Hydrogen production reformer with external stepped flue gas tunnel

Abstract

The invention relates to a hydrogen production reformer with an external stepped flue gas tunnel, which comprises a radiation inlet collecting tube, a pigtail tube, a burner, a radiation chamber and reformer tubes, the stepped flue gas tunnel is arranged outside the bottom of the radiation chamber, the reformer tubes sequentially penetrate through the radiation chamber and the stepped flue gas tunnel and then are connected with a cold wall collecting tube, the reformer tubes are distributed in an array, and the pigtail tube is connected with the burner. Each column of conversion pipes share one stepped flue gas tunnel, a plurality of flue gas guide partition plates are arranged in the stepped flue gas tunnel, and the L-shaped flue gas guide partition plates divide the stepped flue gas tunnel into a plurality of flue gas sub-tunnels. Flue gas enters the stepped flue gas tunnel from the furnace bottom opening in a unified mode, the flue gas diversion partition plates are adopted in the stepped flue gas tunnel to conduct layered diversion on the flue gas, so that the flue gas can be more evenly distributed in the whole tunnel, the problem that the local flue gas flow speed is too high or too low is solved, and the structure which is light in weight and convenient to install is achieved; and the external flue gas tunnel can be modularly produced in a factory and integrally mounted on site.

Description

Technical Field

[0001] This invention relates to the field of hydrogen production equipment technology, specifically to a hydrogen production conversion furnace with an external stepped flue gas tunnel, applicable to the petroleum refining, petrochemical and coal chemical industries. Background Technology

[0002] Currently, most existing hydrogen production converters employ an internal structure design for their flue gas tunnels, placing the tunnels inside the converter. Examples include a small hydrogen production converter with patent number 202021702777.X and a skid-mounted hydrogen production converter with patent number 202123098670.6. However, this internal structure has several drawbacks: 1. The built-in flue gas tunnel will occupy a large amount of effective space inside the hydrogen production converter, which will compress the reaction space inside the converter and thus limit the amount of raw materials processed and the fullness of the reaction.

[0003] 2. Since the flue gas tunnel is located inside the converter and is close to the reaction zone inside the converter, during long-term high-temperature (usually up to 800-1200℃) operation, the outer wall of the flue gas tunnel is easily corroded by corrosive gases (such as CO2, high-temperature flue gas, etc.) in the reaction zone. It may also be prone to creep and fatigue damage due to its own weight and thermal shock, which will significantly shorten the service life of the flue gas tunnel and increase the maintenance cost and replacement frequency of the equipment.

[0004] 3. The flue gas flow path is simple and lacks an effective flow guidance and distribution structure, resulting in uneven flue gas velocity (local velocity differences can reach more than 30%), low heat transfer efficiency, serious energy waste, and easy to cause excessively high local temperature in the converter, which damages the catalyst activity and further affects the hydrogen production conversion efficiency.

[0005] 4. Due to the limitations of the built-in structure, staff need to enter the converter to install, debug and maintain the flue gas tunnel. This not only increases the labor intensity and operational risks of the staff, but also extends the equipment installation cycle (usually 15-20 days) and maintenance time (7-10 days for a single maintenance), reducing the overall operating efficiency of the hydrogen production equipment.

[0006] Therefore, in view of the problems of unreasonable structural design, low energy efficiency, and inconvenient installation and maintenance of existing hydrogen production converters, it is of great practical significance and practical value to develop a hydrogen production converter with novel structural design, high energy efficiency, convenient installation and maintenance, and long service life. Summary of the Invention

[0007] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a hydrogen production converter with an external stepped flue gas tunnel. The flue gas enters the stepped flue gas tunnel uniformly from the bottom opening of the furnace. The stepped flue gas tunnel uses flue gas guide baffles to guide the flue gas in layers, so that the flue gas can be more evenly distributed throughout the tunnel. This solves the problem of local flue gas flow velocity being too fast or too slow, and achieves a lightweight and convenient installation structure. Furthermore, the external flue gas tunnel can be modularly produced in the factory and installed as a whole on site.

[0008] The objective of this invention is achieved as follows: A hydrogen production converter with an external stepped flue gas tunnel includes a radiant inlet manifold, a pigtail pipe, a burner, a radiant chamber, and a conversion tube. The burner is located at the top of the radiant chamber and extends into the radiant chamber. The burner burns fuel to produce flue gas. The top of the conversion tube is connected to the radiant inlet manifold through the pigtail pipe. A stepped flue gas tunnel is provided outside the bottom of the radiant chamber. The conversion tube passes through the radiant chamber and the stepped flue gas tunnel in sequence and then connects to the cold wall manifold. The conversion tubes are arranged in an array, with each row of conversion tubes sharing a stepped flue gas tunnel. Multiple flue gas guide baffles are provided inside the stepped flue gas tunnel. The L-shaped flue gas guide baffles divide the stepped flue gas tunnel into multiple flue gas sub-tunnels.

[0009] Preferably, the inlets of multiple flue gas sub-tunnels are horizontally distributed and the outlets are vertically distributed, forming a gradient arrangement of sub-tunnels, which allows the flue gas to flow in layers.

[0010] Preferably, the flue gas guide baffle is made of fiberboard, nanoboard or lightweight castable board.

[0011] Preferably, the surface of the flue gas guide baffle is coated with a high-temperature anti-corrosion coating with a temperature resistance of not less than 1200℃.

[0012] Preferably, the stepped flue gas tunnel is equipped with an insulating lining.

[0013] Preferably, the thermal insulation lining is made of ceramic fiber modules, ceramic fiber blankets, ceramic fiber boards, nanoboards, refractory bricks, castables or one or more combinations thereof, with a thermal conductivity ≤0.15W / (m・K).

[0014] Preferably, each stepped flue gas tunnel is independent of the others, and the stepped flue gas tunnel is supported and fixed to the ground by a support frame, the bottom of which is provided with an elastic shock absorber.

[0015] Preferably, each stepped flue gas tunnel is detachably connected to the furnace bottom of the converter via flange bolts.

[0016] The beneficial effects of this invention are: 1. This invention achieves external installation of the flue gas tunnel by setting the main body of the stepped flue gas tunnel on the flue gas tunnel support frame at the bottom of the hydrogen production converter. This not only avoids the flue gas tunnel occupying the effective space inside the hydrogen production converter, increasing the reaction space inside the converter, improving the raw material processing capacity and reaction sufficiency, but also facilitates the installation, commissioning, and maintenance of the flue gas tunnel by the staff, reducing the labor intensity and operational risks of the staff, shortening the equipment installation cycle (from the traditional 15-20 days to 3-5 days) and maintenance time (from 7-10 days to 1-2 days), and improving the overall operating efficiency of the hydrogen production equipment.

[0017] 2. The stepped flue gas tunnel body of this invention consists of several independent flue gas sub-tunnels with progressively increasing axial heights, forming a unique stepped structure. This structure allows for differentiated heat distribution during flue gas flow, based on the heat requirements of reaction zones at different heights within the hydrogen production converter. Specifically, lower-height flue gas sub-tunnels provide sufficient heat to the bottom reaction zones requiring more heat, while higher-height sub-tunnels provide suitable heat to the upper reaction zones requiring relatively less heat. This results in a more uniform temperature distribution throughout the hydrogen production converter, improving feedstock conversion efficiency and reducing energy waste (energy savings of ~10%-15%). 3. The baffle plate can guide the flow of flue gas, making the temperature distribution at the bottom of the hydrogen production converter more uniform, avoiding damage to the catalyst by local high temperature, and thus extending the service life of the catalyst (by 2-3 years).

[0018] 4. The elastic damping components installed at the bottom of the flue gas tunnel support frame can effectively reduce the impact of vibrations generated by the hydrogen production converter during operation on the stepped flue gas tunnel body, ensuring the stable operation of the stepped flue gas tunnel body and extending its service life.

[0019] 5. The external stepped flue gas tunnel structure does not occupy the internal space of the hydrogen production converter, making the internal structure of the hydrogen production converter more compact and reasonable. It also facilitates the separate maintenance and repair of the flue gas tunnel, reducing the difficulty and cost of equipment maintenance (maintenance costs are reduced by 40%-50%). Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a hydrogen production converter with an external stepped flue gas tunnel according to the present invention.

[0021] Figure 2 A side view of a single stepped flue gas tunnel.

[0022] Figure 3A top view of a single stepped flue gas tunnel.

[0023] Among them: 1. Radiation inlet manifold; 2. Pig tail pipe; 3. Burner; 4. Radiation chamber; 5. Flue gas; 6. Conversion pipe; 7. External stepped flue gas tunnel; 8. Cold wall manifold; 9. Flue gas guide baffle; 10. Support frame; 11. Elastic shock absorption component; 12. Thermal insulation lining. Detailed Implementation

[0024] See Figure 1-3 This invention relates to a hydrogen production converter with an external stepped flue gas tunnel, comprising a radiation inlet manifold 1, a pig tail pipe 2, a burner 3, a radiation chamber 4, and a conversion pipe 6. The burner 3 is located at the top of the radiation chamber 4 and extends into the radiation chamber 4. The burner 3 burns fuel to produce flue gas 5, which flows from top to bottom inside the radiation chamber 4. The top of the conversion pipe 6 is connected to the radiation inlet manifold 1 through the pig tail pipe 2. A stepped flue gas tunnel 7 is provided outside the bottom of the radiation chamber 4. The conversion pipe 6 passes through the radiation chamber 4 and the stepped flue gas tunnel 7 in sequence and then connects to the cold wall manifold 8.

[0025] The conversion tubes 6 are arranged in an array, with each column of conversion tubes 6 sharing a stepped flue gas tunnel 7. Each stepped flue gas tunnel is independent of the others. The stepped flue gas tunnel 7 is supported and fixed to the ground by a support frame 10. The bottom of the support frame 10 is provided with an elastic damping element 11, which absorbs the vibration generated during the operation of the conversion furnace.

[0026] The stepped flue gas tunnel 7 has a flue gas inlet at the top that communicates with the radiation chamber 4 and a flue gas outlet on the side. The stepped flue gas tunnel 7 is equipped with multiple flue gas guide baffles 9. The L-shaped flue gas guide baffles 9 divide the stepped flue gas tunnel 7 into multiple flue gas sub-tunnels. The inlets of the multiple flue gas sub-tunnels are horizontally distributed and the outlets are vertically distributed, forming a gradient arrangement of sub-tunnels, so that the flue gas flows in layers.

[0027] After absorbing heat from the converter tube 6, the flue gas 5 enters the stepped flue gas tunnel 7. The flue gas guide baffle 9 forcibly divides the flue gas 5 into multiple parallel flue gas sub-tunnels, forcing the flue gas to pass evenly through the preset flue gas sub-tunnels. This makes the flue gas velocity and flow rate distribution more uniform across the entire heat exchange cross section. At the same time, the flue gas guide baffle regulates the flow field, making the flue gas flow smoother and more orderly, eliminating large-scale eddies and dead zones, and reducing the risk of pressure fluctuations and vibrations. The uniform flue gas distribution results in a uniform heat flux density, making the temperature gradient along the length of the converter tube gentler. The flue gas guide baffle can be positioned and angled according to actual needs, thereby adjusting the size or guide angle of different sub-tunnels and fine-tuning specific high-temperature or low-temperature regions.

[0028] The axial height of the flue gas sub-ducts increases sequentially, forming a stepped layout to accommodate the different heat requirements of the reaction zones at different heights in the hydrogen production converter.

[0029] The flue gas sub-tunnels, which are separated by L-shaped flue gas guide baffles, are also L-shaped. The cross-sectional area of ​​the flue gas duct at the bottom of the flue gas sub-tunnel is larger than that of the middle and upper flue gas ducts, so as to realize the adaptive distribution of flue gas flow rate and the flue gas velocity uniformity error is ≤±5%.

[0030] The number of flue gas guide baffles 9 is set according to the size of the flue gas volume and the length of the radiation chamber. Usually, 2-3 flue gas guide baffles are set per meter of flue. The flue gas enters the stepped flue gas tunnel and continues to absorb heat from the flue gas through the conversion tube. The medium in the conversion tube enters the cold wall manifold and leaves the conversion furnace. After the flue gas exits from the flue gas outlet on the side of the stepped flue gas tunnel, it enters the convection chamber to continue heat exchange.

[0031] The flue gas guide baffle 9 is made of fiberboard, nanoboard or lightweight castable board, etc., and the surface of the flue gas guide baffle is coated with a high temperature anti-corrosion coating with a temperature resistance of not less than 1200℃.

[0032] The stepped flue gas tunnel 7 is equipped with an insulation lining 12. The insulation lining 12 can be selected from one or more combinations of ceramic fiber modules, ceramic fiber blankets, ceramic fiber boards, nanoboards, refractory bricks, and castables, with a thermal conductivity ≤0.15W / (m・K).

[0033] Each stepped flue gas tunnel is detachably connected to the converter bottom via flange bolts, allowing for individual disassembly and replacement.

[0034] This invention breaks through the limitations of traditional built-in structures by placing the flue gas tunnel externally and adopting a modular design. It is rigidly connected to the flue gas outlet at the bottom of the converter via flange bolts, enabling factory prefabrication and on-site hoisting and installation. Each modular flue can be independently produced, transported, installed, and replaced, solving the problems of interference between the traditional built-in structure and the converter body, and the long installation cycle. It also provides a structural foundation for subsequent independent maintenance and repair, achieving a rapid operation and maintenance mode of "disassembly and replacement."

[0035] The innovative design incorporates multiple independent flue gas sub-tunnels with progressively increasing axial heights, forming a stepped layout. Taking into account the varying heat demands of different reaction zones at different heights in the hydrogen production converter (the bottom reaction zone requires high heat density, while the upper and middle zones require a gentler heat supply), the flue gas flow distribution is guided by the height difference of the sub-tunnels. This increases the flue gas flow rate in the bottom sub-tunnels by 20-30%, while the flow rate in the upper and middle sub-tunnels is adjusted as needed, achieving precise matching of the entire furnace temperature field and resolving the industry pain point of unbalanced heat distribution in traditional structures.

[0036] Multiple sets of flue gas guide baffles are added inside each stepped flue gas tunnel. The angle of the flue gas guide baffles can be customized within the range of 30°-90° according to the flue gas flow rate and temperature parameters. The flue gas guide baffles not only divide a single flue into multiple independent flow tunnels to prevent flue gas crossflow, but also change the flue gas flow direction by optimizing the angle, extending the residence time of flue gas in the tunnel (by 15-20%), improving heat exchange efficiency, and avoiding equipment wear caused by local high-speed airflow, thus protecting the insulation layer and the tunnel structure.

[0037] The insulation lining can be flexibly selected from ceramic fiber modules, ceramic fiber blankets, ceramic fiber boards, nanoboards, refractory bricks, and castables, or one or more combinations thereof, depending on the operating conditions. This system has a low thermal conductivity (≤0.15W / (m・K) at 800℃), effectively blocking heat loss and reducing heat loss by more than 30% compared to traditional structures. It is also adaptable to different media corrosiveness and temperature levels, improving equipment adaptability.

[0038] The support frame adopts a combination structure of welded steel sections and elastic damping components. Elastic damping components are installed at the bottom to absorb the vibration energy generated during the operation of the converter (with a damping efficiency of 40-50%), preventing problems such as loosening of the external stepped flue flange connection and deformation of the flue structure caused by vibration. Meanwhile, the inner wall of the tunnel and the surface of the guide baffles are coated with a high-temperature anti-corrosion coating (such as an organosilicon coating), with a temperature resistance of over 1200℃. This significantly improves the resistance to corrosive gases such as H2S and CO2, extending the equipment's service life to 8-10 years.

[0039] By using a stepped sub-tunnel design with gradually changing cross-sectional dimensions (the bottom sub-tunnel has a larger cross-sectional area than the middle and upper parts), combined with the angle design of the guide baffles, the flue gas velocity uniformity error is controlled within ±5%, ensuring that the temperature fluctuation in each reaction zone of the converter does not exceed ±10℃.

[0040] In addition to the above embodiments, the present invention also includes other embodiments. All technical solutions formed by equivalent transformation or equivalent substitution should fall within the protection scope of the claims of the present invention.

Claims

1. A hydrogen production converter with an external stepped flue gas tunnel, comprising a radiant inlet manifold, a pigtail pipe, a burner, a radiant chamber, and a conversion tube, wherein the burner is disposed at the top of the radiant chamber and extends into the radiant chamber, the burner burns fuel to generate flue gas, and the top of the conversion tube is connected to the radiant inlet manifold via the pigtail pipe, characterized in that: A stepped flue gas tunnel is provided outside the bottom of the radiation chamber. The conversion tubes pass through the radiation chamber and the stepped flue gas tunnel in sequence and are connected to the cold wall manifold. The conversion tubes are distributed in an array, and each column of conversion tubes shares a stepped flue gas tunnel. Multiple flue gas guide baffles are provided in the stepped flue gas tunnel. The L-shaped flue gas guide baffles divide the stepped flue gas tunnel into multiple flue gas sub-tunnels.

2. The hydrogen production converter with an external stepped flue gas tunnel according to claim 1, characterized in that: The entrances of multiple flue gas sub-tunnels are horizontally distributed, and the exits are vertically distributed, forming a gradient arrangement of sub-tunnels that allows flue gas to flow in layers.

3. The hydrogen production converter with an external stepped flue gas tunnel according to claim 1, characterized in that: The flue gas guide baffle is made of fiberboard, nanoboard or lightweight castable board.

4. A hydrogen production converter with an external stepped flue gas tunnel according to claim 1 or 3, characterized in that: The surface of the flue gas guide baffle is coated with a high-temperature anti-corrosion coating, which can withstand temperatures of not less than 1200℃.

5. A hydrogen production conversion furnace with an external stepped flue gas tunnel according to claim 1, characterized in that: The stepped flue gas tunnel is equipped with an insulating lining.

6. A hydrogen production converter with an external stepped flue gas tunnel according to claim 1 or 5, characterized in that: The thermal insulation lining is made of ceramic fiber modules, ceramic fiber blankets, ceramic fiber boards, nanoboards, refractory bricks, and castables, or a combination thereof, with a thermal conductivity of ≤0.15W / (m・K).

7. A hydrogen production conversion furnace with an external stepped flue gas tunnel according to claim 1, characterized in that: Each stepped flue gas tunnel is independent of the others. The stepped flue gas tunnel is supported and fixed to the ground by a support frame, and the bottom of the support frame is equipped with an elastic shock absorber.

8. A hydrogen production converter with an external stepped flue gas tunnel according to claim 1 or 7, characterized in that: Each stepped flue gas tunnel is detachably connected to the converter bottom via flange bolts.

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