Dynamic Simulations Analysis On Thermal Characteristics Of Double Skin Facade In Hot Summer And Cold Winter Region

Double skin facade, not only has the better artistic characteristics, such as good building transparency, spaciousness and excellent light and shadow effect, but also is a kind of "ecological" energy-saving building envelope, it has gained increasing popularity from architects. The study about double skin facade is relatively late in china, whose research theories are mostly referring to those from foreign developed countries and the analysis methods are largely a simplified steady-state model which can’t accurately analyze the heat transfer process effected by a variety of factors on the ventilated cavity. This study mainly focuses on the basic research of dynamic thermal characteristic of double skin fa?ade with the multi-factor synergism method in hot summer and cold winter area.This paper first analyzes the heat transfer process of double skin fa?ade in theory and studies the ventilation and heat transfer characteristics research under different factors. The main factor includes structural parameters and meteorological parameters, structural parameters as follows: the blind angle, blind location, spacing of blinds, width of blinds, width of ventilated cavity, vent size; meteorological factors are outdoor temperature and solar radiation intensity etc. A computational fluid dynamics simulation is conducted. The steady simulation method is used to analyze the ventilation and heat transfer characteristics under the above structure factors. This paper built two models of the double skin fa?ade, a two-dimensional(height of 2.4m) model and a three-dimensional(fa?ade size 1.5m*2.4m) model, on the assumption that these models locate in the hot summer and cold winter Zhuzhou. The simulation of solar radiation and outdoor temperature of these models is based on the meteorological parameters of a certain meteorological year of july19.Through the establishment of a two-dimensional CFD model, a simulation analysis of the six structure factors of the DSF in steady state is conducted. The research method is as following: A comparative analysis of the curtain wall heat transfer and the ventilation characteristics is conducted under 27 working conditions on the analysis of the model’s comprehensive heat transfer coefficients and the outlet mass flow rate which combines with the temperature field cloud picture and the velocity vector diagram. Finally, optimized simulation results are obtained under all structure factors.Then studied the heat transfer characteristics of curtain wall under the outdoor air temperature and solar radiation intensity dynamic change through built the three-dimensional model, By contrastive analysis six working condition of the results under different ventilation cavity widths, vent sizes, blind locations, conclusions are made as following: ①curtain wall’s ventilation efficiency should be strengthened in summer days and be careful in summer nights; ②outlet mass flow rate is only related to outdoor temperature values, but vents mass flow volume is associated with outdoor meteorological parameters and curtain wall structure parameters. For instance, higher outdoor temperature, wider cavity width, bigger the vent, and the blind position is on the right, the volume of mass flow rate of the curtain wall is greater;③outlet mass flow reflects the performance of curtain wall ventilation, but the comprehensive heat transfer coefficients are more important. Low integrated heat transfer coefficients and good quality of the vents flow guarantee a good performance of the double skin facade. Finally, the deficiencies of this thesis are summarized and what needs to be done in future researches is suggested.