| The building envelop structure is the most important part of building energy consumption,while the glass window is the most important part of the building envelop structure.With the progress of science,more and more new energy saving envelopes are also made.Nano-porous silica aerogel have attracted increasing attention due to their high porosity,low thermal conductivity,low refractive index,and high transmittance.The object of this paper is particle aerogel glass:a glass system made by densely filling granular aerogel material in the interstices of double glass.At present,theoretical analysis of aerogel glass is mostly simulated by K-SC model,which can approximate the photothermal characteristics of aerogels.However,at first,the solar heat gain coefficient and shading coefficient of aerogel glass under specific incident conditions have not taken into account the dynamic changes of glass thermal performance with outdoor weather conditions,and it cannot accurately calculate the solar heat gain at different incident angles.Second,due to the special nature of the aerogel structure,certain parameters of the aerogel glass are difficult to determine,and the existing energy simulation software cannot accurately calculate the light,heat,and radiation transmission processes of the aerogel glass system.Therefore,it is very necessary to carry out dynamic simulation analysis of the photothermal properties of aerogel glass.This paper simulates the aerogel glass heat transfer through three interrelated mathematical models.The solar radiation calculation model can be used to obtain solar radiation and solar incident angles of solar energy reaching the surface of the glass system at different moments.The aerogel glass optical model can be used to obtain various layers of the aerogel glass system at different times through the mathematical model.The medium absorption and total transmission,the first two models provide the basis for the calculation of the final model;heat transfer model,through the final dynamic heat transfer model to obtain the temperature value of each node of the glass system and the hourly heat in the room.Using the simulated temperature and solar radiation transmission data and the data collected from the experiment to compare and analyze,the correctness of the model was verified.The established model was used to simulate the photothermal transfer process of aerogel glass under different working conditions and different orientations on the VC++ platform.The optical calculation model and temperature nodes of the aerogel glass system were simplified.Simplification of optical calculations,when the total solar radiation is particularly high in summer sunny days,the error is relatively large,but the maximum relative error does not exceed 15%,and for the total solar radiation is relatively small or cloudy conditions,simplified calculations Compared with the accurate model,the indoor heat gain is relatively small and there is no error node simplification;this paper analyzes that simplifying multiple heat transfer nodes in the middle layer of aerogel glass into a central node is completely feasible,whether it is sunny conditions or In cloudy conditions,the overall relative error of one day's load calculation will not exceed 1%;for the extinction coefficient of aerogel material,if the extinction coefficient of the aerogel material is reduced to a fixed value,the overall relative error of the daily load calculation Both are less than 6%.Finally,compiling the established calculation model into source code and developing the FMU module,it is convenient for the DeST main program to calculate the call to FMU. |
PDF Full Text Request