Influence of air inlet geometry on the performance of a solar chimney power plant: experimental assessment

In this study, an experimental solar chimney power plant (SCPP) is designed, built, and tested at the University of Chlef, Algeria. The prototype consists of a chimney height (CH) measuring 6 m as well as a chimney diameter (CD) of 0.40 m, with a solar collector of 5 m in diameter, 0.40 m in inlet height, and 5 degrees inclination. This study describes the geometric configuration, material selection, and detailed construction procedure of the SCPP prototype. The experimental investigation aims to examine the effect of air inlet design parameters on the aerodynamic and thermal performance of the system. Measurements are taken under local climatic conditions, with the ambient temperature (AT) averaging 312 K and solar radiation intensity peaking at 817 W m-2. Key parameters, including airflow velocity through the chimney as well as the temperature distribution within the collector, are continuously recorded throughout the experiments. To enhance the airflow distribution beneath the collector, the traditional open-air inlet is modified into a circular configuration. The experimental setup considers air inlet diameters of 10, 20, and 30 cm. In addition, three inlet arrangements comprising 2, 4, and 6 openings are systematically investigated. The findings indicate that the best system performance is achieved using a 20 cm inlet diameter with a four-inlet circular configuration, resulting in an airflow velocity of 3.2 m s-1, a corresponding collector-beneath air temperature of 332 K, and an output power (PO) of 2.72 W. These outcomes confirm that optimising air inlet geometry, particularly through circular air inlet design, significantly enhances airflow distribution and overall system performance.