A small high-precision temperature control device

Abstract

This invention relates to a small, high-precision temperature control device, belonging to the field of spacecraft thermal control technology. A cover plate and a base plate form a closed cavity, which is installed inside the satellite via a heat insulation pad. The temperature-controlled device is mounted on the base plate inside the closed cavity via the heat insulation pad. Heaters and temperature sensors are installed on the temperature-controlled device, the base plate of the temperature control device, and the cover plate, respectively. Depending on the heat dissipation of the temperature-controlled device, thermal insulation or heat dissipation-enhancing thermal control coatings are selected between the temperature-controlled device and the temperature control device, and between the outside of the temperature control device and the satellite. By setting conditional formulas, the controlled temperature of the object, the controlled temperatures of the cover plate and the base plate, the surface area of ​​the cover plate and the base plate, the designed temperature control power of the object, and the designed temperature control power of the cover plate and the base plate are determined, and their rationality is confirmed through parameter verification. This invention can significantly suppress the influence of satellite temperature fluctuations on the temperature of the controlled object, achieving high-precision temperature control of the controlled object.

Description

Technical Field

[0001] This invention relates to the design of a small, high-precision temperature control device, belonging to the field of spacecraft thermal control technology, and particularly to non-sealed satellites with high-precision temperature control requirements. Background Technology

[0002] With the development of satellite application technology, the functions of satellites are becoming increasingly complex. Correspondingly, there are more and more satellite devices that realize various functions. Among them, there is a type of device that is very sensitive to temperature, such as optical devices, temperature calibration and comparison devices, signal synchronization and processing devices, data receiving and processing devices, and satellite timing devices. In special cases, temperature stability requirements better than 0.1K are required.

[0003] As satellites orbit in space, in addition to dissipating heat into the 4K low-temperature environment of space, they also receive direct solar radiation, Earth's infrared radiation, and Earth's albedo. These heat flows are directional; therefore, the surface temperature of the satellite facing these heat flows is higher, while the surface facing away from them is lower. Furthermore, as the satellite adjusts its flight attitude during operation, the direction of these heat flows relative to the satellite's incident radiation may change. The main problem this causes is that the temperature of the satellite's structures and equipment fluctuates significantly due to the changing direction of the external heat flows.

[0004] In the design of satellite temperature control systems, the effects of external heat flow and the low-temperature environment of space are taken into account, and targeted designs are implemented to maintain the satellite temperature in a relatively stable state. However, this temperature stability control is generally maintained at a level of 1K~10K or even higher, which is far from sufficient for temperature-sensitive equipment.

[0005] Addressing the impact of the space environment on high-precision temperature control equipment on satellites can be achieved by improving the overall temperature control level of the satellite or by specifically designing high-precision temperature control for the equipment. However, improving the overall temperature control level of the satellite will significantly increase the satellite's weight and temperature control power. A common design approach is to tailor the design to the installation location of the high-precision temperature control equipment, its temperature control requirements, and the characteristics of the equipment itself. Summary of the Invention

[0006] For small satellite equipment requiring low heat dissipation and high temperature control accuracy, this invention proposes a temperature control device design. Inside the non-sealed satellite, a thermally insulated temperature control device is designed to significantly reduce heat conduction and leakage, allowing heat to be transferred primarily through radiation, thereby mitigating the impact of the environment to some extent. Simultaneously, through the temperature control device's own design, multi-stage temperature control is achieved, suppressing fluctuations in ambient temperature at multiple levels, ultimately realizing high-precision temperature control of the controlled object.

[0007] The specific technical solution is as follows:

[0008] A small, high-precision temperature control device includes a base plate, a cover plate, a heat insulation pad, a heater, a temperature sensor, and a thermal control coating. The device being controlled is mounted on the base plate with thermal insulation. A heater and temperature sensor are arranged on the surface of the controlled object, and a thermal control coating is applied as needed. The cover plate covers the base plate and the outside of the controlled object, forming a closed cavity with the base plate to prevent direct radiative heat exchange between the controlled object and the external environment. A heater and temperature sensor are arranged on the inner or outer surface of the cover plate, and both sides are coated as needed. The assembly of the base plate, cover plate, and controlled object is mounted on a satellite with thermal insulation.

[0009] Furthermore, the base plate and cover plate are made of aluminum alloy, and the thickness is matched according to the size of the controlled object and the heat consumption.

[0010] The heat insulation pad is made of polyimide or fiberglass and has a thickness of not less than 5mm.

[0011] The heater is a polyimide film type electric heater with a maximum operating temperature not exceeding 125℃ and a thickness not exceeding 2mm.

[0012] Temperature sensors employ two-wire thermistors, platinum resistance thermometers, or four-wire platinum resistance thermometers.

[0013] The thermal control coating is selected based on the heat consumption of the equipment being controlled.

[0014] Furthermore, the selection strategy for adjustable parameters is as follows:

[0015] The parameters must meet the conditions of the formula; if not, the temperature control temperature of the controlled object should be adjusted. Temperature control of cover plate and base plate Surface area of ​​cover plate and base plate The design temperature control power of the controlled object The design and temperature control power of the cover plate and base plate ;

[0016] The conditional formula is as follows.

[0017]

[0018] Among them, the temperature control point of the object being temperature controlled is The temperature of the cover plate and the bottom plate is The ambient temperature at the installation location is The heat dissipation of the object under temperature control is The surface coating of the controlled object has a hemispherical emissivity. The hemispherical emissivity of the coating on the cover plate and base plate surface is... The designed temperature control power of the controlled object is The cover plate and base plate are designed with a temperature control power of [missing information]. The surface area of ​​the object being temperature controlled is The surface area of ​​the cover plate and the bottom plate is The temperature difference between the temperature control point of the controlled object and the installation environment meets the heat dissipation requirements of the controlled object, where... Values The unit is: .

[0019] Furthermore, the surface coating of the cover plate and base plate You can choose. The selection range is 0.03 to 0.92.

[0020] Furthermore, after the parameters are selected, the design temperature control power for the controlled object is determined. The design and temperature control power of the cover plate and base plate A review is conducted to determine whether it meets the temperature control accuracy requirements. The specific formula is as follows.

[0021]

[0022]

[0023] The heat capacity of the controlled object is The heat capacity of the cover plate and the bottom plate is The heat dissipation of the controlled object The change is the magnitude of the change, and the maximum range of change is... The temperature change requirement of the controlled object is The temperature control cycle of the controller that outputs temperature control power is Heat capacity and temperature control cycle The units are respectively and .

[0024] Furthermore, if the required temperature control accuracy cannot be met, adjust the heating power. and Alternatively, adjust the heat capacity.

[0025] Furthermore, heat capacity is related to specific heat capacity and weight. Once the material is selected, it is only related to weight. Therefore, adjusting the heat capacity is necessary. Only the weight of the controlled object or the cover plate and base plate needs to be adjusted.

[0026] Furthermore, the heat capacity can be adjusted by increasing the thickness of the mounting surface of the controlled object or by adding an additional aluminum alloy plate at the mounting surface. .

[0027] The beneficial effects of this invention compared to the prior art are:

[0028] 1. High temperature control accuracy. Under conditions of large temperature fluctuations (greater than 2°C) inside the satellite, this device, combined with optimized selection of the heat capacity, heating power, coating, etc. of the controlled equipment, can achieve temperature stability control of the controlled object better than 0.1K.

[0029] 2. Simple structure. The main body of this device consists of only two basic structures: a base plate and a cover plate. It is installed with the controlled object by screws, with no special installation requirements and low requirements for structure and installation accuracy.

[0030] 3. High adaptability. This device is installed in the satellite with thermal insulation, and there are no requirements for the flatness of the installation location. The ambient temperature of the installation location must be lower than the temperature of the controlled object, and the temperature difference must match the heat consumption of the controlled object to achieve the temperature control target.

[0031] 4. For high-precision temperature control equipment with a weight of no more than 2kg and a working heat consumption of no more than 4W, the temperature control device described in this invention is most suitable. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the combination of a small, high-precision temperature control device and the object being controlled, according to the present invention.

[0033] Figure 2 This is an exploded schematic diagram of the design of a small, high-precision temperature control device according to the present invention, including the temperature control device and the components of the object being controlled.

[0034] Figure 3 This is a side view of the temperature control device and the controlled object assembly;

[0035] Figure 4 This is a top view of the temperature control device and the controlled object assembly;

[0036] Figure 5 This is a schematic diagram of the end face of the temperature control device and the controlled object assembly.

[0037] Among them, 1-controlled object, 2-cover plate, 3-heat insulation pad, 4-base plate, 5-outlet hole. Detailed Implementation

[0038] A small, high-precision temperature control device is designed, comprising a base plate, a cover plate, a heat insulation pad, a heater, a temperature sensor, and a thermal control coating, characterized by:

[0039] The temperature-controlled equipment is mounted on the base plate of the device using thermal insulation. Heaters and temperature sensors are installed on the surface of the object being controlled, and a thermal control coating is applied as needed. A cover plate covers the base plate and the outside of the object being controlled, forming a sealed cavity to prevent direct radiative heat exchange between the object and the external environment. Heaters and temperature sensors are installed on the inner or outer surface of the cover plate, and both sides are coated with a thermal control coating as needed. The assembly of the base plate, cover plate, and object being controlled is then mounted to the satellite using thermal insulation.

[0040] The materials and usage constraints involved in this invention are as follows:

[0041] The base plate and cover plate are made of aluminum alloy, and the thickness is matched according to the size of the controlled object and the heat consumption, generally not less than 1mm.

[0042] The heat insulation pads are made of polyimide or fiberglass, and the thickness is generally not less than 5mm.

[0043] The heater is a polyimide film type electric heater with a maximum operating temperature not exceeding 125℃ and a thickness not exceeding 2mm.

[0044] The temperature sensor uses a two-wire thermistor or platinum resistance thermometer (suitable for temperature measurement accuracy requirements of ≥0.1K), or a four-wire platinum resistance thermometer (suitable for temperature measurement accuracy requirements better than 0.1K).

[0045] The thermal control coating is selected based on the heat consumption of the controlled equipment. When the heat consumption of the controlled object is large, a high emissivity aluminum black anodized coating or a high emissivity black paint coating is selected. When the heat consumption of the controlled object is small or negligible, a low emissivity gold-plated coating or multi-layer thermal insulation material is selected.

[0046] The temperature control device of this invention is best suited for high-precision temperature control applications with a weight not exceeding 2kg and a working heat consumption not exceeding 4W. If the weight exceeds 2kg, the device may become too heavy due to mechanical design requirements. Excessive heat consumption will also lead to an oversized temperature control device, or necessitate lowering the maximum temperature level of the installation environment to achieve high-precision and stable temperature control.

[0047] The adjustable parameters, such as materials, coatings, and temperature control power, involved in this invention can be selected using the following strategies:

[0048] If the temperature control point of the object being temperature controlled is The present invention relates to the temperature of the cover plate and the bottom plate. The ambient temperature at its installation location is The heat dissipation of the object under temperature control is The surface coating of the controlled object has a hemispherical emissivity. The hemispherical emissivity of the coating on the cover plate and base plate surface is... The designed temperature control power of the controlled object is The cover plate and base plate are designed with a temperature control power of [missing information]. The surface area of ​​the object being temperature controlled is The surface area of ​​the cover plate and the bottom plate is The units for each parameter are as follows: , , , and This is a proportionality constant, without units.

[0049] The temperature difference between the temperature control point of the controlled object and the installation environment must meet the heat dissipation requirements of the controlled object. The following method can be used for estimation, and the temperature control temperature of the controlled object can be adjusted based on the estimation results. Temperature control of cover plate and base plate Surface area of ​​cover plate and base plate The design temperature control power of the controlled object The design and temperature control power of the cover plate and base plate Meanwhile, the coating on the cover plate and base plate surfaces... Alternatively, this can be chosen. In the formula... Values The unit is: .

[0050]

[0051] When using the device described in this invention, the coating on the surface of the cover plate and the base plate The selectable range is 0.03 to 0.92. Some data correspond to the following coating types:

[0052] Multi-layer thermal insulation components, Gold plating coating, Polished aluminum surfaces or bright aluminum foil, Bright anodizing of aluminum Aluminum black anodized or organic black paint coating, .

[0053] After selecting the above parameters, the temperature control power needs to be designed for the controlled object. The design and temperature control power of the cover plate and base plate A review was conducted to determine whether it met the temperature control accuracy requirements.

[0054] If the heat capacity of the controlled object is The heat capacity of the cover plate and the bottom plate is The heat dissipation of the controlled object The change is the magnitude of the change, and the maximum range of change is... The temperature change requirement of the controlled object is The temperature control cycle of the controller that outputs temperature control power is Heat capacity and temperature control cycle The units are respectively and .

[0055] Then it is necessary to ensure that:

[0056]

[0057]

[0058] In the above two equations, heat capacity It needs to be calculated based on the specific heat capacity and weight of the materials used for the controlled object, the cover plate and the base plate described in this invention.

[0059] If the above requirements cannot be met, the heating power needs to be adjusted. and Or adjust the heat capacity .

[0060] For the controlled object, the heating power is generally adjusted. For the cover plate and base plate described in this invention, their heat capacity generally needs to be adjusted. .

[0061] Due to heat capacity The specific heat capacity is related to both specific heat capacity and weight; once the material is selected, it is only related to weight. Therefore, to adjust the heat capacity... The thickness of the controlled object can be adjusted simply by adjusting the weight of the controlled object or the cover plate and base plate.

[0062] If the heating power of the controlled object cannot be adjusted Alternatively, the mounting surface of the controlled object can be increased (heating power). Application location) thickness, on mounting surface (heating power) Adjusting its heat capacity by adding an additional aluminum alloy plate at the application location. .

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the method of the present invention. In actual design and implementation, the length, width, and thickness of the base plate and cover plate, the heating power design of the heater, the type of temperature sensor selected, the selection of the temperature control point, and the selection of thermal control coatings at various locations all affect the temperature control effect on the controlled object.

[0064] The above modifications do not fundamentally change the method of this invention: a temperature control device is constructed using a base plate and a cover plate, with the controlled object arranged within the enclosed cavity formed by the base plate and cover plate. Heaters, temperature sensors, and thermal control coatings are applied to the surfaces of the base plate, cover plate, and the controlled object. This small-scale device design effectively solves the problem of the impact of ambient temperature fluctuations on the temperature stability of the controlled object. Therefore, they are all considered to be within the scope of protection defined by the claims of this invention.

[0065] The present invention will now be described in further detail with reference to the accompanying drawings.

[0066] Figure 1 This is a schematic diagram of the small, high-precision temperature control device proposed in this invention, comprising: a base plate, a cover plate, a heat insulation pad, and the controlled object. The base plate and cover plate of the temperature control device are combined to form a closed structure. The controlled object is arranged within the closed structure through a heat-insulated mounting method, preventing direct radiative heat exchange between the controlled object and the external environment of the temperature control device. The heat insulation pad between the controlled object and the base plate of the temperature control device significantly reduces thermal conductivity and heat transfer between the controlled object and the temperature control device, as well as the environment surrounding the temperature control device. The components are connected by screws to form an assembly. The disassembled state of the assembly is as follows... Figure 2 As shown.

[0067] Figure 3 yes Figure 1 Side view of the combined structure. The controlled object is positioned at the center of the temperature control device and is thermally insulated from the base plate. Heaters and temperature sensors are installed on the surface of the controlled object, forming the second stage of temperature control to provide high-precision temperature control. An appropriate thermal control coating is selected and applied to the surface of the controlled object based on its heat dissipation. The surfaces of the cover plate and base plate facing the controlled object are also coated with appropriate thermal control coatings based on its heat dissipation. The outer surfaces of the cover plate and base plate facing the installation environment of the temperature control device also require matching thermal control coatings based on the heat dissipation of the controlled object. Simultaneously, heaters and temperature sensors are also installed on the surfaces of the cover plate and base plate to provide the first stage of temperature control, offering a relatively stable radiant temperature boundary for the controlled object. The controlled object's own cable and the first and second stage temperature control cables are led out through the cable outlet holes in the cover plate. The portion of the cover plate's cable outlet hole from which no cables are connected must be sealed with multiple layers of thermal insulation material to prevent heat leakage.

[0068] Figure 4 yes Figure 1 Top view of the combined structure. The controlled object is located at the center of the temperature control device. There are no special requirements for the thermal conductivity between the cover plate and the base plate. The temperature control device and the controlled object assembly are also mounted to the satellite using thermal insulation pads. The installation of thermal insulation pads can significantly reduce heat exchange through the contact surface between the base plate and the satellite.

[0069] Figure 5yes Figure 1 End view of the combined structure. The controlled object is located at the center of the temperature control device. The heater and temperature sensor on the cover plate are only located on the outside of the cover plate when a multi-layer thermal insulation component coating is used; otherwise, the coating is located on the inside of the cover plate facing the controlled object.

[0070] The technical solution of this invention achieves high-precision temperature control for small, high-precision temperature-controlled equipment through a simple temperature control device design. This design significantly reduces the impact of ambient temperature fluctuations on the temperature-controlled equipment located inside the device, enabling the controlled object to maintain high temperature stability. It features simple structure, easy installation, strong adaptability, and good performance.

Claims

1. A small, high-precision temperature control device, comprising a base plate, a cover plate, a heat insulation pad, a heater, a temperature sensor, and a thermal control coating, characterized in that: The temperature-controlled equipment is installed on the base plate of the device via thermal insulation. Heaters and temperature sensors are arranged on the surface of the temperature-controlled object, and a thermal control coating is applied as needed. A cover plate covers the base plate and the outside of the temperature-controlled object, forming a closed cavity to prevent direct radiative heat exchange between the temperature-controlled object and the external environment. Heaters and temperature sensors are arranged on the inner or outer surface of the cover plate, and thermal control coatings are applied to both sides as needed. The assembly of the base plate, cover plate, and temperature-controlled object is installed on the satellite via thermal insulation. Adjustable parameters are determined according to the selection strategy. Once the adjustable parameters are selected, the designed temperature control power of the temperature-controlled object is determined. The design and temperature control power of the cover plate and base plate A review is conducted to determine whether it meets the temperature control accuracy requirements. The specific formula is as follows. The heat capacity of the controlled object is The heat capacity of the cover plate and the bottom plate is The heat dissipation of the controlled object The change is the magnitude of the change, and the maximum range of change is... The temperature change requirement of the controlled object is The temperature control cycle of the controller that outputs temperature control power is Heat capacity and temperature control cycle The units are respectively and , As preset parameters, the emissivity of the hemispherical coating on the surface of the controlled object is... The surface area of ​​the object being temperature controlled is The ambient temperature at the installation location is The temperature of the cover plate and the bottom plate is The temperature control point of the object being controlled is The hemispherical emissivity of the coating on the cover plate and base plate surface is... The surface area of ​​the cover plate and the bottom plate is .

2. The small, high-precision temperature control device according to claim 1, characterized in that: The base plate and cover plate are made of aluminum alloy, and the thickness is matched according to the size of the controlled object and the heat consumption. The heat insulation pads are made of polyimide or fiberglass and are at least 5mm thick. The heater is a polyimide film type electric heater with a maximum operating temperature not exceeding 125℃ and a thickness not exceeding 2mm. The temperature sensor uses a two-wire thermistor or a four-wire platinum resistance thermometer. The thermal control coating is selected based on the heat consumption of the equipment being controlled.

3. A small, high-precision temperature control device according to any one of claims 1-2, characterized in that: The selection strategy for adjustable parameters is as follows: The parameters must meet the conditions of the formula; if not, the temperature control temperature of the controlled object should be adjusted. Temperature control of cover plate and base plate Surface area of ​​cover plate and base plate The design temperature control power of the controlled object The design and temperature control power of the cover plate and base plate ; The conditional formula is as follows. Among them, the temperature difference between the temperature control point of the controlled object and the installation environment meets the heat dissipation requirements of the controlled object, where... Values The unit is: .

4. The small, high-precision temperature control device according to claim 3, characterized in that: The surface coating of the cover plate and base plate has a hemispherical emissivity. The selection range is 0.03 to 0.

92.

5. A small, high-precision temperature control device according to claim 4, characterized in that: If the temperature control accuracy requirement cannot be met, adjust the heating power. and Alternatively, adjust the heat capacity.

6. The small, high-precision temperature control device according to claim 5, characterized in that: Heat capacity is related to specific heat capacity and weight. Once the material is selected, it is only related to weight. Therefore, to adjust the heat capacity... Only the weight of the controlled object or the cover plate and base plate needs to be adjusted.

7. A small, high-precision temperature control device according to claim 6, characterized in that: The heat capacity can be adjusted by increasing the thickness of the mounting surface of the controlled object or by adding an additional aluminum alloy plate at the mounting surface. .

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