JP2017033653A - Solid oxide type fuel battery stack, solid oxide type fuel battery module and solid oxide type fuel battery system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid oxide type fuel battery stack, a solid oxide type fuel battery module and a solid oxide type fuel battery system which enable suppression of accidental fire during combustion of fuel off-gas and oxidant gas with a simple configuration, thereby enabling uniform combustion between the fuel off-gas and the oxidant gas.SOLUTION: A solid oxide type fuel battery stack (30) comprises a cell bundle group (36) and a surface combustion burner (38). The surface combustion burner (38) is provided on a side from which fuel of the cell bundle group (36) is discharged, and has a combustion surface (38a) formed like a mesh into which fuel off-gas discharged from a discharge side intercommunication port flows, the discharge side intercommunication port being at least one of a first intercommunication port and a second intercommunication port and also each intercommunication port on a side from which the fuel is discharged. The surface combustion burner (38) burns fuel off-gas passing through the combustion surface (38a) and oxidant gas in oxidant gas atmosphere.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a solid oxide fuel cell stack, a solid oxide fuel cell module, and a solid oxide fuel cell system in which a plurality of solid oxide fuel cell cylindrical cells are electrically connected.

  Examples of the invention relating to the solid oxide fuel cell stack include the inventions described in Patent Document 1 and Patent Document 2. In the fuel cell stack described in Patent Document 1, a combustion portion is provided above the fuel cell stack. The combustion section burns fuel gas that has not been used for power generation (hereinafter referred to as “fuel off-gas”) and air. Moreover, the cap-shaped member is provided in the edge part by the side of the combustion part of each fuel cell. The cap-shaped member has a tubular portion, and a connection flow path connected to the combustion section is formed. Accordingly, the fuel cell stack described in Patent Document 1 tries to burn the fuel off-gas in the combustion portion above the fuel cell stack by leading the fuel off-gas to the combustion portion.

  On the other hand, the fuel cell stack described in Patent Document 2 burns the first reaction gas and the second reaction gas that are not used for power generation at the end of the porous support. In addition, a metal cylindrical member processed into a slit shape or the like is joined to the end of the porous support on the fuel gas discharge side. Accordingly, the fuel cell stack described in Patent Document 2 is trying to improve the ignitability of the fuel off gas.

JP 2013-33740 A JP 2012-14850 A

  However, in the fuel cell stack described in Patent Document 1, a cap-like member is provided at the end of the fuel cell on the combustion portion side, and the fuel off gas is burned at the tip of the tubular portion. Therefore, when the pitch between adjacent fuel cells (cell pitch) becomes large, the flame of off-gas combustion may not be able to propagate to the adjacent fuel cells. As a result, when misfire occurs in some of the fuel cells, reignition cannot be performed, and unburned gas may be discharged. That is, there is a possibility that the amount of exhaust heat recovered from the fuel cell stack will decrease. Therefore, in order to avoid misfiring of the fuel cells, if it is attempted to narrow the cell pitch between adjacent fuel cells, the fuel cells need to be miniaturized, and the power generation output per fuel cell decreases. To do. For this reason, if an equivalent power generation output is to be obtained, it is necessary to increase the number of fuel cells, which may increase the manufacturing cost.

  On the other hand, in the fuel cell stack described in Patent Document 2, the cylindrical member provided on the porous support is processed into a slit shape or the like. Therefore, the shape of the cylindrical member is complicated, which may increase the manufacturing cost.

  The present invention has been made in view of such circumstances, and enables the suppression of misfire when the fuel off-gas and the oxidant gas are burned with a simple configuration, so that the fuel off-gas and the oxidant gas can be reduced. It is an object of the present invention to provide a solid oxide fuel cell stack, a solid oxide fuel cell module, and a solid oxide fuel cell system capable of uniform combustion.

  A solid oxide fuel cell stack according to the present invention includes a fuel electrode layer that is formed in a cylindrical shape and in which fuel flows from one end side to the other end side, and is laminated outside the fuel electrode layer in an oxidant gas atmosphere. One or a plurality of solid oxide fuel cell cylindrical cells, and an electrolyte layer formed between the fuel electrode layer and the oxidant gas electrode layer. Each fuel electrode layer of the solid oxide fuel cell cylindrical cell that is formed in a bottom cylindrical shape and is received so as to cover one end side of the one or more solid oxide fuel cell cylindrical cells A first main body electrically connected to the first main body, and one or a plurality of the first main body connected to the one end of each fuel flow channel of the solid oxide fuel cell tubular cell A first holder provided with a first series of openings, and the one or more formed in a bottomed cylindrical shape A second main body that is accommodated so as to cover the other end side of the solid oxide fuel cell cylindrical cell and is electrically connected to each of the oxidant gas electrode layers of the solid oxide fuel cell cylindrical cell And a second communication port portion provided in the second main body portion and communicating with the other end portion side of each fuel flow path of the solid oxide fuel cell tubular cell. A plurality of cell bundles including two cell bundles, and adjacent cell bundle groups arranged in a straight line so that the mounting directions in the longitudinal direction of the cell bundles are in the same direction or in the opposite direction, and the cell bundle group A discharge side communication port that is provided on the fuel discharge side, and is at least one of the first communication port portion and the second communication port portion and is a communication port portion on the fuel discharge side. In the form of a network through which the fuel off-gas discharged from the section circulates Comprising a made combustion surface, and a, a surface combustion burner for burning and oxidizing agent gas in the fuel off-gas and the oxidant gas atmosphere that has passed through the combustion surface.

  The solid oxide fuel cell stack according to the present invention includes the surface combustion burner that burns the fuel off-gas that has passed through the combustion surface and the oxidant gas in the oxidant gas atmosphere. The surface combustion burner can burn the fuel off-gas and the oxidant gas in a plane on the combustion surface, suppresses misfiring when the fuel off-gas and the oxidant gas burn, Can be stably burned. Moreover, the combustion surface of the surface combustion burner is formed in a mesh shape, and the fuel off-gas discharged from the discharge side communication port flows. Therefore, the surface combustion burner can reduce the variation in the flow rate of the fuel off gas discharged from the discharge side communication port, and can make the flow rate of the fuel off gas uniform. Therefore, the solid oxide fuel cell stack according to the present invention can suppress misfire when the fuel off-gas and the oxidant gas burn, and can uniformly burn the fuel off-gas and the oxidant gas.

1 is a configuration diagram illustrating an example of a solid oxide fuel cell system 1. FIG. FIG. 3 is a cross-sectional end view of the solid oxide fuel cell module 11 cut in a direction along the longitudinal direction of the solid oxide fuel cell cylindrical cell 31 (arrow Z direction). FIG. 3 is a side view of the cell bundle 35, the manifold 37, and the surface combustion burner 38 of FIG. 4 is a schematic diagram showing an example of a cell aggregate 32. FIG. It is sectional drawing which cut | disconnected the one solid oxide fuel cell cylindrical cell 31 in the direction (arrow Z direction) along the longitudinal direction. It is an end view of the VI-VI direction view of FIG. It is a top view which shows an example of the 1st control member 33f and the 2nd control members 34f and 34f. It is an end view of the VIII-VIII direction view of FIG.

<Solid oxide fuel cell system 1>
As shown in FIG. 1, the solid oxide fuel cell system 1 includes a power generation unit 10 and a hot water storage tank 21. The power generation unit 10 includes a solid oxide fuel cell module 11, a heat exchanger 12, a power conversion device 13, a water tank 14, and a control device 15.

  The solid oxide fuel cell module 11 includes at least a solid oxide fuel cell stack 30 as described later. The solid oxide fuel cell module 11 is supplied with a raw material for reforming, reforming water, and cathode gas (air). Specifically, the solid oxide fuel cell module 11 has one end connected to the supply source Gs and the other end of the reforming material supply pipe 11a to which the reforming material is supplied. A raw material pump 11a1 is provided in the reforming raw material supply pipe 11a. Further, the solid oxide fuel cell module 11 has one end connected to the water tank 14 and the other end of the water supply pipe 11b to which reformed water is supplied. The water supply pipe 11b is provided with a reforming water pump 11b1. Further, the solid oxide fuel cell module 11 has one end connected to the cathode air blower 11c1 and the other end of the cathode air supply pipe 11c to which cathode gas (air) is supplied.

  The heat exchanger 12 is a heat exchanger in which combustion exhaust gas exhausted from the solid oxide fuel cell module 11 is supplied and hot water stored in the hot water storage tank 21 is supplied, and heat is exchanged between the combustion exhaust gas and the hot water storage. is there. Specifically, the hot water storage tank 21 stores hot water, and is connected to a hot water circulation line 22 through which the hot water circulates (circulates in the direction of the arrow in FIG. 1). A hot water circulation pump 22a and the heat exchanger 12 are arranged on the hot water circulation line 22 in order from the lower end to the upper end. The heat exchanger 12 is connected (penetrated) with an exhaust pipe 11 d from the solid oxide fuel cell module 11. The heat exchanger 12 is connected to a condensed water supply pipe 12 a connected to the water tank 14.

  In the heat exchanger 12, the combustion exhaust gas from the solid oxide fuel cell module 11 is introduced into the heat exchanger 12 through the exhaust pipe 11d, and is cooled by being exchanged with the stored hot water. Water vapor contained in the combustion exhaust gas is condensed. The cooled combustion exhaust gas is discharged to the outside through the exhaust pipe 11d. Moreover, the condensed condensed water is supplied to the water tank 14 through the condensed water supply pipe 12a. Note that the water tank 14 can purify condensed water with ion exchange resin, for example.

  The heat exchanger 12, the hot water tank 21, and the hot water circulation line 22 described above constitute an exhaust heat recovery system 20. The exhaust heat recovery system 20 recovers and stores the exhaust heat of the solid oxide fuel cell module 11 in hot water storage.

  The power converter 13 receives the DC voltage output from the solid oxide fuel cell stack 30, converts it to a predetermined AC voltage, and is connected to an AC system power supply 16a and an external power load 16c (for example, an electrical appliance). To the power line 16b. Further, the power conversion device 13 inputs an AC voltage from the system power supply 16a via the power supply line 16b, or inputs a DC voltage of the solid oxide fuel cell stack 30, and converts it to a predetermined DC voltage to compensate. Output to the machine (each pump, blower, etc.) and the control device 15. The controller 15 controls the operation of the solid oxide fuel cell system 1 by driving an auxiliary machine.

<Solid Oxide Fuel Cell Module 11>
As shown in FIG. 2, the solid oxide fuel cell module 11 includes a solid oxide fuel cell stack 30, an evaporation unit 40, a reforming unit 50, and a power generation chamber 39.

(Solid oxide fuel cell stack 30)
As shown in FIG. 2, the solid oxide fuel cell stack 30 includes a cell bundle group 36, a manifold 37, and a surface combustion burner 38. In the cell bundle group 36, a plurality (five in the present embodiment) of cell bundles 35 are arranged in a straight line. Each of the plurality (five) of cell bundles 35 includes a cell assembly 32, a first holder 33, and a second holder 34. Further, as shown in FIGS. 3 and 4, the cell assembly 32 includes a plurality (three in this embodiment) of solid oxide fuel cell cylindrical cells 31, 31, 31 arranged in a straight line. ing. Hereinafter, the configuration of the solid oxide fuel cell cylindrical cell 31 will be described in order.

  As shown in FIG. 4, each of the plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 includes a fuel electrode layer 31a, an electrolyte layer 31b, and an oxidant gas electrode layer 31c. These are formed by laminating them in layers. The fuel electrode layer 31a is formed in a cylindrical shape, and the fuel flows from one end side (arrow Z1 direction side) to the other end side (arrow Z2 direction side). In the present embodiment, the fuel is a reformed gas obtained by reforming a hydrocarbon-based raw material such as natural gas described later, and is also referred to as an anode gas.

  The oxidant gas electrode layer 31c is laminated outside the fuel electrode layer 31a and is provided in an oxidant gas atmosphere. In the present embodiment, the oxidant gas is air and is also referred to as a cathode gas. The electrolyte layer 31b is formed between the fuel electrode layer 31a and the oxidant gas electrode layer 31c. That is, each of the plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 is formed in the order of the fuel electrode layer 31a, the electrolyte layer 31b, and the oxidant gas electrode layer 31c from the inside in the radial direction. ing.

  In addition, a ceria mixture doped with rare earth such as GDC (gadolinium doped ceria), YDC (yttria doped ceria), SDC (samarium doped ceria) is provided between the electrolyte layer 31b and the oxidant gas electrode layer 31c. The reaction preventing layer used can also be provided. In the present embodiment, each of the plurality (three) of the solid oxide fuel cell cylindrical cells 31, 31, 31 is formed in a cylindrical shape, but each solid oxide fuel cell cylindrical cell 31 should just be cylindrical, for example, can also be formed in a cross-sectional square shape.

  The fuel electrode layer 31a includes, for example, a mixture of a catalytic metal such as Ni or Fe and a stabilized zirconia doped with at least one selected from rare earth elements such as Y, Sc and Ce, and a catalytic metal such as Ni and Fe. A mixture of ceria doped with at least one kind of rare earth elements such as Gd, Y, Sm, lanthanum gallate doped with a catalytic metal such as Ni or Fe and at least one kind selected from Sr, Mg, Co, Fe, Cu And at least one kind of mixture.

  The electrolyte layer 31b includes, for example, stabilized zirconia doped with at least one selected from rare earth elements such as Y, Sc, and Ce, ceria doped with at least one selected from rare earth elements such as Gd, Y, and Sm, Ni, and Sr. , Lanthanum gallate doped with at least one selected from Mg, Co, Fe and Cu.

  The oxidant gas electrode layer 31c includes, 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 Lanthanum cobaltite doped with at least one selected from Ni, Cu, barium cobaltite doped with at least one selected from Sr, Fe, silver, silver-palladium alloy, platinum, etc. Is done.

  As shown in FIGS. 4 and 5, each of the plurality (three) of the solid oxide fuel cell cylindrical cells 31, 31, 31 has an end 31 e side of the fuel electrode layer 31 a exposed and a fuel. The other end 31f side of the electrode layer 31a is covered with an oxidant gas electrode layer 31c. Each of the plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 is formed with a fuel electrode layer connected portion 31 a 1 and an oxidant gas electrode layer connected portion 31 c 1. . The fuel electrode layer connected portion 31a1 is formed in the exposed portion on the one end portion 31e side of the fuel electrode layer 31a. The oxidant gas electrode layer connected portion 31c1 is formed on the other end 31h side of the oxidant gas electrode layer 31c.

  In the fuel electrode layer connected portion 31a1, the electrolyte layer 31b and the oxidant gas electrode layer 31c are not formed, but only the fuel electrode layer 31a is formed. A part of the electrolyte layer 31b is exposed. The method for forming the plurality (three) of the solid oxide fuel cell cylindrical cells 31, 31, 31 is not limited. For example, the fuel electrode layer 31a is formed by a known method such as extrusion, pressing, or casting. Sequentially, the electrolyte layer 31b and the oxidant gas electrode layer 31c can be formed by forming a film by a method such as printing, dipping or slurry coating.

  By these methods, each of the plurality (three) of the solid oxide fuel cell cylindrical cells 31, 31, 31 has the fuel electrode layer 31a, the electrolyte layer 31b, and the oxidant gas electrode layer 31c from the inside in the radial direction. In order, the above-described electrode materials are laminated in layers. Further, by performing masking according to the part at the stage of film formation, a part where the fuel electrode layer 31a is exposed and a part where the electrolyte layer 31b is exposed are formed. In addition, it is also possible to produce a plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 in which the outer diameter of an arbitrary part is changed by locally forming a film.

  Further, as shown in FIG. 5, each of the plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 includes the other end 31f of the fuel electrode layer 31a and the other of the fuel electrode layer 31a. The inner wall surface 31g is formed of the same material as the electrolyte layer 31b. Accordingly, an electrical short circuit between the fuel electrode layer 31a and the oxidant gas electrode layer 31c is suppressed on the other end 31f side of the fuel electrode layer 31a. The electrolyte layer 31b is denser than the fuel electrode layer 31a and the oxidant gas electrode layer 31c.

  4 and 5, one end side is illustrated as a side to which fuel is supplied (arrow Z1 direction side). The other end side is illustrated as a side from which fuel is discharged (arrow Z2 direction side). As will be described later, in the present embodiment, a plurality of (for example, 15) solid oxide fuel cell cylindrical cells 31 are electrically connected by both serial connection and parallel connection. Therefore, the attachment direction in the longitudinal direction (arrow Z direction) of the solid oxide fuel cell cylindrical cell 31 may be opposite to the attachment direction shown in FIGS. 4 and 5. In this case, one end side is a side from which fuel is discharged (arrow Z2 direction side), and the other end side is a side to which fuel is supplied (arrow Z1 direction side). Hereinafter, one end side and the other end side have the same direction.

  As shown in FIG. 4, a plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 are arranged in a straight line and electrically connected in parallel, and the cell assembly 32 is It is configured. A plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 constituting the cell assembly 32 are formed by a first conductive paste 32a in which adjacent fuel electrode layers 31a, 31a have conductivity. It is fixed and electrically connected. Further, in the plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 constituting the cell assembly 32, adjacent oxidant gas electrode layers 31c, 31c are made of the second conductive paste 32b. It is fixed and electrically connected.

As the first conductive paste 32a, for example, a conductive paste such as platinum, silver, copper, or a silver-palladium alloy or conductive ceramics can be used. As the conductive ceramic, for example, an ABO ₃ type perovskite oxide can be used, and a lanthanum cobaltite oxide having a relatively high electrical conductivity or a lanthanum chromite oxide stable in an oxidation-reduction atmosphere can be used. good.

  The second conductive paste 32b can be a conductive paste that is more porous than the first conductive paste 32a. The method for forming the porous conductive paste is not limited. For example, it can be formed by blending a binder with the same conductive paste material as the first conductive paste 32a. In this case, the binder is removed by heating to make it porous, and the conductive particles are baked to form a porous conductive paste.

  According to the solid oxide fuel cell stack 30 of this embodiment, adjacent fuel electrode layers 31a, 31a of the cell assembly 32 are fixed and electrically connected by the first conductive paste 32a having conductivity. Has been. Further, the oxidant gas electrode layers 31c, 31c adjacent to each other in the cell assembly 32 are fixed and electrically connected by a porous second conductive paste 32b as compared with the first conductive paste 32a. Therefore, as compared with the case where both the adjacent fuel electrode layers 31a, 31a and the adjacent oxidant gas electrode layers 31c, 31c of the cell assembly 32 are fixed by the first conductive paste 32a, the cell assembly 32 is provided. The stress (torsional stress) generated in a plurality (three) of the solid oxide fuel cell cylindrical cells 31, 31, 31 that constitutes a plurality of (three) solid oxide fuel cell cylindrical cells 31 is reduced. , 31, 31 are prevented from being damaged.

  Each of the plurality (in this embodiment, five) of cell bundles 35 includes a plurality (in this embodiment, three) of solid oxide fuel cell cylindrical cells 31, 31, 31, a first holder 33, and a first holder 33. Two holders 34 are provided. As described above, in the present embodiment, the plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 constitute a cell assembly 32. As shown in FIG. 6, a first holder 33 is provided on one end side (arrow Z1 direction side) of the cell assembly 32, and the other end side (arrow Z2 direction) of the cell assembly 32 is provided. The second holder 34 is provided on the side. The first holder 33 and the second holder 34 can be formed using, for example, ferritic stainless steel, lanthanum chromite, or the like.

  The first holder 33 includes a first main body portion 33a and a first series of opening portions 33b. The first main body 33a is accommodated so as to cover one end 32c side of a plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 (which constitute the cell assembly 32). The solid oxide fuel cell cylindrical cells 31, 31, 31 are electrically connected to the fuel electrode layers 31 a. Specifically, as shown in FIG. 6, the first main body portion 33a is formed in a bottomed cylindrical shape. The first main body portion 33a is disposed such that the inner wall surface of the first main body portion 33a covers a plurality (three) of fuel electrode layer connected portions 31a1, 31a1, and 31a1. The first conductive member 33e is provided in the first main body portion 33a, and each fuel electrode layer 31a (specifically, each fuel electrode layer connected portion 31a1) of the solid oxide fuel cell cylindrical cell 31 is provided. ) And the inner wall surface of the first main body 33a are electrically connected. For the first conductive member 33e, for example, a conductive paste similar to the first conductive paste 32a can be used.

  The first series passage portion 33b is provided in the first main body portion 33a, and each of a plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 (which constitute the cell assembly 32). It communicates with one end side (arrow Z1 direction side) of the fuel flow path 31d. The fuel flow path 31 d is formed in the fuel electrode layer 31 a of the solid oxide fuel cell cylindrical cell 31. The first continuous passage portion 33b is formed in a cylindrical shape, and is erected from the through hole 33a2 provided in the bottom portion 33a1 of the first main body portion 33a toward the side opposite to the fuel electrode layer 31a. In addition, the 1st main-body part 33a can also be provided with several 1st serial opening part 33b.

  The second holder 34 includes a second main body portion 34a and a second communication port portion 34b. The second main body 34a is accommodated so as to cover the other end 32d side of the plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 (which constitute the cell assembly 32). The solid oxide fuel cell cylindrical cells 31, 31, 31 are electrically connected to the oxidant gas electrode layers 31 c. Specifically, as shown in FIG. 6, the second main body portion 34a is formed in a bottomed cylindrical shape. The second main body portion 34a is disposed such that the inner wall surface of the second main body portion 34a covers a plurality (three) of the oxidant gas electrode layer connected portions 31c1, 31c1, 31c1. The second conductive member 34e is provided in the second main body 34a, and each oxidant gas electrode layer 31c (specifically, each oxidant gas electrode layer of the solid oxide fuel cell cylindrical cell 31). The connected portion 31c1) is electrically connected to the inner wall surface of the second main body portion 34a. For the second conductive member 34e, for example, a conductive paste similar to the first conductive paste 32a can be used.

  The second communication port portion 34b is provided in the second main body portion 34a, and each fuel of the plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 (which constitute the cell assembly 32). It communicates with the other end side (arrow Z2 direction side) of the channel 31d. The second communication port portion 34b is formed in a cylindrical shape, and is erected from the through hole 34a2 provided in the bottom portion 34a1 of the second main body portion 34a toward the side opposite to the fuel electrode layer 31a. In addition, the 2nd main-body part 34a can also provide the some 2nd communicating port part 34b.

  The first body 33a of the first holder 33 and the second body 34a of the second holder 34 may be formed with the same dimensions. In addition, the inner dimension of the first main body 33a is slightly larger than the outer dimension when the plurality (three) fuel electrode layer connected portions 31a1, 31a1, 31a1 of the cell assembly 32 are arranged in a straight line. The inner dimension of the second main body 34a is slightly larger than the outer dimension when the plurality of (three) oxidant gas electrode layer connected portions 31c1, 31c1, 31c1 of the cell assembly 32 are arranged in a straight line. You may form as follows.

  Further, each first holder 33 preferably includes a first buffer member 33c, and each second holder 34 preferably includes a second buffer member 34c. As shown in FIG. 6, the first buffer member 33c is provided in the first main body portion 33a. The first buffer member 33 c is formed in a flat plate shape, and a plurality of (three) solid oxide fuel cell cylindrical cells 31, 31, 31 (which constitute the cell assembly 32) constituting the cell bundle 35. It arrange | positions between one edge part 32c and the bottom part 33a1 of the 1st main-body part 33a.

  For example, a porous metal such as a nickel-based alloy, a stainless-based alloy, or a copper-based alloy or a mesh metal formed in a mesh shape can be used for the first buffer member 33c. Porous metal and mesh metal have a higher porosity than ordinary metal materials. Therefore, when a thermal stress is generated in a plurality (three) of the solid oxide fuel cell cylindrical cells 31, 31, 31 in a high temperature atmosphere, the first buffer member 33c The influence (for example, deformation etc.) by the thermal stress which arises in the one end part 32c side of the cylindrical cells 31, 31, and 31 can be relieved.

  Further, when the hole diameter of the first buffer member 33c is reduced, the pressure loss in each fuel flow path 31d increases, and when the hole diameter of the first buffer member 33c is increased, the pressure loss in each fuel flow path 31d decreases. Therefore, it is preferable that the hole diameter of the first buffer member 33c is set so that the fuel can be evenly distributed to each cell bundle 35 based on the allowable pressure loss. Thereby, the solid oxide fuel cell stack 30 can suppress variations in power generation caused by non-uniform fuel supply.

  Similarly, the second buffer member 34c is provided in the second main body portion 34a. The second buffer member 34 c is formed in a flat plate shape, and a plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 (which constitute the cell assembly 32) constituting the cell bundle 35. It is disposed between the other end 32d and the bottom 34a1 of the second main body 34a. The second shock absorbing member 34c can use the same porous metal or mesh metal as the first shock absorbing member 33c, and the first shock absorbing member 33c can obtain the same effects as those described above.

  According to the solid oxide fuel cell stack 30 of the present embodiment, each first holder 33 includes a first buffer member 33c, and each second holder 34 includes a second buffer member 34c. Therefore, the first buffer member 33c relieves thermal stress generated on one end portion 32c side of the plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 (which constitute the cell assembly 32). can do. In addition, the second buffer member 34c relieves thermal stress generated on the other end 32d side of the plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 (which constitute the cell assembly 32). can do. Therefore, the first buffer member 33c and the second buffer member 34c can suppress damage to the solid oxide fuel cell tubular cell 31 due to thermal stress.

Each first holder 33 preferably includes a first seal member 33d, and each second holder 34 preferably includes a second seal member 34d. As shown in FIG. 6, the first seal member 33d is provided in the first main body portion 33a, and the second seal member 34d is provided in the second main body portion 34a. The first seal member 33d and the second seal member 34d are, for example, amorphous glass seals mainly composed of alumina (Al ₂ O ₃ ), silica (SiO ₂ ), boron oxide (B ₂ O ₃ ), or the like. Materials can be used. The amorphous glass sealing material is softened at the time of the first temperature rise, and when the temperature is further raised after the softening, the amorphous glass seal material becomes a solid phase by the operating temperature of the solid oxide fuel cell stack 30. The amorphous glass sealing material has the property of being easily softened again with respect to the temperature rise after the solid phase as compared with the crystalline glass sealing material. As described above, the amorphous glass sealing material is a flexible sealing member as compared with the crystalline glass sealing material, and a dense gas seal is possible.

  The first seal member 33d may be disposed on the opening side of the first main body portion 33a with respect to the first conductive member 33e. The fuel electrode layer 31a is exposed on one end 32c side of the plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 (constituting the cell assembly 32) constituting the cell bundle 35. The fuel electrode layer connected portion 31a1 is formed. Therefore, the first conductive member 33e is provided on the bottom side of the first main body portion 33a. Therefore, the first seal member 33d is preferably disposed on the opening side of the first main body portion 33a with respect to the first conductive member 33e. In the present embodiment, the first seal member 33d is provided at a portion where the electrolyte layer 31b on the opening side of the first main body portion 33a is exposed with respect to the first conductive member 33e.

  On the other hand, the second seal member 34d is preferably disposed on the bottom side of the second main body 34a with respect to the second conductive member 34e. As shown in FIG. 5, each of a plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 (constituting a cell assembly 32) constituting the cell bundle 35 is formed of a fuel electrode layer 31 a. The other end 31f and the other inner wall surface 31g of the fuel electrode layer 31a are formed of the same material as the electrolyte layer 31b. That is, the electrolyte layer 31b is slightly on the other end 32d side of the plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 (which constitute the cell assembly 32) constituting the cell bundle 35. , Exposed. The exposed portion of the electrolyte layer 31b is provided on the bottom side of the second body portion 34a, and the oxidant gas electrode layer 31c is exposed on the opening side of the second body portion 34a. Therefore, it is necessary to suppress the outflow of fuel in the exposed portion of the electrolyte layer 31b. In the present embodiment, the second seal member 34d is provided at a portion where the electrolyte layer 31b on the bottom side of the second main body portion 34a is exposed with respect to the second conductive member 34e.

  According to the solid oxide fuel cell stack 30 of the present embodiment, each first holder 33 includes a first seal member 33d, and each second holder 34 includes a second seal member 34d. Therefore, the first sealing member 33d is the first sealing member 33d from the one end 32c side of the plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 (cell assembly 32) constituting the cell bundle 35. It is possible to prevent the fuel from leaking into the oxidant gas atmosphere through the one main body portion 33a. Further, the second seal member 34d is the second seal member 34d from the other end 32d side of the plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 (cell assembly 32) constituting the cell bundle 35. It is possible to prevent the fuel from leaking into the oxidant gas atmosphere through the two main body portions 34a.

  Further, each first holder 33 includes a first conductive member 33e, a first seal member 33d, and a first regulating member 33f, and each second holder 34 includes a second conductive member 34e, a second seal member 34d, and It is preferable that the second regulating members 34f and 34f are provided. In this case, as shown in FIG. 6, the first seal member 33d is preferably disposed on the opening side of the first main body portion 33a with respect to the first conductive member 33e. The first regulating member 33f is preferably provided between the first conductive member 33e and the first seal member 33d. That is, these members are preferably arranged in the order of the first seal member 33d, the first regulating member 33f, and the first conductive member 33e from the opening side of the first main body portion 33a.

  The first regulating member 33f can be formed of an insulating material having chemically stable and electrically insulating properties such as mica and alumina. As shown in FIG. 7, the first regulating member 33f is formed in a flat plate shape and includes a first through hole 33f1. The first through hole 33f1 is formed in a long hole shape, and a plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 (constituting a cell assembly 32) constituting the cell bundle 35. The one end portion 32c side can be penetrated collectively. Thereby, the first regulating member 33f positions the one end portion 32c side of the solid oxide fuel cell cylindrical cells 31, 31, 31 (which constitute the cell assembly 32) in the first main body portion 33a. can do.

  If the first holder 33 is not provided with the first restricting member 33f, a chemical reaction occurs between the first conductive member 33e and the first seal member 33d, and the metal contained in the first conductive member 33e. There is a possibility that a component (for example, silver or the like) becomes a gas phase and is scattered and diffused outside the first main body portion 33a. In the present embodiment, the first regulating member 33f is provided between the first conductive member 33e and the first seal member 33d in the first main body portion 33a. Therefore, the first regulating member 33f regulates the chemical reaction between the first conductive member 33e and the first seal member 33d, and the metal component (for example, silver) contained in the first conductive member 33e is the first. It is possible to suppress scattering to the outside of the one main body portion 33a.

  On the other hand, the second seal member 34d is preferably disposed on the bottom side of the second main body 34a with respect to the second conductive member 34e. Further, the second restricting members 34f and 34f are preferably provided in two layers so as to sandwich the second conductive member 34e from both sides in the depth direction of the second main body portion 34a. That is, these members are preferably arranged in the order of the second restricting member 34f, the second conductive member 34e, the second restricting member 34f, and the second seal member 34d from the opening side of the second main body 34a. .

  The second restricting members 34f and 34f are made of the same material as the first restricting member 33f and are each formed in a flat plate shape. The second regulating members 34f and 34f are each provided with a second through hole 34f1. The second through holes 34f1 and 34f1 are each formed in a long hole shape, and a plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 (cell assembly 32) constituting the cell bundle 35 are formed. The other end 32d side of the configuration) can be penetrated collectively. Accordingly, the second regulating members 34f and 34f are disposed on the other end 32d side of the solid oxide fuel cell cylindrical cells 31, 31, and 31 (constituting the cell assembly 32) in the second main body 34a. Can be positioned.

  If the second holder 34 is not provided with the second restricting members 34f and 34f, a chemical reaction occurs between the second conductive member 34e and the second seal member 34d, and the second conductive member 34e includes the second restricting member 34f. There is a possibility that the metal component (for example, silver or the like) that is generated becomes a gas phase and is scattered and diffused out of the second main body portion 34a. Further, since the second seal member 34d is provided on the bottom side of the second main body portion 34a with respect to the second conductive member 34e, the second conductive member 34e is also provided on the opening side of the second main body portion 34a. A regulating member that suppresses scattering of contained metal components is required. In the present embodiment, the second restricting members 34f and 34f are provided in two layers so as to sandwich the second conductive member 34e from both sides in the depth direction of the second main body portion 34a. Therefore, the second regulating members 34f and 34f regulate the chemical reaction between the second conductive member 34e and the second seal member 34d, and a metal component (for example, silver) contained in the second conductive member 34e. Can be prevented from being scattered outside the second main body portion 34a.

  According to the solid oxide fuel cell stack 30 of the present embodiment, the first holder 33 includes the first restricting member 33f, and the second holder 34 includes the second restricting members 34f and 34f. Therefore, the solid oxide fuel cell stack 30 of the present embodiment includes a plurality of (three) solid oxide fuel cell cylindrical cells 31, 31, 31 ( Positioning of one end portion 32c of the cell assembly 32) is easy, and a plurality (three) of solid oxide fuel cell tubular cells constituting the cell bundle 35 are formed in the second main body portion 34a. Positioning on the other end 32d side of 31, 31, 31 (which constitutes the cell aggregate 32) is easy. Therefore, the first conductive member 33e can be reliably filled between the inner wall surface of the first main body portion 33a and each fuel electrode layer connected portion 31a1, and the first main body portion 33a and each fuel electrode layer covered portion can be reliably filled. The electrical resistance between the connecting portion 31a1 can be reduced. Similarly, the second conductive member 34e can be reliably filled between the inner wall surface of the second main body portion 34a and each of the oxidant gas electrode layer connected portions 31c1, and the second main body portion 34a and each oxidation member can be reliably filled. The electrical resistance between the agent gas electrode layer connected portion 31c1 can be reduced. Furthermore, when the cell assembly 32, the first holder 33, and the second holder 34 are assembled, a positioning jig for the cell assembly 32 is not required, so that the workability of the assembly work is improved.

  Moreover, since the 1st holder 33 is provided with the 1st control member 33f, it controls the chemical reaction between the 1st electroconductive member 33e and the 1st seal member 33d, and is contained in the 1st electroconductive member 33e. It can suppress that a metal component (for example, silver etc.) scatters out of the 1st main-body part 33a. Moreover, since the 2nd holder 34 is equipped with the 2nd control members 34f and 34f, the chemical reaction between the 2nd electroconductive member 34e and the 2nd seal member 34d is controlled, and the 2nd electroconductive member 34e It can suppress that the metal component (for example, silver etc.) contained is scattered outside the 2nd main-body part 34a.

  Since the first restricting member 33f and the second restricting members 34f, 34f have the same shape, in FIG. 7, these are shown with reference numerals. Moreover, the shape of the 1st control member 33f can be formed according to the inner wall face of the 1st main-body part 33a, for example, The shape is not limited. In addition, for example, the shape of the first regulating member 33f may be changed in accordance with the outer shape of a plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 (which constitute the cell assembly 32). it can. The same applies to the second restricting members 34f and 34f. In the same figure, as a modification, the outer shape of the first restricting member 33f is indicated by a broken line curve 33f2, and the outer shape of the second restricting members 34f and 34f is indicated by a broken line curve 34f2. A curve 33f2 indicates a case where the outer shape of the first regulating member 33f is formed in accordance with the outer shape of the fuel electrode layer connected portion 31a1 (fuel electrode layer 31a). A curve 34f2 shows a case where the outer shape of the second regulating members 34f, 34f is formed in accordance with the outer shape of the oxidant gas electrode layer connected portion 31c1 (oxidant gas electrode layer 31c).

  As shown in FIGS. 2 and 8, the plurality (five) of cell bundles 35 are arranged in a straight line so that the attachment directions in the longitudinal direction (arrow Z direction) of the adjacent cell bundles 35 and 35 are opposite to each other. The cell bundle group 36 is configured. In the cell bundle group 36, the first holders 33 and the second holders 34 of the adjacent cell bundles 35 and 35 are electrically connected by being fixed with a conductive adhesive 36a or an insulating adhesive 36b.

  Specifically, a conductive adhesive 36a is applied between the first main body portion 33a of one cell bundle 35 and one second main body portion 34a of another adjacent cell bundle 35, An insulating adhesive 36b is applied between the first main body portion 33a of one cell bundle 35 and the other second main body portion 34a of another adjacent cell bundle 35. Further, an insulating adhesive 36b is applied between the second main body 34a of one cell bundle 35 and one first main body 33a of another adjacent cell bundle 35, so that one cell A conductive adhesive 36a is applied between the second main body 34a of the bundle 35 and the other first main body 33a of another adjacent cell bundle 35. In this way, a plurality (five) of cell bundles 35 are electrically connected in series, and a plurality (15) of solid oxide fuel cell cylindrical cells 31 constituting the cell bundle group 36 are connected in series and They are electrically connected by both parallel connections. Both end portions of the cell bundle group 36 are connected to the bus bar 36d via the bus bar connecting member 36c.

  The conductive adhesive 36a is not limited as long as it can fix the adjacent first main body portion 33a and second main body portion 34a and can electrically connect them. As the conductive adhesive 36a, for example, a conductive material similar to that of the first conductive paste 32a can be used. The insulating adhesive 36b is not limited as long as it can fix the adjacent first main body portion 33a and second main body portion 34a and can electrically insulate them. As the insulating adhesive 36b, for example, an insulating shim such as alumina or a ceramic adhesive such as ceramer bond can be used.

  According to the solid oxide fuel cell stack 30 of the present embodiment, the cell bundle 35 is configured with a plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 as a unit. Cell bundles 35 are arranged in a straight line to form a cell bundle group 36. Therefore, the solid oxide fuel cell stack 30 of the present embodiment includes a plurality (15) of solid oxide fuel cell cylindrical cells 31 as compared to the case where each of the solid oxide fuel cell cylindrical cells 31 is connected by a connecting member. The electrical connection of the solid oxide fuel cell cylindrical cell 31 can be simplified.

  Further, the adjacent fuel electrode layers 31a, 31a of the cell assembly 32 are fixed by the first conductive paste 32a, and the adjacent oxidant gas electrode layers 31c, 31c of the cell assembly 32 are connected by the second conductive material. It is fixed by the paste 32b. Further, the cell assembly 32 sandwiched between the first holder 33 and the second holder 34 is fixed via the first holder 33 and the second holder 34. Therefore, the solid oxide fuel cell stack 30 of the present embodiment can reduce stress (torsional stress) generated in a plurality (15) of solid oxide fuel cell cylindrical cells 31, and a plurality of (15) ) Can be prevented from being damaged.

  In addition, each first main body portion 33a preferably includes a pair of first contact surfaces 33a3 and 33a3, and each second main body portion 34a preferably includes a pair of second contact surfaces 34a3 and 34a3. As shown in FIG. 8, the pair of first contact surfaces 33a3 and 33a3 are formed on the outer wall surface of the first main body portion 33a, and can be in surface contact with the second main body portion 34a of another adjacent cell bundle 35. And formed in parallel to each other. Similarly, the pair of second contact surfaces 34a3 and 34a3 are formed on the outer wall surface of the second main body portion 34a, can be in surface contact with the first main body portion 33a of another adjacent cell bundle 35, and are mutually connected. They are formed in parallel.

  According to the solid oxide fuel cell stack 30 of the present embodiment, each first main body portion 33a includes a pair of first contact surfaces 33a3 and 33a3, and each second main body portion 34a includes a pair of second contact surfaces. 34a3 and 34a3 are provided. Therefore, it is easy to stack a plurality (five) of cell bundles 35, and the cell bundle group 36 can be easily configured. Further, the cell bundle group 36 can be made compact, and workability when assembling a plurality (five) of cell bundles 35 is improved. Furthermore, since the adjacent fuel electrode layer connected portion 31a1 and the oxidant gas electrode layer connected portion 31c1 can be connected with the shortest distance via the first holder 33 and the second holder 34, the solid oxide type The internal resistance of the fuel cell stack 30 can be reduced.

  When a plurality (five) of cell bundles 35 are connected in parallel, the pair of first contact surfaces 33a3 and 33a3 are formed so as to be in surface contact with the first main body portion 33a of another adjacent cell bundle 35. Can do. The pair of second contact surfaces 34a3 and 34a3 can be formed so as to be in surface contact with the second main body portion 34a of another adjacent cell bundle 35. In these cases, the same effects as those described above can be obtained.

  As shown in FIG. 2, the manifold 37 is formed in a box shape with a metal material (for example, stainless steel) and is provided on one end side (arrow Z1 direction side) of the cell bundle group 36. The manifold 37 is partitioned between the inside and the outside of the manifold 37 by a partition wall 37a. The partition wall 37a is provided with a fuel intake port 37b for introducing fuel into the manifold 37, and one end side of the fuel supply pipe 37b1 is connected to the partition wall 37a. The other end side of the fuel supply pipe 37b1 is connected to the reforming section 50, and fuel reformed by the reforming section 50, which will be described later, flows in the order of the fuel supply pipe 37b1 and the fuel intake port 37b, and is connected to the manifold. 37 is supplied to the inside.

  Here, as shown in FIG. 8, at least one of the first communication port 33 b and the second communication port 34 b, each communication port on the side to which fuel is supplied is defined as a supply-side communication port. 35a. Further, at least one of the first main body portion 33a and the second main body portion 34a and the main body portion on the side where the fuel is supplied is defined as a supply-side main body portion 35b. The supply side communication port portion 35 a passes through a through hole formed in the top plate of the partition wall 37 a, and each distal end portion projects into the manifold 37. An insulating seal member 37c is provided between the outer wall surface at the bottom of the supply-side main body portion 35b and the top plate of the partition wall 37a.

  As the insulating seal member 37c, a member having electrical insulation and capable of gas sealing can be used. For the insulating seal member 37c, for example, crystallized glass mainly composed of alumina, silica, or the like can be used. The insulating seal member 37c is preferably formed in a sheet shape. The crystallized glass softens at the time of the first temperature rise, and flows so as to close a gap between the through hole formed in the top plate of the partition wall 37a and the supply side communication port 35a. When the temperature is further increased after the softening, the crystallized glass is crystallized and becomes a solid phase by the operating temperature of the solid oxide fuel cell stack 30, and the solid phase is maintained. Crystallized glass is less likely to soften in a high-temperature atmosphere than non-crystallized glass. Therefore, the insulating seal member 37c uses a crystallized glass to achieve electrical insulation and gas seal, and also to maintain the structure of the solid oxide fuel cell stack 30 even in a high temperature atmosphere. Is easy.

  According to the solid oxide fuel cell stack 30 of the present embodiment, the supply side communication port portion 35 a passes through the through hole formed in the top plate of the partition wall 37 a, and each tip portion protrudes into the manifold 37. ing. Further, an insulating seal member 37c is provided between the outer wall surface at the bottom of the supply side main body portion 35b and the top plate of the partition wall 37a. Further, the insulating seal member 37c is made of crystallized glass, and closes the gap between the through hole formed in the top plate of the partition wall 37a and the supply side communication port 35a. Thus, the solid oxide fuel cell stack 30 of the present embodiment electrically insulates between the cell bundle group 36 and the manifold 37, and the fuel passes through the gap and passes from the manifold 37 to the oxidizing gas atmosphere. Gas leaks flowing out can be suppressed.

  The surface combustion burner 38 is provided on the side from which the fuel of the cell bundle group 36 is discharged (arrow Z2 direction side). As shown in FIGS. 2 and 8, the surface combustion burner 38 has a combustion surface 38a. The combustion surface 38a is formed in a mesh shape, and fuel off-gas and oxidant gas in the oxidant gas atmosphere are supplied to the combustion surface 38a. The surface combustion burner 38 can suppress local combustion by burning the fuel off-gas and the oxidant gas in a planar shape on the combustion surface 38a. The combustion surface 38a can be formed, for example, by weaving heat-resistant ceramic fibers or heat-resistant metal fibers. Moreover, when forming the combustion surface 38a using a ceramic fiber, the material (for example, silicon carbide etc.) excellent in heat resistance and durability can also be coated on a ceramic fiber. Thereby, the durability of the combustion surface 38a is improved, and stable radiant heat can be obtained from the red-hot combustion surface 38a. The surface combustion burner 38 can also include a combustion catalyst such as platinum. Thereby, the surface combustion burner 38 can accelerate | stimulate the said combustion in the combustion surface 38a.

  Here, as shown in FIG. 8, each communication port portion on the side from which fuel is discharged is at least one of the first series port portion 33b and the second communication port portion 34b. 35c. In addition, each of the first main body portion 33a and the second main body portion 34a on the side from which the fuel is discharged is referred to as a discharge-side main body portion 35d. On the combustion surface 38a of the surface combustion burner 38, the fuel off-gas discharged from the discharge side communication port portion 35c flows. Therefore, the solid oxide fuel cell stack 30 of the present embodiment can use the fuel off-gas that has not been used for power generation as the fuel for combustion of the surface combustion burner 38, and can be used for combustion of the surface combustion burner 38. There is no need to prepare a separate fuel supply source.

  In the surface combustion burner 38, the fuel off-gas and the oxidant gas are burned in a planar shape on the combustion surface 38a, so that compared with the case where the fuel off-gas and the oxidant gas are burned only at the tip of the discharge side communication port 35c. , Less likely to misfire (blown out). Even if a misfire occurs in a part of the combustion surface 38a, re-ignition and re-combustion are possible due to the transfer of fire from the other areas. Thus, the surface combustion burner 38 can suppress misfire when the fuel off-gas and the oxidant gas are burned, and can stably burn the fuel off-gas and the oxidant gas.

  Further, when the mesh (mesh size) of the combustion surface 38a is reduced, the pressure loss at the combustion surface 38a increases, and when the mesh (mesh size) of the combustion surface 38a is increased, the pressure loss at the combustion surface 38a decreases. Therefore, the combustion surface 38a can adjust the flow rate of the fuel off gas discharged from the discharge side communication port portion 35c depending on the size of the mesh (mesh size), and the fuel off gas discharged from the discharge side communication port portion 35c can be adjusted. The variation in the flow rate can be reduced, and the flow rate of the fuel off gas can be made uniform.

  According to the solid oxide fuel cell stack 30 of the present embodiment, the surface combustion burner 38 for burning the fuel off-gas that has passed through the combustion surface 38a and the oxidant gas in the oxidant gas atmosphere is provided. The surface combustion burner 38 can burn the fuel off-gas and the oxidant gas in a plane on the combustion surface 38a, suppresses misfiring when the fuel off-gas and the oxidant gas burn, and suppresses the fuel off-gas and the oxidant. Gas can be combusted stably. Further, the combustion surface 38a of the surface combustion burner 38 is formed in a mesh shape, and the fuel off-gas discharged from the discharge side communication port 35c circulates. Therefore, the surface combustion burner 38 can reduce the variation in the flow rate of the fuel off gas discharged from the discharge side communication port 35c, and can make the flow rate of the fuel off gas uniform. Therefore, the solid oxide fuel cell stack 30 of the present embodiment can suppress misfire when the fuel off-gas and the oxidant gas are burned, and can uniformly burn the fuel off-gas and the oxidant gas.

  Although the shape of the combustion surface 38a of the surface combustion burner 38 is not limited, it is preferable that the combustion surface 38a of the surface combustion burner 38 is formed in a sheet shape. In the surface combustion burner 38, it is preferable that the combustion surface 38a is formed in a rectangular wave shape along the outer wall surface of the bottom portion of the discharge side main body portion 35d and the outer shape of the discharge side communication port portion 35c. As shown in FIG. 8, in the present embodiment, the sheet-like combustion surface 38a is formed in a rectangular wave shape, and the combustion surface 38a includes the outer wall surface at the bottom of the discharge-side main body portion 35d and the discharge-side communication port portion. It is disposed along the outer shape of 35c. For example, the combustion surface 38a can be formed in a rectangular wave shape by weaving ceramic fibers or metal fibers into a sheet shape, extruding a member formed in the sheet shape, and drawing. In this case, a portion (rectangular wave recess) disposed on the outer wall surface of the bottom of the discharge-side main body portion 35d may be formed under pressure. Thereby, the mesh shape of the site | part (convex part of a rectangular wave) which contact | connects the discharge side communication port part 35c among the combustion surfaces 38a is hold | maintained.

  Insulating adhesive 38b is applied between the combustion surface 38a and the outer wall surface of the bottom of the discharge-side main body 35d, and the combustion surface 38a and the outer wall surface of the bottom of the discharge-side main body 35d are electrically connected. It is insulated and fixed. The insulating adhesive 38b is not limited as long as it can fix the combustion surface 38a and the outer wall surface at the bottom of the discharge-side main body portion 35d and can electrically insulate them. As the insulating adhesive 38b, for example, an adhesive similar to the insulating adhesive 36b can be used. In addition, when the combustion surface 38a is formed with electroconductive members, such as a metal fiber, it is necessary to insulate also the outer wall surface of the discharge side communication port part 35c.

  According to the solid oxide fuel cell stack 30 of the present embodiment, the surface combustion burner 38 has a combustion surface 38a formed in a sheet shape. In the surface combustion burner 38, the combustion surface 38a is formed in a rectangular wave shape along the outer wall surface at the bottom of the discharge-side main body portion 35d and the outer shape of the discharge-side communication port portion 35c. Therefore, the surface combustion burner 38 is easy to dispose the combustion surface 38a. Specifically, the discharge side holder (which is at least one of the first holder 33 and the second holder 34 and on the side from which the fuel is discharged, which is the same hereinafter) is covered with the combustion surface 38a. By attaching to, it is easy to position the combustion surface 38a in the protruding direction (arrow Z direction) of the discharge side communication port portion 35c.

  As shown in FIG. 2, the surface combustion burner 38 includes an ignition device 38c on the oxidant gas delivery side. The ignition device 38c can ignite between a pair of rods (not shown) extending from the combustion surface 38a. Thereby, the surface combustion burner 38 can control the ignition in the combustion surface 38a, and can suppress the damage and backfire of the combustion surface 38a. For example, an igniter can be used as the ignition device 38c. When ignited by the ignition device 38c, the flame moves from the left side of FIG. 2 toward the right side of the paper.

  Although the method of assembling the cell bundle group 36, the manifold 37, and the surface combustion burner 38 is not limited, for example, an assembling method including the following first to fifth steps can be used. In the first step, a plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 are arranged in a straight line, and adjacent fuel electrode layers 31 a, 31 a and a first conductive paste therebetween. 32a is applied, and the adjacent oxidant gas electrode layers 31c, 31c and the second conductive paste 32b are applied between them and dried. As a result, a plurality (three) of solid oxide fuel cell cylindrical cells 31, 31, 31 are fixed and electrically connected in parallel to obtain a cell assembly 32.

  In the second step, the first buffer member 33c, the first conductive member 33e, the first regulating member 33f, and the first seal member 33d are laminated in this order in the first main body portion 33a of the first holder 33, In this step, one end side of the cell assembly 32 obtained in the process is accommodated in the first holder 33 and fired to fix the cell assembly 32 and the first holder 33. In the third step, the second buffer member 34c, the second seal member 34d, the second restriction member 34f, the second conductive member 34e, and the second restriction member 34f are placed in the second body 34a of the second holder 34. The other end side of the cell assembly 32 to which the first holder 33 obtained in the second step is fixed is housed in the second holder 34 and fired, and the cell assembly 32 and the second holder 34 are stacked. Is a step of fixing Thereby, the cell aggregate 32, the first holder 33, and the second holder 34 are fixed, and the cell bundle 35 is obtained. In addition, the order of a 2nd process and a 3rd process is not ask | required. Further, by repeating the first to third steps, a plurality (five) of cell bundles 35 are obtained.

  The fourth step is a step of applying and fixing the conductive adhesive 36 a and the insulating adhesive 36 b between the adjacent cell bundles 35, 35. Specifically, the cell bundles 35 and 35 adjacent to each other (five cell bundles 35) are arranged in a straight line so that the attachment direction in the longitudinal direction (arrow Z direction) is opposite. Then, a conductive adhesive 36a is applied between the first main body portion 33a of one cell bundle 35 and one second main body portion 34a of another adjacent cell bundle 35. An insulating adhesive 36b is applied between the first main body portion 33a and the other second main body portion 34a of another adjacent cell bundle 35. Further, an insulating adhesive 36b is applied between the second main body 34a of one cell bundle 35 and one first main body 33a of another adjacent cell bundle 35, and the A conductive adhesive 36a is applied between the second main body 34a and the other first main body 33a of another adjacent cell bundle 35. By repeating this, a plurality (five) of cell bundles 35 are fixed, and a plurality (15) of solid oxide fuel cell cylindrical cells 31 constituting the plurality (five) of cell bundles 35 are connected in series. The cell bundle group 36 electrically connected by both connection and parallel connection is obtained.

  The fifth step is a step of fixing the cell bundle group 36, the manifold 37, and the surface combustion burner 38. Specifically, a through-hole formed in the top plate of the partition wall 37a of the manifold 37 with the supply-side communication port 35a of the cell bundle group 36 sandwiching the insulating seal member 37c between the cell bundle group 36 and the manifold 37. Insert into. Further, an insulating adhesive 38b is applied between the combustion surface 38a and the outer wall surface of the bottom of the discharge side main body portion 35d, and the discharge side holder is mounted so as to cover the combustion surface 38a. Then, the cell bundle group 36, the manifold 37, and the surface combustion burner 38 are fired in an electric furnace or the like. Thereby, the cell bundle group 36, the manifold 37, and the surface combustion burner 38 are fixed.

  The power generation chamber 39 is formed in a box shape with a metal material (for example, stainless steel), and is supplied with fuel and oxidant gas (air). As shown in FIG. 2, the power generation chamber 39 is partitioned between the inside and the outside of the power generation chamber 39 by a partition wall 39a. The partition 39 a has an opening 390 that opens downward, and the opening 390 is closed by the partition 37 a of the manifold 37. Thereby, the inside of the power generation chamber 39 is sealed. The cell bundle group 36, the surface combustion burner 38, and the evaporation unit 40 and the reforming unit 50 described later are provided in the power generation chamber 39.

  An oxidant gas introduction pipe 39b for introducing an oxidant gas into the power generation chamber 39 is provided through the partition wall 39a in the vicinity of the opening 390, and one end of the cathode air supply pipe 11c is connected to the partition wall 39a. . The oxidant gas flows through the cathode air supply pipe 11 c and the oxidant gas introduction pipe 39 b in this order, and is supplied into the power generation chamber 39. The oxidant gas introduction pipe 39b is branched, and a delivery port 39c is provided in one of the branched oxidant gas introduction pipes 39b. The other branched oxidant gas introduction pipe 39b is provided with a delivery port 39d.

  The delivery port 39 c can define the delivery direction of the oxidant gas inside the power generation chamber 39. The delivery port 39c delivers an oxidant gas toward each oxidant gas electrode layer 31c of the plurality (15) of solid oxide fuel cell cylindrical cells 31 constituting the cell bundle group 36. Specifically, the oxidant gas delivered from the delivery port 39c circulates from the left side to the right side in FIG. As a result, the oxidant gas is supplied to each oxidant gas electrode layer 31 c of the plurality (15) of solid oxide fuel cell cylindrical cells 31 constituting the cell bundle group 36. In FIG. 2, the flow direction of the oxidant gas delivered from the delivery port 39c is schematically shown using the arrow Dc1 direction.

  Similarly to the delivery port 39c, the delivery port 39d can define the delivery direction of the oxidant gas inside the power generation chamber 39. The delivery port 39d delivers oxidant gas along the combustion surface 38a of the surface combustion burner 38. Specifically, the oxidant gas delivered from the delivery port 39d circulates from the left side to the right side in FIG. As a result, the oxidant gas is supplied along the combustion surface 38 a of the surface combustion burner 38. Further, the flame moves from the left side of FIG. 2 to the right side of the paper. In FIG. 2, the flow direction of the oxidant gas delivered from the delivery port 39c is schematically shown using the arrow Dc2 direction.

  It is preferable that the solid oxide fuel cell system 1 includes the oxidant gas supply amount adjustment unit 38d. The oxidant gas supply amount adjusting unit 38d supplies oxidant gas to be supplied to the combustion surface 38a of the surface combustion burner 38 in accordance with the discharge amount of the fuel offgas so that the fuel offgas and the oxidant gas are not incompletely combusted. Adjust the amount.

  The oxidant gas supply amount adjusting unit 38d calculates a supply amount of the oxidant gas supplied to the combustion surface 38a of the surface combustion burner 38, and supplies the oxidant gas based on the calculation result of the calculation device. And an adjusting device for adjusting the amount. In the present embodiment, the arithmetic device of the oxidant gas supply amount adjusting unit 38d is provided in the arithmetic device (not shown) of the control device 15. The adjusting device of the oxidizing gas supply amount adjusting unit 38d is provided in the oxidizing gas introduction pipe 39b. As shown in FIG. 2, the adjustment device of the oxidant gas supply amount adjustment unit 38d is, for example, a flow rate adjustment valve capable of adjusting the flow rate of the oxidant gas, and is supplied from the branch pipe of the oxidant gas introduction pipe 39b. It is provided upstream of the branch pipe on the side where the outlet 39d is provided.

  The control device 15 determines each supply amount of fuel and oxidant gas to be supplied to the cell bundle group 36 in accordance with a necessary power generation amount. The control device 15 (oxidant gas supply amount adjusting unit 38d) estimates the discharge amount of the fuel off-gas discharged from the cell bundle group 36 based on the supply amounts of fuel and oxidant gas. The control device 15 (oxidant gas supply amount adjusting unit 38d) is configured to burn the combustion surface 38a of the surface combustion burner 38 so that the fuel offgas and the oxidant gas do not incompletely burn based on the estimated value of the fuel offgas emission. The supply amount of the oxidant gas supplied to is determined.

  For example, the control device 15 (oxidant gas supply amount adjusting unit 38d) has a ratio of the fuel offgas discharge amount and the oxidant gas supply amount to a theoretical ratio of a chemical reaction in which the fuel offgas and the oxidant gas burn. Thus, the supply amount of the oxidant gas can be set. The relationship between each supply amount of the fuel and the oxidant gas and the discharge amount of the fuel off gas can be derived in advance by, for example, simulation, verification by an actual machine, or the like. The same applies to the supply amount of the oxidant gas that does not cause incomplete combustion of the fuel off-gas and the oxidant gas. Note that an actual measurement value can be used as the amount of fuel off-gas discharged.

  The flow rate adjusting valve (oxidant gas supply amount adjusting unit 38d) adjusts the flow rate of the oxidant gas supplied to the combustion surface 38a of the surface combustion burner 38 based on the determined supply amount of the oxidant gas (for example, opens the oxidant gas supply amount adjustment unit 38d). Adjust the degree). Thereby, the supply amount of the oxidant gas supplied from the delivery port 39d to the combustion surface 38a of the surface combustion burner 38 is adjusted to the appropriate supply amount described above.

  According to the solid oxide fuel cell system 1 of the present embodiment, the oxidant gas supply amount adjustment unit 38d is provided. The oxidant gas supply amount adjusting unit 38d supplies oxidant gas to be supplied to the combustion surface 38a of the surface combustion burner 38 in accordance with the discharge amount of the fuel offgas so that the fuel offgas and the oxidant gas are not incompletely combusted. Adjust the amount. Therefore, the oxidant gas supply amount adjusting unit 38d can suppress the incomplete combustion of the fuel offgas and the oxidant gas by making the mixing ratio of the fuel offgas and the oxidant gas appropriate. Further, since the oxidant gas supply amount adjusting unit 38d can make the mixing ratio of the fuel off gas and the oxidant gas appropriate, it is possible to suppress abnormal flame extension on the combustion surface 38a of the surface combustion burner 38. It is possible to suppress a decrease in radiation efficiency.

  In the power generation chamber 39, power is generated by the fuel supplied from the manifold 37 and the oxidant gas sent from the outlet 39c. The fuel is supplied to each fuel electrode layer 31a of a plurality (15 pieces) of solid oxide fuel cell cylindrical cells 31 constituting the cell bundle group 36 via the supply side communication port 35a. Further, the fuel off-gas discharged from the cell bundle group 36 and the oxidant gas delivered from the delivery port 39d are supplied to the combustion surface 38a of the surface combustion burner 38, and the fuel off-gas and oxidant gas are combusted. One or more (two in the present embodiment) exhaust ports 39d and 39d are provided in the ceiling portion of the power generation chamber 39, and combustion exhaust gas passes through the plurality (two) of exhaust ports 39d and 39d. Exhausted. In FIG. 2, the flow direction of the combustion exhaust gas at each exhaust port 39d is schematically shown using the arrow De1 direction.

(Evaporation part 40)
The evaporator 40 is provided above the combustion surface 38 a of the surface combustion burner 38. The evaporator 40 is heated by combustion on the combustion surface 38a of the surface combustion burner 38. Thus, the evaporation unit 40 evaporates the supplied reforming water to generate water vapor and preheats the supplied reforming raw material. The evaporation unit 40 mixes the generated water vapor and the preheated reforming raw material and supplies the mixture to the reforming unit 50. As reforming raw materials, there are gas raw materials for reforming such as natural gas and LP gas, and liquid raw materials for reforming such as kerosene, gasoline, and methanol. In this embodiment, natural gas is used as the raw material for reforming. .

  The other end of the water supply pipe 11 b whose one end (lower end) is connected to the water tank 14 is connected to the evaporation unit 40. The evaporating unit 40 is connected to a reforming material supply pipe 11a having one end connected to the supply source Gs. The supply source Gs is, for example, a gas supply pipe for city gas or a gas cylinder for LP gas.

(Reformer 50)
The reforming unit 50 is provided above the combustion surface 38 a of the surface combustion burner 38. The reforming unit 50 is heated by combustion on the combustion surface 38a of the surface combustion burner 38. Thereby, the reforming unit 50 is supplied with heat necessary for the steam reforming reaction, and generates a reformed gas that is a fuel from the steam supplied from the evaporation unit 40 and the mixed gas of the reforming raw material. The reforming section 50 is filled with a catalyst (for example, Ru or Ni-based catalyst), and the mixed gas reacts with the catalyst to be reformed to generate a gas containing hydrogen and carbon monoxide. (So-called steam reforming reaction).

  The generated gas (so-called reformed gas) is the above-described anode gas, and a plurality (15) of solid oxide fuel cell cylindrical cells are passed through the manifold 37 of the solid oxide fuel cell stack 30. The fuel electrode layers 31a are led out to the fuel electrode layers 31a. The reformed gas contains hydrogen, carbon monoxide, carbon dioxide, steam, unreformed natural gas (methane gas), and reformed water (steam) that has not been used for reforming. As described above, the reforming unit 50 generates reformed gas (fuel) from the reforming raw material and the reformed water, and supplies the reformed gas (fuel) to the solid oxide fuel cell stack 30. The steam reforming reaction is an endothermic reaction.

  According to the solid oxide fuel cell module 11 of the present embodiment, the solid oxide fuel cell module 11 including the solid oxide fuel cell stack 30, the evaporation unit 40, and the reforming unit 50 is described above. The effects of the solid oxide fuel cell stack 30 can be obtained. Moreover, according to the solid oxide fuel cell system 1 of the present embodiment, the power generation including the solid oxide fuel cell module 11, the heat exchanger 12, the power conversion device 13, the water tank 14, and the control device 15. In the solid oxide fuel cell system 1 including the unit 10 and the hot water storage tank 21, it is possible to obtain the effects of the solid oxide fuel cell stack 30 described above.

<Others>
The present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with appropriate modifications within the scope not departing from the gist. For example, the number of solid oxide fuel cell cylindrical cells 31 constituting the cell bundle 35 can be changed as appropriate. Similarly, the number of cell bundles 35 constituting the cell bundle group 36 can be changed as appropriate. Further, the solid oxide fuel cell stack 30 can include a plurality of cell bundle groups 36. Further, the surface combustion burner 38 can also circulate the combustion surface 38a by previously mixing the fuel off-gas discharged from the discharge side communication port 35c and the oxidant gas in the oxidant gas atmosphere.

  As shown in FIG. 2 and FIG. 8, in the embodiment, the cell bundle group 36 has the cell bundles 35, 35 adjacent to each other with a plurality (five) of cell bundles 35, and the attachment direction in the longitudinal direction (arrow Z direction) is reversed. It is arranged in a straight line so as to be in the direction. Therefore, in the cell bundle group 36, a plurality (15 pieces) of solid oxide fuel cell cylindrical cells 31 constituting a plurality (five) of cell bundles 35 are electrically connected by both serial connection and parallel connection. The The cell bundle group 36 can be arranged in a straight line so that a plurality (five) of cell bundles 35 are adjacent to each other in the same direction of attachment in the longitudinal direction (arrow Z direction). . In this case, in the cell bundle group 36, a plurality (15 pieces) of solid oxide fuel cell cylindrical cells 31 constituting a plurality (five) of cell bundles 35 are electrically connected by parallel connection.

  In this case, the supply side communication port portion 35a is only one of the first communication port portion 33b and the second communication port portion 34b (for example, only the first communication port portion 33b), and the supply side main body portion 35b. Is only one of the first main body 33a and the second main body 34a (for example, only the first main body 33a). Further, the discharge side communication port portion 35c is only the other one of the first communication port portion 33b and the second communication port portion 34b (in the above case, only the second communication port portion 34b), and the discharge side main body portion 35d. Is only the other of the first body part 33a and the second body part 34a (in the above case, only the second body part 34a). In addition, some cell bundles 35 (for example, two cell bundles 35 and 35) of the plurality (five) of cell bundles 35 are set as one of serial connection and parallel connection, and a plurality of (five) The other cell bundles 35 (for example, the remaining three cell bundles 35, 35, and 35) may be the other of the serial connection and the parallel connection.

  Thus, the cell bundle group 36 is linear so that a plurality (five) of cell bundles 35 are adjacent to each other in the longitudinal direction (arrow Z direction). Side by side. Thereby, the plurality (15) of solid oxide fuel cell cylindrical cells 31 constituting the plurality (five) of cell bundles 35 are electrically connected by at least parallel connection of series connection and parallel connection. The Each cell bundle 35 can also include one solid oxide fuel cell cylindrical cell 31. In this case, the cell assembly 32 is not configured, and a plurality (five) of the solid oxide fuel cell cylindrical cells 31 constituting the plurality (five) of cell bundles 35 are connected in series connection or parallel connection. It is electrically connected by at least one.

1: Solid oxide fuel cell system,
10: power generation unit,
11: Solid oxide fuel cell module, 12: Heat exchanger, 13: Power conversion device,
14: Water tank, 15: Control device, 16a: System power supply, 16b: Power supply line,
21: Hot water tank
30: Solid oxide fuel cell stack,
31: Solid oxide fuel cell cylindrical cell,
31a: fuel electrode layer, 31b: electrolyte layer, 31c: oxidant gas electrode layer, 31d: fuel flow path,
32: Cell aggregate, 32a: First conductive paste, 32b: Second conductive paste,
33: 1st holder, 33a: 1st main-body part, 33a1: Bottom part, 33b: 1st serial opening part,
33c: first buffer member, 33d: first seal member, 33e: first conductive member,
33f: first regulating member, 33f1: first through hole,
34: 2nd holder, 34a: 2nd main-body part, 34a1: Bottom part, 34b: 2nd communicating port part,
34c: second buffer member, 34d: second seal member, 34e: second conductive member,
34f, 34f: second regulating member, 34f1, 34f1: second through hole,
35: Cell bundle, 35c: Discharge side communication port portion, 35d: Discharge side main body portion,
36: Cell bundle group,
38: surface combustion burner, 38a: combustion surface, 38d: oxidant gas supply amount adjusting unit,
40: evaporation part, 50: reforming part.

Claims (9)

A fuel electrode layer that is formed in a cylindrical shape and in which fuel flows from one end side to the other end side, an oxidant gas electrode layer that is stacked outside the fuel electrode layer and provided in an oxidant gas atmosphere, and the fuel electrode One or more solid oxide fuel cell tubular cells comprising a layer and an electrolyte layer formed between the oxidant gas electrode layer;
Each of the fuel electrodes of the solid oxide fuel cell cylindrical cell is formed in a bottomed cylindrical shape so as to cover one end side of the one or more solid oxide fuel cell cylindrical cells. A first body part electrically connected to the layer, and one communicating with the one end part side of each fuel flow path of the solid oxide fuel cell tubular cell provided in the first body part or A first holder comprising a plurality of first series opening portions;
Each of the oxidizers of the solid oxide fuel cell cylindrical cell that is formed in a bottomed cylindrical shape and is received so as to cover the other end side of the one or more solid oxide fuel cell cylindrical cells A second body portion electrically connected to the gas electrode layer, and a second body portion provided on the second body portion and communicating with the other end of each fuel flow path of the solid oxide fuel cell tubular cell. A second holder comprising one or a plurality of second communication ports;
A group of cell bundles arranged side by side in a straight line such that a plurality of cell bundles adjacent to each other are attached in the same direction or in the opposite direction.
Each of the cell bundle groups is provided on the side from which the fuel is discharged, and is at least one of the first communication port and the second communication port, and each communication port on the side from which the fuel is discharged A combustion surface formed in a mesh shape through which the fuel off-gas discharged from the discharge-side communication port is circulated, and the fuel off-gas passing through the combustion surface and the oxidant gas in the oxidant gas atmosphere are combusted A surface burning burner,
A solid oxide fuel cell stack.   The surface combustion burner is an exhaust side in which the combustion surface is formed in a sheet shape, and is a main body portion that is at least one of the first main body portion and the second main body portion and from which the fuel is discharged. 2. The solid oxide fuel cell stack according to claim 1, wherein the combustion surface is formed in a rectangular wave shape along an outer wall surface of a bottom portion of the main body portion and an outer shape of the discharge side communication port portion. Each said 1st holder is provided in said 1st main-body part, Said one end part of said 1 or several solid oxide fuel cell cylindrical cell which comprises said cell bundle, and said 1st main-body part A first buffer member that relaxes thermal stress generated between the one end portion of the solid oxide fuel cell cylindrical cell,
Each said 2nd holder is provided in said 2nd main-body part, Said other end part of said 1 or several solid oxide fuel cell cylindrical cell which comprises said cell bundle, and said 2nd main-body part 3. A second buffer member that is disposed between the bottom portion of the solid oxide fuel cell and relaxes thermal stress generated on the other end portion side of the solid oxide fuel cell cylindrical cell. Solid oxide fuel cell stack. Each said 1st holder is provided in said 1st main-body part, and in said 1st main-body part from said one edge part side of said 1 or several solid oxide form fuel cell cylindrical cell which comprises said cell bundle Comprising a first seal member that inhibits the fuel from leaking into the oxidant gas atmosphere through
Each said 2nd holder is provided in said 2nd main-body part, and in said 2nd main-body part from said other edge part side of said 1 or several solid oxide fuel cell cylindrical cell which comprises said cell bundle The solid oxide fuel cell stack according to any one of claims 1 to 3, further comprising a second seal member that prevents the fuel from leaking into the oxidant gas atmosphere. Each said 1st holder is provided in said 1st main-body part, and each said fuel electrode layer and said 1st main-body part of said 1 or several solid oxide fuel cell cylindrical cell which comprises said cell bundle A first conductive member that electrically connects the inner wall surface;
With respect to the first conductive member, the first seal member disposed on the opening side of the first main body portion,
The one end of the one or more solid oxide fuel cell tubular cells provided between the first conductive member and the first seal member and formed in a flat plate shape to constitute the cell bundle A first through-hole through which the portion side can penetrate, positioning the one end portion side of the solid oxide fuel cell tubular cell in the first main body portion, and the first conductive member and the first A first regulating member having an insulating property that regulates a chemical reaction between the sealing member and suppresses a metal component contained in the first conductive member from being scattered outside the first body part;
With
Each said 2nd holder is provided in said 2nd main-body part, and each said oxidant gas electrode layer and said 2nd main body of said 1 or several solid oxide fuel cell cylindrical cell which comprises said cell bundle A second conductive member that electrically connects the inner wall surface of the portion;
With respect to the second conductive member, the second seal member disposed on the bottom side of the second main body portion,
The one or more solid oxide forms that are provided in two layers so as to sandwich the second conductive member from both sides in the depth direction of the second main body, and are each formed in a flat plate shape and constitute the cell bundle Each of the other end portions of the fuel cell cylindrical cell is provided with a second through hole through which the other end portion side of the solid oxide fuel cell cylindrical cell is positioned in the second main body portion. Insulating that restricts the chemical reaction between the second conductive member and the second seal member and prevents the metal component contained in the second conductive member from scattering outside the second main body. A second regulating member provided;
The solid oxide fuel cell stack according to claim 4, comprising: Each of the plurality of cell bundles includes a plurality of solid oxide fuel cell cylindrical cells, and the plurality of solid oxide fuel cell cylindrical cells are arranged in parallel in a straight line and electrically connected in parallel. Aggregates are composed,
The plurality of solid oxide fuel cell cylindrical cells constituting the cell assembly are electrically connected to each other while the adjacent fuel electrode layers are fixed by a first conductive paste having conductivity. 6. The oxidant gas electrode layers that are fixed to each other and electrically connected to each other by a porous second conductive paste as compared with the first conductive paste. Solid oxide fuel cell stack. A solid oxide fuel cell stack according to any one of claims 1 to 6;
For reforming provided above the combustion surface of the surface combustion burner, heated by the combustion on the combustion surface of the surface combustion burner, and evaporating the supplied reforming water to generate water vapor and supplied An evaporation section for preheating the raw material;
A reforming unit that is provided above the combustion surface of the surface combustion burner, and that generates a reformed gas as the fuel from the steam supplied from the evaporation unit and a mixed gas of the reforming raw material;
A solid oxide fuel cell module. A power generation unit;
A hot water storage tank for storing hot water,
A solid oxide fuel cell system comprising:
The power generation unit is
A solid oxide fuel cell module according to claim 7,
Heat exchange is performed between the combustion exhaust gas exhausted from the solid oxide fuel cell module and the hot water supplied from the hot water storage tank, and condensed water is discharged by condensing water vapor contained in the combustion exhaust gas. A heat exchanger to
A water tank for purifying the condensed water discharged from the heat exchanger;
A control device for driving an auxiliary machine to control the operation of the solid oxide fuel cell system;
A power converter that converts at least DC power output from the solid oxide fuel cell module to AC power and outputs the AC power to a power line connected to an AC power supply; and
A solid oxide fuel cell system.   An oxidant that adjusts the supply amount of the oxidant gas supplied to the combustion surface of the surface combustion burner in accordance with the discharge amount of the fuel offgas so that the fuel offgas and the oxidant gas do not burn incompletely. The solid oxide fuel cell system according to claim 8, further comprising a gas supply amount adjusting unit.

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