JP7643172B2 - Hot Module and Solid Oxide Fuel Cell System - Google Patents

Description

This disclosure relates to hot modules and solid oxide fuel cell systems.

Solid oxide fuel cells can generate electrical energy by chemically reacting fuels such as hydrogen, with the only by-product being water. As such, they are expected to be used in a variety of fields as a clean energy source.

Patent Document 1 discloses a fuel cell module equipped with 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.

International Publication No. 2014/189135

In conventional modules, a hollow, flat air introduction member is fixed to the cover of a storage container having inner and outer walls, and is inserted between the cell stacks, penetrating the insulation member. Therefore, in order to promote air flow between the fuel cells, it is necessary to combine multiple fragmented insulation members to cover the air introduction member and the cell stack, which can result in a complex shape of the insulation member.

In addition, in conventional modules, the gas introduction member is fixed to the cover, so unless the cover is reinforced, there is a risk that the cover will deform under its own weight when the module is operated at high temperatures. In such cases, the positioning of the air introduction member may shift, causing gaps to form between the multiple fragmented insulation members, and the supplied air may leak through the gaps.

The present disclosure therefore aims to provide a hot module and fuel cell system that can supply air to a cell stack using a simple configuration when using a cell stack of flat solid oxide fuel cells.

The hot module according to the present disclosure includes a plurality of stack units, a housing, and a covering material. The plurality of stack units include a cell stack. The cell stack includes a plurality of flat solid oxide fuel cells, each of which is arranged in the 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 includes a base on which the plurality of stack units are placed and a cover that covers the base, and houses the plurality of stack units. The covering material covers the periphery of the cell stack and forms an air flow path through which air supplied to the air electrode passes. The base is provided with at least one air supply port through which air supplied to the air electrode from outside the housing passes.

A fuel flow path through which fuel supplied to the fuel electrode 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.

The rigidity of the base may be greater than the rigidity of the cover.

The base may be provided with a gas exhaust port through which exhaust gas containing cathode off-gas generated by reaction with air at the air electrode passes.

The exhaust gas may further include at least one of anode off-gas produced by the reaction of fuel at the fuel electrode and combustion gas of the anode off-gas.

The covering material may divide the space within the housing into a first space to which air is supplied via at least one air supply port, and a second space to which exhaust gas is supplied.

Each of the multiple stack units may be arranged in a short axis direction of each of the multiple solid oxide fuel cells perpendicular to the thickness direction. At least one air supply port may be disposed between adjacent stack units among the multiple stack units.

At least one air supply port may extend continuously or intermittently along the thickness direction.

The hot module may further include an air inlet that guides air that has passed through at least one air supply port to the air electrode. The air inlet may include a pipe extending in the thickness direction along the cell stack. The pipe may have at least one air inlet that extends continuously or intermittently along the thickness direction. The air that has passed through the at least one air supply port may be supplied into the housing from the at least one air inlet.

Each of the multiple stack units may be arranged in the short axis direction of each of the multiple solid oxide fuel cells perpendicular to the thickness direction. The air inlet may be disposed between adjacent cell stacks.

The solid oxide fuel cell system disclosed herein is equipped with a hot module.

According to the present disclosure, when a flat solid oxide fuel cell stack is used, it is possible to provide a hot module and a solid oxide fuel cell system that can supply air to the cell stack with a simple configuration.

FIG. 1 is a schematic diagram showing a solid oxide fuel cell system according to an embodiment. FIG. 2 is a cross-sectional view showing a hot module according to an embodiment. 3 is a cross-sectional view of the hot module of FIG. 2 taken along line III-III. 4 is a cross-sectional view of the hot module of FIG. 3 taken along line IV-IV. 4 is a cross-sectional view of the hot module of FIG. 3 taken along line VV. FIG. 2 is a perspective view showing a schematic diagram of a stack unit according to one embodiment; 1 is an enlarged plan view showing a schematic diagram of a stack unit according to one embodiment; FIG. 2 is a cross-sectional view showing a hot module according to an embodiment. 9 is a cross-sectional view of the hot module of FIG. 8 taken along line IX-IX. 10 is a cross-sectional view of the hot module of FIG. 9 taken along line XX. FIG. 2 is a cross-sectional view showing a hot module according to an embodiment.

Below, several exemplary embodiments will be described with reference to the drawings. Note that the dimensional ratios in the drawings have been exaggerated for the convenience of explanation and may differ from the actual ratios.

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

[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. 1 to 7. FIG.

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 fuel supply unit 20, the air supply unit 30, and the exhaust gas combustion unit 40 are connected to the hot module 10.

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.

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 supplied directly to the hot module 10.

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 a filter 32, a blower 33, a flow rate control valve 34, and a 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 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.

The exhaust gas combustion section 40 burns 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 burned. 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, which recovers the heat of 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.

As shown in Figures 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 within the housing 130 to house the plurality of stack units 110.

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.

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 (SOFC 120). 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 contains 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.

The base 131 may include a substrate 135 and a heat insulating material 136 provided on the 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 or may be porous.

The cover 132 may include a base material 137 and a heat insulating material 138 arranged inside the base material 137. This can prevent heat in the space inside the housing 130 from escaping to the outside of the housing 130. The base material 137 may be made of metal. The heat insulating material 138 may include ceramics or may be porous.

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

As shown in Figures 2 to 6, each of the multiple stack units 110 includes two cell stacks 111 and a fuel manifold 112. The fuel manifold 112 is provided with the two cell stacks 111, and the fuel manifold 112 is placed on a base 131.

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 by 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 fuels such as ammonia and hydrogen may be supplied directly to the cell stack 111 from the fuel supply unit 20 without passing through the second hydrogen generation unit 113.

Each of the two cell stacks 111 in the stack unit 110 is arranged in the short axis direction Y. Note that the stack unit 110 needs 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 multiple cell stacks 111.

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 internal stress from increasing even if the SOFCs 120 expand and contract due to temperature fluctuations.

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 nearly perfect circle shape. Specifically, the SOFC 120 is 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, a fuel electrode 122, an air electrode 123, an electrolyte 124, and an interconnector 125. A fuel flow path 126 through which fuel supplied to the fuel electrode 122 passes is provided inside each of the multiple SOFCs 120.

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 the fuel manifold 112 is open and serves as an outlet for discharging fuel.

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.

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 on the surface of each of the multiple SOFCs 120. The electrolyte 124 is arranged between the fuel electrode 122 and the air electrode 123.

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.
H ₂ +O ^2- →2H ₂ O+2e ^- (1)

At 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.
1/2O ₂ +2e ^- →O ^2- (2)

In the electrolyte 124, oxygen ions (O ²⁻ ) generated in the above reaction formula (2) move from the air electrode 123 to the fuel electrode 122. Electrons (e ⁻ ) generated in the above reaction formula (1) are collected via the interconnector 125 and a conductive member (not shown) provided in the air flow path 141.

The support portion 121 is electrically conductive. The support portion 121 may contain at least one of nickel and a nickel compound. The nickel compound may contain nickel oxide (NiO). The support portion 121 may also contain a rare earth oxide. Examples of rare earth elements include yttrium.

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.

The cathode 123 may include an oxide that exhibits electronic conductivity, such as LSM ((La,Sr)MnO ₃ ), LSC ((La,Sr)CoO ₃ ), or LSCF ((La,Sr)(Co,Fe)O ₃ ).

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

The anode off-gas usually also 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, causing the unreacted hydrogen to combust. This combustion heats the second hydrogen generation unit 113 located above the cell stack 111.

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 adjacent SOFCs 120 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, since the periphery of the cell stack 111 is covered with the covering material 140, the flow of air is restricted. Therefore, air can be forcibly sent into the narrow air flow path 141 provided between adjacent SOFCs 120.

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 and the combustion gas of the anode off-gas generated at the air electrode 123 is discharged to the outside of the hot module 10 through the gas exhaust 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.

An air introduction section 150 is disposed within the first space 142. Specifically, an air introduction port 154 of the air introduction section 150 is disposed within the first space 142, and air is supplied to the first space 142 via the air supply port 133 by the air introduction section 150. The first space 142 is formed by being surrounded by the base 131 and the covering material 140. The first space 142 may be formed by being surrounded by the base 131, the covering material 140, and the cover 132.

The second space 143 is connected to 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. A second hydrogen generation section 113 may be disposed within the second space 143. The second space 143 is surrounded and formed by the base 131, the cover 132, and the covering material 140.

It is preferable that the coating material 140 has heat resistance. Therefore, the coating material 140 may contain ceramics. It is also preferable that the coating material 140 has heat insulating properties. By having the coating material 140 have heat insulating properties, it is possible to suppress the dissipation of heat from the SOFC 120. The coating material 140 may be porous.

The air introduction section 150 is disposed inside the housing 130 and supplies air from outside the housing 130 to the air electrode 123. The air introduction section 150 has a plurality of air introduction ports 154, and supplies air from outside the housing 130 to the air electrode 123 through the plurality of air introduction ports 154. This allows oxygen in the air to be continuously supplied to the air electrode 123, allowing the reaction of the SOFC 120 to continue.

The air introduction section 150 includes a pipe 151 which is an air introduction flow path, and the pipe 151 is connected to the air supply port 133. The air introduction section 150 is also disposed within the first space 142. Air supplied to the air electrode 123 from outside the housing 130 passes through the air supply port 133, and the air introduction section 150 guides the air that has passed through the air supply port 133 to the air electrode 123.

The piping 151 includes a main piping 152 and a branch piping 153. The piping 151 is provided without penetrating the covering material 140. The main piping 152 and the branch piping 153 are arranged in the first space 142. The main piping 152 is connected to the air supply port 133. The main piping 152 is arranged in the first space 142 between adjacent stack units 110 in the thickness direction Z, and extends in the short axis direction Y.

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 arranged 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 also arranged between adjacent stack units 110 in the short axis direction Y. However, the branch pipes 153 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. Each of the branch pipes 153 is provided with at least one air inlet 154.

Each of the multiple air inlets 154 is disposed 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 inlets 154 may be disposed at least either between adjacent stack units 110 in the short axis direction Y or between adjacent cell stacks 111 within the stack unit 110.

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, and shape 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 intermittently along the thickness direction Z.

As described above, in the hot module 10 according to this embodiment, the air supply port 133 is provided in the base 131, and the air flow path 141 is formed by the covering material 140. As a result, air passes through the air supply port 133 and the air flow path 141 and is supplied to the air electrode 123. Therefore, the periphery of the cell stack 111 can be covered with the covering material 140 without having to fragment the covering material 140 into multiple parts. Therefore, according to the hot module 10 according to this embodiment, when the cell stack 111 of the flat solid oxide fuel cell 120 is used, air can be supplied to the cell stack 111 with a simple configuration.

[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 second embodiment, an air manifold is used as the air introduction section 150. Other points are the same as those of the SOFC system 1 and hot module 10 according to the first embodiment unless otherwise specified, and therefore description thereof will be omitted.

The air introduction section 150 is provided on the opposite side of the base 131 from the stack unit 110. Air is supplied to the air introduction section 150 from the air supply section 30. The air supply port 133 is an opening that penetrates the base 131 from the air introduction section 150 to the first space 142, and is provided so that air is supplied from the air introduction section 150 to the housing 130 via the air supply port 133.

The base 131 is provided with a plurality of air supply ports 133. The air supply ports 133 are arranged 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. Each of the plurality of air supply ports 133 is arranged between adjacent stack units 110 among the plurality of stack units 110. Each of the plurality of air supply ports 133 is provided to extend continuously along the thickness direction Z.

The shape and size of the multiple air supply ports 133 are not particularly limited. For example, as shown in FIG. 11, each of the multiple air supply ports 133 may be provided intermittently along the thickness direction Z.

The hot module 10 according to this embodiment, like the hot module 10 according to the above embodiment, can supply air to the cell stack 111 with a simple configuration when a cell stack 111 of flat solid oxide fuel cells 120 is used.

As described above, the hot module 10 according to this embodiment includes a plurality of stack units 110, a housing 130, and a covering material 140. The plurality of stack units 110 includes a cell stack 111. The cell stack 111 includes a plurality of flat solid oxide fuel cells 120, each of which 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 includes a base 131 on which the plurality of stack units 110 are placed, and a cover 132 that covers the base 131, and houses the plurality of stack units 110. The covering material 140 covers the periphery of the cell stack 111 and forms an air flow path 141 through which air supplied to the air electrode 123 passes. The base 131 has at least one air supply port 133 through which air passes to be supplied to the air electrode 123 from outside the housing 130.

An air supply port 133 is provided in the base 131, and an air flow path 141 is formed by the covering material 140. This allows air to pass through the air supply port 133 and the air flow path 141 and be supplied to the air electrode 123. Therefore, the periphery of the cell stack 111 can be covered with the covering material 140 without having to fragment the covering material 140 into multiple parts. Therefore, according to the hot module 10 of this embodiment, when a cell stack 111 of a flat solid oxide fuel cell 120 is used, air can be supplied to the cell stack 111 with a simple configuration.

A fuel flow path 126 through which fuel supplied to the fuel electrode 122 passes may be provided inside each of the solid oxide fuel cells 120. The air electrode 123 may be arranged so as to be exposed on the surface of each of the solid oxide fuel cells 120.

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

The rigidity of the base 131 may be greater than the rigidity of the cover 132.

This allows the base 131 to firmly support multiple stack units 110 while reducing the weight of the cover 132.

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.

The gas exhaust port 134 is provided in the base 131, not in the cover 132, which reduces the load on the cover 132 and simplifies the configuration of the hot module 10.

The exhaust gas may further include at least one of anode off-gas produced by the reaction of fuel at the fuel electrode 122 and combustion gas of the anode off-gas.

This eliminates the need to exhaust the cathode off-gas and anode off-gas using dedicated piping, simplifying the configuration of the hot module 10.

The covering material 140 may divide the space within the housing 130 into a space including a first space 142 to which air is supplied via at least one air supply port 133, and a second space 143 to which exhaust gas is supplied.

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 the combustion gas of the anode off-gas is discharged to the outside of the hot module 10 through the gas exhaust port 134. Therefore, since the coating material 140 can form flow paths for the supply gas and the exhaust gas, the configuration of the hot module 10 can be simplified.

Each of the multiple stack units 110 may be arranged in the short axis direction Y of each of the multiple solid oxide fuel cells 120 perpendicular to the thickness direction Z. At least one air supply port 133 may be arranged between adjacent stack units 110 among the multiple stack units 110.

As a result, air is supplied to each cell stack 111 of adjacent stack units 110 via the air inlet 154. This allows air to be efficiently supplied to the solid oxide fuel cells 120 of the cell stack 111.

At least one air supply port 133 may extend continuously or intermittently along the thickness direction Z.

This allows air outside the housing 130 to be easily supplied to the cell stack 111.

The hot module 10 may further include an air inlet 150 that guides the air that has passed through at least one air supply port 133 to the air electrode 123. The air inlet 150 may include a pipe 151 that extends in the thickness direction Z along the cell stack 111. The pipe 151 may have at least one air inlet 154 that extends continuously or intermittently along the thickness direction Z. The air that has passed through at least one air supply port 133 may be supplied into the housing 130 from at least one air inlet 154.

This allows air outside the housing 130 to be easily and efficiently supplied to the cell stack 111.

Each of the multiple stack units 110 may be arranged in the short axis direction Y of each of the multiple solid oxide fuel cells 120 perpendicular to the thickness direction Z. The air inlet 154 may be disposed between adjacent cell stacks 111.

As a result, air is supplied to the side of the cell stack 111 through the air inlet 154. This allows air to be efficiently supplied to the solid oxide fuel cells 120 in the cell stack 111.

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

As described above, the hot module 10 can supply air to the cell stack 111 with a simple configuration. Therefore, the solid oxide fuel cell system 1 equipped with the hot module 10 can also supply air to the cell stack 111 with a simple configuration.

Although several embodiments have been described, the embodiments can be modified or varied based on the above disclosure. All components of the above embodiments and all features described in the claims may be individually extracted and combined, unless they are mutually inconsistent.

This disclosure can contribute, for example, 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."

1. Solid oxide fuel cell system (SOFC system)
10 Hot module 110 Stack unit 111 Cell stack 120 Solid oxide fuel cell (SOFC)
122 Anode 123 Air cathode 124 Electrolyte 126 Fuel flow path 130 Housing 131 Base 132 Cover 133 Air supply port 134 Gas exhaust port 140 Covering material 141 Air flow path 142 First space 143 Second space 150 Air introduction part 151 Pipe 152 Main pipe (pipe)
153 Branch piping (piping)
154 Air inlet Y: Minor axis direction Z: Thickness direction

Claims (9)

a plurality of stack units including a 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 includes a base on which the plurality of stack units are placed and a cover that covers the base, and that houses the plurality of stack units;
a covering material that covers the periphery of the cell stack and forms an air flow path through which air supplied to the air electrode passes;
Equipped with
the base portion is provided with at least one air supply port through which air passes to be supplied to the air electrode from the outside of the housing ;
The base portion includes a substrate and a heat insulating material provided on a surface of the substrate,
The plurality of stack units are placed on the thermal insulation material,
A hot module, wherein the air supply port is an opening that penetrates the base material and the insulation material . The hot module according to claim 1, wherein a fuel flow path through which fuel supplied to the fuel electrode passes is provided inside each of the solid oxide fuel cells, and the air electrode is arranged so as to be exposed on the surface of each of the solid oxide fuel cells. The hot module according to claim 1 or 2, wherein the rigidity of the base is greater than the rigidity of the cover. The hot module according to any one of claims 1 to 3, wherein the base is provided with a gas exhaust port through which exhaust gas containing cathode off-gas generated by reaction with air at the air electrode passes. The hot module according to claim 4, wherein the exhaust gas further includes at least one of an anode off-gas generated by the reaction of fuel at the fuel electrode and a combustion gas of the anode off-gas. The hot module according to claim 4 or 5, wherein the covering material divides the space within the housing into a first space to which air is supplied via the at least one air supply port, and a second space to which the exhaust gas is supplied. 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 any one of claims 1 to 6, wherein the at least one air supply port is disposed between adjacent stack units among the plurality of stack units. The hot module according to claim 7, wherein the at least one air supply port extends continuously or intermittently along the thickness direction. A solid oxide fuel cell system comprising the hot module according to any one of claims 1 to 8 .

Images