Numerical Study Of Cooking Particle Distribution And Movement

There are growing evidences in epidemiological and toxicological studies show that the particulate matter(PM)has a negative impact on human health,which may cause a number of serious health problems such as cerebrovascular disease and lung cancer.Also,individuals spend most of their time(around 80% to 90%)in life indoors.Therefore,the study of air particle pollution has become a hot issue in recently years.This thesis systematically summarized and analyzed the latest progress in the study of mechanism of indoor particulate matter dynamic behavior,including particles infiltrating from outside to inside,particles deposition,coagulation and resuspension,etc.Force analysis of individual suspended particles also was involved.Then this paper summarized the emission characteristics of particles mainly focuses on the particles emitted from the process of cooking.Two commonly used models in Computational Fluid Dynamics(CFD)for numerical simulation were introduced,which would help for the numerical simulation of the particle distribution and movement in the kitchen.In order to investigate the distribution and movement of particulate matters in the kitchen,the numerical simulation method was used,taking into account factors such as the air rate of the exhaust hood,the situation of doors and windows(opened or closed),different heating methods(Radiator heating and low temperature hot water floor radiant heating)and whether there is haze outside and so on.The Discrete Phase Model(DPM)in the frame of Lagrangian method was employed,and several conditions for simulation were set up,considering three different particle size(0.1?m,2.5?m and 10?m respectively).The results showed that trajectories for particles of 2.5?m and 10?m are similar under the different exhaust air volume,and particles of 2.5?m and 10?m are more easily discharged into the chamber,while for ultra-fine particles of 0.1?m,its exclusion is more difficult.Also,as the exhaust air volume increases,the more 0.1 m particles exit the chamber.In addition,different heating methods also have an effect on the distribution of particles.The interior temperature field of floor heating system in the kitchen is not only more uniform,but also the distribution of 2.5?m particle size is more uniform than that of the radiator heating system in the different height plane.When outdoor haze occur,2.5?m particle has relatively high room penetration rate,and can diffuse easily to other rooms or areas under the influence of air.