Thermal energy simulation of the building with heating tube embedded in the wall in the presence of different PCM materials

A large part of energy consumption around the world is spent on buildings. Improving and optimizing the thermal performance of buildings can reduce energy consumption. Phase change materials inside an envelope can act as a latent thermal energy storage tank and also prevent energy loss. In the present study, we have investigated the effects of adding PCM inside the wall of buildings, and a tube for heating is embedded inside the wall. The performance of the system has been evaluated based on computational fluid dynamics simulation in Open Foam software. PIMPLE algorithm and finite volume method were used to solve the governing equations. Three different arrangements of tubes are considered at the upper, middle, and bottom of the wall introduced as UTA, MTA, and BTA, respectively. Furthermore, it is assumed that the heat flux is in the range of solar heat flux that enters the system from the embedded tube. Three different tube arrangements, three heat fluxes, and two different types of PCMs have been investigated in this study to find the best integration of the system. The simulation results revealed that for Lauric acid, by increasing the heat flux from 200 to 400 m2W, the melting time decreases from 9 to 2 h. Also, for Paraffin the melting start time reaches 2.5h from 10 h. Also, Lauric acid can store or discharge thermal energy for the long term. The highest percentage of stored energy is related to Lauric acid, which saves 13.8 % of the total input heat flux as latent energy and Paraffin stores up to 11.8 % of latent heat energy.