Thermal characteristics of phase change materials suitable for Brazilian buildings

Abstract Phase Change Materials (PCMs) have significantly higher thermal capacity than traditional materials. PCMs increase the thermal inertia of buildings and improve their thermal performance depending on the climate conditions. PCMs are generally used in buildings exposed to the Northern Hemisphere's climate conditions; however, there is very little information about the effect of these materials in buildings located in tropical areas. This paper presents the essential thermal characteristics that these materials require (latent heat and melting point) to be able to contribute to improve the thermal performance of Brazilian buildings. Simulations of the thermal response of buildings with and without PCMs were carried out. The first stage aimed to reproduce the thermal behaviour of a real prototype - with PCMs available in the market in order to validate the simulations. The second stage included parametric simulations of the thermal response of a prototype with hypothetical PCMs. The characteristics of these hypothetical materials were obtained from variations of the original ones. The results show the values of the latent heat and melting point most appropriate to Brazilian buildings.

摘要 相变材料（Phase Change Materials，PCMs）相较传统建材具备显著更高的热容量。该类材料可提升建筑热惰性，并依据所处气候条件优化建筑热性能。目前相变材料多应用于受北半球气候影响的建筑场景中，但针对热带地区建筑内此类材料的应用效果，现有公开资料仍极为有限。本文阐明了此类材料需具备的核心热特性——潜热与熔点，以助力改善巴西建筑的热性能。研究开展了有无相变材料的建筑热响应模拟：第一阶段旨在复现搭载市售相变材料的真实建筑原型的热行为，以此验证模拟方法的可靠性；第二阶段则针对搭载假想相变材料的建筑原型开展参数化模拟，此类假想材料的特性由原始材料的参数调整衍生而来。研究结果给出了适配巴西建筑的最优潜热与熔点取值。