JP7675426B2 - Thermoelectric power generation device - Google Patents

Description

This invention relates to a thermoelectric generator that uses waste heat from devices to generate thermoelectric power to power the devices in a system that detects abnormalities in the devices and communicates the abnormalities.

In modern industrial society, a huge amount of waste heat, more than 60% of the total primary energy supply, is discharged into the global environment, particularly from factories, power plants, steelworks, automobiles, buildings, lighting, ships, etc. At these factories and other sites, sensor networks are configured to monitor the status of equipment. However, securing power sources for these sensors is a problem.

Normally, batteries are used as the power source, but because the sensors are placed at high altitudes and there are a huge number of them, battery replacement is troublesome and the replacement costs are enormous.

As a solution to this problem, Patent Document 1 discloses a thermoelectric power generation transmitter that uses heat emitted from the device or into its surroundings to generate power through thermoelectric generation.

As shown in FIG. 7, the thermoelectric power generation transmitter disclosed in Patent Document 1 has a columnar heat conduction member 101 provided on a heat receiving plate 100 that receives heat from an equipment, and a thermoelectric power generation module 102 placed on the heat conduction member 101. The thermoelectric power generation module 102 generates electricity using the temperature difference between the heat transferred from the heat receiving plate 100 via the heat conduction member 101 and the heat dissipation plate 104 provided on the thermoelectric power generation module 102. The power generated by the thermoelectric power generation module 102 is supplied to a circuit board 106 including a processor 107 that processes and communicates signals from a sensor 105 such as a thermocouple.

JP 2018-200518 A

However, the thermoelectric power generation transmitter disclosed in Patent Document 1 has a configuration in which a thermoelectric power generation module 102 is placed on a heat conductive member 101 and a circuit board 106 is arranged around it, so there is a limit to how large the thermoelectric power generation module 102 can be made in order to obtain a large amount of power. In addition, if the heat conductive member 101 and the thermoelectric power generation module 102 are made large, there is an issue that the area of the circuit board 106 cannot be made large.

The present invention was made in consideration of these points, and its main objective is to provide a thermoelectric power generation device that allows the placement of a thermoelectric power generation module without being limited by the area of the heat receiving plate, and that ensures sufficient space for placing a circuit board.

The thermoelectric power generation device according to the present invention comprises a heat receiving plate in contact with a heat source, a thermal conductor erected from the heat receiving plate, and a thermoelectric power generation module attached to the side of the thermal conductor.

In one preferred embodiment, a heat dissipation means is provided on the side of the thermoelectric power generation module opposite the thermal conductor.

In one preferred embodiment, a circuit board that detects abnormalities in the equipment and communicates the detected abnormalities is located in the space inside the heat receiving plate and the heat conductor.

The present invention provides a thermoelectric power generation device that allows the placement of a thermoelectric power generation module without being limited by the area of the heat receiving plate, and that ensures sufficient space for placing a circuit board.

1A to 1C are diagrams showing a configuration of a thermoelectric power generation device according to a first embodiment of the present invention. FIG. 13 is a diagram showing a modified example of the thermoelectric power generation device in the first embodiment. 5A and 5B are diagrams showing the configuration of a thermoelectric power generation device according to a second embodiment of the present invention. 13A and 13B are diagrams showing a first modified example of the thermoelectric power generation device according to the second embodiment. 13A and 13B are diagrams showing a second modified example of the thermoelectric power generation device according to the second embodiment. 13A and 13B are diagrams showing a third modified example of the thermoelectric power generation device according to the second embodiment. FIG. 1 is a diagram showing the configuration of a conventional thermoelectric power generation transmitter.

The following describes in detail an embodiment of the present invention with reference to the drawings. Note that the present invention is not limited to the following embodiment. Furthermore, appropriate modifications are possible without departing from the scope of the effects of the present invention.

(First embodiment)
1(a) to (c) are diagrams showing the configuration of a thermoelectric power generation device in a first embodiment of the present invention, where FIG. 1(a) is a see-through top view, FIG. 1(b) is a cross-sectional view taken along line Ib-Ib in FIG. 1(a), and FIG. 1(c) is a cross-sectional view taken along line Ic-Ic in FIG. 1(a).

As shown in Figs. 1(a) to (c), the thermoelectric power generation device in this embodiment includes a heat receiving plate 3 in contact with a heat source 2, a thermal conductor 4 standing upright from the heat receiving plate 3, and a thermoelectric power generation module 1 attached to the side of the thermal conductor 4. A heat dissipation means 5 is provided on the side of the thermoelectric power generation module 1 opposite the thermal conductor 4. A circuit board 6 is disposed in a space 10 inside the heat receiving plate 3 and the thermal conductor 4, and includes a circuit 7 such as a processor that detects abnormalities in the device with a sensor and processes and communicates the signals. The circuit board 6 is supported by a support portion 9 provided on the heat receiving plate 3, and the heat dissipation means 5 is held by a holder 8 provided on the heat receiving plate 3.

Specifically, a heat transfer plate (thermal conductor) 4 made of an L-shaped metal plate is provided on a heat receiving plate 3, and a thermoelectric power generation module 1 is attached to the side of the heat transfer plate 4. Heat from the heat source 2 is transferred to the thermoelectric power generation module 1 via the heat receiving plate 3 and the heat transfer plate 4. A heat dissipation plate (heat dissipation means) 5 made of an L-shaped metal plate is attached to the opposite side of the thermoelectric power generation module 1.

Thermoelectric power generation module 1 generates effective power due to the temperature difference between the heat transfer plate 4 and the heat sink plate 5. The circuit board 6 can be installed in the large space 10 inside the heat receiving plate 3, heat transfer plate 4, and heat sink plate 5. The thermoelectric power generation module 1 can be attached to the entire side surface of the heat transfer plate 4, and if you want to make it larger, you can simply widen the side surface of the heat transfer plate 4. Therefore, there is no restriction on the size of the thermoelectric power generation module 1 and the circuit board 6.

In a specific example, the heat transfer plate 4 and the heat sink plate 5 can be made of 1 mm thick Al or Cu plates. The size of the thermoelectric power generation device is, for example, 80 mm long and 60 mm wide when viewed from above, with a side length of 25 mm. A thermoelectric power generation module 1 measuring 66 mm x 20 mm is attached to the side of the heat transfer plate 4. With a temperature difference of 44°C between the heat transfer plate 4 and the heat sink plate 5, an output of approximately 14 mW is obtained. This is sufficient to cover the power required by the processor that processes and communicates the sensor signals.

In this embodiment, if the heat transfer plate 4 installed on the heat receiving plate 3 is close to the heat source 2 and has a large heat transfer function, the heat sink plate 4 does not need to be provided.

(Modification of the first embodiment)
FIG. 2 shows a modified example of the thermoelectric power generating device in the first embodiment, and corresponds to FIG.

As shown in FIG. 2, the thermoelectric power generation device in this modified example further has a heat dissipation sheet 11 attached on top of the heat sink 5, which improves heat dissipation. The heat dissipation sheet 11 is preferably a laminated structure of graphite-mixed gauze fiber and graphite sheet. The graphite-mixed gauze fiber has a high thermal conductivity of approximately 13 W/mK and a high emissivity, and since the sheet surface is not smooth, it has a large effective surface area and excellent heat dissipation properties. The graphite sheet has an extremely high thermal conductivity in the planar direction of 1500 W/mK and is thin.

For example, when a structure was used in which a 25 μm graphite sheet was bonded to a 0.2 mm thick graphite-mixed gauze fiber sheet, the temperature difference between the heat transfer plate 4 and the heat sink plate 5 became large at approximately 46°C, and an output increase of approximately 19 mW was obtained.

Second Embodiment
3(a) and (b) are diagrams showing the configuration of a thermoelectric power generation device in the second embodiment, where FIG. 3(a) is a perspective top view and FIG. 3(b) is a cross-sectional view taken along line IIIb-IIIb in FIG. 3(a).

3(a) and (b), in the thermoelectric power generation device of this embodiment, a cylindrical metal heat transfer body 4 is placed upright on a heat receiving plate 3 in contact with a heat source 2, and a thermoelectric power generation module 1 is attached to its outer periphery. The thermoelectric power generation module 1 generates effective power due to the temperature difference between the heat transfer body 4 and the outside air. The thermoelectric power generation module 1 can be attached to the entire outer periphery of the heat transfer body 4, and if you want to make it larger, you can simply increase the diameter of the heat transfer body 4. This makes the space 10 inside the heat transfer body 4 larger, and the space for accommodating the circuit board 6 also becomes larger, so that the constraints of the size of the thermoelectric power generation module 1 and the circuit board 6 are released. It is preferable to provide a resin plate 12 for protection on the upper part of the heat transfer body 4. In addition, it is preferable that the resin plate 12 is made of resin that transmits radio waves for communication.

In a specific example, the heat receiving plate 3 and heat transfer body 4 can be made of Al or Cu plates with a thickness of 1 to 2 mm. The size of the heat receiving plate 3 is, for example, 120 mm square when viewed from above, and the size of the heat transfer body 4 is, for example, an outer diameter of 70 mm and a height of 52 mm. Two thermoelectric generation modules 1 with dimensions of 13 mm x 88 mm are attached to the outer periphery of the heat transfer body 4. With a temperature difference of 7°C between the heat transfer plate 4 and the heat sink plate 5, an output of approximately 8 mW is obtained. This is sufficient to cover the power required by the processor that processes and communicates the sensor signals.

(Modification 1 of the second embodiment)
4(a) and (b) show a first modified example of the thermoelectric power generation device in the second embodiment, where FIG. 4(a) is a perspective top view and FIG. 4(b) is a cross-sectional view taken along line IVb-IVb in FIG. 4(a).

As shown in Figures 4(a) and (b), in the thermoelectric power generation device of this modified example, a metal, rectangular, cylindrical heat transfer body 4 is placed upright on a heat receiving plate 3 that is in contact with a heat source 2, and a thermoelectric power generation module 1 is attached to its outer circumferential surface. The thermoelectric power generation module 1 generates effective power due to the temperature difference between the heat transfer body 4 and the outside air. The thermoelectric power generation module 1 can be attached to the entire outer circumferential surface of the heat transfer body 4, and if a larger module is required, the diameter of the heat transfer body 4 can be increased. This increases the space 10 inside the heat transfer body 4, and also increases the space for accommodating the circuit board 6, freeing the user from the constraints of the size of the thermoelectric power generation module 1 and the circuit board 6.

(Modification 2 of the second embodiment)
5(a) and (b) show a second modified example of the thermoelectric power generation device in the second embodiment, where FIG. 5(a) is a perspective top view and FIG. 5(b) is a cross-sectional view taken along line Vb-Vb in FIG. 5(a).

As shown in Figures 5(a) and (b), in the thermoelectric power generation device of this modified example, a metal, rectangular, half-tubular heat transfer body 4 is placed upright on a heat receiving plate 3 that is in contact with a heat source 2, and a thermoelectric power generation module 1 is attached to its outer periphery. The thermoelectric power generation module 1 generates effective power due to the temperature difference between the heat transfer body 4 and the outside air. The thermoelectric power generation module 1 can be attached to the entire outer surface of the heat transfer body 4, and if a larger module is required, the heat transfer body 4 can be made larger and higher. This makes it possible to use the space outside the heat transfer body 4 and expand the space for the circuit board 6, which results in freedom from size constraints on the thermoelectric power generation module 1 and the circuit board 6.

(Modification 3 of the second embodiment)
6(a) and (b) show a third modified example of the thermoelectric power generation device in the second embodiment, where FIG. 6(a) is a perspective top view and FIG. 6(b) is a cross-sectional view taken along line VIb-VIb in FIG. 6(a).

As shown in Figures 6(a) and (b), the thermoelectric power generation device in this modified example has the configuration shown in Figures 3(a) and (b), in which a heat dissipation heat transfer plate 13 is provided on the outer peripheral surface of the thermoelectric power generation module 1, and heat dissipation fins 14 are attached to the outside of the heat dissipation heat transfer plate 13, thereby improving heat dissipation.

Instead of the heat dissipation heat transfer plate 13, a heat dissipation sheet may be provided on the outer peripheral surface of the thermoelectric power generation module 1. Also, the heat dissipation heat transfer plate 13 may be provided on the outer peripheral surface of the thermoelectric power generation module 1 via a heat dissipation sheet. The heat dissipation sheet is preferably a laminated structure of graphite-mixed gauze fiber and graphite sheet. The graphite-mixed gauze fiber has a high thermal conductivity of about 13 W/mK and a high emissivity, and since the sheet surface is not smooth, it has a large effective surface area and excellent heat dissipation. The graphite sheet has an extremely high thermal conductivity in the planar direction of 1500 W/mK and is thin.

In the embodiment, a structure was used as the heat dissipation sheet, in which a 25 μm graphite sheet was laminated to a graphite-mixed gauze fiber sheet having a thickness of 0.2 mm. This improved heat dissipation, and when the temperature of the heat receiving plate 3 was 63°C at room temperature of 25°C, the temperature difference between the heat transfer body 4 and the outer surface of the thermoelectric power generation module 1 increased to 9°C, and an output improvement of approximately 10 mW was obtained. The heat dissipation fins 14 were made of Al, had a base plate size of 40 mm x 229 mm, a fin height of 20 mm, and 74 fins, and were wrapped around the outer periphery of the thermoelectric power generation module 1, and the temperature difference between the heat transfer body 4 and the outer surface of the thermoelectric power generation module 1 further increased to approximately 12°C, and a further output improvement of approximately 16 mW was obtained.

1 Thermoelectric power generation module
2 Heat source
3 Heat receiving plate
4. Heat transfer plate (thermal conductor)
5 Heat dissipation plate (heat dissipation means)
6 Circuit board
7 Circuit element 10 Space
11. Heat dissipation sheet
12 Resin plate
13 Heat dissipation and heat transfer plate
14 Heat dissipation fin

Claims (8)

A heat receiving plate in contact with a heat source;
A heat conductor standing upright on the heat receiving plate;
a thermoelectric power generation module attached to one side of the thermal conductor;
a heat dissipation means provided on a side surface of the thermoelectric power generation module opposite to the thermal conductor;
A circuit board installed on a support provided on the heat receiving plate;
Equipped with
The circuit board is disposed in an internal space located inside the main surface of the heat receiving plate and the other side surface of the thermal conductor . The thermoelectric power generation device according to claim 1 , wherein the circuit board has a function of detecting an abnormality in the device and communicating the same. 2. The thermoelectric generating device according to claim 1 , wherein the heat dissipation means comprises a laminated structure of graphite-mixed gauze fiber and a graphite sheet, or a heat dissipation fin . The thermoelectric generating device according to claim 1 , wherein the thermal conductor is an L-shaped metal plate. A heat receiving plate in contact with a heat source;
A heat conductor standing upright on the heat receiving plate;
a thermoelectric power generation module attached to a side surface of the thermal conductor;
Equipped with
A thermoelectric power generation device, comprising: a heat dissipation means having a laminated structure of graphite-mixed gauze fiber and a graphite sheet, the heat dissipation means being provided on a side of the thermoelectric power generation module opposite to the thermal conductor . The thermoelectric power generating device according to claim 5 , wherein the thermal conductor is an L-shaped metal plate. An L-shaped heat dissipation plate is disposed above the heat receiving plate,
The thermoelectric power generation device according to claim 6 , wherein the thermoelectric power generation module is sandwiched between the L-shaped metal plate and the L-shaped heat dissipation plate. The thermoelectric power generating device according to claim 6 , further comprising a heat dissipation sheet provided on the L-shaped heat dissipation plate.