Fuel processing apparatus

Abstract

The fuel processing apparatus includes a reforming section and a combustion section. The reforming section has a first cylindrical wall and a second cylindrical wall. A reforming reaction flow path for the flow of raw materials and reforming gas is formed between the first cylindrical wall and the second cylindrical wall. A combustion gas flow path for the flow of combustion gas is formed at a position closer to the inner periphery of the first cylindrical wall, and an outer peripheral flow path for the flow of outer peripheral gas is formed at a position closer to the outer periphery of the second cylindrical wall. The fuel processing apparatus also includes: a merging section where combustion gas flowing through the combustion gas flow path and outer peripheral gas flowing through the outer peripheral flow path merge; an exhaust gas flow path where the combustion gas and outer peripheral gas merging at the merging section flow as exhaust gas; an oxidant flow path for the flow of oxidant supplied from a heating source; an oxidant branch section provided in the oxidant flow path; a combustion-supporting gas flow path connecting the oxidant branch section and the combustion section so that a portion of the oxidant flows as combustion-supporting gas; and an outer peripheral gas introduction flow path connecting the oxidant branch section and the outer peripheral flow path so that another portion of the oxidant flows as outer peripheral gas.

Description

Technical Field

[0001] This invention relates to a fuel processing device. Background Technology

[0002] Fuel processing units are used in fuel cell systems, hydrogen refueling stations, and other applications. They generate reformed gases containing hydrogen through the reforming reaction of hydrocarbon feedstocks such as natural gas, alcohols, or ammonia. Reforming is an endothermic reaction, therefore requiring thermal energy. Consequently, fuel processing units are equipped with burners to generate this thermal energy.

[0003] Patent Document 1 describes a hydrogen generation device. This device includes a reformer, a burner, and an exhaust path. The reformer is filled with a reforming catalyst. The reformer reforms fuel to generate reformed gas containing hydrogen. The burner heats the reformer. The exhaust path covers the perimeter of the outer wall of the reformer. Combustion exhaust from the burner flows through the exhaust path.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-105695 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In the aforementioned hydrogen generation apparatus, the reformer is primarily heated from the outer periphery by combustion exhaust gas; therefore, the heat transfer area between the reformer and the combustion exhaust gas is limited. Consequently, the aforementioned hydrogen generation apparatus suffers from a decrease in thermal efficiency.

[0009] The present invention was made to solve the aforementioned problems, and its object is to provide a fuel processing apparatus that can achieve higher thermal efficiency.

[0010] Solution for solving the problem

[0011] The fuel processing apparatus of the present invention comprises: a reforming unit that generates reformed gas from feedstock; and a combustion unit that combusts fuel and combustion-supporting gas in a combustion space to generate combustion gas. The reforming unit has: a first cylindrical wall; and a second cylindrical wall disposed at a position peripherally adjacent to the first cylindrical wall. A reforming reaction flow path filled with a reforming catalyst and supplying the feedstock and the reformed gas is formed between the first cylindrical wall and the second cylindrical wall. A combustion gas flow path for supplying the combustion gas is formed at a position peripherally adjacent to the first cylindrical wall and adjacent to the reforming reaction flow path via the first cylindrical wall. An outer peripheral flow path for supplying outer peripheral gas is formed at a position peripherally adjacent to the reforming reaction flow path via the second cylindrical wall. Adjacent to each other, the fuel processing device further comprises: a merging section, in which the combustion gas flowing through the combustion gas flow path merges with the peripheral gas flowing through the peripheral flow path; an exhaust gas flow path, in which the combustion gas and the peripheral gas merging at the merging section flow as exhaust gas; an oxidant flow path, in which oxidant supplied from a heating source flows; an oxidant branch section, in which an oxidant branch section is disposed in the oxidant flow path; a combustion-supporting gas flow path, in which the combustion-supporting gas flow path connects the oxidant branch section and the combustion section, so that a portion of the oxidant flows as the combustion-supporting gas; and a peripheral gas inlet flow path, in which the peripheral gas inlet flow path connects the oxidant branch section and the peripheral flow path, so that another portion of the oxidant flows as the peripheral gas.

[0012] The effects of the invention

[0013] According to the present invention, higher thermal efficiency can be obtained in the fuel processing device. Attached Figure Description

[0014] Figure 1 This is a cross-sectional schematic diagram of the fuel processing device according to Embodiment 1.

[0015] Figure 2 This is a graph showing the temperature distribution of the fuel processing device in Embodiment 1.

[0016] Figure 3 This is a cross-sectional schematic diagram of the fuel processing device according to Embodiment 2.

[0017] Figure 4 This is a graph showing the temperature distribution of the fuel processing device in Embodiment 2.

[0018] Figure 5 This is a cross-sectional schematic diagram of the fuel processing device according to Embodiment 3.

[0019] Figure 6 This is a graph showing the temperature distribution of the fuel processing device in Embodiment 3.

[0020] Figure 7 This is a cross-sectional schematic diagram of the fuel processing device according to Embodiment 4.

[0021] Figure 8 This is a cross-sectional schematic diagram of a fuel processing apparatus according to a variation of Embodiment 4.

[0022] Figure 9 This is a cross-sectional schematic diagram of the fuel processing device according to Embodiment 5.

[0023] Figure 10 This is a cross-sectional schematic diagram of the fuel processing device according to Embodiment 6. Detailed Implementation

[0024] Implementation Method 1

[0025] The fuel processing apparatus of Embodiment 1 will be described. Figure 1 This is a cross-sectional schematic diagram of the fuel processing apparatus of this embodiment. Figure 1 The vertical direction indicates the vertical direction.

[0026] like Figure 1 As shown, the fuel processing device 100 has a cylindrical shape centered on a central axis 100a. The central axis 100a extends in the vertical direction. The fuel processing device 100 has a reforming section 110 and a combustion section 120. The combustion section 120 is disposed below the reforming section 110. The combustion section 120 generates combustion gas F51 that heats the reforming section 110.

[0027] The reforming unit 110 has a multi-tube structure comprising a flame tube wall 503, an inner wall 501, a middle wall 502, and an outer wall 504. The flame tube wall 503, inner wall 501, middle wall 502, and outer wall 504 are all cylindrical in shape centered on a central axis 100a. The inner wall 501 is positioned on the outer periphery of the flame tube wall 503, surrounding it. The middle wall 502 is positioned on the outer periphery of the inner wall 501, surrounding it. The outer wall 504 is positioned on the outer periphery of the middle wall 502, surrounding it. The inner wall 501 is an example of a first cylindrical wall. The middle wall 502 is an example of a second cylindrical wall.

[0028] A combustion gas flow path 401 is formed in the space between the flame tube wall 503 and the inner wall 501. The combustion gas flow path 401 is formed in a ring shape in a horizontal cross-section. The combustion gas flow path 401 extends in the vertical direction. The combustion gas F51 flows upward in the combustion gas flow path 401.

[0029] The upper end of the space between the inner wall 501 and the middle wall 502 is closed by a sealing wall 505. The sealing wall 505 is disposed between the inner wall 501 and the middle wall 502.

[0030] A reforming reaction flow path 402 is formed in the space between the inner wall 501 and the middle wall 502. The reforming reaction flow path 402 is formed in a ring shape in a horizontal cross-section. The reforming reaction flow path 402 extends in the vertical direction. The reforming reaction flow path 402 is adjacent to the combustion gas flow path 401 through the inner wall 501. The raw material F52 and the reformed gas F53 flow downward in the reforming reaction flow path 402.

[0031] A reforming catalyst 5 is packed into the reforming reaction flow path 402. A catalyst layer is formed in the reforming reaction flow path 402 by the reforming catalyst 5. The upper end of the reforming catalyst 5 serves as the inlet of the reforming reaction flow path 402. The lower end of the reforming catalyst 5 serves as the outlet of the reforming reaction flow path 402.

[0032] Feedstock F52 is supplied from outside the fuel processing unit 100 to the reforming reaction flow path 402. In the reforming reaction flow path 402, reformed gas F53 is generated from feedstock F52 by the catalytic action of reforming catalyst 5.

[0033] A first raw material preheating section 203 and a second raw material preheating section 203a are provided upstream of the inlet of the reforming reaction flow path 402 in the flow of raw material F52. The second raw material preheating section 203a is located downstream of the first raw material preheating section 203 in the flow of raw material F52. The second raw material preheating section 203a is formed in the space between the inner wall 501 and the middle wall 502. The first raw material preheating section 203 is formed by piping. The first raw material preheating section 203 penetrates the upper surface wall 506 and the closed wall 505 and is connected to the second raw material preheating section 203a.

[0034] Raw material F52 flows sequentially through the first raw material preheating section 203 and the second raw material preheating section 203a into the reforming reaction flow path 402. The reformed gas F53 generated in the reforming reaction flow path 402 flows out to the outside of the fuel processing device 100.

[0035] A reforming gas temperature sensor 9 is installed at the outlet of the reforming reaction flow path 402. The reforming gas temperature sensor 9 detects the temperature of the reforming gas F53 flowing out of the reforming reaction flow path 402 and outputs the detection signal to the control unit 8.

[0036] A catalyst layer peripheral flow path 403 is formed in the space between the middle wall 502 and the outer wall 504. The catalyst layer peripheral flow path 403 is formed in a ring shape in the horizontal cross section. The catalyst layer peripheral flow path 403 extends in the vertical direction. The catalyst layer peripheral flow path 403 is adjacent to the reforming reaction flow path 402 through the middle wall 502. The catalyst layer peripheral gas F54 flows upward in the catalyst layer peripheral flow path 403.

[0037] The upper end of the space on the inner periphery side of the outer wall 504 is closed by the upper surface wall 506. The upper surface wall 506 is formed as a circular plate centered on the central axis 100a. The upper surface wall 506 faces the closing wall 505 with a gap. The gap between the upper surface wall 506 and the closing wall 505 forms a connecting part 510. The space between the flame tube wall 503 and the inner wall 501 and the space between the middle wall 502 and the outer wall 504 are connected by the connecting part 510. The first raw material preheating part 203 passes through the connecting part 510.

[0038] An exhaust gas flow path 404 is connected to the upper surface wall 506. The exhaust gas flow path 404 is disposed on the central shaft 100a of the fuel processing device 100. Exhaust gas F58 flows in the exhaust gas flow path 404.

[0039] In the radial direction of the reforming section 110, the reforming reaction flow path 402 is sandwiched between two sides by the combustion gas flow path 401 and the catalyst layer peripheral flow path 403. The flow directions of the feedstock F52 and reforming gas F53 in the reforming reaction flow path 402 are opposite to the flow directions of the combustion gas F51 in the combustion gas flow path 401 and the catalyst layer peripheral gas F54 in the catalyst layer peripheral flow path 403. In other words, the flow of the feedstock F52 and reforming gas F53 in the reforming reaction flow path 402 forms an opposing flow relative to the flow of the combustion gas F51 in the combustion gas flow path 401 and the catalyst layer peripheral gas F54 in the catalyst layer peripheral flow path 403.

[0040] Heat exchange occurs between the combustion gas F51 in the combustion gas flow path 401 and the feedstock F52 and reformed gas F53 in the reforming reaction flow path 402 via the inner wall 501. Heat exchange also occurs between the catalyst layer peripheral gas F54 in the catalyst layer peripheral flow path 403 and the feedstock F52 and reformed gas F53 in the reforming reaction flow path 402 via the middle wall 502.

[0041] Furthermore, the second raw material preheating section 203a, like the reforming reaction flow path 402, is sandwiched between the combustion gas flow path 401 and the catalyst layer peripheral flow path 403 from both sides. Heat exchange occurs between the combustion gas F51 in the combustion gas flow path 401 and the raw material F52 in the second raw material preheating section 203a via the inner wall 501. Heat exchange also occurs between the catalyst layer peripheral gas F54 in the catalyst layer peripheral flow path 403 and the raw material F52 in the second raw material preheating section 203a via the middle wall 502.

[0042] The gas F54 surrounding the catalyst layer flows through the connecting portion 510 around the first raw material preheating section 203. Heat exchange occurs between the gas F54 surrounding the catalyst layer and the raw material F52 within the first raw material preheating section 203. Furthermore, the first raw material preheating section 203 may also be circumferentially tortuous along the fuel processing device 100 to ensure a larger heat transfer area between the first raw material preheating section 203 and the gas F54 surrounding the catalyst layer.

[0043] The upper part of the internal space of the flame tube wall 503 is closed by a sealing wall 507. The sealing wall 507 faces the upper surface wall 506 with a gap.

[0044] The combustion section 120 includes a burner 1. The burner 1 is mounted on the central axis 100a. The burner 1 is positioned below the flame tube wall 503. Combustion fuel F55, combustion raw material F59, and combustion-supporting gas F56 are supplied to the burner 1. The burner 1 causes the combustion fuel F55 or combustion raw material F59 and combustion-supporting gas F56 to burn. As a result, a flame is formed in the combustion space 202, generating combustion gas F51.

[0045] A flame baffle 3 is disposed inside the flame tube wall 503. The internal space of the flame tube wall 503 is divided vertically by the flame baffle 3. Inside the flame tube wall 503, in the space above the flame baffle 3 and below the enclosed wall 507, heat insulation material 6 is disposed. The space inside the flame tube wall 503 below the flame baffle 3 becomes the radiative heat transfer space 201. The lower end of the flame tube wall 503 is open. The flame baffle 3 faces the burner 1 across the radiative heat transfer space 201. The radiative heat transfer space 201 is surrounded by the flame tube wall 503, the flame baffle 3, and the burner 1.

[0046] Combustion space 202 is formed in the lower part of radiative heat transfer space 201. Radiative heat transfer space 201 is connected to the lower end of combustion gas flow path 401. Combustion gas F51 generated by burner 1 flows into combustion gas flow path 401 through combustion space 202 and radiative heat transfer space 201. Flame baffle 3 is heated by radiant heat radiated from combustion space 202 via radiative heat transfer space 201.

[0047] The combustion space 202 is surrounded by a heat-insulating wall 4. The heat-insulating wall 4 has a cylindrical shape centered on the central axis of the fuel processing device 100. The height of the heat-insulating wall 4 is the same as the height of the combustion space 202, i.e., the height of the flame formed by the burner 1.

[0048] An airflow path 405 is formed on the outer periphery of the heat insulation wall 4. The airflow path 405 is formed in an annular shape surrounding the heat insulation wall 4. Temperature regulating air F57 flows through the airflow path 405. A flow regulating valve 406 is provided upstream of the airflow path 405 to adjust the flow rate of the air F57. The flow regulating valve 406 is an example of a structure for adjusting the flow rate of the air F57.

[0049] Air F57 is supplied from the air flow path 405 to the combustion gas F51, which is located downstream of the combustion space 202 and upstream of the combustion gas flow path 401. This regulates the temperature of the combustion gas F51 flowing into the combustion gas flow path 401.

[0050] Oxidant F50 is supplied to the fuel processing device 100 from a heating source (not shown). The oxidant F50 is supplied to the fuel processing device 100 in a heated state. The oxidant F50 supplied to the fuel processing device 100 has a temperature higher than that of the feedstock F52 supplied to the fuel processing device 100. In this embodiment, the heating source is a high-temperature fuel cell. Furthermore, the oxidant F50 in this embodiment is cathode exhaust gas supplied from a high-temperature fuel cell.

[0051] An oxidant inlet pipe 300 is provided in the fuel processing device 100. An oxidant flow path 600 is formed inside the oxidant inlet pipe 300. Oxidant F50 flows in the oxidant flow path 600.

[0052] The oxidant inlet pipe 300 branches at oxidant branch section 2 into a combustion-supporting gas conduit 302 and a catalyst layer peripheral gas inlet pipe 301. A combustion-supporting gas flow path 602 is formed inside the combustion-supporting gas conduit 302. Combustion-supporting gas F56 flows through the combustion-supporting gas flow path 602. Combustion-supporting gas F56 is a part of the oxidant F50.

[0053] A catalyst layer peripheral gas inlet flow path 601 is formed inside the catalyst layer peripheral gas inlet pipe 301. Catalyst layer peripheral gas F54 flows through the catalyst layer peripheral gas inlet flow path 601. Catalyst layer peripheral gas F54 is another part of oxidant F50. That is, the oxidant F50 flowing in the oxidant flow path 600 is split into combustion-supporting gas F56 and catalyst layer peripheral gas F54 at the oxidant branch 2.

[0054] The flow ratio of the catalyst layer peripheral gas F54 to the combustion-supporting gas F56 at the oxidant branch 2 is preset according to the operating conditions of the fuel processing device 100 and the combustion conditions of the burner 1. For example, when the oxidant F50 is the cathode exhaust gas of a solid oxide fuel cell, the flow ratio of the catalyst layer peripheral gas F54 to the combustion-supporting gas F56 is set to about 3:1 to 11:1.

[0055] Combustion-supporting gas conduit 302 is connected to burner 1. Thus, a portion of the oxidant F50 is supplied to burner 1 as combustion-supporting gas F56. Catalyst bed peripheral gas inlet pipe 301 is connected to the lower part of catalyst bed peripheral flow path 403. Thus, another portion of the oxidant F50 is supplied to catalyst bed peripheral flow path 403 as catalyst bed peripheral gas F54.

[0056] Combustion gas F51 flowing through combustion gas flow path 401 and catalyst layer peripheral gas F54 flowing through catalyst layer peripheral flow path 403 merge at confluence section 200. Confluence section 200 is formed in an annular shape with central axis 100a as its center. In this embodiment, confluence section 200 is located at the upper end of the space between flame tube wall 503 and inner wall 501. The combustion gas F51 and catalyst layer peripheral gas F54 merging at confluence section 200 become exhaust gas F58. Exhaust gas F58 flows out to the outside of fuel processing device 100 through exhaust gas flow path 404.

[0057] Although not shown, the fuel handling device 100 is surrounded by suitable heat insulation. This suppresses heat loss due to heat dissipation from the fuel handling device 100.

[0058] The control unit 8 is configured to control the entire fuel processing unit 100. The control unit 8 has a microcomputer equipped with a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc.

[0059] The operation of the fuel processing apparatus according to this embodiment will now be described. The feedstock F52 supplied to the fuel processing apparatus 100 is preheated by the catalyst layer peripheral gas F54 in the first feedstock preheating section 203. The feedstock F52 is further preheated by the combustion gas F51 and the catalyst layer peripheral gas F54 in the second feedstock preheating section 203a. The feedstock F52 is heated to approximately 350–400°C by preheating in the first feedstock preheating section 203 and the second feedstock preheating section 203a.

[0060] The heated feedstock F52 flows into the reforming reaction flow path 402. The feedstock F52 in the reforming reaction flow path 402 is heated from the inner peripheral side by combustion gas F51 flowing in the combustion gas flow path 401. Additionally, the feedstock F52 in the reforming reaction flow path 402 is also heated from the outer peripheral side by catalyst layer outer peripheral gas F54 flowing in the catalyst layer outer peripheral flow path 403. Thus, the feedstock F52 passing through the reforming catalyst 5 is heated to approximately 550–650°C. Furthermore, the feedstock F52 passing through the reforming catalyst 5 is reformed into reformed gas F53 through a reforming reaction, which is an endothermic reaction.

[0061] For example, when the feedstock F52 is methane and water vapor, a typical reforming reaction is represented by the following formulas (1) and (2). In the reforming reaction flow path 402, an endothermic reaction of methane and water vapor occurs through the catalytic action of the reforming catalyst 5. Hydrogen is produced through this reaction.

[0062]

[0063] The flow rates of methane and water vapor are generally expressed as the S / C ratio. The S / C ratio is the molar fraction of water vapor (S) relative to carbon (C) in the feedstock. Typically, the flow rate of water vapor supplied to the reforming reaction channel 402 is set to keep the S / C ratio constant within the range of approximately 2.5 to 3.5. For example, Ni-based, Pt-based, or Ru-based reforming catalysts are used as the reforming catalyst 5. The reforming catalyst 5 is supported on a support such as Al₂O₃ or MgO.

[0064] Reformed gas F53 is supplied to high-temperature fuel cells while maintaining the temperature after the reforming reaction. High-temperature fuel cells include solid oxide fuel cells and molten carbonate fuel cells.

[0065] In burner 1, combustion gas F51 with a temperature of approximately 700–1200°C is generated through the combustion reaction of combustion-supporting gas F56 with combustion fuel F55 or combustion feedstock F59. Ignition in burner 1 is achieved, for example, by using a spark plug (not shown).

[0066] Combustion gas F51 flows into combustion gas flow path 401 through combustion space 202 and radiative heat transfer space 201. Combustion gas F51 flows upward in combustion gas flow path 401. The heat of combustion gas F51 is transferred to reforming reaction flow path 402 via inner wall 501. As a result, the temperature of combustion gas F51 decreases to approximately 400°C. The heat transferred to reforming reaction flow path 402 becomes part of the thermal energy required for the reforming reaction.

[0067] Heat transfer from the combustion gas flow path 401 to the reforming reaction flow path 402 occurs via convection of the combustion gas F51. Additionally, heat transfer from the combustion gas flow path 401 to the reforming reaction flow path 402 also occurs via radiation from the flame tube wall 503 and from the combustion gas F51. A radiative heat transfer space 201 is formed around the burner 1; therefore, a particularly large amount of heat is applied to the reforming reaction flow path 402 via radiation from the radiative heat transfer space 201.

[0068] In the flow of combustion gas F51, the downstream portion of combustion space 202 is connected to air flow path 405. Therefore, temperature-regulating air F57 mixes with combustion gas F51 at a position downstream of the combustion completion point in combustion space 202. Thus, the temperature of combustion gas F51 can be adjusted without affecting the combustion reaction.

[0069] The temperature of the reformed gas F53 at the outlet of the reforming reaction flow path 402 is detected by the reformed gas temperature sensor 9. The control unit 8 controls the flow rate of air F57 based on the temperature detected by the reformed gas temperature sensor 9. For example, the control unit 8 controls the flow regulating valve 406 so that the higher the temperature of the reformed gas F53, the greater the flow rate of air F57. Thus, the reaction temperature of the reforming reaction, as expressed by equations (1) and (2), can be adjusted.

[0070] Oxidant F50, for example, at a temperature of 650–700°C, is supplied from a heating source to the oxidant flow path 600. At the oxidant branch 2, the oxidant F50 is diverted to the combustion-supporting gas flow path 602 and the catalyst layer peripheral gas inlet flow path 601. A portion of the oxidant F50 flows as combustion-supporting gas F56 in the combustion-supporting gas flow path 602. Combustion-supporting gas F56, flowing through the combustion-supporting gas flow path 602, is supplied to the burner 1.

[0071] Another portion of the oxidant F50 flows as catalyst bed peripheral gas F54 in catalyst bed peripheral gas inlet flow path 601. Catalyst bed peripheral gas F54 flows through catalyst bed peripheral gas inlet flow path 601 and is supplied to catalyst bed peripheral flow path 403. While flowing in catalyst bed peripheral flow path 403, catalyst bed peripheral gas F54 heats reforming reaction flow path 402 via intermediate wall 502. This heat becomes the remaining heat energy required for the reforming reaction. By heating reforming reaction flow path 402, the temperature of catalyst bed peripheral gas F54 is reduced to approximately 400°C.

[0072] The gas F54 surrounding the catalyst layer passes through the connecting part 510 and merges with the combustion gas F51 at the merging part 200. The merged gas flows out to the outside as exhaust gas F58 from the exhaust gas flow path 404.

[0073] Figure 2This is a diagram showing the temperature distribution of the fuel processing apparatus in this embodiment. Figure 2 The horizontal axis represents the position x in the direction of the central axis 100a. For position x, the inlet of the reforming reaction flow path 402 is set to 0, the outlet of the reforming reaction flow path 402 is set to 1, and the length of the reforming reaction flow path 402 in the direction of the central axis 100a is set to L, thus making it dimensionless. The range of negative values ​​for position x represents the second raw material preheating section 203a or the first raw material preheating section 203. In this embodiment, the confluence section 200 is provided at a position less than 0 in the direction of the central axis 100a. Figure 2 The vertical axis represents temperature (°C). Figure 2 The solid line in the figure represents the temperature of the combustion gas F51. Figure 2 The long dashed line in the figure represents the temperature of the gas F54 surrounding the catalyst layer. Figure 2 The short dashed line in the figure represents the temperature of raw material F52 and reforming gas F53.

[0074] When the amount of reforming catalyst 5 is appropriately set, the reforming reaction represented by equations (1) and (2) is affected by the temperature distribution of the feedstock F52 and reforming gas F53 flowing in the reforming reaction flow path 402.

[0075] Combustion-supporting gas F56 is supplied to burner 1. Combustion-supporting gas F56 is a portion of the oxidizer F50 that is diverted at oxidizer branch 2. The flow rate of combustion-supporting gas F56 determines the flame temperature during combustion and affects the combustion state. That is, if the flow rate of combustion fuel F55 is assumed to be constant, the adiabatic flame temperature can theoretically be determined.

[0076] If the flame temperature is too high, the heat resistance of the components constituting the fuel processing device 100 may not be guaranteed. On the other hand, if the flame temperature is too low, heat transfer from the combustion gas F51 to the raw material F52 and the reformed gas F53 becomes difficult. That is, there is an appropriate range for the flame temperature. Furthermore, there is an appropriate range for the oxygen ratio in order to ensure complete combustion of the combustion fuel F55 in the combustion space 202. Therefore, the flow rate of the combustion-supporting gas F56, that is, the distribution ratio at the oxidizer branch 2, is roughly determined.

[0077] In the fuel processing apparatus of this embodiment, when the flow rates of the combustion-supporting gas F56 and the flow rates of the gas F54 surrounding the catalyst layer are appropriately balanced relative to the reforming reaction, a reaction is formed that is approximately as follows: Figure 2 The temperature distribution is shown. That is, when the flame temperature and oxygen ratio are within appropriate ranges corresponding to the flow rate of the combustion fuel F55, and the thermal energy of the catalyst layer peripheral gas F54 and the combustion-supporting gas F56 is within appropriate ranges, from... Figure 2As the flow path shifts from right to left, the temperature of the combustion gas F51 and the temperature of the gas F54 surrounding the catalyst layer decrease in the same manner. Therefore, at the confluence section 200, the temperatures of the combustion gas F51 and the gas F54 surrounding the catalyst layer are at the same level.

[0078] Here, the oxidant F50 is not limited to cathode exhaust gas supplied from a high-temperature fuel cell. The oxidant F50 only needs to have a gas temperature of approximately 600°C or higher and contain the required amount of components that support the combustion reaction. High-temperature oxygen-containing exhaust gas from the plant can be used as the oxidant F50.

[0079] The fuel supplied to burner 1 can be the same as or different from raw material F52. The fuel supplied to burner 1 can also be a mixture of fuel the same as raw material F52 and fuel different from raw material F52.

[0080] For example, when the fuel processing device 100 is installed in a fuel cell system, the combustion fuel F55 can be part or all of the anode exhaust gas. Approximately 70-90% of the hydrogen contained in the reformed gas F53 is consumed by power generation in the fuel cell stack. The remaining hydrogen is contained in the anode exhaust gas. Therefore, it is possible to supply part or all of the anode exhaust gas as combustion fuel F55 to the burner 1.

[0081] The combustion feedstock F59 is the same as feedstock F52. The combustion feedstock F59 is supplied to the burner 1, for example, during the heating process when the fuel treatment device 100 is started. In addition, fuel that is a mixture of part or all of the anode exhaust gas with feedstock F52 is sometimes used as fuel for the burner 1.

[0082] In this embodiment, a portion of the oxidant F50 supplied from the heating source is used as the combustion-supporting gas F56, and another portion of the oxidant F50 is used as the catalyst layer peripheral gas F54. The combustion-supporting gas F56 is supplied to the burner 1 and combusts together with the combustion fuel F55 or the combustion feedstock F59. The catalyst layer peripheral gas F54 heats the second feedstock preheating section 203a and the reforming reaction flow path 402 from the outer peripheral side through the catalyst layer peripheral flow path 403. The combustion gas F51 generated by combustion heats the second feedstock preheating section 203a and the reforming reaction flow path 402 from the inner peripheral side through the combustion gas flow path 401.

[0083] In this way, the second raw material preheating section 203a and the reforming reaction flow path 402 are heated from both the outer and inner peripheral sides. This increases the heat transfer area relative to the second raw material preheating section 203a and the reforming reaction flow path 402, reducing heat loss. Therefore, a fuel processing device with high thermal efficiency is achieved. Furthermore, the improved heat transfer characteristics enable miniaturization of the fuel processing device 100.

[0084] Furthermore, since the reforming reaction flow path 402 is heated from both the outer and inner peripheral sides, the temperature of the reforming reaction flow path 402 can be homogenized in the radial direction of the fuel processing device 100. Therefore, reformed gas F53 with minimal compositional changes due to the reaction can be obtained.

[0085] In the combustion gas F51, a temperature difference may sometimes occur in the circumferential direction due to the combustion state of the burner 1. In this case, a temperature difference may also occur in the circumferential direction of the flame tube wall 503 due to heat transfer from the combustion gas F51. However, in this embodiment, a radiative heat transfer space 201 is provided inside the flame tube wall 503. Therefore, if a temperature difference occurs in the circumferential direction of the flame tube wall 503, heat transfer from the high-temperature part to the low-temperature part of the flame tube wall 503 is generated through radiation in the radiative heat transfer space 201. Therefore, the temperature difference in the circumferential direction of the flame tube wall 503 can be reduced. As a result, the temperature of the reformed gas F53 flowing in the reforming reaction flow path 402 can be made more uniform in the circumferential direction.

[0086] In this embodiment, a flame baffle 3 and a heat-insulating material 6 are provided on the inner circumferential side of the downstream portion of the combustion gas flow path 401. Therefore, heat transfer from the radiative heat transfer space 201 is suppressed in the downstream portion of the combustion gas flow path 401. This prevents overheating of the reforming reaction flow path 402. Consequently, carbon precipitation due to the thermal decomposition of the feedstock F52 can be prevented.

[0087] As described above, the fuel processing apparatus 100 of this embodiment includes a reforming section 110 and a combustion section 120. The reforming section 110 is configured to generate reformed gas F53 from raw material F52. The combustion section 120 is configured to generate combustion gas F51 by burning combustion fuel F55 or combustion raw material F59 and combustion-supporting gas F56 in the combustion space 202.

[0088] The reforming unit 110 has an inner wall 501 and an intermediate wall 502 disposed on the outer periphery of the inner wall 501. A reforming reaction flow path 402 is formed between the inner wall 501 and the intermediate wall 502. A reforming catalyst 5 is filled in the reforming reaction flow path 402. Feed material F52 and reforming gas F53 flow in the reforming reaction flow path 402.

[0089] A combustion gas flow path 401 is formed at a position closer to the inner periphery than the inner wall 501. Combustion gas F51 flows through the combustion gas flow path 401. The combustion gas flow path 401 is adjacent to the reforming reaction flow path 402 across the inner wall 501. A catalyst layer peripheral flow path 403 is formed at a position closer to the outer periphery than the intermediate wall 502. Catalyst layer peripheral gas F54 flows through the catalyst layer peripheral flow path 403. The catalyst layer peripheral flow path 403 is adjacent to the reforming reaction flow path 402 across the intermediate wall 502.

[0090] The fuel processing device 100 also includes a confluence section 200, an exhaust gas flow path 404, an oxidant flow path 600, an oxidant branch section 2, a combustion-supporting gas flow path 602, and a catalyst layer peripheral gas inlet flow path 601.

[0091] At the confluence section 200, the combustion gas F51 flowing through the combustion gas flow path 401 merges with the catalyst layer peripheral gas F54 flowing through the catalyst layer peripheral flow path 403. The combustion gas F51 and the catalyst layer peripheral gas F54 that merge at the confluence section 200 flow as exhaust gas F58 in the exhaust gas flow path 404. Oxidant F50 supplied from the heating source flows in the oxidant flow path 600. An oxidant branch section 2 is provided in the oxidant flow path 600. A combustion-supporting gas flow path 602 connects the oxidant branch section 2 to the combustion section 120. The combustion-supporting gas flow path 602 allows a portion of the oxidant F50 to flow as combustion-supporting gas F56. A catalyst layer peripheral gas inlet flow path 601 connects the oxidant branch section 2 to the catalyst layer peripheral flow path 403. The catalyst layer peripheral gas inlet flow path 601 allows another portion of the oxidant F50 to flow.

[0092] Here, combustion fuel F55 and combustion feedstock F59 are examples of fuels. Inner wall 501 is an example of a first cylindrical wall. Middle wall 502 is an example of a second cylindrical wall. Catalyst layer outer peripheral flow path 403 is an example of an outer peripheral flow path. Catalyst layer outer peripheral gas F54 is an example of an outer peripheral gas. Catalyst layer outer peripheral gas inlet flow path 601 is an example of an outer peripheral gas inlet flow path.

[0093] According to this structure, the feedstock F52 and reformed gas F53 in the reforming reaction flow path 402 are heated from the inner peripheral side by the combustion gas F51 in the combustion gas flow path 401, and from the outer peripheral side by the catalyst layer outer peripheral gas F54 in the catalyst layer outer peripheral flow path 403. This increases the heat transfer area relative to the reforming reaction flow path 402, thus achieving higher thermal efficiency in the fuel processing apparatus 100. Furthermore, the temperature distribution in the reforming reaction flow path 402 can be homogenized in the radial direction, resulting in reformed gas F53 with less compositional variation due to the reaction. Moreover, heat dissipation from the reforming reaction flow path 402 can be suppressed, thereby reducing heat loss.

[0094] The fuel processing apparatus 100 of this embodiment further includes a flame tube wall 503, a flame baffle 3, and a radiant heat transfer space 201. The flame tube wall 503 is disposed at a position closer to the inner periphery than the inner wall 501. The flame baffle 3 is disposed inside the flame tube wall 503 corresponding to the combustion section 120. The radiant heat transfer space 201 is surrounded by the flame tube wall 503, the flame baffle 3, and the combustion section 120.

[0095] According to this structure, the circumferential temperature difference of the flame tube wall 503 can be reduced through radiation in the radiative heat transfer space 201. Therefore, the temperature of the reformed gas F53 flowing in the reforming reaction flow path 402 can be homogenized circumferentially.

[0096] The fuel processing apparatus 100 of this embodiment further includes a first feedstock preheating unit 203. The first feedstock preheating unit 203 preheats the feedstock F52 flowing into the reforming reaction flow path 402 by heat transfer from the gas F54 surrounding the catalyst layer or the combustion gas F51. Here, the first feedstock preheating unit 203 is an example of a feedstock preheating unit. According to this structure, the feedstock F52 is preheated before flowing into the reforming reaction flow path 402, thus promoting the reforming reaction in the reforming reaction flow path 402.

[0097] The fuel processing apparatus 100 of this embodiment also includes an air flow path 405. The air flow path 405 supplies temperature-regulating air F57 to the combustion gas F51 downstream of the combustion space 202. According to this structure, the temperature of the combustion gas F51 can be adjusted without affecting the combustion reaction.

[0098] The fuel processing apparatus 100 of this embodiment further includes a reformed gas temperature sensor 9 and a control unit 8. The reformed gas temperature sensor 9 detects the temperature of the reformed gas F53 at the outlet of the reforming reaction flow path 402. Based on the temperature detected by the reformed gas temperature sensor 9, the control unit 8 controls the flow rate of air F57 supplied to the combustion gas F51. With this structure, the reaction temperature of the reforming reaction can be adjusted.

[0099] In the fuel processing apparatus 100 of this embodiment, the heating source is a fuel cell. The oxidant F50 is cathode exhaust gas supplied from the fuel cell. With this configuration, efficient heat utilization can be achieved in the fuel cell system.

[0100] Implementation Method 2

[0101] The fuel processing apparatus of Embodiment 2 will be described. Figure 3 This is a cross-sectional schematic diagram of the fuel processing apparatus of this embodiment. Figure 3 The vertical direction indicates the vertical direction.

[0102] like Figure 3As shown, in this embodiment, the confluence section 200 is formed between the flame tube wall 503 and the inner wall 501. A combustion gas flow path 401 is formed below the confluence section 200 in the space between the flame tube wall 503 and the inner wall 501. A downstream portion 403b of the catalyst layer outer peripheral flow path 403 is formed above the confluence section 200 in the space between the flame tube wall 503 and the inner wall 501. An upstream portion 403a of the catalyst layer outer peripheral flow path 403 is formed in the space between the middle wall 502 and the outer wall 504. The downstream portion 403b is connected to the upstream portion 403a via a connecting portion 510. The downstream portion 403b is opposite to the upstream portion 403a across the second raw material preheating section 203a and the reforming reaction flow path 402.

[0103] In this embodiment, an oxidant distribution regulator 303 is provided in the catalyst layer peripheral gas inlet flow path 601. The oxidant distribution regulator 303 adjusts the flow ratio of the combustion-supporting gas F56 to the catalyst layer peripheral gas F54. An orifice plate is used, for example, as the oxidant distribution regulator 303. By providing the orifice plate, the pressure loss of the catalyst layer peripheral gas F54 in the catalyst layer peripheral gas inlet flow path 601 changes. By providing an appropriate orifice plate, the combustion-supporting gas F56 and the catalyst layer peripheral gas F54 are distributed at the oxidant branch 2 at the desired flow ratio. The other structures are the same as in Embodiment 1.

[0104] The operation of the fuel processing apparatus according to this embodiment will be described. Catalyst layer peripheral gas F54 flows upward in the upstream portion 403a of the catalyst layer peripheral flow path 403. The flow of catalyst layer peripheral gas F54 in the upstream portion 403a forms a countercurrent flow relative to the flow of feedstock F52 and reformed gas F53 in the reforming reaction flow path 402 and the flow of feedstock F52 in the second feedstock preheating section 203a. The catalyst layer peripheral gas F54 flowing in the upstream portion 403a applies heat energy from the peripheral side to the feedstock F52 and reformed gas F53 flowing in the reforming reaction flow path 402, and also applies heat energy from the peripheral side to the feedstock F52 flowing in the second feedstock preheating section 203a.

[0105] After the catalyst layer peripheral gas F54 flows upward through the upstream section 403a, it passes through the connecting section 510 and reaches a position closer to the inner periphery than the second raw material preheating section 203a and the reforming reaction flow path 402, before flowing into the downstream section 403b. In the downstream section 403b, the catalyst layer peripheral gas F54 flows downward. The flow of the catalyst layer peripheral gas F54 in the downstream section 403b forms a parallel flow with respect to the flow of raw material F52 and reforming gas F53 in the reforming reaction flow path 402 and the flow of raw material F52 in the second raw material preheating section 203a. The catalyst layer peripheral gas F54 flowing in the downstream section 403b applies heat energy to the raw material F52 flowing in the second raw material preheating section 203a from the inner periphery, and also applies heat energy to the raw material F52 and reforming gas F53 flowing in the reforming reaction flow path 402 from the inner periphery.

[0106] The catalyst layer peripheral gas F54 flowing in the downstream section 403b merges with the combustion gas F51 at the confluence section 200. The merged gas flows out to the outside as exhaust gas F58 from the exhaust gas flow path 404.

[0107] Figure 4 This is a graph showing the temperature distribution of the fuel processing apparatus in this embodiment. Figure 4 The horizontal and vertical axes are Figure 2 The horizontal and vertical axes are the same. Here, in this embodiment, the confluence section 200 is located at a position greater than 0 and less than 1 in the direction of the central axis 100a, and is located on the inner periphery side of the reforming reaction flow path 402. The connecting section 510 is located at a position less than 0 in the direction of the central axis 100a. Figure 4 The solid line in the figure represents the temperature of the combustion gas F51. Figure 4 The long dashed line in the figure represents the temperature of the gas F54 surrounding the catalyst layer. Figure 4 The short dashed line in the figure represents the temperature of raw material F52 and reforming gas F53.

[0108] Even when the combustion conditions described above are properly met, if the distribution ratio of the combustion-supporting gas F56 from the oxidant F50 is thermally small, the temperature drop of the combustion gas F51 generated with heat transfer to the reforming reaction flow path 402 is greater than the temperature drop of the catalyst layer peripheral gas F54 generated with heat transfer to the reforming reaction flow path 402. Consequently, the heat transfer performance deteriorates.

[0109] For example, if the distribution ratio of the combustion-supporting gas F56 from the oxidant F50 is low in terms of thermal energy, the thermal energy of the combustion gas F51 will be less even if the combustion temperature is the same. On the other hand, the thermal energy of the gas F54 surrounding the catalyst layer will be greater. Therefore, the closer the position in the direction of the central axis 100a is to the inlet of the reforming reaction flow path 402, the greater the temperature drop of the combustion gas F51 compared to the temperature of the gas F54 surrounding the catalyst layer. As a result, near the inlet of the reforming reaction flow path 402, the temperature difference between the combustion gas F51 and the feedstock F52 and the reformed gas F53 will decrease, thus worsening the heat transfer characteristics.

[0110] On the other hand, even when the position along the central axis 100a is close to the inlet of the reforming reaction flow path 402, the temperature of the gas F54 surrounding the catalyst bed does not decrease as much as the temperature of the combustion gas F51. Therefore, the temperature difference between the gas F54 surrounding the catalyst bed and the feedstock F52 and reformed gas F53 is greater than the temperature difference between the combustion gas F51 and the feedstock F52 and reformed gas F53. Consequently, particularly near the inlet of the reforming reaction flow path 402, the temperature of the reforming reaction flow path 402 becomes uneven in the radial direction of the fuel processing device 100.

[0111] In this embodiment, the catalyst layer peripheral gas F54 first flows in the upstream portion 403a of the catalyst layer peripheral flow path 403. The flow of the catalyst layer peripheral gas F54 in the upstream portion 403a is a countercurrent flow relative to the flow of the feedstock F52 and the reforming gas F53. The catalyst layer peripheral gas F54 in the upstream portion 403a applies thermal energy to the feedstock F52 and the reforming gas F53 from the peripheral side. Figure 4 The interval from point A to point B represents the temperature distribution of the gas F54 surrounding the catalyst layer in the upstream section 403a.

[0112] Subsequently, the catalyst layer peripheral gas F54 reverses direction at the connecting section 510 and flows around to a position closer to the inner periphery of the reforming reaction flow path 402, entering the downstream section 403b of the catalyst layer peripheral flow path 403. The flow of the catalyst layer peripheral gas F54 in the downstream section 403b is parallel to the flow of the feedstock F52 and the reforming gas F53. The catalyst layer peripheral gas F54 in the downstream section 403b applies heat energy to the feedstock F52 and the reforming gas F53 from the inner periphery. Figure 4 The interval from point B to point C represents the temperature distribution of the gas F54 surrounding the catalyst layer in the downstream section 403b.

[0113] That is, in the downstream portion of the reforming reaction flow path 402 during the flow of raw material F52 and reforming gas F53, the catalyst layer peripheral gas F54 heats the flow from the outer peripheral side, and the combustion gas F51 heats the flow from the inner peripheral side. In the upstream portion of the reforming reaction flow path 402, the catalyst layer peripheral gas F54 flowing in the upstream portion 403a heats the flow from the outer peripheral side, and the catalyst layer peripheral gas F54 flowing in the downstream portion 403b heats the flow from the inner peripheral side.

[0114] like Figure 4 As shown, in this embodiment, the temperature difference between the catalyst layer peripheral gas F54 and the raw material F52 and reforming gas F53 in the downstream section 403b can be ensured on the inner peripheral side near the inlet of the reforming reaction flow path 402. Therefore, the heat transfer characteristics of the fuel processing device 100 can be improved. Therefore, even when the distribution ratio of the combustion-supporting gas F56 is small in terms of thermal energy, the thermal efficiency of the fuel processing device 100 can be improved.

[0115] Furthermore, in this embodiment, the temperature of the reforming reaction flow path 402 can be homogenized in the radial direction of the fuel processing device 100. Therefore, even when the distribution ratio of the combustion-supporting gas F56 is small in terms of thermal energy, reformed gas F53 with minimal compositional changes due to the reaction can be obtained.

[0116] Furthermore, in this embodiment, the temperature of the combustion gas F51 at the confluence section 200 can be made close to the temperature of the gas F54 surrounding the catalyst layer at the confluence section 200. Therefore, heat loss can be reduced. Thus, even when the distribution ratio of the combustion-supporting gas F56 is low in terms of heat energy, the thermal efficiency of the fuel processing device 100 can be improved.

[0117] Furthermore, in this embodiment, the combustion reaction can be carried out within a suitable oxygen ratio range, thus achieving stable and complete combustion. Moreover, the heat transfer characteristics are improved in this embodiment, thereby enabling miniaturization of the fuel processing device 100.

[0118] Furthermore, in this embodiment, the oxidant distribution regulator 303 is disposed in the catalyst layer peripheral gas inlet flow path 601, but is not limited thereto. The distribution ratio of the combustion-supporting gas F56 to the catalyst layer peripheral gas F54 is determined by the ratio of the pressure loss of the combustion-supporting gas F56 flow path to the pressure loss of the catalyst layer peripheral gas F54 flow path. Therefore, the oxidant distribution regulator 303 may also be disposed in the combustion-supporting gas flow path 602, or may be disposed in both the combustion-supporting gas flow path 602 and the catalyst layer peripheral gas inlet flow path 601.

[0119] As explained above, in the fuel processing apparatus 100 of this embodiment, an oxidant distribution regulator 303 is provided on at least one of the combustion-supporting gas flow path 602 and the catalyst layer peripheral gas introduction flow path 601 to determine the distribution ratio of the combustion-supporting gas F56 and the catalyst layer peripheral gas F54. According to this structure, the temperature of the reforming reaction flow path 402 can be homogenized in the radial direction, thus obtaining reformed gas F53 with minimal compositional variation due to the reaction.

[0120] In the fuel processing apparatus 100 of this embodiment, the catalyst layer peripheral flow path 403 has an upstream portion 403a and a downstream portion 403b. The upstream portion 403a is formed at a position closer to the outer periphery than the intermediate wall 502. The downstream portion 403b is formed at a position closer to the inner periphery than the inner wall 501. The confluence portion 200 is located at a position closer to the inner periphery than the inner wall 501. The upstream portion 403a and the downstream portion 403b are opposite each other across the reforming reaction flow path 402. According to this structure, even when the distribution ratio of the combustion-supporting gas F56 is small in terms of thermal energy, reformed gas F53 with less compositional change due to the reaction can be obtained, and the thermal efficiency of the fuel processing apparatus 100 can be improved.

[0121] Implementation Method 3

[0122] The fuel processing apparatus of Embodiment 3 will be described. Figure 5 This is a cross-sectional schematic diagram of the fuel processing apparatus of this embodiment. Figure 5 The vertical direction indicates the vertical direction.

[0123] like Figure 5 As shown, in this embodiment, the confluence section 200 is formed between the middle wall 502 and the outer wall 504. A catalyst layer peripheral flow path 403 is formed below the confluence section 200 in the space between the middle wall 502 and the outer wall 504. A downstream section 401b of the combustion gas flow path 401 is formed above the confluence section 200 in the space between the middle wall 502 and the outer wall 504. An upstream section 401a of the combustion gas flow path 401 is formed between the flame tube wall 503 and the inner wall 501. The downstream section 401b is connected to the upstream section 401a via a connecting section 510. The downstream section 401b is opposite to the upstream section 401a across the second raw material preheating section 203a and the reforming reaction flow path 402. The other structures are the same as in Embodiment 1.

[0124] The operation of the fuel processing apparatus according to this embodiment will be described. Combustion gas F51 flows upward in the upstream portion 401a of the combustion gas flow path 401. The flow of combustion gas F51 in the upstream portion 401a forms a countercurrent flow relative to the flow of feedstock F52 and reformed gas F53 in the reforming reaction flow path 402 and the flow of feedstock F52 in the second feedstock preheating section 203a. The combustion gas F51 flowing in the upstream portion 401a applies heat energy from the inner circumference to the feedstock F52 and reformed gas F53 flowing in the reforming reaction flow path 402, and also applies heat energy from the inner circumference to the feedstock F52 flowing in the second feedstock preheating section 203a.

[0125] After flowing upward through the upstream section 401a, the combustion gas F51 passes through the connecting section 510 and flows around to a position closer to the outer periphery than the second raw material preheating section 203a and the reforming reaction flow path 402, before flowing into the downstream section 401b. In the downstream section 401b, the combustion gas F51 flows downward. The flow of the combustion gas F51 in the downstream section 401b forms a parallel flow with respect to the flow of the raw material F52 and reforming gas F53 in the reforming reaction flow path 402 and the flow of the raw material F52 in the second raw material preheating section 203a. The combustion gas F51 flowing in the downstream section 401b applies heat energy to the raw material F52 flowing in the second raw material preheating section 203a from the outer periphery, and also applies heat energy to the raw material F52 and reforming gas F53 flowing in the reforming reaction flow path 402 from the outer periphery.

[0126] Combustion gas F51 flowing in downstream section 401b merges with catalyst layer peripheral gas F54 at confluence section 200. The merged gas flows out to the outside as exhaust gas F58 from exhaust gas flow path 404.

[0127] Figure 6 This is a graph showing the temperature distribution of the fuel processing apparatus in this embodiment. Figure 6 The horizontal and vertical axes are Figure 2 The horizontal and vertical axes are the same. Here, the confluence section 200 of this embodiment is provided at a position greater than 0 and less than 1 in the direction of the central axis 100a, and is provided at a position on the outer periphery of the reforming reaction flow path 402. Figure 6 The solid line in the figure represents the temperature of the combustion gas F51. Figure 6 The long dashed line in the figure represents the temperature of the gas F54 surrounding the catalyst layer. Figure 6 The short dashed line in the figure represents the temperature of raw material F52 and reforming gas F53.

[0128] Even under suitable combustion conditions, if the distribution ratio of the catalyst layer peripheral gas F54 from the oxidant F50 is thermally small, the temperature drop of the catalyst layer peripheral gas F54 generated by heat transfer to the reforming reaction flow path 402 is greater than the temperature drop of the combustion gas F51 generated by heat transfer to the reforming reaction flow path 402. Consequently, the heat transfer performance deteriorates.

[0129] For example, when the distribution ratio of the catalyst layer peripheral gas F54 from the oxidant F50 is low in terms of thermal energy, the thermal energy possessed by the catalyst layer peripheral gas F54 decreases. On the other hand, the thermal energy possessed by the combustion gas F51 increases. Therefore, the closer the position in the direction of the central axis 100a is to the inlet of the reforming reaction flow path 402, the greater the temperature drop of the catalyst layer peripheral gas F54 compared to the temperature of the combustion gas F51. Consequently, near the inlet of the reforming reaction flow path 402, the temperature difference between the catalyst layer peripheral gas F54 and the feedstock F52 and reforming gas F53 decreases, thus worsening the heat transfer characteristics.

[0130] On the other hand, even when the position along the central axis 100a is close to the inlet of the reforming reaction flow path 402, the temperature of the combustion gas F51 does not decrease as much as that of the gas F54 surrounding the catalyst layer. Therefore, the temperature difference between the combustion gas F51 and the feedstock F52 and reformed gas F53 is greater than the temperature difference between the gas F54 surrounding the catalyst layer and the feedstock F52 and reformed gas F53. Consequently, particularly near the inlet of the reforming reaction flow path 402, the temperature of the reforming reaction flow path 402 becomes uneven in the radial direction of the fuel processing device 100.

[0131] In this embodiment, the combustion gas F51 first flows in the upstream portion 401a of the combustion gas flow path 401. The flow of the combustion gas F51 in the upstream portion 401a is opposite to the flow of the raw material F52 and the reforming gas F53. The combustion gas F51 in the upstream portion 401a applies heat energy to the raw material F52 and the reforming gas F53 from the inner peripheral side. Figure 6 The interval from point D to point E represents the temperature distribution of combustion gas F51 in the upstream section 401a.

[0132] Subsequently, the combustion gas F51 reverses direction at the connecting section 510 and flows around to a position closer to the outer periphery of the reforming reaction flow path 402, entering the downstream section 401b of the combustion gas flow path 401. The flow of combustion gas F51 in the downstream section 401b is parallel to the flow of feedstock F52 and reforming gas F53. The combustion gas F51 in the downstream section 401b applies heat energy to feedstock F52 and reforming gas F53 from the outer periphery. Figure 6 The interval from point E to point F represents the temperature distribution of combustion gas F51 in the downstream section 401b.

[0133] That is, in the downstream portion of the reforming reaction flow path 402 during the flow of raw material F52 and reforming gas F53, the combustion gas F51 heats the downstream portion from the inner peripheral side, and the catalyst layer outer peripheral gas F54 heats the upstream portion from the outer peripheral side. In the upstream portion of the reforming reaction flow path 402, the combustion gas F51 flowing in the upstream portion 401a heats the upstream portion from the inner peripheral side, and the combustion gas F51 flowing in the downstream portion 401b heats the downstream portion from the outer peripheral side.

[0134] like Figure 6 As shown, in this embodiment, the temperature difference between the combustion gas F51 and the feedstock F52 and reformed gas F53 in the downstream section 401b can be ensured on the outer periphery near the inlet of the reforming reaction flow path 402. Therefore, the heat transfer characteristics of the fuel processing apparatus 100 can be improved. Thus, even when the distribution ratio of the gas F54 around the catalyst layer is small in terms of thermal energy, the thermal efficiency of the fuel processing apparatus 100 can be improved.

[0135] Furthermore, in this embodiment, the temperature of the reforming reaction flow path 402 can be homogenized in the radial direction of the fuel processing apparatus 100. Therefore, even when the distribution ratio of the gas F54 around the catalyst layer is small in terms of thermal energy, reforming gas F53 with minimal compositional changes due to the reaction can be obtained.

[0136] Furthermore, in this embodiment, the temperature of the combustion gas F51 at the confluence section 200 can be made close to the temperature of the gas F54 surrounding the catalyst layer at the confluence section 200. Therefore, heat loss can be reduced. Thus, even when the distribution ratio of the gas F54 surrounding the catalyst layer is small in terms of heat energy, the thermal efficiency of the fuel processing device 100 can be improved.

[0137] Furthermore, in this embodiment, the combustion reaction can be carried out within a suitable oxygen ratio range, thus achieving stable and complete combustion. Moreover, the heat transfer characteristics are improved, thereby enabling miniaturization of the fuel processing device 100.

[0138] As explained above, in the fuel processing apparatus 100 of this embodiment, the combustion gas flow path 401 has an upstream portion 401a and a downstream portion 401b. The upstream portion 401a is formed at a position closer to the inner periphery than the inner wall 501. The downstream portion 401b is formed at a position closer to the outer periphery than the middle wall 502. The merging portion 200 is located at a position closer to the outer periphery than the middle wall 502. The upstream portion 401a and the downstream portion 401b of the combustion gas flow path 401 are opposite each other across the reforming reaction flow path 402. According to this structure, even when the distribution ratio of the gas F54 around the catalyst layer is small in terms of thermal energy, it is possible to obtain reformed gas F53 with less compositional change due to the reaction, and the thermal efficiency of the fuel processing apparatus 100 can be improved.

[0139] Implementation Method 4

[0140] The fuel processing apparatus of Embodiment 4 will be described. Figure 7 This is a cross-sectional schematic diagram of the fuel processing apparatus of this embodiment. Figure 7 The vertical direction indicates the vertical direction.

[0141] like Figure 7 As shown, the first raw material preheating section 203 penetrates the upper surface wall 506 and the closed wall 505, and is connected to the second raw material preheating section 203a through the connecting section 510. The first raw material preheating section 203 is bent into a spiral shape around the central axis 100a in the connecting section 510. The first raw material preheating section 203 is formed of a circular tube. The first raw material preheating section 203 is configured to absorb changes in the distance between the upper surface wall 506 and the closed wall 505 by extending and retracting the spiral portion in the direction of the central axis 100a. Other structures are the same as in Embodiment 2.

[0142] The operation of the fuel processing apparatus according to this embodiment will be described. Before being introduced into the reforming reaction flow path 402, the feedstock F52 passes through a first feedstock preheating section 203 and a second feedstock preheating section 203a. In the first feedstock preheating section 203, the feedstock F52 receives heat energy from the catalyst layer peripheral gas F54 flowing in the connecting section 510. Thus, the feedstock F52 is preheated. In the second feedstock preheating section 203a, the feedstock F52 receives heat energy from the catalyst layer peripheral gas F54 flowing in the upstream section 403a of the catalyst layer peripheral flow path 403, and also receives heat energy from the catalyst layer peripheral gas F54 flowing in the downstream section 403b of the catalyst layer peripheral flow path 403. Thus, the feedstock F52 is further preheated. The preheated feedstock F52 flows into the reforming reaction flow path 402.

[0143] The fuel processing device 100 has a burner 1 at its lower part on the central axis 100a. Therefore, in the fuel processing device 100, a temperature distribution is formed in which the temperature is higher towards the lower part in the vertical direction and higher towards the inner periphery in the radial direction. In the reforming reaction flow path 402, a roughly one-dimensional temperature distribution is formed, such that the temperature is higher towards the lower part.

[0144] On the other hand, since flammable gases flow through the reforming reaction flow path 402, it is necessary to ensure the strength of the structural components forming the reforming reaction flow path 402. Therefore, it is effective to ensure that the inner wall 501 and the middle wall 502 do not generate thermal stress under high-temperature operating conditions. In this embodiment, the first raw material preheating section 203 is formed in a spiral shape, so the thermal expansion of the inner wall 501 and the middle wall 502 is absorbed by the first raw material preheating section 203.

[0145] According to this embodiment, in addition to the effects of Embodiment 2, the following effects can also be obtained. Since the first raw material preheating section 203 is formed in a spiral shape within the communicating section 510, the heat transfer area of ​​the first raw material preheating section 203 can be increased. Therefore, compared to the case where the raw material F52 is preheated only by the second raw material preheating section 203a, the heat transfer performance can be improved.

[0146] Furthermore, since the first raw material preheating section 203 is formed in a spiral shape, it can absorb the thermal expansion of the inner wall 501 and the middle wall 502. As a result, the reliability of the structural components of the fuel processing apparatus 100 can be improved.

[0147] The following describes variations of this embodiment. Figure 8 This is a cross-sectional schematic diagram of a modified fuel processing apparatus according to this embodiment. Figure 8 As shown, the first raw material preheating section 203 has a structure that allows it to expand and contract in the direction of the central axis 100a, at least between the upper surface wall 506 and the closed wall 505. For example, a bellows with expansion capability is used as the first raw material preheating section 203 between the upper surface wall 506 and the closed wall 505. The other structures are the same as in Embodiment 2.

[0148] Based on this variation, we can obtain the same as... Figure 7 The structure shown achieves the same effect. Furthermore, according to this modified example, the length of the first raw material preheating section 203 in the direction of the central axis 100a can be made greater than... Figure 7 The structure shown is short, thus enabling the fuel processing device 100 to be miniaturized. Furthermore, the first raw material preheating section 203 can also be circumferentially curved along the fuel processing device 100 to ensure a larger heat transfer area between the first raw material preheating section 203 and the gas F54 surrounding the catalyst layer.

[0149] As explained above, in the fuel processing apparatus 100 of this embodiment, the first raw material preheating section 203 has a expandable structure. According to this structure, the thermal expansion of the inner wall 501 and the middle wall 502 can be absorbed by the first raw material preheating section 203, thus improving the reliability of the structural components of the fuel processing apparatus 100.

[0150] Implementation Method 5

[0151] The fuel processing apparatus of Embodiment 5 will be described. Figure 9 This is a cross-sectional schematic diagram of the fuel processing apparatus of this embodiment. Figure 9 The vertical direction indicates the vertical direction.

[0152] like Figure 9As shown, the fuel processing device 100 includes a cathode gas preheating section 204. Cathode gas F60 flows into the cathode gas preheating section 204 from outside the fuel processing device 100. In the cathode gas preheating section 204, the cathode gas F60 is preheated by radiant heat from the combustion chamber 202 and heat transfer from the exhaust gas F58. The preheated cathode gas F60 is supplied as preheated cathode gas F61 to a heating source outside the fuel processing device 100. A high-temperature type fuel cell (not shown) is used as the heating source.

[0153] The cathode gas preheating section 204 includes an exhaust gas flow path 404, a preheating flow path 204a, and a discharge flow path 204b. The exhaust gas flow path 404 is located above the confluence section 200. In its horizontal cross-section, the exhaust gas flow path 404 is formed as an annular shape with the same diameter as the combustion gas flow path 401. The exhaust gas flow path 404 extends vertically. The exhaust gas F58, resulting from the merging of combustion gas F51 and catalyst layer peripheral gas F54, flows upwards through the exhaust gas flow path 404.

[0154] The preheating flow path 204a is positioned on the inner periphery of the combustion gas flow path 401 and the exhaust gas flow path 404. The preheating flow path 204a is formed in a circular shape in a horizontal cross-section. The preheating flow path 204a extends vertically. The preheating flow path 204a is positioned on the side opposite to the radiant heat transfer space 201, separated by the flame baffle 3, i.e., above the flame baffle 3.

[0155] The preheating flow path 204a is adjacent to the combustion gas flow path 401 and the exhaust gas flow path 404 via the flame tube wall 503. Cathode gas F60 supplied from outside the fuel processing device 100 flows downwards in the preheating flow path 204a. The flow of cathode gas F60 in the preheating flow path 204a forms an opposing flow relative to the flow of combustion gas F51 in the combustion gas flow path 401 and the flow of exhaust gas F58 in the exhaust gas flow path 404. The cathode gas F60 in the preheating flow path 204a is preheated through heat exchange with the exhaust gas F58 in the exhaust gas flow path 404 and the combustion gas F51 in the combustion gas flow path 401.

[0156] The discharge flow path 204b is positioned on the inner periphery side of the preheating flow path 204a. The discharge flow path 204b extends vertically. The lower end of the discharge flow path 204b is connected to the lower end of the preheating flow path 204a. The preheated cathode gas F61, preheated in the preheating flow path 204a, flows upwards in the discharge flow path 204b. The preheated cathode gas F61 flowing out of the discharge flow path 204b is supplied to a heating source external to the fuel processing device 100.

[0157] The first raw material preheating section 203 has a structure between the upper surface wall 506 and the closed wall 505 that allows it to extend and retract in the direction of the central axis 100a. The other structures are the same as in Embodiment 1.

[0158] The operation of the fuel processing apparatus according to this embodiment will now be described. Raw material F52 is introduced into the reforming reaction flow path 402 via the first raw material preheating section 203 and the second raw material preheating section 203a. The raw material F52 in the reforming reaction flow path 402 is heated from the inner peripheral side by the combustion gas F51 in the combustion gas flow path 401. Additionally, the raw material F52 in the reforming reaction flow path 402 is also heated from the outer peripheral side by the catalyst layer outer peripheral gas F54 in the catalyst layer outer peripheral flow path 403. In the reforming reaction flow path 402, reformed gas F53 is generated from the raw material F52 through the catalytic action of the reforming catalyst 5.

[0159] On the other hand, in the burner 1, combustion gas F51 at approximately 700–1200°C is generated through the combustion reaction of combustion-supporting gas F56 with combustion fuel F55 or combustion raw material F59. In the radiative heat transfer space 201, heat transfer is promoted by radiative heat from the flame of the burner 1 and convective heat transfer generated by the combustion gas F51, and the flame baffle 3 is heated.

[0160] Combustion gas F51 flows into combustion gas flow path 401. At the confluence section 200, combustion gas F51 merges with gas F54 surrounding the catalyst layer, becoming exhaust gas F58. Exhaust gas F58 flows through exhaust gas flow path 404.

[0161] Cathode gas F60 is supplied from outside the fuel processing unit 100 to the cathode gas preheating section 204. The cathode gas F60 flows into the preheating flow path 204a. The cathode gas F60 in the preheating flow path 204a is preheated through heat exchange with the exhaust gas F58 in the exhaust gas flow path 404 and the combustion gas F51 in the combustion gas flow path 401. The cathode gas F60 receives heat energy from the flame baffle 3 and is further preheated to approximately 550°C. Thus, the cathode gas F60 becomes preheated cathode gas F61. The preheated cathode gas F61 flows out of the fuel processing unit 100 through the discharge flow path 204b and is supplied to the heating source.

[0162] By heating the cathode gas F60 with the exhaust gas F58, the temperature of the exhaust gas F58 is reduced to, for example, about 65°C. The cooled exhaust gas F58 is then discharged to the outside of the fuel processing device 100.

[0163] In this embodiment, the heat energy of the exhaust gas F58 is recovered in the cathode gas preheating section 204, thus enabling operation with higher thermal efficiency than the fuel processing apparatus 100 in embodiments 1 to 4.

[0164] The heat energy recovered in the cathode gas preheating section 204 is used to preheat the cathode gas F60. The preheated cathode gas F60 is then supplied to fuel cells, etc. The exhaust gas from the fuel cell is used as oxidant F50. Thus, efficient heat utilization can be achieved in the fuel cell system. Furthermore, the fuel processing device 100 has a cathode gas heating function, thereby enabling miniaturization and high efficiency of the fuel cell system.

[0165] Furthermore, in this embodiment, the cathode gas F60 is preheated through heat exchange with the combustion gas F51 in the combustion gas flow path 401 and the exhaust gas F58 in the exhaust gas flow path 404, but it is not limited to this. The cathode gas F60 may also be preheated solely through heat exchange with the exhaust gas F58 in the exhaust gas flow path 404. In this case, a heat insulation member or the like may be provided to isolate heat transfer from the combustion gas flow path 401 to the cathode gas preheating section 204.

[0166] In addition, heat insulation material 6 is not provided in this embodiment, but heat insulation material of appropriate thickness can be provided according to the required temperature of preheating cathode gas F61.

[0167] As explained above, the fuel processing apparatus 100 of this embodiment also includes a cathode gas preheating unit 204. The cathode gas preheating unit 204 is configured to preheat the cathode gas F60 supplied to the fuel cell by heat transfer from the exhaust gas F58. According to this structure, efficient utilization of heat can be achieved in the fuel cell system.

[0168] In the fuel processing apparatus 100 of this embodiment, the cathode gas preheating unit 204 may also be configured to preheat the cathode gas F60 by radiant heat from the combustion space 202.

[0169] Implementation Method 6

[0170] The fuel processing apparatus of Embodiment 6 will be described. Figure 10 This is a cross-sectional schematic diagram of the fuel processing apparatus of this embodiment. Figure 10 The vertical direction indicates the vertical direction.

[0171] like Figure 10 As shown, the cathode gas preheating unit 204 has a main body 204c and a housing heat exchange unit 205. The main body 204c has the same structure as the cathode gas preheating unit 204 in Embodiment 5.

[0172] The heat exchange section 205 is box-shaped. The main body 204c of the reforming section 110, the combustion section 120, and the cathode gas preheating section 204 is housed inside the heat exchange section 205. That is, the reforming section 110, the combustion section 120, and the main body 204c of the cathode gas preheating section 204 are surrounded by the heat exchange section 205.

[0173] The heat exchange section 205 of the housing has a preheating flow path 205a and an exhaust gas flow path 205b. The exhaust gas flow path 205b is located on the internal space side of the heat exchange section 205 of the housing, which is closer to the preheating flow path 205a.

[0174] Preheating flow path 205a is connected upstream of preheating flow path 204a. Cathode gas F60 flowing into preheating flow path 204a circulates in preheating flow path 205a. Exhaust gas flow path 205b is connected downstream of exhaust gas flow path 404. Exhaust gas F58 flowing out of exhaust gas flow path 404 circulates in exhaust gas flow path 205b. Heat exchange occurs between the cathode gas F60 of preheating flow path 205a and the exhaust gas F58 of exhaust gas flow path 205b in the heat exchange section 205 of the housing.

[0175] A fuel cell 10 is disposed within the internal space of the heat exchange section 205 of the housing. That is, the fuel cell 10 is surrounded by the heat exchange section 205 of the housing. The fuel cell 10 has an anode 11 and a cathode 12. The anode 11 and the cathode 12 are separated by an electrolyte.

[0176] The inlet of anode 11 is connected to reforming reaction flow path 402. The outlet of anode 11 is connected to burner 1. The inlet of cathode 12 is connected to the outlet flow path 204b of cathode gas preheating section 204. The outlet of cathode 12 is connected to oxidant flow path 600.

[0177] Although not shown in the figure, heat insulation components for suppressing heat transfer between devices are provided as needed inside and outside the heat exchange section 205 of the enclosure.

[0178] The operation of the fuel processing apparatus of this embodiment will now be described. Exhaust gas F58 flowing from exhaust gas flow path 404 flows into exhaust gas flow path 205b of the heat exchange section 205 of the housing. The exhaust gas F58 in exhaust gas flow path 205b applies heat energy to the cathode gas F60 in preheating flow path 205a. As a result, the temperature of the exhaust gas F58 decreases. The exhaust gas F58 flowing through exhaust gas flow path 205b is then discharged from the heat exchange section 205 of the housing to the outside.

[0179] On the other hand, cathode gas F60 flows from the outside into the preheating flow path 205a of the heat exchange section 205 of the housing. The cathode gas F60 in the preheating flow path 205a receives heat energy from the exhaust gas F58 in the exhaust gas flow path 205b. The cathode gas F60 flowing out of the preheating flow path 205a of the heat exchange section 205 of the housing flows into the preheating flow path 204a of the main body section 204c.

[0180] The cathode gas F60 in the preheating flow path 204a receives heat energy from the exhaust gas F58, the combustion gas F51, and the flame baffle 3, becoming the preheated cathode gas F61. The preheated cathode gas F61 flows out from the main body 204c through the discharge flow path 204b and is supplied to the cathode 12 of the fuel cell 10.

[0181] In cathode 12, the oxygen required for the cell reaction of fuel cell 10 is consumed. Therefore, the preheated cathode gas F61 becomes cathode exhaust gas. The cathode exhaust gas flows out of cathode 12 and flows into oxidant flow path 600 as oxidant F50.

[0182] Reformed gas F53 flowing out of reforming reaction path 402 is supplied to the anode 11 of fuel cell 10. In anode 11, hydrogen required for the cell reaction of fuel cell 10 is consumed. Thus, reformed gas F53 becomes anode exhaust gas. Anode exhaust gas flows out of anode 11. At least a portion of the anode exhaust gas flowing out of anode 11 is supplied to burner 1 as combustion fuel F55.

[0183] In this embodiment, the heat exchange between the cathode gas F60 and the exhaust gas F58 takes place in the heat exchange section 205 of the housing. Although the temperature difference between the cathode gas F60 and the exhaust gas F58 is relatively small, the heat transfer area between the cathode gas F60 and the exhaust gas F58 is large, thus enabling effective heat recovery.

[0184] Furthermore, the fuel cell 10, the reforming section 110, the combustion section 120, and the main body 204c of the fuel processing device 100 are surrounded by the casing heat exchange section 205. This allows for suppression of heat dissipation from the fuel cell 10 and the fuel processing device 100.

[0185] Furthermore, the heat transfer area between the cathode gas F60 and the exhaust gas F58 is large in the heat exchange section 205 of the housing, thus enabling miniaturization of the main body 204c of the cathode gas preheating section 204. Therefore, according to this embodiment, high efficiency and miniaturization of the fuel processing device for fuel cells can be achieved.

[0186] Furthermore, the structure of a fuel cell system is not limited to Figure 10The structure is shown. For example, a portion of the anode exhaust gas can be used as combustion fuel F55, and the remainder can be recycled as part of feedstock F52. In this case, the flow path of the anode exhaust gas is configured such that a portion of the anode exhaust gas containing water vapor is condensed before the anode exhaust gas is branched. Additionally, the heat energy contained in the anode exhaust gas can be recovered, for example, utilized as the heat of vaporization to generate water vapor.

[0187] As explained above, in the fuel processing apparatus 100 of this embodiment, the cathode gas preheating section 204 includes a housing heat exchange section 205. The housing heat exchange section 205 surrounds the combustion section 120, the reforming section 110, and the fuel cell 10. Heat exchange between exhaust gas F58 and cathode gas F60 occurs in the housing heat exchange section 205. This structure ensures a large heat transfer area between the cathode gas F60 and the exhaust gas F58, thus enabling effective heat recovery. Furthermore, it allows for suppression of heat dissipation from the fuel cell 10 and the fuel processing apparatus 100.

[0188] Furthermore, in the above embodiment, the flow paths such as the catalyst layer peripheral flow path 403, combustion gas flow path 401, exhaust gas flow path 404, preheating flow path 205a, exhaust gas flow path 205b, and preheating flow path 204a are described as spatial, but these flow paths can also be constructed with fins, particle packing, or other heat transfer-enhancing structures. This further improves heat transfer performance, enabling high efficiency and miniaturization of the fuel processing device 100. Additionally, the second feedstock preheating section 203a, which is upstream of the reforming reaction flow path 402, can also be at least partially constructed to promote heat transfer. This improves heat transfer performance to the feedstock F52, enabling a highly efficient and compact fuel processing device 100.

[0189] Furthermore, in the above embodiment, although not specifically described, in order to homogenize the gas distribution relative to the circumference in the second raw material preheating section 203a from which raw material F52 flows from the first raw material preheating section 203, it is preferable to provide a component for reducing the dynamic pressure of the flow, such as a baffle. Moreover, this content is not limited to the second raw material preheating section 203a; for example, the same applies to the portion where the gas F54 from the outer periphery of the catalyst layer flows into the outer periphery flow path 403 of the catalyst layer.

[0190] The above-described embodiments and variations can be implemented in combination with each other.

[0191] Explanation of reference numerals in the attached figures

[0192] 1. Burner, 2. Oxidant Branch Section, 3. Flame Baffle, 4. Insulation Wall, 5. Reforming Catalyst, 6. Insulation Material, 8. Control Section, 9. Reforming Gas Temperature Sensor, 10. Fuel Cell, 11. Anode, 12. Cathode, 100. Fuel Processing Unit, 100a. Central Shaft, 110. Reforming Section, 120. Combustion Section, 200. Merging Section, 201. Radiant Heat Transfer Space, 202. Combustion Space, 203. First Feedstock Preheating Section, 203a. Second Feedstock Preheating Section, 204. Cathode Gas Preheating Section, 204a. Preheating Flow Path, 204b. Exhaust Flow Path, 204c. Main Body, 205. Housing Heat Exchange Section, 205a. Preheating Flow Path, 205b. Exhaust Gas Flow Path, 300. Oxidant Inlet Pipe, 301. Catalyst Layer Peripheral Gas Inlet Pipe, 302. Combustion Gas Conduit, 303. Oxidant Distribution Regulator, 401. Combustion Gas Flow path, 401a upstream section, 401b downstream section, 402 reforming reaction flow path, 403 catalyst layer peripheral flow path, 403a upstream section, 403b downstream section, 404 exhaust gas flow path, 405 air flow path, 406 flow regulating valve, 501 inner wall, 502 middle wall, 503 flame tube wall, 504 outer wall, 505 closed wall, 506 upper surface wall, 507 closed wall, 510 connecting section, 600 oxidant flow path, 601 catalyst layer peripheral gas inlet flow path, 602 combustion gas flow path, F50 oxidant, F51 combustion gas, F52 feedstock, F53 reforming gas, F54 catalyst layer peripheral gas, F55 combustion fuel, F56 combustion gas, F57 air, F58 exhaust gas, F59 combustion feedstock, F60 cathode gas, F61 preheated cathode gas.

Claims

1. A fuel processing apparatus, wherein, The fuel processing device includes: A reforming unit, wherein the reforming unit generates reformed gas from the feedstock; and The combustion section, which causes fuel and combustion-supporting gas to burn in the combustion space to generate combustion gases, The reforming unit has: First cylindrical wall; and The second cylindrical wall is positioned on the outer periphery side of the first cylindrical wall. A reforming reaction flow path, filled with reforming catalyst and allowing the raw materials and reforming gas to flow, is formed between the first cylindrical wall and the second cylindrical wall. A combustion gas flow path is formed at a position closer to the inner circumference of the first cylindrical wall to allow the combustion gas to flow. The combustion gas flow path is adjacent to the reforming reaction flow path through the first cylindrical wall. An outer peripheral flow path is formed at a position closer to the outer periphery than the second cylindrical wall to allow the flow of outer peripheral gas. The outer peripheral flow path is adjacent to the reforming reaction flow path through the second cylindrical wall. The fuel processing device also includes: A confluence section, in which the combustion gas flowing through the combustion gas flow path merges with the peripheral gas flowing through the peripheral flow path; An exhaust gas flow path, in which the combustion gas and the peripheral gas that merge at the confluence section flow as exhaust gas; An oxidant flow path, wherein an oxidant supplied from a heating source flows through the oxidant; An oxidant branch is provided in the oxidant flow path; A combustion-supporting gas flow path, wherein the combustion-supporting gas flow path connects the oxidant branch to the combustion section, allowing a portion of the oxidant to flow as the combustion-supporting gas; and An external gas inlet flow path connects the oxidant branch to the external flow path, allowing another portion of the oxidant to circulate as the external gas.

2. The fuel processing apparatus according to claim 1, wherein, An oxidant distribution regulator is provided in at least one of the combustion-supporting gas flow path and the peripheral gas inlet flow path to determine the distribution ratio of the combustion-supporting gas and the peripheral gas.

3. The fuel processing apparatus according to claim 1 or 2, wherein, The peripheral flow path has an upstream portion formed at a position on the outer peripheral side of the second cylindrical wall and a downstream portion formed at a position on the inner peripheral side of the first cylindrical wall. The confluence section is located on the inner circumferential side of the first cylindrical wall. The upstream portion of the peripheral flow path and the downstream portion of the peripheral flow path are opposite each other across the reforming reaction flow path.

4. The fuel processing apparatus according to claim 1 or 2, wherein, The combustion gas flow path has an upstream portion formed at a position closer to the inner periphery than the first cylindrical wall and a downstream portion formed at a position closer to the outer periphery than the second cylindrical wall. The confluence section is located on the outer periphery side of the second cylindrical wall. The upstream portion of the combustion gas flow path and the downstream portion of the combustion gas flow path are opposite each other across the reforming reaction flow path.

5. The fuel processing apparatus according to any one of claims 1 to 4, wherein, The fuel processing device also includes: Flame tube wall, wherein the flame tube wall is positioned on the inner periphery side of the first cylindrical wall; A flame baffle, wherein the flame baffle is disposed facing the combustion section inside the flame tube wall; as well as The radiative heat transfer space is surrounded by the flame tube wall, the flame baffle, and the combustion section.

6. The fuel processing apparatus according to any one of claims 1 to 5, wherein, The fuel processing device further includes a raw material preheating unit, which preheats the raw material flowing into the reforming reaction path by heat transfer from the peripheral gas or the combustion gas.

7. The fuel processing apparatus according to claim 6, wherein, The raw material preheating section has a retractable structure.

8. The fuel processing apparatus according to any one of claims 1 to 7, wherein, The heating source is a fuel cell. The oxidant is the cathode exhaust gas supplied from the fuel cell.

9. The fuel processing apparatus according to claim 8, wherein, The fuel processing device further includes a cathode gas preheating unit, which preheats the cathode gas supplied to the fuel cell by heat transfer from the exhaust gas.

10. The fuel processing apparatus according to claim 9, wherein, The cathode gas preheating section also preheats the cathode gas using radiant heat from the combustion space.

11. The fuel processing apparatus according to claim 9 or 10, wherein, The cathode gas preheating section has a casing heat exchange section that surrounds the combustion section, the reforming section, and the fuel cell. The exhaust gas and the cathode gas exchange heat in the heat exchange section of the housing.

12. The fuel processing apparatus according to any one of claims 1 to 11, wherein, The fuel processing device also includes an air flow path that supplies temperature-regulating air to the combustion gas located downstream of the combustion space.

13. The fuel processing apparatus according to claim 12, wherein, The fuel processing device also includes: A reforming gas temperature sensor, said reforming gas temperature sensor detecting the temperature of the reforming gas at the outlet of the reforming reaction flow path; and Control Department The control unit controls the flow rate of the air supplied to the combustion gas based on the temperature detected by the reforming gas temperature sensor.

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