A honeycomb type methanol reforming hydrogen production reactor with high heat and mass transfer uniformity

Abstract

The application discloses a honeycomb type methanol reforming hydrogen production reactor with high heat and mass transfer uniformity, and belongs to the field of methanol reforming hydrogen production equipment. The reactor is sequentially provided with a left end cover, a conical hole block, a sealing plate, a built-in heating core, a honeycomb ceramic reforming reaction carrier module, a shell, an outer wall ceramic heating ring and a right end cover along a medium flow direction, adopts a graphite flexible sealing and flange bolt locking structure, is convenient to disassemble and assemble, and has good sealing performance. The reactor is provided with a conical hole block differential opening and a conical pressure reduction structure through simulation optimization design, balances carrier inlet airflow distribution, and reduces fluid pressure drop; meanwhile, an internal and external composite heating structure of the external ceramic heating ring and the internal heating core can be adopted to adapt to different size carriers, optimize heating layout, and balance a global temperature field. The application improves catalyst utilization, methanol conversion rate and hydrogen production per unit volume, and has strong structural versatility.

Description

Technical Field

[0001] This invention belongs to the technical field of methanol reforming hydrogen production equipment, and particularly relates to a honeycomb methanol reforming hydrogen production reactor with high heat and mass transfer uniformity. Background Technology

[0002] The large-scale promotion and application of hydrogen energy is hindered by the difficulties in distributed deployment of natural gas reforming, the high carbon emissions from coal-to-hydrogen production, the high operating costs of water electrolysis for hydrogen production, the significant safety risks of high-pressure liquid hydrogen storage and transportation, and the lack of supporting infrastructure.

[0003] Methanol has a wide range of feedstock sources, is convenient to store and transport at room temperature and pressure, and has mild reforming reaction conditions. It can be used to achieve distributed hydrogen production based on existing chemical infrastructure and is widely applicable to scenarios such as industrial on-site hydrogen supply, on-board hydrogen power, and backup fuel cell power. It is the core transitional technology for the commercialization of hydrogen energy at this stage.

[0004] The methanol reforming hydrogen production reactor is the core unit of the hydrogen production system. The existing mainstream reactors are divided into three categories: tubular, plate, and microchannel porous reactors. Plate reactors have high processing precision requirements and poor pressure resistance and sealing performance. Microchannel reactors have large gas pressure drop and are difficult to operate for catalyst coating and replacement. Tubular reactors have stable structure, low manufacturing cost, small pressure drop, and excellent basic heat transfer performance, and are the most widely used.

[0005] Existing tubular methanol reforming reactors have two major drawbacks:

[0006] Uneven fluid distribution: The reactants enter the front end of the support at high speed through the inlet. The gas flow rate is high in the central region of the support cross-section and low in the edge region. The gas phase mass transfer distribution is significantly different, the catalyst utilization rate is uneven, and the overall hydrogen production efficiency is reduced.

[0007] Uneven temperature field distribution: Relying solely on external heating of the shell, the radial and axial temperature differences of the honeycomb carrier are large. Locally low temperatures will reduce methanol conversion rate, while local overheating can easily trigger side reactions and accelerate catalyst aging and deactivation. Summary of the Invention

[0008] To address the shortcomings of existing tubular methanol reforming reactors, such as uneven airflow distribution at the inlet of the carrier and large differences in the internal temperature field, this invention provides a honeycomb methanol reforming hydrogen production reactor with high heat and mass transfer uniformity. Through the coordinated design of a conical flow uniform structure and an internal and external composite heating structure, the internal flow field and temperature field of the reactor are optimized simultaneously, thereby improving the methanol conversion rate and hydrogen production per unit volume.

[0009] To solve the above technical problems, the present invention adopts the following technical solution: A honeycomb methanol reforming hydrogen production reactor with high heat and mass transfer uniformity, comprising, from left to right along the medium flow direction, a left end cover, a conical block, a left graphite sealing plate, a heating core, a reforming reaction carrier module, a graphite sealing roll, a shell, a ceramic heating ring, a right graphite sealing plate, and a right end cover. Bolt connection holes are provided on the left and right end covers and the flange end faces of the shell. The three are assembled and locked together by through bolts. The left and right end covers are respectively sandwiched between the reforming reaction carrier module and the left and right end covers to achieve end face sealing. The outer peripheral wall of the reforming reaction carrier module is sealed and fixed to the inner wall of the shell by the graphite sealing roll. The ceramic heating ring is wrapped and fixed to the outer wall of the shell to provide an external heat source. The heating core is inserted through a pre-set section of the reforming reaction carrier module. The heating holes provide an internal heat source. The reforming reaction carrier module is a honeycomb ceramic porous matrix structure with several heating holes axially opened inside the matrix. The inner wall of the honeycomb ceramic porous flow channel is entirely coated with a methanol reforming catalyst. The conical block has a conical expansion structure. The end face of the conical block is radially partitioned with multiple sets of differentiated flow holes. The edge of the conical block has eight evenly distributed contact plates, which are welded and fixed to the inner wall of the left end cover. The outer side of the left end cover is connected to a small-diameter reactant inlet pipe. The hollow area inside the left end cover forms the reforming reactant inlet area. The outer side of the right end cover is connected to a large-diameter product outlet pipe. The hollow area inside the right end cover forms the reforming product outlet area. The complete reaction gas path is: reactant inlet pipe → reforming reactant inlet area → conical block → honeycomb flow channel inside the reforming reaction carrier module → reforming product outlet area → product outlet pipe.

[0010] Furthermore, the diameter, number of openings, and radial distribution of the openings of the conical block flow holes are designed based on the simulated flow field results of the inlet fluid. The conical structure of the conical hole can reduce the pressure loss of the airflow, and the differentiated opening layout can offset the distribution deviation of the high flow velocity at the center and low flow velocity at the edge of the inlet fluid, so that the airflow at the inlet section of the reforming reaction carrier module is evenly distributed.

[0011] Furthermore, the heating core and heating holes are designed in a matching manner: based on the heat transfer simulation results of the reforming reaction carrier module, the number of openings, axial arrangement position, and hole size of the heating holes are adjusted according to the outer diameter and length of the carrier. Small-sized carriers are matched with a small number of heating cores, while large-sized carriers add heating cores and optimize the radial distribution. The ceramic heating ring on the outer side of the shell and the heating core inside the carrier form an internal and external composite heating structure to balance the temperature field of the entire carrier.

[0012] Furthermore, the small-diameter reactant inlet pipe improves the uniformity of the inlet fluid velocity, while the large-diameter product outlet pipe reduces the resistance to the discharge of hydrogen-rich products and accelerates the removal of reaction products.

[0013] Furthermore, the reactor has a rated operating temperature range of 200℃~300℃, during which the main reaction, methanol-water reforming, and the side reaction, water-water reverse conversion, occur.

[0014] The beneficial effects of the present invention after adopting the above structure are as follows:

[0015] (1) The front-end cone hole block adopts a simulation-optimized partitioned variable diameter opening + cone-shaped pressure reduction structure to balance the airflow distribution at the inlet section of the carrier and eliminate the problem of excessive flow at the center and insufficient flow at the edge.

[0016] (2) A composite heating scheme of external ceramic heating ring and internal heating core of carrier is adopted. The heating cores of different sizes are matched with the corresponding number and arrangement to eliminate the radial and axial temperature difference of the carrier and avoid local low temperature to reduce conversion rate and local high temperature to induce side reaction.

[0017] (3) Uniform airflow distribution increases the effective contact area of ​​the catalyst, and balanced temperature field ensures stable and efficient reforming reaction, while simultaneously improving methanol single-pass conversion rate and hydrogen yield per unit carrier volume; the conical flow uniform structure and built-in heating core structure are compatible and have strong structural versatility, and the opening and heating layout can be customized according to different hydrogen production conditions.

[0018] (4) The fully sealed structure adopts graphite sealing plate and graphite sealing roll flexible sealing, which is resistant to high temperature and has excellent air tightness. The overall flange bolt locking assembly is convenient to disassemble and assemble, and facilitates the replacement of honeycomb ceramic carrier and the maintenance of heating element. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0020] Figure 1 This is a three-dimensional exploded assembly diagram of the reactor of the present invention.

[0021] Figure 2 This is a schematic diagram of the multi-angle structure of the conical hole block of the present invention.

[0022] Figure 3 This is a schematic diagram of the assembly of the conical hole block and the left end cap of the present invention.

[0023] Figure 4 This is a schematic diagram showing the matching of different specifications of reforming reaction carrier modules with heating cores and conical blocks according to the present invention.

[0024] Figure 5 This is a schematic diagram of the left end cap structure of the present invention.

[0025] Figure 6 This is a schematic diagram of the right end cap structure of the present invention.

[0026] Figure 7 This is a schematic diagram of the shell flange structure of the present invention.

[0027] Figure 8 This is a schematic cross-sectional view of the internal medium flow path of the reactor of the present invention.

[0028] In the attached diagram: 1. Left end cap, 2. Conical hole block, 3. Left side graphite sealing plate, 4. Heating core, 5. Reforming reaction carrier module, 6. Graphite sealing roll, 7. Shell, 8. Ceramic heating ring, 9. Right side graphite sealing plate, 10. Right end cap, 11. Contact plate, 12. Heating hole, 13. Reforming reactant inlet pipe, 14. Reforming reactant inlet area, 15. End cap bolt connection hole, 16. Reforming product outlet area, 17. Reforming product outlet pipe, 18. Shell bolt connection hole. Detailed Implementation

[0029] like Figure 1 As shown, the reactor is assembled sequentially along the medium flow direction as follows: left end cover 1, conical block 2, left graphite sealing plate 3, heating core 4, reforming reaction carrier module 5, graphite sealing roll 6, shell 7, ceramic heating ring 8, right graphite sealing plate 9, and right end cover 10. The flanges of left end cover 1 and right end cover 10 have end cover bolt connection holes 15, and the flanges at both ends of shell 7 have shell bolt connection holes 18. The bolts pass through the two sets of connection holes and are locked to achieve overall assembly. The left graphite sealing plate 3 and right graphite sealing plate 9 are respectively set between the two end covers and the carrier module. The graphite sealing roll 6 fills the gap between the outer wall of the reforming reaction carrier module 5 and the inner wall of the shell 7, forming a multi-level high-temperature resistant sealing structure.

[0030] The main body of the reforming reaction support module 5 is a honeycomb ceramic porous matrix. Multiple heating holes 12 are axially opened inside the matrix, and the heating core 4 is inserted into the heating hole 12. The inner wall of the heating hole 12 is coated with a methanol reforming copper-based catalyst.

[0031] like Figure 2 , Figure 3 As shown, the conical hole block 2 has a conical structure, and its end face is divided into a central area, an intermediate area, and an edge area along the radial direction. Each area has flow holes with different diameters and densities. The edge of the conical hole block 2 has contact plates 11 that are uniformly distributed on the integrally formed blocks. The contact plates 11 are welded and fixed to the inner wall of the left end cover 1. Based on the CFD inlet airflow field simulation results, the size and number of flow holes in each area are adjusted to balance the airflow flow rate at the inlet section of the carrier. At the same time, the conical structure reduces the resistance of fluid passage and reduces the system pressure drop.

[0032] like Figure 4As shown, the heating core 4 is configured according to the overall size of the reforming reaction carrier module 5: small carriers are configured with only one heating core 4, medium carriers are configured with one heating core 4, and large carriers are configured with one or more heating cores 4; the radial distribution position of the heating holes 12 is optimized in combination with the carrier heat transfer simulation results, and together with the ceramic heating ring 8 on the outer side of the shell 7, synchronous heating inside and outside the carrier is achieved, reducing the temperature difference across the entire carrier.

[0033] like Figure 5 As shown, a small-diameter reforming reactant inlet pipe 13 is welded to the outside of the left end cover 1. The hollow cavity inside the cover body is the reforming reactant inlet area 14. Bolt connection holes of the left end cover 1 are evenly distributed around the flange. The small-diameter inlet pipe constrains the feed flow rate and improves the initial uniformity of the fluid.

[0034] like Figure 6 As shown, a large-diameter reforming product outlet pipe 17 is welded to the outside of the right end cap 10, and the internal hollow cavity is the reforming product outlet area 16; the large-diameter pipe reduces the back pressure of hydrogen-rich gas discharge and promotes rapid product discharge.

[0035] like Figure 7 As shown, flanges are provided at both ends of the housing 7, and bolt connection holes of the housing 7 are evenly distributed around the flanges. The outer wall of the housing 7 is entirely covered with a ceramic heating ring 8 to provide a uniform external heat source.

[0036] like Figure 8 As shown, the internal airflow path of the reactor (dashed line) is as follows: the methanol-water solution enters the reforming reactant inlet zone 14 through the reforming reactant inlet pipe 13, passes through the left graphite sealing plate 3 after being uniformly depressurized by the cone-shaped block 2, and enters the honeycomb flow channel of the reforming reaction carrier module 5 to undergo the reforming reaction; the generated hydrogen-rich mixed gas passes through the right graphite sealing plate 9 and enters the reforming product outlet zone 16, and is finally discharged from the system through the reforming product outlet pipe 17.

[0037] The reactor operates at a stable temperature of ~℃, and two types of core reactions occur internally:

[0038] Main reaction: Methanol-water reforming reaction: ;

[0039] Side reaction: Reverse water-vapor shift reaction: .

[0040] The complete operation of the equipment is divided into three stages: startup, hydrogen production, and shutdown.

[0041] Start-up phase: Simultaneously start ceramic heating ring 8 and heating core 4 to raise the temperature, and purge nitrogen gas throughout the process to protect the catalyst. Switch to feed after the temperature reaches the set value.

[0042] Hydrogen production stage: Methanol aqueous solution is introduced, heating power and feed flow rate are adjusted to stably output hydrogen-rich gas;

[0043] Shutdown phase: Cut off the heating power supply, continuously introduce nitrogen to cool down, and stop the gas supply after the reactor cools to room temperature.

[0044] This invention addresses the pain points of uneven mass and heat transfer in traditional tubular reactors by synergistically optimizing a conical flow equalization structure and an internal and external composite heating structure, thereby improving methanol conversion rate and hydrogen production efficiency per unit volume. The structure can be customized in terms of opening and heating layout based on different hydrogen production flow rates and carrier sizes through fluid and heat transfer simulations, making it highly versatile and applicable to various distributed methanol-to-hydrogen equipment.

[0045] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents. In conclusion, if those skilled in the art, inspired by this description, design similar structural methods and embodiments without departing from the inventive spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A honeycomb methanol reforming hydrogen production reactor with high heat and mass transfer uniformity, characterized in that: Along the direction of medium flow, from left to right, are assembled the following components in sequence: left end cap (1), conical hole block (2), left side graphite sealing plate (3), heating core (4), reforming reaction carrier module (5), graphite sealing roll (6), shell (7), ceramic heating ring (8), right side graphite sealing plate (9) and right end cap (10). The flanges of the left end cover (1) and the right end cover (10) are provided with end cover bolt connection holes (15), and the flanges of both ends of the housing (7) are provided with housing bolt connection holes (18). The left end cover (1) and the right end cover (10) are assembled by locking through bolts. A left graphite sealing plate (3) is sandwiched between the left end cover (1) and the reforming reaction carrier module (5), and a right graphite sealing plate (9) is sandwiched between the right end cover (10) and the reforming reaction carrier module (5) to achieve end face sealing. The outer peripheral wall of the reforming reaction carrier module (5) is sealed and fixed to the inner wall of the housing (7) by graphite sealing roll material (6). The ceramic heating ring (8) is wrapped and fixed to the outer wall of the housing (7) to provide an external heat source. The heating core (4) is inserted into the pre-set heating hole (12) of the reforming reaction carrier module (5) to provide an internal heat source. The reforming reaction carrier module (5) is a honeycomb ceramic porous matrix structure. Several heating holes (12) are axially opened inside the matrix. The inner wall of the heating hole (12) is coated with a methanol reforming catalyst. The conical hole block (2) is set as a conical expansion structure. The end face of the conical hole block (2) is divided into multiple sets of different specifications of flow holes along the radial direction. The edge of the conical hole block (2) is provided with 8 evenly distributed contact plates (11). The contact plates (11) are welded and fixed to the inner wall of the left end cover (1). The outer side of the left end cap (1) is connected to a reactant inlet pipe, and the hollow area inside the left end cap (1) constitutes a reforming reactant inlet area (14). The outer side of the right end cap (10) is connected to a product outlet pipe, and the hollow area inside the right end cap (10) constitutes a reforming product outlet area (16). The internal gas path of the reactor is sequentially connected to the reactant inlet pipe, the reforming reactant inlet area (14), the cone-shaped block (2), the internal honeycomb flow channel of the reforming reaction carrier module (5), the reforming product outlet area (16), and the product outlet pipe.

2. The honeycomb methanol reforming hydrogen production reactor with high heat and mass transfer uniformity according to claim 1, characterized in that: The diameter of the flow hole, the number of openings, and the radial distribution of the openings of the conical hole block (2) are designed based on the flow field simulation results of the air inlet. The conical hole block (2) is a conical expansion structure, and the end face of the conical hole block (2) adopts a differentiated opening layout.

3. A honeycomb methanol reforming hydrogen production reactor with high heat and mass transfer uniformity according to claim 2, characterized in that: The number of heating holes (12) of the reforming reaction carrier module (5), their axial arrangement position, and hole diameter are set based on the carrier heat transfer simulation results, and the arrangement specifications of the heating holes (12) are adaptively adjusted according to the carrier outer diameter and length.

4. A honeycomb methanol reforming hydrogen production reactor with high heat and mass transfer uniformity according to claim 3, characterized in that: The reactant inlet pipe outside the left end cap (1) is a small-diameter pipe, and the product outlet pipe outside the right end cap (10) is a large-diameter pipe.

5. A honeycomb methanol reforming hydrogen production reactor with high heat and mass transfer uniformity according to claim 4, characterized in that: The rated operating temperature range of the reactor is 200℃~300℃.

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