JP7012209B2 - Fuel cell stack - Google Patents

Description

The present invention relates to the structure of a polymer electrolyte fuel cell stack used in a stationary cogeneration system.

In a fuel cell, a fuel gas such as hydrogen and an oxidant gas such as air are electrochemically reacted to generate electricity and heat at the same time.

The polymer electrolyte fuel cell is composed of a cell in which an electrolyte membrane-electrode assembly (hereinafter referred to as “MEA”) is sandwiched between a pair of separators.

The MEA is provided with a pair of electrode layers on both main surfaces of a polymer electrolyte membrane (hereinafter, also referred to as “electrolyte membrane”) that selectively transports hydrogen ions. The pair of electrode layers are composed of a catalyst layer such as a noble metal formed on both sides of the electrolyte membrane and a porous and conductive gas diffusion layer formed on the catalyst layer.

The separators are arranged on both sides of the MEA to mechanically fix the MEA, and also have conductivity because the adjacent MEAs are electrically connected in series with each other.

A groove is formed on the surface of the separator in contact with the MEA, which serves as a gas flow path for supplying a reaction gas such as hydrogen or air to the electrode and carrying away the gas generated by the reaction or excess gas. A groove is formed on the surface of the separator opposite to the surface in contact with the MEA, which serves as a cooling water flow path for supplying and discharging the cooling water for recovering the heat generated by the reaction.

Many fuel cells have a laminated structure in which a large number of MEAs and separators are stacked, and are constantly pressurized and fastened. Further, a pair of current collector plates for extracting electricity generated by the reaction to the outside are arranged at both ends or in the middle of the stacking direction. Such a laminated body is called a cell stack.

The cell stack has a reaction gas manifold that penetrates the cell and supplies and discharges the reaction gas to the gas flow path of the separator, and a cooling water manifold that penetrates the cell and supplies and discharges cooling water to the cooling water flow path of the separator. There is.

The current generated in the stack is adjusted by a power conversion circuit board electrically connected to the current collector and then taken out of the fuel cell system. The current collector plate and the power conversion circuit board are connected by a harness, and the current collector plate is provided with terminals for attaching the harness.

The cell stack having the above configuration uses the heat generated by power generation to maintain the cell stack itself at a high temperature to improve the power generation efficiency. Further, for example, a fuel cell cogeneration system for home use. Then, the energy utilization rate is increased by boiling hot water with the surplus heat energy.

Further, in order to more effectively utilize the thermal energy generated by power generation, it is proposed in Patent Document 1 that the exposed outer surface of the cell stack of the polymer electrolyte fuel cell is covered with a heat insulating material.

FIG. 22 is a schematic perspective view of a state in which a part of the housing of the conventional fuel cell stack disclosed in Patent Document 1 is cut out. As shown in FIG. 22, in the conventional fuel cell stack disclosed in Patent Document 1, the cell stack (laminated body) 50 is covered with a heat insulating housing 60 made of a heat insulating plate 60a in order to maintain heat energy.

Further, at the time of manufacturing or maintenance of the fuel cell system, it may be necessary to measure the voltage of each cell in the cell stack. In that case, since an external measurement voltage is connected to each cell, it is necessary to expose a part of the cell stack. Therefore, the heat insulating material that covers the circumference of the stack needs to be made of a material and structure that can be partially removed and rolled up.

For the above reasons, elastically deformable and flexible materials are often used as the heat insulating material, and it is often difficult to hold the heat insulating material alone in the cell stack. Therefore, in order to fix the heat insulating material, it is disclosed in Patent Document 2 that a tubular cover member is provided so as to cover the periphery of the heat insulating material.

FIG. 23 is a partial cross-sectional view schematically showing how the heat insulating member is compressed and the cover member is attached in the conventional fuel cell stack disclosed in Patent Document 2. As shown in FIG. 23, the conventional fuel cell stack disclosed in Patent Document 2 has a structure in which the laminate 101 is covered with a flexible heat insulating material 105, and is covered to fix the flexible heat insulating material 105. It is pressed down by the member 106.

Japanese Patent No. 501680 Japanese Unexamined Patent Publication No. 2009-252401

As described above, the fuel cell stack is configured by stacking one or more cells having MEA and a separator, and sandwiching both ends of the laminated body with a pair of end plates. The MEA and the separator constituting the cell usually have manufacturing tolerances in the thickness direction (stacking direction) thereof.

Therefore, the fuel cell stack has a tolerance in which the tolerances are accumulated in the stacking direction of the laminated body. Due to these tolerances, it may be difficult to install a heat insulating material or a cover member made of a robust material. Reducing the accumulated tolerances is difficult from a manufacturing point of view and increases costs.

It is also known that it is used with the operation of various auxiliary machines during power generation operation, start-up operation, and stop operation. Therefore, the fuel cell stack may vibrate slightly as the auxiliary equipment is operated. At this time, if there is a gap between the end plate and the heat insulating material or the cover member made of a robust material in the parts in the stack, they may come into contact with each other and be damaged.

In addition, if there is play between the end plate of the parts in the stack and the cover member, abnormal noise and noise may be generated as the auxiliary equipment is operated. Therefore, in the fuel cell stack, it is required to sufficiently suppress or not use the rattling between the end plate and the cover member in the parts in the stack.

In Patent Document 2, in order to solve the above-mentioned problems, the cover member is fixed by using the restoring force when the flexible heat insulating material is compressed. Although the above method greatly improves the problem,
The presence of the cover member does not provide a fundamental solution, and the occurrence of the above problems cannot be prevented depending on the degree.

Also, polymer electrolyte fuel cell systems may require monitoring of individual cell voltages inside the insulation during stack activation during manufacturing and post-installation maintenance. At the time of these processes, since the external voltage measurement terminal is connected to each cell in the cell stack, it is necessary to expose the cell stack.

Therefore, it is necessary to attach / detach the heat insulating material that covers the periphery of the stack and the cover member that fixes the heat insulating material, and the presence of the cover member causes a decrease in work efficiency.

It is an object of the present invention to be made in view of the above problems of the prior art.

In order to solve the above problems, the fuel cell stack of the present invention comprises a laminated body in which a large number of substantially rectangular cells are stacked, and a pair of substantially rectangular end plates arranged at both ends of the laminated body in the stacking direction. The cell stack main body, the elastically deformable sheet-shaped heat insulating material that covers the outer peripheral surfaces of the four surfaces of the laminated body excluding the surface facing the end plate, and the heat insulating material cover the outer peripheral surface of the laminated body. A fuel cell stack comprising a pair of end faces of the cell stack body, a pair of outer peripheral surfaces facing each other, and an annular band for fastening extending around the cell stack body so as to cover the cell stack body. The end plate is located on the two surfaces not covered by the annular band so that the heat insulating material located on the two surfaces not covered by the annular band does not rise from the outer peripheral surface of the laminate. It has a covering portion that covers at least a part of the heat insulating material, and the heat insulating material is arranged on one of two surfaces in which the circumferential end of the laminated body in the heat insulating material is not covered by the annular band. The heat insulating material can be separated from the one surface by deforming the heat insulating material on the surface on which the end portion of the heat insulating material is arranged so that the heat insulating material is not covered by the covering portion. It is composed of.

With this configuration, an elastically deformable sheet-like heat insulating material covering the outer peripheral surfaces of the four surfaces excluding the surface facing the end plate in the cell laminate is fixed by the annular band and the covering portion of the end plate. The insulation separates the insulation from the surface of the laminate that needs to be exposed for stack activation or maintenance during the manufacturing process by deforming the insulation so that it is not covered by the covering. Since it is possible to (roll the heat insulating material), it is not necessary to separately use a cover member for the portion where the heat insulating material is not covered with the annular band.

As a result, the cover member does not need to be attached / detached, and the heat insulating material can be easily attached / detached from the working surface of the laminated body, so that the stack activation in the manufacturing process and the work efficiency at the time of maintenance are improved.

According to the present invention, an elastically deformable sheet-shaped heat insulating material covering the outer peripheral surfaces of four surfaces excluding the surface facing the end plate in the cell laminate is fixed by the annular band and the covering portion of the end plate. Insulation is made from the work surface of the laminate that needs to be exposed for stack activation or maintenance during the manufacturing process by deforming the insulation so that it is not covered by the covering. Since it is possible to separate (roll the heat insulating material), it is not necessary to use a separate cover member for the portion where the heat insulating material is not covered with the annular band.

As a result, it is not necessary to attach / detach the cover member, and the heat insulating material can be easily attached / detached from the working surface of the laminated body, so that the activation of the stack in the manufacturing process and the work efficiency at the time of maintenance are improved. Further, since the cover member is not required, contact damage, abnormal noise and noise of the cover member due to vibration during operation are eliminated.

A perspective view of the appearance of the fuel cell stack according to the first embodiment of the present invention when viewed from diagonally upper right with the surface where the reaction gas and the cooling water inlet / outlet are located as the front. Top view of the fuel cell stack according to the first embodiment of the present invention when viewed from above. Right side view of the fuel cell stack according to the first embodiment of the present invention when viewed from the right side with the side where the reaction gas and the cooling water inlet / outlet are located as the front. Front view of the fuel cell stack according to the first embodiment of the present invention when viewed from the front with the side where the reaction gas and the cooling water inlet / outlet are located as the front. FIG. 1 is a cross-sectional view taken along the line AA. BB line sectional view of FIG. In the fuel cell stack according to the first embodiment of the present invention, a flat surface when the upper heat insulating material is deformed so as not to be covered by the end plate rib on the right side when the upper surface heat insulating material is viewed from above. figure In the fuel cell stack according to the first embodiment of the present invention, the reaction gas and the cooling water inlet / outlet are in a state in which the upper heat insulating material is deformed so that the heat insulating material on the upper surface is not covered by the end plate rib on the right side. Right side view when viewed from the right side with the side with the front as the front In the fuel cell stack according to the first embodiment of the present invention, the reaction gas and the cooling water inlet / outlet are in a state in which the upper heat insulating material is deformed so that the heat insulating material on the upper surface is not covered by the end plate rib on the right side. Front view when viewed from the front with the side with the front as the front In the fuel cell stack according to the first embodiment of the present invention, the state in which the heat insulating material on the upper surface is rolled up and the voltage measurement terminal is connected to the laminated body is viewed from diagonally above right with the surface where the reaction gas and the cooling water inlet / outlet are located as the front. External perspective view when viewed In the fuel cell stack according to the first embodiment of the present invention, a plan view of the state in which the heat insulating material on the upper surface is rolled up is viewed from above. FIG. 11 is a sectional view taken along line CC. FIG. 11 is a sectional view taken along line DD. In the fuel cell stack according to the first embodiment of the present invention, the back edge of the heat insulating material on the upper surface is inserted between the end plate rib on the left side of the end plate on the back side (back side) and the upper surface of the laminate. Top view of the state of being A perspective view of the appearance of the fuel cell stack according to the second embodiment of the present invention when viewed from diagonally above to the right with the surface where the reaction gas and the cooling water inlet / outlet are located as the front. Schematic cross-sectional view showing a cross section when the cell stack main body and the heat insulating material of the fuel cell stack according to the second embodiment of the present invention are cut in a plane parallel to both the stacking direction and the vertical direction. In the fuel cell stack according to the second embodiment of the present invention, the state in which the heat insulating material on the upper surface is rolled up and the voltage measuring terminal is connected to the laminated body is viewed from diagonally above right with the surface where the reaction gas and the cooling water inlet / outlet are located as the front. External perspective view when viewed Schematic cross-sectional view showing a cross section when the cell stack main body and the heat insulating material of the fuel cell stack according to the third embodiment of the present invention are cut in a plane parallel to both the stacking direction and the vertical direction. Top view of the cell stack main body and the heat insulating material of the fuel cell stack according to the third embodiment of the present invention when viewed from above. Schematic cross-sectional view showing a cross section when the cell stack main body and the heat insulating material of the fuel cell stack according to the fourth embodiment of the present invention are cut in a plane parallel to both the stacking direction and the vertical direction. Top view of the cell stack main body and the heat insulating material of the fuel cell stack according to the fourth embodiment of the present invention when viewed from above. Schematic perspective view of a state in which a part of the housing of the conventional fuel cell stack disclosed in Patent Document 1 is cut out. A partial cross-sectional view schematically showing a state in which a heat insulating member is compressed and a cover member is attached in the conventional fuel cell disclosed in Patent Document 2.

The first aspect of the present invention is a cell stack main body having a laminated body in which a large number of substantially rectangular cells are laminated, and a pair of substantially rectangular end plates arranged at both ends in the stacking direction of the laminated body, and the laminated body. A pair of an elastically deformable sheet-shaped heat insulating material that covers the outer peripheral surfaces of four surfaces excluding the surface facing the end plate, and the cell stack main body whose outer peripheral surface of the laminated body is covered with the heat insulating material. A fuel cell stack comprising an end face, a pair of outer peripheral surfaces facing each other, and an annular band for fastening extending around the cell stack body so as to cover the end plate. A coating that covers at least a part of the heat insulating material located on the two surfaces not covered by the annular band so that the heat insulating material located on the two surfaces not covered by the annular band does not rise from the outer peripheral surface of the laminate. The heat insulating material has a portion, and the peripheral end portion of the laminated body in the heat insulating material is arranged on one of two surfaces not covered by the annular band, and the end portion of the heat insulating material is provided. By deforming the heat insulating material on the surface on which the heat insulating material is arranged so that the heat insulating material is not covered by the covering portion, the heat insulating material can be separated from the one surface.

With this configuration, an elastically deformable sheet-like heat insulating material covering the outer peripheral surfaces of the four surfaces excluding the surface facing the end plate in the cell laminate is fixed by the annular band and the covering portion of the end plate. The insulation separates the insulation from the surface of the laminate that needs to be exposed for stack activation or maintenance during the manufacturing process by deforming the insulation so that it is not covered by the covering. Since it is possible to (roll the heat insulating material), it is not necessary to separately use a cover member for the portion where the heat insulating material is not covered with the annular band.

As a result, the cover member does not need to be attached / detached, and the heat insulating material can be easily attached / detached from the working surface of the laminated body, so that the stack activation in the manufacturing process and the work efficiency at the time of maintenance are improved. Further, since the cover member is not required, contact damage, abnormal noise and noise of the cover member due to vibration during operation are eliminated.

In the second invention, in particular, the covering portion in the first invention is composed of at least one or more protrusions formed on the end portion.

This requires the laminate to grab the insulation in areas that are not covered by the protrusions, deform the insulation so that it is not covered by the protrusions, and expose it for stack activation or maintenance during the manufacturing process. Since the work of separating the heat insulating material from the work surface (turning the heat insulating material) can be easily performed, the activation of the stack in the manufacturing process and the work efficiency at the time of maintenance can be further improved. In addition, it is not necessary to use the material of the end plate more than necessary, so that the cost can be reduced.

In the third aspect of the present invention, in particular, the covering portion in the first aspect of the present invention is formed so as to connect the pair of end plates to each other.

As a result, the heat insulating material of the part not covered by the part connecting the pair of end plates (crosslinked part) is grasped, and the heat insulating material is deformed so as not to be covered by the crosslinked part, so that the stack in the manufacturing process can be used. Since the work of separating the heat insulating material from the work surface of the laminate (turning the heat insulating material) that needs to be exposed for activation or maintenance can be easily performed, the work efficiency at the time of stack activation and maintenance in the manufacturing process is further improved. It can be improved. In addition, since it can be suppressed across the heat insulating material, the fixing capacity can be enhanced.

In the fourth aspect of the present invention, in particular, the covering portion in the first aspect of the present invention is configured to be removable in whole or in part from the end plate.

This makes it possible to complicate the shape of the portion that covers the heat insulating material, and thus it becomes possible to adapt to fuel cell stacks having various shapes.

Hereinafter, embodiments of the fuel cell stack of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. In the following description, the surface of the fuel cell stack where the reaction gas and the cooling water inlet / outlet are located is referred to as the front surface of the fuel cell stack.

(Embodiment 1)
Hereinafter, the fuel cell stack (hereinafter, also referred to as “stack”) according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 13.

FIG. 1 is an external perspective view of the stack according to the first embodiment of the present invention. FIG. 2 is a plan view of the stack. FIG. 3 is a right side view of the stack. FIG. 4 is a front view of the stack. FIG. 5 is a cross-sectional view taken along the line AA of FIG. FIG. 6 is a cross-sectional view taken along the line BB of FIG.

FIG. 7 is a plan view of the stack in a state where the upper heat insulating material is deformed so that the upper surface heat insulating material is not covered with the right end plate rib. FIG. 8 is a right side view of the stack in a state where the heat insulating material is deformed. FIG. 9 is a front view of the stack in a state where the heat insulating material is deformed.

FIG. 10 is an external perspective view of the stack in a state where the heat insulating material on the upper surface is rolled up and the voltage measuring terminal is connected to the laminated body. FIG. 11 is a plan view of the stack in a state where the heat insulating material is rolled up. FIG. 12 is a cross-sectional view taken along the line CC of FIG. FIG. 13 is a cross-sectional view taken along the line DD of FIG. FIG. 14 is a plan view of the stack in a state where the back edge of the heat insulating material is inserted between the end plate rib on the left side of the end plate on the back side (back side) and the upper surface of the laminated body.

As shown in FIGS. 1 to 14, the stack 1 of the present embodiment includes a laminated body 2 in which a large number of substantially rectangular cells 14 are stacked in the front-rear direction, and a pair of stacked bodies 2 arranged at both ends of the laminated body 2 in the stacking direction. A substantially rectangular current collector plate 8, a pair of substantially rectangular end plates 3 arranged at both ends of the laminated body 2 and the pair of current collector plates 8 in the stacking direction, and a heat insulating material 15 covering the outer peripheral surface of the laminated body 2. The laminated body 2, the pair of current collector plates 8, and the annular band 11 surrounding the pair of end plates 3 are provided.

In the present embodiment, a stack of a laminated body 2, a pair of current collector plates 8, and a pair of end plates 3 is referred to as a cell stack main body.

Cell 14 has MEA sandwiched between a pair of separators. The MEA includes a pair of electrode layers on both main surfaces of the electrolyte membrane. The pair of electrode layers are composed of a catalyst layer such as a noble metal formed on both sides of the electrolyte membrane and a porous and conductive gas diffusion layer formed on the catalyst layer. Further, the cell 14 is arranged so that one main surface of the cell 14 is the front surface and the other main surface is the back surface.

The separators are arranged on both sides of the MEA to mechanically fix the MEA, and also have conductivity because the adjacent MEAs are electrically connected in series with each other.

A groove is formed on the surface of the separator in contact with the MEA, which serves as a gas flow path for supplying a reaction gas such as hydrogen or air to the electrode and carrying away the gas generated by the reaction or excess gas. A groove is formed on the surface of the separator opposite to the surface in contact with the MEA, which serves as a cooling water flow path for supplying and discharging the cooling water for recovering the heat generated by the reaction.

The current collector plate 8 is provided with an output terminal 8a for attaching a harness for electrically connecting the current collector plate 8 and a power conversion circuit board (not shown).

The outer peripheral surfaces of the upper surface, the bottom surface, the right side surface, and the left side surface of the laminated body 2 (and the pair of current collector plates 8) excluding the front surface and the back surface facing the end plate 3 are in the form of one elastically deformable sheet. It is covered with the heat insulating material 15. Both ends of the heat insulating material 15 in the longitudinal direction are butted against each other, and the heat insulating material 15 has a tubular shape.

One longitudinal end of the insulation 15 is located at the top of the right side of the cell stack body, and the other longitudinal end of the insulation 15 is located at the right edge of the top surface of the cell stack body. , Covers the end face of one end of the heat insulating material 15.

The front surface, the back surface, the right side surface, and the left side surface of the cell stack body whose outer peripheral surface of the laminated body 2 (and the pair of current collector plates 8) are covered with the heat insulating material 15 are a pair of fastenings extending around the cell stack body. It is covered with an annular band 11 for use.

The pair of annular bands 11 for fastening apply a fastening force that compresses the laminated body 2 (and the pair of current collector plates 8) in the stacking direction via the pair of end plates 3, and the reaction gas for power generation is applied. And the cooling water is prevented from leaking from the laminated body 2.

The pair of end plates 3 is a heat insulating material 15 that covers the upper surface and the bottom surface of the laminated body 2 so that the heat insulating material 15 located on the upper surface and the bottom surface not covered by the annular band 11 does not rise from the upper surface and the bottom surface of the laminated body 2. An end plate rib 3a as a covering portion that covers at least a part thereof is provided on the upper surface and the bottom surface, one on each side. Further, the pair of end plates 3 have one leg on the bottom surface that protrudes downward from the end plate rib 3a on the bottom surface. In addition, one or two end plate ribs 3a may be added between the left and right end plate ribs 3a.

In the heat insulating material 15, the circumferential end portion of the laminated body 2 in the heat insulating material 15 is arranged on the upper surface of the two surfaces of the upper surface and the bottom surface not covered by the annular band 11, and the end portion of the heat insulating material 15 is arranged. By deforming the heat insulating material 15 on the upper surface so that the heat insulating material 15 on the upper surface is not covered by the end plate rib 3a, the heat insulating material 15 can be separated (rolled) from the upper surface of the laminated body 2.

In the stack 1 of the present embodiment, a plurality of cells 14 which are single batteries of a polymer electrolyte fuel cell having a structure in which MEA is sandwiched between a pair of separators are stacked. Both ends of the laminated body 2 of the cell 14 in the laminated direction are sandwiched between a pair of end plates 3 via a current collector plate 8 and pressure-fastened in the laminated direction using an annular band 11. Has been done. Further, on the side surface of the laminated body 2, a flexible heat insulating material 15 having a wound structure and elastically deformable is arranged.

A reaction gas manifold 4 is formed in the stack 1, and the reaction gas is supplied from the reaction gas inlet 9 and the exhaust gas is discharged from the reaction gas outlet 10. These gases cause an electrochemical reaction in the MEA to generate electricity and heat.

Further, a cooling water manifold 5 is formed in the stack 1, and cooling water is supplied from the cooling water inlet 6 and drainage is discharged from the cooling water outlet 7. The cooling water keeps the stack 1 in a stable temperature range, and the hot water of the drainage is used separately.

The pair of end plates 3 arranged so as to sandwich the laminate 2 via the current collector plate 8 are, for example, polyphenylene sulfide (PPS), polycarbonate (PC), ultra-high molecular weight polyethylene (UHPE), polyarylate (PAR). ), Polyetherimide (PEI), polyimide (PI) and other insulating resin materials.

The elastically deformable and flexible heat insulating material 15 arranged so as to be wound around the outer peripheral surface of the laminate 2 is made of an elastically deformable and flexible material such as foamed melanin, urethane foam, polyimide foam, and polypropylene foam. ing.

In the present embodiment, at least a part of the upper surface and the bottom surface of the elastically deformable and flexible heat insulating material 15 is covered with a pair of end plate ribs 3a so that the heat insulating material 15 comes into contact with the laminate 2. It is held in and is prevented from falling off.

1 to 6 show the normal state of the stack 1. 7 to 9 show that the central portion in the front-rear direction of the right end portion (free end portion of the heat insulating material 15 on the upper surface) of the upper surface insulating material 15 is lifted, and the heat insulating material 15 on the upper surface is covered with the right end plate rib 3a. It shows a state in which the upper heat insulating material 15 is deformed so as not to be damaged. 10 to 13 show a state in which the heat insulating material 15 on the upper surface is rolled up to expose the upper surface of the laminated body 2.

When changing from the state shown in FIGS. 7 to 9 to the state shown in FIGS. 10 to 13, for example, first, the right end portion of the heat insulating material 15 on the upper surface is lifted, and then the heat insulating material 15 on the upper surface is moved to the front and rear on the right side. The end plate rib 3a is placed on the end plate rib 3a.

Next, the heat insulating material 15 on the upper surface is pulled toward and lifted so that the heat insulating material 15 on the upper surface is not covered by the end plate rib 3a on the left side of the end plate 3 on the back side (back side), and the heat insulating material 15 on the upper surface is lifted. Is placed on the left end plate rib 3a of the end plate 3 on the back side (back side), and then the heat insulating material 15 on the upper surface is placed on the left end plate rib 3a of the end plate 3 on the front side (front side). The heat insulating material 15 on the upper surface is pushed backward and lifted so as not to be covered with, so that the heat insulating material 15 on the upper surface is placed on the left end plate rib 3a of the end plate 3 on the front side (front side). Finally, the free end of the heat insulating material 15 on the upper surface is moved to the left of the left side surface of the stack 1.

In the state shown in FIGS. 10 to 13, the work at the time of activation or maintenance of the stack 1 in the manufacturing process is performed. When returning to the state shown in FIGS. 1 to 6 after the work is completed, for example, first, as shown in FIG. 14, in a state where the heat insulating material 15 on the upper surface is loosened, the inner edge of the heat insulating material 15 on the upper surface is returned. Is inserted between the left end plate rib 3a of the end plate 3 on the back side (back side) and the upper surface of the laminated body 2, and then the front edge of the heat insulating material 15 on the upper surface is the front side (front side). It is inserted between the left end plate rib 3a of the end plate 3 and the upper surface of the laminated body 2.

Next, the free end portion of the heat insulating material 15 on the upper surface is pulled to the right so that the heat insulating material 15 on the upper surface is not loosened between the left end of the heat insulating material 15 on the upper surface and the end plate rib 3a on the left side of the end plate 3. After that, the inner edge of the heat insulating material 15 on the upper surface is inserted between the end plate rib 3a on the right side of the end plate 3 on the back side (back side) and the upper surface of the laminated body 2, and then the heat insulating material on the upper surface is inserted. The front edge of 15 is inserted between the right end plate rib 3a of the end plate 3 on the front side (front side) and the upper surface of the laminated body 2.

As described above, the stack 1 of the present embodiment is a collection of a laminated body 2 in which a large number of substantially rectangular cells 14 are stacked in the front-rear direction and a pair of substantially rectangular cells arranged at both ends of the laminated body 2 in the stacking direction. A cell stack body having an electric plate 8 and a pair of substantially rectangular end plates 3 arranged at both ends of the laminated body 2 and a pair of current collecting plates 8 in the laminating direction, and a laminated body 2 (and a pair of current collectors). An elastically deformable sheet-shaped heat insulating material 15 covering the outer peripheral surfaces of the four surfaces of the upper surface, the bottom surface, the right side surface, and the left side surface excluding the front surface and the back surface facing the end plate 3 in the plate 8), and a laminated body by the heat insulating material 15. 2 (and the pair of current collectors 8) extend around the cell stack body so as to cover the pair of end faces (front and back) of the cell stack body covered with the outer peripheral surfaces, and the right side surface and the left side surface. An annular band 11 for fastening is provided.

The pair of end plates 3 are not covered with the annular band 11 so that the heat insulating material 15 located on the upper surface and the bottom surface of the laminated body 2 not covered by the annular band 11 does not rise from the upper surface and the bottom surface of the laminated body 2. It has a pair of left and right end plate ribs 3a as a covering portion that covers at least a part of the heat insulating material 15 located on the upper surface and the bottom surface.

Then, in the heat insulating material 15, the peripheral end portion of the laminated body 2 in the heat insulating material 15 is arranged on the upper surface of the two surfaces, the upper surface and the bottom surface, which are not covered by the annular band 11, and the end portion of the heat insulating material 15 is arranged. By deforming the arranged heat insulating material 15 on the upper surface so that the heat insulating material 15 on the upper surface is not covered by the end plate rib 3a, the heat insulating material 15 can be separated (rolled) from the upper surface of the laminated body 2. It has been done.

With this configuration, the elastically deformable sheet-shaped heat insulating material 15 that covers the outer peripheral surface of the laminated body 2 is fixed by the annular band 11 and the left and right end plate ribs 3a of the pair of end plates 3, and the heat insulating material 15 is fixed. Insulates from the top surface of the laminate 2 which needs to be exposed for stack activation or maintenance during the manufacturing process by deforming the insulation 15 so that the insulation 15 is not covered by the end plate ribs 3a. Since the material 15 can be separated (the heat insulating material 15 is rolled up), it is not necessary to separately use a cover member for the portion of the annular band 11 that does not cover the heat insulating material 15.

As a result, the cover member does not need to be attached / detached, and the heat insulating material 15 can be easily attached / detached from the upper surface of the laminated body 2 during activation or maintenance of the stack 1. Therefore, during activation and maintenance of the stack 1 in the manufacturing process. Work efficiency is improved.

Further, since the stack 1 of the present embodiment does not require a cover member, contact damage, abnormal noise, and noise of the cover member due to vibration during operation are eliminated.

Further, since the heat insulating material 15 is held on the upper surface and the bottom surface of the laminated body 2 by the left and right end plate ribs 3a on the upper surface and the bottom surface of the pair of end plates 3, the left and right end plates on the upper surface of the pair of end plates 3 are held. By grasping the heat insulating material 15 in the portion not covered by the ribs 3a and deforming the heat insulating material 15 so as not to be covered by the left and right end plate ribs 3a on the upper surface of the pair of end plates 3, the stack 1 in the manufacturing process Since the work of separating the heat insulating material 15 (turning the heat insulating material 15) from the work surface (upper surface) of the laminated body 2 that needs to be exposed for activation or maintenance can be easily performed, the activation of the stack 1 in the manufacturing process and the work of turning the heat insulating material 15 can be easily performed. Work efficiency during maintenance can be further improved. In addition, since it is not necessary to use the material of the end plate 3 more than necessary, the cost of the end plate 3 can be reduced.

(Embodiment 2)
Hereinafter, the stack of the second embodiment of the present invention will be described with reference to FIGS. 15 to 17. In the stack 1 of the present embodiment, the same configurations as the stack 1 of the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.

FIG. 15 is an external perspective view of the stack according to the second embodiment of the present invention. FIG. 16 is a schematic cross-sectional view showing a cross section when the cell stack main body and the heat insulating material of the same stack are cut in a plane parallel to both the stacking direction and the vertical direction. Further, FIG. 17 is an external perspective view of the stack in a state where the voltage measuring terminals are connected to the laminated body.

In the stack 1 of the present embodiment, a plurality of cells 14 which are single batteries of a polymer electrolyte fuel cell having a structure in which the MEA 12 is sandwiched between a pair of separators 13 are stacked. Both ends of the laminated body 2 of the cell 14 in the laminated direction are sandwiched between a pair of end plates 3 via a current collector plate 8 and pressure-fastened in the laminated direction using an annular band 11. Has been done. Further, on the side surface of the laminated body 2, a flexible heat insulating material 15 having a wound structure and elastically deformable is arranged.

In the stack 1 of the present embodiment, the upper surface of the pair of end plates 3 is higher than the upper surface of the heat insulating material 15 that covers the upper surface of the laminated body 2, and the upper surface of the end plate 3 on the front side (front side) is. , The front edge of the heat insulating material 15 covering the upper surface of the laminated body 2 is covered, and the upper surface of the end plate 3 on the back side (back side) covers the rear edge of the heat insulating material 15 covering the upper surface of the laminated body 2. In that respect, it is different from the stack 1 of the first embodiment.

In the present embodiment, the end plate rib 3b protruding in the front-rear direction so as to cover the front-rear edge of the heat insulating material 15 on the upper portion of the end plate 3 is located on the upper surface of the laminate 2 not covered by the annular band 11. The heat insulating material 15 is sandwiched between the upper surface of the laminated body 2 and the lower surface of the end plate rib 3b so that the heat insulating material 15 does not rise (fall off) from the upper surface of the laminated body 2. Holds.

As described above, according to the present embodiment, since the elastically deformable and flexible heat insulating material 15 is fixed by the end plate rib 3b, the cover member 16 as disclosed in Patent Document 2 is configured. No need.

Therefore, contact between the cover member 16 and other members due to vibration during operation of the fuel cell system is eliminated, and damage, abnormal noise, and noise can be completely suppressed.

Further, since the cover member 16 is not provided, the laminated body 2 can be easily exposed by sliding the end portion of the heat insulating material 15 in the direction opposite to the winding direction as shown in FIG. ..

Therefore, in an operation in which it is necessary to remove the heat insulating material 15 to expose the laminated body 2 in order to connect the voltage measuring terminal 17 to the laminated body 2, such as during activation and maintenance of the stack 1 in the manufacturing process. Work efficiency can be improved.

(Embodiment 3)
Hereinafter, the stack of the third embodiment of the present invention will be described with reference to FIGS. 18 and 19. In the stack 1 of the present embodiment, the same configurations as the stack 1 of the first embodiment or the second embodiment are designated by the same reference numerals, and duplicate description will be omitted.

FIG. 18 is a schematic cross-sectional view showing a cross section when the cell stack main body and the heat insulating material of the stack according to the third embodiment of the present invention are cut in a plane parallel to both the stacking direction and the vertical direction. FIG. 19 is a plan view of the cell stack main body and the heat insulating material of the same stack as viewed from above.

The end plate rib 3c in the stack 1 of the present embodiment extends the left and right end plate ribs 3a of the end plate 3 on the front side (front side) in the stack 1 of the first embodiment to the rear, and extends the left and right end plate ribs 3a to the rear side (back side). The left and right end plate ribs 3a of the end plate 3 on the side) are extended forward, and the back surface of the left and right end plate ribs 3a on the front side and the front surface of the left and right end plate ribs 3a on the back side are brought close to each other to form a bridge portion. It has a shape that constitutes it.

The width, number and distance between the crosslinked portions can be optimized by the restoring stress of the heat insulating material 15 which affects the shape and size of the laminated body 2, the material and the thickness of the heat insulating material 15, and the like.

According to the stack 1 of the present embodiment, the shape of the end plate rib 3c for fixing the heat insulating material 15 is such that a crosslinked portion is formed between the end plates 3, so that the heat insulating material 15 and the end plate rib 3c come into contact with each other. The surface becomes large, and the fixing capacity of the heat insulating material 15 can be further improved.

(Embodiment 4)
Hereinafter, the stack of the fourth embodiment of the present invention will be described with reference to FIGS. 20 and 21. In the stack 1 of the present embodiment, the same configurations as the stack 1 of the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.

FIG. 20 is a schematic cross-sectional view showing a cross section when the cell stack main body and the heat insulating material of the stack of the fourth embodiment of the present invention are cut in a plane parallel to both the stacking direction and the vertical direction. FIG. 21 is a plan view of the cell stack main body and the heat insulating material of the same stack as viewed from above.

The end plate component 3d in the stack 1 of the present embodiment corresponds to a structure in which the end plate rib 3a in the stack 1 of the first embodiment is detachably configured from the end plate 3.

The connection method between the end plate 3 and the end plate component 3d may be any connection method such as a tenon structure or a screw bolt structure. The shape and position of the end plate component 3d are determined by the shape and size of the laminate 2, and the restoring stress of the heat insulating material 15 that affects the material and thickness of the heat insulating material 15, and the vibration frequency during operation of the fuel cell system. It is desirable that the natural frequencies of the end plate component 3d do not match.

According to the stack 1 of the fourth embodiment of the present invention, the end plate component 3d for fixing the heat insulating material 15 is configured to be detachable from the end plate 3, and the shape of the end plate component 3d may be complicated. Therefore, it is possible to adapt to the stack 1 having various shapes.

The fuel cell stack according to the present invention does not require a cover member for fixing the heat insulating material covering the outer peripheral surface of the cell stack main body, and can improve the activation of the stack in the manufacturing process and the work efficiency at the time of maintenance. It can be suitably used for a household fuel cell system using a molecular fuel cell or the like.

1 Stack 2 Laminated body 3 End plate 3a End plate rib 3b End plate rib 3c End plate rib 3d End plate parts 4 Reaction gas manifold 5 Cooling water manifold 6 Cooling water inlet 7 Cooling water outlet 8 Current collector plate 8a Output terminal 9 Reaction gas Inlet 10 Reaction gas outlet 11 Circular band 12 MEA
13 Separator 14 Cell 15 Insulation 17 Voltage measurement terminal

Claims (4)

A cell stack main body having a laminated body in which a large number of substantially rectangular cells are laminated, and a pair of substantially rectangular end plates arranged at both ends in the stacking direction of the laminated body.
An elastically deformable sheet-shaped heat insulating material that covers the outer peripheral surfaces of the four surfaces of the laminated body excluding the surface facing the end plate.
For fastening that extends around the cell stack body so as to cover the pair of end faces of the cell stack body whose outer peripheral surface of the laminated body is covered with the heat insulating material and the pair of outer peripheral surfaces facing each other. Circumferential band and
It is a fuel cell stack equipped with
The end plate is the heat insulating material located on the two surfaces not covered with the annular band so that the heat insulating material located on the two surfaces not covered with the annular band does not rise from the outer peripheral surface of the laminate. It has a covering that covers at least part of it,
In the heat insulating material, the circumferential end portion of the laminated body of the heat insulating material is arranged on one of two surfaces not covered by the annular band, and the end portion of the heat insulating material is arranged. The fuel cell stack is configured so that the heat insulating material can be separated from the one surface by deforming the heat insulating material so that the heat insulating material is not covered by the covering portion. The fuel cell stack according to claim 1, wherein the covering portion is at least one or more protrusions formed on the end portion. The fuel cell stack according to claim 1, wherein the covering portion is formed so as to connect the pair of end plates to each other. The fuel cell stack according to claim 1, wherein the covering portion is configured to be removable in whole or in part from the end plate.

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