JP2014110201A - Remote measurement system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a remote measurement system capable of drastically reducing a frequency of maintenance such as exchange of a secondary battery even when not connected with a commercial power supply, and further, that has an independent power supply that enables stable long-time continuous drive without deterioration in performance even in a state that an air pressure outside the measurement device is reduced.SOLUTION: A remote measurement system uses a power supply system having at least a fuel cell device and a secondary battery and having a mechanism for charging the secondary battery by the fuel cell device, as a power supply. The fuel cell device comprises a mechanism capable of changing a pressure and/or a flow rate of air supplied to a fuel cell stack.

Description

The present invention relates to a telemetry system having an independent power source that can be stably driven for a long time without deterioration in performance even when the external air pressure is lowered. For example, it can be used in places with high altitudes and low atmospheric pressure such as high mountains, and can be used for monitoring necessary for monitoring of volcanoes, landslides, earthquakes and other disasters, and monitoring of the surrounding environment and conditions.

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

Even if it is not connected to a commercial power supply, the frequency of maintenance such as replacement of secondary batteries is greatly reduced, and even if the pressure outside the measuring device is lowered, it can be driven continuously for a long time without deterioration in performance. Provide a telemetry system with an independent power supply.

As a result of intensive studies, the present inventors have made an invention that can solve the problems by the following means.
In order to solve the above problems, the present invention provides the following telemetry system.

(1) A remote measurement system including at least a fuel cell device and a secondary battery, and using a power supply system having a mechanism for charging the secondary battery with the fuel cell device as a power source, the fuel cell device being a fuel cell A telemetry system comprising a mechanism capable of changing the pressure and / or flow rate of air supplied to the stack and the fuel cell stack.
(2) The fuel cell device has a mechanism for measuring the atmospheric pressure outside the fuel cell device, and a mechanism for controlling the pressure and / or flow rate of air supplied to the fuel cell stack from the measured atmospheric pressure value. (2) The telemetry system according to (1).
(3) The remote measurement system according to (1) or (2), wherein the fuel cell device is composed of a direct methanol fuel cell.
(4) The remote measurement system according to any one of (1) to (3), further including a mechanism for controlling a pressure of air supplied to the fuel cell stack in a range of a gauge pressure of 0.3 to 0.6 atm.
(5) The method according to any one of (1) to (3), including a mechanism for controlling a flow rate of air supplied to the fuel cell stack in a range of 0 to 13 L / min (temperature 25 ° C., external pressure) Telemetry system.

Even if the telemetry system of the present invention is not connected to a commercial power source, the frequency of maintenance such as replacement of the secondary battery is greatly reduced, and it can be continuously driven over a long period of time without being particularly affected by the altitude. .

It is a block diagram which shows an example of this invention. It is a block diagram which shows an example of this invention.

The remote measurement system according to the present invention is a remote measurement system using a power supply system having a fuel cell device and a secondary battery, and having a mechanism for charging the secondary battery by the fuel cell device, and the fuel cell device is a fuel cell. The air pressure or the air flow rate supplied to the stack and the fuel cell stack is changeable. A conceptual diagram is shown in FIG. The type, structure, number, etc. of remote measurement are not limited and can be selected arbitrarily. For example, rain gauge, seismometer, temperature / humidity meter, landslide sensor, densitometer, surveillance camera, infrared sensor, Barometer, anemometer, water level sensor, pressure sensor, displacement sensor, underground exploration, radioactive substance concentration sensor, radiation dose sensor, etc. In addition, it is useful to be used in combination with other devices such as a wireless communication device, and data obtained by remote measurement can be transmitted by the wireless communication device and remotely monitored at another place.

In the telemetry system of the present invention, a power supply system having a mechanism for charging a secondary battery by a fuel cell as a stand-alone power source is used together with remote measurement, and fuel can be stably supplied even at a measurement place with high altitude and low atmospheric pressure. It is characterized in that the battery can generate electricity. 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.

  In contrast, the telemetry system of the present invention can stably supply power to the secondary battery by the 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 energy is reduced, there is an advantage that the fuel cell can be further stabilized and driven for a long time by compensating for the decrease.

A fuel cell is a power generator having a mechanism that can generate electricity by a chemical reaction using a catalyst by supplying fuel such as hydrogen or methanol to the anode side and supplying air to the cathode side. Because of the power generation by chemical reaction rather than combustion, the exhaust gas has no cleanliness of NOx or SOx, has a clean characteristic, and has a characteristic of not placing a load on the environment of the installation site.

Furthermore, the direct methanol fuel cell uses a proton conductive ion exchange membrane as an electrolyte, the catalyst electrode fine particles and the gas diffusion electrode layer are directly joined to the surface of the membrane, and the anode side of the ion exchange membrane-electrode assembly. This is a power generation system that generates electric power through a chemical reaction using a catalyst by supplying an aqueous methanol solution to the cathode side. Unlike an internal combustion engine that generates combustion, explosion, etc., it is a generator that is quiet in operation in principle. Further, the exhaust gas is clean, has a characteristic that does not generate SOx and NOx, and has a characteristic that it does not place a load on the environment where the apparatus is installed.

  However, there is a problem that the life and output of the direct methanol fuel cell differ depending on the surrounding environment. A direct methanol fuel cell uses a proton-conducting 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. This is a power generation system using a chemical reaction that can extract electricity by catalysis by supplying air to the cathode side. Since the air supplied to the cathode side uses the surrounding air, when the atmospheric pressure in the surrounding environment is low, the problem of a decrease in output of the direct methanol fuel cell due to lack of oxygen is remarkable. Direct methanol fuel cells generate electricity at about 70 ° C. If too much air is supplied to the cathode side, depending on the temperature of the introduced air, the internal temperature may decrease, causing a problem of reduced output. It is remarkable.

  Therefore, the fuel cell device used in the present invention is characterized by having a mechanism capable of changing the flow rate or pressure of air supplied to the fuel cell stack. The air supply source is not particularly limited. For example, a well-known air pump or compressor such as a bellows type, a diaphragm type, an electromagnetic type, a piston type, or a water seal type can be used or combined. May be. The means for adjusting the air pressure or the air flow rate is not particularly limited, but includes a method for controlling the output of the air supply means, a valve of needle type, ball type, gate type, glove type, etc. A well-known thing, such as an air regulator, can be used and may be combined. However, since the fuel cell used in the remote measurement system of the present invention requires power generation by continuous operation, it is not preferable to store pressurized air in an air tank or the like and supply the stored air only when necessary. A method of piping from the air supply source directly to the fuel cell stack so that air can be constantly supplied and controlling the discharge amount of the supply source or controlling the air flow rate or pressure in the piping is preferable. A conceptual diagram is shown in FIG.

The flow rate and pressure of the air supplied to the fuel cell stack used in the remote measurement system of the present invention are adjusted to appropriate set values according to the output capacity of the fuel cell and the external atmospheric pressure value. When a direct methanol type fuel cell is selected as the fuel cell and used at an altitude of 1000 m to 4000 m, the air flow rate is 2 to 3 L / min (temperature 25 ° C., external pressure) at 20 W, and at 90 W according to the atmospheric pressure. The air flow rate is adjusted in the range of 9 to 13 L / min (temperature 25 ° C., external pressure), and when adjusting the air pressure, the gauge pressure is preferably adjusted in the range of 0.3 to 0.6 atm.

In the present invention, it is a preferable technique to install a pressure sensor for measuring the external pressure of the fuel cell device. It is possible to add a function of automatically adjusting the supplied air flow rate or pressure to an appropriate set value by feeding back the measured value output by the sensor to the air flow rate or pressure control circuit. With the above method, it is possible to operate the fuel cell under optimum conditions without using human hands. A conceptual diagram is shown in FIG.

  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 has a practical level of fuel cell technology.

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 If the voltage of the secondary battery drops below the set value, charge is performed.If the voltage of the secondary battery rises sufficiently, control is performed to stop charging. It is possible to keep the operation and the direct methanol fuel cell need not be moved unnecessarily, so that it is possible to operate with the minimum necessary 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. .

  In addition, the remote measurement system of the present invention has a feature that the fuel can be used efficiently because the fuel cell operates only when the voltage of the secondary battery decreases. When a direct methanol fuel cell is used as a fuel cell, it can be operated stably for a long period of time by adjusting the tank capacity of methanol or methanol aqueous solution as a fuel cell, and by setting the size of the methanol tank, Preferably, a telemetry system that does not require refueling for 10 days or more is desired. More suitably, it is preferable that there is no need to refuel for 15 days or longer, more preferably 30 days or longer. The capacity of the methanol tank is preferably 3L to 400L, more preferably 5L to 80L. If the capacity of the methanol tank is 3 L or less, the frequency of fuel change is high, which is not preferable. On the other hand, if it exceeds 400 L, safety considerations are necessary and transportation is inconvenient.

  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 a direct methanol fuel cell and a power generation system that uses natural energy, and a charge adjustment mechanism that can monitor the capacity of the secondary battery and charge it from the power generation system when necessary. Preferably there is. 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, EFOY1600JP (power generation amount: 65 W) manufactured by SFC Energy was used, connected to a lead storage battery GrandStarEB50 (50 Ah) manufactured by GS Yuasa, and a device with a total power consumption of 50 W was connected. The air supply pump was replaced with Nitto Koki VC0101 (discharge flow rate 10 L / min), and a finger valve (VHK2) manufactured by SMC was installed in the middle of the pipe connecting the air supply pump and the fuel cell stack. Using methanol fuel with a concentration of 90% and 80L, bring the above equipment at an altitude of 1000m, set the air supply flow rate to 6.5L / min (temperature 25 ° C, under external pressure), 24 hours / day After continuous operation, continuous use for about 60 days was possible.

(Comparative Example 1)
In Example 1, the EFOY1600JP standard specification VC0100-A1 (discharge flow rate 6 L / min) manufactured by SFC Energy was used as the air supply pump, and the finger valve was removed to perform continuous operation. It decreased to 90% and could only be used continuously for about 54 days.

(Example 2)
When the apparatus used in Example 1 was brought to an altitude of 3000 m above sea level, the air supply flow rate was set to 9.5 L / min (temperature 25 ° C., under external pressure), and continuous operation was performed for 24 hours / day, approximately Continuous use for 60 days was possible.

(Comparative Example 2)
In Example 2, VC0100 (discharge flow rate 6 L / min) of EFOY1600JP standard specification manufactured by SFC Energy was used as the air supply pump, and when the continuous operation was performed by removing the finger valve, the fuel cell output was 60% of that of Example 2. It was able to be used continuously only for about 36 days.

(Example 3)
As a direct methanol fuel cell, EFOY1600JP (power generation amount: 65 W) manufactured by SFC Energy was used, connected to a lead storage battery GrandStarEB50 (50 Ah) manufactured by GS Yuasa, and a device with a total power consumption of 50 W was connected. The air supply pump was replaced with Nitto Koki VC0101 (discharge flow rate 10 L / min), and a KOFLOC mass flow controller (MODEL 3660) was installed in the middle of the pipe connecting the air supply pump and the fuel cell stack. Furthermore, it set so that an air flow rate could be controlled to 5.8-10 L / min (temperature 25 degreeC, under external pressure) with the apparatus external pressure value measured with the atmospheric pressure sensor (SCP1000-D01) by a VTI technology company. Using 90% methanol fuel with a concentration of 90% and bringing the above device in an altitude of 4000 m and performing continuous operation for 24 hours / day, continuous use was possible for about 60 days.

(Comparative Example 3)
In Example 2, the EFOY1600JP standard specification VC0100 (discharge flow rate 6 L / min) manufactured by SFC Energy was used as the air supply pump, and the mass flow controller and the atmospheric pressure sensor were removed. It was reduced to 60% of the above, and it could only be used continuously for about 36 days.

Even if the telemetry system of the present invention is not connected to a commercial power source, the frequency of maintenance such as replacement of the secondary battery is greatly reduced, and it can be continuously driven over a long period of time without being particularly affected by the altitude. .

Claims (6)

A remote measurement system having at least a fuel cell device and a secondary battery, and using a power supply system having a mechanism for charging the secondary battery with the fuel cell device as a power source, the fuel cell device comprising: a fuel cell stack; A telemetry system comprising a mechanism capable of changing a pressure and / or a flow rate of air supplied to a fuel cell stack. The fuel cell device has a mechanism for measuring a pressure outside the fuel cell device and a mechanism for controlling the pressure and / or flow rate of air supplied to the fuel cell stack from the measured pressure value. The telemetry system according to claim 1. The remote measurement system according to claim 1, wherein the fuel cell device includes a direct methanol fuel cell. The telemetry system according to any one of claims 1 to 3, further comprising a mechanism for controlling a pressure of air supplied to the fuel cell stack in a range of a gauge pressure of 0.3 to 0.6 atm. The remote measurement system according to any one of claims 1 to 3, further comprising a mechanism for controlling a flow rate of air supplied to the fuel cell stack in a range of 0 to 13 L / min (temperature: 25 ° C, external pressure). The telemetry system according to claim 1, wherein the telemetry system is used at a high altitude.