JP5383550B2 - Fuel cell module - Google Patents

Description

  The present invention relates to a fuel cell module that houses a plurality of fuel cells.

  In recent years, as a next-generation energy, a cell stack formed by arranging a plurality of fuel cells that can obtain electric power using fuel gas (hydrogen-containing gas) and air (oxygen-containing gas) is stored in a storage container. Various fuel cell modules and fuel cell devices in which the fuel cell module is housed in an outer case have been proposed (see, for example, Patent Document 1).

  In the fuel cell module described in Patent Document 1, a cell stack formed by arranging a plurality of fuel cell cells in a row in a power generation chamber provided in a rectangular parallelepiped storage container including a double wall of an inner wall and an outer wall. A reformer for generating fuel gas to be supplied to the fuel cell is arranged above the cell stack, and an oxygen-containing gas is supplied to the fuel cell between the cell stacks on the inner wall. The plate-like oxygen-containing gas introduction member for the purpose is arranged to hang down. In addition, a wall constituting the power generation chamber is provided inside the inner wall, a space between the wall and the inner wall serves as a flow path for exhaust gas exhausted from the power generation chamber, and an oxygen-containing gas is introduced between the inner wall and the outer wall. An oxygen-containing gas flow path is provided for supplying the oxygen-containing gas to the fuel battery cell via the member.

JP 2007-59377 A

  By the way, in the fuel cell device, in addition to high power generation efficiency, particularly downsizing is required.

  Therefore, an object of the present invention is to provide a fuel cell module that has high power generation efficiency and can be miniaturized.

  The fuel cell module of the present invention is a state in which a plurality of columnar fuel cell cells, each of which is formed by stacking a fuel electrode layer, a solid electrolyte layer, and an oxygen electrode layer in this order in a cylindrical storage container. A cell stack that is arranged in a circular shape and electrically connected, a manifold having a circular planar shape for fixing a lower end of the fuel cell and supplying fuel gas to the fuel cell, and A planar reformer disposed above the cell stack for generating the fuel gas to be supplied to the fuel cell, and the reformer has an entire side wall of the storage container. And between the reformer and the cell stack is a combustion section for burning surplus fuel gas that was not used in power generation of the fuel cell, Side of the combustion part On the side wall of definitive said container, characterized in that it comprises an exhaust portion for discharging the exhaust gas after combustion in the combustion section.

  In such a fuel cell module, a reformer having a circular planar shape is disposed in a cylindrical container so that the entire side surface is in contact with the side wall of the storage container, and a cell stack disposed below the reformer. It is a combustion part for burning excess fuel gas in the space, and an exhaust part for discharging exhaust gas is provided on the side wall of the storage container on the side thereof, so that a compact fuel cell module can be obtained. The fuel cell module can be reduced in size.

  In addition, since the planar shape of the reforming part and the manifold is circular, it is possible to suppress the occurrence of local thermal stress and temperature difference in the reforming part and the manifold, and to improve durability.

  In the fuel cell module of the present invention, a raw fuel introduction pipe for introducing raw fuel into the reformer is connected to a central portion of the upper surface of the reformer, and a bottom central portion of the reformer It is preferable that the upper surface central part of the manifold is connected by a fuel gas supply pipe.

  In such a fuel cell module, since the raw fuel introduction pipe is connected to the center of the upper surface of the reformer, the raw fuel can be efficiently introduced into the reformer, and the fuel gas supply pipe is Since the bottom center of the reformer is connected to the center of the top surface of the manifold, the fuel gas supplied to the manifold can be efficiently supplied to each fuel cell, improving the power generation efficiency. Can do.

  In the fuel cell module of the present invention, the reformer is a reformer that performs steam reforming with raw fuel and water, and vaporizes the water disposed above the reformer. And a reforming unit that is disposed below the reformer and performs steam reforming with the raw fuel and the steam vaporized in the vaporizing unit, and the vaporizing unit, A spiral vaporization passage for flowing the raw fuel introduced from the raw fuel introduction pipe to the central portion toward the peripheral side is provided, and the reforming portion supplies the peripheral portion from the vaporization passage. It is preferable that a spiral reforming section flow path for flowing the raw fuel directed toward the center section is provided.

  In such a fuel cell module, since the vaporizer disposed above the reformer and the reformer disposed below the reformer are provided, the cell stack formed by the endothermic reaction in the vaporizer is provided. A temperature drop can be suppressed, and a reduction in power generation efficiency can be suppressed.

  In addition, the vaporization section includes a spiral vaporization section flow path for flowing the raw fuel introduced from the raw fuel introduction pipe to the central section toward the peripheral side, and the reforming section is supplied to the peripheral side. Since the spiral reforming part flow path for flowing the raw fuel toward the center part side is provided, the length of the vaporization part flow path and the reforming part flow path can be increased, and the raw fuel can be efficiently used. It can be reformed to fuel gas.

  In the fuel cell module of the present invention, an oxygen-containing gas introduction portion having a circular planar shape for supplying oxygen-containing gas to the fuel cells is disposed above the reformer, and the storage container An oxygen-containing gas supply that extends in the vertical direction, has an upper end connected to the center of the bottom surface of the oxygen-containing gas introduction unit, and supplies the oxygen-containing gas to the lower end side of the fuel cell to the lower end side It is preferable that an oxygen-containing gas supply pipe having a port is provided and the fuel gas supply pipe is disposed inside the oxygen-containing gas supply pipe.

  In such a fuel cell module, since the oxygen-containing gas introduction part having a circular planar shape is provided above the reformer, the oxygen-containing gas flowing through the oxygen-containing gas introduction part by heat transmitted from the reformer. The temperature can be raised. In addition, since the fuel gas supply pipe is disposed inside the oxygen-containing gas supply pipe extending vertically in the storage container, the oxygen-containing gas flowing in the oxygen-containing gas supply pipe and the fuel flowing in the fuel gas supply pipe Heat can be exchanged efficiently with the gas, and the temperature of the oxygen-containing gas supplied to the lower end of the fuel cell can be raised. Thereby, the temperature distribution in the vertical direction of the fuel cell can be made closer to the uniform, and a fuel cell module with improved power generation efficiency can be obtained.

The fuel cell module of the present invention further includes a partition wall extending in the vertical direction between the cell stack and the side wall of the storage container, and the space between the side wall of the storage container and the partition wall is the fuel cell. An oxygen-containing gas introduction part for supplying an oxygen-containing gas to the cell is provided, and an oxygen-containing gas introduction port for introducing the oxygen-containing gas into the oxygen-containing gas introduction part from the outside is provided on the side wall of the storage container. It is preferable that an oxygen-containing gas supply port for supplying the oxygen-containing gas to the lower end portion side of the fuel cell is provided on the lower end portion side of the partition wall.

  In such a fuel cell module, a partition wall extending in the vertical direction is provided between the cell stack and the side wall of the storage container, and oxygen introduced through the oxygen-containing gas inlet provided in the side wall of the storage container is provided between the partition walls. The temperature of the oxygen-containing gas flowing through the oxygen-containing gas introduction portion can be increased efficiently by using the containing gas introduction portion and the oxygen-containing gas supply port provided on the lower end side of the partition wall, and the fuel cell The length in the vertical direction of the module can be shortened and the module can be miniaturized.

  In the fuel cell module of the present invention, a planar reformer is disposed in a cylindrical storage container so that the entire side surface is in contact with the side wall of the storage container, and the cell stack disposed below the reformer It is a combustion part for burning excess fuel gas in the space, and an exhaust part for discharging exhaust gas is provided on the side wall of the storage container on the side thereof, so that a compact fuel cell module can be obtained. The fuel cell module can be reduced in size.

It is an external appearance perspective view which shows an example of the fuel cell module of this invention. FIG. 2 is a cross-sectional view schematically showing the fuel cell module shown in FIG. 1. (A) is an external perspective view showing the reforming part, cell stack, and manifold that constitute the fuel cell module shown in FIG. 2, and (b) is the reforming part that constitutes the fuel cell module shown in FIG. FIG. 2 is an external perspective view showing an extracted fuel gas supply pipe and a manifold. It is sectional drawing which extracts and shows the cell stack and fuel gas supply pipe in the AA line cross section shown in FIG. FIG. 2 shows a part of each of a reforming part and a raw fuel introduction pipe constituting the fuel cell module of the present invention, and (a) is an exploded perspective view showing a part of a vaporization part and a raw fuel introduction pipe. It is a figure, (b) is the BB sectional view taken on the line in (a). FIG. 2 shows a part of another example of a reforming part and a fuel gas supply pipe constituting the fuel cell module of the present invention, and (a) is an exploded view showing a part of the reforming part and the fuel gas supply pipe. It is a perspective view, (b) is the CC sectional view taken on the line in (a). It is sectional drawing which shows schematically another example of the fuel cell module of this invention.

  FIG. 1 is an external perspective view showing an example of a fuel cell module 1 (hereinafter sometimes referred to as a module) of the present invention. In the following drawings, the same numbers are assigned to the same members.

  A module 1 shown in FIG. 1 includes a cylindrical storage container 2 that is hollow inside. Note that a raw fuel introduction pipe 3 for introducing raw fuel from the outside, which will be described later, and an oxygen-containing gas introduction pipe 4 for introducing an oxygen-containing gas from the outside are connected to the upper surface of the storage container 2. . Hereinafter, the module 1 will be described with reference to FIG.

  FIG. 2 is a cross-sectional view schematically showing the module 1 shown in FIG. In the storage container 2, an outer frame of the storage container 2 is formed by the outer wall 5, and a power generation chamber 8 having a circular planar shape for storing the fuel cell 9 (cell stack device) is formed therein.

In the power generation chamber 8, a cell stack in which a plurality of fuel cells 9 are arranged, a manifold 10 having a circular planar shape for supplying fuel gas to the fuel cells 9, and a cell stack (fuel cell) A reformer 7 having a circular planar shape for reforming the raw fuel (natural gas, kerosene, etc.) supplied from the raw fuel introduction pipe 3 and generating fuel gas is disposed above the cell 9). Has been. The reformer 7 is disposed such that the entire side surface is in contact with the side wall of the storage container 2. In the cell stack, the lower end portion of the fuel battery cell 9 constituting the cell stack is fixed to the manifold 10 with an insulating adhesive such as a glass sealing material. The raw fuel introduction pipe 3 is inserted from the outside of the storage container 2 and connected to the center of the upper surface of the reformer 7, and the upper end is configured as a raw fuel gas inlet 20 for inflowing the raw fuel gas. Has been. The plurality of fuel cells 9 are arranged in a circular shape in accordance with the shape of the power generation chamber 8.

  In the reformer 7 shown in FIG. 2, when performing an efficient steam reforming reaction, a vaporization unit 11 for vaporizing water supplied from the outside is disposed on the upper side in the reformer 7, and reforming is performed. A reforming unit 12 including a reforming catalyst for reforming the raw fuel is disposed below the inside of the vessel 7. As the reforming catalyst, generally known reforming catalysts can be used. In addition, the water supply pipe for supplying water for performing the steam reforming reaction in the reformer 7 may be provided as a double pipe in addition to sharing the raw fuel introduction pipe 3 or separately. it can. In the following description, the raw fuel introduction pipe 3 is shared.

  Further, above the reformer 7, the oxygen-containing gas introduction section 6 having a circular planar shape for introducing the oxygen-containing gas supplied from the outside through the oxygen-containing gas introduction pipe 4 into the power generation chamber 8 is provided. Is arranged. The oxygen-containing gas introduction unit 6 is also disposed so that the entire side surface is in contact with the side wall of the storage container 2, and the upper surface thereof is disposed in contact with the upper surface of the storage container 2.

  Hereinafter, the flow of the fuel gas and the oxygen-containing gas in the module 1 shown in FIG. 2 will be described.

  The oxygen-containing gas introduced into the oxygen-containing gas introduction section 6 from the outside via the oxygen-containing gas introduction pipe 4 flows through the oxygen-containing gas supply pipe 14 and supplies oxygen-containing gas provided on the lower end side. It is supplied into the power generation chamber 8 through the port 15.

  On the other hand, the raw fuel introduced from the raw fuel introduction pipe 3 (and water when steam reforming is performed) is supplied to the vaporization unit 11 from the raw fuel introduction port 16. In the vaporization unit 11, water supplied from the outside is vaporized into water vapor and mixed with raw fuel (hereinafter, a mixture of raw fuel and water vapor is referred to as raw fuel gas). In the vaporization unit 11 shown in FIG. 2, the raw fuel gas flows in the left-right direction, and flows through the raw fuel gas outlet 21 to the reforming unit 12 having a reforming catalyst therein.

  The raw fuel gas that has flowed to the reforming unit 12 is reformed by the reforming catalyst, and fuel gas is generated. The generated fuel gas flows into the fuel gas supply pipe 3 from the fuel gas inlet 17 and flows into the manifold 10. The fuel gas that has flowed into the manifold 10 flows through a fuel gas flow path (see FIG. 4) provided inside the fuel battery cell 9, and oxygen-containing gas (air or the like) supplied from the oxygen-containing gas supply port 15. Power generation is performed. The fuel gas supply pipe 3 is connected to the center of the bottom surface of the reformer 7 (the reforming unit 12) and the center of the top surface of the manifold 10.

  Excess fuel gas and oxygen-containing gas that were not used for power generation burn in the combustion section 22 between the reformer 7 and the fuel cell 9 (cell stack), and the exhaust gas after combustion burns. The gas is exhausted to the outside through the exhaust gas exhaust port 18 provided on the side wall of the storage container 2 on the side of the portion 22. In the module 1 shown in FIG. 2, the exhaust gas exhaust port 18 corresponds to an exhaust part. Here, the temperature of the reformer 7 can be increased by burning excess fuel gas and oxygen-containing gas that have not been used for power generation above the fuel cell 9, and the reformer 7 Thus, the reforming reaction can be performed efficiently.

  In addition, the site | part located in the vaporization part 11 among the raw fuel introduction pipes 3 becomes the shape of a double pipe with the oxygen-containing gas supply pipe 14, and the fuel gas supply pipe 13 is arranged in the oxygen-containing gas supply pipe 14. The formed part has a double tube shape. The oxygen-containing gas supply pipe 14 has an upper end connected to the central portion of the bottom surface of the oxygen-containing gas introduction portion 6 and penetrates the reformer 7 and has a lower end connected to the central portion of the bottom surface of the manifold 10. Note that the lower end of the oxygen-containing gas supply pipe 14 may be arranged so as not to contact the manifold 10, and in this case, the lower end of the oxygen-containing gas supply pipe 14 has the function of the oxygen-containing gas supply port 15.

  Thereby, the oxygen-containing gas introduced from the oxygen-containing gas introduction pipe 4 is heat-exchanged with the heat of the vaporization section 11 while flowing through the oxygen-containing gas introduction section 6, and flows through the oxygen-containing gas supply pipe 14. Then, heat is exchanged with the fuel gas flowing in the fuel gas supply pipe 13. Thereby, the oxygen-containing gas whose temperature has increased can be supplied to the fuel cell 9. Accordingly, the temperature of the oxygen-containing gas supplied to the lower end side of the fuel battery cell 9 can be increased efficiently, so that the temperature distribution in the vertical direction of the fuel battery cell 9 can be made closer to uniform, and the fuel cell The power generation efficiency of the cell 9 can be improved. In addition, the module 1 having the above-described configuration can reduce the number of channels through which the fuel gas, oxygen-containing gas, and exhaust gas of the conventional module flow, and the module 1 can be downsized.

  In addition, a heat insulating material 19 is appropriately disposed inside the storage container 2 for maintaining the inside of the power generation chamber 8 at a high temperature and suppressing the temperature of the fuel cell 9 from being lowered to reduce the amount of power generation. In the storage container 2 shown in FIG. 2, the storage container 2 is disposed on the side of the cell stack and below the manifold 10.

  FIG. 3A is an external perspective view showing the reformer 7, the cell stack (fuel cell 9), and the manifold 10 extracted from the module 1 shown in FIG. 2, and FIG. 2 is an external perspective view showing the reformer 7, the oxygen-containing gas supply pipe 14, and the manifold 10 extracted from the module 1 shown in FIG. 2, and FIG. It is sectional drawing which extracts and shows the fuel cell 9), the fuel gas supply pipe | tube 13, and the oxygen-containing gas supply pipe | tube 14. FIG. A cell stack device 23 is configured by the reformer 7, the cell stack (fuel cell 9), the manifold 10, and the fuel gas supply pipe 13 shown in FIG.

  In the cell stack apparatus 23 shown in FIG. 3, the reformer 7 and the manifold 10 have a circular planar shape (inside the internal shape of the module 1 shown in FIG. 2) in accordance with the power generation chamber 8 in which the planar shape is formed in a circular shape. It is formed in a hollow cylindrical shape. A plurality of columnar fuel cells 9 are circular (annular) in conformity with the power generation chamber 8 having a circular planar shape via a current collecting member (not shown in FIG. 3, see FIG. 4). The lower end is fixed to the manifold 10 by an insulating bonding material such as a glass sealing material.

  That is, the storage container 2, the reformer 7, the manifold 10 and the power generation chamber 8 are each formed in a circular shape in plan view, and the fuel cells 9 are arranged in an annular shape (see FIG. 4). The temperature distribution in the stack can be made uniform. Thereby, the power generation efficiency of the cell stack (cell stack device 23) can be improved.

  Further, by configuring the module 1 as described above, not only the temperature distribution in the cell stack but also the temperature distribution in the power generation chamber 8 can be made closer to uniform. Thereby, it is possible to suppress the occurrence of local thermal stress and temperature difference in the storage container 2 and the manifold 10. Therefore, it is possible to prevent the joint portion between the cell stack and the manifold 10 from being damaged, the durability of the cell stack device 23 can be improved, and the durability of the storage container 2 can be improved.

  Here, the oxygen-containing gas supply pipe 14 provided with the oxygen-containing gas supply port 15 on the lower end side is disposed so as to be connected to the central portion of the upper surface of the manifold 10. As a result, the oxygen-containing gas can be supplied uniformly by each fuel cell 9 (cell stack) arranged in a circular shape (annular) according to the power generation chamber 8 having a circular planar shape. The power generation efficiency of the stack device 23) can be improved.

  Although not shown in FIG. 3, a fuel gas supply pipe 13 disposed inside the oxygen-containing gas supply pipe 14 for supplying the fuel gas generated by the reformer 7 to the manifold 10 is modified. It is provided so as to connect the center of the lower surface of the mass device 7 and the center of the upper surface of the manifold 10. Thereby, the fuel gas supplied to the manifold 10 is efficiently supplied to the respective fuel cells 9 constituting the cell stack, so that the distribution of the fuel gas supplied to each fuel cell 9 is uniform. The power generation efficiency of the cell stack (cell stack device 23) can be improved.

  Various fuel cells are known as the fuel cell 9, but a solid oxide fuel cell can be used for downsizing the module 1.

  Hereinafter, the columnar fuel cell 9 shown in FIGS. 2 and 3 will be described with reference to FIG. In FIG. 4, a columnar shape having a pair of opposed flat surfaces and having fuel gas flow paths 25 (six in the fuel cell 9 shown in FIG. 4) penetrating the inside for flowing the fuel gas therein. A fuel electrode layer 26, a solid electrolyte layer 27, and an oxygen electrode layer 28 are sequentially laminated on one flat surface of a conductive support 24 (hereinafter sometimes abbreviated as the support 24), and on the other flat surface. Shows a hollow plate type fuel cell 9 provided with an interconnector 29.

  A plurality of such fuel cells 9 are electrically connected in series via the current collecting member 31 between adjacent fuel cells 9 to form a cell stack. In a cell stack formed by arranging a plurality of fuel cells 9 in a circular shape (annular), one of the current collecting members 31 constituting the cell stack is connected to an end current collecting member that is not joined to each other. By setting the value to 32, the current generated by the power generation of the cell stack can be efficiently extracted. In addition, in the cylindrical storage container 2 having a hollow inside, a current extraction part (not shown) that is joined to the end current collecting member 32 and draws an electric current to the outside is inserted from the upper surface side of the storage container 2. By adopting such a configuration, the module 1 can be easily manufactured (assembled).

  A P-type semiconductor layer 30 can also be provided on the outer surface (upper surface) of the interconnector 29. By connecting the current collecting member 31 or the end current collecting member 32 to the interconnector 29 via the P-type semiconductor layer 30, the contact between them becomes an ohmic contact, the potential drop is reduced, and the current collecting performance is reduced. It can be effectively avoided.

  In such a fuel cell 9, the combustion gas emitted from the fuel gas flow path 25 in the combustion unit 22 and not used in the power generation of the fuel cell 9 can be burned. Accordingly, the temperature of the fuel battery cell 9 can be raised or maintained at a high temperature, the temperature of the reformer 7 can be raised, and the reforming reaction in the reformer 7 can be performed efficiently. it can.

  Below, each member which comprises the fuel cell 9 shown in FIG. 4 is demonstrated.

The support 24 is required to be gas permeable to allow the fuel gas to permeate to the fuel electrode layer 26, and to be conductive to collect current via the interconnector 29. Therefore, as the support 24, it is necessary to adopt a material satisfying such a requirement as a material, and for example, conductive ceramics, cermet, or the like can be used.

As the fuel electrode layer 26, generally known materials can be used, and porous conductive ceramics such as ZrO ₂ (referred to as stabilized zirconia) in which a rare earth element is dissolved, Ni and / or NiO are used. And can be formed from

The solid electrolyte layer 27 has a function as an electrolyte that bridges electrons between the electrodes, and at the same time, has to have a gas barrier property in order to prevent leakage between the fuel gas and the oxygen-containing gas. , 3 to 15 mol% of rare earth elements are formed from ZrO ₂ as a solid solution. In addition, as long as it has the said characteristic, you may form using another material etc.

The oxygen electrode layer 28 is not particularly limited as long as it is generally used. For example, the oxygen electrode layer 28 can be formed of a conductive ceramic made of a so-called ABO ₃ type perovskite oxide. The oxygen electrode layer 28 needs to have gas permeability, and the open porosity is preferably 20% or more, particularly preferably in the range of 30 to 50%.

Although the interconnector 29 can be formed from conductive ceramics, it needs to have reduction resistance and oxidation resistance because it comes in contact with a fuel gas (hydrogen-containing gas) and an oxygen-containing gas (air, etc.). Therefore, a lanthanum chromite-based perovskite oxide (LaCrO ₃ -based oxide) is preferably used. The interconnector 29 must be dense in order to prevent leakage of fuel gas flowing through the fuel gas passage 25 formed in the support 24 and oxygen-containing gas flowing outside the support 24, and 93 It is preferable to have a relative density of 95% or more, particularly 95% or more.

  In preparing the fuel cell 9, when the support 24 is prepared by co-firing with the fuel electrode layer 26 or the solid electrolyte layer 27, the iron group metal component (or its oxide) and the specific rare earth oxide are used. It is preferable to form the support 24 from the above. Further, the support 24 preferably has an open porosity of 30% or more, particularly 35 to 50% in order to provide the required gas permeability, and its conductivity is 50 S / cm or more. Preferably it is 300 S / cm or more, and particularly preferably 440 S / cm or more.

Furthermore, examples of the P-type semiconductor layer 30 include a layer made of a transition metal perovskite oxide. Specifically, a material having higher electron conductivity than a lanthanum chromite-based perovskite oxide (LaCrO ₃ -based oxide) constituting the interconnector 29, for example, LaMnO in which Mn, Fe, Co, etc. exist in the B site. P-type semiconductor ceramics made of at least one of _three- based oxides, LaFeO ₃ -based oxides, LaCoO ₃ -based oxides and the like can be used. In general, the thickness of the P-type semiconductor layer 30 is preferably in the range of 30 to 100 μm.

  Although not shown, the solid electrolyte layer 27 and the oxygen electrode layer 28 are firmly joined between the solid electrolyte layer 27 and the oxygen electrode layer 28, and the components of the solid electrolyte layer 27 and the oxygen electrode are It is formed with a composition containing Ce (cerium) and other rare earth elements (Sm, Gd, etc.) for the purpose of suppressing the formation of a reaction layer having a high electrical resistance by reacting with the components of the layer 28. An intermediate layer can also be provided.

  Further, although not shown, it is similar to the fuel electrode layer 26 in order to reduce a difference in thermal expansion between the interconnector 29 and the support 24, and so on. An adhesive layer having a composition can also be provided.

In the cell stack device 23 described above, the fuel gas can be efficiently supplied to the fuel cells 9 by performing steam reforming with high reforming efficiency in the reformer 7. Here, when the reformer 7 has a circular planar shape (a hollow cylindrical shape inside), the influence of temperature change due to heat absorption or heat generation accompanying steam reforming is a specific fuel cell constituting the cell stack. It can suppress affecting only the cell 9, and it will affect each fuel cell 9 substantially equally. As a result, the temperature distribution of the cell stack can be made closer to uniform, and the power generation efficiency of the cell stack (cell stack device 23) can be improved.

  Here, it is preferable that the reformer 7 has a configuration capable of suppressing the influence of the temperature change of the endothermic reaction accompanying the steam reforming from reaching the cell stack (fuel cell 9).

  FIG. 5 is an exploded perspective view showing another example of the reformer constituting the module 1 of the present invention. FIG. 5A is a vaporization section 34 constituting the reformer 33, the raw fuel introduction pipe 3, and the oxygen-containing part. A part of the gas supply pipe 14 is shown, and (b) is a cross-sectional view taken along line BB in (a). In addition, in (a), the state which removed the upper cover which comprises the vaporization part 34 is shown. 6 is an exploded perspective view showing the reforming unit 40, (a) shows a part of the reforming unit 40 and the oxygen-containing gas supply pipe 14 constituting the reformer 33, and (b) shows ( The CC sectional view taken on the line in a) is shown.

  In the reformer 33 shown in FIGS. 5 and 6, a vaporizing section 34 for vaporizing water is disposed above the reforming section 40 that performs the reforming reaction (located above the reforming section). For this reason, it is possible to suppress the influence of the temperature drop due to the endotherm accompanying the vaporization of water in the vaporization section 34 on the cell stack.

  In addition, when steam reforming is performed in the reformer 33, raw fuel such as natural gas and water are supplied from the raw fuel introduction pipe 3. In this case, the raw fuel introduction pipe 3 can be a double pipe, and the raw fuel and water can be supplied from separate pipes. FIG. 5A shows a case where raw fuel such as natural gas and water are supplied from the raw fuel introduction pipe 3.

  The raw fuel and water supplied from the raw fuel introduction pipe 3 disposed inside the oxygen-containing gas supply pipe 14 are vaporized via a raw fuel introduction port 39 that communicates the raw fuel introduction pipe 3 and the vaporization section 34. It is supplied to a raw fuel receiving portion 35 provided at the center of the portion 34. Thus, the raw fuel and water supplied from the raw fuel introduction pipe 3 are temporarily stored in the raw fuel receiving portion 35. The raw fuel and water stored in the raw fuel receiving portion 35 are supplied from a raw fuel delivery port 38 provided in the raw fuel receiving portion 35, one end of which is connected to the raw fuel receiving portion 35 and supplied from the raw fuel introduction pipe 3. The raw fuel flows to the spiral vaporization passage 36 for flowing the raw fuel to the periphery. In this case, a part of the water stored in the raw fuel receiving part 35 can also flow into the vaporization part flow path 36 as water vapor. By configuring the raw fuel receiving portion 35 as described above, the raw fuel receiving portion 35 has a function as a raw fuel delivery portion that connects the raw fuel introduction pipe 3 and the vaporizing portion 34.

  The raw fuel receiving portion 35 is, for example, lower in height than the height of the wall constituting the vaporizing portion flow path 36, and after vaporizing water stored in the raw fuel receiving portion 35 into water vapor, It can also be configured to flow from above the fuel receiving portion 35 to the vaporizing portion flow path 36. In this case, the upper end of the raw fuel receiving portion 35 becomes the raw fuel delivery port 38.

  The raw fuel introduction pipe 3 is disposed so that the lower end of the raw fuel introduction pipe 3 opened is spaced from the bottom surface of the raw fuel receiving portion 35, and the raw fuel introduction pipe 3 is disposed at the lower end of the raw fuel introduction pipe 3. A configuration may be adopted in which a fuel introduction port (hole or the like) is provided and the lower end is joined to the bottom surface of the raw fuel receiving portion 35. FIG. 5A shows a state where the open lower end of the raw fuel introduction pipe 3 is positioned so as to be spaced from the bottom surface of the raw fuel receiving portion 35.

Similarly, the raw fuel such as natural gas supplied from the raw fuel introduction pipe 3 also flows into the vaporization section flow path 36. By making the vaporization part flow path 36 into a spiral shape, the length of the vaporization part flow path 36 can be increased, water can be efficiently vaporized into water vapor, and water vapor and raw fuel can be mixed efficiently. can do. The raw fuel (raw fuel gas) that has flowed to the peripheral side of the vaporization section flow path 36 is reformed through a raw fuel gas outlet 37 provided on the peripheral side (the other end side) of the vaporization section flow path 36. 40 flows. In addition, a ceramic ball or the like for efficiently vaporizing water can be disposed in the vaporizing section flow path 36. In addition, the vaporization part flow path 36 can also be set as the structure inclined so that it may go down toward a peripheral part, in order to flow raw fuel and water vapor | steam to a peripheral side efficiently.

  The raw fuel gas that has flowed through the raw fuel gas outlet 37 flows to the peripheral side of the reforming unit 40. The reforming unit 40 includes a spiral reforming unit flow channel 41 for flowing the raw fuel gas that has flowed into the peripheral side of the reforming unit 40 through the raw fuel gas outlet 37 toward the center side. Yes. Note that the upper surface of the reforming unit 40 is blocked by the bottom surface of the vaporizing unit 34.

  A reforming catalyst for reforming the raw fuel gas into the fuel gas is provided in the reforming section channel 41 (not shown). As the reforming catalyst, a reforming catalyst excellent in reforming efficiency and durability is preferably used. For example, a porous support such as γ-alumina, α-alumina, cordierite, etc., a noble metal such as Ru or Pt, Ni A reforming catalyst carrying a base metal such as Fe can be used.

  The reforming section channel 41 is provided so that one end thereof is positioned in the vicinity of the oxygen-containing gas supply pipe 14 provided so as to penetrate the central portion of the reformer 33 from above. Inside the oxygen-containing gas supply pipe 14, an upper end thereof is located inside the reforming section 40, and a fuel gas supply pipe 13 for supplying the fuel gas generated in the reforming section 40 to the manifold 10 is disposed. Has been.

  The fuel gas supply pipe 13 includes a fuel gas inlet 43 for flowing the fuel gas generated in the reforming section flow path 41 into the fuel gas supply pipe 13. The mass part 40 (the reforming part flow path 41) is connected by a fuel gas inflow part. As a result, the fuel gas generated in the reforming section flow path 41 flows to the fuel gas supply pipe 13 via the fuel gas inflow section 42 and then is supplied to the fuel cells 9 via the manifold 10. In addition, the reforming part flow path 41 can also be configured to be inclined so as to be lowered toward the central part in order to efficiently flow the raw fuel gas to the fuel gas inflow part 42.

  In addition, the fuel gas supply pipe 13 arranged inside the oxygen-containing gas supply pipe 14 may be arranged such that the upper end thereof is joined to the bottom surface of the vaporization section 34, and is spaced from the bottom surface of the vaporization section 34. You may arrange | position so that it may open and may be located. FIG. 6B shows an example in which the fuel gas supply pipe 13 is arranged so that the upper end of the fuel gas supply pipe 13 is located at a distance from the bottom surface of the vaporizing section 34.

  As described above, the reformer 33 is disposed above and includes a vaporization section 34 including a spiral vaporization section flow path 36, and disposed below the vaporization section 34 and includes a spiral reforming section flow path 41. By comprising the reforming unit 40, the reforming reaction can be performed efficiently, and the influence of the temperature decrease due to the endotherm accompanying the vaporization of water in the vaporization unit 34 reaches the cell stack (fuel cell 9). This can be suppressed. By providing such a reformer 33, the module 1 with improved power generation efficiency and durability can be obtained.

  FIG. 7 is a cross-sectional view schematically showing another example of the fuel cell module of the present invention. Compared with the module 1 shown in FIG. 2, the module 44 shown in FIG. 7 includes a partition wall 50 extending in the vertical direction between the side of the cell stack and the side wall of the storage container 2. The difference is that the oxygen-containing gas introduction portion 47 is provided between the side wall and the partition wall 50.

That is, in the module 44 shown in FIG. 7, the lower end of the raw fuel introduction pipe 3 is connected to the reformer 45.
The upper end of the fuel gas supply pipe 13 is connected to the center of the bottom surface of the reformer 12 constituting the reformer 45, and the lower end of the fuel gas supply pipe 13 is Is connected to the center of the upper surface of the manifold 10.

  Thereby, the raw fuel (also water) introduced from the raw fuel introduction pipe 3 is supplied into the vaporization section 11 from the lower end of the raw fuel introduction pipe 3, and the raw fuel gas generated in the vaporization section 11 is It flows to the reforming section 12 through the raw fuel gas outlet 21. The fuel gas generated by the reforming reaction in the reforming unit 12 flows downward through the fuel gas supply pipe 13 and is supplied to the fuel battery cell 9 through the manifold 10.

  Here, in the module 44, a partition wall 50 extending in the vertical direction is provided between the side of the cell stack and the side wall of the storage container 2, and oxygen is added to the side wall of the storage container 2 corresponding to the upper side of the power generation chamber 8. A contained gas inlet 46 is provided.

  The oxygen-containing gas introduced from the oxygen-containing gas introduction port 46 flows downward through the oxygen-containing gas introduction portion 47 formed by the side wall of the storage container 2 and the partition wall 50. The oxygen-containing gas that has flowed downward through the oxygen-containing gas introduction portion 47 is supplied into the power generation chamber 8 from an oxygen-containing gas supply port 48 provided in the partition wall 50 corresponding to the lower end portion of the fuel cell 9. Power generation of the fuel cell 9 is performed.

  Excess fuel gas and oxygen-containing gas that have not been used for power generation of the fuel battery cell 9 are combusted in the combustion part 22 above the fuel battery cell 9, and the exhaust gas after combustion is lateral to the fuel part 22. Is exhausted to the outside through an exhaust gas exhaust pipe 49 connected to the partition wall 50 from the side wall of the storage container 2. In the module 44 shown in FIG. 7, the exhaust gas exhaust pipe 49 corresponds to an exhaust part. Here, the temperature of the reformer 45 can be increased by causing the surplus fuel gas and oxygen-containing gas that have not been used for power generation to burn in the combustion unit 22, and the reformer 45 can efficiently A reforming reaction can be performed.

  The oxygen-containing gas introduced from the oxygen-containing gas introduction port 46 is heat-exchanged with the heat in the power generation chamber 8 while flowing downward through the oxygen-containing gas introduction portion 47. Accordingly, the temperature of the oxygen-containing gas supplied to the lower end side of the fuel battery cell 9 can be increased efficiently, so that the temperature distribution in the vertical direction of the fuel battery cell 9 can be made closer to uniform, and the fuel cell The power generation efficiency of the cell 9 can be improved.

  Further, by configuring the module 44 as described above, the length in the vertical direction of the module 44 can be shortened, and the module 44 can be reduced in size. In this case, it is preferable that the number of flow paths through which the oxygen-containing gas located on the side of the cell stack flows is one. This is because when the number of flow paths is increased, the module 44 may be increased in size.

  In addition, it is preferable to arrange the heat insulating material 19 in the oxygen-containing gas introduction part 47 for the purpose of suppressing the heat in the power generation chamber 8 from being radiated to the outside. The reformer 45 can also be a reformer 45 having a spiral flow path as described above.

  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, in the module 1 shown in FIG. 2, an example in which the oxygen-containing gas introduction pipe 4 is connected to both ends of the oxygen-containing gas introduction section 6 has been shown. For example, the oxygen-containing gas introduction pipe 4 is connected to the oxygen-containing gas introduction section 6.
The oxygen-containing gas introduction part 6 can also be formed in a spiral shape.

DESCRIPTION OF SYMBOLS 1, 44: Fuel cell module 2: Storage container 3: Raw fuel introduction pipe 6, 47: Oxygen-containing gas introduction part 7, 33, 45: Reformer 8: Power generation chamber 9: Fuel cell 10: Manifold 11, 34 : Vaporizer 12, 40: reforming unit 13: fuel gas supply pipe 14: oxygen-containing gas supply pipe 15: oxygen-containing gas supply port 18: exhaust gas exhaust port 22: combustion unit 50: partition wall

Claims (5)

In a cylindrical storage container, a plurality of columnar fuel cells, each having a fuel electrode layer, a solid electrolyte layer, and an oxygen electrode layer stacked in this order, are arranged in a circular pattern and are electrically connected. The cell stack is configured to be connected, the lower end of the fuel cell is fixed, and the planar shape for supplying fuel gas to the fuel cell is a circular manifold, and the cell stack is disposed above the cell stack. The planar shape for generating the fuel gas to be supplied to the fuel battery cell is a circular reformer,
The reformer is arranged such that the entire side surface is in contact with the side wall of the storage container,
Between the reformer and the cell stack is a combustion part for burning the surplus fuel gas that was not used in power generation of the fuel cell,
A fuel cell module comprising an exhaust part for exhausting exhaust gas after combustion in the combustion part on a side wall of the storage container at a side of the combustion part.   A raw fuel introduction pipe for introducing raw fuel into the reformer is connected to the upper surface central portion of the reformer, and a bottom surface central portion of the reformer and an upper surface central portion of the manifold, The fuel cell module according to claim 1, wherein the fuel cell modules are connected by a fuel gas supply pipe.   The reformer is a reformer that performs steam reforming with raw fuel and water, a vaporization section for vaporizing the water disposed above the reformer, and the reformer And a reforming unit that performs steam reforming with the raw fuel and the steam vaporized by the vaporizing unit, which is disposed in the lower part of the fuel, and the vaporizing unit is introduced into the central part from the raw fuel introduction pipe A volatilization-type vaporizing part flow path for flowing the raw fuel directed toward the peripheral side, and the reforming part supplies the raw fuel supplied from the vaporization part flow path to the peripheral side toward the central part side. The fuel cell module according to claim 2, further comprising a spiral reforming section channel for flowing toward the surface. An oxygen-containing gas introduction portion having a circular planar shape for supplying oxygen-containing gas to the fuel battery cell is disposed above the reformer,
Oxygen that extends vertically in the storage container, has an upper end connected to the center of the bottom of the oxygen-containing gas introduction portion, and supplies the oxygen-containing gas to the lower end side of the fuel cell on the lower end side. An oxygen-containing gas supply pipe provided with a containing gas supply port is provided,
The fuel cell module according to claim 2 or 3, wherein the fuel gas supply pipe is disposed inside the oxygen-containing gas supply pipe. A partition wall extending in the vertical direction is provided between the cell stack and the side wall of the storage container, and an oxygen-containing gas is supplied between the side wall of the storage container and the partition wall to the fuel cell. It is an oxygen-containing gas introduction part,
An oxygen-containing gas circulation part for introducing an oxygen-containing gas into the oxygen-containing gas introduction part from the outside is provided on the side wall of the storage container, and the lower end part of the fuel cell unit is provided on the lower end part side of the partition wall. The fuel cell module according to claim 2 or 3, further comprising an oxygen-containing gas supply port for supplying the oxygen-containing gas to a side.

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