Experimental and numerical study of thermal performance of the PCM wall with solar radiation

The phase change material (PCM) layer used for energy storage of the wall in winter can absorb a mass of heat from the solar radiation in daylight and release the heat at night, thus reduce the air-conditioning energy consumption and maintain the indoor air temperature. To study thermal performance of the PCM wall and optimize the application of PCMs, a thermal performance testing equipment was designed and the case that solar light suddenly irradiated the PCM layer in daylight and disappeared at night in an air-conditioning room was experimental and numerical simulated. Results show that PCM layers can change the absorptivity of the wall, and then improve surface temperature and heat flux in heat storage process. The addition of the PCM to the wall can enhance the heat storage in the wall. Besides, the wall surface temperature in heat release process was improved. To make the heat released constantly in a long time at night, the PCM with proper phase change temperature, narrow phase change range and large latent heat should be chosen. The effect of the specific heat capacity and the heat conductivity is unobvious. Using the proper PCM, heat release time can be 10.3 h. It is unnecessary to make the radiation time too long. Two hours radiation time is enough for the PCM used in the experiment to store the solar heat.