阅读说明：本技术 太阳能集热器及其集热管和联箱的密封连接结构 (Solar heat collector and sealing connection structure of heat collecting pipe and header thereof ) 是由 高峰 刘在祥 陈艳凤 蔡园丰 王兵 牛争艳 于 2021-01-14 设计创作，主要内容包括：本申请涉及一种太阳能集热器及其集热管和联箱的密封连接结构,集热管连接孔与联箱内部的水腔相通,集热管的热管伸出端伸入水腔内,集热管的热管上固定设置金属环垫,内周面带有内螺纹的外螺套和外周面带有外螺纹的内螺套将金属环垫轴向密封夹紧,实现集热管尤其是集热管内的热管与联箱的密封连接。本申请在提升太阳能集热器光-水的光热转化效率的同时,增强了集热管与联箱连接处的密封效果。(The application relates to a solar heat collector and a sealing connection structure of a heat collecting pipe and a header thereof, wherein a heat collecting pipe connecting hole is communicated with a water cavity inside the header, a heat pipe extending end of the heat collecting pipe extends into the water cavity, a metal ring gasket is fixedly arranged on the heat pipe of the heat collecting pipe, and the metal ring gasket is axially and hermetically clamped by an outer thread sleeve with an internal thread on the inner peripheral surface and an inner thread sleeve with an external thread on the outer peripheral surface, so that the heat collecting pipe, particularly the heat pipe in the heat collecting pipe, is hermetically connected with the header. The solar collector tube and the header joint have the advantages that the solar collector tube and the header joint are sealed while the light-water photo-thermal conversion efficiency of the solar collector is improved.)

1. A sealing connection structure of a heat collecting pipe and a header of a solar heat collector is disclosed, wherein the heat collecting pipe (a) comprises a vacuum pipe body (1) and a heat pipe (2) inserted in the vacuum pipe body, a heat collecting pipe connecting hole (4) is formed in the wall of the header (b), the heat pipe (2) comprises a heat pipe extending end (201) extending out of the vacuum pipe body (1) and inserted in the heat collecting pipe connecting hole (4),

the heat collecting pipe heat exchanger is characterized in that the heat collecting pipe connecting hole (4) is communicated with a water cavity (3) in the header (b), and the extending end (201) of the heat pipe extends into the water cavity (3);

the sealing connection structure further includes:

the heat collecting pipe connecting structure comprises an outer sleeve (5) with an internal thread on the inner peripheral surface, wherein the outer sleeve is fixed in the heat collecting pipe connecting hole (4), the outer peripheral surface of the outer sleeve is in sealing fit with the wall surface of the heat collecting pipe connecting hole (4), and a circle of first annular inner flange (501) protruding inwards in the radial direction is integrally arranged at the axial inner end of the outer sleeve;

the metal ring gasket (7) is fixedly sleeved outside the heat pipe (2), the inner circumferential surface of the metal ring gasket is in sealing fit with the outer circumferential surface of the heat pipe (2), the heat pipe (2) penetrates through the outer sleeve (5) oppositely, and the metal ring gasket (7) is positioned inside the outer sleeve (5); and

the heat pipe sealing structure is characterized by comprising an inner threaded sleeve (6) with external threads on the peripheral surface, wherein the inner threaded sleeve is movably sleeved outside the heat pipe (2), is locked in the outer threaded sleeve in threaded fit with the outer threaded sleeve (5), and is axially and hermetically clamped between the inner threaded sleeve and the first annular inner flange (501).

2. The sealed connection structure of the collector tube and the header of the solar collector according to claim 1, characterized in that the axially outer end surface of the first annular inner flange (501) and the axially inner end surface of the inner threaded sleeve (6) comprise conical surfaces that cooperate to clamp the metal ring gasket (7).

3. The sealed connection structure of the heat collecting pipe and the header of the solar heat collector as claimed in claim 1, wherein the outer circumferential surface of the outer collar (5) is hermetically welded to the hole wall surface of the heat collecting pipe connection hole (4).

4. The sealed connection structure of the heat collecting pipe and the header of the solar heat collector as claimed in claim 3, wherein the heat collecting pipe connection hole (4) is a flanging hole, and the outer jacket (5) is welded and fixed with the flanging of the flanging hole.

5. The sealed connection structure of the heat collecting pipe and the header of the solar heat collector as claimed in claim 1, wherein the inner circumferential surface of the metal ring gasket (7) is hermetically welded with the outer circumferential surface of the heat pipe (2).

6. The sealing connection structure of the heat collecting pipe and the header of the solar heat collector as claimed in claim 5, wherein the inner hole of the metal ring gasket (7) is a flanging hole, and the heat pipe (2) is welded and fixed with the flanging of the flanging hole.

7. The sealed connection structure of the heat collecting pipe and the header of the solar heat collector according to claim 1, characterized in that a rubber sealing ring (8) is axially clamped between the metal ring gasket (7) and the first annular inner flange (501).

8. The sealed connection structure of the heat collecting pipe and the header of the solar heat collector according to claim 1, characterized in that the inner hole diameter of the first annular inner flange (501) is larger than the diameter of the protruding end (201) of the heat pipe.

9. The sealed connection structure of the heat collecting pipe and the header of the solar heat collector as claimed in claim 1, characterized in that the axially inner end of the inner threaded sleeve (6) is integrally provided with a ring of radially inwardly convex second annular inner flange (601).

10. A solar collector, comprising a sealing connection as claimed in any one of claims 1 to 9.

Technical Field

The application relates to the field of solar energy utilization, in particular to a solar heat collector and a sealing connection structure of a heat collecting pipe and a header of the solar heat collector.

Background

Solar energy, as a renewable energy source, has been widely used, such as photovoltaic power generation, photo-thermal heating, photo-thermal power generation, etc., and solar energy is also a main direction for developing green energy in the future. Two technical approaches for utilizing solar energy exist: namely, photovoltaic power generation, which generally refers to a technology for converting collected solar energy into electric energy, and photothermal heating, which generally refers to a technology for converting collected solar energy into usable heat energy.

Chinese patent application No. CN202010321847.5 discloses a photovoltaic-photothermal device, comprising: the heat collecting device comprises a base frame, a water running tank (header) fixed on the base frame, and a heat collecting pipe connected with the base frame. The heat collecting pipes can be divided into two structural forms of water flowing and water non-flowing, the heat collecting pipes flowing water need to be inserted into the water flowing tank and are directly communicated with the water cavity, and the heat collecting pipes not flowing water (vacuum heat collecting pipes) are inserted into the water flowing tank but are not normally communicated with the water cavity. Specifically, the heat collecting pipe which does not leak water mainly comprises: the vacuum tube body, the heat absorption coating coated on the tube wall of the inner tube of the vacuum tube body and the heat tube movably arranged in the inner tube. The heat pipe comprises a heat pipe extending end (heat pipe extending end) extending out of the vacuum pipe body and inserted into the water tank, and referring to figure 7 of the patent application, although the extending end of the heat pipe is inserted into the water tank but not directly communicated with the inner cavity of the water tank, an inward heat conduction sleeve is hermetically arranged on the wall of the water tank, and the extending end of the heat pipe is inserted into the heat conduction sleeve and is contacted with the heat conduction sleeve. When the water tank works, the heat pipe transmits heat to the heat conduction sleeve, the heat conduction sleeve transmits the obtained heat to the water in the water tank which is directly contacted with the heat conduction sleeve, the heat of the heat pipe can only be transmitted to the water in the water tank by virtue of the heat conduction sleeve but can not be directly transmitted, and the light-water photothermal conversion efficiency is low.

In addition, the above patent application document also introduces a "sealing insertion" manner that the extending end of the heat pipe is directly contacted with water in the water tank: the extending end of the heat pipe inserted into the water tank is directly contacted with the water in the water tank, and the sealing ring is used for keeping the sealing of the splicing part of the end body of the heat pipe and the water tank, so as to prevent water leakage.

However, the sealing using the sealing ring has the following problems:

1. the sealing surface of the sealing ring in the device has two positions, one is the sealing between the peripheral surface of the sealing ring and the water tank, and the other is the sealing between the inner peripheral surface of the sealing ring and the outer side of the heat pipe, namely two positions where water can leak exist in the sealing by adopting the sealing ring.

2. The sealing of the sealing ring is usually based on the flexibility of the material, and the sealing ring is deformed by interference fit with the sealing surface to generate a pre-tightening force, wherein the pre-tightening force is obtained by extruding the sealing ring radially outwards through the heat pipe. Photovoltaic-light and heat device is when in actual use, and it is great to walk the temperature variation interval in the water tank and on the heat pipe, and work in such environment, the sealing washer can be ageing with higher speed, uses later stage sealing washer because ageing can produce pretightning force decay scheduling problem, and then causes sealed and fixed effect not good, finally takes place to leak.

The present application is hereby presented.

Disclosure of Invention

The technical problem that this application will solve is: in order to solve the problems, the solar thermal collector and the sealing connection structure of the thermal collecting tube and the header thereof are provided, so that the sealing effect of the connection part of the thermal collecting tube and the header is enhanced while the light-water photothermal conversion efficiency of the solar thermal collector is improved.

The technical scheme of the application is as follows:

a sealing connection structure of a heat collecting pipe and a header of a solar heat collector comprises a vacuum pipe body and a heat pipe inserted in the vacuum pipe body, wherein a heat collecting pipe connecting hole is formed in the wall of the header, the heat pipe comprises a heat pipe extending end extending out of the vacuum pipe body and inserted in the heat collecting pipe connecting hole,

the heat collecting pipe connecting hole is communicated with a water cavity in the header, and the extending end of the heat pipe extends into the water cavity;

the sealing connection structure further includes:

the outer sleeve is fixed in the heat collecting pipe connecting hole, the outer periphery of the outer sleeve is in sealing fit with the wall surface of the heat collecting pipe connecting hole, and a circle of first annular inner flanges protruding inwards in the radial direction are integrally arranged at the axial inner end of the outer sleeve;

the metal ring gasket is fixedly sleeved outside the heat pipe, the inner circumferential surface of the metal ring gasket is in sealing fit with the outer circumferential surface of the heat pipe, the heat pipe penetrates through the outer sleeve oppositely, and the metal ring gasket is positioned inside the outer sleeve; and

the outer peripheral surface of the inner threaded sleeve is provided with an external thread, the inner threaded sleeve is movably sleeved outside the heat pipe, the inner threaded sleeve and the outer threaded sleeve are locked in the outer threaded sleeve in a threaded fit mode, and the metal ring gasket is axially and hermetically clamped between the inner threaded sleeve and the first annular inner flange.

On the basis of the technical scheme, the application also comprises the following preferable scheme:

the axial outer end face of the first annular inner flange and the axial inner end face of the inner threaded sleeve comprise conical surfaces which are matched with each other to clamp the metal ring gasket.

The peripheral surface of the outer sleeve is hermetically welded with the wall surface of the connecting hole of the heat collecting pipe.

The heat collecting pipe connecting hole is a flanging hole, and the outer sleeve is welded and fixed with a flanging of the flanging hole.

The inner circumferential surface of the metal ring gasket is hermetically welded with the outer circumferential surface of the heat pipe.

The inner hole of the metal ring pad is a flanging hole, and the heat pipe is welded and fixed with the flanging of the flanging hole.

And a rubber sealing ring is clamped between the metal ring gasket and the first annular inner flange.

The inner hole diameter of the first annular inner flange is larger than the diameter of the extending end of the heat pipe.

And a circle of second annular inner flange which is inwards convex in the radial direction is integrally arranged at the axial inner side end of the inner threaded sleeve.

A solar heat collector comprises the sealing connection structure.

The beneficial effect of this application:

1. according to the solar heat collector, the heat pipe of the vacuum heat collecting pipe directly extends into the water cavity in the header and is in direct contact with water in the header, and the light-water photo-thermal conversion efficiency of the solar heat collector is improved.

2. The junction of the heat collecting pipe and the header is provided with a specially designed rigid sealing structure, so that water is effectively prevented from overflowing from the junction of the heat collecting pipe and the header, the problem of easy aging of the traditional flexible sealing ring type sealing structure is solved, and the assembly and the disassembly are very convenient.

3. The opposite sides of the outer sleeve and the inner sleeve are provided with conical surfaces which are matched with each other so as to clamp the metal ring gasket fixed on the heat pipe in the middle, the sealing area between the metal ring gasket and the inner and outer sleeves is increased, and the sealing effect is improved. Moreover, during assembly, the metal ring gasket is extruded and deformed along with the increase of the locking depth of the locking inner sleeve, so that a gap possibly existing in rigid matching is eliminated.

4. The heat collecting pipe connecting hole is provided with a flanging hole with a flanging, after the outer screw sleeve is arranged in the heat collecting pipe connecting hole, the flanging of the heat collecting pipe connecting hole and the outer screw sleeve on the inner side are welded and fixed by adopting a laser welding process, so that the peripheral surface of the outer screw sleeve and the wall surface of the heat collecting pipe connecting hole are mutually fused and sealed. The welding of the outer sleeve and the connecting hole of the heat collecting pipe is facilitated, and the rigid sealing matching of the outer peripheral surface of the outer sleeve and the wall surface of the connecting hole of the heat collecting pipe can be realized.

5. The inner hole of the metal ring pad is designed to be a flanging hole structure, after the metal ring pad is sleeved at a required position on the heat pipe, the flanging of the inner hole of the metal ring pad is welded and fixed with the heat pipe by adopting a laser welding process, so that the inner circumferential surface of the metal ring pad and the outer circumferential surface of the heat pipe are fused and sealed mutually. Not only facilitates the welding of the metal ring gasket and the heat pipe, but also realizes the rigid sealing matching of the inner hole of the metal ring gasket and the heat pipe,

6. the inner hole diameter of the inner flange at the end part of the outer sleeve is set to be larger than the diameter of the extending end of the heat pipe. During assembly, the outer sleeve is welded with the connecting hole of the heat collecting pipe, and the heat pipe sleeved with the inner threaded sleeve penetrates through the inner hole of the outer sleeve inwards to enable the extending end of the heat pipe to extend into the water cavity of the header. And then, rotating the inner threaded sleeve to hermetically clamp the metal ring gasket welded and fixed on the heat pipe between the inner threaded sleeve and the first annular inner flange. Then, a vacuum tube body is sleeved outside the heat pipe. The assembly of the heat collecting pipe and the header is facilitated.

7. A circle of annular inner flanges protruding inwards in the radial direction are integrally arranged at the inner side end of the inner threaded sleeve in the axial direction, so that on one hand, the bearing area of the inner threaded sleeve on the metal ring pad is increased, the possibility that the metal ring pad collapses and deforms due to stress is reduced, and on the other hand, the risk that an external object contacts and damages the metal ring pad is also reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments will be briefly introduced below, and it is apparent that the drawings in the following description only relate to some embodiments of the present application and are not limiting on the present application.

Fig. 1 is an overall schematic view of a solar thermal collector according to an embodiment of the present application.

Fig. 2 is a cross-sectional view of fig. 1.

Fig. 3 is an enlarged view of the X1 portion of fig. 2.

Fig. 4 is an enlarged view of the X2 portion of fig. 2.

Fig. 5 is a schematic view of a heat pipe structure in a heat collecting pipe according to an embodiment of the present disclosure.

Fig. 6 is a perspective view of a metal ring pad in an embodiment of the present application.

Fig. 7 is a schematic cross-sectional view of a metal ring pad in an embodiment of the present application.

Fig. 8 is a perspective view of a middle and outer threaded sleeve in the practice of the present application.

Fig. 9 is a schematic cross-sectional view of an outer thread insert in the practice of the present application.

Fig. 10 is a perspective view of an inner threaded sleeve in the practice of the present application.

Fig. 11 is a schematic cross-sectional view of an inner thread insert in the practice of the present application.

FIG. 12 is a schematic view of a heat pipe structure in a heat collecting pipe according to a second embodiment of the present invention.

Fig. 13 is an enlarged sectional view of a joint between a heat collecting pipe and a header in the second embodiment of the present application.

Fig. 14 is a perspective view of a metal ring pad in an embodiment of the present application.

Fig. 15 is a schematic cross-sectional view of a metal ring pad in an embodiment of the present application.

Fig. 16 is a schematic cross-sectional view of an outer thread insert according to a second embodiment of the present application.

Fig. 17 is a schematic cross-sectional view of an inner insert according to a second embodiment of the present application.

Wherein:

a-a heat collecting pipe, b-a header, 1-a vacuum pipe body, 2-a heat pipe, 3-a water cavity, 4-a heat collecting pipe connecting hole, 5-an outer sleeve, 6-an inner threaded sleeve, 7-a metal ring pad and 8-a rubber sealing ring;

101-outer tube, 102-inner tube, 201-extending end of heat tube, 401-flanging of connecting hole of heat collecting tube, 501-first annular inner flange, 601-second annular inner flange, 602-third annular inner flange, and 701-flanging of metal ring pad.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings of the embodiments of the present application. It should be apparent that the described embodiments are only some of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the application without any inventive step, are within the scope of protection of the application.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. The use of the terms "a" or "an" and the like in the description and in the claims of the present application do not denote a limitation of quantity, but rather denote the presence of at least one.

In the description of the present specification and claims, the terms "upper", "lower", "horizontal", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present application and simplifying the description, but do not indicate or imply that the referred device or unit must have a specific direction, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application.

Specific embodiments of the present application will now be described with reference to the accompanying drawings.

The first embodiment is as follows:

referring to fig. 1 to 11, the solar collector of the present application also includes a heat collecting pipe a and a header b of a conventional solar collector. The heat collecting pipe a is provided with a plurality of pipes, and only one pipe is shown in the drawing for convenience of drawing. The thermal-collecting tube a adopts the vacuum thermal-collecting tube that does not walk water, and it includes: the vacuum tube comprises a vacuum tube body 1 consisting of an outer tube 101 and an inner tube 102 which are coaxially and fixedly connected (a vacuum environment is formed between the inner tube and the outer tube), a heat absorption coating attached to the wall of the inner tube, and a heat pipe 2 inserted into the inner tube and wound with a heat-conducting aluminum foil sheet at the periphery. The phase change material is encapsulated inside the heat pipe 2. The inside of the header b is a water cavity 3 for water to flow, and the wall of the header b is provided with a heat collecting pipe connecting hole 4 for connecting a heat collecting pipe. The heat pipe 2 has a heat pipe extending end 201 extending out of the vacuum pipe body 1, and the heat pipe extending end 201 is inserted into the heat collecting pipe connecting hole 4.

The key improvement of this embodiment is that the heat collecting pipe connecting hole 4 is a through hole communicated with the water chamber 3 inside the header, and the extending end 201 of the heat pipe passes through the heat collecting pipe connecting hole 4 and extends into the water chamber 3. When the heat pipe heat collecting device works, the extending end 201 of the heat pipe is in direct contact with water in the water cavity 3, so that heat is transferred to water in the header more quickly, and the heat collecting efficiency is improved.

Since the heat pipe 2 is inserted into the water chamber 3 to be in direct contact with water, it is necessary to ensure the heat pipe 2 to be sealed with the collector tube connection hole 4, otherwise, a water leakage problem will occur. Based on this, the present embodiment further configures an outer jacket 5, an inner jacket 6 and a metal ring gasket 7 to seal the connection portion of the heat collecting tube a and the header b, specifically, the matching portion of the heat pipe of the heat collecting tube and the heat collecting tube connection hole of the header.

The outer thread 5 is internally threaded on its inner peripheral surface. The outer sleeve 5 is inserted into the heat collecting pipe connecting hole 4, and the outer peripheral surface of the outer sleeve is hermetically welded with the hole wall surface of the heat collecting pipe connecting hole 4. The axial inner end of the outer sleeve 5 is integrally provided with a ring of first annular inner flange 501 which is radially inwardly protruded.

The metal ring gasket 7 is sleeved outside the heat pipe 2, and the inner circumferential surface of the metal ring gasket is hermetically welded with the outer circumferential surface of the heat pipe 2. The heat pipe 2 is penetrated through the outer jacket 5, and the metal ring pad 7 is positioned inside the outer jacket 5.

The outer peripheral surface of the inner thread insert 6 is provided with external threads. The inner threaded sleeve 6 is movably sleeved outside the heat pipe 2, and the inner threaded sleeve and the outer threaded sleeve 5 are locked in the outer threaded sleeve in a threaded fit manner, so that the metal ring gasket 7 is axially and hermetically clamped between the inner threaded sleeve and the first annular inner flange 501.

From the above, the metal ring gasket is sleeved outside the heat pipe 2 and is welded with the heat pipe 2 in a sealing manner, and the metal ring gasket is clamped between the inner thread sleeve 6 and the first annular inner flange 501 at the end part of the outer thread sleeve in a sealing manner, so that water in the water cavity 3 cannot seep outwards.

In order to increase the sealing area between the metal ring gasket 7 and the inner and outer thread sleeves to improve the sealing effect, in this embodiment, conical surface structures are respectively disposed on the axial outer end surface of the first annular inner flange 501 and the axial inner end surface of the inner thread sleeve 6, and the conical surface on the first annular inner flange and the conical surface on the inner thread sleeve are mutually matched to clamp the middle metal ring gasket 7.

In order to more conveniently weld the outer sleeve 5 and the heat collecting pipe connecting hole 4 and realize the sealing fit between the outer peripheral surface of the outer sleeve 5 and the hole wall surface of the heat collecting pipe connecting hole 4, in the embodiment, the heat collecting pipe connecting hole 4 is set to be a flanging hole with a flanging 401, after the outer sleeve 5 is installed in the heat collecting pipe connecting hole 4, the flanging of the heat collecting pipe connecting hole 4 is welded and fixed with the inner outer sleeve 5 by adopting a laser welding process, so that the outer peripheral surface of the outer sleeve 5 and the hole wall surface of the heat collecting pipe connecting hole 4 are mutually fused.

Similarly, for the convenience of welding the metal ring gasket 7 and the heat pipe 2 and the sealing fit between the inner hole of the metal ring gasket 7 and the heat pipe 2, the inner hole of the metal ring gasket 7 is also set to be a flanging hole structure in the embodiment, the metal ring gasket 7 is sleeved on the heat pipe 2 at a required position, and then the flanging of the inner hole of the metal ring gasket 7 is welded and fixed with the heat pipe 2 by using a laser welding process, so that the inner circumferential surface of the metal ring gasket 7 and the outer circumferential surface of the heat pipe 2 are fused and sealed with each other.

The metal ring pad 7 is a copper ring pad which has high heat conductivity and is easy to weld with a copper heat pipe.

In this embodiment, the protruding end 201 of the heat pipe is thicker than the other sections of the heat pipe. If the inner hole diameter of the first annular inner flange 501 is smaller than the diameter of the heat pipe extending end 201, when the solar collector is assembled, the thin end of the heat pipe 2 (the end deviating from the heat collecting pipe extending end) must first pass through the outer sleeve 5, then the outer sleeve 5 is welded to the heat collecting pipe connecting hole 4, and then the vacuum pipe body 1 is sleeved. Therefore, not only is the assembly difficult, but also once the outer sleeve 5 is welded, the heat pipe 2 in the heat collecting pipe cannot be detached from the header.

For the above reasons, the present embodiment sets the inner hole diameter of the first annular inner flange 501 to be larger than the diameter of the heat pipe protruding end 201. During assembly, the outer sleeve 5 and the heat collecting pipe connecting hole 4 are welded firstly, and then the heat pipe 2 sleeved with the inner threaded sleeve 6 penetrates through the inner hole of the outer sleeve 5 inwards, so that the extending end 201 of the heat pipe extends into the water cavity 3 of the header. Then, the inner threaded sleeve 6 is rotated to seal and clamp the metal ring gasket 7 welded and fixed on the heat pipe 2 between the inner threaded sleeve 6 and the first annular inner flange 501. Then, the vacuum tube body 1 is sleeved outside the heat pipe 2.

When the solar heat exchanger is in actual use, the heat exchange tube a on the solar heat exchanger is mostly placed in an inclined mode, namely the extending end 201 of the heat pipe is arranged on the upper portion, and the other end of the heat pipe is arranged on the lower portion. Thus, the heat pipe 2 has a tendency to slide downward under its own weight, which causes the metal ring gasket 7 to be forced and act on the inner thread 6 on the underside of the metal ring gasket 7. If the bearing area of the inner threaded sleeve 6 on the metal ring pad 7 is small, the metal ring pad 7 is easy to deform and even damage. Therefore, in the embodiment, the second annular inner flange 601 protruding inwards in the radial direction is integrally arranged at the inner side end of the inner threaded sleeve 6 in the axial direction, so that on one hand, the bearing area of the inner threaded sleeve 6 on the metal ring gasket 7 is increased, the possibility that the metal ring gasket 7 collapses and deforms due to stress is reduced, and on the other hand, the risk that an external object contacts and damages the metal ring gasket 7 is also reduced.

Further, in the present embodiment, a circle of radially inward protruding third annular inner flange 602 is further integrally disposed at the axial outer end of the inner thread insert 6, so as to further reduce the risk that an external object contacts and damages the metal ring gasket 7, and simultaneously limit the swing space of the heat pipe 2.

Example two:

fig. 12-17 illustrate another embodiment of a solar collector of the present application having substantially the same construction and assembly method as the one described above, except that:

in this embodiment, the axial outer end surface of the outer sleeve first annular inner flange 501 and the axial inner end surface of the inner sleeve 6 are both vertical planes, and no longer have a conical surface structure. And a rubber seal ring 8 is axially sandwiched between the metal ring gasket 7 and the first annular inner flange 501.