CN100592047C - Vacuum degree online detection method for in-service vacuum glass - Google Patents

Abstract

The invention discloses an on-line nondestructive examination method of the vacuum degree of vacuum glass, and the aim is to provide an examination method which can examine the attenuation situation of the vacuum degree of vacuum glass on-line, judge the constancy and the stability of the vacuum degree of vacuum glass, thus realizing the judgment to the service healthy state of the vacuum glass, and providing an examination method for the quality evaluation of the vacuum glass used in the project. The technical scheme is as follows: the relation between the size and the distribution shape of the stress facula on the supporting point of the vacuum glass is observed through a polarized photoelastic photo-elastic instrument, for indirectly describing the retained vacuum degree of the vacuum glass. The method can get the retained stress situation and the attenuation situation of the vacuum degree of the vacuum glass in the project, thereby judging the using state of the vacuum glass performance in service, and providing technical support for the actual repair and the replacement of the vacuum glass. The examination method is simple, has strong operational performance, has intuitive result and is reliable. The on-line damage-free examination is achieved easily, and the method can examine and evaluate the vacuum degree of the in-service vacuum glass in the vacuum glass structure or parts.

Description

Vacuum glass in-line detection method for vacuum level in a kind of military service

Technical field

The invention belongs to the building materials detection range, relate to a kind of vacuum glass vacuum detecting method, be particularly related to a kind of recoverable amount of harmless online detection military service vacuum glass vacuum tightness or the method for loss percentage, in order to evaluation vacuum glass consistency of performance during one's term of military service and stability, thus the practical application of accurate instruction vacuum glass engineering.

Background technology

Along with the great attention of current people to building energy conservation, various energy-saving materials or energy-saving structure emerge in an endless stream.Vacuum glass has obtained fast development and widespread use in recent years because it has good heat preservation and insulation and sound insulation property on building window and curtain wall.Vacuum glass is sealed to form two glass four limits with glass material or resin material, the gap that " stilt " remains on 0.02～0.03mm is set between the layer glass.Because the vacuum glass insulation sound insulation value depends on the vacuum layer between two sheet glass fully, guarantee that the vacuum glass performance brings into play fully, its vacuum tightness should guarantee at least-below the 10Pa, in case decay of vacuum layer vacuum tightness or loss, the performance of vacuum glass will be affected greatly even lose effect fully so, so vacuum glass consistency of performance in-service is a particular importance with stability.In theory, by present scientific and technological productive capacity, the vacuum glass long term life should with kinescope roughly the same, its vacuum tightness can keep decades constant.But because vacuum glass in use is subjected to the corrosion and the external impacts effect of external environment easily, quicken the aging even damaged of vacuum glass, cause the vacuum glass deterioration.Therefore, the support that provides the necessary technical is changed or keeped in repair to the vacuum tightness recoverable amount of online detection military service vacuum glass to estimating the use health status and the permanance thereof of vacuum glass, for vacuum glass, guarantees that the energy-conservation effect of energy saving building is very important.

Because decay of vacuum glass vacuum tightness even total loss with the naked eye are imperceptible fully, its corresponding evaluation does not still have corresponding standard at present both at home and abroad, does not more have corresponding test method.And at present to the quality testing of the finished product vacuum glass that dispatches from the factory, generally be to adopt radiant heat method or sound transmission method, this method uses equipment huge, and complicated operation can't be used for the vacuum tightness recoverable amount of during one's term of military service vacuum glass is detected.

Summary of the invention

The purpose of this invention is to provide a kind of online detection accurate, simple to operate be on active service in the method for vacuum glass vacuum tightness.

The online test method of vacuum glass vacuum tightness in a kind of the military service, be to move on tested vacuum glass surface by portable photoelastic instrument, directly the size and the distribution characteristics of observation and record vacuum glass strong point place stress hot spot are inferred the vacuum tightness of this vacuum glass with this hot spot feature.

In the online test method of vacuum glass vacuum tightness, described portable photoelastic instrument is transmission-type or reflective photoelastic instrument in the described military service.

In the online test method of vacuum glass vacuum tightness, described portable photoelastic instrument is light source with the natural light, makes by orthogonal polarizer slice in polarization direction and checking bias slice in the described military service, and wherein polarizer slice is pressed close to the vacuum glass surface.

In the described military service in the online test method of vacuum glass vacuum tightness, described portable photoelastic instrument main body is a magazine, the front end face of magazine connects rectangular eaves shape opening, eaves shape opening and magazine join domain are installed a polaroid and are done checking bias slice, another eaves of eaves shape opening is installed another polaroid and is done polarizer slice, and the polarization direction of polarizer slice and checking bias slice is orthogonal; The magazine rear end face is provided with viewport and is used for manual observation, installs a miniature photograph side by side with this viewport or picture pick-up device is used to write down observed image.

In the online test method of vacuum glass vacuum tightness, described deduction is according to the size of hot spot and distribution shape is next qualitative or the vacuum tightness of the actual military service vacuum glass of quantitative evaluation in the described military service.

In the described military service in the online test method of vacuum glass vacuum tightness, vacuum tightness qualitative evaluation to vacuum glass is the lateral comparison method, be that stress spot size with same each vacuum glass of vacuum glass engineering carries out lateral comparison, its vacuum tightness that the stress hot spot is more little is poor more.

In the described military service in the online test method of vacuum glass vacuum tightness, vacuum tightness quantitative evaluation to vacuum glass is the longitudinal comparison method, be to set up in advance and the vacuum tightness of the similar sample of examined vacuum glass and the relation of its stress spot size, and draw out corresponding curved line relation, then with actual detected as a result the substitution curve obtain the vacuum values of the vacuum glass that detected.

In the described military service in the online test method of vacuum glass vacuum tightness, the vacuum tightness evaluation criterion of vacuum glass is distributed and the spot size classification according to hot spot, be divided into I～VI level, rank condition of high vacuum degree more is poor more.

Another purpose of the present invention is to provide the portable photoelastic instrument that uses in the online test method of vacuum glass vacuum tightness in a kind of the military service.

Portable photoelastic instrument of the present invention, its main body is a magazine, the front end face of magazine connects rectangular eaves shape opening, eaves shape opening and magazine join domain are installed a polaroid and are done checking bias slice, another eaves of eaves shape opening is installed another polaroid and is done polarizer slice, and the polarization direction of polarizer slice and checking bias slice is orthogonal; The magazine rear end face is provided with viewport and is used for manual observation, installs a miniature photograph side by side with this viewport or picture pick-up device is used to write down observed image.

The portable photoelastic instrument that uses in the online test method of vacuum glass vacuum tightness in the described military service, wherein miniature photograph or picture pick-up device are connected with a computer by lead.

The present invention adopts the photoelasticity principle, photoelastic stress pattern with photoelastic Equipment Inspection vacuum glass inner support point, strong point place stress intensity is described, thus the vacuum tightness of intermediate description vacuum glass, for a kind of simple, effective, reliable method that provides is provided the online harmless vacuum tightness of vacuum glass.

Description of drawings

Figure 1A is a unit vacuum glass structural representation;

Figure 1B shows Figure 1A cross-section structure, represents this unit vacuum glass mechanical model;

Fig. 2 is finite element analogy vacuum glass equivalent stress distribution figure;

Fig. 3 shows σ ₁-σ ₂Distributed areas pattern in supporting plane;

Fig. 4 certain piece vacuum glass stress hot spot figure for observing by photo-elastic instrument;

Fig. 5 A is the photoelastic instrument of plane polarization (transmission-type) index path, and among the figure: 1 is light source, and 2 is polarizer slice, and 3 is test specimen, and 4 is checking bias slice;

Fig. 5 B is the photoelastic instrument of plane polarization (reflective) index path, and 1 is light source, and 2 is polarizer slice, and 3 is test specimen, and 4 is checking bias slice;

Fig. 6 is reflective photoelastic instrument structural drawing, and among the figure: 11 is light source, and 12 is polarizer slice, and 13 is checking bias slice, and 14 is magazine, and 15 is viewport, and 16 is camera, and 17 is data line, and 18 is computer.

Fig. 7 is the vacuum glass stress hot spot figure under the different vacuum tightnesss: (a) vacuum tightness 0.1MPa, and (b) vacuum tightness 0.08MPa, (c) vacuum tightness 0.06MPa, (d) vacuum tightness 0.04MPa, (e) vacuum tightness 0.02MPa is (f) under the vacuum state.

Fig. 8 is spot diameter size and vacuum tightness relation curve.

Embodiment

The present invention detects the method for vacuum glass vacuum tightness in the military service, is the photoelastic stress pattern that detects vacuum glass inner support point with portable photoelastic equipment, the vacuum tightness of intermediate description vacuum glass by describing strong point place's stress intensity.

The ultimate principle of this method is as follows:

Dual-layer vacuum glass externally under the atmospheric pressure effect, will produce certain stress and distortion.For guaranteeing glass not because of atmospheric pressure produces excessive stress, at the many metal supports of the inner placement of vacuum glass, glass and stilt interact and have offset the additional external force that the inside and outside atm difference of glass is brought.Obviously, when atm difference was big more, the interaction force of stilt and glass was big more.For analyzing the vacuum glass stress distribution, according to the vacuum glass design feature, can be that a unit carries out force analysis (shown in Figure 1A) with the every strong point area dividing of vacuum glass, the stressed theory of mechanics computation model of an one unit can be reduced to (shown in Figure 1B).

Prop up admittedly on computation model glass unit four limits, and under the interaction of well-distributed pressure q and anchorage force F, inside of glass plate supports maximum stress (being positioned at the glass surface place of supporting role) σ _MaxBe calculated as follows:

${\mathrm{\&sigma;}}_{\max }=\frac{3\mathrm{<figure-callout\; id="2"\; label="F"\; filenames="C2008101180250011H2.png"\; state="\{\{state\}\}">F</figure-callout>}}{2\mathrm{\&pi;}{t}^2}[(1+v)\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="C2008101180250011H2.png"\; state="\{\{state\}\}">ln</figure-callout>}\frac{2\mathrm{\&alpha;}}{\sqrt{1.6r+t^2-0.675t}}+\mathrm{\&beta;}]---\left(1\right)$

Wherein long a of model and wide b are respectively the horizontal and vertical size distance (the phase mutual edge distances between two fulcrums) of vacuum glass unit, F is the acting force of stilt to glass, F=qab, t is a monolithic glass thickness, r is the stilt radius, and α, β are respectively coefficient, when a/b=1, α=0.0138, β=0.1386.

According to the aforementioned calculation formula, the maximum stress that the supporting point position place produces and vacuum glass support be mutual edge distance when uniform (equate with the vacuum glass unit size), arrangement mode, stilt size mutually, and vacuum glass monolithic glass thickness and vacuum tightness (reaction is that the q value is big or small) are relevant.Finite element analogy vacuum glass stress distribution is seen Fig. 2, and from figure as can be seen, the fulcrum place can produce stress and concentrate, this place's stress maximum, and the additional force that is brought by the glass inside and outside differential pressure is on each fulcrum that uniform state is distributed in vacuum glass inside basically.

Obviously, the stilt of vacuum glass and the interaction of glass produce very big stress at strong point place, and this stress intensity is relevant with the vacuum tightness of glass, stress is big more, illustrate that degree of vacuum glass is good more, when degree of vacuum glass loses fully, also complete obiteration of the acting force between them.The vacuum tightness that therefore can reflect glass with the result that stress detects.

According to the photoelasticity principle, material can produce interim birefringent phenomenon under external force, and this phenomenon can detect by photo-elastic instrument and obtains, and is shown as material and can produces the stress hot spot there being external force to make use, and stress hot spot pattern is relevant with contact point principle stress value.Because actual support thing physical dimension is very little, therefore, strong point place can see anchorage force as load, and glass is regarded the big plane body of semiinfinite as.According to contact theory, vertically act on the stress that the concentrated force P on the surperficial initial point produces in the plane and be calculated as follows near contact point:

${\mathrm{\&sigma;}}_x=\frac{\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="C2008101180250011H2.png"\; state="\{\{state\}\}">P</figure-callout>}}{2\mathrm{\&pi;}}\left[\frac{(1-2v)}{r^2}\right\{(1-\frac{z}{\mathrm{\&rho;}})\frac{x^2-y^2}{{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="C2008101180250011H2.png"\; state="\{\{state\}\}">r</figure-callout>}}^2}+\frac{{\mathrm{<figure-callout\; id="2"\; label="zy"\; filenames="C2008101180250011H2.png"\; state="\{\{state\}\}">zy</figure-callout>}}^2}{{\mathrm{\&rho;}}^3}\}-\frac{3{\mathrm{<figure-callout\; id="2"\; label="zx"\; filenames="C2008101180250011H2.png"\; state="\{\{state\}\}">zx</figure-callout>}}^2}{{\mathrm{\&rho;}}^5}]---\left(2\right)$

${\mathrm{\&sigma;}}_y=\frac{\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="C2008101180250011H2.png"\; state="\{\{state\}\}">P</figure-callout>}}{2\mathrm{\&pi;}}\left[\frac{(1-2v)}{r^2}\right\{(1-\frac{z}{\mathrm{\&rho;}})\frac{y^2-x^2}{{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="C2008101180250011H2.png"\; state="\{\{state\}\}">r</figure-callout>}}^2}+\frac{{\mathrm{<figure-callout\; id="2"\; label="zx"\; filenames="C2008101180250011H2.png"\; state="\{\{state\}\}">zx</figure-callout>}}^2}{{\mathrm{\&rho;}}^3}\}-\frac{3{\mathrm{<figure-callout\; id="2"\; label="zy"\; filenames="C2008101180250011H2.png"\; state="\{\{state\}\}">zy</figure-callout>}}^2}{{\mathrm{\&rho;}}^5}]---\left(3\right)$

${\mathrm{\&sigma;}}_z=\frac{3\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="C2008101180250011H2.png"\; state="\{\{state\}\}">P</figure-callout>}}{2\mathrm{\&pi;}}\frac{z^3}{{\mathrm{\&rho;}}^5}---\left(4\right)$

ρ=(x wherein ²+ y ²+ z ²) ^1/2, r ²=x ²+ y ²

Obviously, in the stress state of contact point vicinity: σ ₁=σ _x, σ ₂=σ _y, σ ₃=σ _z

According to the photoelasticity principle, on isodiff, there is following relation in striped ^[5]:

${\mathrm{\&sigma;}}_1-{\mathrm{\&sigma;}}_2=\frac{\mathrm{\&lambda;}}{c}\frac{N}{d}---\left(5\right)$

Wherein C is a stress-optic constant, and λ is an optical wavelength, and d is a thickness of glass, and N is a fringe value.

Reach (3) as can be known by formula (2)

${\mathrm{\&sigma;}}_1-{\mathrm{\&sigma;}}_2=\frac{\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="C2008101180250011H2.png"\; state="\{\{state\}\}">P</figure-callout>}}{2\mathrm{\&pi;}}\left[\frac{(1-2v)}{r^2}\right\{(1-\frac{z}{\mathrm{\&rho;}})\frac{2}{{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="C2008101180250011H2.png"\; state="\{\{state\}\}">r</figure-callout>}}^2}+\frac{z}{{\mathrm{\&rho;}}^3}\}-\frac{3z}{{\mathrm{\&rho;}}^5}](x^2-y^2)---\left(6\right)$

By formula (6) as can be seen, at x, in the y plane, when x=y, σ ₁-σ ₂=0, there is not stressed cord, σ ₁-σ ₂Distribution range is shaped as blossom type distribution (see figure 3), thereby the stress hot spot also should be a plum blossom shape.Reality is observed vacuum glass stress hot spot shape appearance figure by photo-elastic instrument and is seen Fig. 4, and the hot spot pattern is very similar to theory as seen from the figure.

The photo-elastic instrument structure adopts the linearly polarized light principle, is divided into transmission-type and reflective two kinds, and transmission-type photo-elastic instrument light path is seen Fig. 5 A, and reflective photoelastic instrument light path is seen Fig. 5 B, and among the figure, 1 is light source, and 2 is polarizer slice, and 3 is test specimen, and 4 is checking bias slice.Can observe vacuum glass supporting point position place stress by photo-elastic instrument and concentrate the stress hot spot that produces.

For carrying out the observation of vacuum glass stress hot spot, the present invention designs a kind of portable photoelastic instrument.Referring to shown in Figure 6, this portable photoelastic instrument main body is a magazine 14, the front end face of magazine 14 connects rectangular eaves shape opening, install a polaroid with magazine 14 join domains and do checking bias slice 13, another eaves of eaves shape opening and checking bias slice 13 opposed area are installed another polaroid and are done polarizer slice 12, and polarizer slice 12 and checking bias slice 13 polarization directions are orthogonal; Magazine 14 rear end faces are provided with viewport 15 and are used for manual observation, can install a miniature photograph side by side with this viewport 15 or picture pick-up device 16 is used to write down observed image.During use, the eaves shape opening of photo-elastic instrument directly is affixed on the vacuum glass surface, utilize lamp 11, with the naked eye can observe bearing stress hot spot situation by viewport 15, enable miniature photograph or the observed image of picture pick-up device 16 records in case of necessity, be connected with computer 18 so that computer carries out analyzing and processing to the image that obtains by lead 17.By to the size of the bearing stress hot spot that obtains and the vacuum tightness that distribution shape analysis can be estimated vacuum glass.

Vacuum tightness evaluation method to vacuum glass can adopt two kinds of methods: lateral comparison method and longitudinal comparison method.

Lateral comparison method: generally speaking, the realistic application conditions of same each vacuum glass of vacuum glass engineering is identical basically, but when certain piece vacuum glass vacuum tightness decays even loses fully, then its stress hot spot pattern will can change (mainly showing the size of hot spot, hot spot brightness and the stress hot spot disappearance of indivedual strong points place etc.) with respect to other vacuum glass.Therefore,, can know that damage appears in which piece vacuum glass, thereby screen out those underproof vacuum glass, instruct actual engineering to keep in repair or change by the lateral comparison method.This method can be used for rough qualitative examination.

Longitudinal comparison method:, set up in advance and the vacuum tightness of the similar sample of pre-detection vacuum glass and the relation of its stress spot size, and draw out corresponding curved line relation by test.In actual engineering test, testing result (size of hot spot) and curve are compared, the vacuum tightness of the vacuum glass that can have been detected is quantitatively possessed situation, thereby estimates the use health status of vacuum glass.

Below by the detection scheme of example explanation the present invention, not as restriction to other embodiments of the present invention to vacuum glass vacuum tightness in being on active service.

Detect example:

Object to be checked: certain accurate breadboard whole vacuum glass door and window;

Pick-up unit: portable photoelastic instrument shown in Figure 6, wherein be equiped with digital camera, pixel is 3,000,000.

Operating process and result: 1) initial survey: the opening inclined-plane of photo-elastic instrument directly is affixed on every vacuum glass surface, moves on the vacuum glass surface, monoblock vacuum glass zone is all scanned one time, with the observed hot spot situation of camera record while observing;

2) after each the piece vacuum glass that will put in order the fan door and window is all checked, use the lateral comparison method, the glass that does not observe the stress hot spot is recommended replacement directly;

3) prepare the experiment vacuum glass sample similar in addition, adjust sample vacuum tightness and also survey its stress spot size, draw vacuum tightness and spot size curve to this object to be checked.Fig. 7 shows the stress hot spot figure of this vacuum glass sample in different vacuum tightnesss, and along with the reduction of vacuum tightness, the stress hot spot at strong point place also reduces gradually as seen from Figure 7, to the last disappears.Table 1 is this vacuum glass vacuum tightness grade scale, and Fig. 8 is vacuum tightness and the spot size curve of drawing according to this result.

This vacuum glass engineering of table 1 is calmed down standard

Numbering	Observed and recorded (hot spot distribution)	Spot size (MM)	Vacuum tightness (MPa)	Grading evaluation
					1	Can't see hot spot	0	-0.1	VI (breakage needs to change)
2	Second row has fragmentary hot spot from the border	0.15	-0.08	V (decay is serious, needs to change)
					3	Local support point place does not have hot spot	0.18	-0.06	IV (it is very serious to decay, recommended replacement)
4	Hot spot is evenly distributed, dimness	0.20	-0.04	III (it is more serious to decay, recommended replacement)
					5	Hot spot is evenly distributed, and is brighter	0.25	-0.02	II (in good condition, as can to continue to use)
6	Hot spot is evenly distributed, and is bright	0.30	0 (vacuum state)	I (good, as can to continue to use)

4) with 1) in the measured light spot size substitution curve, obtain the vacuum values (select representational 10 blocks of glass, measured result sees Table 2) of each actual measurement vacuum glass.

5), all are examined vacuum glass provided the evaluation suggestion, referring to table 2 according to the vacuum tightness grade scale.

Each piece vacuum glass vacuum tightness of table 2 actual measurement

Label	Observed and recorded (hot spot distribution)	Spot size (mm)	Vacuum tightness (MPa)	Grade assessment and suggestion
					1	Hot spot is evenly distributed	0.28	-0.015	The II level need not changed
2	Hot spot is evenly distributed	0.30	0	The I level need not changed
					3	Hot spot is evenly distributed	0.28	-0.015	The II level need not changed
4	Hot spot is evenly distributed	0.30	0	The I level need not changed
					5	Hot spot is evenly distributed, and is dim	0.24	-0.03	The II level need not changed
6	Hot spot is evenly distributed	0.28	-0.015	The II level need not changed
					7	Right-hand corner does not have hot spot	0.18	-0.05	The III level, recommended replacement
8	Hot spot is evenly distributed, and is dim	0.24	-0.03	The II level need not changed
					9	Hot spot is evenly distributed	0.28	-0.015	The II level need not changed
10	Hot spot is evenly distributed	0.28	-0.015	The II level need not changed

By above example explanation, use the inventive method can effectively detect the vacuum state of military service glass, simple to operate, equipment is light, and the result is accurate, is effective, the reliable online harmless vacuum detecting method of vacuum glass.

Claims (7)

1, the online test method of vacuum glass vacuum tightness in a kind of the military service, it is characterized in that, move on tested vacuum glass surface by portable photoelastic instrument, directly the size and the distribution characteristics of observation and record vacuum glass strong point place stress hot spot are inferred the vacuum tightness of this vacuum glass with this hot spot feature.

2, the online test method of vacuum glass vacuum tightness in the military service as claimed in claim 1 is characterized in that, described portable photoelastic instrument is transmission-type or reflective photoelastic instrument.

3, as the online test method of vacuum glass vacuum tightness in the military service as described in the claim 2, it is characterized in that, described portable photoelastic instrument is light source with the natural light, makes by orthogonal polarizer slice in polarization direction and checking bias slice, and wherein polarizer slice is pressed close to the vacuum glass surface.

4, as the online test method of vacuum glass vacuum tightness in the military service as described in the claim 2, it is characterized in that, described reflective photoelastic instrument main body is a magazine, the front end face of magazine connects rectangular eaves shape opening, eaves shape opening and magazine join domain are installed a polaroid and are done checking bias slice, another eaves of eaves shape opening is installed another polaroid and is done polarizer slice, and the polarization direction of polarizer slice and checking bias slice is orthogonal; The magazine rear end face is provided with viewport and is used for manual observation, installs a miniature photograph side by side with this viewport or picture pick-up device is used to write down observed image.

As the online test method of vacuum glass vacuum tightness in the military service as described in one of claim 1 to 4, it is characterized in that 5, described deduction is the vacuum tightness of coming qualitative or the actual military service vacuum glass of quantitative evaluation according to the size of hot spot and distribution shape.

6, as the online test method of vacuum glass vacuum tightness in the military service as described in the claim 5, it is characterized in that, vacuum tightness qualitative evaluation to vacuum glass is the lateral comparison method, be that stress spot size with same each vacuum glass of vacuum glass engineering carries out lateral comparison, its vacuum tightness that the stress hot spot is more little is poor more.

7, as the online test method of vacuum glass vacuum tightness in the military service as described in the claim 5, it is characterized in that, vacuum tightness quantitative evaluation to vacuum glass is the longitudinal comparison method, be to set up in advance and the vacuum tightness of the similar sample of examined vacuum glass and the relation of its stress spot size, and draw out corresponding curved line relation, then with actual detected as a result the substitution curve obtain the vacuum values of the vacuum glass that detected.

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