The Numerical Simulation Study And Optimization Design Of Double Skin Facades

Double skin facades can bring beautiful architecture outline, comfortable indoor environment and good effect of energy saving. Nevertheless, the design of double skin facades is a complicated job which needs to consider many factors synthetically. If only we know its energy saving performance, we can correctly design a system of double skin facades meeting the local climate well. Because of the variety and complexity of its effect factors, the domestic study of double skin facades is still at the stage of start. The reference documents about it are not enough so that double skin facades are not widely used in our country. So it is necessary to know its performance of energy saving well by study, then we can provide reference to engineering designers and evidence for the establishment of the criterion concerned.FLUENT , the popular numerical simulation software, is used to study the single storey double skin facades according to the CFD(computational fluid dynamics) theory in this paper. RNG k-e model is used to simulate the air flow in the system of double skin facades and the CFD results are validated against experiment data from the foreign literature and very good agreement between the prediction and measurement is achieved. The experiment method of orthogonal design are used in this paper to analyze the effect law of its height, width, and the height of the inlet and outlet to cavity's ventilation rate and the temperature of the inside glass. Within the setting range, a conclusion is made that double skin facades' width and the outlet's height is the main factor. Cavity's ventilation rate rises as its width and the outlet's height increases while the temperature of the inside glass drops as the outlet's height increases, and first rises greatly then drops slowly as double skin facades' widthincreases. And when the number of its width is between 0.2 and 0.3 metre, the temperature is the lowest.The performance of energy saving of double skin facades which use different glass is also shown in this paper. To single storey double skin facades, the optical property of glass greatly effects the performance of energy saving. If the choice of glass is not reasonable, it is likely to be overheated in the room when it is in the hottest summer. So the choice of glass is very important when designing double skin facades. This study also shows that when using heat-absorbing glass as the outside one and hollow glass which is constituted of Low-E reflection glass and common glass as the inside one in the hot summer area, the various performance of double skin facades are balanced and the effect of energy saving is the best.According to the study, a system of double skin facades which is suitable to use in the hot summer area is designed. The use of this system in transitional season and winter is studied by the method of simulation experiment. In the transitional season, we can choose the supply mode to heat the fresh air or provide natural ventilation to the room, or the exhaust mode to partly or fully use displacement ventilation. While in winter we can close the facades to form a close hollow to promote the its characteristic of heat insulation or use inside circulation ventilation mode to heat the air of the room. All these can save a lot of energy for architectures.(Heating, Ventilation and Air-conditioning Engineering) Supervised by ___________________...