相变材料应用于建筑外墙的温度与能耗模拟

使用EnergyPlus能耗模拟软件对相变材料作为外墙表面隔热材料的应用效果进行模拟,在小空间和小型办公室的模型上,改变相变材料的相变温度、材料结构和用量等使用条件,并进一步考虑室内热源和不同气候区的影响,对比分析在空调季节里空间内部温度的变化情况和空调节能效果。模拟结果表明:相变温度稍高的相变材料更有利于夜间散热蓄冷,同时,结合双层复合结构可获得更好的温度抑制和节能效果;内热源的存在会提高房间空调能耗的基数,从而使相变材料空调节能率计算值降低,并且在一定程度上掩盖了相变材料对室内平均温度的抑制作用,尽管如此,相变材料在有内热源环境下使用时空调节能量仍与无内热源时相当。

Temperature and Energy Consumption Simulation of Phase Change Materials Applied to Building Exterior Wall

EnergyPlus software was employed to simulate the application of PCMs as thermal insulation materials on exterior wall surface.The simulations were performed in a small box model and an office model.By changing the melting/solidification temperature, board structure and the amount of PCMs, and furthermore taking into account the effects of internal heat source and different climate zones, the zone temperature variations and the cooling energy reductions during air conditioning season were analyzed and compared.The simulation results show: PCMs with melting/solidification temperature a little bit over average outdoor air temperature are apt to restore their cool storage during night time.When they are combined with insulation materials to form double layer hybrid structure, it can result in better temperature suppression effect and higher cooling energy reduction rate.Internal heat source also has a negative effect on the contribution of PCM to cooling energy reduction rate and it can, to some degree, override the temperature suppression effect of PCM.Nonetheless, the amount of cooling energy reduction due to the presence of PCM almost remains unchanged in the simulation with or without internal heat source.