Study On Non-gray Characteristics Of Optical And Heat Transferin Multiple-glazing Unit Filled With Paraffin

The glass envelope has the advantages of good lighting performance and beautiful appearance which has been widely used in architecture.But it also has poor thermal insulation performance.The units filled with PCM such as paraffin can effectively utilize solar energy and reduce energy consumption of the glass enclosure structure.The research on the optical and heat transfer of glass structure filled with paraffin is the basis of developing the new type of the enclosure structure,it has already been a hot topic in this field.This article selected the glazed window filled with paraffin as the research object,with measuring the thermal physical properties of paraffin and glass,and consider the material in the solar spectrum has typical non-gray feature and through experiment and numerical simulation method to analysis the optical and thermal performance of the window filled with paraffin to analysis the influence factors of optical and thermal performance.Considering the non-gray feature,a one-dimensional photo-thermal transfer model for multilayer glazing contained paraffin was built.It was used to investigated the influence of winter and summer seasons,different thickness of PCM and air layers and compared with double glazing.The main contents of this paper are as follows:1.This paper set up the experiment device with UV spectrophotometer and temperature control instrument,measured the transmitted spectrum of liquid paraffin in the range of 40?-70? and solid paraffin and glass material at room temperature,and the optical constants of materials were obtained by the double-thickness method.The thermal property parameters of solid and liquid paraffin were measured by Hot Disk thermal constant analyzer,which provided the basic parameters of the simulation calculation in this paper.The results show that the temperature has a ruleless effect on optical constants of paraffin.2.An indoor experimental facility of optical and thermal transfer of multilayer glazing contained paraffin was set up.The experiment measured the different radiation intensity,different thicknesses of paraffin layer and the melting point of paraffin and the effect to the glass structure.The results show that the three-layer window has better heat storage and insulation performance.3.The non-gray characteristics of glass and paraffin materials in solar energy,a one-dimensional photo-thermal transfer model for multilayer glazing contained paraffin was built.The spectrum is segmented by combining the experimental data above and the data in the literature.By comparing with the experimental results,the simulation results of the spectrum are divided into five parts and the results are the most consistent with the experiment.Furthermore,the effect of filling different paraffin,different thickness of paraffin layer and different seasons on photo-thermal transmission performance of glass windows were compared.It is found that the non-grey characteristics of the materials have a great influence on the simulation results.The melting point and the thickness of paraffin also have influence on the optical and heat transfer for the windows.4.The optical and thermal transfer model of multilayer glazing containing paraffin was built,and also considering the spectral selective of materials.Add an air layer on the basis of double glazing,simulation compared the optical and thermal performance of triple-glazed and double glazing containing paraffin in Daqing area in winter and summer.The optimal position of air layer in the structure of glass window and the influence of the air and paraffin layer on the optical and heat transfer of window are obtained.