Tower type solar power generation system and method based on lunar soil particle moving bed heat exchange

Abstract

The invention belongs to the technical field of solar photo-thermal power generation, and discloses a tower type solar power generation system based on lunar soil particle moving bed heat exchange, which utilizes local materials of lunar soil to prepare solid heat storage particles as a heat transfer and heat storage medium, greatly reduces the mass and volume of the system and the cost and risk of transporting materials from the earth, and improves the energy efficiency. The efficient particle moving bed heat exchanger combining the particle receiver and the heat collector utilizes direct efficient contact heat exchange between solid particles and between the particles and a heat exchange working medium, has the characteristics of high heat exchange efficiency, small heat loss and compact structure, and is particularly suitable for space vacuum and microgravity environments; it is ensured that heat is reliably and stably transmitted to the Brayton cycle power generation system from concentrated solar energy, and power is generated through the Brayton cycle power generation system.

Description

Technical Field

[0001] The present invention belongs to the field of solar thermal power generation technology, and specifically relates to a tower-type solar power generation system and method based on heat exchange of a moving bed of lunar soil particles. Background Art

[0002] Establishing a permanent lunar base and conducting space exploration and interstellar colonization research requires a reliable lunar energy system. Due to the unique and extreme conditions on the moon, the long lunar nights and the high costs of transporting supplies from Earth are urgent challenges.

[0003] Space energy generation primarily involves chemical energy conversion, photoelectric conversion, and thermoelectric conversion, corresponding to space fuel cell power generation systems, photovoltaic cell power generation systems, and thermoelectric power generation systems, respectively. Space fuel cell power generation systems, among others, are subject to high manufacturing, maintenance, and regeneration costs, as well as safety and reliability issues. Photovoltaic cell power generation systems are currently the most widely used space power generation technology. However, due to their dependence on solar radiation, they are unable to provide power during the 14-day lunar night. Thermoelectric power generation systems, with their low power output of only a few hundred watts at most, are unable to meet large-scale electricity demand.

[0004] Due to the challenges of overcoming the Earth's gravity, low transportation efficiency, complex landing technology, and the cumulative risk costs, the current cost of lunar transportation is as high as $50,000 to $120,000 per kilogram, forcing humans to develop in-situ resource utilization technology to achieve sustainable lunar development. Summary of the Invention

[0005] The present invention provides a tower-type solar power generation system and method based on heat exchange of a moving bed of lunar soil particles, which solves the problems of energy supply during long lunar nights and the high cost of transporting materials from the Earth.

[0006] To achieve the above object, the present invention provides the following technical solutions: A tower solar power generation system based on heat exchange of a moving bed of lunar soil particles includes a heliostat field and a tower solar heat storage system. The tower solar heat storage system includes a particle receiver, a particle collector, a first storage tank, a moving bed heat exchanger, and a second storage tank connected in sequence. A particle circulation pipeline is connected between the second storage tank and the particle receiver. A closed Brayton cycle power generation system is connected to the moving bed heat exchanger through a fluid circulation pipeline. The heliostat field is arranged on one side of the tower solar heat storage system, and the reflected sunlight from the heliostat field is irradiated on the particle collector.

[0007] Preferably, a guide plate is provided inside the particle collector, and the guide plate is a staggered and continuously arranged tapered inverted V-shaped grid dynamic guide structure, and the dynamic guide structure has a spatial gradient characteristic in which the angle gradually decreases from top to bottom.

[0008] Preferably, the top of the dynamic guide structure adopts a 120° grid angle, and the grid angle is gradually reduced to 30° during the transition to the bottom.

[0009] Preferably, a particle flow regulating valve is provided between the first storage tank and the moving bed heat exchanger.

[0010] Preferably, the particle flow regulating valve controls the flow rate of the particles to be 0.05-0.1 m / s.

[0011] Preferably, the working fluid of the closed Brayton cycle power generation system is supercritical carbon dioxide.

[0012] Preferably, the heliostat field is composed of heliostats with equilateral hexagonal mirror shapes, and adopts a honeycomb seamless splicing layout.

[0013] A tower solar power generation method based on heat exchange in a moving bed of lunar soil particles comprises: during the lunar day, the heliostat field tracks the position of the sun to reflect sunlight onto the heat absorbing surface of a particle collector, and the compacted lunar soil particles enter through a particle receiver at the top of the tower, where they are heated by the light concentrated by the heliostat field and moved to a first storage tank to store the solar energy; during the lunar night when there is a lack of sunlight, when power is needed, the particles enter the moving bed heat exchanger from the first storage tank, exchange heat with the fluid in the fluid circulation pipe, fall into the second storage tank, and enter the particle receiver again through the particle circulation pipe to complete recycling; the fluid that has completed the heat exchange enters the closed Brayton cycle power generation system through the circulation pipe, and the closed Brayton cycle power generation system generates electricity.

[0014] Preferably, the porosity of the lunar soil particles after compaction is less than 0.1, and the particle size of the lunar soil particles is 0.1-1 mm.

[0015] Preferably, the steps for generating electricity in a closed Brayton cycle power generation system are as follows: the fluid compressed by the closed Brayton cycle power generation system compressor enters the moving bed heat exchanger through the fluid circulation pipeline, undergoes sufficient heat exchange with the lunar soil particles, and the fluid after heat exchange is then connected to the turbine inlet through the fluid circulation pipeline and expands to perform work. Finally, the turbine exhaust gas is pre-cooled in the regenerator and returns to the compressor to form a closed cycle.

[0016] Compared with the existing technology, the present invention has the following beneficial effects: the present invention provides a tower solar power generation system based on lunar soil particle moving bed heat exchange, and uses lunar soil to make solid heat storage particles as heat transfer and heat storage media, which greatly reduces the system's mass, volume and the cost and risk of transporting materials from the earth. The particle receiver and collector are combined with an efficient particle moving bed heat exchanger, which utilizes direct and efficient contact heat exchange between solid particles and between particles and heat exchange medium, and has the characteristics of high heat exchange efficiency, low heat loss and compact structure. It is particularly suitable for space vacuum and microgravity environment, ensuring that heat is reliably and stably transferred from concentrated solar energy to the Brayton cycle power generation system, and generating electricity through the Brayton cycle power generation system.

[0017] The heliostat field uses regular hexagonal heliostats. The regular hexagonal honeycomb arrangement can achieve seamless and dense paving, significantly saving scarce flat land on the moon. The hexagonal mirror surface is easier to concentrate in high cosine efficiency areas such as near the lunar equator, improving optical efficiency. The honeycomb structure can effectively disperse lunar dust accumulation and micrometeorite impact loads, effectively resisting the extreme environment of the moon.

[0018] The present invention uses compacted lunar soil particles as a heat storage medium. The lunar regolith soil, as an in-situ resource, has a higher thermal conductivity after specific treatment and can be heated to a higher temperature. It is a very suitable heat storage medium. Because it is easy to obtain and has abundant reserves, it does not require additional transportation from the earth, which significantly reduces costs.

[0019] The internal guide plate of the particle collector of the present invention adopts a tapered inverted V-shaped grid dynamic guide structure, which actively controls the particle flow rate and residence time by changing the angle. A large angle is used in the low-temperature zone of the inlet to increase the particle heating time. The grid angle is gradually reduced during the transition to the high-temperature zone of the outlet to accelerate the discharge of high-temperature particles and avoid sintering or heat loss caused by overheating. The geometric gradient design realizes precise control of the particle heating time and flow rate, further improving the heat transfer efficiency.

[0020] The present invention organically combines a solar thermal power generation system with an energy storage system to convert solar energy into thermal energy and store it in lunar soil particles. When power is needed at night, the heat is transferred to the sCO2 working fluid through a moving bed heat exchanger, and then converted into electrical energy through a closed Brayton cycle power generation system. This solves the problem of energy supply shortages during long lunar nights and achieves continuous and stable power supply.

[0021] The energy storage system of the present invention adopts a moving bed heat exchanger. Its gravity-driven particle flow characteristics enable it to achieve stable operation without an additional power device. Compared with traditional equipment, it has higher heat exchange efficiency, compact structure and space saving, safe and reliable operation, and is suitable for application scenarios with strict reliability requirements, such as lunar bases.

[0022] The present invention adopts a tower-type solar power generation system with a high concentration ratio, which can fully utilize the solar radiation intensity on the lunar surface, which is up to twice that of the Earth. The system adopts a modular design and can use lunar soil to manufacture the heliostat support structure on site. The lack of atmospheric scattering and cloud interference greatly improves the optical efficiency. The fact that the moon is only 1 / 6 of the Earth's size reduces the tower structure load and construction cost, has a scale effect, and can achieve greater power generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural diagram of the tower solar power generation system based on heat exchange of lunar soil particle moving bed of the present invention; Figure: 1. Closed Brayton cycle power generation system; 2. Fluid circulation pipeline; 3. Heliostat; 4. Particle receiver; 5. Particle collector; 6. First storage tank; 7. Second storage tank; 8. Moving bed heat exchanger; 9. Particle circulation pipeline; 10. Dynamic diversion structure; 11. Particle flow control valve. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0026] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0027] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0028] like Figure 1As shown, an embodiment of the present invention provides a tower solar power generation system based on lunar soil particle moving bed heat exchange, including a heliostat field and a tower solar heat storage system, the tower solar heat storage system includes a particle receiver 4, a particle collector 5, a first storage tank 6, a moving bed heat exchanger 8 and a second storage tank 7 connected in sequence, a particle circulation pipe 9 is connected between the second storage tank 7 and the particle receiver 4, and a closed Brayton cycle power generation system 1 is connected to the moving bed heat exchanger 8 through a fluid circulation pipe 2. The heliostat field is arranged on one side of the tower solar heat storage system, and the reflected sunlight of the heliostat field is irradiated on the particle collector 5.

[0029] The particle collector 5 is provided with a guide plate inside. The guide plate is a staggered and continuously arranged tapered inverted V-shaped grid dynamic guide structure 10. The dynamic guide structure 10 has a spatial gradient characteristic in which the angle gradually decreases from top to bottom.

[0030] The top of the dynamic guide structure 10 adopts a 120° grid angle, and the grid angle is gradually reduced to 30° during the transition to the bottom.

[0031] A particle flow regulating valve 11 is provided between the first storage tank 6 and the moving bed heat exchanger 8 .

[0032] The particle flow regulating valve 11 controls the flow rate of the particles to be 0.05-0.1 m / s.

[0033] The working fluid of the closed Brayton cycle power generation system 1 is supercritical carbon dioxide.

[0034] The heliostat field is composed of heliostats 3 with equilateral hexagonal mirror surfaces, and adopts a honeycomb seamless splicing layout.

[0035] Another embodiment of the present invention provides a tower-type solar power generation system based on lunar soil particle moving bed heat exchange, including a heliostat field, a tower-type solar thermal storage system, a closed Brayton cycle power generation system 1 and a fluid circulation pipeline 2. The heliostat field is composed of heliostats 3 with a mirror shape of an equilateral hexagon, and adopts a honeycomb seamless splicing layout to improve land utilization. The tower-type solar thermal storage system includes a particle receiver 4, a particle collector 5, a first storage tank 6, a second storage tank 7, a moving bed heat exchanger 8 and a particle circulation pipeline 9. The particle receiver 4 and the second storage tank 7 are connected by the particle circulation pipeline 9, and the closed Brayton cycle power generation system 1 and the moving bed heat exchanger 8 are connected by the fluid circulation pipeline 2.

[0036] The average particle size of the original lunar soil particles is 0.07 mm, the porosity is 0.33, and the thermal conductivity is 0.012 W / (m·K). After compaction treatment, the porosity is 0.1 and the thermal conductivity is 1 W / (m·K). After screening, lunar soil particles with a particle size of 0.1-1 mm are selected to realize the in-situ resource utilization of the moon.

[0037] The deflector plate within the particle collector comprises a series of staggered, continuous, tapered Λ-shaped dynamic flow guide structures 10. This metal grid exhibits a spatial gradient characteristic, with the angle gradually decreasing from top to bottom. The top utilizes a large 90°-120° grid angle, which gradually decreases to a final angle of 30° as it transitions toward the bottom. This geometric gradient design allows for precise control of particle heating time and flow rate, improving heat transfer efficiency. In other embodiments, the deflector plate may also utilize a tapered Λ-shaped dynamic flow guide structure 10, without limitation.

[0038] The first storage tank 6 is connected to the particle collector 5 and the moving bed heat exchanger 8, and is used to store high-temperature particles discharged from the particle collector 5, and discharge the particles into the moving bed heat exchanger 8 when necessary, thereby realizing heat energy supply during the lunar day.

[0039] The second storage tank 7 is connected to the moving bed heat exchanger 8 and the particle circulation pipe 9, and is used to store the lunar soil particles discharged from the moving bed heat exchanger 8 and discharge the particles into the particle circulation pipe 9, thereby realizing the recycling of the particles.

[0040] A particle flow regulating valve 11 is provided between the first storage tank 6 and the moving bed heat exchanger 8 to control the particle flow rate to 0.05-0.1 m / s, thereby ensuring a uniform particle flow rate in the moving bed heat exchanger 8 cross section.

[0041] The working fluid of the closed Brayton cycle power generation system 1 is supercritical carbon dioxide sCO2, which has high efficiency, compactness and strong adaptability to the lunar environment.

[0042] Another embodiment of the present invention provides a tower solar power generation method based on heat exchange of a moving bed of lunar soil particles. The operation process includes a heliostat field, a tower solar thermal storage system, a closed Brayton cycle power generation system 1, and a fluid circulation pipeline 2, as follows: Heliostat field: During lunar day, it precisely tracks the sun's position and reflects sunlight onto the heat-absorbing surface of the particle collector 5; Tower-type solar thermal storage system: During lunar daytime, compacted lunar soil particles enter through the particle receiver 4 at the top of the tower, are heated by the light concentrated by the heliostat field in the particle collector 5, and are moved to the first storage tank 6 to store solar energy. During the lunar night when there is a lack of sunlight, when power is needed, the particles enter the moving bed heat exchanger 8 from the first storage tank 6, undergo sufficient heat exchange with the sCO2 in the fluid circulation pipe 2, then fall into the second storage tank 7 and enter the particle receiver 4 again through the particle circulation pipe 9 to complete the recycling; Closed Brayton cycle power generation system 1: The sCO2 compressed by the compressor enters the moving bed heat exchanger 8 through the fluid circulation pipe 2, and undergoes sufficient heat exchange with the high-temperature lunar soil particles. The high-temperature and high-pressure sCO2 is then connected to the turbine inlet through the fluid circulation pipe 2 and expands to perform work. Finally, the turbine exhaust gas is pre-cooled in the regenerator and returned to the compressor, forming a closed cycle.

[0043] By organically combining the solar thermal power generation system with the energy storage system, solar energy is converted into thermal energy and stored in lunar soil particles. When power is needed at night, the heat is transferred to the sCO2 working fluid through the moving bed heat exchange and converted into electrical energy through the closed Brayton cycle power generation system1, thus solving the problem of energy supply shortage during long lunar nights and achieving continuous and stable power supply.

[0044] The energy storage system uses a moving bed heat exchanger 8. Its gravity-driven particle flow characteristics enable it to achieve stable operation without the need for additional power devices. Compared with traditional equipment, it has higher heat exchange efficiency, a compact structure that saves space, and safe and reliable operation. It is suitable for application scenarios with strict reliability requirements, such as lunar bases.

[0045] The tower-type solar power generation system has a high concentration ratio and can fully utilize the solar radiation intensity on the lunar surface, which is twice that of the Earth. The system adopts a modular design and can use lunar soil to manufacture the heliostat 3 support structure on site. The lack of atmospheric scattering and cloud interference greatly improves the optical efficiency. The fact that the moon is only 1 / 6 of the Earth's size reduces the tower structure load and construction cost, has economies of scale, and can achieve greater power generation.

[0046] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments and application fields. The above-mentioned specific embodiments are merely illustrative and instructive, and are not restrictive. A person skilled in the art, guided by the description, may devise various forms without departing from the scope of protection of the claims of the present invention, all of which fall within the scope of protection of the present invention.

Claims

1. A tower-type solar power generation system based on heat exchange using a moving bed of lunar soil particles, characterized in that: The invention comprises a heliostat field and a tower solar thermal storage system, wherein the tower solar thermal storage system comprises a particle receiver (4), a particle collector (5), a first storage tank (6), a moving bed heat exchanger (8) and a second storage tank (7) connected in sequence, a particle circulation pipeline (9) being connected between the second storage tank (7) and the particle receiver (4), and a closed Brayton cycle power generation system (1) being connected to the moving bed heat exchanger (8) via a fluid circulation pipeline (2). The heliostat field is arranged on one side of the tower solar thermal storage system, and the reflected sunlight of the heliostat field is irradiated on the particle collector (5).

2. The tower-type solar power generation system based on heat exchange of lunar soil particle moving bed according to claim 1 is characterized in that: A guide plate is provided inside the particle heat collector (5), and the guide plate is a staggered and continuously arranged tapered inverted V-shaped grid dynamic guide structure (10), and the dynamic guide structure (10) has a spatial gradient characteristic in which the angle gradually decreases from top to bottom.

3. The tower-type solar power generation system based on heat exchange of lunar soil particle moving bed according to claim 1 is characterized in that: The top of the dynamic guide structure (10) adopts a 120° grid angle, and in the process of transitioning to the bottom, the grid angle is gradually reduced to 30°.

4. The tower-type solar power generation system based on heat exchange of lunar soil particle moving bed according to claim 1 is characterized in that: A particle flow regulating valve (11) is provided between the first storage tank (6) and the moving bed heat exchanger (8).

5. The tower-type solar power generation system based on heat exchange of lunar soil particle moving bed according to claim 1 is characterized in that: The particle flow regulating valve (11) controls the flow rate of the particles to be 0.05-0.1 m / s.

6. The tower-type solar power generation system based on heat exchange of lunar soil particle moving bed according to claim 1 is characterized in that: The working fluid of the closed Brayton cycle power generation system (1) is supercritical carbon dioxide.

7. The tower-type solar power generation system based on heat exchange of lunar soil particle moving bed according to claim 1 is characterized in that: The heliostat field is composed of heliostats (3) with mirror surfaces in the shape of equilateral hexagons, and adopts a honeycomb seamless splicing layout.

8. A tower-type solar power generation method based on heat exchange of a moving bed of lunar soil particles, characterized in that: include: During the lunar day, the heliostat field tracks the position of the sun and reflects sunlight onto the heat absorbing surface of the particle collector (5). The compacted lunar soil particles enter through the particle receiver (4) at the top of the tower, are heated by the light concentrated by the heliostat field in the particle collector (5), and are moved to the first storage tank (6) to store the solar energy. During the lunar night when there is a lack of sunlight, when power supply is needed, the particles enter the moving bed heat exchanger (8) from the first storage tank (6), exchange heat with the fluid in the fluid circulation pipe (2), fall into the second storage tank (7), and enter the particle receiver (4) again through the particle circulation pipe (9) to complete the recycling. The fluid that has completed the heat exchange enters the closed Brayton cycle power generation system (1) through the circulation pipe (2), and the closed Brayton cycle power generation system (1) generates electricity.

9. The tower-type solar power generation method based on heat exchange of lunar soil particle moving bed according to claim 8 is characterized in that: The porosity of the lunar soil particles after compaction is less than 0.1, and the particle size of the lunar soil particles is 0.1-1mm.

10. The tower-type solar power generation method based on heat exchange of lunar soil particle moving bed according to claim 8 is characterized in that: The steps for generating electricity by the closed Brayton cycle power generation system (1) are as follows: the fluid compressed by the closed Brayton cycle power generation system (1) compressor enters the moving bed heat exchanger (8) through the fluid circulation pipe (2) to fully exchange heat with the lunar soil particles. The fluid after heat exchange is then connected to the turbine inlet through the fluid circulation pipe (2) and expands to perform work. Finally, the turbine exhaust gas is pre-cooled by the regenerator and returns to the compressor, forming a closed cycle.

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