JP2006265046A - Support structure for reformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a support structure for a reformer having high stability and suppressing heat dissipation as much as possible.
SOLUTION: A support structure 40 that supports a reformer 20 includes a plurality of upper support members 41 that are suspended from the peripheral edge of the bottom of the CO shift unit 23 and arranged at a distance in the horizontal direction, and the CO shift unit 23. A plate member 42 that is arranged to face the bottom of the bottom surface and to which the lower end portion of the upper support member 41 is fixed, and hangs down from the plate member 42 and stands on a bottom plate member 47 (bottom surface A1 in the casing A) to be horizontal. It consists of a plurality of lower support members 43 arranged at a distance in the direction. The upper and lower support members 41 and 43 are arranged with their horizontal positions shifted from each other.
[Selection] Figure 1

Description

  The present invention relates to a support structure for a reformer that supports a reformer in which at least a reformer and a carbon monoxide reducing unit are integrally formed.

Conventionally, as an example of a support structure for this type of reformer, one shown in Patent Document 1 “Support structure for a fuel reformer” is known. As shown in FIG. 1 of Patent Document 1, the fuel reformer 10 includes a CO shift section 4 and a heat exchanger 3 as one point of a relatively low temperature portion or a portion that needs to be lowered. In the connection portion 41, the bracket 8 is fixed to the inner wall 61 of the package body 6 through an elastic mount 81. Further, as shown in FIG. 6 of Patent Document 1, the fuel reformer 10 includes a CO shift unit 4 and a CO selective oxidation unit as one point of a relatively low temperature portion or a portion that needs to be lowered in temperature. 5 is fixed to the inner wall 61 of the package body 6 by the bracket 8 and is connected between the lower portion of the fuel reformer 10 and the bottom of the package body 6 ( It is elastically supported by a coil spring member 91). In any case, it is supported by a simple structure and the concentration of thermal stress can be reduced.
JP 2002-284506 A (pages 3-6, FIGS. 1, 3-8)

  In the reformer support structure described in Patent Document 1 described above, the fuel reformer 10 can be supported while mitigating the concentration of thermal stress. However, in the form shown in FIG. 1 of Patent Document 1, since the heavy fuel reformer 10 is suspended and supported on the inner peripheral wall 61 of the package body 6, the strength of the package body 6 and the bracket 8 is required. There is a problem that the stability of the fuel reformer 10 is insufficient. Further, in the format shown in FIG. 6 of Patent Document 1, although the lower part of the fuel reformer 10 is elastically supported by the spring member 9 (coil spring member 91), the heavy fuel reformer 10 is provided. In order to support on the inner peripheral wall 61 of the package body 6, the package body 6 and the bracket 8 need to be strong, and the fuel reformer 10 has insufficient stability. On the other hand, since the heat of the fuel reformer 10 is transmitted (heat radiation) to the package body 6 via the bracket 8, it is necessary to suppress the heat radiation as much as possible.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a support structure for a reformer that has high stability and suppresses heat dissipation as much as possible.

  In order to solve the above-described problem, the structural feature of the invention according to claim 1 is that a reforming apparatus that supports a reforming apparatus integrally configured with at least a reforming section and a carbon monoxide reduction section on a base. In this support structure, the support structure is a plurality of upper support members that are suspended from the bottom of the reformer and are disposed at a distance in the horizontal direction, respectively, and an upper support that is disposed below the bottom surface of the reformer. A plate member to which the lower end of the member is fixed, and a plurality of lower support members that are suspended from the plate member and stand on the base and are spaced apart in the horizontal direction. That is, the horizontal position is shifted.

  A structural feature of the invention according to claim 2 is that, in claim 1, the horizontal position of the lower support member is disposed at a substantially central position of the horizontal position of the upper support member.

  A structural feature of the invention according to claim 3 is that, in claim 1 or claim 2, a portion of the plate member facing the bottom surface of the reformer is cut off.

  A structural feature of the invention according to claim 4 is that, in any one of claims 1 to 3, the reformer and the plate member are covered with a heat insulating material.

  In the invention according to claim 1 configured as described above, the bottom portion of the reformer is supported on the base by the support structure including the upper support member, the plate member, and the lower support member. As a result, the reformer can be supported with sufficient stability as compared with the conventional apparatus. Furthermore, the heat of the reformer is conducted to the base through the upper support member, the plate member, and the lower support member, but the heat conduction is conducted because the upper and lower support members are arranged with their horizontal positions shifted from each other. Since the path is longer in the plate member by the amount of deviation, it is possible to reduce heat conduction through the support structure and reduce heat radiation from the reformer to the base. Therefore, it is possible to provide a support structure for a reformer that has high stability and suppresses heat dissipation as much as possible.

  In the invention according to claim 2 configured as described above, in the invention according to claim 1, the horizontal position of the lower support member is disposed at a substantially central position of the horizontal position of the upper support member. By setting the heat conduction path in the member most efficiently, heat radiation can be reduced most efficiently.

  In the invention according to claim 3 configured as described above, in the invention according to claim 1 or claim 2, since the portion of the plate member facing the bottom surface of the reformer is cut off, It is possible to reduce the weight while preventing heat from being received from the bottom and radiating it.

  In the invention according to Claim 4 configured as described above, in any one of Claims 1 to 3, the reforming device and the plate member are covered with a heat insulating material. By suppressing heat dissipation to the space, heat dissipation from the support structure can be further suppressed.

  The support structure that supports the reformer on the base is designed to increase the distance from the reformer to the base in order to suppress heat transfer from the reformer to the base. At the same time, in order to simultaneously reduce the size of the entire device, the positional relationship of the support members of the support structure is shifted in the horizontal direction, thereby achieving downsizing of the device while lengthening the heat transfer system. . Specifically, the upper support member that directly supports the reformer and the lower support member provided below the reformer are connected via a plate member, and the first support member is connected to the plate member. The connecting portion and the second connecting portion where the lower support member and the plate member are connected are arranged in an offset relationship with respect to the surface direction of the plate member. Each of the upper support member and the lower support member is composed of a plurality of members, and each connection portion is arranged at the peripheral portion with respect to the surface of the plate member, and at the peripheral portion, the connection portion of the upper support member and the connection portion of the lower support member Are arranged in an offset relationship with respect to the surface of the plate member.

  Hereinafter, an embodiment of a fuel cell system to which a support structure for a reformer according to the present invention is applied will be described. FIG. 1 is a schematic diagram showing an outline of this fuel cell system. As shown in FIG. 1, the fuel cell system includes a fuel cell 10 and a steam reforming reformer 20 that generates a reformed gas containing hydrogen gas necessary for the fuel cell 10. The fuel cell 10 includes a fuel electrode 11 and an air electrode 12, and generates power using the reformed gas supplied to the fuel electrode 11 and the air (cathode air) supplied to the air electrode 12.

  The reformer 20 includes a reforming unit 21, a cooling unit 22, a carbon monoxide shift reaction unit (hereinafter referred to as a CO shift unit) 23, a carbon monoxide selective oxidation unit (hereinafter referred to as a CO selective oxidation unit) 24, a combustion. The unit 25 and the evaporation unit 26 are included.

  The reforming unit 21 generates and derives a reformed gas from a mixed gas of fuel and water vapor supplied from the outside. Examples of the fuel include natural gas, LPG, kerosene, gasoline, methanol, and the like. In the present embodiment, description will be made on natural gas. The reforming portion 21 is formed in a bottomed cylindrical shape, and is formed of an outer channel 21a1 and an annular inner channel 21a1 each formed in an annular shape. The return channel 21a is provided.

  The return channel 21 a of the reforming unit 21 is filled with a catalyst 21 b (for example, a Ru or Ni-based catalyst), and the reformed fuel and the steam introduced from the steam supply pipe 32 are filled with each other. The mixed gas reacts and is reformed by the catalyst 21b to generate hydrogen gas and carbon monoxide gas (so-called steam reforming reaction). At the same time, a so-called carbon monoxide shift reaction occurs in which carbon monoxide generated in the steam reforming reaction reacts with steam to transform into hydrogen gas and carbon dioxide. These generated gases (so-called reformed gas) are led to a cooling unit (heat exchange unit) 22. The steam reforming reaction is an endothermic reaction, and the carbon monoxide shift reaction is an exothermic reaction.

  The cooling unit 22 is a heat exchanger in which heat exchange is performed between the reformed gas derived from the reforming unit 21 and a mixed gas of reforming fuel and reforming water (steam). The temperature of the reformed gas is lowered by a low-temperature mixed gas and led out to the CO shift unit 23, and the mixed gas is heated by the reformed gas and led out to the reforming unit 21.

  The CO shift unit 23 is a unit that reduces carbon monoxide in the reformed gas supplied from the reforming unit 21 through the cooling unit 22, that is, a carbon monoxide reducing unit. The CO shift unit 23 includes a cylindrical casing 23a and an inner cylinder 23b disposed coaxially within the casing 23a. The inner cylinder 23b has an upper end connected to the inner peripheral end of an annular support member 23c whose outer peripheral end is connected to the inner peripheral surface of the housing 23a. A reformed gas inlet 23a1 is provided on the upper surface of the housing 23a, and the other end of a connecting pipe 31 having one end connected to the CO selective oxidation unit 24 is connected to a side surface of the housing 23a. A catalyst 23d (for example, a Cu—Zn-based catalyst) is filled in the inner cylinder 23b of the CO shift portion 23 and between the inner cylinder 23b and the housing 23a. The CO shift unit 23 is provided with a temperature sensor 23e for detecting the temperature in the CO shift unit 23, for example, the temperature in the vicinity of the reformed gas introduction port of the CO shift unit 23, and the detection signal is sent to the control device 30. It is output. The temperature sensor 23e is preferably provided on the inlet 23a1 side in the reformed gas flow path in the CO shift unit 23. Thereby, compared with the case where the temperature sensor 23e is provided on the outlet side of the reformed gas flow path, the temperature of the catalyst 23d can be controlled with high responsiveness.

  In the CO shift unit 23 configured as described above, the reformed gas led out from the cooling unit 22 passes through the reformed gas introduction port 23a1 and passes through the catalyst 23d in the inner cylinder 23b, and is turned back to return the inner cylinder 23b. And is led to the CO selective oxidation unit 24 through the inside of the catalyst 23d between the casing 23a. At this time, a so-called carbon monoxide shift reaction occurs in which carbon monoxide and water vapor contained in the introduced reformed gas react with the catalyst 23d to be converted into hydrogen gas and carbon dioxide gas. This carbon monoxide shift reaction is an exothermic reaction.

  The CO selective oxidation unit 24 further reduces the carbon monoxide in the reformed gas supplied from the CO shift unit 23 and supplies it to the fuel cell 10, that is, a carbon monoxide reduction unit, and is formed in a cylindrical shape. Then, the outer peripheral wall of the evaporation part 26 is covered and provided. The CO selective oxidation unit 24 is filled with a catalyst 24 a (for example, a Ru or Pt catalyst), and the reformed gas introduced through the connection pipe 31 flows through the CO selective oxidation unit 24. It comes to derive. Further, the reforming gas supplied to the CO selective oxidation unit 24 is mixed with oxidation air, and the oxidation air is mixed with the reformed gas from the CO shift unit 23 to form the CO selective oxidation unit. 24.

  Therefore, carbon monoxide in the reformed gas introduced into the CO selective oxidation unit 24 reacts with oxygen in the oxidizing air to become carbon dioxide. This reaction is an exothermic reaction and is promoted by the catalyst 24a. Thereby, the reformed gas is derived by further reducing the carbon monoxide concentration (10 ppm or less) by the oxidation reaction, and is supplied to the fuel electrode 11 of the fuel cell 10.

  The combustion part 25 generates combustion gas for heating the reforming part 21 and supplying heat necessary for the steam reforming reaction. The lower end part is inserted into the inner peripheral wall of the reforming part 21. It is arranged with a space. The combustion gas is generated from the inner peripheral flow path 27a along the inner peripheral wall of the reforming section 21, the first outer peripheral flow path 27b folded back from the inner peripheral flow path 27a and along the outer peripheral wall of the reforming section 21, and the first outer peripheral flow path 27b. It is folded and flows through the combustion gas passage 27 constituted by the second outer peripheral passage 27c along the heat insulating portion 28, and is exhausted as combustion exhaust gas through the exhaust pipe. The combustion gas passage 27 is covered with a heat insulating portion 28, and the heat of the combustion gas flowing through the inner peripheral flow passage 27a and the first outer peripheral flow passage 27b is suppressed from radiating to the outside by the heat insulating portion 28, so that the reforming portion. The heat of the combustion gas flowing through the second outer circumferential flow path 27c is effectively utilized for heating the evaporation section 26 because heat dissipation to the first outer circumferential flow path 27b is suppressed by the heat insulating section 28.

  The combustion section 25 is supplied with combustion fuel. The combustion section 25 is supplied with the reformed gas from the reformer 20 during the start-up operation of the fuel cell 10 and is discharged from the fuel cell 10 during the steady operation of the fuel cell 10 (at the fuel electrode 11). A reformed gas containing unused hydrogen) is supplied. Further, the combustion section 25 is supplied with combustion air that is a combustion oxidant gas for burning combustion fuel, reformed gas, or anode off gas. When the combustion unit 25 is ignited, the combustion fuel, reformed gas, or anode off-gas supplied to the combustion unit 25 is burned to generate high-temperature combustion gas.

  The evaporation section 26 heats and boiles the reformed water to generate water vapor and supplies the steam to the reforming section 21 via the cooling section 22. The evaporation section 26 is formed in a cylindrical shape and has a first shape of the combustion gas channel 27. 2 The outer peripheral flow path 27c is provided so as to cover the outer peripheral wall. In the evaporating section 26, the introduced water flows through the evaporating section 26 and is heated to become water vapor, which is led out to the water vapor supply pipe 32.

  Between the CO selective oxidation unit 24 and the fuel electrode 11 of the fuel cell 10, the reformed gas flows through the fuel cell 10 to the combustion unit 25 and directly to the combustion unit 25 without passing through the fuel cell 10. A switching valve 33 is provided for switching between the flow path and the latter flow path during start-up operation, and is switched to the former flow path during steady operation.

  In the reformer 20 described above, the CO shift unit 23 is disposed at the lowermost part, the cooling unit 22 is integrally assembled thereon, and the combustion unit 25 is disposed coaxially in order from the inside. An integral structure including the part 21, the combustion gas flow path 27, the evaporation part 26, and the CO selective oxidation part 24 is integrally assembled. These constituent members are made of a metal material such as stainless steel.

  The above-described fuel cell system is accommodated in the casing A. The reformer 20 is supported and fixed to the bottom surface A <b> 1 in the housing A by the support structure 40. The support structure 40 includes a plurality of upper support members 41 depending on the bottom of the CO shift portion 23, an upper plate member 42 that is a plate member, and a plurality of lower support members 43 depending on the upper plate member 42. Each upper support member 41 is formed of a metal material (for example, stainless steel) in an L shape, and its upper end portion is fixed to the bottom portion of the CO shift portion 23 disposed at the lowermost portion of the reformer 20 by welding or the like. 2 and 3, the lower end portion is fixed to the upper plate member 42 by screwing with bolts 44 and nuts 45 or the like. In addition, between the lower end part of the upper support member 41 and the upper board member 42, the heat insulation member 46 formed from heat insulating materials, such as a ceramic fiber, is interposed, and, thereby, the upper support member 41 and the upper board member are interposed. The heat conduction with 42 is reduced. Further, the upper support members 41 are arranged at a predetermined distance in the horizontal direction or at predetermined angular intervals. In the present embodiment, the three upper support members 41 are arranged around the center point O at a predetermined angle θ1 (120 degrees) with the center axis O of the CO shift portion 23 as the center point O. In addition, the upper support member 41 is preferably fixed to the periphery of the bottom of the CO shift portion 23. Thereby, compared with the case where the upper support member 41 is fixed to the position near the center of the bottom of the CO shift portion 23, the reformer 20 can be supported more stably.

  The upper plate member 42 is formed of a metal material (for example, stainless steel material) into an annular disk. The upper plate member 42 is disposed below the bottom surface of the CO shift unit 23, which is the bottom surface of the reformer 20, with the disk surfaces facing each other in parallel. A portion of the upper plate member 42 facing the bottom surface of the CO shift portion 23 is cut off, and a hole in the upper plate member 42 corresponds to the cut portion. As a result, it is possible to prevent heat from being received from the bottom of the CO shift unit 23, which is the bottom of the reformer 20, and to reduce the weight. Note that the upper plate member 42 is not limited to the annular disk, and may be a hollow rectangular plate, and may not be a connected ring but may be partially cut. However, the upper plate member 42 needs to have a required strength.

  Each lower support member 43 is formed of a metal material (for example, stainless steel) into a square plate shape, and an upper end portion is fixed to the lower surface of the upper plate member 42 by welding or the like, and a lower end portion is fixed to the upper surface of the lower plate member 47. It is fixed by welding. The lower plate member 47 is formed of a metal material (for example, a stainless steel material) in an annular disk like the upper plate member 42, and is disposed in parallel to the upper plate member 42. Note that the lower plate member 47 may not be annular but may be simply a disk shape, a rectangular plate shape, or the like, and is preferably wider than the upper plate member 42 from the viewpoint of stability. The lower plate member 47 is screwed and fixed to the bottom surface A1 in the housing A with bolts 48. In this way, the lower support member 43 stands on the bottom surface A <b> 1 in the casing A that is the base via the lower plate member 47. The lower support member 43 may be directly fixed to the bottom surface A1 in the housing A by screwing or the like without providing the lower plate member 47.

  Further, the lower support members 43 are arranged at a predetermined distance in the horizontal direction or at predetermined angular intervals. In the present embodiment, the three lower support members 43 are arranged around the center point O at a predetermined angle θ2 (120 degrees) with the center axis O of the CO shift portion 23 as the center point O. At this time, the lower support members 43 are arranged so that their horizontal positions are shifted from each other with respect to the upper support members 41 (60 degrees around the center point O). For example, the horizontal position of the lower support member 43 is arranged at a substantially central position of the horizontal position of the upper support member 41. As a result, the heat of the CO shift portion 23 conducted through the upper support member 41 is conducted almost equally to the lower support members 43 and 43 that are at substantially the same distance from the upper support member 41 (having the same thermal resistance). Then, it is conducted to the housing A through the lower support member 43 and the lower plate member 47.

  Thus, the support structure 40 is a structure in which the upper support member 41 that directly supports the reforming apparatus 20 and the lower support member 43 provided in the lower part thereof are connected via the plate member 42, and The positions of the first connection part 42a where the member 41 and the plate member 42 are connected and the second connection part 42b where the lower support member 43 and the plate member 42 are connected are shifted from each other with respect to the surface direction of the plate member 42 ( Offset) relationship. The upper support member 41 and the lower support member 43 are each composed of a plurality of members, and the connection portions 42a and 42b are arranged at the peripheral edge with respect to the surface of the plate member 42, and the connection portion of the upper support member 41 at the peripheral edge. Similarly, the connecting portion 42b of the lower support member 43 and 42a are arranged in an offset relationship with respect to the surface of the plate member 42.

Therefore, the reformer 20 is supported from the bottom by the support structure 40 having a strong and stable structure, and thus the reformer 20 is fixed to the housing A while maintaining high stability.
The heat of the CO shift portion 23 is conducted to the upper plate member 42 through the upper support member 41, and the upper plate member 42 is transferred from the upper support member 41 to the lower support member 43, that is, the upper and lower support members 41, 43. Conducted by the amount of deviation, and then conducted to the lower plate member 47 through the lower support member 43. Therefore, compared to the case where the support members directly connected to the upper and lower support members 41 and 43 are used, the thermal resistance can be increased by the amount of deviation between the upper and lower support members 41 and 43, thereby allowing the support structure to pass directly. Heat can be suppressed as much as possible.

  Further, a part of the above-described reformer 20 and the support structure 40, specifically, at least the upper support member 41 and the upper plate member 42 are covered with the heat insulating material 50. The heat insulating material 50 is made of, for example, a ceramic heat insulating material. Thereby, the heat radiation from the surface of the reformer 20 to the space and the heat radiation from a part of the surface of the support structure 40 to the space can be suppressed.

  As is clear from the above description, in the present embodiment, the bottom portion of the reformer 20 is a casing A that is a base by the support structure 40 including the upper support member 41, the plate member 42, and the lower support member 43. It is supported on the inner bottom surface A1. Thereby, the reformer 20 can be supported while maintaining sufficient stability as compared with the conventional apparatus. Furthermore, the heat of the reformer 20 is conducted to the base through the upper support member 41, the plate member 42, and the lower support member 43, but the upper and lower support members 41, 43 are displaced from each other in the horizontal direction. Since the heat conduction path is longer by the amount of deviation in the plate member 42 due to the arrangement, heat conduction through the support structure 40 is reduced, and heat is dissipated from the reformer 20 to the base (the bottom surface A1 of the casing A). Can be reduced. Therefore, it is possible to provide a support structure for a reformer that has high stability and suppresses heat dissipation as much as possible.

  Further, since the horizontal position of the lower support member 43 is disposed at a substantially central position of the horizontal position of the upper support member 41, the most efficient heat dissipation is achieved by setting the heat conduction path in the plate member 42 most efficiently. Can be reduced.

  Further, since the reforming device 20 and the plate member 42 are covered with the heat insulating material 50, the heat dissipation from the support structure 40 can be further suppressed by suppressing the heat dissipation from the surface of the plate member 42 to the space. .

  The present invention can be applied not only to a steam reforming reaction type reforming apparatus but also to a partial oxidation reforming reaction type reforming apparatus. In this case, the combustion unit 25 is deleted from the constituent members of the reformer 20.

  Further, in the above-described embodiment, it is supported at the bottom of the CO shift unit 23 that is a temperature lowering process in the reformed gas generation process. However, as with the CO shift unit 23, carbon monoxide is reduced. The CO selective oxidation unit 24 that is a carbon monoxide reduction unit may be disposed at the bottom of the reformer 20 and supported at the bottom.

1 is a schematic diagram showing an outline of an embodiment of a fuel cell system to which a support structure for a reformer according to the present invention is applied. It is sectional drawing along the 2-2 line shown in FIG. FIG. 3 is a cross-sectional view taken along line 3-3 shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Fuel cell, 11 ... Fuel electrode, 12 ... Air electrode, 20 ... Reformer, 21 ... Reformer, 21a ... Folding channel, 21b ... Catalyst, 22 ... Cooling unit, 23 ... CO shift unit, 23d ... Catalyst, 24 ... CO selective oxidation section, 24a ... Catalyst, 25 ... Combustion section, 26 ... Evaporation section, 27 ... Combustion gas flow path, 28 ... Heat insulation section, 31 ... Connection pipe, 32 ... Steam supply pipe, 33 ... Switching valve , 40 ... support structure, 41 ... upper support member, 42 ... upper plate member, 42a, 42b ... connection portion, 43 ... lower support member, 50 ... heat insulating material, A ... housing, A1 ... bottom surface of the housing.

Claims (4)

In the support structure of the reformer that supports the reformer that integrally configures at least the reformer and the carbon monoxide reduction unit on the base,
The support structure is a plurality of upper support members that are suspended from the bottom of the reformer and are respectively arranged at a distance in the horizontal direction;
A plate member that is disposed opposite to the bottom of the bottom surface of the reformer and to which the lower end portion of the upper support member is fixed;
A plurality of lower support members that are suspended from the plate member and stand on the base and disposed at a distance in the horizontal direction,
The support structure for a reformer, wherein the upper and lower support members are arranged with their horizontal positions shifted from each other.   The reformer support structure according to claim 1, wherein the horizontal position of the lower support member is disposed at a substantially central position of the horizontal position of the upper support member.   3. A reformer support structure according to claim 1, wherein a portion of the plate member facing the bottom surface of the reformer is cut off. 4. The reformer support structure according to claim 1, wherein the reformer and the plate member are covered with a heat insulating material.

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