Heat transfer analysis of phase change materials with metal foams

With the development of electronic products towards high-density integration, high performance and multifunction, the working frequencies and power consumption rate of electronic components and devices increase substantially. The resulting temperature rise has a great impact on the operation and lifetime of electronic products. Transient temperature control and efficient heat dissipation are essential to the stability and reliability of the electronic components and products. Paraffin wax, as one of the most commonly used phase change materials, has been widely applied in many products requiring transient temperature control due to its melting temperature lying in the range of electronics operation conditions. However, the applicable scopes of phase change materials were limited due to their shortcomings of low thermal conductivity and heat dissipation. In the present paper, both metal forms and carbon nanomaterials are used as thermal enhancers to increase the conduction of paraffin wax, and the heat transfer characters of the composites are investigated by numerical method. The simulation results show that the introduction of Cu or Ni foam as heat conductive enhancers can significantly increase the effective thermal conductivity of paraffin wax composite. The thermal conductivity of the composite with Ni foams is 3.684 times higher than that of the paraffin wax, and the increase is 12.485 times when Cu foam is used instead of Ni foam. Furthermore, the heat transfer of the composites can be strengthened by adding carbon nanomaterials into the paraffin wax so as to increase the thermal conductivity of the matrix. The simulation results show that the impact of dispersed carbon nanomaterials on thermal enhancement of the composites is less significant than that of metal foams.