Combustor and reformer

Abstract

To provide a combustor capable of generating a swirling flow of fuel gas and oxidizing gas and heating the fuel gas and the oxidizing gas with a simple configuration.SOLUTION: A combustor 20 comprises an outer cylinder 22, an inner cylinder 23 placed radially inside the outer cylinder 22, a combustion gas introduction pipe 24 for introducing ammonia gas and air into the outer cylinder 22, and a spark plug 25 for igniting the ammonia gas. Between the outer cylinder 22 and the inner cylinder 23 is formed a combustion tubular gas flow path 27 in which the ammonia gas and air flow toward a front end 22a of the outer cylinder 22. The front end 22a of the outer cylinder 22 is provided with a front blocking wall 28 that blocks the internal space of the outer cylinder 22. At the rear end 22b of the outer cylinder 22 is provided a rear side closing wall 29 that closes the combustion tubular gas flow path 27. The combustion gas introduction pipe 24 introduces the ammonia gas and air into the combustion tubular gas flow path 27 along the circumferential direction of the inner cylinder 23.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a combustor and a reformer. [Background technology]

[0002] For example, Patent Document 1 describes a tubular flame burner that is a combustor. The tubular flame burner described in Patent Document 1 includes a tubular combustion chamber with one open end, a nozzle for blowing fuel gas and oxygen-containing gas into the combustion chamber, an ignition plug for igniting the fuel gas, an outer cylinder with closed front and rear ends that covers the combustion chamber, a pipe connected to the front end of the outer cylinder for supplying fuel gas and oxygen-containing gas to the space formed by the combustion chamber and the outer cylinder, and a pipe connected to the rear end of the outer cylinder for introducing fuel gas and oxygen-containing gas preheated in the space formed by the combustion chamber and the outer cylinder into the nozzle. The nozzle is provided in a direction approximately tangential to the inner circumferential surface of the combustion chamber. A swirling flow is formed in the combustion chamber by blowing the fuel gas and oxygen-containing gas from the nozzle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-93118 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional technology, in order to generate a swirling flow of the fuel gas and the oxygen-containing gas (oxidizing gas) in the combustion chamber, the fuel gas and the oxygen-containing gas are introduced through a nozzle in a direction approximately tangential to the inner peripheral surface of the combustion chamber. Therefore, the nozzle structure for generating the swirling flow of the fuel gas and the oxygen-containing gas becomes complicated, and the nozzle is difficult to manufacture. In addition, the fuel gas and the oxygen-containing gas are heated by the combustion heat in the combustion chamber, and the piping structure for introducing the heated fuel gas and the oxygen-containing gas into the nozzle also becomes complicated.

[0005] An object of the present invention is to provide a combustor and a reformer that can generate swirling flows of a fuel gas and an oxidizing gas and can heat the fuel gas and the oxidizing gas with a simple structure. [Means for solving the problem]

[0006] One aspect of the present invention is a combustor that burns fuel gas, comprising an outer cylinder, an inner cylinder arranged radially inside the outer cylinder, a combustion gas inlet section that introduces a fuel gas and an oxidizing gas into the outer cylinder, and an ignition section that ignites the fuel gas introduced into the outer cylinder, the inner cylinder being arranged such that a front end of the inner cylinder is located closer to the rear end of the outer cylinder than the front end of the outer cylinder, the front and rear ends of the inner cylinder being open, a tubular gas flow passage is formed between the outer cylinder and the inner cylinder through which the fuel gas and oxidizing gas introduced by the combustion gas inlet section flow toward the front end of the outer cylinder, a front blocking wall is provided at the front end of the outer cylinder that closes the internal space of the outer cylinder, and a rear blocking wall is provided at the rear end of the outer cylinder that closes the tubular gas flow passage, the ignition section is fixed to the front blocking wall, the combustion gas inlet section is arranged on the rear end side of the outer cylinder, and the fuel gas and oxidizing gas are introduced into the tubular gas flow passage so as to flow along the circumferential direction of the inner cylinder.

[0007] In such a combustor, when the fuel gas and the oxidizing gas are introduced into the outer cylinder by the combustion gas introduction part, the fuel gas and the oxidizing gas flow toward the front end of the outer cylinder through the tubular gas flow path formed between the outer cylinder and the inner cylinder. At this time, the fuel gas and the oxidizing gas are introduced into the tubular gas flow path so as to flow along the circumferential direction of the inner cylinder, so that they flow toward the front end of the outer cylinder as a swirling flow. Then, the fuel gas is ignited and burned by the ignition part, and the combustion gas flows inside the inner cylinder (inside the inner cylinder). At this time, the fuel gas flowing through the tubular gas flow path (outside the inner cylinder) is heated by the heat of the combustion gas. Since the fuel gas is ignited in this state, the combustion of the fuel gas is stabilized. In this way, the fuel gas and the oxidizing gas flow along the circumferential direction of the inner cylinder through the tubular gas flow path formed between the inner cylinder and the outer cylinder. As a result, a swirling flow of the fuel gas and the oxidizing gas is generated with a simple structure. In addition, the fuel gas and the oxidizing gas flowing outside the inner cylinder are heated by the heat of the combustion gas flowing inside the inner cylinder. This allows the fuel gas and the oxidizing gas to be heated with a simple structure.

[0008] The axial positional relationship of the inner cylinder with respect to the front blocking wall may be set so that the fuel gas and the oxidizing gas introduced into the tubular gas flow passage by the combustion gas introduction section flow in a swirling manner to the front blocking wall. In this configuration, the fuel gas is ignited in a swirling flow state, so that a tubular flame is generated. In addition, the fuel gas with a slow combustion speed is also easily ignited, so that the combustion of the fuel gas is further stabilized.

[0009] The combustor may further include another gas introduction section for introducing at least one of a cooling gas, a fuel gas, and an oxidizing gas into the inner cylinder. In such a configuration, by introducing a cooling gas into the inner cylinder, the temperature of the combustion gas flowing inside the inner cylinder is lowered. By introducing a fuel gas into the inner cylinder, the fuel gas is supplied together with the combustion gas to the downstream side of the inner cylinder, and the temperature of the combustion gas flowing inside the inner cylinder is lowered. By introducing an oxidizing gas into the inner cylinder, the oxidizing gas is supplied together with the combustion gas to the downstream side of the inner cylinder, and the combustion of the fuel gas is promoted.

[0010] The inner cylinder may have a protruding portion protruding from the rear end of the outer cylinder, and other gas inlet portions may be provided on the protruding portion. In this configuration, the cooling gas or the fuel gas is introduced into the inner cylinder with a simple structure.

[0011] Another aspect of the present invention is a reforming device for generating a reformed gas containing hydrogen by reforming the fuel gas using heat generated by burning a fuel gas, the reforming device comprising: an outer cylinder; an inner cylinder arranged radially inside the outer cylinder; a combustion gas introduction section for introducing a fuel gas and an oxidizing gas into the outer cylinder; an ignition section for igniting the fuel gas introduced into the outer cylinder; a catalyst section which heats up the fuel gas by the heat of the combustion gas generated by igniting the fuel gas by the ignition section, combusts the fuel gas, and reforms the fuel gas; and a gas supply section which supplies the fuel gas and the oxidizing gas to the catalyst section, the inner cylinder being arranged such that a front end of the inner cylinder is positioned outboard of a front end of the outer cylinder. The outer cylinder is arranged so as to be located at the rear end side of the outer cylinder, the front and rear ends of the inner cylinder are open, and a tubular combustion gas flow passage is formed between the outer cylinder and the inner cylinder through which the fuel gas and oxidizing gas introduced by the combustion gas inlet flow toward the front end of the outer cylinder, and a front blocking wall that blocks the internal space of the outer cylinder is provided at the front end of the outer cylinder, and a rear blocking wall that blocks the tubular gas flow passage is provided at the rear end of the outer cylinder, the ignition unit is fixed to the front blocking wall, and the combustion gas inlet is arranged at the rear end side of the outer cylinder and introduces the fuel gas and oxidizing gas into the tubular combustion gas flow passage so as to flow along the circumferential direction of the inner cylinder.

[0012] In such a reformer, when the fuel gas and the oxidizing gas are introduced into the outer cylinder by the combustion gas introduction section, the fuel gas and the oxidizing gas flow toward the front end of the outer cylinder through the tubular combustion gas flow path formed between the outer cylinder and the inner cylinder. At this time, the fuel gas and the oxidizing gas are introduced into the tubular combustion gas flow path so as to flow along the circumferential direction of the inner cylinder, so that they flow toward the front end of the outer cylinder as a swirling flow. Then, the fuel gas is ignited and burned by the ignition section, and the combustion gas flows inside the inner cylinder (inside the inner cylinder). At this time, the fuel gas flowing through the tubular combustion gas flow path (outside the inner cylinder) is heated by the heat of the combustion gas. Since the fuel gas is ignited in this state, the combustion of the fuel gas is stabilized. In addition, the fuel gas and the oxidizing gas are supplied to the catalyst section by the gas supply section. Then, the fuel gas is burned in the catalyst section, and the fuel gas is further reformed to generate a reformed gas containing hydrogen. In this way, the fuel gas and the oxidizing gas flow along the circumferential direction of the inner cylinder through the tubular combustion gas flow path formed between the inner cylinder and the outer cylinder. This allows a simple structure to generate swirling flows of the fuel gas and the oxidizing gas. Also, the fuel gas and the oxidizing gas flowing outside the inner cylinder are heated by the heat of the combustion gas flowing inside the inner cylinder. This allows the fuel gas and the oxidizing gas to be heated with a simple structure.

[0013] The axial positional relationship of the inner cylinder with respect to the front blocking wall may be set so that the fuel gas and the oxidizing gas introduced into the combustion tubular gas flow passage by the combustion gas introduction part flow in a swirling manner to the front blocking wall. In this configuration, the fuel gas is ignited in a swirling flow state, so that a tubular flame is generated. In addition, the fuel gas with a slow combustion speed is also easily ignited, so that the combustion of the fuel gas is further stabilized.

[0014] The catalyst section may be housed in the inner cylinder. In this configuration, the axial length of the reformer is reduced, thereby making it possible to reduce the size of the reformer.

[0015] The gas supply unit may have a reforming gas inlet for introducing fuel gas and oxidizing gas into the inner cylinder, and a reforming tubular gas flow passage formed between the inner cylinder and the catalyst unit, through which the fuel gas and oxidizing gas introduced by the reforming gas inlet flow to the front end side of the inner cylinder. In this configuration, when the fuel gas and oxidizing gas are introduced into the inner cylinder, the fuel gas and oxidizing gas flow through the reforming tubular gas flow passage formed between the inner cylinder and the catalyst unit to the front end side of the inner cylinder and are supplied to the catalyst unit. The fuel gas and oxidizing gas flowing in the inner cylinder are heated by the heat of the catalyst unit and then supplied to the catalyst unit. Therefore, the fuel gas is effectively combusted and reformed in the catalyst unit.

[0016] The inner cylinder may have a protruding portion protruding from the rear end of the outer cylinder, and the reforming gas inlet may be provided on the protruding portion. In this configuration, the fuel gas and the oxidizing gas are introduced into the inner cylinder with a simple structure. Effect of the Invention

[0017] According to the present invention, it is possible to generate swirling flows of fuel gas and oxidizing gas and heat the fuel gas and oxidizing gas with a simple structure. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic configuration diagram showing a reforming system including a combustor-equipped reformer, which is a reformer according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of the combustor-equipped reformer shown in FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] FIG. 5 is a plan view showing a combustor-equipped reformer which is a reformer according to a second embodiment of the present invention. [Figure 6] FIG. 11 is a plan view showing a combustor-equipped reformer which is a reformer according to a third embodiment of the present invention. [Figure 7] FIG. 7 is a cross-sectional view of the combustor-equipped reformer shown in FIG. [Figure 8] FIG. 11 is a schematic configuration diagram showing a reforming system including a combustor-equipped reformer, which is a reformer according to a fourth embodiment of the present invention. [Figure 9] FIG. 9 is a plan view of the combustor-equipped reformer shown in FIG. [Figure 10] 3 is a plan view showing a modified example of the combustor-equipped reformer shown in FIG. [Figure 11] 4 is a cross-sectional view showing a modified example of the combustor-equipped reformer shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent elements are designated by the same reference numerals, and duplicated explanations will be omitted.

[0020] Fig. 1 is a schematic diagram showing a reforming system including a combustor-equipped reformer according to a first embodiment of the present invention. In Fig. 1, the reforming system 1 includes an ammonia gas supply source 2, an air supply source 3, and a combustor-equipped reformer 4 according to this embodiment.

[0021] The ammonia gas supply source 2 generates ammonia gas (NH3 gas) which is a fuel gas. Although not shown in the figure, the ammonia gas supply source 2 has an ammonia tank which stores ammonia in a liquid state, and a vaporizer which vaporizes the liquid ammonia to generate ammonia gas.

[0022] The air supply source 3 generates air, which is an oxidizing gas. As the air supply source 3, for example, a blower or the like is used.

[0023] The combustor-equipped reformer 4 is a device that generates a reformed gas containing hydrogen by reforming ammonia gas using heat generated by burning ammonia gas. The combustor-equipped reformer 4 will be described in detail later.

[0024] The reforming system 1 also includes air passages 5 and 6, throttle valves 7 and 8, ammonia gas passages 9 and 10, and injectors 11 and 12.

[0025] The air flow paths 5, 6 connect the air supply source 3 and the combustor-equipped reformer 4. The air flow paths 5, 6 are flow paths through which air generated in the air supply source 3 flows toward the combustor-equipped reformer 4. The throttle valves 7, 8 are disposed in the air flow paths 5, 6, respectively. The throttle valves 7, 8 are flow control valves that control the flow rate of air supplied to the combustor-equipped reformer 4.

[0026] The ammonia gas flow paths 9 and 10 connect the ammonia gas supply source 2 and the injectors 11 and 12, respectively. The ammonia gas flow paths 9 and 10 are flow paths through which ammonia gas generated in the ammonia gas supply source 2 flows toward the injectors 11 and 12, respectively. The injectors 11 and 12 are fuel injection valves that inject ammonia gas toward the combustor-equipped reformer 4. Here, the injectors 11 and 12 inject ammonia gas into the air flow paths 5 and 6 between the throttle valves 7 and 8 and the combustor-equipped reformer 4, respectively.

[0027] The combustor-equipped reformer 4 is connected to the hydrogen utilization device 14 via a reformed gas passage 13. The reformed gas passage 13 is a passage through which the reformed gas generated by the combustor-equipped reformer 4 flows toward the hydrogen utilization device 14.

[0028] The hydrogen utilization device 14 is a device that utilizes hydrogen contained in the reformed gas. Examples of the hydrogen utilization device 14 include an ammonia engine or an ammonia gas turbine that uses ammonia gas as fuel, or a fuel cell that generates electricity by chemically reacting hydrogen with oxygen in the air.

[0029] Fig. 2 is a plan view of the combustor-equipped reformer 4. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3. In Figs. 2 to 4, the combustor-equipped reformer 4 includes a combustor 20 and a reformer 21 disposed downstream of the combustor 20.

[0030] The combustor 20 generates a combustion gas. The combustor 20 has an outer cylinder 22, an inner cylinder 23 arranged radially inside the outer cylinder 22, a combustion gas introduction pipe 24 that introduces ammonia gas and oxygen into the outer cylinder 22, and an ignition plug 25 that ignites the ammonia gas introduced into the outer cylinder 22.

[0031] The outer cylinder 22 and the inner cylinder 23 are cylindrical. The combustor 20 has a double-tube structure consisting of the outer cylinder 22 and the inner cylinder 23. The outer cylinder 22, the inner cylinder 23, and the combustion gas introduction pipe 24 are made of a metal material such as stainless steel that is resistant to corrosion by ammonia gas.

[0032] The inner cylinder 23 is disposed such that the front end 23a of the inner cylinder 23 is located closer to the rear end 22b of the outer cylinder 22 than the front end 22a of the outer cylinder 22. The front end 23a of the inner cylinder 23 is the upstream end of the inner cylinder 23. The front end 22a of the outer cylinder 22 is the end of the inner cylinder 23 corresponding to the upstream side. The front end 23a of the inner cylinder 23 is located, for example, at the center of the axial direction of the outer cylinder 22. The front end 23a and the rear end 23b of the inner cylinder 23 are open. The inner cylinder 23 has a protruding portion 26 that protrudes from the rear end 22b of the outer cylinder 22 to the rear of the outer cylinder 22 (towards the reformer 21). The portion of the inner cylinder 23 other than the protruding portion 26 is housed within the outer cylinder 22.

[0033] Between the inner peripheral surface of the outer cylinder 22 and the outer peripheral surface of the inner cylinder 23, a tubular combustion gas flow passage 27 is formed, through which ammonia gas and air introduced through a combustion gas introduction pipe 24 flow toward the front end of the outer cylinder 22. The ammonia gas introduced into the outer cylinder 22 through the combustion gas introduction pipe 24 is a combustion gas.

[0034] A circular front blocking wall 28 that blocks the internal space of the external cylinder 22 is provided at the front end 22a of the external cylinder 22. That is, the front end 22a of the external cylinder 22 is entirely blocked by the front blocking wall 28. A circular rear blocking wall 29 that blocks the tubular combustion gas flow passage 27 is provided at the rear end 22b of the external cylinder 22. That is, the rear end 22b of the external cylinder 22 is blocked by the rear blocking wall 29 except for the region of the inner cylinder 23.

[0035] The combustion gas introduction pipe 24 is connected to the air flow passage 5. The combustion gas introduction pipe 24 is disposed on the rear end 22b side of the outer cylinder 22. The combustion gas introduction pipe 24 is a combustion gas introduction section that introduces ammonia gas and air into the combustion tubular gas flow passage 27 in the outer cylinder 22. The combustion gas introduction pipe 24 introduces the ammonia gas and air into the combustion tubular gas flow passage 27 so as to flow along the circumferential direction of the inner cylinder 23.

[0036] The combustion gas introduction pipe 24 is attached to the outer cylinder 22 while being inserted inside the outer cylinder 22. A gas outlet portion 24a of the combustion gas introduction pipe 24 is fixed to the outer cylinder 22 and the inner cylinder 23. The combustion gas introduction pipe 24 is disposed so that the axial direction of the combustion gas introduction pipe 24 is perpendicular to the axial directions of the outer cylinder 22 and the inner cylinder 23. Therefore, ammonia gas and air are introduced into the outer cylinder 22 through the combustion gas introduction pipe 24 in the tangential direction of the inner peripheral surface of the outer cylinder 22.

[0037] When ammonia gas and air are introduced into the combustion tubular gas passage 27 in the outer cylinder 22, the ammonia gas and air flow in the combustion tubular gas passage 27 along the circumference of the inner cylinder 23 in the circumferential direction of the inner cylinder 23. Therefore, the ammonia gas and air become a swirling flow (tubular flow) in the combustion tubular gas passage 27 (see FIG. 3).

[0038] At this time, the axial positional relationship of the inner cylinder 23 with respect to the front blocking wall 28 is set so that the ammonia gas and air flow in a swirling state up to the front end 22a of the outer cylinder 22. In other words, the distance between the front end 23a of the inner cylinder 23 and the front blocking wall 28 is set so that the swirling flow of the ammonia gas and air is maintained up to the front blocking wall 28.

[0039] The spark plug 25 is fixed to the radial center of the front blocking wall 28. The spark plug 25 is an ignition part that ignites ammonia gas that has reached the front blocking wall 28, thereby igniting the ammonia gas.

[0040] Combustion gas is generated when ammonia gas is ignited and burned by the spark plug 25. The combustion gas flows inside the outer cylinder 22 toward the inner cylinder 23, and then flows through the internal space of the inner cylinder 23 toward the reformer 21.

[0041] The reformer 21 has a cylindrical housing 30 connected to the rear end 23b of the inner cylinder 23, an ATR catalyst 31 (autothermal reforming catalyst) housed in the housing 30, and a reforming gas introduction pipe 32 that introduces ammonia gas and air into the housing 30. The housing 30 and the reforming gas introduction pipe 32 are formed of the same metal material as the inner cylinder 23.

[0042] The ATR catalyst 31 is a catalytic part that is heated by the heat of the combustion gas generated in the combustor 20, burns the ammonia gas, and decomposes the ammonia gas into hydrogen by the combustion heat (self-heat) of the ammonia gas, thereby reforming the ammonia gas. The ATR catalyst 31 has, for example, a honeycomb structure.

[0043] The ATR catalyst 31 burns ammonia gas in a temperature range of, for example, about 200° C. to 400° C., and reforms the ammonia gas in a temperature range higher than the combustion temperature of the ammonia gas (for example, about 250° C. to 500° C.) As the ATR catalyst 31, for example, a cobalt-based catalyst, a rhodium-based catalyst, a ruthenium-based catalyst, a palladium-based catalyst, or the like is used.

[0044] The reforming gas introduction pipe 32 is connected to the air flow path 6. The reforming gas introduction pipe 32 is attached to the housing 30. The reforming gas introduction pipe 32 introduces ammonia gas and air between the inner cylinder 23 and the ATR catalyst 31 in the housing 30. The reforming gas introduction pipe 32 is a gas supply unit that supplies ammonia gas and air to the ATR catalyst 31. The ammonia gas introduced into the housing 30 by the reforming gas introduction pipe 32 is a reforming gas. In addition, the ammonia gas introduced into the housing 30 by the reforming gas introduction pipe 32 also functions as a cooling gas that cools the combustion gas generated in the combustor 20.

[0045] When the reforming system 1 equipped with the combustor-equipped reformer 4 as described above is started up, the throttle valves 7, 8 and the injectors 11, 12 are opened, causing air to flow through the air passages 5, 6 toward the combustor-equipped reformer 4, and ammonia gas is injected from the injectors 11, 12 toward the combustor-equipped reformer 4. Then, a mixture of ammonia gas and air is supplied to the combustor 20 and reformer 21 of the combustor-equipped reformer 4.

[0046] When the mixed gas is introduced into the external cylinder 22 from the combustion gas introduction pipe 24 of the combustor 20, the mixed gas flows as a swirling flow through the combustion tubular gas flow passage 27 in the external cylinder 22 toward the front end 22a of the external cylinder 22. When the ignition plug 25 ignites in a state where the swirling mixed gas reaches the front end 22a of the external cylinder 22, the ammonia gas in the mixed gas is ignited to form a tubular flame, and the ammonia gas is burned. Specifically, as shown in the following formula, ammonia chemically reacts with oxygen in the air to generate high-temperature combustion gas (exothermic reaction). NH3+3 / 4O2→1 / 2N2+3 / 2H2O …(A)

[0047] The combustion gas swirls and flows inside the outer cylinder 22 toward the inner cylinder 23. The combustion gas then flows through the internal space of the inner cylinder 23 and is supplied to the reformer 21. At this time, the room temperature mixed gas flows outside the inner cylinder 23, and the high temperature combustion gas flows inside the inner cylinder 23. For this reason, mutual heat exchange occurs between the outside and inside of the inner cylinder 23, and the heat of the high temperature combustion gas is taken away by the room temperature mixed gas. As a result, the temperature of the combustion gas drops, the temperature rise of the inner cylinder 23 is suppressed, and the mixed gas is warmed by the heat of the combustion gas.

[0048] In addition, the mixed gas introduced into the housing 30 from the reforming gas inlet pipe 32 of the reformer 21 is supplied to the ATR catalyst 31, and the combustion gas from the combustor 20 is supplied to the ATR catalyst 31, so that the ATR catalyst 31 is warmed by the heat of the combustion gas, and the temperature of the ATR catalyst 31 rises.

[0049] At this time, since the temperature of the ammonia gas introduced into the housing 30 from the reforming gas introduction pipe 32 is room temperature, the combustion gas from the combustor 20 is cooled by the ammonia gas. Therefore, the temperature of the combustion gas supplied to the ATR catalyst 31 is further reduced.

[0050] Then, when the temperature of the ATR catalyst 31 reaches a combustible temperature, the ignition of the spark plug 25 is stopped, and the throttle valve 7 and the injector 11 are closed, thereby stopping the supply of air and ammonia gas to the combustor 20. This completes the generation of combustion gas by the combustor 20.

[0051] Furthermore, when the temperature of the ATR catalyst 31 reaches a combustible temperature, the ammonia gas is combusted by the ATR catalyst 31, causing the exothermic reaction of the above formula (A), and the temperature of the ATR catalyst 31 further increases due to the self-heat of the ATR catalyst 31.

[0052] Then, when the temperature of the ATR catalyst 31 reaches a reforming temperature, the ammonia gas is reformed by the ATR catalyst 31. Specifically, as shown in the following formula, a decomposition reaction of ammonia occurs (endothermic reaction), and a reformed gas containing hydrogen is generated. The reformed gas flows through the reformed gas flow path 13 and is supplied to the hydrogen utilization device 14. NH3→3 / 2H2+1 / 2N2…(B)

[0053] As described above, in this embodiment, when ammonia gas and air are introduced into the outer cylinder 22 by the combustion gas introduction pipe 24, the ammonia gas and air flow through the combustion tubular gas flow passage 27 formed between the outer cylinder 22 and the inner cylinder 23 toward the front end 22a of the outer cylinder 22. At this time, the ammonia gas and air are introduced into the combustion tubular gas flow passage 27 so as to flow along the circumferential direction of the inner cylinder 23, so that they flow toward the front end 22a of the outer cylinder 22 as a swirling flow. Then, the ammonia gas is ignited and burned by the ignition plug 25, and the combustion gas flows inside the inner cylinder 23 (inside the inner cylinder 23). At this time, the ammonia gas flowing through the combustion tubular gas flow passage 27 (outside the inner cylinder 23) is heated by the heat of the combustion gas. Since the ammonia gas is ignited in this state, the combustion of the ammonia gas is stabilized. In addition, ammonia gas and air are supplied to the ATR catalyst 31 by the reforming gas introduction pipe 32. Then, in the ATR catalyst 31, the ammonia gas is burned and further reformed to generate a reformed gas containing hydrogen. In this manner, the ammonia gas and air flow along the circumferential direction of the inner cylinder 23 through the combustion tubular gas flow passage 27 formed between the outer cylinder 22 and the inner cylinder 23. This generates a swirling flow of the ammonia gas and air with a simple structure. Also, the ammonia gas and air flowing outside the inner cylinder 23 are heated by the heat of the combustion gas flowing inside the inner cylinder 23. This allows the ammonia gas and air to be heated with a simple structure.

[0054] In this embodiment, the axial positional relationship of the inner cylinder 23 with respect to the front blocking wall 28 is set so that the ammonia gas and air introduced into the combustion tubular gas flow passage 27 by the combustion gas introduction pipe 24 flow in a swirling manner up to the front blocking wall 28. Therefore, the ammonia gas ignites in a swirling flow state, generating a tubular flame. In addition, the ammonia gas, which has a slow combustion speed, can be easily ignited, further stabilizing the combustion of the ammonia gas.

[0055] In addition, in this embodiment, by introducing ammonia gas into the housing 30 of the reformer 21, the ammonia gas is supplied together with the combustion gas to the ATR catalyst 31 arranged downstream of the inner cylinder 23, and the temperature of the combustion gas supplied to the ATR catalyst 31 is reduced.

[0056] Fig. 5 is a plan view showing a combustor-equipped reformer, which is a reformer according to a second embodiment of the present invention. In Fig. 5, a combustor-equipped reformer 4A of this embodiment includes a combustor 20A and a reformer 21A disposed downstream of the combustor 20A.

[0057] The combustor 20A has the above-mentioned outer cylinder 22, inner cylinder 23, combustion gas introduction pipe 24, and ignition plug 25, as well as a reforming gas introduction pipe 40 that introduces ammonia gas and air into the inner cylinder 23.

[0058] The reforming gas introduction pipe 40 is attached to the protruding portion 26 of the inner cylinder 23. The reforming gas introduction pipe 40 is connected to the air flow path 6. The reforming gas introduction pipe 40 is a reforming gas introduction section (another gas introduction section) that introduces ammonia gas and air into the inner cylinder 23. The ammonia gas introduced into the inner cylinder 23 by the reforming gas introduction pipe 40 also functions as a cooling gas that cools the combustion gas. The reforming gas introduction pipe 40 is a gas supply section that supplies ammonia gas and air to the ATR catalyst 31.

[0059] The reformer 21A has the above-mentioned housing 30 and the ATR catalyst 31. The reformer 21A does not have the above-mentioned reforming gas introduction pipe 32.

[0060] In this embodiment, by introducing ammonia gas into the inner cylinder 23, the ammonia gas is supplied together with the combustion gas to the ATR catalyst 31 arranged downstream of the inner cylinder 23, and the temperature of the combustion gas flowing through the inner cylinder 23 and supplied to the ATR catalyst 31 is reduced. Also, by introducing air into the inner cylinder 23, the air is supplied together with the combustion gas to the ATR catalyst 31 arranged downstream of the inner cylinder 23, and the combustion of the ammonia gas is promoted.

[0061] Moreover, in this embodiment, the reforming gas introduction pipe 40 is provided in the protruding portion 26 of the inner cylinder 23. Therefore, ammonia gas can be introduced into the inner cylinder 23 with a simple structure.

[0062] Fig. 6 is a plan view showing a combustor-equipped reformer which is a reformer according to a third embodiment of the present invention. Fig. 7 is a cross-sectional view of the combustor-equipped reformer shown in Fig. 6. In Figs. 6 and 7, a combustor-equipped reformer 4B of this embodiment includes a combustor 20B and the above-mentioned ATR catalyst 31.

[0063] The combustor 20B has the above-mentioned outer cylinder 22, an inner cylinder 23B arranged radially inside the outer cylinder 22, the above-mentioned combustion gas introduction pipe 24 and ignition plug 25, and a reforming gas introduction pipe 50 that introduces ammonia gas and air into the inner cylinder 23B.

[0064] The inner cylinder 23B is similar to the inner cylinder 23 described above, except for the structure of the front end 23a and the rear end 23b. The ATR catalyst 31 is accommodated in the inner cylinder 23B. The axial and radial dimensions of the ATR catalyst 31 are smaller than the axial and radial dimensions of the inner cylinder 23B. The front end 31a of the ATR catalyst 31 is located closer to the rear end 23b of the inner cylinder 23B than the front end 23a of the inner cylinder 23B. The front end 31a of the ATR catalyst 31 is the upstream end of the ATR catalyst 31. The position of the rear end 31b of the ATR catalyst 31 coincides with the position of the rear end 23b of the inner cylinder 23B.

[0065] Between the outer circumferential surface of the inner cylinder 23B and the ATR catalyst 31, a reforming tubular gas flow passage 54 is formed through which the ammonia gas and air introduced through the reforming gas introduction pipe 50 flow toward the front end 23a of the inner cylinder 23B.

[0066] An annular blocking wall 51 that blocks the reforming tubular gas flow passage 54 is provided at the rear end 23b of the inner cylinder 23B. That is, the rear end 23b of the inner cylinder 23B is blocked by the blocking wall 51 except for the ATR catalyst 31.

[0067] A flange wall 52 is provided at the front end 23a of the inner cylinder 23B, which protrudes radially inward of the inner cylinder 23B. The flange wall 52 bounces the ammonia gas and air flowing through the reforming tubular gas flow passage 54 toward the front end 31a of the ATR catalyst 31. The size of the flange wall 52 is equal to, for example, the size of the blocking wall 51. The flange wall 52 defines an opening 53 through which the combustion gas generated in the combustor 20B passes so as to flow toward the ATR catalyst 31.

[0068] The reforming gas introduction pipe 50 is attached to the protruding portion 26 of the inner cylinder 23B. The reforming gas introduction pipe 50 is connected to the air flow passage 6. The reforming gas introduction pipe 50 is a reforming gas introduction section (another gas introduction section) that introduces ammonia gas into the inner cylinder 23B. The ammonia gas introduced into the inner cylinder 23B by the reforming gas introduction pipe 50 also functions as a cooling gas that cools the combustion gas. The reforming gas introduction pipe 50 may introduce ammonia gas into the inner cylinder 23B in the radial direction of the inner cylinder 23B (as shown in the figure), or may introduce ammonia gas into the inner cylinder 23B in the axial direction of the inner cylinder 23B. The reforming gas introduction pipe 50 and the reforming tubular gas flow passage 54 constitute a gas supply section that supplies ammonia gas and air to the ATR catalyst 31.

[0069] In such a combustor-equipped reformer 4B, ammonia gas and air are introduced into the outer cylinder 22 through the combustion gas introduction pipe 24, and when the ammonia gas is ignited and burned by the ignition plug 25, the combustion gas passes through the opening 53 of the inner cylinder 23B and is supplied to the ATR catalyst 31.

[0070] Ammonia gas and air are introduced into the inner cylinder 23B through the reforming gas introduction pipe 50, and the ammonia gas and air flow through the reforming tubular gas flow passage 54 toward the front end 23a of the inner cylinder 23B. Then, the ammonia gas and air bounce off the flange wall 52 and are supplied to the ATR catalyst 31. Then, the ammonia gas is combusted and reformed in the ATR catalyst 31.

[0071] As described above, according to this embodiment, the ATR catalyst 31 is accommodated in the inner cylinder 23B. Therefore, the axial length of the combustor-equipped reformer 4B is reduced, and the combustor-equipped reformer 4B can be made more compact.

[0072] In this embodiment, when ammonia gas and air are introduced into the inner cylinder 23B, the ammonia gas and air flow through a reforming tubular gas flow passage 54 formed between the inner cylinder 23B and the ATR catalyst 31 toward the front end 23a of the inner cylinder 23B and are supplied to the ATR catalyst 31. The ammonia gas and air flowing through the inner cylinder 23B are heated by the heat of the ATR catalyst 31 and then supplied to the ATR catalyst 31. Therefore, the ammonia gas is effectively combusted and reformed in the ATR catalyst 31.

[0073] Fig. 8 is a schematic diagram showing a reforming system including a combustor-equipped reformer which is a reformer according to a fourth embodiment of the present invention. In Fig. 8, the reforming system 1 includes an ammonia gas supply source 2, an air supply source 3, a combustor-equipped reformer 4C of this embodiment, an air passage 5, a throttle valve 7, an ammonia gas passage 9, and an injector 11. The reforming system 1 does not include the air passage 6, the throttle valve 8, the ammonia gas passage 10, and the injector 12 in the first to third embodiments.

[0074] Fig. 9 is a plan view of a combustor-equipped reformer 4C. In Fig. 9, the combustor-equipped reformer 4C includes the combustor 20 and the ATR catalyst 31. The combustor-equipped reformer 4C does not include the reforming gas introduction pipe 50. The combustion gas introduction pipe 24 also serves as a gas supply unit that supplies ammonia gas and air to the ATR catalyst 31.

[0075] The ATR catalyst 31 is accommodated in the inner cylinder 23 of the combustor 20. In this case, the ATR catalyst 31 may be entirely disposed in the outer cylinder 22 of the combustor 20 (as shown), or a part of the ATR catalyst 31 may be disposed in the protruding portion 26 of the inner cylinder 23.

[0076] In such a combustor-equipped reformer 4C, when ammonia gas and air are introduced into the outer cylinder 22 through the combustion gas introduction pipe 24, some of the ammonia gas and air reach the ignition plug 25, and the ammonia gas is ignited and burned. Then, the combustion gas is supplied to the ATR catalyst 31 in the inner cylinder 23. Also, the remaining ammonia gas and air are supplied to the ATR catalyst 31 in the inner cylinder 23. Then, the ammonia gas is combusted and reformed in the ATR catalyst 31.

[0077] In this embodiment, the system configuration of the reforming system 1 is simplified, and the structure of the combustor-equipped reformer 4C is also simplified.

[0078] The present invention is not limited to the above embodiment. For example, in the above embodiment, the combustion gas introduction pipe 24 of the combustor 20 is disposed so that the axial direction of the combustion gas introduction pipe 24 is perpendicular to the axial directions of the outer cylinder 22 and the inner cylinder 23, but the present invention is not particularly limited to such a configuration.

[0079] As shown in Fig. 10, the combustion gas introduction pipe 24 may be disposed so that its axial direction is inclined with respect to the axial directions of the outer cylinder 22 and the inner cylinder 23. The combustion gas introduction pipe 24 is disposed so that a gas outlet portion 24a (see Fig. 3) faces the front end 22a of the outer cylinder 22. Therefore, when ammonia gas and air are introduced into the outer cylinder 22 by the combustion gas introduction pipe 24, the ammonia gas and air tend to flow toward the front end 22a of the outer cylinder 22.

[0080] Moreover, the axial direction of the reforming gas introduction pipes 32, 40, 50 for introducing the ammonia gas and air to be supplied to the ATR catalyst 31 may also be inclined with respect to the axial direction of the outer cylinder 22 and the inner cylinder 23.

[0081] In the above embodiment, the combustion gas introduction pipe 24 is arranged so that ammonia gas and air are introduced into the outer cylinder 22 in the tangential direction of the inner peripheral surface of the outer cylinder 22, but is not particularly limited to such a form. The combustion gas introduction pipe 24 may be arranged so that ammonia gas and air are introduced into the outer cylinder 22 in a direction shifted from the tangential direction of the inner peripheral surface of the outer cylinder 22, as shown in Fig. 11.

[0082] 11(a), the axial direction of the combustion gas introduction pipe 24 may be inclined with respect to the radial direction of the outer cylinder 22 and the inner cylinder 23. In this case, the ammonia gas and air introduced into the outer cylinder 22 by the combustion gas introduction pipe 24 swirl in the combustion tubular gas flow passage 27 in a direction corresponding to the side to which the combustion gas introduction pipe 24 is inclined.

[0083] 11(b), the gas outlet 24a of the combustion gas introduction pipe 24 may be tapered. The axial direction of the combustion gas introduction pipe 24 coincides with the radial direction of the outer cylinder 22 and the inner cylinder 23. In this case, the ammonia gas and air introduced into the outer cylinder 22 by the combustion gas introduction pipe 24 swirl in the combustion tubular gas flow passage 27 in the direction corresponding to the gas outlet 24a.

[0084] 11(c), a wall portion 60 may be provided between the outer cylinder 22 and the inner cylinder 23 near the gas outlet portion 24a of the combustion gas introduction pipe 24. The axial direction of the combustion gas introduction pipe 24 coincides with the radial directions of the outer cylinder 22 and the inner cylinder 23. In this case, the ammonia gas and air introduced into the outer cylinder 22 by the combustion gas introduction pipe 24 swirl in the combustion tubular gas flow passage 27 in a direction corresponding to the opposite side of the wall portion 60.

[0085] Even if the ammonia gas and air are introduced into the outer cylinder 22 in a direction shifted from the tangential direction of the inner surface of the outer cylinder 22, the ammonia gas and air flow through the combustion tubular gas flow passage 27 along the circumferential direction of the inner cylinder 23, generating a swirling flow of the ammonia gas and air.

[0086] In the above embodiment, the combustion gas introduction pipe 24 introduces the mixed gas of ammonia gas and air into the outer cylinder 22 so as to flow along the circumferential direction of the inner cylinder 23, but is not particularly limited to such a form. For example, an ammonia gas introduction pipe that introduces ammonia gas into the outer cylinder 22 so as to flow along the circumferential direction of the inner cylinder 23 and an air introduction pipe that introduces air into the outer cylinder 22 so as to flow along the circumferential direction of the inner cylinder 23 may be provided separately. In this case, the ammonia gas introduction pipe and the air introduction pipe constitute a combustion gas introduction section that introduces ammonia gas and air into the outer cylinder 22. The same applies to the reforming gas introduction pipes 32, 40, 50 that introduce ammonia gas and air to be supplied to the ATR catalyst 31.

[0087] Furthermore, in the above embodiment, the inner cylinder 23 has the protruding portion 26 protruding from the rear end 22b of the outer cylinder 22, but is not particularly limited to such a form. For example, in the above first and fourth embodiments, the inner cylinder 23 may not have such a protruding portion 26 and may be entirely housed within the outer cylinder 22. In this case, the axial length dimension of the combustor-equipped reformer 4, 4C can be reduced.

[0088] In the above embodiment, the combustor-equipped reformers 4 to 4C have the ATR catalyst 31 that burns ammonia gas and decomposes the ammonia gas into hydrogen, but the present invention is not limited to this embodiment. The combustor-equipped reformers 4 to 4C may have a combustion catalyst that burns ammonia gas and a reforming catalyst that decomposes the ammonia gas into hydrogen separately.

[0089] In the above embodiment, the combustors 20-20B are provided in the reformer of the reforming system 1, but the combustor of the present invention can be applied to devices or systems other than reformers. For example, in an exhaust system, as in the above second embodiment, by introducing air into the inner cylinder 23 of the combustor 20A, it is possible to burn the unburned ammonia flowing inside the inner cylinder 23 and suppress the generation of NOx (nitrogen oxides).

[0090] Furthermore, in the above embodiment, ammonia gas is used as the fuel gas, but the present invention is also applicable to combustors and reformers that use hydrocarbon gas or the like as the fuel gas.

[0091] Furthermore, in the above embodiment, air is used as the oxidizing gas, but the present invention is also applicable to a combustor and a reformer that use oxygen as the oxidizing gas. [Explanation of symbols]

[0092] 4, 4A, 4B, 4C... reformer with combustor (reformer), 20, 20A, 20B... combustor, 22... outer cylinder, 22a... front end, 22b... rear end, 23, 23B... inner cylinder, 23a... front end, 23b... rear end, 24... combustion gas introduction pipe (combustion gas introduction section, gas supply section), 25... ignition plug (ignition section), 26... protrusion, 27... combustion tubular gas flow passage (tubular gas flow passage), 28... front blocking wall, 29... rear blocking wall, 31... ATR catalyst (catalyst section), 40... reforming gas introduction pipe (reforming gas introduction section, other gas introduction section, gas supply section), 50... reforming gas introduction pipe (reforming gas introduction section, other gas introduction section, gas supply section), 54... reforming tubular gas flow passage (gas supply section).

Claims

1. 1. A reformer for generating a reformed gas containing hydrogen by reforming a fuel gas using heat generated by burning the fuel gas, comprising: An outer cylinder, An inner cylinder disposed radially inside the outer cylinder; a combustion gas inlet for introducing the fuel gas and the oxidizing gas into the outer cylinder; an ignition unit that ignites the fuel gas introduced into the outer cylinder; a catalyst section that is heated by heat of a combustion gas generated by igniting the fuel gas by the ignition section, combusts the fuel gas, and reforms the fuel gas; a gas supply unit that supplies the fuel gas and the oxidizing gas to the catalyst unit, the inner cylinder is disposed such that a front end of the inner cylinder is located closer to a rear end of the outer cylinder than a front end of the outer cylinder, The front and rear ends of the inner cylinder are open, a combustion tubular gas flow passage is formed between the outer cylinder and the inner cylinder, through which the fuel gas and the oxidizing gas introduced by the combustion gas inlet flow toward a front end of the outer cylinder; a front blocking wall that blocks an internal space of the outer cylinder is provided at a front end of the outer cylinder, a rear blocking wall that blocks the combustion tubular gas flow passage is provided at a rear end of the outer cylinder, The ignition unit is fixed to the front blocking wall, The combustion gas inlet portion is disposed on the rear end side of the outer cylinder, and introduces the fuel gas and the oxidizing gas into the combustion tubular gas flow passage so as to flow along the circumferential direction of the inner cylinder.

2. The reforming apparatus according to claim 1, wherein the axial positional relationship of the inner cylinder with respect to the front blocking wall is set so that the fuel gas and the oxidizing gas introduced into the combustion tubular gas flow passage by the combustion gas inlet section flow in a swirling manner to the front blocking wall.

3. 3. The reformer according to claim 1, wherein the catalytic portion is accommodated in the inner cylinder.

4. 4. The reforming device according to claim 3, wherein the gas supply section includes a reforming gas inlet section that introduces the fuel gas and the oxidizing gas into the inner cylinder, and a reforming tubular gas flow passage formed between the inner cylinder and the catalyst section, through which the fuel gas and the oxidizing gas introduced by the reforming gas inlet section flow to the front end side of the inner cylinder.

5. the inner cylinder has a protruding portion protruding from a rear end of the outer cylinder, 5. The reforming apparatus according to claim 4, wherein the reforming gas inlet is provided in the protruding portion.

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