JP6215764B2 - Fuel cell module and fuel cell device - Google Patents

Description

  The present invention relates to a fuel cell module and a fuel cell device in which a reformer is disposed above a cell stack.

  In recent years, various fuel cell modules have been proposed as next-generation energy. As such a fuel cell module, one in which a cell stack device in which a plurality of fuel cell cells are electrically connected in series is accommodated in a storage container is known (for example, see Patent Document 1).

  This cell stack device has an alloy reformer disposed above a plurality of cell stacks, and the reformer has a U shape, and vaporizes water by vaporizing water to generate water vapor. And a reforming section for steam reforming the raw fuel gas using the steam generated in the vaporization section. The space between the upper end of the cell stack and the reformer is a combustion region in which exhaust gas from the cell stack burns, and an oxygen-containing gas supply plate made of an alloy for supplying oxygen-containing gas to the cell stack is provided. , And extends from between the vaporization section and the reforming section disposed at the opposing positions to the lower end of the cell stack.

  The vaporizer located at one end of the reformer is connected to a raw fuel gas supply pipe and a water supply pipe, and the other end of the reformer is mixed with the steam generated in the vaporizer and the raw fuel gas. Is supplied to a reforming section located at a position where the raw fuel gas is steam reformed in the reforming section.

  On the other hand, fins and the like are arranged in the portion corresponding to the combustion region of the oxygen-containing gas supply plate, heat of the combustion region is transferred to the oxygen-containing gas in the oxygen-containing gas supply plate, and high-temperature oxygen-containing is contained in the lower end portion of the cell stack. Gas is also supplied to increase the temperature at the lower end of the cell stack (see, for example, Patent Document 2).

JP 2007-207446 A Japanese Unexamined Patent Publication No. 2011-129489

  However, in the fuel cell modules of Patent Documents 1 and 2, heat from the reforming unit or heat in the combustion region is conducted to the oxygen-containing gas in the oxygen-containing gas supply plate, and the amount of heat in the reforming unit is reduced. The temperature of the reforming portion tends to decrease, and the reforming performance tends to decrease. In particular, in recent years, the fuel utilization rate of fuel cell modules has been improved, the amount of exhaust gas discharged from the cell stack has decreased, and the amount of heat in the combustion region tends to decrease, so the reforming section is heated. The amount of heat decreased and the reforming performance tended to decrease.

  An object of the present invention is to provide a fuel cell module and a fuel cell device that can maintain high reforming performance.

The fuel cell module of the present invention includes a reformer disposed above a cell stack, the reformer vaporizes water to generate water vapor, and uses water vapor generated in the vaporizer. And an oxygen-containing gas supply member extending from between the vaporization unit and the reforming unit to the lower end of the cell stack. In addition, a heat insulating material is provided at a position facing the reforming portion of the oxygen-containing gas supply member, and heat exchange is performed on the portion of the oxygen-containing gas supply member located at the center in the vertical direction of the cell stack. The promotion part is provided, It is characterized by the above-mentioned.

Furthermore, the fuel cell module of the present invention has a reformer disposed above the cell stack, and the reformer vaporizes water to generate water vapor and water vapor generated in the vaporizer. An oxygen-containing gas supply member that extends from between the vaporization section and the reforming section to the lower end of the cell stack. And between the reformer and the upper end of the cell stack is a combustion region where the exhaust gas from the cell stack burns, and at a position facing the combustion region of the oxygen-containing gas supply member A heat insulating material is provided , and a heat exchange accelerating portion is provided in a portion of the oxygen-containing gas supply member located at a central portion in the vertical direction of the cell stack .

  A fuel cell device according to the present invention is characterized in that the fuel cell module described above and an auxiliary machine for operating the fuel cell module are housed in an outer case.

  The fuel cell module of the present invention can maintain the reforming section at a high temperature and maintain the reforming performance at the reforming section at a high level. As a result, it is possible to provide a power cell module and a fuel cell device with excellent power generation performance.

It is a longitudinal cross-sectional view which shows one form of a fuel cell module. (A) is a plan view showing a cell stack apparatus having two cell stacks, (b) is a perspective view showing a state in which two cell stacks are provided in the manifold and a reformer is provided above the two cell stacks. FIG. (A) is a perspective view of the reformer, (b) is a plan view showing a state in which a heat insulating material is provided on the reforming portion side of the oxygen-containing gas supply member, and (c) is a reforming of the oxygen-containing gas supply member. FIG. 6 is a plan view showing a state where a heat insulating material is provided only at a position corresponding to a vaporization section on the part side. (A) (b) is a longitudinal cross-sectional view which shows the other form of a fuel cell module. (A) is a longitudinal sectional view showing still another embodiment of the fuel cell module in which a heat insulating material is provided at the position of the oxygen-containing gas supply member corresponding to the combustion region, and (b) is an oxygen-containing gas supply member of (a) and FIG. 4C is a longitudinal sectional view showing still another embodiment of a fuel cell module in which a heat exchange promoting portion is provided in the oxygen-containing gas supply member at the side of the central portion in the vertical direction of the cell stack. . It is a perspective view which shows a fuel cell apparatus. It is a longitudinal cross-sectional view which shows the fuel cell module which has four cell stacks.

  FIG. 1 is a longitudinal sectional view showing an embodiment of a fuel cell module (hereinafter sometimes referred to as a module), and FIG. 2 is a view showing a cell stack device. In addition, the same code | symbol shall be provided about the same component in a different figure.

  The modules 1 are arranged in a row in a rectangular parallelepiped storage container 2 in a state where fuel cells 3 having fuel gas flow paths are erected in the vertical direction, and are gathered between adjacent fuel cells 3. Two cell stacks 5 electrically connected in series via electric members (not shown) are accommodated.

  A lower end portion of the fuel cell 3 extending in the vertical direction is fixed to the manifold 4 with an insulating bonding material (not shown) such as a glass sealing material. Two manifolds 4 are fixed to one manifold 4, and as shown in FIG. 2 (a), leading portions 5 a are connected to both ends of each of the two cell stacks 5. The lead-out portions 5a on the side are connected by a connecting member 5b, and the two cell stacks 5 are electrically connected in series.

  In FIGS. 1 and 2, a hollow flat plate type in which fuel gas flows through a fuel gas flow path provided in the length direction y of the fuel cell 3 inside the fuel cell 3, the fuel is formed on the surface of the support substrate. A solid oxide fuel cell 3 in which a side electrode, a solid electrolyte, and an oxygen side electrode are sequentially provided is illustrated.

  Further, in order to obtain a hydrogen-containing gas used in the fuel battery cell 3, as shown in FIG. 3, a fuel gas (hydrogen-containing gas) is generated by reforming a fuel such as natural gas or kerosene. A letter-shaped alloy-made reformer 6 is arranged above the two cell stacks 5. Then, as shown in FIG. 2B, the fuel gas (reformed gas) generated by the reformer 6 is supplied to the manifold 4 through the reformed gas outlet pipe 7, and the fuel cell unit via the manifold 4. 3 is supplied to a fuel gas flow path provided in the interior of 3. Thereby, the cell stack apparatus 8 is configured. That is, as shown in FIG. 1, the cell stack device 8 has a predetermined distance from the upper end of the cell stack 5 above the manifold 4, the cell stack 5 fixed to the manifold 4, and the two cell stacks 5. And one reformer 6 arranged in the above.

  Excess fuel gas (exhaust gas) that is supplied to the fuel gas flow path of the fuel cell 3 and is not used for power generation is discharged above the fuel cell 3. Excess fuel gas can be reacted with oxygen-containing gas (air) supplied to the outside of the fuel cell 3 and burned. A space between the upper end of the cell stack 5 and the reformer 6 is a combustion region F. The combustion region F is indicated by a one-dot chain line in FIG.

  As shown in FIG. 3, the reformer 6 includes a vaporizer 6a that vaporizes water to generate steam, and a reformer 6b that reforms the raw fuel gas using steam generated by the vaporizer 6a. The vaporization part 6a and the reforming part 6b are located facing each other through a space.

  The reformer 6 has an outward path 10a and a return path 10b. The vaporizer 6a is provided on the upstream side of the outward path 10a, and the reformer 6b is provided on the downstream side of the outward path 10a and the return path 10b. The reforming unit 6b may be provided only in the forward path 10b, and the vaporization unit 6a may be provided in a part of the forward path 10a and the return path 10b. The reformer 6 only needs to have a portion where the vaporizing section 6a and the reforming section 6b are positioned to face each other through a space.

  A water supply pipe 13 for supplying water and a raw fuel gas supply pipe 15 for supplying raw fuel gas are connected to the upstream end of the forward path 10a. A reformed gas outlet pipe 7 is connected to derive the quality reformed gas (fuel gas). The water supply pipe 13, the raw fuel gas supply pipe 15 and the reformed gas outlet pipe 7 are connected to one side of the reformer 6 and are drawn out in the same direction.

Below the forward path 10a and the return path 10b, two cell stacks 5 are respectively positioned as shown by a one-dot chain line in FIG. 3B, and the arrangement direction x of the fuel cells 3 constituting the cell stack 5 A forward path 10a and a return path 10b are extended along the line.

  Since the reformer 6 is heated by the reaction heat of the fuel battery cell 3 and the combustion heat of the surplus fuel gas from the fuel battery cell 3, the water supplied to the vaporizer 6a becomes steam, and this steam and raw fuel gas Are reformed while flowing through the reforming section 6 b, reformed gas (fuel gas) containing hydrogen is generated, and is led out from the reformed gas outlet pipe 7 to the manifold 4.

  The forward path 10a and the return path 10b are made of an alloy tube having a rectangular cross section. A space is formed between the side surface of the tubular body constituting the forward path 10a and the side surface of the tubular body constituting the return path 10b, and this space is made of a hollow plate-like alloy as shown in FIG. The oxygen-containing gas supply member 12 is vertically inserted, and the tip thereof is located between the cell stacks 5 and at the lower end of the cell stack 5. A space is formed between the oxygen-containing gas supply member 12, the side surface of the tubular body that forms the forward path 10a, and the side surface of the tubular body that configures the return path 10b.

  In the forward path 10a of the reformer 6, a partition plate 6c is provided at the center part in the arrangement direction x of the fuel cells 3 and partitions the vaporization part 6a and the reforming part 6b. A ceramic ball is accommodated in the vaporizing portion 6a to promote vaporization, and the partition plate 6c is formed so that water vapor passes but ceramic ball does not pass. The water supply pipe 13 is configured to supply water to the position of the vaporization section 6 a above the center part in the arrangement direction x of the fuel cells 3 of the cell stack 5. Since the temperature tends to be high at the center in the arrangement direction x of the fuel cells 3, vaporization can be promoted. A reforming catalyst is stored in the reforming unit 6b. The partition plate 6c is configured so that water vapor and raw fuel gas can pass but the reforming catalyst cannot pass.

  As shown in FIG. 1, the fuel cell module 1 includes a cell stack device 8 housed in a storage container 2, and is arranged in a direction in which the cell stack 5 is arranged (perpendicular to the arrangement direction x of the fuel cell 3). An oxygen-containing gas introduction path 21 and an exhaust gas discharge path 23 are formed from the outside on the side walls of the storage container 2 on both sides in the direction). The oxygen-containing gas introduction path 21 is formed from the bottom part of the storage container 2 to the upper part through the side part, and is configured to supply oxygen-containing gas to the oxygen-containing gas supply member 12.

  On the other hand, the exhaust gas discharge path 23 is formed from the side part to the bottom part of the storage container 2, and the exhaust gas (combustion gas) from the upper end of the fuel cell 3 is a tube body that forms the forward path 10 a and the pipe body that forms the return path 10 b And a space formed between the oxygen-containing gas supply member 12 and exhausted from the bottom outlet through the side of the storage container 2 by the exhaust gas discharge passage 23. While the oxygen-containing gas flows through the oxygen-containing gas introduction path 21, it is heated by the exhaust gas flowing through the exhaust gas discharge path 23.

  In this embodiment, the hollow plate-shaped oxygen-containing gas supply member 12 extends from the space between the vaporization section 6a and the reforming section 6b to the lower end of the cell stack 5, as shown in FIG. In addition, a heat insulating material 17 is provided only at a position facing the reforming portion 6 b of the oxygen-containing gas supply member 12. As shown in FIG. 3B, the heat insulating material 17 is disposed at the position of the outer surface of the oxygen-containing gas supply member 12 facing the side surface of the reforming portion 6b of the return path 10b. Arrangement direction x) It is arranged on the entire surface. The heat insulating material 17 is desirably formed slightly wider than the side surface at a position facing the side surface of the reforming part 6b.

  The heat insulating material 17 is made of, for example, alumina, silica, or alumina silica material.

In the cell stack apparatus as described above, since the heat insulating material 17 is provided at a position facing the reforming portion 6b of the oxygen-containing gas supply member 12, the heat from the reforming portion 6b is generated in the oxygen-containing gas supply member 12. It is possible to suppress the transfer to the oxygen-containing gas, maintain the temperature of the reforming unit 6b high, and maintain high reforming performance in the reforming unit 6b.

  In addition, as shown in FIG.3 (c), the heat insulating material 17 may be provided only in the position corresponding to the formation position of the vaporization part 6a of the oxygen containing gas supply member 12. FIG. That is, the oxygen-containing gas supply member 12 is a portion sandwiched between the vaporization section 6a and the reforming section 6b, and the heat insulating material 17 is provided on the surface of the oxygen-containing gas supply member 12 on the reforming section 6b side. May be.

  This is because the temperature of the vaporization unit 6a is low, and thus heat from the reforming unit 6b tends to be easily transmitted to the vaporization unit 6a via the oxygen-containing gas supply member 12.

  FIG. 4A shows another form of the fuel cell module. In this form, the distance between the oxygen-containing gas supply plate 12 and the reforming part 6b is such that the oxygen-containing gas supply member 12 and the vaporizing part 6a are separated from each other. Wider than the interval.

  That is, a recess 14 is formed in a portion of the oxygen-containing gas supply member 12 that faces the side surface of the tubular body constituting the return path 10b, and the oxygen-containing gas flow path and the reforming in the oxygen-containing gas supply member 12 are formed. The distance from the part 6b is farther than the distance between the vaporizing part 6a and the oxygen-containing gas flow path in the oxygen-containing gas supply member 12. In other words, the distance between the outer surface of the oxygen-containing gas supply member 12 and the side surface of the tubular body constituting the return path 10b is greater than the distance between the outer surface of the oxygen-containing gas supply member 12 and the side surface of the tubular body constituting the forward path 10a. ing.

  This recessed part 14 is formed in the same position as the formation position of the heat insulating material 17 of the said form. In other words, the oxygen-containing gas supply member 12 is formed on the entire surface in the width direction (arrangement direction x) at the position of the outer surface of the oxygen-containing gas supply member 12 facing the side surface of the reforming portion 6b of the return path 10b. The recess 14 is a portion sandwiched between the vaporization unit 6a and the reforming unit 6b, and may be provided on the surface of the oxygen-containing gas supply member 12 on the reforming unit 6b side.

  In such a fuel cell module, heat from the reforming unit 6b is prevented from being transferred to the oxygen-containing gas in the oxygen-containing gas supply member 12, and the temperature of the reforming unit 6b is maintained high, and reforming is performed. The reforming performance in the part 6b can be maintained high. Note that the oxygen-containing gas supply member 12 itself may be shifted to the vaporization unit 6a side without providing the recess 14.

  Further, in FIG. 4A, the concave portion 14 is provided at a position facing the reforming portion 6b of the oxygen-containing gas supply member 12, but further up to a position facing the combustion region F of the oxygen-containing gas supply member 12. By providing the recess, the amount of heat supplied to the reforming unit 6b can be further increased, the temperature of the reforming unit 6b can be maintained high, and the reforming performance of the reforming unit 6b can be maintained high.

  FIG. 4B shows still another form of the fuel cell module. In this form, a heat insulating material 17 is provided on the surface of the oxygen-containing gas supply plate 12 on the reforming part 6b side. This heat insulating material 17 is provided in the same position as the heat insulating material 17 of the form of FIG. 1, FIG. 3, except the point provided in the oxygen containing gas supply board 12. FIG.

  Thus, heat transfer from the reforming unit 6b is suppressed by the heat insulating material 17, and the distance between the flow path of the oxygen-containing gas in the oxygen-containing gas supply member 12 and the reforming unit 6b is the same as that of the vaporizing unit 6a and oxygen. Since the distance from the flow path of the oxygen-containing gas in the contained gas supply member 12 is further away, the amount of heat transferred from the reforming unit 6b to the oxygen-containing gas supply member 12 is reduced, and the temperature of the reforming unit 6b is reduced. It can be maintained high, and the reforming performance of the reforming part 6b can be maintained high.

  FIG. 5A shows still another form of the fuel cell module. In this form, the surface of the oxygen-containing gas supply member 12 on the reforming part 6b side and the position facing the combustion region F are shown in FIG. A heat insulating material 17 is provided.

  As shown in FIG. 5B, the heat insulating material 17 is disposed on the entire surface in the width direction on the reforming portion 6 b side of the plate-like oxygen-containing gas supply member 12 at a position facing the combustion region F.

  In such a fuel cell module, the heat from the combustion region F is prevented from being transferred to the oxygen-containing gas in the oxygen-containing gas supply member 12, and the amount of heat supplied to the reforming unit 6b is increased, thereby reforming. The temperature of the part 6b can be kept high, and the reforming performance in the reforming part 6b can be kept high. The heat insulating material 17 may be provided not only on both surfaces of the oxygen-containing gas supply member 12 facing the combustion region F, that is, on the surface on the reforming unit 6b side but also on the surface on the vaporizing unit 6a side.

  FIG. 5C shows still another form of the fuel cell module. In this form, as shown in FIG. 1, the heat insulating material 17 is provided at a position facing the reforming portion 6b of the oxygen-containing gas supply member 12. Is provided, and a heat exchange promoting portion 12a is provided at the position of the oxygen-containing gas supply member 12 in the central portion of the cell stack 5 in the vertical direction (length direction y). The heat exchange promoting part 12 a is provided only in the center part in the vertical direction of the cell stack 5 except for the upper and lower ends of the cell stack 5.

  For example, the heat exchange promoting portion 12a is provided with fins on the outer surface or the inner surface of the oxygen-containing gas supply member 12, or by forming irregularities on the outer surface of the oxygen-containing gas supply member 12, thereby increasing the surface area. Is easily transmitted to the oxygen-containing gas in the oxygen-containing gas supply member 12.

  In such a fuel cell module, by providing the heat insulating material 17 at a position facing the reforming section 6b of the oxygen-containing gas supply member 12, the temperature of the reforming section 6b is maintained high, and the reforming section 6b is improved. In addition to maintaining high quality performance, the heat of the central portion in the vertical direction of the cell stack 5 having a high temperature is transferred to the oxygen-containing gas in the oxygen-containing gas supply member 12 via the heat exchange promoting portion 12a, and the cell stack 5 In addition, the temperature at the center of the cell stack 5 can be lowered, the temperature at the lower end of the cell stack 5 can be increased, and the temperature of the cell stack 5 can be equalized in the vertical direction.

  In FIG. 5C, in order to maintain high reforming performance in the reforming unit 6b, not only FIG. 1 but also structures as shown in FIGS. 3 to 5 may be employed.

  FIG. 6 is an exploded perspective view showing an example of a fuel cell device in which the fuel cell module 1 and an auxiliary machine for operating the fuel cell module 1 are housed in an exterior case. In FIG. 6, a part of the configuration is omitted.

  The fuel cell device shown in FIG. 6 divides the inside of an exterior case composed of a column 54 and an exterior plate 55 into upper and lower portions by a partition plate 56, and a module storage chamber 57 for storing the above-described fuel cell module 1 on the upper side. The lower side is configured as an auxiliary equipment storage chamber 58 for storing auxiliary equipment for operating the fuel cell module 1. Auxiliaries stored in the auxiliary machine storage chamber 58 are not shown.

  In addition, the partition plate 56 is provided with an air circulation port 59 for allowing the air in the auxiliary machine storage chamber 58 to flow toward the module storage chamber 57, and a part of the exterior plate 55 constituting the module storage chamber 57 includes An exhaust port 60 for exhausting air in the module storage chamber 57 is provided.

  In such a fuel cell device, it is possible to obtain a fuel cell device with improved power generation efficiency by housing the module 1 as described above in an outer case.

  Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and improvements can be made without departing from the scope of the present invention.

  For example, the shape of the fuel cell 3 may be any of a flat plate type, a cylindrical type, a hollow flat plate type, and the like. In order to efficiently generate power in the fuel cell 3 (cell stack 5), it is preferable to use a hollow plate type fuel cell.

  Further, in the above embodiment, a description has been given of an embodiment in which one reformer 6 is disposed above two cell stacks 5. For example, one reformer is disposed above three or more cell stacks. You may do it.

  Furthermore, although the configuration in which two cell stacks 5 are arranged in one manifold 4 has been described, one cell stack may be arranged in one manifold, and three or more in one manifold. The cell stack may be arranged.

  Moreover, in the said form, although the one reformer 6 was provided in the fuel cell module 1, you may provide two or more. FIG. 7 shows a fuel cell module in which two cell stack devices provided with one reformer are arranged above the two cell stacks 5. In FIG. 7, the two reformers 6 are preferably arranged so that the vaporization section 6 a is positioned on the center side of the storage container 2. Thereby, the vaporization part 6a where temperature falls easily can be arrange | positioned in the center part of the storage container 2, and the heat equalization in the storage container 2 can be achieved.

1: Fuel cell module 2: Storage container 3: Fuel cell 5: Cell stack 6: Reformer 6a: Vaporizer 6b: Reformer 7: Reformed gas outlet tube 12: Oxygen-containing gas supply plate 12a: Heat exchange Promotion unit 13: water supply pipe 15: raw fuel gas supply pipe 17: heat insulating material F: combustion region

Claims (3)

A reformer is disposed above the cell stack, and the reformer reforms the raw fuel gas using a vaporizer that vaporizes water to generate water vapor and water vapor generated in the vaporizer. The oxygen-containing gas supply member has an oxygen-containing gas supply member that includes a reforming portion at a position facing each other and extends from between the vaporization portion and the reforming portion to a lower end portion of the cell stack. of which heat insulating material is provided in the reformer a position facing,
A fuel cell module , wherein a heat exchange promoting portion is provided at a portion of the oxygen-containing gas supply member located at a central portion in the vertical direction of the cell stack . A reformer is disposed above the cell stack, and the reformer reforms the raw fuel gas using a vaporizer that vaporizes water to generate water vapor and water vapor generated in the vaporizer. A reforming unit provided at a position facing each other, and having an oxygen-containing gas supply member extending from between the vaporization unit and the reforming unit to a lower end of the cell stack, and the reformer and the Between the upper end of the cell stack is a combustion region where the exhaust gas from the cell stack burns, and a heat insulating material is provided at a position facing the combustion region of the oxygen-containing gas supply member ,
A fuel cell module , wherein a heat exchange promoting portion is provided at a portion of the oxygen-containing gas supply member located at a central portion in the vertical direction of the cell stack . 3. A fuel cell device comprising: the fuel cell module according to claim 1 or 2; and an auxiliary machine for operating the fuel cell module, housed in an outer case.

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