Aerospace Electronics Product Thermal Vacuum Testing Equipment and Cold-Heat Coordinated Temperature Control Method

Abstract

This invention relates to the field of aerospace environmental simulation testing technology, and particularly to a thermal vacuum testing device for aerospace electronic products and a method for coordinated cold and heat temperature control. The testing device includes a vacuum container, a liquid nitrogen cold plate, an electric heater, a thermally conductive layer, the aerospace electronic product under test, a liquid nitrogen supply system, a pneumatic proportional control valve, a main control temperature sensor, an auxiliary temperature sensor, and a control module. The liquid nitrogen supply system serves as the cold source, and the electric heater serves as the heating source. The method, executed by the control module based on the aforementioned testing device, employs a coordinated cold and heat control approach combining cold path flow regulation and electric heating compensation to achieve closed-loop temperature control. This invention establishes an extremely low thermal resistance heat transfer channel through a stacked integrated structure combining the liquid nitrogen cold plate, electric heater, and thermally conductive layer, effectively improving transmission lag. The coordinated cold and heat temperature control combining cold path flow regulation and electric heater compensation achieves a balance between rapid temperature change and precise steady-state control.

Description

Technical Field

[0001] This invention belongs to the field of aerospace environment simulation test technology, and in particular relates to a thermal vacuum test device for aerospace electronic products and a method for coordinated cold and heat temperature control. Background Technology

[0002] Aerospace electronic products (such as satellite controllers and high-power processing units) must undergo rigorous thermal vacuum testing (vacuum degree ≤ 6.63 × 10⁻⁶) during the ground testing phase. - ³Pa, temperature cycling (-37℃~72℃ or wider) to verify its functional stability under extreme environments. With the development of aerospace technology, the requirements for "temperature change rate" (how fast the temperature drops) and "steady-state accuracy" (temperature fluctuation) in experiments are becoming increasingly stringent, while also requiring reduced experimental energy consumption and cycle time.

[0003] Currently, the mainstream temperature control methods for thermal vacuum testing are mainly divided into "radiation type" and "fluid circulation type", as detailed below: Patent application 1 (Chinese Patent Publication No. CN118637085A, Publication Date: September 13, 2024, Patent Title: "A Method for Thermal Vacuum Testing of Spacecraft") discloses a closed-loop radiation temperature control method for whole-satellite testing. Its core steps include: (1) establishing a whole-satellite thermal analysis model and designing the partitions of the infrared heating cage; (2) establishing a closed-loop feedback system of "heater-cabinet"; (3) determining the target value of the low-temperature operating condition through iterative analysis and applying radiation heating according to the operating condition. This is a typical full-radiation, non-contact system, and the focus is on optimizing the uniformity of radiation heating through software algorithms and model iteration.

[0004] Patent application 2 (Chinese Patent Publication No. CN106275492A, published on January 4, 2017, entitled "Sublimation Water Collection Device for Spacecraft Vacuum Thermal Experiment") belongs to the passive contact condensation scheme. This patent discloses a device for collecting sublimated water vapor. It uses a cold plate assembly and a multi-faceted cold box cover structure, which are fixed with bolts. The low temperature of the cold plate surface is used to passively condense the water vapor. Although a contact (or close-range) cold source of "cold plate" is used, its purpose is unidirectional cooling (condensation). The system design lacks an active heating regulation mechanism and does not have bidirectional precise temperature control capability.

[0005] Patent application 3 (Chinese Patent Publication No. CN116184091A, published on May 30, 2023, entitled "A Mobile Heat Sink Device, Thermal Vacuum Testing Equipment and Testing Method") discloses a movable flexible heat sink with internal cooling fluid channels. During testing, the heat sink is directly attached to the surface of the specimen and connected to an external adjustable temperature cold source. Heat is removed through fluid circulation. This achieves contact heat exchange and solves the problem of low radiation efficiency. However, its temperature control logic relies on "external cold source regulation," that is, controlling the specimen temperature by changing the temperature of the fluid entering the heat sink.

[0006] Patent 4 (Chinese Patent Publication No. CN102768548B, published on September 3, 2014, entitled "Heat Sink Temperature Control System and Method for Thermal Vacuum Testing") discloses a complex fluid temperature control system. It includes a refrigeration system, a refrigerant heater, a circulating pump, and a buffer container. The temperature of the fluid flowing through the heat sink is controlled by heating or cooling the refrigerant (fluid) in a circulating loop outside the heat sink. It employs an "external temperature control + pump circulation" method. Although it has heating and cooling capabilities, the heater and cooler are located outside the heat sink and connected by long pipelines.

[0007] Existing thermal vacuum test temperature control methods have the following disadvantages: 1. Slow cooling rate, high contact thermal resistance in vacuum environment, and low heat exchange efficiency of traditional radiation or ordinary contact methods; 2. Poor temperature control accuracy and slow response, traditional fluid temperature control relies on changing the fluid temperature, and due to pipeline transmission delay, it is easy to generate overshoot and oscillation; 3. High energy consumption, in order to maintain constant temperature, hot and cold fluids are often used to offset each other, resulting in energy waste. Summary of the Invention

[0008] In view of this, the present invention aims to provide a thermal vacuum testing device for aerospace electronic products and a method for coordinated cold and heat temperature control. By using a stacked integrated structure combining a liquid nitrogen cold plate, an electric heater, and a thermally conductive layer, an extremely low thermal resistance heat transfer channel is established, effectively improving transmission lag. Closed-loop temperature control is achieved by combining cold path flow regulation with electric heater compensation, realizing the unity of rapid temperature change and precise steady state.

[0009] To achieve the above objectives, the technical solution created by this invention is implemented as follows: A thermal vacuum testing device for aerospace electronic products includes: a vacuum container, an integrated thermal control assembly, the aerospace electronic product under test, a liquid nitrogen supply system, a pneumatic proportional control valve, a temperature sensor group, and a control module; The integrated thermal control component is housed inside a vacuum container. The integrated thermal control component includes a liquid nitrogen cold plate, an electric heater, and a thermally conductive layer. The electric heater is directly and tightly attached to the bottom surface of the liquid nitrogen cold plate. The aerospace electronic product under test is mounted on the top surface of the liquid nitrogen cold plate. The thermally conductive layer is sandwiched between the aerospace electronic product under test and the liquid nitrogen cold plate. The inlet of the pneumatic proportional control valve is connected to the liquid nitrogen supply system through a pipeline, and the outlet of the pneumatic proportional control valve is connected to the liquid nitrogen cold plate through a pipeline. The flow rate of liquid nitrogen entering the liquid nitrogen cold plate is controlled by adjusting the opening of the pneumatic proportional control valve. The temperature sensor group includes a main control temperature sensor and an auxiliary temperature sensor. The main control temperature sensor is attached to the aerospace electronic product under test and is used to collect the temperature of the aerospace electronic product under test. The auxiliary temperature sensor is arranged on the surface of the liquid nitrogen cold plate, the fluid inlet or the fluid outlet and is used to monitor the temperature of the liquid nitrogen cold plate. The control module is electrically connected to the electric heater, the pneumatic proportional control valve, and the temperature sensor group, respectively, and is used to control the heating power of the electric heater and the opening degree of the pneumatic proportional control valve.

[0010] Furthermore, the vacuum container is made of stainless steel and has internal guide rails for positioning and fixing the aerospace electronics products under test and the liquid nitrogen cooling plate.

[0011] Furthermore, the liquid nitrogen cooling plate is made of copper and has a serpentine flow channel inside, which allows for uniform flow of liquid nitrogen.

[0012] Furthermore, a polyimide film heater is selected as the electric heater.

[0013] Furthermore, the thermally conductive layer is an indium foil material with a thickness ranging from 0.1 mm to 0.5 mm, and the indium foil material is mechanically pressed with a pressure of 0.1 MPa to 0.3 MPa to fill the contact gap between the tested aerospace electronic product and the microscopic surface of the liquid nitrogen cold plate.

[0014] Furthermore, the control module includes a signal input terminal and a signal output terminal. The signal input terminal is used to receive signals from the temperature sensor group, and the signal output terminal is used to output control signals to the electric heater and the pneumatic proportional regulating valve.

[0015] Furthermore, the signals from the temperature sensor array include the temperature of the aerospace electronics product under test. The temperature of the liquid nitrogen cold plate.

[0016] A method for coordinated hot and cold temperature control in thermal vacuum testing of aerospace electronic products, implemented based on any of the aforementioned thermal vacuum testing devices for aerospace electronic products, wherein the method is executed by a control module in any one of the following temperature control modes or a combination of two temperature control modes: Heating mode: When Less than the first preset target temperature and the first preset target temperature is the same as When the difference is greater than the first preset temperature difference, the control module outputs a control signal to command the pneumatic proportional regulating valve to close completely, and at the same time adjusts the heating power of the electric heater to the rated maximum output power or the preset high power setpoint. High Temperature Maintenance Mode: When the first preset target temperature is equal to... When the difference is less than or equal to the second preset target temperature difference, according to The output adjustment amount of the electric heater is calculated, and the control module outputs a control signal command to adjust the heating power of the electric heater. Rapid cooling mode: When Greater than the second preset target temperature and When the difference between the second preset target temperature and the third preset temperature is greater than the difference between the two preset temperatures, the control module outputs a control signal to command the pneumatic proportional regulating valve to fully open and the electric heater to be turned off at the same time. Collaborative stable cooling mode: When When the difference between the second preset target temperature and the fourth preset temperature is less than or equal to the difference, the control module locks the opening of the pneumatic proportional regulating valve. The output adjustment amount of the electric heater is calculated, and the control module outputs a control signal command to adjust the heating power of the electric heater.

[0017] Furthermore, the control module employs a PID algorithm based on either a first preset target temperature or a second preset target temperature. The difference is the input quantity. The output adjustment quantity of the electric heater is obtained through proportional, integral and derivative operations. The output adjustment quantity is then converted into pulse width modulation duty cycle, analog voltage signal or power regulation control signal to adjust the heating power of the electric heater.

[0018] Furthermore, the temperature control mode also includes a monitoring mode. In the monitoring mode, the control module receives signals from the auxiliary temperature sensor. When the temperature of the liquid nitrogen cold plate exceeds the preset temperature threshold, the control module issues an alarm and executes hardware power-off protection measures.

[0019] Compared with the prior art, the present invention can achieve the following beneficial effects: (1) The present invention directly attaches the electric heater to the bottom of the cold plate instead of the surface of the aerospace electronic product being tested, so that the heating source is separated from the fluid circuit. This back-attachment design makes the cold plate a dynamic heat sink that can change temperature quickly. The high thermal conductivity of the metal cold plate ensures temperature uniformity, which avoids the electric heater directly contacting the product and causing local overheating, and also achieves millisecond-level control of thermal response.

[0020] (2) The present invention adopts a cold and heat coordinated temperature control method, combined with PID algorithm for real-time adjustment. In the low temperature maintenance stage, asymmetric control combining constant cold circuit fluid and dynamic electrothermal compensation is adopted. In the heating stage, active thermal control combining cutting off cold circuit fluid and direct electrothermal conduction is adopted. This avoids temperature fluctuations caused by independent cold and heat control and effectively improves temperature control accuracy. At the same time, unnecessary heating or cooling is reduced, effectively reducing energy consumption.

[0021] (3) In this invention, a heat-conducting layer is sandwiched between the aerospace electronic product under test and the liquid nitrogen cold plate. The heat-conducting layer is made of flexible indium foil material with a thickness of 0.1mm to 0.5mm. It is mechanically pressed with a clamping force of 0.1MPa to 0.3MPa, which effectively reduces the contact thermal resistance and allows the cold energy of the cold plate to be directly conducted to the aerospace electronic product under test. Conductive heat transfer replaces radiation, ensuring uniform heat distribution and solving the problem of low heat transfer efficiency in a vacuum environment. Attached Figure Description

[0022] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 A schematic diagram of the thermal vacuum testing device for aerospace electronic products as described in an embodiment of the present invention; Figure 2 A schematic diagram of the temperature control algorithm flow of the cold and heat coordinated temperature control method described in the embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures: 1. Vacuum container; 2. Liquid nitrogen cold plate; 3. Electric heater; 4. Thermal conductive layer; 5. Aerospace electronic product under test; 6. Liquid nitrogen supply system; 7. Pneumatic proportional control valve; 8. Main control temperature sensor; 9. Auxiliary temperature sensor; 10. Control module. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0026] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] like Figure 1 As shown, this embodiment of a thermal vacuum testing device for aerospace electronic products includes a vacuum container 1, an integrated thermal control component, the aerospace electronic product under test 5, a liquid nitrogen supply system 6, a pneumatic proportional control valve 7, a temperature sensor group, and a control module 10.

[0030] An integrated thermal control assembly is housed within the vacuum container 1. This assembly includes a liquid nitrogen cooling plate 2, an electric heater 3, and a heat-conducting layer 4. The electric heater 3 is directly and tightly attached to the bottom surface of the liquid nitrogen cooling plate 2. The aerospace electronic product under test 5 is mounted on the top surface of the liquid nitrogen cooling plate 2. The heat-conducting layer 4 is sandwiched between the aerospace electronic product under test 5 and the liquid nitrogen cooling plate 2. The inlet of the pneumatic proportional control valve 7 is connected to the liquid nitrogen supply system 6 via a pipeline, and the outlet of the pneumatic proportional control valve 7 is connected to the liquid nitrogen cooling plate 2 via a pipeline. The flow of liquid nitrogen is controlled by adjusting the opening of the pneumatic proportional control valve 7. The liquid nitrogen flow rate of plate 2; the temperature sensor group includes a main control temperature sensor 8 and an auxiliary temperature sensor 9. The main control temperature sensor 8 is attached to the aerospace electronic product 5 under test and is used to collect the temperature of the aerospace electronic product 5 under test; the auxiliary temperature sensor 9 is attached to the surface, fluid inlet or fluid outlet of liquid nitrogen cold plate 2 and is used to monitor the temperature of liquid nitrogen cold plate 2; the control module 10 is electrically connected to the electric heater 3, the pneumatic proportional regulating valve 7 and the temperature sensor group respectively, and is used to control the heating power of the electric heater 3 and the opening degree of the pneumatic proportional regulating valve 7.

[0031] The vacuum container 1 is made of stainless steel and has internal guide rails for positioning and fixing the aerospace electronics product under test 5 and the liquid nitrogen cooling plate 2. It provides ≤6.63×10⁻⁶... - A vacuum environment of ³Pa.

[0032] The liquid nitrogen cold plate 2, as the core cold source carrier, is made of copper and utilizes the high thermal conductivity of the metal cold plate. The liquid nitrogen cold plate 2 has a serpentine flow channel inside, which enables uniform flow of liquid nitrogen. The diameter of the serpentine flow channel is 5mm and the total length is about 2m.

[0033] In some embodiments, the liquid nitrogen cooling plate 2 can be replaced with a compressor cooling plate (power <100W, cooling rate 3℃ / min, cost reduction of 20%), which is suitable for small stand-alone units.

[0034] The electric heater 3, as a fast-response heat source, is a polyimide film heater with a power density of 0.8 W / cm², which is directly attached to the bottom surface of the liquid nitrogen cold plate 2. This back-attached design makes the liquid nitrogen cold plate 2 a dynamic heat sink that can change temperature quickly. This avoids local overheating caused by the electric heater 3 directly contacting the tested aerospace electronics product 5, and also ensures temperature uniformity by utilizing the high thermal conductivity of metal.

[0035] A thermally conductive layer 4 is located between the top surface of the liquid nitrogen cooling plate 2 and the aerospace electronic product under test 5. It is made of indium foil with a thickness ranging from 0.1 mm to 0.5 mm, and the indium foil is mechanically pressed under a pressure ranging from 0.1 MPa to 0.3 MPa to fill the contact gap between the microscopic surface of the aerospace electronic product under test 5 and the liquid nitrogen cooling plate 2. Preferably, under a mechanical pressing force of 0.2 MPa, the indium foil undergoes "cold rheological" deformation, filling the microscopic gaps and effectively reducing the contact thermal resistance, thereby constructing a low thermal resistance conduction link.

[0036] In some non-preferred embodiments, the thermally conductive layer 4 can also be a metal spring array or an elastic metal thermally conductive component. The metal spring array fills the local gap between the tested aerospace electronics product 5 and the liquid nitrogen cooling plate 2 through elastic compression. Compared with indium foil, the metal spring array can use standardized elastic components, has lower material and processing costs, and has the advantages of reusability, compensation for assembly errors, and adaptability to thermal cycling deformation; however, its effective contact area and equivalent thermal conductivity are lower than those of indium foil.

[0037] The liquid nitrogen supply system 6 includes liquid nitrogen storage tanks and delivery pipelines, which are responsible for providing cryogenic working fluid with a purity of 99.9% and stable pressure.

[0038] The pneumatic proportional control valve 7, as the coarse adjustment actuator for cooling capacity, is connected between the liquid nitrogen supply system 6 and the liquid nitrogen cold plate 2. It has a response time of <0.5s and can achieve 0%~100% opening adjustment with a flow rate of 0.5L / min~2L / min.

[0039] The temperature sensor group uses a high-precision PT100 resistance temperature detector (accuracy class A or higher). The temperature sensor group includes a main control temperature sensor 8 and an auxiliary temperature sensor 9. The main control temperature sensor 8 is tightly attached to the designated temperature measurement point of the aerospace electronic product 5 under test or a representative temperature control measurement point determined by the thermal design of the aerospace electronic product 5 using thermally conductive adhesive or aluminum foil tape. The temperature of the aerospace electronic product 5 under test collected by this sensor is the only process variable of the entire closed-loop control system, which determines the PID calculation output of the control module 10.

[0040] The auxiliary temperature sensor 9 is attached to the surface of the liquid nitrogen cold plate 2, the fluid inlet or the fluid outlet. Its function is to monitor the temperature of the liquid nitrogen cold plate 2 and determine whether dry burning or overheating has occurred.

[0041] The control module 10 is the core of this experimental setup and employs a programmable logic controller (PLC). The control module 10 includes signal input and signal output terminals. The signal input terminal receives signals from the temperature sensor array, and the signal output terminal outputs control signals to the electric heater 3 and the pneumatic proportional control valve 7. The signals from the temperature sensor array include the temperature of the tested aerospace electronics product 5 collected by the main control temperature sensor 8 and the temperature of the liquid nitrogen cold plate 2 collected by the auxiliary temperature sensor 9.

[0042] In some embodiments, the control module 10 is an embedded microcontroller (such as STM32) to reduce hardware costs.

[0043] This invention also provides a method for coordinated hot and cold temperature control in thermal vacuum testing of aerospace electronic products, which is implemented based on the thermal vacuum testing device for aerospace electronic products according to this invention. The method is executed by the control module 10 using any one of the temperature control modes or a combination of two temperature control modes. Heating mode: When Less than the first preset target temperature and the first preset target temperature is the same as When the difference is greater than the first preset temperature difference, the control module 10 outputs a control signal to command the pneumatic proportional regulating valve 7 to close completely, and at the same time adjusts the heating power of the electric heater 3 to the rated maximum output power or the preset high power set value. High Temperature Maintenance Mode: When the first preset target temperature is equal to... When the difference is less than or equal to the second preset target temperature difference, according to The output adjustment amount of the electric heater 3 is calculated, and the control module 10 outputs a control signal command to adjust the heating power of the electric heater 3; Rapid cooling mode: When Greater than the second preset target temperature and When the difference between the second preset target temperature and the third preset temperature is greater than the difference between the two preset temperatures, the control module 10 outputs a control signal to instruct the pneumatic proportional regulating valve 7 to fully open and at the same time turn off the electric heater 3. Collaborative stable cooling mode: When When the difference between the second preset target temperature and the fourth preset temperature is less than or equal to the difference between the two preset temperatures, the control module 10 locks the opening of the pneumatic proportional regulating valve 7, according to... The output adjustment amount of the electric heater 3 is calculated, and the control module 10 outputs a control signal command to adjust the heating power of the electric heater 3.

[0044] Control module 10 uses a PID algorithm based on the corresponding preset target temperature. (in, x =1 represents the first preset target temperature. x =2 is the second preset target temperature) and The difference is the input quantity. The output adjustment quantity of the electric heater 3 is obtained through proportional, integral and derivative operations. The output adjustment quantity is then converted into pulse width modulation duty cycle, analog voltage signal or power regulation control signal to adjust the heating power of the electric heater 3.

[0045] The specific control method of the PID algorithm is as follows: Control module 10 uses a fixed sampling period collection Calculate the preset target temperature and The difference : ; in, This represents the discrete sampling number at the current sampling time.

[0046] in accordance with Calculate the output adjustment of electric heater 3 : ; in, This is the proportionality coefficient. The integral coefficient is... These are the differential coefficients. The sampling period is Represents the discrete sampling sequence number of the historical sampling time. Indicates the first Temperature difference value corresponding to each sampling time. This represents the temperature difference corresponding to the previous sampling time.

[0047] Control module 10 will output adjustment amount The amplitude is limited to 0%~100% and converted into a pulse width modulation duty cycle, analog voltage signal, or solid-state relay / power regulator control signal to adjust the actual output power of the electric heater 3. In both the high-temperature maintenance mode and the coordinated cooling mode, the PID algorithm uses the temperature of the tested aerospace electronics product 5 collected by the main control temperature sensor 8. As a closed-loop feedback variable, the auxiliary temperature sensor 9 is only used for temperature monitoring, alarm and hardware protection of the liquid nitrogen cold plate 2, and does not participate in the core PID closed-loop calculation.

[0048] In this embodiment, the temperature control mode also includes a monitoring mode. The monitoring mode is as follows: the control module 10 receives the signal from the auxiliary temperature sensor 9. When the temperature of the liquid nitrogen cold plate 2 exceeds the preset temperature threshold, the control module 10 issues an alarm and executes hardware power-off protection measures.

[0049] Figure 2This provides a method for coordinated thermal and thermal temperature control in thermal vacuum testing of aerospace electronic products, encompassing a complete thermal cycle. Figure 1 ,in, To control the first preset target temperature of module 10, To control the second preset target temperature of module 10, The first preset temperature difference value for control module 10, For the control module 10 X Preset temperature difference (where, X =2,3,4). The temperature of the tested aerospace electronics product 5 is collected by the main control temperature sensor 8. The temperature of the liquid nitrogen cold plate 2 is collected by the auxiliary temperature sensor 9.

[0050] Phase 1: Heating Phase. The experiment begins. Set the target high temperature, for example, 70°C; This can be set to 20℃, which is the threshold for entering active heating mode. When... and When the liquid nitrogen supply is cut off, the control module 10 enters the heating mode and commands the pneumatic proportional regulating valve 7 to close completely (0% opening). Simultaneously, based on the set heating rate, such as 3°C / min, the heating power of the electric heater 3 is adjusted to either the rated maximum output power or a preset high power setting. The preset high power setting is a fixed value lower than the rated maximum output power. The temperature of the liquid nitrogen cold plate 2 is collected by the auxiliary temperature sensor 9. The system responds immediately and rapidly increases in temperature. Heat is conducted through the heat-conducting layer 4 to the tested aerospace electronic product 5. The main control temperature sensor 8 collects the temperature of the tested aerospace electronic product 5. It then rises. During this phase, Slightly higher This creates a positive driving temperature difference, enabling efficient heating of the tested aerospace electronics product 5.

[0051] Phase Two: High Temperature Maintenance Phase. It can be set to 5℃, which is the threshold for entering the high-temperature maintenance mode. When and The difference first reaches less than or equal to At this time, control module 10 enters high-temperature maintenance mode and simultaneously activates the high-temperature PID algorithm, while pneumatic proportional regulating valve 7 remains closed. Control module 10, according to... The difference is used to adjust the duty cycle of the high-frequency electric heater 3. During this stage, and High degree of overlap. The system outputs only the minute amount of heat required to offset the radiative heat dissipation of the tested aerospace electronics product 5 into the vacuum environment, achieving a high-precision temperature stability of ±0.5℃. At this time, the control module 10 enters the monitoring mode. When the temperature of the liquid nitrogen cold plate 2 exceeds the preset temperature threshold, the control module 10 issues an alarm and executes hardware power-off protection measures. For example, if If the temperature exceeds the safety limit of electric heater 3, the hardware power-off protection will be triggered immediately. The safety limit of electric heater 3 can be set to 75°C.

[0052] Phase Three: Rapid Cooling Phase. After the high-temperature maintenance period ends, the experiment enters the cooling phase. Set the target low temperature, for example, -35°C; This can be set to 30℃, which is the threshold for entering rapid cooling mode. and At that moment, control module 10 immediately instructs electric heater 3 to stop output. Simultaneously, it instructs pneumatic proportional control valve 7 to open to a large degree, for example, 80%~100%. Liquid nitrogen rushes into liquid nitrogen cooling plate 2, causing... A sharp drop in temperature creates a significant negative temperature difference. This negative temperature difference forces heat to flow rapidly from the tested aerospace electronics product 5 through the heat-conducting layer 4 to the liquid nitrogen cooling plate 2, driving... It is decreasing at a high rate.

[0053] Phase Four: Coordinated and Stable Cooling Phase. It can be set to 3℃, which is the threshold for entering the coordinated cooling mode. When and The difference is less than or equal to the first time The control module 10 switches the pneumatic proportional control valve 7 from a large opening and locks it to a constant small opening, for example, 5%~10%, to provide a stable "cold background". The control module 10 then reactivates the electric heater 3 to... The PID calculation is performed on the main control variable to output an appropriate amount of heating power to counteract the excess cooling. At this time, the experimental device is in a state of "dynamic balance between heat and cold".

[0054] Phase Five: Rewarming Phase. The target temperature is reset to a high temperature, such as 70°C, and the control module 10 re-enters the heating mode and enters the next temperature cycle.

[0055] The thermal vacuum test method for aerospace electronic products in this embodiment uses ANSYS Fluent software for thermal conduction simulation. The tested aerospace electronic product is a satellite controller (200mm×150mm×50mm, 50W power). The simulated temperature response in a vacuum environment is as follows: heating to 72℃ takes 25 minutes; cooling from 70℃ to -37℃ takes 18 minutes; and the constant temperature fluctuation is ±0.3℃. Multiple simulations (power 30W~100W) show a cooling rate ≥4.8℃ / min with an accuracy of ±0.4℃.

[0056] It should be noted that the aerospace electronic product thermal vacuum testing device and the cold and heat coordinated temperature control method of the present invention can also be applied to: (1) Rapid temperature cycling test of semiconductor chips: Adjust the temperature range to -65℃~150℃ for high-power chip reliability verification; (2) Deep space probe component testing: extended to extremely low temperature verification below -100℃, applicable to lunar / Mars probes.

[0057] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0058] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A thermal vacuum testing device for aerospace electronic products, characterized in that, include: Vacuum container, integrated thermal control components, aerospace electronics products under test, liquid nitrogen supply system, pneumatic proportional control valve, temperature sensor group and control module; The integrated thermal control assembly is disposed inside the vacuum container. The integrated thermal control assembly includes a liquid nitrogen cold plate, an electric heater, and a thermally conductive layer. The electric heater is directly and tightly attached to the bottom surface of the liquid nitrogen cold plate. The aerospace electronic product under test is mounted on the top surface of the liquid nitrogen cold plate. The thermally conductive layer is sandwiched between the aerospace electronic product under test and the liquid nitrogen cold plate. The inlet of the pneumatic proportional regulating valve is connected to the liquid nitrogen supply system through a pipeline, and the outlet of the pneumatic proportional regulating valve is connected to the liquid nitrogen cold plate through a pipeline. The flow rate of liquid nitrogen entering the liquid nitrogen cold plate is controlled by adjusting the opening of the pneumatic proportional regulating valve. The temperature sensor group includes a main control temperature sensor and an auxiliary temperature sensor. The main control temperature sensor is attached to the aerospace electronic product under test and is used to collect the temperature of the aerospace electronic product under test. The auxiliary temperature sensor is arranged on the surface, fluid inlet or fluid outlet of the liquid nitrogen cold plate and is used to monitor the temperature of the liquid nitrogen cold plate. The control module is electrically connected to the electric heater, the pneumatic proportional regulating valve, and the temperature sensor group, respectively, and is used to control the heating power of the electric heater and the opening degree of the pneumatic proportional regulating valve.

2. The aerospace electronic product thermal vacuum testing device according to claim 1, characterized in that, The vacuum container is made of stainless steel and has internal guide rails for positioning and fixing the aerospace electronics product under test and the liquid nitrogen cooling plate.

3. The thermal vacuum testing device for aerospace electronic products according to claim 1, characterized in that, The liquid nitrogen cooling plate is made of copper and has a serpentine flow channel inside, which enables uniform flow of liquid nitrogen.

4. The thermal vacuum testing device for aerospace electronic products according to claim 1, characterized in that, The electric heater is a polyimide film heater.

5. The thermal vacuum testing device for aerospace electronic products according to claim 1, characterized in that, The thermally conductive layer is an indium foil material with a thickness ranging from 0.1 mm to 0.5 mm, and the indium foil material is mechanically pressed with a pressure of 0.1 MPa to 0.3 MPa to fill the contact gap between the tested aerospace electronic product and the microscopic surface of the liquid nitrogen cold plate.

6. The thermal vacuum testing device for aerospace electronic products according to claim 1, characterized in that, The control module includes a signal input terminal and a signal output terminal. The signal input terminal is used to receive signals from the temperature sensor group, and the signal output terminal is used to output control signals to the electric heater and the pneumatic proportional regulating valve.

7. The thermal vacuum testing device for aerospace electronic products according to claim 6, characterized in that, The signals from the temperature sensor array include the temperature of the aerospace electronics product under test. And the temperature of the liquid nitrogen cold plate.

8. A method for coordinated temperature control of cold and heat in thermal vacuum testing of aerospace electronic products, implemented based on the thermal vacuum testing device for aerospace electronic products as described in any one of claims 1 to 7, characterized in that, The method involves the control module executing any one of the following temperature control modes or a combination of two temperature control modes: Heating mode: When Less than the first preset target temperature and the first preset target temperature is the same as the first preset target temperature. When the difference is greater than the first preset temperature difference, the control module outputs a control signal to instruct the pneumatic proportional regulating valve to be fully closed, and at the same time adjusts the heating power of the electric heater to the rated maximum output power or the preset high power set value. High Temperature Maintenance Mode: When the first preset target temperature is equal to... When the difference is less than or equal to the second preset target temperature difference, according to the... The output adjustment amount of the electric heater is calculated, and the control module outputs a control signal command to adjust the heating power of the electric heater; Rapid cooling mode: When Greater than the second preset target temperature and the When the difference between the second preset target temperature and the third preset temperature difference is greater than the third preset temperature difference, the control module outputs a control signal to instruct the pneumatic proportional regulating valve to fully open and at the same time turn off the electric heater; Collaborative stable cooling mode: When When the difference between the second preset target temperature and the fourth preset temperature difference is less than or equal to the fourth preset temperature difference, the control module locks the opening of the pneumatic proportional regulating valve, according to the... The output adjustment amount of the electric heater is calculated, and the control module outputs a control signal command to adjust the heating power of the electric heater.

9. The method for coordinated temperature control of cold and heat in thermal vacuum testing of aerospace electronic products according to claim 8, characterized in that, The control module employs a PID algorithm based on a first preset target temperature or a second preset target temperature and the... The difference is the input quantity. The output adjustment quantity of the electric heater is obtained through proportional, integral, and differential operations. The output adjustment quantity is then converted into a pulse width modulation duty cycle, an analog voltage signal, or a power regulation control signal to adjust the heating power of the electric heater.

10. The method for coordinated temperature control of cold and heat in thermal vacuum testing of aerospace electronic products according to claim 8, characterized in that, The temperature control mode also includes a monitoring mode, in which the control module receives the signal from the auxiliary temperature sensor, and when the temperature of the liquid nitrogen cold plate exceeds the preset temperature threshold, the control module issues an alarm and executes hardware power-off protection measures.

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