Scale modeling study of airflow distribution uniformity in large spaces with high heat flux

Abstract

• The uniformity of a large-scale sphere-shaped facility was experimentally explored. • Proposed reference coefficient to assess temperature uniformity in occupied zone. • Optimal ventilation design relied on airflow characteristics and practicality. With regard to the arrangement of air conditioning and ventilation in a building with large spaces, the uniformity of airflow distribution is often related to the air supply mode, heat flux, and location of the heat source. In this study, a 1:38 small-scale model of a large-scale sphere-shaped facility with high heat flux dissipation was constructed for investigating and analyzing the airflow distribution in the upper occupied zone. Additionally, a series of environmental parameters was experimentally obtained to characterize the influence of the location and release rate of the heat source. A dimensionless method was used to process the acquired data and explore the airflow characteristics. The experimental results revealed the evident influence of the release rate and heat source positions on the temperature distribution in the upper occupied zone. Furthermore, a reference temperature non-uniformity coefficient was proposed to assess the temperature uniformity in the occupied zone. Ultimately, the coefficients of temperature non-uniformity, reference temperature non-uniformity, and energy efficiency were reliably predicted. Consequently, a supply air temperature of 18 °C was selected as the optimal design parameter after conducting experiments to maintain the upper occupied zone temperature at 21 ± 1 °C and the corresponding minimum airflow rate could significantly reduce the energy consumption of air processing.