Interfacial Heat Transfer in Phase Change Material Modified Asphalt

Phase Change Materials (PCMs) have the ability to act as thermal energy storage units due to their high latent heat, and are increasingly being used for enhancing energy efficiency and regulating temperature in various applications. In this work, we employ molecular dynamics simulations to investigate the interfacial heat transfer in PCM modified asphalt systems. Specifically, we focus on microencapsulated PCMs in which PCMs are contained inside an inert polymeric shell.

The interfacial thermal conductivity between the PCM and the polymeric shell as well as that between the polymeric shell and the asphalt medium play an important role in governing the overall heat transfer rate in the system. This interfacial thermal conductivity is difficult to measure by experiments. In this study, the interfacial thermal conductivities, as well as thermal conductivities of pure materials are determined using Reverse Non-Equilibrium Molecular Dynamics (RNEMD) simulations. The calculated thermal conductivities for the asphalt, polymer and the PCM are in good agreement with the experimental values. The results show that the interfacial heat transfer resistance makes a substantial contribution to the overall thermal resistance in the encapsulated PCM asphalt system.