Study on the thermal performance of a new double layer PCM trombe wall with multiple phase change points

Abstract

Trombe wall as effective passive design technology can achieve better building energy efficiency and thermal comfort. Considering the advantages of phase change materials in solar energy utilization, a new double layers PCM Trombe wall with multiple phase transition points was proposed in this study. A comparison study was conducted to investigate the thermal performance of the common wall without PCM (shorten as wall A), the common single layer PCM wall (shorten as wall B), and the common double layers PCM Trombe wall (shorten as wall C) along with the new double layers PCM Trombe wall using the validated Computational Fluid Dynamics models. The results showed that the average temperature in the new double layers PCM Trombe room can be reduced by 0.4–0.93C in summer and enhanced by 0.3–6.6 °C in winter. And the peak temperature occurrence time can be significantly delayed in summer. The heat flux can also be reduced by 9.1%–92% in summer and 1.8%–75.7% in winter. In summer/winter, the decrement factor of wall A, wall B, wall C and the new double layers PCM Trombe wall was 0.8003/0.8511, 0.7293/0.7347, 0.6252/0.4289 and 0.5381/0.4091; the aggregate discomfort degree was 19.2/197.59 °C•h, 12.6/152.18 °C•h, 8.5/50.21 °C•h, and 2.4/45.42 °C•h; and the relative fluctuation number was 0.6089/0.3943, 0.4368/0.02633, 0.5416/0.3943, 0.5007/0.02908. The conclusions confirm that the proposed double layers PCM Trombe wall performs excellently in controlling the indoor thermal environment.