A temperature difference power generation device based on radiation cooling and its preparation method

Abstract

The present invention discloses a temperature difference power generation device based on radiation cooling and a preparation method thereof. The device takes a sheet-like temperature difference power generation element as the core, and its cold end is attached to a film-like radiation cooling element. Through radiation cooling, space cold sources are used to achieve all-day cooling. The hot end of the temperature difference power generation element is attached to a plate-like thermal conductive element. The thermal conductive element has a large area and can be set on any flat object outdoors. During the day or on sunny days, the thermal conductive element is used to absorb solar radiation to heat the temperature difference power generation element and the surface near the thermal conductive element at the same time. The heat is retained until night to enhance the power generation effect at night. On cloudy days or at night, the thermal conductive element can absorb nearby waste heat to heat the power generation sheet, so that a temperature difference can be formed on both sides of the temperature difference power generation element in all weather / all seasons, and a voltage is output to the load based on the Seebeck effect.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature difference power generation, and in particular to a temperature difference power generation device based on radiation cooling and a preparation method thereof. Background Art

[0002] At present, the most used energy for power generation is still non-renewable energy such as oil, coal, and natural gas. When these raw materials are not completely burned, they will cause environmental pollution and energy waste. In recent years, although new energy solar energy, tidal energy, and wind energy have developed well and have been put into practical application, they are all subject to time and geographical restrictions. For example, solar energy can only be used during the day, and tidal energy can only be used in coastal areas. If you want to achieve all-day power supply and power supply for various regions, you need to use power storage devices and power grids, which will increase the cost of the entire power generation system.

[0003] Thermoelectric power generation technology is a solid-state energy conversion technology based on the Seebeck effect, which has the characteristics of simple structure and high reliability. The Seebeck effect, also known as the first thermoelectric effect, refers to the thermoelectric phenomenon that the potential difference between two substances is caused by the temperature difference between two different conductors or semiconductors. The essence is that when two metals come into contact, a contact potential difference will be generated, which is caused by the different electron overflow work and the different electron concentrations in the two metals.

[0004] In thermodynamics, any energy conversion process must have a heat source and a cold source to produce useful work, such as electricity. Most renewable energy generation methods, including photovoltaics and solar thermal systems, rely on the sun as a heat source and the Earth's surrounding environment as a cold source. However, at night, there is no such ubiquitous and easily accessible heat source to drive the heat engine. On the other hand, there is a ubiquitous cold source that does exist, but it has been largely overlooked so far: outer space.

[0005] Space cold sources can be obtained all day and everywhere through radiation cooling. Radiative cooling is a passive cooling phenomenon in which objects on Earth emit heat in the form of radiation through the atmospheric window (that is, some bands of celestial radiation that can penetrate the atmosphere) to outer space, thereby cooling the object. Thermoelectric generators using radiation cooling can achieve all-day, off-grid power generation. For example, the generator based on radiation cooling designed by ErzhenMu's team achieved a voltage output of 0.5mV using space cold sources. The radiation-cooled thermoelectric generator proposed by Aaswath P.Raman's team, which works at night, has an output voltage of 79mV and successfully lights up an LED lamp.

[0006] However, most of the proposed radiation cooling thermoelectric generators have the problems of large size and low power generation efficiency, which limits the practical application of the generator. For this reason, how to design a compact and easy-to-manufacture thermoelectric generator has become a technical problem that needs to be solved urgently. Summary of the invention

[0007] The invention discloses a temperature difference power generation device based on radiation cooling and a preparation method thereof, which are used to solve the technical problems of large volume and low power generation efficiency of radiation cooling thermoelectric generators in the prior art.

[0008] In order to solve the above problems, the present invention adopts the following technical solutions:

[0009] In one aspect, the present invention provides a temperature difference power generation device based on radiation cooling, comprising:

[0010] - Radiative cooling element, which includes a material or device having the ability to radiate infrared electromagnetic waves corresponding to the atmospheric window;

[0011] - a thermoelectric power generation element, the thermoelectric power generation element comprising a material having a thermoelectric effect;

[0012] - an insulating element, the insulating element comprising an insulating material;

[0013] - a thermal conductive element, the thermal conductive element comprises a material with a large thermal conductivity and a high absorption rate of solar radiation energy;

[0014] - Conducting wires, which are connected to the thermoelectric generating element and are used for outputting electric energy;

[0015] The cold end surface of the thermoelectric power generation element is connected to the radiation cooling element, and the hot end surface of the thermoelectric power generation element is connected to the thermal conductive element; the thermal insulation element is sleeved around the thermoelectric power generation element; and the thermal conductive element is installed on the outer surface of any outdoor object.

[0016] As a preferred technical solution, the material having the ability to radiate infrared electromagnetic waves through a radiation atmospheric window includes a polymer material or an inorganic material with a coating, and the device having the ability to radiate infrared electromagnetic waves through a radiation atmospheric window includes a radiation gas plate.

[0017] As a preferred technical solution, the polymer material includes at least one of polyvinyl chloride, polystyrene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polymethyl methacrylate, polymethylpentene and polyphenylene ether, modified polymethyl ether resin, ethyl cellulose and cellulose acetate.

[0018] As a preferred technical solution, the inorganic material having the coating layer includes at least one of silicon monoxide, silicon dioxide, silicon oxynitride and silicon nitride.

[0019] As a preferred technical solution, the gas in the radiant gas plate includes ammonia, ethylene oxide or a mixture thereof.

[0020] As a preferred technical solution, the radiation cooling element is in the form of a porous flexible membrane or a rigid plate.

[0021] As a preferred technical solution, the thickness of the radiation cooling element is not less than 50 μm, and the pore size on its surface is 0.02 to 8 μm.

[0022] As a preferred technical solution, the material having thermoelectric effect includes inorganic semiconductor materials, polymer / inorganic semiconductor composite materials, polymer / carbon nanostructure composite materials, polymer / metal particle composite materials or other polymer composite materials.

[0023] As a preferred technical solution, the inorganic semiconductor material includes Bi 2 Te 3 ,PbTe,ZnSb,SiGe,AgSbTe 2 、Gete.

[0024] As a preferred technical solution, the polymer / inorganic semiconductor composite material includes PEDOT:PSS and Te, Bi 2 Te 3 , Cu 2 Se, SnSe, WS 2 、MoS 2 Or hybrid materials of SiC particles.

[0025] As a preferred technical solution, the polymer / carbon nanostructure composite material includes a polyaniline / graphene / carbon nanotube composite material.

[0026] As a preferred technical solution, the polymer / metal particle composite material includes a PEDOT / gold nanoparticle composite material and a PEDOT:PSS / PVA silver nanoparticle composite material.

[0027] As a preferred technical solution, other polymer composite materials include polyaniline / polyethylene glycol composite materials, PEDOT:PSS / polyurethane composite materials, PEDOT:PSS / ionic solution composite materials, and polysodium nickel-ethylene tetrasulfide / polyurethane composite materials.

[0028] As a preferred technical solution, the thermoelectric power generation element is in the shape of a sheet or a plate.

[0029] As a preferred technical solution, the thermal insulation material includes fiber material, glass wool, foam board, vacuum glass board or material with a cavity filled with inert gas.

[0030] As a preferred technical solution, the material with high thermal conductivity and high solar radiation energy absorption rate includes at least one of copper sheet, iron plate, graphite, thermal conductive silicone grease and black thermal conductive glue.

[0031] As a preferred technical solution, the bottom surface area of ​​the temperature conducting element is larger than the bottom surface area of ​​the radiation cooling element.

[0032] In another aspect, the present invention provides a method for preparing a thermoelectric power generation device based on radiation cooling, comprising:

[0033] A thermoelectric power generation element is provided, wherein the thermoelectric power generation element is made of a material having a thermoelectric effect;

[0034] A radiation cooling element is attached to the cold end surface of the temperature difference power generation element, and the radiation cooling element is made of a material having the ability to radiate infrared electromagnetic waves corresponding to the radiation atmospheric window;

[0035] A thermal conductive element is attached to the hot end surface of the thermoelectric generating element, and the thermal conductive element is made of a material with a large thermal conductivity and a high solar radiation energy absorption rate;

[0036] A heat-insulating element is provided around the thermoelectric generating element;

[0037] The thermoelectric power generation element and the load are connected by wires to obtain the thermoelectric power generation function based on radiation cooling.

[0038] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0039] (1) The present invention provides a thermoelectric power generation device based on radiation cooling, which is based on a sheet-like thermoelectric power generation element as the core. The cold end of the thermoelectric power generation element is attached to a film-like radiation cooling element, and the space cold source is used to achieve all-day cooling through radiation cooling. The hot end of the thermoelectric power generation element is attached to a plate-like thermal conductive element. The thermal conductive element has a large area and can be set on any flat object outdoors, such as a roof or a car roof. Taking the roof as an example, on a sunny day, the thermal conductive element absorbs solar radiation to heat the thermoelectric power generation element and the roof near the thermal conductive element. The heat is retained until night to enhance the power generation effect at night. On cloudy days or at night, the thermal conductive element can absorb the waste heat from the roof to heat the power generation sheet, so that a temperature difference can be formed on both sides of the thermoelectric power generation element in all weather / all seasons, and a voltage is output to the load based on the Seebeck effect.

[0040] (2) Since the thermoelectric power generation device in the present invention performs radiative heat exchange to outer space through radiative cooling, it not only reduces the greenhouse effect, but also can achieve a lower temperature, so that a larger temperature difference is formed on both sides of the thermoelectric power generation element to ensure sufficient output voltage, thereby achieving the dual functions of cooling and power generation.

[0041] (3) The temperature difference power generation device in the present invention has a simple structure and a small size. It has no enclosed cavity and can be spliced ​​in a matrix. It can also be connected in series and parallel at will. It can be applied to any flat object outdoors without being restricted by the terrain, so that it can be applied to a large number of scenes and provide high-efficiency power supply, such as roofs, car roofs, airplanes, ships, trains, balconies, fire hydrants, street lights and billboards.

[0042] (4) On the other hand, the present invention provides a method for preparing a temperature difference power generation device based on radiation cooling, which not only has a simple manufacturing process and low cost, but also produces no waste in the entire process, which is green and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments, which constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions explain the present invention and do not constitute improper limitations on the present invention. In the drawings:

[0044] Figure 1 This is a schematic structural diagram of a thermoelectric power generation device in a preferred implementation manner disclosed in Example 1 of the present invention;

[0045] Figure 2 This is a power generation effect test diagram of a temperature difference power generation device in a preferred implementation manner disclosed in Example 1 of the present invention;

[0046] Specifically include the following figure signs:

[0047] Radiative cooling element 10 , thermoelectric power generation element 20 , thermal conduction element 30 , and thermal insulation element 40 . DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. In the description of the present invention, it should be noted that the term "or" is usually used in the sense of including "and / or", unless the content clearly indicates otherwise.

[0049] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] In order to solve the problems existing in the prior art, the embodiment of the present application mainly provides a temperature difference power generation device based on radiation cooling, which includes a radiation cooling element, a temperature difference power generation element, an insulation element, a thermal conductive element and a wire, wherein the radiation cooling element includes a material or device with the ability to radiate infrared electromagnetic waves corresponding to the atmospheric window; the temperature difference power generation element includes a material with thermoelectric effect; the insulation element includes an insulation material; the thermal conductive element includes a material with a large thermal conductivity and a high absorption rate of solar radiation energy; the wire is connected to the temperature difference power generation element for electrical energy output; the cold end face of the temperature difference power generation element is connected to the radiation cooling element, and the hot end face of the temperature difference power generation element is connected to the thermal conductive element; the insulation element is sleeved around the temperature difference power generation element; and the thermal conductive element is installed on the outer surface of any object outdoors.

[0052] Example 1

[0053] In view of the problems of large size and low power generation efficiency of most of the currently proposed radiation cooling thermoelectric generators, this embodiment 1 provides a new type of temperature difference power generation device based on radiation cooling, which has the advantages of small size, simple structure and considerable power generation efficiency.

[0054] refer to Figure 1 In a preferred embodiment, a thermoelectric power generation device based on radiation cooling is provided. The power generation device includes a radiation cooling element 10, a thermoelectric power generation element 20 with a thermoelectric effect, and a thermal conductive element 30, which are arranged in sequence from top to bottom. An insulating element 40 is also arranged around the thermoelectric power generation element 20, and the thermoelectric power generation element 20 outputs a voltage through a wire.

[0055] Preferably, the radiation cooling element 10 arranged at the top of the temperature difference power generation device is in the form of a porous film or plate, and can be set to be flexible or rigid. Furthermore, in order to increase its radiation cooling effect, a flexible white porous film is selected, and the thickness of the film is not less than 50μm, and the pore size is 0.02~8μm, so as to achieve a balance between volume control and radiation cooling effect.

[0056] Preferably, the radiation cooling element 10 can be prepared by selecting a material or device having a radiation atmospheric window corresponding to the infrared electromagnetic wave radiation capability; wherein, the material having a radiation atmospheric window corresponding to the infrared electromagnetic wave radiation capability can preferentially be a polymer material or an inorganic material with a coating, and the device having a radiation atmospheric window corresponding to the infrared electromagnetic wave radiation capability can preferentially be a radiation type gas plate.

[0057] Specifically, since the radiant gas plate has many advantages such as large heat transfer area, small size, good temperature resistance and long life, it can be directly used as the radiant cooling element 10. Preferably, the gas in the radiant gas plate may include ammonia, ethylene oxide or a mixture thereof.

[0058] Furthermore, the inorganic material with the coating is preferably at least one of silicon monoxide, silicon dioxide, silicon oxynitride and silicon nitride. This material has good spectral selective reflection performance, allowing the heat of objects on the earth's surface to be transferred to the film through contact, and most of the infrared radiation emitted by the film is emitted through the atmospheric window (8-13μm, 16-25μm) to the atmospheric space with an absolute temperature close to zero degrees; in the sunlight band (0.28-25um), its reflectivity is higher than 85%, which has a good effect of blocking sunlight. More importantly, its mechanical properties are similar to those of glass, with high hardness and good friction resistance, so it can greatly increase the service life of the temperature difference power generation device.

[0059] Furthermore, the polymer material can be powder, granules, liquid or gas, preferably at least one of polyvinyl chloride, polystyrene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polymethyl methacrylate, polymethylpentene and polyphenylene ether, modified polymethyl ether resin, ethyl cellulose, cellulose acetate, or a coating of a composite polymer material and a polymer binder based on various pigments, or a composite material of an infrared-transmitting polymer mixed with nanoparticles. Since the film made of the above materials has a high reflectivity to sunlight (0.28-2.5 μm) and a high infrared emissivity in the atmospheric window band (8-13 μm, 16-25 μm), it also has a strong radiation cooling ability.

[0060] Furthermore, the above-mentioned polymer material is formed on a substrate by at least one of spin coating, spray coating, scraping, rolling, and etching. The substrate is preferably glass, metal, wood, plastic or a building. More preferably, the film prepared from the above-mentioned polymer is adhered to the substrate using a film with good thermal conductivity, and the thermal conductivity requires that the temperature difference at both ends of the thermal conductive film is less than 1°C; specifically, the film prepared from the above-mentioned polymer can be in an attached state or an independent state.

[0061] In a more preferred embodiment, the radiation cooling element 10 is a radiation cooling film, which is made of a mixture of polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) with an optimal mass ratio of 15% and N,N-dimethylformamide with 85%.

[0062] Preferably, the thermoelectric power generation element 20 is in the form of a sheet or plate to control the overall volume of the thermoelectric power generation device. Furthermore, it is preferably prepared from a material having a thermoelectric effect. The so-called thermoelectric effect is a phenomenon in which current or charge accumulates when electrons in a heated object move from a high temperature zone to a low temperature zone due to a temperature gradient. A material having a thermoelectric effect is a functional material that can convert thermal energy and electrical energy into each other. The thermoelectric power generation element 20 made of this material is small in size, light in weight, has no mechanical rotating parts, operates without noise, has no liquid or gaseous medium, does not cause environmental pollution, has a fast response speed, has a long device life, and can achieve precise temperature control.

[0063] Specifically, the material having the thermoelectric effect is preferably an inorganic semiconductor material, a polymer / inorganic semiconductor composite material, a polymer / carbon nanostructure composite material, a polymer / metal particle composite material or other polymer composite materials.

[0064] In a preferred embodiment, the inorganic semiconductor material comprises Bi 2 Te 3 ,PbTe,ZnSb,SiGe,AgSbTe 2 、Gete.

[0065] In another preferred embodiment, the polymer / inorganic semiconductor composite material comprises PEDOT:PSS and Te, Bi 2 Te 3 , Cu 2 Se, SnSe, WS 2 、MoS 2 Or hybrid materials of SiC particles.

[0066] Preferably, the polymer / carbon nanostructure composite material comprises a polyaniline / graphene / carbon nanotube composite material.

[0067] Preferably, the polymer / metal particle composite material includes a PEDOT / gold nanoparticle composite material and a PEDOT:PSS / PVA silver nanoparticle composite material.

[0068] Preferably, other polymer composite materials include polyaniline / polyethylene glycol composite materials, PEDOT:PSS / polyurethane composite materials, PEDOT:PSS / ionic solution composite materials, polysodium nickel-ethylene tetrasulfide / polyurethane composite materials.

[0069] In a more preferred embodiment, Bi is selected 2 Te 3 Thermoelectric power generation sheet is used as thermoelectric power generation element 20. Since its operating temperature is about 200°C, it is mainly Bi 2 Te 3 and Bi2 Te 3 Solid solution alloy material based on Bi 2 Te 3 The thermoelectric power generation material based on this material has the best ZT figure of merit.

[0070] Furthermore, the thermal conductive element 30 is preferably made of a material with a large thermal conductivity and a high absorption rate of solar radiation energy, so as to ensure that the thermal conductive element 30 can absorb sufficient solar radiation energy and heat during the day, and can also collect nearby heat at night. Preferably, the thermal conductive element 30 can be selected from at least one of copper sheet, iron plate, graphite, thermal conductive silicone grease and black thermal conductive glue. In a more preferred embodiment, the thermal conductive element 30 is a copper sheet, which has a tough texture, good ductility and a reasonable price, and has a high thermal conductivity (400W / (m·K)) and solar radiation absorption coefficient. More preferably, the bottom surface area of ​​the copper sheet is larger than the bottom surface area of ​​the radiation cooling element 10, which can not only ensure that it can be exposed to sunlight during the day, but also ensure that it can absorb sufficient heat at night or on cloudy days to improve the power generation efficiency.

[0071] Preferably, an insulating element 40 is provided around the thermoelectric power generation element 20 to ensure that a temperature difference can be smoothly formed on both sides of the thermoelectric power generation element 20, thereby improving the efficiency of electric energy conversion; the insulating element 40 is preferably a fiber material, glass wool, a foam board, a vacuum glass board or a material with a cavity filled with an inert gas; in a more preferred embodiment, the insulating element 40 is a foam board, which has the advantages of light weight, heat insulation, heat preservation, low cost and easy construction, and can further simplify the structure of the thermoelectric power generation device and control the production cost.

[0072] In a preferred embodiment, the radiation cooling film, Bi 2 Te 3 Thermoelectric power generation sheets and copper sheets are arranged from top to bottom. 2 Te 3 The four parts of the thermoelectric generator are laid with foam boards around them, and the four parts together form a composite device, which can be freely combined in series and parallel, and separated by insulation elements 40, and connected to Bi by wires. 2 Te 3 Thermoelectric generator and load, used for voltage output. Figure 2 It can be seen that in this embodiment, the greater the temperature difference, the higher the power generation efficiency.

[0073] Furthermore, the copper sheet can be installed on the outer surface of any flat object outdoors, such as the top of various vehicles or buildings and signs. For example, if it is applied to the upper surface of a car, it can not only effectively reduce the temperature inside the car, but also use the generated electricity to supply the devices inside the car; if it is applied to an airplane, it further reduces the cloud layer's blocking of radiation, and the power generation effect is more obvious; if it is applied to the roof of a factory, the roof can efficiently heat the hot end, improve the power generation efficiency, and achieve self-sufficient lighting and cooling in the factory. In addition, it can be applied to vehicles such as ships and trains; it can be applied to buildings such as roofs and balconies; it can be applied to road surfaces such as street lamps, fire hydrants, and billboards. It can radiate a large amount of heat into space, contributing to the suppression of the greenhouse effect. The generated electricity can be further applied to refrigeration, lighting, driving, etc., reducing the use of fossil energy and further contributing to mitigating the greenhouse effect.

[0074] Example 2

[0075] refer to Figure 1 This embodiment provides a method for preparing the thermoelectric power generation device as described in Embodiment 1, comprising the following process:

[0076] S1. Provide a thermoelectric power generation element 20, wherein the thermoelectric power generation element 20 is made of a material having a thermoelectric effect;

[0077] Preferably, the thermoelectric power generation element 20 is made of the material mentioned in Example 1, more preferably Bi 2 Te 3 The thermoelectric power generation sheet serves as the thermoelectric power generation element 20 .

[0078] S2. A radiation cooling element 10 is attached to the cold end surface of the temperature difference power generation element 20. The radiation cooling element 10 is made of a material having the ability to radiate infrared electromagnetic waves corresponding to the atmospheric window;

[0079] Preferably, the radiation cooling element 10 uses the material described in Example 1 to make a radiation cooling film. In a more preferred embodiment, a mixture of 15% PVDF-HFP and 85% N,N-dimethylformamide is used, stirred for 4 hours, spread on the glass surface, the thickness is controlled to be 400μm-500μm, formed in a water bath, and dried to obtain a radiation cooling film.

[0080] S3, attaching a thermal conductive element 30 to the hot end surface of the thermoelectric power generation element 20, wherein the thermal conductive element 30 is made of a material with a large thermal conductivity and a high solar radiation energy absorption rate;

[0081] Preferably, the temperature conducting element 30 is a copper sheet, and the area of ​​the copper sheet is required to be larger than the area of ​​the radiation cooling film.

[0082] S4, installing a heat insulating element 40 around the thermoelectric power generation element 20;

[0083] The insulating element 40 is preferably a foam board.

[0084] S5. Use a wire to connect the thermoelectric power generation element 20 and the load to obtain a thermoelectric power generation function based on radiation cooling.

[0085] Preferably, according to specific practical needs, a plurality of assembled temperature difference power generation devices can be connected in series and in parallel and separated by insulation elements 40 in order to obtain higher power generation capacity.

[0086] In a preferred embodiment, a method for preparing a thermoelectric power generation device with better power generation effect is provided:

[0087] First, 15% PVDF-HFP and 85% N,N-dimethylformamide were mixed, stirred for 4 hours, spread on the glass surface, the thickness was controlled at 400μm-500μm, formed in a water bath, and dried to obtain a radiation cooling film;

[0088] Then stick thermal conductive glue under the copper sheet and put a 5mm thick foam board on it; cut a 5.5cm×5.5cm square hole in the middle of the foam board and put the Bi 2 Te 3 The thermoelectric generator is placed in the cavity;

[0089] Finally in Bi 2 Te 3 The above-mentioned radiation cooling film is laid on the thermoelectric power generation sheet and the foam board, and the wires are connected to complete the preparation of the thermoelectric power generation device.

[0090] The present invention has the following advantages:

[0091] (1) The present invention provides a thermoelectric power generation device based on radiation cooling, which is based on a sheet-like thermoelectric power generation element as the core. The cold end of the thermoelectric power generation element is attached to a film-like radiation cooling element, and the space cold source is used to achieve all-day cooling through radiation cooling. The hot end of the thermoelectric power generation element is attached to a plate-like thermal conductive element. The thermal conductive element has a large area and can be set on any flat object outdoors, such as a roof or a car roof. Taking the roof as an example, on a sunny day, the thermal conductive element absorbs solar radiation to heat the thermoelectric power generation element and the roof near the thermal conductive element. The heat is retained until night to enhance the power generation effect at night. On cloudy days or at night, the thermal conductive element can absorb the waste heat from the roof to heat the power generation sheet, so that a temperature difference can be formed on both sides of the thermoelectric power generation element in all weather / all seasons, and a voltage is output to the load based on the Seebeck effect.

[0092] (2) Since the thermoelectric power generation device in the present invention performs radiative heat exchange to outer space through radiative cooling, it not only reduces the greenhouse effect, but also can achieve a lower temperature, so that a larger temperature difference is formed on both sides of the thermoelectric power generation element to ensure sufficient output voltage, thereby achieving the dual functions of cooling and power generation.

[0093] (3) The temperature difference power generation device in the present invention has a simple structure and a small size. It has no enclosed cavity and can be spliced ​​in a matrix. It can also be connected in series and parallel at will. It can be applied to any flat object outdoors without being restricted by the terrain, so that it can be applied to a large number of scenes and provide high-efficiency power supply, such as roofs, car roofs, airplanes, ships, trains, balconies, fire hydrants, street lights and billboards.

[0094] (4) On the other hand, the present invention provides a method for preparing a temperature difference power generation device based on radiation cooling, which not only has a simple manufacturing process and low cost, but also produces no waste in the entire process, which is green and environmentally friendly.

[0095] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A temperature difference power generation device based on radiation cooling, characterized in that: include: - a radiation cooling element, the radiation cooling element comprising a material or device having the ability to radiate infrared electromagnetic waves corresponding to the atmospheric window, the radiation cooling element being in the form of a film; - a thermoelectric power generation element, the thermoelectric power generation element comprising a material having a thermoelectric effect, the thermoelectric power generation element being in a sheet shape; - a thermal insulation element, said thermal insulation element comprising a thermal insulation material; - a thermal conductive element, the thermal conductive element comprises a material with a large thermal conductivity and a high solar radiation energy absorption rate, the material with a large thermal conductivity and a high solar radiation energy absorption rate comprises at least one of a copper sheet, an iron plate, graphite, thermal conductive silicone grease and a black thermal conductive glue; the bottom surface area of ​​the thermal conductive element is larger than the bottom surface area of ​​the radiation cooling element, and the thermal conductive element is in the shape of a sheet or a plate; - a conductor, the conductor being connected to the thermoelectric power generation element for outputting electric energy; The cold end surface of the thermoelectric power generation element is connected to the radiation cooling element, and the hot end surface of the thermoelectric power generation element is connected to the thermal conductive element; the thermal insulation element is sleeved around the thermoelectric power generation element; the thermal conductive element is installed on the outer surface of any outdoor object, and a temperature difference can be formed on both sides of the thermoelectric power generation element in all weather / all seasons, and a voltage can be output to the load based on the Seebeck effect.

2. The thermoelectric power generation device according to claim 1, characterized in that: The material having the capability of radiating the infrared electromagnetic wave through the radiating atmospheric window includes a polymer material or an inorganic material with a coating, and the device having the capability of radiating the infrared electromagnetic wave through the radiating atmospheric window includes a radiative gas plate.

3. The thermoelectric power generation device according to claim 2, characterized in that: The polymer material includes at least one of polyvinyl chloride, polystyrene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polymethyl methacrylate, polymethylpentene, polyphenylene ether, modified polymethyl ether resin, ethyl cellulose and cellulose acetate.

4. The thermoelectric power generation device according to claim 2, characterized in that: The inorganic material having a coating layer includes at least one of silicon monoxide, silicon dioxide, silicon oxynitride and silicon nitride.

5. The thermoelectric power generation device according to claim 2, characterized in that: The gas in the radiant gas panel includes ammonia, ethylene oxide or a mixture thereof.

6. The thermoelectric power generation device according to any one of claims 1 to 5, characterized in that: The radiation cooling element is in the form of a porous flexible film or a rigid plate.

7. The thermoelectric power generation device according to claim 6, characterized in that: The thickness of the radiation cooling element is not less than 50 μm, and the pore size on its surface is 0.02-8 μm.

8. The thermoelectric power generation device according to claim 1, characterized in that: The material with thermoelectric effect includes inorganic semiconductor materials, polymer / inorganic semiconductor composites, polymer / carbon nanostructure composites, polymer / metal particle composites or other polymer composites. The other polymer composites include polyaniline / polyethylene enzyme composites, PEDOT:PSS / polyurethane composites, PEDOT:PSS / ionic solution composites, polysodium nickel-ethylene tetrasulfide / polyurethane composites.

9. The thermoelectric power generation device according to claim 8, characterized in that: The inorganic semiconductor materials include Bi2Te3, PbTe, ZnSb, SiGe, AgSbTe2, and GeTe.

10. The thermoelectric power generation device according to claim 8, characterized in that: The polymer / inorganic semiconductor composite material includes a hybrid material of PEDOT:PSS and Te, Bi2Te3, Cu2Se, SnSe, WS2, MoS2 or SiC particles.

11. The thermoelectric power generation device according to claim 8, characterized in that: The polymer / carbon nanostructure composite material comprises a polyaniline / graphene / carbon nanotube composite material.

12. The thermoelectric power generation device according to claim 8, characterized in that: The polymer / metal particle composite material includes a PEDOT / gold nanoparticle composite material and a PEDOT:PSS / PVA silver nanoparticle composite material.

13. The thermoelectric power generation device according to claim 1, characterized in that: The thermal insulation material includes fiber material, glass wool, foam board, vacuum glass board or material with a cavity filled with inert gas.

14. The method for preparing a thermoelectric power generation device based on radiation cooling according to any one of claims 1 to 13, characterized in that: include: A thermoelectric power generation element is provided, wherein the thermoelectric power generation element is made of a material having a thermoelectric effect; A radiation cooling element is attached to the cold end surface of the temperature difference power generation element, and the radiation cooling element is made of a material having the ability to radiate infrared electromagnetic waves corresponding to the atmospheric window; A thermal conductive element is attached to the hot end surface of the temperature difference power generation element, wherein the thermal conductive element is made of a material with a large thermal conductivity and a high solar radiation energy absorption rate; A heat insulating element is provided around the thermoelectric generating element; The thermoelectric power generation element is connected to a load by using a wire to obtain a thermoelectric power generation function based on radiation cooling.

Images