Dual parabolic cylindrical facet solar energy focusing collector

Abstract

The embodiment of the present application provides a kind of double parabolic cylindrical flap solar focusing heat collector, and the solar focusing heat collector includes: support, heat collecting tube being arranged on support, parabolic cylindrical framework being provided with air leakage gap, reflective film being attached to the parabolic cylindrical concave surface of parabolic cylindrical framework, heat collecting tube sleeve being set on the outer wall of heat collecting tube, two connecting pull rods being respectively arranged at the both ends of parabolic cylindrical framework and elevation angle adjusting device for connecting connecting pull rod to support;Wherein, one end of each connecting pull rod is sleeved on heat collecting tube, and the other end is connected with elevation angle adjusting device;Connecting pull rod is rotated with the center line of heat collecting tube as center by elevation angle adjusting device, and then the elevation angle of parabolic cylindrical framework relative to horizontal plane is adjusted.The double parabolic cylindrical flap with air leakage gap left after combination can effectively reduce wind pressure, and the dust on the surface of reflective film can be removed by wind blowing through air leakage gap, keep high reflectivity, reduce the number of flushing for maintenance.

Description

Technical Field

[0001] This invention relates to the field of solar energy utilization technology, and more specifically, to a double parabolic cylindrical solar concentrator. Background Technology

[0002] Solar energy, as a renewable energy source, is abundant, clean, and efficient. It requires no transportation and causes no environmental pollution. Its thermal energy, in particular, has been widely used worldwide in recent years. The solar radiation reaching the Earth's surface annually is equivalent to approximately 130 trillion tons of coal, making it the largest exploitable energy source in the world today. Although the total amount of solar radiation reaching the Earth's surface is large, the energy flux density is very low. On average, near the Tropic of Cancer, in summer, under relatively clear weather, the solar irradiance is highest at noon, with an average of about 1000W of solar energy received per square meter perpendicular to the direction of sunlight. On an annual day-night average, this is only about 200W. In winter, it is roughly half that, and on cloudy days, it is generally only about one-fifth. Such energy flux density is very low. Because solar energy is relatively dispersed, it is necessary to find ways to concentrate it; therefore, solar collectors are a key component of various solar energy utilization devices.

[0003] Commonly used solar collectors include flat-plate collectors, evacuated tube collectors, solar air collectors, and focusing solar collectors. Focusing solar collectors can significantly increase the collection temperature compared to other collectors. Focusing solar collectors are mainly divided into point-focusing collectors and line-focusing collectors. While point-focusing solar collectors can obtain high-temperature heat sources of several hundred or even thousands of degrees Celsius, their cost is relatively high, and such high temperatures are clearly unnecessary in high-temperature solar energy applications, sometimes even causing damage to the absorber. Currently, line-focusing solar collector systems can be divided into four types according to the type of concentrator: parabolic trough concentrators, line-focusing Fresnel lenses, Fresnel mirrors, and non-imaging concentrators. Among these, parabolic trough solar collector technology is currently the most developed and commercially promising focusing solar thermal technology. Currently, most vacuum tube solar collectors are mounted on the upper part of a parabolic trough reflector via a bracket. When the reflector tracks the sun, the collector tubes rotate with the reflector. However, the collector tubes in the existing technology are easily damaged by external impacts, which is not conducive to the rotation of the reflector and the heat preservation of the collector tubes. Summary of the Invention

[0004] This specification provides a double parabolic cylindrical solar concentrator to overcome at least one technical problem existing in the prior art.

[0005] According to an embodiment of this specification, a double parabolic cylindrical solar collector is provided. The solar collector includes: a support frame, a heat collection tube disposed on the support frame, a parabolic cylindrical frame with an air leakage gap, a reflective film attached to the concave surface of the parabolic column of the parabolic cylindrical frame, a heat collection tube sleeve sleeved on the outer wall of the heat collection tube, two connecting rods respectively disposed at both ends of the parabolic cylindrical frame, and an elevation adjustment device for connecting the connecting rods to the support frame.

[0006] The parabolic cylindrical frame includes a first parabolic cylindrical frame and a second parabolic cylindrical frame; the first parabolic cylindrical frame includes two first parabolic supports and a first parabolic cylindrical surface; the first parabolic cylindrical surface is disposed between the two first parabolic supports; the second parabolic cylindrical frame includes two second parabolic supports and a second parabolic cylindrical surface; the second parabolic cylindrical surface is disposed between the two second parabolic supports; the two first parabolic supports of the first parabolic cylindrical frame and the two second parabolic supports of the second parabolic cylindrical frame are respectively connected by two connecting rods, and the first parabolic cylindrical surface and the second parabolic cylindrical surface form a parabolic cylindrical surface with the air leakage gap in the middle;

[0007] One end of each connecting rod is fitted onto the heat collection tube, and the other end is connected to the elevation adjustment device; the elevation adjustment device drives the connecting rod to rotate around the center line of the heat collection tube, thereby adjusting the elevation angle of the parabolic cylindrical frame relative to the horizontal plane.

[0008] The elevation angle adjustment device includes an elevation angle adjustment rod, an elevation angle tie rod, and an elevation angle pin; the elevation angle adjustment rod has multiple adjustment holes at equal angles; one end of the elevation angle tie rod passes through the connecting tie rod and the elevation angle adjustment rod in sequence, and the other end of the connecting tie rod is fixedly connected to one end of the elevation angle adjustment rod; the elevation angle adjustment rod is fixed to the bracket by passing the elevation angle pin through one of the adjustment holes on the elevation angle adjustment rod.

[0009] Optionally, parabolic cylindrical alloy aluminum plates are attached to both the first and second parabolic cylindrical surfaces; the reflective film is attached to the concave surface of the parabolic cylindrical alloy aluminum plates.

[0010] Optionally, the first parabolic support and the second parabolic support are connected by an auxiliary connecting rod.

[0011] Optionally, the heat collection tube is an alloy aluminum tube with surface anodizing treatment.

[0012] Optionally, asbestos gaskets are provided at both ends of the heat collection tube sleeve.

[0013] Optionally, the heat collection tube sleeve is made of tempered glass.

[0014] Alternatively, the thickness of the heat collection tube sleeve is 5 mm.

[0015] Optionally, the bracket, parabolic cylindrical frame, connecting rod, and elevation adjustment device are all made of aluminum alloy.

[0016] The beneficial effects of the embodiments in this specification are as follows:

[0017] The parabolic cylindrical frame with air gaps allows for air leakage and pressure reduction of the air blowing towards the solar concentrator. This air leakage also helps to blow away dust from the reflective film surface. Furthermore, during regular maintenance water washing of the reflective film, cleaning water can be discharged through the air gaps, making cleaning more convenient and thorough. In addition, a tempered glass tube is fitted over anodized aluminum alloy tubes, enhancing the mechanical strength of the collector tubes, making them more resistant to hail damage, less prone to damage during elevation adjustments, resulting in a longer service life and lower cost.

[0018] The innovative aspects of the embodiments in this specification include:

[0019] 1. In this embodiment, a parabolic cylindrical frame with air leakage gaps is used, which allows the air blowing towards the solar concentrator to leak and reduce pressure. It can also use the air leakage to blow away dust on the surface of the reflective film. Furthermore, when regularly maintaining and spraying water to wash the surface of the reflective film to remove dust, the cleaning water can be discharged through the air leakage gaps, making cleaning more convenient and thorough.

[0020] 2. In this embodiment, an alloy aluminum tube with surface oxidation treatment is used as the heat collection tube. It has high thermal conductivity, high mechanical strength, and can achieve a heat absorption rate of 400W / m. 2 The effect.

[0021] 3. In this embodiment, a tempered glass tube is fitted over the surface-oxidized aluminum alloy tube, which further enhances the mechanical strength of the heat collection tube, enabling it to withstand large hailstorms and making it less prone to damage during elevation angle adjustment, resulting in a longer service life and lower cost. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of the double parabolic cylindrical solar concentrator provided in the embodiments of this specification;

[0024] Figure 2A side view of the first parabolic cylindrical frame of the double parabolic cylindrical solar concentrator provided in the embodiments of this specification;

[0025] Figure 3 A side view of the parabolic cylindrical frame of the double parabolic cylindrical solar concentrator provided in the embodiments of this specification, assembled by connecting rods;

[0026] Explanation of reference numerals in the attached drawings: 1 is the bracket, 2 is the heat collection tube, 3 is the air leakage gap, 4 is the reflective film, 5 is the heat collection tube sleeve, 6 is the connecting rod, 7 is the first parabolic bracket, 8 is the second parabolic bracket, 9 is the auxiliary connecting rod, 10 is the elevation adjustment rod, 11 is the elevation tie rod, 12 is the ventilation hole, 13 is the adjustment hole, 14 is the asbestos gasket, 15 is the connection hole, 16 is the connecting plate, 17 is the mounting hole, 18 is the first connection end, and 19 is the second connection end. Detailed Implementation

[0027] The technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that the terms "comprising" and "having," and any variations thereof, in the embodiments and drawings of this specification are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0029] This specification discloses a double parabolic cylindrical solar concentrator. The following provides a detailed description of each.

[0030] Figure 1 This illustrates a double parabolic cylindrical solar concentrator provided according to an embodiment of this specification. For example... Figure 1 As shown, the solar concentrating collector mainly includes a support frame 1, a heat collection tube 2, a heat collection tube sleeve 5, a parabolic cylindrical frame, a reflective film 4, a connecting rod 6, and an elevation angle adjustment device.

[0031] Among them, bracket 1 is the main fixed support structure of the solar concentrating collector, providing a fixed position for the collector tube 2, connecting rod 6 and elevation adjustment device, and using bracket 1 to fix the overall structure of the solar concentrating collector at the designated position, thus playing a supporting role.

[0032] The collector tube 2, also known as the absorber tube, is a crucial component of the solar concentrating collector and is mounted on the support 1. In the embodiment described in this specification, the collector tube 2 in this solar concentrating collector is made of surface-oxidized aluminum alloy, which has a high thermal conductivity. The thermal conductivity of the blackened aluminum alloy tube towards the inner medium is approximately 240 W / m·K, which is 240 times that of the thermal conductivity of the inner medium in the vacuum glass inner tube of the prior art (only 1 W / m·K). Therefore, a heat absorption rate of 400 W / m can be achieved using the surface-oxidized aluminum alloy tube. 2 The effect.

[0033] To enhance the mechanical strength of the heat collector tube 2, a heat collector tube sleeve 5 is fitted onto the outer wall of the heat collector tube 2. In one specific embodiment, the heat collector tube sleeve 5 is made of tempered glass; that is, a tempered glass tube is fitted over an anodized aluminum alloy tube. Furthermore, the thickness of the heat collector tube sleeve 5 is set to 5mm, enabling it to withstand strong hail attacks with a spherical diameter of 30mm and making it less susceptible to damage from larger hailstones, thus greatly increasing the mechanical strength of the heat collector tube 2. In addition, asbestos gaskets 14 can be installed at both ends of the heat collector tube sleeve 5 to seal the tempered glass tube, preventing hot air from flowing out from both ends and losing heat, thus ensuring a high and stable heat absorption rate for the heat collector tube 2.

[0034] In the embodiments described in this specification, the solar concentrating collector employs a parabolic cylindrical frame with an air gap 3, and a reflective film 4 is attached to the concave surface of the parabolic column of the frame. The collector tube 2 is located within the cavity formed by the parabolic cylindrical frame, and the axis of the collector tube 2 is parallel to the axis of the cavity formed by the parabolic cylindrical frame. In specific implementation, the reflective film 4 can be a high-reflectivity film with high reflectivity and low absorptivity, reflecting most or almost all of the incident light energy back, resulting in good light reflection effect and low heat loss in this solar concentrating collector, which is beneficial to improving heat utilization efficiency.

[0035] The parabolic cylindrical frame is movably connected to the collector tube 2 via two connecting rods 6. Specifically, the two connecting rods 6 are respectively located at both ends of the parabolic cylindrical frame, with one end of each connecting rod 6 fitted onto the collector tube 2, thus connecting the parabolic cylindrical frame to the collector tube 2. The connecting rods 6 are connected to the support 1 via an elevation adjustment device, with the other end of each connecting rod 6 connected to the elevation adjustment device. The elevation adjustment device drives the connecting rods 6 to rotate around the centerline of the collector tube 2, thereby adjusting the elevation angle of the parabolic cylindrical frame relative to the horizontal plane. The elevation angle of the parabolic cylindrical frame relative to the horizontal plane is manually adjusted periodically to focus solar energy onto the collector tube 2 as much as possible, ensuring its thermal efficiency.

[0036] Furthermore, in the embodiments described in this specification, the solar concentrating collector uses a manually adjustable elevation angle adjustment device instead of the complex automatic tracking device in the prior art, which greatly reduces the cost of the equipment. Specifically, the elevation angle adjustment device includes an elevation angle adjustment rod 10, an elevation angle pull rod 11, and an elevation angle pin (not shown in the figure), with multiple adjustment holes 13 formed at equal angles on the elevation angle adjustment rod 10. One end of the elevation rod 11 is sequentially connected to the connecting rod 6 and the elevation adjustment rod 10. The other end of the connecting rod 6 is fixedly connected to one end of the elevation adjustment rod 10, so that the elevation adjustment rod 10, the connecting rod 6 and the parabolic cylindrical frame are fixedly connected. Thus, by holding the elevation rod 11, the connecting rod 6 can be rotated around the center line of the heat collection tube 2 to adjust the elevation angle of the parabolic cylindrical frame relative to the horizontal plane, that is, to adjust the elevation angle of the parabolic cylindrical groove. At this time, the relative position between the elevation adjustment rod 10 and the bracket 1 changes. The elevation adjustment rod 10 is fixed to the bracket 1 by passing the corresponding adjustment hole 13 on the elevation adjustment rod 10 through the elevation pin.

[0037] Since the sun's elevation angle in the sky does not change much between 8:00 AM and 4:00 PM daily (less than ±3°), the solar focusing collector in this embodiment uses a 60mm diameter black-coated aluminum alloy tube 2, ensuring that sunlight is focused on the tube 2 for eight hours. Therefore, a manually adjustable elevation angle device can replace a complex tracking system. In the specific implementation, the angle between two adjacent adjustment holes 13 is designed to be 1.8°, and the number of adjustment holes 13 is set to 27. Adjusted weekly, the sun's trajectory moves approximately 1.8° per week. Therefore, an adjustment hole 13 is opened every 1.8° on the elevation angle adjustment rod 10, for a total of 27 holes. This allows the elevation angle adjustment device to adjust the parabolic trough's elevation angle to a range of ±23.4°, sufficient for 52 weeks of the year. When adjustment is needed, the operator adjusts the sunlight to be parallel to the main axis of the parabolic trough around 10:00 AM (or 2:00 PM) to ensure thermal efficiency for eight hours.

[0038] In one specific embodiment, the parabolic cylindrical frame is composed of a first parabolic cylindrical frame and a second parabolic cylindrical frame that are separable from each other. The first and second parabolic cylindrical frames have the same structure and are symmetrically arranged. Specifically, the first parabolic cylindrical frame includes two first parabolic supports 7 and a first parabolic cylindrical surface (not shown in the figure). The first parabolic cylindrical surface is disposed between the two first parabolic supports 7 and is assembled and installed through the first parabolic supports 7, and provides a mounting position for the reflective film 4 through the first parabolic cylindrical surface. Similarly, the second parabolic cylindrical frame includes two second parabolic supports 8 and a second parabolic cylindrical surface (not shown in the figure). The second parabolic cylindrical surface is disposed between the two second parabolic supports 8 and is assembled and installed through the second parabolic supports 8, and provides a mounting position for the reflective film 4 through the second parabolic cylindrical surface. The two first parabolic supports 7 of the first parabolic cylindrical frame and the two second parabolic supports 8 of the second parabolic cylindrical frame are connected by two connecting rods 6 respectively. The first parabolic cylindrical surface and the second parabolic cylindrical surface form a parabolic cylindrical surface with an air leakage gap 3 in the middle.

[0039] To enhance the mechanical strength of the solar concentrator, parabolic aluminum alloy plates are attached to both the first and second parabolic surfaces, and a reflective film 4 is attached to the concave surface of the aluminum alloy plates. Furthermore, the first parabolic support 7 and the second parabolic support 8 are connected by an auxiliary connecting rod 9, enhancing the stability and robustness of the connection between them. Details are as follows... Figure 2 and Figure 3 As shown, the small ends of the first parabolic support 7 and the second parabolic support 8 are respectively provided with connecting holes 15, and the auxiliary connecting rod 9 is connected to the first parabolic support 7 and the second parabolic support 8 through the connecting holes 15.

[0040] In addition, for example Figure 2 and Figure 3As shown, multiple ventilation holes 12 of different sizes are provided on the first parabolic support 7 and the second parabolic support 8. On the one hand, this reduces the weight of the parabolic cylindrical frame; on the other hand, it reduces wind pressure, preventing damage to the solar concentrator due to strong winds. Furthermore, a connecting plate 16 is provided at the large end of the first parabolic support 7 and the second parabolic support 8, and at least two mounting holes 17 are provided on the connecting plate 16 for connecting the first parabolic support 7 and the second parabolic support 8. The connecting rod 6 includes a connecting part, a first connecting end 18, and a second connecting end 19. The first connecting end 18 and the second connecting end 19 are respectively located at both ends of the connecting part. The connecting part has holes corresponding to the mounting holes 17. The connecting plate 16 of the first parabolic support 7 and the second parabolic support 8 is stacked on the connecting part of the connecting rod 6 and fixedly connected through the mounting holes 17. Both ends of the first parabolic cylindrical frame and the second parabolic cylindrical frame are connected by the connecting rod 6, thus combining them into a complete parabolic cylindrical frame. The parabolic cylindrical frame is fitted onto the heat collection tube 2 via the first connecting end 18 of the connecting rod 6, and is connected to the elevation adjustment device via the second connecting end 19 of the connecting rod 6.

[0041] In another specific embodiment, the first parabolic cylindrical skeleton and the second parabolic cylindrical skeleton are integrally formed, and an air leakage gap 3 is opened in the middle.

[0042] The parabolic cylindrical frame is fitted with parabolic alloy aluminum plates on its parabolic surface. A highly reflective film is attached to the concave side of the aluminum plates. A 40mm wide air gap 3 is left at the ridge of the parabolic cylindrical frame. Since this area is in shadow under sunlight and there is no light reflection, it will not affect the light reflection effect of the solar concentrator. The air gap 3 not only allows air blowing towards the solar concentrator to leak and reduce pressure, but also helps to blow away dust from the reflective film surface. In addition, when regularly maintaining and spraying water to wash away dust from the reflective film surface, water can be discharged through the air gap 3, making cleaning easier.

[0043] In the embodiments described in this specification, the bracket 1, the parabolic cylindrical frame, the connecting rod 6, and the elevation adjustment device are all made of aluminum alloy, which can withstand wind, frost, rain and dew for more than ten years. The structure is more robust and sturdy, not easily damaged by strong winds, hail, etc., and has a longer service life and lower cost.

[0044] In summary, this specification discloses a double parabolic cylindrical solar collector that employs a parabolic cylindrical frame with air leakage gaps. This allows airflow blowing towards the solar collector to leak and reduce pressure. The leaking air also helps to blow away dust from the reflective film surface. Furthermore, during regular maintenance, water spraying to wash away dust from the reflective film surface allows cleaning water to drain through the air leakage gaps, making cleaning more convenient and thorough. In addition, the tempered glass tube is fitted over an anodized aluminum alloy tube, enhancing the mechanical strength of the collector tube, making it more resistant to large hailstorms, less prone to damage during elevation angle adjustments, resulting in a longer service life and lower cost.

[0045] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of one embodiment, and the modules or processes shown in the drawings are not necessarily essential for implementing the present invention.

[0046] Those skilled in the art will understand that the modules in the apparatus of the embodiments can be distributed in the apparatus of the embodiments as described in the embodiments, or they can be located in one or more devices different from this embodiment with corresponding changes. The modules of the above embodiments can be combined into one module, or they can be further divided into multiple sub-modules.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A double parabolic cylindrical solar concentrator, characterized in that, The solar focusing collector includes: a bracket, a heat collection tube disposed on the bracket, a parabolic cylindrical frame with an air leakage gap, a reflective film attached to the concave surface of the parabolic column of the parabolic cylindrical frame, a heat collection tube sleeve sleeved on the outer wall of the heat collection tube, two connecting rods respectively disposed at both ends of the parabolic cylindrical frame, and an elevation adjustment device for connecting the connecting rods to the bracket. The parabolic cylindrical frame includes a first parabolic cylindrical frame and a second parabolic cylindrical frame. The first parabolic cylindrical frame includes two first parabolic supports and a first parabolic cylindrical surface. The first parabolic cylindrical surface is disposed between the two first parabolic supports. The second parabolic cylindrical frame includes two second parabolic supports and a second parabolic cylindrical surface. The second parabolic cylindrical surface is disposed between the two second parabolic supports. The two first parabolic supports of the first parabolic cylindrical frame and the two second parabolic supports of the second parabolic cylindrical frame are respectively connected by two connecting rods. The first parabolic cylindrical surface and the second parabolic cylindrical surface form a parabolic cylindrical surface with an air leakage gap in the middle. The parabolic cylindrical frame with the air leakage gap allows the air blowing towards the solar concentrator to leak and reduce pressure, thereby using the air leakage to blow away dust from the surface of the reflective film. One end of each connecting rod is fitted onto the heat collection tube, and the other end is connected to the elevation adjustment device; the elevation adjustment device drives the connecting rod to rotate around the center line of the heat collection tube, thereby adjusting the elevation angle of the parabolic cylindrical frame relative to the horizontal plane. The elevation angle adjustment device includes an elevation angle adjustment rod, an elevation angle tie rod, and an elevation angle pin; the elevation angle adjustment rod has multiple adjustment holes at equal angles; one end of the elevation angle tie rod passes through the connecting tie rod and the elevation angle adjustment rod in sequence, and the other end of the connecting tie rod is fixedly connected to one end of the elevation angle adjustment rod; the elevation angle adjustment rod is fixed to the bracket by passing the elevation angle pin through one of the adjustment holes on the elevation angle adjustment rod. Parabolic cylindrical surfaces are both covered with parabolic cylindrical alloy aluminum plates; the heat collection tube is made of tempered glass and has a thickness of 5mm.

2. The double parabolic cylindrical solar concentrator according to claim 1, characterized in that, The reflective film is attached to the concave surface of the parabolic cylindrical aluminum alloy plate.

3. The double parabolic cylindrical solar concentrator according to claim 1, characterized in that, The first parabolic support and the second parabolic support are connected by an auxiliary connecting rod.

4. The double parabolic cylindrical solar concentrator according to claim 1, characterized in that, The heat collection tube is an alloy aluminum tube with surface oxidation treatment.

5. The double parabolic cylindrical solar concentrator according to claim 1, characterized in that, Asbestos gaskets are provided at both ends of the heat collection tube sleeve.

6. The double parabolic cylindrical solar concentrator according to claim 1, characterized in that, The bracket, parabolic cylindrical frame, connecting rod, and elevation adjustment device are all made of aluminum alloy.

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