Numerical study of the influence of ventilation modes on the distribution and deposition of particles generated from a specific cooking process in a residential kitchen

摘要

Computational fluid dynamics have been used to numerically study the particle diffusion and deposition in a residential kitchen under several ventilation modes. First, combining the renormalized group turbulent model with cooking release conditions, the airflow field in a kitchen was simulated and its airflow characteristics were analysed. Second, the drift flux model was adopted to predict the spatial distribution of particles, quantifying various mechanisms that affect the particle diffusion. Finally, the deposition flux towards the wall was determined by a semi-empirical particle deposition model. The results show that the rising thermal plume has a great influence on the diffusion of particles. When particles with small sizes diffuse in the kitchen, the influence of turbulence plays a crucial role. The case studies show that the ventilation form is an important factor affecting the concentration distribution and deposition of particles. However, the ultrafine particles distribution with different sizes is little sensitized to changes of the airflow field. The results also show that the main determinant of the deposition flux is the particle concentration near the wall. There is not much difference in the particle deposition flux under different particle sizes, which is related to the larger air exchange rate.