Wall adaptability of the phase-change material layer by numerical simulation

Phase-change material (PCM) has been widely employed to improve the wall thermal perfor-mance, but its contribution efficiency was impacted by wall forms and thereby, it was very important to analyze the wall adaptability of the PCM layer. According to this condition, three typical walls had been built with the different thermal inertias. A numerical model was built with the heat transfer process of melting-solidifying and a model experiment was done to verify this numerical model. The numerical results showed the attenuation coefficients were reduced by 8.76%, 7.54% and 2.02% for the light-weight, middle-weight, and heavy-weight walls, while the time lag was increased by 4.83 h. Due to adding the PCM layer, inner surface heat flow fluctuated more gently. The removed peak heat quantities were 23.48%, 19.29% and 6.60% of the daily heat flow values with reducing the peak heat flows by 32.16w/m2, 25.54 w/m2 and 6.28 w/m2 for the light-weight, middle-weight, and heavy-weight walls respectively. The PCM layer had the higher contribution efficiency in the light-weight and middle-weight walls, but its contribution efficiency was too low to be highly valued in the heavy-weight wall.