The validation and verification of CFD models of heat transfer and airflow within CPV modules

Simulation models are used for predicting a photovoltaic concentrator´s performance. It is desirable to analyse theoretically any given system as extensively as possible before embarking on expensive construction. Calculation of the flow fields both externally to and internally to the CPV module are solved over the flow field. The governing equations are linearised in an implicit form with respect to the dependant variables of interest. A point implicit (Gauss-Seidel) linear equation solver is used in conjunction with an algebraic multi-grid (AMG) method to solve the resultant scalar system of equations. Boundary layers and sizing function are implemented in order to capture the necessary physics of the problem. Size functions are used to smoothly control the growth in the mesh size over the domain starting from the source-the solar cell. Boundary layers were used to grow layers of cells from the trough boundary in order to capture the near wall phenomena of heat transfer The axis-symmetric flow in a straight concentrated photovoltaic (CPV) module is found to be two dimensional in nature. The developing laminar flow inside the module is calculated for DNIs up to 1400W/m² and wind speeds from Om/s to 6m/s. The velocity and temperature profile are shown for successive tilt angles of 0, 15 and 30 degrees at standard test conditions (STC). The temperature profile starts as an axis-symmetric and gradually distorts as the module rotates as it tracks the sun.