JPH0221573A - Fuel cell - Google Patents

Abstract

PURPOSE:To cut off a short-circuit current passing through a feeder in order to suppress expansion of an accident due to a leakage current by providing cut-off resistance in series on the connecting wires as an electric connecting circuit conductively connecting conductive structures such as laminated cells, a feed and discharge device of reaction gas and a cooler. CONSTITUTION:A cooler 9 and a reaction gas manifold 8 are insulated from a laminated cell (generation part) 1 by an insulating material 31 and a seal material made of the insulating material, while being insulated from earthing potential of an enclosed container 7 by insulating couplings 91 and 81. Then, the potential of an optical unit cell 2A of the laminated cell 1 is given by a connecting wire 18 and a connecting wire 19, where cut-off resistance 21 is arranged. Thereby, when any one part of the insulating material 31 or the seal material 41 causes dielectric breakdown, the laminated cell 1 is short- circuited through the dielectric breakdown part, the connecting wires 18, 19, the cooler 9 and the reaction gas manifold 8 but a current is cut-off by a cut-off resistance 21 so that expansion of an accident is suppressed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a stacked fuel cell, particularly a fuel cell equipped with a means for preventing the expansion of an insulation abnormality in an insulating material that insulates a stacked battery, etc. and a conductive structural material. Regarding batteries.

[Conventional technology]

FIG. 14 is a configuration diagram including a cross-sectional view showing a conventional device simplified with a single line. In the figure, 1 is a stacked battery, a stack of unit batteries 2 is provided with a cooling plate 3 for each unit battery, and a pair of gas seal plates 4 and an insulating plate 5 are provided at the end of the stack. A pair of upper and lower tightening plates 6A are attached to the connecting member 6.
By connecting them by B and applying a predetermined tightening load to the stacked surfaces, an integrated stacked battery 1 is formed. The stacked battery 1 is insulated and supported in a grounded metal sealed container Z by an insulating support stand 7A, and a fastening device 6 consisting of a clamping plate 6A and a fastening member 6B is conductively connected to the sealed container 11 by a connecting wire 16. . On the four sides of the stacked battery 1, a pair of manifolds 8 each serve as a reactant gas supply/discharge device for supplying and discharging fuel gas and reaction air as reactive gases to the stacked battery 1, respectively, and four insulating materials that also serve as gas seals are installed. The reactant gas is supplied and discharged through a pair of supply/discharge pipes 8A and 8B, which are airtightly fixed to the stacked battery via the manifold 8 and connected to the manifold 8 via an insulating joint 8It.

Further, 9 is a cooler for the laminated battery 1, and a pair of supply/discharge pipes 9A are insulated from the external piping system by an insulating joint 9I.
and a plurality of cooling pipes 9B that branch from the fruit pipe 9A toward the cooling plate 3, pass through the cooling plate 3 in the longitudinal direction, make a U-turn on the anti-collecting pipe side, and return to the collecting pipe again. . The cooling pipe 9B is housed in a groove 3A formed in a cooling plate 6 made of a single conductive material, as shown in a cross-sectional view in FIG. 16, and is insulated from the cooling plate 3 by an insulating material 3I.

Like this button, closed container7. A manifold 8 and a cooler 9, which are electrically insulated from the stacked battery 1 and serve as a reactant gas supply/discharge device, are connected to a connecting wire 18 serving as an electrical connection circuit. 2A, and the cooler 9 is also conductively connected to the unit 2A through the manifold 8 by connection 819.
As shown in a schematic diagram of the equivalent circuit in FIG. 15, the maximum potential difference between the stacked battery 1 and the conductive structures of the manifold 8 and the cooler 944 is reduced to about % of the output voltage E of the stacked battery 1.

[Problem to be solved by the invention]

In the conventional device configured as described above, either four pieces of insulating material that also serves as a gas seal to insulate the manifold 8 from the stacked battery 1, -ffi or three pieces of insulating material that insulates the cooler 9 from the stacked battery 1 are used. If dielectric breakdown occurs in even one place,
Power is supplied between the insulation breakdown point and the two unit batteries! If short-circuiting occurs through 18 or 19, a large short-circuit current will flow, increasing damage to the dielectric breakdown area, and there is a concern that an accident may occur in which the fuel cell or gas seal is damaged.

If there is dielectric breakdown in the R7 lunges 8 and 9, the two cells must be directly grounded via the power supply line 18 and 19, and the ground potential of the laminated battery 1 and its output circuit is This can sometimes lead to accidents such as ground faults and currents.

This invention aims to limit the short-term current or leakage current caused by dielectric breakdown in the fuel cell to a value that does not interfere with the operation of the fuel cell, and to suppress the spread of accidents due to the leakage current.
Alternatively, it is possible to detect insulation abnormalities at an early stage and take protective measures.

[Means to solve the problem]

In order to solve the above problems, according to the present invention, a stacked battery consisting of unit batteries stacked in multiple stages is provided with a metal sealed container for storing the stacked battery, and either the sealed container or the stacked battery. To? A battery comprising a conductive structure connected via a J edge material, and an electrical connection circuit that provides the conductive structure and the sealed container with the potential of any unit cell or ground potential of the laminated battery, The electrical connection circuit may be provided with a current limiting resistor connected in series, or the electrical connection circuit may be provided with a leakage current detection device connected in series instead of the current limiting resistor.

[Effect]

In the above means, the stacked battery and the reactant gas supply/discharge system fi!
(manifold), a short circuit through the power supply line due to dielectric breakdown of the insulation material by providing a current limiting resistor in series with the connection line as an electrical connection circuit that conductively connects it to a conductive structure such as a cooler. Current is limited to below a predetermined level,
Therefore, the spread of the accident is prevented. Also, pay i1f!
By installing a leakage current detection device in series with A, it is possible to detect short circuits early, making it easy to take protective measures such as stopping the fuel cell's power generation before the accident escalates. can do.

〔Example〕

The present invention will be explained below based on examples.

Fig. 1 is a block diagram of a device showing a first embodiment of the present invention, and Fig. 2 is a schematic diagram of an equivalent circuit of the embodiment device. Hereinafter, the same reference numerals will be used for the same parts as in the conventional device. A detailed explanation will be omitted. In the figure, a cooler 9 and a reaction gas manifold 8 are insulated from an insulating material 3I or a sealing material 4I made of an insulating material and a laminated battery (power generation section) 1, and insulating joints 9, 8:[K] The ground potential of the airtight container 7 is also insulated, and the connecting wire 19 and the connecting wire 19 with the current limiting resistor 21 are connected to each other. Two arbitrary unit batteries in pond 1 are given the potential. In such a configuration, if any part of the insulation material 3 or the sealing material 4 causes dielectric breakdown, the stacked battery 1 will break down between the dielectric breakdown part and the connecting wire 18.
19. The cooler 9° is short-circuited through the reaction gas manifold 8, etc., but the current limiting resistor 21 prevents it! The current is limited and the spread of accidents is suppressed.

3 and 4 are configuration diagrams and schematic diagrams showing a second embodiment of the present invention, in which a cooler 9 and a reaction gas manifold 8 are shown.
is insulated from the laminated battery (power generation section) 1 by an insulating material 3 or a sealing material 4 made of an insulating material, and insulating joints 91 and 8.
It is electrically insulated from ground potential. Airtight terminal 29
A leakage current detection device 61 is disposed in the electrical connection circuit 29 consisting of the connection line 29A and the connection line 29A, and the potential of two arbitrary unit cells in the laminated battery 1 is applied to the connection line 29 and the connection line 19. ing. In such a configuration, if any part of the insulation material 3 or the sealing material 4 causes dielectric breakdown, the stacked battery 1 will break down between the dielectric breakdown part and the connecting wires 29A, 19.
．． Although the cooler 91 is short-circuited through the reaction gas manifold 8, etc., leakage current is detected by the leakage current detection device fi131, and based on this detection 11, it is possible to take measures such as stopping the power generation operation of the fuel cell. Therefore, by detecting an accident early and protecting the equipment, it is possible to completely prevent the accident from expanding.

5 and 6 are a configuration diagram and a schematic diagram showing a sixth embodiment of the present invention, and the difference from FIG. 1 is that there is no connection line 18, and instead a connection line with a current limiting resistor 41 is provided. 39, the cooler 9 reaction gas manifold 8 is electrically conductively connected to the upper clamping plate 6A, and the ground potential is supplied via the connection wire 39, which prevents dielectric breakdown of the insulation material 3 or the seal material 4. It is possible to limit the current leakage current to the ground.

7 and 8 are configuration diagrams and schematic diagrams showing a fourth embodiment of the present invention, and the difference from FIG. 5 is a connection line 49A.
, the insulating material 3
Leakage current to ground is detected when dielectric breakdown occurs in the insulation or sealing material.

FIG. 9 and FIG. 10 are configuration diagrams and schematic diagrams showing the fifth embodiment, and the difference from each of the above-mentioned embodiments is that the airtight container 7
is insulated from the earth by an insulating material 7D, and grounded via a current limiting resistor 61 by a connection line (grounding line) 59 for the closed container Z. In this example device, the insulating material 81.
It is possible to limit the current of all ground fault currents, including dielectric breakdown of ground insulating materials such as 9-wires and insulating plates 5.

FIG. 11 is a configuration diagram showing the sixth embodiment, and the difference from FIG. 9 is that a leakage current detection device 71 is provided in series with the grounding wire 59 of the closed container 7, which is insulated from the earth by an insulating material 7. In addition, it is possible to detect earth fault current at an early stage when it is a leakage current and take protective measures.

FIG. 12 is a block diagram showing the seventh embodiment.
Voltage measurement mark 73. A metal terminal plate 75 supporting an airtight terminal 74 provided at the portion where the thermocouple 72 penetrates the sealed container 7 is insulated from the sealed container 7 by an insulating plate 76, and the terminal plate 75t-connecting wire 79 and limit This differs from the above-described embodiments in that it is conductively connected to the grounded sealed container 7 via a flow resistance 81, and a ground fault caused by an insulation abnormality in the airtight terminal 74 or the thermocouple 72 is caused by the flow Vi.

FIG. 13 is a configuration diagram showing the eighth implementation fpIU.
The difference from the embodiment shown in FIG. 2 is that the terminal plate 75 is connected to the connecting wire 7.
9 and the grounded point via the current detection device 91,
Insulation abnormalities in the airtight terminal 74 and the thermocouple 72 can be detected early at the stage of leakage current, and the fuel cell can be protected. Note that a direct current relay or the like is used as the leakage current detection device.

Although the embodiments of the present invention have been described in detail for each target part, it is possible to combine the first to eighth embodiments to prevent dielectric breakdown and insulation defects of all insulating members from short-circuit current. Current limiting or early detection of leakage current can prevent the spread of accidents.

〔Effect of the invention〕

As described above, the present invention provides an electrical connection circuit (connection circuit) that provides the electrical potential or ground potential of any unit cell of a stacked battery to a conductive structure or sealed container that is connected to the stacked battery or sealed container via an insulating material. A current limiting resistor or a leakage current detector fIt was connected to the Iwaon.As a result,
Conventional technology: If an insulation breakdown accident occurs at any of the points 1 and 2 of the insulating material, a short circuit or ground fault circuit is formed in a part of the laminated layer through an electrical connection circuit, and the accident expands. The problem is that the current limiting action of the fault current by the current limiting resistor suppresses the spread of the fault, and if the leakage current detection device R is fully installed, insulation abnormalities can be detected early at the leakage stage. Because it can protect the fuel cell,
In addition to being able to provide a fuel cell with highly reliable insulation, the present invention has the advantage of contributing to the field of damage to fuel cells and the ease of repair thereof by suppressing the spread of accidents.

[Brief explanation of the drawing]

1 and 2 are block diagrams and schematic diagrams of equivalent circuits showing a first embodiment of the present invention, and FIGS. 6 and 4 are
5 and 6 are block diagrams and schematic diagrams showing the third embodiment row; FIGS. 7 and 8 are block diagrams and schematic diagrams showing the fourth embodiment; 9 and 10 are block diagrams and schematic diagrams showing the fifth embodiment 91, FIG. 11 is a block diagram showing the sixth embodiment row, FIG. 12 is a block diagram showing the seventh embodiment, and FIG. 13 is a block diagram showing the sixth embodiment 91. FIGS. 14 and 15 are block diagrams showing the eighth embodiment, FIGS. 14 and 15 are block diagrams and schematic diagrams showing conventional devices, and FIG. 16 is an enlarged sectional view showing the main parts of FIG. 14. 1...Laminated battery, 2, 2 people...unit! Pond, 7...
Sealed container, 8... Manifold (reactant gas supply/discharge device) 9... Cooler, 3 pieces, 41, 5, 81, 9I, 7E, 76... Insulating material, 1<518.19, 29,39
, 49 , 59 ・'Ifi connection times M (connection #),
21.41.61.81...Current limiting resistance, 31,517
1.91... Leakage current detection device, 75... Terminal board. \1 Qo o-+ YIS diagram

Claims (1)

[Claims] 1) A stacked battery consisting of unit batteries stacked in multiple stages,
A metal sealed container for storing the laminated battery, and a conductive structure coupled to either the sealed container or the laminated battery via an insulating material, In a battery having an electrical connection circuit that provides the potential or ground potential of any unit cell,
A fuel cell characterized by comprising a current limiting resistor connected in series to this electrical connection circuit. 2) The fuel cell according to claim 1, characterized in that a leakage current detection device is connected in series to the electrical connection circuit instead of the current limiting resistor.