Parameters Optimization And Performance Investigation Of The Multilayer Glazing Window With Phase Change Material And Thermal Insulation Material Integration

Contributing to the implementation respected to the strategic goals of"carbon peaking and carbon neutrality"in building sector,the development of clean and low-carbon glazing envelopes that takes into account both energy saving and daylight demands is considered as a vital way.In this regard,a substantial number of studies have shown that the building glazing window with phase change material and aerogel insulation material integration is promising in improving its thermal and optical regulation performance.However,from the perspective of promoting the engineering development of this kind of glazing window,there are still remain three crucial concerns:（1）The material filled in double glazing panes is mostly solid-liquid phase change material specifically paraffin,whose volume varies significantly and exists leakage concerns.（2）It is still unproven that the long-cycle energy saving effect of this kind of glazing window in full-scale buildings.（3）There is still a lack of comprehensive optimization of the window design parameters including media layer thickness,window-to-wall ratio,and window orientation with the object of counterbalancing the demand of energy saving and indoor daylight performance.In response to the above problems,a multi-layer glazing window with polyurethane-based solid-solid phase change material and silica aerogel integration is developed,and its heat transfer characteristics are analyzed.To address the limitation that non-gas insulation and phase change materials cannot be directly incorporated into glazing elements of Energy Plus software,a photothermal equivalent model of the proposed window is developed.The long-term energy saving potential of the full-scale building containing the proposed window is analyzed,and the impact of its important design parameters on building energy efficiency and indoor daylighting is clarified.The main research contents and significant results are summarized as follows:1.A heat transfer model of the multi-layer glazing window with polyurethane-based solid-solid phase change material and silica aerogel integration is established,and the effect of specific heat capacity,thermal conductivity,melting temperature,latent heat,melting temperature breadth,absorption coefficient and refractive index of phase change material on the heat transfer characteristics of the proposed window are analyzed.The results show that the melting temperature,latent heat,and melting temperature breadth have the most significant effect on the heat transfer characteristics of the proposed window,followed by the absorption coefficient and refractive index,while the specific heat capacity and thermal conductivity are the smallest.2.A full-scale building photothermal transfer model for multi-layer glazing window with polyurethane-based solid-solid phase change material and silica aerogel integration is developed,and a sensitivity analysis is carried out to clarify the effect of thermal and optical physical parameters of phase change materials in the proposed window on building energy consumption.The results show that the melting temperature,latent heat,absorption coefficient,and refractive index are more sensitive to building energy consumption under±10%property variations.Among them,the melting temperature is the most sensitive to the building cooling load,which shows an increase by 92.47 k W·h when melting temperature is reduced by 10%.The refractive index is the most sensitive to the building heating load,which shows an increase of 113.74 k W·h when refractive index is decreased by 10%.3.The influence of key photothermal physical property parameters of phase change materials in the proposed window is analyzed.The results show that from the perspective of obtaining larger building energy efficiency,there is an optimal matching relationship between the thermal and optical parameters of phase change materials.Specifically,when the absorption coefficient,refractive index,latent heat,and melting temperature of phase change materials are 40 m^-1,1.7,120 k J/kg and 25°C,respectively,the building energy saving potential is highest corresponding to an energy saving rate of 18.21%.4.The effects of variation in the thicknesses of phase change material and insulation layers,window-to-wall ratio and window orientation on building energy consumption and indoor daylight in the proposed window are clarified.The results show that the variations of phase change layer thickness and window-to-wall ratio have a small effect on the total building load but a large effect on the daylight performance.On the contrary,the variation of aerogel thickness has a large effect on the building load but a small effect on the daylight performance.In addition,the heating and cooling loads of the building differ greatly when the glazing window is configured in different orientations,and the building load is the smallest when it is arranged on the south-facing wall,specifically 9085 k W·h.5.A study on the optimization of glazing window design parameters is carried out for the problem of ineffective compromise between energy saving and daylight demand.The results show that from the perspective of providing the maximum energy saving potential while satisfying the daylight design standard,when the building is only considered to be equipped with a glazing window on a single fa?ade,it is recommended to arrange it on the south-facing wall,and the optimal combination of window-to-wall ratio,thicknesses of phase change layer,and insulation layer,is 0.60+0.012 m+0.015 m（window-to-wall ratio+thickness of the phase change layer+thickness of the insulation layer）.In this case,the annual energy saving rate is 19.38%compared to the reference model（a building containing a double-glazed window with a window-to-wall ratio of 0.50）.