JPH0935737A - Solid polymer electrolyte fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid polymer electrolyte fuel cell capable of easily uniformizing temperature distribution in the stacking direction of unit fuel cells. SOLUTION: A Solid polymer electrolyte fuel cell (stack) 1 uses current collecting plates 51, 51, humidifying devices 2A, 2B, and pressure applying plates 53, 54 instead of a current collector, an electrical insulating plate, and a pressure applying plate used in the conventional cell. The current collecting plates 51, 51 and the pressure applying plates 53, 53 have through holes which communicate to an inlet side flow path 90A and an outlet side flow path 90B formed in the stack of unit cells 8. A heat medium 99 is supplied to the stack 1 from a piping connecting body 991 fixed to the through hole formed in each of the pressure applying plates 53, 54. The humidifying device 2A is constituted by stacking three unit humidifying bodies, and the humidifying device 2B is constituted by stacking two unit humidifying bodies, and an oxidizing agent gas 98 is passed through a groove 631 of the humidifying device 2A, a fuel gas is passed through a groove 631 of the humidifying device 2B, and the heat medium 99 flowing out from the flow path 90B is passed through a groove 641 of the humidifying devices 2A, 2B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid polymer electrolyte fuel cell, and makes it easy to make the temperature distribution of the fuel cells of a unit fuel cell uniform in the stacking direction of the unit fuel cells. To its improved structure.

[0002]

2. Description of the Related Art A fuel cell is a kind of power generator that generates direct current power by using hydrogen and oxygen, and as is well known, it is converted into electric energy as compared with other energy engines. High efficiency and low emission of carbon dioxide, nitrogen oxides and other air pollutants,
It is expected as a so-called clean energy source. Depending on the type of electrolyte used, this fuel cell may be a solid polymer electrolyte type, a phosphoric acid type, a molten carbonate type,
Various fuel cells such as a solid oxide fuel cell are known.

Among these fuel cells, solid polymer electrolyte fuel cells show a low electric resistivity when a polymer resin membrane having a proton (hydrogen ion) exchange group in the molecule is saturated with water. A fuel cell that utilizes the function of a proton conductive electrolyte. A polymer resin membrane having a proton exchange group in the molecule (hereinafter, may be abbreviated as a solid polymer electrolyte membrane or simply PE membrane) is a par.
Fluorine-based ion-exchange resin membranes represented by fluorosulfonic acid resin membranes (for example, Nafion membrane manufactured by DuPont, USA) are well known at this time, but in addition to these, hydrocarbon-based ion-exchange resin membranes and composite membranes are also known. A resin film or the like is used. These solid polymer electrolyte membranes (PE membranes) show an electric resistivity of 20 [Ω · cm] or less at room temperature when they are saturated with water, and both are membranes that function as a proton conductive electrolyte. is there.

First, a unit fuel cell included in a conventional solid polymer electrolyte fuel cell will be described with reference to FIG. Here, FIG. 9 is a cross-sectional view seen from the upper side, schematically showing the main part of the unit fuel cell provided in the solid polymer electrolyte fuel cell of the conventional example in an expanded state. In FIG.
Reference numeral 8 denotes a unit fuel cell (hereinafter, may be simply referred to as a unit cell) composed of the fuel cell 7 and separators 81 and 82 arranged so as to face each of both main surfaces thereof. The fuel cell 7 includes a sheet-shaped solid polymer electrolyte membrane 7C, a sheet-shaped fuel electrode film (also an anode electrode) 7A, and a sheet-shaped oxidant electrode film (also a cathode electrode) 7B. It is configured. The fuel cell 7 has a fuel gas 97 which will be described later on the fuel electrode film 7A.
Further, an oxidant gas 98 described later on the oxidant electrode film 7B
, And generate DC power by the electrochemical reaction described later. In the solid polymer electrolyte membrane 7C,
The PE film described above is used. This PE film 7C is
It has a thickness dimension of about 0.1 [mm] and an outer dimension in the plane direction larger than the outer dimension in the plane direction of the electrode films 7A and 7B. Therefore, in the peripheral portions of the electrode films 7A and 7B. Means that the exposed surface of the PE film 7C exists between the end of the PE film 7C. The outer surface of the fuel electrode film 7A is one side surface 7a of the fuel cell 7, and the outer surface of the oxidant electrode film 7B is the other side surface 7b of the fuel cell 7.

Both the fuel electrode film 7A and the oxidizer electrode film 7B are constituted by including a catalyst layer containing a catalyst active material and an electrode base material, and the both sides of the PE film 7C are formed on the catalyst layer side. It is general that they are brought into close contact with each other by hot pressing. The electrode base material supports the catalyst layer, supplies and discharges a reaction gas (hereinafter, the fuel gas and the oxidant gas may be collectively referred to as such), and has a function as a current collector. It is also a porous sheet (for example, carbon paper is used as the material used).

When the reaction gas is supplied to the fuel electrode film 7A and the oxidizer electrode film 7B, a gas phase (fuel gas) is formed at the interface between the PE layer 7C and the catalyst layer provided on each of the electrode films 7A and 7B. Or oxidant gas), liquid phase (solid polymer electrolyte),
A three-phase interface of a solid phase (a catalyst of the fuel electrode film and the oxidant electrode film) is formed, and a DC power is generated by causing an electrochemical reaction. Incidentally, in many cases, the catalyst layer is formed from a fine particulate platinum catalyst and a fluororesin having water repellency, and by forming a large number of pores in the layer, It is configured to maintain efficient diffusion of the reaction gas to the three-phase interface and form a sufficiently large area of the three-phase interface.

At the three-phase interface, the following electrochemical reaction occurs. First, on the fuel electrode film 7A side, an electrochemical reaction according to the formula (1) occurs.

[0008]

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On the side of the oxidant electrode film 7B, an electrochemical reaction according to the equation (2) occurs.

[0010]

Embedded image

That is, as a result of these electrochemical reactions,
H ⁺ ions (protons) generated in the fuel electrode film 7A
Moves in the PE film 7C toward the oxidant electrode film 7B, and the electrons (e ⁻ ) move to the oxidant electrode film 7B through a load (not shown) of the solid polymer electrolyte fuel cell. On the other hand, in the oxidant electrode film 7B, oxygen contained in the oxidant gas 98, H ⁺ ions transferred from the fuel electrode film 7A in the PE film 7C, and electrons transferred through a load device (not shown). React with each other to generate H ₂ O (steam). Thus, the solid polymer electrolyte fuel cell
It obtains hydrogen and oxygen to generate DC power, and thus H ₂ O (steam) as a by-product.

In many cases, the fuel cell 7 having the above-mentioned function has a thickness of about 1 mm or less, and in the fuel cell 7, the PE film 7C is composed of a fuel gas 97 and an oxidizer. It also serves as a sealing film for preventing mixing with the gas 98. Also,
The separator 81 and the separator 82 are used for the fuel cell 7
The supply of the reaction gas to the fuel cell 7, the discharge of the excess reaction gas from the fuel cell 7, the extraction of the DC power generated in the fuel cell 7 from the fuel cell 7, and the generation of the DC power. It plays a role of removing heat generated from the fuel cell 7 from the fuel cell 7. The side surface 81a of the separator 81 is in close contact with the side surface 7a of the fuel cell 7, and the side surface 82a of the separator 82 is 82a.
Are brought into close contact with the side surfaces 7b of the fuel battery cells 7 so that the fuel battery cells 7 are sandwiched therebetween. Both the separators 81 and 82 do not allow gas to permeate, have good thermal conductivity and good electrical conductivity, and do not pollute the generated water (for example, a carbon-based material or a metal material). Are used.).

Each of the separators 81 and 82 is provided with a groove for gas flow as a means for supplying and discharging a reaction gas to and from the fuel cell 7. That is, the separator 81 is provided on the side surface 81a side that is in contact with the side surface 7a of the fuel cell 7 with a space for allowing the fuel gas 97 to flow therethrough and discharging the excess fuel gas 97 containing unconsumed hydrogen. The concave grooves (grooves for gas flow) 811A provided and the convex partition walls 812A interposed between the grooves 811A are alternately formed. The separator 82 has a side surface 8 that contacts the side surface 7 b of the fuel cell 7.
On the 2a side, a concave groove (groove for gas flow) provided with a space for allowing the oxidant gas 98 to flow therethrough and discharging the excess oxidant gas 98 containing unconsumed oxygen 821A and convex partition walls 822A interposed between the grooves 821A are alternately formed. In addition,
The tops of the convex partition walls 812A and 822A are formed to be flush with the side surfaces 81a and 82a of the separators 81 and 82, respectively.

The separators 81 and 82 are provided with grooves for allowing the heat medium 99 to flow therethrough as a heat exchanger for removing the heat generated in the fuel cell 7 from the fuel cell 7. That is, in the separator 82, a concave groove (a groove for heat medium flow) 8 for allowing the heat medium 99 to flow on the side surface 82b side thereof.
21B is formed, and the side surface 81 of the separator 81 is also formed.
A concave groove (heat medium flow groove) 811B for allowing the heat medium 99 to flow therethrough is formed on the b side.

Further, 73 is a gas seal body made of an elastic material (for example, an O-ring) which has a function of preventing the reaction gas flowing in the gas flow passage from leaking out of the gas flow passage. It is). The gas seal body 73 is housed and mounted in concave grooves 819 and 829 formed in the peripheral portions of the respective separators 81 and 82. Further, on the side surface 81b of the separator 81 and the side surface 82b of the separator 82, concave grooves 818B and 828B are formed surrounding the grooves 811B and 821B, respectively. These concave grooves are for accommodating a seal body (for example, an O-ring) made of an elastic material for preventing the heat medium 99 from leaking out.

By the way, as is well known, the voltage generated by one fuel battery cell 7 is as low as about 1 [V] or less. For this reason, the unit cells 8 having the above-described structure are stacked in plural (often several tens to several hundreds) so that the generated voltages of the fuel cells 7 are connected in series. It is generally constructed as a laminated body of unit cells and used for practical purposes by increasing the voltage. Next, a conventional example of a solid polymer electrolyte fuel cell which is a laminated body of the unit cells will be described.

FIG. 10 is a constitutional view of a main part schematically showing a conventional solid polymer electrolyte fuel cell, in which (a) is a side view thereof and (b) is a top view thereof. , Fig. 11
FIG. 11 is a detailed sectional view of a Q portion in FIG. 10. FIG.
FIG. 12 is an explanatory diagram illustrating a heat medium flow path in the solid polymer electrolyte fuel cell shown in FIGS. 10 and 11. In addition, in FIG. 10 and FIG. 11, as for the reference numerals given in FIG. 9, only representative reference numerals are shown. In addition, in FIG. 12, as for the reference numerals given in FIGS. 9 to 11, only representative reference numerals are shown.

In FIGS. 10 to 12, reference numeral 9 denotes a unit cell 8 which is formed by stacking a plurality of unit cells 8 (in FIG. 10, the number of unit cells 8 is eight). Solid polymer electrolyte fuel cell (hereinafter,
It may be abbreviated as a stack. ). Stack 9
Are current collector plates 91, 91 made of a conductive material such as a copper material for extracting the DC power generated in the cell 8 from the stack 9 at both ends of the stacked body of the cell 8; Electric insulating plates 92, 92 made of an electric insulating material for electrically insulating the electric plate 91 from the structure, and a metal pressing plate made of a metal material such as an iron material disposed on both outer side surfaces of the electric insulating plates 92. 93 and 94 are sequentially laminated. Then, the pressing plates 93, 94
An appropriate pressing force is applied from the outer surface side by a plurality of tightening bolts 95.

In FIG. 11, 825A is a groove 821A.
Is a flow passage through which the oxidant gas 98 is communicated, and the groove 827A surrounds the opening of the flow passage 825A to the side surface 82b, and the oxidant gas 98 is communicated from this portion to the gas flow passage. This is a concave groove for accommodating a gas seal body (for example, an O-ring) 982 made of an elastic material, which has a function of preventing the gas from leaking out. As shown in FIG. 11, the current collector plate 91, the electrical insulating plate 92, and the pressure plate 93 are provided with through holes 91 at positions corresponding to the flow passages 825A.
1, 921, and a through hole 931 with a female thread for a pipe are formed respectively. Although not shown in the drawings, the current collector plate 91, the electrical insulating plate 92, and the pressure plate 93 are not shown.
A fuel gas 9 similar to the communication channel 825A communicating with A
7 through holes 911, 921
Through holes similar to the above, and through holes 931 with female threads for pipes
Through holes 932 similar to the above are respectively formed. Further, through-holes 941 and 942 similar to the through-holes 931 and 932 are formed in the pressure plate 94, respectively, and through-holes are also formed in the electrical insulating plate 92 and the current collector plate 91 adjacent to the pressure plate 94. Through-holes similar to the through-holes 921 and 911 are formed in the portions that match with 941 and 942, respectively.

As a result, when stacking a plurality of unit cells 8, the grooves 811A that all unit cells 8 have are
The gas passages for the fuel gas 97 are communicated with each other. This means that the groove 821 for the oxidizing gas 98 is
The same applies to A. Then, the fuel gas 97 is supplied to the through hole 941 on the side surface which is the outer surface of the stack 9 of the pressure plate 94, and the excess oxidant gas 98 is discharged from the through hole 942. Further, the oxidant gas 98 is supplied to the through holes 931 on the side surface which is the outer surface of the stack 9 of the pressurizing plate 93, and the surplus fuel gas 97 is discharged from the through holes 932. Then, each through hole is surrounded by the opening portion of the through hole 911 on one side surface of the current collector plate 91 and the opening portion on the one side surface side of the through hole 921 of the electric insulating plate 92. Recessed grooves 912 and 922 are formed. Then, each groove 827A, 9
A seal body 982 is attached to each of 12, 922 (see FIG. 11).

In the stack 9, when stacking a plurality of unit cells 8, the grooves 811B and 821B of all the unit cells 8 are arranged in parallel with each other with respect to the flow of the heat medium 99. The inflow section and the outflow section of the heat medium 99 are connected to each other by communicating with each other. Therefore, all the cells 8 have grooves 811B,
The inflow part of the heat medium 99 of 821B is connected continuously with respect to the flow path of the heat medium 99 to form a flow path part 90A on the inlet side of the heat medium 99. Similarly, all the grooves 811
The outflow portions of the heat medium 99 of B and 821B are continuously connected with respect to the flow path of the heat medium 99 to form a flow path portion 90B on the outlet side of the heat medium 99. Pressure plate 94 and pressure plate 94
A through hole (not shown) communicating with the flow passage portion 90A is formed in the electric insulating plate 92 and the current collector plate 91 which are adjacent to each other. In addition, the pressurizing plate 93 and the electric insulating plate 92 and the current collector plate 91 adjacent to the pressurizing plate 93 are connected to the flow passage portion 90B.
An unspecified through hole communicating with the. Among these through holes, the pipe connecting bodies 991 for the heating medium 99 are mounted in the through holes formed in the pressure plates 93 and 94, respectively.

The heat medium 99 supplied to the stack 9 via the pipe connection body 991 is, first, as shown by the dotted line in FIG.
From the end on the pressurizing plate 94 side, and passes through the flow passage portion 90A.
Is divided into a plurality of unit cells 8. Divided heat medium 99
Next, after passing through the grooves 811B and 821B of each unit cell 8 to perform heat exchange with the unit cell 8, they are sequentially joined in the flow path section 90B, and the pressure plate 93 side It flows out from the end and is discharged to the outside of the stack 9 through the pipe connection body 991.

In the case shown as the stack 9, each unit cell 8 has two grooves 811B, 82 respectively.
The flow passage portion 90A and the flow passage portion 90B are formed for each 1B. For this reason, each of the pressure plate 93 and the pressure plate 94 is provided with two pipe connectors 991. In addition, there are a plurality of grooves 8 respectively.
It is needless to say that the inlet side flow passage portion and the outlet side flow passage portion can be collectively formed into one inside the stack 9 with respect to 11B and 821B. It suffices that each of the pressure plates 93 and 94 has one pipe connection body 991.

The tightening bolts 95 are hexagonal bolts and the like mounted across the pressure plates 93 and 94, and the respective tightening bolts 95 are hexagonal nuts and the like fitted with these and provide stable pressure. The unit cells 8 are pressed in the stacking direction in cooperation with a disc spring or the like for giving. The pressure applied by the tightening bolt 95 to the unit cell 8 is generally about 5 [kg / cm ² ] per apparent surface area of the fuel cell 7.

In the stack 9 having the above-described structure, the reaction gas supplied to the fuel cell unit 7 has a gas passage groove 8 formed in each of the separators 81 and 82.
In general, 11A and 821A are arranged so that the supply side thereof is the upper side in the direction of gravity and the discharge side thereof is the lower side in the direction of gravity, as indicated by the arrow in FIG. . This is because, as described above, in the fuel cell 7, steam is generated as a by-product at the time of power generation, but due to this steam, a larger amount of steam is contained in the reaction gas on the downstream side. As a result, in the reaction gas near the discharge end, water vapor corresponding to supersaturation may be condensed and exist as water in a liquid state. By arranging the supply side of the reaction gas on the upper side in the direction of gravity and the discharge side of the reaction gas on the lower side in the direction of gravity, the condensed water is generated by gravity in the reaction gas flow channels 811A and 821A. Since it can flow down by itself, it becomes easy to remove condensed water from each unit cell 8.

Thus, the PE membrane 7C used in the fuel cell 7 is a membrane that functions as a good proton conductive electrolyte by being saturated with water as described above, and has a water content of dried. When it decreases, the electric resistance value increases, so that the power generation performance of the stack 9 decreases. In order to prevent this from occurring, the reaction gas is humidified to an appropriate humidity value, and at a temperature of 70 to 80 ° C.
It is heated to about the temperature and supplied to the stack 9.

By the way, the temperature of the PE film 7C,
The temperature of the unit cell 8 is 70 to 80 in order to smoothly evaporate the water generated in the fuel cell 7 during power generation.
It is generally used at a temperature of about [° C]. Also,
The electrochemical reaction described in the above equations (1) and (2) performed in the fuel cell 7 is an exothermic reaction. Therefore, when power is generated by the electrochemical reaction according to the formulas (1) and (2) in the fuel cell unit 7, it is unavoidable that heat having a value almost equal to the DC power value generated is generated. is there. In order to maintain the temperature of the unit cell 8 at about 70 to 80 [° C.], it is necessary to remove the heat due to this loss from the fuel cell unit 7.

The stack 9 which is still cold at the time of starting is
In order to heat to a temperature of 0 to 80 [° C] or to maintain the operating temperature at a temperature of 70 to 80 ° C,
The main role of the heat medium 99, which is, for example, city water, is to remove the amount of heat generated by the exothermic reaction from the stack 9 during the power generation operation. In the unit cell 8, the heat medium 99 adjusted to a temperature of about 70 to 80 [° C.] is used as the separator 81, 8
By passing the gas through the grooves 811B and 821B formed in No. 2, the fuel cell unit 7 is operated while being maintained at an appropriate temperature. In this case, the heat medium 99 is transferred from the pipe connector 991 mounted on the pressure plate 94 to the stack 9
To the outside of the stack 9 from the pipe connection body 991 mounted on the pressure plate 93.

As the separator, there is also known a separator having a groove 811A for allowing the fuel gas 97 to flow therethrough and a groove 821A for allowing the oxidant gas 98 to flow therethrough on the other side. ing. Furthermore,
As the unit cell, a separator not provided with a groove for allowing the heat medium 99 as the heat exchange body to flow therethrough is used, and instead, a dedicated cooling body as the heat exchange body is inserted in the stacked body of the unit cells. It is also known to do the stack. In this case, the cooling medium is generally supplied with the heat medium 99 via an appropriate pipe.

Next, a fuel cell power generator using the stack 9 will be described with reference to FIG. 13 mainly on the supply path of the reaction gas supplied to the stack 9. Here, FIG. 13 is an explanatory diagram illustrating a supply path of a reaction gas to a solid polymer electrolyte fuel cell of a fuel cell power generation device using a conventional solid polymer electrolyte fuel cell. FIG.
In FIG. 10, the same parts as those in the solid polymer electrolyte fuel cell (stack) according to the conventional example shown in FIGS. 10 to 12 are designated by the same reference numerals, and the description thereof will be omitted. In addition, in FIG. 13, about the code | symbol attached | subjected in FIG. 10-FIG. 12, only the typical code | symbol was described.

In FIG. 13, 7D is a stack 9 and
Humidifier 71 for fuel gas 97, dropper 72, condenser 73
And a humidifier 74 for the oxidant gas 98, a drip remover 75, and a condenser 76. Humidifier 7
Reference numerals 1 and 74 denote known devices that receive supply of the respective reaction gases and humidify these reaction gases, and have, for example, a container that stores water, and supply the supplied reaction gases to a pipeline. It is humidified by being discharged into this water through so-called bubbling. The drop removers 72 and 75 are known devices that remove water droplets generated by condensation of water vapor contained in the respective reaction gases by being humidified by the humidifiers 71 and 74. The drop removers 72 and 75 are
For example, a container for storing the removed water droplets, an inflow pipe attached to the side wall of the container for inflowing respective reaction gases, and an outflow pipe attached to the side wall of the container for outflowing each reaction gas are provided. Have The dropper 72 in this case,
In the container of No. 75, the outflow pipe is installed at a position higher than the inflow pipe, whereby the reaction gas flowing into the container from the inflow pipe is first made to collide with the side wall of the container, and the water droplets are attached to the side wall by colliding. The reaction gas is removed.

Fuel gas 97 discharged from the stack 9
a, in the oxidant gas 98a, as described above,
It contains water vapor generated by an electrochemical reaction and water produced by condensing the water vapor. The condensers 73 and 76 are known devices that reduce the amount of water vapor in the reaction gas 97a and 98a by condensing it and remove water in the reaction gas. The condensers 73 and 76 are, for example, a container for storing the water,
On the side wall of this container, the respective reaction gas 97a, 98a
Of the reaction gas 97a, 9
It has an outflow pipe through which 8a flows out and a water cooling pipe. In this case, first, the reaction gases 97a and 98a flowing through the inflow pipe and discharged into the container are cooled by the water cooling pipe. The water vapor contained in the reaction gas is condensed in an amount according to the degree of decrease in the temperature of the reaction gas. The water generated by this condensation and the water originally contained in the reaction gas are removed from the reaction gas and stored in the container. The above-mentioned droppers 72, 75 and condensers 73, 76 are provided with drainage pipes including drain valves for discharging the water stored in the containers.

Further, in the fuel cell power generator 7, generally, for example, a metal pipe made of stainless steel is used as a pipe through which the reaction gas containing the reaction gases 97a and 98a flows. Then, in order to prevent the temperature of the fuel gas 97 and the oxidant gas 98 from decreasing on the outer surface of the pipe through which the fuel gas 97 and the oxidant gas 98 using this metal tube are passed, a heat insulating layer (not shown) is provided. In general, a layer of an electric heating element (not shown) such as a ribbon heater is formed in addition to the formation of the heat insulating layer. As a result, the temperatures of the fuel gas 97 and the oxidant gas 98 are lowered,
Care is taken to prevent water droplets from being contained in the reaction gas supplied to the stack 9.

Next, conventional examples of different solid polymer electrolyte fuel cells will be described. 14A and 14B are configuration diagrams of a main part schematically showing a different conventional solid polymer electrolyte fuel cell, wherein FIG. 14A is a side view thereof, and FIG. 14B is a top view thereof. FIG. 15 is an explanatory view for explaining the flow path of the heat medium in the solid polymer electrolyte fuel cell shown in FIG. 14, and FIG. 16 is a diagram of a unit humidifier included in the humidifier shown in FIG. It is the longitudinal cross-sectional view which showed typically the state which expanded the part. 14 to 16, the same parts as those of the solid polymer electrolyte fuel cell according to the conventional example shown in FIGS. 9 to 12 are designated by the same reference numerals, and the description thereof will be omitted. FIG.
In FIG. 4, as for the reference numerals given in FIGS. 9 to 12, only representative reference numerals are shown. In addition, in FIG.
About the reference numerals assigned in FIGS. 12 and 14, only representative reference numerals are shown.

14 to 16, 9A is the same as in FIG.
The solid polymer electrolyte fuel cell in which the use of the electric insulating plate 92 on the pressurizing plate 93 side is stopped and the humidifier 6A is additionally provided at that portion in the stack 9 according to the conventional example shown in FIG. (Stack). The humidifier 6A is configured by stacking a plurality of unit humidifiers 6 (in FIG. 14, the number of unit humidifiers 6 is five). The pressure plate 93 and the current collector plate are provided. It is inserted into the stack 9A as shown in FIG.

However, the pressure plate 93 of the stack 9A,
At 94, as shown in FIG. 14, the through hole 931 with the female thread for a pipe is formed and the through hole 9 is formed.
The positions of 32, the through holes 941, and the through holes 942 and the reaction gas flowing through these parts are partially different from those of the stack 9 shown in FIGS. That is, in the case of the stack 9A, the pressure plate 93 has a through hole 931.
Indicates that the vertical position is symmetrical with respect to the position in the case of the stack 9, and the through hole 932 has a horizontal position symmetrical with respect to the position in the case of the stack 9. Has been formed. Further, in the pressurizing plate 94, the through hole 941 is symmetrical in position in the vertical direction with respect to the position in the stack 9, and the through hole 942 is horizontal in position in the stack 9. They are formed at positions symmetrical to each other. Then, the fuel gas 97 passes through the through hole 93.
2 flows in and flows out from the through hole 941.

Each unit humidifier 6 provided in the humidifier 6A includes a sheet-shaped water permeable membrane 61, support plates 62 and 62 for sandwiching the water permeable membrane 61 from both sides, and outer side surfaces of the support plates 62 and 62. Separators 63 and 64 arranged in the respective
And gas seals 65, 65. As the water permeable membrane 61, a polymer resin membrane (solid polymer electrolyte membrane) having a proton exchange group in the molecule, which is also used for the solid polymer electrolyte membrane 7C, is used. The solid polymer electrolyte membrane has not only the above-described property of functioning as a proton conductive electrolyte but also the property of allowing water to move through the film. The unit humidifier 6 utilizes this property of the solid polymer electrolyte membrane.

A porous sheet material is used for the support plate 62 so that reaction gas and water can easily pass therethrough. For example, the sheet material also serves as an electrode base material for the electrode films 7A and 7B. The used carbon paper is used. Then, each of the support plates 62 has an outer dimension in the plane direction smaller than the outer dimension in the plane direction of the water permeable membrane 61, and the peripheral portions of both the support plates 62 have the outer dimensions of the water permeable membrane 61. The exposed surface of the water permeable membrane 61 exists between the end portion. The structure of this portion is the same as that of the fuel electrode film 7A and the oxidant electrode film 7B with respect to the PE film 7C in the fuel cell 7.

The separators 63 and 64 can be made of an appropriate electric insulating material, metal material, or the like. In this case, a heat-resistant hard vinyl chloride resin material is used. Since the separators 63 and 64 are made of a hard vinyl chloride resin material which is an electric insulating material, the electric insulating plate 92 can be unnecessary in the portion where the unit humidifier 6 is mounted. A concave groove 631 that allows the fuel gas 97 or the oxidant gas 98 to flow therethrough is formed on the side surface of the separator 63 facing the support plate 62. A concave groove 641 is formed to allow the medium 99 or water to flow therethrough.
Grooves 631, 641 are formed in the peripheral portions of the separators 63, 64.
Are formed so as to surround the groove with concave grooves 632 and 642. In the grooves 632 and 642, a gas seal body made of an elastic material (for example, a function of preventing the reaction gas or the heat medium 99 flowing in the grooves 631 and 641 from leaking out of the passage). , O-ring.) 65 is attached.

In the separator 63, both ends of the groove 631 are connected in parallel with each other with respect to the flow passage of the reaction gas, and through holes (not shown) serving as the inlet and the outlet of the reaction gas are formed. . In the separator 63, a through hole (not shown) that is not in communication with the groove 631 is formed in a portion that is symmetrical with the both through holes. Further, in the separator 63, a through hole (not shown) is formed at a portion facing a through hole communicating with a groove 641 described later formed in the separator 64. In addition, the separator 6
In FIG. 4, both end portions of the groove 641 are appropriately connected in parallel with each other with respect to the flow path of the heat medium 99 and the like, and further, through holes (not shown) serving as an inlet portion and an outlet portion of the heat medium 99. Are formed. Further, the separator 64 includes
A through hole (not shown) is formed in each of the portions facing the through hole communicating with the groove 631 formed in the separator 63 and the through hole not communicating with the groove 631. .

Thus, in this case, the outer dimensions of the unit humidifier 6 are set to be the same as the outer dimensions of the fuel cell unit 7. Further, the through holes formed in the unit humidifying body 6 are the through holes 931, 932, 941, 942 formed in the pressure plates 93, 94 and the pipe connecting body 9.
It is formed at a position corresponding to each of the through holes (not shown) for mounting 91.

The unit humidifier 6 having the above structure is incorporated in the stack 9A by appropriately matching the through holes formed in the separators 63 and 64 with each other. For two of the five unit humidifiers 6 provided, the groove 631
One of the through holes communicating with the pressure plate 9
3 is incorporated so as to communicate with the through hole 932. Also, regarding the remaining three unit humidifiers 6,
One of the through holes communicating with the groove 631 is
It is incorporated so as to communicate with a through hole 931 formed in the pressure plate 93.

In this way, the heat medium 99 flowing through the laminated body of the unit cells 8 flows into the groove 641 of the separator 64 of each unit humidifier 6. Here, an outline of a flow path in the stack 9A of the heat medium 99 supplied to the stack 9A is shown in FIG.
This will be described with reference to FIG. Heat medium 99 supplied to the stack 9A
First, as shown by the dotted line in FIG. 15 for a typical part, first, it flows into the flow passage portion 90A from the end portion on the pressure plate 94 side, and performs heat exchange with the plurality of unit cells 8. Then, it flows out from the end of the flow passage portion 90B on the pressure plate 93 side, and then flows into the groove 641 of the humidifier 6. Then, in the groove 631 of the separator 63 of the unit humidifying body 6, the fuel gas 97 of the two unit humidifying bodies 6 is 3
The oxidant gas 98 flows through the individual unit humidifiers 6. These reaction gases flowing in the groove 631 are humidified by the heat medium 99 (for example, city water) moving through the water permeable membrane 61.

The stack 9A has the above-mentioned structure, and the humidifier 6A used for humidifying the reaction gas is the stack 9A.
Since it is built in A, the pipe for connecting between the humidifier and the stack, which is required in the fuel cell power generator 7D using the stack 9 described above, becomes unnecessary. At the same time, the water vapor contained in the reaction gas humidified by the humidifier does not condense before the reaction gas flows into the stack. For this, stack 9
In the fuel cell power generator using A, the dropper 72, 75 required in the fuel cell power generator 7D using the stack 9 becomes unnecessary, and the stack 9 of the reaction gas
This has the feature that the configuration of the supply system for A can be simplified compared to the case of the fuel cell power generator 7D.

When the humidifier 6A is provided in the stack in which a dedicated cooling body is inserted in the stack of unit cells, the temperature is raised by passing the humidifier 6A through the dedicated cooling body. The heat medium 99 is supplied to the humidifier 6A.

[0046]

In the solid polymer electrolyte fuel cell (stack) according to the above-mentioned conventional technique, for example, in the above-mentioned stack 9, the fuel cells 7 and the like are separated by the heat medium 99 through the separator or the like. By being cooled and kept at an appropriate temperature for the operation of the stack, the function of DC power generation is sufficiently exerted, and in addition to the above-described operation of the stack 9, the above-described stack 9A has a configuration of a reaction gas supply system. Can be simplified. However, the following problems still remain. That is,
(1) In the stacks 9 and 9A according to the conventional technique, the distribution of the temperature of the fuel cell 7 of each unit cell 8 in the stacking direction of the unit cells 8 is high in the central portion of the stacking direction, and the stacking direction is also high. There is a fact that it is low at both ends of. In the fuel cell 7 having a high temperature because the temperature distribution in the cell stacking direction is not uniform, the PE film 7C used in the fuel cell 7 is dried because water evaporation is promoted. On the other hand, in the fuel cell 7 having a low temperature due to the non-uniform temperature distribution in the cell stacking direction, the evaporation amount of water from the fuel electrode 7A and the oxidant electrode 7B is reduced, The degree of condensation of water on the surface increases.

The electrical resistivity value of the dried PE film 7C increases due to the peculiar properties of the PE film described above. P
When the electric resistivity value of the E film increases, as a result, the electric resistance value of the PE film increases, so that the Joule loss in the fuel cell unit 7 increases and its power generation efficiency decreases. Further, in the fuel electrode 7A and the oxidizer electrode 7B whose surfaces are covered with water, the water is impregnated in the electrodes 7A and 7B to prevent the reaction gas from diffusing in the electrodes 7A and 7B, thereby generating power. Will be reduced.

The cause of the non-uniformity of the temperature distribution in the stacking direction of the unit cells, which causes the deterioration of the performance of these stacks, is as follows. The metal collector plate 91 and the pressure plates 93 and 94, which are good conductors of heat, are mounted.
The presence of these good thermal conductors increases the amount of heat dissipated from this portion, so that the temperature of the fuel cells 7 at both ends of the stacks 9 and 9A lowers. The second cause is the temperature of the heat medium 99 flowing through the pressure plate 94 and the current collector plate 91 adjacent to the pressure plate 94, and the pressure plate 93.
And the temperature of the heat medium 99 flowing through the current collector plate 91 adjacent to the pressure plate 93 is different. That is, the heat medium 99 flowing through the pressurizing plate 94 and the like is the heat medium 9 that has not yet been heated before the heat is removed from the stacked body of the unit cells 8.
Therefore, the temperature of the pressure plate 94 and the like is lower than the temperature of the pressure plate 93 and the like. (2) In the stack 9A according to the conventional technique, the humidifier 6A is attached to the pressurizing plate 93 side, and during the power generation operation of the stack 9A, the unit humidifier 6 included in the humidifier 6A is The heating medium 99, which has flowed through the stacked body of the batteries 8 and has been heated, flows therethrough.
For this reason, the end of the laminated body on the pressure plate 93 side is almost shielded from the outside by the humidifier 6A in terms of its heat conduction condition, and its temperature value is in the stacking direction of the unit cells 8. The temperature value in the central portion is hardly reduced. This means that the difference between the temperature of the end portion of the laminated body on the pressure plate 93 side and the temperature of the end portion of the laminated body on the pressure plate 94 side is larger than that due to the cause of the above item (1). Therefore, as a result, the temperature distribution is as illustrated by the dotted line in FIG. 4 described later.
Due to such a temperature distribution, the power generation performance of the stack 9A is deteriorated, as described in the item (1).

The present invention has been made in view of the above-mentioned problems of the prior art, and an object thereof is to provide a solid polymer electrolyte fuel cell in which the temperature distribution in the stacking direction of unit fuel cells can be easily made uniform. To provide.

[0050]

SUMMARY OF THE INVENTION In the present invention, the aforementioned objects are as follows: 1) a plurality of unit fuel cells, and a plurality of heat exchangers through which a heat medium for removing heat generated in the unit fuel cells flows. And a laminated body in which are laminated, and arranged at both ends of the laminated body,
Each unit fuel cell was provided with a pressure plate for applying a pressing force in the stacking direction, and the unit fuel cell was joined to the electrolyte membrane of a sheet-like solid polymer electrolyte material and both main surfaces thereof. A fuel cell having a fuel electrode film and an oxidant electrode film, which is supplied with a fuel gas and an oxidant gas to generate direct-current power, and is arranged to face each of both main surfaces of the fuel cell. The heat exchange body has a separator formed with a groove for allowing a fuel gas or an oxidant gas supplied to the fuel cell to flow therethrough on a surface facing the fuel cell, In the solid polymer electrolyte fuel cell, which has a through-flow passage and a heat-medium inlet / outlet portion related to this through-passage, the inlet / outlet portions of a plurality of heat exchangers are , Each heat exchanger has The above-mentioned flow passages are connected so as to be parallel to each other so as to be parallel to the flow of the heat medium, and form a flow passage portion on the inlet side and a flow passage portion on the outlet side, respectively. Is made to flow from each of both ends of the above-mentioned inlet-side flow passage portion, and is made to flow out from each of both end portions of the above-mentioned outlet-side flow passage portion, or 2) A laminate in which a plurality of unit fuel cells and a plurality of heat exchangers through which a heat medium for removing heat generated in the unit fuel cells flows are laminated, and arranged at both ends of the laminate.
Each unit fuel cell was provided with a pressure plate for applying a pressing force in the stacking direction, and the unit fuel cell was joined to the electrolyte membrane of a sheet-like solid polymer electrolyte material and both main surfaces thereof. A fuel cell having a fuel electrode film and an oxidant electrode film, which is supplied with a fuel gas and an oxidant gas to generate direct-current power, and is arranged to face each of both main surfaces of the fuel cell. The heat exchange body has a separator formed with a groove for allowing a fuel gas or an oxidant gas supplied to the fuel cell to flow therethrough on a surface facing the fuel cell, It has a flow passage that is made to flow and an inlet / outlet portion of the heat medium related to the flow passage,
A solid polymer electrolyte fuel cell, comprising a humidifier interposed between the laminate and the pressure plate and humidifying the fuel gas and the oxidant gas using heated water, or 3) In the means described in the item 2, the inlet part and the outlet part of a plurality of heat exchange elements are arranged such that the flow passages of each heat exchange element are parallel with respect to the flow of the heat medium. So that they are connected to each other so as to form an inlet-side passage and an outlet-side passage, respectively, and the heat medium is at both ends of the inlet-side passage. The heated water supplied from each of the both ends of the above-mentioned outlet-side flow passage portion and supplied to each humidifier has the above-mentioned outlet-side flow passage. The heat medium flowing out from both ends of the section is used for each 4) In the means described in 2) above, the heated water supplied to each humidifier is heated for humidification supplied from the outside of the solid polymer electrolyte fuel cell. It is achieved by using water as the composition.

[0051]

According to the present invention, in the solid polymer electrolyte fuel cell, (1) the inlet / outlet portions of the plurality of heat exchange elements have the above-mentioned passages of the respective heat exchange elements. The heating medium is connected in parallel with each other so as to be parallel with respect to the flow of the heat medium, and forms a flow passage portion on the inlet side and a flow passage portion on the outlet side, respectively. Inflow from both ends of the through-flow passage part of each of the above, and by flowing out from each of both ends of the above-mentioned outlet-side through-flow passage part, to both ends of the stack of unit cells. The temperature conditions of the heat medium flowing through the arranged pressure plate or the like can be made equal at each end. As a result, the heat medium can heat the end portion of the stack of the single cells under the same conditions.

(2) A plurality of heat exchangers provided with a humidifier interposed between the laminated body and the pressure plate and humidifying the fuel gas and the oxidant gas using heated water. The inlet part and the outlet part of each of the heat exchangers are connected to each other so that the flow passages of the respective heat exchangers are parallel to each other with respect to the flow of the heat medium. An outlet side flow passage part is formed, and the heat medium is introduced from both ends of the inlet side flow passage part, and both ends of the outlet side flow passage part are formed. For the heated water that is discharged from each of the above, and is supplied to each of the above humidifiers, for example, the heat medium that has flowed out from both ends of the above-mentioned outlet side flow passage portion is used respectively. With such a configuration, the insertions inserted at both ends of the unit cell stack are performed. The vessel, heating the heat medium by flowing through the stack in a single cell, will be supplied in the same conditions. As a result, the temperature of each humidifier becomes equal. As a result, both ends of the unit cell stack are substantially shielded from the outside by their respective humidifiers with respect to their heat conduction conditions.

(3) In the above item (2), the heated water supplied to each of the humidifiers is heated for humidification supplied from the outside of the solid polymer electrolyte fuel cell. By using water as the configuration, the temperature of each humidifier becomes approximately equal to the temperature of the humidifying water. As a result, both ends of the unit cell stack are substantially shielded from the outside by their respective humidifiers with respect to their heat conduction conditions. In addition to this, by controlling the temperature value of the water for humidification, it is possible to artificially set the humidity of the reaction gas to the optimum value.

[0054]

Embodiments of the present invention will be described in detail below with reference to the drawings. Example 1; FIG. 5 is a configuration diagram of a main part schematically showing a solid polymer electrolyte fuel cell according to an example of the present invention corresponding to claim 1, and (a) is a side view thereof. , (B)
Is a top view thereof. FIG. 6 is an explanatory diagram for explaining the flow path of the heat medium in the solid polymer electrolyte fuel cell shown in FIG. 5 and 6, the same parts as those in the solid polymer electrolyte fuel cell according to the conventional example shown in FIGS. 9 to 12 are designated by the same reference numerals, and the description thereof will be omitted. Note that FIG.
Among the reference numerals given in FIGS. 9 to 12, only representative reference numerals are shown. In addition, in FIG. 6, as for the reference numerals given in FIGS. 5 and 9 to 12, only representative reference numerals are shown.

In FIGS. 5 and 6, reference numeral 5 designates FIGS.
In the solid polymer electrolyte fuel cell 9 according to the conventional example shown in FIG. 1, instead of the current collectors 91, the electric insulation plates 92 and the pressure plates 93, 94, the current collectors 51, 51 and the electric insulations are respectively replaced. It is a solid polymer electrolyte fuel cell (stack) using plates 52, 52 and pressure plates 53, 54. Each current collecting plate 51, each electric insulating plate 52 and pressure plate 5
Each of the reference numerals 3 and 54 has a through hole (not shown) communicating with the inlet-side flow passage portion 90A formed in the stack of unit cells 8 and an outlet side formed in the stack of unit cells 8. A through hole (not shown) communicating with the flow passage portion 90B is formed in each. That is, the pressurizing plates 53 and 54 will be described. Through holes 931 and 932 for reaction gas are provided.
941 and 942 are the stacks 9 according to the above-mentioned conventional example.
Are formed at positions equivalent to the through holes 931, 932, 941 and 942 for reaction gas formed in the pressure plates 93 and 94 of the. However, in the case of this example, the number of through holes for the heat medium 99 formed in the pressure plates 53 and 54 is
It is twice as large as that of the pressure plates 93 and 94 of the stack 9. Piping connectors 991 for the heat medium 99 are mounted in the through holes for the heat medium 99 formed in the pressure plates 53 and 54, respectively. Each of the pipe connection bodies 991 communicated with the flow passage portion 90A of the pipe connection bodies 991.
The heat medium 99 flows into the stack 5 from the
Is attached to the pressurizing plates 53 and 54, and moreover, the flow passage portion 9
Each of the pipe connection bodies 991 communicated with 0B will flow out of the stack 5.

Since the embodiment shown in FIGS. 5 and 6 has the above-mentioned structure, the heat medium 99 flowing through the inside of the stack 5 is first of all, as shown by the dotted line in FIG. Grooves 811B, 82 which flow into the flow passage portion 90A from both ends thereof and which the plurality of unit cells 8 have respectively.
Divided into 1B. After exchanging heat with each unit cell 8, the heat medium 99 discharged from the grooves 811B, 821B
Flows out from each of both ends of the passage 90B.
Since the heat medium 99 flows through the stack 5 as described above, the temperature conditions of the heat medium 99 flowing through the pressure plates 53, 54 and the like can be made equal at each end of the stack 5. It will be. As a result, the heat medium 99 can heat the current collector plates 51, the electric insulating plates 52, and the pressure plates 53 and 54, which are the end portions of the stack 5, substantially evenly. As a result, each unit cell 8
It is possible to make the temperature distribution of the fuel cells 7 of the cells uniform in the stacking direction of the unit cells 8.

Further, in the above-mentioned configuration of the stack 5,
The flow rates of the heat medium 99 at the inflow portion and the outflow portion of the heat medium 99 with respect to the flow passage portions 90A and 90B,
Since the flow velocity becomes 1/2 of that in the case of the stacks 9 and 9A of the conventional example, the pressure drop value of the heat medium 99 flowing in the flow passage portion 90A and the flow passage portion 90B is reduced, The pressure values of the heating medium 99 in both the flow passage portions 90A and 90B can be made substantially the same in the respective flow passage portions. As a result, the heat medium 99 can flow through the grooves 811B and 821B of each unit cell 8 substantially evenly, and the heat exchange performed with each unit cell 8 is almost the same condition. be able to. Further, in this configuration, if the flow velocity value of the heat medium 99 in the flow passage portions 90A and 90B is set to the same value as in the case of the stacks 9 and 9A of the conventional example, the flow passage areas of the flow passage portions 90A and 90B. The value is the stack 9 of the conventional example,
It can be halved compared to the case of 9 A, and the area of each unit cell 8 and hence the outer shape of the stack 5 can be reduced in size.

Example 2 FIG. 1 is a side view of the essential part schematically showing a solid polymer electrolyte fuel cell according to an example of the present invention corresponding to claims 2 and 3, and FIG. , Figure 1
FIG. 3 is a top view of essential parts schematically showing the solid polymer electrolyte fuel cell shown in FIG. FIG. 3 is an explanatory diagram for explaining a flow path of a heat medium in the solid polymer electrolyte fuel cell shown in FIGS. 1 and 2. 1 to 3, a solid polymer electrolyte fuel cell according to an embodiment of the present invention corresponding to claim 1 shown in FIGS. 5 and 6, and FIGS. 9 to 12 and 14 to 16 are shown. The same parts as those in the solid polymer electrolyte fuel cell according to the conventional example shown are designated by the same reference numerals and the description thereof will be omitted. In addition, in FIG. 1 and FIG. 2, FIG.
2, About the code | symbol attached | subjected in FIGS. 14-16, only the typical code | symbol was described. In addition, in FIG. 3, as for the reference numerals given in FIGS. 1, 2, 5, 9 to 12, and 14 to 16, only representative reference numerals are shown.

1 to 3, reference numeral 1 denotes the solid polymer electrolyte fuel cell 5 according to the present invention shown in FIGS. 5 and 6, in which use of each electric insulating plate 52 is stopped and the portion is humidified. It is a solid polymer electrolyte fuel cell (stack) additionally provided with a container 2A and a humidifier 2B. However, in the pressurizing plates 53 and 54 of the stack 1, as shown in FIG. 1, the through holes 931 with the female threads for pipes formed, the through holes 932, the through holes 941,
Further, the positions of the through holes 942 and the reaction gas flowing therethrough are partially different from those of the stack 5 shown in FIGS. 5 and 6. That is, the pressure plate 5 included in the stack 1
In the case of 3, 54, the positions where the through holes 931, 932, 941 and 942 are formed are the through holes 931 for the reaction gas formed in the pressure plates 93, 94 of the stack 9A according to the conventional example described above. It is formed at the same position as 932, 941 and 942.

Each humidifier 2 provided in the stack 1
A and 2B are plural (in FIGS. 1 to 3, the humidifier 2A has three unit humidifiers 6 and the humidifier 2B has two unit humidifiers 6). The unit humidifiers 6) are laminated. Among these, the humidifier 2A includes the humidifier 2 between the pressure plate 53 and the current collector plate 51.
B is inserted between the pressure plate 54 and the current collector plate 51 as shown in the figure and incorporated in the stack 1. that time,
One of the through holes communicating with the groove 631 of the humidifier 2A is incorporated so as to communicate with the through hole 931 formed in the pressure plate 53, and communicates with the groove 631 of the humidifier 2B. One of the through holes that is formed is incorporated so as to communicate with the through hole 941 formed in the pressure plate 54. In addition, the heating medium 99 flowing through the laminated body of the unit cells 8 into the groove 641 of the separator 64 included in the unit humidifiers 6 included in both the humidifiers 2A and 2B and flowing out from each of both ends of the flow passage portion 90B. Are installed so that they can flow through each.

1 to 3, the fuel gas 97 and the oxidant gas 98 supplied to the stack 1 flow through the humidifier 2B and the humidifier 2A, respectively. Then, it will flow into the unit cell 8. Further, the heat medium 99 supplied to the stack 1 first flows into the flow passage portion 90A from both ends thereof, as shown by the dotted line in FIG. After exchanging heat between them, they flow out from both ends of the passage 90B and are supplied to the humidifiers 2A and 2B. Heat medium 9
9 flows through the stack 1 as described above,
Heat medium 9 flowing through each of the humidifier 2A and the humidifier 2B
The temperature conditions of 9 are almost the same, and it is possible to heat both the humidifiers 2A and 2B to almost the same temperature and further to substantially the same temperature as the temperature of the unit cell 8 included in the stack 1.

As a result, both end portions of the laminated body of the unit cells 8 included in the stack 1 are almost shielded from the outside by the respective humidifiers 2A and 2B with respect to the heat conduction conditions, and as a result, the respective humidifiers 2A and 2B respectively cut off the heat. The distribution of the temperatures of the fuel cells 7 of the unit cells 8 in the stacking direction of the unit cells 8 can be made uniform as illustrated in FIG. Here, FIG. 4 is an example of measuring the temperature distribution of the central portion in the area direction of the fuel cell unit of each unit fuel cell in the unit fuel cell stacking direction of the solid polymer electrolyte fuel cell according to the present invention according to Example 2. 6 is a graph showing in comparison with the case of the conventional example. In FIG. 4, the solid line shows the case of the stack 1, and the dotted line shows the stack 9A of the conventional example.
Shows the case. According to FIG. 4, the temperature difference value between the center and the end of the stack is 5 in the case of stack 9A.
[° C], but 0.5 for stack 1
It has been improved to below [° C]. From the above, it is apparent that in the stack 1, the temperature distribution of the fuel cells 7 of the individual unit cells 8 can be made uniform in the stacking direction of the unit cells 8.

Even in the case of stack 1, stack 5
In the same manner as in the above case, since the heat medium 99 flows in and out from both ends of the flow passage portion 90A and the flow passage portion 90B, respectively, it is possible to reduce the outer shape thereof. Example 2
In the above description, the unit cell 8 included in the stack 1 has the separators 81 and 82 provided with the grooves 811B and 821B that allow the heat medium 99 to flow therethrough, but the present invention is not limited to this. Instead of this, for example, a dedicated cooling body that allows the heat medium 99 to flow therethrough may be used for cooling the fuel cell unit 7. In this case, by passing through the dedicated cooling body, The heated heating medium 99,
It suffices to supply the humidifiers 2A and 2B.

Embodiment 3; FIG. 7 is a schematic view of a main part schematically showing a solid polymer electrolyte fuel cell according to an embodiment of the present invention corresponding to claims 2 and 4, and FIG. It is the side view and (b) is the top view. FIG. 8 is an explanatory diagram for explaining the flow path of the heat medium in the solid polymer electrolyte fuel cell shown in FIG. 7. 7 and 8, a solid polymer electrolyte fuel cell according to an embodiment of the present invention corresponding to claim 1 shown in FIGS. 5 and 6 and claims 2 and 3 shown in FIGS. Corresponding solid polymer electrolyte fuel cell according to one embodiment of the present invention, and FIGS.
The same parts as those of the solid polymer electrolyte fuel cell according to the conventional example shown in FIGS. 14 to 16 are designated by the same reference numerals, and the description thereof will be omitted. In addition, in FIG. 7, FIG. 1, FIG. 2, FIG.
About the code | symbol attached in FIG. 12 and FIG. 14-FIG. 16, only the typical code | symbol was described. In addition, in FIG. 8, FIG. 1, FIG. 2, FIG. 5, FIG. 7, FIG. 9 to FIG. 12, and FIG.
With respect to the reference numerals denoted by, only representative reference numerals are shown.

In FIGS. 7 and 8, reference numeral 3 denotes pressure plates 33 and 34 in place of the pressure plates 53 and 54 for the solid polymer electrolyte fuel cell 1 according to the present invention shown in FIGS. It is a solid polymer electrolyte fuel cell (stack) adapted for use. The above-mentioned stack 1 is attached to the pressure plates 33 and 34.
In addition to the through holes (the through holes for the fuel gas 97, the oxidant gas 98, and the heat medium 99) formed in the pressure plates 53 and 54 provided with, the through holes (not shown) for the humidifying water 4 are provided. Are formed respectively. At least one pair of inflows and outflows for the humidifying water 4 are formed in the through holes, and the pipe connecting bodies 41 for the humidifying water 4 are mounted in the through holes.

In the humidifiers 2A and 2B, the moisturizing water 4 supplied from the outside of the stack 3 is inserted into the grooves 641 of the separators 64 of the unit humidifiers 6 of the humidifiers 2A and 2B. Is incorporated into the stack 3 so that it can flow through. In addition, the heat medium 99 that has flowed through the stacked body of the unit cells 8 and has flowed out from both ends of the flow passage portion 90B does not flow through the groove 641 of the separator 64 of the humidifiers 2A and 2B, It is discharged from the pipe connection body 991 to the outside of the stack 3. Here, the humidifying water 4 is, for example, city water, and its temperature is in a temperature range of the same level as the temperature of the heat medium 99 flowing out from the passage 90B.
Moreover, the temperature value corresponding to the amount of water vapor to be contained in the reaction gas is set and supplied to the stack 3. Humidifier 2
The reaction gas flowing through A and 2B is affected by the temperature of the humidifying water 4 and its temperature value changes, which changes the saturated water vapor content value of the reaction gas. Then, the reaction gas corresponds to the saturated water vapor amount value thus changed,
The humidified water 4 moving through the water permeable membrane 61 humidifies the water, and the amount of water vapor contained in the reaction gas is adjusted.

Since the embodiment shown in FIGS. 7 and 8 has the above-described structure, the fuel gas 97 and the oxidant gas 98 supplied to the stack 3 flow through the humidifier 2B and the humidifier 2A, respectively. Then, the unit cell 8 is humidified by the humidifying water 4.
It will flow into. At that time, since the temperature of the humidifying water 4 is variable as a characteristic configuration according to the third embodiment, the reaction gas is adjusted by adjusting the temperature value of the humidifying water 4,
The humidification is optimum for the operation of the stack 3. The humidifying water 4 flows into the respective humidifiers 2B and 2A from the pipe connection body 41 for the inflow of the humidifying water 4 as shown by the dotted line in FIG. Through the groove 641. Then, the separator 6
After humidifying the reaction gas flowing in the groove 631 of No. 3, the humidifying water 4 is discharged from the pipe connection body 41 to the outside of the stack 3. Further, the heat medium 99 exchanges heat with the plurality of unit cells 8, then flows out from both ends of the passage 90B, and is directly discharged from the pipe connector 991 to the outside of the stack 3.

As a result, the humidifier 2A and the humidifier 2B are heated to the same temperature according to the temperature value of the humidifying water 4 flowing through them. Since this temperature value is a value that is not much different from the temperature of the fuel cell unit 7, both end portions of the stack of the unit cells 8 are almost the same from the outside by the respective humidifiers 2A and 2B with respect to their heat conduction conditions. It will be cut off. Then, in the stack 3, the humidity of the reaction gas can be artificially set to an optimum value by appropriately controlling the temperature value of the humidifying water 4. As a result, in the third embodiment, the fuel cell 7
Regarding the uniformity of the distribution in the stacking direction of the unit cells 8 at the temperature of
By optimizing the humidification state of the fuel cells 7 while obtaining substantially the same actions and effects as in the case of the second embodiment, the power generation characteristics of the stack 3 can be further improved.

In the above description of the second and third embodiments,
In the stacks 1 and 3, the electric insulating plate is not interposed between the current collector plate and the pressure plate located on both sides of the humidifiers 2A and 2B, but the present invention is not limited to this.
For example, when the separator provided in the unit humidifier constituting the humidifier is made of metal, it is necessary to interpose the electrical insulating plate.

[0070]

According to the present invention, the following effects can be obtained by adopting the structure described in the section for solving the above-mentioned problems. The temperature at both ends of the unit fuel cell stack can be maintained at a value close to the temperature at the center of the stack in the stacking direction,
The temperature distribution in the stacking direction of the stack can be made uniform, and the power generation performance of the solid polymer electrolyte fuel cell can be improved. At the same time, the area of the fuel battery cell can be reduced, and the solid polymer electrolyte fuel cell can be downsized. In addition, (2) in the section of means for solving the above problems,
By adopting the configuration according to the item (3), it is possible to maintain the temperature at both ends of the unit fuel cell stack at a level that substantially matches the temperature at the center of the stack in the stacking direction, and It is possible to improve the uniformity of the temperature distribution in the stacking direction. As a result, it becomes possible to improve the power generation performance of the solid polymer electrolyte fuel cell.

By adopting the constitutions of (2) and (4) in the section of means for solving the above-mentioned problems, in addition to the effect of the above-mentioned paragraph, the humidity of the fuel cell unit of the unit fuel cell is increased. Can be set to an optimum value.
As a result, it is possible to further improve the power generation performance of the solid polymer electrolyte fuel cell.

[Brief description of drawings]

FIG. 1 is a side view of an essential part schematically showing a solid polymer electrolyte fuel cell according to an embodiment of the present invention corresponding to claims 2 and 3.

FIG. 2 is a top view of a main part schematically showing the solid polymer electrolyte fuel cell shown in FIG.

FIG. 3 is an explanatory view illustrating a flow path of a heat medium in the solid polymer electrolyte fuel cell shown in FIGS. 1 and 2.

FIG. 4 is an example of measuring the temperature distribution of the central portion in the area direction of the fuel cell unit of each unit fuel cell in the unit fuel cell stacking direction of the solid polymer electrolyte fuel cell according to the present invention according to Example 2; Graph shown in comparison with the case of the conventional example

FIG. 5 is a configuration diagram of a main part schematically showing a solid polymer electrolyte fuel cell according to an embodiment of the present invention corresponding to claim 1, (a) is a side view thereof, and (b) is a view thereof. Top view

6 is an explanatory view for explaining a flow path of a heat medium in the solid polymer electrolyte fuel cell shown in FIG.

FIG. 7 is a configuration diagram of a main part schematically showing a solid polyelectrolyte fuel cell according to an embodiment of the present invention corresponding to claims 2 and 4, (a) is a side view thereof, and (b) is a view. Is the top view

FIG. 8 is an explanatory view illustrating a flow path of a heat medium in the solid polymer electrolyte fuel cell shown in FIG.

FIG. 9 is a cross-sectional view seen from the upper side, schematically showing the main part of a unit fuel cell provided in a solid polymer electrolyte fuel cell of a conventional example in an expanded state.

FIG. 10 is a configuration diagram of a main part schematically showing a conventional solid polymer electrolyte fuel cell, in which (a) is a side view thereof,
(B) Top view

11 is a detailed sectional view of a Q portion in FIG.

FIG. 12 is an explanatory view illustrating a flow path of a heat medium in the solid polymer electrolyte fuel cell shown in FIGS. 10 and 11.

FIG. 13 is an explanatory diagram illustrating a supply path of a reaction gas to a solid polymer electrolyte fuel cell of a fuel cell power generator using a solid polymer electrolyte fuel cell of a conventional example.

FIG. 14 is a configuration diagram of a main part schematically showing a different conventional solid polymer electrolyte fuel cell, in which (a) is a side view thereof and (b) is a top view thereof.

FIG. 15 is an explanatory view illustrating a flow path of a heat medium in the solid polymer electrolyte fuel cell shown in FIG.

16 is a vertical cross-sectional view schematically showing a main part of a unit humidifier included in the humidifier shown in FIG. 14 in a developed state.

[Explanation of Codes] 1 solid polymer electrolyte fuel cell (stack) 2A humidifier 2B humidifier 51 current collector 53 pressure plate 54 pressure plate 6 unit humidifier 631 groove 641 groove 90A flow passage portion 90B flow passage portion 98 Oxidizer gas 99 Heat medium 991 Piping connection body

Claims (4)

[Claims] 1. A laminated body in which a plurality of unit fuel cells and a plurality of heat exchangers through which a heat medium for removing heat generated in the unit fuel cells flows are laminated, and both ends of the laminated body. The unit fuel cell is provided with a pressure plate that applies a pressing force for pressing each unit fuel cell in the stacking direction, and the unit fuel cell includes a sheet-shaped solid polymer electrolyte material electrolyte membrane and both main surfaces thereof. A fuel cell having a fuel electrode film and an oxidant electrode film bonded to each other, and receiving a supply of a fuel gas and an oxidant gas to generate a DC power;
Grooves are formed on both surfaces of the fuel cell so as to face each other, and a groove for passing a fuel gas or an oxidant gas supplied to the fuel cell is formed on the surface facing the fuel cell. In the solid polymer electrolyte fuel cell, the heat exchanger has a flow passage through which the heat medium flows, and an inlet / outlet portion of the heat medium related to this flow passage. The inlet / outlet portions of the plurality of heat exchange elements are
The above-mentioned flow passages of each heat exchanger are connected so as to be parallel to each other so as to be parallel with respect to the flow of the heat medium, and the flow passage portion on the inlet side and the flow passage portion on the outlet side are respectively connected. The heat medium is formed from each of both end portions of the inlet side flow passage portion, and also flows out from each of both end portions of the outlet side communication passage portion. A characteristic solid polymer electrolyte fuel cell. 2. A laminated body in which a plurality of unit fuel cells and a plurality of heat exchangers through which a heat medium for removing heat generated in the unit fuel cells flows are laminated, and both ends of the laminated body. The unit fuel cell is provided with a pressure plate that applies a pressing force for pressing each unit fuel cell in the stacking direction, and the unit fuel cell includes a sheet-shaped solid polymer electrolyte material electrolyte membrane and both main surfaces thereof. A fuel cell having a fuel electrode film and an oxidant electrode film bonded to each other, and receiving a supply of a fuel gas and an oxidant gas to generate a DC power;
Grooves are formed on both surfaces of the fuel cell so as to face each other, and a groove for passing a fuel gas or an oxidant gas supplied to the fuel cell is formed on the surface facing the fuel cell. In the solid polymer electrolyte fuel cell, the heat exchanger has a flow passage through which a heat medium flows, and an inlet / outlet portion of the heat medium related to the flow passage. A solid polymer electrolyte fuel cell, comprising: a humidifier that is interposed between the laminate and the pressure plate and humidifies the fuel gas and the oxidant gas by using heated water. 3. The solid polymer electrolyte fuel cell according to claim 2, wherein a plurality of heat exchange elements have inlets and outlets,
The above-mentioned flow passages of each heat exchanger are connected so as to be parallel to each other so as to be parallel with respect to the flow of the heat medium, and the flow passage portion on the inlet side and the flow passage portion on the outlet side are respectively connected. The heat medium is introduced from each of both ends of the inlet side flow passage portion, and is also made to flow out from each of both end portions of the outlet side passage passage parts. The solid polymer electrolyte fuel cell is characterized in that the heating medium supplied to the humidifier uses the heating medium flowing out from both ends of the outlet side flow passage part, respectively. . 4. The solid polymer electrolyte fuel cell according to claim 2, wherein the heated water supplied to each humidifier is supplied from the outside of the solid polymer electrolyte fuel cell and heated. A solid polymer electrolyte fuel cell, which is water for humidification.