JP4450756B2 - Fuel reformer - Google Patents

Description

  The present invention relates to a fuel reformer that generates hydrogen-rich fuel gas by reforming a reforming fuel.

  For example, in a fuel cell, a gas mainly containing hydrogen (hereinafter also referred to as a hydrogen-containing gas) is supplied as a fuel gas. As this hydrogen-containing gas, generally, a reforming raw material gas is obtained from a hydrocarbon fuel such as fossil fuel such as methanol or LNG, and steam reforming, partial oxidation reforming, autothermal reforming is used as this reforming raw material gas. The reformed gas produced | generated by giving etc. is used.

  For example, in the reformer disclosed in Patent Document 1, as shown in FIG. 9, after the pure water supplied to the evaporator 1 is evaporated through the combustion exhaust gas, the steam passes through the heat exchanger 2. It is configured to be supplied to the reformer 3 through. The evaporator 1 is provided with an evaporating heat exchanger 4 having a heat exchanging portion that evaporates water passing through combustion exhaust gas that is a heat exchange gas and generates water vapor. The evaporative heat exchanger 4 includes a plurality of pipes 5 arranged in parallel to each other, and an inlet manifold 6 and an outlet manifold 7 that open at the upstream end and the downstream end of the pipe 5. The inlet manifold 6 is provided with a fibrous protrusion preventing member 8.

Japanese Patent Laying-Open No. 2003-192304 (FIG. 1)

  By the way, in the above reformer, the evaporator 1, the heat exchanger 2 and the reformer 3 are arranged in the flow direction of steam (arrow X direction), and in practice, the evaporator 1 and the heat exchanger are arranged. Although not shown, 2 and the reformer 3 are connected by a pipe. Therefore, since several piping is used, there exists a problem that the whole reformer becomes large. Moreover, there is a problem in that heat is easily generated from the piping, and heat loss is caused to reduce the heat efficiency.

  The present invention solves this type of problem, and provides a fuel reformer that can reduce piping as much as possible, improve thermal efficiency, and can be configured simply and compactly. For the purpose.

  The present invention is a fuel reformer that generates hydrogen-rich fuel gas by reforming a reforming fuel. The fuel reformer includes an evaporator that evaporates the reforming fuel, a superheater that raises the temperature of the evaporated reforming fuel to a temperature required for the reforming reaction, and the temperature-reforming reforming fuel. And a reformer that generates reformed gas. The superheater and the reformer are connected to each other coaxially and in series.

  The reformer includes an inner cylindrical body and an outer cylindrical body, and an inner side of the inner cylindrical body is filled with a reforming catalyst, and between the inner cylindrical body and the outer cylindrical body. Preferably, a passage through which the reforming fuel is circulated is formed.

  Further, the superheater has a reforming fuel outlet communicating with the passage at the end on the reformer side, and the reformer communicates with the passage at the end opposite to the superheater. It is preferable that a reforming fuel introduction section for supplying the reforming fuel is provided in the inner cylinder.

  Furthermore, the reformer is connected to a tube inserted from the end on the superheater side into the superheater and allowing the reformed gas that has passed through the reforming catalyst to flow as a heating source for the reforming fuel. It is preferable. Moreover, it is preferable that a heat insulating cover member is provided surrounding the reformer.

  Further, it is preferable that the evaporator is disposed concentrically around the superheater, and the superheater and the reformer are connected coaxially and in series.

  Furthermore, a preheater for preheating a heating fluid for evaporating the reforming fuel in the evaporator is provided, and the preheater is connected to the superheater on the opposite side of the reformer coaxially and in series. preferable.

  According to the present invention, since the superheater and the reformer are connected to each other coaxially and in series, the number of pipes is favorably reduced compared to a configuration in which the superheater and the reformer are connected by a pipe ( (Or shortened). Thereby, the heat radiation from the piping is reduced, the thermal efficiency is improved, and the entire fuel reformer can be configured simply and compactly.

  FIG. 1 is a schematic perspective explanatory view of a fuel reformer 10 according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a flow state in the fuel reformer 10.

  The fuel reformer 10 generates, for example, a hydrogen-rich fuel gas by reforming a reforming fuel containing a hydrocarbon such as methane or alcohol, and the like. (Not shown).

  The fuel reformer 10 includes an evaporator 12 for evaporating the reforming fuel, a superheater 14 for raising the temperature of the evaporated reforming fuel to a temperature required for the reforming reaction, and the temperature-reformed reformer. A reformer 16 that reforms the fuel for generating a reformed gas, and a preheater 18 that preheats a heating fluid for evaporating the reforming fuel in the evaporator 12. The evaporator 12 is disposed concentrically around the superheater 14, and the superheater 14 and the reformer 16 are coaxially connected to each other in series. The preheater 18 is coaxially and serially connected to the superheater 14 on the side opposite to the reformer 16.

  As shown in FIGS. 3 to 5, the evaporator 12 includes a bending tube member 20, an inner cylinder member 22 and an outer cylinder that are disposed on both sides of the bending tube member 20 and concentrically with the bending tube member 20. Member 24. The bending tube member 20 is configured as a fixed end that fixes one end (lower end) in the axial direction (arrow A direction) to the first separator 26, and has an opening cross-sectional circle configured with the other end (upper end) in the axial direction as a free end. A plurality of arcuate arcuate tubes 28a and 28b are provided.

  As shown in FIGS. 3 and 6, a plurality of, for example, four arcuate tubes 28a are provided on the same circumference, spaced apart at equal angular intervals, and the four arcuate tubes 28a in the first row are arranged. On the outer periphery, a plurality of, for example, four arcuate tubes 28b are provided concentrically and spaced apart at equal angular intervals on the same circumference. The first row of arcuate tubes 28a and the second row of arcuate tubes 28b are provided out of phase with each other. A first passage 30 is formed in each arcuate tube 28a, 28b to allow the combustion gas, which is a heating fluid, to flow therethrough, and between the inner cylinder member 22, the outer cylinder member 24, and each arcuate tube 28a, 28b. The second passage 32 through which the raw fuel that is the reforming fuel is circulated is formed.

  A curved combustion catalyst 34 is disposed in the curved tube member 20. The curved combustion catalyst 34 has a circular arc shape in cross section, a plurality of and two rows of catalyst outer cylinders in which one axial end is a fixed end fixed to the second separator 36 and the other axial end is a free end. 38a and 38b are provided. The first row of catalyst outer cylinders 38a are arranged one by one in the first row of arcuate tubes 28a, and the second row of catalyst outer cylinders 38b are two in the second row of arcuate tubes 28b. One by one.

  The catalyst outer cylinders 38a are spaced apart at equal angular intervals, and the catalyst outer cylinders 38b are similarly spaced apart at predetermined angular intervals. The catalyst outer cylinders 38a and 38b accommodate flat metal honeycombs 40a and 40b carrying a combustion catalyst.

  As shown in FIGS. 2 and 5, the first separator 26 is fixed to the lower end portion of the outer cylinder member 24, and the second separator 36 is a substantially cylindrical shape disposed outside the outer cylinder member 24. The casing 42 is fixed to the lower end of the casing 42. The first and second separators 26 and 36 are separated by a predetermined distance, and an off-gas fluid path 44 is formed. The off-gas fluid path 44 communicates with passages 46 a and 46 b formed between the first separator 26 and the catalyst outer cylinders 38 a and 38 b, and passes between the casing 42 and the outer cylinder member 24 to form the casing 42. Communicates with the outside through an exhaust port 48 formed at the upper edge of the.

  As shown in FIG. 5, the upper end portion of the outer cylinder member 24 is fixed to the upper end portion of the casing 42, and the lid member 50 is attached to the upper end portions of the arcuate tubes 28a and 28b. A chamber 52 is formed between the upper ends of the arcuate tubes 28a and 28b and the upper ends of the catalyst outer cylinders 38a and 38b. As will be described later, the heated fluid flowing upward through the metal honeycombs 40a and 40b It is turned back in the chamber 52 and sent to the first passage 30.

  As shown in FIGS. 2 and 3, a ring member 54 is attached to the upper end portion of the casing 42. A reforming fuel supply pipe 56 such as methane and an air supply pipe 58 are attached to the ring member 54. A water supply pipe 60 is disposed in the ring member 54, and an end 60 a of the water supply pipe 60 penetrates the ring member 54 and is exposed to the outside. The water supply pipe 60 is formed in a ring shape, and a plurality of holes (not shown) can be provided on the lower side to supply water in a shower shape. A donut-shaped lid 62 is fixed to the upper part of the ring member 54. When methane and air are mixed in advance and supplied from the fuel supply pipe 56, the air supply pipe 58 is not necessary.

  As shown in FIGS. 2 and 7, the superheater 14 includes an outer cylinder 64, and the outer cylinder 64 is fixed to the inner cylinder member 22 of the evaporator 12. The outer cylinder 64 is longer in the direction of the arrow A than the inner cylinder member 22, and a plurality of original cylinders that are positioned below the lower portion of the inner cylinder member 22 and communicate with the second passage 32 at the lower end edge. The fuel inlets 66 are formed at, for example, four locations. The raw fuel inlet 66 has a slit shape or a porous shape extending in the circumferential direction. A third separator 68 is fixed to the lower end portion of the outer cylinder 64.

  As shown in FIG. 7, a plurality of holes 70 are formed in the substantially disc-shaped third separator 68, and one end of a tubular body 72 is fixed to the holes 70 by welding, brazing, or the like. . A plurality of partition plates 74 are fixed to the pipe body 72 at predetermined height positions by press fitting, brazing, or the like. The partition plate 74 is formed with a plurality of holes 76 for inserting the respective tubes 72, and notches 78 are formed at different positions.

  In the outer cylinder 64, an overheating passage 82 is formed which is meandered by the outer peripheral portions of the plurality of tube bodies 72 and the cutout portions 78 of the plurality of partition plates 74 (see FIG. 2). A passage 84 is formed in each tube 72 for flowing the reformed gas (hydrogen-rich gas) heated after the reforming from above to below. A fourth separator 88 is fixed to the upper side of the tube body 72 via a distribution plate 86. The distribution plate 86 is formed with a hole 90 through which the tube 72 is inserted, and a distribution opening (reforming fuel outlet) 92 is provided at the center. The fourth separator 88 is formed with a hole 94 through which the tubular body 72 is inserted.

  As shown in FIGS. 2 and 8, the reformer 16 includes an outer cylinder 96 and an inner cylinder 98, and the raw fuel communicated with the opening 92 between the outer cylinder 96 and the inner cylinder 98. A passage 100 is formed. A closed chamber 102 is formed in the upper portion of the outer cylinder 96, and the raw fuel introduced into the chamber 102 from the raw fuel passage 100 is disposed in the inner cylinder 98 from the reforming fuel introduction portion 105. It is supplied to a plurality of rectifying plates 104.

  Each rectifying plate 104 is formed with a plurality of holes 106 and has a rectifying function for raw fuel. Below the rectifying plate 104, a honeycomb-shaped catalyst portion 108 carrying a reforming catalyst such as Pd, Pt, or Rh is disposed. A fourth separator 88 is fixed to the catalyst portion 108, and a chamber 110 communicating with the passage 84 of each tubular body 72 is formed in the fourth separator 88. A heat insulating cover member 111 is disposed so as to surround the outer cylinder 96, and a heat insulating layer 111 a is formed in the cover member 111.

  As shown in FIGS. 2 and 5, the preheater 18 is connected to the lower end portion of the evaporator 12 via a connecting member 112. The connecting member 112 forms a substantially ring-shaped chamber 114, and a ring-shaped plate member 116 is disposed on the upper side of the chamber 114, and a plurality of holes 118 are formed in the plate member 116. The The plate member 116 is opposed to the second separator 36 of the evaporator 12 and forms a chamber 120 between the plate member 116 and the second separator 36, and the chamber 114 is connected to the catalyst outer cylinder 38 a via the hole 118 and the chamber 120. , 38b.

  As shown in FIG. 2, the connecting member 112 is provided with a passage 122 that communicates with the chamber 114, and this passage 122 communicates with the outer cylinder member 124 that constitutes the preheater 18. Similar to the superheater 14, a plurality of pipe bodies 126 and a plurality of partition plates 128 are disposed in the outer cylinder member 124. The pipe body 126 extends in the direction of arrow A, and a partition plate 128 provided with alternately notched portions 130 is fixed at a predetermined height position of the pipe body 126.

  A passage 132 for allowing the reformed gas that has passed through the superheater 14 to flow vertically downward is provided in the tubular body 126, while the heating fluid meanders through the outer peripheral surface of the tubular body 126 and the partition plates 128. In this way, a preheating passage 134 that leads vertically upward is provided. A supply port 136 for supplying a heating fluid is provided at the outer peripheral lower end edge of the outer cylinder member 124.

  In order to suppress heat transfer to the evaporator 12 between the inner cylinder member 22 constituting the evaporator 12 and the outer cylinder 64 constituting the superheater 14, for example, a fin member 142 Is inserted.

  In the fuel reformer 10, a heat transfer promoting fin member 140 is inserted between the arcuate tubes 28a and 28b constituting the evaporator 12 as shown in FIG. 6, for example. The fin member 140 is formed in a wave shape, but may be linear, and is preferably configured to be shorter than the length of the arcuate tubes 28a and 28b in the arrow A direction.

  Further, although the superheater 14 and the preheater 18 are directly connected, a CO converter (not shown) for converting carbon dioxide in the hydrogen rich gas into hydrogen is interposed between the superheater 14 and the preheater 18. ) May be interposed. Further, a selective oxidation removing device (PROX) for removing carbon monoxide remaining in the hydrogen rich gas may be provided on the downstream side of the preheater 18.

  The operation of the fuel reformer 10 configured as described above will be described below.

  For example, off gas discharged from a fuel cell (not shown) is supplied to the preheater 18 from the supply port 136 of the preheater 18 as a heating fluid. In the preheater 18, as shown in FIG. 2, the heating fluid meanders through a preheating passage 134 formed between the notches 130 of the partition plates 128 and the outer circumferences of the plurality of tubes 126. Move vertically upward. On the other hand, the hydrogen-rich reformed gas generated by reforming as described later is supplied to the passage 132 of the tube body 126 after passing through the superheater 14 and cooled to about 300 ° C., for example. Yes.

  For this reason, the heated fluid is heated by exchanging heat with the reformed gas, and then introduced into the chamber 114 from the passage 122 of the connecting member 112. A plate member 116 is disposed above the chamber 114, and the preheated heated fluid is once introduced into the chamber 120 through a plurality of holes 118 formed in the plate member 116, and then the chamber It moves vertically upward along the metal honeycombs 40a, 40b in the catalyst outer cylinders 38a, 38b communicating with 120. Accordingly, the heated fluid burns through the combustion catalyst carried on the metal honeycombs 40a and 40b, and combustion gas is obtained.

  As shown in FIG. 5, the combustion gas is introduced into a chamber 52 formed between the upper end portions of the catalyst outer cylinders 38a and 38b and the closed upper end portions of the arcuate tubes 28a and 28b. The first passage 30 is moved downward vertically by folding back downward. On the other hand, for example, reforming fuel containing methane or the like is supplied to the fuel supply pipe 56, and air is supplied to the air supply pipe 58. Furthermore, water is supplied to the water supply pipe 60, and reforming fuel air and water are mixed in the ring member 54 to obtain raw fuel.

  The raw fuel flows vertically downward along the second passage 32 formed between the inner cylinder member 22, the outer cylinder member 24 and the arcuate tubes 28 a and 28 b, and the combustion gas flowing in the first passage 30. Heat exchange with the As a result, the raw fuel is introduced into the outer cylinder 64 from the raw fuel inlet 66 formed in the lower part of the outer cylinder 64 constituting the superheater 14 after being vaporized.

  For this reason, as shown in FIG. 2, the vaporized raw fuel passes vertically through the overheating passage 82 formed between the notches 78 provided in the plurality of partition plates 74 and the plurality of pipe bodies 72. Move up. On the other hand, a high-temperature reformed gas (around 650 ° C.) after reforming, which will be described later, moves in a vertically downward direction along the passage 84 in the tube body 72. Therefore, the vaporized raw fuel that moves in the overheating passage 82 is heated by the reformed gas that moves along the passage 84 and is heated to, for example, around 550 ° C., and then from the opening 92 of the distribution plate 86. It is supplied to the reformer 16.

  In the reformer 16, the vaporized and heated raw fuel is once introduced into the chamber 102 through the raw fuel passage 100, and then moves downward from the reforming fuel introduction unit 105. In the reformer 16, a plurality of rectifying plates 104 are arranged in multiple stages, and the raw fuel rectified by the rectifying plates 104 is reformed by the catalyst unit 108 to obtain a reformed gas.

Specifically, in the reformer 16, CH ₄ + 2O ₂ → CO ₂ + 2H ₂ O (exothermic reaction) that is an oxidation reaction and fuel reforming by methane in the reforming fuel, oxygen in the air, and water vapor. The reaction CH ₄ + 2H ₂ O → CO ₂ + 4H ₂ (endothermic reaction) is performed simultaneously. Therefore, a reformed gas containing carbon dioxide and hydrogen is generated, and this reformed gas is supplied from the chamber 110 to the passages 84 of the plurality of pipe bodies 72.

  Further, the high-temperature (around 650 ° C.) reformed gas supplied to the passage 84 heats the raw fuel moving along the superheating passage 82 while moving vertically downward, and then constitutes the preheater 18. It is supplied to the passage 132 in the tube body 126. The reformed gas is supplied to a fuel cell or the like (not shown) after preheating the heated fluid moving along the preheating passage 134 by moving the passage 132 vertically downward.

  In this case, in this embodiment, the superheater 14 that raises the temperature of the raw fuel (reforming fuel) evaporated by the evaporator 12 and the reformer 16 that reforms the heated raw fuel are coaxial with each other. And they are connected in series (see FIG. 2). Specifically, the distribution plate 86 constituting the superheater 14 has an opening 92 as an outlet of reforming fuel gas for supplying raw fuel, which is a reformed fuel whose temperature has been raised, to the reformer 16. In addition, the opening 92 communicates directly with the raw fuel passage 100 provided in the reformer 16.

  Therefore, the raw fuel led out from the superheater 14 is directly supplied from the opening 92 to the raw fuel passage 100 and then supplied from the reforming fuel introduction unit 105 to the rectifying plate 104. For this reason, piping for connecting the superheater 14 and the reformer 16 becomes unnecessary, the piping can be favorably reduced, heat radiation from the piping does not occur, and improvement in thermal efficiency is achieved. The effect that it becomes possible to comprise simply and compactly is acquired.

  Further, a chamber 110 is formed on the reformed gas outlet side of the reformer 16 via a fourth separator 88, and a plurality of pipe bodies 72 constituting the superheater 14 are fixed to the chamber 110. ing. Accordingly, the reformed gas generated by the reformer 16 passes through the passage 84 in the pipe body 72, and heat exchange is immediately performed with the raw fuel flowing in the superheating passage 82. As a result, the high-temperature reformed gas can be used as a superheat source for superheating the raw fuel, and the thermal efficiency can be easily improved.

  Furthermore, a cover member 111 is disposed in the reformer 16 so as to cover the outer cylinder 96, and a heat insulating layer 111 a is formed in the cover member 111. For this reason, the raw fuel flowing in the raw fuel passage 100 formed between the outer cylinder 96 and the inner cylinder 98 can effectively prevent a temperature decrease, and the reforming process by the reformer 16 is efficient. And there is an advantage that it is performed reliably.

  In the present embodiment, the evaporator 12 is disposed concentrically around the superheater 14, and the preheater 18 is coaxially and serially connected to the superheater 14 on the side opposite to the reformer 16. It is connected to. As a result, the piping connecting the evaporator 12, the superheater 14, the reformer 16, and the preheater 18 can be reduced at a stroke, the fuel reforming apparatus 10 can be reduced in size, and the heat radiation from the piping can be suppressed. Therefore, it becomes possible to improve the thermal efficiency. In addition, the fuel reforming apparatus 10 can be started satisfactorily with less starting energy, and energy saving can be reliably performed.

1 is a schematic perspective view of a fuel reformer according to an embodiment of the present invention. It is sectional drawing which shows the flow state in the said fuel reformer. It is a disassembled perspective explanatory drawing of the evaporator which comprises the said fuel reformer. It is a perspective illustration explanatory drawing of a part of the evaporator. It is a partial cross section explanatory view of the evaporator. It is a cross-sectional view of the evaporator. It is a disassembled perspective view of the superheater which comprises the said fuel reformer. It is a disassembled perspective view of the reformer which comprises the said fuel reformer. It is a schematic explanatory drawing of the reforming apparatus of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel reformer 12 ... Evaporator 14 ... Superheater 16 ... Reformer 18 ... Preheater 20 ... Curve pipe member 22 ... Inner cylinder member 24, 124 ... Outer cylinder member 26, 36, 68, 88 ... Separator 28a , 28b ... arc-shaped tubes 30, 32, 84, 122 ... passage 34 ... curved combustion catalyst 38a, 38b ... catalyst outer cylinder 40a, 40b ... metal honeycomb 42 ... casing 52, 102, 110, 114, 120 ... chamber 56 ... fuel Supply pipe 58 ... Air supply pipes 64 and 96 ... Outer cylinder 66 ... Raw fuel inlets 72 and 126 ... Pipe bodies 74 and 128 ... Partition plates 78 and 130 ... Notches 82 ... Superheating passages 86 ... Distribution plates 92 ... Openings 98 ... Inner cylinder 100 ... Raw fuel passage 104 ... Rectifying plate 105 ... Reforming fuel introduction part 111 ... Cover member 112 ... Connecting member 140, 142 ... Fin member

Claims (7)

A fuel reformer that generates hydrogen-rich fuel gas by reforming a reforming fuel,
An evaporator for evaporating the reforming fuel;
A superheater for heating the evaporated reforming fuel to a temperature required for the reforming reaction;
A reformer that reforms the reformed fuel that has been heated to generate reformed gas; and
With
The fuel reformer, wherein the superheater and the reformer are connected to each other coaxially and in series. The fuel reformer according to claim 1, wherein the reformer includes an inner cylinder and an outer cylinder,
The inside of the inner cylinder is filled with a reforming catalyst,
A fuel reformer having a passage through which the reforming fuel flows is formed between the inner cylinder and the outer cylinder. 3. The fuel reformer according to claim 2, wherein the superheater has an outlet for reforming fuel communicating with the passage at an end portion on the reformer side.
The reformer is provided with a reforming fuel introduction section that communicates with the passage and supplies the reforming fuel into the inner cylinder at an end opposite to the superheater. A fuel reformer.   4. The fuel reforming apparatus according to claim 3, wherein the reformer is inserted into the superheater from an end portion on the superheater side, and the reformed gas that has passed through the reforming catalyst is converted into the reforming fuel. A fuel reformer characterized in that a pipe body to be passed as a heating source is connected.   5. The fuel reformer according to claim 1, wherein a heat insulating cover member is provided so as to surround the reformer. 6. The fuel reformer according to any one of claims 1 to 5, wherein the evaporator is disposed concentrically around the superheater,
The fuel reformer, wherein the superheater and the reformer are connected to each other coaxially and in series. The fuel reformer according to any one of claims 1 to 6, further comprising a preheater for preheating a heating fluid for evaporating the reforming fuel by the evaporator.
The fuel reformer is characterized in that the preheater is connected to the superheater coaxially and in series on the opposite side of the reformer.

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