JPS598278A - Liquid fuel cell - Google Patents

Abstract

PURPOSE:To eliminate use of a pump or blower by supplying by utilizing convection to be generated with a heater at least one of liquid fuel supplying to a fuel electrode or air supplying to an air electrode. CONSTITUTION:When heating elements 8 and 10 generats heat by current flowing from a power supply 12, liquid fuel 4 and air 6 are heated, and temperature difference between an upper layer and a lower layer is produced and convection is generated by their density difference. Thereby, a liquid fuel 4 is supplied to a fuel electrode 1 and air 6 is to an air electrode 2. A metal resistor such as tungsten, carbon resistor, or conductive ceramic resistor is used as the heating elements 8 and 10. Since the heating element 8 is immersed in the liquid electrolyte 4, insulating is necessary to prevent electrical shorting, and heating from the outside may be applied if the liquid electrolyte is conductive. Since rotating portions are eliminated, failure is decreased and a compact and light weight cell can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a liquid fuel cell that obtains drowsiness energy through an electrochemical reaction between liquid fuel and air.

FIG. 1 is a conceptual diagram of the main parts of a conventional liquid fuel cell.

In FIG. 1, 1 is a fuel electrode, 2 is an air layer, and 3 is an ion-permeable layer.It is necessary to supply liquid fuel to the fuel electrode 1 and air to the air electrode 2, but conventionally, A pump 5 was used to supply liquid fuel 4 to the fuel electrode, and a blower 7 was used to supply air 6 to the air electrode 2.

Therefore, the amount of liquid sent by the pump 5 must be controlled depending on the consumption status of the fuel 4, and the amount of air blown by the blower 7 must be controlled, and a control circuit for this purpose is required. Moreover, the power source for operating the pump 5, blower 7, and control circuit is generally a fuel cell itself, and the battery output fluctuates, making it difficult to control the operation of the pump 5, blower 7, and so on.

Furthermore, the volume of the fuel cell including the pump 5, the blower 7 and the control circuit, and the electric switch are large, and since the pump 5 and the blower 7 are rotating bodies, there is a drawback that failures are likely to occur.

The present invention has been made in view of the above, and an object of the present invention is to provide a liquid fuel cell that can supply liquid fuel and air without using a pump or blower.

A feature of the present invention is that a heating element is used to supply at least one of the liquid fuel supplied to the fuel electrode of a liquid fuel cell and the air supplied to the air electrode by utilizing a convection phenomenon caused by a temperature difference in the fluid. The point is that the structure is equipped with a supply means.
0 The present invention will be described in detail below with reference to the embodiments shown in FIGS. 2, 4, and 5, and FIG. 3.

FIG. 2 is a conceptual diagram showing an embodiment of the liquid fuel cell according to the present invention, and the same parts as those in FIG. The difference between FIG. 2 and FIG. 1 is that a heating element 8 and a temperature-sensitive switch 9 for turning on and off electricity to the heating element 8 are provided in place of the pump 5 in FIG. As shown in the figure, it is configured to allow convection including the fuel electrode 1, and a heating element [0
A temperature-sensitive switch 11 is provided to turn on and off energization to the heating element 10, and liquid fuel 4 and air 6 are supplied to the fuel electrode 1 and the air electrode 2, respectively, using the convection phenomenon caused by the temperature difference between the liquids. This is what I did.

The temperature-sensitive switches 9 and 11 are activated by detecting the temperature of the fuel cell body, and the contacts open when the set temperature 'vI is reached, and the contacts close when the temperature T2, which is a predetermined temperature lower than T1, is reached. It is composed.

FIG. 3 is a diagram for explaining the operation of the temperature sensitive switches 9 and 11, and the operation of FIG. 2 will be explained below with reference to FIG.

The liquid fuel 4 in contact with the fuel electrode 1 is consumed by the power generation of the fuel cell, and its concentration decreases. In a fuel cell that utilizes an electrochemical reaction, the amount of heat generated decreases as the fuel concentration decreases, and as a result, the concentration of the fuel cell body decreases. The temperature-sensitive switches 9, 11 detect this, and as shown in FIG. 3, the contacts of the temperature-sensitive switches 9, 11 close at the time t1 when the set temperature T decreases to T2''!.
The heating elements 8 and 10 are each energized by a power source 12 and generate heat. When the heating element 8.10 generates heat, the liquid fuel 4
The air 6 is heated and has a temperature difference with that of the upper layer, causing a convection phenomenon due to the density difference, and the liquid fuel 4 is supplied to the fuel electrode 1 and the air 6 is supplied to the air electrode 2. Along with this, the electrochemical reaction progresses, and the temperature of the fuel cell body rises again, and when it reaches the set temperature T1, the temperature-sensitive switch 9, 110 contact opens at time t2, and the heating element 8°1
0 is cut off. The same operation below will be performed automatically.
Moreover, it is repeated continuously.

Here, the power source 1 which is the energy source of the heating elements 8 and 10
2 does not necessarily mean that it may be the fuel cell itself or a separate power source. Alternatively, the heating elements 8 and 10 may be connected in series, and one temperature-sensitive switch may be used. As the heating elements 8 and 10, metal resistors such as tungsten, carbon resistors, conductive ceramic resistors, etc. can be used. Note that since the heating element 8 is immersed in the liquid/fuel 4, it is necessary to insulate it to prevent electrical short circuits. Particular care must be taken when the liquid fuel 4 is conductive. may be heated externally. It is preferable to use methyl alcohol as the liquid fuel 4 because it has good fluidity.

According to the embodiment of the present invention described above, since no pump or blower is used, there are no rotating parts, and a reduction in failures can be expected. In addition, if the fuel cell itself is used as a power source, there is a concern that the pump or blower may not rotate depending on the output voltage, but since the heating system uses heating elements 8 and 10, no problems will occur. do not have. Furthermore, since no pump or plow 7 is required, the entire device can be made smaller and lighter. Further, by energizing the heating element 10 using, for example, a startup signal, air can be promptly supplied to the air electrode 2, thereby shortening the startup time. In addition, when the battery temperature rises after startup and sufficient convection occurs, the heat-generating elements 8 and 10 are activated by the action of the temperature-sensitive switches 9 and 11.
Since power is cut off, energy consumption can be reduced.

FIGS. 4 and 5 are conceptual diagrams showing the main parts of other embodiments of the present invention, and the same parts as in FIGS. 1 and 2 are designated by the same reference numerals. In FIG. 4, the blower 7 in FIG. 1 is left as is, and only the pump 5 is replaced with a heating element 8 and a temperature-sensitive switch 9. In addition, in FIG. 5, the pump 5 in FIG. 1 is left as is, and only the blower 7 is replaced with the heating element 10.
This is a change to the temperature-sensitive switch 11. In this way,
Although the effect is not as good as that shown in Fig. 2, a certain effect can be obtained.

Note that the heating element 8 shown in FIGS. 2 and 4 is intended to promote convection by heating the liquid fuel 4, but in this case, check valves are provided upstream and downstream, or The flow path structure may be such that the high-frequency pressure loss is larger on the downstream side than on the upstream side, and the current flowing through the heating element 8 may be an intermittent current. In this way, a pumping effect occurs in which most of the liquid fuel 4 expanded by heating flows downstream, so that the liquid fuel 4 can be quickly pumped into 5 sq.
can be supplied to

In addition, in each of the above-mentioned embodiments, the temperature-sensitive switch 9°11 is used, but this can be replaced with a switch whose opening/closing is controlled using a temperature detection element and its output, or a semiconductor element whose conduction current is controlled. You can also get the same effect.

Note that the heating elements 8 and 10 may be provided for each cell, but
It may also be provided in a common pipe that supplies liquid fuel 4 or air 6 to several cells.

In this way, the number of heating elements can be reduced, which is economical.

As explained above, according to the present invention, liquid fuel and air can be supplied without using a pump or blower, the size and weight can be reduced, failures can be reduced, and energy consumption can be reduced. This has the effect of being able to reduce this.

[Brief explanation of the drawing]

Fig. 1 is a conceptual diagram of the main part of a conventional liquid fuel cell, Fig. 2 is a conceptual diagram of the main part of an embodiment of the liquid fuel cell of the present invention, and Fig. 3 explains the operation of a temperature-sensitive switch. The blank diagram, FIG. 4, and FIG. 5 are conceptual diagrams of the main part structure corresponding to FIG. 2 showing other embodiments of the present invention. 1...Fuel picture, 2...Air electrode, 4...Liquid fuel,
5...Pump, 6...Air, 7...Blower, 8,
10... Pyrogen (1 other person) $ l eyes

Claims (1)

[Claims] (1) In a liquid fuel cell that obtains electrical energy through an electrochemical reaction between liquid fuel and air, the liquid fuel supplied to the extreme pressure of the fuel of the liquid fuel cell and the air supplied to the air electrode 1. A liquid fuel cell, comprising a supply means using a heat generator that supplies at least one of them by utilizing a convection phenomenon caused by a temperature difference between fluids. 2. The liquid fuel cell according to claim 1, wherein the heating element generates heat when energized. 3. The heating element generates heat when energized,
The liquid fuel cell according to claim 1, wherein energization is controlled depending on the temperature of the fuel cell main body. 4. The liquid fuel cell according to claim 1, 2, or 3, wherein the liquid fuel is methyl alcohol.