Floating type temperature difference thermoelectric generator

Abstract

A first ceramic plate, a first electrode, a thermoelectric power generation module, a second electrode and a second ceramic plate are sequentially arranged from top to bottom, the first electrode and the second electrode are electrodes with opposite polarities, and the thermoelectric power generation module comprises a plurality of p-type and / or n-type bismuth telluride thermoelectric assemblies which are arranged at intervals. The upper surface of the first ceramic plate is further covered with a sunlight selective absorption / thermal radiation coating. The generator takes radiation heat exchange as a bridge, the generator is subjected to solar power generation and radiation cooling by utilizing a thermal radiation coating, continuous electric energy supply in the daytime and at night can be realized, a heat source and a cold source can be automatically converted in the daytime and at night so as to continuously convert temperature difference into electric energy, and thus all-weather power generation is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of energy utilization, and more specifically, to a floating temperature difference thermoelectric generator. Background Art

[0002] With the development of solar technology, its application in human production and daily life continues to expand. However, providing a sustainable, all-weather energy supply solely through solar energy remains a significant challenge. This is because solar radiation is discontinuous in time and space. If the power supply is unstable or interrupted, electrical appliances will not function properly, resulting in operational interruptions or data loss, affecting their effectiveness. In contrast, thermoelectric devices offer significant advantages in utilizing various low-grade waste heat from the environment to generate electrical output.

[0003] The sun and outer space are two thermodynamic sources with extreme temperatures. Due to their large temperature difference and the different wavelength ranges covered, objects can exchange energy with them independently. Like the sun and outer space, the waters on Earth are also an easily accessible thermodynamic source with a temperature range of 0°C to 30°C. Since the temperature span of these three thermodynamic sources is large (from ~5500°C (sun) to 20°C (water) to -270°C (outer space)), by constructing a reasonable and orderly heat transfer method between these three thermodynamic sources, it is theoretically possible to build a bridge between these three different thermodynamic sources that can efficiently capture energy across the entire spectrum. However, most technical solutions still exist only in theory, and few have been put into practice and achieved good technical results.

[0004] In particular, how to provide long-term and stable power supply for relevant sensors in remote water areas (deep sea) to obtain long-term, large-scale data with important reference value for scientific research, disaster warning, and resource management is an urgent problem to be solved in this field. Utility Model Content

[0005] The purpose of this utility model is to overcome the defects of existing solar power generation equipment suitable for remote water areas, such as unstable power supply, easy interruption and low power generation efficiency, and to provide a floating thermoelectric generator. By combining selective absorption and radiation cooling technology and integrating them into a thermoelectric thermoelectric power generation module, the thermoelectric module device is used to capture energy from three thermodynamic sources: the sun, the earth's water bodies and outer space, and has considerable all-weather electrical output performance.

[0006] The technical solution employed in this utility model is a floating thermoelectric generator. The generator comprises, from top to bottom, a first ceramic plate, a first electrode, a thermoelectric generation module, a second electrode, and a second ceramic plate. The first and second electrodes are electrodes of opposite polarity. The thermoelectric generation module comprises a number of spaced-apart p-type and / or n-type bismuth telluride thermoelectric assemblies. The upper surface of the first ceramic plate is also covered with a solar-selective absorption / thermal radiation coating. The first and second electrodes are made of a conductive material (e.g., copper). When the first electrode is positive, the second electrode is negative, and vice versa. The generator utilizes a natural three-body radiation heat exchange system consisting of the sun, water, and outer space. The sun has a temperature of approximately 5500°C, the water has a temperature of approximately 20°C, and outer space is a natural cooling source at approximately -270°C. The generator floats on the water surface, with the second ceramic plate in contact with the water. Using radiation heat exchange as a bridge, the solar-selective absorption / thermal radiation coating enables the generator to generate solar power and radiate cooling, enabling continuous power supply day and night. During the day, solar radiation strikes the generator surface, sending waves into the thermoelectric module to generate electricity via temperature differences. The first ceramic plate acts as a heat source, while the second acts as a cooling source. At night, the module continues to convert the temperature difference into electricity, using the second ceramic plate in contact with the water as a heat source and outer space as a cooling source, thus enabling all-weather power generation.

[0007] Furthermore, the bismuth telluride thermoelectric module includes a p-type Bi2Te3-based compound and an n-type Bi2Te3-based compound, with the p-type Bi2Te3-based compound and the n-type Bi2Te3-based compound arranged alternately. This design optimizes the utilization of the thermoelectric potential of the thermoelectric module, thereby improving the thermoelectric performance of the thermoelectric device. This optimization helps to improve thermoelectric conversion efficiency, reduce heat loss, lower power consumption, and enhance electrical output performance.

[0008] Furthermore, the spacing between two adjacent thermoelectric modules is 5-10 mm. This appropriate spacing helps maintain a temperature gradient between modules, thereby improving thermoelectric conversion efficiency and optimizing heat flow management and electrical connections. This design also facilitates module installation and maintenance.

[0009] Furthermore, the height of the thermoelectric power generation module is 8-12 mm.

[0010] Furthermore, the thermoelectric module is encapsulated with thermally conductive silicone and connected to the first and / or second electrodes. The use of thermally conductive silicone, particularly silicone with low thermal conductivity, can improve the thermal stability and electrical insulation of the thermoelectric module, reduce interface resistance and thermal resistance, and increase device efficiency. Furthermore, the flexibility of the thermally conductive silicone helps absorb stress caused by thermal expansion coefficient mismatch, thereby improving the module's reliability and durability.

[0011] Furthermore, the first ceramic plate is a copper-clad Al2O3 (aluminum oxide) ceramic substrate, and the second ceramic plate is a copper-clad AlN (aluminum nitride) ceramic substrate. This material selection provides high reliability and excellent thermoelectric performance. Alumina ceramic substrates offer higher reliability (high and low temperature impact resistance), a more compatible thermal expansion coefficient, a thinner active metal solder layer, a wide operating temperature range, and excellent insulation. These characteristics make alumina ceramic substrates an ideal choice for thermoelectric power generation modules, helping to improve the efficiency and reliability of the entire system.

[0012] Furthermore, the solar light selective absorption / thermal radiation coating includes a short-wavelength absorption metal ceramic layer, a metal layer, a visible-near-infrared absorption metal ceramic layer, and a phase change layer that can form a nanocavity structure. The phase change layer is tungsten-doped vanadium dioxide. Through the nanocavity, the thermoelectric generator can achieve excellent selective absorption and radiative cooling dynamic spectral response across the entire spectrum of 250-25000nm. That is, during the day, the thermoelectric generator has a selective light absorption of over 90% in the full solar spectrum (250-4000nm) and a thermal radiation characteristic of over 80% in the infrared region (2500-25000nm) at night.

[0013] Furthermore, the shortwave absorption cermet layer and the visible-near-infrared absorption cermet layer are composite cermet layers comprising metal materials and cermet materials. The metal materials include tungsten, nickel, molybdenum, aluminum, titanium, or composite layers thereof; and the cermet materials include silicon dioxide, titanium dioxide, silicon nitride, aluminum oxide, or composite layers thereof. By using a variety of metal and cermet materials, the spectral response of the absorption layer can be optimized, improving its absorption efficiency in specific wavelength bands. This diversity also allows for the adjustment of material properties such as corrosion resistance, mechanical strength, and thermal stability to specific applications.

[0014] Furthermore, the composite metal ceramic layer is tungsten-silicon dioxide (W-SiO2). The tungsten-silicon dioxide composite layer provides excellent optical and thermal properties. The high absorptivity of tungsten and the high reflectivity of silicon dioxide combine to improve solar energy absorption and thermal radiation efficiency.

[0015] Furthermore, the metal layer is tungsten, nickel, molybdenum, aluminum, titanium or a composite layer thereof, and metals with different properties, such as high conductivity, high reflectivity or high absorptivity, can be selected as needed to optimize overall performance.

[0016] Furthermore, the upper surface of the sunlight selective absorption / heat radiation coating is covered with a high-transmittance glass cover plate, which can transmit as much sunlight as possible while protecting the sunlight selective absorption / heat radiation coating.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] The generator disclosed in the utility model is sequentially provided with a first ceramic plate, a first electrode, a thermoelectric power generation module, a second electrode, and a second ceramic plate from top to bottom. It can utilize the natural three-body radiation heat exchange system composed of the sun, water, and outer space. With radiation heat exchange as a bridge, the generator uses solar power generation and radiation cooling to achieve continuous power supply during the day and night. During the day and night, the heat source and cold source are automatically converted to continuously convert the temperature difference into electricity, thereby achieving all-weather power generation. The daytime and nighttime can achieve 1.0mW / cm 2 and 2.0 μW / cm 2 The maximum output power density. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a structural diagram of Example 1;

[0020] Figure 2 This is a reference diagram of output power density according to Example 1;

[0021] Figure 3 This is a structural diagram of Example 2;

[0022] Figure 4 This is a reference diagram of output power density of Example 2;

[0023] Figure 5 This is a structural diagram of Example 3;

[0024] Figure 6 This is the output power density reference diagram of Example 3;

[0025] In the attached figure:

[0026] 1-first ceramic plate; 2-first electrode; 3-thermoelectric power generation module; 4-second electrode; 5-second ceramic plate; 6-sunlight selective absorption / thermal radiation coating; 7-high-transmittance glass cover. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with specific embodiments. The accompanying drawings are for illustrative purposes only and are not to be construed as limiting this patent. Certain components in the accompanying drawings may be omitted, enlarged, or reduced in size to better illustrate the embodiments, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that certain well-known structures and their descriptions may be omitted from the accompanying drawings.

[0028] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "front", "rear", "left", "right" and the like indicating directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. In addition, in the present invention, the descriptions such as "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" or "second" can explicitly or implicitly include at least one such feature.

[0029] Example 1

[0030] This embodiment provides a floating thermoelectric generator. Figure 1 as well as Figure 2 The generator is provided with a first ceramic plate 1, a first electrode 2, a thermoelectric power generation module 3, a second electrode 4 and a second ceramic plate 5 from top to bottom, wherein the first electrode 2 and the second electrode 4 are electrodes with opposite polarities. That is, when the first electrode 2 is a positive electrode, the second electrode 4 is a negative electrode. Conversely, when the first electrode 2 is a negative electrode, the second electrode 4 is a positive electrode. In this embodiment, the first electrode 2 and the second electrode 4 are both electrodes made of copper. Of course, in some other embodiments, the first electrode 2 and the second electrode 4 can also be made of other materials with high conductivity (such as silver). The thermoelectric power generation module 3 includes a number of p-type and / or n-type bismuth telluride thermoelectric components arranged at intervals, and the upper surface of the first ceramic plate 1 is also covered with a sunlight selective absorption / thermal radiation coating 6. The first ceramic plate 1 is a copper-clad Al2O3 ceramic substrate, and the second ceramic plate 5 is a copper-clad AlN ceramic substrate in this embodiment. This material selection can provide high reliability and excellent thermoelectric performance. Al2O3 and AlN ceramic substrates offer advantages such as higher reliability (high and low temperature impact resistance), better thermal expansion coefficients, thinner active metal solder layers, a wide operating temperature range, and excellent insulation. These characteristics make Al2O3 and AlN ceramic substrates ideal for thermoelectric modules, helping to improve the efficiency and reliability of the entire system. Of course, in other embodiments, the first ceramic plate 1 and the second ceramic plate 5 may also be made of other suitable ceramic materials.

[0031] The generator utilizes a natural three-body radiation heat exchange system consisting of the sun, water, and outer space, where the temperature of the sun is about 5500°C, the temperature of the water is about 20°C, and the outer space is a natural cold source with a temperature of about -270°C. The generator floats on the water surface so that the second ceramic plate 5 is in contact with the water. Using radiation heat exchange as a bridge, the generator is cooled by solar power generation and radiation using the sunlight selective absorption / thermal radiation coating 6, which can achieve continuous power supply during the day and night. During the day, solar energy irradiates the surface of the generator (i.e., the sunlight selective absorption / thermal radiation coating 6), and the wavelength enters the thermoelectric power generation module 3 for temperature difference power generation. At this time, the first ceramic plate 1 and / or the sunlight selective absorption / thermal radiation coating 6 serve as the heat source, and the second ceramic plate 5 serves as the cold source. At night, the thermoelectric heating module 3 uses the second ceramic plate 5 in contact with the water as the heat source and outer space as the cold source to continue to convert the temperature difference into electrical energy, thus achieving all-weather power generation. At the same time, the heat generated during the generator's power generation process can also be dissipated through the water, ensuring that the generator does not overheat during operation. Utilizing the sunlight selective absorption / thermal radiation coating 6, the generator achieves excellent selective absorption and radiative cooling dynamic spectral response across the entire spectrum of 250-20,000 nm. Combined with the thermoelectric heating module 3, it enables all-weather energy capture from multiple thermodynamic sources.

[0032] The solar light selective absorption / thermal radiation coating 6 includes a short-wave absorption metal ceramic layer, a metal layer, a visible near-infrared absorption metal ceramic layer and a phase change layer that can form a nanocavity structure, and the phase change layer is tungsten-doped vanadium dioxide. Through the nanocavity, the thermoelectric generator can achieve excellent selective absorption and radiative cooling dynamic spectral response in the entire spectrum range of 250-25000nm. Among them, the short-wave absorption metal ceramic layer is a composite metal ceramic layer with a thickness of 70nm, specifically, tungsten-silicon dioxide (W-SiO2); the metal layer is a metal tungsten (W) layer with a thickness of 10nm; the visible near-infrared absorption metal ceramic layer is a composite metal ceramic layer with a thickness of 40nm, specifically, tungsten-silicon dioxide (W-SiO2); the phase change layer is a tungsten-doped vanadium dioxide (W) with a thickness of 90nm. x V 1-x O2), where x (0.01-0.1) represents the doping atomic ratio of tungsten element. The tungsten-doped vanadium dioxide phase change layer can change its optical properties when the temperature changes, thereby realizing dynamic adjustment of the spectral response and improving the adaptability and efficiency of the thermoelectric generator.

[0033] Specifically, the generator is electrically connected to an electrical appliance (such as a sensor) placed on the sea surface or the seabed via a cable (or other power transmission structure), which can provide a stable power supply to the electrical appliance around the clock. The bismuth telluride thermoelectric component includes a p-type Bi2Te3-based compound and an n-type Bi2Te3-based compound, and the p-type Bi2Te3-based compound and the n-type Bi2Te3-based compound are arranged alternately. This design can optimize the thermoelectric performance of the thermoelectric component and achieve significantly improved thermoelectric performance, such as achieving a maximum ZT value over a wide temperature range. This optimization helps to improve thermoelectric conversion efficiency, reduce power consumption, and increase cooling speed.

[0034] This embodiment is installed on the surface of a body of water. During the day, solar energy irradiates the generator surface (i.e., the solar selective absorption / thermal radiation coating 6), and the wavelength enters the thermoelectric generation module 3 to generate electricity by temperature difference. At this time, the first ceramic plate 1 and / or the solar selective absorption / thermal radiation coating 6 serve as the heat source, and the second ceramic plate 5 serves as the cooling source. At night, the thermoelectric heating module 3 uses the second ceramic plate 5 in contact with the water as the heat source and outer space as the cooling source, continuing to convert the temperature difference into electrical energy. Figure 2 In this embodiment, the maximum output power density of the generator under the irradiation of one sun is about 0.95mW / cm 2 In this embodiment, the water acts as a heat sink during the day and a heat source at night. Compared with the surrounding air, the temperature of the water is lower during the day and higher at night. Compared with a heat sink exposed to the air for natural convection, its heat flow is higher and its performance is better.

[0035] Example 2

[0036] like Figure 3 As shown, this embodiment provides another floating temperature difference thermoelectric generator based on the first embodiment. The difference from the first embodiment is that, in this embodiment, the thermoelectric power generation module 3 is encapsulated by thermally conductive silicone and connected to the first electrode 2 and / or the second electrode 4. The thermally conductive silicone also fills the gaps between the thermoelectric power generation modules 3. The use of thermally conductive silicone, especially silicone with low thermal conductivity, can improve the thermal stability and electrical insulation of the thermoelectric power generation module 3, reduce interface resistance and thermal resistance, and improve device efficiency. In addition, the flexibility of the thermally conductive silicone helps absorb stress caused by the mismatch of thermal expansion coefficients, thereby improving the reliability and durability of the thermoelectric power generation module 3.

[0037] In this embodiment, the spacing and height of the thermoelectric power generation module 3 are optimized based on the maximum temperature difference that can be constructed between the first ceramic plate 1 and the second ceramic plate 5, and the optimal size can be designed to ensure the maximum output density. Specifically, the spacing between the p-type Bi2Te3-based compound and the n-type Bi2Te3-based compound (also called thermoelectric legs) of the thermoelectric power generation module 3 is 8 mm, and the height of the thermoelectric legs is 10 mm. This structure can construct a temperature difference of about 36°C indoors, and the open circuit voltage can reach ~130mV. When the lower surface of the second ceramic plate 5 is in direct contact with the water, refer to Figure 4 The maximum output power density of the generator under one sun intensity is about 1.00mW / cm 2 .

[0038] Of course, it should be noted that, according to the specific heat dissipation structure or heat dissipation medium configured, the spacing between the thermoelectric legs and / or the height parameters of the thermoelectric legs can also be appropriately adjusted, and the spacing between two adjacent thermoelectric power generation modules 3 (i.e., thermoelectric legs) can be 5-10 mm. Appropriate spacing helps to maintain the temperature gradient between modules, thereby improving the thermoelectric conversion efficiency, optimizing heat flow management and electrical connections. At the same time, this design also facilitates the installation and maintenance of the module. Similarly, in other embodiments, the height of the thermoelectric legs can also be 8 cm, 12 cm, or any value between 8-12 cm.

[0039] Example 3

[0040] See Figure 5 Based on the first embodiment, this embodiment provides another floating thermoelectric generator. The difference from the first embodiment is that this embodiment is used in an environment where the contact medium at the bottom of the generator is a medium other than water, such as a terrestrial environment, in which case the lower surface of the second ceramic plate 5 is in direct contact with the air or soil. Because the temperature of the air or soil is also significantly different from that of the sun and outer space, based on the same principle, the generator of this embodiment utilizes a natural three-body radiation heat exchange system consisting of the sun-soil / air-outer space, and can still achieve continuous power supply during the day and night through solar power generation and radiation cooling.

[0041] In this embodiment, the upper surface of the sunlight selective absorption / heat radiation coating 6 is covered with a high light transmittance glass cover plate 7, which can transmit as much sunlight as possible while protecting the sunlight selective absorption / heat radiation coating 6. Of course, it should be noted that the high light transmittance glass cover plate 7 is not a necessary feature of the technical solution of this embodiment. Figure 6 The maximum output power density of this embodiment under the irradiation of one sun is about 0.25mW / cm 2Compared to the previous embodiment, by dynamically adjusting the distribution, thickness, and other parameters of the various layers of the sunlight selective absorption / heat radiation coating 6, the maximum output power density of the generator can be significantly increased. Of course, this test result was achieved under the premise that the lower surface of the second ceramic plate 5 was in direct contact with the air. It is reasonable to infer that the maximum output power density of the generator should be further increased by adding an appropriate heat dissipation structure or heat dissipation medium to this embodiment.

[0042] Of course, in other embodiments, the shortwave absorbing metal-ceramic layer and the visible-near infrared absorbing metal-ceramic layer may also include other metal materials and other metal-ceramic materials, and are not limited to the tungsten-silicon dioxide (W-SiO2) in this embodiment. The metal material may be any one of tungsten, nickel, molybdenum, aluminum, and titanium, or a composite layer thereof; and the metal-ceramic material may be any one of silicon dioxide, titanium dioxide, silicon nitride, and aluminum oxide, or a composite layer thereof.

[0043] In some other embodiments, the metal layer may also be any one of nickel, molybdenum, aluminum, titanium or a composite layer thereof.

[0044] In the specific contents of the above-mentioned specific implementation methods, the various technical features can be combined in any non-contradictory manner. In order to make the description concise, not all possible combinations of the above-mentioned technical features are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. A person skilled in the art will be able to make other variations or modifications based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A floating thermoelectric generator, which is arranged in order from top to bottom: A first ceramic plate (1), a first electrode (2), a thermoelectric power generation module (3), a second electrode (4) and a second ceramic plate (5), wherein: The first electrode (2) and the second electrode (4) are electrodes with opposite polarities, It is characterized in that The thermoelectric power generation module (3) comprises a plurality of p-type and / or n-type bismuth telluride thermoelectric components arranged at intervals, and the upper surface of the first ceramic plate (1) is also covered with a sunlight selective absorption / heat radiation coating (6).

2. The floating thermoelectric generator according to claim 1, characterized in that: The bismuth telluride thermoelectric component includes a p-type Bi2Te3-based compound and an n-type Bi2Te3-based compound, and the p-type Bi2Te3-based compound and the n-type Bi2Te3-based compound are alternately arranged.

3. The floating thermoelectric generator according to claim 2, characterized in that: The interval between two adjacent thermoelectric generation modules (3) is 5-10 mm.

4. The floating thermoelectric generator according to claim 3, characterized in that: The height of the thermoelectric power generation module (3) is 8-12 mm.

5. The floating thermoelectric generator according to claim 3, characterized in that: The thermoelectric power generation module (3) is encapsulated by heat-conductive silica gel and connected to the first electrode (2) and / or the second electrode (4).

6. The floating thermoelectric generator according to claim 1, characterized in that: The first ceramic plate (1) is a copper-clad Al2O3 ceramic substrate, and the second ceramic plate (5) is a copper-clad AlN ceramic substrate.

7. The floating thermoelectric generator according to any one of claims 1 to 6, characterized in that: The sunlight selective absorption / heat radiation coating (6) comprises a short-wave absorption metal ceramic layer capable of forming a nanocavity structure, a metal layer, a visible near-infrared absorption metal ceramic layer and a phase change layer, wherein the phase change layer is tungsten-doped vanadium dioxide.

8. The floating thermoelectric generator according to claim 7, characterized in that: The short-wave absorption metal ceramic layer and the visible-near-infrared absorption metal ceramic layer are composite metal ceramic layers containing metal materials and metal ceramic materials. The metal materials include tungsten, nickel, molybdenum, aluminum, titanium or their composite layers; the metal ceramic materials include silicon dioxide, titanium dioxide, silicon nitride, aluminum oxide or their composite layers.

9. The floating thermoelectric generator according to claim 8, characterized in that: The composite metal ceramic layer is tungsten-silicon dioxide.

10. The floating thermoelectric generator according to claim 7, characterized in that: The metal layer is tungsten, nickel, molybdenum, aluminum, titanium or a composite layer thereof.

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