Optimization of double-layer shaped phase change wallboard in buildings in two typical climate areas in China

Phase change material (PCM) applied in buildings can significantly improve thermal comfort and realize building energy conservation. In recent years, double-layer shaped phase change wallboards (DLSPCWs) that depends on the latent heat absorption and release of two kinds of PCMs can effective control the indoor temperature fluctuation, and have been play an important role in improving the indoor thermal environment. The related researches show that, it is rare but necessary to optimize the DLSPCWs in different typical climate areas in order to further promote the application development of PCMs in buildings for energy conservation. Aimed this, fifty-four different DLSPCWs were constructed in this study by selecting different phase change thermal storage layer from four kinds of form-stable PCMs and changing the thickness of the layer to optimize the structure of DLSPCW in two typical climate areas, including severe cold area (Xining city, China) and hot summer and warm winter area (Haikou city, China) respectively. Comsol Multiphysics was used for heat transfer simulation and calculation of the DLSPCW in order to determine its best structure combination pattern for the two areas, and DesignBuilder for comparing and analyzing the building energy conservation effect when using the optimal DLSPCW in buildings. Compared with the ordinary wall, the optimized DLSPCW saved 14,198.96 kW·h electric energy during the heating period in Xining, while 18,816.62 kW·h electric energy in Haikou during the cooling period. The results proved that the optimum structure of the DLSPCW not only reduced the heating load and the cooling load but realized the maximum utilization of the PCMs.