Abstract: To improve the heat dissipation efficiency and uniformity of cross-shaped electronic components, this study investigated the thermal performance of composite phase-change materials (PCM) consisting of copper oxide (CuO) or graphene nanoplatelets (GNP) mixed with paraffin wax, as well as the effect of nanoparticle content on heat dissipation. The cooling methods and temperatures were varied to compare their cooling performance. The results show that higher CuO or GNP content in the composite PCM leads to improved heat dissipation efficiency. When the volume fraction of CuO or GNP reaches 2%, the heat dissipation efficiency of CuO/paraffin and GNP/paraffin composite PCMs increases by 69.81% and 157.14%, respectively, compared to pure paraffin.Furthermore, the study examined the cooling performance of coupled phase-change heat dissipation with different liquid cooling methods. The results indicate that immersion liquid cooling provides better heat dissipation uniformity than single-wall cooling plate methods. For the GNP/paraffin composite PCM-immersion liquid cooling coupled system, higher graphene content and lower cooling temperatures lead to improved heat dissipation efficiency. When the cooling temperature decreases from 304 K to 302 K, the cross-shaped electronic component exhibits the maximum temperature drop of 0.83 K.

Key words: composite phase change materials, phase change heat dissipation, liquid cooling heat dissipation, numerical simulation, solidification-melting model