JP7191289B2 - thermal generator - Google Patents

Description

The present invention relates to a thermoelectric generator that converts light energy into electrical energy.

2. Description of the Related Art Conventionally, a technique of storing solar energy as heat and using the heat to generate power is known.
Japanese Patent Application Laid-Open No. 05-167104 (Patent Document 1) discloses a panel that uses a flat panel for thermoelectric generation, receives sunlight on one side, and stores the heat in a heat storage tank. A method of storing heat in the material is adopted.
The schematic structure thereof is shown in FIG. 9(A), and the thermoelectric element module 100 comprises a thermoelectric element 105 formed by joining a p-type semiconductor 101 and an n-type semiconductor 102 with a metal plate 103 to form a thermocouple. Adjacent thermoelectric elements 105 are electrically connected in series by metal terminals 106 . These thermoelectric element modules 100 are supported by a pair of ceramic substrates 108 and 109 .

FIG. 9(B) is a functional schematic diagram thereof, in which a heat storage tank 120 is brought into contact with one end side of the thermoelectric element module 100, and a heat storage material 121 is accommodated therein.
The sunlight is converged by the reflecting mirror 130 to heat the hot plate 122 of the heat storage tank 120 and heat the heat storage material 121 inside.
The heat of the heat storage material 121 is transferred to the thermoelectric element module 100, and the electrical energy generated in the thermoelectric element module 100 is taken out through the terminals 111 and 112. FIG.

However, according to this known example, since the heat storage tank is in contact with the thermoelectric element module only on one side, when power is generated at night using the stored heat, the heat tends to escape from the other side. There is a problem that the stored heat is not utilized effectively for power generation because of its low ratio.
In addition, it is essential that the heat storage material can be used repeatedly, but the document does not mention a sealing structure for the heat storage tank, and does not disclose a structure for effectively blocking contact with the outside air.

JP-A-05-167104

The problem to be solved by the present invention, in view of the above-mentioned problems of the prior art, is to provide a thermal power generator for converting light energy into electrical energy, in which heat stored in a heat storage material due to solar heat is converted into electrical energy without loss. To provide a structure which can be used and which does not cause deterioration of a heat storage material.

In order to solve the above-mentioned problems, a thermoelectric generator according to the present invention is a thermoelectric generator that converts light energy into electrical energy, the thermoelectric generator having a sealing portion at an end and a A sealed tubular container, a thermoelectric conversion unit provided on the inner surface of the tubular container, a heat storage unit provided inside the thermoelectric conversion unit, electrically connected to the thermoelectric conversion unit, and the sealing unit and a lead portion provided so as to penetrate the.

Further, the thermoelectric conversion part includes an annular hole transport part and an annular electron transport part that are alternately arranged in the tube axis direction via an insulating material, and the hole transport part and the electron transport part are electrically connected by a conductive portion.
Further, the insulating material is characterized by being made of a directional heat-conducting material having higher heat conductivity in the radial direction than in the axial direction of the tubular container.
In addition, the conductive portion includes a first electrode that is in contact with the inner peripheral surfaces of the adjacent hole transport portion and the electron transport portion to electrically connect them, and the adjacent electron transport portion and the hole transport portion. The second electrode is in contact with the inner surface of the tubular container, and the lead portion is connected to one of the electrodes. It is characterized by

The thermoelectric conversion part has the hole transport part arranged at one end in the axial direction and the electron transport part arranged at the other end, and the lead part abuts against the inner surface of the tubular container. is connected to the second electrode that is connected to the second electrode.
In addition, the insulating material includes a first electrode that abuts on the inner peripheral surfaces of the pair of hole transporting portions and the electron transporting portion, and another pair of the hole transporting portion and the electron transporting portion that are adjacent to the first electrode. A first insulating material disposed between the first electrode in contact with the inner peripheral surface, a second electrode in contact with the outer peripheral surface of the pair of the electron-transporting portion and the hole-transporting portion, and others adjacent thereto. a second insulating material disposed between a pair of the electron-transporting portion and a second electrode in contact with the outer peripheral surface of the hole-transporting portion, the outer peripheral portion of which is in contact with the inner surface of the tubular container. Characterized by

According to the thermoelectric generator of the present invention, the thermoelectric conversion section is provided inside the sealed tubular container, and the heat storage section is provided inside the thermoelectric conversion section. Since all the heat stored in is transferred from the inside to the thermoelectric conversion section and used for conversion into electrical energy, efficient thermoelectric conversion is performed without heat energy loss.
In addition, since the heat storage material forming the heat storage unit is stored in a sealed state in the tubular container whose ends are sealed, its deterioration can be suppressed.
Furthermore, the insulating material interposed between the hole transporting part and the electron transporting part constituting the thermoelectric conversion part is made of a directional thermal conductive material having a high thermal conductivity in the radial direction of the tubular container. , heat conduction from the sunlight or heat conduction from the heat storage unit functions effectively.

1 is a schematic cross-sectional view of a thermoelectric generator of the present invention; FIG. AA sectional view (A), BB sectional view (B), CC sectional view (C), and DD sectional view (D) of FIG. FIG. 2 is a partially enlarged view of FIG. 1; FIG. 4 is a partially enlarged view showing another arrangement of thermoelectric conversion elements; (Daytime) action explanatory drawing. (Nighttime) action explanatory drawing. Partial cross-sectional view of another embodiment. A partial cross-sectional view of still another embodiment. Explanatory drawing of a prior art.

FIG. 1 is a cross-sectional view showing the entire thermoelectric generator of the present invention, and FIGS. Fig. DD is a sectional view.
A cylindrical tubular container 1 is made of a translucent material such as a glass tube such as quartz glass or soda glass, and comprises a main body 2 in the center and sealing portions 3, 3 at both ends thereof. A thermoelectric conversion section 4 is provided on the inner surface of the body section 2 of the tubular container 1 .
The thermoelectric conversion section 4 has a thermoelectric conversion element 5 , an insulating material 8 and a conductive section 10 . The thermoelectric conversion element 5 consists of a hole transporting portion 6 and an electron transporting portion 7 which are both annular. are arranged at predetermined intervals.

An insulating material 8 is provided between the hole-transporting portion 6 and the electron-transporting portion 7 to prevent electrical continuity between them at an undesired portion.
As shown in detail also in FIG. protrudes further toward the inner surface of the tubular container 1 than the first hole-transporting portion 61 and the first electron-transporting portion 71 and contacts the inner surface of the tubular container 1 . Also, the second insulating material 82 between the first electron transporting portion 71 and the second hole transporting portion 62 is more tubular than the first electron transporting portion 71 and the second hole transporting portion 62 . It protrudes toward the center of the container 1 .

The conductive portion 10 is composed of a first electrode 11 and a second electrode 12. The first electrode 11 is in contact with the inner peripheral surfaces of the adjacent hole transport portion 6 and electron transport portion 7 to electrically connect them. In addition to the connection, the second electrode 12 is in contact with the outer peripheral surfaces of the adjacent electron transporting portion 7 and the hole transporting portion 6 to electrically connect them, and is in contact with the inner surface of the tubular container 1 .
1 and 3, the second electrode 12 in contact with the outer peripheral surface of the first hole transport portion 61 and the pair of first electron transport portions adjacent thereto. A first insulating material 81 is interposed between 71 and the second electrode 12 in contact with the outer peripheral surface of the second hole transport portion 62 to electrically insulate them.

On the other hand, the first electrode 11 abutted against the inner peripheral surfaces of the pair of first hole transporting portions 61 and the first electron transporting portion 71, and the other pair of second hole transporting portions adjacent thereto. A second insulating material 82 is interposed between the portion 62 and the first electrode 11 in contact with the inner peripheral surface of the second electron transport portion 72 to insulate them.
With such a configuration, the second electrode 12, the first hole transport portion 61, the first electrode 11, the first electron transport portion 71, the second electrode 12, the second hole transport portion 62, . . . Electrical connections are made.

The material of the hole transporting portion 6 and the electron transporting portion 7 may be either an organic material or an inorganic material.
CuPc, PEDOT/PSS, m-TDATA, TPD, α-NPD, TCTA, TAPC, or the like is used as the hole transport portion 6 made of an organic material. A p-type semiconductor made of a degenerate semiconductor is used as the hole transport portion 6 made of an inorganic material.
On the other hand, as the electron transport portion 7, Alq3, BCP, t-Bu-PBD, silole derivatives, BND, PBD, etc. are used in the case of organic materials, and n-type semiconductors made of degenerate semiconductors are used in the case of inorganic materials. be.

In order to improve the characteristics of the thermoelectric conversion element, it is useful to make each of the hole transporting portion 6 and the electron transporting portion 7 have a porous structure. By forming the porous structure, the hole transporting portion 6 and the electron transporting portion 7 become a low thermal conductivity material. Since heat is difficult to transfer to the element itself, it can be expected to further improve the performance of thermoelectric conversion by maintaining the temperature difference.

The first electrode 11 and the second electrode 12 forming the conductive portion 10 are made of metal such as copper, iron, titanium, aluminum and SUS, and transparent conductive materials such as TCO, TIO and FTO. In order to efficiently store heat in the heat storage section, which will be described later, it is preferable to use a transparent conductive material from the viewpoint of allowing light to effectively reach the heat storage section.
Between the conductive portion 10 (first electrode 11, second electrode 12) and the thermoelectric conversion element 5 (hole transport portion 6, electron transport portion 7), a bonding layer such as aluminum or silver solder is provided. good too.

PDMS or SiO ₂ is used as the insulating material 8 interposed between the hole transporting portion 6 and the electron transporting portion 7 .
The insulating material 8 is preferably made of a directional heat-conducting material having a higher heat conductivity in the radial direction than in the axial direction of the tubular container 1 . By doing so, the heat from the sunlight from the periphery of the tubular container 1 can be efficiently conducted to the heat storage section 13 located at the center of the tubular container 1, which will be described later.
As such a directional heat-conducting material, fibrous materials such as carbon fibers (including carbon nanotubes) and aluminum fibers are aligned in the radial direction of the tubular container 1 in a matrix made of a dielectric such as silicone resin or glass. can be used.

The interior of the tubular container 1 in which the thermoelectric conversion section 4 described above is formed is filled with a heat storage material that constitutes the heat storage section 13 .
Various heat storage materials such as sensible heat storage materials and latent heat storage materials can be used for this heat storage material. Deterioration of internal members is suppressed.
Paraffins, sugar alcohols, inorganic salt hydrates, aliphatic hydrocarbon compounds, esters, fatty acids and the like are used as such heat storage materials.

As described above, the tubular container 1 provided with the thermoelectric conversion unit 4 and filled with the heat storage material constituting the heat storage unit 13 is provided with the sealing units 3, 3 at both ends to seal the inside of the tubular container 1. doing.
The sealing portions 3, 3 are similar to the sealing portion structure such as the pinch seal in the arc tube in the lamp technology. Internal leads 16, 16 and external leads 17, 17 extending outward from the sealing portions 3, 3 are welded to the metal foils 15, 15 embedded in the sealing portions 3, 3 at both ends of the tubular container 1. A lead portion 18 is composed of these internal leads 16 and external leads 17 . Then, both ends of the tubular container 1 are softened by heating and crushed around the metal foils 15, 15 to form the sealing portions 3, 3. As shown in FIG. As a result, both ends of the tubular container 1 in which the heat storage material is enclosed are sealed, and the inside of the tubular container 1 is sealed in a liquid-tight state.
Also, in this embodiment, the internal leads 16, 16 in the sealing portions 3, 3 at both ends are connected to the second electrodes 12, 12, respectively.

In the present embodiment, the pinch seal structure is shown as the structure of the sealing portions 3, 3, but the structure is not limited to the pinch seal structure as long as it is a structure that allows conduction while maintaining airtightness against the external environment. For example, there is a shrink seal structure for shrink-sealing the metal foil portion, a step joint seal, and a structure for metallizing the end portion of the tubular container 1 as seen in a sapphire lamp and joining a sealing plate made of a metal plate or the like. Also good. In addition, in the shrink seal structure and the stepped seal, instead of the metal foil, a metal pipe may be welded to the glass, and the outer end portion of the metal pipe may be crimped and sealed.

Another embodiment is shown in FIG. 4. In this embodiment, the arrangement of the hole-transporting portion 6 and the electron-transporting portion 7 of the thermoelectric conversion portion 4 is different from that of the embodiment shown in FIG. is.
As shown in FIG. 4, the first electron transporting portion 71 is arranged at the left end in the axial direction, followed by the first hole transporting portion 61 with an insulating material 81 interposed therebetween. The inner peripheral surface of the first insulating material 81 extends inward so as to penetrate the first electrode 11 , and the outer peripheral surface is in contact with the second electrode 12 . By doing so, the first electron transporting portion 71 and the first hole transporting portion 61 are insulated from each other by the first insulating material 81 on the inner peripheral surface side of the ring, and are electrically connected on the outer peripheral surface side. .
In such an arrangement, the internal lead 16 is connected to the inner first electrode 11 .

Although not shown here, it is also possible to connect the internal lead 16 to the second electrode 12 on the outside by using the electron transporting portion 7 on the right side in the arrangement of FIG.
By changing the arrangement of the hole transporting portion 6 and the electron transporting portion 7 in this way, it is possible to configure the internal lead 16 to be connected to either the first electrode 11 or the second electrode 12 .
However, the structure in which the inner lead 16 is connected to the second electrode 12 arranged along the tube wall of the tubular container 1 has the advantage of simplifying the wiring work.

Next, the operation of the thermoelectric generator of the present invention will be described with reference to FIGS. 5 and 6. FIG.
FIG. 5 is a diagram of operation in the daytime for the configuration shown in FIGS. 1 to 3, in which the outside temperature of the tubular container 1 becomes higher than the inside temperature (the temperature of the heat storage section 13) due to the irradiation of sunlight. Heat from sunlight is conducted from the outside of the tubular container 1 to the heat storage section 13 inside the tubular container 1 through the insulating material 8 made of a directional heat-conducting material.
When the external temperature is higher than the internal temperature, the charge of the thermoelectric conversion element 5 moves toward the lower temperature side, that is, toward the central portion of the tubular container 1 .
That is, in the hole transport portion 6 of the thermoelectric conversion element 5, positively charged holes move from the high temperature side to the low temperature side (from the outer side to the inner side in the radial direction). Further, in the electron transport portion 7, electrons having negative charges move from the high temperature side to the low temperature side.
As a result, current flows radially inward in the hole-transporting portion 6 and current flows outward in the electron-transporting portion 7 . Since the hole-transporting portion 6 and the electron-transporting portion 7 are connected by the inner first electrode 11, current flows through the thermoelectric conversion element 5 from the left end side to the right side in FIG.
The current taken out from here flows from the right to the left in FIG.

FIG. 6 illustrates the state of power generation during the nighttime. During the nighttime when the sun goes down, the temperature gradient is reversed from that during the daytime, and the external temperature of the tubular container 1 becomes lower than the temperature of the heat storage section 13 . In accordance with this temperature gradient, the charge of the thermoelectric conversion element 5 moves to the lower temperature side, that is, to the outer side in the radial direction of the discharge vessel 1, and the direction of the current flowing in the thermoelectric conversion element 5 is different from that in the daytime (Fig. 5). It reverses and flows from the right side to the left side in FIG. As a result, the current taken out flows from the left to the right in FIG.

Another embodiment is shown in FIG. 7, in which a rectifier diode 20 is placed in the circuit of the tapped current. By doing this, the flow of current is blocked during the daytime, no power generation is performed, and the energy stored in the heat storage unit 13 by sunlight during the daytime is not consumed for power generation, and only the heat is stored. done.
As shown in FIG. 7, more electric power can be supplied by using the energy stored during the daytime for power generation at nighttime.

Still another embodiment is shown in FIG. 8, and when the heat storage material forming the heat storage section 13 is conductive, the entire thermoelectric conversion section 4 can be covered with an insulating coating layer 21 as shown in the figure. can. By doing so, it is possible to prevent a short circuit between the first electrodes 11 on the inner peripheral surface of the thermoelectric conversion part 4 and between the first electrode 11 and the second electrode 12 on the end surface.
As an insulating material for the insulating coating layer 21, silicon-based, urethane/acrylic-based, fluorine-based, resin-based, and oxide inorganic materials such as alumina can be used.
Among the heat storage materials exemplified in paragraph 0019, those having conductivity include inorganic salt hydrates (becomes conductive by absorbing water), sugar alcohols (sugar alcohols themselves are insulative, but have conductivity). used by dissolving in a solvent).

One specific example of the thermoelectric generator of the present invention is described below.
<Example of dimensions and materials>
○ Tubular container ・Material: Quartz glass ・Length: 1000mm
・Outer diameter: 20mm
・Inner diameter: 18 mm
○Thermoelectric conversion element:
・Hole transport part ・Material: CuPc
・Dimensions: width 10 mm, thickness 0.5 mm
・Electron transport part:
・Material: BCP
・Dimensions: width 10 mm, thickness 0.5 mm
○Conductive part (electrode)
・Material: TCO
・Dimensions: thickness 10 μm
○ Insulating material (directional heat transfer material):
・Material: Silicon resin (insulation) + carbon nanofiber (thermal conductivity)
・Dimensions: Width 2 mm, thickness 0.5 mm or more ○ Heat storage part (heat storage material):
・Material: Paraffin (melting point: 46°C)

Next, an example of the method for manufacturing the thermoelectric generator of the present invention is as follows.
<First method>
(1) A conductive portion (electrode) is formed on one surface of a flat insulating film such as a PET film using a sputtering vapor deposition technique.
(2) Masking the portion where the second electrode is to be formed and removing the rest by etching, as in the semiconductor film forming technique.
(3) Next, an insulating material (a directional heat-conducting material) is formed on the removed portion.
(4) After that, the mask is removed, a mask is attached to a portion other than the portion where the hole transport portion is to be formed, and the hole transport portion is formed using a semiconductor film forming technique.
(5) Next, an electron transport portion is formed by a similar method.
(6) Similarly, an insulating material and a first electrode are formed in necessary portions by forming a mask.
(7) The flat plate-like thermoelectric conversion part thus formed is rolled up together with the PET film, inserted into a glass tube, and the PET film is brought into contact with the inner surface of the glass tube.
(8) Connect a lead wire to the second electrode.
(9) The glass tube is filled with paraffin as a heat storage material.
(10) Both ends of the glass tube are heated and melted to reduce the diameter to form a sealing portion.
(11) Attach a rectifier diode to the lead wire, etc., if necessary.

<Second method>
(1) A thermoelectric conversion part is formed on a flat film such as a PET film using a film forming technique using an inkjet printer.
(2) Next, the thermoelectric conversion part is coated with an insulating material to form an insulating coating layer. (3) The PET film is rounded and inserted into the glass tube, and placed in the glass tube so that the PET film contacts the glass tube.
(4) Connect a lead wire to the second electrode.
(5) The diameter of one end of the glass tube is reduced by heating to form a sealed portion. The other end is similarly sealed, but is provided with a narrow tube for filling with the heat storage material.
(6) Using this narrow tube, the glass tube is filled with an electrically conductive heat storage material (such as liquid sugar alcohol or inorganic salt hydrate).
(7) The thin tube is heat-melted and sealed.

<Third method>
(1) An electrode pattern is formed on the entire inner surface of the glass tube using a mask, and a conductive film is formed in accordance with the electrode pattern using a spray pyrolysis method (SPD) or the like, followed by sintering.
(2) The thermoelectric element portion is drawn directly on the conductive film using an inkjet printer technique, and sintering is performed.
(3) The anisotropic material is applied to the inner surface of the glass tube formed up to the thermoelectric element portion by, for example, a suction method, and sintered. Thereafter, the anisotropic material formed in unnecessary portions is removed by surface polishing or etching to form an insulating material.
(4) A conductive film is formed on the surface of the thermoelectric element portion facing the center of the glass tube in the same manner as in (1) so as to match the electrode pattern, and sintering is performed.
(5) If necessary, a coating material is applied to the innermost surface and the side surface of the thermoelectric element and dried to form an insulating coating layer.
(6) Connect a lead wire to the second electrode.
(7) Both ends of the glass tube are heated and melted to reduce the diameter to form a sealed portion.
(8) The glass tube is filled with paraffin as a heat storage material.
(9) After filling the paraffin, in order to airtightly seal the inside of the glass tube, the metal pipe embedded in the sealing portion is crimped and sealed, or the branch pipe formed in advance in the glass tube is heated and melted. etc.

As described above, according to the thermoelectric generator according to the present invention, the thermoelectric conversion section is provided inside the sealed tubular container, and the heat storage section is provided inside the thermoelectric conversion section. When power is generated at night, all the heat stored in the heat storage part by the sunlight is transferred from the inside to the thermoelectric conversion part and used for conversion into electrical energy, so there is no heat energy loss and efficient thermoelectric conversion is achieved. is done.
In addition, since the heat storage material forming the heat storage section is stored in a sealed state in the tubular container whose ends are sealed, its deterioration can be suppressed.

Reference Signs List 1: tubular container 2: main body 3: sealing portion 4: thermoelectric conversion portion 5: thermoelectric conversion element 6: hole transport portion 7: electron transport portion 8: insulating material 10: conductive portion 11: first electrode 12: second 2 electrodes 13: heat storage part 15: metal foil 16: internal lead 17: external lead 18: lead part 20: rectifier diode 21: insulating coating layer

Claims (6)

A thermoelectric generator that converts light energy into electrical energy,
The thermoelectric generator is
The inside is sealed with a sealing part at the endconsists of a single tubea tubular container;
provided on the inner surface of the tubular containerannulara thermoelectric conversion unit;
a heat storage unit provided inside the thermoelectric conversion unit;
a lead portion electrically connected to the thermoelectric conversion portion and provided to penetrate the sealing portion;
and
The annular thermoelectric conversion part is provided so that its outer peripheral surface is in contact with the inner surface of the tubular container,
A heat storage material forming the heat storage unit is filled inside the tubular container, and the heat storage material is in contact with an inner peripheral surface of the thermoelectric conversion unit.
A thermoelectric generator characterized by:
The thermoelectric conversion part includes an annular hole transport part and an annular electron transport part that are alternately arranged in the tube axis direction with an annular insulating material interposed therebetween, and the hole transport part and the electron transport part 2. The thermoelectric generator according to claim 1, wherein the are electrically connected by a conductive portion. 3. The thermoelectric power generator according to claim 2, wherein the insulating material is made of a directional heat-conducting material having a higher thermal conductivity in the radial direction than in the axial direction of the tubular container. The conductive portion includes a first electrode that is in contact with the inner peripheral surfaces of the adjacent hole transport portion and the electron transport portion and conducts them, and the outer periphery of the adjacent electron transport portion and the hole transport portion. a second electrode that is in contact with the surface and conducts them,
The second electrode is in contact with the inner surface of the tubular container,
3. The thermoelectric generator according to claim 2, wherein the lead portion is connected to one of the electrodes. The thermoelectric conversion part has the hole transport part arranged at one end in the axial direction and the electron transport part arranged at the other end,
5. The thermoelectric generator according to claim 4, wherein the lead portion is connected to the second electrode that is in contact with the inner surface of the tubular container. The insulating material is
A first electrode in contact with the inner peripheral surfaces of the pair of the hole-transporting portion and the electron-transporting portion, and a second electrode in contact with the inner peripheral surfaces of the other pair of the hole-transporting portion and the electron-transporting portion adjacent thereto. a first insulating material disposed between the one electrode;
A second electrode in contact with the outer peripheral surfaces of the pair of the electron transporting portion and the hole transporting portion, and a second electrode in contact with the outer peripheral surfaces of the other pair of the electron transporting portion and the hole transporting portion adjacent thereto. a second insulating material disposed between and having an outer peripheral portion in contact with the inner surface of the tubular container;
The thermoelectric generator according to any one of claims 2 to 5, characterized by comprising:

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