Computational Analysis and Design Exploration of Solar Updraft Towers
Nathawani, Darsh Kiritbhai
MetadataShow full item record
The solar chimney power plant works on the principle of natural convection. Thesolar chimney system consists of three components: a collector that is made of a transparentmaterial like glass or polycarbonate sheets, a chimney that is typically made ofcement and located at the center of the collector, and a turbine that is placed at thechimney base. The collector receives and transmits solar radiation to the ground. Theground absorbs some energy and transfers some energy to the air by convection. Thewarm air has low density and therefore it rises and moves toward the chimney. Lowpressure is generated at the chimney base due to the chimney effect. This low pressurecreates an updraft for the inside air and the air exits at the chimney top. The turbineuses the pressure drop and the updraft velocity to generate power. A commercial codeANSYS Fluent was used to numerically model a solar chimney system. Simpler geometrieswere first used to study the nature of the flow inside a chimney-collector system.The boundary conditions were explored to accurately model the complex geometry. Asolar chimney was simulated with the ground as an energy storage medium using aradiation model to analyze the system performance. The solar chimney system withreduced chimney height was explored. The velocity decreased with decreasing chimneyheight, while the temperature increased. A new solar chimney design with a conical diffuserwas created to study the effect of geometry in the performance. The diffuser wasmodeled for different heights and diameter ratios. The updraft velocity and the poweroutput increased significantly with diffuser model compared to the original model.