Study On The Air Distribution Of Ceiling-Mounted Cassette Type Indoor Unit

The ceiling-mounted cassette indoor unit is used widely in various occasions. However, researches on the air distribution of this type indoor unit are quite few. The quality of the design of the air distribution influences the indoor air quality,thermal comfort and energy saving performance of the air conditioning directly, hence, it is extremely important to evaluate the air distribution reasonably. At present,there are a lot of index for the evaluation of air distribution, but the effects on energy saving of air distribution design is not paid enough attentions.The air distribution of ceiling-mounted cassette indoor unit is studied with both experimental methods and CFD method in this paper. The contents of the experiments include: velocity distribution on the outlets of the air conditioning, temperature distribution and velocity distribution in room. The air distribution of ceiling-mounted cassette type indoor unit is evaluated with temperature asymmetry coefficient,velocity asymmetry coefficient and energy using coefficient. Based on the deficiencies of energy using coefficient pointed out in this paper, a new index for evaluating the energy saving performance of air distribution which is called validity of energy using is proposed to evaluate the air distribution more reasonable, then the design and improvement of the air distribution can be guided with this index.The air distribution is simulated with the software FLUENT and the boundary conditions of outlets and heat source are discussed as well. The simulation model is validated with the comparison of simulation result and experimental results. The values of new index are obtained with this reliable simulation model, and it is showed that the new index is feasible and rationale from the analysis.