Simulation of solar thermal panel systems with nanofluid flow and PCM for energy consumption management of buildings

The present study simulates a solar thermal panel using the finite element method (FEM) in COMSOL Multiphysics. A cropper pipe of a water-Al₂O₃ nanofluid flow was used under a solar panel. A number of elliptic fins were attached to the pipe. The fins were holed and configured in three models. The system of the pipe and fins was placed in a chamber filled with CaCl₂.6H₂O as a phase change material (PCM) under the panel. The proposed solar system was used on a pitched roof to partially supply the energy demand of the Boarding clinic. The energy calculations were carried out in Design Builder. It was found that PCM began to melt at t=40 min. The fins with a central hole led to 10.4% higher melted PCM than double-hole fins at t=100 min. The centrally-holed fins minimized the output flow temperature. However, they also minimized the PVT temperature. It was also found that the proposed system could supply 9.11% of the heating demand of the building in the coldest month of the year. In hot months, however, up to 33.3% of the energy required to heat water could be supplied by the PVT + PCM system.