Investigating the Influence of Absorber Plate Geometry on Solar Chimney Performance

Abstract

Population growth, increase in energy demand, and environmental problems of fossil fuels have led to the use of renewable energies. One of the applications of solar energy is the solar chimney thermal power plant. Building a solar chimney is not cost-effective due to its low thermal efficiency, so studies have been conducted to increase its efficiency. Among the studies conducted, few have studied the influence of absorber geometry on system performance. In this research, the solar chimney was designed in small dimensions and effect of changing the geometry of the absorbent surface was investigated. The numerical model has been validated with experimental data of Manzanares pilot plant. The geometry was numerically simulated in Ansys Fluent software. Realizable k-ε model for turbulence and DO irradiation model for radiation has been used. The solar radiation 1000 \({W \mathord{\left/ {\vphantom {W {m^{2} }}} \right. \kern-0pt} {m^{2} }}\) is selected. The coupled arithmetic was used as the pressure–velocity coupling scheme. Besides, the discretization method for the pressure term was PRESTO! Algorithm while other terms were second-order. The criterion of convergence in solving all equations is \(10^{ - 6}\). The results showed that the maximum velocity for height 0.1 and 0.2 m has increased by 6.945% and 8.048%, respectively, compared to the smooth absorber surface. By increasing the height in the center of the solar chimney, the maximum power is obtained at a height of 0.2 m with a value of 2.338 w. Therefore, changing the geometry of the absorber affects the performance of the chimney and can strengthen it.