Precise temperature control device based on bionic structure and multi-layer temperature control

Abstract

The invention discloses a precise temperature control device based on a bionic structure and multi-layer temperature control, and relates to a temperature controller technology. In order to solve the problems of low heat conduction efficiency, weak anti-fluctuation capability and insufficient precision in the prior art, the device comprises a nested three-layer constant temperature structure (10) comprising an inner layer (11), a middle layer (12) and an outer layer (13), and inert gas is filled between the layers to realize step-by-step temperature control; the bionic fractal heat conduction structure (20) is arranged between the inner layer and the middle layer; the electric heating sheet (30) and the inverse Peltier (31) are connected to the tail end of the heat conduction structure, connected with the middle layer and used for actively adjusting temperature; and the sensor matrix (40) is distributed on the inner layer and is used for accurate monitoring. By combining a multi-layer structure, efficient bionic heat conduction and intelligent adjustment, the temperature control precision, efficiency and response speed are remarkably improved, and the device is suitable for precise instruments such as satellite atomic clocks.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature control, and particularly to a device for high-precision temperature control, specifically a temperature precise control device based on a bionic structure and multi-layer temperature control. Background Art

[0002] In many fields such as aerospace, precision instruments, and biomedicine, it is crucial to precisely and stably control the temperature of specific components or spaces. For example, in a satellite navigation system, the atomic clock, as a core component, provides a high-precision time reference, and its frequency stability and accuracy are extremely sensitive to temperature fluctuations. Traditional temperature control devices, such as using simple homogeneous material patches or single metal columns for heat conduction, often have low heat conduction efficiency and poor temperature distribution uniformity. Using a single cavity temperature control structure, its ability to resist ambient temperature fluctuations inside is limited. Although there are studies attempting to use random branch configurations to improve heat conduction, they usually face problems such as complex processing and high costs.

[0003] Space application environments such as satellites pose higher requirements for temperature control systems. Traditional satellite thermal control designs, including passive temperature control (such as being coated with multi-layer thermal insulation materials) and active temperature control (such as adjusting the power of heating sheets), often have problems such as poor heat distribution uniformity, insufficient cooling capacity, and difficulty in eliminating local hot spots when facing complex thermal environments and high-precision requirements, which limit the full performance of on-board precision payloads (such as atomic clocks).

[0004] Therefore, there is an urgent need for a temperature control device that can achieve high precision, high stability, high efficiency, and uniform temperature distribution to meet the growing demand for precision temperature control. Summary of the Invention

[0005] The main purpose of the present invention is to overcome the deficiencies of the prior art and provide a temperature precise control device based on a bionic structure and multi-layer temperature control, which has the advantages of high temperature control precision, excellent heat conduction efficiency, good temperature uniformity, fast response speed, etc.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows: A temperature precise control device based on a bionic structure and multi-layer temperature control, the core feature of which is the combination of a multi-layer nested constant temperature structure, an efficient bionic fractal heat conduction structure, an active heating / cooling element, and a precise temperature sensing feedback system.

[0007] This device includes: Three - layer constant - temperature structure (10): From the inside out, it consists of an inner layer (11), a middle layer (12), and an outer layer (13). These three layers are nested with each other to form physical isolation and buffering. The inner layer (11) directly surrounds or houses the components to be temperature - controlled (such as atomic clocks) that require precise temperature control. Preferably, the spaces between the layers and the interior of the inner layer (11) can be sealed and filled with inert gases (such as argon, nitrogen, etc.). The purpose is to use the low thermal conductivity of inert gases to reduce convective and conductive heat transfer between the layers, further enhancing the thermal insulation performance and the stability of the cavity environment. This three - layer structure realizes step - by - step temperature control in function: The outer layer (13) is responsible for resisting the main temperature fluctuations in the external environment and achieving rough temperature control (coarse temperature control zone); the middle layer (12) conducts more refined temperature regulation (fine temperature control zone); and the inner layer (11) realizes the final precise temperature control (precision temperature control zone) in an extremely stable thermal environment.

[0008] Bionic heat - conducting structure (20): It is cleverly set between the inner layer (11) and the middle layer (12) and serves as an efficient heat transfer channel between them. The design inspiration of this structure comes from the efficient transport networks in nature, such as the vein structure of plants, and is designed using the principle of fractal geometry. Specifically, it can be a multi - level branching structure, such as a four - level branching structure, including a main channel (21), a first - level channel (22), a second - level channel (23), a third - level channel (24), and a fourth - level channel (25). The channels branch off from the main trunk step by step until the end. The branching direction is designed to be perpendicular to the inter - layer structure of the inner and middle layers to ensure that heat can be effectively transferred from one plane to another. More importantly, the size (especially the cross - sectional area) of the channels is optimized according to the improved Murray's law. By analogizing the heat conduction problem to the fluid flow problem (as shown in Table 1), an optimization criterion applicable to the heat conduction scenario is derived: When the ratio of the cross - sectional areas of adjacent - level channels (such as the mother channel and the child channel) reaches a specific value (for example, the theoretically derived 1.587:1), the thermal resistance of the entire heat conduction network is minimized, thereby achieving the highest heat conduction efficiency. This bionic optimization design enables heat to be transferred quickly and with low loss between the heating element / cooling element and the inner layer.

[0009] Table 1 Correspondence table of basic physical quantity analogies

[0010] Active temperature control elements: Include at least one electric heating sheet (30) and at least one Peltier cooler (31) (also known as a thermoelectric cooler TEC). These elements are respectively connected to different end channels (such as the four-stage channel 25) of the bionic heat conduction structure (20), and they all establish good thermal contact with the middle layer (12). When the electric heating sheet (30) is energized, Joule heat is generated for heating the inner layer. When the Peltier cooler (31) is energized and working, it can actively pump heat from its cold end (the side close to the inner layer or the bionic structure) to its hot end (the side close to the middle layer or the outside), thereby realizing active cooling or heat dissipation of the inner layer. By synergistically controlling the heating sheet and the Peltier cooler, bidirectional precise regulation of the inner layer temperature can be achieved.

[0011] Sensor matrix (40): Composed of multiple high-precision temperature sensors, these sensors are distributed at key positions on the inner layer (11) to form a sensing network. Their function is to monitor the temperature distribution on the surface of the inner layer (11) in real time and accurately, and feedback these temperature data to the control system.

[0012] In addition, in order to further improve the overall performance, the outer surface of the outer layer (13) can be coated with multiple layers of multi-layer insulation (MLI) to minimize the radiative heat exchange with the external environment. At the same time, high-power electric heaters and corresponding temperature sensors can also be pasted on the outer layer (13) for coarse temperature control adjustment of the outer layer, and their heat dissipation is usually connected to the overall thermal management system of platforms such as satellites.

[0013] The beneficial effects that the present invention can bring are as follows.

[0014] The control system receives real-time temperature data from the sensor matrix (40). When it is monitored that the temperature of the inner layer is lower than the set value, the control system commands the electric heating sheet (30) to work, and the heat is quickly transferred to the inner layer (11) through the efficient bionic heat conduction structure (20). When it is monitored that the temperature of the inner layer is higher than the set value, the control system commands the Peltier cooler (31) to work, and actively pumps out the excess heat of the inner layer (11) through the bionic heat conduction structure (20). The three-layer constant temperature structure provides a strong thermal buffering ability and gradually attenuates external interference. The bionic heat conduction structure ensures the efficiency and uniformity of heat transfer. The sensor matrix provides precise feedback. This design combining multiple aspects enables the device to achieve: 1) Ultra-high-precision temperature control: Through the cooperation of the precision layer, the sensing matrix and the active adjustment elements, temperature stability control with an accuracy of mK level or even higher can be achieved.

[0015] 2) Efficient heat transfer: The bionic fractal structure significantly reduces the thermal resistance. Whether it is heating or cooling, the heat transfer speed is fast and the efficiency is high.

[0016] 3) Excellent temperature uniformity: The optimized heat conduction path helps to form a uniform temperature field in the inner layer.

[0017] 4) Quick response ability: The combination of active heating and refrigeration enables a rapid response to temperature changes.

[0018] 5) Strong anti-interference ability: The multi-layer structure effectively isolates external environmental fluctuations.

[0019] Examples of beneficial effects applications: Apply this device to the temperature control scenario of a satellite atomic clock. The inner layer (11) tightly wraps the atomic clock body, and the sensor matrix (40) monitors the temperature of key parts of the atomic clock. The control system adjusts the electric heating sheet (30) and the inverse Peltier (31) according to the feedback, and precisely maintains the temperature of the atomic clock at the optimal working point (for example, 40.000 °C), with a very small temperature fluctuation range (such as on the order of ±0.01 °C), far better than the traditional method (such as Figure 8 、 Figure 9 shown large deviations and gradients). This ensures the long-term frequency stability and accuracy of the atomic clock, and thus improves the performance of the entire satellite navigation system. Brief Description of the Drawings

[0020] Figure 1 It is a schematic diagram of the overall structure of the device provided by the embodiment of the present invention.

[0021] Figure 2 It is a partial enlarged and relative position schematic diagram of the bionic heat conduction structure (20), the electric heating sheet (30), the inverse Peltier (31) and the sensor matrix (40).

[0022] Figure 3 It is a schematic diagram of an exemplary configuration of the bionic heat conduction structure (20).

[0023] Figure 4 It is a vertical view of the bionic heat conduction structure (20), showing its connection relationship with the electric heating sheet (30) and the inverse Peltier (31).

[0024] Figure 5 It is a schematic diagram of the thermal simulation result of the bionic heat conduction structure, showing the heat distribution.

[0025] Figure 6 It is the temperature gradient curve of the device of the present invention under specific working conditions (target 40 °C, environment 35 °C, working for 180S).

[0026] Figure 7 It is the temperature gradient curve of the device of the present invention after reaching a stable state under specific working conditions.

[0027] Figure 8 It is the temperature gradient curve after working for 180S under the same working conditions by using the prior art method.

[0028] Figure 9 It is the temperature gradient curve after reaching the steady state under the same working conditions by using the existing technology method.

[0029] Markings in the figure: 10 - three - layer constant - temperature structure, 11 - inner layer, 12 - middle layer, 13 - outer layer, 20 - bionic heat - conducting structure, 21 - main channel, 22 - primary channel, 23 - secondary channel, 24 - tertiary channel, 25 - quaternary channel, 30 - electric heating sheet, 31 - reverse Peltier, 40 - sensor matrix. Specific embodiments

[0030] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are exemplary only for explaining the present invention and are not used to limit the scope of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0031] Embodiment 1 Referring to Figures 1 to 5 , this embodiment provides a temperature precise control device for satellite atomic clock temperature control based on bionic structure and multi - layer temperature control.

[0032] The device includes a three - layer constant - temperature structure (10), a bionic heat - conducting structure (20), an electric heating sheet (30), a reverse Peltier (31) and a sensor matrix (40).

[0033] The three - layer constant - temperature structure (10) is composed of an inner layer (11), a middle layer (12) and an outer layer (13) nested in sequence. The material can be selected as a metal or alloy with a low coefficient of thermal expansion, such as Invar or titanium alloy. The inner layer (11) is designed as a cylindrical shape and tightly wraps the cylindrical atomic clock body. The gaps between the inner layer (11), the middle layer (12) and the outer layer (13) and the space around the atomic clock inside the inner layer (11) are sealed and filled with an inert gas with a low thermal conductivity, such as argon (Ar), and the pressure can be set slightly higher than the external environmental pressure to prevent leakage. The outer layer (13) constitutes the coarse temperature control area, the middle layer (12) constitutes the fine temperature control area, and the inner layer (11) constitutes the precision temperature control area.

[0034] The bionic heat-conducting structure (20) is arranged between the inner layer (11) and the middle layer (12), and is made of a material with a high thermal conductivity coefficient, such as oxygen-free copper or aluminum alloy. The structure is designed to imitate a four-level fractal branching structure of plant veins, including a main channel (21), a primary channel (22), a secondary channel (23), a tertiary channel (24) and a quaternary channel (25). The channel starts from the trunk (main channel 21) and branches step by step at a specific angle and ratio until the fourth channel (25) at the end. The branching direction is perpendicular to the interlayer structure of the inner and middle layers. According to the improved Murray law optimization design, the cross-sectional area ratio between adjacent channels (such as the main channel and the primary channel, the primary channel and the secondary channel, etc.) is set to 1.587:1 to minimize the overall thermal resistance.

[0035] A plurality of electric heating sheets (30) (e.g., thin film heaters) and a plurality of inverse Peltiers (31) (TEC modules) are evenly or distributed as needed on the inner surface of the middle layer (12), and are well connected to the ends of the four-level channels (25) of the bionic thermal conductive structure (20) via thermal conductive interface materials.

[0036] The high-precision sensor matrix (40) is composed of a plurality of surface-mount platinum resistance temperature sensors (RTDs) and is attached to the outer surface of the inner layer (11) to accurately monitor the temperature of different areas of the inner layer.

[0037] The outer layer (13) is wrapped with multi-layer insulation material (MLI) and a high-power coarse control heating plate and temperature sensor are attached to the satellite and connected to the satellite's integrated thermal control system.

[0038] During operation, the central controller accurately adjusts the heating power of the electric heater (30) and the cooling power (or the direction and magnitude of the working current) of the inverse Peltier (31) according to the feedback from the sensor matrix (40) through PID (proportional-integral-differential) or other advanced control algorithms, so as to stabilize the temperature of the inner layer (11) at a preset value (e.g., 40.000±0.01°C), effectively suppressing the influence of internal and external thermal disturbances on the atomic clock, as shown in the thermal simulation results. Figure 6 and Figure 7 shown.

[0039] The idea of ​​designing a bionic heat-conducting structure is: to imitate the fractal structure of plant leaf veins (the fractal dimension D can be 0.625), and to use the improved Murray law to optimize the heat-conducting metal path (heat flow is analogous to fluid flow, thermal resistance and flow resistance); . is the radius of the main channel (21), For the The radius of the 0th - level channel. This is an existing equation. Through the four - level branched heat - conduction structure, the 4th - level channel at the end finally reaches the plane where the electric heating sheet (30) is pasted and the plane of the inverse Peltier (31) for heat dissipation. The heat is gradually transferred from the electric heating sheet (30) through the 4th - level channel at the end to the main channel (21); for heat dissipation, it is gradually transferred from the main channel (21) to the 4th - level channel at the end.

[0040] For Table 1: The table of the analogical correspondence of basic physical quantities, the relevant equation laws are improved as follows: Fluid (Poiseuille's law): , the fluid flow rate Q l is proportional to the fourth power of the radius and inversely proportional to the resistance. R is the radius of the pipe, p 1 -p 2 is the pressure difference between the two ends of the pipe, η is the dynamic viscosity of the fluid, and l is the length of the pipe. Heat conduction (Fourier's law): , the heat flow rate Q r is proportional to the cross - sectional area A and the thermal conductivity k, and inversely proportional to the length L. Among them, q x is the heat flux density, T 1 is the temperature on the high - temperature side, T 2 is the temperature on the low - temperature side, and the length L is the distance between these two points.

[0041] The derivation process of Murray's law for heat conduction is as follows: 1) The goal is to find the distribution of the cross - sectional area A that minimizes the heat - resistance loss.

[0042] 2) In the ideal state, the bifurcation is a symmetric structure that divides into two, the material texture is uniform (the thermal conductivity k is constant), convection and radiation are ignored, and heat conduction is considered.

[0043] 3) Variable definitions: Mother channel: length L 0 , cross - sectional area A 0 , heat flow Q 0 ; Sub - channel: length L 1 , cross - sectional area A 1 , heat flow Q 1 (the flow rate of each sub - channel is Q 0 / 2).

[0044] Thermal resistance of a single channel: ; Among them, R d is the radius of the single channel, L d is the length of the single channel, A d is the cross - sectional area of the single channel.

[0045] 5) Minimization of the total thermal resistance: If the mother channel is branched into 16 sub-channels at 4 levels, the total thermal resistance needs to satisfy: ; 6) Material constraint: Assume that the total material volume is fixed [analogous to the biological metabolic cost (product weight is fixed)]: ; By solving the constrained optimization problem using the Lagrange multiplier method, we can finally obtain: ; In the improved Murray's law representing the heat conduction plate, the exponent is adjusted from 4 / 3 to 3 / 2. Since the thermal resistance is inversely proportional to the cross-sectional area, and the flow resistance is inversely proportional to the fourth power of the radius.

[0046] It is obtained that when the cross-sectional area of the mother channel is 1.587 times that of the sub-channel, the total thermal resistance is the smallest.

[0047] Example 2 This example is basically the same as Example 1, the differences are as follows: Bionic heat conduction structure (20): Adopt a three-level fractal branch structure, that is, it only includes the main channel (21), the first-level channel (22) and the second-level channel (23). The second-level channel (23) is used as the end channel to connect the electric heating sheet (30) and the inverse Peltier (31). At the same time, the cross-sectional area ratio of adjacent channels is adjusted to 1.6:1 according to different boundary conditions or optimization objectives (considering processing constraints). The material is selected as an aluminum-based composite material with excellent thermal conductivity and light weight.

[0048] Filling gas: The gas filled between layers and inside the inner layer is xenon (Xe). Xenon has a lower thermal conductivity than argon, so it can provide better passive heat insulation effect, which helps to further reduce the heat transfer from the middle layer to the inner layer and improve the stability of the precision temperature control layer, but the cost is relatively high.

[0049] Sensor: The sensor matrix (40) adopts an array of high-sensitivity thermistors, which has higher resolution in a specific temperature range.

[0050] This example is applicable to scenarios with extremely high requirements for heat insulation performance and allowing a slightly simplified complexity of the heat conduction structure.

[0051] Example 3 The main difference between this example and Example 1 is: Interlayer heat insulation method: The gaps between the inner layer (11), the middle layer (12), and the outer layer (13) and the internal space of the inner layer (11) are not filled with inert gas, but heat insulation is achieved by evacuating. Adopt a high-vacuum environment (for example Or lower) can maximize the elimination of gas convection and heat conduction, providing excellent thermal insulation performance. This requires that the sealing structure between layers has extremely high airtightness and may require maintaining the vacuum degree in orbit for a long time.

[0052] Bionic heat conduction structure material: Considering the outgassing characteristics of materials in a vacuum environment, the bionic heat conduction structure (20) selects high thermal conductivity materials with low outgassing rates, such as specially treated oxygen-free copper or heat-conducting graphite materials. The structure can still adopt a four-level branch, and the cross-sectional area ratio is 1.587:1.

[0053] Sensor type: The sensor matrix (40) selects temperature sensors suitable for a vacuum environment, such as thin-film platinum resistors or thermocouples with special encapsulation.

[0054] Application object: The device of this embodiment can be used for temperature control of other precision optical or electronic devices with extremely high requirements for temperature stability and cleanliness, such as the pump source of a high-performance laser or the infrared focal plane array on a space detector.

[0055] This embodiment demonstrates another feasible solution in terms of the adiabatic method and material selection, which is particularly suitable for applications in a vacuum environment or applications with concerns about gas insulation.

[0056] Embodiment 4 This embodiment is a simplification based on Embodiment 1. The main differences are as follows: Active temperature control element: Only an electric heating sheet (30) is installed in the middle layer (12), and the reverse Peltier (31) is not installed. This means that the device mainly relies on heating for active temperature control, while cooling depends on passive heat dissipation to the external environment through the bionic structure (20), the middle layer (12), the outer layer (13), and the satellite platform heat dissipation system.

[0057] Applicable scenarios: This simplified solution is applicable to application scenarios where the working environment temperature is always lower than the target control temperature and the heat dissipation requirement is not high. Or as a low-cost and low-complexity alternative in cases where a certain temperature overshoot and a slower cooling rate are allowed.

[0058] This embodiment shows that according to the actual heat load and environmental conditions, the configuration of the active temperature control element can be flexibly adjusted to meet different performance and cost requirements.

[0059] Through several specific embodiments above, the core concept and technical solutions of the present invention have been elaborated in detail. These embodiments demonstrate the flexibility and scalability of the present invention in terms of structural hierarchy, material selection, heat insulation method, active element configuration, and application object, all of which fall within the scope of protection required by the present invention. For those skilled in the art, various modifications, combinations, or equivalent replacements can be made to these embodiments without departing from the spirit and principle of the present invention, and these should all be regarded as within the scope of protection of the present invention.

Claims

1. A temperature precision control device based on bionic structure and multi-layer temperature control, characterized in that: include: A three-layer constant temperature structure (10), comprising an inner layer (11), a middle layer (12), and an outer layer (13) which are nested in sequence, wherein the inner layer (11) is used to accommodate or fix a component to be temperature-controlled; A bionic heat-conducting structure (20) is arranged between the inner layer (11) and the middle layer (12); the bionic heat-conducting structure (20) is a multi-level branching structure, the branching direction of which is perpendicular to the interlayer structure of the inner layer (11) and the middle layer (12), and has a plurality of terminal channels; At least one electric heating sheet (30) and at least one inverse Peltier (31), respectively connected to different end channels of the bionic heat-conducting structure (20) and in thermal contact with the middle layer (12); A sensor matrix (40) is distributed on the inner layer (11) and is used to monitor the temperature distribution of the inner layer (11).

2. The device according to claim 1, characterized in that The space between the inner layer (11), the middle layer (12) and the outer layer (13) and the interior of the inner layer (11) are sealed and filled with an inert gas.

3. The device according to claim 1 or 2, characterized in that: The outer layer (13) constitutes a coarse temperature control zone, the middle layer (12) constitutes a fine temperature control zone, and the inner layer (11) constitutes a precise temperature control zone, thereby achieving step-by-step temperature control.

4. The device according to claim 1, characterized in that The bionic heat-conducting structure (20) is a fractal structure that imitates the veins of plant leaves.

5. The device according to claim 4, characterized in that The bionic heat-conducting structure (20) is a four-level branch heat-conducting structure, comprising a main channel (21), a primary channel (22), a secondary channel (23), a tertiary channel (24), and a quaternary channel (25) which are connected in sequence, and the quaternary channel (25) is the terminal channel.

6. The device according to claim 5, characterized in that The cross-sectional area ratio between channels at adjacent branch levels in the bionic heat-conducting structure (20) is set to an optimized value that minimizes the total thermal resistance.

7. The device according to claim 6, characterized in that The cross-sectional area ratio between adjacent channels is 1.587:

1.

8. The device according to claim 1, characterized in that The outer surface of the outer layer (13) is covered with multiple layers of reflective heat insulation material, and is attached with an electric heater for rough temperature control and a corresponding temperature sensor.

9. The device according to claim 1, characterized in that The sensor matrix (40) is connected to a control system, and the control system adjusts the heating power of the electric heating plate (30) and the working state of the inverse Peltier (31) according to the temperature information monitored by the sensor matrix (40), so as to maintain a preset temperature of the inner layer (11).

10. The device according to claim 1, characterized in that The component to be temperature controlled is a satellite atomic clock.

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