Chemical looping combustion air reactor and chemical looping combustion device

Abstract

The chemical looping combustion air reactor comprises a conveying channel, and the conveying channel comprises a mixing chamber, a separation chamber and a fly ash chamber which are communicated with one another in the ascending direction of particulate matter; the chemical looping combustion air reactor further comprises membrane type water cooling walls arranged on the heating wall faces of the mixing chamber and the separation chamber, a bare tube water cooling wall arranged on the heating wall face of the fly ash chamber and a screen type radiation heat exchanger arranged on the top of the fly ash chamber.

Description

Technical Field

[0001] This article relates to chemical chain combustion technology, and more particularly to a chemical chain combustion air reactor and a chemical chain combustion device. Background Technology

[0002] Chemical looping combustion is a revolutionary technology for CO2 emission reduction. It relies on the reaction, migration, and regeneration of oxygen carriers between a fuel reactor and an air reactor to achieve indirect oxidation of fuel and release of heat energy, thereby achieving efficient carbon dioxide capture at the source. The air reactor is not only used for oxygen carrier regeneration but also undertakes the tasks of system heat release and heat exchange. Its internal structure typically incorporates various heating surfaces to efficiently transfer heat to the water-steam system.

[0003] Currently, the design experience of circulating fluidized bed boilers is often used as a reference for air reactors in engineering. The main features of the layout scheme include: screen heat exchangers are evenly distributed in the vertical direction, the fly ash area is used as the main anti-wear zone, and thickened tubes and anti-wear fins are used to enhance the structure. However, when applied to chemical combustion chain devices, this leads to problems such as poor adaptability of the layout scheme, frequent wear failures, and uneven distribution of heat exchange capacity. Summary of the Invention

[0004] This application provides a chemical looping combustion air reactor and a chemical looping combustion device, which can match the arrangement of the heating surface with the gas-solid flow and thermal environment, thereby improving the heat transfer efficiency and structural stability of the entire system.

[0005] This application provides a chemical looping combustion air reactor, comprising: a conveying channel, wherein the conveying channel includes a mixing chamber, a separation chamber, and a fly ash chamber that are interconnected along the upward direction of the particulate matter; the particulate matter concentration and particle size of the mixing chamber, the separation chamber, and the fly ash chamber decrease sequentially; The chemical loop combustion air reactor also includes membrane water-cooled walls on the heated walls of the mixing chamber and the separation chamber, bare tube water-cooled walls on the heated walls of the fly ash chamber, and a screen-type radiant heat exchanger on the top of the fly ash chamber.

[0006] In one exemplary embodiment, the heated surface of the membrane water-cooled wall has a wear-resistant layer.

[0007] In one exemplary embodiment, the surface hardness of the heated surfaces of the mixing chamber and the separation chamber is not less than HRC60, and the thickness of the wear-resistant layer is not less than 3 mm.

[0008] In one exemplary embodiment, the bare tube water-cooled wall is vertically disposed on the heated wall surface of the fly ash chamber.

[0009] In one exemplary embodiment, the screen-type radiant heat exchanger is made of high-temperature resistant stainless steel, and the heat-receiving surface of the screen-type radiant heat exchanger has a high-emissivity coating.

[0010] In one exemplary embodiment, the particle concentration of oxygen carrier particles and fly ash particles in the mixing chamber is 2500–3500 kg / m3, and the particle size of the oxygen carrier particles and fly ash particles is between 100–300 μm.

[0011] In one exemplary embodiment, the particle size of the oxygen carrier particles and fly ash particles in the separation chamber is 30–200 μm, and the particle concentration of the oxygen carrier particles and fly ash particles is between 1500–2500 kg / m3.

[0012] In one exemplary embodiment, the particle size of the oxygen carrier particles and fly ash particles in the fly ash chamber is 5–50 μm, and the particle concentration of the oxygen carrier particles and fly ash particles is between 1000–1500 kg / m3.

[0013] This application provides a chemical looping combustion device, including: a chemical looping combustion air reactor, a fuel reactor, and a feed return device connecting the chemical looping combustion air reactor and the fuel reactor as described in any of the above embodiments.

[0014] This application implements a chemical looping combustion air reactor based on the gas-solid flow characteristics and thermal distribution features. The combustion channel is divided into a mixing chamber, a separation chamber, and a fly ash chamber. Considering the differences in particle concentration, particle size, temperature distribution, and wear behavior in each chamber, wear-resistant membrane water-cooled wall heat exchange structures are arranged in the mixing and separation chambers to alleviate structural stress concentration caused by high-speed particle scouring and thermal expansion. Bare tube water-cooled walls are arranged in the fly ash chamber, and a screen-type radiant heat exchanger is installed at the top of the fly ash chamber to recover heat from the high-temperature flue gas. This achieves precise adaptation between the heating surface and the local gas-solid behavior. The chemical looping combustion air reactor of this application embodiment has a more suitable heating surface arrangement that matches the gas-solid flow and thermal environment, improving the heat transfer efficiency and structural stability of the entire system.

[0015] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application can be realized and obtained by means of the embodiments described in the description and the accompanying drawings. Attached Figure Description

[0016] The accompanying drawings are used to provide an understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0017] Figure 1This is a schematic diagram of the internal conveying channel of the chemical looping combustion air reactor according to an embodiment of this application; Figure 2 This is a schematic diagram of the heat exchange structure of the chemical looping combustion air reactor according to an embodiment of this application; Figure 3 This is a schematic cross-sectional view of the bare tube water-cooled wall according to an embodiment of this application.

[0018] Figure reference numerals: Chemical loop combustion air reactor-100; Conveying sleeve-1; Mixing chamber-11; Separation chamber-12; Fly ash chamber-13; Membrane water-cooled wall-2; Wear-resistant layer-21; Bare tube water-cooled wall-3; Screen-type radiant heat exchanger-4. Detailed Implementation

[0019] This application describes several embodiments, but these descriptions are exemplary and not limiting, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with, or may replace, any feature or element of any other embodiment.

[0020] This application includes and contemplates combinations of features and elements known to those skilled in the art. The embodiments, features, and elements disclosed in this application can also be combined with any conventional features or elements to form unique inventive solutions. Any feature or element of any embodiment can also be combined with features or elements from other inventive solutions to form another unique inventive solution. Therefore, it should be understood that any feature shown and / or discussed in this application can be implemented individually or in any suitable combination. Therefore, the embodiments are not limited except by the limitations imposed by the appended claims and their equivalents. Furthermore, various modifications and changes can be made within the scope of the appended claims.

[0021] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described herein, to the extent that it does not depend on such a specific order. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation of the claims. Moreover, the claims concerning the method and / or process should not be limited to the steps performed in the written order, and those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments of this application.

[0022] like Figure 1 , Figure 2 As shown, this application embodiment provides a chemical looping combustion air reactor 100 including a conveying channel 1. The conveying channel 1 includes a mixing chamber 11, a separation chamber 12, and a fly ash chamber 13 that are interconnected along the upward direction of the particulate matter (see Figure 1). Figure 1 (The areas are divided by dashed lines). The chemical looping combustion air reactor 100 also includes membrane water-cooled walls 2 on the heated walls of the mixing chamber 11 and the separation chamber 12, bare tube water-cooled walls 3 on the heated walls of the fly ash chamber 13, and a screen-type radiant heat exchanger 4 on top. The mixing chamber 11 contains mixed oxygen carrier particles and fly ash particles, the separation chamber 12 contains separated oxygen carrier particles and fly ash particles, and the fly ash chamber 13 contains separated fly ash particles.

[0023] In the chemical looping combustion air reactor 100 of this application embodiment, the particulate matter concentration and particle size decrease sequentially in the mixing chamber 11, separation chamber 12, and fly ash chamber 13. The particle concentration of oxygen carrier particles and fly ash particles in the mixing chamber 11 is 2500–3500 kg / m³, and the particle size of the oxygen carrier particles and fly ash particles is between 100–300 μm. The particle size of oxygen carrier particles and fly ash particles in the separation chamber 12 is 30–200 μm, and the particle concentration of oxygen carrier particles and fly ash particles is between 1500–2500 kg / m³. The particle size of oxygen carrier particles and fly ash particles in the fly ash chamber 13 is 5–50 μm, and the particle concentration of oxygen carrier particles and fly ash particles is between 1000–1500 kg / m³.

[0024] In this embodiment of the chemical looping combustion air reactor 100, the frictional forces in the mixing chamber 11, separation chamber 12, and fly ash chamber 13 decrease sequentially. Considering the differences in particle concentration, particle size, temperature distribution, and wear behavior among the chambers, erosion-resistant membrane water-cooled walls 2 are arranged in the mixing chamber 11 and separation chamber 12 to withstand the erosion from high-concentration oxygen-carrying particles. Sliding supports and flexible connection components are also provided to accommodate the high-speed erosion of the mixed particles and the non-uniform stress caused by high-temperature thermal expansion. Since the particle frictional force in the fly ash chamber 13 is minimized, a bare tube water-cooled wall 3 is arranged in the fly ash chamber 13 as a heating surface to improve heat exchange efficiency. To further increase heat exchange efficiency, a screen-type radiant heat exchanger 4 is arranged on the top of the fly ash chamber 13, and the heating surface is coated with a high-emissivity emission coating to enhance heat exchange efficiency.

[0025] This embodiment of the application, based on the gas-solid flow characteristics and thermal distribution features within the chemical looping combustion air reactor 100, divides the combustion channel into a mixing chamber 11, a separation chamber 12, and a fly ash chamber 13. Taking into account the differences in particle concentration, particle size, temperature distribution, and wear behavior in each chamber, wear-resistant membrane water-cooled walls 2 are arranged in the mixing chamber 11 and the separation chamber 12 to alleviate structural stress concentration caused by high-speed particle scouring and thermal expansion. A bare tube water-cooled wall 3 is arranged in the fly ash chamber 13, and a screen-type radiant heat exchanger 4 is arranged on top of the fly ash chamber 13 to recover heat from the high-temperature flue gas, thereby achieving precise adaptation between the heating surface and the local gas-solid behavior. The chemical looping combustion air reactor 100 of this embodiment is better matched to the gas-solid flow and thermal environment in terms of heating surface arrangement, improving the heat transfer efficiency and structural stability of the entire system.

[0026] During the design process, CFD simulation can be introduced to optimize the spacing, arrangement, and heat flow coupling structure of the heating surfaces in each zone, making the heat exchange capacity distribution more balanced and the system operation more stable. It can be applied to the design, optimization, and modification of air reactors in chemical loop combustion systems, and is particularly suitable for chemical loop combustion engineering scenarios that place higher demands on the reliability and thermal efficiency of the heating surfaces under high parameters and high load conditions.

[0027] like Figure 3 As shown, the heat-receiving surface of the membrane water-cooled wall 2 has a wear-resistant layer 21, which can be a concrete pouring layer. The surface hardness of the heat exchange tube of the membrane water-cooled wall 2 is not less than HRC60 (HRC: Rockwell hardness), and the thickness of the wear-resistant layer 21 is not less than 3 mm, so as to achieve high wear resistance.

[0028] like Figure 2 As shown, the bare tube water-cooled wall 3 is vertically installed on the heat-receiving surface of the fly ash chamber 13. The screen-type radiant heat exchanger 4 is made of high-temperature resistant stainless steel, and the heat-receiving surface of the bare tube water-cooled wall 3 has a high-emissivity emissive coating.

[0029] The chemical loop combustion air reactor 100 of this application embodiment precisely matches the gas-solid behavior by dividing the conveying channel into a mixing chamber 11, a separation chamber 12, and a fly ash chamber 13. Based on the particle concentration, flow rate, particle size, and temperature characteristics of each region, corresponding heating surface arrangement schemes are adopted respectively, which significantly improves the adaptability of the heating surface to the actual gas-solid coupling state and solves the problems of concentrated wear of the heating surface and uneven distribution of heat exchange capacity in the traditional arrangement.

[0030] The structure of the chemical loop combustion air reactor 100 in this embodiment can be designed flexibly to improve operational reliability: by addressing the problem of significant differences in heat load and temperature gradient in different areas, sliding supports and flexible connection structures are introduced in key parts to alleviate tube deformation, weld fatigue and loosening caused by asynchronous thermal expansion and contraction, extend the service life of the heated surface, and adapt to higher loads and more complex operating conditions.

[0031] The chemical loop combustion air reactor 100 of this application embodiment has enhanced anti-wear and anti-fouling measures to improve long-term stability: the heating surfaces of the mixing chamber 11 and the separation chamber 12 are made of erosion-resistant membrane water-cooled wall 2, which effectively reduces the impact of particle erosion on heat exchange efficiency and equipment life, and is particularly suitable for chemical loop combustion systems with complex fuel types and frequent operation fluctuations.

[0032] The chemical loop combustion air reactor 100 of this application embodiment can combine CFD simulation to perform coupled simulation of flow field, temperature field and particle distribution, optimize the spacing, arrangement angle and arrangement position of various heat exchange structures, avoid local overheating or heat exchange blind spots caused by relying on experience arrangement, and realize heat exchange balance and energy utilization maximization at the system level.

[0033] The chemical loop combustion air reactor 100 of this application embodiment, based on the functional zoning differences to match gas-solid coupling behavior, integrates flexible structural design and simulation optimization guidance for comprehensive heating surface arrangement process, significantly improves the thermal efficiency, operational safety and structural reliability of chemical loop combustion system, and is particularly suitable for the engineering promotion and application of high-parameter, high-load and large-size air reactors.

[0034] The chemical looping combustion air reactor 100 of this application achieves precise matching of particle flow states, heat transfer mechanisms, and structural characteristics in different regions by employing a gas-solid behavior-based zoned heating surface arrangement process. This overcomes problems such as blind arrangement, concentrated wear, and large thermal deviations in existing technologies. Through the integrated design of zoned arrangement and flexible structure, the risk of heating surface failure caused by particle scouring is effectively mitigated, the utilization efficiency of flue gas waste heat is improved, and the reactor structure's adaptability to thermal expansion and load fluctuations is enhanced. This process exhibits good operational stability, heat transfer efficiency, and structural safety, and is suitable for the design and upgrading of different types of chemical looping combustion devices, demonstrating significant engineering application value and promising prospects for widespread application.

[0035] Taking a 20 MWth chemical looping combustion air reactor as an example, this is applicable to pilot-scale chemical looping combustion devices with a heat input scale of approximately 20 MW. The air reactor is designed to simulate the gas-solid coupling behavior and the response characteristics of the heated surface under actual engineering conditions. The chemical looping combustion air reactor 100 of this embodiment is internally divided into a mixing chamber 11, a separation chamber 12, and a fly ash chamber 13 from bottom to top. The mixing chamber 11 and the separation chamber 12 are equipped with erosion-resistant membrane water-cooled wall structures, using a wear-resistant coating with a hardness of HRC60 or higher and a thickness of not less than 3 mm. The structure uses a guide rail sliding support and is flexibly connected to the upper structure through corrugated expansion joints to cope with deformation caused by thermal expansion and contraction. In the fly ash chamber 13, a vertical bare tube water-cooled wall 3 is arranged as the heated surface, and a screen-type radiant heat exchanger 4 is arranged at the top with a high-emissivity coating on the heated surface. The material is high-temperature resistant stainless steel, and the surface is coated with a high-emissivity ceramic high-emissivity coating.

[0036] To optimize the relationship between layout parameters and structural response, CFD simulations of gas-solid two-phase flow, temperature field distribution, and local heat transfer intensity were performed using ANSYS Fluent software. The surface density and installation angle were determined, and the thermal stress response under different operating loads was analyzed and optimized. This layout process operated stably in a pilot plant and can provide a structural verification basis for the design of medium- and large-scale industrial plants.

[0037] This application also provides a chemical looping combustion device, including: a chemical looping combustion air reactor 100 as described in any of the above embodiments, a fuel reactor, and a feed return device connecting the chemical looping combustion air reactor and the fuel reactor.

[0038] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and 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, and therefore should not be construed as a limitation of this application.

[0039] Furthermore, the terms "first," "second," etc., 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 with "first," "second," etc., may explicitly or implicitly include at least one of those features.

[0040] In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise expressly and specifically limited.

[0041] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0042] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0043] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," 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 this application. In this specification, the 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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0044] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A chemical looping combustion air reactor, characterized in that, include: The conveying channel includes interconnected mixing chambers, separation chambers, and fly ash chambers along the upward direction of the particles; the particle concentration and particle size of the mixing chamber, separation chamber, and fly ash chamber decrease sequentially. The chemical loop combustion air reactor also includes membrane water-cooled walls on the heated walls of the mixing chamber and the separation chamber, bare tube water-cooled walls on the heated walls of the fly ash chamber, and a screen-type radiant heat exchanger on the top of the fly ash chamber.

2. The chemical looping combustion air reactor according to claim 1, characterized in that, The heated surface of the membrane water-cooled wall has a wear-resistant layer.

3. The chemical looping combustion air reactor according to claim 2, characterized in that, The surface hardness of the heated surfaces of the mixing chamber and the separation chamber is not less than HRC60, and the thickness of the wear-resistant layer is not less than 3 mm.

4. The chemical looping combustion air reactor according to claim 1, characterized in that, The bare tube water-cooled wall is vertically installed on the heated wall surface of the fly ash chamber.

5. The chemical looping combustion air reactor according to claim 1, characterized in that, The screen-type radiant heat exchanger is made of high-temperature resistant stainless steel, and the heat-receiving surface of the screen-type radiant heat exchanger has an emissive coating.

6. The chemical looping combustion air reactor according to claim 1, characterized in that, The particle concentration of oxygen carrier particles and fly ash particles in the mixing chamber is 2500–3500 kg / m3, and the particle size of the oxygen carrier particles and fly ash particles is between 100–300 μm.

7. The chemical looping combustion air reactor according to claim 1, characterized in that, The particle size of the oxygen carrier particles and fly ash particles in the separation chamber is 30–200 μm, and the particle concentration of the oxygen carrier particles and fly ash particles is between 1500–2500 kg / m3.

8. The chemical looping combustion air reactor according to claim 1, characterized in that, The particle size of the oxygen carrier particles and fly ash particles in the fly ash chamber is 5–50 μm, and the particle concentration of the oxygen carrier particles and fly ash particles is between 1000–1500 kg / m3.

9. A chemical looping combustion device, characterized in that, include: The chemical looping combustion air reactor, the fuel reactor, and the feeder connecting the chemical looping combustion air reactor and the fuel reactor as described in any one of claims 1-8.

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