Hydrogen production reformer furnace bottom external progressive rising flue tunnel

Abstract

This invention discloses an externally mounted, ascending flue gas tunnel at the bottom of a hydrogen production converter, relating to the technical field of thermal systems in hydrogen production equipment. The external tunnel comprises a main body, a baffle plate assembly, an independent support frame, and a flue cover plate assembly. The main body is located outside the bottom of the converter's radiant chamber and connects to the chamber via a flue gas inlet. Inside the main body, a continuously rising slope flow channel is formed from the inlet to the outlet. The baffle plate assembly is spaced along the cross-sectional direction of the main body to create multiple parallel flue gas flow channels. The flue cover plate assembly is located at the top inlet area of ​​the main body, with each cover plate corresponding to and connected to an independent flow channel formed by the baffle plate assembly. The independent support frame is not structurally nested with the converter's furnace body and independently bears the entire weight of the main body. This invention improves on-site installation adaptability.

Description

Technical Field

[0001] This invention relates to the technical field of thermal systems for hydrogen production equipment, and in particular to an externally mounted, ascending flue gas tunnel at the bottom of a hydrogen production converter. Background Technology

[0002] The externally mounted, ascending flue gas tunnel at the bottom of the hydrogen production converter is a core component of the thermal system of the hydrogen production converter. It is located at the bottom of the radiant chamber of the converter and is connected to the flue gas inlet of the radiant chamber. It is a special flue gas guiding structure used to guide the high-temperature flue gas flow discharged from the radiant chamber to the waste heat recovery device. Through special flow channel, flow guide and support design, it realizes orderly flow of flue gas and efficient heat recovery. It is a key structure to ensure the stability of the thermal process of the hydrogen production converter.

[0003] Currently, in the field of industrial hydrogen production, the flue gas diversion of hydrogen production converters generally adopts an internal brick-built flue gas tunnel structure. This structure is formed by stacking refractory bricks and refractory mortar, and is nested inside the converter body and furnace bottom foundation. It relies on the furnace bottom foundation for overall load-bearing. The flow channel has a single rectangular cross section, without a dedicated flue gas diversion structure design, and there is no corresponding independent sealing structure for the flue gas inlet. This is the mainstream traditional method for flue gas diversion in hydrogen production converters at this stage.

[0004] The existing built-in brick flue gas tunnel structure completely encloses the tunnel within the converter body and foundation. Maintenance requires first shutting down the furnace for cooling, then removing the furnace bottom insulation layer, protective panels, and other external structures, and finally erecting internal scaffolding before work can proceed. Each maintenance of this type of built-in structure requires a significant investment of manpower, has a long maintenance cycle, results in substantial direct economic losses, and the working environment is at height and in a confined space, posing extremely high safety risks. Summary of the Invention

[0005] This application provides an externally mounted, ascending flue gas tunnel at the bottom of a hydrogen production converter, which improves on-site installation adaptability.

[0006] This application provides a hydrogen production converter with an externally mounted, progressive flue gas tunnel at the furnace bottom, employing the following technical solution: An externally mounted, progressively rising flue gas tunnel at the bottom of a hydrogen production converter includes a radiant inlet manifold, a burner, a radiant chamber, and an externally mounted, progressively rising tunnel. The burner is vertically installed at the top of the radiant chamber and extends inward. During operation, the high-temperature flue gas generates a natural downward flow path due to density differences. The externally mounted, progressively rising tunnel is located outside the bottom of the radiant chamber and contains a flue gas guide baffle, a flue cover, and a cold wall manifold. The flue gas guide baffle divides the tunnel cavity into multiple ordered flow channels, and the flue cover is located at the top of the tunnel and connects to the radiant chamber.

[0007] Preferably, the flue gas guiding baffles are arranged at intervals along the length of the tunnel, the number of baffles is positively correlated with the length of the radiation chamber, and the separation area is dynamically adjusted according to the actual flue gas flow parameters.

[0008] Preferably, the flue gas guide baffle divides the flue gas flow into multiple parallel streams, with independent flow channels formed between adjacent baffles, and the cross-sectional width of the flow channel is matched with the flue gas flow rate parameter.

[0009] Preferably, the flue cover plate and the flue gas guide baffle plate are in a one-to-one correspondence, each cover plate constitutes an independent flue gas inlet, and the edge of the cover plate is provided with a sealing structure and is fixedly connected to the top of the radiation chamber.

[0010] Preferably, the flue cover is made of silicon carbide-based composite material or refractory castable, and the material has performance parameters of thermal shock resistance coefficient ≥80 cycles and room temperature flexural strength ≥40MPa.

[0011] Preferably, the external step-by-step tunnel is independently supported by a steel structure bracket, the bottom of the bracket is physically isolated from the foundation structure of the radiation chamber, and the distance between the outer shell of the tunnel and the outer wall of the radiation chamber is not less than 150mm.

[0012] Preferably, the inner wall of the external step-by-step tunnel is covered with a multi-layer composite insulation layer, which is composed of alternating layers of lightweight refractory bricks and ceramic fiber blankets, with a total thickness between 120-200mm.

[0013] Preferably, the outer surface of the insulation layer is covered with a metal armor layer, which is made of an alloy plate with a thickness of 0.8-1.2mm and is fixed to the tunnel shell by a snap-fit ​​connection structure.

[0014] Preferably, an annular cooling water jacket is provided at the bottom of the radiation chamber, the cooling water jacket extends around the bottom of the burner and maintains a distance of 200-300mm from the external step-by-step tunnel foundation.

[0015] Preferably, the cold wall manifold has an inverted conical structure, and the inside of the cold wall manifold is provided with spiral baffles, the spacing of which increases along the gas flow direction.

[0016] In summary, this application has the following beneficial effects: By improving the internal flow structure design of the flue, the on-site installation cycle of the equipment can be significantly shortened, the utilization efficiency of flue gas thermal energy can be improved, the service life of the entire converter equipment can be extended, and the maintenance cost during long-term operation of the equipment can be reduced. This effectively solves various technical problems existing in the practical application of the flue gas tunnel of the existing hydrogen production converter.

[0017] 1. To further optimize the function of the tunnel structure by ensuring orderly flow of high-temperature flue gas and reducing flow resistance, while avoiding direct interference from the high temperature of the furnace body, the present invention also sets up a channel body located outside the bottom of the radiation chamber, and designs a progressively rising slope flow channel inside it from the inlet end to the outlet end. This enables the flue gas to be naturally guided by thermal buoyancy, significantly reducing the flow resistance of the flue gas, while physically isolating the tunnel from the furnace body, avoiding direct erosion of the tunnel structure by the high temperature conditions inside the furnace, and improving the temperature resistance of the structure.

[0018] 2. To further optimize the function of uneven flue gas flow velocity and the tendency to form eddy currents, which leads to uneven heat recovery and heat exchange, this invention also sets up a group of guide baffles distributed at intervals along the cross-section of the external channel body. The baffles are corrugated and the peaks and troughs are staggered. This is used to divide the flue gas into multiple parallel flue gas channels and form an S-shaped guide path, eliminating flue gas eddies and local accumulation, allowing the flue gas to be evenly distributed, improving the contact efficiency between the flue gas and the heat exchange components, and reducing the effect of local erosion and corrosion.

[0019] 3. Subsequently, in order to address the issue of the tunnel structure being nested with the furnace body and the mutual influence of forces, which could easily lead to structural instability due to thermal deformation, this invention further optimizes the design by setting up an independent support frame that is not structurally nested with the furnace body. This frame consists of a bottom base and a vertical column assembly, which enables the tunnel structure to bear the entire weight of the external channel body independently, ensuring that the tunnel structure is completely independent of the forces and avoiding interference from furnace body thermal deformation and force transmission. At the same time, the adjustable screw mechanism can finely adjust the flow channel angle, improving the adaptability of on-site installation.

[0020] 4. To further optimize the system by addressing issues such as easy cross-interference of flue gas, poor sealing performance, and inconvenient maintenance, this invention also includes a flue cover plate assembly located at the top inlet area of ​​the external channel body. This assembly is integrally cast from silicon carbide composite material, enabling one-to-one correspondence between the cover plate and the independent flue gas duct. The edge elastic sealing gaskets form an embedded seal, preventing cross-inflow and leakage of flue gas. Furthermore, the corresponding cover plate can be disassembled individually for localized maintenance without requiring a complete shutdown of the furnace. Attached Figure Description

[0021] Figure 1 This is a front view of an externally mounted, ascending flue gas tunnel at the bottom of a hydrogen production converter according to the present invention.

[0022] Figure 2 This is a top view of an externally mounted, ascending flue gas tunnel at the bottom of a hydrogen production converter according to the present invention.

[0023] Figure 3 This is a left-side view of an externally mounted, ascending flue gas tunnel at the bottom of a hydrogen production converter according to the present invention.

[0024] Explanation of reference numerals in the attached diagram: 1. Radiation inlet manifold; 2. Pig tail pipe; 3. Burner; 4. Radiation chamber; 5. Flue gas; 6. Conversion pipe; 7. External step-by-step tunnel; 8. Cold wall manifold; 9. Baffle plate. Detailed Implementation

[0025] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content. Example

[0026] This invention discloses an externally mounted, ascending flue gas tunnel at the bottom of a hydrogen production converter, such as... Figure 1 As shown, it includes a radiation inlet manifold 1, a pig tail pipe 2, a burner 3, and a radiation chamber 4.

[0027] In the specific assembly structure, the burner 3 is fixed at the top of the radiation chamber 4 and extends vertically into the interior space of the radiation chamber 4. When the burner 3 is in operation, the flue gas 5 it generates will form a downward flow path inside the radiation chamber 4. During this process, the conversion tube 6 will continuously absorb the heat energy contained in the flue gas 5 released by the burner 3.

[0028] The burner 3 is vertically fixed at the top of the radiation chamber 4 and extends into the internal space. During operation, the high-temperature flue gas 5 naturally forms a vertical flow path from top to bottom due to the density difference between the hot and cold media. This flow pattern requires no additional forced flow guidance equipment, relying entirely on natural forces to achieve the orderly movement of the flue gas 5. The conversion tube 6 installed inside the radiation chamber 4 forms full and continuous contact with the falling high-temperature flue gas 5. The heat energy contained in the flue gas 5 is continuously transferred to the conversion tube 6 through thermal radiation and convection, providing the necessary high-temperature heat source for the chemical reaction of methane reforming to hydrogen production within the tube, completing the initial efficient absorption of the heat energy from the flue gas 5. This structure deeply integrates the installation layout of the burner 3 with the natural flow law of the flue gas 5, ensuring the stability of the heat source supply for the core hydrogen production reaction and building a continuous and orderly flow pattern for the secondary heat energy absorption and flue gas 5 guidance of the subsequent externally mounted ascending flue gas tunnel. This forms a "primary heat absorption - orderly flow guidance" heat utilization connection logic, which is an important pre-guarantee for the entire hydrogen production system's thermal process.

[0029] First, the natural downward flow of flue gas 5 creates a stable flow inertia, which, together with the rising slope of the subsequent external rising tunnel, forms a "fall-rise" flow channel. The initial gravity guidance makes the flow of flue gas 5 more regular, and the subsequent rising flow guided by thermal buoyancy can further reduce the overall flow resistance of flue gas 5. Under the dual effect, the fluid energy consumption of the system is greatly reduced, and there is no need to add forced ventilation equipment.

[0030] Secondly, the vertical unidirectional flow of flue gas 5 avoids the flue gas 5 in the radiation chamber 4 from turning back and forming eddies, which reduces the probability of ash accumulation and pipe blockage in the furnace, reduces the frequency of ash cleaning and maintenance and labor costs, and shortens the residence time of flue gas 5 in the high-temperature zone, significantly reducing the generation of thermal NOx, thus achieving a synergy between reducing the burden of operation and maintenance and meeting environmental protection standards.

[0031] In addition, the vertically penetrating layout of the burner 3 allows the flame and high-temperature flue gas 5 to be distributed more evenly in the radiation chamber 4, making the thermal field of the radiation chamber 4 more stable, avoiding local overheating of the conversion tube 6, effectively extending the service life of the conversion tube 6, and forming a long-cycle operation synergy with the long-life structure of the external tunnel.

[0032] Finally, uniform heat transfer improves the reaction efficiency of the reforming reaction in the converter tube 6, making the hydrogen production capacity more stable. Combined with the subsequent secondary heat absorption of flue gas 5, it further improves the overall thermal efficiency, achieving a two-way synergy between stable production capacity and improved energy efficiency, and reducing the overall operating cost of the hydrogen production system in multiple dimensions.

[0033] An externally mounted flue gas tunnel is deployed in the outer area at the bottom of the radiation chamber 4. After the flue gas 5 has undergone preliminary heat absorption by the conversion tube 6, it enters the internal chamber of the tunnel through the flue cover plate at the top of the externally mounted flue gas tunnel. Then, with the guidance of the flow guide baffle 9, the flue gas 5 is evenly distributed in the flue, avoiding the accumulation of local flue gas 5. Specifically, the externally mounted, ascending flue gas tunnel is independently deployed outside the bottom of the radiation chamber 4, physically isolated from the furnace. This avoids direct interference from the high-temperature conditions inside the furnace on the tunnel structure and ensures an orderly connection between the flue gas 5 flow path and the core thermal process of the furnace. After initial heat absorption by the conversion tube 6, the flue gas 5 still possesses a certain temperature and flow kinetic energy. The flue cover plate at the top of the tunnel facilitates smooth flow from the radiation chamber 4 to the tunnel. As a connecting node for the flow of flue gas 5, the flue cover plate provides initial buffering of the flue gas 5 flow velocity. After entering the tunnel chamber, the flue gas 5, with the help of the flow guide baffle 9, is divided into multiple orderly streams, breaking the aggregation trend caused by local velocity differences. This allows the flue gas 5 to be evenly distributed across the tunnel cross-section, making its flow more regular. This creates stable fluid conditions for subsequent natural flow guided by the ascending slope and secondary heat absorption. The overall principle balances flue gas 5 flow control with the independent adaptability of the structure.

[0034] First, the uniform flow distribution achieved by the baffle plate 9 allows for more thorough contact between the flue gas 5 and the conversion tube 6 within the tunnel, significantly improving the efficiency of secondary heat absorption. Simultaneously, it prevents localized high-temperature erosion of the tunnel lining caused by the accumulation of flue gas 5, reducing thermal shock damage. This, combined with the high-temperature resistant design of the external structure, extends the overall service life of the tunnel. Second, the top-mounted flue gas inlet design of the flue cover forms a unidirectional flow barrier between the radiation chamber 4 and the tunnel, effectively preventing the flue gas 5 from flowing back into the radiation chamber 4, ensuring a stable thermal field for the reforming reaction within the furnace. The one-to-one correspondence between the cover and the baffle plate 9 allows for independent control of flue gas inlet and flow guidance in individual areas. During localized maintenance, only the corresponding cover needs to be removed without shutting down the furnace. This, combined with the modular characteristics of the external structure, reduces maintenance costs and downtime losses.

[0035] Furthermore, the uniformly distributed flue gas flow pattern eliminates local eddies, significantly reducing the probability of ash accumulation and pipe blockage within the tunnel. Combined with the natural flow guidance of the ascending structure, this reduces the operational load on auxiliary equipment such as acoustic cleaning. In conjunction with the tunnel's thermal insulation design, this further reduces system energy consumption and maintenance frequency. Finally, the external layout combined with uniform flow guidance completely isolates the high-temperature flue gas from the foundation of the radiation chamber 4, preventing thermal deformation of the foundation concrete and corrosion of the steel structure caused by localized high-temperature baking. This, along with the independent support system, enhances the structural safety and stability of the entire converter equipment. These benefits reinforce each other, creating synergy across four dimensions: energy efficiency, lifespan, operation and maintenance, and safety, enabling the hydrogen production system to operate long-term, low-cost, and highly efficient.

[0036] Regarding the internal structure of the externally mounted ascending flue gas tunnel, multiple built-in baffles 9 are provided. The specific number of these components needs to be determined comprehensively based on the actual flow parameters of the flue gas 5 and the length of the radiation chamber 4. After the flue gas 5 enters the externally mounted ascending flue gas tunnel, the conversion pipe 6 will perform secondary absorption of the remaining heat energy in the flue gas 5. After the heat absorption process is completed, the flue gas 5 will be discharged from the conversion furnace system through the cold wall manifold 8. The baffles 9 are arranged in a customized manner with multiple quantities. The number of baffles is not a fixed value, but is determined by comprehensive calculation based on the actual flow parameters of flue gas 5 and the length of radiation chamber 4. This ensures that the number and width of the flow channels divided by the baffles are compatible with the actual flow state of flue gas 5, and avoids uneven flow velocity or flow guide failure caused by the disconnect between flow channel design and operating conditions.

[0037] After the flue gas 5 enters the tunnel, multiple baffles divide the flue gas 5 into multiple parallel and orderly streams, allowing the flue gas 5 to contact the conversion pipe 6 inside the tunnel evenly and fully. This enables the conversion pipe 6 to efficiently absorb the remaining medium-temperature heat energy of the flue gas 5 after the first heat absorption, completing the cascade recovery and utilization of the heat energy of the flue gas 5 and maximizing its thermal utilization value. After the secondary heat absorption is completed, the flue gas 5, with a significantly reduced temperature, is guided to the cold wall manifold 8 for unified collection and discharge.

[0038] First, the customized design of the number of baffles allows for flexible adjustment of the flow channel layout according to changes in hydrogen production capacity, adapting to the increase or decrease in flue gas flow rate without requiring large-scale modifications to the furnace and tunnel body. In conjunction with the modular structure of the external tunnel, it significantly improves the equipment's capacity expansion adaptability and reduces the cost of later upgrades and modifications.

[0039] Secondly, the multi-baffle segmentation of the flow channel allows the flue gas 5 to contact the conversion tube 6 evenly, which not only improves the secondary heat absorption efficiency, but also makes the cooling process of the flue gas 5 in the tunnel more uniform. The temperature of the flue gas 5 when entering the cold wall manifold 8 tends to be uniform, avoiding thermal stress cracks caused by local high temperature in the manifold. Together with the temperature resistance design of the cold wall manifold 8, it significantly extends the overall service life of the exhaust system.

[0040] Third, the uniform secondary heat absorption keeps the flue gas discharge temperature stable, which greatly reduces the heat exchange load fluctuation of the subsequent waste heat recovery device, and ensures that the economizer, air preheater and other equipment are always operating under stable conditions. This improves the heat exchange efficiency and operational stability of the entire waste heat recovery system and forms a synergistic effect with the furnace heat recovery system.

[0041] The number of flue covers corresponds one-to-one with the number of baffles 9, and the flue covers are made of materials with excellent high-temperature resistance to adapt to the high-temperature working environment inside the tunnel. This one-to-one correspondence design ensures that each independent flue gas channel divided by a baffle 9 is equipped with a dedicated flue cover as a smoke inlet. This allows the smoke 5 entering the tunnel from the radiation chamber 4 to be directly guided into the corresponding channel, preventing cross-flow and mutual interference between different channels. This ensures the uniform guidance of the smoke 5 by the baffles 9 from the source of the smoke, guaranteeing the regularity of the smoke 5's flow pattern. Meanwhile, as a key component connecting the flue gas 5 of the radiation chamber 4 and the external tunnel, the flue gas cover plate directly contacts the flue gas 5, which is still at a high temperature after the initial heat absorption by the radiation chamber 4. It is also in a thermal environment with long-term temperature fluctuations. It is made of materials with excellent high-temperature resistance, which can effectively resist the thermal shock, chemical corrosion and thermal expansion deformation of the high-temperature flue gas 5, ensure the structural integrity and sealing performance of the cover plate, and prevent problems such as flue gas 5 leakage and poor flue gas intake due to cover plate failure. It builds a solid front-end structural barrier for the flue gas 5 diversion and heat recovery process of the entire external tunnel.

[0042] The one-to-one correspondence structure forms a modular flue gas control unit. When a single flow channel has problems such as ash accumulation or corrosion, only the corresponding flue cover plate needs to be removed to carry out local maintenance. There is no need to shut down the entire furnace or remove all the covers plate. In conjunction with the modular maintenance characteristics of the external tunnel and the independent flow channel design of the flow guide baffle 9, unplanned downtime is greatly reduced, and the manpower and economic costs of maintenance are reduced.

[0043] Secondly, the independent cover plate can achieve precise opening and closing of a single flow channel. It can flexibly adjust the amount of flue gas entering each flow channel according to the actual flow rate of flue gas 5 and the heat load changes of the radiant chamber 4, further optimizing the uniformity of the flow state of flue gas 5, allowing the flue gas 5 to have more sufficient contact with the conversion tube 6, and working in conjunction with the flow distribution effect of the guide baffle 9 and the secondary heat absorption function of the conversion tube 6 to improve the overall waste heat recovery efficiency.

[0044] Moreover, the high-temperature resistant material ensures that the cover plate does not deform or crumble and peel off under long-term high-temperature conditions, and maintains good sealing performance, effectively preventing the leakage of high-temperature flue gas. In conjunction with the sealing design of the external tunnel and the independent support system, it not only prevents safety accidents and thermal pollution caused by the escape of high-temperature flue gas, but also avoids the loss of thermal efficiency caused by the leakage of flue gas.

[0045] This lays a solid thermal foundation for the secondary heat absorption of flue gas 5 and the stable operation of the tunnel. The fundamental function of laying insulation material is to block the heat conduction, heat radiation and heat convection of the medium and high temperature flue gas 5 in the tunnel, reduce the loss of heat energy from the cavity to the outside of the tunnel, maintain the temperature gradient inside the tunnel, ensure the heat exchange efficiency between the conversion pipe 6 and the flue gas 5, and allow the secondary heat absorption process to fully exploit the remaining heat energy of the flue gas 5, thereby maximizing the utilization of the heat energy of the hydrogen production system.

[0046] The wide range of insulation material selection is based on the differentiated needs of various industrial applications: new materials such as ceramic fiber modules and nanoboards have lower thermal conductivity, are lightweight, and are easy to construct, making them suitable for new hydrogen production projects with high temperature, high energy-saving requirements, or rapid construction; traditional materials such as refractory bricks and castables have a stable structure and are resistant to flue gas erosion and thermal shock, making them suitable for scenarios with large flue gas flow, strong abrasion, or the upgrading of old equipment. Flexible selection allows the insulation structure to be precisely matched to actual working conditions, ensuring both core insulation performance and consideration of construction feasibility, structural durability, and economic cost, achieving a high degree of fit between insulation function and on-site requirements.

[0047] It is worth noting that the properties of different insulation materials can work synergistically with the uniform flow distribution effect of the diversion baffle 9 in the tunnel. The excellent thermal insulation properties of the new materials reduce overall heat loss, while the erosion resistance of the traditional materials resists the impact of the directional flow of the flue gas 5 after diversion, avoiding local damage to the insulation layer, extending the service life of the insulation structure and the tunnel body, and reducing the maintenance work of repairing the insulation layer.

[0048] Working principle: First, the burner 3 is vertically installed at the top of the radiation chamber 4 and extends inward. When the burner 3 is working, the high-temperature flue gas 5 generated naturally forms a vertical flow path from top to bottom due to the density difference between the hot and cold media. The conversion tube 6 installed in the radiation chamber 4 comes into full contact with the falling high-temperature flue gas 5. The heat energy contained in the flue gas 5 is transferred to the conversion tube 6 through thermal radiation and thermal convection, providing the required high-temperature heat source for the chemical reaction of methane reforming to produce hydrogen in the tube, completing the initial efficient absorption of the heat energy of the flue gas 5. At the same time, the stable vertical flow makes the flow pattern of the flue gas 5 more regular, laying the foundation for subsequent guidance.

[0049] Then, the flue gas 5, after its initial heat absorption by the conversion pipe 6, still possesses a certain temperature and flow kinetic energy. It will enter the tunnel cavity through the flue cover plate on the top of the external step-by-step tunnel 7 outside the bottom of the radiation chamber 4. The flue cover plate and the guide baffle 9 are in a one-to-one correspondence. Each cover plate constitutes an independent flue gas inlet. The sealing structure at its edge can effectively prevent the flue gas 5 from crossing and leaking, allowing the flue gas 5 to be accurately guided into the corresponding flow channel. At the same time, it achieves the initial buffering of the flow rate of the flue gas 5, avoiding the generation of impact turbulence when the flue gas 5 enters the tunnel.

[0050] Subsequently, after the flue gas 5 enters the external step-by-step tunnel 7, it is divided into multiple parallel and orderly streams by the flow guide baffles 9 arranged at intervals along the tunnel length. The number of flow guide baffles 9 is dynamically adjusted according to the length of the radiation chamber 4 and the actual flow parameters of the flue gas 5. The cross-sectional width of the flow channel is also matched with the flow parameters of the flue gas 5, which completely eliminates the problems of eddy currents and local accumulation of the flue gas 5, so that the flue gas 5 is evenly distributed on the cross-section of the tunnel, creating stable fluid conditions for subsequent secondary heat absorption.

[0051] Next, the rising slope of the flow channel inside the external step-by-step tunnel 7 allows the flue gas 5 to be naturally guided by thermal buoyancy, which greatly reduces the flow resistance of the flue gas 5. The multi-layer composite insulation layer, which is made of alternating lightweight refractory bricks and ceramic fiber blankets, laid on the inner wall of the tunnel can effectively reduce the loss of heat energy from the tunnel to the outside, maintain the temperature gradient inside the tunnel, and allow the evenly distributed flue gas 5 to fully contact the conversion pipe 6 inside the tunnel. The conversion pipe 6 performs secondary efficient absorption of the remaining heat energy in the flue gas 5, completes the cascade recovery and utilization of the heat energy of the flue gas 5, and maximizes the heat utilization value of the flue gas 5.

[0052] Meanwhile, the annular cooling water jacket at the bottom of the radiation chamber 4 extends around the bottom of the burner 3 and maintains a safe distance of 200-300mm from the foundation of the external step-by-step tunnel 7, avoiding the high-temperature flue gas 5 from causing heat baking and structural erosion to the tunnel foundation. The independent steel structure support of the external step-by-step tunnel 7 completely isolates its stress from that of the radiation chamber 4, effectively avoiding the impact of furnace thermal deformation on the tunnel structure and ensuring the structural stability of the tunnel under high-temperature conditions.

[0053] Finally, the flue gas 5, whose temperature has dropped significantly after the second heat absorption, is guided to the cold wall manifold 8 inside the external step-by-step tunnel 7. The cold wall manifold 8 has an inverted conical structure, and the spacing of the spiral baffles inside the pipe increases along the gas flow direction, which allows the flue gas 5 to pass through the manifold evenly and avoids impact damage caused by excessive local flow velocity. After being collected by the cold wall manifold 8, the flue gas 5 is finally discharged from the converter system and flows to the subsequent waste heat recovery device. The entire working process realizes the orderly guidance of the flue gas 5, the efficient recovery of heat energy, and the stable operation of the equipment structure, ensuring the continuity and efficiency of the thermal process of the hydrogen production converter in all aspects.

[0054] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A type of externally mounted, ascending flue gas tunnel at the bottom of a hydrogen production converter, characterized in that, It includes a radiation inlet manifold (1), a burner (3), a radiation chamber (4), and an external step-by-step tunnel (7); the burner (3) is vertically installed at the top of the radiation chamber (4) and extends inward. The high-temperature flue gas (5) generated during operation forms a natural flow path from top to bottom through the density difference; the external step-by-step tunnel (7) is located outside the bottom of the radiation chamber (4). The external step-by-step tunnel (7) is equipped with a flow guide baffle (9), a flue cover plate, and a cold wall manifold (8) inside. The flow guide baffle (9) divides the inner cavity of the tunnel into multiple orderly flow channels. The flue cover plate is located at the top of the tunnel and connects with the radiation chamber (4).

2. The externally mounted ascending flue gas tunnel at the bottom of the hydrogen production converter according to claim 1, characterized in that, The flow guide baffles (9) are arranged at intervals along the length of the tunnel. The number of baffles is positively correlated with the length of the radiation chamber (4), and the separation area is dynamically adjusted according to the actual flow parameters of the flue gas (5).

3. The externally mounted ascending flue gas tunnel at the bottom of the hydrogen production converter according to claim 2, characterized in that, The flow guide baffle (9) divides the flue gas (5) into multiple parallel flow streams, and independent flow channels are formed between adjacent baffles. The cross-sectional width of the flow channel is matched with the flow rate parameter of the flue gas (5).

4. The externally mounted ascending flue gas tunnel at the bottom of the hydrogen production converter according to claim 1, characterized in that, The flue cover plate and the flow guide plate (9) are in a one-to-one correspondence. Each cover plate constitutes an independent flue gas inlet. The edge of the cover plate is provided with a sealing structure and is fixedly connected to the top of the radiation chamber (4).

5. The externally mounted ascending flue gas tunnel at the bottom of the hydrogen production converter according to claim 4, characterized in that, The flue cover is made of silicon carbide-based composite material or refractory castable, and the material has the performance parameters of thermal shock resistance coefficient ≥80 cycles and room temperature flexural strength ≥40MPa.

6. The externally mounted ascending flue gas tunnel at the bottom of the hydrogen production converter according to claim 1, characterized in that, The external step-by-step tunnel (7) is independently supported by a steel structure bracket. The bottom of the bracket is physically isolated from the foundation structure of the radiation chamber (4). The distance between the outer shell of the tunnel and the outer wall of the radiation chamber (4) is not less than 150mm.

7. The externally mounted ascending flue gas tunnel at the bottom of the hydrogen production converter according to claim 1, characterized in that, The inner wall of the external step-by-step tunnel (7) is covered with a multi-layer composite insulation layer, which is composed of alternating layers of lightweight refractory bricks and ceramic fiber blankets, with a total thickness between 120-200mm.

8. The externally mounted ascending flue gas tunnel at the bottom of the hydrogen production converter according to claim 7, characterized in that, The outer surface of the insulation layer is covered with a metal armor layer, which is made of an alloy plate with a thickness of 0.8-1.2mm and is fixed to the tunnel shell by a snap-fit ​​connection structure.

9. The externally mounted ascending flue gas tunnel at the bottom of the hydrogen production converter according to claim 1, characterized in that, The bottom of the radiation chamber (4) is provided with an annular cooling water jacket, which extends around the bottom of the burner (3) and maintains a distance of 200-300mm from the foundation of the external step-by-step tunnel (7).

10. The externally mounted ascending flue gas tunnel at the bottom of the hydrogen production converter according to claim 1, characterized in that, The cold wall manifold (8) has an inverted conical structure. The inside of the cold wall manifold (8) is provided with spiral baffles, and the spacing between the baffles increases along the gas flow direction.

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