Numerical Simulation Of Internal Partitions' Influence On Indoor Air Quality In An Enclosure With Underfloor Ventilation System

In office building each space has its unique features.such as room geometry, obstructions, ventilation system,etc.which could influence the air movement,then influence indoor airflow pattern and contaminant distribution. Although the design of a ventilation system considered the air flow in an empty space in advance, the air movement could easily be affected by the final layout. Interior decoration, office furniture, partitions, etc. could be obstructions in the room.The supplied air flow could easily be blocked and diverted by the presence of obstructions. The change in the air flow pattern would often lead to a change in the ventilation performance.This paper investigated the effect of partitions in an office on the performance of under floor air supply ventilation system.The flow field,temperature field and pollutant distribution was studied. The results revealed that for the location of furniture and outlet arrangement according to the form of case A, the existence of partition could block the supply air from sending directly arrived in human ankles to some extent, help to improve the situation of feet cold.For the location of furniture and outlet arrangement according to the form of case B,however, when the effective temperature difference was large, the existence of partition would result in the presence of decreased temperature near the ankle,and easily lead to uncomfortable situation of feet cold.The results also showed that the existence of partition lead to flow velocity of the surface of human respiratory tend to increase, when indoor air temperature difference increases,the influence of partition to human body around velocity decreases. On the plane of human ankle place,the airflow showed the symmetry of distribution characteristics.When there was a gap between the internal partition and the floor, air velocity increasing. The gap had some influences on the temperature distribution on the plane of human ankle,and had slightly influences on the temperature distribution around human body. Partition height had little effect on CO2 stratification height, but had some influence on the concentration,the higher the partition was, the accumulation of CO2 concentrations in upper room was larger. In the case of large effective temperature difference, the changes of location of furniture and outlet arrangement had little influences on the distribution of CO2 concentration. When there were case2, case3 type of partition in the room, the CO2 concentration around the human body was significantly higher than casel, air quality was poorer. The gap had significant influences on human exhaled CO2 diffusion characteristic, CO2 was taken back to the compartment, resulting in CO2 accumulation in the compartment, which was unfavorable to the exclusion of CO2.