Numerical Simulation Of Benzene Concentration In Office Building With Different Inventilation Way

Because of badly ventilating and the wide use of building materials that contain a lot of harmful components, the concentration of VOCs in indoor environment increases highly and indoor air quality deteriorates seriously. Air distribution has great influence on the control of indoor pollutants, So the study of the pollutant distribution in indoor environment under different ventilation mode will help the improvement of indoor air quality.In this paper, veneer widely used in fitment is regarded as the source of indoor pollutants, and benzene that is typical in the indoor pollutants is selected as the simulation target. The concentration of benzene in two typical office buildings under different ventilation modes were studied using numerical simulation technique.First, theoretical and non-theoretical VOCs emission model for dry materials were compared and analysed carefully on the basis of the principles of heat and mass transfer, and one appropriate emission model was chosen. By disdimensioning of the model, emission coefficient equation was obtained and programmed into Fluent boundary condition by UDF. It was more reasonable for wood-base panel condition because the above boundary condition was unsteady.It is found that ventilation mode influences the distribution of the concentration of VOCs. This paper made numerical simulation for three typical ventilation modes, i.e. ceiling square diffuser ventilation, side grill ventilation, and displacement ventilation. It is found that the concentration of VOCs is lower under displacement ventilation mode than under the other two ventilation modes in ordinary office.However, for open-plan office, the clapboard has a great influence on airflow. When the air flow direction and clapboard are vertical, displacement ventilation can not reduce the concentration of indoor pollutants; When the air flow direction and clapboard are parallel, the indoor pollutants concentrations decrease distinct.The choose of the airflow must be considered according to the layout of the work space in the open-plan office.Furthermore, according to the running schedule of office, the concentration of indoor pollutants can be lowered and indoor air quality can be improved with the change of starting time of ventilation system.