Solar medium-temperature vacuum heat collecting tube and heat collector

Abstract

The utility model relates to solar middle temperature heat collecting technical field discloses a solar middle temperature vacuum heat collecting tube and heat collector, vacuum heat collecting tube includes vacuum glass tube, the inner tube of vacuum glass tube is equipped with the heat absorption fin of section U along its diameter direction, and the heat absorption fin props on the inner wall of inner tube, the outer tube of vacuum glass tube has the reflection layer, the bottom of heat absorption fin is towards the reflection layer, and the both ends of heat absorption fin are respectively bent outwards and form the clamping portion, and the inner tube is also equipped with the heat conduction oil pipe of U shape along its diameter direction, and the heat conduction oil pipe is clamped on the clamping portion, and the heat conduction oil pipe has the heat conduction oil in it. After setting heat absorption fin, can greatly increase the heat exchange area of heat conduction oil pipe and vacuum glass tube, thereby improve the heat collecting efficiency of vacuum heat collecting tube. Meanwhile, heat absorption fin also plays the supporting role to heat conduction oil pipe, avoids the collision of heat conduction oil pipe with inner tube when installing, or the collision of heat conduction oil pipe with inner tube because of vibration when working, produces the noise or leads to the damage of vacuum glass tube.

Description

Technical Field

[0001] This utility model relates to the field of solar medium-temperature heat collection technology, and in particular to a solar medium-temperature vacuum heat collection tube and collector. Background Technology

[0002] With the increasing awareness of environmental protection and energy conservation, solar energy, as a new type of renewable and clean energy, has been widely used in people's daily lives. However, existing vacuum tube collectors can only provide hot water at around 70°C, which greatly reduces the scope of solar thermal utilization.

[0003] Therefore, solar medium-temperature (80 to 150°C) collector technology has emerged. This technology involves circulating heat-conducting oil through a vacuum glass tube to raise the oil's temperature to a medium level before supplying it to other heat-consuming equipment. For example, patent CN208398400U discloses a series-connected U-shaped tube pressurized medium-temperature solar collector, including a collector manifold, vacuum tubes, and U-shaped tubes. Multiple equally spaced vacuum tubes are installed on the side of the collector manifold. U-shaped tubes, made of rare-earth aluminum, are installed inside each vacuum tube. The U-shaped tubes are connected in series, with some located inside the collector manifold arranged in a spiral pattern. Heat-conducting oil is placed inside each U-shaped tube. This medium-temperature collector allows the heat-conducting oil to enter from one end of the U-shaped tube and gradually heat up, eliminating the need for medium vaporization and condensation, resulting in high thermal efficiency. Furthermore, the U-shaped tubes fold through the vacuum tubes, increasing the surface area for heat conduction and improving the system's start-up speed.

[0004] However, because the U-tube converts light and heat through its surface, and only exchanges heat with the vacuum collector tube through its surface, the U-tube's small surface area results in a small heat exchange area, leading to low photothermal conversion efficiency in this type of medium-temperature collector. Furthermore, since the U-tube is directly inserted into the vacuum collector tube, there is a gap between the U-tube and the inner tube, making it prone to collisions with the inner wall of the vacuum collector tube during installation. This can severely damage the vacuum collector tube, affecting its heat collection efficiency. Additionally, the flow of heat transfer oil within the U-tube causes vibration. Due to its length, the U-tube vibrates and collides with the inner tube of the vacuum collector tube during vibration, which can also easily lead to the vacuum collector tube breaking over time. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a solar medium-temperature vacuum collector tube and collector to solve the problem of low heat collection efficiency of medium-temperature collectors in the background art.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0007] A solar medium-temperature vacuum collector tube includes a vacuum glass tube. The inner tube of the vacuum glass tube has U-shaped heat-absorbing fins along its diameter, which are supported on the inner wall of the inner tube. The outer tube of the vacuum glass tube is coated with a reflective layer. The bottom of the heat-absorbing fins faces the reflective layer. Both ends of the heat-absorbing fins are bent outwards to form snap-fit ​​portions. A U-shaped heat-conducting oil pipe is also provided along its diameter inside the inner tube, and the heat-conducting oil pipe is snapped onto the snap-fit ​​portions. Heat-conducting oil flows through the heat-conducting oil pipe.

[0008] Furthermore, the part of the snap-fit ​​portion that contacts the heat-conducting oil pipe is an arc-shaped surface that matches the outer wall of the heat-conducting oil pipe. The central angle corresponding to this arc-shaped surface is β, which satisfies 180°<β<270°.

[0009] Furthermore, the edge of the snap-fit ​​portion is a bent flange, and the plane containing the flange passes through the center of the arc-shaped surface.

[0010] Furthermore, the inner tube is eccentrically positioned inside the outer tube, and both ends of the outer tube are circular mounting portions with diameters smaller than the diameter of the middle part of the outer tube. Both mounting portions are coaxial with the inner tube, and the reflective layer is located inside the outer tube near the inner tube.

[0011] A solar medium-temperature vacuum collector tube further includes a frame and two main oil pipes fixedly connected to the frame. The vacuum collector tube is fixedly connected to the frame, and the two ends of the heat-conducting oil pipe are respectively fixedly connected to the two main oil pipes.

[0012] Furthermore, the vacuum heat collection tubes are several parallel tubes, and the heat-conducting oil pipes of adjacent vacuum heat collection tubes are connected end to end to form a serpentine tube. The two ends of the serpentine tube are respectively fixedly connected to two main oil pipes.

[0013] Furthermore, the two main oil pipes are parallel to each other, and each main oil pipe has a joint at both ends. The two ends of the serpentine tube are fixedly connected to the side walls of the two main oil pipes respectively.

[0014] The positive effects of this utility model are:

[0015] A vacuum solar collector tube consists of a vacuum glass tube and heat-absorbing fins housed within an inner tube of the vacuum glass tube. Heat-conducting oil pipes are attached to the heat-absorbing fins. The addition of heat-absorbing fins significantly increases the heat exchange area between the heat-conducting oil pipes and the vacuum glass tube, thereby improving the heat collection efficiency of the vacuum solar collector tube and increasing the utilization rate of solar energy. Simultaneously, the heat-absorbing fins, supported within the inner tube, also provide support for the heat-conducting oil pipes, preventing collisions during installation or operation due to vibration, which could generate noise or damage the vacuum glass tube. Multiple vacuum solar collector tubes can be installed on a frame to form a solar collector. Multiple collectors can be connected in parallel according to site requirements, thereby increasing the total solar heat exchange capacity. Attached Figure Description

[0016] Figure 1 This is a structural schematic diagram of Example 1;

[0017] Figure 2 yes Figure 1 A cross-sectional view of the AA section;

[0018] Figure 3 This is the optical path diagram when the inner and outer tubes are coaxially arranged;

[0019] Figure 4 This is the optical path diagram when the inner tube is eccentrically set;

[0020] Figure 5 This is the front view of Embodiment 2;

[0021] Figure 6 yes Figure 3 Enlarged view of the main oil pipe section;

[0022] Figure 7 yes Figure 4 A schematic diagram of the B-direction;

[0023] In the picture:

[0024] 1. Inner tube; 2. Outer tube; 3. Reflective layer; 4. Mounting part; 5. Heat-absorbing fins; 6. Heat-conducting oil pipe; 7. Vacuum glass tube; 8. Frame; 9. Main oil pipe; 10. Connector; 11. Snap-fit ​​part. Detailed Implementation

[0025] Example 1

[0026] like Figure 1 and Figure 2 As shown, a solar medium-temperature vacuum collector tube includes a vacuum glass tube 7. The vacuum glass tube 7 includes an inner tube 1 with an opening at the left end and an outer tube 4 sleeved around the inner tube 1. Both the inner tube 1 and the outer tube 4 are made of transparent glass. The left ends of the inner tube 1 and the outer tube 4 are connected, and a vacuum is drawn between the inner tube 1 and the outer tube 4. The outer tube 2 is coated with a reflective layer 3, which is arranged along the inner wall of the outer tube 1 within a range of 180 degrees from the central angle. The outer surface of the inner tube 1 is coated with a heat-absorbing layer, and the inner tube 1 is encased within the heat-absorbing layer.

[0027] When in use, a portion of the sunlight that hits the outer tube 4 passes through the outer tube 4 and directly shines on the heat-absorbing layer on the sun-facing side of the inner tube 1, while the other portion of the sunlight that hits the outer tube 4 is reflected by the reflective layer 3 and then onto the heat-absorbing layer on the other side of the inner tube 1, thereby heating the inner tube 1.

[0028] The inner tube 1 has U-shaped heat-absorbing fins 5 along its diameter, which are made of aluminum or aluminum alloy. The heat-absorbing fins 5 are elastically supported on the inner wall of the inner tube 1, with the bottom of the fins facing the reflective layer 3 of the vacuum glass tube 7. Both ends of the heat-absorbing fins 5 are bent outwards to form snap-fit ​​parts 11. The inner tube 1 also has a U-shaped heat-conducting oil pipe 6 along its diameter, which is snapped onto the snap-fit ​​parts 11. Both ends of the heat-conducting oil pipe 6 extend out of the vacuum glass tube 7, and heat-conducting oil flows through the heat-conducting oil pipe 6.

[0029] The part of the snap-fit ​​portion 11 that contacts the heat-conducting oil pipe 6 is an arc-shaped surface that matches the outer wall of the heat-conducting oil pipe 6. The central angle corresponding to the arc-shaped surface is β, which satisfies 180°<β<270°, preferably 220°.

[0030] The edge of the snap-fit ​​part 11 is a bent flange, and the plane of the flange passes through the center of the arc-shaped surface. The flange can facilitate the insertion of the heat-conducting oil pipe 6 into the snap-fit ​​part.

[0031] The addition of heat-absorbing fins 5 significantly increases the heat exchange area between the heat-conducting oil pipe 6 and the inner tube 2, thereby improving the heat collection efficiency of this invention and increasing the utilization rate of solar energy. Simultaneously, the heat-absorbing fins 5, which are embedded in the inner tube 2, also support the heat-conducting oil pipe 6, preventing it from colliding with the inner tube 2 during installation or operation due to vibration, which could damage the vacuum glass tube 7.

[0032] Example 2

[0033] Combination Figure 3 and Figure 4 As shown, the difference between this embodiment and Embodiment 1 is that:

[0034] The inner tube 1 is eccentrically positioned inside the outer tube 2 of the vacuum glass tube 7. Both ends of the outer tube 2 are circular mounting portions 4. The diameter of each mounting portion 4 is smaller than the diameter of the middle part of the outer tube 2. Both mounting portions 4 are coaxial with the inner tube 1. The reflective layer 3 is located inside the outer tube 2 near the inner tube 1.

[0035] To avoid clutter from too many lines, Figure 3 and Figure 4 In the drawing, only the incident light rays on the left half of the vacuum glass tube 7 are shown. (For example...) Figure 3 As shown, if the inner tube 2 and the outer tube 1 are coaxially arranged, most of the light rays that pass through the gap between the inner tube 2 and the outer tube 1 and hit the reflective layer 3 will not be reflected back to the heat-absorbing layer of the inner tube 2. Figure 4In this design, because the inner tube 2 is eccentrically positioned inside the outer tube 1, meaning the inner tube 2 is offset towards the reflective layer 3, most of the light reflected by the reflective layer 3 is reflected onto the heat-absorbing layer of the inner tube 1, thus resulting in higher photothermal conversion efficiency. This structure is described in a solar vacuum collector tube disclosed in patent publication number CN2610279Y.

[0036] Example 3

[0037] Combination Figures 5 to 7 As shown, a solar collector using a solar medium-temperature vacuum collector tube as described in Embodiment 2 also includes a rectangular frame 8 and two parallel main oil pipes 9 fixedly connected to the middle of the frame 8.

[0038] There are 40 vacuum collector tubes arranged in parallel. These 40 tubes are divided into two groups of 20 tubes each, symmetrically arranged on both sides of the two oil injection pipes 9. The mounting parts 4 at both ends of each vacuum collector tube are fixedly connected to the frame 8. The heat-conducting oil pipes 6 of every 10 adjacent vacuum collector tubes are connected end to end to form a serpentine tube, and the two ends of the serpentine tube are fixedly connected to the two main oil pipes 9 respectively.

[0039] Each main oil pipe 9 has a connector 10 at both ends, and the two ends of the serpentine pipe are fixedly connected to the side walls of the two main oil pipes 9 respectively.

[0040] Of the two main oil pipes 9, one is the inlet pipe and the other is the return pipe. The oil pressure in the inlet pipe is greater than that in the return pipe, thus allowing the heat transfer oil to flow within the heat transfer oil pipe 6. In this embodiment, multiple solar collectors can be connected in parallel as needed on site to increase the total solar heat exchange capacity.

[0041] The above-described embodiments are detailed and specific, illustrating preferred embodiments of the present utility model. They are only used to illustrate the technical ideas and features of the present utility model, with the aim of enabling those skilled in the art to understand the content of the present utility model and implement it accordingly. However, they are not limited to the present utility model, and the patent scope of the present utility model cannot be limited by this embodiment alone. That is, any equivalent changes or modifications made to the spirit disclosed in the present utility model, without departing from the structure of the present utility model, such as local improvements within the system and modifications or transformations between subsystems, are still within the patent scope of the present utility model.

Claims

1. A solar medium-temperature vacuum collector tube, comprising a vacuum glass tube (7), characterized in that, The inner tube (1) of the vacuum glass tube (7) is provided with heat-absorbing fins (5) with a U-shaped cross section along its diameter direction. The heat-absorbing fins (5) are supported on the inner wall of the inner tube (1). The outer tube (2) of the vacuum glass tube (7) is coated with a reflective layer (3). The bottom of the heat-absorbing fins (5) faces the reflective layer (3). The two ends of the heat-absorbing fins (5) are bent outward to form a snap-fit ​​part (11). The inner tube (1) is also provided with a U-shaped heat-conducting oil pipe (6) along its diameter direction. The heat-conducting oil pipe (6) is snapped on the snap-fit ​​part (11). Heat-conducting oil flows through the heat-conducting oil pipe (6).

2. A solar medium-temperature vacuum collector tube according to claim 1, characterized in that, The part of the snap-fit ​​part (11) that contacts the heat-conducting oil pipe (6) is an arc-shaped surface that matches the outer wall of the heat-conducting oil pipe (6). The central angle corresponding to the arc-shaped surface is β, which satisfies 180°<β<270°.

3. A solar medium-temperature vacuum collector tube according to claim 2, characterized in that, The edge of the snap-fit ​​part (11) is a bent flange, and the plane on which the flange is located passes through the center of the arc-shaped surface.

4. A solar medium-temperature vacuum collector tube according to claim 1, characterized in that, The inner tube (1) is eccentrically positioned inside the outer tube (2). Both ends of the outer tube (2) are circular mounting parts (4). The diameter of the two mounting parts (4) is smaller than the diameter of the middle part of the outer tube (2). The two mounting parts (4) are coaxial with the inner tube (1). The reflective layer (3) is located inside the outer tube (2) near the inner tube (1).

5. A solar collector, characterized in that, The solar medium-temperature vacuum collector tube according to any one of claims 1 to 4 further includes a frame (8) and two main oil pipes (9) fixedly connected to the frame (8). The vacuum collector tube is fixedly connected to the frame (8), and the two ends of the heat-conducting oil pipe (6) are fixedly connected to the two main oil pipes (9) respectively.

6. A solar collector according to claim 5, characterized in that, The vacuum heat collection tubes are several parallel tubes, and the heat-conducting oil pipes (6) of adjacent vacuum heat collection tubes are connected end to end to form a serpentine tube. The two ends of the serpentine tube are respectively fixedly connected to two main oil pipes (9).

7. A solar collector according to claim 6, characterized in that, The two main oil pipes (9) are parallel to each other, and each main oil pipe (9) has a connector (10) at both ends. The two ends of the serpentine pipe are fixedly connected to the side walls of the two main oil pipes (9).

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