Hot Module and Solid Oxide Fuel Cell System

Abstract

To provide a hot module and a solid oxide fuel cell system that, when a cell stack of a flat solid oxide fuel cell is used, can make uniform the temperature distribution of the solid oxide fuel cell.SOLUTION: A hot module 10 comprises: a plurality of stack units 110 that include a plurality of flat solid oxide fuel cells 120; and an air introduction unit 150 that has a plurality of air introduction ports 154 provided at different positions in a longitudinal direction of the plurality of solid oxide fuel cells 120 and supplies air to air electrodes 123 through the plurality of air introduction ports 154.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a hot module and a solid oxide fuel cell system. [Background technology]

[0002] Solid oxide fuel cells can generate electrical energy by chemically reacting fuels such as hydrogen, and the only by-product is water. Therefore, they are expected to be used in a variety of fields as a clean energy source.

[0003] Patent Document 1 discloses a fuel cell module including a cell stack in which solid oxide fuel cells are arranged. A heat insulating member is provided near the cell stack to prevent air from being discharged from the side of the cell stack and to promote air flow between the solid oxide fuel cells. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2014 / 189135 Summary of the Invention [Problem to be solved by the invention]

[0005] Since the temperature of a solid oxide fuel cell rises due to the reaction, the air supplied to the cell stack is not only used for the reaction in the solid oxide fuel cell, but can also be used to cool the solid oxide fuel cell in order to improve the power generation efficiency of the solid oxide fuel cell. However, in conventional modules, air is supplied only from the lower end of the solid oxide fuel cell. The air supplied from the lower end of the solid oxide fuel cell rises between the solid oxide fuel cells while being heated by the solid oxide fuel cell.

[0006] As a result, the lower side of the solid oxide fuel cell is air-cooled, but the upper side remains hot because it is not cooled, which can cause a temperature distribution along the longitudinal axis of the solid oxide fuel cell. If such a temperature distribution occurs, the power generation efficiency of the solid oxide fuel cell can be reduced.

[0007] Therefore, an object of the present disclosure is to provide a hot module and a fuel cell system that can achieve a uniform temperature distribution in a solid oxide fuel cell when a cell stack of flat solid oxide fuel cells is used. [Means for solving the problem]

[0008] The hot module according to the present disclosure includes a plurality of stack units, a housing, an air introduction section, and a covering material. The plurality of stack units includes at least one cell stack. The at least one cell stack includes a plurality of flat solid oxide fuel cells, and each of the plurality of solid oxide fuel cells is arranged in a thickness direction. Each of the plurality of solid oxide fuel cells includes a fuel electrode, an air electrode provided so as to be in contact with the air surrounding each of the plurality of solid oxide fuel cells, and an electrolyte disposed between the fuel electrode and the air electrode. The housing accommodates the plurality of stack units. The air introduction section is disposed inside the housing. The air introduction section has a plurality of air introduction ports provided at different positions in a long axis direction perpendicular to the thickness direction of each of the plurality of solid oxide fuel cells, and supplies air outside the housing to the air electrode through the plurality of air introduction ports. The covering material covers the periphery of at least one cell stack and forms an air flow path through which air supplied to the air electrode passes.

[0009] A fuel flow passage through which fuel supplied to the anode passes may be provided inside each of the solid oxide fuel cells. The air electrode may be arranged so as to be exposed on the surface of each of the solid oxide fuel cells.

[0010] Each of the plurality of stack units may be arranged in a minor axis direction of each of the plurality of solid oxide fuel cells perpendicular to the thickness direction. The plurality of air inlets may be disposed between adjacent cell stacks.

[0011] The air introduction section may include an air introduction flow path extending in the longitudinal direction. Each of the plurality of air introduction ports may be provided in the air introduction flow path along the longitudinal direction.

[0012] The air introduction section may include a plurality of pipes extending in a thickness direction along at least one cell stack. The plurality of air inlets may be provided in the plurality of pipes so as to extend continuously or discontinuously in the thickness direction.

[0013] The housing may include a base on which the stack units are placed and a cover that covers the base. The base may be provided with a gas exhaust port through which exhaust gas including cathode off-gas generated by reaction with air at the air electrode passes.

[0014] The exhaust gas may further include at least one of an anode off-gas generated by a reaction of the fuel at the fuel electrode and a combustion gas of the anode off-gas.

[0015] The covering material may divide the space within the housing into spaces including a first space to which air is supplied via an air supply port provided in the base, and a second space to which the exhaust gas is supplied.

[0016] The solid oxide fuel cell system according to the present disclosure may include a hot module. Effect of the Invention

[0017] According to the present disclosure, it is possible to provide a hot module and a solid oxide fuel cell system that can achieve a uniform temperature distribution in a solid oxide fuel cell when using a cell stack of flat solid oxide fuel cells. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic diagram showing a solid oxide fuel cell system according to an embodiment; [Diagram 2] FIG. 2 is a cross-sectional view showing a hot module according to an embodiment. [Diagram 3] 3 is a cross-sectional view of the hot module of FIG. 2 taken along line III-III. [Figure 4] 4 is a cross-sectional view of the hot module of FIG. 3 taken along line IV-IV. [Diagram 5] 4 is a cross-sectional view of the hot module of FIG. 3 taken along line VV. [Figure 6] FIG. 2 is a perspective view showing a schematic diagram of a stack unit according to one embodiment; [Figure 7] 1 is an enlarged plan view showing a schematic diagram of a stack unit according to one embodiment; [Figure 8] FIG. 2 is a cross-sectional view showing a hot module according to an embodiment. [Figure 9] 9 is a cross-sectional view of the hot module of FIG. 8 taken along line IX-IX. [Figure 10] 10 is a cross-sectional view of the hot module of FIG. 9 taken along line XX. [Figure 11] 10 is a cross-sectional view of the hot module of FIG. 9 taken along line XI-XI. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, some exemplary embodiments will be described with reference to the drawings. Note that the dimensional ratios of the drawings are exaggerated for the convenience of explanation and may differ from the actual ratios.

[0020] In the following embodiments, the thickness direction of the flat solid oxide fuel cell will be described as the thickness direction Z. The direction perpendicular to the thickness direction Z and in which the long axis of the flat solid oxide fuel cell extends in the planar direction will be described as the long axis direction X. The direction perpendicular to the long axis X and the thickness direction Z and in which the short axis of the flat solid oxide fuel cell extends, which is shorter than the long axis of the flat solid oxide fuel cell in the planar direction, will be described as the short axis direction Y. In the long axis direction X, the base side of the solid oxide fuel cell will be described as the lower side of the long axis direction X, and the side opposite the base will be described as the upper side of the long axis direction X.

[0021] [First embodiment] First, a solid oxide fuel cell system 1 (SOFC system 1) and a hot module 10 according to a first embodiment will be described with reference to FIGS.

[0022] As shown in Fig. 1, the SOFC system 1 according to this embodiment includes a hot module 10. The SOFC system 1 also includes a fuel supply unit 20, an air supply unit 30, and an exhaust gas combustion unit 40. The hot module 10 is connected to the fuel supply unit 20, the air supply unit 30, and the exhaust gas combustion unit 40.

[0023] The fuel supply unit 20 supplies fuel into the hot module 10. The fuel supply unit 20 includes a fuel supply pipe 21, an ammonia supply source 22, a flow rate adjustment mechanism 23, and a first hydrogen generation unit 24. The fuel supply pipe 21 connects the ammonia supply source 22 and the hot module 10. The fuel supply pipe 21 is provided with the ammonia supply source 22, the flow rate adjustment mechanism 23, and the first hydrogen generation unit 24. The ammonia supply source 22 is, for example, a pressure vessel such as a cylinder that stores ammonia. The flow rate adjustment mechanism 23 adjusts the flow rate of ammonia flowing through the fuel supply pipe 21. The flow rate adjustment mechanism 23 may be a mass flow controller, or a pump such as a diaphragm pump or a rotary vane pump. The first hydrogen generation unit 24 generates hydrogen from ammonia by heating the ammonia.

[0024] In this embodiment, hydrogen is generated using ammonia as a raw material, but hydrogen may be generated using an organic compound such as a hydrocarbon as a raw material. Also, a cylinder for storing ammonia is used, but a cylinder for storing hydrogen instead of ammonia may be used and hydrogen may be supplied to the hot module 10. Also, hydrogen is generated from ammonia in the first hydrogen generation unit 24, but ammonia may be directly supplied to the hot module 10.

[0025] The air supply unit 30 supplies air containing oxygen to the hot module 10. The air supply unit 30 includes an air supply pipe 31, a filter 32, a blower 33, a flow rate control valve 34, and a heat exchanger 35. One end of the air supply pipe 31 is connected to the hot module 10. The air supply pipe 31 is provided with the filter 32, the blower 33, the flow rate control valve 34, and the heat exchanger 35. The filter 32 removes dust from the air introduced into the air supply pipe 31. The blower 33 is provided downstream of the filter 32 in the air supply pipe 31, and supplies air to the hot module 10 at a pressure of, for example, 10 kPaG or more. The flow rate control valve 34 adjusts the flow rate of the air supplied to the hot module 10. The heat exchanger 35 exchanges heat between the air passing through the air supply pipe 31 and the exhaust gas passing through the exhaust pipe 41, heating the air supplied to the hot module 10 and cooling the exhaust gas discharged from the hot module 10.

[0026] The exhaust gas combustion section 40 combusts exhaust gas, including anode off-gas and cathode off-gas, exhausted from the hot module 10. This allows unreacted hydrogen remaining in the exhaust gas to be combusted. The exhaust gas combustion section 40 includes an exhaust pipe 41, an exhaust gas combustor 42, a heat recovery device 43, and a gas-liquid separation section 44. One end of the exhaust pipe 41 is connected to the hot module 10. The exhaust gas combustor 42 includes a heater such as an electric heater or a gas burner, and burns the exhaust gas by heating it. The heat recovery device 43 is a water-cooled or air-cooled radiator, and recovers heat from the exhaust gas discharged from the exhaust gas combustor 42 and cools the exhaust gas. The gas-liquid separation section 44 separates the gas obtained by cooling in the heat recovery device 43 from water.

[0027] As shown in Figs. 2 to 5, the hot module 10 includes a plurality of stack units 110, a second hydrogen generation section 113, a housing 130, a covering material 140, and an air introduction section 150. The housing 130 houses the plurality of stack units 110 and the covering material 140. The housing 130 includes a base 131 and a cover 132 that covers the base 131. The base 131 and the cover 132 form a space in the housing 130 that houses the plurality of stack units 110.

[0028] Six stack units 110 are placed on the base 131. Three stack units 110 are arranged in the short axis direction Y, and two stack units 110 are arranged in the thickness direction Z. However, two or four or more stack units 110 may be arranged in the short axis direction Y. Also, only one stack unit 110 may be arranged in the thickness direction Z, or three or more stack units 110 may be arranged.

[0029] The base 131 is provided with an air supply port 133 and a gas exhaust port 134. The air supply port 133 is an opening that penetrates the base 131, and the air outside the housing 130 supplied by the air supply unit 30 passes through the air supply port 133 and is supplied to the air electrode 123 of the solid oxide fuel cell 120 (SOFC120). The gas exhaust port 134 is an opening that penetrates the base 131, and exhaust gas including cathode off-gas generated by reaction with air at the air electrode 123 passes through the gas exhaust port 134 and is exhausted to the outside of the housing 130. The exhaust gas includes at least one of anode off-gas generated by reaction of fuel at the fuel electrode 122 and combustion gas of the anode off-gas. The off-gas that passes through the gas exhaust port 134 is combusted in the exhaust gas combustion unit 40.

[0030] The base 131 may include a substrate 135 and a heat insulating material 136 provided on a surface of the substrate 135. The stack units 110 may be placed on the heat insulating material 136. This can prevent heat generated by the reaction of the SOFC 120 from being directly transferred to the substrate 135. The substrate 135 may be made of metal. The heat insulating material 136 may include ceramics, and may be porous.

[0031] The cover 132 may include a base material 137 and a heat insulating material 138 disposed inside the base material 137. This makes it possible to suppress the heat in the space inside the housing 130 from escaping to the outside of the housing 130. The base material 137 may be formed of a metal. The heat insulating material 138 may include ceramics, and may be porous.

[0032] The rigidity of the base 131 may be higher than the rigidity of the cover 132. This allows the base 131 to firmly support the multiple stack units 110 and reduces the weight of the cover 132. The rigidity of the substrate 135 may be higher than the rigidity of the substrate 137. In this specification, rigidity refers to bending rigidity expressed by the product of Young's modulus and the second moment of area at room temperature (about 20°C).

[0033] 2 to 6, each of the multiple stack units 110 includes two cell stacks 111 and a fuel manifold 112. The two cell stacks 111 are provided in the fuel manifold 112, and the fuel manifold 112 is placed on a base 131.

[0034] The second hydrogen generation unit 113 generates hydrogen from a fuel such as ammonia supplied by the fuel supply unit 20. The second hydrogen generation unit 113 is connected to the fuel manifold 112, and hydrogen generated in the second hydrogen generation unit 113 is supplied to the cell stack 111 via the fuel manifold 112. The second hydrogen generation unit 113 is disposed between the SOFC 120 and the cover 132 in the longitudinal axis direction X. Specifically, the second hydrogen generation unit 113 is disposed on the opposite side of the cell stack 111 from the fuel manifold 112 in the longitudinal axis direction X, with a space therebetween. Note that fuel such as ammonia and hydrogen may be directly supplied to the cell stack 111 from the fuel supply unit 20 without passing through the second hydrogen generation unit 113.

[0035] Each of the two cell stacks 111 in the stack unit 110 is arranged in the short-axis direction Y. Note that it is sufficient for the stack unit 110 to include at least one cell stack 111. Therefore, the stack unit 110 may include only one cell stack 111, or may include three or more cell stacks 111.

[0036] Each of the multiple cell stacks 111 includes multiple SOFCs 120. The multiple SOFCs 120 are arranged in the thickness direction Z. As shown in Fig. 7, an air flow path 141 through which air can pass is provided between adjacent SOFCs 120 among the multiple SOFCs 120. One end of each of the multiple SOFCs 120 is connected to the fuel manifold 112, and the other end is a free end. This makes it possible to suppress an increase in internal stress even when the SOFCs 120 expand and contract due to temperature fluctuations.

[0037] As shown in Fig. 7, the SOFC 120 has a flat plate shape. This allows the power density of the cell stack 111 to be higher than that of a cylindrical SOFC having a substantially perfect circle shape. The SOFC 120 is specifically a cylindrical flat plate type solid oxide fuel cell, and has a flat cylindrical shape. Each of the multiple SOFCs 120 includes a support 121, an anode 122, an air cathode 123, an electrolyte 124, and an interconnector 125. A fuel flow path 126 through which fuel supplied to the anode 122 passes is provided inside each of the multiple SOFCs 120.

[0038] The support portion 121 is provided with a plurality of fuel flow paths 126. Each of the plurality of fuel flow paths 126 is arranged in the minor axis direction Y and extends along the major axis direction X. One end of the fuel flow path 126 is connected to the fuel manifold 112. The end of the fuel flow path 126 opposite to the fuel manifold 112 is open and serves as an outlet for discharging fuel.

[0039] The support 121 has a flattened cylindrical shape. The fuel electrode 122 is disposed on the surface of the support 121. The support 121 includes a porous body that allows the fuel flowing through the fuel flow passage 126 to pass through the fuel electrode 122. The outer surface of the support 121 is surrounded by the fuel electrode 122 and the interconnector 125 so that the fuel that has passed through the fuel flow passage 126 does not leak. The support 121, the fuel electrode 122, and the interconnector 125 extend from a fixed end fixed to the fuel manifold 112 of the SOFC 120 toward a free end. In this embodiment, the support 121 and the fuel electrode 122 are different members, but the fuel electrode 122 may include the support 121. That is, the fuel electrode 122 and the support 121 may be the same, and the fuel flow passage 126 may be provided inside the fuel electrode 122.

[0040] The air electrode 123 is provided so as to be in contact with the air surrounding each of the multiple SOFCs 120. Specifically, the air electrode 123 is arranged so as to be exposed to the surface of each of the multiple SOFCs 120. The electrolyte 124 is arranged between the fuel electrode 122 and the air electrode 123.

[0041] At the fuel electrode 122, as shown in the following reaction formula (1), hydrogen is oxidized and an anode off-gas containing water and unreacted fuel is generated. H2+O 2- →2H2O+2e - (1)

[0042] In the air electrode 123, oxygen is reduced as shown in the following reaction formula (2), and a cathode off-gas containing unreacted oxygen is generated. 1 / 2O2+2e - →O 2- (2)

[0043] In the electrolyte 124, oxygen ions (O 2- ) moves from the air electrode 123 to the fuel electrode 122. The electrons (e - ) is collected via a conductive member (not shown) provided in the interconnector 125 and the air flow path 141.

[0044] The support section 121 has electrical conductivity. The support section 121 may contain at least one of nickel and a nickel compound. The nickel compound may contain nickel oxide (NiO). The support section 121 may also contain a rare earth oxide. An example of the rare earth is yttrium.

[0045] The fuel electrode 122 may contain at least one of nickel and a nickel compound. The nickel compound may contain nickel oxide (NiO). The fuel electrode 122 may further contain a solid oxide having oxide ion conductivity, such as yttria-stabilized zirconia.

[0046] The cathode 123 may include an oxide that exhibits electronic conductivity, such as LSM ((La,Sr)MnO3), LSC ((La,Sr)CoO3), or LSCF ((La,Sr)(Co,Fe)O3).

[0047] The electrolyte 124 may include a solid oxide having oxide ion conductivity, such as yttria-stabilized zirconia.

[0048] The anode off-gas usually contains unreacted hydrogen. This unreacted fuel is discharged from the free end of the SOFC 120. When the SOFC system 1 is in operation, the inside of the hot module 10 becomes hot, and the unreacted hydrogen is burned. The second hydrogen generation unit 113 arranged above the cell stack 111 is heated by this combustion heat.

[0049] The covering material 140 covers the periphery of the cell stack 111 in each of the multiple stack units 110. The covering material 140 has an air flow path 141 through which air supplied to the air electrode 123 passes. The air flow path 141 is provided between the SOFCs 120 adjacent to each other in the thickness direction Z. Therefore, the air flow path 141 is surrounded by the SOFCs 120 and the covering material 140. The SOFCs 120 are arranged in the thickness direction Z, and the gap between the SOFCs 120 in the cell stack 111 is narrow. However, in this embodiment, the periphery of the cell stack 111 is covered with the covering material 140, so that the flow of air is restricted. Therefore, air can be forcibly sent into the narrow air flow path 141 provided between the adjacent SOFCs 120.

[0050] The covering material 140 divides the space in the housing 130 into a space including a first space 142 and a second space 143. Air is supplied to the first space 142 through the air supply port 133. Exhaust gas is supplied to the second space 143. As a result, the air supplied through the air supply port 133 rises in the air flow path 141 and reacts at the air electrode 123. Then, exhaust gas containing at least one of the anode off-gas generated at the air electrode 123 and the combustion gas of the anode off-gas is discharged to the outside of the hot module 10 through the gas discharge port 134. Therefore, since the covering material 140 can form flow paths for the supply gas and the exhaust gas, the configuration of the hot module 10 can be simplified.

[0051] An air introduction section 150 is disposed in the first space 142. Specifically, an air introduction port 154 of the air introduction section 150 is disposed in the first space 142, and air is supplied to the first space 142 through the air supply port 133 by the air introduction section 150. The first space 142 is divided into a plurality of spaces in the long axis direction X by the covering material 140. Specifically, the first space 142 is partitioned into a space 142a and a space 142b by the covering material 140. The space 142a is formed by being surrounded by the base 131 and the covering material 140. The space 142a may be formed by being surrounded by the base 131, the covering material 140, and the cover 132. The space 142b is disposed between the space 142a and the second space 143, and is formed by being surrounded by the covering material 140.

[0052] The second space 143 communicates with the gas exhaust port 134, and the exhaust gas supplied to the second space 143 is supplied to the exhaust gas combustion section 40 via the gas exhaust port 134. The second hydrogen generation section 113 may be disposed in the second space 143. The second space 143 is surrounded and formed by the base 131, the cover 132, and the covering material 140.

[0053] The coating material 140 preferably has heat resistance. Therefore, the coating material 140 may contain ceramics. In addition, the coating material 140 preferably has heat insulating properties. When the coating material 140 has heat insulating properties, it is possible to suppress the dissipation of heat from the SOFC 120. The coating material 140 may be porous.

[0054] The air introduction part 150 is disposed inside the casing 130 and supplies air outside the casing 130 to the air electrode 123. The air introduction part 150 has a plurality of air inlets 154 provided at different positions in the long axis direction X, and supplies air outside the casing 130 to the air electrode 123 via the plurality of air inlets 154. This allows oxygen in the air to be continuously supplied to the air electrode 123, and the reaction in the SOFC 120 to continue.

[0055] The air introduction part 150 includes a pipe 151 which is an air introduction flow path 155, and the pipe 151 is connected to the air supply port 133. In addition, the air introduction part 150 is disposed within the first space 142. Air supplied to the air electrode 123 from the outside of the housing 130 passes through the air supply port 133, and the air introduction part 150 guides the air which has passed through the air supply port 133 to the air electrode 123.

[0056] The pipe 151 includes a main pipe 152 and a branch pipe 153. The main pipe 152 and the branch pipe 153 are arranged in the space 142a and the space 142b. The main pipe 152 is connected to the air supply port 133. The main pipe 152 branches in the housing 130 and extends in the space 142a and the space 142b. The main pipe 152 is arranged between the stack units 110 adjacent to each other in the thickness direction Z in the space 142a and the space 142b, and extends in the short axis direction Y.

[0057] Each of the branch pipes 153 branches off from the main pipe 152 and extends in the thickness direction Z along each of the cell stacks 111. The branch pipes 153 are disposed on both sides of the stack units 110 in the short axis direction Y, between the stack units 110 and the cover 132. The branch pipes 153 are disposed between adjacent stack units 110 in the short axis direction Y. However, the branch pipes 153 may be disposed at least either between adjacent stack units 110 or between adjacent cell stacks 111 in the stack unit 110 in the short axis direction Y. Each of the branch pipes 153 is provided with at least one air inlet 154.

[0058] The multiple air inlets 154 are arranged between adjacent cell stacks 111. Therefore, air that has passed through the air supply port 133 is supplied into the housing 130 from at least one air inlet 154. The air inlet 154 may be arranged at least either between adjacent stack units 110 or between adjacent cell stacks 111 in the stack unit 110 in the short axis direction Y.

[0059] The multiple air inlets 154 extend continuously along the thickness direction Z and are provided in each of the multiple branch pipes 153. However, the position, size, shape, and the like of the air inlets 154 provided in the branch pipes 153 are not particularly limited. The multiple air inlets 154 may be provided in each of the multiple branch pipes 153 discontinuously along the thickness direction Z.

[0060] In this embodiment, piping 151 including a main piping 152 and a branch piping 153 is arranged in the space 142a and the space 142b. Therefore, each of the multiple air inlets 154 is provided at a different position in the longitudinal axis direction X. This allows air to be supplied from the air inlets 154 to multiple locations in the SOFC 120 in the longitudinal axis direction X. This not only allows air to be supplied to the SOFC 120 as a reaction raw material, but also allows the temperature distribution of the SOFC 120 to be made uniform.

[0061] [Second embodiment] Next, the SOFC system 1 and hot module 10 according to the second embodiment will be described with reference to Fig. 8 to Fig. 11. In the hot module 10 according to the second embodiment, the shape of the air introduction section 150 is changed. Unless otherwise specified, other points are the same as those of the SOFC system 1 and hot module 10 according to the first embodiment, and therefore description thereof will be omitted.

[0062] The air introduction section 150 includes a plurality of air introduction channels 155. One end of each of the plurality of air introduction channels 155 is connected to the cover 132 of the housing 130. The air introduction channels 155 are disposed on both sides of the plurality of stack units 110 in the short axis direction Y, between the stack units 110 and the cover 132. However, the air introduction channels 155 may be disposed at least either between adjacent stack units 110 or between adjacent cell stacks 111 in the stack unit 110.

[0063] The air introduction flow path 155 is a rectangular box having a space therein for air to pass through. The air introduction flow path 155 extends and spreads in the long axis direction X and thickness direction Z along the side surface of the cell stack 111. The air introduction flow path 155 is provided penetrating the covering material 140 from the ceiling of the housing 130, and is disposed in the first space 142 and the second space 143. The air introduction flow path 155 is provided with a plurality of air introduction ports 154.

[0064] The air inlet 154 is disposed in the first space 142. Specifically, the air inlet 154 is disposed in the space 142a and the space 142b, and each of the multiple air inlet 154 is provided in the air introduction flow path 155 discontinuously along the long axis direction X. Also, each of the multiple air inlet 154 is provided in the air introduction flow path 155, extending continuously along the thickness direction Z. However, the multiple air inlet 154 may be provided in the air introduction flow path 155 discontinuously.

[0065] The air supplied to the air introduction section 150 by the air supply section 30 flows from the ceiling of the housing 130 toward the air introduction port 154, and is introduced into the housing 130 through the air introduction port 154. The air introduced into the housing 130 is supplied to the air electrode 123 through the air flow path 141.

[0066] Note that cover 132 of housing 130 may include an outer wall and an inner wall, and air introduction part 150 may be provided on the inner wall of cover 132. Air outside housing 130 may be supplied to air introduction flow path 155 of air introduction part 150 through a flow path that is the space between the outer wall and the inner wall.

[0067] The hot module 10 according to this embodiment can also make the temperature distribution of the SOFC 120 uniform, similar to the hot module 10 according to the above embodiment.

[0068] As described above, the hot module 10 according to the present embodiment includes a plurality of stack units 110, a housing 130, an air introduction section 150, and a covering material 140. The plurality of stack units 110 includes at least one cell stack 111. The at least one cell stack 111 includes a plurality of flat solid oxide fuel cells 120, and each of the plurality of solid oxide fuel cells 120 is arranged in the thickness direction Z. Each of the plurality of solid oxide fuel cells 120 includes a fuel electrode 122, an air electrode 123 provided so as to be in contact with the air surrounding each of the plurality of solid oxide fuel cells 120, and an electrolyte 124 disposed between the fuel electrode 122 and the air electrode 123. The housing 130 accommodates the plurality of stack units 110. The air introduction section 150 is disposed inside the housing 130. The air introduction section 150 has a plurality of air inlets 154 provided at different positions in a longitudinal axis direction X perpendicular to a thickness direction Z of each of the plurality of solid oxide fuel cells 120, and supplies air outside the casing 130 to the air electrode 123 via the plurality of air inlets 154. The covering material 140 covers the periphery of at least one cell stack 111, and forms an air flow path 141 through which air supplied to the air electrode 123 passes.

[0069] In this manner, air outside the casing 130 is supplied to the air electrode 123 through a plurality of air inlets 154 provided at different positions in the longitudinal axis direction X. This allows air outside the casing 130 to be supplied to different positions of the SOFC 120 in the longitudinal axis direction X. This allows the temperature distribution of the solid oxide fuel cell 120 to be made uniform.

[0070] A fuel flow passage 126 through which fuel supplied to the fuel electrode 122 passes may be provided inside each of the plurality of solid oxide fuel cells 120. The air electrode 123 may be disposed so as to be exposed on the surface of each of the plurality of solid oxide fuel cells 120.

[0071] This allows the surface of each of the multiple solid oxide fuel cells 120 to be effectively cooled by the air inlet section 150 .

[0072] Each of the multiple stack units 110 may be arranged in a minor axis direction Y of each of the multiple solid oxide fuel cells 120 perpendicular to the thickness direction Z. The multiple air inlets 154 may be arranged between adjacent cell stacks 111.

[0073] As a result, air is supplied to the side surface of the cell stack 111 via the air inlet 154. Therefore, the solid oxide fuel cells 120 in the cell stack 111 can be efficiently cooled.

[0074] The air inlet section 150 may include an air inlet flow passage 155 extending in the longitudinal axis direction X. Each of the multiple air inlets 154 may be provided in the air inlet flow passage 155 along the longitudinal axis direction X.

[0075] This allows air outside the casing 130 to be easily supplied to different positions of the SOFC 120 in the longitudinal axis direction X.

[0076] The air introduction section 150 may include a plurality of pipes 151 extending in the thickness direction Z along at least one cell stack 111. The plurality of air inlets 154 may be provided in each of the plurality of pipes 151 so as to extend continuously or discontinuously along the thickness direction Z.

[0077] This makes it possible to easily supply air from outside the casing 130 to the cell stack 111.

[0078] The housing 130 may include a base 131 on which the multiple stack units 110 are placed, and a cover 132 that covers the base 131. The base 131 may be provided with a gas exhaust port 134 through which exhaust gas including cathode off-gas generated by reaction with air at the air electrode 123 passes.

[0079] Since the gas exhaust port 134 is provided in the base 131 instead of the cover 132, the load on the cover 132 can be reduced, and the configuration of the hot module 10 can be simplified.

[0080] The exhaust gas may further include at least one of an anode off-gas generated by the reaction of the fuel at the fuel electrode 122 and a combustion gas of the anode off-gas.

[0081] This eliminates the need to use dedicated piping to exhaust the cathode off-gas and the anode off-gas, thereby simplifying the configuration of the hot module 10.

[0082] The covering material 140 may divide the space within the housing 130 into spaces including a first space 142 to which air is supplied via an air supply port 133 provided in the base 131, and a second space 143 to which the exhaust gas is supplied.

[0083] As a result, air supplied through the air supply port 133 reacts at the air electrode 123, and exhaust gas containing at least one of the generated anode off-gas and a combustion gas of the anode off-gas is exhausted to the outside of the hot module 10 through the gas exhaust port 134. Therefore, flow paths for the supply gas and the exhaust gas can be formed by the covering material 140, and the configuration of the hot module 10 can be simplified.

[0084] The solid oxide fuel cell system 1 may include a hot module 10 .

[0085] As described above, the hot module 10 can make the temperature distribution of the solid oxide fuel cells 120 uniform. Therefore, the solid oxide fuel cell system 1 including the hot module 10 can also make the temperature distribution of the solid oxide fuel cells 120 uniform.

[0086] Although several embodiments have been described, the embodiments can be modified or modified based on the above disclosure. All components of the above embodiments and all features described in the claims may be individually extracted and combined as long as they are not mutually inconsistent.

[0087] This disclosure can, for example, contribute to Goal 7 of the United Nations-led Sustainable Development Goals (SDGs), which is to "Ensure access to affordable, reliable, sustainable and modern energy for all." [Explanation of symbols]

[0088] 1. Solid oxide fuel cell system (SOFC system) 10 Hot Module 110 Stack Unit 111 Cell Stack 120 Solid Oxide Fuel Cells (SOFC) 122 Fuel electrode 123 Air pole 124 Electrolytes 126 Fuel flow passage 130 Case 131 Base 132 Cover 133 Air supply port 134 Gas exhaust port 140 Covering material 141 Air flow path 142 1st space 143 Second space 150 Air intake section 151 Piping 152 Main piping (piping) 153 Branch piping (piping) 154 Air inlet 155 Air intake channel X Long axis direction Y short axis direction Z thickness direction

Claims

1. a plurality of stack units including at least one cell stack including a plurality of flat solid oxide fuel cells, each of the plurality of solid oxide fuel cells including a fuel electrode, an air electrode provided so as to be in contact with the air surrounding the plurality of solid oxide fuel cells, and an electrolyte disposed between the fuel electrode and the air electrode, each of the plurality of solid oxide fuel cells being arranged in a thickness direction; a housing that houses the plurality of stack units; an air inlet section that is disposed inside the housing and has a plurality of air inlets provided at different positions in a major axis direction perpendicular to the thickness direction of each of the plurality of solid oxide fuel cells, and that supplies air from outside the housing to the air electrode via the plurality of air inlets; a covering material that covers the periphery of the at least one cell stack and forms an air flow path through which air supplied to the air electrode passes; Equipped with the housing includes a base on which the plurality of stack units are placed and a cover that covers the base, the base is provided with a gas exhaust port through which exhaust gas including a cathode off-gas generated by reaction with air at the air electrode passes; the covering material divides a space within the housing into spaces including a first space to which air is supplied and a second space to which the exhaust gas is supplied, The first space is divided into a plurality of spaces in the longitudinal direction by the covering material, A hot module, wherein a plurality of air inlets are disposed in each of the plurality of spaces.

2. 2. The hot module according to claim 1, wherein a fuel flow path through which fuel supplied to the anode passes is provided inside each of the plurality of solid oxide fuel cells, and the cathode is arranged so as to be exposed on a surface of each of the plurality of solid oxide fuel cells.

3. Each of the plurality of stack units is arranged in a minor axis direction of each of the plurality of solid oxide fuel cells perpendicular to the thickness direction, The hot module according to claim 1 or 2, wherein the plurality of air inlets are disposed between adjacent cell stacks.

4. The air introduction section includes an air introduction flow passage extending in the longitudinal direction, The hot module according to claim 3 , wherein each of the plurality of air inlets is provided in the air inlet passage along the longitudinal direction.

5. the air introduction section includes a plurality of pipes extending in the thickness direction along the at least one cell stack, The hot module according to claim 3 , wherein the plurality of air inlets are provided in the plurality of pipes, respectively, so as to extend continuously or discontinuously along the thickness direction.

6. 6. The hot module according to claim 1, wherein the exhaust gas further includes at least one of an anode off-gas generated by a reaction of fuel at the fuel electrode and a combustion gas of the anode off-gas.

7. A hot module described in any one of claims 1 to 6, wherein air is supplied to the first space through an air supply port provided in the base.

8. A solid oxide fuel cell system comprising the hot module according to any one of claims 1 to 7.

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