JP2007220614A - Survival voltage discharge method and survival voltage discharge device of fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a survival voltage discharge method and a survival voltage discharge device of fuel cell which facilitate handling of a fuel cell stack from power generation test to mounting on a vehicle and can extend a lifetime of the cell. <P>SOLUTION: After assembly of a fuel cell stack (fuel cell 50), power generation test is carried out, thereafter, a first wiring 54 is connected to a positive electrode 52 of the fuel cell stack and a second wiring 55 is connected to a negative electrode 53, and a positive electrode side terminal 56 and a negative electrode side terminal 57 installed at the tip of these first and second wiring 54, 55 are contacted and the survival voltage remaining in the fuel cell stack is discharged. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel cell residual voltage discharge method and a fuel cell residual voltage discharge apparatus.

  For example, in a fuel cell that generates power by supplying hydrogen and oxygen to a polymer electrolyte membrane, a trace amount of reactive gas may remain in the fuel cell stack after power generation, thereby causing a voltage to remain.

As a technique for removing such residual voltage from the fuel cell stack, for example, a short circuit that short-circuits the positive electrode and the negative electrode of the output circuit that outputs power from the fuel cell stack is provided. A technique for discharging the residual voltage inside the fuel cell stack by turning on the short-circuit switch has been proposed (see, for example, Patent Document 1).
JP-A-9-139221

  However, in the technique described in Patent Document 1, since the residual voltage of the fuel cell is discharged for the first time at the inspection after mounting on the vehicle, the remaining voltage remaining in the power generation test after assembling the fuel cell is handled as it is. No consideration is given to the case of storage, storage, or assembly in a vehicle. For this reason, the residual voltage remains in the fuel cell after the power generation test until it is mounted on the vehicle, which requires considerable care in handling in terms of electric shock and shortens the battery life.

  Accordingly, the present invention provides a method for discharging a residual voltage of a fuel cell and a fuel cell capable of facilitating handling during a period from a power generation test of a fuel cell stack to mounting on a mounted portion and extending the battery life. An object is to provide a residual voltage discharge device.

  In the fuel cell residual voltage discharging method according to the present invention, after the fuel cell stack is assembled, a power generation test is performed, and then the first wiring is connected to the positive electrode of the fuel cell stack and the second wiring is connected to the negative electrode. Then, the terminals provided at the tips of the first and second wires are brought into contact with each other to discharge the residual voltage remaining in the fuel cell stack.

  The residual voltage discharge device for a fuel cell according to the present invention includes discharge means for discharging residual voltage remaining in a power generation test after assembly of the fuel cell stack, and the discharge means is connected to a positive electrode of the fuel cell stack. A first wiring; a second wiring connected to the negative electrode; a terminal connected to the tips of the first and second wirings; and a terminal fixing means for contacting and fixing the terminals.

  According to the fuel cell residual voltage discharge method of the present invention, the residual voltage remaining after the fuel cell stack is assembled and the power generation test is performed is a simple method in which the terminals at the ends of the wires connected to the positive electrode and the negative electrode are brought into contact with each other. Since it can be discharged, it is easy to handle the fuel cell, such as being able to carry it out to the vehicle assembly process in a safe state during the period from the power generation test to mounting the fuel cell on the mounted part. Life can be extended.

  Moreover, according to the fuel cell residual voltage discharge device of the present invention, since the discharge means for discharging the residual voltage remaining in the power generation test after the assembly of the fuel cell stack is provided, it remains in the discharge means after the power generation test. The residual voltage can be easily discharged.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

"Overall structure of fuel cell"
FIG. 1 is a perspective view of a fuel cell in which the fuel cell stack is housed in a case, FIG. 2 is a perspective view showing the overall configuration of the fuel cell stack, and FIG. 3 is an enlarged cross-sectional view of a single fuel cell. The fuel cell stack and the case constituting the fuel cell are examples of the present invention and are not limited to the embodiments described below.

  The fuel cell 50 is configured by housing the assembled fuel cell stack 1 in, for example, a square case 51. In this case 51, a positive electrode 52 and a negative electrode 53 (not shown in FIG. 1) provided in the fuel cell stack 1 described later are provided so as to protrude from opposite side surfaces.

  As shown in FIG. 2, the fuel cell stack 1 is a laminate in which a predetermined number of fuel cell single cells 2 as unit cells that generate an electromotive force by the reaction of fuel gas (hydrogen gas) and oxidant gas (oxygen) are stacked. 3, the current collector plate 4, the insulating plate 5 and the end plate 6 are arranged at both ends of the laminate 3, the laminate 3 is fastened with a tie rod 7, and a nut 14 is screwed onto the end of the tie rod 7. It is composed of that.

  In this fuel cell stack 1, fuel gas introduction for allowing fuel gas, oxidant gas and refrigerant (cooling water) to flow through each flow path formed in a separator (not shown) of each fuel cell single cell 2. A port 8, a fuel gas outlet 9, an oxidant gas inlet 10, an oxidant gas outlet 11, a refrigerant inlet 12 and a refrigerant outlet 13 are formed in one end plate 6.

  In the fuel cell stack 1 having such a configuration, the fuel gas is introduced from the fuel gas inlet 8, flows through the fuel gas passage formed in the separator, and is discharged from the fuel gas outlet 9. The oxidant gas is introduced from the oxidant gas introduction port 10, flows through the oxidant gas flow path formed in the separator, and is discharged from the oxidant gas discharge port 11. The refrigerant is introduced from the refrigerant introduction port 12, flows through the refrigerant flow path formed in the separator, and is discharged from the refrigerant discharge port 13.

  As shown in FIG. 3, the fuel cell single cell 2 includes a membrane electrode assembly (MEA) 15 in which fuel gas is supplied from one side and oxidant gas is supplied from the other side, and this membrane An anode separator 16 disposed on one surface of the electrode assembly 15 and a cathode separator 17 disposed on the other surface of the membrane electrode assembly 15, and the membrane electrode assembly 15 is formed by the anode separator 16 and the cathode separator 17. The structure is laminated so as to be sandwiched.

  The membrane electrode assembly 15 includes, for example, a solid polymer electrolyte membrane 18 that is a polymer electrolyte membrane that allows hydrogen ions (protons) to pass through, an anode electrode 19 provided on one surface of the solid polymer electrolyte membrane 18, and a solid polymer electrolyte. The cathode electrode 20 is provided on the other surface of the film 18. The anode electrode 19 includes a catalyst layer 21 disposed on the solid polymer electrolyte membrane 18 side and a gas diffusion layer 22 disposed on the anode separator 16 side, and the cathode electrode 20 similarly includes the solid polymer electrolyte membrane 18. The catalyst layer 23 is disposed on the side, and the gas diffusion layer 24 is disposed on the cathode separator 17 side.

  The anode separator 16 is formed with a fuel gas flow path 25 for allowing the fuel gas to flow in an active region contributing to power generation (a central region in contact with the solid polymer electrolyte membrane 18). On the other hand, the cathode separator 17 is formed with an oxidant gas flow path 26 for circulating an oxidant gas in the active region.

"Residual voltage discharge device for fuel cells"
FIG. 4 is a schematic configuration diagram showing the overall configuration of the residual voltage discharge device, and FIG. 5 is an enlarged view of a main part showing a discharge means portion of the residual voltage discharge device.

  The residual voltage discharge device includes discharge means for discharging the residual voltage remaining in the power generation test after assembling the fuel cell stack. The discharging means includes a first wiring 54 connected to the positive electrode 52 of the fuel cell stack 1, a second wiring 55 connected to the negative electrode 53 of the fuel cell stack 1, and first and second wirings 54 and 55. The positive electrode side terminal 56 and the negative electrode side terminal 57 which are connected to the tip of each of them, and a bolt 58 and a nut 59 which are terminal fixing means for contacting and fixing the positive electrode side terminal 56 and the negative electrode side terminal 57.

  One end of the first wiring 54 is connected to the positive electrode 52 of the fuel cell stack 1, and the positive terminal 56 is attached to the other end. The positive terminal 56 is a ring-shaped terminal with a circular hole formed in the center. One end of the second wiring 55 is connected to the negative electrode 53 of the fuel cell stack 1, and the negative electrode side terminal 57 is attached to the other end. Similarly to the positive electrode side terminal 56, the negative electrode side terminal 57 is a ring-shaped terminal in which a circular hole is formed in the center.

  The bolt 58 and the nut 59 are brought into contact with the positive electrode side terminal 56 attached to the first wiring 54 and the negative electrode side terminal 57 attached to the second wiring 55 and discharged, and then they are overlapped and tightened. Thus, the positive terminal 56 and the negative terminal 57 are fixed.

"Residual voltage discharge method for fuel cells"
Next, a method for discharging the residual voltage of the fuel cell 50 using the residual voltage discharge device including the discharge means configured as described above will be described.

  After the fuel cell stack 1 is assembled, it is necessary to inspect whether or not the fuel cell can generate electric power normally. Therefore, a power generation test is performed on the fuel cell alone. After the end of the power generation test, the reaction gases (hydrogen and oxygen) may remain without being completely removed from the fuel cell stack 1, so that if left as they are, potentials accumulate at the positive electrode 52 and the negative electrode 53. . Therefore, the first wiring 54 is connected to the positive electrode 52 protruding from the opposite side surfaces of the case 51. Next, the second wiring 55 is connected to the negative electrode 53. Then, the positive terminal 56 provided at the front end of the first wiring 54 and the negative terminal 57 provided at the front end of the second wiring 55 are brought into contact with each other to cause a short circuit.

  Then, the residual voltage accumulated in the fuel cell stack 1 is discharged, and the residual voltage is released from the fuel cell stack 1. If the positive electrode side terminal 56 and the negative electrode side terminal 57 are brought into contact with each other, there is no electric shock for a while, so after the positive electrode side terminal 56 and the negative electrode side terminal 57 are overlapped with each other, a bolt 58 and a nut 59 are used. Fix these terminals together. Thus, the residual voltage inside the fuel cell stack 1 can be removed, and a safe state can be ensured.

  As described above, according to the present embodiment, the residual voltage remaining after the fuel cell stack 1 is assembled and the power generation test is performed is easily brought into contact with the terminals 56 and 57 at the leading ends of the wires connected to the positive electrode 52 and the negative electrode 53. The fuel cell can be discharged into the vehicle assembly process in a safe state during the period from the power generation test until the fuel cell is mounted on the mounted part (for example, a vehicle such as an automobile). Can be easily handled and the battery life can be extended.

  Moreover, according to this embodiment, since the terminals 56 and 57 are brought into contact with each other and short-circuited, damage to the fuel cell stack 1 itself due to discharge can be prevented.

  Further, according to the present embodiment, since the discharge means for discharging the remaining voltage remaining in the power generation test after assembling the fuel cell stack is provided, the remaining voltage remaining in the discharge means after the power generation test is easily discharged. be able to.

  Moreover, according to this embodiment, since the volt | bolt 58 and the nut 59 are used as a discharge means, an apparatus structure can be simplified and a residual voltage discharge apparatus can be reduced in cost.

"Other embodiments"
FIG. 6 is a diagram illustrating another configuration example of the residual voltage discharge device. In this example, a male connector 60 in which a male terminal (not shown) is accommodated in an insulating housing and a female connector 61 in which a female terminal (not shown) is accommodated in the insulating housing are coupled to each other. To discharge the residual voltage inside the fuel cell stack 1.

  If male and female connectors are used in this way, the residual voltage inside the fuel cell stack 1 can be discharged more safely.

  FIG. 7 is a schematic configuration diagram showing the overall configuration of a residual voltage discharge apparatus provided with a residual voltage display means for displaying the residual voltage.

  As the residual voltage display means, for example, a residual voltage display component 62 such as a resistor and a voltmeter or a diode is used. Use a diode that lights at 5V or higher. If the voltage is less than 5V, it is safe for humans. Therefore, if the diode is not lit, it can be visually confirmed that the remaining voltage is less than 5V. When a voltmeter is used, it is possible to know how much the residual voltage is at a glance by looking at the display, and work can be performed safely.

  FIG. 8 is a schematic configuration diagram showing the overall configuration of a residual voltage discharging apparatus showing another example of the discharging means.

  In this example, the positive electrode side terminal 66 provided at the tip of the first wire 54 and the negative electrode side terminal 57 provided at the tip of the second wire 55 are turned on by the relay 63 as the discharging means. is there. That is, by pressing a button 65 attached to the relay box 64, the positive electrode side terminal 66 inserted into the relay box 64 is brought into contact with the negative electrode side terminal 67.

  Thus, the remaining voltage inside the fuel cell stack 1 can be discharged safely and easily by simply pressing the button 65 using the relay 63.

It is a perspective view of the fuel cell which accommodated the fuel cell stack in the case. It is a perspective view which shows the whole structure of a fuel cell stack. It is an expanded sectional view of a fuel cell single cell. It is a schematic block diagram which shows the whole structure of a residual voltage discharge apparatus. It is a principal part enlarged view which shows the discharge means part of a residual voltage discharge apparatus. It is a figure which shows another structural example of a residual voltage discharge apparatus. It is a schematic block diagram which shows the whole structure of the residual voltage discharge apparatus provided with the residual voltage display means which displays a residual voltage. It is a schematic block diagram which shows the whole structure of the residual voltage discharge apparatus which shows the other example of a discharge means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fuel cell stack 2 ... Fuel cell single cell 50 ... Fuel cell 52 ... Positive electrode 53 ... Negative electrode 54 ... 1st wiring (discharge means)
55. Second wiring (discharge means)
56 .. Positive side terminal (discharge means)
57 .. Negative terminal (discharge means)
58 ... Bolt (terminal fixing means)
59 ... Nut (terminal fixing means)
60 ... Male connector (discharge means)
61 ... Female connector (discharge means)
62 ... Residual voltage display component (remaining voltage display means)

Claims (6)

After the fuel cell stack is assembled, a power generation test is performed, and then the first wiring is connected to the positive electrode of the fuel cell stack and the second wiring is connected to the negative electrode, and the tips of the first and second wirings are connected. A remaining voltage discharging method for a fuel cell, wherein the provided terminals are brought into contact with each other to discharge the remaining voltage remaining in the fuel cell stack. In the residual voltage discharging device of the fuel cell provided with discharging means for discharging the residual voltage remaining in the power generation test after assembling the fuel cell stack,
The discharging means includes
A first wiring connected to the positive electrode of the fuel cell stack;
A second wiring connected to the negative electrode of the fuel cell stack;
A terminal connected to the tips of the first and second wirings;
A fuel cell residual voltage discharging apparatus, comprising: terminal fixing means for contacting and fixing the terminals together. The residual voltage discharge device for a fuel cell according to claim 2,
The terminal fixing means includes a bolt and a nut. A fuel cell residual voltage discharging apparatus. The residual voltage discharge device for a fuel cell according to claim 2,
The terminal fixing means comprises a connector that accommodates the terminal. A residual voltage discharging device for a fuel cell, wherein: A residual voltage discharge device for a fuel cell according to any one of claims 2 to 4, comprising:
A residual voltage display device for a fuel cell, characterized in that residual voltage display means for displaying the residual voltage is provided on either of the first and second wirings. A fuel cell residual voltage discharging apparatus according to claim 5,
The residual voltage display means is a voltmeter or a diode.

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