Numerical Study On Convecting Transfer Heat Of Underfloor Air Supply

Since the 1980s, with the developing of air-condition technology, men begin thinking much of room condition quality, displacement ventilation has been given a good favour for its higher ventilation effectiveness and air exchange efficiency. Displacement ventilation also has higher energy using ration than other supply air systems, ie it has higher temperature effectiveness, and that displacement ventilation system always has part quantity of heat lying upside area of room, air supply outlet lies at low side, supply air direct come into workaround, and only absorb heat and humid of workaround, assure satisfaction of the design conditions of workaround. Only the heat gain from the heat source and the heat coming from lower part of the wall is taken into account, the heat gain of higher zone of the room isn' t calculated. As the return of flow is being, one side the heat gain of higher zone will be lead back, on the other hand, the heat has been transmitted to upside also will return, so the heat gain will increase. The methods of using numerical simulating has been used to analyze the factors influecing convecting transfer heat in this paper.In this paper, using PHOENICS software to compute and analyze the variety rule of the convecting transfer heat at the basis of computing and analyzing the temperature and velocity field of one underfloor supply air room with a focus hot source , and concluding that the number of the hot source and the supply air outlet> the intensity of the hot source and the volume of supply air will influence convecting transfer heat, and obtained its correlativity formula . At the same time, I discover that the number of the return air inlet has a little influecing and it can be neglected. When there is hot resource at upperside of the room, the hot jet and supply air jet togetheraffecting. At the same lower part heat intensity, a utmost wind speed exist, the supply air speed lower, the more heat intensity on the upside , the less convecting transfer heat, whereas. So when the underfloor air supply system is been used in engineering, different supply air speed will be adopted on the basis of different heat intensity of upside and low side of room. So to economize energy.