JP2003286003A - Reformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reformer provided with a reforming catalyst layer having a structure capable of efficiently heating and uniformizing the temperature distribution not only in the thickness direction of the reforming catalyst layer but in a direction intersecting the flow direction of a gaseous starting material at right angles. <P>SOLUTION: In the reforming catalyst layer 31, a plurality of heat transfer fins 33 are arranged along the flow direction of the gaseous starting material to form a plurality of layers in the flow direction of the gaseous starting material. In each layer, a plurality of the fins are arranged with a prescribed pitch in a direction intersecting the flow direction of the gaseous starting material to deviate of each position of the heat transfer fins of the adjacent layers in the direction intersecting the flow direction of the gaseous starting material to the direction intersecting the flow direction of the gaseous starting material. In such a case, it is most desirable to shift the heat transfer fin by 1/2 pitches. Further, the length of the heat transfer fin positioned in the downstream side in the flow direction of gaseous starting material is made shorter than that of the heat transfer fin positioned in the upstream side in the flow direction of the gaseous starting material. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reformer for reforming a raw material gas to generate a reformed gas, and is useful when applied to a reformer in a fuel cell power generation system for distributed power sources.

[0002]

2. Description of the Related Art After steam is added to a raw material gas (hydrocarbon-based gas such as natural gas), the steam-added raw material gas is flowed to a heated reforming catalyst to improve the reforming catalyst. A reformer for a fuel cell that produces a hydrogen-rich reformed gas by promoting a quality reaction is known. The reformed gas generated in this reformer is supplied to the hydrogen electrode side of the fuel cell after carbon monoxide harmful to the fuel cell is removed by a chemical reaction in the latter-stage shift converter.

FIG. 11 is an explanatory view showing a state of heat transfer in a conventional reforming catalyst layer. As shown in FIG. 11 (a),
Generally, a reformer is provided with a reforming catalyst layer 2 formed by filling a space portion with a granular (spherical) reforming catalyst 1. The raw material gas to which steam has been added flows from the top to the bottom in the reforming catalyst layer 2 as indicated by arrow A, and is reformed by the reforming reaction in the reforming catalyst layer 2. As a result, hydrogen-rich reformed gas comes out from the lower side of the reforming catalyst layer 2 (arrow B). Then, in order to promote the reforming reaction (endothermic reaction) in the reforming catalyst layer 2 at this time, in the case of the one-side heating method, a high temperature gas is flown to one side of the reforming catalyst layer 2 as shown by an arrow C, and this high temperature The gas is used to heat the reforming catalyst layer 2 from one side as indicated by arrow A.

However, in this case, the temperature distribution in the reforming catalyst 2 becomes a temperature distribution as shown in FIG. 11 (b). That is, in the radial direction (thickness direction of the reforming catalyst layer 2)
In, the temperature of one side (the side through which the high temperature gas flows) of the reforming catalyst layer 2 is high, and the temperature on the other side (the side through which the high temperature gas does not flow) is low. In particular, when the carrier of the reforming catalyst 1 is made of porous ceramics, the thermal conductivity of the reforming catalyst itself is poor, so that the temperature difference between the one side and the other side of the reforming catalyst 2 becomes large. Further, in order to make the reformer compact, it is sufficient to increase the thickness of the reforming catalyst layer 2 and reduce the length of the reforming catalyst layer 2. And the temperature difference on the opposite side becomes even larger.

If the temperature difference between the one side and the opposite side of the reforming catalyst layer 2 is large, the equilibrium gas composition of the reforming gas greatly differs between the one side and the opposite side of the reforming catalyst layer 2, resulting in a desired uniform distribution. A reformed gas having a different gas composition cannot be obtained.

Therefore, in the past, Japanese Patent Laid-Open No. 2000-2610 has been used.
As disclosed in Japanese Patent Laid-Open Publication No. 1-2003, heat transfer characteristics are improved by providing heat transfer fins on the inner surface (heat transfer surface) of the reforming catalyst layer. The outline of the reformer shown in the publication will be described with reference to FIG. In addition, FIG.
Is a longitudinal sectional view of the reformer, and FIG. 12 (b) is E of FIG. 12 (a).
It is a sectional view taken along the line E.

The reformer shown in FIG. 12 has a granular (spherical) reforming catalyst 1 in the space between the intermediate cylinder 11 and the inner cylinder 12.
A reforming catalyst layer 13 filled with 8 is provided. When the raw material gas is passed through the reforming catalyst layer 13 from top to bottom, the raw material gas is reformed by the reforming reaction in the reforming catalyst layer 13. As a result, hydrogen-rich reformed gas comes out from the lower side of the reforming catalyst layer 13. A combustion cylinder 14 is provided inside the inner cylinder 12, and a burner 15 is provided in the combustion cylinder 14. A plurality of heat transfer fins 17 extending in the vertical direction are provided on the inner surface 16 of the reforming catalyst layer 13 (the outer peripheral surface of the inner cylindrical body 12) so as to project in the circumferential direction at regular intervals by welding or the like.

Therefore, in this reformer, high temperature gas is produced by supplying fuel and air to the burner 15 and burning it, and the high temperature gas is generated between the inner cylinder 12 and the combustion cylinder 14. When flowing from the bottom to the top in the flow path 20, the high temperature gas causes the reforming catalyst layer 13 to be on one side (the inner peripheral side of the inner cylindrical body 12).
Is heated from. At this time, the heat of the high-temperature gas is efficiently transferred in the radial direction by the heat transfer fins 17, so that one side of the reforming catalyst layer 13 (inner side of the reforming catalyst layer 13).
The temperature difference on the opposite side (outer diameter side of the reforming catalyst layer 13) becomes smaller.

[0009]

However, since the heat transfer fins 17 are integral with each other and extend in the vertical direction, the temperature distribution in the circumferential direction of the reforming catalyst layer 13 depends on the heat transfer fins 1.
7, the temperature is highest, the temperature decreases as it moves away from the heat transfer fins 17, and the temperature distribution has the lowest temperature at the intermediate position between the adjacent heat transfer fins 17. That is, although the raw material gas is mixed by the static mixer effect in the reforming catalyst layer 13, in the conventional heat transfer fin 17, the heat transfer fin 17 and the central portion between the heat transfer fins 17 are mixed.
A relatively large temperature difference will occur between the vicinity of and.

To solve this, it is necessary to increase the number of heat transfer fins 17 and narrow the interval (pitch) between the heat transfer fins 17 (for example, 20 mm or less). In this case, the reforming catalyst layer 13 Since the heat capacity of the reforming catalyst 18 increases and the filling portion of the reforming catalyst 18 decreases, it is necessary to lengthen the reforming catalyst layer 13 in the vertical direction, and the reformer capacity increases.

Further, in order to make the reformed gas have a desired gas composition (to reduce the amount of methane), it is necessary to control the reformed gas temperature at the outlet of the reforming catalyst layer 13 to a set temperature. With such an integrated heat transfer fin 17, not only the heat conduction in the radial direction but also the heat conduction occurs in the upward direction along the flow direction of the raw material gas (reformed gas). In order to control the quality gas temperature to the set temperature, it is necessary to give more heat than necessary to the reforming catalyst layer 13 in consideration of the upward heat conduction by the heat transfer fins 17, so that the heating efficiency is poor.

Therefore, in view of the above circumstances, the present invention enables efficient heating, and makes the temperature distribution not only in the thickness direction of the reforming catalyst layer but also in the direction orthogonal to the flow direction of the raw material gas. An object of the present invention is to provide a reformer provided with a reforming catalyst layer having a structure capable of achieving the above.

[0013]

[Means for Solving the Problems] First to solve the above problems
In the reformer of the invention, heat transfer fins are provided on the inner surface of the reforming catalyst layer, and a raw material gas is caused to flow through the reforming catalyst layer and a surface of the reforming catalyst layer on which the heat transfer fins are provided is projected. In a reformer that generates a reformed gas by flowing a high-temperature gas on the opposite side and heating the reforming catalyst layer with the high-temperature gas to promote the reforming reaction in the reforming catalyst layer, A plurality of the heat transfer fins are arranged along the flow direction of the raw material gas to form a plurality of layers in the flow direction of the raw material gas, and each layer has a predetermined direction in a direction orthogonal to the flow direction of the raw material gas. A plurality of sheets are arranged at a pitch, and the positions of the heat transfer fins of the adjacent layers in the direction orthogonal to the flow direction of the raw material gas are arranged so as to be displaced in the direction orthogonal to the flow direction of the raw material gas. It is characterized by

The reformer of the second invention is the reformer of the first invention, wherein the heat transfer fins are arranged in a direction orthogonal to the flow direction of the source gas between the heat transfer fins of the adjacent layers. The position is 1 in the direction orthogonal to the flow direction of the raw material gas.
It is characterized in that they are arranged so as to be shifted by / 2 pitch.

The reformer of the third invention is the first or second reformer.
In the reformer of the invention, the heat transfer fin located on the downstream side in the flow direction of the raw material gas is longer than the heat transfer fin located on the upstream side in the flow direction of the raw material gas in the flow direction of the raw material gas. Is shorter.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment> FIG. 1 is a longitudinal sectional view of a fuel cell reformer according to a first embodiment of the present invention (H-H in FIG. 2).
2 is a sectional view taken along the line GG of FIG. 1, FIG. 3 is a perspective view of the reforming catalyst layer portion of the reformer, and FIG.
Is a diagram showing an arrangement of heat transfer fins provided in the reforming catalyst layer,
FIG. 5 is a diagram showing a method of processing the heat transfer fins. Further, FIG. 6 is a front view showing another arrangement example of the heat transfer fins, and FIG.
7A is a perspective view showing another arrangement example of the heat transfer fins, FIG.
FIG. 7B is a view of the heat transfer fin shown in FIG.
FIG. 8 is a perspective view showing an example of a flat reforming catalyst layer.

As shown in FIGS. 1 and 2, the reformer for a fuel cell according to this embodiment has a cylindrical configuration as a whole, and has a cylindrical container 21 at the center thereof. . Container 2
Reference numeral 1 denotes a cylindrical outer cylindrical body 22 made of metal such as stainless steel,
A cylindrical inner cylindrical body 2 made of a metal such as stainless steel, which is arranged inside the outer cylindrical body 22 with a distance from the outer cylindrical body 22.
3 has a double structure, and the space between the outer cylinder 22 and the inner cylinder 23 serves as a high temperature gas flow path 25.

The lower end of the outer cylinder 22 is closed by a disc-shaped bottom plate 24 made of metal such as stainless steel, while the lower end 23a of the inner cylinder 23 is separated from the bottom plate 24. The inside and the outside (the high temperature gas flow path 25) of the inner cylindrical body 23 communicate with each other through the portion 23 a and the bottom plate 24.

Inside the inner cylindrical body 23, a cylindrical flame holding cylinder 26 for burner made of metal such as stainless steel is interposed.
A burner 27 is provided. Therefore, this burner 27
When a high temperature gas for heating is generated by supplying fuel and air to and burning the same, this high temperature gas is indicated by an arrow F in FIG.
As shown in FIG. 4, the inner tubular body lower end portion 23 a and the bottom plate 24 are passed between the inner tubular body 23 and the bottom plate 24 to flow into the high temperature gas passage 25.
Flow 5 from bottom to top.

On the other hand, on the outside of the outer cylindrical body 22, a double cylinder 2 made of metal such as stainless steel is provided at a distance from the outer cylindrical body 22.
8 is arranged, and the double cylinder 28 is filled with a heat insulating material 29 such as kao wool. Alternatively, a vacuum heat insulation system in which the pressure inside the double cylinder 28 is vacuum may be adopted. Then, the space between the double cylinder 28 and the outer cylinder 22 is filled with the granular (spherical) reforming catalyst 30 having a diameter of, for example, about 3 mm, so that the total length is, for example, 300 m.
A reforming catalyst layer 31 of about m is provided. Reforming catalyst 3
0 is supported on a ceramic carrier. The lower end side of the reforming catalyst layer 31 has a holding member 3 such as a perforated plate or a wire mesh.
Held by 5. If the upper end side of the reforming catalyst layer 31 is also held by a similar holding member (not shown), the reforming catalyst 30 will not be displaced from a predetermined position during transportation.

When a raw material gas (hydrocarbon-based gas such as natural gas) to which steam has been added to this reforming catalyst layer 31 flows from top to bottom as indicated by arrow J in FIG. 1, the reforming catalyst layer 31 The raw material gas is reformed by the reforming reaction in. as a result,
Hydrogen-rich reformed gas comes out from the lower side of the reforming catalyst layer 31 (arrow K). Then, the reforming catalyst layer 31 at this time
In order to accelerate the reforming reaction (endothermic reaction) in (1), the reforming catalyst layer 31 is heated from one side by flowing the high temperature gas through the high temperature gas passage 25 (one side heating method).

Further, in order to improve the heat conduction in the reforming catalyst layer 31 at this time, the inner surface of the reforming catalyst layer 31 (the outer peripheral surface of the outer cylindrical body 22) 32 has a heat transfer fin made of metal such as stainless steel. 33 is projected. The high-temperature gas flows on the side opposite to the surface (heat transfer surface) 32 on which the heat transfer fins 33 are provided.

As shown in FIGS. 2 and 3, the heat transfer fin 33 has a length H (for example, 30) in the flow direction of the raw material gas.
A plurality of layers are formed in the flow direction of the raw material gas by arranging a plurality of sheets along the flow direction (vertical direction) of the raw material gas. The shape of the heat transfer fin 33 is not necessarily limited to a rectangular shape, and may be a triangular shape, a trapezoidal shape, a semicircular shape, or the like as long as it has a certain length in the flow direction of the source gas.

Moreover, as shown in FIGS. 2, 3 and 4, the heat transfer fins 33 have a predetermined (constant) shape in each layer in a direction orthogonal to the flow direction of the raw material gas (circumferential direction of the reforming catalyst layer 31). A plurality of sheets are arranged at the pitch P, and the positions of the heat transfer fins 33 of the adjacent layers in the direction orthogonal to the flow direction of the raw material gas (circumferential direction of the reforming catalyst layer 31) are orthogonal to the flow direction of the raw material gas. Are arranged so as to be displaced by ½ pitch (P / 2) in the direction (circumferential direction of the reforming catalyst layer 31).

Therefore, as compared with the conventional integrated heat transfer fin 17 (see FIG. 12), it is possible to suppress heat conduction in the heat transfer fin 33 toward the upstream side in the flow direction of the raw material gas. Also, the heating amount can be reduced to efficiently heat the reforming catalyst layer 31.

In addition, as shown by the arrows in FIG. 5 showing the flow of the raw material gas, in the heat transfer fin layer on the upstream side, the heat transfer fins 33 and the intermediate portion between the heat transfer fins 33 (the farthest from the heat transfer fins 33). The raw material gas flowing in the (position) collides with the heat transfer fins 33 in the next heat transfer fin layer on the downstream side and is separated on both sides of the heat transfer fins 33, and thus flows in the vicinity of the heat transfer fins 33. become. On the other hand, the source gas flowing in the vicinity of the heat transfer fin 33 in the upstream heat transfer fin layer flows in the intermediate portion between the heat transfer fin 33 and the heat transfer fin 33 in the next downstream heat transfer fin layer. become. That is, the source gas alternately flows in the vicinity of the heat transfer fins → the middle of the heat transfer fins → the vicinity of the heat transfer fins → the middle of the heat transfer fins, and the distances from the heat transfer fins 33 at each position are averaged. . In addition, the effect of promoting the mixing of the raw material gas can be obtained by the effect of dispersing the raw material gas by the heat transfer fins 33.

Therefore, the source gas has a temperature distribution not only in the thickness direction (radial direction) of the reforming catalyst layer 31 but also in the direction orthogonal to the flow direction (circumferential direction of the reforming catalyst layer 31). It will be made uniform. Therefore, the reforming catalyst layer 31
It is possible to obtain a sufficiently uniform temperature distribution in, and it is possible to obtain a reformed gas having a desired uniform gas composition. Further, since the interval (pitch) between the heat transfer fins can be increased, the number of heat transfer fins in the direction orthogonal to the flow direction of the source gas (circumferential direction of the reforming catalyst layer 31) is reduced to reduce the heat capacity. You can also

Here, a method of processing the heat transfer fins 33 will be described with reference to FIG. As shown in FIG.
First, long heat transfer fins 33 extending vertically are provided on the outer peripheral surface 32 of the outer cylindrical body 22 by welding or brazing at intervals of 1/2 pitch (P / 2). And each heat transfer fin 3
The unnecessary part (hatching part) of 3 is scraped off. As a result, the heat transfer fins 33 are arranged as shown in FIG. According to this processing method, the number of times of welding or brazing can be reduced as compared with the case of welding or brazing the heat transfer fins 33 that have been previously processed to be short (length H) one by one.

The heat transfer fins 33 are not necessarily limited to being attached to the outer peripheral surface 32 of the outer cylindrical body 22 by welding or brazing, and if possible, they may be cast or cut out to form the outer cylindrical body 22. It may be molded integrally with.

Further, the positions of the heat transfer fins 33 in the adjacent layers in the direction orthogonal to the flow direction of the raw material gas are most efficiently shifted by 1/2 pitch in the direction orthogonal to the flow direction of the raw material gas. It is considered that the temperature distribution in the reforming catalyst layer 31 can be made uniform, but the present invention is not necessarily limited to this, and as shown in FIG. 6, for example, 1/3 in the direction orthogonal to the flow direction of the source gas. The pitch (P / 3) may be shifted.

In the examples shown in FIGS. 1 to 4, the lower end positions of the heat transfer fins 33 in the upstream heat transfer fin layer and the heat transfer fins in the downstream heat transfer fin layer in the flow direction of the raw material gas. Although the upper end position of 33 is the same, the present invention is not limited to this. For example, as shown in FIG. 7, the heat transfer fins 33 are arranged in a direction orthogonal to the flow direction of the raw material gas (the circumference of the reforming catalyst layer 31). Direction), the lower ends of the heat transfer fins 33 in the upstream heat transfer fin layer and the upper ends of the heat transfer fins 33 in the downstream heat transfer fin layer overlap with each other in the flow direction of the source gas. You may arrange.

Further, the present invention is not necessarily limited to a cylindrical reformer (reforming catalyst layer), and is also applied to a flat plate reformer (reforming catalyst layer) as shown in FIG. can do. In the reformer shown in FIG. 8, a space between a flat plate member 41 made of a metal such as stainless steel and a flat plate member made of a metal such as stainless steel (for example, a double flat plate filled with a heat insulating material) 42. The reforming catalyst layer 43 is provided by filling the portion with the reforming catalyst 30 (only a part of which is shown and other portions are not shown).

The raw material gas to which steam has been added flows from the top to the bottom of the reforming catalyst layer 43 as indicated by the arrow M, and is reformed by the reforming reaction in the reforming catalyst layer 43. As a result, hydrogen-rich reformed gas comes out from the lower side of the reforming catalyst layer 43 (arrow N). Then, in order to promote the reforming reaction (endothermic reaction) in the reforming catalyst layer 43 at this time,
A high temperature gas is caused to flow outside the reforming catalyst layer 43 (flat plate member 41) as indicated by an arrow O, and the high temperature gas heats the reforming catalyst layer 31 from one side (one side heating method).

Further, in order to improve heat conduction in the reforming catalyst layer 43 at this time, the heat transfer of short length H is performed on the inner surface (side surface of the outer tubular body 22) 44 on one side of the reforming catalyst layer 43. A plurality of fins 33 are projected. The high-temperature gas flows on the side opposite to the surface (heat transfer surface) 44 on which the heat transfer fins 33 are provided. Moreover, the plurality of heat transfer fins 33 are arranged along the flow direction (vertical direction) of the raw material gas in the reforming catalyst layer 43 to form a plurality of layers in the flow direction of the raw material gas.

The heat transfer fins 33 are arranged in each layer at a predetermined (constant) pitch P in a direction orthogonal to the flow direction of the raw material gas (width direction of the reforming catalyst layer 43), and
The position in the direction (width direction of the reforming catalyst layer 43) orthogonal to the flow direction of the source gas between the heat transfer fins 33 of the adjacent layers is
They are arranged so as to be offset by ½ pitch (P / 2) in the direction (width direction of the reforming catalyst layer 43) orthogonal to the flow direction of the source gas. Therefore, this plate-shaped reformer (reforming catalyst layer)
Also in the above, by arranging the heat transfer fins 33, it is possible to obtain the same action and effect as the above-mentioned cylindrical reformer (reforming catalyst layer).

<Second Embodiment> FIG. 9 is a perspective view showing the structure of a reforming catalyst layer portion of a reformer according to a second embodiment of the present invention. FIG. 10 (a) is a temperature chart of the reforming catalyst layer. FIG. 10B is a view showing the distribution, and FIG. 10B is a P direction arrow view of the heat transfer fins shown in FIG. 9.

As shown in FIGS. 9 and 10 (b), in the reformer of the second embodiment, the heat transfer fins located downstream (downstream of the reforming catalyst layer 31) in the flow direction of the raw material gas. 33
Has a shorter length H ₂ in the flow direction of the raw material gas than the heat transfer fins 33 located on the upstream side in the flow direction of the raw material gas (upstream side of the reforming catalyst layer 31) (H ₁ >). H ₂ ).
The reforming catalyst is not shown in FIG. Also,
The other configurations of the first embodiment are also the same as those of the first embodiment, and therefore the description and illustration thereof are omitted here (see FIGS. 1, 2, 3 and the like).

According to the second embodiment, the heat transfer fins 33 located on the downstream side in the flow direction of the raw material gas have a higher flow rate than the heat transfer fins 33 located on the upstream side in the flow direction of the raw material gas. Since the length in the flow direction is shortened, heat transfer in the flow direction of the raw material gas by the heat transfer fins 33 is further suppressed on the downstream side in the flow direction of the raw material gas. Therefore, as shown in FIG. 10A, the temperature gradient on the downstream side of the reforming catalyst layer 31 has the same length (H ₁ = It can be made smaller than the case of H ₂ ).

When the reformed gas temperature at the outlet of the reforming catalyst layer 31 is to be controlled to a set temperature (for example, 650 ° C.), the heat flux required for that purpose is the reforming catalyst layer 31.
Since it is proportional to the temperature gradient on the downstream side of, the heating amount can be further reduced and the reforming catalyst layer 31 can be efficiently heated in the second embodiment.

[0041]

As described above in detail with the embodiments of the invention, the reformer of the first invention has heat transfer fins projecting from the inner surface of the reforming catalyst layer, And a high-temperature gas is supplied to the side of the reforming catalyst layer opposite to the surface on which the heat transfer fins are projected, and the high-temperature gas heats the reforming catalyst layer to heat the reforming catalyst. In a reformer that generates a reformed gas by accelerating a reforming reaction in a layer, a plurality of heat transfer fins are arranged along a flow direction of the raw material gas to cause a flow of the raw material gas. A plurality of layers in each direction, and in each layer, a plurality of sheets are arranged at a predetermined pitch in a direction orthogonal to the flow direction of the raw material gas, and are orthogonal to the flow direction of the raw material gas between the heat transfer fins of adjacent layers. Position is perpendicular to the flow direction of the source gas. Characterized in that it is arranged to be shifted in the direction.

Therefore, according to the reformer of the first invention,
Compared to conventional integrated heat transfer fins, heat conduction in the flow direction of the raw material gas in the heat transfer fins, in particular, heat conduction to the upstream side, can be suppressed, so the heating amount can be reduced compared to the past. Therefore, the reforming catalyst layer can be efficiently heated. Moreover, since the positions of the heat transfer fins of the adjacent layers in the direction orthogonal to the flow direction of the raw material gas are displaced from each other in the direction perpendicular to the flow direction of the raw material gas, the raw material gas has a heat transfer fin at each position. The distance from will be averaged. Further, the effect of promoting the mixing of the raw material gas can be obtained by the effect of dispersing the raw material gas by the heat transfer fins. Therefore, the raw material gas has a uniform temperature distribution not only in the thickness direction of the reforming catalyst layer but also in the direction orthogonal to the flow direction, and the reformed gas having a desired uniform gas composition is obtained. Can be obtained. Further, since the interval (pitch) between the heat transfer fins can be increased, it is possible to reduce the heat capacity by reducing the number of heat transfer fins in the direction orthogonal to the flow direction of the source gas.

The reformer of the second invention is the reformer of the first invention, wherein the heat transfer fins are in a direction orthogonal to the flow direction of the source gas between the heat transfer fins of the adjacent layers. The position is 1 in the direction orthogonal to the flow direction of the raw material gas.
It is characterized in that they are arranged so as to be shifted by / 2 pitch.

Therefore, according to the reformer of the second invention,
In the heat transfer fin layer on the upstream side, the heat transfer fins and the heat transfer fins 33
The raw material gas flowing in the middle part (the position farthest from the heat transfer fins) collides with the heat transfer fins in the next downstream heat transfer fin layer and is separated into both sides of the heat transfer fins. The raw material gas flowing near the heat transfer fins in the upstream heat transfer fin layer while flowing in the vicinity of the heat transfer fins is transferred to the heat transfer fins and the heat transfer fins in the next downstream heat transfer fin layer. Therefore, the temperature distribution in the reforming catalyst layer can be uniformed most efficiently.

The reformer of the third invention is the first or second reformer.
In the reformer of the invention, the heat transfer fin located on the downstream side in the flow direction of the raw material gas is longer than the heat transfer fin located on the upstream side in the flow direction of the raw material gas in the flow direction of the raw material gas. Is shorter.

Therefore, according to the reformer of the third invention,
On the downstream side in the flow direction of the raw material gas, heat transfer by the heat transfer fins in the flow direction of the raw material gas is further suppressed. For this reason,
Since the temperature gradient on the downstream side of the reforming catalyst layer can be made smaller than when the heat transfer fins on the downstream side and the heat transfer fins on the upstream side have the same length, the heating amount can be further reduced. The reforming catalyst layer can be efficiently heated.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view (cross-sectional view taken along the line HH of FIG. 2) of a fuel cell reformer according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line GG in FIG.

FIG. 3 is a perspective view of a reforming catalyst layer portion in the reformer.

FIG. 4 is a diagram showing an arrangement of heat transfer fins provided in the reforming catalyst layer.

FIG. 5 is a diagram showing a method of processing the heat transfer fins.

FIG. 6 is a front view showing another example of arrangement of heat transfer fins.

7A is a perspective view showing another arrangement example of the heat transfer fins, and FIG. 7B is a view of the heat transfer fins shown in FIG.

FIG. 8 is a perspective view showing an example of a flat reforming catalyst layer.

FIG. 9 is a perspective view showing a configuration of a reforming catalyst layer portion of a reformer according to a second embodiment of the present invention.

10 (a) is a diagram showing a temperature distribution in the reforming catalyst layer, and FIG. 10 (b) is a P direction arrow view of the heat transfer fins shown in FIG.

FIG. 11 is an explanatory diagram showing a heat transfer state in a conventional reforming catalyst layer.

FIG. 12 (a) is a longitudinal sectional view of a reformer, and FIG. 12 (b) is (a).
FIG. 7 is a cross-sectional view taken along the line EE of FIG.

[Explanation of symbols]

21 containers 22 Outer cylinder 23 Inner cylinder 23a Lower end of inner cylinder 24 Bottom plate 25 high temperature gas flow path 26 Burner Flame Retainer 27 burners 28 double cylinder 29 Thermal insulation 30 reforming catalyst 31 reforming catalyst layer 32 Inner surface of reforming catalyst layer (outer peripheral surface of outer cylinder) 33 heat transfer fins 35 holding member 41 Flat member 42 Flat member 43 Reforming catalyst layer

Claims (3)

[Claims] 1. A heat transfer fin is provided on an inner surface of the reforming catalyst layer, a raw material gas is caused to flow through the reforming catalyst layer, and the opposite side of the surface of the reforming catalyst layer on which the heat transfer fin is provided is projected. In the reformer that generates a reformed gas by flowing a high-temperature gas into the reforming catalyst layer and heating the reforming catalyst layer with the high-temperature gas to accelerate the reforming reaction in the reforming catalyst layer, The fins form a plurality of layers in the flow direction of the raw material gas by arranging a plurality of fins along the flow direction of the raw material gas, and each fin has a plurality of fins at a predetermined pitch in a direction orthogonal to the flow direction of the raw material gas. It is characterized in that the heat transfer fins of the adjacent layers are arranged such that the positions of the heat transfer fins in adjacent layers in the direction orthogonal to the flow direction of the raw material gas are displaced from each other in the direction orthogonal to the flow direction of the raw material gas. And reformer. 2. The reformer according to claim 1, wherein in the heat transfer fins, a position in a direction orthogonal to a flow direction of the raw material gas between the heat transfer fins of the adjacent layers is equal to that of the raw material gas. A reformer characterized by being arranged so as to be displaced by ½ pitch in a direction orthogonal to the flow direction. 3. The reformer according to claim 1, wherein the heat transfer fin located downstream in the flow direction of the raw material gas is located upstream in the flow direction of the raw material gas. The reformer is characterized in that the length of the raw material gas in the flow direction is shorter than that of the reformer.