59. A Model to Estimate Ambient Conditions and Behavior of the Airflow Inside a Solar Chimney

This chapter presents models to estimate the environmental conditions and the behavior of the airflow within a prototype of a small-scale solar chimney located in Belo Horizonte, Brazil. A correlation from the literature for diffuse radiation, based on clearness index and global radiation, was evaluated. A model from the literature was used to estimate the ambient temperature of the device. The results of both parameters were compared with the experimental data. An energy balance was applied to find the heat interactions between the ground, airflow, coverage, and environment, based on the estimated incident solar radiation and ambient temperature. Literature correlations were used to estimate the convective heat transfer coefficients. Consolidated correlations were then applied to estimate the mass airflow rate and outlet temperature of the airflow inside the prototype. The results were compared with the experimental data for 4 days in autumn and good agreements were found. The model was then used to estimate the airflow parameters for 1 year. The analysis performed was transient, with results provided for each hour of the day, for 365 days. These results showed good accordance with the experimental data. The greater differences were found in the mass flow rate at night.