All-glass solar heat collection straight-through pipe with glass and metal sealing ports

Abstract

The utility model relates to the technical field of solar energy application, in particular to an all-glass solar heat collection straight-through pipe with a port sealed by glass and metal, which comprises a glass inner pipe and a glass outer pipe sleeved on the periphery of the glass inner pipe. The end part of the glass inner tube and the end part of the glass outer tube are sealed through metal kovar melting, a vacuum interlayer is formed in an area enclosed by the metal kovar, the glass outer tube and the glass inner tube, and the cross section of the metal kovar is arc-shaped; the end parts of the glass outer tube and the glass inner tube are different in thickness during sealing, and the temperature difference between the glass inner tube and the glass outer tube can be prevented from being too large; the metal kovar with the arc-shaped cross section is adopted, so that different elongation of the glass inner tube and the glass outer tube caused by temperature difference in the axial direction and the radial direction can be balanced, the thermal shock of the glass inner tube and the glass outer tube can be reduced, and the safety of the solar heat collection straight-through tube is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to solar application technical field, concretely relates to a full glass solar heat collecting straight pipe with glass and metal sealed port. BACKGROUND

[0002] The vacuum solar heat collecting pipe is generally composed of a glass inner tube and a glass outer tube, the glass outer tube is sleeved on the periphery of the glass inner tube, and the end portions of the glass inner tube and the glass outer tube are sealed by glass, so that a vacuum interlayer is formed between the glass inner tube and the glass outer tube, and a metal support is arranged in the vacuum interlayer to support the glass inner tube, however, the metal support will generate a thermal bridge effect during use of the solar heat collecting pipe; on the one hand, the thermal bridge effect will cause great heat loss and reduce energy utilization, on the other hand, the thermal bridge effect will aggravate the temperature difference between the inner tube and the outer tube, especially at the port, the temperature difference between the inner tube and the outer tube can reach more than 200 degrees, which is easy to cause the pipe to burst; in addition, the glass-to-glass sealing at the end portion of the heat collecting pipe will cause the thickness of the vacuum interlayer at the end portion to be inconsistent and cause problems such as material accumulation, which will cause great stress and is easy to cause the pipe to burst. Therefore, due to the defects of the structure and the glass material of the existing vacuum solar heat collecting pipe, the safety is low and the cost is high, which seriously affects the development and application promotion of the product. SUMMARY

[0003] The utility model aims at overcoming the above-mentioned prior art's shortcomings, providing a full glass solar heat collecting straight pipe with glass and metal sealed port, the heat collecting straight pipe port, the inner and outer glass tubes are connected through metal, which avoids the pipe burst caused by too large temperature difference between the inner and outer glass tubes, and balances the elongation difference between the inner and outer glass tubes caused by temperature difference during work to ensure the safety of the heat collecting pipe.

[0004] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme:

[0005] The utility model provides a full glass solar heat collecting straight pipe with glass and metal sealed port, which comprises a glass inner tube and a glass outer tube, the glass outer tube is sleeved on the periphery of the glass inner tube, the end portion of the glass inner tube and the end portion of the glass outer tube are sealed by metal Kovar, the area surrounded by the metal Kovar, the glass outer tube and the glass inner tube forms a vacuum interlayer, and the cross section of the metal Kovar is in the shape of a circular arc or an inverted S.

[0006] Specifically, when the cross section of the metal Kovar is in the shape of a circular arc, the radian is 150 to 180 degrees.

[0007] Specifically, the outer surface of the metal Kovar is covered with a heat preservation layer.

[0008] Specifically, the material of the metal Kovar is iron-nickel based expansion alloy, and the expansion coefficient is 4.5*10 -6 / ℃ to 5.5*10 -6 / ℃.

[0009] Specifically, the material of the glass inner tube and the glass outer tube is low borosilicate glass, and the expansion coefficient is 4.5*10-6 / ℃~5.5*10-6 / ℃.

[0010] Specifically, the surface of the glass inner tube is coated with a solar energy absorption layer in the vacuum interlayer, and the surface of the solar energy absorption layer is a silicon oxide film.

[0011] Specifically, a vacuum exhaust port is arranged on the glass outer tube.

[0012] Compared with the prior art, the technical scheme provided by the utility model has the following beneficial effects:

[0013] (1) The end of the glass outer tube and the glass inner tube is fused by metal Kovar, the inner diameter of the metal Kovar is fused with the glass inner tube, and the outer diameter of the metal Kovar is fused with the glass outer tube, so that the metal Kovar can support the glass inner tube and the glass outer tube, and the thickness inconsistency of the glass during sealing can be avoided, and the temperature difference between the glass inner tube and the glass outer tube can be avoided.

[0014] (2) The cross section of the metal Kovar is arc-shaped or inverted S-shaped, so that the elongation difference of the glass inner tube and the glass outer tube caused by the temperature difference in the axial direction and the radial direction can be balanced, the stress difference between the glass inner tube and the glass outer tube can be avoided to cause the burst of the solar heat collecting straight pipe, and meanwhile, the structure of the metal Kovar can also reduce the thermal shock of the glass inner tube and the glass outer tube, so that the pipe opening can not burst in a harsh environment. BRIEF DESCRIPTION OF DRAWINGS

[0015] The drawings incorporated into the description and forming part of the description are used together with the description to explain the principles of the utility model.

[0016] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced as follows, and obviously, other drawings can also be obtained by the drawings without creative labor for the ordinary skilled in the art.

[0017] Figure 1 It is a structural schematic diagram of the solar heat collecting straight pipe of the utility model;

[0018] Figure 2 It is a whole structure schematic diagram of the metal Kovar of the utility model;

[0019] Figure 3 It is a top view structure schematic diagram of the metal Kovar of the utility model;

[0020] Figure 4 It isFigure 3 Cross-sectional view at A-A.

[0021] Reference numerals: 1, metal Kovar; 2, glass outer tube; 3, vacuum interlayer; 4, glass inner tube; 5, vacuum exhaust port. DETAILED DESCRIPTION

[0022] The exemplary embodiments will be described in detail herein with reference to the accompanying drawings. In the following description, unless otherwise indicated, like numbers in the different drawings represent the same or similar elements. The following exemplary embodiments are described with reference to the drawings, wherein:

[0023] In order to make the technical scheme of the present application better understood by those skilled in the art, the present application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0024] EMBODIMENT

[0025] Reference Figures 1 to 4 A full-glass solar heat collecting straight pipe with port sealed by glass and metal, comprising a glass inner tube 4 and a glass outer tube 2, the glass outer tube 2 is sleeved on the periphery of the glass inner tube 4, the end of the glass inner tube 4 and the end of the glass outer tube 2 are fused and sealed by metal Kovar 1, the inner diameter of the metal Kovar 1 is fused and sealed with the glass inner tube 4, and the outer diameter is fused and sealed with the glass outer tube 2, the area surrounded by the metal Kovar 1, the glass outer tube 2 and the glass inner tube 4 forms a vacuum interlayer 3, the cross section of the metal Kovar 1 is circular arc or inverted S shape, and the cross section of the metal Kovar 1 in the embodiment is preferably circular arc.

[0026] In the embodiment, the end of the glass inner tube 4 and the glass outer tube 2 of the solar heat collecting straight pipe is fused and sealed by the metal Kovar 1, which can also avoid the case that the thickness of the glass is inconsistent when sealed, and the metal Kovar 1 is located at the end of the solar heat collecting straight pipe, which can play a supporting role and a transition role between the end of the glass inner tube 4 and the glass outer tube 2 in the working process, so as to avoid that the temperature difference between the glass inner tube 4 and the glass outer tube 2 is too large; in addition, the cross section of the metal Kovar 1 in the embodiment is circular arc or inverted S shape, which can stretch in the radial direction and the axial direction, so as to balance the different elongations in the axial direction and the radial direction caused by the temperature difference of the glass inner tube 4 and the glass outer tube 2, avoid that the stress difference between the glass inner tube and the glass outer tube causes the solar heat collecting straight pipe to burst, and at the same time, the structure of the metal Kovar 1 in the present application can also reduce the thermal shock of the glass inner tube and the glass outer tube, so as to ensure that the pipe opening will not burst in harsh environment.

[0027] In this embodiment, the cross-sectional arc of the metal Kovar 1 is 150° to 180°, and is preferably 160°, to ensure that the radial and axial stretchable distance of the metal Kovar 1 can meet the deformation requirements of the inner glass tube 4 and the outer glass tube 2.

[0028] To reduce heat loss from the solar collector tube, this invention covers the outer surface of the Kovar 1 metal with an insulation layer.

[0029] The material of the metal Kovar 1 is an iron-nickel based expansion alloy with an expansion coefficient of 4.5 × 10⁻⁶. -6 / ℃~5.5×10 -6 The inner glass tube 4 and the outer glass tube 2 are both made of low borosilicate glass with a coefficient of thermal expansion of 4.5×10⁻⁶ / ℃ to 5.5×10⁻⁶ / ℃. In this embodiment, the coefficient of thermal expansion of the metal Kovar 1 is close to that of the glass used in the solar collector tube. This allows the fusion interface between the metal Kovar 1 and the inner glass tube 4 or the outer glass tube 2 to maintain high stability during thermal cycling. Specifically, the material of the metal Kovar 1 can be 4J29 alloy, 4J44 alloy, or other iron-nickel based alloys that meet the requirements.

[0030] In this embodiment, the surface of the glass inner tube 4 is coated with a solar energy absorption layer within the vacuum interlayer 3. The surface of the solar energy absorption layer is provided with a silicon oxide film, which can prevent the oxidation of the solar energy absorption layer, reduce the reflection of sunlight, improve the absorption rate of sunlight, and extend the life of the solar energy absorption layer.

[0031] In this embodiment, a one-way vacuum exhaust port 5 is provided on the outer glass tube 2. Before using the solar collector tube, the vacuum jacket 3 is evacuated to a vacuum state through the vacuum exhaust port 5.

[0032] The above description is merely a specific embodiment of this utility model, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this utility model.

[0033] It should be understood that this utility model is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of this utility model is limited only by the appended claims.

Claims

1. An all-glass solar heat collecting straight tube with port sealed by glass and metal, characterized in that, The glass inner tube (4) and the glass outer tube (2) are provided, the glass outer tube (2) is sleeved on the periphery of the glass inner tube (4), the end of the glass inner tube (4) is fused with the end of the glass outer tube (2) through the metal Kovar (1), the area surrounded by the metal Kovar (1), the glass outer tube (2) and the glass inner tube (4) forms a vacuum interlayer (3), the cross section of the metal Kovar (1) is circular arc or inverted S type.

2. The all-glass solar heat collecting straight tube sealed with glass and metal according to claim 1, wherein, When the cross section of the metal Kovar (1) is circular arc, the radian is 150-180 degrees.

3. The all-glass solar heat collecting tube with glass-to-metal seal port according to claim 1, wherein, The outer surface of the metal Kovar (1) is covered with a heat preservation layer.

4. The all-glass solar heat collecting tube with glass-to-metal seal port according to claim 1, wherein, The metal Kovar (1) is an iron-nickel based expansion alloy with an expansion coefficient of 4.5 x 10 -6 / °C to 5.5 x 10 -6 / °C.

5. The all-glass solar heat collecting tube sealed with glass and metal according to claim 1, wherein, The material of the glass inner tube (4) and the glass outer tube (2) is low borosilicate glass, and the expansion coefficient is 4.5*10-6 / ℃-5.5*10-6 / ℃.

6. The all-glass solar heat collecting tube sealed with glass and metal according to claim 1, wherein, In the vacuum interlayer (3), the surface of the glass inner tube (4) is coated with a solar energy absorption layer, and the surface of the solar energy absorption layer is a silicon oxide film.

7. The all-glass solar heat collecting tube with glass-to-metal seal port according to claim 1, wherein, The glass outer tube (2) is provided with a vacuum exhaust port (5).

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