A rotary compression concentrating solar water splitting hydrogen production reactor

Abstract

This invention discloses a rotary compression concentrating solar water splitting hydrogen production reactor, relating to the field of energy conversion and storage technology, solving the problems of low efficiency and complex solid-phase reheating processes in traditional solar hydrogen production methods. The invention comprises several hydrogen production reactors connected in series on a shaft, used in conjunction with an external solar concentrator. Each hydrogen production reactor includes a front cover, a rear cover, a rotor, a reaction chamber, and a cam, with the front cover, reaction chamber, and rear cover connected sequentially. A rotor is located within the reaction chamber, dividing it into multiple chambers. The rotor is mounted on the shaft via a cam. The reaction chamber has quartz windows and vents; solar radiation collected by the solar concentrator is transmitted to the reaction chamber through the quartz windows and undergoes gas exchange through the vents. A cerium oxide oxygen carrier is mounted on the rotor. This invention significantly simplifies the reactor structure by optimizing the solid-phase reheating process of the oxygen carrier, achieving highly efficient conversion of solar energy to hydrogen energy.

Description

Technical Field

[0001] This invention relates to the field of energy conversion and storage technology, specifically to a rotary compression concentrating solar water splitting hydrogen production reactor. Background Technology

[0002] With the continuous growth of global energy demand and the increasing severity of environmental problems, the search for and development of clean and renewable energy technologies has become a research hotspot in the global energy sector. Hydrogen energy is a clean, efficient, and renewable energy source. Hydrogen is widely distributed and abundant in Earth's water bodies; hydrogen has a high calorific value, giving it an advantage in energy density; and its combustion product is only water, making it a zero-pollution energy source. Therefore, it has enormous potential for energy transition and carbon emission reduction. Traditional fossil fuel-based hydrogen production methods suffer from inefficiency, environmental pollution, and resource constraints; therefore, developing new clean energy hydrogen production technologies is particularly important.

[0003] Solar energy, as a nearly inexhaustible renewable energy source, is considered an important component of the future energy structure due to its clean and environmentally friendly characteristics. Thermochemical hydrogen production using solar energy—that is, the decomposition of water into hydrogen and oxygen through a solar-driven chemical reaction—is a technology with broad application prospects. Currently, there are several different approaches: photoelectrochemical decomposition, photocatalytic hydrogen production, and thermochemical hydrogen production. Photoelectrochemical decomposition utilizes a photoelectrochemical cell consisting of a photoanode and a cathode. In the presence of an electrolyte, electrons generated after the photoanode absorbs light flow to the cathode, where hydrogen ions in the water accept electrons to produce hydrogen. This requires a semiconductor photoanode, such as TiO2, but its efficiency still needs improvement. Photocatalytic hydrogen production uses a photocatalyst to catalyze the decomposition of water into hydrogen under certain light conditions, but its efficiency is currently low. Thermochemical hydrogen production uses a solar concentrator to generate a high-temperature heat source, driving an oxidation-reduction cycle in a metal oxide oxygen carrier. In this two-step reaction, water is decomposed into hydrogen and oxygen. However, the hydrogen-oxygen separation problem and the oxygen carrier reheating problem in traditional rotary solar hydrogen production reactors remain the main factors limiting hydrogen production efficiency.

[0004] Traditional solar thermochemical reactors typically employ fixed-bed or fluidized-bed designs, which have limitations in high-temperature operation and the circulation of solid oxygen carriers. For example, high-temperature operation requires reactor materials with excellent high-temperature resistance and good corrosion resistance, often leading to increased equipment costs. Simultaneously, the oxygen carrier reheating process is complex, resulting in low thermal efficiency, and the equipment structure and operation control are relatively complex, making large-scale application difficult. Summary of the Invention

[0005] To address the aforementioned problems of low efficiency and complex solid-phase regeneration processes in traditional solar-powered hydrogen production methods, this invention proposes a rotary compression concentrating solar water splitting hydrogen production reactor. By optimizing the solid-phase regeneration process of the oxygen carrier, this invention significantly simplifies the reactor structure and achieves highly efficient conversion of solar energy into hydrogen energy.

[0006] This invention proposes a rotary compression-type concentrating solar water splitting hydrogen production reactor, which specifically includes a front cover, a rear cover, a rotor, a shaft, a reaction chamber, a cam, and a solar concentrator; the front cover, reaction chamber, and rear cover are connected in sequence; a rotor is installed in the reaction chamber, and the rotor divides the cavity inside the reaction chamber into multiple chambers; the rotor is mounted on the shaft via a cam; a quartz window and a solar concentrator are installed on the reaction chamber, and the solar radiation collected by the solar concentrator is transmitted into the reaction chamber through the quartz window; four vents are provided on the reaction chamber for gas exchange; cerium oxide is installed on the rotor; several rotary compression-type concentrating solar water splitting hydrogen production reactors are connected in series on the shaft.

[0007] Furthermore, the rotor has a Reichstag triangle structure.

[0008] Furthermore, a seal is provided between the rotor apex and the inner wall of the reaction chamber.

[0009] Furthermore, each arcuate surface on the rotor is provided with a groove, and cerium oxide is disposed in the groove.

[0010] Furthermore, the cerium oxide is formed into a porous structure by pressing.

[0011] Furthermore, a sealing gear is provided on the front end cover, and the sealing gear is fitted on the shaft; an internal gear is provided on the rotor, and the internal gear meshes with the sealing gear.

[0012] Furthermore, the rotors of the several rotary compression concentrating solar water splitting hydrogen production reactors connected in series on the shaft are installed in different phases.

[0013] The beneficial effects of the rotary compression concentrating solar water splitting hydrogen production reactor described in this invention are as follows:

[0014] (1) The rotary compression type concentrated solar water splitting hydrogen production reactor of the present invention overcomes the problem of low efficiency of traditional solar hydrogen production methods. Under typical conditions (solar concentration ratio of 3000, reduction temperature of 1773K, oxidation temperature of 1073K, gas phase heat recovery efficiency of 0.9, mechanical energy recovery efficiency of 0.85, and molar flow ratio of scavenging gas to cerium oxide of 10), when the rotary reactor with Reilly triangular rotor and geometric compression ratio of 13 is used, the system can achieve the optimal solar energy to chemical energy conversion efficiency of 17%.

[0015] (2) The rotary compression concentrating solar water splitting hydrogen production reactor described in this invention overcomes the problem of difficult separation of hydrogen and oxygen. The rotary reactor is set to divide the entire oxidation-reduction cycle into an endothermic reduction reaction and an exothermic oxidation reaction. The four gas holes are set to inject different gases into the reaction chamber when the rotor rotates to different phases, so that hydrogen and oxygen are generated at different stages, thereby avoiding the mixing of hydrogen and oxygen.

[0016] (3) The rotary compression concentrating solar water splitting hydrogen production reactor described in this invention overcomes the problem of complex solid-phase reheating process. By connecting several hydrogen production reactors in series on the shaft, the rotors of the several hydrogen production reactors are mounted on the shaft by cams and are installed in different phases. When the gas expands, the rotor does work on the shaft, and when the gas is compressed, the shaft needs to do work on the rotor. Through energy exchange in different phase cycles, the internal gear and the sealing gear set on the rotor mesh, and the sealing gear drives the shaft to rotate, recovering the solid-phase sensible heat between the oxidation and reduction thermodynamic states in the form of mechanical energy, while not affecting the solar-fuel conversion efficiency. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0018] In the attached diagram:

[0019] Figure 1 This is a three-dimensional structural schematic diagram of a rotary compression concentrating solar water splitting hydrogen production reactor according to the present invention.

[0020] Figure 2 This is an exploded view of the structure of a rotary compression concentrating solar water splitting hydrogen production reactor according to the present invention.

[0021] Figure 3 This is a schematic diagram of the rotor structure of a rotary compression concentrating solar water splitting hydrogen production reactor according to the present invention.

[0022] Figure 4 This is a schematic diagram of the reaction chamber of a rotary compression concentrating solar water splitting hydrogen production reactor according to the present invention.

[0023] Figure 5 This is a schematic diagram of the shaft and cam structure of a rotary compression concentrating solar water splitting hydrogen production reactor according to the present invention.

[0024] Figure 6 This is a schematic diagram of the structure of the sealing gear in a rotary compression concentrating solar water splitting hydrogen production reactor according to the present invention.

[0025] Figure 7 This is a schematic diagram of the gas path in the reaction chamber of a rotary compression concentrating solar water splitting hydrogen production reactor according to the present invention.

[0026] Wherein: 1-front end cover; 2-rear end cover; 3-sealing gear; 4-rotor; 5-shaft; 6-reaction chamber; 7-quartz window; 8-scavenging port; 9-cam. Detailed Implementation

[0027] The technical solution of this invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of, and not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0028] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] Specific implementation method one: See Figures 1-7This embodiment is described in detail. The rotary compression concentrating solar water splitting hydrogen production reactor described in this embodiment specifically includes a front cover 1, a rear cover 2, a rotor 4, a shaft 5, a reaction chamber 6, a cam 9, and a solar concentrator. The front cover 1, reaction chamber 6, and rear cover 2 are connected sequentially. The rotor 4 is installed inside the reaction chamber 6, dividing the cavity inside the reaction chamber 6 into multiple chambers. The rotor 4 is mounted on the shaft 5 via the cam 9, allowing the rotor 4 to rotate within the reaction chamber 6 in an eccentric planetary motion. The rotor 4 and the reaction chamber 6 are in sliding contact, and the front and rear of the reaction chamber 6 are sealed by the front cover 1 and the rear cover 2. The volume of each chamber changes periodically with the rotation of rotor 4 due to the relative movement of rotor 4 and reaction chamber 6. Quartz window 7 and solar concentrator are installed on reaction chamber 6. Solar radiation collected by the solar concentrator is transferred to reaction chamber 6 through quartz window 7 to heat the reduction reaction. Four vents 8 are installed on reaction chamber 6 for gas exchange. Cerium oxide is installed on rotor 4 for the production of hydrogen and oxygen. Several rotary compression concentrating solar water splitting hydrogen production reactors are connected in series on shaft 5.

[0032] The rotor 4 has a Reilly triangle structure; the Reilly triangle prism structure of the rotor 4 and the elliptical shell of the reaction chamber 6 constitute this reactor. The vertex of the rotor 4 is in dynamic contact with the shell of the reaction chamber 6. The side surface of the rotor 4 is arc-shaped, forming three independent reaction chambers with the shell of the reaction chamber 6. The reaction chambers are sealed at the vertex of the rotor 4 away from the cerium oxide using a sealing element.

[0033] Each arc-shaped surface of the rotor 4 is provided with a groove, and cerium oxide is placed in the groove. The cerium oxide is made into a porous structure by pressing to improve the solar energy absorption efficiency.

[0034] A sealing gear 3 is installed on the front cover 1, and the sealing gear 3 is mounted on the shaft 5. An internal gear is installed on the rotor 4, and the internal gear meshes with the sealing gear 3. The rotors 4 of several rotary compression concentrating solar water splitting hydrogen production reactors connected in series on the shaft 5 are installed in different phases. When the gas expands in the reaction chamber 6 of one part of the hydrogen production reactor, the gas does work on the rotor 4. The rotor 4 drives the sealing gear 3 through the internal gear, and the sealing gear 3 drives the shaft 5 to rotate. This power is then transferred to the rotors 4 of another part of the hydrogen production reactor for gas compression. The energy exchange cycle is achieved through the different phases of the rotors 4.

[0035] The specific working principle of the rotary compression concentrating solar water splitting hydrogen production reactor described in this invention is as follows:

[0036] Among the various metal oxides studied, cerium was selected as the reference material for this reactor due to its rapid kinetics and abundant thermodynamic data. The redox cycle comprises an endothermic reduction reaction and an exothermic oxidation reaction, as shown in the following equations:

[0037]

[0038] like Figure 7 As shown, rotor 4 rotates clockwise. For cerium oxide on each curved surface of rotor 4, the rotation can be divided into three stages depending on the phase:

[0039] In the first stage, solar radiation is concentrated into the reaction chamber through quartz window 7. A groove on the rotor and cerium oxide are positioned directly opposite the quartz window; this is considered the initial phase. Nitrogen gas in the reaction chamber is compressed to its minimum volume for the entire cycle, and cerium oxide is reduced. During this stage, the reaction chamber reaches its highest pressure and temperature for the entire cycle. Subsequently, as rotor 4 rotates, the cerium oxide leaves the solar radiation irradiation area. Due to gas expansion, the temperature inside the reaction chamber drops to near the oxidation temperature, and the pressure drops to near ambient pressure. Nitrogen gas is introduced to purge the oxygen produced during the reduction stage.

[0040] In the second and third stages, the rotor rotates to the 2π / 3 and 4π / 3 phases, respectively, and excess steam is purged from the reaction chamber through two pairs of vents 8 on the reaction chamber 6. Under ambient pressure, the reduced cerium oxide is re-oxidized by the excess steam, and the generated hydrogen gas is purged out with the excess steam. Finally, before returning to the first stage, the reaction chamber is purged with pure nitrogen gas and heated to the reduction temperature using mechanical compression.

[0041] Correspondingly, the same cycle also occurs in the remaining two reaction chambers, with phase lags of 2π / 3 and 4π / 3, respectively.

[0042] The compression process has a contradictory effect on the reactor. While reaching equilibrium oxygen partial pressure makes cerium oxide easier to heat, it also reduces the degree of reduction. In reality, the reduction reaction reaches equilibrium more quickly during compression. The loss of oxygen released per unit mass of cerium oxide can be compensated for by increasing the rotation speed. Considering the convenience of heating through compression, a compression process is implemented before the reduction stage.

[0043] The compression process requires work input to the system, while the expansion process involves work done by the system on the environment. Cyclic energy exchange provides a method for recovering sensible heat in the solid phase between different thermodynamic states during the oxidation and reduction stages in the form of mechanical energy. Connecting multiple rotors operating at different phases to the same shaft 5 makes the cyclic energy exchange smoother. Therefore, the reactor can smoothly and periodically compress and expand, recovering solid-phase heat in the form of mechanical energy.

[0044] Under typical conditions (solar concentration ratio of 3000, reduction temperature of 1773 K, oxidation temperature of 1073 K, gas phase heat recovery efficiency of 0.9, mechanical energy recovery efficiency of 0.85, and molar flow ratio of purge gas to cerium dioxide of 10), the solar-fuel conversion efficiency is 13.2%. Efficiency can be significantly improved by increasing the solar concentration ratio, reduction temperature, gas phase and mechanical energy recovery efficiencies, and decreasing the molar flow ratio of purge gas to cerium dioxide.

[0045] This reactor is best suited for dish-type solar concentrators with a solar concentration ratio of 3000. If installed in a tower system with a solar concentration ratio of 1000, the efficiency will decrease significantly; while increasing the solar concentration ratio to above 3000 will only slightly improve the efficiency.

[0046] This reactor performs solid-phase heat recovery of cerium oxide without affecting its solar-fuel conversion rate.

[0047] In summary, the rotary compression concentrating solar water splitting hydrogen production reactor of this invention overcomes the low efficiency problem of traditional solar hydrogen production methods. Under typical conditions (solar concentration ratio of 3000, reduction temperature of 1773K, oxidation temperature of 1073K, gas phase heat recovery efficiency of 0.9, mechanical energy recovery efficiency of 0.85, and molar flow ratio of scavenging gas to cerium oxide of 10), using a rotary reactor with a Reilly triangular rotor 4 and a geometric compression ratio of 13, the system can achieve an optimal solar-to-chemical energy conversion efficiency of 17%. Furthermore, the rotary compression concentrating solar water splitting hydrogen production reactor of this invention overcomes the difficulty of hydrogen-oxygen separation by dividing the entire redox cycle into an endothermic reduction reaction and an exothermic oxidation reaction through the rotary reactor. By injecting different gases into the reaction chamber 6 through four air holes 8 when the rotor 4 rotates to different phases, hydrogen and oxygen are generated at different stages, thereby avoiding the mixing of hydrogen and oxygen. The rotary compression concentrating solar water splitting hydrogen production reactor of the present invention overcomes the problem of complex solid-phase reheating process. By connecting several hydrogen production reactors in series on the shaft 5, the rotors 4 of the several hydrogen production reactors are mounted on the shaft 5 through cams 9 and are mounted at different phases. When the gas expands, the rotor 4 does work on the shaft 5, and when the gas is compressed, the shaft 5 needs to do work on the rotor 4. Through energy exchange in different phase cycles, the internal gear and the sealing gear 3 set on the rotor 4 mesh, and the sealing gear 3 drives the shaft 5 to rotate, recovering the solid-phase sensible heat between the oxidation and reduction thermodynamic states in the form of mechanical energy, without affecting the solar-fuel conversion efficiency.

[0048] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the invention. They can also be reasonable combinations of the features described in the above embodiments. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A rotary compression-type concentrated solar water splitting hydrogen production reactor, characterized in that: It includes a front cover (1), a rear cover (2), a rotor (4), a shaft (5), a reaction chamber (6), a cam (9), and a solar concentrator; the front cover (1), the reaction chamber (6), and the rear cover (2) are connected in sequence; the rotor (4) is installed in the reaction chamber (6), and the rotor (4) divides the cavity inside the reaction chamber (6) into multiple chambers; the rotor (4) is mounted on the shaft (5) via the cam (9); the reaction chamber (6) is equipped with a quartz window (7) and a solar concentrator, and the solar radiation collected by the solar concentrator is transmitted to the reaction chamber (6) through the quartz window (7); the reaction chamber (6) is equipped with four vents (8), through which gas exchange takes place; cerium oxide is installed on the rotor (4); several rotary compression concentrating solar water splitting hydrogen production reactors are connected in series on the shaft (5); The rotors (4) of the several rotary compression concentrating solar water splitting hydrogen production reactors connected in series on the shaft (5) are installed in different phases; the rotors (4) rotate in the reaction chamber (6) to perform eccentric planetary motion. The rotor (4) and the reaction chamber (6) are in sliding contact. Through the relative movement of the rotor (4) and the reaction chamber (6), the volume of each chamber changes periodically with the rotation of the rotor (4).

2. The rotary compression concentrating solar water splitting hydrogen production reactor according to claim 1, characterized in that: The rotor (4) has a Reilly triangle structure.

3. The rotary compression concentrating solar water splitting hydrogen production reactor according to claim 1 or 2, characterized in that: A sealing element is provided between the apex of the rotor (4) and the inner wall of the reaction chamber (6).

4. The rotary compression concentrating solar water splitting hydrogen production reactor according to claim 2, characterized in that: Each arc-shaped surface of the rotor (4) is provided with a groove, and cerium oxide is provided in the groove.

5. The rotary compression concentrating solar water splitting hydrogen production reactor according to claim 1 or 4, characterized in that: The cerium oxide is formed into a porous structure by pressing.

6. The rotary compression concentrating solar water splitting hydrogen production reactor according to claim 1, characterized in that: The front cover (1) is provided with a sealing gear (3), which is mounted on the shaft (5); the rotor (4) is provided with an internal gear, which meshes with the sealing gear (3).

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