Fuel cell unit and power supply device

Abstract

To improve the temperature control efficiency of a multilayer body by heat exchange with a temperature control fluid.SOLUTION: A cell multilayer body 11 in which a plurality of multilayer objects including at least separators 21, 22 and MEA 23 are stacked, and a pair of end plates 12, 12 disposed on both ends of the cell multilayer body 11 are provided. The multilayer objects are in close contact with each other between both plates 12, 12. The cell multilayer body 11 is in close contact with both plates 12, 12. An air intake guide 13 that forms an air intake path L, in which the air to control the temperature of the multilayer body 11 by heat exchange with the multilayer body 11 in contact with the multilayer body 11, passes along one side of the multilayer objects in the multilayer body 11 is formed between the multilayer body 11 and the air intake guide 13 beside the multilayer body 11. In the multilayer body 11, the respective multilayer objects are stacked so that convex parts 11a and concave parts 11b are present alternately in the stacking direction of the multilayer objects in a first counter part facing the air intake guide 13 at an outer peripheral surface of the multilayer body 11.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a fuel cell unit in which a stack of multiple laminated materials, including at least fuel cell separators and fuel cell membrane electrode assemblies, is sandwiched between a pair of substrates, and to a power supply device that includes such a fuel cell unit and is configured to be able to supply power to a target. [Background technology]

[0002] For example, the following patent document discloses an invention of a polymer electrolyte fuel cell system (hereinafter simply referred to as a "fuel cell system"), in which a laminated cell stack, a cross-flow fan, and an axial flow fan are housed in a case, and a fuel tank containing hydrogen gas is disposed outside the case.

[0003] The battery stack is composed of two battery assemblies, each of which has a plurality of unit battery cells stacked with a metal separator interposed therebetween. In this case, in this fuel cell system, the battery stack is composed of a heat sink-integrated metal separator with a heat sink portion integrally formed therewith. The cross flow fan is disposed so as to face one of the heat sink portions of each metal separator of the battery stack. The axial flow fan is disposed so as to face the cross flow fan across the battery stack and face the other heat sink portion of the metal separator.

[0004] In this fuel cell system, a crossflow fan draws in cooling air through an air intake in the case and blows it toward the cell stack (each heat sink portion on one side of the metal separator), while an axial fan draws in air from the cell stack side and exhausts it outside the case through an exhaust port in the case. This prevents excessive temperature rise in the cell stack and prevents a decrease in power generation efficiency and damage to the unit battery cells. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-055832 A (pages 6-12, figures 1-9) Summary of the Invention [Problem to be solved by the invention]

[0006] However, the fuel cell system disclosed in the above patent document has the following problems to be solved: Specifically, the fuel cell system disclosed in the above patent document employs a configuration in which a cross-flow fan disposed opposite one heat sink portion of the cell stack (metal separator) draws in air outside the case from an intake port and blows it toward one heat sink portion, and an axial fan disposed opposite the other heat sink portion of the cell stack (metal separator) draws in air near the cell stack and exhausts it outside the case from an exhaust port, thereby avoiding excessive temperature rise in the cell stack.

[0007] In this case, the air blown by the crossflow fan comes into contact with the cell stack (one of the heat sink portions) and cools it through heat exchange with the one of the heat sink portions, while moving inside the case along the surface of the cell stack where the one of the heat sinks is formed, and then leaving the cell stack. Therefore, in the fuel cell system disclosed in the above patent document, the direction of the air blown by the crossflow fan is changed after coming into contact with the cell stack, which causes turbulence in the cooling air inside the case, making it difficult to properly bring the air drawn in sequentially by the crossflow fan into contact with one of the heat sinks in the cell stack.

[0008] Furthermore, in the fuel cell system disclosed in the above patent document, when the air inside the case is exhausted to the outside by the axial flow fan, the air that has come into contact with the other heat sink in the cell stack and cooled it is dragged along by the flow of air that has cooled it, and the air that has not come into contact with the other heat sink is exhausted. As such, in the fuel cell system disclosed in the above patent document, it is currently difficult to improve the cooling efficiency of the cell stack by the air intake by the cross flow fan and the air exhaust by the axial flow fan, and this problem needs to be solved.

[0009] The present invention has been made in consideration of the above-mentioned problems to be solved, and its main object is to provide a fuel cell unit that can sufficiently improve the temperature adjustment efficiency of the stack through heat exchange with a temperature-adjusting fluid, and a power supply device equipped with such a fuel cell unit. [Means for solving the problem]

[0010] In order to achieve the above object, a fuel cell unit according to claim 1 includes an N-sided pillar-shaped stack formed by stacking a plurality of flat plate-shaped laminated materials that have an N-sided shape in a planar view (N is a natural number of 3 or more) and that include at least fuel cell separators and fuel cell membrane electrode assemblies, and a pair of substrates disposed on both ends of the stack, wherein the laminated materials are closely attached to each other between the two substrates and the stack is also closely attached to the two substrates, and a flow path forming member is disposed in parallel with the stack, the flow path forming member forming a flow path between the stack and the laminated materials and allowing a temperature control fluid that is in contact with the stack and adjusts the temperature of the stack by heat exchange with the stack to pass along one side of the laminated materials in the stack, and the laminated materials are stacked such that convex portions that protrude outward in the plate surface direction of the laminated materials and concave portions that are concave inward in the plate surface direction are alternately present in the stacking direction of the laminated materials at a first opposing portion that faces the flow path forming member on the outer circumferential surface of the stack. The flow path forming member has a second opposing portion facing the stacked body, and an abutting portion that contacts the first opposing portion is formed in the second opposing portion. are.

[0012] Claim 2 The fuel cell unit described is a fuel cell unit comprising: an N-sided pillar-shaped stack formed by stacking a plurality of flat plate-shaped laminated materials that have an N-sided shape in a planar view (N is a natural number of 3 or more) and that include at least fuel cell separators and fuel cell membrane electrode assemblies; and a pair of substrates disposed on both ends of the stack, wherein the laminated materials are closely attached to each other between the two substrates and the stack is closely attached to the two substrates; a flow path forming member is disposed in parallel with the stack, the flow path forming member forming a flow path between the stack and the laminated materials and allowing a temperature control fluid that is in contact with the stack and adjusts the temperature of the stack by heat exchange with the stack to pass along one side of the laminated materials in the stack; and the laminated materials are stacked such that, at a first opposing portion that faces the flow path forming member on the outer circumferential surface of the stack, convex portions that protrude outward in the plate surface direction of the laminated materials and concave portions that are concave inward in the plate surface direction are alternately present in the stacking direction of the laminated materials;The stack and the flow path forming member are configured so that at least one of a first distance between a second opposing portion that faces the stack in the flow path forming member and the tip of the convex portion, and a second distance between the second opposing portion and the bottom of the concave portion, becomes larger downstream in the direction in which the temperature regulating fluid passes through the flow path.

[0013] Claim 3 The power supply device according to claim 1 or 2 The device is equipped with the fuel cell unit described above and a fluid movement mechanism that moves the temperature-adjusting fluid, and is configured to be able to adjust the temperature of the stack using the temperature-adjusting fluid that is moved by the fluid movement mechanism and passed through the flow path, while supplying the electricity generated by the fuel cell unit to an external device. [Effects of the Invention]

[0014] Claim 1 ,2 In the fuel cell unit described, a flow path forming member is arranged in parallel with the stack body, and the flow path forms between the stack body and the stacked objects, through which a temperature control fluid that is in contact with the stack body and controls the temperature of the stack body by heat exchange with the stack body passes along one side of the stacked objects in the stack body, and the stacked objects are stacked so that convex portions that protrude outward in the plate surface direction of each stacked object and concave portions that are concave inward in the plate surface direction are alternately present in the stacking direction of each stacked object at a first opposing portion that faces the flow path forming member on the outer circumferential surface of the stack body. 3 The power supply device described is configured to include the fuel cell unit described above.

[0015] Therefore, claim 1 ,2 The fuel cell unit according to the invention and the claims 3According to the described power supply device, the temperature control fluid drawn into the flow path moves smoothly within the flow path along one side of each stacked object in the stack without significantly departing from the position in contact with the stack, and as a result, heat is exchanged favorably between the stack and the temperature control fluid within the flow path, allowing for efficient temperature control of the stack. Furthermore, compared to a configuration in which there are no convex or concave portions in the first opposing portion of the stack, the surface area of ​​the stack within the flow path is sufficiently large, and the efficiency of heat exchange between the stack and the temperature control fluid is sufficiently improved, allowing for even more efficient temperature control of the stack.

[0016] Also, Claim 1 In the fuel cell unit and the power supply device equipped with such a fuel cell unit, the second opposing portion of the flow path forming member facing the stack has an abutment portion that abuts against the first opposing portion. This prevents the first opposing surface (the tip of the convex portion) of the stack and the second opposing portion of the flow path forming member from being closer than the height of the abutment portion, preventing the effective cross-sectional area of ​​the flow path from becoming excessively small even if the fuel cell unit (power supply device) is subjected to vibration or impact. This allows the temperature-regulating cooling fluid to pass smoothly through the flow path.

[0017] Also, Claim 2According to the described fuel cell unit and a power supply device equipped with such a fuel cell unit, the stack and the flow path forming member are configured so that at least one of the first distance between the second opposing portion facing the stack in the flow path forming member and the tip of the convex portion, and the second distance between the second opposing portion and the bottom of the concave portion, becomes larger toward the downstream side in the direction of passage of the temperature control fluid in the flow path.This causes the effective cross-sectional area of ​​the flow path to gradually increase from the upstream side to the downstream side, and the passing speed of the temperature control fluid in the flow path to gradually decrease as it moves from the upstream side to the downstream side, making it possible to achieve sufficient heat exchange between the stack and the temperature control fluid even downstream of the flow path, thereby ensuring temperature control from the upstream side to the downstream side in the direction of passage of the temperature control fluid in the first opposing portion of the stack. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a configuration diagram of a power supply device 1. [Figure 2] FIG. 2 is a cross-sectional view of the fuel cell unit 2. [Figure 3] FIG. 3 is a cross-sectional view taken along the line B1-B1 in FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view taken along the line B2-B2 in FIG. 2. [Figure 5] FIG. 2 is an enlarged cross-sectional view of the cell stack 11. [Figure 6] FIG. 5 is a cross-sectional view taken along the line C1-C1 in FIGS. [Figure 7] FIG. 5 is a cross-sectional view taken along the line C2-C2 in FIGS. [Figure 8] FIG. 5 is a cross-sectional view taken along the line C3-C3 in FIGS. [Figure 9] FIG. 2 is a cross-sectional view of a fuel cell unit 2A. [Figure 10] FIG. 2 is a cross-sectional view of a fuel cell unit 2B. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of a fuel cell unit and a power supply device will be described with reference to the accompanying drawings.

[0020] The power supply device 1 shown in Figure 1 is an example of a "power supply device" and is configured to generate electricity when supplied with power-generating gases (for example, hydrogen gas and air (atmospheric air: oxygen)) and supply the electricity to various supply targets. Specifically, the power supply device 1 is configured to include a fuel cell unit 2, a hydrogen gas supply unit 3, suction pumps 4 and 5a, a fan 5b, an inverter 6, and a control unit 7.

[0021] The fuel cell unit 2 is an example of a "fuel cell unit" and is configured to include a cell stack 11, end plates 12, 12, air guide plates 13, 13, and bolts 14, 14, as shown in Figures 2 to 4. The cell stack 11 is also an example of a "stack," and as shown in Figure 5, separators 21, 22, an MEA 23, and a separator 24 are stacked and sandwiched between the end plates 12, 12. In Figures 2 to 5, to facilitate understanding of the configuration of the fuel cell unit 2, the thicknesses of the separators 21, 22, 24 and the MEA 23 are shown thicker, and the number of separators 21, 22, 24 and MEAs 23 sandwiched between the end plates 12, 12 is shown fewer than the actual number.

[0022] Separator 21 is a metal separator, which is an example of a "fuel cell separator," and comprises plate 21a having a plurality of slits formed therein, plate 21b having a plurality of through holes formed therein that connect the slits of plate 21a, and plate 20a that blocks the through holes of plate 21b, and plates 21a, 21b, and 20a are stacked so that the slits of plate 21a and the through holes of plate 21b form a flow path (groove portion) for hydrogen gas.

[0023] Separator 22 is a metal separator, which is another example of a "fuel cell separator," and comprises plate 22a having a plurality of slits formed therein, plate 22b having a plurality of through holes formed therein that connect the slits of plate 22a, and plate 20b that blocks the through holes of plate 22b, and plates 22a, 22b, and 20b are stacked so that the slits of plate 22a and the through holes of plate 22b form flow paths (grooves) for air to react with hydrogen gas.

[0024] The MEA 23 is an example of a "membrane electrode assembly for fuel cells," and includes a fuel electrode section 23b (catalyst layer and gas diffusion layer) and an air electrode section 23c (catalyst layer and gas diffusion layer) sandwiching an electrolyte section 23a (electrolyte membrane). In this case, the fuel cell unit 2 of this example employs a configuration in which a frame-shaped gasket 23d is disposed so as to surround the fuel electrode section 23b and the air electrode section 23c, and the MEA 23 is disposed between the separators 21 and 22 such that the gasket 23d is sandwiched between the electrolyte section 23a and the separators 21 and 22 (plates 21a and 22a).

[0025] Separator 24 is a metal separator configured to allow the passage of a temperature-regulating fluid (for example, air (atmosphere)) that regulates the temperature of separators 21, 22 and MEA 23, and comprises plate 24a having a plurality of slits formed therein, plate 24b having a plurality of through holes that connect the slits of plate 24a, and plate 20a that blocks the through holes of plate 24b, and plates 24a, 24b, and 20a are stacked so that the slits of plate 24a and the through holes of plate 24b form flow paths (grooves) for the temperature-regulating fluid.

[0026] In this case, the fuel cell unit 2 of this example employs, as an example, a configuration in which one plate 20a is shared between the separators 21 and 24, but it is also possible to employ a configuration in which, instead of the plate 20a of the separator 21, the plate 20b of the separator 22 is shared between the separators 22 and 24. Also, instead of the plate 20a of the separator 24, a dedicated plate similar to the plate 20a of the separator 21 or the plate 20b of the separator 22 can be disposed.

[0027] In the fuel cell unit 2 of this example, the above-mentioned plates 20a, 20b, 21a, 21b, 22a, 22b, 24a, 24a, electrolyte section 23a, fuel electrode section 23b and air electrode section 23c each correspond to a "flat plate-shaped stacked object having an N-sided polygonal shape in a planar view", and in this example, as an example, these "stacked objects" are each formed into an N=4 square shape, and the stacked object, that is, the cell stack 11, is formed into an N=4 square pillar shape.

[0028] 2 to 4, the end plates 12 are an example of "a pair of substrates disposed on both ends of the stack," and are formed as flat plates that are sufficiently thicker than the above-mentioned plates 20a, 20b, 21a, 21b, 22a, 22b, 24a, and 24a, and are disposed on both ends of the cell stack 11. In this case, in the fuel cell unit 2 of this example, with the cell stack 11 sandwiched between the end plates 12, 12, the end plates 12, 12 can be pulled toward each other by the bolts 14, 14 in a direction (the stacking direction of the "stacked objects" in the cell stack 11) so that the "stacked objects" are brought into close contact with each other between the end plates 12, 12, and the cell stack 11 is brought into close contact with the end plates 12, 12.

[0029] The air guide plate 13 corresponds to a "flow path forming member" and, as an example, is arranged next to the cell stack 11 so as to be sandwiched between the end plates 12, 12. The air guide plate 13 contacts the cell stack 11 and forms an air guide path L (an example of a "flow path") between the cell stack 11 and the air guide plate 13, through which a "temperature adjustment fluid (e.g., air (atmosphere))" that adjusts the temperature of the cell stack 11 by heat exchange with the cell stack 11 passes along one side of the "stacked object" in the cell stack 11. In addition, in the fuel cell unit 2 of this example, screw holes into which bolts 14 can be screwed are provided at both ends of the air guide plate 13, and the bolts 14 inserted through the end plates 12 can be screwed into the air guide plate 13 to draw the two end plates 12 closer to each other.

[0030] In this case, as shown in Figure 5, in the fuel cell unit 2 of this example, the cell stack 11 is configured by stacking each "stacked object" so that, at the portion of the outer surface of the cell stack 11 facing the air guide plate 13 (the upper and lower portions of the cell stack 11 shown in Figures 3 and 4: an example of the "first opposing portion"), convex portions 11a protruding outward in the plate surface direction of each "stacked object" constituting the cell stack 11 and concave portions 11b concave inward in the plate surface direction of the "stacked object" are alternately present in the stacking direction of each "stacked object" (the left-right direction in Figures 3 to 5).

[0031] Specifically, in the fuel cell unit 2 of this example, as an example, the aforementioned plates 20a, 20b, 21a, 22a, 24a and MEA 23 (electrolyte portion 23a and gasket 23d) are formed larger than plates 21b, 22b, 24b, and by stacking these stacked objects, the aforementioned plates 20a, 20b, 21a, 22a, 24a and MEA 23 (electrolyte portion 23a and gasket 23d) form convex portions 11a on two opposing side surfaces (two ``first opposing portions'') of the N=4 rectangular pillar-shaped cell stack 11, and the plates 21b, 22b, 24b form the bottom of the concave portion 11b.

[0032] 3, 4, and 6, in the fuel cell unit 2 of this example, a plurality of contact portions 13a (an example of a "contact portion") that contact the "first opposing portion" of the cell stack 11 are formed in a portion (an example of a "second opposing portion") of the air guide plate 13 that faces the outer peripheral surface (first opposing portion) of the cell stack 11. Specifically, in the fuel cell unit 2 of this example, as an example, the contact portions 13a are formed in three locations, at both ends and the center in the "stacking direction of the stacked objects" of the air guide plate 13 that is arranged in parallel with the cell stack 11, and the air guide plate 13 is arranged in parallel with the cell stack 11 so that these protruding ends contact the "first opposing portion (the protruding end of the convex portion 11a)" of the cell stack 11.

[0033] 7 and 8, in the fuel cell unit 2 of this example, the portions of the "second opposing portion" of the air guide plate 13 other than the abutting portion 13a are formed to be substantially flat. As a result, in the fuel cell unit 2 of this example, the separation distances D2a-D2b (see FIG. 8: an example of the "second separation distance") between the "second opposing portion" of the air guide plate 13 and the bottom of the recessed portion 11b are formed to be larger than the separation distance D1 (see FIG. 7: an example of the "first separation distance") between the "second opposing portion" of the air guide plate 13 and the tip of the convex portion 11a of the cell stack 11.

[0034] Furthermore, in the fuel cell unit 2 of this example, as shown in Figure 7, the cell stack 11 and the air guide plate 13 are configured so that the separation distance D1 (first separation distance) between the "second opposing portion" of the air guide plate 13 and the tip of the convex portion 11a in the cell stack 11 is a constant distance from the upstream side to the downstream side in the air passage direction (the direction of arrow A in Figures 2, 6 to 8) in the air guide channel L through which air as a "temperature adjusting fluid" passes, and as shown in Figure 8, the cell stack 11 and the air guide plate 13 are configured so that the separation distance D2a to D2b (second separation distance) between the "second opposing portion" of the air guide plate 13 and the bottom of the concave portion 11b in the cell stack 11 becomes larger toward the downstream side in the air passage direction in the air guide channel L (so that separation distance D2b is larger than separation distance D2a).

[0035] Specifically, in the fuel cell unit 2 of this example, as shown in Fig. 7, for example, the plates 20a, 20b, 21a, 22a, and 24a and the MEA 23 that constitute the convex portion 11a are formed in a rectangular shape in a plan view, and are sandwiched between the other "stacked objects" that constitute the concave portion 11b, so that the "first separation distance" is constant from the upstream side to the downstream side. Also, in the fuel cell unit 2 of this example, as shown in Fig. 8, for example, the plates 21b, 22b, and 24b that constitute the concave portion 11b are formed in a trapezoidal shape in a plan view, and are sandwiched between the other "stacked objects" that constitute the convex portion 11a so that the long side (the left side in Fig. 8) is located on the upstream side of the "flow path" and the short side (the right side in Fig. 8) is located on the downstream side of the "flow path," so that the "second separation distance" gradually increases from the upstream side to the downstream side, as shown in Fig. 8, as shown by separation distances D2a to D2b.

[0036] In Figures 3, 4, 6 to 8, and Figures 9 and 10, which will be referred to later, the size of the air guide duct L, which is an example of a "flow path" (height in each figure: "first separation distance" and "second separation distance"), is exaggerated and illustrated large in order to make it easier to understand the configuration of the "fuel cell unit."

[0037] On the other hand, the hydrogen gas supply unit 3 is configured, for example, to be connectable to a portable gas tank filled with hydrogen gas, and supplies hydrogen gas from the gas tank to the fuel cell unit 2 (each separator 21) under the control of the control unit 7. The suction pump 4 draws air from the fuel cell unit 2 (each separator 22) under the control of the control unit 7, thereby supplying new air to be reacted with hydrogen gas to the fuel cell unit 2 (each separator 22). Note that instead of the suction pump 4, a pressure pump that pressure-feeds the air to be reacted with hydrogen gas toward the fuel cell unit 2 (each separator 22) can also be provided to configure a "power supply device."

[0038] The suction pump 5a draws air from the fuel cell unit 2 (each separator 24) under the control of the control unit 7, thereby supplying fresh air to the fuel cell unit 2 (each separator 24) for adjusting the temperature of the fuel cell unit 2. Note that the "power supply device" can also be configured with a pressure pump that pressure-feeds temperature-adjusting air toward the fuel cell unit 2 (each separator 24) instead of the suction pump 5a. The fan 5b is an example of a "fluid movement mechanism," and in the power supply device 1 of this example, it is located downstream of the aforementioned air guide duct L in the fuel cell unit 2 and fixed to the fuel cell unit 2, as shown by the dashed line in FIG. 2. This fan 5b draws air from the air guide duct L under the control of the control unit 7, thereby causing fresh air to flow into the air guide duct L. Note that the fan 5b can also be configured to flow air into the air guide duct L by being located upstream of the air guide duct L and fixed to the fuel cell unit 2.

[0039] The inverter 6 converts the DC power generated by the fuel cell unit 2 into AC power and outputs it under the control of the control unit 7. The control unit 7 exercises overall control over the power supply device 1. Specifically, the control unit 7 controls the supply of hydrogen gas to the fuel cell unit 2 by the hydrogen gas supply unit 3, the suction of air from the fuel cell unit 2 by the suction pumps 4 and 5a (supply of air to the fuel cell unit 2), the suction of air from the fuel cell unit 2 (air guide duct L) by the fan 5b (supply of air to the air guide duct L), and the AC conversion process by the inverter 6, and supplies the AC power converted by the inverter 6 to a supply target.

[0040] When power is supplied to a target object by this power supply device 1, the control unit 7 controls the hydrogen gas supply unit 3 to supply hydrogen gas to the fuel cell unit 2 (separator 21), and controls the suction pump 4 to suck air from the fuel cell unit 2 (separator 22) to supply new air to the fuel cell unit 2 (separator 22). As a result, electricity is generated in the fuel cell unit 2 by a reaction between hydrogen gas and air (oxygen), and this DC electricity is converted to AC electricity by the inverter 6 and supplied to the target object.

[0041] On the other hand, in this type of power supply device 1, the temperature of the fuel cell unit 2 rises due to power generation (reaction between hydrogen and oxygen) in the fuel cell unit 2. Therefore, in order to prevent a state in which the power generation efficiency of the fuel cell unit 2 decreases due to an excessive temperature rise in the fuel cell unit 2, the power supply device 1 of this example employs a configuration in which the suction pump 5a sucks air from the fuel cell unit 2 (separator 24) and causes new air to flow into the separator 24, thereby cooling the cell stack 11 (separators 21, 22, 24 and MEA 23) through heat exchange with the air. Furthermore, in the power supply device 1 of this example, in parallel with the suction of air from the separator 24 by the suction pump 5a, the fan 5b sucks air from the air guide channel L of the fuel cell unit 2 and causes new air to flow into the air guide channel L, thereby cooling the cell stack 11 (separators 21, 22, 24 and MEA 23) through heat exchange with the air.

[0042] In this case, in the fuel cell unit 2 (power supply device 1) of this example, as described above, the air guide plate 13 is arranged alongside the cell stack 11 so as to be sandwiched between both end plates 12, 12, thereby forming an air guide path L through which temperature-adjusting (cooling) air passes between the cell stack 11 and the air guide plate 13. Therefore, in the fuel cell unit 2 of this example, new air that is sucked into the air guide path L by the suction of air in the air guide path L by the fan 5b moves smoothly within the air guide path L along one side of each "stacked object" in the cell stack 11 without leaving the position in contact with the cell stack 11.

[0043] Furthermore, in the fuel cell unit 2 (power supply device 1) of this example, as described above, the cell stack 11 is configured so that convex portions 11a and concave portions 11b are alternately present in the portion (first opposing portion) of the outer peripheral surface of the cell stack 11 that faces the air guide plate 13. Therefore, compared to a configuration including a "stack" that does not have convex portions 11a or concave portions 11b, the surface area of ​​the cell stack 11 in the air guide channel L is sufficiently wide, and the efficiency of heat exchange between the cell stack 11 and the air is sufficiently improved.

[0044] Furthermore, in the fuel cell unit 2 (power supply device 1) of this example, the distances D2a-D2b between the portion of the air guide plate 13 facing the cell stack 11 (second facing portion) and the bottom of the recessed portion 11b of the cell stack 11 are greater than the distance D1 between the portion of the air guide plate 13 facing the cell stack 11 (second facing portion) and the tip of the convex portion 11a of the cell stack 11. In other words, in the fuel cell unit 2 of this example, the "second facing portion" of the air guide plate 13 is less uneven than the "first facing portion" of the cell stack 11 (in this example, it is substantially flat). As a result, in the fuel cell unit 2 of this example, compared to a configuration in which the ``second opposing portion'' of the air guide plate 13 is uneven like the ``first opposing portion'' of the cell stack 11, a situation in which the resistance to air passage within the air guide channel L becomes excessively large is avoided, and the cooling air can move smoothly within the air guide channel L.

[0045] Furthermore, in the fuel cell unit 2 of this example, the cell stack 11 and the air guide plate 13 are configured so that the distances D2a-D2b between the portion of the air guide plate 13 facing the cell stack 11 (second facing portion) and the bottom of the recessed portion 11b in the cell stack 11 increase toward the downstream side in the direction in which air (temperature adjusting fluid) passes through the air guide channel L. In this case, when cooling air is passed through the air guide channel L by suction from the fan 5b, the temperature of the air in the air guide channel L gradually increases as it moves downstream due to heat exchange with the cell stack 11, whose temperature has increased due to power generation. As a result, there is a risk that the cooling efficiency of the cell stack 11 may be lower downstream than upstream in the air passage direction.

[0046] Therefore, in the fuel cell unit 2 (power supply device 1) of this example, as described above, the separation distances D2a-D2b between the "second opposing portion" of the air guide plate 13 and the bottom of the recessed portion 11b of the cell stack 11 are made larger toward the downstream side in the air passage direction, so that the effective cross-sectional area of ​​the air guide passage L gradually increases from the upstream side toward the downstream side, and the cell stack 11 and the air guide plate 13 are formed so that the passage speed of the air in the air guide passage L gradually decreases as it moves from the upstream side toward the downstream side. This makes it possible to achieve sufficient heat exchange between the cell stack 11 and the air even on the downstream side of the air guide passage L.

[0047] Furthermore, in the fuel cell unit 2 of this example, as described above, a contact portion 13a that contacts the outer peripheral surface (first opposing portion) of the cell stack 11 is formed on the air guide plate 13 at a portion (second opposing portion) that faces the cell stack 11. Specifically, in the fuel cell unit 2 of this example, as shown in Fig. 6, the abutment portion 13a is formed on the air guide plate 13 so as to contact the tip of the convex portion 11a of the cell stack 11. This prevents the tip of the convex portion 11a of the cell stack 11 and the "second opposing portion" of the air guide plate 13 from coming closer together than the height of the abutment portion 13a, so that even if the fuel cell unit 2 (power supply device 1) is subjected to vibration or impact, it is possible to avoid a situation in which the effective cross-sectional area of ​​the air guide passage L becomes excessively small.

[0048] In this case, in the fuel cell unit 2 of this example, an air guide plate 13 is arranged in parallel with the cell stack 11, and an air guide passage L is formed between the cell stack 11 and the air guide plate 13, and a configuration is adopted in which a fan 5b sucks in air so that cooling air passes through the air guide passage L along one side of each of the "stacked objects" that make up the cell stack 11. Therefore, the air that flows into the air guide passage L and comes into contact with the cell stack 11 (first opposing surface) moves within the air guide passage L without leaving the cell stack 11, and the cell stack 11 can be efficiently cooled by heat exchange with this air.

[0049] In this way, in this fuel cell unit 2, an air guide plate 13 is provided in parallel with the cell stack 11. The air guide plate 13 forms an air guide path L between the cell stack 11 and the cell stack 11, through which a "temperature adjusting fluid (air in this example)" that comes into contact with the cell stack 11 and adjusts the temperature of the cell stack 11 by heat exchange with the cell stack 11 passes along one side of the "objects to be stacked" in the cell stack 11, and the "objects to be stacked" are stacked at a "first opposing portion" facing the air guide plate 13 on the outer circumferential surface of the cell stack 11 so that convex portions 11a that protrude outward in the plate surface direction of each "object to be stacked" and concave portions 11b that are concave inward in the plate surface direction are alternately present in the stacking direction of each "object to be stacked." The power supply device 1 is also configured with the above-mentioned fuel cell unit 2.

[0050] Therefore, with this fuel cell unit 2 and power supply device 1, the air drawn into the air guide channel L can move smoothly within the air guide channel L along one side of each "stacked object" in the cell stack 11 without significantly departing from the position in contact with the cell stack 11, and as a result, heat is exchanged favorably between the cell stack 11 and the air within the air guide channel L, making it possible to efficiently cool the cell stack 11. Furthermore, compared to a configuration in which the "first opposing portion" of the cell stack 11 does not have the convex portion 11a or the concave portion 11b, the surface area of ​​the cell stack 11 within the air guide channel L is sufficiently large, and the efficiency of heat exchange between the cell stack 11 and the air is sufficiently improved, making it possible to cool the cell stack 11 even more efficiently.

[0051] Furthermore, in this fuel cell unit 2 and power supply device 1, by forming a contact portion 13a on the "second opposing portion" of the air guide plate 13 that contacts the "first opposing portion" of the cell stack 11, the "first opposing surface (in this example, the tip of the convex portion 11a)" of the cell stack 11 and the "second opposing portion" of the air guide plate 13 are never in close proximity to each other at a distance shorter than the height of the contact portion 13a, so even if the fuel cell unit 2 (power supply device 1) is subjected to vibration or impact, it is possible to prevent the effective cross-sectional area of ​​the air guide path L from becoming excessively small. This makes it possible to maintain a state in which cooling air can pass smoothly.

[0052] Furthermore, according to this fuel cell unit 2 and power supply device 1, the cell stack 11 and the air guide plate 13 are configured so that the "second separation distance (separation distance D2a to D2b)" between the "second opposing portion" of the air guide plate 13 and the bottom of the recessed portion 11b of the cell stack 11 becomes larger toward the downstream side in the passage direction of the "temperature adjusting fluid (air)" in the air guide channel L.As a result, the effective cross-sectional area of ​​the air guide channel L gradually becomes larger from the upstream side to the downstream side, and the passage speed of the air in the air guide channel L gradually decreases as it moves from the upstream side to the downstream side.As a result, it is possible to achieve sufficient heat exchange between the cell stack 11 and the air even on the downstream side of the air guide channel L, and thereby it is possible to reliably cool from the upstream side to the downstream side in the passage direction of the air in the "first opposing portion" of the cell stack 11.

[0053] The configuration of the "fuel cell unit" is not limited to the example of the configuration of the fuel cell unit 2 described above.

[0054] For example, in the above-mentioned fuel cell unit 2, the cell stack 11 and the air guide plate 13 are configured so that the distance D2a to D2b (second distance) between the "second opposing portion" and the bottom of the concave portion 11b becomes larger toward the downstream side in the direction of air passage in the air guide channel L. However, as in the fuel cell unit 2A (another example of a "fuel cell unit") shown in Figure 9, the cell stack 11A and the air guide plate 13 can also be configured so that the distance D1a to D1b (an example of a "first distance") between the "second opposing portion" of the air guide channel 13 and the tip of the convex portion 11a in the cell stack 11 becomes larger toward the downstream side in the direction of air passage (the direction of arrow A in the same figure) in the air guide channel L through which air as a "temperature adjusting fluid" passes (so that the distance D1b is larger than the distance D1a). Specifically, in this fuel cell unit 2A, the plate 25a constituting the convex portion 11a is formed in a trapezoidal shape when viewed from above, with the long side (left side in the figure) positioned upstream of the "flow path" and the short side (right side in the figure) positioned downstream of the "flow path", and is sandwiched between other "stacked objects" constituting the concave portion 11b, so that the "first separation distance" gradually increases from the upstream side to the downstream side.

[0055] In this case, when the "first separation distance" is configured to be larger toward the downstream side in the passage direction of the "temperature adjusting fluid," the separation distance D1 between the "second opposing portion" of the air guide plate 13 and the tip of the convex portion 11a of the cell stack 11 can be set to a constant distance from the upstream side to the downstream side in the passage direction of the "temperature adjusting fluid" in the air guide channel L (the direction of arrow A in the same figure), as in fuel cell unit 2B (yet another example of a "fuel cell unit") shown in Figure 10.

[0056] Even when a configuration such as these fuel cell units 2A and 2B is adopted, as in the aforementioned fuel cell unit 2, the effective cross-sectional area of ​​the air guide passage L gradually increases from the upstream side to the downstream side, and the air passing speed in the air guide passage L gradually decreases as it moves from the upstream side to the downstream side, so that sufficient heat exchange can be achieved between the cell stack 11 and the air even on the downstream side of the air guide passage L, thereby ensuring cooling from the upstream side to the downstream side of the air passage direction in the ``first opposing portion'' of the cell stack 11.

[0057] In addition, instead of a configuration such as the cell stack 11 in the fuel cell units 2, 2A, 2B (or in addition to a configuration such as the cell stack 11), it is also possible to tilt the ``second opposing portion'' in the ``flow path forming member'' relative to the ``first opposing portion'' in the ``stack'', so that the ``first separation distance'' between the ``second opposing portion'' and the tip of the ``convex portion'', and the ``second separation distance'' between the ``second opposing portion'' and the bottom of the ``concave portion'' become larger toward the downstream side in the ``passage direction of the temperature regulating fluid'' in the ``flow path'' (not shown).

[0058] In addition, the above description uses an example of a configuration in which cooling air as a "temperature-adjusting fluid" is introduced into the air guide channel L formed between the cell stack 11 and the air guide plate 13 to cool the cell stack 11, whose temperature has risen due to power generation. However, in addition to (or instead of) this configuration, a configuration in which a "temperature-adjusting fluid" is introduced into the "flow channel" for the purpose of heating the "stack" can also be employed. For example, when the power supply device 1 is started in winter, the temperature of the cell stack 11 is low, approximately the same as the ambient temperature, resulting in low power generation efficiency. Therefore, by providing a heat source (such as an electric heater) at the entrance of the air guide channel L and passing air heated by the heat source through the air guide channel L as a "temperature-adjusting fluid," the cell stack 11 is heated by heat exchange with this air, thereby enabling sufficiently high power generation efficiency immediately after start-up.

[0059] Furthermore, although the configuration using air (atmosphere) as the "temperature adjusting fluid" has been described as an example, it is also possible to adopt a configuration using various gases other than air or various liquids as the "temperature adjusting fluid."

[0060] In addition, the cell stack 11 has been described as an example in which large "stacked objects (plates 20a, 20b, 21a, 22a, 24a and MEA 23)" and small "stacked objects (plates 21b, 22b, 24b)" are alternately stacked to form convex portions 11a in the large "stacked objects" and concave portions 11b in the small "stacked objects." However, instead of this configuration, a "stack" can be configured in which "stacked objects" of similar size are shifted along the plate surface direction and protrude from adjacent "stacked objects" to form "convex portions." In such a "stack" configuration, the opposing sides of the "stacked objects" that form the "convex portions" as described above form the bottoms of "concave portions" that are recessed inward in the plate surface direction relative to the adjacent "stacked objects."

[0061] Furthermore, while the configuration has been described with reference to an example in which the cell stack 11 has a quadrangular prism shape formed by stacking "materials to be stacked" each having a quadrangular shape in a planar view, the configuration may also include a "stack" having a triangular prism shape formed by stacking "materials to be stacked" each having a triangular shape in a planar view, or a "stack" having a polygonal prism shape formed by stacking "materials to be stacked" each having a polygonal shape with N=5 or more sides in a planar view. In a "fuel cell unit" of this configuration, a "flow path forming member" is provided in parallel with the "stack" to form a "flow path" through which the "temperature adjusting fluid" passes along one side of the "materials to be stacked," thereby achieving the same effect as the fuel cell unit 2 described above. [Explanation of symbols]

[0062] 1 Power supply 2, 2A, 2B fuel cell unit 3 Hydrogen gas supply unit 4,5a suction pump 5b Fan 6 inverters 7 Control Unit 11 Cell stack 11a Convex part 11b Concave part 12 End plate 13 Wind guide plate 13a Contact part 14 volts 20a, 20b, 21a, 21b, 22a, 22b, 24a, 24b, 25a, 25b Plates 21, 22, 24 Separator 23 MEA 23a Electrolyte section 23b Fuel electrode part 23c Air electrode 23d gasket L Air guide path D1,D1a,D1b,D2,D2a,D2b Separation distance

Claims

1. an N-sided pillar-shaped stack formed by stacking a plurality of flat plate-shaped stacked objects each having an N-sided shape in a plan view (N is a natural number of 3 or more), the N-sided pillar-shaped stack including at least a fuel cell separator and a fuel cell membrane electrode assembly; a pair of substrates disposed on both ends of the laminate; A fuel cell unit in which the objects to be stacked are closely attached to each other between the two substrates and the stack body is closely attached to the two substrates, a flow path forming member is provided in parallel with the stack body, the flow path forming member forming a flow path between the stack body and the temperature adjusting fluid that is in contact with the stack body and adjusts the temperature of the stack body by heat exchange with the stack body and that passes along one side of the stacked material in the stack body; The stacked body is configured such that convex portions protruding outward in a plate surface direction of each stacked object and concave portions concave inward in the plate surface direction are alternately present in a stacking direction of each stacked object at first opposing portions that are opposed to the flow path forming member on the outer peripheral surface of the stacked body, The flow path forming member has a second opposing portion that faces the stack, and an abutting portion that contacts the first opposing portion is formed in the second opposing portion.

2. an N-sided pillar-shaped stack formed by stacking a plurality of flat plate-shaped stacked objects each having an N-sided shape in a plan view (N is a natural number of 3 or more), the N-sided pillar-shaped stack including at least a fuel cell separator and a fuel cell membrane electrode assembly; a pair of substrates disposed on both ends of the laminate; A fuel cell unit in which the objects to be stacked are closely attached to each other between the two substrates and the stack body is closely attached to the two substrates, a flow path forming member is provided in parallel with the stack body, the flow path forming member forming a flow path between the stack body and the temperature adjusting fluid that is in contact with the stack body and adjusts the temperature of the stack body by heat exchange with the stack body and that passes along one side of the stacked material in the stack body; The stacked body is configured such that convex portions protruding outward in a plate surface direction of each stacked object and concave portions concave inward in the plate surface direction are alternately present in a stacking direction of each stacked object at first opposing portions that are opposed to the flow path forming member on the outer peripheral surface of the stacked body, A fuel cell unit in which the stack and the flow path forming member are configured so that at least one of a first distance between a second opposing portion that faces the stack in the flow path forming member and the tip of the convex portion, and a second distance between the second opposing portion and the bottom of the concave portion, becomes larger downstream in the direction in which the temperature regulating fluid passes in the flow path.

3. a fuel cell unit according to claim 1 or 2; a fluid movement mechanism for moving the temperature adjustment fluid, A power supply device configured to adjust the temperature of the stack using the temperature-adjusting fluid moved by the fluid movement mechanism and passed through the flow path, while supplying the electricity generated by the fuel cell unit to an external device.

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