Comparative Numerical study of the Thermal and Electrical Performance of Combined and Separated Solar Chimneys for Passive Space Cooling in Multi-Storey Buildings

The present study employs numerical analysis to examine the thermal and electrical performance of distinct photovoltaic/thermal (PV/T) hybrid solar chimney configurations integrated into multi-story buildings, to enhance passive space cooling.Various configurations are considered, including a single chimney, a combined chimney, a separated chimney, and a shunt chimney.The focus is on the impact of multiple air inlets on circulation and heat dissipation.The modeling is based on a two-dimensional mixed convection model, utilizing the Boussinesq approximation to simulate heat exchange and air movement.The transfer equations are discretized using the finite difference technique.The resulting system of equations is then solved using the Thomas algorithm in combination with the iterative Gauss-Seidel method.Numerical simulations compared the performance of each configuration, focusing on heat transfer and electrical efficiency stability at different Reynolds numbers.The results show that the combined, separated, and shunt configurations significantly improve heat dissipation and electrical efficiency stability.In particular, the separated stack provides a homogeneous distribution of heat thanks to the segmentation of the airflow, which avoids hot spots and ensures more efficient cooling of the photovoltaic cells.These integrated PV/T systems, therefore, offer the potential to optimize the use of solar energy in multistory buildings, while reducing energy requirements for passive cooling of interior spaces.