A prefabricated flexible thermoelectric cover surface layer, its preparation method and application

Abstract

This invention discloses a prefabricated flexible thermoelectric cover layer, its preparation method, and its application. The prefabricated flexible thermoelectric cover layer includes a flexible substrate and a flexible thermoelectric conversion layer disposed on the flexible substrate. The flexible thermoelectric conversion layer includes a flexible heat-conducting region, a conductive insulating region, and a thermoelectric conversion region arranged sequentially. The thermoelectric conversion region includes P-type and N-type regions. The P-type and N-type regions are alternately arranged to form multiple thermoelectric units, which are electrically connected to each other. This invention achieves heat-to-electric conversion by partitioning the flexible thermoelectric conversion layer. The flexible heat-conducting region transfers heat from the road surface to the thermoelectric conversion region, rapidly reducing road surface temperature and mitigating the heat island effect. Furthermore, the flexible material of the thermoelectric cover layer allows it to adapt to road surface deformation to the greatest extent possible, accommodating various complex surface conditions such as different smoothness and cross slopes without damaging the road structure, thus ensuring the stability of the road surface structure.

Description

Technical Field

[0001] This invention belongs to the field of thermoelectric materials technology, and particularly relates to a prefabricated flexible thermoelectric cover layer, its preparation method and application. Background Technology

[0002] In most parts of my country, summer temperatures are high, causing asphalt pavements to heat up rapidly under solar radiation, resulting in a significant amount of unused heat. Furthermore, the increased temperature accelerates the thermo-oxidative aging of asphalt, leading to pavement defects and severely impacting road safety and pavement lifespan. The large amount of heat generated by asphalt roads in cities contributes to the urban heat island effect, seriously affecting the surrounding environment. Therefore, effectively reducing pavement temperature and utilizing the heat energy within asphalt pavements for energy conversion has become a crucial issue that urgently needs to be addressed.

[0003] Currently, the application of thermoelectric materials in road surfaces typically involves prefabricating thermoelectric materials into thermoelectric conversion devices, which are then buried in the road surface layer or laid on the roadside. Heat is then transferred from the road surface to the roadside via heat-conducting plates, and the thermoelectric conversion is completed by the roadside thermoelectric conversion device. However, due to the significant difference in modulus between the road surface structure and the conversion device and the road surface layer, burying the device can affect the structural strength of the road. Summary of the Invention

[0004] To overcome the shortcomings of the aforementioned thermoelectric material application technologies, this invention provides a prefabricated flexible thermoelectric cover layer, its preparation method, and its application. This prefabricated flexible thermoelectric cover layer exhibits rapid thermal conductivity, stable thermoelectric performance, and good bonding with the road structure layer, thus ensuring the stability of the road structure.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A prefabricated flexible thermoelectric cover layer includes a flexible substrate and a flexible thermoelectric conversion layer disposed on the flexible substrate; wherein the flexible thermoelectric conversion layer includes a flexible thermally conductive region, a thermally conductive insulating region and a thermoelectric conversion region disposed sequentially; the thermoelectric conversion region includes a P-type region and an N-type region; the P-type region and the N-type region are alternately arranged to form a plurality of thermoelectric units, and the plurality of thermoelectric units are electrically connected to each other.

[0007] Preferably, the flexible substrate is one or more composite flexible materials selected from glass fiber, base paper, fabric, and fiber felt.

[0008] Preferably, the material forming the flexible thermally conductive zone is a flexible thermally conductive material.

[0009] Preferably, the material forming the thermally conductive insulating region is a flexible insulating material with a high thermal conductivity.

[0010] Preferably, the P-type region is formed of P-type semiconductor material and the N-type region is formed of N-type semiconductor material.

[0011] Preferably, the flexible thermally conductive material is one or more of carbon fiber, graphene, and flexible metal foil; the flexible insulating material with high thermal conductivity is one or more of silicon carbide, silicon, diamond, and boron nitride; the P-type semiconductor material is Bi2Te3, and the N-type semiconductor material is Sb2Te3.

[0012] Preferably, the thermoelectric conversion zone is connected to a cooling device and an energy storage device; the wire terminal of the thermoelectric unit is connected to the energy storage device; and the end of the thermoelectric conversion zone away from the flexible insulation zone is connected to the cooling device through a heat joint.

[0013] Preferably, an anti-slip layer is provided above the flexible thermal conductive area; an adhesive layer is provided on the side of the flexible substrate away from the flexible thermoelectric conversion layer.

[0014] This invention also provides a method for preparing a prefabricated flexible thermoelectric cover layer, comprising the following steps:

[0015] Fabrication of a flexible thermoelectric conversion layer: A flexible thermally conductive material is printed at one end of a flexible substrate to form a flexible thermally conductive region; P-type semiconductor material and N-type semiconductor material are printed at the other end of the flexible substrate to form a thermoelectric conversion region; a flexible insulating material is printed between the flexible thermally conductive region and the thermoelectric conversion region to form a thermally conductive insulating region;

[0016] Preparation of anti-slip layer: Adhesive material and sand are laid sequentially on the flexible heat-conducting area to form an anti-slip layer;

[0017] Preparation of adhesive layer: Adhesive material is laid on the side of the flexible substrate away from the flexible thermoelectric conversion layer to form an adhesive layer, thus obtaining a prefabricated flexible thermoelectric cover layer.

[0018] The present invention also provides the application of the above-mentioned prefabricated flexible thermoelectric cover layer in road surface.

[0019] This invention lays a flexible thermoelectric cover layer on the road surface and then connects the thermoelectric conversion zone to the energy storage device using wires; the thermoelectric conversion zone is bent and placed together with the top of the cooling device in a heat joint.

[0020] The beneficial effects of this invention are:

[0021] The thermoelectric cover layer prepared by this invention can adapt to road deformation to the maximum extent by using flexible materials. It can adapt to various complex surface conditions such as different flatness and cross slope. It can be directly laid on existing or newly paved roads without damaging the road structure and ensuring the stability of the road structure.

[0022] This invention achieves the conversion of heat to electricity by dividing the flexible thermoelectric conversion layer into zones. The flexible heat-conducting zone transfers heat from the road surface to the thermoelectric conversion zone, which can quickly reduce the road surface temperature, reduce the heat island effect, and ensure the service life of the road surface. The generated electricity can be used in various scenarios such as street lighting, power supply for communication equipment, voltage boosting and transmission to service areas, and grid connection, which is in line with the development concepts of environmental protection, energy conservation and sustainable development.

[0023] The flexible thermoelectric cover layer provided by this invention can divide the thermoelectric conversion zone into P-type and N-type regions to form a bundle of thermoelectric devices, which makes it easier to place the cold end in a cooling device, effectively reducing the size of the device and increasing space utilization efficiency. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below.

[0025] Figure 1 This is a schematic diagram of a prefabricated flexible thermoelectric cover surface layer structure according to the present invention;

[0026] Figure 2 This is a schematic diagram of the flexible thermoelectric conversion layer structure;

[0027] Figure 3 This is a schematic diagram of the thermoelectric unit connection.

[0028] In the figure, 1 is the flexible substrate; 2 is the flexible thermoelectric conversion layer; 21 is the flexible thermally conductive area; 22 is the thermally conductive insulating area; 23 is the thermoelectric conversion area; 24 is the thermoelectric device bundle; 3 is the anti-slip layer; 4 is the adhesive layer; 5 is the thermal connector; 6 is the cooling device; 7 is the metal wire; and 8 is the energy storage device. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] This invention provides a prefabricated flexible thermoelectric cover layer, such as... Figures 1-2 As shown, the system includes a flexible substrate 1 and a flexible thermoelectric conversion layer 2 disposed on the flexible substrate 1. The flexible thermoelectric conversion layer 2 includes a flexible thermally conductive region 21, a thermally conductive insulating region 22, and a thermoelectric conversion region 23 arranged sequentially. The thermoelectric conversion region 23 includes a P-type region and an N-type region. An anti-slip layer 3 is also disposed above the flexible thermally conductive region 21. An adhesive layer 4 is disposed on the side of the flexible substrate 1 away from the flexible thermoelectric conversion layer 2. A cooling device 6 and an energy storage device 8 are connected to the thermoelectric conversion region 23.

[0031] like Figures 2-3 As shown, P-type and N-type zones are alternately arranged to form multiple thermoelectric units, which are connected in series or parallel via metal wires 7; the wires of the thermoelectric units are connected to the energy storage device 8. The end of the thermoelectric conversion zone 23 away from the thermally conductive insulation zone 22 is connected to the cooling device 6 via a heat joint 5; the cooling device 6 can be a heat pipe, water tank, or other device.

[0032] This invention also provides a method for preparing a prefabricated flexible thermoelectric cover layer, comprising the following steps:

[0033] (1) Preparation of flexible thermoelectric conversion layer: A flexible thermally conductive material is printed at one end of the flexible substrate 1 to form a flexible thermally conductive region 21; P-type semiconductor material and N-type semiconductor material are printed at the other end of the flexible substrate 1 to form a thermoelectric conversion region 23; a flexible insulating material is printed between the flexible thermally conductive region 21 and the thermoelectric conversion region 23 to form a thermally conductive insulating region 22.

[0034] (2) Preparation of anti-slip layer: A bonding material and sand are laid on top of the flexible heat-conducting zone 21 to form anti-slip layer 3; the sand particle size is 2-10mm to enhance anti-slip performance.

[0035] (3) Preparation of adhesive layer: Adhesive material is laid on the side of flexible substrate 1 away from flexible thermoelectric conversion layer 2 to form adhesive layer 4. The adhesive material used for anti-slip layer 3 and adhesive layer 4 can be a flexible adhesive material with high adhesion performance, such as epoxy resin or modified asphalt.

[0036] After the flexible thermoelectric cover is laid on the road surface, the thermoelectric conversion zone 23 is connected to the energy storage device 8 using metal wires 7. One end of the cooling device 6 and the bent part of the thermoelectric conversion zone 23 are placed together in the heat joint 5. Alternatively, the thermoelectric conversion zone can be divided into P-type and N-type zones to form a thermoelectric device bundle 24. The cold end of the thermoelectric device bundle 24 is bent and placed in the heat joint 5.

[0037] In some embodiments, the two ends of the thermally conductive insulating region in step (1) overlap with the flexible thermally conductive region and the thermoelectric conversion region, respectively. The flexible substrate 1 can be one or more composite flexible materials selected from glass fiber, base paper, fabric, and fiber felt. The material forming the flexible thermally conductive region 21 can be one or more composite flexible thermally conductive materials such as carbon fiber, graphene, and flexible metal foil. The material forming the thermally conductive insulating region 22 can be a flexible insulating material with high thermal conductivity such as silicon, diamond, and boron nitride. The P-type region can be formed from P-type semiconductor materials such as Bi2Te3, and the N-type region can be formed from N-type semiconductor materials such as Sb2Te3.

[0038] In some embodiments, the P-type region is formed by printing a conductive paste obtained by mixing 10 parts of P-type semiconductor material with 1-6 parts of conductive polymer, and the N-type region is formed by printing a mixture of 10 parts of N-type semiconductor powder with 1-6 parts of conductive polymer. The conductive polymer is polyaniline, polyphenylene, polypyrrole, polythiophene, etc.

[0039] To illustrate the present invention, specific embodiments are described below. It should be understood that these embodiments are for illustrative purposes only and should not be construed as limiting the invention in any way.

[0040] Example 1

[0041] A method for preparing a prefabricated flexible thermoelectric cover surface layer includes the following steps:

[0042] (1) A flexible thermally conductive region 21 is formed by printing a graphene solution as ink at one end of a glass fiber. Bi2Te3 and Sb2Te3 are mixed with conductive polymers polyaniline and ethanol in a ratio of 10 parts: 2 parts: 100 parts to obtain a thermoelectric material slurry. The slurry containing Bi2Te3 and the slurry containing Sb2Te3 are alternately printed on the other end of the glass fiber to form alternating P-type and N-type regions, which is the thermoelectric conversion region 23. A silicon carbide nanoparticle dispersion is printed between the flexible thermally conductive region 21 and the P-type and N-type regions to form a thermally conductive insulating region 22, with both ends of the thermally conductive insulating region 22 overlapping with the flexible thermally conductive region 21 and the thermoelectric conversion region 23, respectively. The glass fiber after printing the slurry is dried at 80°C and 10MPa pressure to obtain the flexible thermoelectric conversion layer 2.

[0043] Different P-type and N-type zones are connected by metal wires to form a thermoelectric unit, and different thermoelectric units are connected in series or parallel. The thermoelectric units on both sides are connected to the energy storage device 8 by metal wires 7.

[0044] (2) SBS modified asphalt is laid on top of the flexible heat-conducting zone 21, and stones with a particle size of 2.36mm-9.5mm are spread to increase the surface friction and form an anti-skid layer 3.

[0045] (3) A layer of epoxy resin adhesive is laid in the area at the bottom of the glass fiber corresponding to the flexible thermal conductive area to form an adhesive layer 4.

[0046] (4) Connect the thermoelectric conversion zone 23 to the energy storage device 8 using the metal wire 7, and place one end of the cooling device 6 and the bent part of the thermoelectric conversion zone 23 together in the heat joint 5 to obtain a prefabricated flexible thermoelectric cover layer.

[0047] Example 2

[0048] Prepare a 1m×1m flexible thermoelectric cover surface layer. Lay this flexible thermoelectric cover surface layer directly on the newly paved road surface, reserving the thermoelectric conversion zone to the side of the road surface. This zone will not serve as a load-bearing structure for the road surface. The road surface temperature during paving should not be lower than 60℃. Then, place the bottom of the cooling device's heat pipes into the corrugated guardrail posts, which are buried 1-2m deep into the road surface along the roadside. Figure 1 As shown, the thermoelectric conversion zone is divided into P-type and N-type zones to form a bundle of thermoelectric devices. One end of the bundle is bent and placed in the heat-conducting medium of the roadside heat joint. The top of the heat pipe is placed in the heat joint and immersed in the heat-conducting medium. Since the bottom of the heat pipe is connected to the roadbed, heat is introduced into the roadbed. The heat pipe is used as the cold end, and the road surface heat-conducting material layer is used as the hot end. The thermoelectric conversion is achieved by utilizing the temperature difference between the two.

[0049] The temperature difference between the road surface and the roadbed was measured at different time periods, and the temperature was measured at 1m. 2 Power generation of the flexible thermoelectric cover layer. The voltage and current of the flexible thermoelectric cover layer were measured using a multimeter, and its power generation at different time periods was calculated. The relevant test results are shown in Table 1.

[0050] Table 1

[0051] time 8:00 12:00 15:00 18:00 Road surface temperature (°C) 25 32 45 33 Roadbed temperature (°C) 10 10 10 10 Voltage (mV) 1.64 1.97 2.54 1.99 Power (mW) 1.88 2.37 3.96 2.38

[0052] As can be seen from the table, at 12:00 noon and 15:00 in the afternoon, the road surface temperature is high while the roadbed temperature remains relatively constant, resulting in a large temperature difference between the two ends of the thermoelectric device. Consequently, the power generation voltage and power are both high, indicating that the flexible thermoelectric cover layer prepared by this invention can effectively utilize the temperature difference to generate electricity.

[0053] In summary, this invention allows for the construction of overlay layers on existing or newly paved roads without damaging the road structure, thus ensuring its stability. Due to the unique characteristics of the road surface structure, the heat-conducting components are mostly layered. Using flexible thermoelectric materials allows for the stacking of two-dimensional planar thermoelectric devices in three-dimensional space, transforming the planar thermoelectric devices into bundles. This facilitates placing the cold ends within the cooling device, effectively reducing device size and increasing space utilization efficiency. The use of flexible materials maximizes adaptability to road deformation, accommodating various complex surface conditions such as different smoothness and cross slopes. The heat pipes of the cooling device are embedded within the corrugated guardrail posts, eliminating the excavation process required for traditional heat pipe construction. The crushed stone paving of the anti-skid layer effectively increases the friction coefficient of the surface layer, ensuring driving safety. The flexible thermoelectric cover layer provided by this invention can quickly reduce road surface temperature, reduce the heat island effect, ensure the service life of the road surface, and can apply the obtained electrical energy to various applications such as street lighting, power supply for communication equipment, voltage boosting and transmission to service areas, and grid connection. This is a new type of environmentally friendly energy acquisition method that meets the strategic needs of my country's sustainable development and is of great significance to achieving my country's dual-carbon goals.

[0054] It should be noted that all the above embodiments belong to the same inventive concept, and the descriptions of each embodiment have different focuses. Where the description in a particular embodiment is not detailed, please refer to the description in other embodiments.

[0055] The embodiments described above are merely illustrative of implementation methods of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A prefabricated flexible thermoelectric cover surface layer, characterized in that, Includes a flexible substrate (1) and a flexible thermoelectric conversion layer (2) disposed on the flexible substrate (1); The flexible thermoelectric conversion layer (2) includes a flexible thermally conductive region (21), a thermally conductive insulating region (22), and a thermoelectric conversion region (23) arranged sequentially. The thermoelectric conversion region (23) includes a P-type region and an N-type region. The P-type region and the N-type region are arranged alternately to form multiple thermoelectric units, and the multiple thermoelectric units are electrically connected to each other. The prefabricated flexible thermoelectric cover layer is laid directly on the road surface during use, and the thermoelectric conversion zone (23) is reserved to the side of the road surface; The flexible substrate (1) is one or more of glass fiber, base paper, fabric, and fiber felt; The material forming the flexible thermally conductive region (21) is a flexible thermally conductive material; The material forming the thermally conductive insulating region (22) is a flexible insulating material with a high thermal conductivity.

2. The prefabricated flexible thermoelectric cover surface layer according to claim 1, characterized in that, The P-type region is formed of P-type semiconductor material, and the N-type region is formed of N-type semiconductor material.

3. The prefabricated flexible thermoelectric cover surface layer according to claim 2, characterized in that, The flexible thermally conductive material is one or more of carbon fiber, graphene, and flexible metal foil; the flexible insulating material with high thermal conductivity is one or more of silicon carbide, silicon, diamond, and boron nitride; the P-type semiconductor material is Bi2Te3, and the N-type semiconductor material is Sb2Te3.

4. The prefabricated flexible thermoelectric cover surface layer according to claim 1, characterized in that, The thermoelectric conversion zone (23) is connected to a cooling device (6) and an energy storage device (8); the wire terminal of the thermoelectric unit is connected to the energy storage device (8); the end of the thermoelectric conversion zone (23) away from the thermally conductive insulation zone (22) is connected to the cooling device (6) through a heat joint (5).

5. The prefabricated flexible thermoelectric cover surface layer according to claim 1, characterized in that, An anti-slip layer (3) is also provided above the flexible heat-conducting area (21); an adhesive layer (4) is provided on the side of the flexible substrate (1) away from the flexible thermoelectric conversion layer (2).

6. A method for preparing a prefabricated flexible thermoelectric cover surface layer according to any one of claims 1-5, characterized in that, Includes the following steps: Fabrication of a flexible thermoelectric conversion layer: A flexible thermally conductive material is printed at one end of a flexible substrate to form a flexible thermally conductive region; P-type and N-type semiconductor materials are printed at the other end of the flexible substrate to form a thermoelectric conversion region. Flexible insulating material is printed between the flexible thermally conductive region and the thermoelectric conversion region to form a thermally conductive insulating region; Preparation of anti-slip layer: Adhesive material and sand are sequentially laid on the flexible heat-conducting area to form an anti-slip layer; Preparation of adhesive layer: Adhesive material is laid on the side of the flexible substrate away from the flexible thermoelectric conversion layer to form an adhesive layer, thereby obtaining the prefabricated flexible thermoelectric cover layer.

7. The application of the prefabricated flexible thermoelectric cover layer according to any one of claims 1-5 in road pavement.

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