Optimal Design and Simulation Analysis of Phase Change Material Composite Self-Insulating Block in a Typical Cold Region City of China in Summer

Incorporating PCMs (Phase Change Materials) into the building envelope can achieve the purpose of regulating heat transfer and enhancing indoor comfort. In recent years, lots of patents for new phase change concretes have been proposed and applied to the envelope. This study aimed to explore the optimum phase change temperature and installation position of PCM by optimizing different concrete blocks to improve the thermal behavior of concrete compound self-insulating blocks. Firstly, based on the existing patents, five new types of phase change self-insulating blocks were proposed. The thermal insulation performance of different blocks was tested using ANSYS simulation. Then, the feasibility of using EnergyPlus to simulate the thermal environment of the room was verified by taking a summer south-facing room in Hohhot City as a research object. Finally, 13 phase-change block types containing 4 phase-change temperatures and 3 PCM installation locations were designed for further testing. A three-row staggered perforated block was selected, and the heat transmission coefficient of the masonry wall was 0.437 W/(m2·K). The optimal phase change temperatures of outdoor, medium- temperature, high-temperature, and low-temperature periods in summer, were 24.0 oC, 30.0 oC, and 28.0 oC, respectively. The optimal phase change temperature in the whole summer was 26.0~ 28.0 oC, and the best phase transition layer location was the inner hole of the block. The PCM mounting position has a greater effect on room temperature than the PCM phase change temperature. The study results are of great significance for stabilizing room temperature and building energy conservation.