Modeling aspects in simulation of phase change materials used for thermal regulation of buildings

Phase change materials applications involve a wide variety of fields starting from building engineering through the development of new types of material for thermal regulation of buildings, going to the development of hi-tech material for thermal comfort in apparel. Improving civil engineering solutions and develop new materials for more efficient building leads to very significant opportunities to decrease the energy demand for civil purpose, as well as to reduce global energy consumption and greenhouse gas emissions at the buildings’ level. The set-up of a modelling tool able to simulate the thermal evolution over model sample of a phase change material allows to investigate on the role played by materials’ thermo-physical properties as well as on geometric characteristic of the material system composed by the phase change material encapsulated on a classical building material matrix. On the other hand, the set-up of such virtual tool is not trivial because it requires the coupling of phenomena of different nature: phase change material droplet dispersion simulation; the heat transfer within the system composed by different domines and its mutual coupling. In this work, the modelling aspects related to the simulation of a transient thermal evolution through a material model developed by programming tools are presented. Particularly, the study was devoted to analysing the insulating performances of a building material made by cellular concrete added with 1% of glycerine. The simulation was performed for 90min with a wall temperature of 25°C and an initial temperature 2°C.