Numerical Simulation Research Of Air And Particles Matter Distribution In Indoor Room

With the rapidly development of scientific technology and economy, the requirement of quality of air is getting higher and higher with improved people’s living standards. The time of people live indoor is 80%, so the influence of indoor environment on human health and work efficiency is more important. But with the energy crisis and the worsening of outdoor environment, the improvement of indoor air quality(IAQ) is the focus of attention and research hot spots how to effectively utilize the energy to improve the effectiveness of the air condition and ventilation and control particle concentration level.It takes a simple air conditioning room in the season of summer as physical object to simulate air distribution and particle matter by using commercial software FLUENT combination with User Defined Function. The turbulence model of room is set up by RNG k-ε model and wall-function method. The particle model of room is set up by Discrete Random Walk model based on Lagrangian method. The main contents and innovations are as follows:(1)The physical model of classical experiment is simulated by the model of turbulence and particle as well as the assumed boundary conditions in this thesis. The simulation result and the experiment result are in good agreement. The result shows that: the numerical simulation of this thesis is reasonable and practical.(2)It is simulated three species airflow organization way including same side upper supply and bottom return mode, opposite side upper supply and bottom return mode as well as bottom supply and upper return mode in the ventilation rate of 5-h and 10-h. It gets the distribution of the velocity field, temperature field, mean age of air field and PMV-PPD thermal comfort index. It gets the influence of different of temperature and humidity conditions on the thermal comfort of people. The results show that: the airflow organization way of same side upper supply and bottom return mode is best. The ventilation of opposite side upper supply and bottom return mode causes no air circulation in a room somewhere. The ventilation of bottom supply and upper return mode causes the obvious temperature stratification and the highest energy utilization coefficient. The indoor air quality gets significant improvement with the increasing ventilation rate. Temperature has great influence on the thermal comfort of people. However humidity has little influence on the thermal comfort of people.(3)It is simulated motion and diffusion of two kinds of particle source generated by indoor personnel daily activities and office behavior in the airflow organization of same side upper supply and bottom return mode as well as bottom supply and upper return mode. It gets the time evolution characteristics and spatial distribution regularity of particles. The results show that: particle pollution generated by office behavior has great influence on human mental health. The particles diameter less than 5μm follow with airflow move and are mainly controlled by air force and thermal buoyancy lift. Whereas the particles diameter greater than 10μm are controlled by gravity. The ventilation of same side upper supply and bottom return mode mainly clears particles in the way of ventilation exhaust. However the ventilation of bottom supply and upper return mode mainly clears particles in the way of particle deposition. If being able to ensure to clean particle depositions in room regularly, the ventilation of bottom supply and upper return mode is better than the ventilation of same side upper supply and bottom return mode in restraining and eliminating particle contaminants at different locations.