Numerical and experimental study of the impact of conical chimney angle on the thermodynamic characteristics of a solar chimney power plant

Abstract

The goal of this paper is to study and optimize the conical chimney angle (α) of a divergent solar chimney power plant (DSCPP) by using CFD technique. The local airflow characteristics were analyzed in four configurations with different conical angles α = 0°, α = 3°, α = 6° and α = 9°. The first design is validated experimentally by using a pilot prototype build at the National School of Engineers of Sfax, Tunisia. In addition, some experimental results of the temperature, the velocity and the power output were presented during a typical day. A novel mathematical correlation was developed to prove the effect of the conical angle and the DSCPP scale on the power output. In fact, the relationship between the optimum conical angle and the system scale was performed based on both quadratic and cubic regressions. The computational results ensure that the conical chimney angle presents a parabolic tendency with the turbulence airflow characteristics and the power output. The performance of the DSCCP was degraded since the conical angle is greater than α = 3°. Furthermore, the optimum angle decreases with an increasing system scale. A commercial solar chimney with a conical angle around α = 1° presents an efficient system.

Solar Chimney Power Plants for Sustainable Air Quality Management Integrating Photocatalysis and Particulate Filtration: A Comprehensive Review

“…An increased height of the chimney causes a rise in performance [76][77][78], but there is a limitation. Performance enhancement with an increase in the chimney diameter is also noted but only up to some optimum value [79][80][81]. The impact of the chimney's shape has been noticed by different researchers.…”

Experimental Treatment of Solar Chimney Power Plant—A Comprehensive Review

“…Chimney shape also has an impact on the performance of SCPPs, with cylindrical, convergent, and divergent shapes being considered in the literature. Divergent-shaped chimneys (refer to Table 7) have shown better performance, and an optimum divergent angle has been reported by Nasraoui et al [75], Das and Chandramohan [76], and Yapici et al [64]. Patel et al [62] found that an optimum divergence angle of 2 • resulted in the best performance.…”

“…Patel et al [62] found that an optimum divergence angle of 2 • resulted in the best performance. Ohya et al [77] reported that a divergence angle of 4 • maximized the updraft, while Hassan et al [78] and Nasraoui et al [75] suggested optimal divergence angles of 1 • and 3 • , respectively. The chimney divergence is also measured by area ratio.…”

Study of a solar chimney characterized by a convergent collector output and a divergent chimney bottom

“…Sedighi et al 17 studied the performance of a solar power plant with an energy storage layer in the soil under the impacts of solar radiation, the pressure drop of the turbine and the porosity of the soil. Nasraoui et al 18 presented numerical and experimental study of the impact of conical chimney angle on the thermodynamic characteristics of an SCPP. Results showed that the conical chimney angle presents a parabolic tendency with the turbulence airflow characteristics and the power output.…”

“…Nasraoui et al. 18 presented numerical and experimental study of the impact of conical chimney angle on the thermodynamic characteristics of an SCPP. Results showed that the conical chimney angle presents a parabolic tendency with the turbulence airflow characteristics and the power output.…”