JPH0416378Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a molten carbonate stacked fuel cell that facilitates the supply of electrolyte.

[Prior Art] In recent years, molten carbonate type stacked fuel cells have been proposed. In this fuel cell, as shown in FIG. 4, an electrolyte plate 1 in which a porous material is impregnated with an electrolyte such as a carbonate such as Li ₂ CO ₃ or K ₂ CO ₃ is connected to a cathode 2.
and the anode 3 from both sides, and supply fuel such as H ₂ gas to the flow path 5 formed on the anode 3 side, and supply air containing CO ₂ to the flow path 4 formed on the cathode 2 side. _By ^supplying _{an oxidizing gas} ^{consisting of} _{​ ​ ​} ^​ The electrolyte plate 1, which is a good conductor of carbonate ions, is sandwiched between the cathode 2 and the anode 3, and electricity is generated by the potential difference generated between the cathode 2 and the anode 3. By laminating multiple layers with separators 6 in between, the voltage can be increased to a required level.

[Problems to be solved by the invention] However, in both the matrix method and the paste method described above, the holding material is impregnated with liquid electrolyte in the state of parts, and the productivity of the parts is poor, making them unsuitable for mass production. Further, as the fuel cell operates, it is consumed due to evaporation of the electrolyte, etc., and after a certain period of time, it becomes impossible to obtain the required electromotive force. Therefore, the electrolyte plate must be replaced after a predetermined period of time, making maintenance extremely troublesome.

The present invention aims to improve productivity and maintainability by making it possible to supply electrolyte to an electrolyte plate in the assembled state of a fuel cell.

[Means for Solving the Problems] The present invention consists of stacking a plurality of electrolyte plates sandwiched on both sides by a cathode and an anode through separators that define a fuel gas flow path and an oxidation gas flow path. In the molten carbonate stacked fuel cell in which the supply and discharge of oxidizing gas to the cathode and the supply and discharge of fuel gas to the anode are carried out separately, the plurality of stacked fuel cells are separated by an upper holder and a lower holder. An electrolyte reservoir is formed in the upper holder, and an electrolyte supply channel is provided that communicates with the electrolyte reservoir and penetrates to the lower holder and opens on the outer surface of the lower holder, and a drain pipe is connected to the opening of the electrolyte supply channel in the lower holder. death,
A heater for heating the drain pipe is provided around the drain pipe, and a groove communicating with the electrolyte supply path is carved on the outer periphery of the contact surface of the separator with the electrolyte plate.

[Operation] When dissolved electrolyte is stored in the electrolyte reservoir, the electrolyte flows down the electrolyte supply path. If the heater that heats the drain pipe downstream of the supply path is in a stopped state, the electrolyte is cooled and solidified, and the drain pipe is blocked. Therefore, the supply channels are filled with electrolyte, and the grooves are also filled with electrolyte, and the electrolyte quickly permeates into the electrolyte plate through the supply channels and the grooves. If excess electrolyte is left in the supply path, the electrolyte will overflow from the electrolyte plate to the electrodes. When draining excess electrolyte, the drain pipe is opened by heating the drain pipe and dissolving the solidified electrolyte inside the drain pipe.

[Example] Hereinafter, an example of the present invention will be described based on FIGS. 1 to 3.

The multi-layered electrolyte plate 1, separator 6, etc. are held between an upper holder 7 and a lower holder 8, forming an electrolyte reservoir 10 having a supply port 9 in the upper holder 7. From upper holder 7 to lower holder 8
An electrolyte supply path 11 is provided that penetrates through the electrolyte supply path 11 , and the upper end of the supply path 11 is opened to the electrolyte reservoir 10 , and a drain pipe 12 that communicates with the electrolyte supply path 11 is provided outside the lower holder 8 . A heater 13 for opening and closing the drain pipe is provided around the drain pipe 12. In the figure, 14 is an electrolyte receiver, and 15 is a lid for the electrolyte reservoir.

Further, as shown in FIGS. 2 and 3, a groove 18 communicating with the electrolyte supply channel 11 is carved in the outer peripheral edge of the contact surface of the separator 6 with the electrolyte plate 1, and the electrolyte is also supplied from the groove 18. It is designed to penetrate into plate 1.

Electrolyte supply includes initial impregnation of the electrolyte plate 1 during assembly and replenishment after use.

For initial impregnation, a solid electrolyte (carbonate) is charged into the electrolyte reservoir 10, and the fuel cell 16 is heated by a heating device (not shown). At this time, drain pipe 1
Step 2: Avoid heating.

The electrolyte in the electrolyte reservoir 10 is melted by heating, and descends from the supply path 11 to reach the drain pipe 12 . Since the drain pipe 12 is not heated, the electrolyte solidifies inside the drain pipe 12 and blocks the drain pipe 12. That is, the dissolved electrolyte is not discharged from the drain pipe 12, but remains in the fuel cell 16, and quickly permeates into the electrolyte plate 1 through the supply path 11 and the groove 18 over time.

When the entire electrolyte plate 1 is impregnated with electrolyte, the heater 1
3 to heat the drain pipe 12. When the drain pipe 12 is heated, the electrolyte blocking the drain pipe is melted, and excess electrolyte is discharged from the drain pipe 12 to the electrolyte receiver 14.

If the supply path 11 is narrow, the electrolyte often does not enter properly. In this case, heat the drain pipe 12 from the beginning, heat the electrolyte, and pour it in.
When the electrolyte flows out from the drain pipe 12, the drain pipe 12 is rapidly cooled. In this way, the supply channel 11 can be completely filled with electrolyte.

This completes the initial impregnation work. Further, when replenishing the electrolyte, the heated and melted electrolyte may be supplied to the electrolyte reservoir 10 from the supply port 9, and the same operation as the above-described initial impregnation operation may be performed.

[Effects of the invention] As described above, according to the invention, by the simple operation of turning on and off the heater, the electrolyte plate can be quickly impregnated with electrolyte from the electrolyte supply channel and the groove in the assembled state, improving productivity. At the same time, electrolyte replenishment becomes easy and maintainability is improved.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view showing an embodiment of the present invention, Fig. 2 is a partial sectional view of the embodiment shown in Fig. 1, Fig. 3 is a view taken along arrow A-A in Fig. 2, and Fig. 4 is a schematic sectional view showing an embodiment of the present invention. 1 is a partial cross-sectional view showing the structure of a conventional fuel cell. 1 is an electrolyte plate, 2 is a cathode, 3 is an anode,
4 and 5 are flow channels, 7 is an upper holder, 8 is a lower holder, 10 is an electrolyte reservoir, 12 is a drain pipe, 13 is a heater, and 18 is a groove.

Claims (1)

[Scope of utility model registration request] A plurality of electrolyte plates sandwiched on both sides by a cathode and an anode are stacked with separators interposed therebetween to define a fuel gas flow path and an oxidant gas flow path, and oxidant gas is supplied and discharged to the cathode and to the anode. In a molten carbonate stacked fuel cell in which fuel gas is supplied and discharged separately, the plurality of stacks are held between an upper holder and a lower holder, and an electrolytic chamber reservoir is formed in the upper holder. At the same time, an electrolyte supply path that communicates with the electrolyte reservoir, penetrates to the lower holder, and opens on the outer surface of the lower holder is provided, a drain pipe is connected to the electrolyte supply path opening of the lower holder, and the drain pipe is heated around the drain pipe. 1. A molten carbonate stacked fuel cell, characterized in that a heater is provided, and a groove communicating with the electrolyte supply path is carved in the outer peripheral edge of the contact surface of the separator with the electrolyte plate.