JP7563012B2 - solid oxide fuel cell - Google Patents

Description

The present invention relates to a solid oxide fuel cell.

A solid oxide fuel cell (SOFC, hereafter simply referred to as "SOFC") has a cell with an electrolyte layer sandwiched between an anode layer and a cathode layer. Since the power generation performance of an SOFC is positively correlated with temperature, in order to improve the power generation output of an SOFC, the entire reaction surface of the cell must be kept at a high temperature. In a fuel cell, some of the heat generated by power generation is transported by heat transfer from the supply gas, so regardless of the gas supply method (co-flow, counter-flow, cross-flow), it is inevitable that a temperature distribution will occur on the reaction surface. The maximum temperature of the reaction surface must be lower than the heat resistance temperature of the material. If the temperature difference within the reaction surface is large, the entire reaction surface cannot be heated to a high temperature, which hinders the improvement of power generation output.

A fuel cell stack structure has been proposed that aims to achieve low electrical resistance and high output by uniformly heating the reaction surfaces of the cells (see Patent Document 1). This stack structure has a square internal manifold-type separator, and multiple anode manifolds and cathode manifolds are formed on each of the four sides of the square at positions symmetrical with respect to the center of the cell. The separators are stacked at each stage of the fuel cell, rotated 90° around the cell center. This makes the fuel and oxidant supply method for each cell a crossflow, and further makes the fuel flow direction perpendicular and the oxidant flow direction perpendicular for each stage.

Japanese Patent Application Publication No. 11-67259

In the technology described in Patent Document 1, manifolds are formed on all four sides to change the flow direction for each cell, and at least four manifolds and manifold seal parts are required per cell. As a result, the structure of the manifold and the auxiliary equipment associated with the manifold becomes complicated, making it difficult to actually apply the technology.

Therefore, the present invention aims to provide a solid oxide fuel cell that can combine gas supply methods (co-flow, counter-flow, cross-flow) with a simple structure.

In order to achieve the above object, the present invention provides a solid oxide fuel cell having a cell frame supporting a cell having an electrolyte layer sandwiched between an anode layer and a cathode layer. The cell frame has a main body portion formed from a hollow member having a hollow portion, and a cell support portion connected to the main body portion and supporting the cell. The main body portion has an inlet side manifold portion, an outlet side manifold portion, and a frame portion connecting the inlet side manifold portion and the outlet side manifold portion. The frame portion has a rectangular shape having four sides surrounding the periphery of the cell supported by the cell support portion. The cell frame further has an inlet-side manifold communicating portion formed in the inlet-side manifold portion and communicating with the hollow portion, an outlet-side manifold communicating portion formed in the outlet-side manifold portion and communicating with the hollow portion, a supply-side cell communicating portion formed in the frame portion communicating between the cell and the hollow portion and supplying a fluid flowing through the hollow portion to the cell, and a discharge-side cell communicating portion formed in the frame portion communicating between the cell and the hollow portion and discharging a fluid flowing through the cell to the hollow portion. The supply-side cell communicating portion is formed on any one of four sides of the frame portion, and the discharge-side cell communicating portion is formed on the other side symmetrically to the one side on which the supply-side cell communicating portion is formed, and the flow direction of the fluid flowing through the cell is set to a direction from any one of the sides toward the other side.

According to the present invention, the hollow portion of the hollow member that constitutes the main body of the cell frame is used as a gas flow passage. The gas flow direction can be selected by changing the formation positions of the supply side cell communication portion and the discharge side cell communication portion while keeping the basic structure of the main body of the cell frame the same. Therefore, it is possible to combine gas supply methods (co-flow, counter flow, cross flow) with a simple structure.

FIG. 2 is a perspective view showing a cell stack assembly of a solid oxide fuel cell disassembled into a skirt, a heat insulator, a pair of end plates, and a stack. FIG. 2 is a plan view of the insulation and stack of FIG. 1. 2 is a perspective view showing the stack shown in FIG. 1 disassembled into cell units, together with inter-unit seals. FIG. FIG. 4 is a perspective view showing the cell unit shown in FIG. 3 disassembled into a cell frame and separators, and the cell frame disassembled further into a main body and a cell support part that supports the cells, together with the seal between the units. 5 is a cross-sectional view taken along line 5-5 in FIG. 4 in a state in which the cell units are stacked. 6 is a cross-sectional view taken along line 6-6 in FIG. 4, showing the cell units and the inter-unit seals stacked together. FIG. 2 is a plan view showing a cell frame. FIG. 7B is an enlarged perspective view of a portion 7B surrounded by a dashed line in FIG. 7A. 7C is a cross-sectional view taken along line 7C-7C in FIG. 7A. FIG. 11 is a perspective view showing a state in which two main body constituents that configure the main body of the cell frame are separated. FIG. 10 is a diagram showing a schematic diagram of a temperature distribution in a stack when the supply system of the fuel gas and the oxidant gas is a combination of co-flow and counter-flow. FIG. 11 is a perspective view showing a main body of a cell frame in which a fuel gas and an oxidant gas are supplied in a co-flow manner. FIG. 9B is a plan view showing the upper second body portion constituent shown in FIG. 9A. FIG. 9B is a plan view showing the lower first body portion constituent shown in FIG. 9A. FIG. 11 is a perspective view showing a main body of a cell frame in which the fuel gas and the oxidant gas are supplied in counter flow. FIG. 10B is a plan view showing the upper second body portion constituent shown in FIG. 10A. FIG. 10B is a plan view showing the lower first body portion constituent shown in FIG. 10A. FIG. 10 is a diagram showing a schematic diagram of temperature distribution in a stack when the supply system of fuel gas and oxidant gas is a combination of cross-flow and cross-flow. FIG. 1 is a perspective view showing a main body of a cell frame in which the fuel gas and the oxidant gas are supplied in a cross-flow manner. FIG. 12B is a plan view showing the upper second body portion constituent shown in FIG. 12A. FIG. 12B is a plan view showing the lower first body portion constituent shown in FIG. 12A. 12B is a perspective view showing a main body of a cell frame in which the fuel gas and oxidant gas are supplied in a cross-flow manner and the fuel gas flows in a direction opposite to that shown in FIG. 12A . FIG. 13B is a plan view showing the upper second body portion constituent shown in FIG. 13A. FIG. 13B is a plan view showing the lower first body portion constituent shown in FIG. 13A. FIG. 13 is a diagram showing a stack to which a cell frame according to Modification 1 is applied, in which the supply method for fuel gas and oxidant gas is a combination of co-flow and counter-flow. FIG. 11 is a plan view showing a main body of a cell frame in which a fuel gas and an oxidant gas are supplied in a co-flow manner. FIG. 11 is a plan view showing a main body of a cell frame in which the fuel gas and the oxidant gas are supplied in counter flow. FIG. 13 is a diagram showing a stack to which a cell frame according to Modification 1 is applied, in which the supply system for fuel gas and oxidant gas is a combination of cross-flow and cross-flow. FIG. 2 is a plan view showing a main body of a cell frame in which the fuel gas and the oxidant gas are supplied in a cross-flow manner. 15C is a plan view showing a main body of a cell frame in which the fuel gas and oxidant gas are supplied in a cross-flow manner and the fuel gas flows in a direction opposite to the direction shown in FIG. 15B. 13 is a perspective view showing a modified example of the communication portion of the cell frame. FIG. 13 is a perspective view showing another modified example of the communication portion of the cell frame. FIG. 13 is a plan view showing a modified example of the hollow member of the cell frame. FIG. This is a cross-sectional view taken along line 17B-17B in Figure 17A. 17B , showing a cross-sectional view corresponding to FIG. 17B , illustrating a modified example of a hollow member of the cell frame.

Below, an embodiment of the present invention will be described with reference to the attached drawings. Note that the following description does not limit the technical scope or the meaning of the terms described in the claims. Also, the dimensional ratios in the drawings have been exaggerated for the convenience of explanation and may differ from the actual ratios.

A solid oxide fuel cell (SOFC) according to an embodiment will be described with reference to the figure. For ease of explanation, an XYZ Cartesian coordinate system is shown in the figure. The X-axis and Y-axis are parallel to the horizontal direction, and the Z-axis is parallel to the vertical direction.

Figure 1 is a perspective view showing a cell stack assembly 10 of an SOFC according to an embodiment disassembled into a skirt 11, a heat insulator 12, an upper end plate 13a, a lower end plate 13b, and a stack 14, and Figure 2 is a plan view showing the heat insulator 12 and the stack 14. Figure 3 is a perspective view showing the stack 14 disassembled into cell units 20 together with the inter-unit seal 30. Figure 4 is a perspective view showing the cell unit 20 disassembled into a cell frame 100 and a separator 110, and the cell frame 100 disassembled into a main body 120 and a cell support part 140 supporting the cell 130 together with the inter-unit seal 30. Figure 5 is a cross-sectional view taken along line 5-5 in Figure 4 showing the cell units 20 stacked together, and Figure 6 is a cross-sectional view taken along line 6-6 in Figure 4 showing the cell units 20 and the inter-unit seal 30 stacked together.

As shown in FIG. 1, the cell stack assembly 10 of the SOFC according to the embodiment includes a stack 14, an upper end plate 13a and a lower end plate 13b that sandwich the stack 14 from above and below, a heat insulating material 12 that covers the periphery of the stack 14, and a skirt 11 that covers the side portions of the heat insulating material 12. The skirt 11 is welded or bolted to the upper end plate 13a and the lower end plate 13b.

As shown in FIG. 2, the closed spaces 15, 16 between the stack 14 and the insulation material 12 form a flow path through which the oxidizer gas flows. The closed space 15 on the left side of the figure constitutes an inlet manifold portion for the oxidizer gas, and the closed space 16 on the right side of the figure constitutes an outlet manifold portion for the oxidizer gas. The oxidizer gas flows in the positive X direction.

As shown in FIG. 3, the stack 14 is made up of multiple cell units 20 stacked with inter-unit seals 30 between them. Hereinafter, the vertical direction of the stack 14, indicated by the Z axis in the figure, will also be referred to as the "stacking direction." The surface directions of each layer constituting the cell unit 20 correspond to the XY surface directions.

As shown in Figures 4 and 5, the cell unit 20 has a cell 130, a cell frame 100 that supports the cell 130, and a separator 110 in which a flow path portion is formed. In the cell unit 20, the separator 110 is sealed and fixed to the cell frame 100 that supports the cell 130.

The cell 130 has an anode layer 131, a cathode layer 132, and an electrolyte layer 133. The electrolyte layer 133 is sandwiched between the anode layer 131 and the cathode layer 132. The cathode layer 132 is an oxidizer electrode, and converts oxygen molecules into oxide ions by reacting an oxidizer gas (e.g., oxygen contained in air) with electrons. Examples of materials for forming the cathode layer 132 include oxides made of lanthanum, strontium, manganese, cobalt, and the like. The electrolyte layer 133 has a function of separating a fuel gas from an oxidizer gas. The electrolyte layer 133 allows oxide ions to pass from the cathode layer 132 to the anode layer 131, but does not allow gas and electrons to pass through. The material for forming the electrolyte layer 133 is not particularly limited, and _examples thereof _{include solid oxide ceramics such as stabilized zirconia doped with rare earth oxides (e.g., one or more selected from Y2O3, Sc2O3, Gd2O3 , Sm2O3 , Yb2O3 , Nd2O3 , etc. )} , ceria-based solid solutions, and perovskite oxides (e.g., _SrCeO3 , _BaCeO3 , _CaZrO3 , _SrZrO3, etc.). The anode layer ₁₃₁ is a fuel electrode that reacts a fuel gas (e.g., hydrogen) with oxide ions to generate an oxide of the fuel gas and extract electrons. Examples of the material for forming the anode layer 131 include metals such as Ni and Fe, and cermets of the metals and the ceramics listed as the materials for forming the electrolyte layer 133. The anode layer 131 is a porous body having a plurality of pores formed therein. A catalyst is impregnated into the pores in the anode layer 131. As the catalyst for the anode layer 131, for example, a metal catalyst such as Ni or Cu can be used.

The cell frame 100 supports the cell 130. The cell frame 100 has a main body 120 formed from a hollow member 121 having a hollow portion 122, and a cell support 140 connected to the main body 120 and supporting the cell 130.

The main body 120 of the cell frame 100 has an inlet manifold 151, an outlet manifold 152, and a frame 153 that connects the inlet manifold 151 and the outlet manifold 152. The main body 120 uses the hollow portion 122 of the hollow member 121 as a passage through which fuel gas flows. The frame 153 has a rectangular shape and is composed of a first frame 161, a second frame 162, a third frame 163, and a fourth frame 164. The first frame 161 is located on the left front side in the X direction and extends in the Y direction. The second frame 162 is away from the first frame 161 in the X positive direction and faces the first frame 161, and extends in the Y direction. The third frame 163 is located on the right front side in the Y direction and extends in the X direction. The fourth frame 164 faces the third frame 163 away from the third frame 163 in the positive Y direction and extends in the X direction. In the illustrated example, a pair of inlet side manifold sections 151 are arranged on the first frame 161 at a distance in the Y direction. A pair of outlet side manifold sections 152 are arranged on the second frame 162 at a distance in the Y direction. Fuel gas supplied to the cells 130 flows through the inlet side manifold section 151. Fuel gas discharged from the cells 130 flows through the outlet side manifold section 152. The main body section 120 is formed from a dense metal material that does not allow gas to pass through, such as stainless steel. A detailed configuration of the main body section 120 of the cell frame 100 will be described later.

The cell support 140 of the cell frame 100 holds the cell 130 from the periphery. As shown in FIG. 5, the cell support 140 is formed from a thin plate and has an opening 141 in which the cell 130 is placed. The cathode layer 132 of the cell 130 is bonded to the upper surface of the cell support 140 in the figure. The cell support 140 is formed from a dense metal material that does not allow gas to pass through, such as stainless steel. The surface of the cell support 140 is insulated. The outer periphery of the cell support 140 is bonded to the lower surface of the main body 120 in the figure by welding or brazing. Note that the reference numeral 142 in FIG. 5 denotes an edge seal 142 that covers and seals the outer periphery of the cell 130.

The separator 110 has a flow path portion 113 that divides and forms a gas flow path. As shown in FIG. 5, the flow path portion 113 has an uneven shape. The flow path portion 113 in the illustrated example extends in a substantially straight line in one direction (X direction). In this form, the flow direction of the gas flowing along the flow path portion 113 is the X direction. The outer periphery of the separator 110 is joined to the upper surface of the main body portion 120 of the cell frame 100 in the figure by welding or brazing. As shown in FIG. 4, the separator 110 has a first flow path 111 that communicates with the inlet side manifold portion 151 of the cell frame 100 and a second flow path 112 that communicates with the outlet side manifold portion 152. Fuel gas flows through the first flow path 111 and the second flow path 112. As described above, the stack 14 is formed by stacking a plurality of cell units 20. In the stack 14, an oxidant flow path 114 and a fuel flow path 115 are formed between the separator 110 and the cell 130. Focusing on the separator 110 of the lower cell unit 20 in FIG. 5, the space between the separator 110 and the anode layer 131 in the lower cell 130 is the fuel flow path 115, and the space between the separator 110 and the cathode layer 132 in the upper cell 130 is the oxidant flow path 114.

The inter-unit seal 30 prevents fuel gas from mixing with the oxidant gas flow path from the first flow path 111 and the second flow path 112 of the separator 110. The inter-unit seal 30 is made of, for example, thermoculite, which has heat resistance and sealing properties.

[Configuration of main body portion 120 of cell frame 100]
Next, the configuration of the main body 120 of the cell frame 100 will be described. Fig. 7A is a plan view showing the cell frame 100, Fig. 7B is an enlarged perspective view showing part 7B of Fig. 7A, and Fig. 7C is a cross-sectional view taken along line 7C-7C of Fig. 7A. Fig. 7D is a perspective view showing the state in which the two main body constituents 201 and 202 constituting the main body 120 of the cell frame 100 are separated.

As described above, the main body 120 of the cell frame 100 utilizes the hollow portion 122 of the hollow member 121 as a passage through which the fuel gas flows. The cell frame 100 has a simple structure that allows the combination of gas supply methods (coflow, counterflow, crossflow). Regarding the gas supply method, when the fuel gas and oxidizer gas flow directions are parallel, the method in which they flow in the same direction is coflow, and when they flow in the opposite directions is counterflow. When the fuel gas and oxidizer gas flow directions are perpendicular to each other, the method is crossflow.

One embodiment of the cell frame 100 will be described with reference to Figures 7A, 7B, 7C, and 7D. The dashed lines in Figure 7D diagrammatically indicate the inlet manifold communication portion, the outlet manifold communication portion, the supply cell communication portion, and the discharge cell communication portion.

The cell frame 100 has a plurality of communication parts that connect the hollow part 122 to the outside in order to use the hollow part 122 as a fuel gas passage. The communication parts include an inlet side manifold communication part 171, an outlet side manifold communication part 172, a supply side cell communication part 173, and an exhaust side cell communication part 174. The inlet side manifold communication part 171 is formed in the inlet side manifold part 151 and communicates with the hollow part 122. The inlet side manifold communication part 171 allows fuel gas to flow from the inlet side manifold part 151 into the hollow part 122. The outlet side manifold communication part 172 is formed in the outlet side manifold part 152 and communicates with the hollow part 122. The outlet side manifold communication part 172 allows fuel gas to flow from the hollow part 122 to the outlet side manifold part 152. The supply side cell communication part 173 is formed in the frame part 153 and connects the cell 130 to the hollow part 122. The supply side cell communication part 173 supplies the fuel gas flowing through the hollow part 122 to the cell 130. The discharge side cell communication part 174 is formed in the frame part 153 and connects the cell 130 to the hollow part 122. The discharge side cell communication part 174 discharges the fuel gas that has flowed through the cell 130 to the hollow part 122.

As shown in Figures 7B, 7C, and 7D, the main body 120 can be constructed by stacking two main body constituents 201, 202 each having an inlet side manifold 151, an outlet side manifold 152, and a frame 153. For convenience of explanation, one main body constituent 201 shown on the lower side in the figure is referred to as the first main body constituent 201, and the other main body constituent 202 shown on the upper side is referred to as the second main body constituent 202. As shown in Figure 7D, the first main body constituent 201 has an inlet side manifold communication portion 171 and a supply side cell communication portion 173, and the second main body constituent 202 has an outlet side manifold communication portion 172 and a discharge side cell communication portion 174. The inlet side manifold communication portion 171 of the first main body constituent 201 is formed on the inner peripheral edge of the inlet side manifold 151. The outlet side manifold communication part 172 of the second main body part constituent 202 is formed on the inner peripheral edge of the outlet side manifold part 152. The supply side cell communication part 173 of the first main body part constituent 201 is formed in the first frame 161 of the frame part 153, opening toward the X positive direction. The discharge side cell communication part 174 of the second main body part constituent 202 is formed in the second frame 162 of the frame part 153, opening toward the X negative direction. In this way, the main body part 120 of the cell frame 100 is stacked with the first main body part constituent 201 and the second main body part constituent 202 in a state in which the supply side cell communication part 173 and the discharge side cell communication part 174 are arranged in symmetrical positions with respect to the cell 130.

As shown in FIG. 7C, each of the first body part constituent 201 and the second body part constituent 202 has a pair of case bodies 210 having a cross-sectional concave shape. The case body 210 is formed by etching a frame material (having a thickness of, for example, about 1 mm) made of stainless steel corresponding to the planar shape of the body part 120. The pair of case bodies 210 are fixed by welding or the like with their concave portions facing each other. Then, as shown in FIG. 7A and FIG. 7B, a semicircular hole is formed in the edge of the case body 210 in the Z direction to form a communication portion (in FIG. 7A and FIG. 7B, the outlet side manifold communication portion 172 and the discharge side cell communication portion 174). The communication portion can be formed at a desired position and at a desired pitch. The first body part constituent 201 and the second body part constituent 202 have a common structure before the communication portion is formed. The first body constituent 201 and the second body constituent 202 only differ in the position where the communication portion is formed. As is clear from FIG. 7D, when the first body constituent 201 and the second body constituent 202 have a point-symmetric structure in the XY plane, the first body constituent 201 and the second body constituent 202 can be used by rotating the same body constituent by 180 degrees in the XY plane.

The first body constituent 201 and the second body constituent 202 each ensure their own rigidity by the welds that secure the case bodies 210 to each other. The body portion 120 of the cell frame 100 is secured by welding or the like to the stacked first body constituent 201 and second body constituent 202. The cell frame 100 ensures its overall rigidity by joining the cell support portion 140 (thin metal plate) to the body portion 120.

[Combination of co-flow and counter-flow]
Next, the temperature distribution of the stack 14 in the case where the supply method of the fuel gas and the oxidizing gas is a combination of coflow and counterflow will be described. Fig. 8 is a diagram showing the temperature distribution of the stack 14. Fig. 9A is a perspective view showing the main body 120 of the cell frame 100 in which the supply method of the fuel gas and the oxidizing gas is coflow, Fig. 9B is a plan view showing the second main body constituent 202 on the upper side, and Fig. 9C is a plan view showing the first main body constituent 201 on the lower side. Fig. 10A is a perspective view showing the main body 120 of the cell frame 100 in which the supply method of the fuel gas and the oxidizing gas is counterflow, Fig. 10B is a plan view showing the second main body constituent 204 on the upper side, and Fig. 10C is a plan view showing the first main body constituent 203 on the lower side.

In each figure, the solid arrows indicate the flow of fuel gas, and the dashed arrows indicate the flow of oxidizer gas. The dashed lines in Figures 9A, 9B, 9C, 10A, 10B, and 10C diagrammatically indicate the inlet side manifold communication portion 171, the outlet side manifold communication portion 172, the supply side cell communication portion 173, and the discharge side cell communication portion 174.

As shown in FIG. 8, in this stack 14, fuel gas flows in the X-positive direction in the first, third, and fifth cell units 20 from the top of the figure, and fuel gas flows in the X-negative direction in the second and fourth cell units 20. Oxidant gas flows in the X-positive direction between the cell units 20. Therefore, the first, third, and fifth cell units 20 have a coflow supply method for fuel gas and oxidant gas. The second and fourth cell units 20 have a counterflow supply method for fuel gas and oxidant gas.

(Cell frame 100 with co-flow gas supply system)
As shown in Figures 9A, 9B, and 9C, the first body part constituent 201 has an inlet side manifold communication part 171 and a supply side cell communication part 173, and the second body part constituent 202 has an outlet side manifold communication part 172 and a discharge side cell communication part 174. The inlet side manifold communication part 171 of the first body part constituent 201 is formed on the inner peripheral edge of the inlet side manifold part 151. The outlet side manifold communication part 172 of the second body part constituent 202 is formed on the inner peripheral edge of the outlet side manifold part 152. The supply side cell communication part 173 of the first body part constituent 201 is formed in the first frame 161 of the frame part 153, opening toward the X positive direction. The discharge side cell communication part 174 of the second body part constituent 202 is formed in the second frame 162, opening toward the X negative direction.

As shown in Figures 9A and 9C, the fuel gas flowing through the inlet manifold section 151 flows into the hollow section 122 through the inlet manifold communication section 171 of the first main body constituent 201. The fuel gas flows through the first frame 161 and is supplied to the cell 130 through the supply side cell communication section 173. The fuel gas flows in the positive X direction over the anode layer 131 of the cell 130. The fuel gas flow path section 113 of the separator 110 extends in an approximately straight line in the X direction (see Figure 5).

As shown in Figures 9A and 9B, the fuel gas that has passed through the cell 130 is discharged into the hollow portion 122 through the discharge side cell communication portion 174 of the second main body constituent 202. The fuel gas flows through the second frame 162 and flows out into the outlet side manifold portion 152 through the outlet side manifold communication portion 172.

As shown in Figures 9B and 9C, the inlet manifold section 15 for the oxidizer gas is formed between a pair of inlet manifold sections 151 for the fuel gas, and the outlet manifold section 16 for the oxidizer gas is formed between a pair of outlet manifold sections 152 for the fuel gas (see also Figure 2). The oxidizer gas flows in the positive X direction over the cathode layer 132 of the cell 130. The flow path section 113 for the oxidizer gas of the separator 110 extends in an approximately straight line in the X direction (see Figure 5).

In this way, by providing the cell frame 100 shown in Figures 9A, 9B, and 9C, the fuel gas flows in the X-positive direction within the cell unit 20, and the oxidant gas flows in the X-positive direction between adjacent cell units 20 in the stacking direction. The supply method for the fuel gas and the oxidant gas is co-flow.

(Cell frame 100 with counter flow gas supply system)
10A, 10B, and 10C, unlike the above-described cell frame 100, the supply side cell communication part 173 of the first main body constituent 203 is formed in the second frame 162 so as to open toward the X negative direction. The discharge side cell communication part 174 of the second main body constituent 204 is formed in the first frame 161 so as to open toward the X positive direction.

As shown in Figures 10A and 10C, the fuel gas flowing through the inlet manifold section 151 flows into the hollow section 122 through the inlet manifold communication section 171 of the first main body constituent 203. The fuel gas flows in the X-positive direction through the third frame 163 and the fourth frame 164 to reach the second frame 162, and is supplied to the cell 130 through the supply side cell communication section 173. The fuel gas flows in the X-negative direction over the anode layer 131 of the cell 130. The fuel gas flow path section 113 of the separator 110 extends in an approximately straight line in the X-direction (see Figure 5).

As shown in Figures 10A and 10B, the fuel gas that has passed through the cell 130 is discharged into the hollow portion 122 through the discharge side cell communication portion 174 of the second main body constituent 204. The fuel gas flows in the positive X direction from the first frame 161 through the third frame 163 and the fourth frame 164, and flows out into the outlet side manifold portion 152 through the outlet side manifold communication portion 172.

As shown in Figures 10B and 10C, the oxidant gas flows in the positive X direction over the cathode layer 132 of the cell 130. The flow path portion 113 for the oxidant gas of the separator 110 extends in an approximately straight line in the X direction (see Figure 5).

In this way, by providing the cell frame 100 shown in Figures 10A, 10B, and 10C, the fuel gas flows in the negative X direction within the cell unit 20, and the oxidant gas flows in the positive X direction between adjacent cell units 20 in the stacking direction. The supply method for the fuel gas and the oxidant gas is counterflow.

(Temperature distribution)
As shown in FIG. 8, within the same stack 14, the gas supply method can be switched between co-flow and counter-flow for each cell unit 20.

The first, third, and fifth cell units 20 use a coflow method for supplying fuel gas and oxidant gas. In this case, the temperature of the cell units 20 increases along the X-positive direction (see temperature distribution 301). The second and fourth cell units 20 use a counterflow method for supplying fuel gas and oxidant gas. In this case, the temperature of the cell units 20 increases along the X-positive direction, but decreases along the X-positive direction after passing the central portion (see temperature distribution 302). By stacking cell units 20 with different temperature distributions in this way, heat is transferred to each other and the temperature peaks of both cancel each other out. Therefore, as shown in temperature distribution 303, the maximum temperature is lowered and the temperature gradient in the reaction surface is reduced. Since the temperature difference in the reaction surface can be reduced, the entire reaction surface can be heated, as shown in temperature distribution 304. As a result, the power generation output can be improved. Furthermore, since the vicinity of the outlet of the reaction surface is a high-temperature area, it is easy to grasp the cell temperature.

[Combination of Cross Flow and Cross Flow]
Next, the temperature distribution of the stack 14 in the case where the supply method of the fuel gas and the oxidant gas is a combination of cross-flow and cross-flow will be described. FIG. 11 is a diagram showing the temperature distribution of the stack 14. FIG. 12A is a perspective view showing the main body 120 of the cell frame 100 in which the supply method of the fuel gas and the oxidant gas is cross-flow, FIG. 12B is a plan view showing the second main body constituent 206 on the upper side, and FIG. 12C is a plan view showing the first main body constituent 205 on the lower side. FIG. 13A is a perspective view showing the main body 120 of the cell frame 100 in which the supply method of the fuel gas and the oxidant gas is cross-flow and the direction in which the fuel gas flows is opposite to the direction shown in FIG. 12A, FIG. 13B is a plan view showing the second main body constituent 208 on the upper side, and FIG. 13C is a plan view showing the first main body constituent 207 on the lower side.

As shown in FIG. 11, in this stack 14, from the top in the figure, fuel gas in the first, third, and fifth cell units 20 flows in the Y negative direction, and fuel gas in the second and fourth cell units 20 flows in the Y positive direction. Oxidant gas flows in the X positive direction between the cell units 20. Therefore, the first, third, and fifth cell units 20 have a crossflow method of supplying fuel gas and oxidant gas, and fuel gas flows in the Y negative direction. The second and fourth cell units 20 have a crossflow method of supplying fuel gas and oxidant gas, and fuel gas flows in the Y positive direction.

(Cell frame 100 with cross-flow gas supply system (fuel gas flow direction is Y negative direction))
As shown in Figures 12A, 12B, and 12C, the first body part constituent 205 has an inlet side manifold communication part 171 and a supply side cell communication part 173, and the second body part constituent 206 has an outlet side manifold communication part 172 and a discharge side cell communication part 174. The inlet side manifold communication part 171 of the first body part constituent 205 is formed on the inner peripheral edge of the inlet side manifold part 151. The outlet side manifold communication part 172 of the second body part constituent 206 is formed on the inner peripheral edge of the outlet side manifold part 152. The supply side cell communication part 173 of the first body part constituent 205 is formed in the fourth frame 164, opening toward the Y negative direction. The discharge side cell communication part 174 of the second body part constituent 206 is formed in the third frame 163, opening toward the Y positive direction.

12A and 12C, the fuel gas flowing through the inlet manifold 151 flows into the hollow 122 through the inlet manifold communication 171 of the first main body component 205. A portion of the fuel gas flows in the Y-positive direction through the first frame 161 and reaches the fourth frame 164. The remainder of the fuel gas flows in the X-positive direction through the third frame 163 and in the Y-positive direction through the second frame 162 and reaches the fourth frame 164. The fuel gas is supplied to the cell 130 through the supply cell communication 173. The fuel gas flows in the Y-negative direction over the anode layer 131 of the cell 130. Although not shown, the fuel gas flow path 113 of the separator 110 extends in an approximately straight line in the Y-direction.

As shown in Figures 12A and 12B, the fuel gas that has passed through the cell 130 is discharged into the hollow portion 122 through the discharge cell communication portion 174 of the second main body component 206. A portion of the fuel gas flows in the X-positive direction within the third frame 163 and reaches the outlet side manifold communication portion 172. The remainder of the fuel gas flows in the X-negative direction within the third frame 163, in the Y-positive direction within the first frame 161, and in the X-positive direction through the fourth frame 164, and reaches the outlet side manifold communication portion 172. The fuel gas flows out through the outlet side manifold communication portion 172 to the outlet side manifold portion 152.

As shown in Figures 12B and 12C, the oxidant gas flows in the positive X direction over the cathode layer 132 of the cell 130. The flow path 113 for the oxidant gas in the separator 110 extends in an approximately straight line in the X direction (see Figure 5).

In this way, by providing the cell frame 100 shown in Figures 12A, 12B, and 12C, the fuel gas flows in the negative Y direction within the cell unit 20, and the oxidant gas flows in the positive X direction between adjacent cell units 20 in the stacking direction. The supply method for the fuel gas and oxidant gas is cross-flow (the fuel gas flows in the negative Y direction).

(Cell frame 100 with cross-flow gas supply system (fuel gas flow direction is Y positive direction))
13A, 13B, and 13C, unlike the above-described cell frame 100, the supply side cell communication part 173 of the first main body constituent 207 is formed in the third frame 163 and opens toward the Y positive direction. The discharge side cell communication part 174 of the second main body constituent 208 is formed in the fourth frame 164 and opens toward the Y negative direction.

13A and 13C, the fuel gas flowing through the inlet manifold 151 flows into the hollow 122 through the inlet manifold communication 171 of the first main body component 207. A portion of the fuel gas flows in the Y negative direction through the first frame 161 to reach the third frame 163. The remainder of the fuel gas flows in the X positive direction through the fourth frame 164 and in the Y negative direction through the second frame 162 to reach the third frame 163. The fuel gas is supplied to the cell 130 through the supply cell communication 173. The fuel gas flows in the Y positive direction over the anode layer 131 of the cell 130. Although not shown, the fuel gas flow path 113 of the separator 110 extends in an approximately straight line in the Y direction.

As shown in Figures 13A and 13B, the fuel gas that has passed through the cell 130 is discharged into the hollow portion 122 through the discharge cell communication portion 174 of the second main body component 208. A portion of the fuel gas flows in the X-positive direction within the fourth frame 164 and reaches the outlet side manifold communication portion 172. The remainder of the fuel gas flows in the X-negative direction within the fourth frame 164, in the Y-negative direction within the first frame 161, and in the X-positive direction through the third frame 163, and reaches the outlet side manifold communication portion 172. The fuel gas flows out through the outlet side manifold communication portion 172 to the outlet side manifold portion 152.

As shown in Figures 13B and 13C, the oxidant gas flows in the positive X direction over the cathode layer 132 of the cell 130. The flow path portion 113 for the oxidant gas of the separator 110 extends in an approximately straight line in the X direction (see Figure 5).

In this way, by providing the cell frame 100 shown in Figures 13A, 13B, and 13C, the fuel gas flows in the Y-positive direction within the cell unit 20, and the oxidant gas flows in the X-positive direction between adjacent cell units 20 in the stacking direction. The supply method for the fuel gas and the oxidant gas is cross-flow (the fuel gas flows in the Y-positive direction).

(Temperature distribution)
As shown in FIG. 11 , within the same stack 14, the gas supply method can be switched for each cell unit 20 between cross flow (fuel gas flows in the Y negative direction) and cross flow (fuel gas flows in the Y positive direction).

The first, third, and fifth cell units 20 use a cross-flow method for supplying fuel gas and oxidant gas (the fuel gas flows in the negative Y direction). In this case, the temperature of the cell unit 20 increases in a generally concentric manner, with the highest temperature being at a portion slightly shifted in the positive X direction and the negative Y direction from the approximate center (see temperature distribution 305). The second and fourth cell units 20 use a cross-flow method for supplying fuel gas and oxidant gas (the fuel gas flows in the positive Y direction). In this case, the temperature of the cell unit 20 increases in a generally concentric manner, with the highest temperature being at a portion slightly shifted in the positive X direction and the positive Y direction from the approximate center (see temperature distribution 306). By stacking cell units 20 with different temperature distributions in this way, heat is transferred to each other and the temperature peaks of both are cancelled out. For this reason, as shown in temperature distribution 307, the maximum temperature is lowered and the temperature gradient in the reaction surface is reduced. Since the temperature difference in the reaction surface can be reduced, the entire reaction surface can be heated. As a result, the power generation output can be improved. Furthermore, since the area near the outlet of the reaction surface is a high-temperature area, it is easy to grasp the cell temperature.

[Modification 1 of the cell frame 100]
In the above-described cell frame 100, the main body 120 is configured by stacking two main body constituents 201, 202, etc., but the present invention is not limited to this case. The cell frame 100 may have a single-layer main body 120. Below, a stack 14 in which a co-flow and a counter flow are combined, and a stack 14 in which a cross flow and a cross flow are combined, will be described by applying the cell frame 100 according to the first modification.

[Combination of co-flow and counter-flow]
Fig. 14A is a diagram showing a stack 14 to which the cell frame 100 according to the first modification is applied, in which the supply method of the fuel gas and the oxidant gas is a combination of co-flow and counter flow. Fig. 14B is a plan view showing a main body 221 of the cell frame 100 in which the supply method of the fuel gas and the oxidant gas is co-flow, and Fig. 14C is a plan view showing a main body 222 of the cell frame 100 in which the supply method of the fuel gas and the oxidant gas is counter flow.

As shown in FIG. 14A, in this stack 14, fuel gas flows in the X-positive direction in the first, third, and fifth cell units 20 from the top of the figure, and fuel gas flows in the X-negative direction in the second and fourth cell units 20. Oxidant gas flows in the X-positive direction between the cell units 20. Therefore, the first, third, and fifth cell units 20 have a coflow supply method for fuel gas and oxidant gas. The second and fourth cell units 20 have a counterflow supply method for fuel gas and oxidant gas.

(Cell frame 100 with co-flow gas supply system)
As shown in Fig. 14B, the main body 221 of the cell frame 100 has an inlet side manifold 151, an outlet side manifold 152, and a frame portion 153 that connects the inlet side manifold 151 and the outlet side manifold 152. The cell frame 100 further has an inlet side manifold communication portion 171, an outlet side manifold communication portion 172, a supply side cell communication portion 173, and a discharge side cell communication portion 174. One inlet side manifold 151 is disposed at the end of the first frame 161 of the frame portion 153 in the negative Y direction. One outlet side manifold 152 is disposed at the end of the second frame 162 in the positive Y direction. The inlet side manifold communication portion 171 is formed on the inner periphery of the inlet side manifold 151. The outlet side manifold communication portion 172 is formed on the inner periphery of the outlet side manifold 152. The supply side cell communication part 173 is formed in the first frame 161 and opens in the X positive direction. The discharge side cell communication part 174 is formed in the second frame 162 and opens in the X negative direction.

The main body 221 has a first partition plate 231 that blocks the gas flow from the first frame 161 to the third frame 163, a second partition plate 232 that blocks the gas flow from the first frame 161 to the fourth frame 164, a third partition plate 233 that blocks the gas flow from the second frame 162 to the third frame 163, and a fourth partition plate 234 that blocks the gas flow from the second frame 162 to the fourth frame 164.

The fuel gas flowing through the inlet manifold section 151 flows into the hollow section 122 through the inlet manifold communication section 171. The fuel gas flows through the first frame 161 and is supplied to the cell 130 through the supply side cell communication section 173. The fuel gas flows in the positive X direction over the anode layer 131 of the cell 130. The fuel gas flow path section 113 of the separator 110 extends in an approximately straight line in the X direction (see FIG. 5).

The fuel gas that passes through the cell 130 is discharged into the second frame 162 through the discharge cell communication part 174. The fuel gas flows through the second frame 162 and flows out into the outlet side manifold part 152 through the outlet side manifold communication part 172.

The oxidant gas flows in the positive X direction over the cathode layer 132 of the cell 130. The flow path 113 for the oxidant gas in the separator 110 extends in an approximately straight line in the X direction (see FIG. 5).

In this way, by providing the main body portion 221 shown in FIG. 14B, the fuel gas flows in the X-positive direction within the cell unit 20, and the oxidizer gas flows in the X-positive direction between adjacent cell units 20 in the stacking direction. The supply method for the fuel gas and the oxidizer gas is coflow.

(Cell frame 100 with counter flow gas supply system)
14C , unlike the above-described cell frame 100, the supply side cell communication part 173 is formed in the second frame 162 and opens toward the X negative direction. The discharge side cell communication part 174 is formed in the first frame 161 and opens toward the X positive direction.

The main body 222 has a fifth partition plate 235 that blocks the gas flow from the inlet manifold communication part 171 to the first frame 161, and a sixth partition plate 236 that blocks the gas flow from the second frame 162 to the outlet manifold communication part 172.

The fuel gas flowing through the inlet manifold section 151 flows into the hollow section 122 through the inlet manifold communication section 171. The fuel gas flows in the X-positive direction through the third frame 163 to reach the second frame 162, and is supplied to the cell 130 through the supply cell communication section 173. The fuel gas flows in the X-negative direction over the anode layer 131 of the cell 130. The fuel gas flow path section 113 of the separator 110 extends in an approximately straight line in the X-direction (see FIG. 5).

The fuel gas that has passed through the cell 130 is discharged into the first frame 161 through the discharge side cell communication part 174. The fuel gas flows from the first frame 161 through the fourth frame 164 in the positive X direction, and flows out into the outlet side manifold part 152 through the outlet side manifold communication part 172.

The oxidant gas flows in the positive X direction over the cathode layer 132 of the cell 130. The flow path 113 for the oxidant gas in the separator 110 extends in an approximately straight line in the X direction (see FIG. 5).

In this way, by providing the main body portion 222 shown in FIG. 14C, the fuel gas flows in the negative X direction within the cell unit 20, and the oxidizer gas flows in the positive X direction between adjacent cell units 20 in the stacking direction. The supply method for the fuel gas and the oxidizer gas is counterflow.

(Temperature distribution)
As shown in FIG. 14A, even when the cell frame 100 according to the first modification is applied, the gas supply method can be switched between co-flow and counter-flow for each cell unit 20 in the same stack 14.

The temperature distribution is the same as that shown in Figure 8, and by stacking cell units 20 with different temperature distributions, heat is transferred between them and the temperature peaks of both are cancelled out. This lowers the maximum temperature and reduces the temperature gradient within the reaction surface. Since the temperature difference within the reaction surface can be reduced, the entire reaction surface can be heated to a high temperature. As a result, the power generation output can be improved. Furthermore, since the area near the outlet of the reaction surface is the high temperature area, it is also easy to grasp the cell temperature.

[Combination of Cross Flow and Cross Flow]
Fig. 15A is a diagram showing a stack 14 to which the cell frame 100 according to the first modification is applied, in which the supply method for the fuel gas and the oxidant gas is a combination of cross-flow and cross-flow. Fig. 15B is a plan view showing a main body 223 of the cell frame 100 in which the supply method for the fuel gas and the oxidant gas is the cross-flow, and Fig. 15C is a plan view showing a main body 224 of the cell frame 100 in which the supply method for the fuel gas and the oxidant gas is the cross-flow and further in which the fuel gas flows in the opposite direction to the direction shown in Fig. 15B.

As shown in FIG. 15A, in this stack 14, from the top in the figure, fuel gas flows in the Y negative direction in the first, third, and fifth cell units 20, and fuel gas flows in the Y positive direction in the second and fourth cell units 20. Oxidant gas flows in the X positive direction between the cell units 20. Therefore, the first, third, and fifth cell units 20 have a crossflow method of supplying fuel gas and oxidant gas, and fuel gas flows in the Y negative direction. The second and fourth cell units 20 have a crossflow method of supplying fuel gas and oxidant gas, and fuel gas flows in the Y positive direction.

(Cell frame 100 with cross-flow gas supply system (fuel gas flow direction is Y negative direction))
As shown in Fig. 15B, the main body 223 of the cell frame 100 has an inlet side manifold 151, an outlet side manifold 152, and a frame 153 connecting the inlet side manifold 151 and the outlet side manifold 152. The cell frame 100 further has an inlet side manifold communication part 171, an outlet side manifold communication part 172, a supply side cell communication part 173, and a discharge side cell communication part 174. One inlet side manifold 151 is disposed at the end of the first frame 161 in the negative Y direction. One outlet side manifold 152 is disposed at the end of the second frame 162 in the positive Y direction. The inlet side manifold communication part 171 is formed on the inner periphery of the inlet side manifold 151. The outlet side manifold communication part 172 is formed on the inner periphery of the outlet side manifold 152. The supply side cell communication part 173 is formed in the fourth frame 164 and opens in the Y negative direction. The discharge side cell communication part 174 is formed in the third frame 163 and opens in the Y positive direction.

The main body 223 has a seventh partition plate 237 that blocks the gas flow from the first frame 161 to the third frame 163, and an eighth partition plate 238 that blocks the gas flow from the fourth frame 164 to the second frame 162.

The fuel gas flowing through the inlet manifold section 151 flows into the hollow section 122 through the inlet manifold communication section 171. The fuel gas flows in the X-positive direction from the first frame 161 through the fourth frame 164, and is supplied to the cell 130 through the supply side cell communication section 173. The fuel gas flows in the Y-negative direction over the anode layer 131 of the cell 130. Although not shown, the fuel gas flow path section 113 of the separator 110 extends in an approximately straight line in the Y direction.

The fuel gas that passes through the cell 130 is discharged into the third frame 163 through the discharge cell communication part 174. The fuel gas flows in the X-positive direction through the third frame 163, flows in the Y-positive direction through the second frame 162, and flows out into the outlet side manifold part 152 through the outlet side manifold communication part 172.

The oxidant gas flows in the positive X direction over the cathode layer 132 of the cell 130. The flow path 113 for the oxidant gas in the separator 110 extends in an approximately straight line in the X direction (see FIG. 5).

In this way, by providing the main body portion 223 shown in FIG. 15B, the fuel gas flows in the negative Y direction within the cell unit 20, and the oxidant gas flows in the positive X direction between adjacent cell units 20 in the stacking direction. The supply method for the fuel gas and the oxidant gas is cross-flow (the flow direction of the fuel gas is the negative Y direction).

(Cell frame 100 with cross-flow gas supply system (fuel gas flow direction is Y positive direction))
15C , unlike the above-described cell frame 100, the supply side cell communication part 173 is formed in the third frame 163 and opens toward the Y positive direction. The discharge side cell communication part 174 is formed in the fourth frame 164 and opens toward the Y negative direction.

The main body 224 has a ninth partition plate 239 that blocks the gas flow from the inlet manifold communication portion 171 to the first frame 161, a tenth partition plate 240 that blocks the gas flow from the third frame 163 to the second frame 162, an eleventh partition plate 241 that blocks the gas flow from the first frame 161 to the fourth frame 164, and a twelfth partition plate 242 that blocks the gas flow from the fourth frame 164 to the second frame 162.

The fuel gas flowing through the inlet manifold section 151 flows into the hollow section 122 through the inlet manifold communication section 171. The fuel gas flows in the X-positive direction within the third frame 163 and is supplied to the cell 130 through the supply side cell communication section 173. The fuel gas flows in the Y-positive direction over the anode layer 131 of the cell 130. Although not shown in the figure, the fuel gas flow path section 113 of the separator 110 extends in an approximately straight line in the Y-direction.

The fuel gas that passes through the cell 130 is discharged into the fourth frame 164 through the discharge cell communication part 174. The fuel gas flows in the X-positive direction within the fourth frame 164 and flows out into the outlet side manifold part 152 through the outlet side manifold communication part 172.

The oxidant gas flows in the positive X direction over the cathode layer 132 of the cell 130. The flow path 113 for the oxidant gas in the separator 110 extends in an approximately straight line in the X direction (see FIG. 5).

In this way, by providing the main body portion 224 shown in FIG. 15C, the fuel gas flows in the Y-positive direction within the cell unit 20, and the oxidant gas flows in the X-positive direction between adjacent cell units 20 in the stacking direction. The supply method for the fuel gas and the oxidant gas is cross-flow (the fuel gas flows in the Y-positive direction).

(Temperature distribution)
As shown in FIG. 15A, even when the cell frame 100 relating to variant example 1 is applied, the gas supply method can be switched between cross flow (fuel gas flow direction is the Y negative direction) and cross flow (fuel gas flow direction is the Y positive direction) for each cell unit 20 within the same stack 14.

The temperature distribution is the same as that shown in Figure 11, and by stacking cell units 20 with different temperature distributions, heat is transferred between them and the temperature peaks of both are cancelled out. This lowers the maximum temperature and reduces the temperature gradient within the reaction surface. Since the temperature difference within the reaction surface can be reduced, the entire reaction surface can be heated to a high temperature. As a result, the power generation output can be improved. Furthermore, since the area near the outlet of the reaction surface is the high temperature area, it is also easy to grasp the cell temperature.

[Other Modifications of the Cell Frame 100]
Next, another modification of the cell frame 100 will be described.

Figure 16A is a perspective view showing a modified example of the communication part of the cell frame 100, and Figure 16B is a perspective view showing another modified example of the communication part of the cell frame 100.

The communication portion of the cell frame 100 is not limited to being formed by drilling a semicircular hole in the Z direction. For example, as shown in FIG. 16A, the communication portion 175 can be formed by drilling a through hole in a direction parallel to the XY plane. Also, as shown in FIG. 16B, the communication portion 176 can be formed by drilling a groove in a direction parallel to the XY plane.

Figure 17A is a plan view showing a modified example of the hollow member 123 of the cell frame 100, and Figure 17B is a cross-sectional view taken along line 17B-17B in Figure 17A. Figure 17C is a cross-sectional view equivalent to Figure 17B showing a modified example of the hollow member 124 of the cell frame 100.

The hollow member 121 forming the main body 120 of the cell frame 100 is not limited to a form in which a pair of case bodies 210 are fixed by welding or the like. For example, as shown in Figures 17A and 17B, the hollow member 123 can be formed by drawing or extrusion. Also, as shown in Figure 17C, the hollow member 124 having two stages of hollow portions 122 can also be formed by drawing or extrusion. Reference numeral 177 in Figures 17A and 17B indicates a communication portion that communicates between the hollow portion 122 and the outside.

An example of a stack 14 in which the fuel gas supply direction is different for each cell unit 20 has been shown. However, the stack 14 can have different fuel gas supply directions for each of multiple cell units 20.

The stack 14 in which the oxidant gas supply direction is constant (X positive direction) has been exemplified. However, the stack 14 can have a different oxidant gas supply direction for each of the multiple cell units 20, or can have a different oxidant gas supply direction for each cell unit 20. For example, by reversing the oxidant gas inlet, the oxidant gas can be supplied in the X negative direction.

The stack 14 is illustrated in which the hollow portion 122 of the hollow member 121 that constitutes the main body 224 of the cell frame 100 is used as a flow path for fuel gas. However, the hollow portion 122 of the hollow member 121 can also be used as a flow path for oxidizer gas.

The cell frame 100 in which the main body 120 is formed by stacking two main body constituents 201, 202 has been exemplified. However, the main body 120 can be formed by stacking three or more main body constituents. When stacking an odd number of main body constituents, the number of layers forming the supply side cell communication portion 173 can be different from the number of layers forming the discharge side cell communication portion 174.

As explained above through the embodiments and various modified examples, the solid oxide fuel cell has the following effects. Note that only representative reference numbers are used for the components.

The solid oxide fuel cell has a cell frame 100 that supports the cells 130. The cell frame 100 has a main body 120 formed from a hollow member 121 with a hollow portion 122, and a cell support portion 140 that is connected to the main body 120 and supports the cells 130. The main body 120 has an inlet side manifold portion 151, an outlet side manifold portion 152, and a frame portion 153 that connects the inlet side manifold portion 151 and the outlet side manifold portion 152. The cell frame 100 further has an inlet side manifold communication portion 171, an outlet side manifold communication portion 172, a supply side cell communication portion 173, and a discharge side cell communication portion 174.

The solid oxide fuel cell thus constructed uses the hollow portion 122 of the hollow member 121 constituting the main body 120 of the cell frame 100 as a gas flow passage. The gas flow direction can be selected by changing the formation positions of the supply side cell communication portion 173 and the discharge side cell communication portion 174 while keeping the basic structure of the main body 120 of the cell frame 100 the same. Therefore, it is possible to combine gas supply methods (coflow, counterflow, crossflow) with a simple structure. Since the structure of the cell frame 100 is simplified, the cell frame 100 can be made smaller, and through this, the stack 14 of the solid oxide fuel cell can also be made smaller. Since the basic structure of the main body 120 of the cell frame 100 is the same, the number of parts can also be reduced.

In the above-mentioned Patent Document 1, it is necessary to form manifolds on all four sides in order to change the flow direction for each cell. On the other hand, in the solid oxide fuel cell of this invention, by changing the formation positions of the supply side cell communication part 173 and the discharge side cell communication part 174, it is only necessary to install manifolds on a minimum of two sides.

The main body 120 of the cell frame 100 is constructed by stacking at least two main body constituents 201, 202, one of which, the first main body constituent 201, has an inlet side manifold communication part 171 and a supply side cell communication part 173, and the other, the second main body constituent 202, has an outlet side manifold communication part 172 and a discharge side cell communication part 174. The main body 120 of the cell frame 100 is constructed by stacking at least two main body constituents 201, 202 in a state in which the supply side cell communication part 173 and the discharge side cell communication part 174 are arranged symmetrically with respect to the cell 130. By configuring in this way, the gas flow direction can be selected by changing the formation position of the supply side cell communication part 173 and the discharge side cell communication part 174 while keeping the basic structure of the main body constituents 201, 202 the same. Therefore, it is possible to combine gas supply methods with a simple structure.

The cell unit 20 is made by sealing and fixing a separator 110 having a flow path 113 formed therein to a cell frame 100 supporting the cells 130. By configuring it in this way, the basic structure of the main body 120 of the cell frame 100 remains the same, but the gas flow direction within the cell unit 20 can be selected by changing the formation positions of the supply side cell communication part 173 and the discharge side cell communication part 174.

The stack 14 is made by stacking multiple cell units 20 and forming an oxidant flow path 114 and a fuel flow path 115 between the separator 110 and the cell 130. By configuring it in this way, it is possible to switch between gas supply methods (coflow, counterflow, crossflow) within the same stack 14.

In the stack 14, the fuel or oxidant supply direction differs for each of the multiple cell units 20. By configuring in this way, cell units 20 with different temperature distributions are stacked, and heat is transferred between them, canceling out the temperature peaks of both. This lowers the maximum temperature and reduces the temperature gradient within the reaction surface. Since the temperature difference within the reaction surface can be reduced, the entire reaction surface can be heated. As a result, the power generation output can be improved. Furthermore, since the area near the outlet of the reaction surface is the high temperature area, it is also easy to grasp the cell temperature.

In the stack 14, the fuel supply direction is different for at least one cell unit 20. By configuring it in this way, cell units 20 with different temperature distributions are stacked one layer at a time, and the effect of mutual heat transfer and canceling out the temperature peaks of both becomes prominent. This lowers the maximum temperature and reduces the temperature gradient within the reaction surface. Since the temperature difference within the reaction surface can be made smaller, the entire reaction surface can be made hotter. As a result, the power generation output can be further improved.

In the stack 14, the oxidant supply direction differs for at least one cell unit 20. By configuring it in this way, as described above, cell units 20 with different temperature distributions are stacked one layer at a time, and the effect of mutual heat transfer and cancellation of the temperature peaks of both becomes prominent. As a result, it is possible to further improve the power generation output.

The fuel and oxidant supply method is a combination of co-flow and counter flow, or a combination of cross-flow in which the fuel or oxidant is supplied in a different direction. This configuration allows cell units 20 with different temperature distributions to be stacked, and heat can be transferred between them to cancel out the temperature peaks of both. As a result, the power generation output can be improved. Furthermore, since the area near the outlet of the reaction surface becomes a high-temperature area, it is also easy to grasp the cell temperature.

In the cell frame 100, a part of the hollow portion 122 in the main body portions 221, 222, 223, and 224 is sealed. By configuring in this way, the gas flow path can be set more freely using the hollow portion 122. The gas flow direction can be selected by changing the position where the hollow portion 122 is sealed and the formation position of the supply side cell communication portion 173 and the discharge side cell communication portion 174 while keeping the basic structure of the main body portions 221, 222, 223, and 224 of the cell frame 100 the same. Therefore, it is possible to combine gas supply methods (coflow, counterflow, crossflow) with a simple structure. The main body portions 221, 222, 223, and 224 of the cell frame 100 are only one layer, and the number of parts can be reduced compared to when the main body portion 120 is configured by stacking the main body portion constituents 201 and 202.

14 stacks,
20 cell units,
30 Inter-unit seal,
100 cell frames,
110 Separator,
113 flow path portion,
114 oxidant flow path,
115 fuel flow path,
120, 221, 222, 223, 224 main body portion,
121, 123, 124 hollow member,
122 hollow portion,
130 cells,
131 anode layer,
132 cathode layer,
133 electrolyte layer,
140 Cell support part,
141 opening,
151 inlet side manifold portion,
152 outlet side manifold portion,
153 frame part,
161 first frame,
162 second frame,
163 3rd frame,
164 4th frame,
171 inlet side manifold communication part,
172 outlet side manifold communication part,
173 supply side cell communication part,
174 Discharge side cell communication part,
201, 203, 205, 207 first main body component (main body component),
202, 204, 206, 208 second main body component (main body component),
231 to 242 1st partition plate to 12th partition plate.

Claims (9)

A solid oxide fuel cell having a cell frame supporting a cell having an electrolyte layer sandwiched between an anode layer and a cathode layer,
the cell frame has a main body portion formed of a hollow member having a hollow portion, and a cell support portion connected to the main body portion and supporting the cell,
the main body portion has an inlet side manifold portion, an outlet side manifold portion, and a frame portion connecting the inlet side manifold portion and the outlet side manifold portion, the frame portion having a rectangular shape having four sides surrounding the periphery of the cells supported by the cell support portions,
the cell frame further includes an inlet-side manifold communication portion formed in the inlet-side manifold portion and communicating with the hollow portion, an outlet-side manifold communication portion formed in the outlet-side manifold portion and communicating with the hollow portion, a supply-side cell communication portion formed in the frame portion and communicating with the cell and the hollow portion for supplying a fluid flowing through the hollow portion to the cell, and a discharge-side cell communication portion formed in the frame portion and communicating with the cell and the hollow portion for discharging the fluid flowing through the cell to the hollow portion ,
a supply side cell communicating portion formed on any one of four sides of the frame portion, and a discharge side cell communicating portion formed on another side symmetrically positioned to the one side on which the supply side cell communicating portion is formed, and a flow direction of fluid flowing through the cell is set to a direction from any one of the sides toward the other side . the main body portion of the cell frame is configured by stacking at least two main body constituents each having the inlet side manifold portion, the outlet side manifold portion, and the frame portion,
one of the main body constituents has the inlet side manifold communication part and the supply side cell communication part, and the other of the main body constituents has the outlet side manifold communication part and the discharge side cell communication part,
2. The solid oxide fuel cell according to claim 1, wherein the main body of the cell frame is formed by stacking at least two of the main body constituents in a state in which the supply side cell communicating portion and the discharge side cell communicating portion are arranged in symmetrical positions with respect to the cell. The solid oxide fuel cell according to claim 1 or 2, which has a cell unit in which a separator having a flow path is sealed and fixed to the cell frame that supports the cell. The solid oxide fuel cell according to claim 3, comprising a stack in which a plurality of the cell units are stacked, and an oxidant flow path and a fuel flow path are formed between the separator and the cell. The solid oxide fuel cell according to claim 4, wherein the stack has a different fuel or oxidant supply direction for each of the multiple cell units. The solid oxide fuel cell according to claim 5, wherein the stack has a different fuel supply direction for at least one of the cell units. The solid oxide fuel cell according to claim 5, wherein the stack has a different oxidant supply direction for at least one of the cell units. The solid oxide fuel cell according to claim 6 or 7, wherein the fuel and oxidant supply method is a combination of coflow and counterflow, or a combination of crossflow in which the fuel or oxidant is supplied in different directions. The solid oxide fuel cell according to claim 8, wherein the cell frame is formed by sealing a portion of the hollow portion in the main body.