JPS60216469A - Heating device of fuel cell - Google Patents

Abstract

PURPOSE:To efficiently heat a cell by arranging a combustion chamber containing a fuel gas injection nozzle and an igniting means near the fuel cell inlet of a cathode gas feed system and controlling the gas feed quantity to the nozzle in response to load conditions. CONSTITUTION:The anode gas 2 and cathode gas 3 are fed to the anode chamber and cathode chamber of a fuel cell 1 respectively for power generation. In addition, a combustion chamber 8 containing an anode gas injection nozzle 9 and an ignition unit 10 is arranged near the cell 1 inlet of a cathode gas feed system, and the gas is fed to the anode gas injection nozzle 9 from a branch passage 13 having a flow control valve 12 controlled by an arithmetic circuit 11. Accordingly, the fuel gas feed quantity to the nozzle 9 is controlled in response to the load conditions, temperature, gas feed quantity, etc. during the operation start of low- load operation, and the cell can be heated to an optimum temperature efficiently in a short time, thus the operation efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heating device for a fuel cell, and in particular, to a heating device for a fuel cell.
The present invention relates to a heating device for a fuel cell that uses flammable gas as fuel and has a cell operating temperature that is relatively higher than room temperature.

Conventional configurations and their problems Many fuel cells that use flammable gas as fuel have an operating temperature that is significantly higher than normal temperature.

Page 2 For example, the operating temperature of a phosphoric acid fuel cell using phosphoric acid as the electrolyte is 170 to 20
The temperature is quite high, 0 to 7 Q O'c.

Conventionally, to start these fuel cells at room temperature, the fuel gas supply piping is heated externally and the heated gas indirectly raises the temperature of the cell, or the cell is directly heated with a heater or burner. Various methods have been used to heat the battery to operating temperature. On the other hand, when a fuel cell starts operating and is under a certain load, there is no need to heat it, as it generates heat due to electrode reactions and resistance loss, but rather needs to be cooled to prevent overheating. I can't stand it. However, even if the fuel cell is in operation, if the load is very light, or in extreme cases there is no load, the battery itself will not generate heat due to the causes mentioned above, and the battery temperature will rise unless it is heated externally. As the temperature decreases, it is necessary to heat and keep the battery warm using the same method used when starting the battery.

When operating a fuel cell such as a fuel cell with 3 pebs or more, it is necessary to heat the cell during startup and low load operation.

As mentioned above, this heating method includes a method of heating the supply gas by heating the supply gas piping and indirectly heating the battery, and a method of directly heating the battery body with a heater or burner. In addition, a catalyst for room-temperature combustion is provided on the anode gas supply side (not yet in the manifold), and when raising the temperature, the anode gas and cathode gas are mixed to below the explosion limit, and this is transferred to the anode interface or inside the manifold. There is also a method of catalytic combustion and raising the temperature using the heat. However, these methods have the following drawbacks.

The first method of heating the gas by heating the pipes has poor thermal efficiency due to heat conduction, and temperature rise is also slow. Therefore, the time and energy losses are extremely large. Furthermore, a heat exchanger is required to effectively heat the gas, which is disadvantageous in terms of equipment.

In addition, in the second method, as the stacked battery becomes larger, the heating becomes more uneven, and to improve this, it is necessary to install heaters or burners at various locations, which only increases the complexity of the device. It is inevitable that it will be disadvantageous in terms of cost.

Since the third method uses catalytic combustion, it is difficult to obtain high temperatures, and it is difficult to apply it to high-temperature fuel cells. Furthermore, there is a problem that the catalyst is poisoned by components contained in the anode gas or cathode gas, resulting in a decrease in its performance.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a device for heating a fuel cell uniformly and in a short time with a simple structure while reducing the thermal efficiency and time loss of the conventional devices.

Structure of the Invention The present invention provides a fuel cell using flammable gas as fuel.
A combustion chamber containing a fuel gas injection nozzle and ignition means is provided near the fuel cell entrance of the cathode gas supply line, and the fuel gas is supplied to the fuel gas injection nozzle according to the load condition of the fuel cell, temperature, gas supply amount, etc. A flow rate control device is provided to control the supply amount.

Description of examples 5 pebs FIG. 1 shows an embodiment of a heating device according to the invention.

1 is a fuel cell, 2 is an anode gas supply source, and 3 is a cathode gas supply source, the anode gas being supplied to the anode chamber of the cell by a thread 6 having a regulating valve 4, and the cathode gas having a regulating valve 6. The thread 7 is adapted to supply the cathode chamber of the battery. Furthermore, a combustion chamber 8 is disposed near the fuel cell inlet of the cathode gas supply line.
Inside the combustion chamber are an anode gas jet nozzle 9 and an ignition device 1.
゜ is installed. And the anode gas jet nozzle 9
Anode gas is supplied from a branch line 13 having a flow control valve 12 controlled by an arithmetic circuit 11 . This anode gas supply line 13 is connected to the anode gas control valve 4.
It is preferable to branch off from the yarn path 5 before the anode gas jet nozzle, and to have a pressure sufficiently higher than the internal pressure of the combustion chamber 8, and to install a flashback prevention device before the anode gas jet nozzle.

In this example, a molten carbonate fuel cell stack with an operating temperature of 650 °C was used as the fuel cell, and its scale was 30 °C.
It was made up of 6 pages made by laminating 20 rn-square unit cells, and the surrounding area was completely insulated with heat insulating material. The combustion chamber is cylindrical with a diameter of approximately 5 (7) and a length of 13 cm.
The surrounding pipe 10α and the fuel cell are completely insulated with heat insulating material. Further, the anode gas contained 80% hydrogen, and the cathode gas contained 66% air and 35% carbon dioxide gas, both of which were supplied at a gas temperature of 300°C.

When starting the fuel cell, the cathode gas flow rate 6011
5'j-, the anode gas supply amount to the combustion chamber and fuel cell was 1o to 2011/l, respectively; f) When the temperature was raised under the conditions, the cell temperature reached 650°C in about 2 hours and was ready for operation. Yes. In the conventional method of heating pipes indirectly, it takes about 7 to 70 minutes to reach an operable temperature.
Compared to the previous method that required 10 hours and a large amount of thermal energy, the temperature could be raised efficiently in a short time. Further, the temperature difference between each part of the battery was within 2°C, and uniform heating was possible.

Next, when the battery is under no load, the temperature of the battery
The operating temperature could be maintained at 650°C±10°C while the zonode gas supply rate varied between 0 and 101/min. Thereafter, no abnormalities such as deterioration of battery performance were observed even when the system shifted to load operation. Furthermore, no abnormal combustion such as explosion was observed in the combustion chamber during operation of this heating device.

Although the above-described example uses a molten carbonate fuel cell, other types of fuel cells may be used. For example, in a phosphoric acid fuel cell,
By reducing the amount of anode gas sent to the combustion chamber and keeping the temperature of the cathode gas low, it can be directly sent to the battery and used for heating.

In short, any mechanism is sufficient as long as it sends an appropriate amount of anode gas to the combustion chamber placed near the fuel cell inlet of the cathode gas supply line, burns it, and uses the combustion heat to heat the battery. The formula can be of any type.

Effects of the Invention As described above, according to the present invention, a fuel cell can be efficiently and quickly heated, and heating can be performed uniformly. Furthermore, compared to conventional heating methods, this method has the advantage that the device can be made extremely compact.

[Brief explanation of the drawing]

The figure shows an example of the configuration of a battery heating device according to an embodiment of the present invention. 1... Fuel cell, 2... Anode gas supply source, 3... Cathode gas supply source, 8...
- Combustion chamber, 9... Nozzle, 1o... Ignition device, 11... Arithmetic circuit, 12... Flow rate control valve.

Claims (1)

[Claims] A heating device for a fuel cell using flammable gas as fuel, comprising:
A combustion chamber containing a fuel gas injection nozzle and ignition means is arranged near the fuel cell inlet of the cathode gas supply system, and the fuel cell load condition and temperature are also controlled. A flow rate control device is installed to control the amount of fuel gas supplied to the fuel gas jetting nozzle according to the amount of gas supplied.