Wing-free double-vacuum glass-metal spiral U-shaped heat collecting tube

Abstract

A wing-free double-vacuum glass-metal spiral U-shaped heat collecting tube comprises an inlet end, an outlet end, a spiral U-shaped tube, a stainless steel sealing cover and a double-layer glass vacuum tube. The spiral U-shaped pipe is in a U-shaped spiral rising shape; the spiral outer diameter of the spiral U-shaped tube is smaller than the inner diameter of a glass tube in the double-layer glass vacuum tube, and the closer the inner diameter is, the better the inner diameter is; an inner cavity between the double-layer glass vacuum tube and the U-shaped tube is a vacuum interlayer; the heat transfer area is multiplied through the spiral rising shape of the U-shaped heat collecting pipe, heat transfer wings are saved, and the U-shaped heat collecting pipe can be used in series and in parallel without limitation according to actual conditions.

Description

Technical Field

[0001] The utility model relates to the technical field of heat collecting tubes, in particular to a metal spiral U-shaped heat collecting tube. Background Art

[0002] In recent years, with the continuous enhancement of my country's comprehensive national strength, economic development has gradually shifted from high-speed growth to high-quality growth, and industrial production in the real economy has made an increasingly greater economic contribution. In all aspects of industrial production, heat transfer is an extremely common problem. With the need for higher production requirements for industrial production equipment, how to enable industrial equipment with high heat flux density to achieve fast and efficient heat transfer, thereby ensuring high-efficiency and high-quality operation of the equipment, is a problem that needs to be further addressed.

[0003] With the popularity of solar collectors, the exploration of improving their heat collection efficiency has become a major research direction and has received great attention. In my country, all-glass vacuum tube solar collectors are widely used in building heating systems. They have good heating performance and are easy to transport and install.

[0004] Finned tubes are currently the most commonly used means of enhancing heat exchange in industry and commerce. Internal finned tubes were first proposed in 1970. There are many ways to make internal finned tubes, which can be processed using special processes. The purpose of finned tubes is to increase the fluid-solid heat exchange area in the tube, while enhancing the fluid turbulence effect, destroying the development of the boundary layer, and achieving the purpose of enhancing heat exchange. However, the disadvantages of finned tubes are also obvious. The invalid space in the tube is too large, resulting in low internal convection heat transfer efficiency, which greatly affects the heat exchange performance.

[0005] In traditional finned tubes, fins are added inside the glass tube to ensure better heat conduction, which will occupy a larger space of the U-shaped collector tube and most of the space is invalid. Utility Model Content

[0006] In order to solve the problem that a U-shaped heat collecting tube with good heat conduction effect occupies a large ineffective space, the utility model provides a wing-free double vacuum glass-metal spiral U-shaped heat collecting tube.

[0007] A wingless double vacuum glass-metal spiral U-shaped heat collecting tube, comprising a spiral U-shaped tube, a stainless steel sealing cover and a double-layer glass vacuum tube; the spiral U-shaped tube is U-shaped as a whole, with one side being a straight structure and the other side being a spiral ascending shape; the spiral U-shaped tube is arranged inside the inner glass tube of the double-layer glass vacuum tube; the double-layer glass vacuum tube is a U-shaped structure with an upper opening and a double-layer outer wall structure, and the inner cavity between the double-layer outer wall structures is a vacuum interlayer; the stainless steel sealing cover covers the opening of the double-layer glass vacuum tube.

[0008] The above-mentioned wing-free double vacuum glass-metal spiral U-shaped heat collecting tube is U-shaped as a whole, with one side being a straight structure and the other side being a spiral ascending shape, which doubles the heat transfer area and saves heat transfer wings.

[0009] The above-mentioned wingless double vacuum glass-metal spiral U-shaped heat collecting tube can carry liquid or gas and is made of copper, aluminum, stainless steel or other corrosion-resistant and high-temperature resistant composite materials that are cheap, light, have excellent heat dissipation performance, good corrosion resistance and oxidation resistance.

[0010] The above-mentioned wingless double vacuum glass-metal spiral U-shaped collector tube, the spiral outer diameter of the spiral U-shaped tube should be smaller than the inner diameter of the glass tube inside the double-layer glass vacuum tube, and the closer the better, so as to save space in the collector and reduce the volume of the collector.

[0011] The above-mentioned wing-free double vacuum glass-metal spiral U-shaped heat collecting tube has a vacuum between the inner and outer walls of the double-layer glass vacuum tube, which has a good heat preservation effect.

[0012] The above-mentioned wingless double vacuum glass-metal spiral U-shaped heat collecting tube, the inner cavity between the double-layer glass vacuum tube and the U-shaped tube is a vacuum interlayer with good thermal insulation effect, which can effectively suppress the conduction and convection heat loss of the air in the vacuum tube.

[0013] The above-mentioned wing-free double vacuum glass-metal spiral U-shaped heat collecting tube can be used in unlimited series and parallel connection according to actual conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is an overall schematic diagram of a wingless double vacuum glass-metal spiral U-shaped heat collecting tube of the utility model;

[0015] Figure 2 The utility model is a schematic diagram of a spiral U-shaped tube structure of a wing-free double vacuum glass-metal spiral U-shaped heat collecting tube. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0017] Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar symbols throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0018] In the description of the present invention, it is necessary to understand that the terms "center", "longitudinal", "lateral", "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention or simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0019] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0020] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix", "join", "hinge" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] A wingless double vacuum glass-metal spiral U-shaped heat collecting tube comprises a spiral U-shaped tube 4, a stainless steel sealing cover 3 and a double-layer glass vacuum tube 5; the spiral U-shaped tube 4 is U-shaped as a whole, and one side is a straight structure, and the other side is a spiral ascending shape; the spiral U-shaped tube 4 is arranged inside the inner glass tube of the double-layer glass vacuum tube 5; the double-layer glass vacuum tube 5 is a U-shaped structure with an upper opening, and a double-layer outer wall structure, and the inner cavity between the double-layer outer wall structures is a vacuum interlayer; the stainless steel sealing cover 3 covers the opening of the double-layer glass vacuum tube 5.

[0022] In a specific embodiment of the present invention, the spiral U-shaped tube 4 is in a U-shape as a whole, with one side being a straight line structure, and the other side spirally ascending around the straight line.

[0023] In a specific embodiment of the present invention, the spiral U-shaped tube 4 is made of copper, aluminum, stainless steel or other corrosion-resistant and high-temperature-resistant composite materials.

[0024] In a specific embodiment of the present invention, the spiral U-shaped tube 4 can be filled with liquid or gas as a heat transfer medium.

[0025] In a specific embodiment of the present invention, one side of the spiral U-shaped tube 4 is a spiral ascending inlet end, and the other side is a linear outlet section. The two ends are located in a straight line and are both higher than and parallel to the stainless steel sealing cover.

[0026] In a specific embodiment of the present invention, the inner cavity between the double-layer glass vacuum tube 5 and the spiral U-shaped tube 4 is a vacuum interlayer.

[0027] In a specific embodiment of the present invention, the interval between the double-layer vacuum glass 5 is about 0.5-2 cm and the interlayer is a vacuum layer.

[0028] In a specific embodiment of the present invention, the stainless steel sealing cover 3 and the opening of the double-layer glass vacuum tube 5 are sealed by heat melting.

[0029] In a specific embodiment of the present invention, the spiral U-shaped tube 4 has openings at both ends, and the spiral U-shaped tubes of multiple metal spiral U-shaped heat collecting tubes can be connected in series.

[0030] Example 1

[0031] A wing-free double vacuum glass-metal spiral U-shaped heat collecting tube, such as Figure 1 As shown, it includes an inlet end 1, an outlet end 2, a stainless steel sealing cover 3, a spiral U-shaped tube 4 and a double-layer vacuum glass 5; wherein, the spiral U-shaped heat collecting tube type vacuum tube collector is a double-layer glass vacuum tube 5 in which a spiral U-shaped heat collecting tube 4 is installed, the collector is air-dried, and the heat is taken out by the working medium circulating in the spiral U-shaped heat collecting tube 4, directly heating the water or heating the water through the coil heat exchange in the water tank. The metal spiral U-shaped heat collecting tube type vacuum collector inherits the advantages of high performance, high reliability and accurate tracking of the all-glass vacuum tube, and also has the incomparable advantages of the direct plug-in collector: high operating safety factor, the working medium circulates in the spiral U-shaped heat collecting tube, not directly in the vacuum tube, the whole system can operate under pressure, and the whole system can operate normally when the vacuum tube breaks; the antifreeze requirements are not high, because the antifreeze working medium or gas circulates in the pipeline, and the working medium has a low freezing point; easy on-site installation and simple assembly.

[0032] The metal spiral U-shaped collector tube adopts double vacuum technology to eliminate the convection and conduction heat loss of the gas, and applies a selective absorption coating to minimize the radiation heat loss of the vacuum collector tube. In this way, the vacuum tube solar collector can operate at medium and high temperatures, and can also operate in winter in cold areas and in areas with low sunshine and changeable weather, expanding the application field.

[0033] Example 2

[0034] Solar thermal power generation technology is a way to develop and utilize solar energy on a large scale. As the only commercial solar thermal power generation technology at present, trough solar thermal power generation has been promoted and applied to a certain extent. For the spiral U-shaped collector tube, it is a double vacuum collector tube that can be used in trough solar thermal power stations. The spiral U-shaped collector tube is coated with a spectrally selective absorption coating on the surface of the inner glass tube using a special process to absorb solar radiation energy to the maximum extent. First, the sunlight irradiates the outer wall of the vacuum tube, part of the heat is absorbed by the vacuum tube wall, part is reflected to the sky, and the remaining part continues to irradiate the inner wall of the vacuum tube. The inner wall surface of the vacuum tube is coated with a heat-absorbing material, which has the characteristics of high absorption rate and low emissivity, and absorbs solar heat to the maximum extent. The solar radiation heat in the sunlight heats the inner wall collector plate of the cylindrical vacuum tube through direct radiation and scattered radiation. After the temperature of the cylindrical collector plate rises, the heat diffuses to both sides. One side diffuses to the tube wall through radiation loss and convection loss; the other side diffuses to the stainless steel pressure-bearing inner tank through radiation heating and convection heating. The temperature of the tube wall rises after the pressure tank is heated, and then the medium in the large tube is heated by convection. The key is that in terms of the unit investment cost of solar thermal power generation, the unit cost of the wingless double vacuum glass-metal spiral U-shaped collector tube for solar thermal power generation is only 50% of the unit cost of trough solar thermal power generation, or even lower.

[0035] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes within the scope disclosed by the present invention according to the technical solution and concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. Wingless double vacuum glass-metal spiral U-shaped heat collecting tube, characterized in that: It includes a spiral U-shaped tube, a stainless steel sealing cover and a double-layer glass vacuum tube; The spiral U-shaped tube is U-shaped as a whole, with one side being a straight structure and the other side being a spiral ascending shape; the spiral U-shaped tube is arranged inside the inner glass tube of the double-layer glass vacuum tube; the double-layer glass vacuum tube is a U-shaped structure with an upper opening and a double-layer outer wall structure, and the inner cavity between the double-layer outer wall structures is a vacuum interlayer; the stainless steel sealing cover covers the opening of the double-layer glass vacuum tube.

2. The wingless double vacuum glass-metal spiral U-shaped heat collecting tube according to claim 1, characterized in that: The spiral U-shaped tube is in a U-shape as a whole, with one side being a straight line structure and the other side spirally ascending around the straight line.

3. The wingless double vacuum glass-metal spiral U-shaped heat collecting tube according to claim 2, characterized in that: The spiral U-shaped tube is made of copper, aluminum, stainless steel or a corrosion-resistant and high-temperature-resistant composite material.

4. The wingless double vacuum glass-metal spiral U-shaped heat collecting tube according to claim 2, characterized in that: The spiral U-shaped tube can be filled with liquid or gas as a heat transfer medium.

5. The wingless double vacuum glass-metal spiral U-shaped heat collecting tube according to claim 2, characterized in that: One side of the spiral U-shaped tube is a spiral ascending inlet end, and the other side is a linear outlet section. The two ends are located in a straight line and are both higher than and parallel to the stainless steel sealing cover.

6. The wingless double vacuum glass-metal spiral U-shaped heat collecting tube according to claim 1, characterized in that: The inner cavity between the double-layer glass vacuum tube and the spiral U-shaped tube is a vacuum interlayer.

7. The wingless double vacuum glass-metal spiral U-shaped heat collecting tube according to claim 1, characterized in that: The double-layer glass vacuum tube has a spacing of about 0.5-2 cm and the interlayer is a vacuum layer.

8. The wingless double vacuum glass-metal spiral U-shaped heat collecting tube according to claim 1, characterized in that: The stainless steel sealing cover and the opening of the double-layer glass vacuum tube are sealed by heat melting.

9. The wingless double vacuum glass-metal spiral U-shaped heat collecting tube according to claim 1, characterized in that: The spiral U-shaped tube has openings at both ends, and the spiral U-shaped tubes of a plurality of the metal spiral U-shaped heat collecting tubes can be connected in series.

Images