Space station thermal protection structure and system using synthetic jet and control method

Abstract

The invention discloses a space station thermal protection structure and system using synthetic jet flow and a control method.The thermal protection structure comprises a synthetic jet flow unit, the synthetic jet flow unit comprises a prismatic column body with the hollow interior, and a piezoelectric vibration piece is installed in the prismatic column body; the piezoelectric vibration piece divides the interior of the prismatic column body into two oscillation cavities, one side of each oscillation cavity is a contraction end, the other side of each oscillation cavity is an expansion end, a cavity body between the contraction ends and the expansion ends is gradually expanded, a nozzle is formed in the wall face, corresponding to the expansion ends of the oscillation cavities, of the prismatic column body, and the edge of the nozzle is in a sawtooth shape. According to the thermal protection structure, the gas compression efficiency is effectively improved through the oscillation cavity in a special shape and the nozzle, the flow turbulence energy of jet flow and the mixed flow intensity are increased, the heat transfer performance of the synthetic jet flow unit is improved, the thermal protection system can achieve accurate temperature regulation and control, and the thermal protection structure is suitable for thermal protection of various photoelectric devices.

Description

Technical Field

[0001] The present invention relates to the field of advanced space thermal management technologies, and particularly to a space thermal protection structure, system and control method using synthetic jets. Background Art

[0002] With the rapid development of space technology, the on-orbit operation time of space stations and their carried space optoelectronic devices (such as optical cameras, laser communication devices, etc.) is getting longer and longer, and the faced thermal environment is becoming more complex and extreme. When a space station operates in orbit, it is affected by multiple heat sources such as solar radiation, Earth infrared radiation, and heat generated by internal equipment of the space station, resulting in uneven surface temperature distribution of space optoelectronic devices, and even local overheating or overcooling. These temperature fluctuations will seriously affect the performance, lifespan and reliability of space optoelectronic devices, and even lead to equipment failure.

[0003] Synthetic jet technology is an active flow control technology based on the principle of fluid dynamics. By periodically vibrating a diaphragm, pressure changes are generated in the cavity, thereby forming a high-speed jet. This technology has significant advantages such as a compact structure, no moving parts, fast response speed, and low energy consumption, and shows great potential in the field of thermal management. Its working principle is that a driving element (such as a piezoelectric ceramic or an electromagnetic coil) causes the diaphragm to generate high-frequency vibration, and the gas in the cavity is periodically compressed and expanded, thereby forming a high-speed jet at the outlet. This jet can effectively enhance local convective heat transfer and is suitable for the precise temperature control requirements in complex thermal environments such as space stations.

[0004] In recent years, active thermal control technology has gradually become a research hotspot. Among them, synthetic jet technology is considered a potential space thermal control solution due to its advantages such as a simple structure, fast response speed, and low energy consumption. However, the application of existing synthetic jet technology in space station thermal protection still faces the following challenges: (1) Limited heat transfer efficiency: The gas compression efficiency of traditional synthetic jet generators is low, resulting in insufficient jet intensity and heat transfer performance; (2) High energy consumption: Under high-frequency vibration, the energy consumption of traditional driving elements is large, making it difficult to meet the energy-saving requirements for long-term on-orbit operation of space stations; (3) Insufficient control accuracy: Existing technologies lack intelligent control algorithms and cannot dynamically adjust jet parameters according to the real-time thermal environment, making it difficult to achieve precise thermal protection. Summary of the Invention

[0005] Object of the Invention: Aiming at the above disadvantages, the present invention provides a space thermal protection structure, system and control method using synthetic jets.

[0006] Technical solution: To solve the above problems, the present invention adopts a space station thermal protection structure using synthetic jets, including a synthetic jet unit. The synthetic jet unit includes a rhombic column main body with a hollow interior. A piezoelectric vibrator is installed inside the rhombic column main body. The piezoelectric vibrator divides the interior of the rhombic column main body into two oscillation chambers. One side of the oscillation chamber is a contraction end, and the other side is an expansion end. The cavity between the contraction end and the expansion end gradually expands. A nozzle is opened on the wall surface of the rhombic column main body corresponding to the expansion end of the oscillation chamber, and the edge of the nozzle is serrated.

[0007] Further, the rhombic column main body is a symmetric hexagonal prism, the piezoelectric vibrator is installed on the symmetry plane of the rhombic column main body, and the two oscillation chambers have the same shape.

[0008] Further, a flexible seal is provided at the connection between the piezoelectric vibrator and the rhombic column main body.

[0009] Further, the nozzle is rectangular, and the long side edge of the rectangle is serrated.

[0010] The present invention also provides a thermal protection system including the above thermal protection structure, further including a temperature sensor and a control module. The temperature sensor is used to monitor the temperature of the electronic device to be cooled, and the control module is used to control the vibration frequency and amplitude of the piezoelectric vibrator according to the data of the temperature sensor.

[0011] Further, the control module includes a driving unit, a data processing unit, and a predictive control algorithm unit. The data processing unit is used to receive and process the temperature data of the temperature sensor and the preset thermal model parameters. The predictive control algorithm unit is used to output the optimal jet intensity and frequency of the synthetic jet unit according to the data output by the data processing unit and the preset thermal environment model. The driving unit is used to adjust the vibration frequency and amplitude of the piezoelectric vibrator according to the optimal jet parameters.

[0012] Further, the data processing unit fuzzifies the temperature into three classifications: "low temperature", "medium temperature", and "high temperature", and the three classifications are divided according to the preset temperature thresholds.

[0013] Further, the thermal environment model predicts the thermal load distribution of the electronic device in a preset future period according to the temperature classification and the preset thermal model parameters. The thermal model parameters include solar radiation intensity, surface heat conduction characteristics of the electronic device to be cooled, and historical temperature data.

[0014] Further, the vibration frequency range of the piezoelectric vibrator is 1 kHz to 100 kHz, and the jet velocity range is 10 m / s to 100 m / s.

[0015] The present invention also provides a control method for the thermal protection system, including the following steps:

[0016] Step 1: Install different numbers of synthetic jet units and temperature sensors according to the heat generation conditions at different positions of the electronic device;

[0017] Step 2: Monitor the device temperature in real time through the temperature sensor and transmit the temperature data to the control module;

[0018] Step 3: The control module adjusts the vibration frequency and amplitude of the piezoelectric vibrator in real time according to the data of the temperature sensor.

[0019] Beneficial effects: Compared with the prior art, the remarkable advantages of the present invention are as follows: (1) The thermal protection structure effectively improves the gas compression efficiency, increases the flow turbulent kinetic energy and the mixed flow intensity of the jet, and improves the heat transfer performance of the synthetic jet unit through the contraction-expansion oscillation cavity and the zigzag nozzle structure; (2) The thermal protection system and the control method predict the future heat load distribution based on the thermal environment model and the real-time temperature data, realize the dynamic optimization of the jet parameters, and improve the accuracy and adaptability of the thermal protection; (3) By dynamically adjusting the synthetic jet unit, the surface temperature fluctuation of the space optoelectronic device is controlled within ±5°C, the energy consumption is reduced by about 30% compared with the traditional thermal control method, the equipment life is extended by about 20%, and the economy and stability of the on-orbit operation are improved. Description of the Drawings

[0020] Figure 1 It is a schematic diagram of the overall structure of the synthetic jet unit of the present invention;

[0021] Figure 2 It is a top view of the synthetic jet unit of the present invention;

[0022] Figure 3 It is a schematic diagram of the working principle of the synthetic jet unit of the present invention;

[0023] Figure 4 It is a schematic diagram of the working principle of the temperature sensor module and the control module of the present invention;

[0024] Figure 5 It is a schematic diagram of the working process of the thermal protection system of the present invention;

[0025] Figure 6 It is a schematic diagram of the overall structure of the thermal protection system of the present invention. Detailed Embodiments

[0026] Such as Figures 1 to 3As shown in the figure, a space station thermal protection structure using synthetic jets in this embodiment includes a synthetic jet unit 1. The synthetic jet unit 1 includes a rhombic column main body 11 with a hollow interior, and a piezoelectric vibrator 12 is installed inside the rhombic column main body 11. In this embodiment, the rhombic column main body 11 is a symmetric hexagonal prism, and the piezoelectric vibrator 12 is installed on the symmetry plane of the rhombic column main body 11. A flexible seal is provided at the connection between the piezoelectric vibrator 12 and the rhombic column main body 11 to ensure the airtightness of the oscillation cavity.

[0027] The piezoelectric vibrator 12 divides the interior of the rhombic column main body 11 into two oscillation cavities 13 with the same shape. One side of the oscillation cavity 13 is the contraction end, and the other side is the expansion end. The cavity between the contraction end and the expansion end gradually expands. A nozzle 14 is opened on the wall surface of the rhombic column main body 11 corresponding to the expansion end of the oscillation cavity 13. The nozzle 14 is rectangular, and the long side edge of the rectangle is serrated.

[0028] The synthetic jet unit 1 drives the compression and expansion of the gas in the oscillation cavity 13 through the high-frequency vibration of the piezoelectric vibrator 12, so that a high-intensity synthetic jet is generated at the nozzle 14. The expanding oscillation cavity of the present invention accelerates the air flow through the change of cross-sectional area, forming an effect similar to "inertial supercharging", enhancing the gas compression efficiency; and it causes an increase in the velocity gradient in the flow channel, accelerating the instability of the shear layer, inducing the generation of vortex rings, the rupture of the vortex rings during the transport process, releasing energy and converting it into turbulent kinetic energy, increasing the turbulent kinetic energy of the jet flow, thereby improving the heat transfer performance of the jet. The edge of the nozzle is serrated, and the sharp corners of the serrated nozzle edge form streamwise vortices, which destroy the axisymmetry of the jet, increase the transverse momentum exchange. The non-uniform geometric shape of the serrated edge introduces initial disturbances at the nozzle exit, accelerating the evolution of the instability of the jet shear layer. The disturbances are amplified during the development of the jet, resulting in an earlier transition to turbulence, enhancing the turbulent mixing intensity, further optimizing the flow characteristics of the jet, and improving the heat transfer performance.

[0029] The present invention also provides a thermal protection system, including the above-mentioned synthetic jet unit 1, a temperature sensor 2, and a control module 3. The temperature sensor 2 is used to monitor the temperature of the electronic device to be cooled, and the control module 3 is used to control the vibration frequency and amplitude of the piezoelectric vibrator 12 according to the data of the temperature sensor 2.

[0030] Specifically, as Figure 4 and Figure 5 shown, the control module 3 includes a driving unit 31, a data processing unit 32, and a predictive control algorithm unit 33. The data processing unit 32 is used to receive and process the temperature data of the temperature sensor 2 and the preset thermal model parameters. The data processing unit 32 fuzzifies the temperature into three classifications: "low temperature", "medium temperature", and "high temperature". The three classifications are divided according to the preset temperature thresholds. The thermal model parameters include solar radiation intensity, surface heat conduction characteristics of the electronic device to be cooled, and historical temperature data.

[0031] The predictive control algorithm unit 33 is configured to output the optimal jet intensity and frequency of the synthetic jet unit 1 according to the data output by the data processing unit 32 and a preset thermal environment model. Specifically, the thermal environment model predicts the thermal load distribution of the electronic device over a preset period of time in the future based on temperature classification and preset thermal model parameters, and calculates the optimal jet intensity and frequency according to the future thermal load distribution, so that the electronic device can maintain a stable temperature over a period of time in the future. The thermal environment model is trained and optimized through numerical simulation and machine learning methods to improve its prediction accuracy.

[0032] The driving unit 31 is configured to adjust the vibration frequency and amplitude of the piezoelectric vibrator 12 according to the optimal jet parameters. During the entire adjustment process, the vibration frequency range of the piezoelectric vibrator 12 is from 1 kHz to 100 kHz, and the jet velocity range is from 10 m / s to 100 m / s.

[0033] The present invention also provides a control method for the above thermal protection system, including the following steps:

[0034] Step 1: Install different numbers of synthetic jet units 1 and temperature sensors 2 according to the heat generation conditions at different positions of the optoelectronic device 5. In high-heat areas, such as processors, power amplifiers, etc., the synthetic jet units are arranged in a dense array with a unit spacing of 5 - 12 mm; in medium-heat areas, such as memories, sensors, etc., the synthetic jet units are arranged in a medium density with a unit spacing of 12 - 20 mm; in low-heat areas, such as the housing, support structure, etc., the synthetic jet units are arranged in a sparse array with a unit spacing of more than 20 mm. A temperature sensor 2 is provided near each synthetic jet unit 1 for temperature monitoring, as Figure 6 shown.

[0035] Step 2: Real-time monitor the device temperature through the temperature sensor 2 and transmit the temperature data to the control module 3.

[0036] Step 3: The control module 3 adjusts the vibration frequency and amplitude of the piezoelectric vibrator 12 in real time according to the data of the temperature sensor 2. Specifically, the data processing unit 32 receives the temperature data of the temperature sensor 2, classifies the temperature data according to a preset temperature threshold, and determines whether it belongs to "low temperature", "medium temperature" or "high temperature". At the same time, the data processing unit 32 receives the preset thermal environment model parameters such as the current solar radiation intensity, the surface heat conduction characteristics of the optoelectronic device to be cooled, and the historical temperature data. The data processing unit 32 transmits the processed temperature data and thermal environment model parameters to the predictive control algorithm unit 33. The thermal environment model predicts the thermal load distribution of the electronic device in a preset future period according to the temperature classification and the preset thermal model parameters, calculates the optimal jet intensity and frequency of the synthetic jet unit 1, and then the driving unit 31 adjusts the vibration frequency and amplitude of the piezoelectric vibrator 12 according to the optimal jet parameters, so that the synthetic jet unit 1 reaches the preset heat transfer efficiency and ensures the stability of the temperature of the optoelectronic device.

[0037] The thermal protection structure of the present invention effectively improves the gas compression efficiency, increases the flow turbulent kinetic energy and the mixed flow intensity of the jet through the contraction-expansion oscillating cavity and the serrated nozzle structure, and improves the heat transfer performance of the synthetic jet unit. The thermal protection system and control method of the present invention predict the future thermal load distribution based on the thermal environment model and real-time temperature data, realize the dynamic optimization of the jet parameters, and improve the accuracy and adaptability of thermal protection. By dynamically adjusting the synthetic jet unit, the surface temperature fluctuation of the space optoelectronic device is controlled within ±5°C, the energy consumption is reduced by about 30% compared with the traditional thermal control method, the equipment life is extended by about 20%, and the economy and stability of on-orbit operation are improved.

Claims

1. A space station thermal protection structure using synthetic jets, characterized in that: The synthetic jet unit (1) comprises a prismatic column main body (11) with a hollow interior, a piezoelectric vibrating plate (12) installed in the prismatic column main body (11), the piezoelectric vibrating plate (12) dividing the interior of the prismatic column main body (11) into two oscillation cavities (13), one side of the oscillation cavity (13) being a contraction end and the other side being an expansion end, the cavity between the contraction end and the expansion end gradually expanding, a nozzle (14) being opened on the wall surface of the prismatic column main body (11) corresponding to the expansion end of the oscillation cavity (13), the edge of the nozzle (14) being serrated.

2. The space station thermal protection structure using synthetic jets as claimed in claim 1, characterized in that: The prismatic column main body (11) is a symmetrical hexagonal column, the piezoelectric vibrating piece (12) is mounted on a symmetrical surface of the prismatic column main body (11), and the two oscillation cavities (13) are of the same shape.

3. The space station thermal protection structure using synthetic jets as claimed in claim 1, characterized in that: A flexible sealing member is provided at the connection between the piezoelectric vibrating piece (12) and the prismatic column body (11).

4. The space station thermal protection structure using synthetic jets as claimed in claim 1, characterized in that: The nozzle (14) is in the shape of a rectangle, and the long side edge of the rectangle is in a sawtooth shape.

5. A thermal protection system comprising the thermal protection structure according to any one of claims 1 to 4, characterized in that: It also comprises a temperature sensor (2) and a control module (3), wherein the temperature sensor (2) is used to monitor the temperature of the electronic device to be cooled, and the control module (3) is used to control the vibration frequency and amplitude of the piezoelectric vibrating piece (12) according to data from the temperature sensor (2).

6. The thermal protection system according to claim 5, characterized in that The control module (3) comprises a driving unit (31), a data processing unit (32), and a predictive control algorithm unit (33); the data processing unit (32) is used to receive and process temperature data from a temperature sensor (2) and preset thermal model parameters; the predictive control algorithm unit (33) is used to output an optimal jet intensity and frequency of the synthetic jet unit (1) based on data output by the data processing unit (32) and a preset thermal environment model; and the driving unit (31) is used to adjust the vibration frequency and amplitude of the piezoelectric vibrator (12) based on the optimal jet parameters.

7. The thermal protection system according to claim 6, characterized in that The data processing unit (32) fuzzifies the temperature into three categories: "low temperature", "medium temperature" and "high temperature", wherein the three categories are divided according to preset temperature thresholds.

8. The thermal protection system according to claim 7, characterized in that The thermal environment model predicts the heat load distribution of the electronic device for a preset period of time in the future according to the temperature classification and preset thermal model parameters, wherein the thermal model parameters include solar radiation intensity, heat conduction characteristics of the surface of the electronic device to be cooled, and historical temperature data.

9. The thermal protection system according to claim 5, characterized in that The vibration frequency range of the piezoelectric vibrating piece (12) is 1 kHz to 100 kHz, and the jet velocity range is 10 m / s to 100 m / s.

10. A control method for a thermal protection system according to any one of claims 5 to 9, characterized in that: The following steps are involved: Step 1: installing different numbers of synthetic jet units (1) and temperature sensors (2) according to the heating conditions at different locations of the electronic device; Step 2: monitor the device temperature in real time through the temperature sensor (2) and transmit the temperature data to the control module (3); Step 3: The control module (3) adjusts the vibration frequency and amplitude of the piezoelectric vibrating piece (12) in real time according to the data from the temperature sensor (2).

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