JPH06219705A - Fuel reformer - Google Patents

Abstract

PURPOSE:To provide a light and small-sized fuel reformer exhibiting a short starting-time by improving a combustion burner, a reforming reaction tube and the heat transfer performance of a reforming catalyst in the reforming reaction tube. CONSTITUTION:This fuel reformer has a structure mentioned below; A reforming reaction tube 10 packed with a reforming catalyst 7 and a combustion burner 26 are arranged so that the heat transfer surface of the reforming reaction tube and the combustion surface of the burner may face to each other. The combustion burner is composed of plural fuel jet nozzles and air jet nozzles arranged around there. In addition, a reforming reactor and a catalyst combustor are adjacently arranged so that the respective heat transfer surfaces may be in contact with each other. Further, a fuel reforming stack is composed by piling up plural fuel reforming units each composed of a combination of a catalyst combustor and a reforming reaction unit so that the catalyst combustion unit and the reforming reaction unit may be alternately adjacent to each other. A raw material gas and a previously mixed fuel gas are fed respectively through each manifold from the side end part of the above fuel reforming stack and the reformed gas and the combustion gas are discharged therethrough.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for producing hydrogen necessary for, for example, a fuel cell for a general power source or a fuel cell mounted on an electric vehicle. For example, a reforming reaction filled with a reforming catalyst. The present invention relates to a fuel reformer for heating a pipe by a combustion burner to convert a hydrocarbon raw material or an alcohol raw material supplied to a reforming reaction pipe into a hydrogen-rich reformed gas, and more particularly to reduction in size and weight of the fuel reformer.

[0002]

2. Description of the Related Art FIG. 20 shows, for example, Japanese Patent Laid-Open No. 1-266843.
FIG. 1 is a cross-sectional view showing a conventional fuel reforming apparatus disclosed in Japanese Patent Publication No. JP-A No. 2003-242242, in which 1 is a raw material gas, 2 is a reformed gas, 3 is an inner pipe, and 4 is a concentric arrangement on the outer peripheral side of the inner pipe. The provided outer pipe, 5 is an intermediate pipe concentrically arranged between the inner pipe and the outer pipe, and 6 is a first pipe into which the raw material gas formed between the inner pipe and the intermediate pipe is introduced. An annular portion, 7 is a catalyst layer formed by filling the first annular portion with a reforming catalyst, 8 is a second annular portion through which the reformed gas formed between the intermediate pipe and the outer pipe flows, Reference numeral 9 denotes an annular end cap disposed at the other end of each of the inner pipe and the outer pipe, which communicates the first annular portion 6 and the second annular portion 8 with each other, and the reformed gas flowing out from the catalyst layer 7. The flow direction is reversed to flow into the second annular portion 8, and the second annular portion 8 is caused to flow in the direction opposite to the flowing direction of the source gas. Reference numeral 10 is an annular reforming reaction tube, 11 is a high temperature combustion gas as a heating gas, and 12 is a flow path for the combustion gas provided inside the inner tube. In the flow passage 12 for the combustion gas, there is shown in FIG.
As shown in Japanese Patent Publication No. 57-7539 or Japanese Patent Publication No. 57-7539, heat-transfer filler particles 13 made of, for example, a ceramic material or a metal material are filled.

FIG. 22 is a sectional view showing a state in which a plurality of reforming reaction tubes are incorporated in a heating furnace. 14 is a heating furnace, 15 is a combustion burner arranged in the heating furnace, and 16 is a raw material. Reference numeral 17 is a gas introduction manifold, 17 is a reformed gas discharge manifold, 18 is a combustion gas discharge manifold, and 19 is a furnace wall heat insulating material.

Next, the operation will be described with reference to FIG. The raw material gas 1 composed of hydrocarbon and steam or alcohol and steam is introduced from the introduction manifold 16 into the first annular portion 6 and comes into contact with the reforming catalyst 7. here,
The raw material gas 1 causes a reforming reaction and becomes a reformed gas 2 such as H ₂ , CO, or CO ₂ . High temperature (about 800 ° C) after the reaction
Of the reformed gas 2 flows out into the annular end cap 9 through a gas passage hole (not shown in the figure) of the receiving tray, and the flow is reversed so that the second annular portion 8 between the intermediate pipe 5 and the outer pipe 4 is reversed. And flows in the second annular portion 8 in the direction opposite to the direction in which the source gas 1 flows. During the process of flowing through the second annular portion 8, heat is transferred from the reformed gas 2 to the intermediate pipe 5, and the sensible heat of the reformed gas 2 is recovered in the catalyst layer 7 via the intermediate pipe 5. Then reformed gas 2
Is discharged from the discharge manifold 17 and supplied to the fuel cell. Combustion gas 11 which is a heating source of the reforming reaction tube 10 is generated from a combustion burner (not shown in the figure) installed in the heating furnace 14, and flows through the flow passage 12 inside the inner tube 3 of the reforming reaction tube. . The inner tube 3 is filled with heat transfer packing particles 13, and the combustion gas mainly heats the heat transfer packing particles by convective heat transfer. Heat is mainly transferred by solid radiation between the heat transfer filling particles to heat the reforming reaction tube 10. In this way, the heat transfer packing particles act as a heat transfer medium for effectively transferring the sensible heat of the combustion gas to the reforming reaction tube 10.

Recently, examples of using a catalytic combustor in a fuel reforming device for a fuel cell include Vol. 31, No. 35690 and Ishikawajima Harima Heavy Industries Technical Report, Vol. 31, No. 6, (November 1991). Published in the month). In both cases, a conventional combustion burner forming a flame is replaced with a catalytic combustor composed of an oxidation catalyst layer for combustion in the same arrangement as the conventional burner.

[0006]

Since the conventional fuel reformer is constructed as described above and the combustion burner and the reforming reaction tube 10 are provided separately in position, the heat generated by the combustion is generated by the combustion gas. The sensible heat is indirectly transmitted to the reforming reaction tube 10, and the heat of combustion is not directly transmitted to the reforming reaction tube. Therefore, the maximum temperature of the combustion burner rises to a temperature close to the adiabatic flame temperature, and it is necessary to select a material that can withstand high temperatures. The high temperature combustion gas generated from the combustion burner heats the reforming reaction tube 10 mainly by convection heat transfer. Generally, the heat transfer coefficient due to the forced convection of the combustion gas is small, and in order to obtain the heat transfer amount necessary for the reforming reaction, it is necessary to make the heat transfer area large, and there is a problem that the device becomes large.

Therefore, when the combustion gas passage 12 is filled with the heat transfer filling particles 13 in order to improve the heat transfer between the combustion gas 11 and the reforming reaction tube 10, the weight of the apparatus becomes large and the heat capacity also becomes large. . When a fuel reformer having a large heat capacity is started up from room temperature, it takes a long time to heat it to a predetermined operating temperature, and extra fuel is consumed. Further, the pressure loss of the combustion gas 11 increases due to the filling particles 13, and there is a problem that extra power is required to pressurize the fuel gas and the combustion air.

As for the heat transfer between the inner wall of the reforming reaction tube 10 and the reforming catalyst 7, the reforming catalyst layer in the reforming reaction tube is formed of a packed bed, so that the reforming catalyst layer near the wall surface of the reforming reaction tube 10 is improved. The fine catalyst particles are easily heated, but the internal catalyst particles are hard to be heated. Further, the thermal resistance between the wall surface and the catalyst particles and between the particles is large, and the heat transfer performance cannot be said to be sufficient.

Further, in the fuel reformer using the catalytic combustor, conventionally, there has been a problem in heat resistance of the oxidation catalyst for combustion.
Since the fuel is instantly oxidized on the surface of the oxidation catalyst, the temperature of the catalyst surface rises to the adiabatic flame temperature, causing thermal deterioration. A fuel reformer for a fuel cell uses a cell off-gas with a low calorific value as a fuel gas, and therefore has a lower adiabatic flame temperature than ordinary fuel and is suitable for catalytic combustion, but completely avoids this problem. I couldn't do that.

The present invention has been made to solve the above problems, and an object thereof is to obtain a fuel reformer which is small in size and light in weight and has a short start-up time by improving heat transfer performance.

[0011]

In the fuel reforming apparatus according to the invention of claim 1, the heat transfer surface of the reforming reaction tube loaded with the reforming catalyst and the combustion surface of the combustion burner are arranged to face each other. It was done.

A fuel reformer according to a second aspect of the present invention is the fuel reformer according to the first aspect, wherein the combustion burner is composed of a plurality of fuel injection nozzles around which air injection nozzles are arranged. is there.

In the fuel reforming apparatus according to the third aspect of the present invention, the combustion surface of the cylindrical combustion burner and the heat transfer surface of the cylindrical reforming reaction tube loaded with the reforming catalyst are opposed to each other. In addition to the concentric circular shape, the cylindrical exhaust gas flow passage and the cylindrical combustion air inlet flow path are adjacently arranged concentrically.

Further, the fuel reforming apparatus according to the invention of claim 4 is a reforming reactor having a reforming catalyst for producing hydrogen from a hydrocarbon or alcohol raw material by a reforming reaction, and a fuel gas premixed with air. And a catalytic combustor for heating the reforming reactor by the catalytic combustion of the catalytic converter to obtain a hydrogen-rich reformed gas. And are provided adjacent to each other.

A fuel reforming apparatus according to a fifth aspect of the present invention is the fuel reforming apparatus according to the fourth aspect, wherein an electric heater is provided adjacent to at least one of the reforming reactor and the catalytic combustor.

Further, in the fuel reforming apparatus according to the invention of claim 6, a reforming reaction part having a reforming catalyst for producing hydrogen from a hydrocarbon or alcohol raw material by a reforming reaction, and a fuel gas premixed with air. And a catalytic combustion unit that heats the reforming reaction unit by combustion of the fuel, and a catalytic reforming unit and a reforming reaction unit are alternately adjacent to each other in a fuel reforming unit including a pair of the catalytic combustion unit and the reforming reaction unit. A plurality of units are stacked to form a fuel reforming stack as described above, and the raw material gas and the premixed fuel gas are supplied from the side end portions of the fuel reforming stack through the respective manifolds, and the reforming gas and the combustion gas are supplied. It is configured to be discharged.

A fuel reforming apparatus according to a seventh aspect of the present invention is the fuel reforming apparatus according to the sixth aspect, wherein at least one of the raw material gas passage and the fuel gas passage is divided into a plurality of partial gas passages, A gas mixing section is provided between the partial gas channels.

A fuel reforming apparatus according to an eighth aspect of the present invention is the fuel reforming apparatus according to the sixth or seventh aspect, in which the combustion flame is formed inside the fuel supply manifold toward the side surface of the fuel reforming stack. A burner is arranged.

A fuel reforming apparatus according to a ninth aspect of the present invention is the fuel reforming apparatus according to any one of the first to eighth aspects, wherein the reforming reaction tube, the reforming reactor, the reforming reaction section, the catalytic combustor, or the catalytic combustion. Heat transfer fins for promoting heat transfer to the catalyst are provided on the inner wall surface of the section.

A fuel reforming apparatus according to a tenth aspect of the present invention is the fuel reforming apparatus according to any one of the first to ninth aspects, wherein the reforming reaction tube, the reforming reactor, the reforming reaction section, the catalytic combustor, or the catalytic combustion. A catalyst film is formed on the inner wall surface of the portion or on the surface of the heat transfer fin of claim 9.

[0021]

According to the invention of claim 1, the heat transfer surface of the reforming reaction tube and the combustion surface of the combustion burner are arranged so as to face each other. Therefore, the reforming reaction tube is directly formed by radiant heat from the solid surface of the combustion burner. To heat. Therefore, if the temperature of the combustion gas near the combustion burner is made uniform, the reforming reaction tube can be heated uniformly. Further, since the radiant heat transfer to the reforming reaction tube acts on the combustion burner, the maximum temperature of the combustion burner is lowered.

According to the second aspect of the present invention, the combustion burner is composed of a plurality of fuel injection nozzles around which air injection nozzles are arranged. Therefore, the area of the flame forming surface is increased and radiation heat transfer is promoted. be able to.

Further, in the invention of claim 3, the combustion surface of the cylindrical combustion burner and the heat transfer surface of the cylindrical reforming reaction tube loaded with the reforming catalyst are opposed to each other and are concentrically formed. Therefore, the combustion heat generated from the combustion burner can be effectively used for heating the reforming reaction tube. Further, since the exhaust passage of the cylindrical combustion gas and the inflow passage of the cylindrical combustion air are adjacently arranged to be concentric, heat exchange between the combustion gas and the combustion air can be achieved.

Further, in the invention of claim 4, since the reforming reactor and the catalytic combustor are provided adjacent to each other with their heat transfer surfaces in contact with each other, the heat generated in the catalytic combustor is directly applied to the reforming reactor. Be transmitted to. Furthermore, since the combustion catalyst is cooled by the heat absorption of the reforming reaction, it is possible to prevent the temperature of the combustion catalyst from rising above the heat resistant temperature.

According to the invention of claim 5, the above-mentioned claim 4 is adopted.
In this case, since an electric heater is provided adjacent to at least one of the reforming reactor and the catalytic combustor, the reforming catalyst and the combustion catalyst are mainly used when starting the catalytic combustor and the reforming reactor. The fuel reformer can be quickly started by uniformly heating to the operating temperature.

Further, in the invention of claim 6, the reforming reaction section having a reforming catalyst for producing hydrogen from a hydrocarbon or alcohol raw material by a reforming reaction, and the above reforming by combustion of a fuel gas premixed with air. A plurality of fuel reforming units including a catalytic combustion unit for heating the reaction unit, the fuel reforming unit including a pair of the catalytic combustion unit and the reforming reaction unit are stacked so that the catalytic combustion unit and the reforming reaction unit are alternately adjacent to each other. To form the fuel reforming stack, and to supply the raw material gas and the premixed fuel gas from the side ends of the fuel reforming stack through the respective manifolds, and to discharge the reforming gas and the combustion gas. Therefore, a large amount of hydrogen can be efficiently produced with a relatively small volume.

In the invention of claim 7, the above-mentioned claim 6
In this case, at least one of the raw material gas passage and the fuel gas passage is divided into a plurality of partial gas passages, and the gas mixing section is provided between the partial gas passages. Even if the flow of the combustion gas is partially non-uniform, the gas is uniformly mixed in the gas mixing section, so that the non-uniformity of the flow is prevented from affecting the reforming reaction and the combustion reaction.

According to the invention of claim 8, the above-mentioned claim 6 is used.
Or 7, the combustion burner that forms the combustion flame toward the side surface of the fuel reforming stack is arranged inside the fuel supply manifold. Therefore, when starting the fuel reforming stack, the combustion catalyst at the inlet of the catalyst combustion section Also, the reforming catalyst at the inlet of the reforming reaction section can be efficiently preheated to the operating temperature, and the fuel reforming stack can be started quickly.

According to the invention of claim 9, the above-mentioned claim 1
8 to 8, the heat transfer fins for promoting heat transfer to the catalyst are provided on the inner wall surface of the reforming reaction tube, the reforming reactor, the reforming reaction section, the catalytic combustor, or the catalytic combustion section. The heat from the combustion gas and the heat from the reformed gas are transferred to the heat transfer fins via the reforming reaction tube, and the heat transferred to the heat transfer fins is effectively transferred to the reforming catalyst by radiant heat transfer and convective heat transfer. Therefore, the heat transfer performance between the inner wall of the reforming reaction tube and the reforming catalyst can be improved.

According to a tenth aspect of the present invention, in the above first to ninth aspects, the reforming reaction tube, the reforming reactor,
Reforming reaction section, catalytic combustor, or inner wall surface of catalytic combustion section,
Alternatively, since the catalyst film is formed on the surface of the heat transfer fin in claim 9, for example, the heat transferred to the wall surface of the reforming reaction tube is
Since it is directly transferred to the reforming catalyst by heat conduction via the heat transfer fins, the thermal resistance between the wall surface of the reforming reaction tube and the catalyst can be significantly reduced.

[0031]

Embodiments of the present invention will be described below with reference to the drawings. Example 1. The basic configuration and operation of the fuel reforming apparatus according to the invention of claim 1 will be described with reference to FIG. FIG. 1 is a diagram schematically showing a configuration of a combustion burner of a fuel reformer and a surrounding of a reforming reaction tube. In the figure, the same or corresponding parts as those of the conventional fuel reformer shown in FIGS. 20, 21 and 22 are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 20 is a cell off gas (fuel gas) discharged from the fuel cell, 21 is a fuel manifold for supplying the fuel gas to the burner, 22 is a fuel injection nozzle for injecting the fuel gas from the burner, and 23 is for combustion. Required air, 24 is an air manifold that supplies air to the burner,
25 is an air injection nozzle for injecting air from the burner, 2
6 is a combustion burner having a large number of adjacent fuel injection nozzles and air injection nozzles on a plane, 27 is a flame surface formed by combustion, and 11 is a combustion gas. On the other hand, the flow passage configuration of the raw material gas 1 and the reformed gas 2 is the same as that of the conventional fuel reformer.

Next, the operation of this fuel reformer will be described. First, the procedure for starting the fuel reformer will be described.
City gas as fuel gas at startup (13A: mixed gas containing methane as a main component and ethane, propane, butane)
The case of using will be described. In order to ensure the ignition of the city gas, the city gas premixed with the primary air is supplied as the fuel gas 20 to the fuel manifold 21. At the same time, the secondary air is supplied to the air manifold 24. The fuel gas 20 is injected into the combustion space from the combustion burner 26 via the fuel injection nozzle 22, and the air 23 is injected into the combustion space from the combustion burner 26 via the air injection nozzle 25. The fuel gas 20 and the air 23 injected from the nozzle diffuse and mix with each other to form a flame surface 27 by combustion. In order to form a flame evenly and uniformly, it is necessary to make the injection amount of fuel gas and air from each nozzle uniform. The fuel gas and air injected from this are sufficiently diffused and mixed, and uniform combustion is performed. In this way, the surface combustion burner 26 causes combustion on the entire flame surface 27, and the radiant heat mainly heats the reforming reaction tube 10 uniformly. The hot combustion gas 11 flows downward along the reforming reaction tube 10 and, during this time, heats the reforming reaction tube 10 by convection heat transfer. Further, the combustion gas 11 reverses its flow at the lower end of the reforming reaction tube 10, and this time flows upward along the reforming reaction tube 10 and the air tube to heat the reforming reaction tube 10 again and to burn the combustion air 23. Preheat.

When the temperature of the reforming reaction tube 10 reaches a temperature suitable for the reforming reaction, for example, 800 ° C. or higher, city gas containing steam is introduced into the reforming catalyst layer 7 as the raw material gas 1.
The reformed gas 2 exiting the reforming reaction tube 10 exchanges heat with the raw material gas 1, is cooled to the operating temperature of the fuel cell, and is supplied to the fuel cell. Since hydrogen is consumed in the fuel cell, the hydrogen-rich reformed gas becomes hydrogen-lean cell off-gas.
When the battery off gas is supplied to the fuel reformer as the fuel gas 20 in place of the city gas, the start-up ends and the operation shifts to the steady operation.

In the steady operation, the cell off-gas 20 is supplied to the fuel manifold 21, the combustion of the cell off-gas 20 heats the reforming reaction tube 10, and the continuous operation of the fuel reformer is maintained. Since the combustible component of the battery off gas 20 is hydrogen, which has a good ignitability, the premixed air required for burning city gas is not required to burn this hydrogen.

Example 2. An embodiment relating to a specific configuration of a combustion burner of a fuel reforming apparatus according to the invention of claim 2 is shown in FIG.
2A to 2D. The combustion burner of this embodiment is composed of a large number of fuel injection nozzles 22 around which air injection nozzles 25 are arranged. The nozzles 22 and 25 are arranged on the same surface so that they are adjacent to each other, and a flame having a large surface area is provided. Form a surface.

The arrangement of the fuel injection nozzle 22 and the air injection nozzle 25 shown in FIG. 2 (a) is called a face-centered arrangement. With this arrangement, the fuel / air injection nozzles can be arranged most densely in a certain flame forming surface. Four air injection nozzles 25 are arranged around one fuel injection nozzle 22, while four fuel injection nozzles 22 are arranged around one air injection nozzle 25. Since the air flow rate is larger than the fuel flow rate, in order to equalize the pressure loss, the diameter D _A of the air injection nozzle is made larger than the diameter D _F of the fuel injection nozzle as shown in the figure. In the figure, P _F is the pitch of the fuel injection nozzles and P _A is the pitch of the air injection nozzles.

The arrangement of the fuel injection nozzle 22 and the air injection nozzle 25 shown in FIG. 2B is called a square arrangement. This arrangement can reduce the number of nozzles per flame formation area even if the nozzle pitches P _A and P _F are the same as compared with the face-centered arrangement. Considering the diffusion of fuel and air, it is necessary to increase the nozzle diameter as the distance between the nozzles increases.

The arrangement of the fuel injection nozzle 22 and the air injection nozzle 25 shown in FIG. 2C is called a hexagonal arrangement. Six air injection nozzles 25 are arranged in a regular hexagon around one fuel injection nozzle 22. The ratio of the air injection nozzles 25 to the fuel injection nozzles 22 is 2: 1 and the number of the fuel injection nozzles 22 can be reduced. In this example, the fuel injection nozzle 22 is located at the center of the hexagon, but it is also conceivable that the air injection nozzle 25 is located at the center and the fuel injection nozzle 22 is arranged around it. However, in the hexagonal arrangement of the fuel injection nozzles 22, oxygen tends to be insufficient due to the degree of diffusion of air injected from the center. In particular, the hexagonal arrangement of the air injection nozzles 25 is desirable when burning a hydrocarbon-based fuel that requires a large amount of oxygen per fuel flow rate.

The arrangement of nozzles shown in FIG. 2D is called concentric arrangement. The fuel injection nozzle 22 is located at the center, and the air injection nozzle 25 is arranged in the concentric annular portion. As shown in Fig. 2 (e), the nozzle has a notch (chamfer) in the cross section taken along the line AA ', and the air flow line and the fuel flow line are bent at right angles to each other, so that the fuel and the air flow Promotes mixing. This notch can also be provided for other nozzle arrangements. If the mixture of fuel and air is improved, the flame forming surface becomes closer to the end surface of the nozzle, and the radiation heat transfer from the burner surface can be promoted.

Example 3. An embodiment relating to a specific configuration of the fuel reforming apparatus according to the invention of claim 3 will be described with reference to FIGS. 3 and 4. In the fuel reformer of this embodiment, the conventional fuel reformer shown in FIG. 22 is composed of a single combustion burner and a plurality of reforming reaction tubes 10, whereas a pair of combustion burners is modified. It is composed of quality reaction tubes. Further, the heat transfer filling particles 13 filled in the combustion gas passage in FIG. 21 are also removed.

FIG. 3 shows an example in which the combustion burner 26 is arranged on the outer peripheral side of the heating furnace, and the annular reforming reaction tube 10 to be heated is arranged inside thereof. A fuel manifold 21 is provided between the outermost heat insulating material 19 and the surface combustion burner 26, and an air manifold 24 is provided inside thereof. The fuel gas 20 and the combustion air 23 are injected toward the center from the fuel injection nozzle 22 and the air injection nozzle 25, respectively, and burned. The combustion gas 11 flows from the outer side to the inner side along the reforming reaction tube 10 and preheats the combustion air 23 flowing at the center. In the external flame inflow type in which the combustion burner 26 is provided on the outer peripheral side and the combustion gas 11 flows from the outside to the inside, the heat transfer area of the combustion burner 26 is large, so that the combustion burner 26 transfers to the reforming reaction tube 10. The amount of heat transfer can be maximized. On the other hand, since the temperature of the outer peripheral portion of the heating furnace becomes high, heat radiation to the outside becomes large, and if the heat insulating material 19 is thickened to suppress it, the device becomes large. Therefore, in this type of fuel reformer, it is effective to cover the inner wall of the heat insulating material 19 with a material having a low emissivity in order to suppress heat radiation to the outside to suppress radiant heat transfer to the outside.

Example 4. In FIG. 4, the surface combustion burner 26 is arranged on the central axis of the heating furnace, and the annular reforming reaction tube 10 is heated.
Is an example in which is arranged on the outside. A fuel manifold 21 is provided on the central axis, and an air manifold 24 is provided on the outside thereof. The fuel gas 20 and the combustion air 23 are radially ejected outward from the fuel injection nozzle 22 and the air injection nozzle 25 to perform combustion. The exhaust gas 11 after combustion flows from the inner side to the outer side along the reforming reaction tube 10, and preheats the combustion air 23 flowing to the outermost side. Since the internal flame outward flow type in which the combustion burner 26 flows on the central axis and the combustion gas 11 flows from the inner side to the outer side is smaller in heat transfer area of the surface combustion burner 26 than the external flame inward flow type described above, Reforming reaction tube 1
The amount of heat transferred to 0 is relatively small. However, as compared with the conventional concentrated burner, since the combustion burner 26 and the reforming reaction tube 10 face each other, the radiant heat can be effectively used. Further, since the diameter of the annular reforming reaction tube 10 can be made larger than that of the external flame inward flow type, the amount of the reforming catalyst 7 that can be filled can be increased, which is advantageous in extending the life of the catalyst. In addition,
In this type of fuel reformer, since combustion is performed inside the heating furnace, it is possible to reduce heat radiation to the outside.

Example 5. An embodiment in which the invention of claim 9 is applied to the above-mentioned first, third, and fourth embodiments will be described with reference to FIG. In the figure, 28 is a corrugated heat transfer fin provided inside the reforming reaction tube 10, and this heat transfer fin 28 simultaneously forms the raw material gas flow path 1a. The heat transferred from the wall surface of the reforming reaction tube 10 to the heat transfer fins 28 by heat conduction is transferred to the reforming catalyst 7 via the heat transfer fins 28. By providing the heat transfer fins 28 in the raw material gas passage 1a in this way, the heat transfer area is increased, and heat transfer to the reforming catalyst 7 is promoted. The heat transfer fin 28 is made of a material having excellent thermal conductivity, high emissivity at high temperature, and strength enough to withstand thermal expansion / contraction.

The heat transfer fin 28 shown in FIG. 5 is a straight fin having a corrugated (corrugated) arc shape.
Depending on the shape of the corrugate, square, trapezoidal, or triangular fins are possible. FIG. 6 shows an example of the shape of the heat transfer fins in which the corrugations are displaced by a half pitch. This heat transfer fin has a zigzag arrangement in which one corrugation (square shape) is displaced by a half pitch, and the reforming catalyst 7 is filled inside this corrugation. Arrows A and B indicate two ways of flowing the source gas. Flow A is when the source gas flows at a right angle to the corrugate, and flow B is when the source gas flows parallel to the corrugate. In the flow A, the number of contact between the raw material gas and the catalyst increases, but the pressure loss also increases. On the other hand, in the flow B, the number of contact between the source gas and the catalyst is relatively small, but the pressure loss is small. For example, the flow A is adopted in a place where the reforming reaction is desired to be promoted, and the flow B is adopted in a place where the reforming reaction is suppressed. It is also possible to consider a flow having an inclined angle with respect to the flow A and the flow B. In addition,
The amount of heat transferred from the heat transfer fins 28 to the catalyst by heat radiation is
There is no difference between the two flows because it is determined by the form factors of the catalyst particles and the heat transfer fins 28 and their respective emissivities.
For convective heat transfer, the A appears to be the more disturbed the flow.

Example 6. FIG. 7 shows another embodiment in which the heat transfer fins 28 are provided inside the reforming reaction tube 10. In this embodiment, the heat transfer fins 28 are provided so that the flow of the raw material gas 1 spirally swirls, so that not only the heat transfer area is increased but also the flow rate of the raw material gas is increased to promote the reaction. In the heat transfer fin 28 of this shape, as the spiral angle θ shown in the figure increases, the flow velocity of the source gas and the heat transfer area increase, so the spiral angle θ
Is changed in the flow direction, the thermal resistance between the inner wall surface of the reforming reaction tube 10 and the reforming catalyst 7 can be changed in the flow direction of the raw material gas.

Example 7. An embodiment in which the invention of claim 10 is applied to the above-mentioned first, third, and sixth embodiments will be described with reference to FIG. In the figure, 28 is a corrugated heat transfer fin provided inside the reforming reaction tube 10, and 29 is a reforming catalyst film which is coated on the surface of the heat transfer fin 28 and fixed to the wall of the tube and integrated. In this embodiment, heat is transferred from the wall surface directly to the catalyst film 29 coated by heat conduction in the solid, so that convective heat transfer to the catalyst in the packed bed,
Heat is transferred much faster than radiant heat transfer. As a result, the thermal resistance between the wall surface of the reforming reaction tube and the reforming catalyst can be significantly reduced. The reforming catalyst film 29 may be coated on the inner wall surface of the reforming reaction tube 10.

Next, a method of coating the surface of the heat transfer fins 28 and the wall surface of the reforming reaction tube 10 with a catalyst will be described. Usually, the reforming catalyst is composed of a porous ceramic material such as alumina or magnesia carrying a catalytically active substance such as nickel or ruthenium. On the other hand, as the material of the heat transfer fins 28 and the reforming reaction tube 10, stainless steel, which is an alloy of steel, nickel, and chromium, is used. In order to form the catalyst film 29 on the surface of the heat transfer fin 28, for example, a material such as alumina or magnesia that becomes a catalyst carrier is formed to a thickness of about 0.5 to 1.0 mm by a thermal spraying method such as plasma spraying. It is fixed to the surface of the heat transfer fin 28. The heat transfer fin 28 to which the carrier material of the catalyst is fixed is immersed in an aqueous solution of a metal salt having catalytic activity such as nickel,
After depositing the active metal, for example 2 to 30% by weight of the carrier,
A method of taking steps of drying and thermal decomposition can be used. Alternatively, the surface of the heat transfer fin 28 may be activated after thermal spraying of a powder of a normal reforming catalyst. In addition, after the porous carrier layer is formed by the electrophoretic method, it is immersed in a solution containing an active metal to deposit the active metal and then activated, or a Raney catalyst generally used as a reforming catalyst. (For example, a Raney nickel catalyst having a large surface area obtained by providing a Ni-Al alloy layer having a nickel content of 30 to 50% on the surface of the heat transfer fin 28, and then developing Al)
Any catalyst having an appropriate activity formed on the surface of the heat transfer fins 28 can be used as a catalyst having the same effect as that of the above-mentioned embodiment.

Example 8. Another embodiment of the fuel reforming apparatus according to the invention of claim 9 will be described with reference to FIG. The structure of the annular reforming reaction tube 10 and the flows of the raw material gas 1 and the reformed gas 2 of the fuel reforming apparatus according to this embodiment are the same as those of the fifth embodiment shown in FIG. This is different from Example 5 (FIG. 5) in that the flow path is divided into two by different filling patterns of the reforming catalyst 7. In the figure, 2
Reference numeral 8 is a heat transfer fin, 30a is an inlet side raw material gas flow path in which the reforming catalyst 7 is filled in only one side of the heat transfer fin corrugate, 3
Reference numeral 0b is an outlet-side raw material gas flow path in which the reforming catalyst 7 is filled in the entire corrugate.

The raw material gas 1 is introduced into the inlet side flow passage 30a, and a reforming reaction is caused by the reforming catalyst 7. However, since the raw material gas that has flowed into the corrugation not filled with the reforming catalyst 7 does not cause the reforming reaction, it is possible to suppress an excessive reforming reaction. Since the reforming catalyst 7 is filled in all of the corrugates in the outlet side flow passage 30b, the inlet side flow passage 3
The raw material gas that has flowed to the corrugation not filled with the catalyst of 0a is also reformed here. In this way, by changing the filling pattern of the reforming catalyst 7 depending on the flow direction of the raw material gas, the reforming reaction can be uniformly caused and the endothermic distribution can be made uniform.

In this embodiment, the raw material gas flow path is set to 2
Although it was divided, the reforming reaction can be made more uniform by increasing the catalyst filling pattern and increasing the number of divisions. Further, not only the catalyst filling pattern, but also the shapes of the heat transfer fins and the catalyst coating amount can be changed to change the constitution of the raw material gas passages as shown in the fifth, sixth and seventh embodiments. .

Example 9. An embodiment of the fuel reforming apparatus according to the invention of claim 4 will be described with reference to FIG. FIG. 10 is a diagram schematically showing the configuration of a fuel reformer in which a catalytic combustor is applied to a combustion burner. In the figure, 31 is a premixed gas of fuel gas and combustion air, 32 is a heat transfer fin provided inside the combustor, 33 is a combustion catalyst, and 34 is a catalytic combustor. As the combustion catalyst 33, a carrier of alumina is used.
A porous catalyst supporting Pt and Pd is used. The combustible components and oxygen in the premixed gas 31 diffuse in the pores of the catalyst 33,
By adsorbing on the surface of the metal particles, the oxidation reaction of the combustible component proceeds. Carbon dioxide gas and steam generated by the oxidation reaction diffuse in the pores in the direction opposite to the reaction gas and are discharged to the outside of the catalyst particles. The heat generated in the combustion catalyst 33 is transferred to the heat transfer fins 32 by the convection of the combustion gas and the radiation between the surfaces of the catalyst particles and the heat transfer fins 32. The catalytic combustor 34 is adjacent to the reforming reactor 10 and transfers heat generated by combustion to the reforming reactor 10.
To communicate efficiently.

Conventionally, in catalytic combustion, fuel burns instantaneously on the surface of the catalyst, so the temperature of the surface of the catalyst rises to the adiabatic flame temperature, and the catalyst thermally deteriorates. Since the fuel reformer for a fuel cell uses a low calorific value of cell off-gas as a fuel gas, the adiabatic flame temperature is lower than that of a normal fuel, which is suitable for catalytic combustion. Further, in the present embodiment, the combustion catalyst 33 is cooled by the heat absorption of the reforming reaction, and the temperature of the combustion catalyst 33 can be lowered to the heat resistant temperature or lower.

FIG. 11 shows a fuel reformer in which one heat transfer fin 28 also serves as the partition wall of the reforming reactor and the catalytic combustor. In the figure, the reforming catalyst 7 is filled in the upper surface of the heat transfer fin 28, and the combustion catalyst 33 is filled in the lower surface. Reforming catalyst 7
Since the partition wall of the combustion catalyst 33 is composed of one heat transfer fin 28, the thermal resistance due to the contact between the heat transfer fin 28 and the partition wall can be reduced. Although the upper surface is filled with the reforming catalyst 7 and the lower surface is filled with the combustion catalyst 33, the upper surface may be filled with the combustion catalyst 33 and the lower surface may be filled with the reforming catalyst 7.

Example 10. FIG. 12 shows an embodiment in which the invention of claim 10 is applied to that of FIG. In this example, one side of the heat transfer fin 28 is coated with the combustion catalyst 33, and the other side thereof is coated with the reforming catalyst 7.
Since the convection of the combustion gas and the radiation between the walls are present in the conventional heat transfer path, the reaction rate of the reforming reaction is often heat transfer rate limiting. In this embodiment, the combustion heat generated in the combustion catalyst 33 passes through the heat transfer fins 28 by heat conduction and is transmitted to the reforming catalyst 7, so that the thermal resistance becomes extremely small. Therefore, the reaction rate of the reforming reaction can exhibit the original reaction rate of the catalyst.

Example 11. FIG. 13 shows still another embodiment of the invention of claim 4. FIG. 13A is a perspective view, FIG.
FIG. 7 is a sectional view taken along line BB ′. The catalytic combustor 34 is provided in the outermost annular portion of the cylindrical shape, and the reforming reactor 10 is provided in the inner annular portion thereof. As described in the related art, the reforming reactor 10 has a double tube structure of a reforming gas flow path in which the flow is reversed with the catalyst filling portion. The flow of the high temperature combustion gas that has left the catalytic combustor 34 is also reversed and flows toward the center to preheat the combustion air.

In this embodiment, as shown in FIG. 13 (b), the flow of each gas is provided with a catalytic combustor 34 at the outermost periphery, and the flow of each gas is directed from the outer periphery toward the center. However, the catalytic combustor 34 may be provided at the center so that the gas flow is directed from the center to the outer peripheral direction, and the same effect as that of the above embodiment is obtained. In addition, in the case of this example as well, the heat transfer fin 28 is provided in
As shown in FIG. 7, it may be provided in a spiral shape, and the same effect as in the case of FIG. 7 can be obtained.

Example 12 An embodiment of the fuel reforming apparatus according to the invention of claim 5 will be described with reference to FIG. 14
Shows the structure of a fuel reformer using an electric heater 54 to heat the catalytic combustor 34. In this embodiment, the catalytic combustor 34 is heated uniformly at the time of startup, so the catalytic combustor 3
An electric heater 54 is provided adjacent to No. 4. Combustion catalyst 33
Is heated by an electric heater 54 to the operating temperature of the catalyst. Then, the fuel gas 31 premixed with air is supplied to the catalytic combustor 34, and the reforming reactor 10 is heated to the operating temperature by the combustion heat. Thus, the output of the electric heater 54 is determined by the amount of heat that heats the combustion catalyst 33 to the operating temperature in a predetermined time. When the heat capacity of the catalytic combustor 34 is large, it is inefficient to heat the whole to the operating temperature.
It is also possible to employ a method in which the catalyst at the combustor inlet is intensively heated by the electric heater 54, and the catalyst at the downstream side is heated by the combustion of the catalyst at the inlet.

FIG. 15 shows the catalytic combustor 34 and the reforming reactor 10.
The structure of the fuel reformer using the electric heater 54 for both heating is shown. In this embodiment, if an electric heater 54 is provided between the catalytic combustor 34 and the reforming reactor 10, both can be heated by one electric heater 54. This system is effective when the fuel reformer is frequently started, operated, and stopped, or when the catalytic combustor 34 alone cannot heat the reforming reactor 10 uniformly.

In addition, in the structure shown in FIGS. 11 and 12, an electric heater wire is built in a part of the heat transfer fins 28 provided in the catalyst combustion section and the reforming reaction section, and the catalyst combustion section and the reforming reaction section are connected. There is also a method of directly heating.

Example 13. An embodiment of the fuel reforming apparatus according to the invention of claim 6 will be described with reference to FIGS. 16 (a) and 16 (b). FIG. 16A is a perspective view in which the fuel / air supply manifold 36, the raw material supply manifold 37, the reformed gas discharge manifold 38, and the combustion gas discharge manifold 39 are attached to the four side surfaces of the fuel reforming stack. Here, the cross-flow type in which the flow of the raw material gas / reformed gas and the flow of the fuel gas / combustion gas are orthogonal to each other is adopted.
FIG. 16b is a partial perspective view of the fuel reforming stack with the manifold open. A fuel reforming stack 43 is formed by stacking a plurality of fuel reforming units 42 each including a pair of catalytic combustion units 40 and reforming reaction units 41 so that the catalytic combustion units and the reforming reaction units are alternately adjacent to each other. ing. In the reforming reaction section 41, the raw material gas is converted into a hydrogen-rich reformed gas by the action of the reforming catalyst 7, and the heat required for the reforming reaction is transferred by combustion heat from the vertically adjacent catalytic combustion sections 40. .
In addition, the catalytic combustion unit 40 includes vertically adjacent reforming reaction units 41.
Is cooled by. As described above, in the fuel reforming stack, the fuel reforming unit including the pair of catalytic combustion section 40 and the reforming reaction section 41 serves as a basic element and satisfies the functions of combustion and reforming reaction. A conventional fuel reformer is composed of a single combustion burner and a plurality of reforming reaction tubes, and the combustion and the reforming reaction are performed separately. In the fuel reforming stack of the present invention, the combustion and the reforming reaction are performed by the catalytic combustion unit 40 having one partition wall.
Occurs in the reforming reaction section 41 and is closely related thermally. Therefore, the combustion heat generated in the catalytic combustion unit 40 is immediately consumed to absorb the reforming reaction, so that the temperature of the combustion gas does not rise rapidly. Because, the rate of combustion heat generated on the surface of the combustion catalyst heats the combustion gas,
This is because the speed at which the partition wall is heated and transmitted to the reforming catalyst 7 is faster.

In this embodiment, both the combustion catalyst 33 and the reforming catalyst 7 are in the form of packed particles, but if the coating catalyst integrated with the heat transfer fin is used as shown in FIG. The thermal resistance between the combustion catalyst 33 and the reforming catalyst 7 is only heat conduction, which is negligibly smaller than the thermal resistances on the combustion gas and reforming gas sides, and the combustion heat is used as it is for the endothermic reaction of the reforming reaction. become. Further, the temperature difference between the catalytic combustion section 40 and the reforming reaction section 41 becomes extremely small.

By adopting the fuel reforming stack 43 in which the fuel reforming units 42 are stacked in this way, the apparatus can be made smaller and lighter than the conventional fuel reforming apparatus, and combustion of a large amount of fuel gas and raw materials can be performed. The gas can be reformed. Also,
Since the fuel reforming unit 42 is a basic structural unit, the number of stacked fuel reforming units 43 may be taken into consideration when designing the apparatus when it is desired to arbitrarily change the rated gas flow rate that can be processed. Further, it can be manufactured for each fuel reforming unit 42, and there are many advantages in manufacturing.

Example 14 An embodiment of the fuel reformer according to the invention of claim 7 will be described with reference to FIG. In the present invention, the raw material gas flow path / reformed gas flow path is divided into a plurality of partial gas flow paths, that is, multistage, and the gas mixing section 44 is provided between each partial gas flow path, that is, between each multistage. The raw material gas flow path and the reformed gas flow path are configured so that the converted stages are connected in series. FIG. 17 is a cross-sectional view of the fuel reforming stack when the raw material gas passages are in two stages. The raw material gas 1 is guided from the raw material gas supply manifold 37 to the raw material gas side of the fuel reforming stack. In this embodiment, the source gas supply manifold 37 is disposed adjacent to the reformed gas discharge manifold 38, and heat exchange is performed between the high temperature reformed gas and the low temperature source gas. The raw material gas 1 is distributed from the supply manifold 37 to each fuel reforming cell. The raw material gas flowing into the first-stage raw material gas passage is converted into hydrogen gas 2 by the action of the reforming catalyst 7.
Is reformed to. After that, the reformed gas 2 is guided to the reformed gas return manifold 45 arranged on the stack side surface opposite to the stack side surface on which the raw material supply manifold is arranged, and the reformed gas flowing to each fuel reforming cell is Meet here. The reformed gas is uniformly mixed in the gas mixing section 44 while reversing the flow. The reversal of gas flow creates a myriad of fluid vortices that promote gas mixing. Therefore, even if there is a difference in flow distribution among the cells, the gas distribution in the return manifold 45 once eliminates the non-uniform flow distribution. The reformed gas is distributed from the return manifold 45 to each fuel reforming cell again. In the second-stage reformed gas passage, the unreformed raw material in the reformed gas is reformed, and the reformed gas 2 flowing into each cell is exhausted by the exhaust manifold 38.
Join at.

The raw material gas 1 may be discharged without being reformed without coming into contact with the reforming catalyst 7 due to the filling condition of the reforming catalyst 7 or the gap at the end of the raw material gas passage. In particular, since the reforming reaction is accompanied by the expansion of the volume, the rate at which the raw material gas 1 bypasses the gap between the ends increases due to the reaction. In the present invention, the bypassed unreformed raw material gas and the gas reformed in the first-stage raw material gas flow passage are uniformly mixed in the return manifold 45 and guided to the second-stage raw material gas flow passage. Most of the bypassed unreformed raw material is reformed by the second-stage reforming catalyst 7. The reformed gas 2 is exhausted from the reformed gas exhaust manifold 38 and supplied to the fuel cell or to another device that requires hydrogen.

In the above embodiment, the raw material gas flow passage has two stages, but it is also possible to have multiple stages with the same structure.
If the number of stages is increased, the gas mixing section also increases.
Although it is possible to further reduce the adverse effects of the bypass and non-uniformity of gas distribution between cells, on the other hand, the gas flow velocity increases and the gas flow path becomes longer, so the pressure loss increases.

In the embodiment shown in FIG. 17, the flow paths of the raw material gas 1 and the reformed gas 2 are multistage, but the fuel gas 3
1. The flow path of the combustion gas 11 can be multistage. For example, the flow paths of the raw material gas / reforming gas and the fuel gas in FIG.
The reforming catalyst 7 and the combustion catalyst 3 are exchanged with the flow path of the combustion gas.
If 3 is replaced, it is possible to easily realize multi-stage fuel gas / combustion gas. When the combustion causes local heat generation and the volume of the combustion gas 11 expands rapidly to cause nonuniformity in the flow of the combustion gas 11, the mixing of the gases due to the multistage combustion gas causes the nonuniform flow. It is a very effective means for mixing unburned fuel and bypassed fuel.

Example 15 Next, FIGS. 18a and 18b show an example of a fuel reforming apparatus in which the raw material gas / reforming gas passages are provided in two stages and the fuel gas / combustion gas passages are provided in three stages. In order to bring the flows of the two gases close to a parallel flow, the fuel / combustion gas forms a gas flow path that is symmetrical with respect to the center line as shown in FIG. 18b. The fuel supply manifold 36 is adjacent to the first gas mixing section 46, and the fuel gas 31 premixed with air is guided to the first fuel gas passage from here. The fuel gas passage is filled with a combustion catalyst 33 to burn the fuel gas 31. The fuel / combustion gas goes straight from the inlet of the first fuel gas flow path, changes its direction at a right angle in the separation zone along the central axis, goes straight a little, and then changes its direction at a right angle again.
Flowing into the gas mixing section 46 of. The fuel / combustion gas that has left the first gas mixing section 46 is guided to the second fuel / combustion gas passage, and the unburned fuel gas is burned. The combustion gas goes straight through the second fuel gas passage and flows into the second gas mixing section 47. The third fuel gas flow path has a similar shape to the first flow path and forms a U-shaped flow path. The combustion gas 11 that has completed combustion is exhausted from the exhaust manifold 39.

Example 16. Further, another embodiment of the present invention will be described with reference to FIGS. 17, 18a and 18b.
This embodiment relates to the flow directions of the fuel 31 / combustion gas 11 and the raw material 1 / reformed gas 2 in the fuel reforming stack 43. Generally, the catalytic reaction is likely to occur at the inlet of the catalyst layer where the partial pressure of the reaction gas is high, that is, the driving force for chemical equilibrium is large, and the reaction rate and the reaction amount are large. Therefore, in the reforming reaction section 41, the reforming reaction is likely to occur at the inlet, and the amount of heat absorption is large. On the other hand, even in the catalytic combustion unit 40, combustion is likely to occur actively at its inlet, and the calorific value is large. Therefore, if the inlet of the source gas 1 and the inlet of the fuel gas 31 are aligned,
A lot of combustion can be generated in a portion of the reforming reaction that requires a large amount of heat. From this, the fuel reforming unit 4
It is possible to balance the heat within the two surfaces and make the temperature distribution uniform. Thus, the inlet of the raw material gas 1 and the fuel gas 3
In order to make the inlets of 1 coincide with each other, it is necessary to configure the gas flow path so that the flow of the fuel / combustion gas and the flow of the raw material / reforming gas are parallel.

However, making the flow of the fuel 31 / combustion gas 11 and the flow of the raw material 1 / reformed gas 2 completely parallel to each other complicates the structure of the gas flow path and the manifold. Here, FIG. 17 shows an embodiment in which the gas flow passages are multi-staged and a flow close to parallel flow is realized. FIG. 17 shows an example in which the fuel 31 and the combustion gas 11 are in one stage and the raw material 1 and the reformed gas 2 are in two stages as described above, and the inlets of the raw material gas 1 and the fuel gas 31 are substantially the same. However, the flows of the raw material gas 1 and the combustion gas 31 are orthogonal to each other when viewed locally. The second-stage reformed gas flow passage coincides with the combustion gas outlet. The temperature of the outlet of the combustion gas is high due to the heat of combustion, and considering the chemical equilibrium of the reforming reaction, a higher reforming reaction rate can be obtained, and the ratio of conversion of hydrocarbons into hydrogen gas will be high. . If the fuel 31 and the combustion gas 11 are required to be in two stages rather than the raw material 1 and the reformed gas 2 in two stages, these flow paths may be exchanged, and the heat balance is the same. effective.

Example 17 Still another embodiment will be described with reference to FIGS. 18a and 18b. The flow path configuration of the raw material 1 and the reformed gas 2 is exactly the same as that of FIG.
The flow path of the combustion gas 11 has three stages. Than this,
The degree to which the flows are parallelized is increased, and the range in which heat is balanced can be made wider. As described above, as the number of stages is increased, the flow of the raw material gas 1 / the reformed gas 2 and the flow of the fuel gas 31 / the combustion gas 11 can be brought closer to an ideal co-current flow. Also increases.
Therefore, the design of the number of stages must be determined in consideration of the bypass of the raw material 1 and the fuel gas 31, the degree of gas distribution, the temperature distribution, the pressure loss, and the like.

Example 18. An embodiment of the fuel reforming apparatus according to the invention of claim 8 will be described with reference to FIG. FIG. 19
Is an example in which a combustion burner 48 for forming a combustion flame toward the side surface of the fuel reforming stack inside the fuel gas supply manifold 36 and preheating the catalytic combustion portion to the operating temperature is installed. At the time of start-up, the fuel gas 20 and the combustion air 23 are guided to the combustion burner 48, and an ignition device (not shown in the figure) is installed at a location where the fuel and the air injected from the fuel injection nozzle 22 and the air injection nozzle 25 are sufficiently mixed. It is provided and the fuel is ignited. The ignited fuel becomes combustion gas and is guided to the fuel gas passage of the fuel reforming stack 43 to preheat the combustion catalyst to the operating temperature of the catalyst. Further, the radiant heat from the surface of the combustion burner 48 heats the fuel gas inlet side surface of the fuel reforming stack 43, and is transferred to the internal combustion catalyst by heat conduction. When the combustion catalyst has an operating temperature of the catalyst, for example, 35
When heated to about 0 ° C., the supply of the fuel gas 20 is temporarily stopped to extinguish the flame. Next, if the fuel gas 20 is supplied again without operating the ignition device, the air 23 and the fuel 20
After being sufficiently premixed in the fuel supply manifold 36, it is guided to the catalytic combustion section in the fuel reforming stack 43 and burned by the catalyst.

[0073]

According to the invention of claim 1, since the heat transfer surface of the reforming reaction tube filled with the reforming catalyst and the combustion surface of the combustion burner are arranged to face each other, the radiant heat of the combustion burner is mainly used. As a result, the reforming reaction tube is heated uniformly, and the temperature distribution in the axial direction of the reforming reaction tube can be made uniform. Moreover, since the radiant heat transfer has a higher heat transfer coefficient than the convective heat transfer, the heat transfer area of the reforming reaction tube is reduced, and the heat transfer packing particles used in the conventional fuel reformer are deleted. It is possible to reduce the size and weight of the device. Further, when the heat capacity is reduced due to the elimination of the filling particles, it is possible to shorten the time required to heat the apparatus to the operating temperature when starting the apparatus, and to save the fuel consumption at the time of starting.

According to a second aspect of the present invention, in the first aspect, the combustion burner is composed of a plurality of fuel injection nozzles around which air injection nozzles are arranged. There is an effect that the area of the formation surface can be increased and the radiation heat transfer can be promoted.

According to the third aspect of the present invention, the combustion surface of the cylindrical combustion burner and the heat transfer surface of the cylindrical reforming reaction tube loaded with the reforming catalyst are opposed to each other in a concentric shape. With the configuration, the exhaust passage of the cylindrical combustion gas and the inflow passage of the cylindrical combustion air are contiguously arranged so that the combustion heat generated from the combustion burner can be effectively converted into the reforming reaction tube. It can be used for heating, and heat exchange between combustion gas and combustion air can be achieved.

Further, according to the invention of claim 4, since the reforming reactor and the catalytic combustor are provided adjacent to each other with their heat transfer surfaces in contact with each other, the heat generated in the catalytic combustor is directly reformed. Informed to the reactor. Furthermore, since the combustion catalyst is cooled by the heat absorption of the reforming reaction, it is possible to prevent the temperature of the combustion catalyst from rising above the heat resistant temperature.

Further, according to the invention of claim 5, in the invention of claim 4, an electric heater is provided adjacent to at least one of the reforming reactor and the catalytic combustor. When starting the reforming reactor, the reforming catalyst and the combustion catalyst can be uniformly heated to the operating temperature of the catalyst, and the fuel reforming device can be started quickly.

According to the invention of claim 6, the reforming reaction section having a reforming catalyst for producing hydrogen from a hydrocarbon or alcohol raw material by a reforming reaction, and the combustion gas of the fuel gas premixed with the above A plurality of fuel reforming units, each of which includes a pair of the catalyst combustion units and the reforming reaction unit, such that the catalyst combustion units and the reforming reaction units are alternately adjacent to each other. Units are stacked to form a fuel reforming stack, and the raw material gas and the premixed fuel gas are supplied from the side ends of the fuel reforming stack through the respective manifolds, and the reforming gas and the combustion gas are discharged. Since it is configured, it is possible to achieve a higher catalyst packing density than a reforming reaction tube type fuel reformer,
A large amount of hydrogen can be efficiently produced with a relatively small volume.

According to a seventh aspect of the present invention, in the above-mentioned sixth aspect, at least one of the raw material gas passage and the fuel gas passage is divided into a plurality of partial gas passages, and the partial gas flow is obtained. Since the gas mixing section is provided between the passages, even if there is partial non-uniformity in the flow of the raw material / reformed gas or fuel / combustion gas, the gas mixing section will mix it uniformly, so that the flow will be non-uniform. It is possible to suppress the influence on the reforming reaction and the combustion reaction.

According to an eighth aspect of the present invention, in the above sixth or seventh aspect, a combustion burner that forms a combustion flame toward the side surface of the fuel reforming stack is arranged inside the fuel supply manifold. Therefore, when starting the fuel reforming stack, the combustion catalyst at the catalyst combustion section inlet and the reforming catalyst at the reforming reaction section inlet can be efficiently preheated to the operating temperature, and the fuel reforming stack is quickly started. be able to.

According to a ninth aspect of the present invention, the inner wall surface of the reforming reaction tube, the reforming reactor, the reforming reaction section, the catalytic combustor, or the catalytic combustion section in the first to eighth aspects is used. Since the heat transfer fins that promote heat transfer to the catalyst are installed in the
For example, the heat from the combustion gas and the heat from the reformed gas are transferred to the heat transfer fins via the reforming reaction tube, and the heat transferred to the heat transfer fins is effectively transmitted to the reforming catalyst by radiant heat transfer and convective heat transfer. Since the heat is transferred, the heat transfer performance between the inner wall of the reforming reaction tube and the reforming catalyst can be improved.

According to a tenth aspect of the present invention, in the above first to ninth aspects, the inner wall surface of the reforming reaction tube, the reforming reactor, the reforming reaction section, the catalytic combustor, or the catalytic combustion section. Alternatively, since the catalyst film is formed on the surface of the heat transfer fin according to claim 9, the heat transferred to the wall surface of the reforming reaction tube is directly transferred to the reforming catalyst by heat conduction via the heat transfer fin. Therefore, the thermal resistance between the wall surface of the reforming reaction tube and the catalyst can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram illustrating a basic configuration and an operation according to an embodiment of a fuel reforming apparatus according to the invention of claim 1.

FIG. 2 is a configuration diagram and a sectional view showing an arrangement of a fuel injection nozzle and an air injection nozzle of a combustion burner according to a second aspect of the invention.

FIG. 3 is a configuration diagram showing a specific configuration according to an embodiment of the fuel reforming apparatus according to the invention of claim 3.

FIG. 4 is a configuration diagram showing a specific configuration according to another embodiment of the fuel reforming apparatus according to the invention of claim 3;

FIG. 5 is a configuration diagram showing a basic configuration of a main part of an embodiment when the invention of claim 9 is applied to the first, third, and fourth embodiments.

FIG. 6 is a perspective view showing another embodiment of the heat transfer fins according to the invention of claim 9;

FIG. 7 is a perspective view showing another embodiment when the invention of claim 9 is applied to the first, third, and fourth embodiments.

FIG. 8 is a cross-sectional view showing a main part of an embodiment in which the invention of claim 10 is applied to those of Embodiments 1, 3 to 6.

FIG. 9 is a sectional configuration diagram showing a main part of another embodiment of the fuel reforming apparatus according to the invention of claim 9;

FIG. 10 is a sectional configuration diagram showing a specific configuration of an embodiment of the fuel reforming apparatus according to the invention of claim 4;

FIG. 11 is a sectional configuration diagram showing a main part of another embodiment of the fuel reforming apparatus according to the invention of claim 4;

FIG. 12 is a sectional configuration diagram showing a main part of an embodiment in which the invention of claim 10 is applied to that of FIG. 11.

FIG. 13 is a perspective view and a sectional view taken along the line BB ′ of yet another embodiment of the fuel reforming apparatus according to the invention of claim 4.

FIG. 14 is a sectional configuration diagram showing an embodiment of a fuel reformer according to the invention of claim 5;

FIG. 15 is a sectional configuration diagram showing another embodiment of the fuel reforming apparatus according to the invention of claim 5;

FIG. 16 is a perspective view showing an embodiment of the fuel reforming apparatus according to the invention of claim 6 and showing a state in which each manifold is attached to the fuel reforming stack, and a partial perspective view of the fuel reforming stack.

FIG. 17 is a sectional view showing a main part of an embodiment of a fuel reforming apparatus according to the invention of claim 7;

FIG. 18 is a sectional view showing a main part of another embodiment of the fuel reforming apparatus according to the invention of claim 7;

FIG. 19 is a sectional view showing a main part of an embodiment of a fuel reforming apparatus according to the invention of claim 8;

FIG. 20 is a cross-sectional view showing a reforming reaction tube of a conventional fuel reforming apparatus.

FIG. 21 is a sectional view showing a reforming reaction tube of another conventional fuel reforming apparatus.

FIG. 22 is a cross-sectional view showing a conventional fuel reformer.

[Explanation of symbols]

 1 raw material gas 2 reformed gas 7 reforming catalyst 10 reforming reaction tube 11 combustion gas 20 fuel gas 22 fuel injection nozzle 23 air 25 air injection nozzle 26 combustion burner 28 heat transfer fin 29 coating reforming catalyst layer 31 air premixed fuel Gas 33 Combustion catalyst 34 Catalytic combustor 36 Fuel gas supply manifold 37 Raw material gas supply manifold 38 Reformed gas exhaust manifold 39 Combustion gas exhaust manifold 40 Catalytic combustion part 41 Reforming reaction part 42 Fuel reforming cell 43 Fuel reforming stack 44 Gas mixing section 45 Return manifold 48 Combustion burner for startup 54 Electric heater

[Procedure amendment]

[Submission date] April 28, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

According to the invention of claim 9, the above-mentioned claim 1
To the ones of the 8, the reforming reaction tube, the reforming reactor, the reforming reaction unit, catalytic combustor, or the inner wall surface of the catalytic combustion portion is provided with the heat transfer fins to promote heat transfer to the catalyst, heat Is burning
Radiant heat from the calcining catalyst to the reforming catalyst via the heat transfer fins
Since it is transferred by heat transfer or convection heat transfer, heat transfer performance can be improved.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

According to a tenth aspect of the present invention, in the above first to ninth aspects, the reforming reaction tube, the reforming reactor,
Reforming reaction section, catalytic combustor, or inner wall surface of catalytic combustion section,
Alternatively, since the catalyst film is formed on the surface of the heat transfer fin according to claim 9, heat is directly transferred from the combustion catalyst film to the reforming catalyst film.
Since the heat is transferred only by the heat conduction of the fins, the thermal resistance can be greatly reduced.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction content]

Next, the operation of this fuel reformer will be described. First, the procedure for starting the fuel reformer will be described.
City gas as fuel gas at startup (13A: mixed gas containing methane as a main component and ethane, propane, butane)
The case of using will be described. In order to ensure the ignition of the city gas, the city gas premixed with the primary air is supplied as the fuel gas 20 to the fuel manifold 21. At the same time, the secondary air is supplied to the air manifold 24. The fuel gas 20 is injected into the combustion space from the combustion burner 26 via the fuel injection nozzle 22, and the air 23 is injected into the combustion space from the combustion burner 26 via the air injection nozzle 25. The fuel gas 20 and the air 23 injected from the nozzle diffuse and mix with each other to form a flame surface 27 by combustion. In order to form a flame evenly and uniformly, it is necessary to make the injection amount of fuel gas and air from each nozzle uniform. The fuel gas and air injected from this are sufficiently diffused and mixed, and uniform combustion is performed. In this way, the surface combustion burner 26 causes combustion on the entire flame surface 27, and the radiant heat mainly heats the reforming reaction tube 10 uniformly. The hot combustion gas 11 flows downward along the reforming reaction tube 10 and, during this time, heats the reforming reaction tube 10 by convection heat transfer. Further, the combustion gas 11 reverses its flow at the lower end of the reforming reaction tube 10, and this time flows upward between the reforming reaction tube 10 and the air tube to heat the reforming reaction tube 10 again and to burn the combustion air 23. Preheat.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction content]

Example 4. In FIG. 4, the surface combustion burner 26 is arranged on the central axis of the heating furnace, and the annular reforming reaction tube 10 is heated.
Is an example in which is arranged on the outside. A fuel manifold 21 is provided on the central axis, and an air manifold 24 is provided on the outside thereof. The fuel gas 20 and the combustion air 23 are radially ejected outward from the fuel injection nozzle 22 and the air injection nozzle 25 to perform combustion. The exhaust gas 11 after combustion flows from the inner side to the outer side along the reforming reaction tube 10, and preheats the combustion air 23 flowing to the outermost side. Since the internal flame outward flow type in which the combustion burner 26 flows on the central axis and the combustion gas 11 flows from the inner side to the outer side is smaller in heat transfer area of the surface combustion burner 26 than the external flame inward flow type described above, Reforming reaction tube 1
The amount of heat transferred to 0 is relatively small. However, as compared with the conventional concentrated burner, since the combustion burner 26 and the reforming reaction tube 10 face each other, the radiant heat can be effectively used. In addition, since the diameter of the annular reforming reaction tube 10 can be made larger than that of the external flame inward flow type, the filling amount of the reforming catalyst 7 that can be filled can be increased, which is advantageous for extending the life of the catalyst. Is.
In this type of fuel reformer, since combustion is performed inside the heating furnace, it is possible to reduce heat radiation to the outside.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0045

[Correction method] Change

[Correction content]

The heat transfer fin 28 shown in FIG. 5 is a straight fin having a corrugated (corrugated) arc shape.
Depending on the shape of the corrugate, square, trapezoidal, or triangular fins are possible. FIG. 6 shows an example of the shape of the heat transfer fins in which the corrugations are displaced by a half pitch. This heat transfer fin has a zigzag arrangement in which one corrugation (square shape) is displaced by a half pitch, and the reforming catalyst 7 is filled inside this corrugation. Arrows A and B indicate two ways of flowing the source gas. Flow A is when the source gas flows at a right angle to the corrugate, and flow B is when the source gas flows parallel to the corrugate. In the flow A, the number of contact between the raw material gas and the catalyst increases, but the pressure loss also increases. On the other hand, in the flow B, the number of contact between the source gas and the catalyst is relatively small, but the pressure loss is small. For example, the flow A is adopted in a place where the reforming reaction is desired to be promoted, and the flow B is adopted in a place where the reforming reaction is suppressed. Furthermore, corrugated flow A, in addition to the flow B
It can also be considered a flow with a tilted angle to the over bets. Since the amount of heat transferred from the heat transfer fins 28 to the catalyst by heat radiation is determined by the form factors of the catalyst particles and the heat transfer fins 28 and their respective emissivities, there is no difference between the two flows. For convective heat transfer, the A appears to be the more disturbed the flow.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0061

[Correction method] Change

[Correction content]

Example 13. An embodiment of the fuel reforming apparatus according to the invention of claim 6 will be described with reference to FIGS. 16 (a) and 16 (b). FIG. 16A is a perspective view in which the fuel / air supply manifold 36, the raw material supply manifold 37, the reformed gas discharge manifold 38, and the combustion gas discharge manifold 39 are attached to the four side surfaces of the fuel reforming stack. Here, the cross-flow type in which the flow of the raw material gas / reformed gas and the flow of the fuel gas / combustion gas are orthogonal to each other is adopted.
FIG. 16b is a partial perspective view of the fuel reforming stack with the manifold open. A fuel reforming stack 43 is formed by stacking a plurality of fuel reforming units 42 each including a pair of catalytic combustion units 40 and reforming reaction units 41 so that the catalytic combustion units and the reforming reaction units are alternately adjacent to each other. ing. In the reforming reaction section 41, the raw material gas is converted into a hydrogen-rich reformed gas by the action of the reforming catalyst 7, and the heat required for the reforming reaction is generated by the combustion heat transferred from the vertically adjacent catalytic combustion section 40. Bribe
Be seen . Further, the catalytic combustion section 40 is cooled by the vertically adjacent reforming reaction sections 41. As described above, in the fuel reforming stack, the fuel reforming unit including the pair of catalytic combustion section 40 and the reforming reaction section 41 serves as a basic element and satisfies the functions of combustion and reforming reaction. A conventional fuel reformer is composed of a single combustion burner and a plurality of reforming reaction tubes, and the combustion and the reforming reaction are performed separately. In the fuel reforming stack of the present invention, the combustion and the reforming reaction occur in the catalytic combustion section 40 and the reforming reaction section 41, which are separated by one partition wall, and are closely related thermally. Therefore, the combustion heat generated in the catalytic combustion unit 40 is immediately consumed to absorb the reforming reaction, so that the temperature of the combustion gas does not rise rapidly. This is because the rate at which the combustion heat generated on the surface of the combustion catalyst heats the partition walls and is transferred to the reforming catalyst 7 is faster than the rate at which the combustion gas is heated.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0064

[Correction method] Change

[Correction content]

Example 14 An embodiment of the fuel reformer according to the invention of claim 7 will be described with reference to FIG. In the present invention, the raw material gas flow passage / reformed gas flow passage is divided into a plurality of partial gas flow passages, that is, multistage, and the gas mixing section 44 is provided between each partial gas flow passage, that is, between each multistage. The raw material gas flow path and the reformed gas flow path are configured so that the converted stages are connected in series. FIG. 17 is a cross-sectional view of the fuel reforming stack when the raw material gas passages are in two stages. The raw material gas 1 is guided from the raw material gas supply manifold 37 to the raw material gas side of the fuel reforming stack. In this embodiment, the source gas supply manifold 37 is disposed adjacent to the reformed gas discharge manifold 38, and heat exchange is performed between the high temperature reformed gas and the low temperature source gas. The raw material gas 1 is distributed from the supply manifold 37 to each fuel reforming unit . The raw material gas flowing into the first stage raw material gas flow passage is reformed into hydrogen gas 2 by the action of the reforming catalyst 7. After that, the reformed gas 2 is supplied to the reformed gas return manifold 4 arranged on the stack side surface opposite to the stack side surface on which the raw material supply manifold is arranged.
The reformed gas that has been introduced into the fuel cell 5 and has flowed into each fuel reforming unit joins here. The reformed gas is uniformly mixed in the gas mixing section 44 while reversing the flow. By reversing the gas flow,
Innumerable fluid vortices are formed and gas mixing is promoted. Therefore, even if there is a difference in the flow distribution between the units , the nonuniform flow distribution is once eliminated by the gas mixing in the return manifold 45. The reformed gas is distributed from the return manifold 45 to each fuel reforming unit again. In the second-stage reformed gas passage, the unreformed raw material in the reformed gas is reformed, and the reformed gas 2 flowing into each cell joins at the exhaust manifold 38.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0066

[Correction method] Change

[Correction content]

In the above embodiment, the raw material gas flow passage has two stages, but it is also possible to have multiple stages with the same structure.
If the number of stages is increased, the gas mixing section also increases.
Although it is possible to further reduce the adverse effects of the bypass and uneven distribution of gas between the units , on the other hand, since the gas flow velocity increases and the gas flow path becomes longer, the pressure loss increases.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Name of item to be corrected] 0072

[Correction method] Change

[Correction content]

Example 18. An embodiment of the fuel reforming apparatus according to the invention of claim 8 will be described with reference to FIG. FIG. 19
Is an example in which a combustion burner 48 for forming a combustion flame toward the side surface of the fuel reforming stack inside the fuel gas supply manifold 36 and preheating the catalytic combustion portion to the operating temperature is installed. At the time of start-up, the fuel gas 20 and the combustion air 23 are guided to the combustion burner 48, and an ignition device (not shown in the figure) is installed at a location where the fuel and the air injected from the fuel injection nozzle 22 and the air injection nozzle 25 are sufficiently mixed. It is provided and the fuel is ignited. The ignited fuel becomes combustion gas and is guided to the fuel gas passage of the fuel reforming stack 43 to preheat the combustion catalyst to the operating temperature of the catalyst. The fuel gas inlet side of the fuel reformer stack 43 is heated by radiant heat from the surface of the combustion burner 48, heat is transferred <br/> inside the combustion catalyst by thermal conduction. When the combustion catalyst is heated to the operating temperature of the catalyst, for example, about 350 ° C., the supply of the fuel gas 20 is temporarily stopped to extinguish the flame. Next, if the fuel gas 20 is supplied again without operating the ignition device, the air 23 and the fuel 20 are sufficiently premixed in the fuel supply manifold 36, and then are introduced to the catalytic combustion section in the fuel reforming stack 43. Combustion by the catalyst is performed.

Claims (10)

[Claims] 1. A reforming reaction tube having a reforming catalyst for producing hydrogen from a hydrocarbon or alcohol raw material by a reforming reaction, and a combustion burner for heating the reforming reaction tube by burning fuel gas and air. In a fuel reformer for obtaining hydrogen-rich reformed gas, the heat transfer surface of the reforming reaction tube loaded with the reforming catalyst and the combustion surface of the combustion burner are arranged to face each other. Characteristic fuel reformer. 2. The fuel reformer according to claim 1, wherein the combustion burner is composed of a plurality of fuel injection nozzles around which air injection nozzles are arranged. 3. The combustion surface of a cylindrical combustion burner and the heat transfer surface of a cylindrical reforming reaction tube loaded with a reforming catalyst are concentrically arranged so as to face each other, and a cylindrical combustion gas is provided. 3. The fuel reformer according to claim 1, wherein the exhaust passage and the cylindrical inflow passage of the combustion air are adjacently arranged in a concentric shape. 4. A reforming reactor having a reforming catalyst for producing hydrogen from a hydrocarbon or alcohol raw material by a reforming reaction, and a catalyst for heating the reforming reactor by catalytic combustion of fuel gas premixed with air. In a fuel reforming apparatus that includes a combustor and obtains a hydrogen-rich reformed gas, the reforming reactor and the catalytic combustor are provided adjacent to each other with their heat transfer surfaces in contact with each other. Fuel reformer that does. 5. The fuel reformer according to claim 4, wherein an electric heater is provided adjacent to at least one of the reforming reactor and the catalytic combustor. 6. A reforming reaction section having a reforming catalyst for producing hydrogen from a hydrocarbon or alcohol raw material by a reforming reaction, and catalytic combustion for heating the reforming reaction section by burning a fuel gas premixed with air. And a plurality of units, and a plurality of fuel reforming units each including a pair of the catalytic combustion unit and the reforming reaction unit are stacked so that the catalytic combustion unit and the reforming reaction unit are alternately adjacent to each other to form a fuel reforming stack. A fuel reformer configured to supply a raw material gas and a premixed fuel gas from a side end portion of the fuel reforming stack through a manifold, respectively, and to discharge a reformed gas and a combustion gas. 7. The fuel reformer according to claim 6, wherein at least one of the raw material gas passage and the fuel gas passage is divided into a plurality of partial gas passages, and a gas mixing section is provided between the partial gas passages. apparatus. 8. The fuel reformer according to claim 6, wherein a combustion burner that forms a combustion flame toward a side surface of the fuel reforming stack is arranged inside the fuel supply manifold. 9. A reforming reaction tube, a reforming reactor, a reforming reaction section,
9. The fuel reformer according to claim 1, wherein heat transfer fins that promote heat transfer to the catalyst are provided on the inner wall surface of the catalyst combustor or the catalyst combustion section. 10. A catalyst film is formed on the inner wall surface of the reforming reaction tube, the reforming reactor, the reforming reaction section, the catalytic combustor, or the catalytic combustion section, or the surface of the heat transfer fin according to claim 9. Item 10. The fuel reformer according to any one of Items 1 to 9.