Thermophysical properties and energy-saving efficiency of phase change microcapsule foamed cement composite insulation materials

The addition of phase change materials (PCMs) to building envelopes can improve building thermal stability and reduce energy consumption. In this study, phase change paraffin microcapsules are combined with foamed cement to create composite thermal insulation materials with varying mass ratios of microcapsules. A heat transfer characterization experimental platform was established to investigate the heat transfer laws. The incorporation of phase change microcapsules (MPCMs) into foamed cement resulted in a reduction in thermal conductivity. The thermal conductivity of the test blocks exhibited a linear relationship with the mass ratio of MPCMs, with an average thermal conductivity of 0.053 W/(m-K) observed for 20 % MPCMs. The impact of foamed cement containing MPCMs on building energy consumption was analyzed in five different climate zones in China using EnergyPlus. The results show that energy savings are more significant in cities with higher heating demand. In non-cold regions, energy savings are highest when the phase change temperature is close to the local annual average temperature. The optimal energy saving program is evaluated by energy consumption simulation. The results show that it achieves the highest energy savings in Harbin, which saves a total of 1074,007 kWh. Additionally, it has the highest energy saving rate in Beijing, with a rate of 14.66 %.