Enhanced solar chimney design with double-glass photovoltaic panels and nanoparticle-enriched paraffin for combined ventilation and power generation

This study explores a novel approach to enhance solar chimney performance by combining a double-glass photovoltaic (PV) panel on the top with a paraffin-based thermal energy storage (TES) unit at the bottom of the inclined chimney channel. The paraffin (RT25) in the TES was enhanced with MgO nanoparticles and further optimized using porous alumina foam to improve thermal conductivity. The system was analyzed for three inclination angles (30°, 45°, and 60°), and various configurations were simulated: a traditional solar chimney, a chimney with PV only, a chimney with PV and TES, and a chimney with PV-TES integrated with porous foam. The simulations were conducted using ANSYS FLUENT, incorporating site-specific meteorological data (heat flux, air temperature, and wind speed) for Mosul, Iraq. The turbulent airflow within the air zone, including buoyancy force effects, was modeled using the RNG k-ε approach, and radiation heat transfer was accounted with the surface-to-surface (S2S) model. The performance was evaluated through contours in the air zone, as well as temperature and liquid fraction distributions in the TES. Key findings highlight that addition of the PV-TES-Porous foam configuration increased the mean absorber temperature by approximately 6.13% compared to the traditional system. Increasing the chimney angle from 30° to 60° improved the inlet mass flow rate by about 15%. The highest useful heat output (388.76 W) was observed for the chimney with PV at an angle of 30°, with a 23.14% increase when the angle was adjusted from 60° to 30°. Furthermore, incorporating porous foam improved the liquid fraction of the TES by 47% at an angle of 60°. Electrical efficiency, which was lowest for the PV-only case at 30°, increased by 1.4% when the system was equipped with a porous TES and operated at 60°.