A modular high-precision solar vacuum cavity structure for light-to-heat conversion

Abstract

The application discloses a kind of modular high-precision solar vacuum cavity structures for photo-thermal conversion, including vacuum cavity, outer tube and inner tube, solid lubricating layer is arranged between inner tube and outer tube, scraper assembly and storage mechanism are arranged inside vacuum cavity, one-way stepping drive mechanism is also arranged inside vacuum cavity, detection module and heating module are arranged on vacuum cavity.The application is slid by setting outer tube that can be axially relative to inner tube, scraper fixed in cavity inner wall and storage mechanism that stores spare foil, foil is pulled out from storage mechanism and spread on the surface after scraping by the friction of outer tube sliding when using shape memory alloy spring contraction to drive outer tube sliding, without stopping, without damaging vacuum, the segmented update of heat-absorbing body surface can be completed, which greatly reduces operation and maintenance cost, and ensures the continuous operation of heat collection field.

Description

Technical Field

[0001] This invention belongs to the field of solar thermal utilization technology, and in particular relates to a modular high-precision solar vacuum cavity structure for photothermal conversion. Background Technology

[0002] In solar thermal conversion systems, the vacuum chamber structure is a key component for achieving efficient heat collection. Existing solar vacuum chambers typically employ a glass-metal sealed structure with an absorber internally coated with a selective absorption layer. A concentrator focuses sunlight onto the absorber surface to achieve photothermal conversion. To improve collection efficiency, some vacuum chambers utilize a modular design, with multiple chamber modules connected in series or parallel to form a heat collection array. Some structures also integrate phase change thermal storage materials to achieve integrated photothermal conversion and thermal energy storage. Furthermore, detachable vacuum tube heat collectors allow for quick installation and removal of the collector tubes through a detachable connection structure, facilitating maintenance.

[0003] However, the aforementioned existing technologies all suffer from the following problems during long-term concentrated solar power operation: the selective absorption coating on the absorber surface undergoes microstructural degradation under continuous high-energy photon irradiation, leading to a decrease in absorptivity and an increase in reflectivity and emissivity. Traditional solutions require shutdown, vacuum disruption, replacement of the absorber, or recoating, resulting in high operating costs and disruption to the continuous operation of the solar collector. Existing vacuum chambers lack mechanical structures capable of in-situ repair or renewal of the absorber surface without disrupting the vacuum. To address these issues, a modular, high-precision solar vacuum chamber structure for photothermal conversion is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a modular, high-precision solar vacuum cavity structure for photothermal conversion, thereby solving the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: This invention relates to a modular, high-precision solar vacuum chamber structure for photothermal conversion, comprising a vacuum chamber, an outer tube disposed inside the vacuum chamber, and an inner tube passing through the outer tube. A solid lubricating layer is provided between the inner tube and the outer tube, and the outer tube can slide axially relative to the inner tube. The vacuum chamber contains a scraper assembly and a material storage mechanism. The scraper assembly scrapes off the aged coating on the surface of the outer tube, and the material storage mechanism provides fresh foil to the scraped surface of the outer tube. The vacuum chamber also contains a unidirectional stepping drive mechanism for driving the outer tube to slide unidirectionally. The vacuum chamber is equipped with a detection module and a heating module. The detection module detects the degree of aging of the coating on the outer tube surface, and the heating module triggers a driving action based on the detection result. When the detection module detects that the coating aging degree exceeds a threshold, the heating module activates, driving the unidirectional stepping drive mechanism to slide the outer tube, the scraper assembly scrapes off the aged coating, and the material storage mechanism simultaneously lays fresh foil onto the scraped surface.

[0006] Preferably, the unidirectional stepping drive mechanism includes a push block fixedly disposed on the circumferential side of the outer tube, a first spring pin, a stop block fixedly disposed at the bottom of the first spring pin, and a shape memory alloy spring connected between the left end cap and the outer tube. The left end cap is also provided with a heater for heating the shape memory alloy spring. When the shape memory alloy spring is heated and contracts, it pulls the outer tube to slide to the left. The push block pushes the stop block to overcome the pressure of the elastic element and passes the stop block. When the shape memory alloy spring cools and stretches, the stop block is blocked by the push block under the action of the elastic element, preventing the outer tube from retracting to the right.

[0007] Preferably, the scraper assembly includes a scraper, the inner wall of which is fitted with the peripheral side of the outer tube, and the scraper has a three-layer composite structure, consisting of a working layer, a heat-conducting layer, and a wear compensation layer from the side closest to the outer tube to the side furthest from the outer tube.

[0008] Preferably, the working layer is a low-friction, wear-resistant material layer, the thermally conductive layer is a high-thermal-conductivity metal material layer, and the wear compensation layer is a shape memory alloy material layer; when the working layer wears, the wear compensation layer is electrically heated to shrink it, thereby driving the scraper to move closer to the outer tube.

[0009] Preferably, the heat-conducting layer and wear-compensating layer of the scraper, as well as the mounting ring, are provided with interconnected flow holes. The vacuum cavity is provided with a vacuum feed passage, one end of which is connected to the flow hole. When the working layer is worn out, the paste material is injected into the interface between the working layer and the heat-conducting layer through the vacuum feed passage and the flow hole by external pressure. After being heated and cured, a new working layer is formed.

[0010] Preferably, the storage mechanism includes a storage box, a foil strip wound inside the storage box, and a pressing mechanism, wherein the pressing mechanism includes a second spring pin and a pressure roller disposed at the bottom end of the second spring pin.

[0011] Preferably, the detection module includes a first transparent window and a second transparent window disposed on the vacuum cavity. A light source is disposed at the first transparent window, and a photoelectric sensor is disposed at the second transparent window. A comparator electrically connected to the photoelectric sensor is fixedly disposed on one side of the left end cover, and the output terminal of the comparator is electrically connected to the heating module.

[0012] Preferably, both the left and right end caps are fixedly provided with corrugated pipes between themselves and the outer tube.

[0013] Preferably, a collection box is provided at the bottom of the vacuum chamber, located below the scraper.

[0014] Preferably, the solid lubricating layer is a molybdenum disulfide coating or a graphite coating.

[0015] The present invention has the following beneficial effects: 1. This invention achieves in-situ scraping of the aged coating on the surface of the heat absorber and simultaneous renewal of the fresh light-absorbing surface. Specifically, it is achieved by setting an outer tube that can slide axially relative to the inner tube, a scraper fixed to the inner wall of the cavity, and a storage mechanism storing spare foil strips. The outer tube is driven to slide by the thermal contraction of the shape memory alloy spring, so that the scraper scrapes off the aged coating on the surface of the outer tube. At the same time, the friction force of the outer tube when it slides pulls the foil strip out from the storage mechanism and spreads it on the scraped surface. The segmented renewal of the heat absorber surface can be completed without stopping the machine or breaking the vacuum, which greatly reduces the operation and maintenance costs and ensures the continuous operation of the heat collection field. 2. This invention achieves low-friction scraping, rapid frictional heat dissipation, and automatic compensation for edge wear of the scraper. Specifically, the scraper is designed with a three-layer composite structure. The working layer uses a low-friction, wear-resistant material that directly contacts the outer tube coating. The heat-conducting layer uses a high-thermal-conductivity metal material to rapidly conduct frictional heat to areas far from the edge. The wear compensation layer uses a shape memory alloy material, which shrinks after the working layer wears out by being electrically heated, causing the scraper to move closer to the outer tube. This allows the scraper to simultaneously possess the three functions of low friction, high thermal conductivity, and wear compensation, extending the scraper's service life and ensuring the long-term stability of the scraping effect. 3. This invention enables online regeneration of the scraper's working layer in a vacuum environment. Specifically, interconnected flow holes are created inside the heat-conducting layer and wear-compensating layer of the three-layer scraper, as well as inside the mounting ring. A vacuum feedthrough connected to the flow holes is also provided in the vacuum chamber. When the working layer is worn out, a curable paste-like material is injected into the interface between the working layer and the heat-conducting layer through the vacuum feedthrough and flow holes under external pressure. After heating and curing, a new working layer is formed. The regeneration of the working layer can be completed without disassembling the scraper or breaking the vacuum, further extending the overall service life of the scraper.

[0016] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments 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.

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a cross-sectional structural diagram of the present invention; Figure 3 for Figure 2 A magnified schematic diagram of the local structure at point A; Figure 4 for Figure 2 A magnified schematic diagram of the local structure at point B; Figure 5 for Figure 2 A magnified schematic diagram of the local structure at point C; Figure 6 for Figure 2 A magnified schematic diagram of the local structure at point D; Figure 7 This is a schematic diagram of the internal structure of the cavity in this invention; Figure 8 for Figure 7 A schematic diagram of the cross-sectional structure; Figure 9 This is a schematic diagram of the mating structure of the inner and outer tubes of the present invention; Figure 10 This is a schematic diagram of the scraper and collection box of the present invention; Figure 11 This is a schematic diagram of the foil strip laying structure of the present invention.

[0019] The components represented by each number in the attached diagram are listed below: 1. Vacuum chamber; 2. Outer tube; 3. Inner tube; 4. Left end cap; 5. Right end cap; 6. Light source; 7. Comparator; 8. Vacuum feedthrough; 9. Bellows; 10. Scraper; 11. Heater; 12. Shape memory alloy spring; 13. Photoelectric sensor; 14. First transparent window; 15. Second transparent window; 16. Solid lubricant layer; 17. First spring pin; 18. Push block; 19. Stop block; 20. Second spring pin; 21. Storage box; 22. Foil strip; 23. Pressure roller; 24. Collection box; 25. Mounting ring; 26. Wear compensation layer; 27. Thermal conductive layer; 28. Working layer. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention 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.

[0021] In the description of this invention, it should be understood that the terms "upper," "middle," "outer," "inner," etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0022] Please see Figures 1-11 As shown, the present invention is a modular high-precision solar vacuum cavity structure for photothermal conversion, including a vacuum cavity 1 and an outer tube 2 disposed inside the vacuum cavity 1. An inner tube 3 is inserted inside the outer tube 2, and a solid lubricating layer 16 is disposed between the inner tube 3 and the outer tube 2. The outer tube 2 can slide axially relative to the inner tube 3.

[0023] Please combine Figures 1 to 4 The vacuum chamber 1 has a left end cap 4 and a right end cap 5 fixedly installed at both ends. The inner tube 3 extends through the left end cap 4 and the right end cap 5 to the outside of the vacuum chamber 1, connecting to an external heat transfer oil circulation pipeline. Inside the vacuum chamber 1 are a scraper assembly and a material storage mechanism. The scraper assembly scrapes off the aged coating on the surface of the outer tube 2, and the material storage mechanism provides fresh foil strip 22 to the scraped surface of the outer tube 2. The vacuum chamber 1 also has a unidirectional stepping drive mechanism for driving the outer tube 2 to slide unidirectionally. The vacuum chamber 1 is equipped with a detection module and a heating module. The detection module detects the degree of aging of the coating on the surface of the outer tube 2, and the heating module triggers the drive action based on the detection results.

[0024] Please combine Figures 2 to 4The unidirectional stepping drive mechanism includes several push blocks 18 fixedly disposed on the sides of the outer tube 2, a first spring pin 17, a stop block 19 fixedly disposed at the bottom of the first spring pin 17, and a shape memory alloy spring 12 connecting the left end cap 4 and the outer tube 2. The shape memory alloy spring 12 is made of nickel-titanium (NiTi) shape memory alloy wire with a nickel content of 49.5~51.0 at%. By adjusting the nickel content and heat treatment process, the austenitic phase transformation end temperature of the shape memory alloy spring 12 can be adjusted within the range of 80℃ to 120℃. In this embodiment, the nickel content is preferably 50.8 at%, and the austenitic phase transformation end temperature is 100℃. The push blocks 18 are equidistantly distributed along the axial direction of the outer tube 2. The left side of the push block 18 is a gentle slope, and the right side is a steep slope. The slope of the stop block 19 is adapted to the slope of the push block 18. The left end cap 4 is also equipped with a heater 11 for heating the shape memory alloy spring 12. The heater 11 is a PTC thermistor heater, which is annular and sleeved on the outer surface of the left end of the shape memory alloy spring 12. Corrugated tubes 9 are respectively provided between the left end cap 4 and the outer tube 2 and between the right end cap 5 and the outer tube 2. One end of the corrugated tube 9 is fixed to the inner wall of the end cap, and the other end is fixed to the outer cylindrical surface of the outer tube 2, so as to allow the outer tube 2 to slide axially while maintaining a vacuum seal.

[0025] Please combine Figure 2 and Figure 5 When the shape memory alloy spring 12 contracts due to heat, it pulls the outer tube 2 to slide to the left. The gentle slope of the push block 18 pushes the stop block 19 to overcome the pressure of the first spring pin 17 and lift it upward. After the push block 18 passes the stop block 19, the stop block 19 resets under the action of the first spring pin 17 and locks into the groove between adjacent push blocks 18. When the shape memory alloy spring 12 cools and stretches, the steep slope of the stop block 19 locks the steep slope of the push block 18, preventing the outer tube 2 from retracting to the right, thereby realizing the unidirectional stepping movement of the outer tube 2.

[0026] Please combine Figure 6 and Figure 10 The scraper assembly includes a mounting ring 25 and a scraper 10. The mounting ring 25 is fixedly disposed on the inner wall of the vacuum chamber 1, and the inner wall of the scraper 10 is in contact with the circumferential side of the outer tube 2. The scraper 10 has a three-layer composite structure, consisting of a working layer 28, a heat-conducting layer 27, and a wear compensation layer 26, arranged sequentially from the side closest to the outer tube 2 to the side furthest away from the outer tube 2. The working layer 28 is a diamond-like carbon or molybdenum disulfide composite coating, which has a low coefficient of friction and high hardness; the heat-conducting layer 27 is made of copper or silver, which has high thermal conductivity; and the wear compensation layer 26 is made of nickel-titanium shape memory alloy.

[0027] When the working layer 28 wears down due to long-term use, the wear compensation layer 26 is heated by electricity to cause it to shrink in phase. The wear compensation layer 26 drives the scraper 10 to move closer to the outer tube 2, compensating for the wear of the working layer 28 and ensuring that the scraper 10 always keeps in close contact with the surface of the outer tube 2.

[0028] Please combine Figure 6 and Figure 10 The heat-conducting layer 27 and wear-compensating layer 26 of the scraper 10, as well as the interior of the mounting ring 25, are all provided with interconnected flow holes. A vacuum feeder 8 is provided on the vacuum chamber 1. One end of the vacuum feeder 8 is located outside the vacuum chamber 1, and the other end communicates with the flow hole inside the mounting ring 25. The vacuum feeder 8 is a fluid-feed type vacuum sealing joint, with a stainless steel outer shell and an internal through-hole for fluid passage. A mounting flange matching the wall thickness of the vacuum chamber 1 is provided in the middle of the vacuum feeder 8. A vacuum seal is achieved between the mounting flange and the vacuum chamber 1 using a metal gasket or copper gasket, and it is fixed with bolts. A standard compression fitting or VCR fitting (not shown in the figure) is provided at the end of the vacuum feeder 8 located outside the vacuum chamber 1 for connecting to an external supply pipeline. The vacuum feeder 8, located inside the vacuum chamber 1, has an insertion interface that matches the flow hole inside the mounting ring 25. A sealing ring (not shown in the figure) is embedded in the insertion interface. When the inner end of the vacuum feeder 8 is inserted into the flow hole of the mounting ring 25, the sealing ring forms a seal between them, preventing the paste-like material from leaking into the vacuum chamber 1. The outer end of the vacuum feeder 8 is connected to a storage box 21, which stores a curable paste-like material. This paste-like material is a mixture of photothermal conversion nanoparticles and a high-temperature resistant binder.

[0029] When the working layer 28 is worn out, the paste material in the storage box 21 is injected into the interface between the working layer 28 and the heat-conducting layer 27 through the vacuum feed 8 and the flow hole by external pressure. Under the action of surface tension, the paste material spreads evenly along the interface to form a thin film, and then is heated by the heater 11 to solidify the binder in the paste material, forming a new working layer 28.

[0030] Please combine Figure 5 The storage mechanism includes a storage box 21, a foil strip 22 wound inside the storage box 21, and a pressing mechanism. The storage box 21 is fixedly installed on the top of the inner wall of the vacuum chamber 1, located to the left of the scraper 10. The foil strip 22 is an arc-shaped sheet with a pre-formed selective absorption coating, and its curvature matches the upper semi-circular surface of the outer tube 2. The pressing mechanism includes a second spring pin 20 and a pressure roller 23 disposed at the bottom end of the second spring pin 20. The pressure roller 23 rolls in contact with the surface of the foil strip 22, pressing the foil strip 22 tightly against the surface of the outer tube 2.

[0031] Please combine Figure 2 and Figure 8 The detection module includes a first transparent window 14 and a second transparent window 15 disposed on the vacuum chamber 1. A light source 6, which is an LED light source, is disposed at the first transparent window 14. A photoelectric sensor 13, which is a photodiode, is disposed at the second transparent window 15. A comparator 7, which is electrically connected to the photoelectric sensor 13, is fixedly disposed on one side of the left end cover 4. The output terminal of the comparator 7 is electrically connected to the heater 11.

[0032] The light beam emitted by the light source 6 passes through the first transparent window 14 and illuminates the surface of the outer tube 2. After being reflected by the surface of the outer tube 2, it passes through the second transparent window 15 and is received by the photoelectric sensor 13. When the selective absorption coating on the surface of the outer tube 2 undergoes aging and segregation due to photon irradiation, the scattering characteristics of the reflected light change, and the signal received by the photoelectric sensor 13 drifts. The comparator 7 compares the received signal with a preset threshold. When the signal drift exceeds the threshold, the comparator 7 controls the heater 11 to be energized, triggering the unidirectional stepping drive mechanism to operate.

[0033] Please combine Figure 2 , Figure 3 and Figure 7 A collection box 24 is provided at the bottom of the vacuum chamber 1, located below the scraper 10, for collecting the aged coating debris scraped off by the scraper 10. The inner wall of the collection box 24 is coated with a low-adhesion fluorocarbon coating to prevent the debris from sticking together.

[0034] The solid lubricating layer 16 is a molybdenum disulfide coating or a graphite coating. The outer wall of the inner tube 3 is coated with molybdenum disulfide, and the inner wall of the outer tube 2 is coated with graphite. The two form a sliding friction pair, which is non-volatile and maintenance-free in a vacuum environment.

[0035] Through the above technical solution, the scraper 10 is designed as a three-layer composite structure, which enables it to maintain low friction scraping while having the ability to automatically compensate for wear, solving the problem that a single material cannot simultaneously achieve wear resistance, heat conduction and wear compensation; through the flow hole provided in the heat conduction layer 27 and the mounting ring 25 and the vacuum feed 8, the vacuum feed 8 is a fluid-feeding vacuum sealing joint, its outer shell is made of stainless steel, and its interior is provided with a through hole for fluid to pass through; The vacuum feeder 8 has a mounting flange in the middle that matches the wall thickness of the vacuum chamber 1. The mounting flange and the vacuum chamber 1 are vacuum-sealed by a metal gasket and fixed by bolts. One end of the vacuum feeder 8 located outside the vacuum chamber 1 is equipped with a standard compression fitting for connecting to an external supply line. The other end of the vacuum feeder 8 located inside the vacuum chamber 1 is equipped with a plug-in interface that matches the flow hole in the mounting ring 25. An O-ring is embedded in the plug-in interface. When the inner end of the vacuum feeder 8 is inserted into the flow hole of the mounting ring 25, the O-ring forms a seal between the two, preventing the paste-like material from leaking into the vacuum chamber 1. Unlike conventional vacuum feedthroughs, the vacuum feedthrough 8 in this design uses a plug-in sealed connection with the flow hole inside the mounting ring 25, rather than a fixed connection. This is because the scraper 10 will undergo slight displacement during wear compensation, and a fixed connection would lead to stress concentration or seal failure in the pipeline. The plug-in connection, combined with an O-ring seal, allows for a slight relative displacement between the inner end of the vacuum feedthrough 8 and the flow hole of the mounting ring 25 while maintaining a seal. This adapts to changes in the position of the scraper 10, allowing for the online injection of a paste material after the working layer 28 has worn out and solidified to form a new working layer. This achieves online regeneration of the scraper 10 without disassembling the scraper 10 or disrupting the vacuum. The unidirectional stepping drive mechanism, consisting of shape memory alloy spring 12, push block 18, and stop block 19, enables intermittent unidirectional stepping movement of outer tube 2. In conjunction with scraper 10 and material storage mechanism, it completes the in-situ scraping of aged coating on the surface of outer tube 2 and the synchronous laying of fresh foil strip 22.

[0036] Working principle: The vacuum chamber 1 is connected to the vacuum pumping system through an external pipeline to maintain the internal vacuum environment; the two ends of the inner tube 3 are connected to the heat transfer oil circulation pipeline to remove the heat absorbed by the outer tube 2; the light source 6 and the photoelectric sensor 13 monitor the aging degree of the coating on the surface of the outer tube 2 in real time through a transparent window. Under normal heat collection conditions, sunlight shines through the concentrating system onto the selective absorption coating on the upper semi-circular surface of the outer tube 2. The coating absorbs light energy and converts it into heat energy. The heat is transferred to the inner tube 3 through the wall of the outer tube 2 and the solid lubricating layer 16, and then carried away by the heat-conducting oil inside the inner tube 3. Under long-term photon irradiation, the coating on the surface of the outer tube 2 gradually undergoes aging and segregation, resulting in changes in the reflected light signal. When the signal drift detected by the photoelectric sensor 13 exceeds the preset threshold of the comparator 7, the comparator 7 controls the heater 11 to be energized. The heater 11 heats the left end of the shape memory alloy spring 12, and the heat is conducted through the spring itself to raise the temperature of the entire shape memory alloy spring 12 above the phase transformation temperature. The shape memory alloy spring 12 undergoes a martensitic-to-austenitic phase transformation and contracts, pulling the outer tube 2 to slide a small step to the left; When the outer tube 2 slides to the left, the push block 18 on its surface pushes the stop block 19 to overcome the pressure of the first spring pin 17 and lifts it upward. After the push block 18 passes the stop block 19, the stop block 19 resets and gets stuck in the groove between the next push block 18. At the same time, the working layer 28 of the scraper 10 scrapes off the aged coating on the upper semi-circular surface of the outer tube 2, and the scraped debris falls into the collection box 24 at the bottom. At the same time, the frictional force of the outer tube 2 sliding to the left is transmitted to the foil strip 22 through the pressure roller 23, pulling out the fresh foil strip 22 from the storage box 21. After the foil strip 22 is pulled out from the arc-shaped outlet of the storage box 21, it adheres to the upper semi-circular surface of the outer tube 2 under the pressure of the pressure roller 23, covering the area scraped off by the scraper 10; When the heater 11 is de-energized, the shape memory alloy spring 12 cools and returns to its original length. However, because the steep slope of the stop 19 blocks the steep slope of the pusher 18, the outer tube 2 cannot retract to the right and remains in the new position. When the next signal drift exceeds the threshold, the above process is repeated, and the outer tube 2 continues to slide to the left by one step, realizing the segmented update of the coating on the surface of the outer tube 2. When the working layer 28 of the scraper 10 gradually wears down after long-term use, the wear compensation layer 26 is heated by electricity, causing it to shrink and move the scraper 10 as a whole towards the outer tube 2, thus compensating for the wear of the working layer 28. When the working layer 28 is completely worn out, the paste material in the storage box 21 is injected into the interface between the working layer 28 and the heat-conducting layer 27 through the vacuum feed 8 and the flow hole by external pressure. After the paste material is spread, it is heated and cured to form a new working layer 28, completing the online regeneration of the scraper 10. Through the above steps, the vacuum chamber 1 can automatically complete the removal of the aged coating on the surface of the outer tube 2, the laying of a new fresh foil strip 22, the wear compensation of the scraper 10, and the online regeneration of the working layer 28 without disrupting the vacuum or stopping the machine, achieving long-term stable operation of the heat absorber surface.

[0037] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0038] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A modular high-precision solar vacuum cavity structure for photothermal conversion, comprising a vacuum cavity (1), an outer tube (2) disposed inside the vacuum cavity, and an inner tube (3) passing through the outer tube, characterized in that: A solid lubricating layer (16) is provided between the inner tube (3) and the outer tube (2), and the outer tube (2) can slide axially relative to the inner tube; The vacuum chamber (1) is equipped with a scraper assembly and a storage mechanism. The scraper assembly is used to scrape off the aged coating on the outer tube surface, and the storage mechanism is used to provide fresh foil strip (22) to the scraped outer tube surface. The vacuum chamber (1) is also equipped with a unidirectional stepping drive mechanism for driving the outer tube to slide in a unidirectional stepping manner. The vacuum chamber (1) is equipped with a detection module and a heating module. The detection module is used to detect the aging degree of the coating on the surface of the outer tube, and the heating module is used to trigger the driving action according to the detection result. When the detection module detects that the coating aging exceeds the threshold, the heating module is activated, driving the unidirectional stepping drive mechanism to slide the outer tube (2), the scraper assembly scrapes off the aged coating, and the storage mechanism simultaneously lays fresh foil strips onto the scraped surface.

2. The modular high-precision solar vacuum cavity structure for photothermal conversion according to claim 1, characterized in that, The unidirectional stepping drive mechanism includes a push block (18) fixedly disposed on the periphery of the outer tube (2), a first spring pin (17), a stop block (19) fixedly disposed at the bottom of the first spring pin (17), and a shape memory alloy spring (12) connected between the left end cap (4) and the outer tube (2). The left end cap (4) is also provided with a heater (11) for heating the shape memory alloy spring (12). When the shape memory alloy spring (12) is heated and contracts, it pulls the outer tube (2) to slide to the left. The push block (18) pushes the stop block (19) to overcome the pressure of the elastic element and pass the stop block (19). When the shape memory alloy spring (12) cools and stretches, the stop block (19) is blocked by the push block (18) under the action of the elastic element, preventing the outer tube (2) from retracting to the right.

3. The modular high-precision solar vacuum cavity structure for photothermal conversion according to claim 1, characterized in that, The scraper assembly includes a scraper (10), the inner wall of which is attached to the circumferential side of the outer tube (2). The scraper (10) has a three-layer composite structure, consisting of a working layer (28), a heat-conducting layer (27), and a wear compensation layer (26) from the side closest to the outer tube (2) to the side furthest from the outer tube (2).

4. A modular high-precision solar vacuum cavity structure for photothermal conversion according to claim 3, characterized in that, The working layer (28) is a low-friction wear-resistant material layer, the thermally conductive layer (27) is a high thermal conductivity metal material layer, and the wear compensation layer (26) is a shape memory alloy material layer; When the working layer (28) wears, the wear compensation layer (26) is heated by electricity to shrink it, which drives the scraper (10) to move closer to the outer tube (2).

5. A modular high-precision solar vacuum cavity structure for photothermal conversion according to claim 3, characterized in that, The heat-conducting layer (27) and wear compensation layer (26) of the scraper (10) and the mounting ring (25) are all provided with interconnected flow holes. The vacuum cavity (1) is provided with a vacuum feed passage (8), and one end of the vacuum feed passage (8) is connected to the flow hole. When the working layer (28) is worn out, the paste material is injected into the interface between the working layer (28) and the heat-conducting layer (27) through vacuum feed (8) and flow hole by external pressure, and a new working layer (28) is formed after heating and curing.

6. A modular high-precision solar vacuum cavity structure for photothermal conversion according to claim 1, characterized in that, The storage mechanism includes a storage box (21), a foil strip (22) wound inside the storage box (21), and a pressing mechanism. The pressing mechanism includes a second spring pin (20) and a pressure roller (23) disposed at the bottom end of the second spring pin (20).

7. A modular high-precision solar vacuum cavity structure for photothermal conversion according to claim 1, characterized in that, The detection module includes a first transparent window (14) and a second transparent window (15) disposed on the vacuum cavity (1). A light source (6) is disposed at the first transparent window (14), and a photoelectric sensor (13) is disposed at the second transparent window (15). A comparator (7) electrically connected to the photoelectric sensor (13) is fixedly disposed on one side of the left end cover (4). The output end of the comparator (7) is electrically connected to the heating module.

8. A modular high-precision solar vacuum cavity structure for photothermal conversion according to claim 1, characterized in that, Both the left end cap (4) and the right end cap (5) are fixedly provided with corrugated pipes (9) between them and the outer tube (2).

9. A modular high-precision solar vacuum cavity structure for photothermal conversion according to claim 1, characterized in that, The vacuum chamber (1) has a collection box (24) located below the scraper (10) at its bottom.

10. A modular high-precision solar vacuum cavity structure for photothermal conversion according to claim 1, characterized in that, The solid lubricating layer (16) is a molybdenum disulfide coating or a graphite coating.

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