Improvement of PVT air-cooling by the integration of a chimney tower (CT/PVT)

Highlights: • A numerical modeling of a new concept CT/PVT was developed. • The optimal design of the new hybrid system has been obtained. • Improvement of the heat transfer rate by around 78.13% compared to the conventional case. - Abstract: In this work, a bi-dimensional numerical simulation of the turbulent natural convection for cooling of the solar panel in a new concept of hybrid photovoltaic/thermal solar collector by integration of a chimney tower has been analysed. The hydrodynamic flow field is governed by the Navier–Stokes equations in the fluid region, thermal field by the energy equation. The standard k-ε turbulence model is used for describing the turbulent fluctuations of velocities and scalar quantities. The Influences of the dimensionless geometric parameters, such as the collector diameter ratio (Dc^∗), the absorber length (La^∗) and the chimney tower diameter ratio and the chimney tower height (Dt^∗, Ht^∗) on the flow features and heat transfer rate are presented. The obtained results show that the optimum dimensionless geometrical parameters of the new hybrid system proposed (La^∗ = 0.625, Dc^∗ = 3, Ht^∗ = 0.625, and Dt^∗ = 2) produce an improvement in the heat transfer rate of 78.13% compared to the base case, for Ra = 5 × 10⁶. Correlations of the average Nusselt numbers are obtained and discussed.