Numerical research on the hot air delaminating phenomenon of ceiling air supply in large space

Hot air is popularly used in die air conditioning and ventilating buildings to raise the indoor temperature in winter. The phenomenon of delaminatine exists popularly in air supply system of air-conditioning, especially in the occasion of ceiling register air supply in large spaces, which results in the bad effect of thermal comfort and waste of energy. In many, cases the ventilating engineers should predicate the delaminating phenomenon and thermal environment of the hot air in air conditioning and ventilation systems so as to prevent delaminating and to adjust the properties of the air-conditioning design. However. they have not gotten a simple but effective way to solve the problem. In this paper the air distribution of ceiling air supply in a large air-conditioned space is discussed, and the temperature distribution in this case is a major concern. Thermal delaminating was found to be affected by many factors, including supply air temperature, room air temperature.. supply air velocity.. room geometry duty cycle, and register locations. The dominating factor influencing the height of delaminating was supply air deference temperature and supply velocity With the method of CFD, all the air distribution of varying parameters were analyzed, and the relationship between the height of delaminating and air supply temperature, supply velocity was gain. The results can be referred to by engineers in air-conditioning.