The influence of indoor thermal conditions on ventilation flow and pollutant dispersion in downstream industrial workshop

Abstract

Natural ventilation is often used in industrial workshops with high intensity heat sources and pollution sources indoors, because such workshops require large amounts of ventilation. In this study, a numerical simulation of the pollutant dispersion between two adjacent industrial workshops is performed, with a focus on the effects of the downstream workshop's thermal conditions on the flow and pollutant dispersion. The results indicate that there is a significant interaction between the wind and buoyancy generated by the downstream workshop's heat source. And this relationship can be evaluated using the Richardson number (Ri). Firstly, the Richardson number affects the ventilation direction of the downstream workshop. When Ri < 1.6, the airflow is mainly driven by wind, which flows from the leeward of the downstream workshop to the street canyon. When Ri > 1.6, buoyancy's effect begins non-negligible, the ventilation of the downstream workshop comes from the street canyon. There is a low concentration of the pedestrian breathing area and downstream workshop, when the airflow is driven by wind. When the airflow is driven by buoyancy, the pollutants migrate to the pedestrian breathing area and the downstream workshop.