section near the heating surface and in the X-cross section near the upper surface of the gallium heat sink are better than other regions. The average effective thermal conductivity of the gallium heat sink reaches 71.97 W/(m.K). The natural convection promotes the overall melting rate, but it results in the inefficient heat transfer in the middle melting stage and worse heat transfer in the later melting stage. Compared with the copper foam/paraffin composite heat sink in the same size, the overall and most of melting time of the gallium heat sink is reduced by 55.5% and 56.0%, respectively. At the same thermal storage capacity, the volume and weight of the gallium heat sink are reduced by 67% and 18%, respectively, compared with the copper foam/paraffin composite heat sink.