Predicting the temperature distribution of a non-enclosed atrium and adjacent zones based on the Block model

Abstract

The thermal conditions of a non-enclosed atrium and the adjacent zones are significantly related. We propose an extended Block model to predict their vertical temperature distribution by incorporating mass and heat transfer processes (horizontal convection and descending flow deflection). Regarding the air flowing horizontally from the adjacent zones into the atrium and deflecting to other adjacent zones during descent, the deflection modulus Dn was derived to evaluate the deflection states. Therefore, a mathematical model for predicting the indoor temperature was built by coupling the typical airflow patterns in a non-enclosed atrium with the Block model. The accuracy of the predicted temperatures was verified using the field measurement results obtained in a shopping mall. Using the proposed model, the effects of indoor parameters (including the height of the opening connecting the atrium and the adjacent zones and the heat source conditions indicated by the atrium's ceiling and floor surface temperatures) on the temperature distribution and airflow patterns were analysed. The temperature inside the atrium, especially the temperature gradient in the upper spaces, is mainly affected by the heat transferred from the ceiling but is weakly affected by the temperature level near the floor. The more heat is transferred from the ceiling relative to the floor, the earlier the airflow's deflection stops during descent. Shortening the opening height reduces the adjacent zones' vertical temperature gradient without affecting the deflection states. The method and conclusion of this study provide insights for predicting and optimising the thermal environment of similar spaces.