JPH088109B2 - Molten carbonate fuel cell - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a molten carbonate fuel cell, and in particular, supplies an appropriate amount of electrolyte to a highly laminated electrolyte plate without stopping power generation. The present invention relates to a molten carbonate fuel cell suitable for

[Conventional technology]

The life of the conventional molten carbonate type fuel cell is about several thousand hours, and in order to extend the life, the method of stopping the power generation, replacing the electrolyte, or injecting the electrolyte from the side of the electrolyte plate has been adopted. However, all of them had a drawback that the power generation operation was stopped and the gas manifold and the like had to be disassembled.

[Problems to be Solved by the Invention]

An object of the present invention is to efficiently replenish the molten carbonate electrolyte to the electrolyte plate during operation without stopping the power generation operation of the battery and disassembling the gas manifold etc., high operating rate, long-life melting It is to provide a carbonate fuel cell. Another object is to automate replenishment of molten carbonate electrolyte during operation.

[Means for solving the problem]

The above-mentioned object is a molten carbonate fuel cell including a negative electrode, an electrolyte plate, a positive electrode, and a battery body in which separators are stacked one above the other, a carbonate tank for storing a carbonate electrolyte, and a titanium-based or stainless steel heat-resistant material. A large number of pores are formed on the side surfaces vertically arranged at the four corners of the electrolyte plate that is made of a corrosion-resistant metal tube and a ceramic layer with high electrical insulation that is sintered on the outer surface of the metal tube and that does not contact the electrodes of the battery body. A plurality of insulating pipes having, an electrolyte supply pipe connecting the carbonate tank and the plurality of insulating pipes, and a control valve provided in the electrolyte supply pipe, and opening the control valve during operation It is achieved by having the function of replenishing the carbonate electrolyte to the electrolyte plate of the battery main body through the pores of the insulating tube.

It is preferable to provide a heater for heating the electrolyte supply pipe with electricity or reaction heat of the fuel cell.

Further, the automation of the replenishment of the molten carbonate electrolyte during the operation is further provided with a voltmeter and a control device for detecting the output voltage of the battery body, and the control device controls the battery output voltage detected by the voltmeter to the electrolyte plate. This is achieved by performing control such that the control valve is opened when it is lower than the threshold value as compared with the threshold value indicating deterioration and the control valve is closed when the output voltage is restored.

[Action]

The battery output voltage is detected by a voltmeter in order to automatically supply the electrolyte from the outside without disassembling it while the battery is operating, and the electrolyte outside the battery is detected when the voltage falls below the required voltage. Automatically open and close the supply control valve from the tank,
An electrolyte can be supplied into the battery through a supply pipe to the battery.In the battery, a titanium-based or stainless-based metal tube is sintered on the outer surface of highly electrically insulating ceramics,
The electrolyte plate can be replenished with an appropriate amount of electrolyte through an electrolyte supply pipe having a large number of pores. As a result, the battery performance is restored, and the battery can be operated with the required performance for a long time.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. In the embodiment shown in FIG. 1, the battery body 1 is composed of a negative electrode 5, a positive electrode 6, an electrolyte plate 2, a separator 3 and an electrolyte supply pipe 4. FIG. 2 shows a cross section taken along the line AA in FIG. 1. The electrolyte supply pipe 4 is composed of a corrosion resistant pipe 9 and an insulator 8, and has a pore portion 10 for electrolyte supply. This allows the electrolyte supply pipe 4 to be supplied from the outside of the battery even during power generation of the battery.
Then, by feeding the carbonate electrolyte 7, the electrolyte 7 is supplied to the electrolyte plate 2 through the pores 10 of the tube.

FIG. 3 shows a carbonate electrolyte supply control system, in which the output voltage of the battery main body 1 is measured by the voltmeter 12, and when a voltage drop lower than the threshold value of the output voltage is detected, through the control device 11, The control valve 13 is opened to show that an appropriate amount of electrolyte is supplied from the carbonate tank 15 through the supply pipe 14 to the electrolyte plate of the battery body 1. If the voltage value recovers, the control device
With the signal from 11, the control valve 13 is closed and efficient automatic supply can be performed.

The electrolyte plate uses a lithium aluminate-based ceramic substrate, and the electrolyte 7 is a mixed salt of lithium carbonate and potassium carbonate, which is well liquefied at a battery operating temperature of 650 ° C. Good supply. Experiments have confirmed that it is better to dispose one electrolyte supply tube 4 at each of the four corners of the electrolyte plate 2 that is not in contact with the electrodes. As the material of the supply pipe 4, a material obtained by sintering silicon carbide or a lithium aluminate-based ceramic having a high electric insulation property on the outer surface of a stainless steel or titanium base was used. A large number of pores 10 having a diameter of 0.3 to 2.0 mm were provided by laser processing or the like. As the material of the electrolyte tank 15 and the pipe 14, a glass fiber resin was used. The electrolyte can be supplied by gravity dropping using gravity, gas pressure feeding using nitrogen or carbon dioxide, or mechanical pressure feeding using a pump. In order to facilitate transfer of the electrolyte 7, a heater 16 by electricity or the heat of battery reaction was provided in the middle of the piping system 14 to promote liquefaction. 1
It is also possible to carry out parallel supply from a single electrolyte tank 15 to a large number of batteries.

〔The invention's effect〕

According to the present invention, there is an effect that the battery life can be extended from the conventional thousands of hours to tens of thousands hours. Further, the electrolyte can be replenished without stopping the power generation, and the operational effect of the power plant can be obtained. Also, with the automatic feeder,
There is no need to disassemble the battery body, and maintenance efficiency is improved.

In addition, the insulation tube itself for supplying the electrolyte serves as a guide rod for high stacking of the battery main body, which facilitates stacking and assembling work.
The unevenness on the side surface is also eliminated, and the airtightness of the mounting surface of the fuel gas manifold is improved.

[Brief description of drawings]

1 is an external view of the fuel cell main body, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a carbonate electrolyte supply control system diagram. 1 ... Fuel cell main body, 2 ... Electrolyte plate, 3 ... Separator, 4 ... Electrolyte supply tube, 5 ... Negative electrode, 6 ... Positive electrode, 7 ... Carbonate electrolyte, 8 ... Insulator, 9 ... Corrosion resistant tube, 10 ... Many pores, 11 ... Control device, 12 ... Voltmeter, 13 ... Control valve, 14 ... Carbonate supply pipe, 15 ... Carbonate tank, 16 ... Heater.

Claims (2)

[Claims] 1. A molten carbonate fuel cell comprising a battery body in which a negative electrode, an electrolyte plate, a positive electrode, and a separator are stacked one above the other in a molten carbonate fuel cell, and a carbonate tank for storing a carbonate electrolyte and a titanium-based or stainless-based metal. A plurality of holes having a large number of pores on the side surfaces vertically arranged at the four corners of the electrolyte plate which is made of a ceramic tube and a ceramic layer having a high electrical insulation property which is sintered on the outer surface of the metal tube and which does not contact the electrodes of the battery body. Insulation pipe, an electrolyte supply pipe connecting the carbonate tank and the plurality of insulation pipes, and a control valve provided in the electrolyte supply pipe, and the insulation is provided by opening the control valve during operation. A molten carbonate fuel cell, which has a function of replenishing a carbonate electrolyte to an electrolyte plate of a battery main body through pores of a tube. 2. A voltmeter for detecting the output voltage of the battery body and a control device, wherein the control device is provided when the battery output voltage detected by the voltmeter is lower than a threshold value indicating deterioration of the electrolyte plate. 2. The molten carbonate fuel cell according to claim 1, wherein the control valve is opened and the control valve is closed when the control valve is higher than a threshold value.