Self-adaptive thermoelectric coordinated regulation and control system and regulation and control method for mass concrete temperature field

Abstract

According to the mass concrete temperature field self-adaptive thermoelectric coordinated regulation and control system and method, the temperature difference between the inside and the outside of mass concrete is reduced through active directional heat transfer and self-adaptive thermal resistance regulation. The flexible thermoelectric thin film device prepared by the invention has high flexibility, high thermoelectric efficiency and strong environmental adaptability, and can meet the temperature control requirement of mass concrete, and the manufacturing process is compatible with the existing microelectronic processing technology, so that the flexible thermoelectric thin film device has large-scale production potential; the flexible thermoelectric device is attached to the surface of concrete, directional transmission of heat between the concrete and the thermoelectric module from a high-temperature area to a low-temperature area is achieved by switching the current direction through the Peltier effect, temperature balance is achieved completely through the active thermoelectric effect and passive heat conduction optimization, the temperature lag and durability defects of a phase change material are avoided, and the service life of the concrete is prolonged. And the heat transfer efficiency is improved through the heat conductivity coefficient gradient and the thermally induced variation characteristic of the gradient heat conduction interface material layer.

Description

Technical Field

[0001] The present invention belongs to the field of civil engineering materials and intelligent temperature control technology, and specifically relates to an adaptive thermoelectric coordinated control system and control method for the temperature field of large-volume concrete. Through the combined design of a flexible thermoelectric module and a gradient thermal conductive interface material layer, the directional conduction of heat from the high-temperature zone to the low-temperature zone inside the concrete is achieved, thereby reducing the temperature difference between the inside and outside of the concrete and preventing cracks caused by the temperature difference. Background Art

[0002] Due to its large volume, large-volume concrete accumulates hydration heat internally, resulting in a large temperature difference between the inside and outside (peak temperatures can reach 60-80°C). As the surface cools and contracts, the interior continues to expand, generating tensile stress. When this stress exceeds the concrete's tensile strength, it will crack. Therefore, it is necessary to reduce the temperature difference between the inside and outside to minimize the risk of cracking.

[0003] At present, there are mainly the following methods to reduce the temperature difference between the inside and outside of large volume concrete:

[0004] (1) Traditional cooling water pipe method: Relying on pre-buried water pipes for circulation cooling, it has problems such as complex pipe layout, inability to dynamically adjust in the later stage, and easy blockage;

[0005] (2) Phase change material temperature control: Although phase change materials (PCM) can passively absorb / release heat, their phase change temperature is fixed and their thermal conductivity is low, making them unable to adapt to dynamic temperature field changes;

[0006] (3) Single thermoelectric technology: Existing thermoelectric modules mostly adopt a rigid structure, which is difficult to fit on the concrete surface and lacks efficient thermal coupling design with the substrate, resulting in large energy loss.

[0007] Therefore, there is an urgent need for an intelligent temperature control system that does not rely on phase change materials, can be actively adjusted, and is highly compatible with concrete, so as to achieve precise control of the temperature gradient and ensure the consistency of the temperature inside and outside the concrete to the greatest extent. Summary of the Invention

[0008] In view of the defects of the existing technology, the purpose of the present invention is to provide a large-volume concrete temperature field adaptive thermoelectric coordinated control system and control method, which reduces the temperature difference between the inside and outside of the large-volume concrete through active directional heat transfer and adaptive thermal resistance adjustment.

[0009] To achieve the above objectives, the solutions adopted by the present invention are as follows:

[0010] In a first aspect, the present invention provides a method for adaptive thermoelectric coordinated control of the temperature field of large-volume concrete, comprising the following steps:

[0011] Provided is a flexible thermoelectric device, comprising a flexible substrate, a core layer formed on a front surface of the flexible substrate, and a gradient thermal interface material layer formed on a back surface of the flexible substrate, wherein the core layer comprises a thermoelectric module array and conductive wires connecting the thermoelectric modules, the thermoelectric module array comprising alternating p-type and n-type Bi2Te3 thermoelectric arms, and the gradient thermal interface material layer comprises a first thermal conductive layer and a second thermal conductive layer, wherein the first thermal conductive layer faces the back surface of the flexible substrate, and the thermal conductivity of the first thermal conductive layer is higher than that of the second thermal conductive layer;

[0012] Attaching the flexible thermoelectric device to a concrete surface, with the second thermally conductive layer of the gradient thermal interface material facing the concrete;

[0013] An array of temperature sensors is embedded in the concrete to monitor the temperature field distribution in real time;

[0014] connecting the conductive wires of the flexible thermoelectric device and the temperature sensor array to a controller, wherein the controller is configured to supply power to the flexible thermoelectric device, collect and analyze the temperature of the temperature sensor array, and output the temperature to the flexible thermoelectric device; and

[0015] When it is detected that the temperature difference in a certain area exceeds the set threshold, the thermoelectric module array of the flexible thermoelectric device in the area is energized. The thermoelectric module array produces a Peltier effect and realizes the directional transfer of heat from the high-temperature area to the low-temperature area by switching the direction of the current.

[0016] In a second aspect, the present invention further provides a mass concrete temperature field adaptive thermoelectric coordinated control system, comprising:

[0017] A flexible thermoelectric device comprising a flexible substrate, a core layer formed on the front surface of the flexible substrate, and a gradient thermal interface material layer formed on the back surface of the flexible substrate, wherein the core layer comprises an array of thermoelectric modules and conductive wires connecting the thermoelectric modules;

[0018] an array of temperature sensors disposed within the concrete; and

[0019] A controller connected to the conductive wires of the flexible thermoelectric device and the temperature sensor array is used to supply power to the flexible thermoelectric device, collect and analyze the temperature of the temperature sensor array, and output the temperature to the flexible thermoelectric device.

[0020] Preferably, the flexible substrate is a polyimide film, and the thickness of the flexible thermoelectric device is 0.5-2.0 mm; the flexible thermoelectric device also includes a protective layer formed on the side of the core layer opposite to the flexible substrate, and the thickness of the protective layer is 0.15-0.25 mm. Preferably, the material of the protective layer is polydimethylsiloxane (PDMS) film.

[0021] Preferably, the thermoelectric module array is composed of p-type and n-type Bi2Te3 thermoelectric arms arranged alternately; preferably, the thermoelectric module array is composed of p-type and n-type Bi2Te3 thermoelectric arms doped with Sb2Te3 and Bi2Se3 arranged alternately.

[0022] Preferably, the size of the thermoelectric module array is (5-15) cm×(5-15) cm, the operating voltage is 0-5 V, and the maximum current is 3 A; the size of each thermoelectric arm is (0.5-5) mm×(0.5-5) mm×(0.1-1) mm (length×width×height); preferably, it includes one or more of the flexible thermoelectric devices.

[0023] Preferably, the gradient thermal interface material layer includes a first thermal conductive layer and a second thermal conductive layer, the first thermal conductive layer faces the back surface of the flexible substrate, and the thermal conductivity of the first thermal conductive layer is higher than that of the second thermal conductive layer.

[0024] Preferably, the first heat-conducting layer is a graphene / epoxy resin composite material with a thermal conductivity of 15-20 W / (m·K); the second heat-conducting layer is a carbon nanotube / silicone rubber composite material with a thermal conductivity of 5-10 W / (m·K).

[0025] Preferably, in the first thermally conductive layer, the mass percentage content of graphene is 0.1%-0.5%, the mass percentage content of the epoxy resin matrix is 99.0%-99.9%, the coating thickness is 0.15-0.25mm, and it is cured at a temperature of 50-70°C; in the second thermally conductive layer, the mass percentage content of carbon nanotubes is 0.1%-7.5%, the mass percentage content of the silicone rubber matrix is 92.5%-99.9%, the coating thickness is 0.25-0.35mm, and it is cured at room temperature.

[0026] Preferably, it also includes a bonding layer formed between the flexible substrate and the gradient thermal conductive interface material layer, which is used to enhance the bonding between the flexible substrate and the gradient thermal conductive interface material layer, and the thickness of the bonding layer is 0.15-0.25 mm; preferably, the bonding layer is a polydimethylsiloxane (PDMS) film.

[0027] Preferably, the controller includes a main control chip, a power module and a communication module; the main control chip is respectively connected to the flexible thermoelectric device and the temperature sensor array, and is used for collecting and performing algorithm analysis on the temperature data of the temperature sensor array, and outputting the data to the flexible thermoelectric device; the power module is connected to the flexible thermoelectric device and supports bidirectional current output; the communication module is a LoRa wireless transmission module, which is used for remote monitoring of the flexible thermoelectric device, the temperature sensor array and the controller itself.

[0028] Compared with the existing technology, the beneficial effects of the present invention are:

[0029] The present invention provides a large-volume concrete temperature field adaptive thermoelectric coordinated control system and control method. The prepared flexible thermoelectric thin film device has high flexibility, high thermoelectric efficiency and strong environmental adaptability, which can meet the temperature control requirements of large-volume concrete. In addition, its manufacturing process is compatible with existing microelectronics processing technology and has the potential for large-scale production. The flexible thermoelectric device is attached to the concrete surface, and the Peltier effect is utilized to achieve directional transfer of heat from the high-temperature zone to the low-temperature zone between the concrete and the thermoelectric module by switching the current direction. Temperature balance is achieved entirely through active thermoelectric effect and passive thermal conductivity optimization, avoiding the temperature hysteresis and durability defects of phase change materials, and improving the heat transfer efficiency through the thermal conductivity gradient and thermovariation characteristics of the gradient thermal conductive interface material layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic structural diagram of the adaptive thermoelectric coordinated control system for temperature field of large-volume concrete according to the present invention;

[0031] Figure 2 This is a schematic structural diagram of a flexible thermoelectric device in the adaptive thermoelectric coordinated control system for temperature field of large-volume concrete according to the present invention;

[0032] Figure 3 This is a diagram of the heat transfer mode of the adaptive thermoelectric coordinated control system of the temperature field of large-volume concrete involved in the present invention when one side of the concrete is in the high-temperature zone and the other side of the flexible thermoelectric device is in the low-temperature zone.

[0033] Figure 4 This is a diagram of the heat transfer mode of the adaptive thermoelectric coordinated control system of the temperature field of large-volume concrete involved in the present invention when one side of the concrete is in a low-temperature zone and the other side of the flexible thermoelectric device is in a high-temperature zone.

[0034] Figure 5 This is a temperature control logic flow chart of the adaptive thermoelectric coordinated control system for the temperature field of large-volume concrete involved in the present invention. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further described below with reference to the accompanying drawings and specific embodiments.

[0036] The present invention provides a large volume concrete temperature field adaptive thermoelectric coordinated control system, such as Figure 1 As shown, including:

[0037] (1) Flexible thermoelectric device 100, combined with Figure 2 As shown, the flexible thermoelectric device 100 includes a flexible substrate 110, a core layer 120 formed on the front surface of the flexible substrate 110, and a gradient thermal conductive interface material layer 130 formed on the back surface of the flexible substrate 110, wherein the core layer 120 includes an array of thermoelectric modules 121 and conductive wires 122 connecting the respective thermoelectric modules 121;

[0038] According to the solution of the present invention, the present invention attaches the above-mentioned flexible thermoelectric device 100 to the surface of concrete 001. Its function is to utilize the Peltier effect to achieve directional heat transfer from the high-temperature area to the low-temperature area between the concrete 001 and the thermoelectric module 121 by switching the direction of current. In the present invention, the maximum temperature difference driving capability is set at ΔT≧15°C.

[0039] According to known technology, the Peltier effect was discovered by French physicist Jean Charles Athanase Peltier in 1834. It means that when two different metals A and B are connected to form a loop, if a current I is passed through the loop, heat absorption and heat release phenomena will occur at the two connection points of A and B respectively. That is, the Peltier effect describes the property of a material to convert electrical energy into thermal energy.

[0040] According to the solution of the present invention, the present invention realizes the Peltier effect by forming a core layer 120 including an array of thermoelectric modules 121 on a flexible substrate 110. The array of thermoelectric modules 121 used is composed of alternating p-type and n-type Bi2Te3 thermoelectric arms. The flexible substrate 110 used is a polyimide film material, and the Bi2Te3 thermoelectric arms of each thermoelectric module 121 are connected by conductive wires 122 to form a series electrical connection. The conductive wires 122 used can be, for example, copper wires. Snake-shaped copper wires are commonly used in the art.

[0041] According to known technology, Bi2Te3 is a thermoelectric material with the best Peltier effect performance near room temperature. It has a high ZT value (≥1) near room temperature and is suitable for concrete temperature control scenarios (20-60°C). Moreover, Bi2Te3 is a narrow bandgap semiconductor with a band gap of about 0.15eV and a hexahedral layered structure. Bi and Te are shaped according to Te. 1 -Bi-Te 2 -Bi-Te 1The alternating order of the layers results in anisotropic thermoelectric properties in Bi2Te3, with p-type and n-type Bi2Te3 thermoelectric materials doped with Sb2Te3 and Bi2Se3 exhibiting superior thermoelectric performance. A thermoelectric module array consisting of alternating p-type and n-type Bi2Te3 thermoelectric arms doped with Sb2Te3 and Bi2Se3, formed on a flexible substrate, can be fabricated into a flexible thermoelectric thin-film device. This device can be bent and conformed to non-planar surfaces, such as the rough surface of large volumes of concrete used in the present invention, combining thermoelectric conversion functionality with mechanical flexibility.

[0042] According to the solution of the present invention, in the flexible thermoelectric device 100 of the present invention, a gradient thermal conductive interface material layer 130 is further formed on the reverse side of the flexible substrate 110. In some specific embodiments, Figure 3 As shown, the gradient thermal interface material layer 130 used in the present invention includes a first thermal conductive layer 131 and a second thermal conductive layer 132. The first thermal conductive layer 131 faces the back side of the flexible substrate 110, and the thermal conductivity of the first thermal conductive layer 131 is higher than that of the second thermal conductive layer 132.

[0043] According to the solution of the present invention, the present invention attaches the above-mentioned flexible thermoelectric device 100 to the surface of concrete 001, and the second thermal conductive layer 132 with low thermal conductivity of the gradient thermal conductive interface material layer 130 faces the concrete 001, so that the flexible thermoelectric device 100 of the present invention has the characteristic of gradually changing from the second thermal conductive layer 132 with low thermal conductivity on the side contacting the concrete 001 to the first thermal conductive layer 131 with high thermal conductivity on the side of the thermoelectric module 121, and a thermal conductivity gradient is formed in the vertical direction of the flexible thermoelectric device 100. In addition, in the process of the thermoelectric module 121 of the present invention using the Peltier effect to switch the current direction to achieve directional heat transfer from the high temperature zone to the low temperature zone between the concrete 001 and the thermoelectric module 121, a low thermal resistance heat transfer channel is formed on the gradient thermal conductive interface material layer 130. For example: one situation is, Figure 3 As shown, the side of the concrete 001 is a high temperature area, and the side of the thermoelectric module 121 of the flexible thermoelectric device 100 is a low temperature area. Through the forward current, the temperature heat of the concrete 001 side is transferred to the side of the thermoelectric module 121, and the heat is transferred from the second heat-conducting layer 132 with low thermal conductivity in contact with the side of the concrete 001 to the first heat-conducting layer 131 with high thermal conductivity in contact with the side of the thermoelectric module 121. Another case is, Figure 4As shown, the side of concrete 001 is a low-temperature zone, and the side of the thermoelectric module 121 of the flexible thermoelectric device 100 is a high-temperature zone. Through reverse current, the temperature heat on the side of the thermoelectric module 121 is transferred to the side of concrete 001, and the heat is transferred from the first thermal conductive layer 131 with high thermal conductivity in contact with the side of the thermoelectric module 121 to the second thermal conductive layer 132 with low thermal conductivity in contact with the side of the concrete 001; the present invention adopts a gradient thermal conductive interface material layer 130, which can form a low thermal resistance heat transfer channel in the process of realizing the directional transmission of heat between the concrete 001 and the thermoelectric module 121 from the high-temperature zone to the low-temperature zone, and can improve the heat transfer efficiency compared with not adopting the gradient thermal conductive interface material layer 130.

[0044] According to the solution of the present invention, in the gradient thermal interface material layer 130 of the present invention, the first thermal conductive layer 131 used is a graphene / epoxy resin composite material with a thermal conductivity coefficient of 15-20W / (m·K), and the second thermal conductive layer 132 used is a carbon nanotube / silicone rubber composite material with a thermal conductivity coefficient of 5-10W / (m·K).

[0045] As a specific embodiment, the present invention employs a graphene / epoxy resin composite material as the first thermally conductive layer 131, wherein the graphene content by mass is 0.1%-0.5% and the epoxy resin matrix content by mass is 99.0%-99.9%. The composite material achieves its optimal tensile strength and mechanical modulus within this addition range. Higher additions of graphene may cause agglomeration, reducing the composite material's thermal conductivity. The present invention employs the graphene / epoxy resin composite material with the aforementioned ratio as the first thermally conductive layer 131, with a coating thickness of 0.15-0.25 mm and curing at a temperature of 50-70°C. The resulting graphene / epoxy resin composite layer utilizes the high thermal conductivity within the graphene layer, achieving a thermal conductivity coefficient of 15-20 W / (m·K).

[0046] As a specific embodiment, the carbon nanotube / silicone rubber composite material used in the present invention as the second thermally conductive layer 132 has a carbon nanotube content of 0.1% to 7.5% by mass and a silicone rubber matrix content of 92.5% to 99.9% by mass. The composite material achieves its optimal tensile strength and mechanical modulus within this addition range. While a higher addition of carbon nanotubes can improve thermal conductivity, it may also affect flexibility. The present invention uses the carbon nanotube / silicone rubber composite material with the aforementioned ratio as the second thermally conductive layer 132, with a coating thickness of 0.25 to 0.35 mm and room temperature curing. The resulting carbon nanotube / silicone rubber composite material utilizes the high axial thermal conductivity of the carbon nanotubes, achieving a thermal conductivity coefficient of 5 to 10 W / (m·K). The silicone rubber matrix provides flexibility and interfacial adhesion, allowing it to adapt to the roughness of the concrete 001 surface.

[0047] According to the present invention, the gradient thermal interface material layer 130 employed in the present invention also exhibits thermotropic properties. For example, when the local temperature of the concrete 001 surface exceeds a threshold value of, for example, 40°C, the carbon nanotube network of the second thermally conductive layer 132 facing the concrete 001 undergoes thermal expansion and reconfiguration, increasing the thermal conductivity by over 30%. The present invention employed a composite film formed from a 7.5wt% carbon nanotube silicone rubber composite (film thickness 0.3mm) and a 0.5wt% graphene epoxy resin composite (film thickness 0.2mm) as a sample. The transient plane heat source method (using standard ISO 22007-2) was employed to test the thermal conductivity of the 7.5wt% carbon nanotube silicone rubber composite film at different temperatures. The test results are shown in Table 1.

[0048] Table 1

[0049] Temperature (℃) Thermal conductivity (W / (m·K)) 25 7.2 40 9.4(↑30％) 50 10.8(↑50％)

[0050] As can be seen from Table 1, the thermal conductivity of the silicone rubber composite coating containing 7.5 wt% carbon nanotubes at 40°C is 30% higher than that at 25°C, and the thermal conductivity at 50°C is 50% higher than that at 25°C, reflecting the thermotropic conductivity of the carbon nanotube / silicone rubber composite material in the second thermal conductive layer 132 facing the concrete 001.

[0051] According to the solution of the present invention, combined with Figure 2 As shown, the flexible thermoelectric device 100 of the present invention further includes a protective layer 140 formed on a side of the core layer 120 opposite to the flexible substrate 110. The thickness of the protective layer 140 is 0.15-0.25 mm. In some embodiments, the material of the protective layer 140 is polydimethylsiloxane (PDMS) film.

[0052] According to the solution of the present invention, combined with Figure 2 As shown, the flexible thermoelectric device 100 of the present invention further includes a bonding layer 150 formed between the flexible substrate 110 and the gradient thermal conductive interface material layer 130, for enhancing the bonding between the flexible substrate 110 and the gradient thermal conductive interface material layer 130. The thickness of the bonding layer 150 is 0.15-0.25 mm. In some embodiments, the bonding layer 150 can be made of a conventional silane coupling agent, without limitation, and commonly used, for example, is polydimethylsiloxane (PDMS).

[0053] According to the solution of the present invention, the present invention further provides a method for manufacturing the flexible thermoelectric device 100 as described above, comprising the following steps:

[0054] Step (1), pretreatment of the polyimide film flexible substrate 110: ultrasonically cleaning the polyimide flexible substrate 110 with a thickness of 0.05 mm to 0.15 mm (e.g., 0.1 mm) using a solvent such as acetone or ethanol to remove surface impurities;

[0055] In some embodiments, a 50 mm thick titanium / copper layer (Ti / Cu) may be sputtered on the surface of the polyimide flexible substrate 110 to enhance the adhesion of the subsequent plating of the thermoelectric module 121 and the serpentine copper wire 122 ;

[0056] Step (2), preparation of the serpentine copper conductor 122: first, a photoresist is coated on the front surface of the polyimide flexible substrate 110, and a serpentine conductor pattern is formed by photolithography through mask exposure. Then, a copper layer with a thickness of 20 μm is electroplated on the exposed area to form a serpentine copper conductor. Finally, the photoresist is stripped off, and the Ti / Cu seed layer in the uncovered area is etched, leaving only the serpentine copper conductor portion.

[0057] Step (3), preparation of the thermoelectric module 121 array: using magnetron sputtering or electrochemical deposition, alternately growing p-type and n-type Bi2Te3 thermoelectric arms (preferably p-type (Bi2Te3-Bi2Se3) thermoelectric material and n-type (Bi2Te3-Sb2Te3) thermoelectric material) at the wire nodes, and forming a single thermoelectric arm with a size of (0.5-5) mm × (0.5-5) mm × (0.1-1) mm (e.g., 1 mm × 1 mm × 0.5 mm) (length × width × height), and then annealing in an argon environment at 300°C for about 1 hour to optimize the crystal structure of the thermoelectric material;

[0058] Step (4), encapsulation of the protective layer 140: liquid polydimethylsiloxane (PDMS) is evenly coated on the surface of the alternating p-type and n-type Bi2Te3 thermoelectric arms, covering the thermoelectric module 121 array and the serpentine copper wire 122, and then cured at 80°C for about 2 hours to form a flexible thermoelectric film;

[0059] Step (5), prefabrication of the gradient thermal interface material layer 130: scraping a silicone rubber composite material containing 0.1wt%-7.5wt% carbon nanotubes into a coating with a thickness of 0.25mm-0.35mm (e.g., 0.3mm), curing at room temperature to form a second thermal conductive layer 132, then spraying an epoxy resin composite material containing 0.1wt%-0.5wt% graphene on the surface of the second thermal conductive layer 132 to form a coating with a thickness of 0.15mm-0.25mm (e.g., 0.2mm), and curing at a temperature of 50-70°C to form a first thermal conductive layer 131;

[0060] Step (6), encapsulation of the gradient thermal conductive interface material layer 130: coating a layer of liquid polydimethylsiloxane (PDMS) on the reverse side (i.e., the mounting surface) of the polyimide flexible substrate 110 of the flexible thermoelectric film formed in step (4), and then attaching and laminating the gradient thermal conductive interface material layer 130 formed in step (5), with the first thermal conductive layer 131 facing the reverse side of the polyimide flexible substrate 110 of the flexible thermoelectric film, and then curing at 80° C. for about 2 hours to form a bonding layer 150 with a thickness of 0.15-0.25 mm between the two to ensure a close fit between the interfaces;

[0061] Step (7), module cutting: using a laser to cut the flexible thermoelectric film formed in step (6) into individual flexible thermoelectric devices 100 of (5-15) cm×(5-15) cm (eg, 10 cm×10 cm).

[0062] In the manufacturing method of the flexible thermoelectric device 100 provided by the present invention, the purpose of manufacturing the serpentine copper wire 122 is to release bending stress through serpentine routing and avoid wire breakage (traditional straight wires are prone to cracking when bent).

[0063] The flexible thermoelectric device 100 obtained by the above-mentioned manufacturing method of the present invention includes a polyimide film flexible substrate 110, a core layer 120 formed on the front side of the polyimide film flexible substrate 110, including an array of thermoelectric modules 121 and serpentine copper wires 122 connecting each thermoelectric module 121, a gradient thermal conductive interface material layer 130 formed on the back side of the polyimide film flexible substrate 110, including a first thermal conductive layer 131 and a second thermal conductive layer 132, a protective layer 140 and an adhesive layer 150, and the overall thickness does not exceed 2 mm.

[0064] According to the solution of the present invention, one or more of the above-mentioned flexible thermoelectric devices 100 are attached to the surface of concrete 001. By utilizing the Peltier effect, the heat of the concrete 001 is directional-transferred from the high-temperature area to the low-temperature area by switching the direction of the current. The Bi2Te3 thermoelectric arms of each thermoelectric module 121 are connected via serpentine copper wires 122 to form a series electrical connection. Then, each flexible thermoelectric device 100 is connected to the power module of the subsequent controller via a flexible cable to form an array-powered network.

[0065] According to the solution of the present invention, the flexible thermoelectric device 100 used in the present invention is prepared into a thermoelectric film with high flexibility, high thermoelectric efficiency and strong environmental adaptability through a polyimide flexible substrate 110, a core layer 120 formed on the front side of the polyimide film flexible substrate 110, including an array of thermoelectric modules 121 and serpentine copper wires 122 connecting each thermoelectric module 121, a gradient thermal conductive interface material layer 130 formed on the back side of the polyimide film flexible substrate 110, including a first thermal conductive layer 131 and a second thermal conductive layer 132, and a protective layer 140 and an adhesive layer 150 made of polydimethylsiloxane (PDMS). It can meet the temperature control requirements of large-volume concrete, and its manufacturing process is compatible with existing microelectronics processing technology and has the potential for large-scale production.

[0066] (2) An array of temperature sensors 200 is provided inside the concrete 001 (e.g. Figure 1 shown);

[0067] According to the solution of the present invention, the temperature sensor 200 is pre-buried during concrete pouring, so that an array of the temperature sensor 200 is formed inside the concrete 001 .

[0068] In some specific embodiments, the temperature sensor 200 used in the present invention is, for example, an NTC (negative temperature coefficient) thermistor sensor with an accuracy of ±0.5°C and a protection level of IP67. It is directly embedded in the concrete. Each temperature sensor 200 is also connected to a regional hub via a waterproof cable and to the main control chip of a subsequent controller to collect and analyze the temperature inside the large volume concrete 001.

[0069] (3) a controller connected to the conductive wires 130 of the flexible thermoelectric device 100 and the array of temperature sensors 200, the controller being used to supply power to the flexible thermoelectric device 100, collect and analyze the temperature of the array of temperature sensors 200, and output the temperature to the flexible thermoelectric device 100;

[0070] According to the present invention, the controller includes a main control chip, a power module, and a communication module. Specifically, the main control chip is connected to the flexible thermoelectric device 100 and the temperature sensor array 200, respectively, and is used to collect and perform algorithmic analysis on temperature data from the temperature sensor array 200, and output the data to the flexible thermoelectric device 100. In some specific embodiments, the main control chip used in the present invention is an ARM Cortex-M7 microcontroller (e.g., STM32H743).

[0071] Furthermore, in the controller provided by the present invention, the power module is connected to the flexible thermoelectric device 100 for powering the flexible thermoelectric device 100. In some embodiments, the power module used is an adjustable DC power supply (0-5V / 3A) and supports bidirectional current output to meet the requirement that after the flexible thermoelectric device 100 is attached to the surface of the concrete 001, the Peltier effect is utilized to switch the current direction to achieve the function of directional transmission of heat from the high temperature zone to the low temperature zone of the concrete 001. In the present invention, the maximum temperature difference driving capability is set at ΔT≧15°C.

[0072] Furthermore, in the controller provided by the present invention, the communication module is a LoRa wireless transmission module, which is used for remote monitoring of the flexible thermoelectric device, the temperature sensor array, and the controller itself. This module enables remote interaction and control of system-wide data through LoRa wireless transmission. Specifically, remote monitoring of the temperature sensor array involves transmitting temperature distribution data within the concrete, allowing a remote platform to analyze temperature differences, hotspot locations, and other factors. Remote monitoring of the flexible thermoelectric device involves reporting module operating parameters (such as current, voltage, and heat dissipation status), supporting remote start / stop or adjustment.

[0073] According to the solution of the present invention, the transmission mode between the controller and the temperature sensor 200 array is, for example, RS-485 bus transmission or wireless transmission, and the controller and the flexible thermoelectric device 100 are connected and transmitted, for example, through a PWM control circuit.

[0074] Based on the above-mentioned mass concrete temperature field adaptive thermoelectric coordinated control system, the present invention further provides a mass concrete temperature field adaptive thermoelectric coordinated control method, comprising the following steps:

[0075] Step S1, providing a flexible thermoelectric device 100 as described above;

[0076] Step S2, pre-embedding the temperature sensor 200 array during concrete pouring;

[0077] Step S3, attaching one or more flexible thermoelectric devices 100 to the surface of concrete 001, with the second thermal conductive layer 132 of the gradient thermal conductive interface material 130 in the flexible thermoelectric device 100 facing the concrete 001;

[0078] In this step, in order to enhance the bonding strength between the flexible thermoelectric device 100 and the surface of the concrete 001, the surface of the concrete 001 needs to be cleaned after the concrete is poured and the formwork is removed to remove the dust on the surface. Then, a thin layer of silane coupling agent (such as polydimethylsiloxane, PDMS) is applied to the surface of the formed large volume concrete 001. Finally, the flexible thermoelectric device 100 is attached to the surface of the concrete 001. The self-adhesiveness of the applied thin layer of silane coupling agent (such as polydimethylsiloxane, PDMS) is used to preliminarily fix the flexible thermoelectric device 100. Then, it can be attached by pressing or rolling, for example, applying a pressure of 0.1 MPa by a rolling device to ensure that there is no gap between the flexible thermoelectric device 100 and the concrete 001. It is required that the second thermal conductive layer 132 of the gradient thermal conductive interface material 130 in the flexible thermoelectric device 100 faces the concrete 001 side during the attachment.

[0079] Step S4, connecting the conductive wires 122 of one or more flexible thermoelectric devices 100 and the array of temperature sensors 200 to a controller, wherein the controller is configured to supply power to the flexible thermoelectric device 100, collect and analyze the temperature of the array of temperature sensors 200, and output the temperature to the flexible thermoelectric device 100;

[0080] In this step, the conductive wires 122 of one or more flexible thermoelectric devices 100 are connected in series with the power module of the controller through flexible cables to form an array connection network. The main control chip of the controller is connected to the flexible thermoelectric device 100 and the temperature sensor 200 array respectively, for collecting and performing algorithm analysis on the temperature data of the temperature sensor 200 array and outputting it to the flexible thermoelectric device 100.

[0081] like Figure 5The temperature control logic flow chart shown in the figure shows that the array of temperature sensors 200 embedded in the concrete 001 is connected to the main control chip of the controller to monitor the temperature field distribution inside the concrete 001 in real time. The main control chip of the controller collects temperature data inside the concrete 001 (for example, every 10 minutes) and generates a three-dimensional temperature cloud map. When it is detected that the temperature difference in a certain area exceeds a set threshold (for example, the threshold is set at 15°C, that is, ΔT≧15°C), the array of thermoelectric modules 121 of the flexible thermoelectric device 100 in the area is energized to start the thermoelectric modules 121. The array of thermoelectric modules 121 produces a Peltier effect, and heat is transferred from the high temperature area to the high temperature area by switching the direction of the current. Directional transmission in the low-temperature zone. For example, if the core temperature of the concrete 001 is higher than the surface temperature, the power module of the controller causes the thermoelectric module 121 to pass a forward current to conduct heat from the core of the concrete 001 to the surface. If the core temperature of the concrete 001 is lower than the surface temperature, the current direction is switched, and the power module of the controller causes the thermoelectric module 121 to pass a reverse current to achieve reverse heat transfer. At the same time, the thermal conductivity gradient and thermovariant characteristics of the gradient thermal interface material layer 130 are used to improve the heat transfer efficiency. When the temperature difference between the core temperature and the surface temperature of the concrete 001 is lower than the specification limit (for example, 25°C), the thermoelectric module 121 is turned off, and the temperature control of the concrete 001 is terminated.

[0082] In some specific embodiments, the software logic and control strategy of the controller used in the present invention include:

[0083] 1. Temperature data collection and processing:

[0084] The temperature data of the controller's main control chip is collected synchronously: the temperature data of the entire area is collected every 10 minutes, and the noise is eliminated through Kalman filtering;

[0085] Temperature difference calculation: Calculate the temperature difference between the core layer and the surface layer of each regional grid ΔT = T core -T surface , if ΔT ≧ threshold (for example, the threshold is 15°C, which is an adjustable threshold), it is marked as "thermoelectric region";

[0086] 2. Thermoelectric module control logic:

[0087] Current direction control:

[0088] Forward mode (heat dissipation from internal to external): When T core >T surface , the controller's power module allows the thermoelectric module to pass a forward current, and the heat is directed from the inside of the concrete to the surface;

[0089] Reverse mode (heat transfer from outside to inside): When T core <T surfaceThe power module of the controller switches the current direction, so that the thermoelectric module passes the reverse current, and the heat is guided from the outside of the concrete to the inside, but the backflow of heat should be avoided;

[0090] Current intensity regulation: Dynamically adjusts the current (0-3A) based on the temperature difference ΔT, in accordance with the formula: I = k·ΔT (k = 0.2A / °C). At the same time, it limits the maximum power consumption of a single module to ≤ 5W to prevent overheating and damage to the controller's power module.

[0091] 3. Adaptive algorithm of the controller's main control chip:

[0092] Fuzzy PID control:

[0093] Input: ΔT and its rate of change d(ΔT) / dt;

[0094] Output: PWM duty cycle (control current intensity) and direction signal;

[0095] Priority Scheduling:

[0096] When multiple hot spots coexist, the area with the largest ΔT is cooled first and higher current resources are allocated;

[0097] Dynamic power regulation: Adjusts input current (0-3A) based on the temperature difference. The greater the temperature difference, the higher the current intensity. At the same time, the maximum power consumption of a single module is limited to ≤5W to prevent overheating and damage to the controller's power module.

[0098] Sensor → Controller: Transmit temperature data via SPI bus;

[0099] Controller → Power module: PWM signal controls MOSFET switching frequency and adjusts output voltage / current;

[0100] Controller → H-bridge circuit: GPIO pins control the direction of current flow (high level forward, low level reverse).

[0101] In some specific embodiments, the software control algorithm of the controller used in the present invention includes:

[0102] 1. Calculation of temperature difference change rate (d(ΔT) / dt):

[0103] Record ΔT every Δt = 1 min and calculate the rate of change according to the following formula:

[0104]

[0105] For example: If Δt = 1 min, and ΔT rises from 15°C to 18°C, then dΔT / dt = 3°C / min;

[0106] 2. Current intensity mapping rules:

[0107] Base current: linearly adjusted according to the current ΔT, according to the formula:

[0108] I base =k1·ΔT (k1=0.2A / ℃)

[0109] Dynamic compensation current: adjusted according to dΔT / dt, according to the formula:

[0110] I comp =k2·d(ΔT) / dt(k2=0.1)

[0111] Total current: According to the formula:

[0112] I total =I base +I comp

[0113] Constraints:

[0114] Total current ≤ 3A;

[0115] Single module power consumption ≤ 5W (i.e. I 2 R≤5W, );

[0116] 3.PID closed-loop control:

[0117] Error input: target temperature difference ΔT_ target =15℃, actual temperature difference ΔT_ actual ;

[0118] Output correction: According to the formula:

[0119]

[0120] Table 2 shows the application examples.

[0121] Table 2

[0122] Test conditions Maximum current (A) Response time (s) Temperature drop rate (℃ / h) ΔT=15℃,dΔT / dt=0 3.0 60 2.5 ΔT=20℃,dΔT / dt=5℃ / min 3.0 (Limited) 30 4.2 ΔT=10℃,dΔT / dt=-3℃ / min 0.5 - 0 (reverse inhibition)

[0123] The present invention is further illustrated below with reference to the examples, the purpose of which is to better understand the content of the present invention and to embody the essential features of the present invention. Therefore, the examples given should not be construed as limiting the scope of protection of the present invention. It is also particularly noted that the specific experimental methods and equipment involved in the examples are conventional methods or carried out under the conditions recommended by the manufacturer's instructions unless otherwise specified, and the reagents involved are commercially available unless otherwise specified.

[0124] Example:

[0125] The mass concrete temperature field adaptive thermoelectric coordinated control system of the present invention is applied in a super high-rise raft foundation:

[0126] (1) Verification of temperature difference control effect:

[0127] Testing steps:

[0128] Test piece: pouring 2 groups of 1.5m 3 Concrete test blocks (C40 cement), one group using the control system of the present invention (experimental group), and the other group using the traditional cooling water pipe method (control group);

[0129] Sensor arrangement: 12 temperature sensors are embedded inside each specimen (4 each in the surface layer, middle layer, and core layer);

[0130] Temperature rise monitoring: record temperature data within 7 days after pouring, with a sampling interval of 1 hour;

[0131] The experimental group started the thermoelectric module and controller, and the control group started the cooling water circulation (flow rate of 2 L / min, water temperature of 15°C);

[0132] The test data are shown in Table 3.

[0133] Table 3

[0134] Group Maximum temperature difference on the 3rd day (℃) Maximum temperature difference on the 5th day (℃) Peak temperature difference (℃) Experimental group 16.2 18.1 18.5 control group 24.7 27.9 28.3

[0135] (Note: Maximum daily temperature difference = core temperature - surface temperature)

[0136] As can be seen from Table 3, by using the control system of the present invention, the temperature difference control can reduce the maximum temperature difference between the inside and outside from 28°C to 18°C, which is lower than the regulatory limit of 25°C.

[0137] (2) Energy saving effect verification:

[0138] Experimental group: The control system of the present invention was used to record the total power consumption of the thermoelectric module (power meter model: YOKOGAWAWT310) and calculate the energy consumption per unit volume (unit: kWh / m 3 );

[0139] Control group: The traditional cooling water pipe method was used to record the total power consumption of the water pump and chiller (the power meter model was the same as the experimental group);

[0140] Test conditions: ambient temperature 25°C, humidity 60%, continuous operation for 72 hours, covering the peak period of concrete temperature rise;

[0141] The test data are shown in Table 4.

[0142] Table 4

[0143] Group Total energy consumption (kWh) <![CDATA[Energy consumption per unit volume (kWh / m 3 )]]> Energy consumption ratio (vs. liquid cooling) Experimental group 4.8 3.2 15％ control group 32.0 21.3 100％

[0144] It can be seen from Table 4 that the energy consumption per cubic meter of concrete temperature control using the control system of the present invention is only 15% of that of the traditional liquid cooling method.

[0145] (3) Durability test:

[0146] Aging test was used to evaluate the durability of gradient thermal interface materials.

[0147] Test conditions: Gradient thermal interface material aged for 1000 hours at 60°C / 85% RH.

[0148] Thermal conductivity test:

[0149] Testing instrument: LFA467 laser flash thermal conductivity meter (NETZSCH);

[0150] Test standard: ASTM E1461;

[0151] Test frequency: sampling once every 200 hours, a total of 5 sets of data;

[0152] The test data are shown in Table 5.

[0153] Table 5 Aging test data of gradient thermal interface materials

[0154]

[0155] As can be seen from Table 5, by using the control system of the present invention, the thermal conductivity attenuation of the gradient thermal interface material is less than 5% after aging for 1000 hours in a 60°C / 85% RH environment.

[0156] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for adaptive thermoelectric coordinated control of temperature field of mass concrete, characterized in that: The following steps are involved: Provided is a flexible thermoelectric device, comprising a flexible substrate, a core layer formed on a front surface of the flexible substrate, and a gradient thermal interface material layer formed on a back surface of the flexible substrate, wherein the core layer comprises a thermoelectric module array and conductive wires connecting the thermoelectric modules, the thermoelectric module array comprising alternating p-type and n-type Bi2Te3 thermoelectric arms, and the gradient thermal interface material layer comprises a first thermal conductive layer and a second thermal conductive layer, wherein the first thermal conductive layer faces the back surface of the flexible substrate, and the thermal conductivity of the first thermal conductive layer is higher than that of the second thermal conductive layer; Attaching the flexible thermoelectric device to a concrete surface, with the second thermally conductive layer of the gradient thermal interface material facing the concrete; An array of temperature sensors is embedded in the concrete to monitor the temperature field distribution in real time; connecting the conductive wires of the flexible thermoelectric device and the temperature sensor array to a controller, wherein the controller is configured to supply power to the flexible thermoelectric device, collect and analyze the temperature of the temperature sensor array, and output the temperature to the flexible thermoelectric device; and When it is detected that the temperature difference in a certain area exceeds the set threshold, the thermoelectric module array of the flexible thermoelectric device in the area is energized. The thermoelectric module array produces a Peltier effect and realizes the directional transfer of heat from the high-temperature area to the low-temperature area by switching the direction of the current.

2. A mass concrete temperature field adaptive thermoelectric coordinated control system, characterized in that: include: A flexible thermoelectric device comprising a flexible substrate, a core layer formed on the front surface of the flexible substrate, and a gradient thermal interface material layer formed on the back surface of the flexible substrate, wherein the core layer comprises an array of thermoelectric modules and conductive wires connecting the thermoelectric modules; a temperature sensor array disposed within the concrete; as well as A controller connected to the conductive wires of the flexible thermoelectric device and the temperature sensor array is used to supply power to the flexible thermoelectric device, collect and analyze the temperature of the temperature sensor array, and output the temperature to the flexible thermoelectric device.

3. The mass concrete temperature field adaptive thermoelectric coordinated control system according to claim 2 is characterized in that: The flexible substrate is a polyimide film, and the thickness of the flexible thermoelectric device is 0.5-2.0 mm; the flexible thermoelectric device also includes a protective layer formed on the side of the core layer opposite to the flexible substrate, and the thickness of the protective layer is 0.15-0.25 mm. Preferably, the material of the protective layer is polydimethylsiloxane (PDMS) film.

4. The mass concrete temperature field adaptive thermoelectric coordinated control system according to claim 2 is characterized in that: The thermoelectric module array is composed of alternately arranged p-type and n-type Bi2Te3 thermoelectric arms; preferably, the thermoelectric module array is composed of alternately arranged p-type and n-type Bi2Te3 thermoelectric arms doped with Sb2Te3 and Bi2Se3.

5. The mass concrete temperature field adaptive thermoelectric coordinated control system according to claim 4 is characterized in that: The size of the thermoelectric module array is (5-15) cm×(5-15) cm, the operating voltage is 0-5 V, and the maximum current is 3 A; the size of each thermoelectric arm is (0.5-5) mm×(0.5-5) mm×(0.1-1) mm (length×width×height); preferably, it includes one or more of the flexible thermoelectric devices.

6. The mass concrete temperature field adaptive thermoelectric coordinated control system according to claim 2 is characterized in that: The gradient thermal interface material layer includes a first thermal conductive layer and a second thermal conductive layer. The first thermal conductive layer faces the back surface of the flexible substrate. The thermal conductivity of the first thermal conductive layer is higher than that of the second thermal conductive layer.

7. The mass concrete temperature field adaptive thermoelectric coordinated control system according to claim 6 is characterized in that: The first heat-conducting layer is a graphene / epoxy resin composite material with a thermal conductivity of 15-20W / (m·K); the second heat-conducting layer is a carbon nanotube / silicone rubber composite material with a thermal conductivity of 5-10W / (m·K).

8. The mass concrete temperature field adaptive thermoelectric coordinated control system according to claim 7 is characterized in that: In the first heat-conducting layer, the mass percentage content of graphene is 0.1%-0.5%, the mass percentage content of the epoxy resin matrix is 99.0%-99.9%, the coating thickness is 0.15-0.25mm, and it is cured at a temperature of 50-70°C; in the second heat-conducting layer, the mass percentage content of carbon nanotubes is 0.1%-7.5%, the mass percentage content of the silicone rubber matrix is 92.5%-99.9%, the coating thickness is 0.25-0.35mm, and it is cured at room temperature.

9. The mass concrete temperature field adaptive thermoelectric coordinated control system according to claim 2, characterized in that: It also includes a bonding layer formed between the flexible substrate and the gradient thermal conductive interface material layer, which is used to enhance the bonding between the flexible substrate and the gradient thermal conductive interface material layer. The thickness of the bonding layer is 0.15-0.25 mm; preferably, the bonding layer is a polydimethylsiloxane (PDMS) film.

10. The mass concrete temperature field adaptive thermoelectric coordinated control system according to claim 2, characterized in that: The controller includes a main control chip, a power module and a communication module; the main control chip is connected to the flexible thermoelectric device and the temperature sensor array respectively, and is used to collect and perform algorithm analysis on the temperature data of the temperature sensor array and output it to the flexible thermoelectric device; The power module is connected to the flexible thermoelectric device and supports bidirectional current output; the communication module is a LoRa wireless transmission module, which is used for remote monitoring of the flexible thermoelectric device, the temperature sensor array and the controller itself.

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