Experimental validation of a numerical model for heat transfer in vacuum glazing

Fang, Yueping; Eames, Philip C.; Norton, Brian; Hyde, Trevor

doi:10.1016/j.solener.2005.04.002

Cited by 89 publications

(61 citation statements)

References 7 publications

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“…Heat transfer by long-wave radiation between the three internal glass surfaces coated with low-emissivity tin-oxide coatings was incorporated by employing a 6 µm layer on the inner surface of the glass sheet with the emissivity of tin-oxide. In the three-dimensional finite-element model, the support pillars were incorporated and modelled directly; similar to the modelling approach used by Fang et al [8] and Zhao et al [6]. The cylindrical pillars of radius r employed in the fabricated triple vacuum glazing were represented by the same number of pillars with the same cross-sectional areas in the developed finite-element model.…”

Section: Finite-element Modelling Approachmentioning

confidence: 99%

“…This method used indium or one of its alloys to seal the edges of the glass sheets hermetically at a temperature of less than 200˚C. The predicted, and experimentally determined, thermal transmittance of an indium sealed double vacuum glazing was reported to be less than 1 Wm -2 K -1 for the central glazing area [6][7][8]. To reduce the heat loss to a level where the thermal transmittance of the central glazing area is less than 0.5 Wm -2 K -1 [9], the concept of triple vacuum glazing was introduced [10].…”

Section: Introductionmentioning

confidence: 99%

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A new low-temperature hermetic composite edge seal for the fabrication of triple vacuum glazing

Memon

Farukh

Eames

et al. 2015

Vacuum

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Please cite this article as: Memon S, Farukh F, Eames PC, Silberschmidt VV, A new low-temperature hermetic composite edge seal for the fabrication of triple vacuum glazing, Vaccum (2015Vaccum ( ), doi: 10.1016Vaccum ( / j.vacuum.2015 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 2 AbstractHigh performance low-cost vacuum glazing is a key development in the move to more energy-efficient buildings. This study reports the results of experimental and theoretical investigations into the development of a new low-temperature (less than 200˚C) composite edge seal. A prototype triple vacuum glazing of dimensions 300mmx300mm was fabricated with a measured vacuum pressure of 4.8x10 -2 Pa achieved. A three-dimensional finite-element model for this prototype triple vacuum glazing with the composite edge seal was also developed. Centre-of-pane and total thermal transmittance values for this small prototype of the triple vacuum glazing were predicted to be 0.33 Wm -2 K -1 and 1.05 Wm -2 K -1 , respectively. It was predicted using the developed model that the thermal performance could be improved by reducing the width of the composite edge seal and by the use of soft low-emissivity coatings on the glass surfaces. Detailed three-dimensional isothermal contour plots of the modelled triple vacuum glazing are presented.

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Section: Finite-element Modelling Approachmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A new low-temperature hermetic composite edge seal for the fabrication of triple vacuum glazing

Memon

Farukh

Eames

et al. 2015

Vacuum

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“…For given air temperatures within the cold and hot chambers the hot box calorimeter allows an accurate measurement of the heat flow through the panel. The calculation method for the U-value of the test sample is reported elsewhere (Fang et al, 2006). The air temperatures in the hot and cold chambers and heat transfer coefficients of the flat vacuum panels before and after the panels are evacuated are presented in Table 1 and Table 2 respectively.…”

Section: Thermal Performancementioning

confidence: 99%

Fabrication and Characterisation of Slim Flat Vacuum Panels Suitable for Solar Applications

Arya

Hyde

Henshall³

et al. 2015

Proceedings of the EuroSun 2014 Conference

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The concept of providing an evacuated space between two planar surfaces and exploiting its thermal properties was initially proposed in 1913 for window applications in buildings (Zoller, 1913). Since then a number of designs for the fabrication of evacuated windows have been proposed investigating sealing methods for the periphery of the glass panes and methods of maintaining the separation of the glass panes under the influence of atmospheric pressure (Collins et al., 1995). Evacuated windows have also been used in solar applications by creating a vacuum (less than 0.01mbar) around a solar absorber to reduce the convective heat losses resulting in higher efficiencies. Maintaining the vacuum pressure over the life time of the panel is challenging. This is largely dependent on the materials used in the fabrication process. Forming a durable hermetic seal around the periphery of the vacuum enclosure is particularly crucial. In this work prototypes of flat vacuum panels with solar applications are fabricated and tested. Indium is used as a sealing material to create a hermetic seal around the periphery the panel. A heat transmission of 0.86 Wm -2 K -1 in the centre of the vacuum panel has been achieved for a 0.4m by 0.4m panel.

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“…The hermetic edge seal of a triple vacuum glazing must be capable of maintaining vacuum pressure of less than 0.1 Pa in order to suppress gaseous conduction for long term duration [5]. Sealing of two glass panes edges using high power laser through quartz window in vacuum chamber was developed by Benson et al [6].…”

Section: Introductionmentioning

confidence: 99%

Thermal Conductivity Measurement of Vacuum Tight Dual- Edge Seal for the Thermal Performance Analysis of Triple Vacuum Glazing

Memon¹

2018

Impact of Thermal Conductivity on Energy Technologies

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A vacuum tight glass edge seal's thermal conductivity is one of the principal factor in determining the heat distribution towards the centre of pane, ultimately influences the thermal transmittance (U-value) of a triple vacuum glazing. So far indium and solder glass have proven to be vacuum tight edge sealing materials but both have certain limitations. In this chapter, a new low-temperature vacuum tight glass edge seal composite's thermal conductivity, Cerasolzer CS186 alloy and J-B Weld epoxy-steel resin, were measured and validated with the mild-steel and indium using transient plane source method with a sensor element of double spiral and resistance thermometer in a hot disk thermal constants analyser TPS2500s are reported. The thermal conductivity data of Cerasolzer CS186 alloy and J-B Weld epoxy steel resin were measured to be 46.49 and 7.47 Wm À1 K À1 , with the deviations (using analytical method) of AE4 and AE7% respectively. These values were utilised to predict the thermal transmittance value of triple vacuum glazing using 3D finite element model. The simulated results show the centre-of-glass and total U-value of 300 Â 300 mm triple vacuum glazing to be 0.33 and 1.05 Wm À2 K À1 , respectively. The influence of such a wide edge seal on the temperature loss spreading from the edge to the central glazing area is analysed, in which the predictions show wider edge seal has affected the centre-of-glass U-value to 0.043 Wm À2 K À1 due to the temperature gradient loss spread to 54 and 84 mm on the cold and warm side respectively.

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Experimental validation of a numerical model for heat transfer in vacuum glazing

Cited by 89 publications

References 7 publications

A new low-temperature hermetic composite edge seal for the fabrication of triple vacuum glazing

A new low-temperature hermetic composite edge seal for the fabrication of triple vacuum glazing

Fabrication and Characterisation of Slim Flat Vacuum Panels Suitable for Solar Applications

Thermal Conductivity Measurement of Vacuum Tight Dual- Edge Seal for the Thermal Performance Analysis of Triple Vacuum Glazing

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