JP2009004254A - Assembly method of fuel cell stack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely keep a desired fastening of load on a fuel cell stack as a whole and, to effectively block load omission, and to impart optimum surface pressure. <P>SOLUTION: This assembly method of a fuel cell stack includes a first process of imparting a set load not smaller than the power generation maximum load that acts on the fuel cell stack, in the stacking direction with respect to a stacked body in the stacking direction, when the fuel cell stack is actually operated; a second process of supplying pressure air to a reactive gas passage and a cooling medium passage in the stacked body; and a third process of imparting the load set to the inside of a casing, in a state where the stacked body is housed in the casing. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method of assembling a fuel cell stack in which a laminate in which a plurality of unit cells each having an electrolyte / electrode structure having a pair of electrodes provided on both sides of an electrolyte and a separator are housed in a casing is accommodated. .

  For example, a polymer electrolyte fuel cell employs an electrolyte membrane (electrolyte) made of a polymer ion exchange membrane. A fuel cell is configured by sandwiching an electrolyte membrane / electrode structure in which an anode side electrode and a cathode side electrode are provided on both sides of the electrolyte membrane with a separator.

  Normally, this fuel cell is used as a fuel cell stack in which a predetermined number (for example, several tens to several hundreds) is stacked in order to obtain a desired power generation. In this fuel cell stack, the stacked fuel cells need to be reliably pressurized and held in order to prevent an increase in the internal resistance of the fuel cell and a decrease in the sealing performance of the reaction gas.

  Thus, for example, a fuel cell stack tightening structure disclosed in Patent Document 1 is known. In Patent Document 1, as shown in FIG. 12, the fuel cell stack 1 is sandwiched between a pair of end plates 2, and the end plates 2 are temporarily tightened in advance by a tightening plate 5 under the tightening action of tightening bolts 4. Has been.

  The fuel cell stack 1 is attached to a pressure vessel 8. In this pressure vessel 8, the fuel cell stack 1 has one clamping plate 5 placed on the pressure vessel bottom base 6 with the stacking direction oriented in the vertical direction, and the pressure plate 7 is disposed on the other clamping plate 5. . Pressure is applied to the fuel cell stack 1 from the pressure plate 7 via the actuator 9, and a decrease in the height of the fuel cell stack 1 is detected by a dial gauge G provided outside the pressure vessel 8. ing.

JP 58-93173 A

  However, in Patent Document 1 described above, after applying a predetermined tightening load to the fuel cell stack 1 via the pressure plate 7 under the action of the actuator 9 and tightening the tightening bolt 4 to assemble the fuel cell stack, The thickness of the separator constituting the fuel cell stack 1, the thickness of the seal member, the thickness of the electrolyte membrane, and the like are easily changed by the tightening load.

  For example, if the fuel cell stack 1 is left in a state where a press load is applied, the press load, that is, the tightening load decreases with time, so-called load loss occurs. This load loss may actually be several tens of percent, and it is necessary to leave the fuel cell stack 1 under pressure for a relatively long time until the overall dimensions of the fuel cell stack 1 are stabilized. There is. As a result, it has been pointed out that the assembly time of the fuel cell stack becomes considerably long and the productivity is remarkably lowered.

  The present invention solves this type of problem, and can reliably hold the entire fuel cell stack at a desired tightening load, effectively preventing load loss and applying an optimum surface pressure. It is an object to provide a method for assembling a possible fuel cell stack.

  The present invention relates to a method of assembling a fuel cell stack in which a laminate in which a plurality of unit cells each having an electrolyte / electrode structure having a pair of electrodes provided on both sides of an electrolyte and a separator are housed in a casing is accommodated. Is.

  This assembly method includes a first step of applying a set load that is equal to or greater than a maximum power generation load acting in the stacking direction to the stack in the stacking direction when the fuel cell stack is actually operated; A second step of supplying a pressure fluid to the reaction gas passage and the cooling medium passage, and a third step of applying the set load in the casing in a state where the casing is assembled. .

  Moreover, in the first step, it is preferable to repeat the application of the set load to the laminate only a plurality of times.

  Further, in the third step, it is preferable to confirm the tightening load applied to the fuel cell stack in the stacking direction by detecting the distortion of the side panel that constitutes the casing and is disposed on the side of the stack.

  Furthermore, in the third step, a set load may be applied to the laminate in the casing in a state in which the laminate after the first step and the second step are accommodated in the casing. preferable.

  Further, it is preferable that a set load application mechanism is disposed in the casing instead of a predetermined number of the unit cells, and the set load is applied to the laminate by the set load application mechanism.

  In the present invention, a set load equal to or greater than the maximum power generation load is applied to the laminate to prevent the load from being lost, and the pressure fluid is supplied to adjust the shared load of the seal. On the other hand, a set load is applied in the casing in a state where the casing is assembled. For this reason, after the casing is initially deformed, the final assembly of the fuel cell stack is performed. Thereby, while being able to prevent load loss effectively, the optimal surface pressure can be reliably given with respect to the laminated body in a casing.

  FIG. 1 is a partially exploded schematic perspective view of a fuel cell stack 10 to which an assembly method according to an embodiment of the present invention is applied, and FIG. 2 is a partial cross-sectional side view of the fuel cell stack 10.

  The fuel cell stack 10 includes a stacked body 14 in which a plurality of unit cells 12 are stacked in the horizontal direction (arrow A direction). A terminal plate 16a, an insulating plate 18 and an end plate 20a are sequentially disposed at one end in the stacking direction (arrow A direction) of the stacked body 14 toward the outside. At the other end in the stacking direction of the stacked body 14, a terminal plate 16b, an insulating spacer member 22 (the insulating plate 18 may be used) and an end plate 20b are sequentially disposed outward. The fuel cell stack 10 is integrally held by a casing 24 including end plates 20a and 20b each having a rectangular shape as end plates.

  As shown in FIGS. 2 and 3, each unit cell 12 includes an electrolyte membrane / electrode structure (electrolyte / electrode structure) 30, and a thin plate-shaped first and second sandwiching the electrolyte membrane / electrode structure 30. Second metal separators 32 and 34 are provided. Instead of the first and second metal separators 32 and 34, for example, a carbon separator may be used.

  An oxidant gas supply for supplying an oxidant gas, for example, an oxygen-containing gas, communicates with each other in the arrow A direction at one end edge of the unit cell 12 in the long side direction (the arrow B direction in FIG. 3). A communication hole 36a, a cooling medium supply communication hole 38a for supplying a cooling medium, and a fuel gas discharge communication hole 40b for discharging a fuel gas, for example, a hydrogen-containing gas, are provided.

  The other end edge in the long side direction of the unit cell 12 communicates with each other in the direction of arrow A, and a fuel gas supply communication hole 40a for supplying fuel gas, and a cooling medium discharge communication hole for discharging the cooling medium. 38b and an oxidizing gas discharge communication hole 36b for discharging the oxidizing gas are provided.

  The electrolyte membrane / electrode structure 30 includes, for example, a solid polymer electrolyte membrane 42 in which a perfluorosulfonic acid thin film is impregnated with water, and an anode side electrode 44 and a cathode side electrode 46 that sandwich the solid polymer electrolyte membrane 42. With.

  The anode side electrode 44 and the cathode side electrode 46 are uniformly coated with a gas diffusion layer (not shown) made of carbon paper or the like and porous carbon particles carrying a platinum alloy on the surface thereof. And an electrode catalyst layer (not shown) formed. The electrode catalyst layers are formed on both surfaces of the solid polymer electrolyte membrane 42.

  A fuel gas flow path 48 that connects the fuel gas supply communication hole 40 a and the fuel gas discharge communication hole 40 b is formed on the surface 32 a of the first metal separator 32 facing the electrolyte membrane / electrode structure 30. The fuel gas channel 48 is constituted by, for example, a plurality of grooves extending in the arrow B direction. On the surface 32b of the first metal separator 32, a cooling medium flow path 50 that connects the cooling medium supply communication hole 38a and the cooling medium discharge communication hole 38b is formed. The cooling medium flow path 50 is configured by a plurality of grooves extending in the arrow B direction.

  The surface 34a of the second metal separator 34 facing the electrolyte membrane / electrode structure 30 is provided with, for example, an oxidant gas flow path 52 composed of a plurality of grooves extending in the direction of arrow B, and this oxidant gas. The flow path 52 communicates with the oxidant gas supply communication hole 36a and the oxidant gas discharge communication hole 36b. A cooling medium flow path 50 is integrally formed on the surface 34 b of the second metal separator 34 so as to overlap the surface 32 b of the first metal separator 32.

  A first seal member 54 is integrally formed on the surfaces 32 a and 32 b of the first metal separator 32 around the outer peripheral edge of the first metal separator 32. The first seal member 54 surrounds the fuel gas supply communication hole 40a, the fuel gas discharge communication hole 40b, and the fuel gas flow path 48 on the surface 32a so as to communicate with each other, and on the surface 32b, the cooling medium supply communication hole 38a, The medium discharge communication hole 38b and the cooling medium flow path 50 are surrounded and communicated with each other.

  A second seal member 56 is integrally formed on the surfaces 34 a and 34 b of the second metal separator 34 around the outer peripheral edge of the second metal separator 34. The second seal member 56 surrounds and communicates the oxidant gas supply communication hole 36a, the oxidant gas discharge communication hole 36b, and the oxidant gas flow path 52 on the surface 34a, while the cooling medium supply communication hole on the surface 34b. 38a, the cooling medium discharge communication hole 38b, and the cooling medium flow path 50 are surrounded and communicated.

  As shown in FIG. 2, a seal 57 is interposed between the first and second seal members 54 and 56 in order to prevent the outer periphery of the solid polymer electrolyte membrane 42 from directly contacting the casing 24. Is done.

  As shown in FIG. 1, rod-shaped terminal portions 58a and 58b projecting in the stacking direction are formed at substantially the center portions of the terminal plates 16a and 16b. For example, a load such as a traveling motor is connected to the terminal portions 58a and 58b.

  The casing 24 includes end plates 20a and 20b which are end plates, a plurality of side plates (side panels) 60a to 60d arranged on the side of the laminated body 14, and end portions of the side plates 60a to 60d that are close to each other. Angle members (for example, L angles) 62a to 62d to be connected, and connecting pins 64a and 64b having different lengths for connecting the end plates 20a and 20b and the side plates 60a to 60d are provided. The side plates 60a to 60d are made of, for example, a thin metal plate.

  Two first connection portions 66a and 66b are formed to project from the upper and lower sides of the end plates 20a and 20b, respectively, and one first connection portion 66c and 66d is formed to project from each side of each side. The Holes 67a to 67d are formed through the first connecting portions 66a to 66d. Mount bosses 68a and 68b are formed at the lower ends of the respective sides of the end plates 20a and 20b. The boss portions 68a and 68b are fixed to a mounting portion (not shown) via a bolt or the like, so that the fuel cell stack 10 is mounted on, for example, a vehicle.

  Two second connecting portions 70a and 70b are formed at both ends in the longitudinal direction (arrow A direction) of the side plates 60a and 60c arranged on both sides in the arrow B direction of the laminate 14. Three second connecting portions 72a and 72b are formed at both ends in the longitudinal direction of the side plates 60b and 60d disposed on the upper and lower sides of the laminated body 14, respectively. Holes 71a and 71b are formed in the second connecting portions 70a and 70b, and holes 73a and 73b are formed in the second connecting portions 72a and 72b.

  Between the second connection portions 70a and 70b of the side plates 60a and 60c, first connection portions 66c and 66d on both sides of the end plates 20a and 20b are arranged, and a short connection pin 64a is integrally formed therewith. Inserted into the first hinge structure 75a. The side plates 60a and 60c are attached to the end plates 20a and 20b by the first hinge structure 75a.

  Similarly, the second connecting portions 72a and 72b of the side plates 60b and 60d are alternately arranged with the first connecting portions 66a and 66b on the upper and lower sides of the end plates 20a and 20b, and a long connecting pin 64b is provided on these. The second hinge structure 75b is configured by being integrally inserted. The side plates 60b and 60d are attached to the end plates 20a and 20b by the second hinge structure 75b.

  The side plates 60a to 60d are formed with a plurality of screw holes 74 at both edges in the short direction, respectively, while the sides 76 of the angle members 62a to 62d are formed with holes 76 corresponding to the screw holes 74. Is done. When the screws 77 inserted into the holes 76 are screwed into the screw holes 74, the side plates 60a to 60d are fixed to each other via the angle members 62a to 62d. Thereby, the casing 24 is configured (see FIG. 4).

  In addition, while forming screw holes in the angle members 62a to 62d and forming holes in the side plates 60a to 60d and arranging the angle members 62a to 62d inward of the side plates 60a to 60d, these are integrated. Alternatively, it may be screwed.

  A method of assembling the fuel cell stack 10 configured as described above will be described below along the flowchart shown in FIG.

  First, as shown in FIG. 1, two first strain gauges 80a for detecting strain in the stacking direction (arrow A direction) are provided on each side of the side plates 60a to 60d, and strain in a direction crossing the stacking direction. Two second strain gauges 80b that detect the above are disposed. The strain is measured by a 4-active gauge method using each of the first strain gauge 80a and the second strain gauge 80b. On the inner surfaces of the side plates 60a to 60d, a temperature sensor 82 is disposed between the first strain gauge 80a and the second strain gauge 80b.

  Therefore, various settings of the fuel cell stack 10 are performed (step S1 in FIG. 5). Specifically, the tightening load P1 of the entire fuel cell stack 10 is set.

  The tightening load P1 is set, and the shared load of the first and second seal members 54 and 56 and the shared load of the electrolyte membrane / electrode structure 30 are also set in advance.

  Next, a plurality of unit cells 12 are stacked to obtain a stacked body 14, and the process proceeds to step S <b> 2, and the maximum power generation is performed between the end plates 20 a and 20 b disposed outside both ends in the stacking direction of the stacked body 14. A set load P3 greater than the load P2 is applied (see FIG. 6). Here, the maximum power generation load P2 refers to a load at which a load increase due to swelling of the electrolyte membrane / electrode structure 30 due to power generation becomes a maximum surface pressure when the fuel cell stack 10 is actually operated.

  For this reason, in the laminate 14, the electrolyte membrane / electrode structure 30 and the first and second metal separators 32 and 34 are compressively deformed, and the dimension of the laminate 14 in the stacking direction (stack dimension) is reduced. Then, after temporarily stopping the application of the set load P3 to the laminate 14, the operation of applying the set load P3 is performed a plurality of times, for example, only three times.

  Thereby, the change of the dimension of the whole laminated body 14 is converged in the predetermined range. In this state, when the tightening load P <b> 1 is applied to the laminate 14, variations in the electrode surface pressure are suppressed within a predetermined range.

  Furthermore, it progresses to step S3 and supply of a pressure fluid is performed with respect to the laminated body 14. FIG. Specifically, a pressure fluid (for example, pressurized air) is supplied from the oxidant gas supply communication hole 36 a to the oxidant gas flow path 52, and a pressure is supplied from the fuel gas supply communication hole 40 a to the fuel gas flow path 48. A fluid (eg, pressurized air) is supplied.

  For this reason, the pressure in the oxidant gas flow path 52 and the fuel gas flow path 48 increases, and the first and second seal members 54 and 56, the electrolyte membrane / electrode structure 30, and the first and second metal separators 32, At 34, the stress is removed.

  Further, by supplying a pressure fluid (for example, pressurized air) from the cooling medium supply communication hole 38 a to the cooling medium flow path 50, the first and second seal members 54 and 56, the electrolyte membrane / electrode structure 30, and the first In the first and second metal separators 32 and 34, the stress is removed.

  Thereby, as shown in FIG. 7, the shared load of the first and second seal members 54 and 56 and the shared load of the electrolyte membrane / electrode structure 30 are corrected appropriately through the pressure fluid pressure and the load fluctuation. The In FIG. 7, the stack compression load P1 ′ is an initial load before processing, and the stack compression load (tightening load) P1 is a set load. In FIG. 7, the dotted line is before processing, while the solid line is after processing.

  As described above, the laminated body 14 after step S3 is accommodated in the casing 24, and in this state, the set load P3 is applied to the casing 24 (step S4).

  At that time, as shown in FIG. 8, a set load applying mechanism 90 is arranged instead of one or more predetermined number of unit cells 12. The set load applying mechanism 90 includes a flexible container 92, and a cavity 94 for filling the pressurizing liquid is formed in the flexible container 92. The container 92 is provided with a pipe 96 communicating with the cavity 94. Although not shown, the pipe 96 is taken out from an opening or a groove provided in the casing 24 and connected to the pressurized liquid supply unit. . In the casing 24, a load sensor (not shown) for detecting a load applied by the set load applying mechanism 90 may be disposed.

  Therefore, when fluid is pressed into the cavity 94 of the flexible container 92 through the pipe 96, the flexible container 92 expands in the direction of arrow A. For this reason, the entire laminated body 14 extends in the direction of arrow A, and a load in the direction of arrow A is applied to the casing 24. Therefore, a load is applied to the casing 24 to press the end plates 20a and 20b in a direction away from each other, and the strain gauges 80a and 80b provided on the side plates 60a to 60d are connected to the side plates 60a to 60d. Detect surface distortion.

  Based on the strain data detected by the strain gauges 80a and 80b, loads applied to the side plates 60a to 60d (hereinafter also referred to as panel loads) are detected. Then, as shown in FIG. 9, the set load application mechanism 90 is controlled until the panel load reaches the set load P3, whereby the dimensional changes of the side plates 60a to 60d due to the variation in the panel load are detected.

  Further, after the panel load reaches the set load P3, the panel load is reduced. At that time, the side plates 60a to 60d are deformed by the initial leveling, and the panel dimensions vary.

  On the other hand, a temperature sensor 82 is mounted on the inner surface side of the side plates 60a to 60d, and the temperature of the side plates 60a to 60d is detected. Therefore, the relationship between the panel load and the panel strain due to the temperatures T1 to T3 is calibrated as shown in FIG.

  Next, FIG. 11 shows the relationship between the distance L (panel length) between the connecting pins of the panels (side plates 60a to 60d) and the stack compression load P. As a result, the panel is initially deformed by the initial permanent elongation.

  After the above step S4 is completed, the set load applying mechanism 90 is removed from the casing 24, and a predetermined number of unit cells 12 are returned into the casing 24. Thereby, the fuel cell stack 10 is assembled.

  As described above, after the fuel cell stack 10 is assembled, the process proceeds to step S5 and an initial power generation process is performed. In this initial power generation process, during power generation, the stack load variation due to temperature, humidity and gas pressure is monitored, and the power generation maximum load P2 is confirmed. Then, load sharing between the electrolyte membrane / electrode structure 30 and the first and second seal members 54 and 56 and adjustment of the tightening load P1 and the set load P3 are performed.

  Furthermore, it progresses to step S6 and the power generation durability confirmation process is performed. Specifically, the load on the electrolyte membrane / electrode structure 30 and the first and second seal members 54 and 56 is reduced due to the decrease in the tightening load P1 during the power generation, the sealing property, and the resistance overvoltage while the power generation is continuously performed. The sharing, the tightening load P1 and the set load P3 are determined.

  In this case, in the present embodiment, a set load P3 equal to or greater than the maximum power generation load P2 is applied to the laminate 14 to prevent the load from being lost, and the fuel gas channel 48, the cooling medium channel 50, and the oxidant gas Pressure air is supplied to the flow path 52 to adjust the shared load of the first and second seal members 54 and 56.

  Next, the set load P <b> 3 is applied to the casing 24 via the set load applying mechanism 90 in a state where the laminate 14 is accommodated in the casing 24. Therefore, after the initial deformation of the casing 24, the fuel cell stack 10 is finally assembled.

  Thereby, the laminated body 14 and the casing 24 can effectively prevent load loss during power generation, and can reliably apply an optimum surface pressure to the laminated body 14 in the casing 24. The effect that it can be obtained.

  In the present embodiment, when the initial deformation process of the casing 24 is performed, the laminated body 14 in which the set load applying mechanism 90 is disposed is accommodated in the casing 24, but the present invention is not limited to this. For example, a jig corresponding to the laminate 14 may be prepared, and the jig may be housed in the casing 24 together with the set load applying mechanism 90 or another set load applying mechanism, and the initial deformation process of the casing 24 may be performed. . Thereafter, the laminate 14 may be accommodated in the casing 24 instead of the jig.

  Next, the operation of the fuel cell stack 10 will be described.

  In the fuel cell stack 10, first, as shown in FIG. 4, an oxidant gas such as an oxygen-containing gas is supplied to the oxidant gas supply communication hole 36a of the end plate 20a, and hydrogen is supplied to the fuel gas supply communication hole 40a. Fuel gas such as contained gas is supplied. Further, a coolant such as pure water or ethylene glycol is supplied to the coolant supply passage 38a. For this reason, in the stacked body 14, the oxidant gas, the fuel gas, and the cooling medium are supplied in the arrow A direction to the plurality of unit cells 12 stacked in the arrow A direction.

  As shown in FIG. 3, the oxidant gas is introduced into the oxidant gas flow path 52 of the second metal separator 34 through the oxidant gas supply communication hole 36 a, and along the cathode side electrode 46 of the electrolyte membrane / electrode structure 30. Move. On the other hand, the fuel gas is introduced into the fuel gas passage 48 of the first metal separator 32 through the fuel gas supply communication hole 40 a and moves along the anode side electrode 44 of the electrolyte membrane / electrode structure 30.

  Therefore, in each electrolyte membrane / electrode structure 30, the oxidant gas supplied to the cathode side electrode 46 and the fuel gas supplied to the anode side electrode 44 are consumed by an electrochemical reaction in the electrode catalyst layer, Power generation is performed.

  Next, the oxidant gas consumed by being supplied to the cathode side electrode 46 flows along the oxidant gas discharge communication hole 36b, and then is discharged to the outside from the end plate 20a. Similarly, the fuel gas consumed by being supplied to the anode side electrode 44 is discharged to the fuel gas discharge communication hole 40b, flows, and is discharged from the end plate 20a to the outside.

  The cooling medium flows in the direction of arrow B after being introduced into the cooling medium flow path 50 between the first and second metal separators 32 and 34 from the cooling medium supply communication hole 38a. The cooling medium cools the electrolyte membrane / electrode structure 30, and then moves through the cooling medium discharge communication hole 38b and is discharged from the end plate 20a.

1 is a partially exploded schematic perspective view of a fuel cell stack to which an assembling method according to an embodiment of the present invention is applied. It is a partial cross section side view of the said fuel cell stack. It is a disassembled perspective explanatory drawing of the unit cell which comprises the said fuel cell stack. It is a perspective view of the fuel cell stack. It is a flowchart explaining the said assembly method. It is a related figure of stack compression load and stack size. It is a related figure of a stack compression load and a shared load. It is a partial cross section explanatory view in the state where a setting load giving mechanism is arranged in a casing. It is a related figure of a panel load and a panel dimension. It is a related figure of the panel load corresponding to temperature, and panel distortion. It is a related figure of panel length and stack compression load. It is explanatory drawing of the fuel cell laminated body fastening structure currently disclosed by patent document 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel cell stack 12 ... Unit cell 14 ... Laminated body 16a, 16b ... Terminal plate 18 ... Insulating plate 20a, 20b ... End plate 22 ... Spacer member 24 ... Casing 30 ... Electrolyte membrane and electrode structure 32, 34 ... Metal separator DESCRIPTION OF SYMBOLS 42 ... Solid polymer electrolyte membrane 44 ... Anode side electrode 46 ... Cathode side electrode 48 ... Fuel gas flow path 50 ... Cooling medium flow path 52 ... Oxidant gas flow path 54, 56 ... Seal member 60a-60d ... Side plate 90 ... Setting Load applying mechanism 92 ... flexible container 94 ... cavity 96 ... piping

Claims (5)

An assembly method of a fuel cell stack in which a laminated body in which a plurality of unit cells each having a separator and an electrolyte / electrode structure provided with a pair of electrodes on both sides of an electrolyte is housed in a casing,
When the fuel cell stack is actually operated, a first step of applying a set load greater than or equal to the maximum power generation load acting in the stacking direction to the stack in the stacking direction;
A second step of supplying a pressure fluid to the reaction gas passage and the cooling medium passage in the laminate;
A third step of applying the set load in the casing in the assembled state of the casing;
A method for assembling a fuel cell stack, comprising:   2. The method of assembling a fuel cell stack according to claim 1, wherein, in the first step, application of the set load to the stacked body is repeated a plurality of times.   2. The assembly method according to claim 1, wherein, in the third step, the fuel cell stack is arranged in the stacking direction by detecting distortion of a side panel that constitutes the casing and is disposed on a side portion of the stack. A method for assembling a fuel cell stack, wherein the applied tightening load is confirmed.   4. The assembly method according to claim 1, wherein in the third step, the laminated body in which the first step and the second step are finished is housed in the casing. A method for assembling a fuel cell stack, wherein the set load is applied to the stacked body in the casing.   5. The assembly method according to claim 4, wherein a set load application mechanism is arranged in the casing instead of a predetermined number of the unit cells, and the set load is applied to the laminate by the set load application mechanism. A method of assembling a fuel cell stack characterized by the above.

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