Solar thermochemical reactor with layered cavity structure

Abstract

This disclosure provides a layered cavity structure solar thermochemical reactor, comprising: a secondary concentrator, a quartz window, an annular sealing ring, a feed channel, an annular inlet, a discharge channel, an outer partition, an inner partition, an insulating filling layer, a regenerative countercurrent pipe, a porous medium, and a shell. The annular sealing ring seals the connection between the secondary concentrator, the quartz window, and the shell; the secondary concentrator directs concentrated solar radiation into the shell through the quartz window; the outer and inner partitions radially divide the interior of the shell into a layered cavity structure, forming a reaction space; the insulating filling layer fills the gap between the reaction space and the shell; the annular inlet communicates with the regenerative zone of the reaction space, the regenerative countercurrent pipe is located within the regenerative zone, and the feed channel and discharge channel are located on the side of the shell, passing through the insulating filling layer and communicating with the annular inlet and the regenerative countercurrent pipe, respectively; the porous medium absorbs solar radiation to provide high-temperature conditions for the thermochemical reaction within the reaction space.

Description

Technical Field

[0001] This disclosure relates to the field of solar thermochemical high-temperature reactor technology, and more particularly to a solar thermochemical reactor with a layered cavity structure. Background Technology

[0002] Energy is the foundation upon which human society depends for survival and development. With the continuous development of society and the economy, the heavy reliance on and overexploitation of traditional fossil fuels has caused serious climate problems such as global warming and air pollution. Faced with the severe climate and environmental situation, developing clean and efficient alternative energy sources and energy-saving and emission-reduction technologies has become a broad consensus.

[0003] Among various energy sources, solar energy possesses enormous application potential due to its wide availability, clean and pollution-free nature, and large total volume. However, solar energy suffers from problems such as uneven spatial and temporal distribution, low average energy density, and difficulty in storage and transportation, which restrict its application and development. Therefore, various types of energy storage and energy complementarity technologies have emerged. Common energy storage methods include electric energy storage, sensible thermal energy storage, phase change thermal energy storage, and thermochemical technologies. Compared to conventional solar energy utilization technologies such as sensible thermal energy storage and phase change thermal energy storage, solar chemical technologies are receiving increasing attention due to their advantages such as strong dispatchability and flexible and diverse output forms.

[0004] Solar thermochemical technology utilizes high-temperature thermal energy obtained from concentrated solar power to drive endothermic chemical reactions, converting and storing fluctuating solar radiation energy into stable, high-grade chemical energy. This energy can be utilized at night or when solar radiation is insufficient, or transferred to other areas, freeing solar energy utilization from the constraints of time and space. It offers advantages such as low long-term energy storage losses and diversified output forms, improving the stability of solar energy storage and the continuity of its utilization. Currently, widely studied solar thermochemical processes mainly include: high-temperature solar water splitting for hydrogen production, high-temperature solar methane reforming, and medium- and low-temperature solar methanol cracking / reforming.

[0005] Direct solar thermochemical reactors, which directly heat the catalyst bed using concentrated solar energy, can serve as the core component of solar thermochemical energy storage, characterized by high heat collection temperatures. However, due to the influence of the solar concentrator, the radiative flux curve of the concentrated solar energy exhibits a Gaussian distribution, resulting in uneven distribution of solar intensity within the catalyst bed. Furthermore, the thermal conductivity of the catalyst support is typically insufficient for heat transfer between surfaces, leading to hot spots and significant temperature gradients within the catalyst bed, which substantially impacts reactor operation. Summary of the Invention

[0006] To address the problems of existing technologies, this disclosure provides a layered cavity structure solar thermochemical reactor. By adjusting the flow field distribution and flow characteristics of the thermochemical reactor, and optimizing the reactor design and operating parameters, the heat transfer and thermochemical reaction processes within the thermochemical reactor are coordinated, thereby improving the efficiency and reliability of the chemical reaction and maximizing the utilization of solar energy.

[0007] This disclosure provides a layered cavity structure solar thermochemical reactor, comprising: a secondary concentrator, a quartz window, an annular sealing ring, a feed channel, an annular inlet, a discharge channel, an outer partition, an inner partition, an insulating filling layer, a regenerative countercurrent pipe, a porous medium, and a shell. The annular sealing ring seals the connection between the secondary concentrator, the quartz window, and the shell. The secondary concentrator directs concentrated solar radiation into the shell through the quartz window. The outer and inner partitions divide the interior of the shell radially into a layered cavity structure, forming a reaction space. From the outside in, the reaction space consists of a regenerative zone, a main reaction zone, and a reaction deepening zone. The insulating filling layer fills the gap between the reaction space and the shell. The annular inlet communicates with the regenerative zone, and the regenerative countercurrent pipe is located within the regenerative zone. The feed channel and discharge channel are located on the side of the shell and pass through the insulating filling layer, respectively communicating with the annular inlet and the regenerative countercurrent pipe. The porous medium absorbs solar radiation to provide high-temperature conditions for the thermochemical reactions occurring within the reaction space.

[0008] According to embodiments of this disclosure, reactants enter the regenerating zone through the feed channel and annular inlet for preheating, then flow counter-currently along the outer partition to the radiation receiving surface of the reaction space near the quartz window, where a thermochemical reaction occurs in the main reaction zone. They then flow forward along the inner partition to the end of the reaction space away from the quartz window, where the thermochemical reaction is deepened in the reaction deepening zone. The high-temperature products generated by the thermochemical reaction exchange heat with the nearby porous medium and reactants in the feed channel through the regenerating counter-current pipe, preheating the reactants entering the reaction space. Finally, low-temperature products are output through the discharge channel.

[0009] According to embodiments of this disclosure, the solar radiation gathered by the secondary concentrator exhibits a Gaussian distribution; the porous medium includes a first porous medium, a second porous medium, and a third porous medium, with the pore density of the first porous medium, the pore density of the second porous medium, and the pore density of the third porous medium decreasing sequentially; the first porous medium is located near the regenerating counterflow pipe to absorb solar radiation of a first radiation density and the residual heat of high-temperature products in the regenerating counterflow pipe, providing heat for preheating the reactants; the second porous medium is located near the outer partition plate to absorb solar radiation of a second radiation density to drive the thermochemical reaction; the third porous medium is located near the inner partition plate to absorb solar radiation of a third radiation density to deepen the thermochemical reaction; wherein, the first radiation density, the second radiation density, and the third radiation density increase sequentially.

[0010] According to embodiments of this disclosure, the porous medium material includes foamed metal material.

[0011] According to embodiments of this disclosure, the reaction occurring in the reactor is an endothermic chemical reaction, and the reactants are a mixture of methane and water vapor or carbon dioxide. The mixture of methane and water vapor undergoes a wet reforming reaction in the reaction space, and the mixture of methane and carbon dioxide undergoes a dry reforming reaction in the reaction space; or, the reactants are a mixture of methanol and water vapor or carbon dioxide, and the mixture of methanol and water vapor undergoes a wet reforming reaction in the reaction space, and the mixture of methanol and carbon dioxide undergoes a dry reforming reaction in the reaction space; or, the reactant is methanol, and methanol undergoes a methanol cracking reaction in the reaction space; or, the reactant is water vapor, and water vapor undergoes a high-temperature water decomposition reaction to produce hydrogen in the reaction space.

[0012] According to embodiments of this disclosure, the secondary concentrator employs a rotating parabolic mirror, which is mirror-polished and coated with a reflective coating.

[0013] According to embodiments of this disclosure, the quartz window is made of a high-temperature resistant and high-transmittance material; the annular sealing ring is made of a high-temperature resistant material; and the insulation filling layer is made of a high-temperature resistant insulation material.

[0014] According to embodiments of this disclosure, the high-temperature resistant and high-transmittance material includes quartz glass or high-silica glass; the high-temperature resistant material includes flexible graphite material or metal material; and the high-temperature resistant insulation material includes aluminum silicate fiber insulation material, rock wool material, or high-temperature glass wool material.

[0015] The solar thermochemical reactor with a layered cavity structure provided according to the embodiments of this disclosure has at least the following beneficial effects:

[0016] The shell is divided into a layered cavity structure by outer and inner partitions, forming a regenerating zone, a main reaction zone, and a reaction deepening zone. A regenerating counterflow pipe is set in the outermost regenerating zone, which can recover and utilize the sensible heat of high-temperature products to preheat low-temperature reactants. This significantly reduces the loss of sensible heat energy from solar energy conversion to reactants, maximizes the utilization of solar radiation heat energy, and effectively improves the efficiency of thermochemical reactions.

[0017] By placing porous media with progressively decreasing pore density near the regenerating zone, the main reaction zone, and the reaction deepening zone, the absorption of solar radiation with different radiation densities is achieved. This enables the coordinated utilization and matching of radiant energy at each stage, effectively adjusting the distribution of the flow field and chemical field within the reactor. This helps improve the matching and coordination of the light, heat, and chemical physical fields, making the absorption and conversion of high-concentration-ratio radiant energy in the reactor more rational and efficient, and reducing the irreversibility of the thermochemical process. Attached Figure Description

[0018] Figure 1 A cross-sectional view of a solar thermochemical reactor with a layered cavity structure provided in an embodiment of the present disclosure is shown schematically.

[0019] Figure 2 The diagram schematically illustrates the overall structure of a solar thermochemical reactor with a layered cavity structure provided in an embodiment of this disclosure.

[0020] Figure 3 The schematic diagram illustrates the principle of a layered cavity structure solar thermochemical reactor receiving uneven solar radiation, as provided in an embodiment of this disclosure. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0023] In this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0024] In the description of this disclosure, it should be understood that the terms "longitudinal", "length", "circumferential", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the subsystem or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0025] Throughout the accompanying drawings, identical elements are represented by the same or similar reference numerals. Conventional structures or constructions have been omitted where they may cause confusion in understanding this disclosure. Furthermore, the shapes, dimensions, and positional relationships of the components in the drawings do not reflect actual size, scale, or actual positional relationships. Additionally, any reference numerals placed between parentheses in the claims should not be construed as limiting the claims.

[0026] Similarly, to simplify this disclosure and aid in understanding one or more of the various aspects of the disclosure, in the above description of exemplary embodiments of the present disclosure, various features of the present disclosure are sometimes grouped together in a single embodiment, figure, or description thereof. The use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refers to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present disclosure. 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.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] This disclosure provides a layered cavity structure solar thermochemical reactor. The reactor's flow field structure is designed using the "light-dependent flow" method to improve the multi-energy conversion characteristics of radiation, heat, and chemical energy during the solar thermochemical conversion process. It also makes full use of the high-temperature heat energy of the reaction products to preheat the low-temperature reactants, thereby maximizing the utilization of solar radiation heat energy.

[0029] The layered cavity structure solar thermochemical reactor provided in the embodiments of this disclosure will be described in detail below with reference to the specific accompanying drawings.

[0030] Figure 1 A cross-sectional view of a solar thermochemical reactor with a layered cavity structure provided in an embodiment of the present disclosure is shown schematically.

[0031] Figure 2 The diagram schematically illustrates the overall structure of a solar thermochemical reactor with a layered cavity structure provided in an embodiment of this disclosure.

[0032] like Figure 1 and Figure 2As shown, the layered cavity structure of the solar thermochemical reactor includes: a secondary concentrator 1, a quartz window 2, a shaped sealing layer 3, a feed channel 4, an annular inlet 5, a discharge channel 6, an outer partition 7, an inner partition 8, a thermal insulation filling layer 9, a reheat counterflow pipe 10, a porous medium 11, and an outer shell 12.

[0033] The outer shell 12 serves as the cavity of the layered cavity structure of the solar thermochemical reactor, and its shape can be a hollow cylinder. One end of the outer shell 12 is open, while the other parts are sealed. A quartz window 2 is located at the opening of the outer shell 12. The output end of the secondary concentrator 1 is connected to and aligned with the quartz window 2. An annular sealing ring 3 seals the connection between the secondary concentrator 1, the quartz window 2, and the outer shell 12, isolating the interior of the outer shell 12 from the outside environment, providing a sealed space for the thermochemical reaction, and preventing leakage of reactants and products. The secondary concentrator 1 directs the concentrated solar radiation into the outer shell 12 through the quartz window 2. The solar radiation concentrated by the secondary concentrator 1 has a Gaussian distribution, providing energy for the thermochemical reaction.

[0034] The outer partition 7 and the inner partition 8 divide the interior of the outer shell 12 into a layered cavity structure along the radial direction of the outer shell 12, forming a reaction space. The reaction space consists of a regenerating zone, a main reaction zone, and a reaction deepening zone from the outside to the inside. The heat-insulating filling layer 9 fills the gap between the reaction space and the outer shell 12, providing heat insulation for the reaction space. The annular inlet 5 is connected to the regenerating zone, and the regenerating counterflow pipe 10 is located within the regenerating zone. The feed channel 4 and the discharge channel 6 are located on the side of the outer shell 12 and pass through the heat-insulating filling layer 9, respectively connecting to the annular inlet 5 and the regenerating counterflow pipe 10.

[0035] The porous medium 11 is used to absorb the solar radiation gathered by the secondary concentrator 1, providing high-temperature conditions for the thermochemical reactions that occur in the reaction space.

[0036] Figure 3 The schematic diagram illustrates the principle of a layered cavity structure solar thermochemical reactor receiving uneven solar radiation, as provided in an embodiment of this disclosure.

[0037] like Figure 3 As shown, the reactants enter the regenerating zone through the feed channel 4 and the annular inlet 5 for preheating, and then flow counter-currently along the outer partition 7 to the radiation receiving surface of the reaction space near the quartz window 2. Thermochemical reaction occurs in the main reaction zone, and then flows forward along the inner partition 8 to the end of the reaction space away from the quartz window 2. The thermochemical reaction is deepened in the reaction deepening zone. The high-temperature products generated by the thermochemical reaction exchange heat with the nearby porous medium 11 and the reactants in the feed channel 4 through the regenerating counter-current pipe 10 to preheat the reactants entering the reaction space. Finally, the low-temperature products are output through the discharge channel 6.

[0038] Continue reading Figures 1-3In the embodiments disclosed herein, the reaction space is divided into a regenerating zone, a main reaction zone, and a reaction deepening zone according to their different functions, and the porous media 11 arranged in different zones are different.

[0039] The porous medium 11 includes a first porous medium, a second porous medium, and a third porous medium, with the pore density of the first porous medium decreasing sequentially. The first porous medium is located near the regenerating countercurrent pipe 10 (regenerating zone) to absorb solar radiation of a first radiation density and residual heat from the high-temperature products within the regenerating countercurrent pipe 10, providing heat for preheating the reactants. The second porous medium is located near the outer partition 7 (main reaction zone) to absorb solar radiation of a second radiation density to drive the thermochemical reaction. The third porous medium is located near the inner partition 8 (reaction deepening zone) to absorb solar radiation of a third radiation density to deepen the thermochemical reaction. The first, second, and third radiation densities increase sequentially.

[0040] In other words, in the regenerating zone, the first porous medium near the annular inlet 5 absorbs low-density concentrated radiation and residual heat from the products in the regenerating countercurrent pipe 10, which is used for preheating the reactants. In the main reaction zone, the second porous medium near the outer partition 7 absorbs high-density concentrated radiation, which is used to drive the thermochemical reaction. In the reaction deepening zone, the third porous medium near the inner partition 8 absorbs peak concentrated radiation, which further deepens the thermochemical reaction under high-temperature conditions. Based on this, the coordinated utilization and matching of radiant energy at each stage can be achieved.

[0041] Furthermore, as an optional implementation, the first porous medium has a pore density of 40–50 PPI (Pores per inch), the second porous medium has a pore density of 35–40 PPI, and the third porous medium has a pore density of 30–35 PPI. The porous medium 11 is made of foamed metal material. Foamed metal with a pore density of 40–50 PPI is used near the reheat countercurrent pipe 10 to improve the absorption of low-density radiation, thereby increasing the utilization rate of solar radiation energy. Foamed metal with a pore density of 35–40 PPI is used in the medium radiation density zone near the outer partition 7, and foamed metal with a pore density of 30–35 PPI is used in the high radiation density zone near the inner partition 8. This effectively absorbs solar radiation energy while improving the penetration ability of radiation, promoting chemical reactions deep within the reactor.

[0042] As an optional implementation, the secondary concentrator 1 employs a rotating parabolic reflector. This reflector is mirror-polished and coated with a reflective coating, enabling adjustment of the concentrated radiation distribution. The quartz window 2 is made of a high-temperature resistant, high-transmittance material, which can include quartz glass or high-silica glass. Generally, the high-temperature resistant, high-transmittance material has a transmittance greater than 90% and an impurity content less than 0.0001%, reducing radiation loss. The annular sealing ring 3 is made of a high-temperature resistant material, which can include flexible graphite or metal, ensuring the airtightness of the reaction space. The thermal insulation layer 9 comprises a high-temperature resistant insulation material, which can be aluminum silicate fiber insulation, rock wool, or high-temperature glass wool, reducing heat loss.

[0043] In this embodiment, the reaction occurring within the reactor is an endothermic chemical reaction. The endothermic chemical reaction may include: the reactants being a mixture of methane and water vapor or carbon dioxide; the mixture of methane and water vapor undergoing a wet reforming reaction in the reaction space, or the mixture of methane and carbon dioxide undergoing a dry reforming reaction in the reaction space. Alternatively, the reactants are a mixture of methanol and water vapor or carbon dioxide; the mixture of methanol and water vapor undergoes a wet reforming reaction in the reaction space, or the mixture of methanol and carbon dioxide undergoes a dry reforming reaction in the reaction space. Alternatively, the reactant may be methanol, which undergoes a methanol cracking reaction in the reaction space. Alternatively, the reactant may also be water vapor, which undergoes a high-temperature water decomposition reaction to produce hydrogen in the reaction space.

[0044] It should be noted that the structural parameters of the reactor can be adjusted according to the actual thermochemical reaction and the solar radiation energy received.

[0045] It should be noted that in the actual use of the layered cavity structure solar thermochemical reactor, the layered cavity structure solar thermochemical reactor is fixed in place. It can be placed on the focal plane of the dish collector and change along with the incident angle of sunlight.

[0046] In summary, the layered cavity structure solar thermochemical reactor provided in this disclosure utilizes a regenerative method to recover and reuse the sensible heat of high-temperature products for preheating low-temperature reactants. This significantly reduces the loss of sensible heat energy from solar energy conversion into reactants, maximizes the utilization of solar radiation heat energy, and effectively improves the efficiency of thermochemical reactions. Furthermore, the layered cavity structure of the solar thermochemical reactor achieves step-by-step coordinated utilization and matching of radiant energy, effectively adjusting the distribution of the flow field and chemical field within the reactor. This helps improve the matching and coordination of the light, heat, and chemical physical fields, making the absorption and conversion process of high-concentration-ratio radiant energy more rational and efficient, and reducing the irreversibility of the thermochemical process.

[0047] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of this disclosure. It should be understood that the above descriptions are merely specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A layered cavity structure solar thermochemical reactor, comprising: The secondary concentrator (1), quartz window (2), annular sealing ring (3), feed channel (4), annular inlet (5), discharge channel (6), outer partition (7), inner partition (8), insulation filling layer (9), reheat counterflow pipe (10), porous medium (11), and outer shell (12), wherein: The annular sealing ring (3) is used to seal the connection between the secondary concentrator (1), the quartz window (2) and the outer shell (12); the secondary concentrator (1) is used to direct the concentrated solar radiation into the outer shell (12) through the quartz window (2); The outer partition (7) and the inner partition (8) divide the interior of the outer shell (12) into a layered cavity structure along the radial direction of the outer shell (12), forming a reaction space. Along the radial direction of the outer shell (12), the reaction space consists of a regenerating zone, a main reaction zone, and a reaction deepening zone from the outside to the inside. The heat insulation filling layer (9) fills the gap between the reaction space and the outer shell (12). The annular inlet (5) is connected to the regenerating zone. The regenerating counterflow pipe (10) is located in the regenerating zone. The feed channel (4) and the discharge channel (6) are located on the side of the outer shell (12) and pass through the heat insulation filling layer (9) to connect with the annular inlet (5) and the regenerating counterflow pipe (10) respectively. The porous medium (11) is used to absorb the solar radiation to provide high-temperature conditions for the thermochemical reaction that occurs in the reaction space; The reactants enter the regenerating zone through the feed channel (4) and the annular inlet (5) for preheating, and then flow counter-currently along the outer partition (7) to the radiation receiving surface of the reaction space near the quartz window (2). Thermochemical reaction is carried out in the main reaction zone, and then flows forward along the inner partition (8) to the end of the reaction space away from the quartz window (2). The thermochemical reaction is deepened in the reaction deepening zone. The high-temperature product generated by the thermochemical reaction exchanges heat with the nearby porous medium (11) and the reactants in the feed channel (4) through the regenerating counter-current pipe (10) to preheat the reactants entering the reaction space. Finally, the low-temperature product is output through the discharge channel (6).

2. The solar thermochemical reactor with a layered cavity structure according to claim 1, wherein, The solar radiation collected by the secondary concentrator (1) has a Gaussian distribution; The porous medium (11) includes a first porous medium, a second porous medium and a third porous medium, wherein the pore density of the first porous medium, the pore density of the second porous medium and the pore density of the third porous medium decrease sequentially. The first porous medium is located near the regenerating counterflow pipe (10) to absorb the solar radiation of the first radiation density and the residual heat of the high-temperature products in the regenerating counterflow pipe (10), and to provide heat for the preheating of the reactants; The second porous medium is disposed near the outer partition (7) to absorb solar radiation of the second radiation density to drive the thermochemical reaction; The third porous medium is located near the inner partition (8) to absorb solar radiation of the third radiation density, thereby deepening the thermochemical reaction; The first radiation density, the second radiation density, and the third radiation density increase sequentially.

3. The solar thermochemical reactor with a layered cavity structure according to claim 2, wherein, The porous medium (11) is made of foamed metal material.

4. The solar thermochemical reactor with a layered cavity structure according to claim 1, wherein, The reactions occurring within the reactor are endothermic chemical reactions, including: The reactants are a mixture of methane and water vapor or carbon dioxide. The mixture of methane and water vapor undergoes a wet reforming reaction in the reaction space, and the mixture of methane and carbon dioxide undergoes a dry reforming reaction in the reaction space. Alternatively, the reactants are a mixture of methanol and water vapor or carbon dioxide, wherein the mixture of methanol and water vapor undergoes a wet reforming reaction in the reaction space, and the mixture of methanol and carbon dioxide undergoes a dry reforming reaction in the reaction space. Alternatively, the reactant is methanol, which undergoes a methanol cracking reaction in the reaction space; Alternatively, the reactant is water vapor, which undergoes a high-temperature water decomposition reaction to produce hydrogen in the reaction space.

5. The solar thermochemical reactor with a layered cavity structure according to claim 1, wherein, The secondary concentrator (1) is a rotating parabolic reflector, which is mirror polished and coated with a reflective coating.

6. The solar thermochemical reactor with a layered cavity structure according to claim 1, wherein, The quartz window (2) is made of a high-temperature resistant and high-transmittance material; the annular sealing ring (3) is made of a high-temperature resistant material. The material of the thermal insulation filling layer (9) includes high-temperature resistant thermal insulation material.

7. The solar thermochemical reactor with a layered cavity structure according to claim 6, wherein, The high-temperature resistant and high-transmittance material includes quartz glass or high-silica glass; the high-temperature resistant material includes flexible graphite material or metal material; the high-temperature resistant insulation material includes aluminum silicate fiber insulation material, rock wool material, or high-temperature glass wool material.

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