The Research Of Indoor Air Distribution For VAV System

As the energy-saving technology is paid more and more attention in the whole world, the variable air volume (VAV) air conditioning systems have been widely used. However, due to the change of supplying air volume corresponding to the change of cooling or heating load, the field of indoor air temperature and velocity will make the relevant change, which will lead to the bad indoor air distribution and uncomfortable environment. Therefore, studying on the change of indoor environment at different velocities is very important to the application of the VAV system.This dissertation took CFD software as research instrument and made experiments in a VAV climate chamber containing two different modes of supplying and returning air. Firstly, with the application of professional CFD software, 3-D fields of indoor air temperature and velocity were simulated at different modes of supplying and returning air and at different supply air volumes in the winter condition, then the experimental results were used to improve the simulation model and the boundary conditions to make the simulation results match the experimental results. Then the simulation model was applied in the other conditions and the results were discussed. At last, by the value of ADPI, the indoor air distribution was made integrated evaluation.Through the research work of this dissertation, the reasonable simulation model for fields of indoor air temperature and velocity has been established, and the rule of indoor air distribution 'change for VAV air conditioning system has been gained at three different air supplying and returning modes for both summer and winter condition, different supplying air parameters and different air supply device. All those are the guidance to the design of air distribution for VAV system...