JPH10284109A - Fuel cell and lining fitting method to its gas manifold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell which has excellent phosphoric acid resistance, electrical insulating performance and sufficient corrosion resistance for a long time, by fitting lining, which is made of a phosphoric acid resistant resin sheet formed in a smaller size in advance than an inner surface size of a gas manifold considering the thermal expansion during operation loosely to the inner surface of a manifold. SOLUTION: It is preferable to use a PFA resin sheet which has low permeability of phosphoric acid and is excellent in heat resistance and mechanical strength for a phosphoric acid resistant resin sheet. By making a thickness of the resin sheet to 0.1-1 mm, phosphoric acid permeability and electrical insulating performance become reliable. Lining 20 made of this phosphoric acid resistant resin sheet is jointed at 4 corners and formed in a box shape so that it becomes smaller by an approximate expansion difference portion L/2 than the gas manifold 30 considering thermal expansion. The lining 20 is not fixed directly to the manifold 30, but is fitted loosely to sufficiently absorb heat expansion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a fuel cell,
In particular, the present invention relates to a fuel cell improved to prevent phosphoric acid corrosion of a gas manifold.

[0002]

2. Description of the Related Art A fuel cell supplies hydrogen, which is obtained by reforming a hydrocarbon fuel such as natural gas or methane gas, and air, which is an oxidizing agent, to the inside of a fuel cell main body. The cell generates an electric energy by performing an electrochemical reaction through the cell, and has a stacked structure (cell stack structure) in which a plurality of unit cells having the above-described power generation function are stacked.

FIG. 30 is an exploded perspective view showing a cell stack structure of a conventionally used fuel cell. That is, in the unit cell 1 of the fuel cell main body, the fuel electrode 3 to which hydrogen is supplied in the direction of arrow A in the figure is disposed on one side of the matrix layer 2 holding the electrolyte, and the arrow An air electrode 4 to which air is supplied in the B direction is arranged, and electrode bases 5 and 6 with grooves are laminated on the fuel electrode 3 and the air electrode 4, respectively. Separator 7 on one side
Are laminated. Each time a plurality of the unit cells 1 are stacked, the cooling plate 8 is inserted to form one sub-stack 9, and a large number of the sub-stacks 9 are stacked to form a cell stack 10. A fastening plate 11 is attached to each of the uppermost portion and the lowermost portion of the cell stack 10, and the cell stack 10 and the upper and lower fastening plates 11 are fastened by tie rods 12 and integrated as a battery stack 13. .

[0004] Further, as shown in FIG. 31, a pair of fuel gas manifolds are provided on four side surfaces of the battery stack 13 configured as described above so that fuel gas and air flow in directions perpendicular to each other. 15a, 15b and a pair of air gas manifolds 16a, 16b are mounted at positions facing each other. A gasket 18 is provided on the contact surface between the battery stack 13 and each of the gas manifolds 15a, 15b, 16a, and 16b in order to prevent problems such as a decrease in power generation efficiency due to leakage of air or fuel gas.
Is provided.

Incidentally, the gas manifold 15a,
When fuel and air are respectively supplied to the fuel cell 16a, a part of the phosphoric acid impregnated in the matrix layer 2 and the grooved electrode materials 5 and 6 of the unit cell 1 constituting the cell stack 10 becomes part of the fuel gas and air. It diffuses into the stream and is discharged out of the cell stack (ie, inside the gas manifold) in the form of phosphoric acid vapor.

However, since the temperature of the gas manifold is slightly lower than the cell stack temperature, part of the phosphoric acid vapor discharged into the gas manifold condenses and adheres to the inner wall of the gas manifold. As described above, when the fuel gas containing phosphoric acid and the air come into direct contact with the inner surface of the metal gas manifold, the metal gas manifold is severely eroded in a high temperature state, and there is a possibility that a hole is immediately formed.

As a method for protecting the gas manifold from phosphoric acid, US Pat.
A method of coating a fluorine-based resin on the inner surface of a gas manifold as shown in Japanese Patent No. 50563 is used.

[0008]

However, the method for coating the inner surface of a gas manifold with a fluorine-based resin has the following problems, and it is difficult to completely prevent the gas manifold from phosphoric acid corrosion. Met.

In other words, in the method of coating the inner surface of the gas manifold with the fluorine resin, the starting and stopping of the gas manifold are problematic because there is a problem of intrusion of phosphoric acid from a pinhole and a linear expansion coefficient of the resin coating is about 10 times that of the gas manifold. There is a problem that the adhesion of the resin coating is poor due to the repetition of the temperature change due to the load fluctuation and the load, and the coating peels off.

In addition, since the coating is relatively thin, phosphoric acid easily penetrates and corrodes the base material, and thus lacks reliability. Furthermore, in order to increase the reliability of the coating, it is necessary to increase the thickness of the coating film, and the heating, application, and cooling steps have to be repeated many times, which increases the processing time and the number of processing steps. . Further, since the coating process is a series of the gas manifold manufacturing process, it has been a hindrance factor for shortening the construction period.

In the event that the coating is broken during operation of the fuel cell and an abnormality such as peeling occurs, the abnormality cannot be detected in a short time, which may lead to corrosion of the gas manifold and poor electrical insulation. was there.

The present invention has been proposed in order to solve the above-mentioned problems of the prior art. The first object of the present invention is to provide excellent phosphoric acid resistance and electrical insulation, and to provide sufficient long-term resistance. An object of the present invention is to provide a fuel cell having corrosiveness. A second object is to provide a fuel cell in which the lining of the lining is prevented from being damaged. A third object is to provide a fuel cell having means for confirming the soundness of the lining.

A fourth object of the present invention is to provide a highly reliable method of attaching a lining to a gas manifold of a fuel cell.

[0014]

In order to achieve the above object, the fuel cell according to the first aspect of the present invention has an inner surface of a gas manifold disposed on a side surface of a cell stack constituting the fuel cell. A lining formed by forming a phosphoric acid resin sheet in accordance with the inner surface shape of the gas manifold is loosely attached, and this lining is formed in advance so as to be substantially thermally expanded during operation of the fuel cell and smaller than the inner surface shape of the gas manifold. It is characterized by having.

According to the first aspect of the present invention having the above structure, the entire inner surface of the gas manifold can be covered with a lining made of a phosphoric acid-resistant resin sheet formed in accordance with the inner surface shape. Therefore, phosphoric acid corrosion of the metal gas manifold base material can be prevented. In addition, since the lining can be formed in advance in accordance with the inner surface shape of the gas manifold, the lining can be manufactured in a step different from that of the gas manifold, and the construction period can be shortened. In addition, even if the temperature inside the gas manifold rises and the lining expands, the lining conforms to the size and shape of the inner surface of the gas manifold. Can be prevented.

According to a second aspect of the present invention, in the fuel cell according to the first aspect, the phosphoric acid-resistant resin sheet constituting the lining is a PFA (ethylene tetrafluoride / perfluoroalkoxyethylene copolymer) resin sheet. Alternatively, it is a FEP (ethylene tetrafluoride / propylene hexafluoride copolymer) resin sheet.
According to a third aspect of the present invention, in the fuel cell according to the first aspect, the phosphoric acid-resistant resin sheet constituting the lining is a PTFE (tetrafluoroethylene) resin sheet. It is. According to the second or third aspect of the present invention having the above-described configuration, it is possible to form a lining having a small amount of phosphoric acid permeation and excellent heat resistance temperature and mechanical strength.

According to a fourth aspect of the present invention, in the fuel cell according to the first aspect, either the female hook or the male hook is attached to the phosphate-resistant resin sheet constituting the lining, and the inner surface of the gas manifold is provided. A male hook or a female hook that engages with the hook attached to the lining is attached at a predetermined position. According to the invention described in claim 4 having the above-described configuration, the lining can be detachably supported on the gas manifold by a simple fixing means.

According to a fifth aspect of the present invention, in the fuel cell according to the fourth aspect, a perforated patch is attached to the phosphoric acid-resistant resin sheet constituting the lining, and a female hook or a female hook is provided between the sheet and the patch. It is characterized in that one of the male hooks is movably mounted. According to the fifth aspect of the invention having the above configuration, the lining can be loosely attached to the gas manifold, so that the difference in thermal expansion between the lining and the gas manifold can be absorbed.

According to a sixth aspect of the present invention, in the fuel cell according to the first aspect, the thickness of the phosphate-resistant resin sheet constituting the lining is 0.1 mm to 1 mm. It is. According to the invention as set forth in claim 6 having the above-described configuration, it is possible to form a lining that reduces the amount of phosphoric acid permeated and maintains excellent mechanical strength and electrical insulation.

According to a seventh aspect of the present invention, in the fuel cell according to the first aspect, a joining margin of a corner portion of the phosphate-resistant resin sheet constituting the lining is 1 mm to 10 m.
m. According to the invention described in claim 7 having the above-described configuration, the strength of the joint of the lining can be improved.

According to an eighth aspect of the present invention, in the fuel cell according to the first aspect, the corner portion of the phosphate-resistant resin sheet constituting the lining is heat-pressed to a temperature equal to or higher than the melting point of the resin sheet. It is characterized by being joined. According to the invention as set forth in claim 8, having the above-described structure, the molecules between the two sheets are sufficiently entangled by heating and pressure bonding at a temperature equal to or higher than the melting point temperature, so that the phosphoric acid-resistant resin constituting the lining is formed. The corners of the sheet are completely joined.

According to a ninth aspect of the present invention, in the fuel cell according to the first aspect, a joining portion of the phosphoric acid-resistant resin sheet constituting the lining is joined by impulse welding. . According to the ninth aspect of the present invention having the above-described structure, the joint portions of the phosphate-resistant resin sheets constituting the lining can be joined in a short time, the finished state is beautiful, the variation in the joining strength is small, and the lining is stable. In this case, it is possible to perform a proper joining. In addition, bonding can be performed under conditions such as a relatively wide range of heating temperature, heating time, and compression surface pressure during heating.

According to a tenth aspect of the present invention, in the fuel cell according to the ninth aspect, the heating temperature range at the time of joining the impulse weld is from the melting point temperature of the phosphoric acid-resistant resin sheet constituting the lining to 400 ° C. It is characterized by having. An eleventh aspect of the present invention is the fuel cell according to the ninth aspect, wherein a heating time for bonding the impulse weld is 5 seconds to 300 seconds. According to the tenth or eleventh aspect of the present invention having the above-described configuration, by setting the joining conditions of the impulse weld properly, reliable joining can be performed, so that the strength of the lining is improved. be able to.

According to a twelfth aspect of the present invention, in the fuel cell according to the ninth aspect, at the time of joining the impulse weld, 0.01 to 0.1 mm is provided between the joining surfaces of the phosphate-resistant resin sheets constituting the lining. It is characterized in that it is joined by sandwiching a PFA (tetrafluoroethylene / perfluoroalkoxyethylene copolymer) film having a thickness of 04 mm. According to the twelfth aspect of the present invention having the above-described configuration, the thin PFA film heated and melted functions as an adhesive, so that the bonding strength by impulse welding can be increased.

According to a thirteenth aspect of the present invention, in the fuel cell according to the ninth aspect, the compression surface pressure at the time of joining the impulse weld is set to 0.05 to 0.2 MPa. is there. According to the invention of the thirteenth aspect having the above configuration, since the molecules between the two sheets are sufficiently entangled, the phosphoric acid-resistant resin sheet constituting the lining can be completely joined.

According to a fourteenth aspect of the present invention, in the fuel cell according to the ninth aspect, the cooling temperature at the time of joining the impulse weld is set to be equal to or lower than the glass transition temperature of the phosphoric acid resistant resin sheet constituting the lining. It is characterized by the following. According to the invention of the fourteenth aspect having the above-described configuration, the solidification state is established by cooling the glass to a temperature equal to or lower than the glass transition temperature, so that the joining strength of the lining can be improved.

According to a fifteenth aspect of the present invention, in the fuel cell according to the first aspect, pressure monitoring means for monitoring a pressure between the lining and the gas manifold is provided. is there. According to the invention as set forth in claim 15 having the above configuration, the soundness of the lining can be monitored.

According to a sixteenth aspect of the present invention, in the fuel cell according to the first aspect, the lining has a cutout of 138 ± 3 at the four corners of the phosphate-resistant resin sheet.
After cutting at an angle of degrees, the notch is opposed pressure-bonded,
It is characterized by being formed in a flanged box shape. According to the invention as set forth in claim 16 having the above configuration, it is possible to form a lining that matches the shapes of the four corners and the flange of the gas manifold.

According to a seventeenth aspect of the present invention, in the fuel cell according to the first aspect, a flange cover is attached to the gas supply / discharge flange portion of the gas manifold. The invention according to claim 18 is the fuel cell according to claim 17, wherein the flange cover is joined to a bottom surface of the phosphate-resistant resin sheet for lining by heat compression. . According to a nineteenth aspect of the present invention, in the fuel cell according to the seventeenth aspect, the flange cover is formed by pressing an opening-side end of the lining phosphoric acid-resistant resin sheet formed in a ring shape. It is characterized by the following. The invention according to claim 20 is the fuel cell according to claim 17, wherein the flange cover is a PFA.
(Ethylene tetrafluoride / perfluoroalkoxyethylene copolymer) It is characterized by comprising a resin sheet. According to the invention of the seventeenth to twentieth aspects having the above-described configuration, by attaching the flange cover to the flange portion of the gas manifold, it is possible to prevent phosphoric acid corrosion in the flange portion.

According to a twenty-first aspect of the present invention, in the fuel cell according to the first aspect, the lining is also attached to a divider part that partitions an internal space formed by a fuel-side gas manifold. Is what you do. According to the invention of the twenty-first aspect having the above configuration, the divider portion of the fuel-side gas manifold is also covered with the lining, so that the phosphoric acid corrosion of the fuel-side gas manifold can be more completely prevented. .

According to a twenty-second aspect of the present invention, in the fuel cell according to the first aspect, the outer peripheral portion of the phosphoric acid-resistant resin sheet is bent along a flange portion of a peripheral portion of the gas manifold to form a gas manifold flange. It is characterized by being clamped and fixed together with a part by a clamp. According to the invention having the above structure, the peripheral end of the gas manifold can also be completely covered with the lining made of the phosphoric acid-resistant resin sheet. Phosphoric acid corrosion of the material can be more effectively prevented.

According to a twenty-third aspect of the present invention, in the fuel cell according to the first aspect, the thickness of the phosphoric acid-resistant resin sheet constituting the lining is adjusted in each of the gas manifolds disposed on the side surface of the cell stack. It is characterized by being changed based on the phosphoric acid discharge amount. According to a twenty-fourth aspect of the present invention, in the fuel cell according to the first aspect, the thickness of the lining lining the air supply side gas manifold is smaller than the thickness of the lining lining the other parts. Is what you do. According to the invention as set forth in claims 23 and 24 having the above configuration, the thickness of the resin sheet is determined based on the amount of phosphoric acid discharged from each gas manifold disposed on the side surface of the battery stack. By changing the ratio, the permeation of phosphoric acid can be prevented rationally and reliably.

According to a twenty-fifth aspect of the present invention, in the fuel cell of the first aspect, a heat-resistant paint is applied to at least an inner surface of the gas manifold. According to the twenty-fifth aspect of the present invention having the above configuration, by applying a heat-resistant paint to at least the inner surface of the gas manifold, the contact surface between the lining and the metal gas manifold becomes smoother.

According to a twenty-sixth aspect of the present invention, in the fuel cell according to the fifteenth aspect, the pressure monitoring means is connected to a pressure end of which the one end opening is connected via a pressure measuring plug provided in the gas manifold. The other end opening of the drawer tube is inserted into water.
According to a twenty-seventh aspect of the present invention, in the fuel cell according to the twenty-sixth aspect, a U-shaped arrangement portion is formed in a state where the other end opening of the pressure extraction tube is open to the atmosphere. The U-shaped arrangement portion is filled with water. According to the invention described in claim 26 and claim 27 having the above configuration, the soundness of the lining can be monitored.

According to a twenty-eighth aspect of the present invention, in the fuel cell according to the fifteenth aspect, the pressure monitoring means is connected to a one-side end opening via a pressure measuring plug provided in a gas manifold. A pressure gauge is connected to the other end opening of the tube. According to a twenty-ninth aspect of the present invention, in the fuel cell according to the fifteenth aspect, the pressure monitoring means is connected to one end opening through a pressure measuring plug provided in a gas manifold. In the other end opening of
It is characterized by connecting a flow meter. According to the invention described in claims 28 and 29 having the above configuration, the soundness of the lining can always be automatically monitored.

According to a thirtieth aspect of the present invention, in the fuel cell according to the first aspect, the side face covering portion of the gas-resistant manifold of the phosphoric acid-resistant resin sheet constituting the lining is extended so as to be in contact with the lining end of the adjacent gas manifold. It is characterized by joining and covering the corner portion of the battery laminate. According to the invention described in claim 30 having the above configuration, it is possible to prevent the leakage of combustible gas from the battery stack.

A method of attaching a lining to a gas manifold of a fuel cell according to a thirty-first aspect of the present invention captures the invention of the first aspect from the viewpoint of the method. A phosphoric acid-resistant resin sheet is formed on the inner surface of the gas manifold provided in accordance with the inner surface shape of the gas manifold, so that the thermal expansion during operation of the fuel cell is smaller than the inner surface shape of the gas manifold. It is characterized by the loose lining attached. According to the invention according to claim 31 having the above configuration, the entire inner surface of the gas manifold can be covered with the lining made of the phosphoric acid-resistant resin sheet, so that the metal gas manifold base material is subjected to phosphoric acid corrosion. Can be prevented.

According to a thirty-second aspect of the present invention, in the method for attaching a lining of a fuel cell to a gas manifold according to the thirty-first aspect, the outer peripheral portion of the phosphoric acid-resistant resin sheet is formed with a flange portion at the peripheral portion of the gas manifold. And is clamped and fixed together with the gas manifold flange by a clamp. According to the invention described in claim 32 having the above configuration, the peripheral end of the gas manifold can also be completely covered with the lining made of the phosphoric acid-resistant resin sheet. Phosphoric acid corrosion of the material can be more effectively prevented.

A lining mounting method for a fuel cell according to a thirty-third aspect of the present invention captures the invention according to the fourth aspect from the viewpoint of the method, wherein the phosphoric acid-resistant resin sheet is provided on the inner surface of the gas manifold. A lining is formed by molding according to the shape, and either a female hook or a male hook is attached to the phosphoric acid-resistant resin sheet constituting the lining, and the lining is provided at a predetermined position on the inner surface of the gas manifold. A male hook or a female hook that engages with the attached hook is attached, and the lining is attached to the gas manifold by engaging both hooks. According to the invention according to claim 33 having the above-described configuration, the lining made of the phosphoric acid-resistant resin sheet can be detachably attached to the gas manifold by a simple fixing means. Phosphoric acid corrosion of the material can be prevented.

According to a thirty-fourth aspect of the present invention, in the method for attaching a lining to a gas manifold of a fuel cell according to the thirty-third aspect, the outer peripheral portion of the phosphoric acid-resistant resin sheet constituting the lining is formed around the gas manifold. It is characterized in that it is bent along the flange of the section and is clamped and fixed together with the gas manifold flange by a clamp.

According to the thirty-fourth aspect of the present invention, the peripheral end of the gas manifold is also
Since the metal gas manifold base material can be completely covered with the lining made of the phosphoric acid-resistant resin sheet, phosphoric acid corrosion can be more effectively prevented.

According to a thirty-fifth aspect of the present invention, in the fuel cell according to the first aspect, the lining is formed by blowing a phosphate-resistant resin sheet into a box shape by blow molding. . According to the invention according to claim 35 having the above-described configuration, the lining attached to the gas manifold is formed into a box shape by blow molding, so that a highly reliable lining without a joint can be easily obtained. be able to.

According to a thirty-sixth aspect of the present invention, in the fuel cell according to the thirty-fifth aspect, the heating temperature range during the blow molding of the lining is set to be equal to or higher than the softening point of the phosphoric acid-resistant resin sheet and equal to or lower than the melting point. It is a feature. According to the invention according to claim 36 having the above configuration, by setting the heating temperature range during blow molding of the lining to an appropriate range, it is possible to obtain a uniform and highly accurate lining, and In addition, the molding operation becomes easy.

[0044]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

[1. First Embodiment] In this embodiment, the entire inner surface of a gas manifold of a fuel cell is covered with a lining made of a phosphoric acid-resistant resin sheet.

[1-1. Configuration of First Embodiment] That is, in the present embodiment, as shown in FIG. 1, a phosphoric acid-resistant resin sheet is formed in accordance with the inner surface shape of the gas manifold, and predetermined portions (four corners, flange portions, etc.) To form a box-shaped lining 20. Then, by attaching the lining 20 to the inner surface of the gas manifold attached to the four side surfaces of the battery stack 13 as shown in FIG. 31, the inner surface of the gas manifold is lined. When the phosphoric acid-resistant resin sheet is molded according to the inner shape of the gas manifold,
The gas manifold is formed to be smaller than the inner surface shape of the gas manifold by substantially the amount of thermal expansion during fuel cell operation.

FIG. 1 shows a lining attached to the inner surface of the air-side gas manifold.
Flange cover 23 and patch 4 to be described later
5 is attached. In addition, the lining 20
As shown in FIG. 2, the joint is formed into a box shape by joining joints 25 provided at the folded portions corresponding to the four corners and the flange of the gas manifold. Further, FIG.
Is a PFA resin sheet 22 constituting the air-side lining
FIG. 4 is a development view of FIG. 3, and FIG.
It is the figure which showed the enlarged view of the part. That is, the joint 25 is cut out at an angle of 138 ± 3 degrees according to the shape of the four corners and the flange of the gas manifold. Then, as shown in FIGS. 5 and 6, the PFA resin sheets 22 constituting the lining are pressure-bonded to each other at the joint 25 thereof. It should be noted that “m” in the drawing indicates a bonding margin.

That is, as shown in FIG. 7, the lining 20 made of the phosphoric acid-resistant resin sheet takes into consideration the difference in thermal expansion on the inner surface of the gas manifold.
It is formed and joined in a box shape at the corners of the four corners so that the difference in extension L / 2 is smaller.

[1-1-1. Material of Phosphoric Acid-Resistant Resin Sheet] As the phosphoric acid-resistant resin sheet constituting the lining of the present invention, the one having less phosphoric acid permeability can be reduced in thickness as the lining sheet, and is economical. Therefore, the present inventors have selected PFA (ethylene tetrafluoride / perfluoroalkoxy ethylene copolymer) resin sheet and PTFE (ethylene tetrafluoride) in order to select a phosphoric acid-resistant resin sheet suitable for forming the lining. The permeability of phosphoric acid was examined for the resin sheet and the FEP (ethylene tetrafluoride / propylene hexafluoride copolymer) resin sheet.

The results are as shown in FIG. 8, and the PFA resin sheet having low phosphoric acid permeability or FEP
It is desirable to use a resin sheet as the lining sheet material. As shown in FIG. 8, the PFA resin sheet and the FEP resin sheet are equivalent in terms of permeability,
Since the PFA resin sheet is superior in terms of heat resistance and mechanical strength, it is more preferable to use a PFA resin sheet. The PTFE resin sheet is also inferior to the PFA resin sheet in terms of permeability, but has high mechanical strength, so it is effective for frequent start / stop, and can be used as a lining sheet material. It is.

[1-1-2. Configuration of Flange Section] FIG. 9 is a plan view of an air-side gas manifold lining (hereinafter, referred to as an air-side lining) 20, FIG. 10 is a cross-sectional view of the flange section shown in FIG. 3 is an enlarged view of a portion C of FIG. That is, as shown in FIGS. 9 to 11, the flange 31 of the gas manifold 30 is used.
Is formed integrally with the gas manifold 30 by welding (welding), and the lining 20 is
It is cut out circularly in accordance with the position and shape of the flange 31 of the gas manifold. On the other hand, a flange cover 23 is lined on the inner surface of the flange 31 of the gas manifold.
Are joined at a Y portion shown in FIG.

FIG. 12A is a plan view of a lining 21 for a fuel outlet side gas manifold (hereinafter, referred to as a fuel side lining), and FIG. 12B is a perspective view. Further, FIG. 13A is a GG sectional view of the fuel outlet flange shown in FIG. 12, and FIG. 13B is a perspective view of the fuel outlet flange. That is, as shown in FIGS. 12 and 13, the flange 33 of the fuel outlet side gas manifold 32 is formed integrally with the gas manifold 32 by welding, and the lining 21 is formed of the flange 33 of the gas manifold. It is cut out circularly according to the position and shape of. On the other hand, a flange cover 24 is lined on the inner surface of the flange 33 of the gas manifold.
And the lining 21 are joined at a Z portion shown in FIG. In FIG. 13, reference numeral 34 denotes a divider provided for turning the fuel gas, and its inner surface is also covered with the lining 21 (see the next section).

As the flange covers 23 and 24, machined products of PTFE are used, and as described above, the phosphate-resistant resin sheets 20 and 21 for lining are respectively used.
Are joined by heat welding to form a flange portion of the lining. The flange cover 2
In Nos. 3 and 24, after forming the phosphate-resistant resin sheet for lining into a ring shape, the flange can be formed by pressing the opening-side end of the ring, and according to this method, the economic efficiency is greatly improved. . The material of the flange covers 23 and 24 is P
By making the FA resin sheet, the permeation resistance of phosphoric acid is improved and the thickness can be further reduced, so that the bonding property is further improved.

[1-1-3. Configuration of Divider Section] FIG.
As shown in FIG. 3, the fuel outlet side gas manifold 32 is provided with a divider 34 for partitioning the internal space of the gas manifold in the longitudinal direction in order to turn the fuel gas. And the fuel side lining 21 also covers this divider part. FIG. 14 is a perspective view showing a state in which the fuel outlet lining 21 is covered on the fuel outlet side gas manifold 32. That is, the fuel-side lining 21 is formed and joined so as to cover also a part of the divider 34 that partitions the inside of the fuel gas manifold 32 into two chambers. In addition, a to e in the drawing indicate the joining order of the fuel-side lining 21.

[1-1-4. Configuration of Gas Manifold Peripheral End] Next, FIGS. 15A and 15B are cross-sectional perspective views showing the peripheral portion of the gas manifold.
3 shows an EE cross section of FIG. That is, FIG.
As shown in (A), at the peripheral ends of the gas manifolds 30 and 32, the linings 20 and 21 are turned back to cover the peripheral ends of the gas manifold, and a U-shaped plastic clamp 36 having a U-shaped cross section from above. The linings 20, 21 are fixed to the gas manifolds 30, 32 by sandwiching them at appropriate intervals. FIG.
As shown in (B), the linings 20 and 21 are similarly folded back to cover the peripheral end of the gas manifold, and the linings 20 are sandwiched at appropriate intervals by a metal clamp 39 via a PFA strip sheet 38 from above. , 21
May be fixed to the gas manifolds 30 and 32. In addition, a heat-resistant tape 37 is attached to the peripheral edges of the linings 20 and 21 over the entire circumference,
Lip portions 35 of gas manifolds 30 and 32 together with 21
And are fixed integrally.

[1-1-5. Fixing means for gas manifold and lining] FIG.
At its bottom, the gas manifolds 30, 3
FIG. 4 is a cross-sectional view showing a configuration of a hook portion 40 supported by the hook 2;
FIG. 13 shows a DD section of FIGS. 9 and 12. Also,
FIG. 17 is a plan view of FIG.

That is, as shown in FIG. 16, the hook portion 40 comprises a male hook 41 and a female hook 43 which engage with each other.
It is composed of Further, a donut-shaped thin stainless steel plate 42 is integrated with the male hook 41 by caulking, and this stainless steel plate 42 is
2 is fixed by spot welding.

On the other hand, a donut-shaped sheet 44 having some rigidity is integrated with the female hook 43 by caulking.
On the back surfaces of the linings 20 and 21, a patch 45 made of the same material as that of the lining is previously heat-pressed to a predetermined position. In addition, this patch 45 includes FIG.
As shown in FIG. 6 and FIG. 18, a hole 45a larger than the radius of the female hook 43 by "G" is formed.

Then, the patch 45 and the lining 2
By inserting the sheet 44 integrated with the female hook 43 between 0 and 21, the female hook 43 can be supported movably by “G” with respect to the linings 20 and 21. By using such fixing means,
Since the lining can be loosely attached to the gas manifold, the difference in thermal expansion between the lining and the gas manifold can be absorbed.

In the example shown in FIG. 16, the male hook is mounted on the gas manifold side and the female hook is mounted on the lining side. However, the female hook is mounted on the gas manifold side and the male hook is mounted on the lining side. Needless to say, it is good. FIG. 19 is a perspective view showing a state in which the patch 45 is thermocompression-bonded to the PFA resin sheet 22. FIGS. 20A and 20B are views in which the flange covers 23 and 24 are thermocompression-bonded to the PFA resin sheet 22, respectively. It is a perspective view showing the state where it did. Further, sectional views showing a state where the PFA resin sheet 22 is attached to the gas manifolds 30 and 32 are already shown in FIGS.

[1-1-6. Thickness of phosphoric acid-resistant resin sheet ... Part 1] The thickness of the phosphoric acid-resistant resin sheet used for lining the gas manifold is the most important point for protecting the metal gas manifold from phosphoric acid. Therefore, the present inventors examined the relationship between the thickness of the phosphoric acid-resistant resin sheet at 200 ° C. and the permeation amount of phosphoric acid.

This experiment was performed using an apparatus as shown in FIG. That is, the phosphoric acid-resistant resin sheet 51 and the phosphoric acid absorbent 52 are overlapped and sandwiched by the measuring cell 53, phosphoric acid is put on the phosphoric acid-resistant resin sheet 51 side of the measuring cell 53, and the whole is sealed. After being sealed in a container 54, the mixture was heated to 200 ° C. in a dryer. Then, after heating for 15,000 hours, the phosphoric acid absorbent 52 was taken out, and the amount of phosphorus reacted on the surface of the absorbent was analyzed to determine the amount of permeated phosphoric acid.

In this experiment, a PFA resin sheet was used as the phosphoric acid-resistant resin sheet 51, and its thickness was changed to 0.025 to 1.5 mm. Phosphoric acid having a concentration of 95% is used.
mm mild steel was used. However, it has been previously confirmed that the phosphoric acid absorbent can capture nearly 100% of the transmitted phosphoric acid.

FIG. 22 shows the results of this experiment. That is, it has been found that the amount of permeated phosphoric acid decreases in inverse proportion to the increase in the thickness of the phosphoric acid-resistant resin sheet. In particular, when the thickness of the phosphoric acid-resistant resin sheet was 0.10 mm or less, the amount of phosphoric acid permeated increased sharply, whereas when the thickness was 1 mm or more, there was no significant difference in the amount of phosphoric acid permeated.

However, when the thickness of the phosphoric acid-resistant resin sheet is 1
If it is not less than mm, the weight of the entire lining increases, it is difficult to fix the lining to the metal gas manifold, and the material cost increases substantially in proportion to the weight, so that the cost increases.
When the resin sheet is heated and welded, the thickness is 1 mm.
Above, the heat conduction is poor, a temperature distribution occurs in the thickness direction of the sheet, and it is difficult to uniformly melt the entire sheet. In other words, the resin sheet starts to decompose in the part near the heat source, and does not melt in the part far from the heat source, and the welding of the sheet is incomplete, so the mechanical strength of the joined part is weakened and damaged, There is a problem that gas leaks.

Further, another important function of the resin sheet for the fuel cell, that is, the electrical insulation between the cell body and the metal gas manifold increases in proportion to the thickness of the film. For example, in the case of a fuel cell, it is 2,000 volts if a dielectric breakdown voltage at least 10 times the rated voltage is required. When a PFA resin sheet is used as the phosphoric acid-resistant resin sheet, the thickness of the film is at least 0.1 mm or more because the dielectric breakdown voltage is 20,000 volts at a thickness of 1 mm.

Therefore, by setting the thickness of the resin sheet used for the lining of the gas manifold to 0.1 to 1 mm, a highly reliable gas manifold having excellent resistance to phosphoric acid permeation and reliable electric insulation can be obtained. Can be provided.

[1-1-7. Thickness of phosphoric acid-resistant resin sheet ... Part 2] When the amount of phosphoric acid discharged from the actual battery to the gas manifold was examined, it was found that the fuel inlet, outlet, air inlet, and outlet differed greatly. That is, phosphoric acid is relatively more discharged to the air-side gas manifold than the fuel-side gas manifold, and when compared at the inlet side and the outlet side, both the fuel-side gas manifold and the air-side gas manifold are closer to the outlet side than the inlet side. It turns out that there is a tendency to be more.

Further, it is necessary to change the thickness of the resin sheet in consideration of the gas distribution system. For example, in the case of the gas distribution shown in FIG. 23, the gas outlet 30b on the air outlet side emits the largest amount of phosphoric acid, followed by the gas manifold 32c on the fuel turn side and the gas manifold 32b on the fuel inlet / outlet side. , 32a in that order, and the gas manifold 30a on the air inlet side emits the least amount of phosphoric acid. Therefore, it is reasonable to change the thickness of the resin sheet in proportion to the phosphoric acid discharge amount.

For example, the air outlet side which emits a large amount of phosphoric acid>
The thickness of the resin sheet constituting the lining can be changed from 0.5 mm to 0.1 mm in the order of fuel turn side> fuel inlet / outlet side> air inlet side. As described above, by changing the thickness of the resin sheet in proportion to the phosphoric acid discharge amount, it is possible to rationally and surely prevent the permeation of phosphoric acid.

[1-1-8. Bonding allowance of phosphoric acid-resistant resin sheet] Subsequently, the present inventors examined jointing margins at four corners (corner portions) of the phosphoric acid-resistant resin sheet for lining. As a result, it was found that if the joining margin was 1 mm or less, sufficient joining strength could not be obtained, and a portion having poor reliability was generated due to variation in joining. On the other hand, the joint cost is 10m
Above m, the joint tip contacts the four corners of the metal gas manifold, and when gas flows into the gas manifold, the pressure causes the joint tip to bend and extra stress to concentrate on the joint. For example, if the shear stress is concentrated, there is a risk of damaging the sheet at the joint.

When the joining strength was examined by a peel test of two sheets, most of the joining distance was 10 mm.
It was found that a bonding distance of 10 mm was sufficient to obtain a sufficient bonding strength from the fact that it was peeled off at the portion within. From the above, it is possible to improve the strength of the lining and to provide a highly reliable gas manifold by setting the bonding margins at the four corners of the phosphate-resistant resin sheet for lining to 1 to 10 mm.

[1-1-9. Bonding method of phosphoric acid-resistant resin sheet: heating temperature] Next, the method of joining the four corners of the phosphoric acid-resistant resin sheet for lining was examined. found. In other words, in the joint portion, two resin sheets are overlapped so as to be joined together, and the overlapped ends are heated to a melting point or higher while being pressed by a plate-shaped heater to join the two resin sheets. . For example,
In the case of a PFA resin sheet, the melting point is about 310 ° C.,
Below this melting point, the molecules are not sufficiently entangled between the two sheets, resulting in incomplete bonding. On the other hand, it is considered that the molecules between the two sheets are sufficiently entangled by being heated to a temperature equal to or higher than the melting point and pressure-bonded, and are completely joined.

As described above, when joining the four corners of the phosphoric acid-resistant resin sheet for lining, the resin sheet is heated to the melting point or more and then press-bonded, so that reliable joining can be performed. And a highly reliable gas manifold can be provided.

The heating temperature at the time of joining is desirably in the range of the melting point of the PFA resin sheet to 400 ° C.
For complete joining, it is desirable that the temperature is 315 to 340 ° C. The reason is that if the heating temperature at the time of joining is 315 ° C. or less, the temperature may locally become 310 ° C. or less due to the temperature distribution, and the joining at that portion becomes insufficient. Further, it is necessary to lengthen the heating time, which is not economical. On the other hand, if the heating temperature at the time of joining is 340 ° C. or higher, the melt viscosity of the PFA resin sheet decreases, and the sheet easily flows, so that the thickness of the joining portion becomes thin and the strength of the joining portion decreases. Furthermore, if the heating temperature at the time of joining rises to 400 ° C. or higher, decomposition starts from the sheet surface, generating harmful gas or foaming, and the joining strength is extremely reduced.

As described above, the heating temperature at the time of joining the PFA resin sheet is at least in the range of the melting point to 400 ° C., and it is desirable to perform pressure bonding at the melting point plus 5 to 30 ° C. As a result, the bonding can be reliably performed in a short time, so that the strength of the lining can be improved, and a highly reliable gas manifold can be provided.

[1-1-10. Next, the heating time when bonding the phosphoric acid-resistant resin sheet for lining was examined, and it was found that heating was preferably performed for 5 seconds to 300 seconds. The reason is that if the heating time is 5 seconds or less, a large proportion of the heat is absorbed by the heater and other members, so that complete joining cannot be performed. When the heating time was 5 seconds or less, the defective rate was 50% or more. On the other hand, if the heating time is 300 seconds or more, the heating time is too long, and the joining portion is creeped and thinned, and the strength is reduced. In addition, it takes a long time for joining, which is not economical. From these facts, it is desirable that the heating time in the bonding be 5 seconds to 300 seconds, and as a result, a highly reliable gas manifold can be provided.

[1-1-11. Method of joining phosphoric acid-resistant resin sheet ... Part 1] The present inventors have studied various methods to find an optimal method for joining a corner portion of a phosphoric acid-resistant resin sheet for lining.
That is, as a method of joining by applying heat, there are an external heating method of heating from the outside and an internal heating method of heating from the inside, but here, heat welding and impulse welding are considered as methods of heating from the outside. . Ultrasonic welding and high-frequency welding were examined as a method of heating from the inside.

As a result, the method of heating from the inside failed to join the corner portions of the phosphating-resistant resin sheet for lining in both the ultrasonic weld and the high-frequency weld. This is presumably because the phosphoric acid-resistant resin is composed of rigid molecules and the sheet itself generates insufficient heat.

On the other hand, among the methods of heating from the outside, heat welding is a joining method in which the apparatus is simple and inexpensive, but after heating and joining, the hot plate is separated while hot. And the strength of the joint tended to be inferior. In addition, it has been found that the bonding strength has a large variation.

On the other hand, in the impulse welding, the capacity of the heater is reduced, and a large current is applied in a short time to heat the heater.
This is a method in which, after joining and current interruption, the compressed state is maintained until the temperature of the joint cools, and the joint is taken out after cooling. According to this impulse weld, bonding can be performed in a short time, the finished state is beautiful, and the bonding strength tends to be higher than that of heat weld. Also, there is little variation in bonding strength,
It was found that stable bonding was possible. Furthermore, since it is possible to perform bonding in a short time even if there is some temperature variation, it has been found that bonding can be performed under a relatively wide range of conditions such as heating temperature, heating time, and compression surface pressure during heating. This is presumed to be due to the fact that in the case of a fluororesin sheet such as the PFA, the melt viscosity is high and the width of the molecular weight distribution is relatively small.

As described above, by joining the corner portions of the phosphating-resistant resin sheet for lining by impulse welding, it is possible to provide a gas manifold having excellent joining strength and reliability.

[1-1-12. Method for joining phosphoric acid-resistant resin sheet ... Part 2] In impulse welding used for joining a corner portion of a phosphoric acid-resistant resin sheet for lining, a PFA film thinner than the resin sheet is put between two resin sheets to be joined. It has been found that by performing the impulse weld bonding between them, the bonding time can be shortened and the bonding strength can be further increased.

Although the clear reason is unknown, the PFA film sandwiched between the two resin sheets is thin and has a small heat capacity, so that when heated, it completely melts and acts as an adhesive. It is assumed that the resin sheets are completely joined.

Also, a thin P sandwiched between two resin sheets
As a result of examining the effect of the thickness of the FA film, it was found that the value of 0.
An increase in strength was observed for PFA films of 01-0.04 mm. Above all, the bonding strength of the 0.025 mm film increased most.

Thus, between the two resin sheets,
By sandwiching a PFA film of 0.01 to 0.04 mm, bonding strength by impulse welding can be increased, and a highly reliable phosphoric acid resistant gas manifold can be provided.

[1-1-13. Method for joining phosphoric acid-resistant resin sheet ... Part 3] Next, in the impulse weld used for joining the corners of the phosphoric acid-resistant resin sheet for lining, the compression surface pressure of the impulse heater during joining was examined. That is, PFA as a resin sheet
Using a 0.5 mm sheet, the current density flowing through the impulse heater and the pressing time were kept constant, the compression surface pressure of the impulse heater was changed to 0.025 to 0.6 MPa, and the bonding strength was examined. FIG. 24 shows the results. As is clear from the figure, the peak of the bonding strength is in the range of 0.05 to 0.2 MPa in the compression surface pressure of the impulse heater, and the bonding strength is otherwise. Has a tendency to decrease.

This is because molecules bonded between two sheets need to be entangled in order to join the sheets melted by heating.
It is presumed that a compression surface pressure of about 0.05 to 0.2 MPa is required for that purpose. In addition, the compression surface pressure is 0.0
At 5 MPa or less, the entanglement of the molecules is insufficient. On the other hand, at 0.2 MPa or more, the entanglement of the molecules is sufficient, but conversely, the compression surface pressure becomes excessive and the thickness of the joint becomes thin, It is considered that the strength decreased.

As described above, in the joining by impulse welding, the compression surface pressure of the impulse heater at the time of joining is desirably about 0.05 to 0.2 MPa, whereby the joining can be surely performed, the joining strength is high, and the reliability is high. A phosphoric acid resistant gas manifold can be provided.

[1-1-14. Method of joining phosphoric acid-resistant resin sheet ... 4] Next, the influence of the cooling temperature on the impulse weld used for joining the corners of the phosphoric acid-resistant resin sheet for lining was examined. In particular,
After the joint was cooled to a certain degree, it was examined whether or not the joint strength was highest when the joint was taken out. That is, a PFA 0.5 mm sheet was used as the resin sheet, the current density flowing through the impulse heater, the heating time, the compression surface pressure were kept constant, the cooling temperature was changed, and the bonding strength was examined. FIG. 25 shows the result. As is clear from the figure, the cooling temperature has a peak of the bonding strength in the range of 70 to 100 ° C., and other than that, the bonding strength tends to decrease. There was found.

[0091] It is considered that when the cooling temperature is 100 ° C or higher, the cooling is insufficient and the bonding strength is low because the melting and solidification are in progress. Conversely, when the temperature is 70 ° C. or lower, it is considered that the cooling time becomes longer and the compressive surface pressure is applied during that time, so that the joint part somewhat creeped and the thickness became thinner, so that the strength decreased. That is, the glass transition temperature at which the solidification state is considered to be established in the process of melting → solidification is 70 to 1
It is considered to be in the range of 00 ° C., and it is desirable to cool the glass transition temperature or lower. This makes it possible to provide a highly reliable phosphoric acid resistant gas manifold having a high bonding strength.

[1-2. Specific Example of Method of Attaching Lining to Gas Manifold] An embodiment of a method of attaching a lining to a gas manifold will be described below.
First, a cut line is formed on the phosphoric acid-resistant resin sheet with an oil-based pen in consideration of a predetermined thermal elongation suitable for the shape of the gas manifold. At this time, the four corners are cut out so as to form a box when bent (the tip angle is 138 °). The notches at the four corners may be cut off after being bent into a box shape. Subsequently, for fixing when the phosphoric acid-resistant resin sheet is attached to the gas manifold, several or more perforated small piece patches are pressure-bonded to the phosphoric acid-resistant resin sheet at several places.

Further, a phosphoric acid-resistant resin sheet is rolled in advance and pressure-bonded into a sleeve shape, and a flange cover formed by heat-forming both ends into a flange shape is pressure-bonded to a position corresponding to a supply / exhaust flange portion of the gas manifold. Attach by Next, the joining portions at the four corners of the phosphoric acid-resistant resin sheet are joined together by pressure bonding. Then, the four sides are bent in accordance with the four corners and formed into a box shape to form a lining.

Further, a male hook in which a thin stainless steel plate was previously caulked and integrated was assembled into the small piece patch which was pressure-bonded to a phosphoric acid-resistant resin sheet. On the other hand, a female hook in which a donut-shaped sheet is integrated by caulking is attached to the gas manifold at a position corresponding to the male hook by spot welding. Then, a box-shaped lining with a male hook is incorporated into the gas manifold with a female hook, and a flange cover is fitted into the flange portion of the gas manifold. And fix it.

Finally, the periphery of the lining is bent along with the flange at the periphery of the gas manifold, and the bent end of the lining and the flange of the gas manifold are simultaneously clamped and fixed at two or more places on each side.

[1-3. Actions and Effects of First Embodiment] As described above, according to the present embodiment, the entire inner surface of the gas manifold is covered with the lining formed of the phosphoric acid-resistant resin sheet, so that the metal gas manifold base material can be reduced. Phosphoric acid corrosion can be prevented. In addition, by setting a sufficient size of the folded end of the gas manifold, a sufficient electrical insulation creepage distance can be ensured, so that a gas manifold having high phosphoric acid resistance and electrical insulation can be obtained.

Further, the lining is not directly fixed to the gas manifold, but is attached loosely so that the difference in thermal expansion can be sufficiently absorbed, so that it is possible to cope with the thermal expansion of the sheet due to a temperature change at the time of starting or stopping or a load change. Further, since the lining and the gas manifold can be manufactured separately, it is possible to shorten the construction period.

[2. Second Embodiment] In the present embodiment, the gas manifold is improved in order to prevent the lining lining the metal gas manifold from being damaged. In the lining as shown in the first embodiment, it is difficult to reduce the bending radius at the bending portion, and therefore, the metal lining is bent at the engagement portion between the bending portion of the metal gas manifold and the metal lining. It is necessary to minimize the bending radius on the gas manifold side. The present inventors have repeatedly studied the bending radius on the metal gas manifold side. As a result, if the bending radius is set to 2 mm or less, the engagement between the bent portion of the lining and the bent portion of the metal gas manifold becomes smooth. It was found that the lining could be prevented from being damaged.

The metal gas manifold is formed not only by bending but also partially by welding. In particular, since the four corners and the lip connected to the four corners are formed by welding, it is necessary to flatten the lining so that the projection of the weld bead does not damage the lining. Therefore, if only the projections are finished with a grinder, the contact with the lining becomes smooth, and there is no danger of damaging the lining. Furthermore, as a method of smoothing the contact with the lining, it has been found that a high effect can be obtained by applying a heat-resistant paint to at least the inner surface of the metal gas manifold.

As described above, according to the present embodiment, the contact between the metal gas manifold and the lining can be made smooth, so that the lining can be prevented from being damaged by the metal gas manifold.

[3. Third Embodiment] This embodiment aims at confirming the soundness of the lining by monitoring the pressure between the lining and the gas manifold. In the present embodiment, FIGS. 26 and 27
As shown in the above, each gas manifold is provided with a means for monitoring the pressure between the lining and the gas manifold. That is, one side end opening of the pressure extraction tube 61 is connected to the other side end opening of the pressure measuring plug 62 which is airtightly attached to the gas manifold and has one side end opening in the space between the lining and the gas manifold. The other end of the pressure extraction tube 61 has a water cup 63.
It is configured so that it can be easily inserted into the water and easily detect bubbles.

Further, the pressure extraction tube 61 is constituted by a tube which can be visually observed inside, a U-shaped arrangement portion is provided, the U-shaped arrangement portion is filled with water, and one side end opening is opened to the atmosphere. If so, the airtightness can be maintained, and since the gasket acts as the U-shaped manometer 64, the pressure between the lining and the gas manifold can be monitored.

Further, as a method for automatically monitoring the pressure between the lining and the gas manifold, a pressure gauge 65 for transmitting a pressure signal or a flow meter 66 for transmitting a flow rate signal is used.
Is connected to the pressure extracting tube 61 and the pressure between the lining and the gas manifold and the leak flow rate are measured, so that the soundness of the lining can be constantly checked.

As described above, by monitoring the pressure between the lining and the gas manifold, the soundness of the lining can be confirmed for the following reasons. In other words, in the unlikely event that lining joints or PFA
This is because, when a leak occurs from the resin sheet itself, the internal pressure of both the air-side gas manifold and the fuel-side gas manifold becomes higher than the atmospheric pressure due to the back pressure.

[4. Fourth Embodiment] In the present embodiment, the joint between the air-side lining and the fuel-side lining is improved. That is, as shown in FIG. 28, both sides of the air-side lining 20 and the fuel-side lining 21 are configured to be longer, and both linings are joined at the end 67.

With such a configuration, the corners of the battery stack 13 exposed to the atmosphere can be covered with the ends of the air-side lining 20 and the fuel-side lining 21. Gas leakage can be prevented, and a highly safe fuel cell power generator can be obtained.

[5. Fifth Embodiment] In this embodiment, the lining is formed by blow molding. That is, as shown in FIG. 29, a phosphoric acid-resistant resin sheet 71 is placed on the surface of a mold 70 having the same shape as the gas manifold, an iron plate 72 is placed thereon, and the periphery is fixed with a clamp 73 and sealed. A connecting portion 75 for connecting to a vacuum pump 74 provided outside is provided on the bottom surface of the mold 70, and a pressure equalizing plate 76 is provided so as to cover the entire bottom surface. The pressure equalizing plate 76 is made of a porous material, and is used to uniformly evacuate the bottom surface.

Next, the mold 70 covered with the phosphoric acid-resistant resin sheet 71 is placed in a heating furnace, and while being sucked by the vacuum pump 74, the sheet is heated at a temperature between the softening point and the melting point of the phosphoric acid-resistant resin sheet. Heating / suctioning is performed until the shape becomes the same as that of the mold 70, and then quenching is performed to obtain a box-shaped lining.

Here, the reason why the heating temperature range at the time of molding the lining is not less than the softening point and not more than the melting point of the phosphate-resistant resin sheet constituting the lining will be described. In other words, below the softening point, elongation of the sheet is small and molding is difficult. On the other hand, above the melting point, it is easily affected by the temperature distribution, and if there is a part with a slightly higher temperature, the sheet in that part becomes extremely elongated, the thickness of the sheet becomes thinner, and phosphoric acid may penetrate, This is because, in a more prominent case, the sheet may be cut and cannot be formed.

As described above, when the lining is formed by blow molding, a highly reliable lining having no joint can be easily obtained.

[0111]

As described above, according to the present invention, it is possible to provide a fuel cell which is excellent in phosphoric acid resistance and electric insulation and has sufficient corrosion resistance for a long period of time. Further, it is possible to provide a fuel cell in which damage to the lining is prevented. Further, it is possible to provide a fuel cell including means for confirming the soundness of the lining. In addition, a highly reliable method of attaching a lining to a gas manifold of a fuel cell can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an air-side lining lined in a gas manifold of the present invention.

FIG. 2 is an enlarged view of a portion X of the air-side lining shown in FIG.

FIG. 3 is a PF constituting the air-side lining shown in FIG. 1;
Exploded view of A resin sheet

FIG. 4 is an enlarged view of a Y part of the PFA resin sheet for air side lining shown in FIG. 3;

FIG. 5 is a perspective view showing a folded state of the air-side lining PFA resin sheet shown in FIG. 3 at the time of heat bonding;

FIG. 6 is an enlarged view of a main part showing a folded state of the PFA resin sheet for air side lining shown in FIG. 5 at the time of heat bonding;

FIG. 7 is a cross-sectional view showing a state where the lining is attached to the gas manifold.

FIG. 8 is a view showing the amount of phosphoric acid permeated by various resin sheets.

FIG. 9 is a plan view showing the configuration of the air-side lining.

FIG. 10 is a sectional view taken along line BB of FIG. 9;

FIG. 11 is an enlarged view of a portion C in FIG. 10;

12A and 12B are diagrams showing a configuration of a fuel outlet side lining, wherein FIG. 12A is a plan view and FIG. 12B is a perspective view.

13A and 13B are diagrams showing a configuration of a flange portion of a fuel outlet side gas manifold, wherein FIG. 13A is a cross-sectional view, and FIG.

FIG. 14 is a perspective view showing a state in which a lining is lined in a divider section of the fuel-side gas manifold.

15 (A) and 15 (B) are cross-sectional perspective views showing peripheral portions of a gas manifold, and are views showing cross sections taken along line EE in FIGS. 9 and 12.

16 is a cross-sectional view showing a configuration of a lining fixing hook portion, and a cross-sectional view taken along line DD of FIGS. 9 and 12;

FIG. 17 is a plan view of FIG. 16;

FIG. 18 is a plan view of a patch attached to the lining.

FIG. 19 is a perspective view showing a state in which a patch is heated and pressed on a resin sheet.

FIGS. 20A and 20B are perspective views showing a state in which a flange cover is heat-pressed to a resin sheet;

FIG. 21 is a schematic diagram showing the configuration of a phosphoric acid permeation test apparatus for a lining PFA resin sheet.

FIG. 22 is a view showing a result of a phosphoric acid permeation test of a PFA resin sheet for lining.

FIG. 23 is a diagram showing gas distribution in a gas manifold.

FIG. 24 is a view showing the relationship between the compression surface pressure and the bonding strength of a PFA resin sheet for lining.

FIG. 25 is a view showing the relationship between the ultimate cooling temperature of the lining PFA resin sheet and the bonding strength.

FIG. 26 is a conceptual diagram showing pressure monitoring means for monitoring the pressure between the lining and the gas manifold.

FIG. 27 is a cross-sectional view showing the configuration of a pressure detection plug for detecting the pressure between the lining and the gas manifold;

FIG. 28 is a sectional view showing a state in which linings attached to adjacent gas manifolds are joined to each other;

FIG. 29 is a sectional view showing an example in which the lining is formed by blow molding.

FIG. 30 is an exploded perspective view showing the structure of a cell stack of a fuel cell.

FIG. 31 is a perspective view showing a state where a gas manifold is attached to the battery stack.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Single cell 10 ... Cell stack 13 ... Battery laminated body 15, 16 ... Gas manifold 20, 21 ... Lining 23, 24 ... Flange cover 30, 32 ... Gas manifold 31 ... Gas manifold flange 33 ... Flange 34 ... Divider 36 ... Clamp 40 ... Hook part 41 ... Male hook 43 ... Female hook 45 ... Patch 61 ... Pressure extraction tube 62 ... Pressure measurement plug 70 ... Mold 74 ... Vacuum pump 76 ... Pressure equalizing plate

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiro Konno 2-4-4 Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Toshiba ITEC Co., Ltd. Toshiba Keihin Works Co., Ltd.

Claims (36)

[Claims] Claims: 1. A lining formed by processing a phosphoric acid-resistant resin sheet according to the inner surface shape of the gas manifold is loosely attached to an inner surface of a gas manifold provided on a side surface of a cell stack constituting a fuel cell; The fuel cell according to claim 1, wherein the lining is formed in advance so as to be substantially thermal expansion during operation of the fuel cell and smaller than the inner surface of the gas manifold. 2. The phosphoric acid-resistant resin sheet constituting the lining is a PFA (tetrafluoroethylene / perfluoroalkoxyethylene copolymer) resin sheet or FE.
2. The fuel cell according to claim 1, which is a P (ethylene tetrafluoride / propylene hexafluoride copolymer) resin sheet. 3. The fuel cell according to claim 1, wherein the phosphate-resistant resin sheet constituting the lining is a PTFE (tetrafluoroethylene) resin sheet. 4. A female hook or a male hook is attached to a phosphate-resistant resin sheet constituting the lining, and a predetermined position on the inner surface of the gas manifold is provided.
2. The fuel cell according to claim 1, wherein a male hook or a female hook that engages with a hook attached to the lining is attached. 5. The method according to claim 1, wherein a perforated patch is attached to the phosphate-resistant resin sheet constituting the lining, and either a female hook or a male hook is movably attached between the sheet and the patch. Item 6. The fuel cell according to Item 4, 6. The fuel cell according to claim 1, wherein the thickness of the phosphoric acid-resistant resin sheet constituting the lining is 0.1 mm to 1 mm. 7. The fuel cell according to claim 1, wherein a joining margin of a corner portion of the phosphoric acid-resistant resin sheet constituting the lining is 1 mm to 10 mm. 8. The fuel cell according to claim 1, wherein the corner portions of the phosphoric acid-resistant resin sheet constituting the lining are joined by being heat-pressed to a temperature not lower than the melting point of the resin sheet. 9. The fuel cell according to claim 1, wherein the joint portions of the phosphate-resistant resin sheets constituting the lining are joined by impulse welding. 10. The fuel cell according to claim 9, wherein the heating temperature range at the time of joining the impulse weld is from the melting point temperature of the phosphoric acid-resistant resin sheet constituting the lining to 400 ° C. 11. The fuel cell according to claim 9, wherein the heating time at the time of joining the impulse weld is 5 seconds to 300 seconds. 12. At the time of joining the impulse weld,
It is characterized in that a PFA (tetrafluoroethylene / perfluoroalkoxyethylene copolymer) film having a thickness of 0.01 to 0.04 mm is sandwiched between the joining surfaces of the phosphoric acid-resistant resin sheets constituting the lining. The fuel cell according to claim 9. 13. The fuel cell according to claim 9, wherein the compression surface pressure at the time of joining the impulse weld is 0.05 to 0.2 MPa. 14. The cooling temperature at the time of joining of the impulse weld is set to be equal to or lower than the glass transition temperature of the phosphate-resistant resin sheet constituting the lining.
The fuel cell as described. 15. The fuel cell according to claim 1, further comprising pressure monitoring means for monitoring a pressure between the lining and the gas manifold. 16. The lining is formed in a box shape with a flange after cutting the cutouts at the four corners of the phosphoric acid-resistant resin sheet at an angle of 138 ± 3 degrees, and joining the cutouts by opposing pressure bonding. The fuel cell according to claim 1, wherein 17. The fuel cell according to claim 1, wherein a flange cover is attached to the gas supply / discharge flange of the gas manifold. 18. The fuel cell according to claim 17, wherein the flange cover is joined to a bottom surface of the lining phosphoric acid-resistant resin sheet by heat compression. 19. The fuel cell according to claim 17, wherein the flange cover is formed by pressing an opening-side end portion of the lining phosphate-resistant resin sheet formed in a ring shape. 20. The fuel cell according to claim 17, wherein the flange cover is made of a PFA (ethylene tetrafluoride / perfluoroalkoxyethylene copolymer) resin sheet. 21. The lining according to claim 1, wherein the lining is also attached to a divider part that defines an internal space formed by a fuel-side gas manifold.
The fuel cell as described. 22. An outer peripheral portion of the phosphoric acid-resistant resin sheet is bent along a flange at a peripheral portion of the gas manifold, and is clamped and fixed together with the gas manifold flange by a clamp. 2. The fuel cell according to 1. 23. The apparatus according to claim 23, wherein the thickness of the phosphoric acid-resistant resin sheet constituting the lining is changed based on the amount of phosphoric acid discharged from each gas manifold disposed on the side surface of the battery stack. Item 7. The fuel cell according to Item 1. 24. The fuel cell according to claim 1, wherein the thickness of the lining lining the air supply side gas manifold is smaller than the thickness of the lining lining the other part. 25. The fuel cell according to claim 1, wherein a heat-resistant paint is applied to at least an inner surface of the gas manifold. 26. The pressure monitoring means, wherein the other end opening of the pressure drawing tube connected to the one end opening via a pressure measuring plug provided in the gas manifold is inserted into water. The fuel cell as described. 27. A U-shaped arrangement portion is formed in a state where the other end opening of the pressure extraction tube is open to the atmosphere, and at least the U-shaped arrangement portion is filled with water. 27. The fuel cell according to claim 26. 28. The pressure monitoring means, wherein a pressure gauge is connected to the other end opening of the pressure drawing tube to which one end opening is connected via a pressure measuring plug provided in the gas manifold. Item 16. The fuel cell according to Item 15, 29. The pressure monitoring means, wherein a flow meter is connected to the other end opening of the pressure drawing tube to which one end opening is connected via a pressure measuring plug provided in the gas manifold. Item 16. The fuel cell according to Item 15, 30. A gas manifold side surface covering portion of a phosphoric acid-resistant resin sheet constituting the lining is extended and joined to a lining end of an adjacent gas manifold,
The fuel cell according to claim 1, wherein a corner portion of the cell stack is covered. 31. A phosphoric acid-resistant resin sheet is formed on an inner surface of a gas manifold provided on a side surface of a cell stack constituting a fuel cell according to the inner surface shape of the gas manifold, and the fuel cell is operated during the fuel cell operation. Almost thermal expansion at
A method of attaching a lining to a gas manifold of a fuel cell, wherein a lining configured to be smaller than the inner surface shape of the gas manifold is attached loosely. 32. The gasket according to claim 31, wherein the outer peripheral portion of the phosphoric acid-resistant resin sheet is bent along a flange at the peripheral portion of the gas manifold, and is clamped and fixed together with the gas manifold flange. How to attach lining to gas manifold of fuel cell. 33. A lining is formed by molding a phosphoric acid-resistant resin sheet in accordance with the inner surface shape of the gas manifold, and either a female hook or a male hook is attached to the phosphoric acid-resistant resin sheet constituting the lining. ,
Further, a male hook or a female hook that engages with a hook attached to the lining is attached to a predetermined position on the inner surface of the gas manifold, and the lining is attached to the gas manifold by engaging both hooks. How to attach lining to gas manifold of fuel cell. 34. An outer peripheral portion of the phosphoric acid-resistant resin sheet constituting the lining is bent along a flange portion of a peripheral portion of the gas manifold, and is clamped and fixed together with the gas manifold flange portion. Item 33
A method for attaching the lining of the fuel cell to the gas manifold. 35. The fuel cell according to claim 1, wherein the lining is formed by blow molding a phosphoric acid-resistant resin sheet into a box shape. 36. The fuel cell according to claim 35, wherein a heating temperature range during blow molding of the lining is equal to or higher than the softening point of the phosphoric acid-resistant resin sheet and equal to or lower than the melting point.