Simulation And Analysis Of Performance For Aerogel Glazing System In Hot Summer And Cold Winter Zone In China

Transparent building envelop is the weakest link in the building insulation.With the advance of building energy efficiency,thermal performance of building envelope has been improved.More and more researches have been done on the insulating technology and materials of glazing systems.Nano-porous silica aerogel has been popularized and applied in the field of energy-saving glazing system because of its characteristics such as light weight,transparency and highly insulation.Granular silica aerogel glazing system is a three-layer glazing system made by filling silica aerogel granules in the cavity of double glazing.Based on the climate characteristics of hot summer and cold winter zone in China,it is meaningful to study the performance of this innovative aerogel glazing for reducing building energy consumption.To study the performance of aerogel glazing,current researches are mainly based on thermal parameters from the experimental study or simulation results from software without considering the dynamic outdoor meteorological parameters,temperature variation caused by heat absorption of aerogel,and the effect of these variation on the energy consumption of building.In this paper,optical and thermal performance of granular aerogel glazing are studied by numerical simulation and experimental test.Energy saving effect of aerogel glazing in hot summer and cold winter area is discussed compared with hollow glazing,which provides references for its practical application in the future.Firstly,solar incident angle and radiation intensity are calculated by the solar radiation model.Then,according to the principle of interface energy balance,a dynamic optical model is established to obtain the optical performance parameters with the variation of incidence angle.Based on the principle of energy balance,a state space model is established to calculate the temperature of the each glass layer,and then calculate indoor heat gain through the windows,which can be used for further annual energy consumption simulation.The model was validated by test data involving radiation intensity and temperature from the aerogel glazing experimental platform.Thermal and energy performance of aerogel glazing at different orientations are compared with hollow glazing in both summer and winter seasons in Changsha based on the proposed model.The results show that the optimum installation position of aerogel glazing is in the south facade of the building.After using aerogel glazing,heat transfer from interior glass increases in summer while indoor transmitted solar radiation decreases,leading to around 20%decrement in total heat gain.In winter,heat loss through aerogel glazing’s interior glass is greatly reduced,and the indoor net heat gain can be increased by 40%.At the same time,the influence of different thickness of aerogel layer on indoor heat gain is analyzed by simulating the aerogel glazing in the south.In a word,aerogel glazing system,thermal insulating performance of which is superior to traditional hollow glazing,has the potential in energy-saving in hot summer and cold winter zones like Changsha.