JP2014110718A - Remote measuring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a remote measuring system capable of continuous drive over a long period of time without being influenced by surrounding environment and weather, by significantly reducing a frequency of maintenance such as replacement of a secondary battery even if not being connected with a commercial power supply.SOLUTION: A remote measuring system uses an electrical power system comprising: at least a direct methanol fuel cell and a secondary battery; and a mechanism for charging the secondary battery by the direct methanol fuel cell.

Description

The present invention is a telemetry system having an independent power source that is independent of the weather and the surrounding environment, can be continuously driven for a long time without maintenance, and has low noise. For example, it can be used for monitoring necessary for disaster monitoring such as monitoring of road surface freezing due to temperature, landslides, and earthquakes.

Until now, many things using a secondary battery have been proposed as an example of a measuring instrument in a remote place. For example, CO ₂ measurement (Patent Literature 1), environmental measurement such as temperature (Patent Literature 2), disaster detection (Patent Literature 3) and the like can be mentioned. However, these devices can only operate within the range of the capacity of the secondary battery, and maintenance such as replacement of the secondary battery is necessary when continuously used for a long period of time.

In order to supply electric energy to the secondary battery, it is possible to combine a wind power generator and solar power generation. However, since the power generation system uses natural energy, it is difficult to secure a stable power source.

JP 2012-83294 A JP 2009-89605 A JP 2001-283348 A

  Provide a remote measurement system that can be driven continuously for a long time without being affected by the weather or the surrounding environment, greatly reducing the frequency of maintenance such as replacement of secondary batteries, even when not connected to a commercial power source.

In order to solve the above problems, the present invention provides the following telemetry system.

(1) A remote measurement system using a power supply system having at least a direct methanol fuel cell and a secondary battery, and having a mechanism for charging the secondary battery with the direct methanol fuel cell.
(2) The remote measurement system according to (1), further comprising a mechanism for charging the secondary battery with one or more power generation systems selected from the group consisting of solar power generation, wind power generation, and hydropower generation.
(3) When the amount of charge from one or more power generation systems selected from the group consisting of solar power generation, wind power generation, and hydropower generation is insufficient, the direct methanol fuel cell operates to charge the secondary battery. (2) The telemetry system characterized by having a mechanism.
(4) The telemetry system according to any one of (1) to (3), wherein an operation sound at a place 1 m away is 40 dB or less.

The telemetry system of the present invention greatly reduces the frequency of maintenance such as replacement of secondary batteries even when not connected to a commercial power source, and can be continuously driven for a long time without being affected by the weather or surrounding environment. Is possible. Moreover, since it operates silently, the influence on measurement data can be reduced.

It is a block diagram of the telemetry system of this invention

The telemetry system of the present invention is a telemetry system having a power supply system having a remote measurement and a mechanism for charging a secondary battery with a direct methanol fuel cell as an independent power source. The type, structure, number, etc. of telemetry are not limited and can be arbitrarily selected. Moreover, it can also be used in combination with other devices such as a wireless communication device. For example, it is possible to adopt a configuration in which data obtained by remote measurement can be confirmed at another location by the wireless communication device. Examples of measurements include meteorological observation at remote locations with thermometers, hygrometers, barometers, rain gauges, etc., disaster measurements with seismometers, displacement meters, accelerometers, etc., and temperature measurements on power transmission lines, pipelines, etc. However, it is not limited to these.

The telemetry system of the present invention is characterized in that it has a power supply system having a mechanism for charging a secondary battery with a direct methanol fuel cell as an independent power source as well as remote measurement. In many cases, a commercial power source is used as a power source for remote measurement, but there is a problem that it is difficult to use the commercial power source in some places. When it is difficult to connect to a commercial power source, it has already been proposed to use a power generation system that uses natural energy, such as solar power generation, wind power generation, hydroelectric power generation, and geothermal power generation. Power generation has the problem that the amount of power generation decreases accordingly due to unseasonable weather such as snowfall and rain, and sunshine hours due to the surrounding environment. Wind power generation is too large even if the wind speed is too small. However, there is a problem that it is difficult to use depending on the installation location such as mountainous depressions, etc., and hydroelectric power generation has a problem that it cannot be generated if the rainfall decreases. Has a problem that the cost becomes large.

  On the other hand, the remote measurement system of the present invention can stably charge a secondary battery by a direct methanol fuel cell, and even when combined with a power generation system using natural energy such as solar power generation, When the power generation amount from the power generation system using the power source decreases, there is an advantage that the direct methanol fuel cell can be further stabilized and driven for a long time by compensating for the decrease.

A direct methanol fuel cell uses a proton conductive ion exchange membrane as an electrolyte, and catalyst electrode fine particles and a gas diffusion electrode are directly joined to the surface thereof. A methanol aqueous solution is provided on the anode side of the ion exchange membrane-electrode assembly. It is a power generation system using a fuel cell fueled with methanol that wants to use a chemical reaction that can extract electricity by catalysis by supplying air to the cathode side. Unlike an internal combustion engine, it is an essentially quiet generator because of its power generation through chemical reaction. In addition, since side reaction is slight because highly reactive methanol is used as fuel, the exhaust gas is clean, there are few problems that adversely affect the human body such as carbon monoxide poisoning, and NOx and SOx are not generated. is there.

  Other fuel cells use pure hydrogen as fuel, hydrogen generated by reforming methanol, etc., and liquids such as formic acid, dimethyl ether, hydrazine hydrate, and borohydride aqueous solution. Fuel cells to be used are known. However, when a high-pressure cylinder is used to store pure hydrogen, there is a problem that a lot of maintenance is required. In addition, when a hydrogen storage alloy is used, there is a problem that the amount of storage per weight is small and it is difficult to change the fuel. Furthermore, although hydrogen can be generated by a chemical reaction such as water and calcium hydride, it is difficult to control the reaction and it is difficult to cope with intermittent operation. When reforming methanol, etc., equipment for that is required, which causes problems of large size and weight of the device, and high temperature is required at the reforming part, which may affect the surroundings. is there. Fuel cells using other liquid fuels such as formic acid still have many technical problems and are difficult to use. In that respect, the direct methanol fuel cell is most suitable because it uses liquid methanol, has high energy density, is easy to handle, and the technology as a fuel cell is at a practical level.

By combining this direct methanol fuel cell with a secondary battery, using the secondary battery as a power buffer, and operating the direct methanol fuel cell while monitoring changes in the charging state and operating conditions of the secondary battery By adding a mechanism that performs charging when the secondary battery voltage drops below the set value and stops charging when the secondary battery voltage rises sufficiently, the secondary battery is always in the set range. It is possible to maintain the state of charge and to eliminate the need to move the direct methanol fuel cell unnecessarily, so that it is possible to operate with the minimum required fuel consumption. Therefore, fuel can be used effectively, and electricity can be supplied for a long time for remote measurement. Therefore, it is possible to operate telemetry constantly and stably in a highly reliable state.

The output of the direct methanol fuel cell is preferably in the range of 20 W to 2.5 kW, more preferably in the range of 25 W to 1 kW, and more preferably in the range of 25 W to 500 W. When the output is less than 20 W, the power supply amount may be insufficient. On the other hand, when it exceeds 2.5 kW, the heat generated by the side reaction is large and the size becomes large, so that it tends not to be suitable for a telemetry system.

The secondary battery connected to the direct methanol fuel cell is not particularly limited, but preferred examples include a lead storage battery, a nickel hydride battery, a nickel cadmium battery, a lithium ion battery, a lithium polymer battery, and a vanadium battery. As mentioned. Particularly preferred are lead storage batteries, nickel metal hydride batteries or lithium ion batteries. Lead acid batteries and nickel metal hydride batteries are highly safe batteries, and are effective in providing a highly reliable telemetry system in the telemetry system of the present invention. Since a lithium ion battery can be reduced in size, it can provide a merit that it is easy to carry. Moreover, as a secondary battery, what has durability in repeated charging / discharging is preferable, and a deep cycle lead acid battery, a nickel hydride battery, and a lithium ion battery are preferable.

As the capacity of the secondary battery, it is preferable to use a battery having a 5-hour rate capacity of 20 Ah to 3 kAh. Particularly preferred is 35 Ah to 2 kAh. If it is 20 Ah or less, the battery capacity tends to be insufficient, and if it exceeds 3 kAh, it tends to be too large. As an example, 20 Ah to 100 Ah when using a 20 W direct methanol fuel cell, 30 Ah to 160 Ah for 40 W, 40 Ah to 400 Ah for 100 W, 50 Ah to 1 kAh for 500 W, 80 Ah to 2 kAh for 1 kW are one standard. .

  The remote measurement system of the present invention has a feature of combining a direct methanol fuel cell and a secondary battery, and has a feature of excellent quietness as an independent power source. Because it generates electricity through a chemical reaction, it is quiet, unlike ordinary engine-type generators. In order to make use of this feature, the noise at a location 1 m away is preferably 40 dB or less, more preferably 30 dB or less. By setting the noise to 40 dB or less, it is possible to monitor the situation without being noticed by a suspicious person. A direct methanol fuel cell has a pump inside for supplying fuel or air. At that time, it is important to select a pump with as little sound as possible. For example, with a polystyrene foam, rubber, suspension, etc. The method for suppressing the vibration of the pump can be suitably used to reduce the sound. For example, it is preferable to use a diaphragm pump or a pump having a screw structure as the pump.

  In a preferred embodiment of the telemetry system of the present invention, since the direct methanol fuel cell operates only when the voltage of the secondary battery decreases, there is a feature that the fuel can be used efficiently, and methanol that is the fuel Alternatively, it is possible to operate stably for a long period of time by adjusting the tank capacity of the methanol aqueous solution, and preferably by setting the size of the methanol tank, preferably a remote measurement system that does not require fuel replacement for 10 days or more It is desirable to make it. More suitably, it is preferable that there is no need to refuel for 15 days or longer, more preferably 30 days or longer. As a capacity | capacitance of a methanol tank, 3L-80L is preferable, More preferably, it is 5L-30L. If the capacity of the methanol tank is 3L or less, the frequency of fuel change increases, which is not preferable. On the other hand, if the capacity exceeds 80L, the tank is not convenient to carry.

  In the present invention, the frequency of maintenance can be further reduced by combining solar power generation, wind power generation, and hydroelectric power generation in a power generation system using natural energy, and continuous driving for a long period of time becomes possible. Among power generation systems using natural energy, solar power generation is preferable because it is inexpensive and easily obtains high output. In the present invention, the power generation system using natural energy preferably has a mechanism for charging the secondary battery. The charging mechanism includes an adjustment mechanism between the direct methanol fuel cell and the power generation system using natural energy, and a charge adjustment mechanism that monitors the capacity of the secondary battery and can be charged from the power generation system when necessary. It is preferable. Each of the direct methanol fuel cell, the secondary battery, and the power generation system using natural energy may have an adjustment mechanism, or may be a mechanism that controls a plurality.

EXAMPLES Hereinafter, although this invention is demonstrated concretely using an Example, this invention is not limited to these Examples.

Example 1
As a direct methanol fuel cell, SFC Energy's EFOY900JP (output 40W) was connected to a Panasonic lead storage battery caos75B24L (48Ah), and a remote measurement system was constructed by connecting to a temperature and humidity measurement system with 5W power consumption. . When continuous operation was performed for 24 hours a day using 10 L of methanol as fuel, continuous use for about 54 days was possible. The noise was very quiet at 28 dB at a distance of 1 m from the telemetry system.

(Comparative Example 1)
In Example 1, when a direct methanol fuel cell was not connected and only a lead storage battery was used, it could be operated only for about 4 days. From this, it can be seen that when a direct methanol fuel cell is connected, it is possible to supply electricity to the remote measurement system for a long time and to operate stably.

(Example 2)
A solar power generation system with an output of 40 Wh was connected to the remote measurement system of Example 1. When tests were conducted in the mountainous area in winter, solar power generation was only less than expected due to lack of snow and sunshine hours, but continuous operation for about 110 days was possible.

(Comparative Example 2)
A solar power generation system with an output of 40 Wh was connected to the remote measurement system of Comparative Example 1. When the test was performed at the same place and time as Example 2, the storage battery was replaced 10 times during 90 days due to the shortage of the remaining storage battery capacity.

(Example 3)
A wind power system with an output of 40 Wh was connected to the telemetry system of Example 1. When a test was conducted in a mountainous area, continuous operation for about 80 days was possible.

(Comparative Example 3)
A wind power system with an output of 40 Wh was connected to the visual camera system of Comparative Example 1. When the test was conducted in a mountainous area, the storage battery was replaced 13 times during 90 days due to the shortage of the remaining storage battery capacity.

  The telemetry system of the present invention can provide a telemetry system that can be driven stably and for a long period of time with greatly reduced maintenance, and is excellent in reliability.

Claims (4)

A remote measurement system using a power supply system having at least a direct methanol fuel cell and a secondary battery and having a mechanism for charging the secondary battery with the direct methanol fuel cell. The remote measurement system according to claim 1, further comprising a mechanism for charging the secondary battery by one or more power generation systems selected from the group consisting of solar power generation, wind power generation, and hydropower generation. When the amount of charge from one or more power generation systems selected from the group consisting of solar power generation, wind power generation, and hydropower generation is insufficient, the direct methanol fuel cell operates to charge the secondary battery. The telemetry system according to claim 2. The telemetry system according to any one of claims 1 to 3, wherein an operation sound at a place 1 m away is 40 dB or less.