Study On Photo-thermal Transfer Of A Novel Paraffin-filled Double Skin Glazing Facade

Glazing facade has the advantages of beauty and good daylighting,which is widely used in high and large buildings such as office buildings,shopping centres and gymnasiums.However the thermal loss of this structure is huge due to its poor thermal insulation and high light transmission,which results in big thermal building load in the winter and summer.According to statistics,building energy consumption is accounted for about 30% of total social energy consumption,and the thermal loss of building envelope is accounted by 50% of building energy consumption,and the energy consumption of glazing facade is particularly serious.According to the proposal to cope with global climatic variation and green low carbon progress of 13 th Five-Year Plan period of China,developing a novel glazing facade is becoming a prerequisite of green building and ecological construction.At present,it is one of the advanced technologies to improve thermal performance of the glazing unit with semitransparent PCMs such as paraffin,but its heat transfer mechanism and material properties investigation are still in the initial stage.Considering rich solar energy resources of high latitude and cold region,developing glazing facade technology containing PCMs such as paraffin can effectively utilize solar energy and reduce energy consumption,which has a great significance to develop green building and ecological architecture.In this paper,a new type of glazing facade with paraffin was developed.By analyzing the present research situation of glass enclosure structure,the existing problems were discovered.In order to develop glazing facade containing paraffin,the spectral characteristics of translucent material were measured,and the photothermal transfer characteristics of paraffinfilled glazing unit were experimentally analyzed,and the effects of optical properties on photothermal transfer process was investigated by using heat transfer model of glass envelope structure containing paraffin,ant then heat transfer and flow characteristics of paraffin blind embedded in fa?ade were modelled by FLUENT software.The studied details are as follows:1.The optical properties of glass were obtained with double-thickness method,and the optical properties of paraffin were established by using a novel model of the double-thickness method.And the effect of the paraffin thickness on the heat transfer characteristics was experimental investigated by using building glass structure containing paraffin indoor measuring platform.2.The photothermal transfer outdoor experiment devices of paraffin-filled glass envelope were built,and the radiation intensity and ambient temperature influences on the heat transfer in Daqing area in autumn and winter were analyzed,and the effect of paraffin melting range on the photothermal transfer were investigated.3.Considering the solar radiation and phase transformation characteristics of paraffin wax,a one-dimensional steady heat conduction,phase transformation and radiation coupled heat transfer model of glazing unit filled with paraffin was established,which was solved based on Bouguer law and finite volume method.And the effect of radiation heat transfer on the photothermal transimission of glass envelope with paraffin was investigated.a onedimensional unsteady heat conduction,phase transformation and radiation coupled heat transfer model of glazing unit filled with paraffin was solved by using the finite difference method,and the influence of optical constants and thermal physical parameters of paraffin material were discussed.4.A two-dimensional heat transfer model of glazing facade filled with paraffin blind was established,and the effects of blind angle and radiation intensity on the heat transfer and flow were studied by using Fluent software.Through the study of this paper,a novel model of double-thickness method to measure optical properties of semi-transparent materials was developed,and the optical constants of glass and paraffin wax were obtained,and the photothermal transfer of glazing units with paraffin was also studied.The research results can offer a theoretical principle for the innovation and development of new glass envelope technology.