Power generation module

Abstract

This power generation module generates power on the basis of energy emitted from a heat source. The power generation module includes: a plurality of reflectors that are arranged so as to cover the heat source, gradually decrease in diameter as distanced further from the heat source, and are open at the leading end; an optical rectenna element provided in an opening of each of the reflectors; and an infrared wavelength selection film provided further to the heat source side than the optical rectenna element.

Description

Power generation module

[0001] This disclosure relates to a power generation module. This application claims priority to Japanese Patent Application No. 2023-193824, filed on November 14, 2023, the contents of which are incorporated herein by reference.

[0002] Attention has been focused on power generation technology that uses unused energy, such as waste heat from plants. One example of this type of technology is known from Patent Document 1 below. The technology disclosed in Patent Document 1 below is said to be able to generate power using waste heat as a heat source by using a metamaterial coupled antenna.

[0003] Special table 2019-531016 publication

[0004] However, in the parts of the plants where waste heat is generated, in addition to heat, light energy such as infrared rays is also actually present. Conventionally, the idea of ​​utilizing such light energy has not been proposed, which has led to the problem that effective utilization of unused energy has been limited.

[0005] The present disclosure provides a power generation module that can effectively utilize unused light energy.

[0006] The power generation module of the present disclosure is a power generation module that generates electricity based on energy emitted from a heat source, and includes a plurality of reflectors arranged to cover the heat source, gradually reducing in diameter as they move away from the heat source along an axis, and having an open tip, an optical rectenna element provided in the opening of the reflector, and an infrared wavelength selection film provided on the heat source side in the axial direction of the optical rectenna element.

[0007] According to the present disclosure, it is possible to provide a power generation module that can effectively utilize unused light energy.

[0008] Fig. 1 is a cross-sectional view showing the configuration of a power generation module and a heat source (piping) according to an embodiment of the present disclosure; Fig. 2 is a cross-sectional view showing the configuration of a power generation module according to a first embodiment of the present disclosure; Fig. 3 is a cross-sectional view showing the configuration of a power generation module according to a second embodiment of the present disclosure; Fig. 4 is a cross-sectional view showing the configuration of a power generation module according to a third embodiment of the present disclosure; Fig. 5 is a cross-sectional view showing a modified example of a power generation module common to each embodiment of the present disclosure.

[0009] First Embodiment (Configuration of Power Generation Module) A power generation module 1 according to a first embodiment of the present disclosure will be described below with reference to Fig. 1 and Fig. 2. As shown in Fig. 1, the power generation module 1 is attached to the outer surface of a pipe 100 through which a high-temperature fluid (for example, approximately 200°C) flows, such as a drainage pipe in a power plant. In other words, the pipe 100 is a heat source, and radiant heat is emitted from the heat source as light energy, which is infrared radiation. The power generation module 1 is a device for generating electric power from this energy.

[0010] As shown in FIG. 2 , the power generation module 1 includes an infrared wavelength selective film 10 , a reflector 20 , an optical rectenna element 30 , a Peltier element 40 , and an outer cover 50 .

[0011] (Infrared Wavelength Selective Film) The infrared wavelength selective film 10 is cylindrical and covers the outer periphery of the pipe 100. The infrared wavelength selective film 10 transmits only some wavelength components of infrared rays emitted from the pipe 100, which serves as a heat source. Specifically, the infrared wavelength selective film 10 transmits infrared rays of wavelengths at which the power generation efficiency of the optical rectenna element 30, described below, is highest. Components other than the selected wavelengths are reflected by the infrared wavelength selective film 10 and return to the heat source side. A metamaterial that combines multiple cylinders whose longitudinal dimension is the desired wavelength size is preferably used as the infrared wavelength selective film 10. More specifically, a metamaterial that combines multiple cylindrical members with openings at intervals on a plane, or a metamaterial in which multiple cavities are formed on a plane, can be considered.

[0012] (Reflector) The reflector 20 is provided further outward from the infrared selective film. The reflector 20 is a concentrator that converges infrared light transmitted through the infrared wavelength selective film 10. More specifically, the reflector 20 has a Winston cone shape with its axis pointing away from the heat source. That is, the reflector 20 has a cone shape whose diameter gradually decreases as it moves away from the heat source. In other words, the reflector 20 constitutes a compound parabolic concentrator. An opening is formed at the tip of the reflector 20 (i.e., the end opposite the heat source). Infrared light incident on the inner periphery of the reflector 20 is reflected multiple times on the inner periphery and finally converges to a focal point at the opening. A plurality of such reflectors 20 are arranged in a lattice pattern at intervals along the outer surface of the infrared wavelength selective film 10.

[0013] (Optical Rectenna Element) The optical rectenna element 30 is provided in the opening of the reflector 20. The optical rectenna element 30 generates electric power by converting the optical energy of infrared rays that pass through the reflector 20 and are incident on the optical rectenna element 30. The electric power energy generated by the optical rectenna element 30 is collected by wiring laid inside the outer cover 50 that covers the outside of the optical rectenna element 30 and extracted to the outside.

[0014] (Peltier element) A Peltier element 40 is attached to the outer peripheral surface of the reflector 20. The Peltier element 40 generates electric power based on thermal energy generated on the outer peripheral surface of the reflector 20 to which it is attached. In other words, specific wavelength components of infrared rays radiated from a heat source are converted into electric power by the optical rectenna element 30, while the thermal energy that does not reach the optical rectenna element 30 heats the reflector 20, causing a temperature difference between the outer peripheral surface of the reflector 20 and the outer peripheral surface of the Peltier element 40. The Peltier element 40 generates electric power based on this temperature difference.

[0015] (External Cover) The external cover 50 covers the outside of the multiple arranged reflectors 20. The external cover 50 protects the reflectors 20 and other components from impact and dirt, and also houses wiring for collecting the power (current) generated by the optical rectenna element 30 and Peltier element 40 described above.

[0016] (Effects) In recent years, attention has been focused on power generation technology that uses unused energy, such as waste heat from plants. As an example of this type of technology, a device that uses waste heat as a heat source and generates electricity using a metamaterial-coupled antenna has been proposed. However, in the parts of plants where waste heat is generated, light energy such as infrared rays is also actually present as heat. Until now, the idea of ​​utilizing such light energy has not been proposed, which has led to the problem of limited scope of utilization of unused energy. Therefore, the present embodiment employs the above-described configurations.

[0017] According to the above configuration, infrared rays emitted from a high-temperature heat source can be converged by the reflector 20 at the opening and irradiated onto the optical rectenna element 30. This allows the optical rectenna element 30 to generate electricity (generate power) from optical energy. Furthermore, an infrared wavelength selective film 10 is provided closer to the heat source than the optical rectenna element 30. This allows only infrared rays with wavelengths that maximize the power generation efficiency of the optical rectenna element 30 to be selectively extracted and directed toward the optical rectenna element 30. This enables highly efficient power generation from optical energy. In addition, the remaining wavelength components not selected by the infrared wavelength selective film 10 are reflected by the film and returned to the heat source. The infrared rays, whose wavelengths are converted again upon contact with the heat source, are then radiated again from the heat source toward the power generation module 1, repeating the above-described power generation cycle. In this way, by using only the heat source and the power generation module 1, power can be generated from the heat source semi-permanently. This makes it possible to realize even more effective use of unused energy.

[0018] Here, some components of the infrared rays emitted from the heat source are absorbed as thermal energy by the reflector 20 itself as they travel inside the reflector 20, causing it to heat up. With the above configuration, a temperature difference occurs between the inner and outer surfaces of the Peltier element 40 provided on the outer surface of the reflector 20. Electricity can be generated based on the thermal energy resulting from this temperature difference. In other words, the thermal energy of the infrared rays absorbed by the reflector 20 can also be effectively utilized by the Peltier element 40 to generate electricity. This makes it possible to realize the effective use of unused energy with even greater efficiency. As a result, it becomes possible to further improve the overall energy efficiency of a plant or the like in which a heat source is installed.

[0019] According to the above configuration, because the infrared wavelength selective film 10 is provided between the reflector 20 and the heat source, the wavelength of the infrared light directed toward the reflector 20 is converted in advance to a band that maximizes the power generation efficiency of the optical rectenna element 30. This makes it possible to further increase the power generation efficiency of the optical rectenna element 30.

[0020] According to the above configuration, because reflector 20 has a Winston cone shape, infrared rays emitted from the heat source can be efficiently converged in accordance with this shape at the tip of reflector 20. This makes it possible to concentrate infrared rays at optical rectenna element 30 provided at the tip of reflector 20, further improving the efficiency of power generation by optical rectenna element 30.

[0021] The first embodiment of the present disclosure has been described above. Note that various changes and modifications can be made to the above configurations without departing from the gist of the present disclosure.

[0022] Second Embodiment Next, a second embodiment of the present disclosure will be described with reference to Fig. 3. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0023] The power generation module 1 according to this embodiment differs from the first embodiment in that it does not include a Peltier element 40 but includes a heat insulating cover 60 .

[0024] (Thermal insulation cover) The thermal insulation cover 60 is provided further inside the infrared wavelength selective film 10, that is, on the heat source side. The thermal insulation cover 60 covers the pipe 100 (heat source) from the outside. Furthermore, a space is formed between the thermal insulation cover 60 and the infrared wavelength selective film 10. This space forms a vacuum thermal insulation layer 70. In other words, this vacuum thermal insulation layer 70 absorbs part or most of the heat generated from the pipe 100 and prevents it from dissipating to the outside.

[0025] (Effects) According to the above configuration, a vacuum insulation layer 70 is formed by the heat insulating cover 60 between the heat source and the infrared wavelength selective film 10. Therefore, most of the heat emitted from the heat source is absorbed by the vacuum insulation layer 70 and does not dissipate to the outside. This makes it possible to replace conventional heat insulating materials. Furthermore, because the heat is less likely to reach the reflector 20, other components such as the Peltier element 40 for utilizing the heat are not required, making it possible to configure the power generation module 1 with a simpler structure and at a lower cost. As a result, even when a heat source is located over a long distance, such as the piping 100 of a plant, the cost disadvantages can be avoided and the power generation module 1 can be applied widely with high versatility.

[0026] The second embodiment of the present disclosure has been described above. It should be noted that various changes and modifications can be made to the above configuration without departing from the gist of the present disclosure. For example, it is possible to provide the insulating cover 60 and also attach the Peltier element 40 described in the first embodiment to the reflector 20. In this case, even if thermal energy is generated that cannot be absorbed by the vacuum insulating layer 70, it can be fully recovered by the Peltier element 40 and converted into electrical energy. This allows for even more effective utilization of unused energy.

[0027] Third Embodiment Next, a third embodiment of the present disclosure will be described with reference to Fig. 4. Note that the same components as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0028] (Infrared Wavelength Selective Film) In this embodiment, the position at which the infrared wavelength selective film 10 is provided is different from that of the above-described embodiments. Specifically, the infrared wavelength selective film 10 is provided for each optical rectenna element 30 in contact with the optical rectenna element 30. More specifically, the infrared wavelength selective film 10 is attached to the surface of the optical rectenna element 30 that faces the heat source. Therefore, the area of ​​the infrared wavelength selective film 10 is equal to the area of ​​the opening of the reflector 20.

[0029] (Inner Cover) The heat source side of the reflector 20 is covered with an inner cover 80. The inner cover 80 is preferably made of a synthetic resin and is made of a film material that is capable of transmitting infrared rays.

[0030] (Effects) According to the above configuration, the infrared wavelength selective film 10 is provided for each optical rectenna element 30 while abutting against the optical rectenna element 30. This reduces the amount of infrared wavelength selective film 10 used, and significantly reduces the manufacturing and maintenance costs of the power generation module 1. Furthermore, according to the above configuration, the area of ​​the infrared wavelength selective film 10 is limited, so that all wavelength bands of infrared light generated from the heat source are temporarily captured by the reflector 20. Therefore, for example, if a Peltier element 40 is provided on the reflector 20, the thermal energy of infrared light in all of the above wavelength bands can be converted into electricity by the Peltier element 40. This makes it possible to achieve both lower costs for the device and further improve energy efficiency.

[0031] (Other Embodiments) Although each embodiment of the present disclosure has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like within the scope that does not deviate from the gist of the present disclosure are also included.

[0032] For example, in each of the above-described embodiments, an example has been described in which the power generation module 1 is applied to a pipe 100 serving as a heat source. However, the heat source is not limited to the pipe 100, and may be a wall surface 110 inside which a heat source such as a high-temperature fluid or a mechanical device is present, as shown in Fig. 5. By attaching the power generation module 1 to this wall surface 110, it is possible to obtain the same effects as those described above.

[0033] Furthermore, the reflector 20 does not necessarily have to have a Winston cone shape, and any optical element that can converge light to one point can be used as the reflector 20.

[0034] Furthermore, depending on the temperature range of the heat source, it is possible to provide a heat insulating material 90 between the heat source and the power generation module 1. In this case, the same effects as those described above can be obtained.

[0035] In addition, in each of the above-described embodiments, an example has been described in which there is no filler between the reflectors 20, and there is space between them. However, from the viewpoint of ensuring the strength and rigidity of the entire power generation module 1, it is possible to fill this space with a translucent synthetic resin or the like that does not impede the passage of light. In addition, in order to further prevent heat from radiating to the outside, it is also possible to fill this space with a resin or porous body with high thermal insulation properties.

[0036] <Additional Notes> The power generation module 1 described in each embodiment can be understood, for example, as follows.

[0037] (1) The power generation module 1 of the first aspect is a power generation module 1 that generates power based on energy emitted from a heat source, and includes a plurality of reflectors 20 arranged to cover the heat source, gradually reducing in diameter as they move away from the heat source along an axis, and having open tips, an optical rectenna element 30 provided in the opening of the reflector 20, and an infrared wavelength selection film 10 provided on the heat source side in the axial direction of the optical rectenna element 30.

[0038] According to the above configuration, infrared rays emitted from a high-temperature heat source can be converged at the opening by reflector 20 and irradiated onto optical rectenna element 30. This makes it possible for optical rectenna element 30 to generate electric power from optical energy.

[0039] (2) The power generation module 1 according to a second aspect is the power generation module 1 according to (1), further comprising a Peltier element 40 provided on the outer surface of the reflector 20 .

[0040] Here, some components of the infrared rays emitted from the heat source heat the reflector 20 itself with thermal energy as they travel inside the reflector 20, creating a temperature difference between the outer surface of the reflector 20 and the outer surface of the Peltier element 40 provided on the outer surface of the reflector 20, and electricity can be generated based on the thermal energy resulting from this temperature difference.

[0041] (3) The power generation module 1 according to a third aspect is the power generation module 1 according to (1) or (2), in which the infrared wavelength selective film 10 is provided between the reflector 20 and the heat source.

[0042] According to the above configuration, because the infrared wavelength selective film 10 is provided between the reflector 20 and the heat source, the wavelength of the infrared light directed toward the reflector 20 is converted in advance to a band that maximizes the power generation efficiency of the optical rectenna element 30. This makes it possible to further increase the power generation efficiency of the optical rectenna element 30.

[0043] (4) The power generation module 1 according to a fourth aspect is the power generation module 1 of (3), further comprising an insulating cover 60 that forms a vacuum insulating layer 70 between the heat source and the infrared wavelength selective film 10.

[0044] According to the above configuration, a vacuum insulation layer 70 is formed by the heat insulating cover 60 between the heat source and the infrared wavelength selective film 10. Therefore, most of the heat emitted from the heat source is absorbed by the vacuum insulation layer 70 and is not dissipated to the outside. This makes it possible to replace conventional heat insulating materials.

[0045] (5) The power generation module 1 according to the fifth aspect is the power generation module 1 of (1) or (2), in which the infrared wavelength selective film 10 is provided in contact with the optical rectenna element 30 for each optical rectenna element 30.

[0046] According to the above configuration, the infrared wavelength selective film 10 is provided for each optical rectenna element 30 while being in contact with the optical rectenna element 30. This reduces the amount of infrared wavelength selective film 10 used, and significantly reduces the manufacturing costs and maintenance costs of the power generation module 1.

[0047] (6) The power generation module 1 according to the sixth aspect is a power generation module 1 according to any one of the aspects (1) to (5), wherein the reflector 20 has a Winston cone shape with its axis pointing away from the heat source.

[0048] According to the above configuration, the reflector 20 has a Winston cone shape, so that the infrared rays emitted from the heat source can be efficiently converged at the tip of the reflector 20 in accordance with the shape.

[0049] According to the present disclosure, it is possible to provide a power generation module that can effectively utilize unused light energy.

[0050] DESCRIPTION OF SYMBOLS 1... Power generation module 10... Infrared wavelength selective film 20... Reflector 30... Optical rectenna element 40... Peltier element 50... Outer cover 60... Heat insulating cover 70... Vacuum heat insulating layer 80... Inner cover 90... Heat insulating material 100... Piping 110... Wall surface

Claims

1. A power generation module that generates electricity based on energy emitted from a heat source, comprising: a plurality of reflectors arranged to cover the heat source, the diameter of which gradually decreases with increasing distance from the heat source and which have an open tip; an optical rectenna element provided in the opening of the reflector; and an infrared wavelength selection film provided on the heat source side of the optical rectenna element.

2. The power generating module according to claim 1, further comprising a Peltier element provided on the outer surface of the reflector.

3. The power generating module according to claim 1 or 2, wherein the infrared wavelength selective film is provided between the reflector and the heat source.

4. The power generation module according to claim 3, further comprising a heat insulating cover forming a vacuum heat insulating layer between the heat source and the infrared wavelength selective film.

5. A power generating module according to claim 1 or 2, wherein the infrared wavelength selection film is provided for each of the optical rectenna elements in contact with the optical rectenna elements.

6. The power generation module according to claim 1 or 2, wherein the reflector has a Winston cone shape with its axis extending in a direction away from the heat source.

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