Prediction of vertical thermal stratification of large space buildings based on Block-Gebhart model: Case studies of three typical hybrid ventilation scenarios

Abstract

Although nozzle air supply is considered to be dominant when creating the thermal environment of the occupied area in a large space building, natural ventilation and air infiltration can interact with nozzle jets, resulting in a complex air distribution inside the building. This study focuses on the prediction of indoor vertical temperature distribution in large space buildings under the coupling of multiple airflows. Based on the validated regional model, Block-Gebhart (B-G) model, three auxiliary models were introduced for three types of common building ventilation scenarios, namely nozzle air supply, natural ventilation, and air infiltration. The auxiliary models were combined with the basic model to predict the indoor thermal environment of large space buildings in three hybrid ventilation scenarios. Field measurements of the vertical air temperatures of these three buildings were carried out to verify the feasibility and accuracy of the composite model. The results showed that the average deviations of air temperature in the International Gymnastics Stadium, the Ecological Demonstration Building and the Engineering Training Plant were 0.85, 0.80, and 0.32 °C, respectively. The building with the minimum deviation was the training plant, because the prediction of air temperature of this building took into account both jet entrainment and air infiltration phenomenon, so that the description of its indoor airflow pattern was the most accurate. The composite model proposed in this paper extends the application of the B-G model in hybrid ventilation scenarios and supplements the present design system of air distribution in large space buildings.