Modification unit

Abstract

To efficiently heat a vaporization part and a reforming part with combustion heat from a combustion part and make a reforming unit more compact.SOLUTION: A reforming unit constitutes a fuel cell module together with a fuel cell that generates power on the basis of anode gas and cathode gas. The unit comprises: a combustion part which has a combustion chamber to which off gas from a fuel cell is introduced and burns the off gas in the combustion chamber by a combustion device by igniting the off gas; a vaporization part which is arranged in the combustion chamber and generates water vapor by introducing reforming water; an outer pipe which is formed in a cylindrical shape so as to surround the combustion chamber with a prescribed interval to the outer surface of the combustion chamber; and a reforming part which is arranged in a space between the outer surface of the combustion chamber and the inner surface of the outer pipe, introduces raw fuel gas and introduces the water vapor from the vaporization part to generate the anode gas with water vapor reforming.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This specification discloses a reforming unit.

Background Art

[0002] Conventionally, as this type of reforming unit, in a fuel cell module including a fuel cell that can generate electricity using anode gas and cathode gas, there is known one comprising a vaporization unit that vaporizes reformed water to generate water vapor, a reforming unit that reforms a raw fuel gas into anode gas using the water vapor, and a combustion unit that burns off-gas discharged from the fuel cell and heats the vaporization unit and the reforming unit with the combustion heat. For example, Patent Document 1 discloses a reforming unit that constitutes the reforming unit with a reforming catalyst layer having an annular cross-sectional shape and arranges a combustion space inside the reforming unit. Further, Patent Document 2 discloses a reforming unit in which a vaporization unit (evaporation unit) and a reforming unit, each formed in a cylindrical shape and having their cylindrical ends connected to each other, are arranged in a combustion space.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the reforming unit described in Patent Document 1, since the vaporization section is located outside the combustion chamber, a separate space must be secured in the combustion chamber for the vaporization section to receive heat from combustion, resulting in a larger reforming unit. In addition, in the reforming unit described in Patent Document 2, since both the vaporization section and the reforming section are located within the combustion space, heat that is not used to heat the vaporization section or the reforming section increases as heat escapes from the outside of the combustion space. Furthermore, since the vaporization section is cooled by the heat of vaporization and becomes colder than the surroundings, if the vaporization section and the reforming section are connected as in the reforming unit described in Patent Document 2, a difference in thermal expansion due to the temperature difference will occur at the connection point between the two, which may lead to damage or other problems.

[0005] The primary objective of the reforming unit disclosed herein is to efficiently heat the vaporization section and the reforming section using combustion heat from the combustion section, while also making the reforming unit more compact. [Means for solving the problem]

[0006] The modification unit of this disclosure employs the following means to achieve the primary objective described above.

[0007] The modification unit in this disclosure is A reforming unit that constitutes a fuel cell module together with a fuel cell that generates electricity based on anode gas and cathode gas, A combustion section having a combustion chamber into which off-gas from the fuel cell is introduced, and a combustion device ignites and burns the off-gas in the combustion chamber, A vaporization unit is located inside the combustion chamber and generates steam by introducing reformed water, An outer tube formed in a cylindrical shape to surround the combustion chamber at a predetermined distance from the outer surface of the combustion chamber, A reforming unit is provided, which is located in the space between the outer surface of the combustion chamber and the inner surface of the outer tube, and which introduces raw fuel gas and water vapor from the vaporization unit to generate the anode gas by water vapor reforming. The gist of it is that it is equipped with the following features.

[0008] In the reforming unit of this disclosure, the vaporization section is located inside the combustion chamber, and the reforming section is located in the space between the inner surface of the cylindrical outer tube surrounding the combustion chamber and the outer surface of the combustion chamber. This allows the vaporization section and the reforming section to be heated both inside and outside the combustion chamber, thereby reducing the amount of heat escaping from the combustion chamber to the outside, and ultimately improving the efficiency of the fuel cell system, including the fuel cell module. Furthermore, by locating the vaporization section inside the combustion chamber, the length of the outer tube in the axial direction only needs to be adjusted to the amount of reforming catalyst required for reforming in the reforming section and the heat exchange length required for heat exchange with the combustion exhaust gas, thus making the reforming unit more compact.

[0009] In such a reforming unit of the present disclosure, a pressure equalization section may be provided, which has a space between one closed end of the outer tube in the axial direction and one closed end of the combustion chamber on the same side as the one end of the outer tube, into which the raw fuel gas is introduced and which connects the outlet of the vaporization section and the inlet of the reforming section through the space. In this case, by interposing the pressure equalization section, the raw fuel gas and water vapor can be flowed substantially uniformly in the circumferential direction to the reforming section, and the reforming catalyst packed in the reforming section can be used without waste. As a result, the life of the reforming catalyst can be extended or the amount of reforming catalyst to be packed can be reduced. In this case, at least one end of the outer tube in the axial direction may have a larger diameter than the central part in the axial direction. In this case, compared to making the outer diameter of the outer tube uniform between the central part and the ends, the outer diameter of the central part of the outer tube, i.e., the size of the reforming section, can be made more suitable while securing the space of the pressure equalization section. Furthermore, sufficient space can be secured at the end face of one end of the outer pipe for attaching the piping, thereby improving the workability of the installation process. In addition, an inlet for the raw fuel gas may be formed at the end face of one end of the outer pipe, and a reformed water introduction pipe for introducing reformed water into the vaporization section and a combustion exhaust gas outlet pipe for dischargering combustion exhaust gas from the combustion chamber may also pass through it.

[0010] Furthermore, in the reforming unit of this disclosure, the vaporization section may have the reformed water inlet and the water vapor outlet formed on the same plane. This makes it possible to suppress damage to the vaporization section due to differences in thermal expansion. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram of the fuel cell module including the reforming unit of this embodiment. [Figure 2] This is a schematic diagram of the modification unit. [Modes for carrying out the invention]

[0012] Embodiments for carrying out the present invention will be described with reference to the drawings.

[0013] Figure 1 is a schematic diagram of the fuel cell module 10 including the reforming unit 20 of this embodiment. As shown in Figure 1, the fuel cell module 10 of this embodiment comprises a fuel cell stack 11 that generates electricity through an electrochemical reaction between hydrogen in the anode gas and oxygen in the cathode gas, a reforming unit 20 that generates anode gas by reforming raw fuel gas (e.g., natural gas or LPG) by steam reforming, first and second heat exchangers 41 and 42, and a condenser 50. The fuel cell stack 11, the reforming unit 20, and the first and second heat exchangers 41 and 42 are housed in a box-shaped module case 12 with thermal insulation properties. The fuel cell module 10, together with a raw fuel gas supply device, a reforming water supply device, an air supply device, and a hot water storage tank (not shown), constitutes a fuel cell system. The raw fuel gas supply device supplies raw fuel gas to the reforming unit 20 (vaporization section 21), the reformed water supply device supplies reformed water necessary for reforming the raw fuel gas to anode gas (steam reforming) to the reforming unit 20 (vaporization section 21), and the air supply device supplies air as cathode gas to the fuel cell stack 11. The hot water storage tank recovers and stores the heat generated in the fuel cell module 10.

[0014] The fuel cell stack 11 comprises a plurality of solid oxide single cells arranged vertically, each having an electrolyte such as zirconium oxide and an anode electrode and a cathode electrode that sandwich the electrolyte. An anode gas passage is formed within the anode electrode of each single cell. A cathode gas passage is also formed within the cathode electrode of each single cell.

[0015] As shown in Figures 1 and 2, the reforming unit 20 includes a vaporization section 21, a reforming section 22, a combustion section 23, and a pressure equalization section 24 (see Figure 2). These are covered by an outer tube 25 that is cylindrical in shape and has both ends closed in the axial direction of the cylinder, as shown in Figure 2.

[0016] The vaporization unit 21 is connected to the reformed water piping 32 of the reformed water supply system, and reformed water is introduced through the reformed water piping 32.

[0017] The vaporization unit 21 heats the introduced reformed water with heat from the combustion unit 23 (heat of combustion), evaporating the reformed water and generating steam. The steam generated by the vaporization unit 21 is mixed with the raw fuel gas introduced into the pressure equalization unit 24 in the pressure equalization unit 24, and the mixed gas flows into the reforming unit 22.

[0018] The reforming unit 22 has a reforming catalyst 221 (see Figure 2) filled inside, for example, a Ru-based or Ni-based one, and in the presence of heat from the combustion unit 23, the reforming catalyst 221 reacts with the mixed gas (steam reforming reaction) to produce hydrogen gas and carbon monoxide. Furthermore, the reforming unit 22 produces hydrogen gas and carbon dioxide through a reaction between the carbon monoxide produced in the steam reforming reaction and steam (carbon monoxide shift reaction). As a result, the reforming unit 22 produces an anode gas containing hydrogen, carbon monoxide, carbon dioxide, steam, and unreformed raw fuel gas. The anode gas produced by the reforming unit 22 flows through the anode gas piping 33 into the anode gas passage of each single cell of the fuel cell stack 11 and is supplied to the anode electrode.

[0019] Also, air as the cathode gas flows from the air supply device through the cathode gas pipe 34 into the cathode gas passage of each single cell of the fuel cell stack 11 and is supplied to the cathode electrode.

[0020] At the cathode electrode of each single cell, oxide ions (O 2- ) are generated, and the oxide ions permeate through the electrolyte and react with hydrogen or carbon monoxide at the anode electrode to obtain electrical energy. The output terminals of the fuel cell stack 11 are connected to the input terminals of a power conditioner (not shown), and the generated power of the fuel cell stack 11 is converted into AC power by the power conditioner and supplied to an electrical load.

[0021] The anode gas (hereinafter referred to as "anode off-gas") that has not been used in the electrochemical reaction (power generation) in each single cell is once led out of the module case 12 through the anode off-gas pipe 35 and supplied to a condenser 50 (cooler) installed outside the module case 12. Then, the anode off-gas supplied to the condenser 50 is cooled by heat exchange with the hot water from the hot water storage tank, and after the water vapor contained in the anode off-gas is removed, it is re-introduced into the module case 12 and supplied to the combustion part 23 of the reforming unit 20. The water obtained by condensing the water vapor contained in the anode off-gas is stored in the reformed water tank and used as reformed water.

[0022] Also, the cathode gas (hereinafter referred to as "cathode off-gas") that has not been used in the electrochemical reaction (power generation) in each single cell is supplied to the combustion part 23 through the cathode off-gas pipe 36.

[0023] The anode off-gas flowing into the combustion section 23 is a combustible gas containing fuel components such as hydrogen and carbon monoxide, and is mixed with the cathode off-gas containing oxygen that flows into the combustion section 23. When the mixed gas (hereinafter referred to as "off-gas") is ignited in the combustion section 23 by the burner device 235 and burns, the combustion of the off-gas generates heat necessary for the generation of water vapor in the vaporization section 21 and the water vapor reforming reaction in the reforming section 22. In addition, combustion exhaust gas containing unburned fuel is generated in the combustion section 23, and this combustion exhaust gas is discharged to the outside air through the combustion exhaust gas piping 37 and a combustion catalyst. The combustion catalyst is an oxidation catalyst for re-combusting the unburned fuel in the combustion exhaust gas.

[0024] The first and second heat exchangers 41 and 42 are both installed inside the module case 12. The first heat exchanger 41 performs heat exchange between the anode off gas flowing upstream of the condenser 50 in the anode off gas piping 35 and the anode off gas flowing downstream of the condenser 50 in the anode off gas piping 35. The second heat exchanger 42 performs heat exchange between the combustion exhaust gas flowing through the combustion exhaust gas piping 37 and the cathode gas flowing through the cathode gas piping 34.

[0025] In the reforming unit 20, as shown in Figure 2, the combustion section 23 includes a combustion chamber 231 formed in a cylindrical shape with both ends in the axial direction of the cylinder closed by end walls 232 and 233, and a burner device 235 provided on the inner surface side of the end wall 232 of the combustion chamber 231. An anode off gas pipe 35 is connected to the end wall 232 of the combustion chamber 231 so that anode off gas flows into the combustion chamber 231 from the inside of the burner device 235, and a cathode off gas pipe 36 is connected so that cathode off gas flows into the combustion chamber 231 from the outside of the burner device 235. In addition, a combustion exhaust gas pipe 37 is connected to the end wall 233 of the combustion chamber 231 opposite to the end wall 232 so that combustion exhaust gas generated by the combustion of anode off gas and cathode off gas in the combustion chamber 231 flows out of the unit.

[0026] The vaporization unit 21 has a vaporization chamber 211 located inside the combustion chamber 231. The vaporization chamber 211 is positioned at a predetermined distance from the end wall 233 of the combustion chamber 231 opposite to the end wall 232 where the burner device 235 is located. A reformed water pipe 32 is positioned at the end wall 213 of the closed end of the vaporization chamber 211 on the same side as the end wall 233 of the combustion chamber 231, allowing reformed water to flow in. The vaporization chamber 211 is filled with spherical alumina with high thermal conductivity, and when the alumina is heated by the combustion heat generated in the combustion chamber 231, reformed water flows in (drips) from the reformed water pipe 32, causing the reformed water to evaporate and produce steam. Furthermore, a steam pipe 214 is connected to the same end wall 232 where the reformed water pipe 32 of the vaporization chamber 211 is located. The steam generated in the vaporization chamber 211 flows out through the steam pipe 214 to the pressure equalization section 24 and is supplied to the reforming section 22 via the pressure equalization section 24. In other words, the inlet and outlet of the vaporization chamber 211 are formed on the same plane. This effectively prevents damage to the wall surface of the vaporization chamber 211 due to thermal expansion differences based on the temperature difference between the flowing reformed water and steam. In this embodiment, the reformed water pipe 32 and the steam pipe 214 are formed as double pipes.

[0027] The reforming section 22 has a reforming catalyst 221 positioned in a cylindrical space (cylindrical space) formed between the outer surface of the side wall (circumferential wall) 234 of the combustion chamber 231 and the inner surface of the side wall (circumferential wall) 251 of the outer tube 25. The reforming section 22 receives steam and raw fuel gas from one end in the cylindrical axis direction of the cylindrical space, and discharges the anode gas generated by steam reforming from the other end in the cylindrical axis direction. The anode gas discharged from the reforming section 22 is supplied to the anode electrode of the fuel cell stack 11 through the anode gas piping 33.

[0028] The pressure equalization section 24 has a space defined by the end wall 233 of the combustion chamber 231 and the end wall 254 of the outer tube 25. The reformed water pipe 32 and the combustion exhaust gas pipe 37 are attached to the end wall 254 of the outer tube 25 so as to penetrate the pressure equalization section 24, and the raw fuel gas pipe 31 is connected so that the raw fuel gas flows into the pressure equalization section 24. The space of the pressure equalization section 24 is also in communication with the vaporization chamber 211 via the steam pipe 214. As a result, the raw fuel gas and steam flow into the reforming section 22 via the pressure equalization section 24, so that the pressure equalization section 24 functions as a buffer space, and the raw fuel gas and steam can be supplied to the cylindrical space (reformed catalyst 221) of the reforming section 22 in a substantially uniform manner in the circumferential direction. As a result, the reformed catalyst 221 can be used without waste, the lifespan of the reformed catalyst 221 can be extended, and the amount of reformed catalyst 221 to be filled can be reduced.

[0029] The length of the outer tube 25 in the axial direction is determined by the amount of reforming catalyst 221 required for steam reforming and the heat exchange length required to heat the reforming section 22 (reforming catalyst) through heat exchange with the combustion exhaust gas. As described above, since the vaporization section 21 is located inside the combustion chamber 231, the axial length of the reforming unit 20 can be shortened compared to arranging the vaporization section 21 in the axial direction of the reforming section 22 and the outer tube 25. As a result, the size of the reforming unit 20 can be kept within the size range of the fuel cell stack 11 located below the reforming unit 20, making the fuel cell module 10 more compact.

[0030] Furthermore, the outer pipe 25 has a larger diameter at both ends 252 and 253 in the axial direction than the central part. At the end 253 of the outer pipe 25, in addition to the reformed water piping 32, the combustion exhaust gas piping 37, and the raw fuel gas piping 31, a temperature sensor 51 (thermistor) for detecting the temperature of the gas (raw fuel gas and water vapor) flowing into the reforming section 22 is attached. By making the end 253 of the outer pipe 25 larger in diameter than the central part, sufficient space can be secured for the installation of various pipes (raw fuel gas piping 31, reformed water piping 32, and combustion exhaust gas piping 37) and the temperature sensor 51, improving the workability of the installation work. Also, by making the end 253 of the outer pipe 25 larger in diameter than the central part, it is possible to suppress the expansion of the outer diameter of the central part of the outer pipe 25 where the reforming section 22 is located. In other words, the cylindrical space filled with the reforming catalyst 221 can be made to an appropriate volume according to the required amount of reforming catalyst, while ensuring sufficient space between the side wall 251 of the outer tube 25 and the side wall 234 of the combustion chamber 231 to allow for smooth flow of raw fuel gas, water vapor, and anode gas, and ensuring sufficient heat exchange length of the reforming section 22.

[0031] In the reforming unit 20 of this embodiment described above, the vaporization section 21 is located inside the combustion chamber 231, and the reforming section 22 is located in the space between the inner surface of the cylindrical outer tube 25 surrounding the combustion chamber 231 and the outer surface of the combustion chamber 231. This allows the vaporization section 21 and the reforming section 22 to be heated both inside and outside the combustion chamber 231, thereby reducing the amount of heat escaping from the combustion chamber 231 to the outside, and consequently improving the efficiency of the fuel cell system including the fuel cell module 10. Furthermore, by arranging the vaporization section 21 inside the combustion chamber 231, the length of the outer tube 25 in the axial direction only needs to be adjusted to the amount of catalyst required for reforming in the reforming section 22 and the heat exchange length required for heat exchange with the combustion exhaust gas, making the reforming unit 20 more compact.

[0032] Furthermore, in the reforming unit 20 of this embodiment, the raw fuel gas is introduced, and a pressure equalization section 24 is formed by the space defined by the end wall 233 of the combustion chamber 231 and the end wall 254 of the outer tube 25, so as to connect the outlet of the vaporization section 21 and the inlet of the reforming section 22. By supplying a mixed gas of raw fuel gas and water vapor to the reforming section 22 via the pressure equalization section 24, the mixed gas can be flowed substantially uniformly in the circumferential direction to the reforming section 22, and the reforming catalyst 221 filled in the reforming section 22 can be used without waste. As a result, the lifespan of the reforming catalyst 221 can be extended, or the amount of reforming catalyst to be filled can be reduced.

[0033] Furthermore, since the end portion 253 of the outer pipe 25 is wider in diameter than the central portion, compared to a design where the outer diameter of the outer pipe 25 is uniform between the central and end portions, it is possible to ensure space for the pressure equalization portion 24 while making the outer diameter of the central portion of the outer pipe 25, i.e., the size of the reforming portion 22, more suitable. In addition, sufficient space can be secured on the end wall 254 of the outer pipe 25 for attaching piping (raw fuel gas piping 31, reformed water piping 32, combustion exhaust gas piping 37), thereby improving the workability of the installation work.

[0034] Furthermore, since the inlet for the reformed water and the outlet for the steam of the vaporization section 21 are formed on the same surface as the combustion chamber, damage to the vaporization section 21 due to differences in thermal expansion can be suppressed.

[0035] In the embodiment described above, both ends 252 and 253 of the outer tube 25 are made to be larger in diameter than the central part, but it is also acceptable to make only one end 253 larger in diameter, or to make the outer diameter uniform in the direction of the cylinder axis without making the ends larger in diameter.

[0036] In the embodiment described above, the reformed water piping 32 and the steam piping 214 connected to the vaporization section 21 are formed as double pipes, but they may be provided in parallel without being double pipes.

[0037] In the embodiment described above, the anode off-gas from the fuel cell stack 11 is supplied to the condenser 50, where the water vapor contained in the anode off-gas is removed before being supplied to the combustion unit 23. However, the anode off-gas from the fuel cell stack 11 may be supplied directly to the combustion unit 23. In this case, the combustion exhaust gas generated by the combustion of the off-gas in the combustion unit 23 is supplied to the condenser, and the water vapor contained in the combustion exhaust gas is condensed.

[0038] The correspondence between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem will be explained. In the embodiment, the fuel cell stack 11 corresponds to the "fuel cell" of this disclosure, the combustion section 23 corresponds to the "combustion section", the vaporization section 21 corresponds to the "vaporization section", the outer tube 25 corresponds to the "outer tube", and the reforming section 22 corresponds to the "reforming section". Also, the pressure equalization section 24 corresponds to the "pressure equalization section".

[0039] Furthermore, the correspondence between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem is merely an example to specifically explain the form in which the embodiment implements the invention described in the section on means for solving the problem, and does not limit the elements of the invention described in the section on means for solving the problem. In other words, the interpretation of the invention described in the section on means for solving the problem should be based on the description in that section, and the embodiment is merely one specific example of the invention described in the section on means for solving the problem.

[0040] Although embodiments for carrying out the present invention have been described above using examples, the present invention is not limited in any way to these embodiments, and can be carried out in various forms without departing from the spirit of the present invention. [Industrial applicability]

[0041] This invention can be used in industries such as the manufacturing of reforming units and fuel cell modules. [Explanation of Symbols]

[0042] 10 Fuel cell module, 11 Fuel cell stack, 12 Module case, 20 Reforming unit, 21 Vaporization section, 22 Reforming section, 23 Combustion section, 24 Pressure equalization section, 25 Outer pipe, 31 Raw fuel gas piping, 32 Reformed water piping, 33 Anode gas piping, 34 Cathode gas piping, 35 Anode off-gas piping, 36 Cathode off-gas piping, 37 Combustion exhaust gas piping, 41 First heat exchanger, 42 Second heat exchanger, 50 Condenser, 51 Temperature sensor, 211 Vaporization chamber, 213 End wall, 214 Steam piping, 221 Reforming catalyst, 231 Combustion chamber, 232, 233 End walls, 234 Peripheral wall, 235 Burner device, 251 Side wall, 252, 253 End section, 254 End wall.

Claims

1. A reforming unit that constitutes a fuel cell module together with a fuel cell that generates electricity based on anode gas and cathode gas, A combustion section having a combustion chamber into which off-gas from the fuel cell is introduced, and a combustion device ignites and burns the off-gas in the combustion chamber, A vaporization unit is located inside the combustion chamber and generates steam by introducing reformed water, An outer tube formed in a cylindrical shape to surround the combustion chamber at a predetermined distance from the outer surface of the combustion chamber, A reforming unit is provided, which is located in the space between the outer surface of the combustion chamber and the inner surface of the outer tube, and which introduces raw fuel gas and water vapor from the vaporization unit to generate the anode gas by water vapor reforming. Between one closed end of the outer tube in the axial direction and the closed end of the combustion chamber on the same side as the one end of the outer tube, there is a space that does not contain a reforming catalyst, into which the raw fuel gas is introduced and the outlet of the vaporization section and the inlet of the reforming section are connected through this space, and the equalizing section functions as a buffer space that supplies a mixture of the raw fuel gas and water vapor to the reforming section substantially uniformly in the circumferential direction, A modification unit equipped with the following features.

2. A modification unit according to claim 1, At least one of the ends of the outer tube in the axial direction is larger in diameter than the central part in the axial direction. Modification unit.

3. A reforming unit that constitutes a fuel cell module together with a fuel cell that generates electricity based on an anode gas and a cathode gas, A combustion section having a combustion chamber into which off-gas from the fuel cell is introduced, and a combustion device ignites and burns the off-gas in the combustion chamber, A vaporization unit is located inside the combustion chamber and generates steam by introducing reformed water, An outer tube formed in a cylindrical shape to surround the combustion chamber at a predetermined distance from the outer surface of the combustion chamber, A reforming unit is provided, which is located in the space between the outer surface of the combustion chamber and the inner surface of the outer tube, and which introduces raw fuel gas and water vapor from the vaporization unit to generate the anode gas by water vapor reforming. A pressure equalization section is provided, having a space between one closed end of the outer tube in the axial direction and one closed end of the combustion chamber on the same side as the one end of the outer tube, into which the raw fuel gas is introduced and which connects the outlet of the vaporization section and the inlet of the reforming section through the space, Equipped with, A modification unit in which at least one of the ends of the outer tube in the axial direction is larger in diameter than the central part in the axial direction.

4. A modification unit according to claim 2 or 3, An inlet for the raw fuel gas is formed at the end face of one end of the outer tube, and a reformed water introduction pipe for introducing reformed water into the vaporization section and a combustion exhaust gas outlet pipe for guiding combustion exhaust gas from the combustion chamber pass through it. Modification unit.

5. A modification unit according to any one of claims 1 to 4, The vaporization section has the inlet for reformed water and the outlet for water vapor formed on the same plane. Modification unit.

Images