Dynamic Heat Transfer Calculation Model And Program Implementation Of Ventilated Double Skin Glass Curtain Wall

Ventilated double skin glass curtain wall is an enclosure structure that appeared in the 90s of the last century,and it has been used more and more in engineering.Its structure includes the inner glass layer,ventilation cavity,louver layer,double hollow glass layer.Good appearance,good light transmittance,and high energy efficiency are its advantages.However,because the optical analysis of the double skin glass curtain wall system is difficult and the flow state of the air flow in the cavity is complicated,there are many factors affecting the heat transfer process,and a mature calculation method is needed to calculate its thermal performance and energy consumption.Happening.First,a solar radiation calculation model was established.Through the date,latitude and longitude,time,wall orientation,and wall tilt angle,the solar radiation amount at each moment of the vertical wall surface in different orientations was calculated.As glass and louvers are the main components of double skin glass curtain walls,their optical properties play an important role in the thermal performance of double skin glass curtain walls.Considering the influence of glass and louvers,an optical performance model of a double skin glass curtain wall was proposed.Finally,considering the influence of air flow in the cavity on the thermal performance of the curtain wall,the energy conservation equations are listed for each energy layer of the curtain wall system to establish the model.At the same time,considering the analysis of the air flow in the cavity,the temperature of the indoor side glass and the solar heat gain entering the room are obtained.The architecture of the program is introduced in detail.The program includes three modules:solar radiation module,optical module and heat transfer module.The solar radiation module mainly calculates the direct radiation,scattered radiation and total radiation of the sun.The optical module mainly calculates the transmittance,scattering rate and absorption rate of sunlight through the curtain wall system.The heat transfer module calculates the indoor side glass temperature and the indoor heat.The specific content of the program is given in the appendix,which is convenient for readers to consult.Using the results of the existing Matlab program and the results of the C++program written,the typical days of summer(July 22)and winter(January 22)of the typical meteorological year were selected as typical days,representing summer and winter respectively.The result shows that the calculation result of C++ program is and the calculation result of Matlab program can meet the accuracy requirement of engineering calculation.