Computational Fluid Dynamics (CFD) Analysis of Building Integrated Photovoltaic Thermal (BIPV/T) Systems

This paper presents CFD study of a BIPV/T system with forced convection. Air was circulated behind PV arrays and used as a coolant with various air flow rates (air velocities) to recover the thermal energy that could be used for space and/or domestic water heating. Turbulent flows were considered with Reynolds number ranging from 5199 to 9392. COMSOL Multiphysics finite element analysis (FEA) software was used to develop CFD models for the BIPV/T system using: (a) measured temperature profile at different flow rates, and (b) measured solar radiation as boundary condition. Predictions of the air temperature profiles inside the air flow channel and the backside of the PV were obtained and compared to experimentally obtained temperature profiles using both boundary conditions. In general, better agreement with the experimentally measured temperature profiles was obtained when the measured solar radiation was used as a boundary condition. The results of the study can be used to establish relationships between the average/local convective heat transfer coefficients and air flow velocity. The relationships obtained will also be useful for developing correlations and simple mathematical models that facilitate the design and optimization of different parts of the BIPV/T system, such as inlet regions.