Potential need for vestibule structures in solar updraft tower

Abstract

A solar updraft tower (SUT) is a power-generating structure that transforms solar energy into electricity through the kinetic energy of air rising due to solar-radiation-induced buoyancy. In traditional architecture, a vestibule is a small room that leads to the main room, and it separates the indoor and outdoor atmospheres, thereby reducing heat loss and improving the thermal performance of the main room. Herein, we propose a canopy-attached divider structure that can create a vestibule-like space and increase the overall thermo-fluid dynamic efficiency of SUTs. A computer simulation study was conducted for various divider geometries in terms of their locations and shapes to create diverse vestibules. The control parameters were the gap between the divider tip and the ground and the length along the radial direction, which determines the vestibule volume. SUT efficiency was analyzed using the velocity, temperature, and turbulence kinetic energy (TKE) contours obtained herein. The vestibule created by installing a divider with a gap of 0.06 m and a length of 4.6 m can increase the outlet velocity by up to 6.97%. The results of this study indicate the possibility of applying this thermo-fluid dynamic engineering technology used in other fields to SUTs.