Filling type thermoelectric device

Abstract

A filling type thermoelectric device provided by the present invention comprises thermoelectric arms, conductive sheets and heat-conducting ceramic plates, the thermoelectric arms comprise P-type thermoelectric arms and N-type thermoelectric arms, the P-type thermoelectric arms and the N-type thermoelectric arms are uniformly distributed between the heat-conducting ceramic plates at a hot end and a cold end at intervals, and the adjacent P-type thermoelectric arms and N-type thermoelectric arms are sequentially connected in series through the conductive sheets. The thermoelectric device further comprises a heat conduction layer, the heat conduction layer is arranged close to the hot end of the thermoelectric device, the gaps between the thermoelectric arms are filled with the heat conduction layer, and the heat conduction layer is in close contact with the thermoelectric arms and the hot end heat conduction ceramic plate. And meanwhile, backflow of heat to the cold end is reduced, so that the overall effect of pulse current thermoelectric refrigeration is improved.

Description

Technical Field

[0001] The present application relates to the technical field of thermoelectric devices, and in particular to a filled thermoelectric device. Background Art

[0002] The cooling performance of thermoelectric devices is mainly determined by the thermoelectric materials used. The coefficient of performance (COP) of thermoelectric devices is closely related to the thermoelectric figure of merit (ZT value) of thermoelectric materials. Generally, the higher the ZT value of the thermoelectric material, the better the cooling effect of the device. However, due to the limited thermoelectric performance of existing thermoelectric materials, the efficiency of thermoelectric devices is relatively low, making thermoelectric power generation and cooling technologies more applied in some fields with smaller demand, and it is difficult to achieve large-scale application. In recent years, with the advancement of materials technology and the deepening of theoretical research, various new thermoelectric materials have been continuously developed, and the ZT value of materials has also been significantly improved. Despite this, how to further improve the thermoelectric performance of materials in an environment close to room temperature remains a challenge.

[0003] In addition, as the application fields of thermoelectric devices continue to expand, it is particularly important to improve the assembly process of high-performance thermoelectric devices. This not only requires the large-scale production of thermoelectric materials with high ZT values, but also requires in-depth exploration in device structure design, optimization of heterogeneous interfaces (including electrical contact and thermal contact), electrode connection technology, and packaging technology. Therefore, optimizing the manufacturing process of thermoelectric devices and rationally designing heterogeneous interfaces are crucial to improving the overall performance of thermoelectric devices.

[0004] In recent decades, research on thermoelectric technology at home and abroad has mainly focused on several key directions, including the development of thermoelectric materials, optimization of device structure, improvement of heat dissipation at the hot end, and the establishment and improvement of relevant theoretical models. Although some progress has been made in these areas, it will still take a long time to explore new and efficient thermoelectric materials, especially the development of high-merit coefficient materials is difficult and there is still a long way to go before practical application.

[0005] The heat dissipation system of the thermoelectric cooler is crucial to ensure the stable operation of the device. Especially when the material and size of the thermoelectric element are limited, improving the heat exchange capacity of the heat dissipation system can effectively reduce the temperature difference between the hot and cold ends of the thermoelectric element, thereby greatly improving the cooling capacity and COP value. Improving the overall cooling performance by optimizing the heat dissipation system has become one of the main research directions of thermoelectric cooling technology. This strategy indirectly improves the overall performance of the system by improving the heat dissipation design.

[0006] The calculation of the cooling capacity of the thermoelectric cooler is usually obtained by ignoring the Thomson effect and analyzing the heat balance of the cold end of the thermoelectric unit by the law of conservation of energy. It is generally believed that half of the Joule heat generated by the Joule effect flows to the hot end and the other half flows to the cold end; at the same time, the heat conduction caused by the Fourier effect is transferred from the hot end to the cold end, and finally the heat is offset by the heat generated by the Peltier effect at the cold end, thus achieving thermal balance.

[0007] By improving the heat dissipation conditions at the hot end, the adverse effects caused by the temperature difference inside the thermoelectric device are reduced, thereby indirectly improving the overall cooling performance. This strategy of structural optimization and heat dissipation enhancement can not only effectively alleviate the cooling capacity loss caused by Joule heating and Fourier heat conduction, but also provide a practical performance improvement solution under the current material performance limitations. Therefore, optimizing the heat dissipation at the hot end has become one of the important directions to solve the insufficient cooling performance of thermoelectric devices, and provides the possibility for thermoelectric cooling technology to be used in a wider range of application scenarios. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a filled thermoelectric device in response to the above-mentioned problems. The device is optimized by locally filling a heat-conducting layer. The introduction of the heat-conducting layer significantly improves the thermal conductivity of some areas, which can effectively accelerate the dissipation of the Joule heat generated during the thermoelectric cooling process, while reducing the heat backflow to the cold end, thereby improving the overall effect of pulse current thermoelectric cooling.

[0009] The embodiment of the present application is implemented as follows:

[0010] An embodiment of the present application provides a filled thermoelectric device, comprising a thermoelectric arm, a conductive sheet and a thermally conductive ceramic plate, wherein the thermoelectric arm comprises a P-type thermoelectric arm and an N-type thermoelectric arm, wherein the P-type thermoelectric arm and the N-type thermoelectric arm are evenly spaced between the thermally conductive ceramic plates at the hot end and the cold end, and two adjacent P-type thermoelectric arms and N-type thermoelectric arms are connected in series in sequence through the conductive sheet, and the conductive sheet is connected to an input power supply, and is characterized in that it also comprises a thermally conductive layer, wherein the thermally conductive layer is arranged near the hot end of the thermoelectric device, fills in the gap between the thermoelectric arms, and is in close contact with the thermoelectric arms and the thermally conductive ceramic plates at the hot end.

[0011] In some optional embodiments, a certain distance is set between the heat conductive layer and the cold end of the thermoelectric device.

[0012] In some optional embodiments, the heat conductive layer is made of alumina ceramics, zirconium oxide ceramics or aluminum nitride ceramics.

[0013] In some optional embodiments, the P-type thermoelectric arm is made of bismuth telluride-based alloy or half-Heusler alloy or tin selenide material.

[0014] In some optional embodiments, the N-type thermoelectric arm is made of bismuth telluride-based alloy or half-Heusler alloy or YbAl3 material.

[0015] In some optional embodiments, the conductive sheet is made of copper or silver and alloys thereof, and is disposed in contact with the inner side surface of the thermally conductive ceramic plate.

[0016] In some optional embodiments, the filling ratio of the heat-conducting layer in the height direction of the thermoelectric device is 1%-90%.

[0017] In some optional embodiments, the thermally conductive ceramic plate has a length of 0.1-80 mm, a width of 0.1-80 mm, and a thickness of 0.1-3 mm.

[0018] In some optional embodiments, the thermoelectric arm has a length of 0.1-10 mm, a width of 0.1-10 mm, and a height of 0.1-10 mm.

[0019] In some optional embodiments, the thickness of the conductive sheet is 0.01-0.2 mm.

[0020] The beneficial effects of the present application are as follows: a filled thermoelectric device provided by the present application optimizes the structure of the thermoelectric cooling device by locally filling a heat-conducting layer, thereby increasing the heat exchange rate between the thermoelectric arm and the heat dissipation end of the thermoelectric cooling device, and reducing the Joule heat refluxed to the cooling end in the thermoelectric cooling device, thereby increasing the cooling capacity of the cold end of the thermoelectric cooling device, so that the thermoelectric device significantly reduces the cold end temperature of the device when the heat load is large, thereby improving the cooling capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 This is a schematic diagram of the structure of an embodiment of the present application;

[0023] Figure 2 A comparison chart of the theoretical cooling capacity of the filled thermoelectric device of the embodiment of the present application and the conventional thermoelectric device under different temperature differences;

[0024] Figure 3 The average temperature of the cooling end / heat dissipation end of the filling device of the embodiment of the present application at different filling layer ratios;

[0025] Figure 4The average temperature of the cold end of the filling device of the embodiment of the present application under different hot end heat dissipation coefficients and filling layer ratios;

[0026] Figure 5 It is the average cold end temperature of the filling device of the embodiment of the present application under different cold end heat loads and filling layer ratios. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0029] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0030] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0031] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0032] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0033] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] The features and performance of the present application are further described in detail below in conjunction with the embodiments.

[0035] like Figure 1 As shown, the present invention proposes a filled thermoelectric device, including a thermoelectric arm, a conductive sheet 1 and a thermally conductive ceramic plate 2, the thermoelectric arm including a P-type thermoelectric arm 3 and an N-type thermoelectric arm 4, the P-type thermoelectric arm and the N-type thermoelectric arm are evenly spaced between the thermally conductive ceramic plates at the hot end and the cold end, two adjacent P-type thermoelectric arms and N-type thermoelectric arms are connected in series through the conductive sheet in turn, the conductive sheet is connected to the input power supply, and also includes a thermally conductive layer 5, which is arranged near the hot end of the thermoelectric device, fills in the gap between the thermoelectric arms, and is in close contact with the thermoelectric arms and the thermally conductive ceramic plates at the hot end.

[0036] A certain distance is set between the heat-conducting layer and the cold end of the thermoelectric device to prevent the heat flow from being quickly conducted to the cold end, which affects the overall heat dissipation effect. It ensures that the heat is concentrated at the hot end for effective dissipation, avoids excessive rise in the temperature of the cold end, and thus improves the cooling performance and reliability of the thermoelectric device under high load. This structural optimization strategy further expands the application potential of thermoelectric refrigeration technology in the field of efficient heat dissipation and precise temperature control. Through the analysis of the cold end of the thermoelectric device, it can be seen that compared with conventional flat-plate thermoelectric devices, the advantage of the filled thermoelectric device lies in the introduction of a key new structure-the heat-conducting layer. By filling the heat-conducting layer between the thermoelectric arms close to the hot end and utilizing the high thermal conductivity of the filling material, the Joule heat generated by the thermoelectric arm can be quickly conducted to the thermal conductive ceramic plate at the hot end. This design not only significantly improves the thermal conductivity of the thermoelectric arm to the hot end, but also when thermal equilibrium is reached, the temperature of the hot end is higher, which enhances the heat dissipation capacity of the hot end to the external environment. In addition, this structure also effectively reduces the conduction of Joule heat to the cold end, thereby increasing the cooling capacity Qc of the cold end.

[0037] When the thermoelectric cooling device is working, the cooling end usually carries a certain heat load, and the presence of the filling structure significantly improves the thermal conductivity of the hot end part of the device. When the system is under a large heat load, the cooling effect of the filled thermoelectric device is more significant, showing superior cooling performance. This optimized design improves the heat dissipation efficiency while minimizing unnecessary heat reflux, effectively enhancing the overall cooling capacity, especially showing obvious performance advantages in high heat load application scenarios.

[0038] In addition, in pulsed thermoelectric cooling applications, filled thermoelectric devices exhibit better cooling effects and thermal stability.

[0039] Due to the presence of the thermal conductive layer, the thermal capacity of the device is improved, which plays an important role in thermal buffering during pulse cooling and significantly reduces the instantaneous overheating of the cold end. This thermal buffering effect helps to maintain the stability of the cold end temperature, thereby further improving the performance of pulse thermoelectric cooling. In summary, filled thermoelectric devices can not only significantly increase the cooling capacity in pulse cooling applications, but also have better thermal stability, showing great potential in the field of efficient pulse cooling.

[0040] The thermal conductive layer usually uses insulating ceramic materials with high thermal conductivity, such as aluminum oxide, zirconium oxide, or aluminum nitride ceramics. The P-type thermoelectric arm material usually uses P-type thermoelectric materials, such as bismuth telluride-based alloys, half-Heusler alloys, tin selenide, etc. The N-type thermoelectric arm material usually uses N-type thermoelectric materials, such as bismuth telluride-based alloys, half-Heusler alloys, YbAl3, etc. The conductive sheet material is usually copper, silver, and alloys thereof. The insulating ceramic plate material is usually aluminum oxide, zirconium oxide, or aluminum nitride ceramics.

[0041] The length of the thermally conductive ceramic plate is in the range of 0.1-80 mm, the width is in the range of 0.1-80 mm, and the thickness is in the range of 0.1-3 mm; the thickness of the conductive sheet material is in the range of 0.01-0.2 mm.

[0042] The length of the P-type thermoelectric arm and the N-type thermoelectric arm is in the range of 0.1-10mm, the width is in the range of 0.1-10mm, and the height is in the range of 0.1-10mm.

[0043] The heat-conducting layer is usually fully filled in the solid state between the P-type thermoelectric arm and the N-type thermoelectric arm and the insulating heat-conducting ceramic plate at the heating end of the device, and the filling ratio of the heat-conducting layer in the height direction is 1%-90%.

[0044] The input current of a thermoelectric cooling device is usually a steady-state current or a pulse current. The input steady-state current I is between 0.1 and 50A, and the maximum input pulse current does not exceed 150A.

[0045] The thermoelectric device of the present application is suitable for scenarios where the heat load q is in the range of 0-1000W / cm2 and the heat dissipation coefficient h is in the range of 200-5000W / m2 / K.

[0046] Example 1

[0047] In this embodiment, a new type of filled thermoelectric device is used to efficiently dissipate heat from electronic components. The specific operation steps are as follows:

[0048] First, the cooling end of the thermoelectric device is bonded to the heat-generating part of the electronic component, and the contact surface is coated with thermal conductive silicone grease to reduce the interface thermal resistance and improve the heat conduction efficiency. Then, the heat dissipation end of the thermoelectric device is bonded to the heat dissipation water cooling module or air cooling module, and the contact surface is also coated with thermal conductive silicone grease to further reduce the interface thermal resistance. Next, the positive and negative wires of the thermoelectric device are connected to the control power supply, and the size of the input current is controlled by the computer.

[0049] In actual use, the input current is adjusted according to the heat source. When the electronic component generates instantaneous high heat density, a large pulse current is passed to obtain an instantaneous large cooling capacity and quickly reduce the component temperature; when the heat load is stable, the input matching optimal current is input to obtain a greater cooling effect than conventional thermoelectric devices.

[0050] In this embodiment, the P-type thermoelectric arm adopts BST (Bi1.5Sb0.5Te3) material, and the N-type thermoelectric arm adopts BTS (Bi2Te2.7Se0.3) material. The thermal conductive layer material is alumina thermal conductive ceramic, and the filling ratio is 50%. The relevant parameters of the material refer to the COMSOL Multiphysics 6.0 material library. The external thermal conditions in the experiment are set as follows: the heat load density of the cooling end of the thermoelectric device is 20000W / m 2The heat dissipation coefficient of the heat dissipation end is 2000W / (m 2 ·K), and the ambient temperature is 297.15K.

[0051] like Figure 2 As shown in the figure, under the above thermal environment, when the input steady-state current is 3A, the filled thermoelectric device can reduce the average temperature of the cooling end to 295.51K, while the conventional device using the same thermoelectric material can only reduce the average temperature of the cooling end to 298.52K. Compared with the conventional device, the average temperature of the cooling end of the filled thermoelectric device is reduced by 5K.

[0052] When the input reference current is 3A, the pulse amplitude is 3A, and the pulse width is a rectangular pulse current of 0.3s, the lowest average temperature of the cold end of the filled thermoelectric device during the pulse cooling process is 290.86K, while the lowest average temperature of the cold end of the conventional device under the same conditions is 294.14K. In comparison, the pulse supercooling effect of the filled thermoelectric device is improved by 3.28K.

[0053] Example 2

[0054] Under different thermodynamic working conditions (such as the heat load at the cooling end of the thermoelectric device and the heat dissipation coefficient at the heat dissipation end of the thermoelectric device), the optimal ratio of the filling layer will be different. In this example, the temperature of the cold end of the thermoelectric device is monitored by changing the thermal boundary conditions and the filling layer ratio of the thermoelectric device to find the optimal filling layer ratio that makes the cold end temperature reach the lowest value.

[0055] In this embodiment, the P-type thermoelectric arm uses BST (Bi1.5Sb0.5Te3) material, the N-type thermoelectric arm uses BTS (Bi2Te2.7Se0.3) material, and the thermal conductive layer material is alumina thermal conductive ceramic, with a filling ratio of 50%. The relevant parameters of the materials refer to the COMSOL Multiphysics 6.0 material library. The external thermal conditions of the experiment are set as follows: the heat load density of the cooling end of the thermoelectric device is 0, 10000, 20000, 30000 W / m 2 The heat dissipation coefficient of the heat dissipation end is 1000, 2000, 3000, 4000, 5000W / (m 2 ·K), the input current is 3A, and the ambient temperature is 297.15K.

[0056] The heat load density at the cooling end of the thermoelectric device is 20000W / m 2 、The heat dissipation coefficient of the heat dissipation end is 2000W / (m 2 ·K) and the input current is 3A, the average temperature change trend of the cooling end and the heat dissipation end of the thermoelectric device is obtained, such as Figure 3As shown in the figure: With the increase of the filling layer ratio, the temperature of the cooling end first decreases and then increases, while the cooling capacity of the cold end increases and then decreases. When the filling layer ratio is 38%, the temperature of the cooling end reaches the lowest value, and the cooling effect of the thermoelectric device is the best at this time.

[0057] Under different cooling end heat loads, the trend of the average cooling end temperature changing with the filling layer ratio is as follows: Figure 4 As shown in the figure, with other conditions unchanged, as the heat load q of the cooling end increases, the optimal filling layer ratio of the thermoelectric device also increases accordingly. When the heat load of the cold end is 0, the optimal filling layer ratio is about 5%; when the heat load of the cold end increases to 30000W / m 2 When , the optimal filling layer ratio increases to 53%.

[0058] Under different heat dissipation coefficients, the trend of the average temperature of the cooling end changing with the filling layer ratio is as follows: Figure 5 As shown in the figure, when other conditions remain unchanged, as the heat dissipation coefficient h of the heat dissipation end increases, the optimal filling layer ratio of the thermoelectric device also increases. When the heat dissipation coefficient of the heat dissipation end is 1000W / (m 2 ·K), the optimal filling layer ratio is about 22%; and when the heat dissipation coefficient increases to 5000W / (m 2 K), the optimum filling layer ratio increases to 45%.

Claims

1. A filled thermoelectric device, comprising a thermoelectric arm, a conductive sheet and a thermally conductive ceramic plate, wherein the thermoelectric arm comprises a P-type thermoelectric arm and an N-type thermoelectric arm, wherein the P-type thermoelectric arm and the N-type thermoelectric arm are evenly spaced between the thermally conductive ceramic plates at the hot end and the cold end, and two adjacent P-type thermoelectric arms and N-type thermoelectric arms are sequentially connected in series through the conductive sheet, and the conductive sheet is connected to an input power supply, characterized in that: It also includes a heat-conducting layer, which is arranged close to the hot end of the thermoelectric device, fills the gap between the thermoelectric arms, and is in close contact with the thermoelectric arms and the hot end heat-conducting ceramic plate.

2. A filled thermoelectric device according to claim 1, characterized in that: A certain distance is set between the heat-conducting layer and the cold end of the thermoelectric device.

3. A filled thermoelectric device according to claim 2, characterized in that: The heat conducting layer is made of alumina ceramics, zirconium oxide ceramics or aluminum nitride ceramics.

4. A filled thermoelectric device according to claim 2 or 3, characterized in that: The P-type thermoelectric arm is made of bismuth telluride-based alloy or half-Heusler alloy or tin selenide material.

5. A filled thermoelectric device according to claim 4, characterized in that: The N-type thermoelectric arm is made of bismuth telluride-based alloy or half-Heusler alloy or YbAl3 material.

6. A filled thermoelectric device according to claim 5, characterized in that: The conductive sheet is made of copper or silver or an alloy thereof, and is arranged to be attached to the inner side surface of the thermally conductive ceramic plate.

7. A filled thermoelectric device according to claim 2 or 6, characterized in that: The filling ratio of the heat-conducting layer in the height direction of the thermoelectric device is 1%-90%.

8. A filled thermoelectric device according to claim 3 or 6, characterized in that: The heat-conducting ceramic plate has a length of 0.1-80 mm, a width of 0.1-80 mm, and a thickness of 0.1-3 mm.

9. The filled thermoelectric device according to claim 6, characterized in that: The thermoelectric arm has a length of 0.1-10 mm, a width of 0.1-10 mm, and a height of 0.1-10 mm.

10. The filled thermoelectric device according to claim 6, characterized in that: The thickness of the conductive sheet is 0.01-0.2 mm.

Images