Impact of Phase Change Material's Thermal Properties on the Thermal Performance of Phase Change Material Hollow Block Wall

Abstract

Composite phase change material (PCM) hollow block wall (CPCMHBW) can be established by introducing PCM into the holes of generally used hollow block wall, and good thermal insulation performance will probably produce together with the energy storage function from PCM simultaneously. In this article, the impact of PCM's thermal properties on the thermal performance of CPCMHBW has been analyzed, using two-dimensional enthalpy model. The conclusions include: complete melting and freezing processes and a bit amount of remaining PCM which has not melted or solidified, are fundamental and necessary for high performance; furthermore, that the average surrounding temperature equals to PCM's central phase change temperature determines whether the PCM's function can be used; besides, the PCM's total latent heat controls wall's thermal storage level; in addition, relatively low block material's thermal conductivity and Fourier number (better smaller than 1.0 W·m⁻¹·K⁻¹ and 59.83) and medium PCM's corresponding values (lies in the ranges 0.2–0.7 W·m⁻¹·K⁻¹ and 0.80–2.80) generate optimum thermal performance. Finally, the thermal factors are ranked with the functions in descending order.