JPH11325984A - Power supply for lp gas meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need of frequent change of cells as a power source of an LP gas meter. SOLUTION: A sec. cell 9 is provided as a power source of an LP gas meter, and a thermoelectric generator unit 13 for charging the sec. cell 9 is provided between a gas outlet 11 of an LP gas bomb 1 and piping 5 and has a thermoelectric element disposed on the inner wall of a piping in a housing, utilizing the Seebeck effect for generating an electromotive force due to the temp. difference. The LP gas generates the heat of vaporization in use to reduce its temp. more than the open air temp. and the thermoelectric generator unit 13 generates an electromotive force based on the temp. difference between them, thereby charging the sec. cell 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply for an LP gas meter for driving an electric component such as a sensor for detecting gas consumption.

[0002]

2. Description of the Related Art A recent LP gas meter is a so-called microcomputer meter using electric or electronic parts.
Such an LP gas meter requires a power supply for driving a sensor or the like used for detecting gas usage, detecting gas leakage, and the like. At present, a battery composed of a primary battery is generally used as a power source for driving these sensors and the like (for example, see Japanese Patent Publication No. Hei 6-23610 and Japanese Patent Publication No. Hei 4-23169).

[0003]

However, when a primary battery is used as a power source of an LP gas meter, a troublesome operation of replacing the battery when the battery is exhausted is required. In addition to detecting gas leaks, the use of many other sensors and liquid crystal display of gas consumption are expected to increase the power consumption due to computerization, so the frequency of battery replacement due to battery exhaustion will increase. .

Further, it is required to replace the LP gas meter after it has been used for 10 years.
Since it is required to continue using the battery for a year, it is necessary to repeatedly replace the battery during the continuous use.

Therefore, an object of the present invention is to eliminate the need for frequent battery replacement as a power supply device for an LP gas meter.

[0006]

According to one aspect of the present invention, there is provided a secondary battery serving as a power supply for driving an electric component such as a sensor for detecting a gas usage amount;
A thermoelectric element for charging the secondary battery is provided.

[0007] According to the power supply device of the LP gas meter having such a configuration, the secondary battery is charged by the thermoelectric element, the life of the battery is prolonged, and the frequency of battery replacement is reduced.

According to a second aspect of the present invention, in the configuration of the first aspect, the thermoelectric element generates an electromotive force due to a difference between the LP gas and the outside air temperature.

[0009] According to the above configuration, the temperature of the LP gas is lowered by the heat of vaporization during use and becomes lower than the outside air temperature. The temperature difference causes the thermoelectric element to generate an electromotive force and charge the secondary battery.

According to a third aspect of the invention, in the configuration of the second aspect, the thermoelectric element is provided on an inner wall of a gas flow path through which the LP gas flows.

According to the above configuration, when the LP gas flows through the gas flow path, the thermoelectric element installed on the inner wall of the LP gas absorbs heat from the outside air outside the gas flow path and radiates heat to the LP gas.
This generates an electromotive force.

According to a fourth aspect of the present invention, in the configuration of the third aspect, the gas passage in which the thermoelectric element is installed is formed by a hollow housing connected to a pipe connecting the LP gas cylinder and the LP gas meter. ing.

According to the above configuration, the LP gas flows through the gas flow path in the housing, so that the thermoelectric element installed on the inner wall absorbs heat from the outside air outside the gas flow path,
The heat is released to the gas, thereby generating an electromotive force.

According to a fifth aspect of the present invention, in the configuration of the fourth aspect, the housing is provided near a gas outlet of the LP gas cylinder.

According to the above configuration, the thermoelectric element provided in the housing efficiently radiates heat to the lower-temperature LP gas after vaporization of the gas outlet of the LP gas cylinder.

According to a sixth aspect of the present invention, in the configuration of the fifth aspect, a heat absorbing fin is provided on an outer wall of the housing.

According to the above configuration, the heat of the outside air is efficiently transmitted to the housing via the heat absorbing fins and transmitted to the thermoelectric element.

According to a seventh aspect of the present invention, in the configuration of the first aspect of the present invention, during the wiring of the charging current flowing from the thermoelectric element to the secondary battery, the flow of the current flowing in the opposite direction to the charging current is controlled. A blocking diode was provided.

According to the above configuration, when the outside air temperature is lower than the LP gas temperature or when thermoelectric power generation is not performed, the backflow of current from the secondary battery to the thermoelectric element is avoided.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.
It is a schematic block diagram of the gas supply equipment using the power supply device of P gas. The LP gas cylinder 1 containing LP gas and the LP gas meter 3 are connected by a pipe 5,
Gas is supplied to combustion equipment such as a hot water heater and a gas stove (not shown) by a gas supply pipe 7 connected to the gas meter 3.

The LP gas meter 3 is a so-called microcomputer meter which is provided with a sensor for detecting gas consumption and a sensor for detecting gas leakage, and is a so-called microcomputer meter, and serves as a power source for driving these electronic or electric components. ,
A secondary battery 9 such as a nickel-cadmium battery is built in.

On the other hand, the gas outlet 11 of the LP gas cylinder 1
A thermoelectric power generation unit 13 is provided between and the pipe 5. The thermoelectric generation unit 13 is an enlarged A of FIG.
As shown in FIG. 2 which is a cross-sectional view of FIG. 2A, a hollow housing 15 through which LP gas flows is provided. Housing 15
Has four side walls 19 forming a hollow portion 17 as a gas passage having a substantially square cross section, and end plates 21 for closing openings at both ends in a direction perpendicular to the paper surface in FIG. L
At the center of the end plate 21 on the side of the P gas cylinder 1, a through hole 21a is formed as shown in FIG. 2, and the gas outlet 11 is connected to the through hole 21a. On the other hand, though not shown, a through hole similar to the above is also formed in the end plate 21 on the pipe 5 side,
The pipe 5 is connected to this through hole.

A thermoelectric element 23 is provided on an inner wall 19a of the housing 15. As shown in FIG. 3, the thermoelectric element 23 has a p-type semiconductor 25 and an n-type semiconductor 27 connected in series with each other. In this case, the Seebeck effect in which an electromotive force E is generated by a temperature difference T between the two parts is used as a low-temperature heat radiation side of the metal plate 31 of the section.

When the LP gas is used, the temperature thereof becomes lower than the outside air temperature due to heat of vaporization. When the temperature drop of the LP gas when one household gas stove was actually used was measured, a temperature drop of 1.8 ° C. was measured at the outlet of the LP gas cylinder. Therefore, the thermoelectric element 23 here is configured to absorb heat from high-temperature outside air and release heat to low-temperature LP gas.

As an example of thermoelectric power generation utilizing the Seebeck effect, there is an example of an electronic wrist watch using body temperature as a heat absorbing source in JP-A-63-20881. In this example, twice C
2.65 V electromotive force is obtained with 7000 thermoelectric elements at the temperature difference of. Assuming that the electromotive force is simply proportional to the temperature difference and the number of elements, if the temperature difference between the LP gas and the outside air is 1.8 degrees C and the number of elements is 10000, the electromotive force is (1.8 / 2). × (10000/7000) × 2.
65 = 3.4 V, which is sufficient for use as a power source for the LP gas meter. Also, when more power is required, the installation space is less restricted compared to the electronic wristwatch described above, so it is relatively easy to increase the number of thermoelectric elements, and it is possible to easily cope with the increase in power. .

Lead wires 33 as wirings respectively drawn from the p-type semiconductor and the n-type semiconductor of the thermoelectric element 23
And 35 are connected to a secondary battery 9 built in the LP gas meter 3, and the above-described electromotive force E is applied to the secondary battery 9 so that a charging current flows. A lead wire 33 through which a charging current flows from the thermoelectric element 23 to the secondary battery 9 is provided with a diode 37 that blocks a current flow in a direction opposite to the charging direction. Further, the thermoelectric elements 23 installed on each inner wall 19a are connected to each other by leads 39.

Heat absorbing fins 41 are mounted on the outer wall 19b of the housing 15. The heat absorbing fins 41 are attached to the outer wall 1.
The bottom plate portion 41a is in close contact with the bottom plate portion 9b, and a plurality of fin portions 41b are formed to protrude outward from the bottom plate portion 41a.

Next, the operation will be described. When the LP gas is used, the liquefied gas in the LP gas cylinder 1 decreases to a temperature lower than the outside air temperature due to heat of vaporization at the time of vaporization. As a result, an electromotive force is generated by the Seebeck effect based on the temperature difference between the LP gas and the outside air temperature.

The generation of the electromotive force causes the lead wires 33, 3
The charging current is supplied to the secondary battery 9 in the LP gas meter 3 connected by 5 to perform a charging operation. This allows
The secondary battery 9 can be used continuously for a long period of time, and frequent replacement of a battery which is a power supply for driving electronic or electric components such as sensors in the LP gas meter 3 becomes unnecessary.
Convenience is improved.

Since the thermoelectric power generation unit 13 is directly attached to the gas outlet 11 of the LP gas cylinder 1, the thermoelectric element 23 comes into contact with the lower-temperature LP gas immediately after vaporization, and the thermoelectric effect is reduced. It works well. It is preferable that the thermoelectric power generation unit 13 is mounted as close as possible to the LP gas cylinder 1. Good.

Further, since the heat absorbing fins 41 are provided on the outer wall 19b of the housing 15 in the thermoelectric power generation unit 13, the outside air heat is efficiently absorbed by the thermoelectric element 23, and the charging efficiency for the secondary battery 9 is improved. I do.
Further, since the diode 37 is provided on the lead wire 33 through which the charging current flows from the thermoelectric element 23 toward the secondary battery 9, even if the outside air temperature becomes lower than the temperature of the LP gas, the diode 37 is provided in the opposite direction to the charging current. The flow of current is prevented, and the current can be prevented from flowing from the secondary battery 9 to the thermoelectric generation unit 13 even when thermoelectric generation is not performed.

[0033]

As described above, according to the first aspect of the present invention, a secondary battery serving as a power source for driving an electric component such as a sensor for detecting a gas usage amount, and the secondary battery With the configuration including the thermoelectric element for charging, the secondary battery serving as a power source can be used continuously for a long time without frequently performing complicated battery replacement, and the convenience can be improved.

According to the second aspect of the present invention, the temperature of the LP gas is lowered by the heat of vaporization during use and becomes lower than the outside air temperature. Therefore, the thermoelectric element generates an electromotive force based on this temperature difference, Battery can be charged.

According to the third aspect of the present invention, the thermoelectric element installed on the inner wall of the gas flow path absorbs heat from the outside air outside the gas flow path and radiates heat to the LP gas flowing through the gas flow path.
An electromotive force can be generated to charge a secondary battery.

According to the fourth aspect of the present invention, the thermoelectric element installed on the inner wall of the housing absorbs heat from outside air outside the housing and radiates heat to the LP gas flowing in the housing, thereby generating an electromotive force. The next battery can be charged.

According to the fifth aspect of the present invention, the housing is
Because it is located near the gas outlet of the LP gas cylinder, the thermoelectric element comes into contact with the LP gas that is lower in temperature after vaporization, and heat is efficiently released to the LP gas and charging efficiency is improved. I do.

According to the sixth aspect of the present invention, since the heat absorbing fin is provided on the outer wall of the housing, the heat of the outside air can be efficiently transmitted to the thermoelectric element through the heat absorbing fin.

According to the seventh aspect of the present invention, since a diode is provided in the middle of the wiring of the charging current flowing from the thermoelectric element to the secondary battery, the diode blocking the current flowing in the opposite direction to the charging current. The backflow of current from the secondary battery to the thermoelectric element can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of gas supply equipment using an LP gas power supply device according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along the line AA of FIG. 1;

FIG. 3 is a diagram illustrating the operation of the Seebeck effect used in the thermoelectric generation unit of the power supply device of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 LP gas cylinder 3 LP gas meter 5 piping 9 secondary battery 11 gas outlet 15 housing 17 hollow part (gas flow path) 19a inner wall 19b outer wall 23 thermoelectric element 33, 35 lead wire (wiring) 37 diode 41 heat absorbing fin

Claims (7)

[Claims] An LP comprising: a secondary battery serving as a power supply for driving an electric component such as a sensor for detecting a gas usage amount; and a thermoelectric element for charging the secondary battery. Power supply for gas meter. 2. The power supply device for an LP gas meter according to claim 1, wherein the thermoelectric element generates an electromotive force based on a difference between the LP gas and the outside air temperature. 3. The power supply device for an LP gas meter according to claim 2, wherein the thermoelectric element is installed on an inner wall of a gas flow path through which the LP gas flows. 4. A gas passage in which a thermoelectric element is installed is LP
The power supply device for an LP gas meter according to claim 3, wherein the power supply device is formed by a hollow housing connected to a pipe connecting the gas cylinder and the LP gas meter. 5. The power supply for an LP gas meter according to claim 4, wherein the housing is provided near a gas outlet of the LP gas cylinder. 6. The power supply device for an LP gas meter according to claim 5, wherein heat absorbing fins are provided on an outer wall of the housing. 7. A method according to claim 1, further comprising the step of: providing a diode for preventing a flow of a current flowing in a direction opposite to the charging current, in the middle of wiring of a charging current flowing from the thermoelectric element to the secondary battery. A power supply device for the LP gas meter according to the above.