CN101798184B

CN101798184B - Sealing connection method of metal and glass of novel medium-high temperature solar energy heat collection pipe

Info

Publication number: CN101798184B
Application number: CN2010101166129A
Authority: CN
Inventors: 刘雪莲; 张秀廷; 刘荣; 张志鹏; 范兵; 陈步亮
Original assignee: BEIJING TRX SOLAR TECHNOLOGY Co Ltd
Current assignee: Beijing Tianruxing Vacuum Technology Development Co., Ltd.
Priority date: 2010-02-26
Filing date: 2010-02-26
Publication date: 2012-09-05
Anticipated expiration: 2030-02-26
Also published as: CN101798184A

Abstract

The invention discloses a sealing connection method of metal and glass of a novel medium-high temperature solar energy heat collection pipe, which relates to a method for matched sealing connection of two materials: the metal of kovar alloy and the glass of neutral borosilicate glass with the similar thermal expansion coefficients. The invention provides a novel method for manufacturing the metal glass medium-high temperature solar energy heat collection pipe. In the method, the difference of the thermal expansion coefficient of the kovar alloy and the thermal expansion coefficient of the neutral borosilicate glass is in a range between 5 percent and 10 percent, the difference of the thermal expansion coefficient of the transition section glass and the thermal expansion coefficient of the neutral borosilicate glass is in a range between 5 and 10 percent, the sealing connection temperature of the neutral borosilicate glass and the transition section glass is between 600 and 1000 DEG C, the heating temperature of the sealing connection region of the kovar alloy and the transition section glass is between 600 and 1200 DEG C, the length of the sealing connection opening is between 3 and 8 mm, and the whole sealing connection section of the neutral borosilicate glass, the transition section glass and the kovar alloy after the sealing connection carries out the annealing processing at the annealing temperature between 450 and 600 DEG C for 10 to 60 minutes.

Description

The method for sealing of a kind of novel middle high-temperature solar thermal-collecting tube metal and glass

Technical field

The invention belongs to the Application of Solar Energy field, be specifically related to metal and glass-sealed method in a kind of novel middle high temperature solar vacuum heat collection pipe.

Background technology

Domestic at present, in metallic glass in the high temperature solar vacuum heat-collecting pipe manufacturer, because kovar alloy commonly used and sun power high-boron-silicon glass (3.2 * 10 commonly used ^-6-3.6 * 10 ^-6/ ℃) thermal expansivity certain difference is arranged, so metal and glass is difficult to directly carry out sealing-in, as realizing matched seal, dual mode arranged then:

One, need to add a plurality of transition sections, the increase of transition section makes the possibility of gas leakage increase, and causes the resistance to air loss of whole device to reduce; The long ratio that makes transition apparatus account for whole thermal-collecting tube of transition section strengthens, and has reduced the collecting efficiency of thermal-collecting tube; And the domestic output of middle transitional glass is few, and price is high, has increased the production cost of thermal-collecting tube; Complex process is not suitable for scale operation.

Two, need to change the thermal expansivity of glass or metal, the thermal expansivity of kovar alloy commonly used is 4.7 * 10 at present ^-6-5.2 * 10 ^-6/ ℃; The coefficient of expansion technology that changes it is very complicated; Production in enormous quantities can't guarantee the stability of its thermal expansivity; So select the thermal expansivity of change glass more simple and feasible, because present neutral borosilicate glass have had the condition of production in enormous quantities, this neutral borosilicate glass that many medical flask for medicinal preparations just are being to use.Therefore selecting this neutral borosilicate glass to substitute thermal expansivity commonly used is 3.2 * 10 ^-6-3.6 * 10 ^-6/ ℃ the high-boron-silicon glass that uses of field of solar energy reduced difficulty as sealing process undoubtedly, also practiced thrift cost.

And the also prematurity still of other unmatched sealing technology, Glass tubing is prone to burst, and is difficult to the requirement of the work of reaching a high temperature.

Summary of the invention

The method for sealing that the purpose of this invention is to provide a kind of novel middle high-temperature solar thermal-collecting tube metal and glass.Neutral borosilicate glass and the sealing-in of transition section glass elder generation; Then transition section glass again with the direct sealing-in of kovar alloy; The thermal expansivity of kovar alloy and the coefficient of expansion of neutral borosilicate glass differ scope 5%～10%, and the coefficient of expansion scope that differs of the neutral borosilicate glass of middle transitional section glass and solar energy heat collection pipe also is 5%～10%; Neutral borosilicate glass and transition section glass sealing temperature be--1000 ℃, the sealing-in district Heating temperature of kovar alloy and transition section glass is 600 ℃--1200 ℃ at 600 ℃; About 3mm～the 8mm of sealing-in mouth length; After the sealing-in whole sealing-in section is carried out anneal, annealing temperature is at 450 ℃～600 ℃, and the time was at 10～60 minutes.

Existing neutral borosilicate glass and kovar alloy sealing-in, the thermal expansivity and the kovar alloy of neutral borosilicate glass are close, and the scope that differs in theory can matched seal in 10%; But because the softening temperature of the neutral borosilicate glass of this kind is 780 ℃, when sealing temperature was too high, the thermal expansivity of kovar alloy changed too greatly, so the present invention uses one section glass transition section; Transition section glass uses domestic electronic glass DM308, has practiced thrift production cost, has also improved the utilization ratio of solar energy heat collection pipe when having increased the sealing-in safety, because have only one section transition section; So just have only two welds, weld is few more, the gas leakage point is just few more; Greatly improve the stopping property of thermal-collecting tube, just prolonged the life-span of thermal-collecting tube, reduced the gas leakage point simultaneously; Also just reduce the possibility that thermal-collecting tube bursts, improved the yield rate of thermal-collecting tube indirectly, reduced the production cost of thermal-collecting tube; And transition section is few more, and it is few more to mean that this section accounts for the ratio of thermal-collecting tube length overall, so the useful length of thermal-collecting tube is just long more; Transition section of every minimizing, the useful length of thermal-collecting tube just increases by 10～20mm, has therefore also improved the utilization ratio of solar energy heat collection pipe.

Description of drawings

Fig. 1 is the structural representation that is connected with kovar alloy for the neutral borosilicate glass of high-temperature solar thermal-collecting tube among the present invention.

Among the figure:

The neutral borosilicate glass of 1-; 2-transition section glass; The 3-kovar alloy.

Embodiment

To combine accompanying drawing and embodiment that the present invention is done further detailed description below.

The present invention be a kind of novel in the method for sealing of high-temperature solar thermal-collecting tube metal and glass, as shown in Figure 1, neutral borosilicate glass 1 and the 2 first sealing-ins of transition section glass, then transition section glass 2 again with kovar alloy 3 direct sealing-ins.Neutral borosilicate glass 1, transition section glass 2 are respectively 4.8 * 10 with the coefficient of expansion of kovar alloy 3 ^-6～5.2 * 10 ^-6/ ℃, 4.7 * 10 ^-6～5.2 * 10 ^-6/ ℃ and 4.7 * 10 ^-6～5.2 * 10 ^-6/ ℃, transition section glass 2 adopts electronic glass DM308.Described neutral borosilicate glass are meant that thermal expansivity is 4.8～5.2 * 10 ^-6/ ℃ (20～300 ℃), transmittance is 91% glass, its stable chemical performance, water-fast one-level, acidproof one-level, alkaline-resisting first class, and have strong cold-and-heat resistent impact and very high physical strength.. three kinds of material transition method for sealing are following:

1) at first, utilize glass work lathe that neutral borosilicate glass tube and the sealing-in of transition section Glass tubing is good, the length of transition section glass 2 is 15～30mm, and sealing temperature is at 600 ℃--1000 ℃.

2) then, kovar alloy 3 is cleaned up, put into hydrogen-burning stove and carry out the annealing in hydrogen atmosphere processing, afterwards, kovar alloy 3 is put into the bottom heated oxide of ratio-frequency heating head.

3) with 1) in the good neutral borosilicate glass of sealing-in 1 and the Glass tubing of transition section glass 2 also to put into the ratio-frequency heating head inner, the end of the termination of transition section glass 2 and kovar alloy 3 is just in time to last.

4) at 600 ℃--under 1200 ℃ the temperature, with kovar alloy 3 low red heats, this moment, the last layer oxide compound was adhered on the surface of kovar alloy 3 uniformly, and the staple of oxide compound is an iron protoxide.Thickness of oxide layer is 1-2 μ m, and area density is best during for 0.3-0.7mg/m2.Because the end region temperature of kovar alloy 3 is high; Transition section glass 2 near kovar alloy 3 terminations becomes molten state; Because gravity directly is inserted into kovar alloy 3 in the transition section glass 2 depth of penetration 5-8mm; Make the Glass tubing of molten state evenly be coated on kovar alloy pipe outer wall, it is finalized the design with graphite.

5) the sealing-in section of the neutral borosilicate glass after will docking 1 and kovar alloy 3 is placed into and removes internal stress in the lehre, and time dimension is held in 10-60 minute, and temperature maintenance is at 450 ℃-600 ℃.

Claims

One kind novel in the method for sealing of high-temperature solar thermal-collecting tube metal and glass, it is characterized in that: the first sealing-in of neutral borosilicate glass and transition section glass, then transition section glass again with the direct sealing-in of kovar alloy;

A) at first, utilize glass work lathe that neutral borosilicate glass tube and the sealing-in of transition section Glass tubing is good, sealing temperature is at 600 ℃--and 1000 ℃;

B) then, kovar alloy is cleaned up, put into hydrogen-burning stove and carry out the annealing in hydrogen atmosphere processing, afterwards, kovar alloy is put into the bottom heated oxide of ratio-frequency heating head;

C) sealing-in in a) is good neutral borosilicate glass are also put into ratio-frequency heating head inside with the Glass tubing of transition section glass, and the termination of transition section glass and the end of kovar alloy are just in time to last;

D) at 600 ℃--under 1200 ℃ the temperature; With the kovar alloy low red heat, this moment, the last layer oxide compound was adhered on the surface of kovar alloy uniformly, became molten state near the transition section glass of kovar alloy termination; Directly kovar alloy is inserted in the transition section glass; Depth of penetration 5-8mm makes the Glass tubing of molten state evenly be coated on kovar alloy pipe outer wall, with graphite it is finalized the design;

E) the whole sealing-in section of neutral borosilicate glass after will docking and kovar alloy is placed into and carries out anneal in the lehre, and time dimension is held in 10-60 minute, and temperature maintenance is at 450 ℃-600 ℃.
2. method for sealing according to claim 1 is characterized in that: the staple of described oxide compound is an iron protoxide, and thickness of oxide layer is 1-2 μ m, and area density is 0.3-0.7mg/m ²
3. according to any described method for sealing of claim 1～2; It is characterized in that; The thermal expansivity of kovar alloy and the coefficient of expansion of neutral borosilicate glass differ scope 5%～10%, and the coefficient of expansion scope of differing of transition section glass and neutral borosilicate glass is 5%～10%.
4. according to any described method for sealing of claim 1～2, it is characterized in that transition section glass is electronic glass DM308, length is 15～30mm.
5. according to any described method for sealing of claim 1～2, it is characterized in that the sealing-in mouth length of neutral borosilicate glass and kovar alloy is 3mm～8mm.