Composite thermoelectric concrete wall structure with thermoelectric power generation and heat preservation functions

Abstract

The invention discloses a composite thermoelectric concrete wall structure with thermoelectric power generation and heat preservation functions, and belongs to the technical field of building energy conservation and energy recovery. The wall structure is sequentially provided with a high thermal conductivity concrete layer, a thermal conductivity enhancement layer, a thermoelectric assembly layer, a low thermal conductivity concrete layer and a phase change heat storage layer from outside to inside. The high-thermal-conductivity concrete layer is prepared by mixing a cement-based material with a thermal conductive aggregate and is used for absorbing and conducting external heat; the heat conduction enhancement layer enhances directional heat conduction; a plurality of thermoelectric power generation modules are embedded in the thermoelectric component layer, the hot end is connected with the heat conduction enhancement layer, and the cold end faces the inner side; the low-thermal-conductivity concrete layer is prepared by mixing a cement-based material with light thermal-insulation aggregate and is used for preventing heat from being conducted indoors; the phase change heat storage layer is arranged near the cold end of the thermoelectric assembly layer and used for adjusting the temperature of the cold end to maintain a stable temperature difference. A detachable connection structure is arranged between the thermoelectric assembly layer and the heat conduction enhancement layer, so that later replacement and maintenance are facilitated. Energy recovery is achieved through the temperature difference of the outer wall of the building, and the system is suitable for residences or industrial factory buildings or passive energy-saving buildings.

Description

Technical Field

[0001] The present invention relates to the field of building materials, and in particular to a composite thermoelectric concrete wall structure with temperature difference power generation and heat preservation functions. Background Art

[0002] With the global energy crisis and increasingly severe environmental issues, building energy conservation and the use of renewable energy have become hot topics in current research. As the interface between a building and the external environment, the building envelope not only provides insulation but also possesses enormous potential for energy harvesting. In particular, technologies that harness the temperature difference between the inside and outside of building walls to generate electricity have garnered widespread attention in recent years.

[0003] At present, concrete is one of the most commonly used materials in the construction field, and its application research in the field of thermoelectric power generation has made certain progress. For example, CN113904590A discloses a concrete wall thermoelectric power generation device and a method for making a graphene-concrete wall. The device includes a graphene-concrete wall, a heat collection system, and an electric energy conversion device. The device uses the n-type conductivity of concrete and the p-type conductivity of graphene to form an electron-hole distribution, thereby enhancing the thermoelectric performance of the material[1]. CN111082707A proposes a building wall thermoelectric power generation system, in which a thermoelectric material layer is set inside the wall. When there is a temperature difference between the inside and outside of the wall, the heat is collected through the thermoelectric material layer and converted into usable electrical energy[2].

[0004] In terms of thermal management and thermal conductivity, CN103633882A introduces a heat-conducting asphalt concrete pavement thermoelectric power generation system, which forms a heat-collecting layer by adding thermally conductive fillers such as graphite to the asphalt concrete, and combines it with thermally conductive aluminum sheets to enhance the heat conduction efficiency [3]. This idea provides a reference for improving the thermal conductivity of building materials. The thermoelectric phase change enclosure system disclosed in CN109004863A combines thermoelectric power generation sheets with phase change enclosure structures. It can not only generate electricity from solar radiation energy, but also regulate temperature through phase change materials to reduce building energy consumption [4]. CN115823673B proposes an integrated structure of radiative cooling and thermoelectric power generation, combining radiative cooling technology with semiconductor thermoelectric power generation technology, and generating and storing electricity through the temperature difference generated by radiative cooling [5].

[0005] However, the existing technology still has the following problems: First, it is difficult for conventional concrete walls to maintain a stable and effective temperature difference, resulting in low thermoelectric conversion efficiency. The thermoelectric power generation devices in the existing technology are mostly surface-mounted, the heat conduction path is not direct enough, the thermal resistance is large, and this affects the power generation efficiency. Secondly, the existing thermoelectric components are mostly fixedly installed. Once damaged or need to be upgraded, the entire system requires large-scale transformation, and the maintenance cost is high. Third, the thermal management function of the concrete wall in the existing technology is single, and it is difficult to meet the dual needs of thermal conductivity and thermal insulation at the same time, especially in different seasons and climatic conditions, and intelligent regulation of heat flow cannot be achieved. Finally, the power generation power of the existing system is unstable, and it is difficult to meet the continuous power supply needs of low-power equipment in buildings. The overall integration and practicality of the system need to be improved.

[0006] Therefore, there is an urgent need to develop a new type of composite thermoelectric concrete wall structure that can effectively improve the efficiency of temperature difference power generation, while having modular design and good thermal management functions to meet the dual needs of building energy saving and energy collection. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a composite thermoelectric concrete wall structure with temperature difference power generation and thermal insulation functions, in response to the problems existing in the prior art such as difficulty in maintaining temperature difference, poor integration of thermoelectric modules, difficulty in balancing wall thermal management and structural safety, and insufficient power generation. This invention realizes the self-generating function of the building wall.

[0008] The technical solution adopted by the present invention to solve its technical problems is: to provide a composite thermoelectric concrete wall structure with temperature difference power generation and thermal insulation functions, including a high thermal conductivity concrete layer, a thermal conductivity reinforcement layer, a thermoelectric component layer, a low thermal conductivity concrete layer and a phase change heat storage layer arranged in sequence from the outside to the inside, wherein the thermoelectric component layer and the thermal conductivity reinforcement layer are connected in a detachable structure.

[0009] Preferably, the high thermal conductivity concrete layer is made of cement-based materials mixed with thermal conductive aggregates, which is used to absorb and conduct external heat; the thermal conductive aggregates are copper powder, graphite powder, carbon fiber or a combination thereof; the high thermal conductivity concrete layer has a thickness of 20-50 mm, which is used to quickly absorb and conduct external heat to the thermoelectric layer.

[0010] Preferably, the thermal conductivity enhancement layer is arranged between the high thermal conductivity concrete layer and the thermoelectric component to enhance the directional conduction of heat; the thermal conductivity enhancement layer is a thermal bridge structure formed by embedded copper sheets, graphite sheets or carbon nanomaterials, forming a directional heat flow channel to reduce heat diffusion loss.

[0011] Preferably, the thermoelectric component layer is embedded with a plurality of thermoelectric power generation modules, with the hot end connected to the thermally conductive enhancement layer and the cold end facing inward; the thermoelectric power generation modules are made of bismuth telluride, lead telluride or nano-composite thermoelectric materials; the thermoelectric components are embedded through slots, slide rails or module frames, which is convenient for later replacement and maintenance.

[0012] Preferably, a micro heat sink or a natural convection channel is provided on the cold end side of the thermoelectric component to enhance the cooling efficiency.

[0013] Preferably, the low thermal conductivity concrete layer is made of cement-based materials mixed with lightweight insulating aggregates to prevent heat from being conducted into the room; the thermal conductivity of the low thermal conductivity concrete layer is less than 0.2 W / m·K; the lightweight insulating aggregate is made of lightweight materials such as expanded perlite and foamed ceramsite.

[0014] Preferably, the phase change heat storage layer is arranged near the cold end of the thermoelectric component layer, and is used to adjust the cold end temperature to maintain a stable temperature difference; the phase change heat storage layer is filled with paraffin, fatty acid, PEG or its composite phase change material with a phase change temperature between 20 and 30°C, which can stabilize the temperature difference during the day and night cycle and avoid the hot end and cold end temperature convergence.

[0015] Preferably, the structure further includes a micro-power DC-DC conversion module and an energy storage device arranged behind the thermoelectric component, which are used to store the electric energy output by the power generation module or use it for power supply, thereby realizing the self-powered node function.

[0016] Preferably, the structure is used for building exterior walls and is suitable for residential buildings, industrial plants or passive energy-saving buildings.

[0017] The beneficial effects of the present invention are: through the combination of a multi-layer thermal conductivity gradient design and a phase change temperature control system, the temperature difference between the hot end and the cold end is increased by 30-100%, which greatly improves the TEG output power compared with the existing technology; the modular design makes the TEG easy to replace, all materials meet building standards, and the strength and durability meet the standards; the output power of a single TEG module is increased to 100-500μW per module (based on a daily temperature difference of 15-25℃), and it can stably supply power to low-power wireless nodes; this structure is suitable for urban residences, passive buildings, and the outer walls of industrial plants, realizing integrated building power generation and having the characteristics of green energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention.

[0019] Among them, 1 is a high thermal conductivity concrete layer, 2 is a thermal conductivity enhancement layer, 3 is a thermoelectric component layer, 4 is a low thermal conductivity concrete layer, and 5 is a phase change heat storage layer. DETAILED DESCRIPTION

[0020] The technical solutions of the present invention will be described clearly and completely below with reference to the accompanying drawings and embodiments. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0021] Example 1

[0022] A composite thermoelectric concrete wall structure with temperature difference power generation and thermal insulation functions includes a high thermal conductivity concrete layer, a thermal conductivity enhancement layer, a thermoelectric component layer, a low thermal conductivity concrete layer and a phase change heat storage layer arranged in sequence from the outside to the inside.

[0023] The high-thermal-conductivity concrete layer, made of cement-based materials mixed with thermally conductive aggregate, absorbs and conducts external heat. This layer uses ordinary Portland cement as its base material, with graphite powder added as a thermally conductive aggregate at a ratio of 15% by weight of cement. Appropriate amounts of fine and coarse aggregate are also added, with river sand being the fine aggregate and crushed stone being the coarse aggregate. The water-cement ratio is controlled at 0.45. The high-thermal-conductivity concrete layer is 120 mm thick and has a thermal conductivity of 2.5 W / m·K, significantly higher than that of ordinary concrete. This layer, located on the outermost edge of the wall and directly exposed to the external environment, effectively absorbs solar heat and ambient heat.

[0024] The thermal conductivity enhancement layer is placed between the high-conductivity concrete layer and the thermoelectric modules to enhance directional heat conduction. This layer utilizes a thermal bridge structure formed by embedded copper sheets. The copper sheets are 2mm thick and 50mm wide, and their length is tailored to the wall dimensions. Multiple copper sheets are arranged in parallel, with 100mm spacing. One end of the copper sheet is in close contact with the high-conductivity concrete layer, while the other end is connected to the hot end of the thermoelectric module layer, forming an efficient heat conduction channel. The copper sheet surface is oxidized to enhance adhesion to the concrete and prevent oxidative corrosion during long-term use. The total thickness of the thermal conductivity enhancement layer is 10mm, and the thermal conductivity reaches 380 W / m·K.

[0025] The thermoelectric module layer is embedded with multiple thermoelectric modules, with the hot end connected to the thermally conductive reinforcement layer and the cold end facing inward. The thermoelectric modules are made of bismuth telluride, each measuring 40mm × 40mm × 4mm. They are rated for a 30°C operating temperature differential, at which point a single module has an output power of 1.2W. The modules are arranged in a matrix with 60mm spacing between rows and columns, allowing for approximately 25 modules per square meter of wall. The thermoelectric modules are slotted into the wall structure using high-strength engineering plastics, offering excellent insulation and mechanical strength. The slots are designed as dovetail grooves, allowing the modules to slide into the slots from the inside of the wall and secure with a locking mechanism, facilitating future replacement and maintenance. The thermoelectric module layer and the thermally conductive reinforcement layer utilize a removable bolted connection. Each module is connected to the copper sheet of the thermally conductive reinforcement layer using four M3 stainless steel bolts, with bolt holes located at the four corners of the module for easy assembly and disassembly. The total thickness of the thermoelectric module layer is 15mm.

[0026] A micro heat sink is installed on the cold side of the thermoelectric module to enhance cooling efficiency. Made of aluminum alloy, the heat sink is 1mm thick and has a surface area three times that of the thermoelectric module. It maintains close contact with the cold end of the thermoelectric module via thermal grease. The heat sink is black anodized to improve heat dissipation. A 10mm wide natural convection channel is designed around the heat sink, creating a chimney effect that promotes air circulation and further enhances heat dissipation.

[0027] The low-thermal-conductivity concrete layer, made from cement-based materials mixed with lightweight insulating aggregates, blocks heat transfer into the interior. This layer uses ordinary Portland cement as its base material, incorporating lightweight insulating aggregates such as expanded perlite and ceramsite. A suitable amount of foaming agent is added to create a closed-cell structure, further reducing thermal conductivity. The low-thermal-conductivity concrete layer is 150 mm thick and has a thermal conductivity of 0.18 W / m·K, lower than that of ordinary concrete. Applied inside the wall, this layer effectively blocks heat transfer into the interior, maintaining a stable indoor temperature.

[0028] The phase-change heat storage layer is located near the cold end of the thermoelectric component layer and is used to regulate the cold end temperature to maintain a stable temperature difference. This layer uses a phase-change material encapsulated in microcapsules, which is filled into a polymer matrix to form a plate-like structure. The phase-change material is paraffin wax, with a phase change temperature of 25°C and a latent heat of 180 J / g. The microcapsules have a diameter of 5-10μm, and the shell material is polymethyl methacrylate with a thickness of approximately 0.5μm. The phase-change heat storage layer is 20mm thick and is located between the cold end of the thermoelectric component and the low-thermal conductivity concrete layer. It can absorb or release heat, maintaining the cold end temperature of the thermoelectric component stable at around 25°C, ensuring that the thermoelectric component has a stable operating temperature difference.

[0029] The composite thermoelectric concrete wall structure also includes a micropower DC-DC conversion module and energy storage device located behind the thermoelectric assembly, which are used to store or use the electrical energy output by the power generation module for power supply. The DC-DC conversion module uses a boost converter with an input voltage range of 0.5-5V, a stable output voltage of 5V, and a maximum output current of 500mA. The energy storage device uses a supercapacitor with a capacity of 1000F and a rated voltage of 2.7V. Multiple supercapacitors are connected in series and parallel to form an energy storage unit with a total capacity of 10,000J. The DC-DC conversion module and energy storage device are integrated into a waterproof housing measuring 100mm×80mm×30mm. It is installed on the inside of the wall and connected to the thermoelectric assembly via a waterproof junction box.

[0030] This composite thermoelectric concrete wall structure is used for building exterior walls and is suitable for residential, industrial, or passive energy-saving buildings. In actual use, the outside of the wall is exposed to direct sunlight and ambient temperature fluctuations, while the inside maintains a constant indoor temperature environment. When the outside temperature is higher than the indoor temperature, heat is transferred from the high-thermal-conductivity concrete layer to the thermally conductive reinforcement layer, and then to the hot end of the thermoelectric component. The temperature of the cold end of the thermoelectric component is regulated by the phase-change heat storage layer to remain relatively stable, forming a temperature difference. The thermoelectric component converts the temperature difference into electrical energy. The generated electrical energy is boosted by the DC-DC conversion module and stored in the energy storage device. It can be used to power low-power devices inside the building, such as sensors and LED lighting.

[0031] Under typical summer operating conditions, when the exterior wall temperature reaches 50°C and the indoor temperature is 25°C, a temperature difference of approximately 20°C forms across the thermoelectric module, generating approximately 25W of electricity per square meter of wall. In winter, when the indoor temperature is higher than the outdoor temperature, the heat flow is reversed, and the thermoelectric module can still generate electricity, but at a lower efficiency. The average annual power generation is approximately 60kWh per square meter of wall.

[0032] This composite thermoelectric concrete wall structure not only provides the load-bearing and thermal insulation capabilities of a traditional wall, but also utilizes the temperature difference between the inside and outside of the wall to generate electricity, achieving energy recycling and improving building energy efficiency. Furthermore, the modular design allows for easy replacement and maintenance of thermoelectric components, extending the service life of the overall structure.

[0033] Example 2

[0034] A composite thermoelectric concrete wall structure with temperature difference power generation and thermal insulation functions includes a high thermal conductivity concrete layer, a thermal conductivity enhancement layer, a thermoelectric component layer, a low thermal conductivity concrete layer and a phase change heat storage layer arranged in sequence from the outside to the inside.

[0035] The high-thermal-conductivity concrete layer is made of cement-based materials mixed with thermally conductive aggregates, and is used to absorb and conduct external heat. This layer uses ordinary Portland cement as its base material, with carbon fibers added as thermally conductive aggregate. The carbon fibers are 5-10mm long and 7μm in diameter, and are added in a ratio of 10% of the cement mass. Appropriate amounts of fine and coarse aggregate are also added, with river sand being the fine aggregate and crushed stone being the coarse aggregate. The water-cement ratio is controlled at 0.42. The high-thermal-conductivity concrete layer is 100mm thick and has a thermal conductivity of 2.2W / m·K, far exceeding that of ordinary concrete. This layer is located on the outermost side of the wall, directly exposed to the external environment, effectively absorbing solar radiation and ambient heat.

[0036] The thermal enhancement layer, located between the high-conductivity concrete layer and the thermoelectric modules, enhances directional heat conduction. This layer utilizes a thermal bridge structure formed by graphite sheets. The sheets are 1mm thick and 60mm wide, and their length is tailored to the wall dimensions. Multiple sheets are arranged in parallel, with 120mm spacing. One end of the graphite sheet is in close contact with the high-conductivity concrete layer, while the other end is connected to the hot end of the thermoelectric module layer, forming an efficient heat conduction channel. The graphite sheet surface is specially treated to enhance bonding with the concrete. The total thickness of the thermal enhancement layer is 8mm, with a thermal conductivity of 1500 W / m·K.

[0037] The thermoelectric assembly layer is embedded with multiple thermoelectric modules, with the hot end connected to the thermally conductive reinforcement layer and the cold end facing inward. The thermoelectric modules are made of lead telluride, each measuring 50mm × 50mm × 5mm. They are rated for a 25°C operating temperature differential, at which point the output power of a single module is 1.5W. The modules are arranged in a matrix with 70mm spacing between rows and columns, allowing for approximately 20 modules per square meter of wall. The thermoelectric modules are embedded in the wall structure using slides made of aluminum alloy, which offers excellent thermal conductivity and mechanical strength. The slides feature a T-slot design, allowing the thermoelectric modules to slide into the rails from the inside of the wall and secure with spring clips, facilitating future replacement and maintenance. The thermoelectric assembly layer and the thermally conductive reinforcement layer utilize a removable snap-on connection. Each thermoelectric module is connected to the graphite sheet of the thermally conductive reinforcement layer via four elastic clips, making assembly and disassembly easy. The total thickness of the thermoelectric assembly layer is 18mm.

[0038] A natural convection channel is provided on the cold side of the thermoelectric module to enhance cooling efficiency. The convection channel utilizes a grid-like structure with a mesh size of 5mm x 5mm and a channel depth of 15mm, creating a micro-chimney effect that promotes air circulation and enhances heat dissipation. The inner wall of the channel is coated with a highly thermally conductive material to further improve heat dissipation efficiency.

[0039] The low-thermal-conductivity concrete layer, made from cement-based materials mixed with lightweight insulating aggregates, blocks heat transfer into the interior. This layer uses ordinary Portland cement as its base material, incorporating lightweight insulating aggregates such as expanded vermiculite and glass microspheres. A suitable amount of foaming agent is added to create a closed-cell structure, further reducing thermal conductivity. The low-thermal-conductivity concrete layer is 180 mm thick and has a thermal conductivity of 0.15 W / m·K, lower than that of ordinary concrete. Applied inside the wall, this layer effectively blocks heat transfer into the interior, maintaining a stable indoor temperature.

[0040] The phase-change heat storage layer is located near the cold end of the thermoelectric module layer and is used to regulate the cold-end temperature to maintain a stable temperature differential. This layer uses a phase-change material encapsulated in microcapsules, filled into a polymer matrix to form a plate-like structure. The phase-change material is fatty acid, with a phase change temperature of 28°C and a latent heat of 200 J / g. The microcapsules have a diameter of 8-15μm, and the shell material is polypropylene with a thickness of approximately 0.8μm. The phase-change heat storage layer is 25mm thick and is located between the cold end of the thermoelectric module and the low-thermal conductivity concrete layer. It can absorb or release heat, maintaining the cold-end temperature of the thermoelectric module at a stable level of around 28°C, ensuring a stable operating temperature differential for the thermoelectric module.

[0041] The composite thermoelectric concrete wall structure also includes a micropower DC-DC conversion module and energy storage device located behind the thermoelectric assembly, which are used to store or power the electrical energy output by the power generation module. The DC-DC conversion module uses a boost converter with an input voltage range of 0.8-6V, outputs a stable 12V voltage, and has a maximum output current of 300mA. The energy storage device uses a lithium-ion battery with a capacity of 2000mAh and a rated voltage of 3.7V. Multiple lithium-ion batteries are connected in series and parallel to form an energy storage unit with a total capacity of 30,000J. The DC-DC conversion module and energy storage device are integrated into a waterproof housing measuring 120mm × 90mm × 35mm. It is installed on the inside of the wall and connected to the thermoelectric assembly via a waterproof junction box.

[0042] This composite thermoelectric concrete wall structure is used for building exterior walls and is suitable for industrial plants. In practical applications, the exterior of the wall is exposed to direct sunlight and fluctuating ambient temperatures, while the interior maintains a constant indoor temperature. When the outside temperature is higher than the indoor temperature, heat is transferred from the high-thermal-conductivity concrete layer to the thermally conductive reinforcement layer, and then to the hot end of the thermoelectric component. The temperature of the cold end of the thermoelectric component is regulated by the phase-change heat storage layer to remain relatively stable, creating a temperature difference. The thermoelectric component converts this temperature difference into electrical energy. The generated electrical energy is boosted by a DC-DC converter module and stored in an energy storage device. It can be used to power low-power devices within the building, such as sensors and monitoring equipment.

[0043] Under typical summer operating conditions, when the exterior wall temperature reaches 55°C and the indoor temperature is 28°C, a temperature difference of approximately 22°C forms across the thermoelectric module, generating approximately 28W of electricity per square meter of wall. In winter, when the indoor temperature is higher than the outdoor temperature, the heat flow is reversed, and the thermoelectric module can still generate electricity, but at a lower efficiency. The average annual power generation is approximately 70kWh per square meter of wall.

[0044] Example 3

[0045] A composite thermoelectric concrete wall structure with temperature difference power generation and thermal insulation functions includes a high thermal conductivity concrete layer, a thermal conductivity enhancement layer, a thermoelectric component layer, a low thermal conductivity concrete layer and a phase change heat storage layer arranged in sequence from the outside to the inside.

[0046] The high-thermal-conductivity concrete layer, made of cement-based materials mixed with thermally conductive aggregate, absorbs and conducts external heat. This layer uses ordinary Portland cement as its base material, with a mixture of copper powder and graphite powder added as the thermally conductive aggregate. The mass ratio of copper powder to graphite powder is 3:2, for a total addition ratio of 18% of the cement mass. Appropriate amounts of fine and coarse aggregate are also added, with river sand being the fine aggregate and crushed stone being the coarse aggregate. The water-cement ratio is controlled at 0.40. The high-thermal-conductivity concrete layer is 130 mm thick and has a thermal conductivity of 3.0 W / m·K, significantly higher than that of ordinary concrete. This layer is placed on the outermost edge of the wall, directly exposed to the external environment, effectively absorbing solar heat and ambient heat.

[0047] The thermal conductivity enhancement layer is placed between the high-conductivity concrete layer and the thermoelectric module to enhance directional heat conduction. This layer uses a thermal bridge structure formed by carbon nanomaterials, specifically a carbon nanotube thermal conductive film with a thickness of 0.5mm and a width of 70mm. The length is tailored to the wall size, and multiple sheets of thermal conductive film are arranged in parallel with a spacing of 80mm. One end of the thermal conductive film is in close contact with the high-conductivity concrete layer, and the other end is connected to the hot end of the thermoelectric module layer, forming an efficient heat conduction channel. The surface of the thermal conductive film is plasma treated to enhance its bonding with the concrete. The total thickness of the thermal conductivity enhancement layer is 5mm, and the thermal conductivity reaches 2000 W / m·K.

[0048] The thermoelectric module layer is embedded with multiple thermoelectric modules, with the hot end connected to the thermally conductive reinforcement layer and the cold end facing inward. The thermoelectric modules are made of nanocomposite thermoelectric material, each measuring 45mm × 45mm × 3mm. They are rated for a 20°C operating temperature differential, at which point a single module has an output power of 1.8W. The modules are arranged in a matrix with 65mm spacing between rows and columns, allowing for approximately 22 modules per square meter of wall. The thermoelectric modules are embedded within the wall structure using a module frame made of ABS engineering plastic, which offers excellent insulation and mechanical strength. The module frame features a snap-on design, allowing the thermoelectric modules to snap into place from the inside of the wall and secure with a rotating locking mechanism, facilitating future replacement and maintenance. The thermoelectric module layer and the thermally conductive reinforcement layer utilize a removable magnetic connection. Each thermoelectric module is connected to the thermally conductive film of the thermally conductive reinforcement layer via four strong NdFeB magnets, enabling easy assembly and disassembly. The total thickness of the thermoelectric module layer is 12mm.

[0049] The cold end of the thermoelectric module is equipped with both a micro-heat sink and a natural convection channel to enhance cooling efficiency. The heat sink is made of aluminum alloy, 0.8mm thick, and has a surface area four times that of the thermoelectric module. It maintains close contact with the cold end of the thermoelectric module via thermal grease. The heat sink is black anodized to improve heat dissipation. Natural convection channels, 12mm wide and 20mm deep, surround the heat sink, creating an enhanced chimney effect that promotes air circulation and further enhances heat dissipation.

[0050] The low-thermal-conductivity concrete layer, made from cement-based materials mixed with lightweight insulating aggregates, blocks heat transfer into the interior. This layer uses ordinary Portland cement as its base material, incorporating lightweight insulating aggregates such as aerogel particles and expanded perlite. A suitable amount of foaming agent is added to create a closed-cell structure, further reducing thermal conductivity. The low-thermal-conductivity concrete layer is 160 mm thick and has a thermal conductivity of 0.12 W / m·K, lower than that of ordinary concrete. Applied inside the wall, this layer effectively blocks heat transfer into the interior, maintaining a stable indoor temperature.

[0051] The phase-change heat storage layer is located near the cold end of the thermoelectric module layer, regulating the cold-end temperature to maintain a stable temperature differential. This layer utilizes a phase-change material encapsulated in microcapsules, filled into a polymer matrix to form a plate-like structure. The phase-change material used is PEG (polyethylene glycol), with a phase transition temperature of 22°C and a latent heat of 170 J / g. The microcapsules have a diameter of 6-12 μm, and the shell is made of melamine formaldehyde resin, approximately 0.6 μm thick. The phase-change heat storage layer is 22 mm thick and is located between the cold end of the thermoelectric module and the low-thermal-conductivity concrete layer. It absorbs and releases heat, maintaining a stable cold-end temperature of approximately 22°C, ensuring a stable operating temperature differential for the thermoelectric module.

[0052] The composite thermoelectric concrete wall structure also includes a micropower DC-DC conversion module and energy storage device located behind the thermoelectric assembly, which are used to store or power the electrical energy output by the power generation module. The DC-DC conversion module uses a boost converter with an input voltage range of 0.3-4V, a stable output voltage of 3.3V, and a maximum output current of 800mA. The energy storage device uses a hybrid energy storage system consisting of a supercapacitor and a lithium-ion battery. The supercapacitor has a capacity of 500F and a rated voltage of 2.7V, while the lithium-ion battery has a capacity of 1500mAh and a rated voltage of 3.7V, with a total capacity of 25,000J. The DC-DC conversion module and energy storage device are integrated into a waterproof housing measuring 110mm × 85mm × 32mm. It is installed on the inside of the wall and connected to the thermoelectric assembly via a waterproof junction box.

Claims

1. A composite thermoelectric concrete wall structure with thermoelectric power generation and heat preservation functions, characterized in that: Including from the outside to the inside: A high thermal conductivity concrete layer (1), which is made of a cement-based material mixed with a thermal conductive aggregate and is used to absorb and conduct external heat; A heat conduction enhancement layer (2) is provided between the high heat conduction concrete layer and the thermoelectric assembly and is used to enhance directional heat conduction; A thermoelectric component layer (3) is embedded with a plurality of thermoelectric power generation modules, with the hot end connected to the thermally conductive enhancement layer and the cold end facing inward; A low thermal conductivity concrete layer (4), which is made of a cement-based material mixed with a lightweight thermal insulation aggregate, and is used to block heat conduction into the room; The phase change heat storage layer (5) is arranged near the cold end of the thermoelectric component layer and is used to adjust the temperature of the cold end to maintain a stable temperature difference. The thermoelectric component layer and the heat conduction enhancement layer are connected in a detachable structure.

2. The composite thermoelectric concrete wall structure according to claim 1, characterized in that: The thermal conductive aggregate is copper powder, graphite powder, carbon fiber or a combination thereof.

3. The composite thermoelectric concrete wall structure according to claim 1, characterized in that: The thermal conductivity enhancement layer is a thermal bridge structure formed by embedded copper sheets, graphite sheets or carbon nanomaterials.

4. The composite thermoelectric concrete wall structure according to claim 1, characterized in that: The thermoelectric power generation module is made of bismuth telluride, lead telluride or nano-composite thermoelectric material.

5. The composite thermoelectric concrete wall structure according to claim 1, characterized in that: The thermoelectric components are embedded in the form of card slots, slide rails or module frames, which is convenient for later replacement and maintenance.

6. The composite thermoelectric concrete wall structure according to claim 1, characterized in that: The phase change heat storage layer is filled with paraffin, fatty acid, PEG or a composite phase change material with a phase change temperature between 20 and 30°C.

7. The composite thermoelectric concrete wall structure according to claim 1, characterized in that: A micro heat sink or a natural convection channel is provided on the cold end side of the thermoelectric component to enhance the cooling efficiency.

8. The composite thermoelectric concrete wall structure according to claim 1, characterized in that: It also includes a micro-power DC-DC conversion module and an energy storage device arranged behind the thermoelectric component, which are used to store the electric energy output by the power generation module or use it for power supply.

9. The composite thermoelectric concrete wall structure according to claim 1, characterized in that: The thermal conductivity of the low thermal conductivity concrete layer is less than 0.2 W / m·K.

10. The composite thermoelectric concrete wall structure according to claim 1, characterized in that: The structure is used for building exterior walls and is suitable for residences, industrial plants or passive energy-saving buildings.

Images