JP2010009945A - Fuel cell unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell unit capable of preventing reduction in current collecting performance, while improving connection work efficiency, when electrically connecting mutual cells of a fuel cell. <P>SOLUTION: This fuel cell unit has a gas tank 3 having an opening part, a cell 4 of the fuel cell having an inside passage communicating with the inside of the gas tank 3 via the opening part and having an outside electrode layer, a cell 4 of the fuel cell having the inside passage communicating with the inside of the gas tank 3 via the opening part and having an inside electrode layer, an outside electrode terminal 42 electrically connected to the outside electrode layer of the cell 4 of the fuel cell, an inside electrode terminal electrically connected to the inside electrode layer of the cell 4 of the fuel cell, and a connecting terminal 52 for electrically connecting the outside electrode terminal 42 and the inside electrode terminal. The outside electrode terminal 42 and the connecting terminal 52 are arranged so as to be sealed in the gas tank 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell unit used in a solid oxide fuel cell (SOFC).

  Conventionally, such a fuel cell unit includes a gas tank having an opening, and a plurality of fuel cells having an internal passage communicating with the inside of the gas tank through the opening and having outer and inner electrodes. (For example, refer to Patent Documents 1 to 3 below). In Patent Documents 1 to 3 (Japanese Patent Publication No. 2001-518688, Japanese Patent Application Laid-Open No. 2004-31172, and Japanese Patent Application Laid-Open No. 2008-71712), a plurality of fuel cells are electrically connected in series.

In Patent Document 1 (Japanese Patent Publication No. 2001-518688), a part of a fuel cell is protruded into a gas tank, and an outer terminal is disposed so as to be electrically connected to an outer electrode in the protruding part of the fuel cell. Has been. The outer terminal is electrically connected to the inner electrode of one adjacent fuel cell via a wire. In patent document 2 (Unexamined-Japanese-Patent No. 2004-31172), the current collection member is connected to each of the outer electrode and inner electrode of a fuel cell. In the gas tank, the current collecting member connected to the outer electrode of one fuel battery cell and the current collecting member connected to the inner electrode of one fuel battery cell adjacent to the fuel battery cell are electrically connected by the conductive member. Connected. In Patent Document 3 (Japanese Patent Laid-Open No. 2008-71712), an outer terminal electrically connected to the outer electrode is disposed at one end of the fuel cell, and an inner terminal electrically connected to the inner electrode is disposed at the other end. Has been placed. An outer terminal of one fuel battery cell and an inner terminal of one fuel battery cell adjacent to the fuel battery cell are electrically connected by a connection member or a connection electrode terminal.
Special table 2001-518688 gazette JP 2004-31172 A JP 2008-71712 A

  By the way, in patent document 1 (special table 2001-518688 gazette), since an inner side electrode and a wire will be directly connected, the contact area of a wire and an inner electrode is small. For this reason, the conduction resistance at the connection point between the inner electrode and the wire is increased, and the current collecting performance may be deteriorated. Moreover, since it is necessary to connect an inner electrode and a wire, the operation | work which electrically connects fuel cell cells cannot be performed efficiently and easily.

  In Patent Document 2 (Japanese Patent Application Laid-Open No. 2004-31172), since the thickness of each current collecting member is thin, it is necessary to perform connection work through a conductive member very carefully, and workability is poor. In addition, the mechanical strength at the connection point between the current collecting member and the conductive member is low, and cracks or the like are generated at the connection point, which may increase the conduction resistance. Furthermore, since the current collecting member connected to the outer electrode is exposed to the atmosphere, it is necessary to separately adopt a measure for preventing oxidation. When the current collecting member is oxidized, the conduction resistance of the current collecting member is increased, and the current collecting performance is deteriorated.

  Therefore, an object of the present invention is to provide a fuel cell unit that can improve the connection workability when the fuel cells are electrically connected to each other and can prevent the deterioration of the current collecting performance.

  In order to solve the above-described problems, a fuel cell unit according to the present invention is a fuel cell unit used in a fuel cell, and includes a gas tank having an opening and an interior communicating with the inside of the gas tank through the opening. A first fuel cell having a passage and an outer electrode; a second fuel cell having an inner passage communicating with the gas tank through the opening; and the first fuel cell. An outer electrode terminal electrically connected to the outer electrode of the battery cell; an inner electrode terminal electrically connected to the inner electrode of the second fuel battery cell; the outer electrode terminal and the inner electrode terminal; A conductive member that electrically connects the outer electrode terminal and the conductive member, wherein the outer electrode terminal and the conductive member are disposed so as to be sealed in the gas tank.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel cell unit which can prevent the fall of current collection performance can be provided, improving the connection workability | operativity at the time of electrically connecting fuel cell cells.

  Prior to describing the best mode for carrying out the present invention, the function and effect of the present invention will be described.

  A fuel cell unit according to the present invention is a fuel cell unit used in a fuel cell, and includes a gas tank having an opening, an internal passage communicating with the inside of the gas tank through the opening, and an outer electrode. Electricity is supplied to the first fuel cell, the second fuel cell having an internal passage communicating with the gas tank through the opening, and having an inner electrode, and the outer electrode of the first fuel cell. An outer electrode terminal electrically connected, an inner electrode terminal electrically connected to the inner electrode of the second fuel cell, and a conductive member electrically connecting the outer electrode terminal and the inner electrode terminal The outer electrode terminal and the conductive member are arranged so as to be sealed in the gas tank.

  In the present invention, the outer electrode terminal and the inner electrode terminal are provided, and the outer electrode terminal and the inner electrode terminal are electrically connected by the conductive member. As described above, according to the present invention, the connection work using the terminals is possible for both the inner electrode and the outer electrode, so that the connection workability when the fuel cells are electrically connected is improved.

  Moreover, in this invention, since the electrical connection structure of fuel cell is implement | achieved by the terminal, the contact area in the connection location of a terminal and an electrically-conductive member is comparatively large. As a result, the conduction resistance at the connection location is small, and a reduction in current collection efficiency can be suppressed.

  Furthermore, in the present invention, since the outer electrode terminal and the conductive member are disposed so as to be sealed in the gas tank, it is possible to prevent the outer electrode terminal and the conductive member from being exposed to the atmosphere. This prevents oxidation of the outer electrode terminal and the conductive member, and does not increase the conduction resistance in the outer electrode terminal and the conductive member. In addition, it is also possible to use a relatively inexpensive metal material as the material of the outer electrode terminal and the conductive member. In this case, the cost of the fuel cell unit can be reduced.

  In the fuel cell unit according to the present invention, each of the first and second fuel cells includes a gas tank protruding portion protruding into the gas tank, and the outer electrode terminal is the first fuel cell. It is also preferable that the cell is disposed at the protruding portion in the gas tank. In this preferable aspect, the sealing arrangement of the outer electrode terminal and the conductive member in the gas tank can be reliably and easily realized.

  In the fuel cell unit according to the present invention, the inner electrode is formed on the inner peripheral surface of the second fuel cell, and the inner electrode terminal is connected to the inner electrode of the second fuel cell. It is also preferable to be electrically connected to the inner electrode by surface contact. In this preferred embodiment, the conduction resistance at the connection point between the inner electrode and the inner electrode terminal can be reduced, and the current collecting performance can be further improved.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same components are denoted by the same reference numerals as much as possible in the drawings, and redundant descriptions are omitted.

  FIG. 1 is a front view showing an embodiment of a fuel cell module according to the present invention. FIG. 2 is a perspective view showing the fuel cell assembly and the gas tank.

  As shown in the figure, the fuel cell module FC has ten fuel cell stacks 400 arranged side by side in a space sealed by the cover member 1 and the base member 2. Therefore, in the fuel cell module FC, the cover member 1 and the base member 2 form a container that contains the fuel cell 4 and the like. In each fuel cell stack 400, 16 fuel cells 4 are arranged in two rows. These fuel cells 4 are electrically arranged in series. The fuel cell module FC of the present embodiment includes a fuel cell unit.

  In the fuel cell module FC, a fuel cell assembly 401 is constituted by ten fuel cell stacks 400. In the fuel cell assembly 401, 160 fuel cells 4 are arranged in a matrix. In the present embodiment, the fuel cells 4 are arranged in 8 rows × 20 columns.

  Each fuel battery cell 4 has a tubular shape, and a gas flowing from one end 4a of the fuel battery cell 4 to the other end 4b in the pipe of the fuel battery cell 4, and from one end 4a outside the pipe. It operates by the action of the gas flowing to the other end 4b. In the present embodiment, the gas flowing in the pipe of the fuel battery cell 4 is a fuel gas such as reformed gas obtained by reforming hydrogen or hydrocarbon fuel, and the gas flowing outside the pipe of the fuel battery cell 4 contains oxygen. Contains oxidant gas such as air.

  The fuel cell unit 30 will be described with reference to FIG. As shown in FIG. 3, the fuel cell unit 30 is a tubular structure formed by the fuel cells 4 and extending in the vertical direction, and includes a cylindrical fuel cell 4 and one end of the fuel cell 4. An inner electrode terminal 40 and an outer electrode terminal 42 attached to 4a.

  The fuel cell 4 includes a cylindrical inner electrode layer 44, a cylindrical outer electrode layer 48, a cylindrical electrolyte layer 46 disposed between the electrode layers 44, 48, and an inner electrode. And a through flow channel 50 configured inside the layer 44. An inner electrode surface 44 a from which the inner electrode layer 44 is exposed is provided at one end 4 a of the fuel cell 4. Further, one end 4a of the fuel cell 4 is constituted by an outer electrode surface 48a from which the outer electrode layer 48 is exposed. The through channel 50 functions as an internal passage. The inner electrode layer 44 functions as an inner electrode, and the outer electrode layer 48 functions as an outer electrode. The inner electrode surface 44 a becomes the inner peripheral surface of the fuel cell 4, and the outer electrode surface 48 a becomes the outer peripheral surface of the fuel cell 4.

  The inner electrode layer 44 includes, for example, a mixture of Ni and zirconia doped with at least one selected from rare earth elements such as Ca, Y, and Sc, ceria doped with at least one selected from Ni and rare earth elements, And a mixture of Ni and lanthanum gallate doped with at least one selected from Sr, Mg, Co, Fe, and Cu. The electrolyte layer 46 includes, for example, zirconia doped with at least one selected from rare earth elements such as Y and Sc, ceria doped with at least one selected from rare earth elements, lanthanum gallate doped with at least one selected from Sr and Mg, Formed from at least one of the following. The outer electrode layer 48 is made of, for example, lanthanum manganite doped with at least one selected from Sr and Ca, lanthanum ferrite doped with at least one selected from Sr, Co, Ni, and Cu, Sr, Fe, Ni, and Cu. It is formed from at least one selected from samarium cobalt and silver doped with at least one selected. In this case, the inner electrode layer 44 becomes a fuel electrode, and the outer electrode layer 48 becomes an air electrode. The thickness of the inner electrode layer 44 is, for example, 1 mm, the thickness of the electrolyte layer 46 is, for example, 30 μm, the thickness of the outer electrode layer 48 is, for example, 30 μm, and the outer diameter is For example, it is 1-10 mm.

  As shown in FIG. 4, the inner electrode terminal 40 has a main body portion 40a having a substantially C-shaped cross section and an extending portion 40b. The main body portion 40a is disposed at one end 4a of the fuel battery cell 4 so as to cover the inner electrode surface 44a from substantially the entire inner periphery and is electrically connected thereto. The extending part 40b extends in the longitudinal direction of the fuel cell 4 from the main body part 40a. The outer peripheral surface of the main body portion 40 a is in contact with the inner electrode surface 44 a of the inner electrode layer 44. That is, the inner electrode terminal 40 is electrically connected to the inner electrode surface 44a by being in surface contact with the inner electrode surface 44a. In the present embodiment, the extending portion 40b is formed integrally with the main body portion 40a and in a substantially plate shape. The inner electrode terminal 40 is made of a metal material such as stainless steel.

  As shown in FIG. 5, the outer electrode terminal 42 includes a main body portion 42a having a substantially C-shaped cross section and an extending portion 42b. The main body portion 42a is disposed at one end 4a of the fuel cell 4 so as to cover the outer electrode surface 48a from the outside over substantially the entire circumference and is electrically connected thereto. The extending portion 42b extends from the main body portion 42a in the outer direction of the fuel cell 4 and then extends in the longitudinal direction. The inner peripheral surface of the main body portion 42 a is in contact with the outer electrode surface 48 a of the outer electrode layer 48. That is, the outer electrode terminal 42 is electrically connected to the outer electrode surface 48a by being in surface contact with the outer electrode surface 48a. In the present embodiment, the extending portion 42b is formed integrally with the main body portion 42a and in a substantially plate shape. As with the inner electrode terminal 40, the outer electrode terminal 42 is made of a metal material such as stainless steel.

  Next, the fuel cell stack 400 will be described with reference to FIGS. 6 and 7. In FIG. 6, connection terminals 52 described later are not shown. The fuel cell stack 400 includes 16 fuel cell units 30 and a support plate 400a. The support plate 400a is rectangular, and each of the support plates 400a is a through-hole (not shown in the figure) that fits into the tubular portion of one end 4a of the fuel cell 4 so as to support the fuel cell unit 30 in 2 columns × 8 rows. )have. The support plate 400a is made of an electrically insulating material, for example, heat resistant ceramics. Specifically, it is preferable to use alumina, zirconia, spinel, forsterite, magnesia, titania or the like.

  The 16 fuel cell units 30 are arranged so that they are electrically connected in series. Specifically, the fuel cell unit 30 is adjacent to the inner electrode terminal 40 of one fuel cell unit 30 (including the fuel cell 4 as the second fuel cell) and the fuel cell unit 30. An outer electrode terminal 42 of one fuel cell unit 30 (including the fuel cell 4 as the first fuel cell) is electrically connected by a connection terminal 52. The connection terminal 52 is fixed to the extension portions 40b and 42b so as to sandwich the extension portion 40b of the inner electrode terminal 40 and the extension portion 42b of the outer electrode terminal 42. Examples of the method for fixing the connection terminal 52 include caulking, soldering, brazing, or laser welding. The connection terminal 52 is made of a metal material such as stainless steel, for example, like the inner electrode terminal 40 and the outer electrode terminal 42. The connection terminal 52 functions as a conductive member.

  Since the extended portion 40b of the adjacent inner electrode terminal 40 and the extended portion 42b of the outer electrode terminal 42 are bent outward as described above, the fuel cell It approaches in the state arranged in the cell stack 400. Thereby, the connection work using the connection terminal 52 can be easily performed.

  Since the extended portion 42 b extends in the outer direction of the fuel cell 4, the extended portion 42 b is configured not to come into contact with the inner electrode terminal 40, the inner electrode layer 44, or the like in the same fuel cell unit 30. Thereby, it is possible to prevent the short-circuit between the outer electrode terminal 42, the inner electrode terminal 40 and the inner electrode layer 44.

  The inner electrode terminals 40 and the outer electrode terminals 42 at both ends of the 16 fuel cell units 30 connected in series are provided with external terminals (not shown) for electrical connection with the outside. Yes. The external terminals of each fuel cell stack 400 are electrically connected in series, and both ends thereof are connected to electrode bars (not shown).

  Returning to FIG. 1, the fuel cell module FC will be described. The cover member 1 is formed in a rectangular parallelepiped shape by a side wall (not shown) on the front side, side walls 101 and 102 in the arrangement direction of the fuel cell units 30, a side wall 103 on the back side, and a ceiling 104. A flange portion 1 a is formed at the lower end portion of the side wall 101. By bringing the flange portion 1 a of the cover member 1 into contact with the base member 2, a space sealed by the cover member 1 and the base member 2 is formed.

  An internal space formed by the cover member 1 and the base member 2 is separated into two spaces by a partition plate 15. Among the spaces separated by the partition plate 15, the space where the fuel cell stack 400 is disposed is the power generation chamber 16. Of the spaces separated by the partition plate 15, the other space is an exhaust gas chamber 17.

  The gas tank 3 is placed on the partition plate 15. Ten fuel cell stacks 400 are arranged side by side in the gas tank 3, and fuel gas is supplied from the gas tank 3 to the fuel cell 4 constituting each fuel cell stack 400.

  More specifically, an opening (not shown) having substantially the same shape as the support plate 400a of the fuel cell stack 400 is provided on the upper surface of the gas tank 3, and the support plate 400a is in close contact with the opening. The gas tank 3 and each fuel cell stack 400 are connected. Therefore, the fuel cells 4 constituting the fuel cell stack 400 are erected on the gas tank 3 with their tip portions facing upward. The support plate 400 a constitutes a part of the top plate of the gas tank 3.

  In a state where the fuel cell stack 400 is attached to the gas tank 3, one end 4 a side of the fuel cell 4 (fuel cell unit 30) protrudes into the gas tank 3 as shown in FIG. 7. It becomes. As a result, the fuel cell 4 (fuel cell unit 30) includes a gas tank protrusion protruding into the gas tank 3. And the inner side electrode terminal 40 and the outer side electrode terminal 42 are here arrange | positioned at the protrusion part in a gas tank mentioned above.

  The outer electrode terminal 42 and the connection terminal 52 are all disposed in the gas tank 3. Thereby, the outer electrode terminal 42 and the connection terminal 52 are sealed in the gas tank 3. Of course, the inner electrode terminal 40 is also disposed in the gas tank 3 because it is disposed on the one end 4a side of the fuel cell 4 (fuel cell unit 30).

  On the other hand, above each fuel cell assembly 401 is a combustion section 18 in which air and fuel gas are mixed and burned. The fuel gas rises from the gas tank 3 through the in-pipe flow path 30 c of the fuel cell unit 30 toward the combustion unit 18. Further, the air flowing outside the fuel cell 4 also rises toward the combustion unit 18. An ignition device 19 for starting combustion of combustion gas and air is provided in a portion corresponding to the combustion unit 18 in the rear side wall 102. The ignition device 19 mixes and burns fuel gas and air. The fuel cells 4 constituting the fuel cell assembly 401 are heated from above by the combustion unit 18.

  The fuel gas is introduced into the fuel cell module FC through the fuel gas supply pipe 8. The fuel gas supply pipe 8 is connected to the reformer 5 via a pipe 6 </ b> A standing upright with respect to the partition plate 15. An air supply pipe (not shown) is also connected to the pipe 6A (the reformer 5). The fuel gas supply pipe 8 and the air supply pipe are joined before being connected to the pipe 6A, and the reformer 5 is configured to be able to supply a premixed fuel gas and air. Although not clearly shown in FIG. 1 and the like, in the present embodiment, electromagnetic valves are attached to the fuel gas supply pipe 8 and the air supply pipe, respectively, and each electromagnetic valve outputs an instruction signal output from a CPU as a control unit. The ratio between the fuel gas and the air supplied to the reformer 5 can be changed.

  The fuel gas (which may be mixed with water vapor) and air (which may be only fuel gas) introduced into the reformer 5 is reformed by the reforming catalyst contained in the reformer 5. Is done. The reformed fuel gas and air are supplied to the gas tank 3 through the pipe 6B (reformed gas supply pipe). The portion where the pipe 6A is connected to the reformer 5 and the portion where the pipe 6B is connected to the reformer 5 are separated from each other in the vicinity of one end and the other end in the longitudinal direction. As a result, the fuel gas and air supplied to the reformer 5 can sufficiently come into contact with the reforming catalyst. Further, as shown in FIGS. 2 and 5, the pipes 6 </ b> A and 6 </ b> B are provided in a straight line in the projection region of the reformer 5 when viewed from the longitudinal direction of the fuel cell 4. That is, the pipes 6 </ b> A and 6 </ b> B are provided in a region that does not protrude from the reformer 5 when viewed from above the reformer 5.

  A reforming catalyst is enclosed in the reformer 5. As the reforming catalyst, a catalyst in which nickel is applied to the surface of the alumina sphere and a catalyst in which ruthenium is applied to the surface of the alumina sphere are appropriately used. These reforming catalysts are spheres.

  Further, the side walls 101, 102, 103 and the ceiling 104 of the cover member 1 have a double wall structure, and are configured so that gas can pass through the space between the double walls. The internal space of the side wall 102, the internal space of the ceiling 104, and the internal space of the side wall 103 are connected to each other. An air supply pipe 10 is communicated with the lower portion of the side wall 102 so that air is supplied.

  The air supplied to the side wall 102 flows from the ceiling 104 to the side wall 103, and is heated by heat transmitted from the power generation chamber 16 in the flow process. The air that has flowed into the side wall 103 is configured to flow into the air flow path 103a. The air channel 103 a is formed so as to extend from the side wall 101 toward the side wall 102, and is disposed along the vicinity of the upper surface of the partition plate 15 inside the side wall 103. The air flow path 103a is provided with air inflow holes 103b at a predetermined interval.

  The air that flows into the air flow path 103a from the side wall 103 is configured to flow into the power generation chamber 16 through the air inflow hole 103b. The air that has flowed into the power generation chamber 16 through the air inflow hole 103 b flows from the lower side to the upper side of each fuel cell 4 through the passage outside the fuel cell 4. The air that reaches the upper side of each fuel battery cell 4 is burned together with the fuel gas that has passed through the pipe flow path of each fuel battery cell 4.

  On the inner side of the side wall 102, an orienting portion 20A for directing the air flowing upward from the lower side of each fuel cell 4 to the combustion portion 18 through the air inflow hole 103b is provided adjacent to the pipe 6A. More specifically, the directing portion 20A is a side wall 102, and the side wall 102 is provided close to the pipe 6A.

  A similar structure is also provided on the inner side of the side wall 101. That is, an orientation portion 20B for bringing the air flowing upward from the lower side of each fuel battery cell 4 closer to the combustion portion 18 is also provided inside the side wall 102 adjacent to the pipe 6B. More specifically, the directing portion 20B is a side wall 101, and the side wall 101 is provided close to the pipe 6B. By such directing portions 20 </ b> A and 20 </ b> B, the air flowing upward from the lower side of each fuel cell 4 is restricted within the projection region of the reformer 5 in the width direction of the fuel cell unit 30.

  An exhaust gas outflow slit 103 c is provided at the inner upper end of the side wall 103. Exhaust gas generated by combustion of fuel gas and air above each fuel cell 4 enters the internal space of the side wall 103 through the exhaust gas outflow slit 103c. The exhaust gas that has entered the side wall 103 flows downward through the internal space of the side wall 103, reaches the exhaust gas chamber 17, and is temporarily stored. The exhaust gas that has reached the exhaust gas chamber 17 is discharged to the outside of the fuel cell module FC through the exhaust gas pipe 11.

  As described above, in the present embodiment, the inner electrode terminal 40 and the outer electrode terminal 42 are provided, and the inner electrode terminal 40 and the outer electrode terminal 42 are electrically connected by the connection terminal 52. Become. Therefore, since connection work using the terminals 40, 42, and 52 is possible for both the inner electrode layer 44 and the outer electrode layer 48, the fuel cell units 4 (fuel cell unit 30) are electrically connected to each other. Improves connection workability when connecting.

  Moreover, in this embodiment, since the electrical connection structure between the fuel cells 4 (fuel cell units 30) is realized by the terminals 40, 42, 52, the connection locations of the terminals 40, 42, 52 are as follows. The contact area at is relatively large. As a result, the conduction resistance at the connection location is small, and a decrease in the current collection efficiency in the fuel cell stack 400 can be suppressed.

  Further, in the present embodiment, the outer electrode terminal 42 and the connection terminal 52 are disposed in the gas tank 3 and are sealed in the gas tank 3, so that the outer electrode terminal 42 and the connection terminal 52 are connected to the power generation chamber. It is possible to prevent exposure to air (atmosphere) that has flowed into the interior 16. Thereby, the oxidation of the outer electrode terminal 42 and the connection terminal 52 is prevented, and the conduction resistance does not increase in the outer electrode terminal 42 and the connection terminal 52. Since the inner electrode terminal 40 is disposed inside the fuel battery cell 4, it is not exposed to the air that has flowed into the power generation chamber 16.

  As a material for the outer electrode terminal 42 and the connection terminal 52, it is also possible to use a relatively inexpensive metal material (for example, stainless steel). In this case, the cost of the fuel cell module FC can be reduced. Further, the main body portions 40a and 42a and the extending portions 40b and 42b are not necessarily formed integrally, and may be formed of separate members.

  In this embodiment, each fuel cell 4 (fuel cell unit 30) includes a gas tank protrusion that protrudes into the gas tank 3. And the inner side electrode terminal 40 and the outer side electrode terminal 42 are arrange | positioned at the protrusion part in the gas tank of the fuel cell 4 (fuel cell unit 30). Accordingly, the sealing arrangement of the outer electrode terminal 42 and the connection terminal 52 to the gas tank 3 can be realized reliably and easily.

  In the present embodiment, the inner electrode terminal 40 is electrically connected to the inner electrode surface 44a by being in surface contact with the inner electrode surface 44a. Thereby, the conduction | electrical_connection resistance in the connection location of the inner side electrode surface 44a and the inner side electrode terminal 40 can be aimed at, and the current collection performance in the fuel cell stack 400 can be improved further.

  Then, each modification of this embodiment is demonstrated, referring FIGS. 8-12.

  In the modification shown in FIG. 8, the extended portion 40b of the inner electrode terminal 40 and the extended portion 42b of the outer electrode terminal 42 are formed wide, and the inner electrode terminal 40 (extension portion 40b) and the outer electrode terminal are formed. The contact area with 42 (extension part 42b) is expanded. Thereby, in this modification, the conduction | electrical_connection resistance in the connection location of each terminal 40 and 42 is further reduced, and the current collection performance in the fuel cell stack 400 can be improved further.

  In the modification shown in FIGS. 9 to 11, the shape of each terminal 40, 42, 52 is different from the above-described embodiment.

  As shown in FIG. 10, the inner electrode terminal 40 has a main body portion 40a and an extended portion 40b. In the present embodiment, the extending portion 40 b is formed integrally with the main body portion 40 a and extends from the main body portion 40 a in the longitudinal direction of the fuel cell 4. The extending portion 40b has a curvature substantially the same as that of the main body portion 40a and is curved. A hole 40c through which the connection terminal 52 is inserted is formed in the extended portion 40b.

  As shown in FIG. 11, the outer electrode terminal 42 has a main body portion 42a and an extended portion 42b. In the present embodiment, the extending portion 42 b is formed integrally with the main body portion 42 a and extends from the main body portion 42 a in the longitudinal direction of the fuel cell 4. The extending portion 42b has a curvature substantially the same as that of the main body portion 42a and is curved. A hole 42c through which the connection terminal 52 is inserted is formed in the extending portion 42b.

  The connection terminal 52 has a substantially column shape. Since the extended portion 40b and the extended portion 42b extend in the longitudinal direction of the fuel cell 4, they are positioned with a predetermined distance from each other. The connection terminal 52 is spanned between the extension part 40b and the extension part 42b, and electrically connects the adjacent extension part 40b (inner electrode terminal 40) and extension part 42b (outer electrode terminal 42). is doing. The connection terminal 52 is fixed to the extension portions 40b and 42b in a state where the connection terminal 52 is inserted into the hole 40c formed in the extension portion 40b and the hole 42c formed in the extension portion 42b.

  In the modification shown in FIGS. 9 to 11, the extended portions 40 b and 42 b have substantially the same curvature as the main body portions 40 a and 42 a and have a shape that can be easily processed. For this reason, the inner electrode terminal 40 and the outer electrode terminal 42 can be provided relatively inexpensively, and the cost of the fuel cell module FC can be reduced.

  The modification shown in FIG. 12 is different from the modification shown in FIGS. 9 to 11 described above with respect to the configuration and arrangement of each fuel cell unit 30.

  The outer electrode terminal 42 is arranged such that a part of the main body portion 42a overlaps with one end 4a of the fuel cell 4 and the remaining portion of the main body portion 42a protrudes from the one end 4a. The inner electrode terminal 40 is arranged at one end 4a of the fuel cell 4 so that the main body portion 42a is located in the fuel cell 4 and the extending portion 40b protrudes from the one end 4a. .

The fuel cell unit 30 is supported by the support plate 400a so that the main body portion 42a of the outer electrode terminal 42 does not protrude from the surface of the support plate 400a (the surface facing the power generation chamber 16). In this modification, the fuel cell unit 30 is supported by the support plate 400a such that one end 4a substantially coincides with the back surface of the support plate 400a (the surface facing the bottom surface of the gas tank 3). The outer electrode terminal 42 is sealed by a sealing member 54 so as not to be exposed to the power generation chamber 16. Thereby, the outer electrode terminal 42 and the connection terminal (not shown) are disposed so as to be sealed in the gas tank 3. The sealing member 54 is made of a material having electrical insulation and heat resistance. Specifically, a ceramic adhesive or a glass sealing material is used. As the ceramic adhesive, alumina, zirconia, silica, magnesia, zircon or the like is used as a base, and a binder, a solvent, or the like is added. As the glass seal _{material, SiO 2, B 2 O 3} , MgO, CaO, Al 2 O 3, Na 2 O, that like K ₂ O is used as the component preferable.

  The outer electrode terminal 42 and the connection terminal 52 are not necessarily arranged in the gas tank 3 as a whole. The outer electrode terminal 42 and the connection terminal 52 are arranged so as to be sealed in the gas tank 3 even if a part thereof is located outside the internal space of the gas tank 3 as in the modification shown in FIG. Just do it. Of course, in order to reliably prevent the outer electrode terminal 42 and the connection terminal 52 from being exposed to the air (atmosphere) that has flowed into the power generation chamber 16, the entire outer electrode terminal 42 and the connection terminal 52 are in the gas tank 3. It is preferable to arrange | position.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims. Needless to say, these are also included within the scope of the present invention.

  In the present embodiment described above, the fuel cell stack 400 electrically connects 16 fuel cells 4 in series, but the number of fuel cells 4 to be connected is arbitrary. Further, regarding the arrangement of the fuel cells 4, the number of columns and rows is not limited to the number of the above-described embodiments, and is arbitrary.

It is a front view which shows the fuel cell module which concerns on this embodiment. It is a perspective view which shows a fuel cell assembly and a gas tank. It is a figure for demonstrating a fuel cell unit. It is a perspective view which shows an inner side electrode terminal. It is a perspective view which shows an outer side electrode terminal. It is a figure for demonstrating a fuel cell stack. It is a figure for demonstrating the arrangement structure of a fuel cell unit. It is a figure for demonstrating the fuel cell stack concerning the modification of this embodiment. It is a figure for demonstrating the arrangement structure of the fuel cell unit which concerns on the modification of this embodiment. It is a perspective view which shows the inner side electrode terminal which concerns on a modification. It is a perspective view which shows the outer side electrode terminal which concerns on a modification. It is a figure for demonstrating the arrangement structure of the fuel cell unit which concerns on the further modification of this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 3 ... Gas tank, 4 ... Fuel cell, 16 ... Power generation chamber, 17 ... Exhaust gas chamber, 18 ... Combustion part, 19 ... Ignition device, 30 ... Fuel cell unit, 40 ... Inner electrode terminal, 42 ... Outer electrode terminal, 44 ... inner electrode layer, 46 ... electrolyte layer, 48 ... outer electrode layer, 52 ... connecting terminal, 54 ... sealing member, 400 ... fuel cell stack, FC ... fuel cell module.

Claims (3)

A fuel cell unit used in a fuel cell,
A gas tank having an opening;
A first fuel battery cell having an internal passage communicating with the gas tank through the opening and having an outer electrode;
A second fuel cell having an internal passage communicating with the gas tank through the opening and having an inner electrode;
An outer electrode terminal electrically connected to the outer electrode of the first fuel cell;
An inner electrode terminal electrically connected to the inner electrode of the second fuel cell;
A conductive member that electrically connects the outer electrode terminal and the inner electrode terminal;
The fuel cell unit, wherein the outer electrode terminal and the conductive member are disposed so as to be sealed in the gas tank. Each of the first and second fuel cells includes a gas tank protruding portion protruding into the gas tank,
2. The fuel cell unit according to claim 1, wherein the outer electrode terminal is disposed in a protruding portion in the gas tank of the first fuel cell. The inner electrode is formed on the inner peripheral surface of the second fuel cell,
The fuel cell unit according to claim 1 or 2, wherein the inner electrode terminal is electrically connected to the inner electrode by being in surface contact with the inner electrode of the second fuel cell.

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