Effect of phase change heat storage on thermal insulation and power generation performance of photovoltaic phase change composite envelope structure

Based on the coupling characteristics of photovoltaic power generation and phase change heat storage, a photovoltaic phase change composite building envelope structure was proposed and the effect of phase change heat storage on the performance of the composite building envelope was further analyzed. Firstly, the heat flow transfer model of photovoltaic phase change composite envelope structure was constructed, and then the influence of phase change layer structure position, phase change temperature and phase change thickness on its power generation capacity and thermal insulation effect was explored. On this basis, by comparing the thermal characteristics of traditional envelope structure and composite envelope structure, the indoor environmental load regulation and energy saving potential of composite envelope structure were expounded. The research shows that the phase change heat storage has a great influence on the power generation and thermal insulation performance of the photovoltaic phase change composite envelope structure. The closer the phase change material is to the room, the better the thermal insulation effect is; and the indoor temperature shows a tendency to approach the phase change temperature. The phase change material close to the photovoltaic panel means that the heat can be stored more fully, and the photovoltaic power generation is higher. When the phase change material is close to the photovoltaic panel, the power generation is 1 263.06 J, which is significantly improved compared with the photovoltaic envelope structure. At the same time, when the thickness of the phase change material is 40 mm, the power generation reaches the maximum value, which is 0.55% higher than the working condition of 10 mm. In addition, within one operating cycle, the photovoltaic phase change composite envelope structure significantly reduces the building's cooling load, showing good heat insulation and energy saving effects.