JP2008135351A - Power generating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for a power generation device using a solid oxide fuel cell in which labor concerning a maintenance work of the power generation device can be alleviated, by lessening positions where sealing is necessary. <P>SOLUTION: The power generation device using a solid oxide fuel cell is provided with a cell-group housing chamber to house a group of fuel cells and an exhaust gas passage chamber which is formed around the cell-group housing chamber and through which exhaust gas exhausted from the cell-group housing chamber to an outside of the power generating device passes, and at least one portion of an outer surface of the cell-group housing chamber is not covered by the exhaust gas passage chamber. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus for generating electricity by a fuel cell using a solid oxide.

A fuel cell using a solid oxide has high efficiency and is expected to be suitable for a power generation apparatus of several kilowatts to several tens of kilowatts.
A fuel cell using a solid oxide requires a fuel gas and an aerobic gas (usually air). The fuel cell generates electric power by reacting a reformed gas obtained by reforming a fuel gas and an aerobic gas.

An example of a power generation device using a fuel cell using a solid oxide is disclosed in Patent Document 1.
In the power generation device of Patent Document 1, a cell group accommodation chamber that accommodates a fuel cell group is disposed at the center, and an exhaust gas passage chamber through which combustion exhaust gas discharged from the cell group accommodation chamber flows is surrounded on the outside. Further, an air passage chamber for supplying air to the cell group accommodation chamber surrounds the outside. Since the exhaust gas passage chamber surrounds the cell group accommodation chamber and the air passage chamber surrounds the outside thereof, the off-gas combustion heat and power generation heat can be used to maintain the cell group accommodation chamber at an appropriate power generation temperature. . The combustion heat of the off gas is about 900 ° C., and by using it, the power generation device can be made to be heat independent.

JP 2005-235526 A

  When the configuration is such that the cell group housing chamber is surrounded by the exhaust gas passage chamber as in Patent Document 1, the wiring of the power extraction line that takes out power from the fuel cell group to the outside of the power generation apparatus becomes a problem. The power lead-out line from the fuel cell group must pass through the wall surface between the cell group accommodation chamber and the exhaust gas passage chamber. It is necessary to provide a seal member on the wall surface through which the power lead-out line passes in order to prevent gas mixture. In the technology of Patent Document 1, the air passage chamber surrounds the outside of the exhaust gas passage chamber. In such a case, the power extraction line must not pass through the wall surface between the exhaust gas passage chamber and the air passage chamber. Don't be. Furthermore, the outer wall outside the air passage chamber must be penetrated. Therefore, in order to draw the power lead-out line to the outside of the power generation device, many places must be sealed.

  It is preferable that the number of places where sealing is required inside the power generation apparatus is as small as possible. When performing work such as replacement of the seal member as maintenance of the power generation device, various devices are densely arranged inside the power generation device, and it is difficult to replace the seal member without removing these devices. is there. As the portion where the power lead-out line penetrates the wall surface increases, the number of places where the seal is necessary increases, and the maintenance work of the power generation apparatus becomes complicated.

  When monitoring the temperature of the fuel cell during power generation, it is necessary to draw out a temperature detection line for outputting a signal from a temperature sensor in the cell group accommodation chamber to a control board outside the power generation device. Also for such temperature detection lines, the wall surface between the cell group accommodation chamber and the exhaust gas passage chamber, the wall surface between the exhaust gas passage chamber and the air passage chamber, and the outer wall outside the air passage chamber must be penetrated. Accordingly, the number of places to be sealed increases, and the maintenance work for the power generation apparatus becomes very complicated.

  The present invention provides a technology capable of reducing labor required for maintenance work of a power generation device by reducing the number of places where sealing is required in a power generation device using a solid oxide fuel cell. Objective.

  The present invention is embodied as a power generator using a solid oxide fuel cell. The power generator includes a cell group storage chamber that stores a fuel cell group, and an exhaust gas passage chamber that is formed around the cell group storage chamber and through which exhaust gas discharged from the cell group storage chamber to the outside of the power generation device passes. And at least part of the outer surface of the cell group accommodation chamber is not covered with the exhaust gas passage chamber.

In the above power generation device, an exhaust gas passage chamber is formed around a cell group accommodation chamber that is at a high temperature suitable for power generation in the fuel cell group, and the exhaust gas discharged from the cell group accommodation chamber is the cell group accommodation chamber. Flowing around. Since the exhaust gas discharged from the cell group storage chamber is at a high temperature, the heat dissipation from the cell group storage chamber can be suppressed and the cell group storage chamber can be maintained at a high temperature by adopting such a configuration.
Further, in the above power generation device, at least a part of the outer surface of the cell group accommodation chamber is not covered with the exhaust gas passage chamber, and therefore, there is no wall surface separating the cell group accommodation chamber and the exhaust gas passage chamber in this portion. Therefore, the number of places to be sealed can be reduced by adopting a configuration in which the power extraction line and the temperature detection line drawn from the cell group accommodation chamber to the outside of the power generation device penetrate the portion not covered with the exhaust gas passage chamber. it can. Maintenance work of the power generator can be easily performed.

  The power generation device is formed around the exhaust gas passage chamber, and further includes an aerobic gas passage chamber through which an aerobic gas supplied to the cell group accommodation chamber from the outside of the power generation device passes. The at least part of the outer surface of the chamber is preferably not covered by the exhaust gas passage chamber or the aerobic gas passage chamber.

In the above power generator, an aerobic gas passage chamber is formed around the exhaust gas passage chamber, and the aerobic gas supplied to the power generator is supplied to the cell group accommodation chamber after flowing around the exhaust gas passage chamber. . With such a configuration, the aerobic gas before being supplied to the cell group accommodation chamber can be preheated by the exhaust gas flowing through the exhaust gas passage chamber. Since the preheated aerobic gas is supplied to the cell group accommodation chamber, the cell group accommodation chamber can be maintained at a high temperature. In addition, since the temperature of the exhaust gas is reduced by preheating the aerobic gas, the exhaust gas discharged to the outside of the power generation apparatus can be cooled to an appropriate low temperature.
Further, in the above power generation device, at least a part of the outer surface of the cell group accommodation chamber is not covered by the exhaust gas passage chamber or the aerobic gas passage chamber. There are no wall surfaces for partitioning the exhaust gas passage chamber and the aerobic gas passage chamber. Therefore, the power extraction line and the temperature detection line drawn out from the cell group accommodation chamber to the outside of the power generation device are configured to pass through a portion that is not covered by the exhaust gas passage chamber or the aerobic gas passage chamber. It is possible to reduce the number of places to be processed. Maintenance work of the power generator can be easily performed.

  In the above power generation device, it is preferable that the at least part of the outer surface of the cell group accommodation chamber is at least a part of the side surface of the cell group accommodation chamber.

Of the outer surfaces of the cell group accommodation chamber, the upper surface is the highest temperature during power generation, and therefore it is desirable that the cell group accommodation chamber is covered with an exhaust gas passage chamber to prevent heat dissipation from the power generation device. In addition, because the bottom surface of the cell group storage chamber is generally formed with an inlet / outlet port for fuel gas, air, and combustion exhaust gas from the outside of the power generation device, the power extraction line and temperature detection line are drawn from the bottom surface of the cell group storage chamber. As a result, locations to be sealed are concentrated on the lower surface of the cell group housing chamber, which makes maintenance work difficult.
Like the power generator described above, by configuring at least a part of the side surface of the cell group housing chamber not to be covered with the exhaust gas passage chamber, it is possible to suppress excessive heat dissipation from the power generator, while suppressing the power extraction line and the temperature detection line. It is possible to reduce the number of parts to be sealed in order to draw out the outside of the apparatus. Moreover, since the location which should be sealed is not crowded, the maintenance operation | work of an electric power generating apparatus can be performed easily.

  In the above power generation device, the upper part of the cell group accommodation chamber communicates with the exhaust gas passage chamber, the lower part of the exhaust gas passage chamber communicates with the outside of the power generation device, and the bottom surface of the exhaust gas passage chamber becomes the aerobic gas passage chamber. Preferably it is not covered.

When the upper part of the cell group accommodation chamber communicates with the exhaust gas passage chamber and the lower part of the exhaust gas passage chamber communicates with the outside of the power generation device, the exhaust gas flows from the upper part of the cell group accommodation chamber to the upper part of the exhaust gas passage chamber, It flows downward in the exhaust gas passage chamber along the cell group accommodation chamber, and is discharged from the lower part of the exhaust gas passage chamber to the outside of the power generator. The exhaust gas flowing in the exhaust gas passage chamber is cooled by the aerobic gas flowing in the aerobic gas passage chamber. However, if the exhaust gas is excessively cooled by the aerobic gas, condensation occurs in the exhaust gas passage chamber and water is accumulated. If water accumulates in the exhaust gas passage chamber, the exhaust gas passage chamber may be blocked or the internal members may be corroded.
According to the above power generator, since the bottom surface of the exhaust gas passage chamber is not covered with the aerobic gas passage chamber, the exhaust gas from the cell group housing chamber is caused by the aerobic gas when flowing through the upper part or the side part of the exhaust gas passage chamber. Although it is cooled, it is not cooled by an aerobic gas when it flows through the lower part of the exhaust gas passage chamber. By adopting such a configuration, it is possible to suppress excessive cooling of the exhaust gas in the power generation device, to prevent dew condensation inside the power generation device, and to avoid problems caused by accumulation of water inside the power generation device.

  ADVANTAGE OF THE INVENTION According to this invention, in the electric power generating apparatus using a solid oxide fuel cell, the location which needs a seal | sticker can be reduced and the labor concerning the maintenance work of an electric power generating apparatus can be reduced.

Hereinafter, preferred embodiments of the present invention will be described.
(Mode 1) The fuel cell group forms a rod-shaped cell stack, an off-gas combustion section is provided near the tip of the cell stack, and the side surface along the direction in which the cell stack extends covers the exhaust gas passage chamber. I have not been told.

(First embodiment)
A first embodiment of a power generator embodying the present invention will be described with reference to the drawings.
As shown in FIGS. 1 to 3, the power generation unit 10 includes a cell group accommodation chamber 44 inside, and a plurality of cell stacks 14 are accommodated in the cell group accommodation chamber 44. The cell stack 14 is obtained by stacking a plurality of fuel battery cells 12 in a rod shape. The cell stack 14 extends from the horizontal manifold 24 disposed in the vicinity of the center of the cell group storage chamber 44 along the longitudinal direction of the cell group storage chamber 44 (left-right direction in FIG. 1). It is growing towards. As apparent from FIG. 2, a plurality of cell stacks 14 extend from the same horizontal manifold 24, and current collecting members 22 are interposed between the adjacent cell stacks 14. A pair of horizontal manifolds 24 are arranged at the same height in the cell group storage chamber 44, and from one horizontal manifold 24 to one side surface in the longitudinal direction of the cell group storage chamber 44 (for example, the right side surface in FIG. 1). The cell stack 14 extends toward the other side, and the cell stack 14 extends from the other horizontal manifold 24 toward the other side surface in the longitudinal direction of the cell group storage chamber 44 (for example, the left side surface in FIG. 1). In the cell group accommodation chamber 44, the pair of horizontal manifolds 24 and a plurality of cell stacks 14 extending therefrom are arranged so as to form a plurality of stages at different heights. An air supply member 16 that supplies air (an example of an aerobic gas) to the outer surface of the cell stack 14 is disposed below each cell stack 14. The air supply member 16 is a box-shaped member having air holes formed on the upper surface, and the direction in which the cell stack 14 extends and the direction in which the air supply member 16 extends intersect each other.

As shown in FIG. 4, the cross section of each fuel cell 12 is elliptical, and a little more than half of the circumferential surface of the fuel electrode 12a formed in the elliptical column shape is covered with the solid electrolyte layer 12b, and the remaining circumferential surface Is covered with the interconnector 12d, and the oxygen electrode 12c covers the outside of the solid electrolyte layer 12b. A plurality of reformed gas passages 20 penetrating in the direction in which the cell stack 14 extends (the vertical direction in FIG. 4) are formed in parallel inside the fuel electrode 12a. When the reformed gas is supplied to the reformed gas passage 20, the fuel battery cell 12 generates electric power by reacting the supplied reformed gas with the surrounding aerobic gas.
The fuel electrode 12a is porous and is made of nickel / YSZ cermet (mixed sintered body) whose main component is nickel (Ni). The solid electrolyte layer 12b is dense and is made of a mixture obtained by adding yttria (Y ₂ O ₃ ) to zirconia (ZrO ₂ ). The oxygen electrode 12c is porous and is made of LSM (La _1-x Sr _x MnO ₃ ), which is a perovskite oxide. The interconnector 12d is made of a conductive ceramic.
The current collecting member 22 is a conductive metal member folded in a bellows shape. Regarding the two adjacent cell stacks 14, the oxygen electrode 12c of the fuel cell 12 of one cell stack 14 and the fuel electrode 12a of the fuel cell 12 of the other cell stack 14 connect the current collecting member 22 and the interconnector 12d. Is electrically connected. Since the current collecting member 22 is formed in a bellows shape, it does not prohibit air from passing between adjacent cell stacks 14.

  As shown in FIGS. 1 and 2, a pair of vertical manifolds 29 are arranged in the cell group accommodation chamber 44, and a plurality of horizontal manifolds 24 extend from one vertical manifold 29 at different heights. The vertical manifold 29 extends in the cell group accommodation chamber 44 in the vertical direction, and the horizontal manifold 44 extends in the cell group accommodation chamber 44 in the horizontal direction. The horizontal manifold 24 and the vertical manifold 29 have flow paths through which the reformed gas flows. The reformed gas supplied from the reformer 18 is supplied to the vertical manifold 29 via the reformed gas supply pipe 25. , And supplied to each cell stack 14 via each horizontal manifold 24. The reformed gas passage 20 is opened at the tip of each cell stack 14, and the reformed gas (off gas) that has not been consumed for power generation is released. A spark electrode (not shown) is provided near the tip of each cell stack 14, and when the spark electrode sparks, off gas flowing out from the tip of each cell stack 14 reacts with the surrounding air. Burn.

  A baffle plate 52 extends horizontally from the air supply member 16 toward the reformer 18. The combustion gas in which the off-gas is burned near the tip of the cell stack 14 is guided toward the reformer 18 by the baffle plate 52 directly above, and heats the reformer 18.

  The reformer 18 is disposed at a position facing the tip of each cell stack 14. Inside the reformer 18, a mixed gas obtained by mixing fuel gas and water vapor is supplied from the mixer 130, and the reformer 18 reforms the mixed gas using the combustion heat of the off gas. In the reformer 18, a flat box-shaped casing made of metal and a meandering path are formed, and the reforming catalyst is filled in the path. The mixed gas is reformed into a reformed gas composed of hydrogen and carbon monoxide by the reforming catalyst while passing through the reformer 18. This reforming reaction involves heat absorption, and in the power generation unit 10 of this embodiment, the combustion heat of off-gas is used for the reforming reaction. The reformed gas that has been reformed by the reformer 18 is distributed from the reformed gas supply pipe 25 to each horizontal manifold 24 via the vertical manifold 29, and from the horizontal manifold 24 to the reformed gas passage 20 of each cell stack 14. Is sent to. The pair of reformers 18 have both reformed gas outlet portions connected to each other by a crossover pipe 28 to ensure a balanced reformed gas outlet pressure.

  An exhaust gas passage chamber 46 is provided outside the cell group accommodation chamber 44. The cell group storage chamber 44 has a box shape with an open top, and the exhaust gas passage chamber 46 is provided so as to surround the bottom surface of the cell group storage chamber 44, both side surfaces in the longitudinal direction, and the open top. It has been. Exhaust gas passage chambers 46 are not formed on both side surfaces of the cell group housing chamber 44 in the short direction (vertical direction in FIG. 2). Combustion exhaust gas discharged along with off-gas combustion near the tip of the cell stack 14 heats the reformer 18, then flows upward in the cell group accommodation chamber 44, and flows into the upper portion of the exhaust gas passage chamber 46. To do. The combustion exhaust gas that has flowed into the upper part of the exhaust gas passage chamber 46 sequentially passes through the side portion and the lower part of the exhaust gas passage chamber 46 in the longitudinal direction (left and right direction in FIG. 1), and communicates with the lower part of the exhaust gas passage chamber 46. It is discharged from 60 to the outside.

  Fins 56 are attached to the sides of the exhaust gas passage chamber 46 in the longitudinal direction. The fin 56 is formed by folding a long metal plate member into a substantially bellows shape. Although not shown, the upper and lower fins 56 are attached with a pitch shifted by half. Since the fins 56 are attached in this way, a plurality of thin prismatic passages extending in the vertical direction are formed in the longitudinal sides of the exhaust gas passage chamber 46.

  As shown in FIGS. 1 and 3, the cell group accommodation chamber 44 is lifted up in the exhaust gas passage chamber 46 by a fixing wall 36a. A plurality of holes 36b are formed in the fixing wall 36a so that the combustion exhaust gas can freely flow. The gap immediately below the cell group accommodation chamber 44 forms the lower part of the exhaust gas passage chamber 46. The exhaust gas passage chamber 46 communicates with the outside through an exhaust gas exhaust pipe 60, and combustion exhaust gas is exhausted through the exhaust gas exhaust pipe 60.

  The mixer 130 is disposed below the exhaust gas passage chamber 46 and is heated by the combustion exhaust gas flowing through the exhaust gas passage chamber 46. A fuel gas supply pipe 62 and a water supply pipe 64 are connected to the mixer 130, and fuel gas and water are supplied from the outside of the power generation unit 10. The water supplied to the mixer 130 evaporates into water vapor and is mixed with the fuel gas. The mixed gas of fuel gas and water vapor is preheated while passing through the mixer 130. The preheated mixed gas is supplied to the reformer 18 via the mixed gas supply pipe 27.

  An air passage chamber 48 is provided outside the exhaust gas passage chamber 46. The air passage chamber 48 is provided so as to surround both the side surfaces in the longitudinal direction of the exhaust gas passage chamber 46 and the upper surface. A side portion of the air passage chamber 48 in the longitudinal direction (left-right direction in FIG. 1) communicates with the air introduction tube 34 at the lower end, and the air introduced from the outside by the air introduction tube 34 is the longitudinal direction of the air passage chamber 48. It flows upward in the direction side and flows into the air supply pipe 50 from the upper part of the air passage chamber 48.

  Fins 54 are attached to the sides of the air passage chamber 48 in the longitudinal direction. The fins 54 are formed by folding a long metal plate member in a lateral direction into a substantially bellows shape. Although not shown, the upper and lower fins 54 are attached with a pitch shifted by half. Since the fins 54 are attached in this way, a plurality of thin prismatic passages extending in the vertical direction are formed on the side portions in the longitudinal direction of the air passage chamber 48.

  The upper part of the air passage chamber 48 communicates with the air supply pipe 50. The air supply pipe 50 is made of metal, and extends in the cell group accommodation chamber 44 in the vertical direction as shown in FIGS. 1 and 3, and the upper end opens to the air passage chamber 48. The air flowing into the air supply pipe 50 from the air passage chamber 48 is distributed to each air supply member 16 and blown from the upper surface of the air supply member 16 toward the cell stack 14 in the immediate upper part.

  A heat insulating outer wall 40 is formed outside the air passage chamber 48. The outer wall 40 is formed so as to cover all six surfaces of the power generation unit 10. The outer wall 40 is in contact with the air passage chamber 48 at the upper portion and the longitudinal side portion of the power generation unit 10. At the bottom of the power generation unit 10, the outer wall 40 is in contact with the exhaust gas passage chamber 46. The outer wall 40 is in contact with the cell group accommodation chamber 44 at the lateral side of the power generation unit 10.

  The cell group accommodation chamber 44 has the highest temperature, the exhaust gas passage chamber 46 has the second highest temperature, and the air passage chamber 48 has the third highest temperature. The highest temperature cell group accommodation chamber 44 is surrounded by the second highest temperature exhaust gas passage chamber 46, and the outside is surrounded by the third highest temperature air passage chamber 48. Therefore, the temperature in the cell group housing chamber 44 that accommodates the cell stack 14 and the reformer 18 is maintained at 800 to 850 ° C., which is an appropriate temperature for power generation, only by heat generated with power generation and combustion heat of off-gas. be able to. Can heat independent.

As shown in FIG. 2, a power lead-out line 100 for taking out the generated power from the outermost cell stack 14 in the group of cell stacks 14 connected to each other by the current collecting member 22 extends. The power lead-out line 100 extends from the side surface in the short direction of the cell group housing chamber 44 through the outer wall 40 to the control board 110 provided outside. The power lead-out line 100 is a platinum wire, and the periphery is protected by an insulator tube 102.
As shown in FIG. 5, a stepped insulator tube 104 is inserted from the outside of the outer wall 40 into a portion where the power extraction line 100 penetrates the outer wall 40, and the power extraction line 100 is placed inside the stepped insulator tube 104. It is drawn through the formed hole. The stepped insulator tube 104 is inserted so as to sandwich the seal packing 106, and is fixed to the outer wall 40 by a fixing plate 108 from the outside. The fixing plate 108 is screwed from the outside of the outer wall 40.

As shown in FIG. 2, each stage of the cell stack 14 is provided with a sheath thermocouple 120 that detects the temperature of the cell stack 14. The sheath thermocouple 120 includes a thermocouple wire inside the sheath. The temperature measuring unit 122 at the tip of the sheath thermocouple 120 is disposed so as to be located immediately above the center of the stage of the cell stack 14.
As shown in FIG. 5, the sheath thermocouple 120 is inserted from the outside of the outer wall 40 and penetrates the outer wall 40. The sheath thermocouple 120 includes a flange 124, and the flange 124 is fixed to the outer wall 40 by the fixing plate 108 with the seal packing 126 sandwiched from the outside of the outer wall 40. The two terminals 128 that output the detected values of the sheath thermocouple 120 are connected to the control board 110 outside the power generation unit 10.

  FIG. 6 schematically shows a portion where the power extraction line 100 and the sheath thermocouple 120 corresponding to each stage of the cell stack 14 penetrate the outer wall 40. As shown in FIG. 6, the power lead-out line 100 is drawn from each stage of the cell stack 14 to the control board 110, and the power of each stage is taken out separately. By adopting such a configuration, the electric power taken out from each stage of the cell stack 14 can be separately controlled by the control board 110. The sheath thermocouple 120 is also drawn from each stage of the cell stack 14 to the control substrate 110, and the temperature of the cell stack 14 at each stage is separately detected. With such a configuration, the state of each stage of the cell stack 14 can be monitored in detail by the control board 110.

  In the power generation unit 10 of the present embodiment, both side surfaces in the short direction of the cell group accommodation chamber 44 are not covered with the exhaust gas passage chamber 46 or the air passage chamber 48. By adopting such a configuration, the power lead-out line 100 and the sheath thermocouple 120 can be pulled out from the side surface in the short direction of the cell group housing chamber 44 without penetrating the wall surface other than the outer wall 40. For this reason, it suffices to seal only the portion where the power lead-out line 100 and the sheath thermocouple 120 penetrate the outer wall 40, and the number of portions to be sealed is minimized. Maintenance work of the power generation unit 10 can be easily performed.

  Hereinafter, the power generation operation of the power generation unit 10 will be described. Water and fuel gas supplied to the power generation unit 10 are preheated and mixed in the mixer 130, and are sent to the reformer 18 from the mixed gas supply pipe 27. The mixed gas sent to the reformer 18 is reformed into a reformed gas containing hydrogen and carbon monoxide, and passes through the vertical manifold 29 and the horizontal manifold 24 to the reformed gas passage 20 of each cell stack 14. Sent.

  The air sent from the air introduction pipe 34 is sent to the air passage chamber 48, passes through the fins 54, reaches the upper portion, flows above the air passage chamber 48, and flows into the air supply pipe 50. The preheated air that has flowed into the air supply pipe 50 moves downward, is distributed to the air supply members 16 of each stage, and is blown from the air supply port above the air supply member 16 to the outer peripheral surface of the cell stack 14 immediately above. It is done.

  The air blown to the cell stack 14 rises upward or obliquely upward, and is distributed over the entire lower side of the cell stack 14. Oxygen is ionized, passes through the solid electrolyte layer 12b, reaches the fuel electrode 12a, reacts with hydrogen or carbon monoxide, and generates a potential difference between the oxygen electrode 12c and the fuel electrode 12a. That is, it generates electricity.

When, for example, 80% of the reformed gas supplied to the cell stack 14 is used for power generation, 20% of the reformed gas (off-gas) not used for power generation flows out from the tip of the cell stack 14. Further, when, for example, 20% of the air supplied to the cell stack 14 is used for power generation, 80% of the air that is not used for power generation passes through the gap of the current collecting member 22 of the cell stack 14. This air is guided to the front end side of the cell stack 14 along the bottom surface of the air supply member 16 directly above and the baffle plate 52.
The spark electrode disposed in the vicinity of the tip of the cell stack 14 undergoes spark discharge, so that the off gas reacts with air and burns. The combustion heat of the off gas is absorbed by the reformer 18 and used for the reforming reaction.

The environmental temperature at which the electrochemical reaction of the fuel cell 12 proceeds efficiently is a high temperature of about 800 ° C. If this environmental temperature decreases, the power generation efficiency decreases. Therefore, it is necessary to preheat the air supplied to the cell stack group 14 in order to obtain an environmental temperature of about 800 ° C.
The combustion exhaust gas rising in the cell group storage chamber 44 flows into the upper portion of the exhaust gas passage chamber 46. The combustion exhaust gas flowing into the upper portion of the exhaust gas passage chamber 46 flows into the side portion of the exhaust gas passage chamber 46, flows downward through a plurality of narrow prismatic passages extending in the vertical direction, and flows into the lower portion of the exhaust gas passage chamber 46. . The combustion exhaust gas flowing into the lower part of the exhaust gas passage chamber 46 is discharged to the outside from the exhaust gas exhaust pipe 60.
At this time, the air introduced from the air introduction pipe 34 flows into the air passage chamber 48 and passes upward through a plurality of thin prismatic passages extending in the vertical direction. Heat exchange is performed between the combustion exhaust gas passing through the exhaust gas passage chamber 46 and the air passing through the air passage chamber 48. The heat exchange rate is further enhanced by the fins 56 provided on the side of the exhaust gas passage chamber 46 and the fins 54 provided on the side of the air passage chamber 48. By this heat exchange, the air supplied to the cell stack group 14 can be preheated. Since the preheated air can be supplied to the cell stack group 14, the cell stack group 14 can be maintained at a power generation appropriate temperature.
The flue gas is cooled by preheating the air. The cooled combustion exhaust gas is sufficiently hot to preheat the mixed gas of fuel gas and water vapor in the mixer 130, and not so hot as to deposit carbon from the fuel gas. By supplying the premixed mixed gas to the reformer 18 and burning off-gas in the vicinity of the reformer 18, the entire reformer 18 can be maintained at an appropriate reforming temperature. The power generation unit 10 according to the present embodiment can be heat independent.

If the combustion exhaust gas flowing through the exhaust gas passage chamber 46 is excessively cooled, condensation occurs from the combustion exhaust gas, and water accumulates in the lower part of the exhaust gas passage chamber 46. If water accumulates in the exhaust gas passage chamber 46, the exhaust gas passage chamber 46 may be blocked or the internal equipment may be corroded.
In the power generation unit 10 of the present embodiment, since the air passage chamber 48 does not cover the bottom surface of the exhaust gas passage chamber 46, the combustion exhaust gas is not excessively cooled in the lower portion of the exhaust gas passage chamber 46. Thereby, the dew condensation of the combustion exhaust gas in the exhaust gas passage chamber 46 is suppressed, and the trouble due to the accumulation of water inside the apparatus is avoided.

(Modification of the first embodiment)
FIG. 7 shows a cross section of a power generation unit 200 which is a modification of the power generation unit 10 of the first embodiment.
In the power generation unit 200, the exhaust gas passage chamber 46 is provided so as to surround the bottom surface of the cell group storage chamber 44, both side surfaces in the longitudinal direction, both side surfaces in the lateral direction, and the opened top. The central portion 202 on both side surfaces of the cell group storage chamber 44 in the short direction (vertical direction in FIG. 7) is not covered with the exhaust gas passage chamber 46, and the peripheral portion 204 excluding the central portion 202 is the exhaust gas passage chamber 46. Covered with. The exhaust gas passage chamber 46 formed outside the peripheral portion 204 on both side surfaces in the short direction of the cell group storage chamber 44 forms a flow path extending in the vertical direction of the power generation unit 200 (the vertical direction in FIG. 2). The fin 56 is formed inside.

  The air passage chamber 48 is provided so as to surround both side surfaces of the exhaust gas passage chamber 46 in the longitudinal direction, both side surfaces of the short side direction, and the upper surface. The air passage chambers 48 formed on both side surfaces of the exhaust gas passage chamber 46 in the short direction form a flow path extending in the vertical direction of the power generation unit 200 (perpendicular to the paper surface of FIG. 2), and the fins 54 are formed inside. Is formed. Central portions 202 on both side surfaces in the short direction of the cell group housing chamber 44 are not covered by the exhaust gas passage chamber 46 or the air passage chamber 48.

  In the power generation unit 200, the central portions 202 on both side surfaces in the short direction of the cell group housing chamber 44 are not covered by the exhaust gas passage chamber 46 or the air passage chamber 48, and are directly covered by the outer wall 40. Yes. By adopting a configuration in which the power lead-out line 100 and the sheath thermocouple 120 are drawn out so as to penetrate the central portions 202 on both side surfaces in the short direction, the number of places to be sealed can be minimized. Maintenance work of the power generation unit 200 can be easily performed.

As mentioned above, although embodiment of this invention was described in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. The technology illustrated in this specification or the drawings achieves a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

The figure which shows the longitudinal cross-section of the electric power generation unit 10. FIG. The figure which shows the cross section of the electric power generation unit 10 (II-II sectional view taken on the line of FIG. 1). The figure which shows another longitudinal cross-section of the electric power generation unit 10 (III-III sectional view taken on the line of FIG. 1). The figure which shows the cross section of the fuel battery cell 12 typically. The figure which shows typically the cross section of the part through which the electric power extraction line 100 and the sheath thermocouple 120 penetrate the wall surface 40. FIG. The figure which shows typically the part through which the electric power extraction line 100 and the sheath thermocouple 120 penetrate the wall surface 40. FIG. The figure which shows the cross section of the electric power generation unit 200. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Power generation unit 12 ... Fuel cell 12a ... Fuel electrode 12b ... Solid electrolyte layer 12c ... Oxygen electrode 12d ... Interconnector 14 ... Cell stack 16 ... ..Air supply member 18 ... Reformer 20 ... Reformed gas passage 22 ... Current collecting member 24 ... Horizontal manifold 25 ... Reformed gas supply pipe 27 ... ··· Mixed gas supply pipe 28 ··· Crossover pipe 29 ··· Vertical manifold 34 ··· Air inlet tube 36a · Fixing wall 36b · Fixing wall hole 40 · · · Outer wall 44 ... Cell group accommodation chamber 46 ... Exhaust gas passage chamber 48 ... Air passage chamber 50 ... Air supply pipe 52 ... Baffle plate 54 ... Fin 56 ...・ Fin 60... Exhaust gas discharge pipe 62... Fuel gas supply pipe 64. Supply pipe 100 ... Power extraction line 102 ... Insulator pipe 104 ... Stepped insulator pipe 106 ... Seal packing 108 ... Fixed plate 110 ... Control board 120 ... Sheath thermocouple 122. ..Temperature measuring unit 124 ... flange 126 ... seal packing 128 ... terminal 130 ... mixer 200 ... power generation unit 202 ... center of both side surfaces in the short direction of the cell group housing chamber Part 204: Peripheral part of both side surfaces in the short direction of the cell group storage chamber

Claims (4)

A power generation device using a solid oxide fuel cell;
A cell group storage chamber for storing fuel cell groups;
It is formed around the cell group storage chamber, and includes an exhaust gas passage chamber through which exhaust gas discharged from the cell group storage chamber to the outside of the power generation device passes.
At least a part of the outer surface of the cell group housing chamber is not covered with the exhaust gas passage chamber. It is formed around the exhaust gas passage chamber, and further includes an aerobic gas passage chamber through which the aerobic gas supplied to the cell group housing chamber from the outside of the power generation device passes.
2. The power generator according to claim 1, wherein the at least part of the outer surface of the cell group housing chamber is not covered by the exhaust gas passage chamber or the aerobic gas passage chamber.   The power generator according to claim 1 or 2, wherein the at least part of the outer surface of the cell group accommodation chamber is at least a part of a side surface of the cell group accommodation chamber. The upper part of the cell group storage chamber communicates with the exhaust gas passage chamber,
The lower part of the exhaust gas passage chamber communicates with the outside of the power generator,
The power generator according to claim 3, wherein the bottom surface of the exhaust gas passage chamber is not covered with the aerobic gas passage chamber.

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