JPS63307671A - Laminated fuel cell - Google Patents

Abstract

PURPOSE:To prevent the electrode reaction from proceeding on a cell with deteriorated performance by inserting a plug bar into the plug bar inserting groove of a separator feeding and discharging the gas to the cell with deteriorated performance to stop the flow of the gas. CONSTITUTION:A conductive member is pinched between measuring terminals of upper and lower separators 4 partitioning a cell with deteriorated performance from upper and lower cells to short-circuit the cell with deteriorated performance. One end of a tube 9 is cut off simultaneously, a plug bar 10 is inserted into the tube 9 from here, the plug bar 10 is inserted into the groove 8 of a gas communication section 7 on one face of the separator 4, and the flow of the gas from a gas feeding/discharging hole 5 to a gas passage 6 is cut off by the plug bar 10 in the groove 8. The electrode reaction is thereby prevented from proceeding.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a stacked fuel cell used in the energy sector for directly converting the chemical energy of fuel into electrical energy.

[Prior Art] Among fuel cells, molten carbonate fuel cells in particular
As an example shown in the figure, an electrolyte plate (tile) 1 made of porous material impregnated with molten carbonate is sandwiched between a cathode (oxygen electrode) 2 and an anode (fuel electrode) 3 from both sides, and the cathode 2 side One cell is one in which power is generated by the potential difference generated between the cathode 2 and the anode 3 by supplying the oxidizing gas OG and the fuel gas [G to the anode 3 side. A fuel cell stack is known in which fuel cells are stacked in multiple layers with separators 4 interposed therebetween.

Normally, a fuel cell generates electricity by stacking cells in multiple layers, such as several hundred stages, and supplying oxidizing gas and fuel gas to each stage of cells, but some cells deteriorate in performance during operation. Come out. If a cell with degraded performance is left unattended, current will also flow to the cell with degraded performance, but if current flows to the cell with degraded performance, the voltage will be abnormally low and the cell will Corrosion reaction is promoted and metal dissolution reaction occurs, carbonate is lost, electrolyte plate 1 is damaged, and cross leakage of oxidizing gas and fuel gas occurs. When this cross leak occurs, a combustion reaction occurs, and the cells above and below the cell whose performance has deteriorated also reach a high temperature and become damaged.

Therefore, conventionally, in stacked fuel cells, when a cell with deteriorated performance appears, in order to easily replace that cell, one block is made up of several stacked cells, and several blocks are stacked one on top of the other. There are two approaches: when a cell with degraded performance is found, it is replaced in each block containing that cell, or the other approach is to electrically short-circuit the cell whose performance has degraded and bypass it.

[Problems to be solved by the invention] However, the idea of stacking several cells together as one block and replacing them in block units when a cell with degraded performance occurs requires that the oxidizing gas and fuel gas supply/discharge equipment be replaced. It is necessary to assemble each block independently, which poses problems in that the equipment becomes large-scale and maintenance is also difficult. In addition, if the idea is to electrically short-circuit a cell whose performance has deteriorated, there is no problem with blocking it, but even if the current is bypassed, if both oxidizing gas and fuel gas are flowing, the electrode reaction will occur. There is a problem that this process accelerates the deterioration of the cell and damages the electrolyte plate.

Therefore, the present invention is based on the concept of electrically shorting the cell when a cell with degraded performance appears, and the electrode reaction progresses by stopping the flow of gas to the cell with degraded performance. This is what we try to avoid.

[Means for Solving the Problems] In order to achieve the above object, the present invention sandwiches both sides of an electrolyte plate between cathode and anode electrodes, supplies oxidizing gas to the cathode side, and supplies fuel to the anode side. In a stacked fuel cell in which cells that are designed to supply gas are stacked in multiple layers with separators in between, there is a A groove for inserting a plug rod is provided to stop the flow of gas to one of the gas passages, and the plug rod is inserted into the groove from outside the separator so as to be freely inserted backwards.

[Function] When a cell with degraded performance is found, inserting a plug rod into the gas passage for either the oxidizing gas or the fuel gas supplied to that cell will stop the gas from flowing to the gas passage. The flow is stopped by the plug rod. This prevents combustion from occurring in that cell.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show an embodiment of the present invention, in which both sides of an electrolyte plate 1 having gas supply/discharge holes 5 at the periphery are sandwiched between a cathode 2 and an anode 3. One cell I is configured to supply oxidizing gas OG to the 2 side and fuel gas FG to the anode 3 side, and has a gas supply/discharge hole 5 at the periphery and at the center of both the front and back surfaces. In a structure in which gas passages 6 are stacked in multiple stages with separators 4 formed by concave and convex structures, holes 5 for supplying and discharging oxidizing gas and fuel gas are provided around the separators 4 in each stage;
A groove 8 that crosses the gas communication part 7 is formed in the gas communication part 7 that communicates with the gas passage 6 formed in the central part excluding the peripheral part for flowing gas to the electrode side of the cathode 2 or the anode 3. A hole 11 is formed as shown in FIG.
One end of a tube 9 is fixed and connected to the hole opening on the outer surface of the separator 4, and the tube 9 is passed through and inserted into the groove 8 of the gas communication part 7 to control the flow of gas from the supply/discharge hole 5 to the gas passage 6. A plug rod 10 is prepared to stop the plug.

Note that the grooves 8 may be provided only on one side of the separator 4, and as in the embodiment, the grooves 8 may be provided on the surface through which the fuel gas FG to be supplied to the anode side flows. Moreover, the groove 8 is
The cross-sectional shape of the tube 9 is semicircular or square, and the end of the tube 9 is closed to prevent gas between the separator 4 and the electrodes from leaking to the outside when the performance of the cell ■ is good. Make it.

When power is generated using a stacked fuel cell in which cells are stacked in multiple stages, if it is found through analysis of voltage or emitted gas that the performance of the cells in each stage has deteriorated, the performance will be reduced. In order to prevent current from flowing through cells that have deteriorated,
A conductive member (not shown) is interposed between each instrumentation terminal (not shown) of the upper and lower separators 4 that separate the cell whose performance has deteriorated from the cells above and below, so as to short-circuit the cell whose performance has deteriorated. At the same time, cut the end of the tube 9, insert the plug rod 10 into the tube 9, and insert the plug rod 10 into the groove 8 of the gas communication part 7 on one side of the separator 4 to supply and discharge gas. The flow of gas from the gas hole 5 to the gas passage 6 is blocked by a plug rod 10 in the groove 8. As a result, the flow of gas (fuel gas in the example) that is about to flow from the supply/discharge hole 5 to the gas passage 6 is stopped, and only the other gas (oxidizing gas in the example) is allowed to flow. become a state. If the flow of one gas is stopped, there is no possibility that the electrode reaction will proceed even if the other gas is allowed to flow.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and for example, the flow of oxidizing gas may be stopped. You can also use something that expands.
Further, although the case is shown in which the tube 9 is connected to the hole that opens the groove 8 around the separator 4, a type without the tube 9 may be used.゛ [Effects of the Invention] As described above, according to the stacked fuel cell of the present invention, it is possible to stop either the oxidizing gas or the fuel gas flowing into each stacked cell from flowing toward the electrode side. A groove for inserting a plug rod is provided on one side of the separator that partitions each cell, and a hole is provided to open the groove on the outer surface of the separator, and the plug rod is inserted into the groove through the hole to allow the gas to flow. Therefore, when it is found that the performance of a cell in a stage has deteriorated, it is necessary to insert the plug rod of the separator, which is designed to supply and discharge gas to the cell whose performance has deteriorated. By inserting the plug rod into the groove, the flow of gas can be stopped, and an excellent effect can be achieved in that combustion will not occur in the cell whose performance has deteriorated.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a separator showing an embodiment of the stacked fuel cell of the present invention, FIG. 2 is a sectional view of the stacked fuel cell of the present invention,
FIG. 3 is a sectional view showing an example of a conventional fuel cell. DESCRIPTION OF SYMBOLS 1... Electrolyte plate, 2... Cando, 3... Anode, 4... Separator, 5... Supply/discharge hole, 6...
Gas passage, 7... Gas communication section, 8... Groove, 10...
・Plug rod.

Claims (1)

[Claims] 1) Cells are stacked in multiple layers with separators in between, with both sides of an electrolyte plate sandwiched between cathode and anode electrodes, and oxidizing gas being supplied to the cathode side and fuel gas being supplied to the anode side. In a stacked fuel cell, a groove for inserting a plug rod is provided on the gas supply/discharge side of the separator that forms the gas passage for oxidizing gas and fuel gas for each cell to stop the flow of gas to either one of the gas passages. What is claimed is: 1. A stacked fuel cell comprising: a plug rod which can be freely inserted into and removed from the groove from outside the separator;