Heat transfer performance analysis of a solar flat-plate collector with an integrated metal foam porous structure filled with paraffin

The analysis of energy storage process of a solar flat-plate collector with an integrated aluminum foam porous structure filled with paraffin as the phase-change medium is reported in this paper. The momentum conservation of liquid paraffin is modeled with Darcy’s law with the Brinkman–Forchheimer’s extension, while heat transfer between the metal foams and paraffin in solid and liquid phases is modeled with a two-temperature model. It is shown that the assumption of the local thermal equilibrium between the metal foams and paraffin invoked in previous studies is inappropriate in predicting the heat transfer behavior, whereas the two-temperature model proposed in this work without this assumption can more realistically predict the real-world phase-change heat transfer process in the solar collector. In particular, the numerical results indicate that the heat transfer performance can be significantly improved by using the aluminum foams filled with paraffin.