Evaluation of 15-m-Height Solar Chimney Model Integrated with TES under Tropical Climate

Abstract

The present study examines a solar chimney power generation model under tropical conditions, with a focus on the impact of ground absorber dimensions on system efficacy. An experimental and numerical analysis was conducted using a 15-meter-high solar chimney, where the ground was transformed into a sensible thermal energy storage system through the application of black-painted pebbles. Three configurations were assessed to determine system performance: Case-1 and Case-2, featuring collector diameters of 4.9 m and 6.6 m respectively, and Case-3, which introduces an innovative design extending the diameter of the sensible thermal energy storage (TES) by 2.0 m beyond the collector's canopy. Performance was gauged using a metric defined by the product of mass flow rate and temperature increase of the air. Numerical models were validated against experimental outcomes, with results showing a satisfactory correlation. It was found that the performance metric in Case-2 doubled, while in Case-3, it tripled relative to Case-1. The enhancement in performance in Case-3 was further evidenced by a 30.4% increase in air velocity at the chimney base over Case-2, and a 36.7% increase over Case-1, highlighting the efficacy of the extended sensible TES. These findings suggest that enlarging the TES area beyond the collector's canopy can significantly improve solar chimney performance, potentially enabling a reduction in construction scale and a concurrent decrease in electricity production costs. This approach represents a promising avenue for addressing the dual challenges of structural height and efficiency that currently hamper the feasibility of solar chimney power generation on an industrial scale.