JP2022027050A - buoy - Google Patents

Abstract

To provide a buoy capable of generating power in various attitudes by having arrangement of thermoelectric elements relaxed.SOLUTION: A buoy including a floating body includes: a closed housing provided with a heat accumulating unit on an inner periphery surface as the floating body; a first heat transmission unit and a second heat transmission unit coming into contact thermally with the heat accumulation unit on an opposite side of the first heat transmission unit respectively exposed outside the closed housing; a plurality of electro-thermal power generation units retained in a sealed housing liquid-tightly as well as carrying out electro-thermal power generation by difference in temperature between the first heat transmission unit and the second heat transmission unit; and an electronic device connected to the plurality of electro-thermal power generation units and having power supplied.SELECTED DRAWING: Figure 2

Description

The present invention relates to a buoy (buoy) floating on water on which an energy harvesting device is mounted.

Conventionally, this type of buoy is, for example, the one shown in Patent Document 1, in which a float having a shape horizontally flat with respect to a floating water surface, a chamber fixed to the float, and a thermoelectric power generation element mounted therein are used. It has a rechargeable battery and has a structure that transfers heat to the thermoelectric power generation element.

Japanese Patent No. 5978963

However, in the above-mentioned conventional buoy, since the buoy uses a flat float, the arrangement of the thermoelectric power generation elements is fixed, so that there is a problem that power can be generated only when the temperature is higher than the seawater temperature (or vice versa). In addition, since a flat float is used, there is a problem that it can be mounted only on a buoy whose front and back can be fixed to the sea surface due to its buoyancy, center of gravity and shape. Generally, a thermoelectric power generation element is composed of a high temperature side electrode and a low temperature side electrode, and power is generated by arranging a high temperature side electrode on the high temperature side and a low temperature side electrode on the low temperature side, but vice versa.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a buoy capable of generating electricity in various postures by relaxing the arrangement of thermoelectric power generation elements.

The buoy of the present invention is a buoy including a floating body, and the closed housing having a heat storage portion on the inner peripheral surface as the floating body, a first heat transfer portion exposed to the outside from the closed housing, and the first heat transfer portion, respectively. It has a second heat transfer section that is in thermal contact with the heat storage section on the opposite side of the first heat transfer section, is held liquid-tightly in the closed housing, and has the first heat transfer section and the second heat transfer section. It is characterized by having a plurality of thermoelectric power generation units that generate heat electricity by a temperature difference between the heat units, and an electronic device connected to the plurality of thermoelectric power generation units to supply power.

According to the power generation device of the present invention, it is possible to provide a buoy capable of generating power in various postures by relaxing the arrangement of a plurality of thermoelectric power generation units in the buoy.

It is a perspective view which conceptually shows the buoy of 1st Example. It is sectional drawing which shows the buoy cut along the line xx of FIG. It is sectional drawing which conceptually shows the buoy of 1st Example. It is sectional drawing which conceptually shows the buoy of 1st Example. It is sectional drawing which conceptually shows the buoy of 1st Example. It is sectional drawing which conceptually shows the buoy of 2nd Example.

Hereinafter, the power generation device according to the embodiment of the present invention will be described with reference to the drawings. In the examples, components having substantially the same function and configuration are designated by the same reference numerals, so that duplicate description will be omitted.

(First Example)
(Explanation of configuration)
FIG. 1 is a perspective view showing a buoy 1 floating on the sea according to the first embodiment. FIG. 2 is a cross-sectional view showing a buoy 1 cut along the line xx of FIG. Inside the sealed buoy 1, a heat storage unit 2, a plurality of thermoelectric power generation units 3, an electronic device 4, and a power storage device 5 are arranged.

[Closed housing]
The buoy 1 includes a closed housing 1a (also referred to as an outer shell) as a floating body. A transparent wall such as a water-resistant resin or glass can be used for the closed housing 1a in order to block the influence of water or air and allow heat or electromagnetic waves to pass from the outside to the inside. Further, the closed housing 1a may have a heat insulating structure by creating a vacuum between the heat storage portion 2 and the transparent wall. It is preferable to use a transparent wall made of an appropriate material in consideration of the transmission characteristics of sunlight and infrared rays.

A heat storage unit 2 is provided on the inner peripheral surface of the closed housing 1a of this embodiment. The heat storage unit 2 defines the internal cavity SP (space where the heat storage unit is absent) inside the buoy 1 in a state of covering the inside of the outer shell of the buoy 1 as shown in FIG. The inner surface of the heat storage unit 2 may be covered with a known suitable heat insulating material (not shown) that covers the heat storage unit 2.

The electronic device 4 and the power storage device 5 can also be arranged in the cavity SP of the heat storage unit 2 of the buoy 1. According to this configuration, the temperature of the electronic device 4 and the like can be kept near, for example, an intermediate temperature between the maximum temperature and the minimum temperature of the external environment, thereby protecting the electronic device 4 and the like from temperature stress and making it stable. Can be operated.

The outer shape of the buoy 1 is a sphere, a polyhedron, a prismatic shape, a cylindrical shape, or the like, and is a shape that allows rotation due to disturbances such as waves and wind.

[Heat storage unit]
It is preferable that the heat storage unit 2 has a configuration capable of performing heat exchange (heat absorption and heat dissipation) with the external environment with higher efficiency. It suffices if the heat storage unit 2 can absorb electromagnetic wave energy in all directions and raise the temperature. Therefore, it is preferable that the heat exchange surface of the heat storage unit 2 has a dark color such as black. The heat exchange surface of the heat storage unit 2 is an outer surface of the heat storage unit 2 excluding the contact area with the thermoelectric power generation unit 3, that is, a surface facing the closed housing 1a.

The heat storage unit 2 preferably has a high heat storage property. Therefore, the heat storage unit 2 can be made of a commercially available material such as a black rubber material. The material of the heat storage unit 2 is not limited as long as it has characteristics similar to those of a black body.

As a modification, the heat storage unit 2 may be made of a solid metal or a non-metal. In this case, the heat storage unit 2 uses an aluminum block or a plastic block whose heat exchange surface is coated with black. Is preferable.

Further, the heat storage unit 2 may be made of a waterproof container in which the heat exchange surface of the heat storage unit 2 is coated with black and is filled with a liquid such as water. In this case, the heat storage unit 2 is connected to the thermoelectric power generation unit 3 on the wall of the container. The contact area has thermal conductivity. The liquid that fills the container may be any liquid as long as it does not easily spoil and freeze. For example, pure water, a mixture of pure water and antifreeze, or pure water and a preservative. Can be used as a mixture of. The liquid also includes a gel-like one.

Furthermore, a latent heat storage material may be used for the heat storage unit 2. In this case, the heat exchange surface of the heat storage unit 2 houses the phase change (phase transition) substance of the latent heat storage material in a waterproof container coated with black. The latent heat storage material utilizes the heat of fusion or solidification at the phase change temperature, such as sodium acetate hydrate, sodium sulfate hydrate, or paraffin of refined petroleum products, and is a liquid or solid having a constant specific heat. The heat storage unit 2 has a larger heat capacity than the heat storage unit including the heat storage unit 2.

Further, due to the structure, for example, if the entire heat storage unit 2 is not completely covered by the outer shell of the buoy 1 and waterproofing is ensured, a part of the heat storage unit 2 may be in contact with the external environment. The entire heat storage unit 2 may be in contact with the external environment as a closed housing 1a (outer shell).

[Thermoelectric power generation unit]
Each of the plurality of thermoelectric power generation units 3 has a high-temperature side heat transfer unit 3a and a low-temperature side heat transfer unit 3b having low thermal resistance, and a thermoelectric power generation element 3c having high thermal resistance that is sandwiched between them and has high thermal resistance. A heat insulating portion 3d made of a heat insulating material having high thermal resistance (for example, an air layer) is provided around the side surfaces of the high temperature side heat transfer portion 3a, the low temperature side heat transfer portion 3b, and the thermoelectric power generation element 3c. The heat insulating portion 3d prevents the temperature difference between both ends of the thermoelectric power generation element 3c (the high temperature side heat transfer portion 3a and the low temperature side heat transfer portion 3b) from being obtained.

As the thermoelectric power generation element 3c, any one capable of converting thermal energy into electrical energy can be used, but in this embodiment, for example, KELGEN manufactured by KELK, which utilizes the Seebeck effect, can be used. Each of the thermoelectric power generation units 3 is liquid-tightly held in the closed housing 1a to waterproof the inside of the buoy 1.

A plurality of thermoelectric power generation units 3 are arranged alternately on the front and back sides of the outer shell of the buoy 1. That is, in the plurality of thermoelectric power generation units 3, the high temperature side heat transfer unit 3a is oriented on the back side and the low temperature side heat transfer unit 3b is oriented on the back side so that the high temperature side heat transfer unit 3a is oriented on the front side and the low temperature side heat transfer unit 3b is oriented on the back side. Are arranged so that they are oriented.

As a modification, it is possible to form irregularities on the surface of only the low temperature side heat transfer portion 3b exposed to the outside of the thermoelectric power generation unit 3 to make the contact area with water or air as large as possible. Thereby, for example, when the heat storage unit 2 becomes higher than the air temperature due to solar radiation, it is cooled by the air and the thermoelectric power generation unit 3 can be electromotive.

[Electronic devices, etc.]
The thermoelectric power generation element 3c of each thermoelectric power generation unit 3 is connected to an electronic device 4 such as a wireless sensor by a wiring 6 (wiring of a positive electrode and a negative electrode). The electronic device 4 has, for example, a sensor function, an antenna function, and a control function. Further, the electronic device 4 is connected to the power storage device 5 by the wiring 6. The electronic device 4 and the power storage device 5 do not have to be in the buoy as long as the electric power is supplied from the inside of the buoy by the wiring 6. In this case, it is premised that the electronic device 4, the power storage device 5, and the wiring 6 are completely waterproofed. Examples of the electronic device 4 include a data transmission device, an underwater acoustic sensor, and the like in a poaching monitoring system.

(Explanation of operation)
For example, it is known that the temperature difference between the maximum and minimum daily temperatures in various parts of Japan is about 10 ° C on average, so even if the buoy 1 of this embodiment is placed in the sea near Japan, it will be one. The daily temperature difference is expected to be about 10 ° C.

Assuming the temperature in the sea near Japan, in any sea area on the earth, the heat storage part 2 is heated by the solar radiation in the daytime, while the heat storage part 2 is cooled by radiative cooling at night, and the day and night are repeated. Causes temperature changes.

Therefore, in the buoy 1 of the present embodiment, the heat storage unit 2 which is easily affected by heat from the sun at sea and one end (high temperature side heat transfer unit 3a or low temperature side heat transfer unit 3b) are in thermal contact with the outside air. A thermoelectric power generation unit 3 in which the other end (low temperature side heat transfer unit 3b or high temperature side heat transfer unit 3a) is in thermal contact with the heat storage unit 2 is provided, and the temperature of the heat storage unit 2 is raised or lowered according to the temperature change of the environment. Thus, a voltage proportional to the temperature difference automatically generated between the outside and the heat storage unit 2 can be taken out from the thermoelectric power generation unit 3. In the buoy 1 of the present embodiment, the high temperature side heat transfer unit 3a of the thermoelectric power generation unit 3 may receive the seawater temperature, the low temperature side heat transfer unit 3b may receive the air temperature, and vice versa. May be good.

The shape of the buoy 1 is a sphere or a cylinder, and rotation due to disturbances such as waves and wind is allowed. The high temperature side heat transfer unit 3a of a certain thermoelectric power generation unit 3 receives the temperature of the heat storage unit 2, the low temperature side heat transfer unit receives the temperature of the seawater temperature, and the other thermoelectric power generation unit 3 has a combination opposite to the above combination. Is receiving the temperature.

FIG. 3 shows the power generation operation of the buoy 1 in the daytime. The electromagnetic wave energy including sunlight reaches the buoy 1, and the electromagnetic wave energy transmitted through the outer shell of the buoy 1 is absorbed by the heat storage unit 2. Then, the temperature of the heat storage unit 2 rises, and the temperature of the heat storage unit 2 becomes higher than the seawater temperature.

Of the thermoelectric power generation units 3, the thermoelectric power generation unit 3 that receives the temperature of the heat storage unit 2 in the high temperature side heat transfer unit 3a and the seawater temperature in the low temperature side heat transfer unit 3b generates power. The generated electric power is transmitted to the electronic device 4 by the wiring 6. The electronic device 4 consumes the transmitted electric power by the electronic device 4 itself. The electronic device 4 stores the surplus electric power or the electric power transmitted during the period when it is not necessary to operate the main function in the electric storage device 5 by the wiring 6. The electronic device 4 may supply electric power insufficient for operation from the power storage device 5.

Since the buoy 1 can be located on the water so that most of the heat exchange surface of the heat storage unit 2 faces the sun, the heat storage unit 2 can efficiently receive sunlight even if the sunshine angle changes throughout the season.

FIG. 4 shows the power generation operation of the buoy 1 at night. Depending on the air temperature, the temperature of the heat storage unit 2 decreases, and the seawater temperature becomes higher. The daytime temperature condition of FIG. 3 is reversed, and among the thermoelectric power generation units 3, the high temperature side heat transfer unit 3a receives the seawater temperature, and the low temperature side heat transfer unit 3b receives the temperature of the heat storage unit 2. 3 generates electricity. Other operations are the same as the daytime power generation operation described above. In this way, power can be generated even in a situation where the temperature of the heat storage unit 2 becomes the seawater temperature and the temperature of the air temperature becomes higher in the nighttime situation.

FIG. 5 shows a power generation operation when the buoy 1 rotates due to a disturbance. Even if the buoy 1 rotates, one of the plurality of thermoelectric power generation units 3 arranged alternately on the front and back of the buoy 1 becomes a temperature condition capable of generating power, and the thermoelectric power generation is continued.

The outer shape of the buoy 1 is a sphere, a polyhedron, a prismatic shape, a cylindrical shape, or the like, and rotation due to disturbance such as waves or wind is allowed, but the shape of the buoy 1 is not necessarily limited to a rotating shape. This is because even in a shape that does not rotate, it is possible to generate power during the day and night by arranging the thermoelectric power generation units 3 alternately on the front and back sides.

Further, the plurality of thermoelectric power generation units 3 do not necessarily have to be arranged alternately on the front and back sides.

(Explanation of effect)
As described above, according to the first embodiment, by arranging the plurality of thermoelectric power generation units 3 alternately on the front and back sides, it is possible to obtain the effect that power generation is possible day and night. In particular, in the daytime, the heat storage unit 2 inside the buoy 1 absorbs electromagnetic wave energy including sunlight and raises the temperature, so that an effect that thermoelectric power generation can be efficiently obtained can be obtained.

By arranging a plurality of thermoelectric power generation units 3 uniformly and sparsely (evenly distributed) on the outer shell of the buoy 1, the effect that power can be generated even if the buoy 1 rotates in a plane perpendicular to the sea surface is obtained. Be done.

When the buoy 1 according to the present embodiment is used as a power source for an electronic device such as a wireless sensor, an independent power source that does not require power supply wiring from a commercial power source to the electronic device or battery replacement work can be obtained. The electronic device can be freely installed on the required water.

Further, the buoy 1 of this embodiment is installed on a water surface that can receive direct sunlight, and the heat storage unit 2 has a structure that is easily exposed to sunlight and is easily radiatively cooled at night. If the difference between the maximum temperature and the minimum temperature of 2 is made larger, the generated power can be further increased.

(Second Example)
FIG. 6 is a cross-sectional view conceptually showing the buoy 1 of the second embodiment. In this embodiment, instead of the cavity SP (space where the heat storage unit is absent) inside the heat storage unit 2 of the first embodiment, the inside of the buoy 1 is filled with a filling material all around the electronic device 4 and the power storage device 5. It is the same as the first embodiment.

As shown in FIG. 6, the heat storage unit 2 may be formed by completely filling the inside of the buoy 1, and it is sufficient that the heat storage unit 2 absorbs electromagnetic wave energy in all directions and can raise the temperature.

Also in this embodiment, a plurality of thermoelectric power generation units 3 for thermoelectric power generation are used, and the thermoelectric power generation units 3 are arranged alternately on the front and back sides, so that the temperature difference between the heat storage unit 2 and the seawater does not matter. Thermoelectric power generation can be performed in the same manner as in the first embodiment (even if it is inverted) or regardless of the direction of the temperature difference between the heat storage unit 2 and the temperature (even if it is inverted).

1 buoy 2 heat storage unit 3 thermoelectric power generation unit 3a high temperature side heat transfer unit 3b low temperature side heat transfer unit 3c thermoelectric power generation element 4 electronic device 5 power storage device 6 wiring

Claims (8)

A buoy that includes a floating body
A closed housing having a heat storage portion on the inner peripheral surface as the floating body,
Each has a first heat transfer section exposed to the outside from the closed housing and a second heat transfer section that is in thermal contact with the heat storage section on the opposite side of the first heat transfer section. A plurality of thermoelectric power generation units that are held liquid-tightly and generate thermoelectric power by the temperature difference between the first heat transfer unit and the second heat transfer unit.
An electronic device connected to the plurality of thermoelectric power generation units to supply electric power, and
A buoy characterized by having. The buoy according to claim 1, wherein the closed housing transmits heat or electromagnetic waves from the outside to the heat storage portion. The buoy according to claim 1 or 2, wherein each of the plurality of thermoelectric power generation units is provided with a heat insulating portion between the closed housing and the thermoelectric power generation unit. The buoy according to any one of claims 1 to 3, wherein the plurality of thermoelectric power generation units are uniformly distributed and arranged on the heat storage unit. The buoy according to any one of claims 1 to 4, wherein the buoy is surrounded by the heat storage unit and has a space in which the heat storage unit is absent. The buoy according to claim 5, wherein the electronic device is arranged in the space where the heat storage unit is absent. Claims 1 to 6 of the plurality of thermoelectric power generation units, wherein the first heat transfer section and the second heat transfer section are arranged so as to alternate on the front and back along the heat storage section. The buoy described in any one of the items. The buoy according to any one of claims 1 to 7, wherein the closed housing has a spherical shape, a polyhedron, a prismatic shape, or a cylindrical shape.

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