Investigation on melting process characteristics of phase change materials reinforced by copper foam

Numerical research was conducted to examine how copper foam influences the melting of pure paraffin for phase change energy storage, focusing on the melting of both pure paraffin and copper foam/paraffin composites with varying porosities and heating scenarios. To verify the reliability of simulation results, the melting process of pure paraffin and copper foam/paraffin composites with a porosity of 0.98 under a heat flux of 1200 W/m(2) was studied through a visualization experiment, which was found to be consistent with numerical results. The results show that both two ways namely increasing heat flux and adding metal foam with certain porosity can enhance the heat storage process of pure paraffin. Melting time of liquid phase fraction up to 1 of pure paraffin at 1750 W/m(2) is almost the same as that of the 0.9 porosity copper foam/paraffin composite at 1450 W/m(2), indicating that the complete melting time by two ways may be the same if selecting appropriate parameters. However, by increasing heat flux, the maximum temperature difference of pure paraffin increases with thermal stratification occurring earlier, while adding metal foam leads to a more uniform temperature distribution. For composite materials, increasing heat flux results in a high melting rate but a decreasing increase degree, and decreasing the porosity decreases the complete melting time of composite materials. The same melting rate of pure paraffin and copper foam/paraffin composites occurs at a certain time.