Hydrogen generation apparatus and method for manufacturing the same

Abstract

To provide a reliable hydrogen generating apparatus.SOLUTION: A combustion exhaust gas flow path 140 is provided along an air flow path 120b via a combustion cylinder 101 and along an evaporation section 121 via an inner cylinder 102. Water is evaporated in the evaporation section 121, hydrogen and carbon monoxide are generated from the evaporated water by a reforming catalyst, and the concentration of carbon monoxide is reduced by a CO reduction catalyst. A fixing body fixes the inner cylinder 102 to the combustion cylinder 101. A first pipe discharges combustion exhaust gas from the combustion exhaust gas flow path 140. A second pipe supplies water to the evaporation section 121. A third pipe discharges hydrogen from the CO reduction catalyst. The first pipe, the second pipe, and the third pipe extend away from an axis O. The fixing body, the first pipe, the second pipe, and the third pipe are arranged in this order from top to bottom. A second distance L2 between the first pipe and the second pipe is larger than a first distance L1 between the fixing body and the first pipe and larger than a third distance L3 between the second pipe and the third pipe.SELECTED DRAWING: Figure 1B

Description

Technical Field

[0001] The present disclosure relates to a hydrogen generator and a method for manufacturing the same.

Background Art

[0002] Hydrogen generators are known. In a hydrogen generator, a heating section combusts combustible gas and air to generate heat. Water evaporates in an evaporation section. Hydrogen and carbon monoxide are generated from a raw material gas and the evaporated water by a reforming catalyst. The concentration of carbon monoxide is reduced by a CO reduction catalyst. Patent Document 1 describes an example of a hydrogen generator.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of Invention

Problem to be Solved by the Invention

[0004] The present disclosure provides a technique suitable for realizing a reliable hydrogen generator.

Means for Solving the Problem

[0005] The present disclosure provides: a combustion cylinder having a shaft extending in a vertical direction, an inner cylinder surrounding the combustion cylinder, an outer cylinder surrounding the inner cylinder, an air flow path through which air flows in the combustion cylinder, a combustion section which is supplied with the air from the air flow path and generates flame and combustion exhaust gas, an evaporation section which allows water to flow from top to bottom between the inner cylinder and the outer cylinder to evaporate the water, a reforming catalyst that generates hydrogen and carbon monoxide from the raw material gas and the evaporated water, a CO reduction catalyst that reduces the concentration of carbon monoxide, Between the combustion cylinder and the inner cylinder, the combustion exhaust gas flows from bottom to top, and the combustion exhaust gas flow path is located along the air passage via the combustion cylinder and along the evaporation section via the inner cylinder, A fixing body for fixing the inner cylinder to the combustion cylinder, A first pipe for discharging the combustion exhaust gas from the combustion exhaust gas passage, A second pipe that supplies the water to the evaporation section, The system comprises a third pipe for discharging the hydrogen from the CO reduction catalyst, The first pipe, the second pipe, and the third pipe extend away from the axis, The fixed body, the first pipe, the second pipe, and the third pipe are arranged in this order from top to bottom. The distance between the fixed body and the first pipe in the vertical direction is defined as the first distance. The distance between the first pipe and the second pipe in the vertical direction is defined as the second distance. When the distance between the second pipe and the third pipe in the vertical direction is defined as the third distance, The second distance is greater than the first distance and greater than the third distance. We provide a hydrogen generation device.

[0006] In another respect, this disclosure is: An inner cylinder having a shaft, The outer cylinder surrounds the inner cylinder, An evaporation section for evaporating water between the inner cylinder and the outer cylinder, The system comprises a reforming catalyst that generates hydrogen from a raw material gas and the evaporated water, The inner cylinder has a protrusion extending around its entire circumference so as to move away from the shaft, The aforementioned protrusion contacts the outer cylinder over the entire circumference of the inner cylinder, The inner cylinder has a helical structure, The aforementioned spiral structure and the outer cylinder partition the spiral evaporation section, The contact width between the protrusion and the outer cylinder is defined as the first width. When the contact width between the helical structure and the outer cylinder is defined as the second width, The first width is larger than the second width, there is provided a hydrogen generator.

[0007] In another aspect, the present disclosure provides: an inner cylinder having an axis; an outer cylinder surrounding the inner cylinder; an evaporation section that evaporates water between the inner cylinder and the outer cylinder; a reforming catalyst that generates hydrogen from a raw material gas and the evaporated water, the inner cylinder has a projection protruding away from the axis over the entire circumference of the inner cylinder, the projection is in contact with the outer cylinder over the entire circumference of the inner cylinder, the inner cylinder has a helical structure, the helical structure and the outer cylinder define the helical evaporation section, which is a method for manufacturing a hydrogen generator, comprising: surrounding the inner cylinder with the outer cylinder, wherein a protrusion height of the projection is larger than a protrusion height of the helical structure in a direction away from the axis; and contracting the outer cylinder toward the inner cylinder such that the protrusion height of the projection is reduced. there is provided a manufacturing method. Effects of the Invention

[0008] The technology according to the present disclosure is suitable for realizing a reliable hydrogen generator. Brief Description of the Drawings

[0009] [Figure 1A] FIG. 1 is a longitudinal cross-sectional view showing a configuration of a hydrogen generator in Embodiment 1. [Figure 1B] FIG. 2 is a partially enlarged view of the hydrogen generator in Embodiment 1. [Figure 2] FIG. 3 is a longitudinal cross-sectional view showing a configuration of a hydrogen generator in Embodiment 2. [Figure 3A] FIG. 4 is a longitudinal cross-sectional view showing a configuration of a hydrogen generator in Embodiment 3. [Figure 3B]This is an explanatory diagram of the contact area between the inner cylinder and the outer cylinder in Embodiment 3. [Figure 4A] This is a process diagram showing the manufacturing process of the hydrogen generator in Embodiment 3. [Figure 4B] This is a process diagram showing the manufacturing process of the hydrogen generator in Embodiment 3. [Figure 4C] This is a process diagram showing the manufacturing process of the hydrogen generator in Embodiment 3. [Figure 5] This is a flowchart of the manufacturing method for the hydrogen generation device according to Embodiment 3. [Modes for carrying out the invention]

[0010] The embodiments will be described in detail below with reference to the drawings. However, unnecessary details may be omitted. For example, detailed explanations of already well-known matters or redundant explanations of substantially identical configurations may be omitted. The accompanying drawings and the following description are provided for the full understanding of the disclosure by those skilled in the art and are not intended to limit the subject matter described in the claims.

[0011] (Embodiment 1) Embodiment 1 will be described below with reference to Figures 1A and 1B.

[0012] [1-1. Structure] Figure 1A is a longitudinal cross-sectional view showing the configuration of the hydrogen generator 100 in Embodiment 1. The hydrogen generator 100 includes a combustion cylinder 101, an inner cylinder 102, an outer cylinder 103, a first partition wall 105, a heating section 120, an evaporation section 121, a reforming section 122, a CO reduction section 123, a combustion exhaust gas flow path 140, a return flow path 141, a supply pipe 143, a combustion exhaust gas exhaust pipe 144, a hydrogen gas exhaust pipe 145, and a bracket 146.

[0013] The combustion cylinder 101 has an axis O extending in the vertical direction AD. In Figure 1A, the radial direction RD is a linear direction perpendicular to the vertical direction AD. The circumferential direction CD is a direction perpendicular to the vertical direction AD and is a direction that circumfers around axis O. The inner cylinder 102 surrounds the combustion cylinder 101. The outer cylinder 103 surrounds the inner cylinder 102. The first partition wall 105 surrounds the inner cylinder 102. The combustion cylinder 101, inner cylinder 102, outer cylinder 103, and first partition wall 105 are coaxial. The combustion cylinder 101, inner cylinder 102, outer cylinder 103, and first partition wall 105 are plate-like bodies. The combustion cylinder 101, inner cylinder 102, outer cylinder 103, first partition wall 105, supply pipe 143, combustion exhaust gas exhaust pipe 144, hydrogen gas exhaust pipe 145, and bracket 146 contain metal.

[0014] A heating section 120 is provided inside the combustion cylinder 101. The heating section 120 extends along axis O. The heating section 120 includes an air intake port 120a, an air passage 120b, a combustible gas passage 120c, and a combustion section 120d. The combustion section 120d is located below the air intake port 120a. The air intake port 120a draws in air. The air passage 120b allows air to flow from top to bottom, from the air intake port 120a to the combustion section 120d. The combustible gas passage 120c allows combustible gas to flow from top to bottom to the combustion section 120d. In the combustion section 120d, air and combustible gas burn, forming a downward flame and generating combustion exhaust gas. In the illustrated example, the heating section 120 is a burner. The combustion section 120d is the opening of the burner.

[0015] A combustion exhaust gas passage 140 is provided between the inner cylinder 102 and the combustion cylinder 101. A combustion exhaust gas exhaust pipe 144 is connected to the upper part of the inner cylinder 102. The combustion exhaust gas generated in the combustion section 120d enters the combustion exhaust gas passage 140 from a gap below the combustion cylinder 101 and flows through the combustion exhaust gas passage 140 from bottom to top. The heat of the combustion exhaust gas in the combustion exhaust gas passage 140 is transferred to the air in the air passage 120b, the raw material gas and water in the evaporation section 121, and the raw material gas and water in the reforming section 122. After flowing through the combustion exhaust gas passage 140, the combustion exhaust gas is discharged from the combustion exhaust gas exhaust pipe 144. The inner cylinder 102 is fixed to the combustion cylinder 101 by a bracket 146. In this embodiment, the bracket 146 is a plate-like body with a hole in the center in the radial direction RD.

[0016] The outer cylinder 103 includes an upper portion and a lower portion. The diameter of the lower portion is larger than the diameter of the upper portion. The outer cylinder 103 surrounds the inner cylinder 102. A supply pipe 143 is connected to the outer cylinder 103. The supply pipe 143 is supplied with a raw material gas containing hydrocarbons and water. The raw material gas and water are supplied to the evaporation section 121.

[0017] An evaporation section 121 is provided between the inner cylinder 102 and the outer cylinder 103. Raw material gas and water are supplied from the supply pipe 143 to the evaporation section 121. The evaporation section 121 flows the raw material gas and water from top to bottom. Water evaporates in the evaporation section 121. Flowing the fluid from top to bottom means that the fluid outlet is located below the fluid inlet. Flowing the fluid from bottom to top means that the fluid outlet is located above the fluid inlet. The same applies to other similar expressions.

[0018] The inner cylinder 102 includes a helical structure 161 and a lower structure 162. The helical structure 161 and the lower structure 162 are surrounded by the outer cylinder 103. The helical structure 161 and the upper part of the outer cylinder 103 define a helical space. This helical space is the evaporation section 121. The lower structure 162 is located below the helical structure 161.

[0019] In Embodiment 1, the inner cylinder 102 is bent to surround the axis O, thereby forming a cylindrical shape. Furthermore, the inner cylinder 102 is bent to have a convex structure that protrudes outward in the radial direction RD in the illustrated example, away from the axis O. This convex structure is the helical structure 161. The inner cylinder 102 and the outer cylinder 103 define a helical space along the helical structure 161, i.e., the evaporation section 121. The helical structure 161 functions as a partition that helically divides the area inside the outer cylinder 103.

[0020] A reforming section 122 is provided between the lower part of the outer cylinder 103 and the lower structure 162. The reforming section 122 is filled with a reforming catalyst. The raw material gas and water vapor that have flowed out from the evaporation section 121 flow through the reforming section 122. The reforming catalyst generates a primary hydrogen-containing gas from the raw material gas and water vapor through a reforming reaction. The primary hydrogen-containing gas contains carbon monoxide and hydrogen.

[0021] The first partition wall 105 is a bottomed cylindrical shape. The first partition wall 105 includes an upper portion, a lower portion, and a bottom. The diameter of the lower portion is smaller than the diameter of the upper portion.

[0022] The lower portion of the first partition wall 105 surrounds the lower portion of the outer cylinder 103. There is a gap between the bottom of the first partition wall 105 and the lower end of the outer cylinder 103 through which the primary hydrogen-containing gas flows. A return channel 141 is provided between the lower portion of the first partition wall 105 and the lower portion of the outer cylinder 103. The return channel 141 redirects the flow of the primary hydrogen-containing gas that has flowed downward from the reforming section 122 upward and guides it to the CO reduction section 123.

[0023] The upper portion of the first partition wall 105 surrounds the upper portion of the outer cylinder 103. A CO reduction section 123 is provided between the upper portion of the first partition wall 105 and the upper portion of the outer cylinder 103. A hydrogen gas exhaust pipe 145 is connected to the first partition wall 105 at a position above the CO reduction section 123.

[0024] The CO reduction section 123 is filled with a CO reduction catalyst. The primary hydrogen-containing gas that flows out from the reforming section 122 contains carbon monoxide. The CO reduction catalyst reduces the concentration of carbon monoxide through a modification reaction, thereby generating a secondary hydrogen-containing gas. The reduced concentration of carbon monoxide and hydrogen from the CO reduction catalyst are discharged from the hydrogen gas exhaust pipe 145.

[0025] In this embodiment, the combustion exhaust gas passage 140 and the air passage 120b are aligned with each other via the combustion cylinder 101. This configuration is suitable for inducing heat exchange between the combustion exhaust gas in the combustion exhaust gas passage 140 and the air in the air passage 120b. Furthermore, the combustion exhaust gas passage 140 and the evaporation section 121 are aligned with each other via the inner cylinder 102. This configuration is suitable for inducing heat exchange between the combustion exhaust gas in the combustion exhaust gas passage 140 and the raw material gas and water in the evaporation section 121. These heat exchanges can contribute to the recovery of heat from the combustion exhaust gas in the hydrogen generator 100 and to the efficient operation of the hydrogen generator 100. Moreover, in this embodiment, the hydrogen generator 100 is configured so that the amount of these heat exchanges is appropriately adjusted, as will be described below.

[0026] The bracket 146, combustion exhaust gas pipe 144, supply pipe 143, and hydrogen gas pipe 145 extend outward in the radial direction RD in the illustrated example, away from axis O. The bracket 146, combustion exhaust gas pipe 144, supply pipe 143, and hydrogen gas pipe 145 are arranged in this order from top to bottom. The bracket 146, combustion exhaust gas pipe 144, supply pipe 143, and hydrogen gas pipe 145 are spaced apart from each other.

[0027] Figure 1B is a partially enlarged view of the hydrogen generator 100 in Embodiment 1. The distance between the bracket 146 and the combustion exhaust gas pipe 144 in the vertical direction AD is the first distance L1. The distance between the combustion exhaust gas pipe 144 and the supply pipe 143 in the vertical direction AD is the second distance L2. The distance between the supply pipe 143 and the hydrogen gas pipe 145 in the vertical direction AD is the third distance L3.

[0028] The second distance L2 is greater than the first distance L1 and also greater than the third distance L3. This is suitable for achieving both efficiency and reliability in the hydrogen generation device 100. This balance will be explained in detail below.

[0029] To operate the hydrogen generator 100 efficiently, it is effective to suppress heat dissipation from the hydrogen generator 100. To achieve this, it is effective to efficiently recover heat from the combustion exhaust gas in the hydrogen generator 100. To achieve this, it is conceivable to increase the amount of heat transferred from the combustion exhaust gas in the combustion exhaust gas flow path 140 to the air in the air flow path 120b. To achieve this, it is conceivable to expand the upper end of the combustion exhaust gas flow path 140 upward and move the combustion exhaust gas pipe 144 upward.

[0030] When performing the above expansion and relocation, it is conceivable to expand the upper end of the evaporation section 121 upward and relocate the supply pipe 143 upward. However, if this is done, the heat transferred from the combustion exhaust gas in the combustion exhaust gas flow path 140 to the water in the evaporation section 121 may become excessive. This could make temperature control of the CO reduction section 123 difficult. Specifically, in the CO reduction section 123, an exothermic reaction occurs due to the CO reduction catalyst. If the water has excessive heat, it is difficult to properly cool the CO reduction catalyst with water. This could impair the reliability of the hydrogen generator 100.

[0031] In contrast, in this embodiment, the second distance L2 is greater than the first distance L1 and also greater than the third distance L3. This relative size makes it easier to secure the second distance L2. Therefore, it is possible to ensure that the heat supplied from the combustion exhaust gas in the combustion exhaust gas flow path 140 to the water in the evaporation section 121 is not excessive, while still ensuring that the heat supplied from the combustion exhaust gas in the combustion exhaust gas flow path 140 to the air in the air flow path 120b is secured. This allows for efficient recovery of heat from the combustion exhaust gas while properly maintaining the temperature control function of the CO reduction section 123 using water. Consequently, both the efficiency and reliability of the hydrogen generation device 100 can be achieved.

[0032] If we only consider the dimensions of the jig for welding the bracket 146, combustion exhaust gas pipe 144, supply pipe 143, and hydrogen gas pipe 145, it is conceivable to arrange the bracket 146, combustion exhaust gas pipe 144, supply pipe 143, and hydrogen gas pipe 145 evenly in the vertical direction AD. In contrast, in this embodiment, the second distance L2 is deliberately made larger than the first distance L1 and larger than the third distance L3. This provides the above-mentioned effect.

[0033] Specifically, in the hydrogen generator 100, above the supply pipe 143, the combustion exhaust gas passage 140 and the air passage 120b are aligned with each other, but there is a region where the combustion exhaust gas passage 140 and the evaporation section 121 are not aligned with each other. The length of the vertical AD in which the combustion exhaust gas passage 140 and the air passage 120b are aligned with each other may be longer than the length of the vertical AD in which the combustion exhaust gas passage 140 and the evaporation section 121 are aligned with each other.

[0034] [1-2. Operation] The operation of the hydrogen generator 100 will be explained below.

[0035] In the hydrogen generator 100, raw material gas and water are supplied from the supply pipe 143 to the evaporation section 121. The water flows spirally from top to bottom through the evaporation section 121, receiving heat from the combustion exhaust gas. As a result, the water turns into steam and mixes with the raw material gas. The mixed gas of raw material gas and steam flows into the reforming section 122. The mixed gas is heated and reformed by a reforming catalyst into a primary hydrogen-containing gas containing hydrogen and carbon monoxide. The primary hydrogen-containing gas flows into the return channel 141, flows upward, and is supplied to the CO reduction section 123. The CO reduction section 123 reduces the carbon monoxide contained in the primary hydrogen-containing gas to produce a secondary hydrogen-containing gas. The secondary hydrogen-containing gas is discharged to the outside of the hydrogen generator 100 through the hydrogen gas discharge pipe 145. The secondary hydrogen-containing gas is supplied to hydrogen utilization equipment such as fuel cell power generators.

[0036] Combustion in the heating section 120 generates combustion exhaust gas. The combustion exhaust gas flows from top to bottom along the inner circumference of the combustion cylinder 101. Next, the combustion exhaust gas folds back upward through the gap between the bottom of the inner cylinder 102 and the lower end of the combustion cylinder 101. Next, the combustion exhaust gas exchanges heat with the air passage 120b, the reforming section 122, and the evaporation section 121 as it flows through the combustion exhaust gas passage 140. Finally, the combustion exhaust gas is discharged to the outside of the hydrogen generator 100 from the combustion exhaust gas discharge pipe 144.

[0037] The temperature of the combustion exhaust gas immediately after it is generated in the heating section 120 is, for example, between 800°C and 900°C. The temperature of the combustion exhaust gas discharged from the combustion exhaust gas pipe 144 to the outside of the hydrogen generator 100 is, for example, less than 50°C. The CO reduction section 123 is cooled by the raw material gas and water supplied to the CO reduction section 123. The temperature of the CO reduction catalyst in the CO reduction section 123 is, for example, between 200°C and 300°C.

[0038] The hydrogen generator of the embodiment described later can also operate in the same manner as the hydrogen generator 100 according to Embodiment 1.

[0039] Several other embodiments are described below. In the following, elements common to embodiments already described and those described later are denoted by the same reference numerals, and their descriptions may be omitted. The descriptions of each embodiment are mutually applicable, as long as they do not technically contradict each other. As long as they do not technically contradict each other, each embodiment may be combined with each other.

[0040] (Embodiment 2) Embodiment 2 will be described below with reference to Figure 2.

[0041] [2-1. Structure] Figure 2 is a longitudinal cross-sectional view showing the configuration of the hydrogen generator 200 in Embodiment 2.

[0042] The combustion exhaust gas flow path 240 includes a first flow path 240a and a second flow path 240b. The first flow path 240a is located below the supply pipe 143. The second flow path 240b is located above the supply pipe 143. The flow path cross-sectional area of ​​the second flow path 240b is smaller than that of the first flow path 240a. This relative size makes it easier to reduce the flow path cross-sectional area of ​​the second flow path 240b. A smaller flow path cross-sectional area can increase the flow velocity of the combustion exhaust gas while disrupting its flow. This can improve the thermal conductivity parameter required for heat exchange between the combustion exhaust gas in the second flow path 240b and the air in the air flow path 120b, thereby improving the efficiency of the heat exchange. As a result, the hydrogen generator 100 can efficiently recover heat from the combustion exhaust gas.

[0043] In Embodiment 2, the combustion cylinder 201 includes a first wall 201a and a second wall 201b. The first wall 201a is located below the supply pipe 143. The second wall 201b is located above the supply pipe 143. The first flow path 240a is provided between the first wall 201a and the inner cylinder 102. The second flow path 240b is provided between the second wall 201b and the inner cylinder 102. The second wall 201b is thicker than the first wall 201a. Thus, in Embodiment 2, the relative thicknesses of the walls of the combustion cylinder 201 determine the relative cross-sectional areas of the combustion exhaust gas flow path 240. In the illustrated example, the thickness of the first wall 201a is the dimension of the first wall 201a in the direction away from axis O, specifically the dimension of the first wall 201a in the radial direction RD. The same applies to the second wall 201b, the third wall, and the fourth wall.

[0044] In a modified example, the inner cylinder includes a third wall and a fourth wall. The third wall is located below the supply pipe 143. The fourth wall is located above the supply pipe 143. The first flow path 240a is provided between the combustion cylinder and the third wall. The second flow path 240b is provided between the combustion cylinder and the fourth wall. The fourth wall is thicker than the third wall. In this way, the relative thicknesses of the inner cylinder walls can be used to form the relative cross-sectional areas of the combustion exhaust gas flow path 240. Alternatively, the relative cross-sectional areas of the combustion exhaust gas flow path 240 can also be formed by bending at least one component selected from the group consisting of the combustion cylinder and the inner cylinder.

[0045] (Embodiment 3) Embodiment 3 will be described below with reference to Figures 3A to 5.

[0046] [3-1. Structure] Figure 3A is a longitudinal cross-sectional view showing the configuration of the hydrogen generator 300 in Embodiment 3.

[0047] The inner cylinder 302 has a spiral structure 161 and a lower structure 162, as well as a protrusion 302p. The protrusion 302p protrudes outward in the radial direction RD in the illustrated example, away from axis O, above the evaporator 121, above the supply pipe 143 in the illustrated example. The protrusion 302p is provided around the entire circumference of the inner cylinder 302, specifically in an annular shape. The protrusion 302p contacts and is welded to the inner surface of the outer cylinder 303 around the entire circumference of the inner cylinder 302 so as to close the evaporator 121 from above. Specifically, the inner cylinder 302 includes a single component 302x. The outer cylinder 303 includes a single component 303x. The single component 302x includes the protrusion 302p and the spiral structure 161. The single component 303x includes an opposing wall 303f and a partition wall 303c. The opposing wall 303f faces the protrusion 302p. The partition wall 303c surrounds the helical structure 161. The evaporation section 121 is partitioned by the partition wall 303c and the helical structure 161. The protrusion 302p is welded to the opposing wall 303f around the entire circumference of the inner cylinder 302, so as to close the evaporation section 121 from above.

[0048] The above-described contact and welding configurations can reduce the number of parts in the hydrogen generator 300. This point will be explained below in comparison with Embodiment 1.

[0049] In Embodiment 1 shown in Figure 1A, the inner cylinder 102 includes a single component 102x. The single component 102x includes a helical structure 161. The outer cylinder 103 includes a single component 103x and a single component 103y. The single component 103x surrounds the helical structure 161. The single component 103y is located above the single component 103x and constitutes the lid of the outer cylinder 103. The single components 102x, 103x, and 103y are welded to each other. In Embodiment 1, the closure of the space above the evaporation section 121 is achieved by the three single components: single component 102x, single component 103x, and single component 103y.

[0050] In contrast, in Embodiment 3 shown in Figure 3A, the closure of the space above the evaporation section 121 is achieved by two single components, single component 302x and single component 303x. Therefore, Embodiment 3 is advantageous from the viewpoint of reducing the number of parts in the hydrogen generator 300. Note that a single component is not made by joining multiple parts and therefore does not include a joining interface. A single component is manufactured, for example, from the same material by molding.

[0051] The protrusion 302p includes an upper portion 302pa, a lower portion 302pb, and a strip-shaped portion 302pc. The upper portion 302pa and the lower portion 302pb are spaced apart from the outer cylinder 303. The lower portion 302pb is located below the upper portion 302pa. The strip-shaped portion 302pc is located between the upper portion 302pa and the lower portion 302pb with respect to the vertical direction AD. The strip-shaped portion 302pc has a non-zero dimension in the width direction of its strip shape. In a cross-section including axis O, the upper portion 302pa and the lower portion 302pb are curved. In the same cross-section, the strip-shaped portion 302pc is straight.

[0052] The strip-shaped portion 302pc extends along the entire circumference of the opposing wall 303f of the outer cylinder 303 so as to be in contact with the opposing wall 303f of the outer cylinder 303. The contact between the inner cylinder 302 and the outer cylinder 303 is surface contact, not point contact. With this configuration, the inner cylinder 302 and the outer cylinder 303 can be easily welded in the third step S3 described later.

[0053] Similar to embodiments 1 and 2, the inner cylinder 302 is bent to have a helical structure 161. The helical structure 161 protrudes away from the axis O, specifically outward in the radial direction RD. The helical structure 161 extends from bottom to top while rotating around the axis O. The helical structure 161 and the outer cylinder 303 define the helical evaporation section 121.

[0054] Figure 3B is an explanatory diagram of the contact area of ​​the inner cylinder 302 and the outer cylinder 303 in Embodiment 3. Specifically, Figure 3B shows the contact area expanded in the circumferential direction CD. The contact width between the protrusion 302p of the inner cylinder 302 and the outer cylinder 303 is defined as the first width W1. The contact width between the helical structure 161 and the outer cylinder 303 is defined as the second width W2. In this case, the first width W1 is larger than the second width W2. With this configuration, it is easy to secure the first width W1. Therefore, a sufficient contact width can be secured between the protrusion 302p of the inner cylinder 302 and the opposing wall 303f of the outer cylinder 303. This makes it possible to reliably close the space above the evaporation section 121, and thus contributes to the realization of a reliable hydrogen generation device 300. Furthermore, in the third step S3 described later, the inner cylinder 302 and the outer cylinder 303 can be easily welded. Note that the contact width is the length of the contact area in the unidirectional direction.

[0055] [3-2. Manufacturing method] Figures 4A to 4C are process diagrams showing the manufacturing process of the hydrogen generator 300 in Embodiment 3. Figure 5 is a flowchart of the manufacturing method of the hydrogen generator 300 according to Embodiment 3. The manufacturing method of the hydrogen generator 300 will be described below with reference to Figures 4A to 5. Note that known techniques can be applied to the manufacturing methods of parts of the hydrogen generator 300 other than those described below.

[0056] As shown in Figure 5, the manufacturing method of the hydrogen generator 300 includes the first step S1, the second step S2, and the third step S3 in that order.

[0057] In the first step S1, as shown in Figure 4A, the inner cylinder 302 is surrounded by the outer cylinder 303. The inner cylinder 302 surrounded here is in a state where the protruding height H1 of the convex portion 302p is greater than the protruding height H2 of the helical structure 161. In this context, the protruding height is the height of the protrusion in the direction away from the axis O, specifically outward in the radial direction RD. Also in the first step S1, the inner cylinder 302 is surrounded by the outer cylinder 303 such that the helical structure 161 is spaced apart from the outer cylinder 303.

[0058] Next, in the second step S2, as shown in Figure 4B, the outer cylinder 303 is contracted toward the inner cylinder 302. As a result, as shown in Figure 4C, the outer cylinder 303 comes into contact with the helical structure 161, and the protrusion 302p is crushed by the outer cylinder 303, reducing the protrusion height H1. As a result, the protrusion 302p comes into surface contact with the opposing wall 303f around the entire circumference of the inner cylinder 302. The protrusion height of the protrusion 302p and the protrusion height of the helical structure 161 become the same. The upper portion 302pa, lower portion 302pb, and strip portion 302pc are obtained. In addition, the relationship in which the first width W1 is larger than the second width W2 is obtained.

[0059] Suppose the upper portion 302pa, lower portion 302pb, and strip-shaped portion 302pc are formed by bending the inner cylinder 302 with hydraulic pressure. In that case, it would be necessary to apply high hydraulic pressure to the inner cylinder 302 so that the upper portion 302pa and lower portion 302pb have a sharp bend in the cross-section including the axis O. In contrast, in this embodiment, it is sufficient to apply a reduced pressure to the inner cylinder 302 so that the upper portion 302pa and lower portion 302pb have a gentle bend in the same cross-section. This is because the convex portion 302p is later crushed by the outer cylinder 303, causing the bends of the upper portion 302pa and lower portion 302pb to become steeper, thus obtaining the upper portion 302pa, lower portion 302pb, and strip-shaped portion 302pc with the intended shape.

[0060] Next, in the third step S23, the protrusion 302p and the outer cylinder 303 are welded. Specifically, the protrusion 302p and the opposing wall 303f are welded.

[0061] According to the manufacturing method described in [3-2. Manufacturing Method] above, the hydrogen generation device 300 described in [3-1. Configuration] above can be manufactured. For example, a size relationship is obtained in which the first width W1 is larger than the second width W2.

[0062] (Note) This disclosure provides the following technologies. The terms shown in quotation marks below are used. These terms may correspond to the terms in Embodiments 1 to 3 as follows. The "fixing body" may correspond to the bracket 146 of Embodiments 1 to 3. The "first pipe" can correspond to the combustion exhaust gas exhaust pipe 144 of Embodiments 1 to 3. The "second pipe" may correspond to the supply pipe 143 of Embodiments 1 to 3. The "third pipe" may correspond to the hydrogen gas exhaust pipe 145 of Embodiments 1 to 3. In the descriptions of Embodiments 1 to 3, the terms used in Embodiments 1 to 3 may be replaced with the terms shown in quotation marks. In the following description of the technology, the terms shown in quotation marks may be replaced with the terms used in Embodiments 1 to 3. The correspondence between terms is not limited to these.

[0063] (Technology 1) A combustion cylinder having an axis extending in the vertical direction, The inner cylinder surrounding the combustion cylinder, The outer cylinder surrounds the inner cylinder, An air passage for flowing air within the combustion cylinder, A combustion section is provided, in which the air is supplied from the air passage and a flame and combustion exhaust gas are generated. An evaporation section is provided between the inner cylinder and the outer cylinder, which allows water to flow from top to bottom and evaporate. A reforming catalyst that generates hydrogen and carbon monoxide from a raw material gas and the evaporated water, The CO reduction catalyst that reduces the concentration of carbon monoxide, Between the combustion cylinder and the inner cylinder, the combustion exhaust gas flows from bottom to top, and the combustion exhaust gas flow path is located along the air passage via the combustion cylinder and along the evaporation section via the inner cylinder, A fixing body for fixing the inner cylinder to the combustion cylinder, A first pipe for discharging the combustion exhaust gas from the combustion exhaust gas passage, A second pipe that supplies the water to the evaporation section, The system comprises a third pipe for discharging the hydrogen from the CO reduction catalyst, The first pipe, the second pipe, and the third pipe extend away from the axis, The fixed body, the first pipe, the second pipe, and the third pipe are arranged in this order from top to bottom. The distance between the fixed body and the first pipe in the vertical direction is defined as the first distance. The distance between the first pipe and the second pipe in the vertical direction is defined as the second distance. When the distance between the second pipe and the third pipe in the vertical direction is defined as the third distance, The second distance is greater than the first distance and greater than the third distance. Hydrogen generator.

[0064] Technology 1 is suitable for realizing a reliable hydrogen generation device.

[0065] (Technology 2) The combustion exhaust gas passage includes a first passage located below the second pipe and a second passage located above the second pipe. The cross-sectional area of ​​the second channel is smaller than the cross-sectional area of ​​the first channel. A hydrogen generation device as described in Technology 1.

[0066] According to Technology 2, the heat from combustion exhaust gas can be efficiently recovered in the hydrogen generation device.

[0067] (Technology 3) The inner cylinder has a protrusion extending around its entire circumference that is above the evaporation section and the second tube and moves away from the axis. The aforementioned protrusion is in contact with the outer cylinder over the entire circumference of the inner cylinder. A hydrogen generation apparatus as described in Technology 1 or 2.

[0068] Technology 3 is suitable for realizing a reliable hydrogen generation device.

[0069] (Technology 4) The inner cylinder includes a first single component, The first single component includes the protrusion and the helical structure, The outer cylinder includes a second single component, The second single component includes an opposing wall facing the protrusion and a partition wall surrounding the helical structure, The partition wall and the spiral structure partition the spiral evaporation section, The aforementioned protrusion is in contact with the opposing wall over the entire circumference of the inner cylinder. A hydrogen generation device as described in Technology 3.

[0070] Technology 4 could contribute to reducing the number of parts in a hydrogen generation device.

[0071] (Technology 5) The aforementioned protrusion is, The upper portion separated from the outer cylinder, A lower portion that is spaced apart from the outer cylinder and located below the upper portion, It has a strip-shaped portion that is located between the upper portion and the lower portion in the vertical direction and extends along the entire circumference of the outer cylinder so as to be in contact with the outer cylinder, A hydrogen generation apparatus as described in Technology 3 or 4.

[0072] Technology 5 is suitable for realizing a reliable hydrogen generation device.

[0073] (Technology 6) The inner cylinder has a helical structure, The aforementioned spiral structure and the outer cylinder partition the spiral evaporation section, The contact width between the protrusion and the outer cylinder is defined as the first width. When the contact width between the helical structure and the outer cylinder is defined as the second width, The first width is larger than the second width. A hydrogen generation apparatus as described in any one of the technical items 3 to 5.

[0074] Technology 6 is suitable for realizing a reliable hydrogen generation device.

[0075] (Technology 7) The aforementioned protrusion and the outer cylinder are welded to each other. A hydrogen generation apparatus as described in any one of the technical items 3 to 6.

[0076] According to Technology 7, the protrusion and the outer cylinder can be fixed to each other.

[0077] (Technology 8) An inner cylinder having a shaft, The outer cylinder surrounds the inner cylinder, An evaporation section for evaporating water between the inner cylinder and the outer cylinder, The system comprises a reforming catalyst that generates hydrogen from a raw material gas and the evaporated water, The inner cylinder has a protrusion extending around its entire circumference so as to move away from the shaft, The aforementioned protrusion contacts the outer cylinder over the entire circumference of the inner cylinder, The inner cylinder has a helical structure, The aforementioned spiral structure and the outer cylinder partition the spiral evaporation section, The contact width between the protrusion and the outer cylinder is defined as the first width. When the contact width between the helical structure and the outer cylinder is defined as the second width, The first width is larger than the second width. Hydrogen generator.

[0078] Technology 8 is suitable for realizing a reliable hydrogen generation device.

[0079] (Technology 9) An inner cylinder having a shaft, The outer cylinder surrounds the inner cylinder, An evaporation section for evaporating water between the inner cylinder and the outer cylinder, The system comprises a reforming catalyst that generates hydrogen from a raw material gas and the evaporated water, The inner cylinder has a protrusion extending around its entire circumference so as to move away from the shaft, The aforementioned protrusion contacts the outer cylinder over the entire circumference of the inner cylinder, The inner cylinder has a helical structure, The aforementioned spiral structure and the aforementioned outer cylinder partition the spiral evaporation section, in a method for manufacturing a hydrogen generation apparatus. The inner cylinder, in which the protrusion height of the convex portion is greater than the protrusion height of the helical structure in the direction away from the axis, is surrounded by the outer cylinder, This includes contracting the outer cylinder toward the inner cylinder so that the protruding height of the convex portion decreases, Manufacturing method.

[0080] Technology 9 is suitable for realizing a reliable hydrogen generation device.

[0081] (Technology 10) This includes shrinking the outer cylinder toward the inner cylinder, and then welding the protrusion and the outer cylinder. The manufacturing method described in Technical 9.

[0082] According to technology 10, the protrusion and the outer cylinder can be fixed to each other. [Industrial applicability]

[0083] This disclosure is applicable to containers in which condensation occurs on the inner wall surface. Specifically, it is applicable to hydrogen generators that produce hydrogen-containing gas with a low carbon monoxide concentration, as well as fuel cell power generators and hydrogen purification systems that supply hydrogen gas after removing impurities. [Explanation of Symbols]

[0084] 100, 200, 300 Hydrogen Generators 101, 201 Combustion cylinder 102, 302 inner cylinder 103, 303 Outer cylinder 102x, 103x, 103y, 302x, 303x Single Part 105 1st bulkhead 120 Heating section 120a air intake 120b Airflow channel 120°C Flammable gas flow path 120d Combustion section 121 Evaporation section 122 Modification section 123 CO Reduction Section 140 Combustion exhaust gas flow path 141 Return channel 143 Supply pipe (second pipe) 144 Combustion exhaust gas pipe (No. 1 pipe) 145 Hydrogen gas exhaust pipe (pipe No. 3) 146 Bracket (fixing element) 161 Spiral structure 162 Lower structure 201a, 201b, 303c Wall 240a, 240b channel 302p Convex part 302pa, 302pb, 302pc part AD vertical direction CD circumferential direction RD radial direction O-axis

Claims

1. A combustion cylinder having an axis extending in the vertical direction, The inner cylinder surrounding the combustion cylinder, The outer cylinder surrounds the inner cylinder, An air passage for flowing air within the combustion cylinder, A combustion section is provided, in which the air is supplied from the air passage and a flame and combustion exhaust gas are generated. An evaporation section is provided between the inner cylinder and the outer cylinder, which allows water to flow from top to bottom and evaporate. A reforming catalyst that generates hydrogen and carbon monoxide from a raw material gas and the evaporated water, The CO reduction catalyst that reduces the concentration of carbon monoxide, Between the combustion cylinder and the inner cylinder, the combustion exhaust gas flows from bottom to top, and the combustion exhaust gas flow path is located along the air passage via the combustion cylinder and along the evaporation section via the inner cylinder, A fixing body for fixing the inner cylinder to the combustion cylinder, A first pipe for discharging the combustion exhaust gas from the combustion exhaust gas passage, A second pipe that supplies the water to the evaporation section, The system comprises a third pipe for discharging the hydrogen from the CO reduction catalyst, The first pipe, the second pipe, and the third pipe extend away from the axis, The fixed body, the first pipe, the second pipe, and the third pipe are arranged in this order from top to bottom. The distance between the fixed body and the first pipe in the vertical direction is defined as the first distance. The distance between the first pipe and the second pipe in the vertical direction is defined as the second distance. When the distance between the second pipe and the third pipe in the vertical direction is defined as the third distance, The second distance is greater than the first distance and greater than the third distance. Hydrogen generator.

2. The combustion exhaust gas passage includes a first passage located below the second pipe and a second passage located above the second pipe. The cross-sectional area of ​​the second channel is smaller than the cross-sectional area of ​​the first channel. The hydrogen generation apparatus according to claim 1.

3. The inner cylinder has a protrusion extending around its entire circumference that is above the evaporation section and the second tube and moves away from the axis. The aforementioned protrusion is in contact with the outer cylinder over the entire circumference of the inner cylinder. The hydrogen generation apparatus according to claim 1.

4. The inner cylinder includes a first single component, The first single component includes the protrusion and the helical structure, The outer cylinder includes a second single component, The second single component includes an opposing wall facing the protrusion and a partition wall surrounding the helical structure, The partition wall and the spiral structure partition the spiral evaporation section, The aforementioned protrusion is in contact with the opposing wall over the entire circumference of the inner cylinder. The hydrogen generation apparatus according to claim 3.

5. The aforementioned protrusion is, The upper portion separated from the outer cylinder, A lower portion that is spaced apart from the outer cylinder and located below the upper portion, It has a strip-shaped portion that is located between the upper portion and the lower portion in the vertical direction and extends along the entire circumference of the outer cylinder so as to be in contact with the outer cylinder, The hydrogen generation apparatus according to claim 3.

6. The inner cylinder has a helical structure, The aforementioned spiral structure and the outer cylinder partition the spiral evaporation section, The contact width between the protrusion and the outer cylinder is defined as the first width. When the contact width between the helical structure and the outer cylinder is defined as the second width, The first width is larger than the second width. The hydrogen generation apparatus according to claim 3.

7. The aforementioned protrusion and the outer cylinder are welded to each other. A hydrogen generating apparatus according to any one of claims 3 to 6.

8. An inner cylinder having a shaft, The outer cylinder surrounds the inner cylinder, An evaporation section for evaporating water between the inner cylinder and the outer cylinder, The system comprises a reforming catalyst that generates hydrogen from a raw material gas and the evaporated water, The inner cylinder has a protrusion extending around its entire circumference so as to move away from the shaft, The aforementioned protrusion contacts the outer cylinder over the entire circumference of the inner cylinder, The inner cylinder has a helical structure, The aforementioned spiral structure and the outer cylinder partition the spiral evaporation section, The contact width between the protrusion and the outer cylinder is defined as the first width. When the contact width between the helical structure and the outer cylinder is defined as the second width, The first width is larger than the second width. Hydrogen generator.

9. An inner cylinder having a shaft, The outer cylinder surrounds the inner cylinder, An evaporation section for evaporating water between the inner cylinder and the outer cylinder, The system comprises a reforming catalyst that generates hydrogen from a raw material gas and the evaporated water, The inner cylinder has a protrusion extending around its entire circumference so as to move away from the shaft, The aforementioned protrusion contacts the outer cylinder over the entire circumference of the inner cylinder, The inner cylinder has a helical structure, The aforementioned spiral structure and the aforementioned outer cylinder partition the spiral evaporation section, in a method for manufacturing a hydrogen generation apparatus. The inner cylinder, in which the protrusion height of the convex portion is greater than the protrusion height of the helical structure in the direction away from the axis, is surrounded by the outer cylinder, This includes contracting the outer cylinder toward the inner cylinder so that the protruding height of the convex portion decreases, Manufacturing method.

10. This includes shrinking the outer cylinder toward the inner cylinder, and then welding the protrusion and the outer cylinder. The manufacturing method according to claim 9.

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