【作者】 刘飞；

【导师】 朱娜；

【作者基本信息】 华中科技大学 ， 建筑与土木工程， 2019， 硕士

【摘要】 面对日益增长的能耗需求,相变材料因其储能密度大、近似恒温下吸热和放热等优点受到了人们的广泛关注。相变材料与建筑围护结构结合能有效地减少室内温度波动、降低建筑能耗,现有研究大多集中在研究相变外墙和相变地板的节能效果。全年中,水平太阳辐射总量最大。通过屋顶的得热在建筑负荷中占有重要影响。本文提出将相变材料与建筑屋顶复合,探究相变屋顶对建筑节能的影响。本文研究的对象是双层定型相变屋顶结构,即将具有两种不同相变温度的相变层安装在普通建筑屋顶内壁面,且低温相变层更加靠近室内侧。已有研究表明这种结构的双层相变材料能更好的减少建筑能耗,相比于单层相变材料,两种相变材料的结合能减少建筑全年的总能耗,达到建筑节能的效果。相变温度是相变材料在建筑中能否充分发挥积极作用的关键因素。本文首先探究了两种相变材料的最佳相变温度。通过TRNSYS软件模拟对比不同屋顶结构的房间室内总负荷,以全年总负荷最低为目标函数,分别确定高温相变层和低温相变层的最佳相变温度。接着本文分别在夏季开空调、夏季不开空调、冬季开空调、冬季不开空调四种不同的工况下进行模拟。通过对比不同工况下室内空气温度和屋顶内表面热流,分析双层相变屋顶对室内热环境的影响,探究双层相变屋顶全年的节能潜力。本文研究了双层相变屋顶的全年节能潜力以及对室内热环境的调节能力,为相变材料与建筑的结合提供了更多可能性,促进了相变材料在建筑节能中的应用。更多还原

【Abstract】 With the increasing demand for energy consumption,phase change materials(PCM)have attracted extensive attention due to their advantages such as high energy storage density,heat absorption and heat release under approximately constant temperature.The combination of PCM and building envelope can effectively reduce indoor temperature fluctuations and building energy consumption.Most of the existing studies focus on the combination of PCM,building external walls and floors to explore the energy saving effect of phase change materials.In this paper,the effect of PCM on building roof is studied.The object of this paper is the double layers PCM roof structure.Double layers PCM are installed inside the roof of the building,and the low-temperature PCM are closer to the indoor side.Previous studies have shown that the double-layer PCM of this structure can better reduce building energy consumption,Compared with single-layer PCM,the combination of double layers PCM can reduce the total annual energy consumption of the building and achieve the effect of building energy conservation.In this paper,the optimal phase transition temperature of two kinds of PCMs was first explored.The optimal phase transition temperature of high-temperature PCM and lowtemperature PCM was determined by comparing the total indoor load of rooms with different roof structures through TRNSYS simulation software.In order to explore the energy saving potential of the double-layer PCM in building roof throughout the year,the simulation study was carried out under four different working conditions of opening air conditioning in summer,not opening air conditioning in summer,opening air conditioning in winter and not opening air conditioning in winter.By comparing the indoor air temperature of different roof structures and the heat flow on the inner surface of the roof,the influence of the two-layer PCM in building roof on the indoor thermal environment is studied.In this paper,the ability of the PCM to adjust the indoor thermal environment and the annual energy saving potential of two-layer PCM in building roof are studied,which provides a variety of possibilities for the combination of PCM and buildings,and promotes the application of PCM in real life.更多还原