JPS6145569A - Power supply for automobile - Google Patents

Abstract

PURPOSE:To improve the starting characteristic of a fuel cell during the time of low temperatures by feeding a current from a battery to a heater to heat the liquid electrolyte of the fuel cell when the temperature of the electrolyte is below a given level. CONSTITUTION:When the temperature of the electrolyte of a fuel cell detected by a liquid temperature sensor 9 is below a given level, a switch 14 is connected to contacts (a) and (a') through a switching circuit 13 controlled by signals from a controller 12 to heat a heater 11 by feeding a current from a battery 15 to the heater 11. When the temperature of a liquid electrolyte 10 reaches a given level, the switch 14 is switched to contacts (b) and (b') through the switching circuit 13 controlled by switching signals from the controller 12 to supply the electromotive force of the fuel cell to a battery 15 used as a load thereby charging the battery 15. Thus, when the temperature of the electrolyte is low, it is heated by feeding a current from the battery 15 to the heater 11 installed in the container. Accordingly, it is possible to prevent any decrease in the electromotive force of the fuel cell and to improve its starting characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a power supply device for an automobile that uses a combination of a battery and a fuel cell, and that improves the starting characteristics of the fuel cell at low temperatures.

(b) Conventional technology
It is used under the border, and is sometimes used in sub-zero or extremely cold regions. When used in such a low-temperature environment, a large amount of electric power is required to start the engine, so the power source must be able to secure sufficient electromotive force even at low temperatures. Therefore, the conventional method of
However, the so-called 2, which is chargeable and dischargeable, has been used conventionally.
It is conceivable to use a fuel cell in combination with a battery for the purpose of supporting a secondary battery (any secondary battery is sufficient).

However, fuel cells have the problem of poor power generation efficiency at low temperatures.

(Object of the Invention and Invention The present invention has been made in view of the above-mentioned points.It is an object of the present invention to improve the starting characteristics of the fuel cell at low temperatures in an automobile power supply device that combines a battery and a fuel cell. For the purpose.

In order to achieve this objective, a heating means for heating the electrolyte of the fuel cell was provided, and when the temperature of the electrolyte was below a predetermined temperature, electricity was supplied to the heating means by a battery to heat the electrolyte. .

(Middle Embodiment FIG. 1 shows an embodiment of an automobile power supply device according to the present invention.

In the figure, numerals 4' and 6 indicate the container of the fuel cell, 2 indicates the fuel electrode which electrochemically oxidizes a liquid such as methanol, which is placed inside the container 1), and 3 indicates the container 1. A diaphragm 4 is provided between the fuel electrode 2 and the oxygen electrode 3. 5 is an oxygen electrode that electrochemically reduces oxygen in the air. Drainage 0.6 is air intake 0.7
8 is an exhaust port for carbon dioxide gas generated at the fuel electrode 2, and 8 is an exhaust port for water vapor and unreacted nitrogen gas in the air. 9 is a liquid temperature sensor such as a thermistor that detects the temperature of the electrolytic solution IO; 1
Reference numeral 1 denotes a heater made of a resistor such as carbon that heats the electrolytic solution 10, and its surface is thinly coated with an insulator such as Teflon to avoid electrical contact with the fuel FHG 2. I2 is the electric current fy detected by the liquid temperature sensor 9.
f A controller that outputs a switching signal according to the liquid temperature, 1
Reference numeral 3 indicates that the switch 14 is connected to the contact a on the heater 11 side of the fuel cell (shown by the solid line) based on the switching signal from the controller 12.
, a' and contacts S and b'' on the electrodes 2 and 3 side (broken line), 15 is a battery (secondary battery), and contacts c and c' of switch 14 are connected to the positive and negative electrodes. has been done.

During operation of the fuel cell, when the electrolyte temperature detected by the liquid temperature sensor 9 is below a predetermined temperature (for example, 0° C.), the switch 14 is activated by the switching circuit 13 to connect contacts a and a based on a switching signal from the controller 12. ' is connected to the side. As a result, heater 1 from batch IJ-15
1 is energized and the heater is heated. In this way, electrolyte 10
is heated and reaches a predetermined temperature (for example, 0°C),
In response to a switching signal from the controller 12, the switch 4 is switched to contact b' via the switching circuit 13. Thereafter, the electromotive force of the fuel cell is supplied to the battery 15 as a load, and the battery 15 is charged.

In this way, when the temperature is low, the battery supplies electricity to the heater provided in the container and heats the electrolyte, thereby preventing a drop in electromotive force.

The starting characteristics of the fuel cell can be improved.

FIG. 2 shows another embodiment of the automotive power supply device according to the present invention. In the figures, the same components as those in the embodiment shown in FIG. 1 are designated with the same reference numerals.

A fuel cell is constructed by stacking jm constant IO battery cells, and in this embodiment, three battery cells are stacked as an example.

The fuel jf:) electrode 16 used in this embodiment is a porous carbon plate 16a with excellent conductivity as a carrier, and a small amount of platinum or tin is adhered thereon to form an electrode 16b.
The carbon plate 16a functions as a heater. Electrode plate 16
is provided with one current collecting terminal electrically connected to the carbon plate 16a and the surface electrode 16b, and another current collecting terminal electrically connected only to the carbon plate 16a.

Reference numerals 14a, 14b, and 14c are switches which are switched between contacts a and b in conjunction with a switching circuit [3].

Now, when the electrolyte temperature detected by the liquid temperature sensor 9 is lower than a predetermined temperature (for example, 0° C.) at a low temperature, the switches 14a and 14b are activated based on a switching signal from the controller 12.

14c is linked by the switching circuit 13 to contact a (solid line side)
can be switched to As a result, Kutsute! Electricity is applied in series from J-15 to the carbon plate 16a of the fuel electrode 16 in each container l, heating it and raising the temperature of the electrolytic solution 10. When the temperature of the electrolytic solution 10 rises to a predetermined temperature (for example, 0° C.), the switches 14a, 14b, and 14c are operated in conjunction with the switching signal from the controller I2 to close contact b (dashed line side).
can be switched to As a result, the electromotive force generated between the fuel electrode 16 and the oxygen electrode 13 in each mold tank l is added in series and supplied to the fuel electrode 15 as a load.
Charge 15. At this time, since the temperature of the electrolytic solution is higher than the predetermined temperature, the electromotive force obtained as a result of one power generation does not decrease, and good starting characteristics can be obtained.

For example, when starting a fuel cell in a cold region, the electric capacity of the battery itself is limited to room temperature (for example, 25
Since the battery has about 1/3 of its capacity at temperatures (°C), this electrical energy of the battery is used to improve the starting characteristics of the fuel cell, and when the fuel cell reaches near its rated temperature, the power generated by the fuel cell is increased. lff makes efficient use of power by supplying power to the battery and charging the battery.
1 can be done.

Here, an example has been shown in which the electrolytic solution temperature is detected and the electrolytic solution is heated when the temperature is low, but other methods (such as heating the entire fuel cell by using the battery container itself as a heater) are also possible.

(Effects of the Invention As explained above, the present invention provides a vehicle that uses a combination of a battery and a fuel cell as a power supply device for an automobile. A heating means for heating the fuel cell is provided, and the electrolytic solution is kept at a temperature below a predetermined temperature. Since the fuel cell is heated by supplying electricity to the battery, it is possible to improve the starting characteristics of the fuel cell at low temperatures and to provide high efficiency as a power source.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of one embodiment of the power supply device for an automobile according to the present invention, and FIG. 2 is a schematic diagram of another embodiment of the power supply device for a vehicle according to the present invention. l...Fuel cell container 2...Fuel electrode 3...
Oxygen electrode 4...Diaphragm 9...Liquid temperature sensor 10...Electrolyte 11...Heater
12...Controller 13...Switching circuit
14... Switch 15... Battery patent applicant Nissho Jidosha Co., Ltd. Agent Patent attorney Hiroshi Suzuki Figure 1 Figure 2

Claims (1)

[Claims] A power supply device for an automobile equipped with a battery and a fuel cell, comprising a heating means for heating an electrolyte of the fuel cell, and an energizing means for energizing the heating means by a battery when the temperature of the electrolyte is below a predetermined temperature. An automotive power supply device characterized by: