JP3240712B2 - Fuel cell - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell used in the energy sector for directly converting chemical energy of fuel into electric energy.

[0002]

2. Description of the Related Art Among fuel cells, for example, a contact carbonate type fuel cell comprises a tile (electrolyte plate) formed by impregnating a contact carbonate with a porous material as an electrolyte and a cathode (oxygen electrode) and an anode (fuel electrode). 1) sandwiching both electrodes from both sides, supplying oxidizing gas to the cathode side and supplying fuel gas to the anode side to cause a reaction on the cathode side and the anode side respectively to generate power. Cells are formed, and each cell is stacked in multiple layers via a separator to form a stack.

[0003] In the fuel cell having the above-mentioned stack, it is necessary that the cell performance be maintained well for each cell. In the electrode reaction section, each electrode of the cathode and the anode, the tile and the separator have a uniform pressure distribution. In the case of an internal manifold type fuel cell, the sealing property of the peripheral wet seal portion is maintained,
It is required to have a follow-up property to a change in stack height during operation. Therefore, it is necessary to uniformly tighten the entire fuel cell with a fixed tightening force.

As a conventional fuel cell satisfying such a need, as shown in an example in FIG. 7, a stack 1 in which cells are stacked in multiple layers via a separator is placed on a lower holder 3 on a lower bolster 5. An upper holder 2 is placed above the stack 1 and a metal bellows 6 inflated by sealing a fluid such as air is placed on the upper holder 2. The upper bolster 4 is arranged on the upper side, and the upper and lower bolsters 4 and 5 are tightened by the tightening rod 7 and the nut 8 to apply a uniform tightening force to the stack 1 via the bellows 6 and the holders 2 and 3. There is something like that.

[0005] A fuel cell formed by stacking the above cells to form a stack is degreased and impregnated at a factory before assembling and before operation, and then transported to the site for installation. Since the carbonate powder on the tile surface is melted and permeated into the tiles for each cell, the thickness of the tiles shrinks due to impregnation, and this thickness shrinks for each cell. Large shrinkage.

The amount of shrinkage of this large stack is determined by the bellows 6
Only the amount of elongation is absorbed, and the amount of change in the stack height during operation of the fuel cell is also followed by the elongation of the bellows 6.

For this reason, conventionally, the bellows 6 interposed between the upper holder 2 and the upper bolster 4 has a large thickness (height) so as to have a large elongation.

[0008]

However, the higher the lamination, the higher the bellows 6 needs to be.
When interposed between the upper holder 2 and the upper bolster 4,
The overall height is higher, the footprint is larger,
It is difficult to carry the fuel cell to the site, and in the case of a pressurized fuel cell, the pressurized container itself needs to be large.

Therefore, the present invention provides a method for assembling a fuel cell,
The purpose of the present invention is to make it possible to sufficiently absorb the shrinkage amount of the stack when degreased and impregnated in a factory, and to reduce the size of the stack to carry it on site.

[0010]

According to the present invention, in order to solve the above-mentioned problems, a stack sandwiched between upper and lower holders is supported by a lower bolster, and an upper bolster on an upper holder is formed by an inner bolster and an outer bolster. As a double structure,
A bellows is interposed therebetween, and a cushion or bellows that can follow a height change during fuel cell operation is interposed between the inner bolster and the upper holder, and the lower bolster and the inner bolster Is tightened with a tightening rod and an outer nut / turn buckle of the inner bolster, and the inner bolster and the outer bolster are screwed together with the nut / turn buckle. It is configured to be detachably fastened with.

Further, the stack in the above configuration is divided into an upper stack and a lower stack with an intermediate holder interposed therebetween, and a tightening rod for tightening the lower bolster and the inner bolster is passed through the intermediate holder. It is configured to be able to move along the tightening rod and to have a cushion or a bellows interposed between the lower holder and the lower bolster.

Further, the stack is divided into an upper stack and a lower stack with an intermediate holder interposed in the middle of the stack, and the intermediate holder is fixed by a gantry, and the upper stack, the upper holder, the inner bolster and the outer bolster are placed on the intermediate holder. While the upper bolster having the double structure is arranged in order, the lower stack, the lower holder, the inner bolster and the outer bolster are arranged in order below the intermediate holder, and the upper bolster is arranged between the upper holder and the inner bolster above the lower holder. And, between the lower holder and the lower inner bolster, a cushion or a bellows capable of following the height change during the fuel cell operation is interposed, and the inner bolster and the outer bolster Bellows are interposed between them, and are fixed to the above-mentioned intermediate holder, and the tightening bolts are extended above and below the intermediate holder. The inner bolster is fastened to the upper and lower stacks by tightening the inner bolster to the intermediate holder side with a nut and turn nut buckle outside the inner bolster of each of the inner bolsters. Are detachably fastened with a short shaft fastening rod screwed onto the nut / turnbuckle and a nut.

Still further, instead of fixing the intermediate holder with the gantry, the lower end of the tightening rod extending downward from the intermediate holder is supported by a support member, and the intermediate holder is supported by the tightening rod.

[0014] A stopper may be provided inside the cushion or bellows below the lower holder to receive the upper end plate of the cushion or bellows.

[0015]

[Function] After assembling the fuel cell, degreasing and impregnation are performed.
At this time, the shrinkage of the entire stack is absorbed by the bellows.
When degreasing and impregnation are completed, the bolster and bellows outside the turnbuckle are removed to reduce the size, and to carry them to the site. The contraction and expansion of the stack during the operation of the fuel cell is followed by a cushion or bellows. If a stopper is installed inside the cushion or bellows on the lower side of the lower holder, the load applied to the cushion or bellows during assembly can be received by the stopper, and assembly can be performed stably.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. Similar to the conventional fuel cell shown in FIG. 7, a fuel cell stack 1 is sandwiched between upper and lower holders 2 and 3, and furthermore, upper and lower bolsters 4 are provided. , 5, and a structure in which a high tightening force is applied to the stack 1 using a metal bellows 6 having a high height, the upper bolster 4 is replaced with an inner bolster 4a.
And an outer bolster 4b, and a metal cushion 9 with air pressure control interposed between the inner bolster 4a and the upper holder 2 so as to follow a thickness change during operation of the fuel cell. Bolster 4a and outer bolster 4
b, a metal bellows 6 having an elongation large enough to follow the shrinkage of the stack 1 at the time of degreasing and impregnation is interposed, and a nut / turnbuckle 10 is provided outside the inner bolster 4a. Is screwed to the tightening rod 7, and the short-axis tightening rod 11 passed through the outer bolster 4 b is screwed to the nut / turnbuckle 10 to be connected to the nut / turnbuckle 10. And the upper double bolster 4 via the nut 12
a, 4b and the lower bolster 5 apply a tightening force to the stack 1. Reference numeral 13 denotes a bottom support material.

A fuel cell stack 1 is constructed in a factory, and fastening rods 7 and 11, a nut / turnbuckle 10, a nut 12, upper bolsters 4a and 4b, and a lower bolster 5 are provided.
When the assembly is performed so that the tightening force is applied to the stack 1, as operations before the start of operation, degreasing for removing organic substances added at the time of manufacturing the electrolyte plate and impregnation for soaking the carbonate powder into the electrolyte plate are performed. However, the large shrinkage of the stack 1 during the degreasing and impregnation is absorbed by the elongation of the bellows 6.

When the shrinkage of the stack 1 during degreasing and impregnation is absorbed by the elongation of the bellows 6, the nut / turnbuckle 10 is retightened to the tightening rod 7 on the inner bolster 4a, and at the same time, the short axis The tightening rod 11 is separated from the nut / turnbuckle 10, the outer bolster 4b and the bellows 6 are removed, carried into the site, and installed. As a result, the entire apparatus is reduced in size, and can be easily carried into the site, and the installation space can be reduced.

The operation of the fuel cell is started after installation, but the height (thickness) of the stack 1 changes due to creep of the electrodes during operation, and the difference between the extension of the rod and the stack at the time of cold and at the time of hot. Can be absorbed by the extension of the cushion 9.

When the fuel cell of the present invention is put in a pressure vessel and is operated as a pressurized type, the air pressure of the cushion 9 may be controlled in conjunction with the pressure inside the pressure vessel.

FIG. 2 shows another embodiment of the present invention. In the same configuration as shown in FIG. 1, the stack 1 is divided into an upper stack 1a and a lower stack 1b, and an intermediate holder 14 is interposed therebetween. , The tightening rod 7 is passed through the intermediate holder 14 in a loosely fitted state, and a cushion 9 is interposed between the lower holder 3 and the lower bolster 5.

In this embodiment, when degreasing and impregnating are performed after assembling, the contraction of the entire stack 1a, 1b is controlled by the contraction between the upper inner bolster 4a and the outer bolster 4b as in the case of FIG. When it is absorbed by the amount of expansion of the bellows 6, the tightening rod 1 is
1, the outer bolster 4b and the bellows 6 are removed, and the tightening rod 7 and the intermediate holder 14 are fixed.
It is vertically symmetrical with respect to the intermediate holder 14.

The above procedure is followed by transporting to the site and installation. Also in this case, the size can be reduced as a whole, so that there is an advantage that the carry-in can be easily performed.

FIG. 3 shows still another embodiment of the present invention. The intermediate holder 14 is supported by a gantry 15 to form a fixed support base structure.
The upper stack 1a, the upper holder 2, the cushion 9, the inner bolster 4a, the bellows 6, and the outer bolster 4b are arranged in this order in the same manner as shown in FIG. A predetermined tightening force is applied to the upper stack 1a by the nut / turnbuckle 10, the tightening rod 11 and the nut 12 screwed to the nut / turnbuckle 10, and the lower side of the intermediate holder 14. In the above, the same configuration as the above configuration on the intermediate holder is arranged, and it is vertically symmetrical,
The lower stack 1b below the intermediate holder 14 includes a tightening rod 7, an inner bolster 4a, a nut / turnbuckle 10, a tightening rod 11, an outer bolster 4b, and a nut 1.
It is configured to be hung at 2.

In the embodiment shown in FIG. 3, after assembling, degreasing and impregnation are performed, and when the contraction amount of the upper stack 1a and the lower stack 1b is absorbed by the extension amount of the upper and lower bellows 6, respectively, the nut and turnbuckle 10 is used. After the inner bolster 4a is held by the tightening rod 7 in both the upper and lower directions, the outer bolster 4b and the bellows 6 are removed in both the upper and lower directions, carried into the site, and installed. As a result, the size can be reduced as a whole, and the same effects as in the above embodiments can be obtained.

FIG. 4 shows a modification of FIG. 3. Instead of fixing and supporting the intermediate holder 14 on the gantry 15, the fastening rod 7 is fixed to the intermediate holder 14 and the fastening below the intermediate holder 14 is performed. The lower end of the rod 7 is attached to the support member 1
3, and the intermediate holder 14 is received by the tightening rod 7.

According to this embodiment, there is an advantage that the stand 15 of FIG. 3 can be dispensed with, and when the fuel cell is used in a pressurized container, the diameter of the container does not need to be increased.

FIG. 5 shows still another embodiment of the present invention. The inside of the cushion 9 below the lower holder 3 in the embodiment shown in FIG. 2 or the embodiment shown in FIG. A stopper 16 is provided at the factory so that the load received by the cushion 9 during assembly at the factory is supported by the stopper 16 to prevent large deformation and crushing of the cushion 9 and to ensure stability during assembly.

That is, in the case of the embodiment shown in FIG.
In the case of the embodiment shown in FIG. 4, the lower holder 3 and the lower stack 1 b are supported on the lower bolster 5 and the inner bolster 4 a supported on the support material 13, and the tightening rod erected on the support material 13. 7, the intermediate holder 14, the upper stack 1a, the upper holder 2, etc. are supported.
At the time of assembling at a factory, at a minimum, after placing the cushion 9 on the lower bolster 5 or the lower inner bolster 4a, the lower holder 3, the lower stack 1b, the intermediate holder 14, the upper stack 1a, the upper holder 2, etc. In order to assemble by laminating sequentially, it is necessary to adjust the internal pressure so as to withstand the load of the cushion 9 placed thereon, but if the cushion 9 becomes unstable due to deformation or collapse,
Lamination may become difficult.

In such a case, as shown in FIGS. 5 (a) and 5 (b), the thickness (height) of the cushion 9 when it is extended to the maximum is placed inside the cushion 9 below the lower holder 3. The height is slightly lower than the size and the cushion 9
A stopper 16 having a cross-sectional area slightly smaller than the cross-sectional area of the upper end plate 9a of the cushion 9 and having an upper end surface parallel to the upper end plate 9a of the cushion 9 and capable of uniformly receiving the upper end plate 9a. 5 (b), the upper end plate 9a of the cushion 9 can be received against the upper end surface of the stopper 16 so that all the load applied to the cushion 9 is supported by the stopper 16, The cushion 9 is prevented from being further deformed or crushed.

According to this embodiment, the upper part of the cushion 9 is not stacked one after another while adjusting the internal pressure of the cushion 9 as shown in FIG. Since the plate 9a can be stacked and assembled in a state where the plate 9a is in contact with the upper end surface of the stopper 16, the cushion 9 is not deformed or further collapsed, so that stability during assembly can be secured. Further, after assembly, degreasing and impregnation are performed. At this time, in the case of the embodiment shown in FIG.
When there is no cushion 6, it is necessary to control the internal pressure of both the cushion 9 and the bellows 6 and to control it accurately. However, since the cushion 9 and the bellows 6 must be controlled separately, the precision of the control is high. May not be able to be raised. In this regard, if the stopper 16 is provided inside the cushion 9 and the load received by the cushion 9 is received by the stopper 16, there is no need to adjust the internal pressure of the cushion 9, and only the internal pressure of the bellows 6 needs to be controlled. Therefore, there is also an advantage that control becomes easy.

FIG. 6A is a modification of FIG.
The cushion 9 is replaced with a plurality of bellows 17 similar to the bellows 6, and the required height and diameter are provided inside each bellows 17 below the lower holder 3 as shown in FIGS. Is provided with a stopper 18 having

6, the lower holder 3, the lower stack 1b, and the intermediate holder 14 are sequentially stacked by receiving the upper end plate 17a of the bellows 17 at the upper end surface of the stopper 18 during assembly. Since the load of the upper stack 1a, the upper holder 2 and the like can be received by the stopper 18, stability during assembly can be ensured.

In the above embodiment, the support material 13
Although the case where the stopper 16 or 18 is installed inside the cushion 9 or the bellows 17 on the upper lower bolster 5 or the inner bolster 4a is shown, in FIGS. 4 and 6, the stopper is installed inside the lower bellows 6. 1, 2 and 3.
It is a matter of course that the cushion 9 in each embodiment shown in (1) may be replaced with a bellows, and that a spring may be used as the cushion 9.

[0036]

As described above, according to the fuel cell of the present invention, the stack sandwiched between the upper and lower holders is supported by the lower bolster, and the upper bolster on the upper holder is formed by a double of the inner bolster and the outer bolster. As a structure, a bellows is interposed therebetween, and between the inner bolster and the upper holder, a cushion or a bellows capable of following a height change during the fuel cell operation is interposed, and the lower bolster and the lower bolster are interposed. The inner bolster is fastened by a tightening rod and a nut / turnbuckle outside the inner bolster, and furthermore, a short shaft is screwed on the inner bolster and the outer bolster to the nut / turnbuckle. It can be configured to be detachably fastened with a rod and nut, or the upper slide with an intermediate holder in the middle of the stack. The lower bolster and the inner bolster are passed through the intermediate holder so that the intermediate holder can be moved along the tightening rod, and the lower holder and the lower bolster are separated from each other. Between the upper stack and the lower stack with an intermediate holder in the middle of the stack, and fix the intermediate holder with a base, and place the upper stack on the intermediate holder. ,
An upper holder, an upper bolster having a double structure of an inner bolster and an outer bolster are arranged in order, and a lower stack, a lower holder, an inner bolster and an outer bolster are arranged in order below the intermediate holder, and the upper holder is arranged. And a cushion or bellows interposed between the lower holder and the inner bolster below the lower holder and the inner bolster above the lower bolster so as to be able to follow the height change during the fuel cell operation, and A bellows is interposed between each of the inner bolster and the outer bolster, and a fastening rod fixed to the intermediate holder and extended upward and downward of the intermediate holder and a turnbuckle serving as a nut outside each of the inner bolsters. By tightening the inner bolster to the intermediate holder side to apply a tightening force to the upper and lower stacks, Instead of fixing each of the inner bolster and the outer bolster with the short shaft tightening rod screwed to the nut / turnbuckle and the nut so as to be detachable, or fixing the intermediate holder with a gantry ,
Since the lower end of the tightening rod extending downward from the intermediate holder is supported by the support member and the intermediate holder is supported by the tightening rod, the entire body is removed by removing the bellows and the outer bolster after degreasing and impregnation. The outer bolster and bellows can be reused because they can be miniaturized, and the tightening rod for tightening the inner bolster and outer bolster can be of a short axis because the lower end is screwed to the nut / turnbuckle. It is easy to carry in and install to the site, and the occupied space can be reduced, and the height change during operation can be followed by the extension of the cushion or bellows, so that there is no trouble in operation. In this case, the intermediate holder is supported by the tightening rod. If a stopper is installed inside the cushion or bellows to be able to follow the height change during operation, which is installed under the hopper, the load when sequentially stacking on the cushion or bellows during assembly Can be received by the stopper, and an excellent effect that the stability at the time of assembling can be enhanced as compared with the case where the internal pressure of the cushion or the bellows is adjusted can also be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing one embodiment of the present invention.

FIG. 2 is a schematic side view showing another embodiment of the present invention.

FIG. 3 is a schematic side view showing still another embodiment of the present invention.

FIG. 4 is a schematic side view showing a modification of FIG.

5A and 5B show another embodiment of the present invention, wherein FIG. 5A is a cross-sectional view of a cushion below a lower holder, FIG. 5B is a plan view of a stopper of FIG. 5A, and FIG. FIG. 6 is a cross-sectional view showing a state in which the upper end plate is received by a stopper.

6 shows yet another embodiment in which a stopper is provided inside the bellows in place of the bellows in place of the cushion of FIG. 4, (a) is a schematic side view showing only the lower part of the tightening device of the fuel cell, (B) is a cross-sectional view of the bellows replacing the cushion, and (c) is a plan view of the stopper shown in (b).

FIG. 7 is a schematic side view showing an example of a conventional fuel cell.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stack 1a Upper stack 1b Lower stack 2 Upper holder 3 Lower holder 4 Upper bolster 4a Inner bolster 4b Outer bolster 5 Lower bolster 6 Bellows 7 Tightening rod 9 Cushion 9a Upper end plate 10 Nut / turnbuckle 14 Intermediate holder 15 Stand 16 Stopper 17 Bellows 17a Upper end plate 18 Stopper

Continuation of the front page (56) References JP-A-2-291670 (JP, A) JP-A-58-164168 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 8 / twenty four

Claims (5)

(57) [Claims] 1. A stack sandwiched between upper and lower holders is supported by a lower bolster, and an upper bolster on an upper holder has a double structure of an inner bolster and an outer bolster.
A bellows is interposed therebetween, and a cushion or bellows that can follow a height change during fuel cell operation is interposed between the inner bolster and the upper holder, and the lower bolster and the inner bolster Is tightened with a tightening rod and an outer nut / turn buckle of the inner bolster, and the inner bolster and the outer bolster are screwed together with the nut / turn buckle. A fuel cell having a configuration in which the fuel cell is detachably tightened. 2. The stack is divided into an upper stack and a lower stack with an intermediate holder interposed in the middle of the stack, and a tightening rod for tightening the lower bolster and the inner bolster is passed through the intermediate holder. 2. The fuel cell according to claim 1, wherein the fuel cell is adapted to be able to move along with the lower holder, and a cushion or a bellows is interposed between the lower holder and the lower bolster. 3. The stack is divided into an upper stack and a lower stack with an intermediate holder interposed in the middle of the stack, and the intermediate holder is fixed by a gantry.
An upper holder, an upper bolster having a double structure of an inner bolster and an outer bolster are arranged in order, and a lower stack, a lower holder, an inner bolster and an outer bolster are arranged in order below the intermediate holder, and the upper holder is arranged. And a cushion or bellows interposed between the lower holder and the inner bolster below the lower holder and the inner bolster above the lower bolster so as to be able to follow the height change during the fuel cell operation, and A bellows is interposed between each of the inner bolster and the outer bolster, and a fastening rod fixed to the intermediate holder and extended upward and downward of the intermediate holder and a turnbuckle serving as a nut outside each of the inner bolsters. By tightening the inner bolster to the intermediate holder side to apply a tightening force to the upper and lower stacks, A fuel cell characterized by having the structure and the respective inner bolster and the outer bolster, which removably clamped at the nut combined clamping rod of the minor axis which is screwed into the turnbuckle and nuts. 4. The method according to claim 3, wherein the lower end of the tightening rod extending downward from the intermediate holder is supported by a support member, and the intermediate holder is supported by the tightening rod, instead of fixing the intermediate holder with the gantry. The fuel cell as described. 5. The fuel according to claim 2, wherein a stopper for receiving an upper end plate of the cushion or the bellows is installed inside a cushion or a bellows installed below the lower holder. battery.