Electromagnetic clean spacecraft thermal control device and electromagnetic clean design method thereof

Abstract

The application provides a spacecraft thermal control device with electromagnetic cleanliness and a method for electromagnetic cleanliness design of the spacecraft thermal control device, and the method comprises the following steps: setting a notch feature on the side of a double-layer single-loop electric heater, so that the electric heater can be fixed on a curved surface; for the connecting wire between the double-layer single-loop electric heater and the rear-end wire of the temperature element, a structure that a pair of twisted wires is connected with another pair of twisted wires in a local area is adopted, so as to prevent the electric heater from generating electromagnetic interference signals when the electric heater is powered on and powered off; a grounding point network is arranged on the surface of a multilayer thermal insulation assembly, and after the grounding position is determined, an integrated equipotential grounding design is performed on each grounding point in the multilayer thermal insulation assembly. The electromagnetic signals generated when the heating loop is powered on and powered off are weakened, the risk hidden danger is eliminated, the electromagnetic stray signals are inhibited, and the equipotential effect of the multilayer thermal insulation assembly is significantly enhanced; meanwhile, the electromagnetic cleanliness design is performed on the propulsion system, and the electromagnetic cleanliness effect is further realized.

Description

Technical Field

[0001] This invention relates to the field of spacecraft thermal control technology, specifically to an electromagnetically clean spacecraft thermal control device and its electromagnetically clean design method. Background Technology

[0002] With the future deep space exploration missions in mind, especially the application requirements for in-situ detection of space particles and high-precision magnetic field measurement, the urgency of ensuring a clean electromagnetic environment for spacecraft is becoming increasingly prominent in the top-level design.

[0003] Existing theoretical research on electromagnetic cleanliness methods for spacecraft is abundant, mainly focusing on source suppression, propagation blocking, and system management. This involves employing low-noise devices, material shielding, filtering, and grounding technologies during the design and manufacturing phases, and implementing time-sharing operation of equipment during the operational phase. These measures can reduce the electromagnetic interference generated by the spacecraft itself to a low level while resisting external interference, ensuring its operation in complex space environments.

[0004] A review of domestic and international research and references revealed that most studies focused on the theoretical aspects of electromagnetic cleanliness for spacecraft. However, for thermal control products specifically designed for electromagnetic cleanliness, the design methods were unclear, the design standards were insufficient, the implementation was not practical, and there was a lack of real-world guidance.

[0005] Currently, no descriptions or reports of technologies similar to this invention have been found, and no similar information has been collected domestically or internationally. Summary of the Invention

[0006] In view of the above-mentioned deficiencies in the prior art, this invention provides an electromagnetically clean spacecraft thermal control device and its electromagnetically clean design method for spacecraft that require electromagnetic cleanliness characteristics.

[0007] According to one aspect of the present invention, an electromagnetic cleanliness design method for spacecraft thermal control equipment is provided, comprising:

[0008] Electromagnetic clean design for electric heaters; a notch is provided on the side of the double-layer single-loop electric heater so that it can be fixed to the curved surface; the wires connecting the double-layer single-loop electric heaters and the rear wires of the temperature element are all connected by a structure in a local area between one pair of twisted wires and another pair of twisted wires to prevent electromagnetic interference signals from being generated when the electric heater is powered on and off.

[0009] Electromagnetic clean design for multi-layer thermal insulation components; wherein, a grounding point network is set on the surface of the multi-layer thermal insulation components, and after determining the grounding location, an integrated equipotential grounding design is carried out for each grounding point in the multi-layer thermal insulation components.

[0010] Preferably, the above method further includes: electromagnetic cleanroom design for the thermal control equipment of the propulsion system; wherein:

[0011] The heating strip in the pipeline is designed to consist of polyimide insulating tape and metal wires, with the metal wires being routed in a folded-back manner.

[0012] A polyimide material layer is applied to the surface of the gas cylinder's thermal conductive film, and a grounding point is set up with a grounding wire led out to be grounded at the same potential as the satellite;

[0013] The high-temperature heat shield near the main thruster is designed using carbon fiber-ceramic composite material with conductive properties to form an equipotential structure.

[0014] An aluminum foil heat-insulating cloth is placed between the secondary surface mirror and the internal multi-layer unit in the multi-layer heat insulation assembly near the small thruster, and the aluminum foil heat-insulating cloth is made into conductive contact with the secondary surface mirror and the reflective layer.

[0015] According to a second aspect of the present invention, an electromagnetically clean spacecraft thermal control device is provided; wherein, a notch feature is provided on the side of the double-layer single-loop electric heater; the wires connecting the double-layer single-loop electric heaters and the rear wires of the temperature element are all constructed by connecting one pair of twisted wires to another pair of twisted wires in a local area; a grounding point network is provided on the surface of the multi-layer heat insulation assembly, and each grounding point in the multi-layer heat insulation assembly adopts an integrated equipotential grounding design.

[0016] Preferably, the above-mentioned device further includes:

[0017] In the propulsion system:

[0018] The pipeline heating tape is composed of polyimide insulating tape and metal wires, with the metal wires being routed in a folded-back manner.

[0019] A polyimide material layer is applied to the surface of the gas cylinder's thermal conductive film, and a grounding point is set up with a grounding wire leading out to be grounded at the same potential as the satellite;

[0020] The high-temperature heat shield near the main thruster is made of carbon fiber-ceramic composite material with conductive properties to form an equipotential structure.

[0021] An aluminum foil heat-insulating cloth is provided between the secondary surface mirror and the internal multi-layer unit in the multi-layer heat insulation assembly near the small thruster. The aluminum foil heat-insulating cloth is in conductive contact with the secondary surface mirror and the reflective layer.

[0022] By adopting the above technical solution, the present invention has at least one of the following beneficial effects compared with the prior art:

[0023] This invention provides an electromagnetic cleanliness design for a double-layer single-circuit electric heater, which reduces the electromagnetic signals generated when the heating circuit is energized and de-energized; the design of the double-layer single-circuit electric heater configuration with the curved surface allows the electric heater to fit better with the curved surface, eliminating potential risks; the twisted pair layout of the electric heater's lead wires suppresses electromagnetic stray signals.

[0024] This invention relates to electromagnetic cleanliness design for multi-layer thermal insulation components. It adopts a surface grounding layout design method and proposes a cross-sectional conductive grounding method for multi-layer thermal insulation components. Through the above methods, the overall equipotential effect of the multi-layer thermal insulation components is significantly enhanced, achieving the effect of electromagnetic cleanliness in thermal control equipment.

[0025] This invention provides an electromagnetic cleanliness design for the heating belts in the propulsion system pipelines, the heat-conducting membranes of the gas cylinders, the high-temperature heat insulation screens near the main thruster, and the multi-layer heat insulation components near the small thruster, thereby further realizing the electromagnetic cleanliness effect of the thermal control equipment.

[0026] This invention has had a positive impact on fields such as spacecraft thermal control technology, and has played a technological role in promoting the next generation of deep space exploration missions, especially in the in-situ detection of space particles and high-precision magnetic field measurement. Attached Figure Description

[0027] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0028] Figure 1 This is a schematic diagram of a double-layer single-loop electric heater and its internal structure after unfolding, according to a preferred embodiment of the present invention; wherein, (a) is the overall structure of the electric heater, and (b) is the unfolded structure of the electric heater.

[0029] Figure 2 This is a schematic diagram showing the dimensions of a double-layer single-loop electric heater in a preferred embodiment of the present invention.

[0030] Figure 3 This is a schematic diagram of the wire connection between electric heaters in a preferred embodiment of the present invention.

[0031] Figure 4 The present invention provides a preferred embodiment of the grounding location design and wiring design for the multilayer thermal insulation component; wherein, (a) is the grounding location design and (b) is the wiring design.

[0032] Figure 5 This is a schematic diagram of the grounding of the cross-section of a multilayer thermal insulation component in a preferred embodiment of the present invention.

[0033] Figure 6The outline of the three-layer hemispherical electric heater in a preferred embodiment of the present invention is shown; wherein, (a) is the first layer electric heater, (b) is the second layer electric heater, and (c) is the third layer electric heater.

[0034] Figure 7 This is a schematic diagram of the pipeline heating belt structure in a preferred embodiment of the present invention.

[0035] In the diagram, 1 is the twisted pair lead, 2 is the etched metal foil, 3 is the insulation layer, 4 is the current direction, 5 is the wire connection area, 6 is the boundary grounding point, 7 is the internal grounding point, 8 is the background template of the grounding area, 9 is the internal boundary of the multi-layer thermal insulation component, 10 is the external boundary of the multi-layer thermal insulation component, 11 is the external grounding wire, 12 is the internal grounding wire, 13 is the secondary surface mirror, 14 is the internal reflective layer of the multi-layer thermal insulation component, 15 is the internal spacer layer of the multi-layer thermal insulation component, 16 is the area without spacer layer, 17 is the metal foil, 18 is the rivet clamping structure, 19 is the center line, 20 is the folding feature of the heating metal wire, 21 is the insulation layer of the heating band, and 22 is the heating metal wire. Detailed Implementation

[0036] The embodiments of the present invention are described in detail below: These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

[0037] Existing technologies are all theoretical studies on electromagnetic cleanliness for spacecraft. However, thermal control products for specific electromagnetic cleanliness often suffer from problems such as unclear design methods, insufficient design specifications, weak implementation operability, and lack of practical guidance.

[0038] To address the aforementioned problems, one embodiment of the present invention provides an electromagnetic clean design method for spacecraft thermal control equipment with practical application significance. The spacecraft thermal control equipment may include: thin-film isoelectric heaters, multi-layer thermal insulation components, and thermal control equipment in propulsion systems, etc., so as to ensure that the electromagnetic clean design process of the equipment is standardized, applicable, and operable.

[0039] Specifically, the electromagnetic clean design method for spacecraft thermal control equipment provided in this embodiment can include the following three aspects:

[0040] S1, electromagnetic clean design for electric heaters; wherein, a notch feature is provided on the side of the double-layer single-loop electric heater, so that the double-layer single-loop electric heater can be fixed to the curved surface; for the wires connecting the double-layer single-loop electric heaters and the rear wires of the temperature element, a structure is adopted in which one pair of twisted wires is connected to another pair of twisted wires in a local area to prevent the electric heater from generating electromagnetic interference signals when the power is turned on and off.

[0041] S2 is an electromagnetic clean design for multi-layer thermal insulation components. It involves setting a grounding point network on the surface of the multi-layer thermal insulation components and, after determining the grounding location, performing an integrated equipotential grounding design for each grounding point within the multi-layer thermal insulation components.

[0042] Furthermore, in the electromagnetic cleanroom design for electric heaters, the implementation method is as follows.

[0043] The electric heater adopts a double-layer single-circuit form, such as Figure 1 As shown, the structure is specifically an insulating layer-etched metal foil-insulating layer-etched metal foil-insulating layer. The two etched metal foils are connected in series, and the etched structures inside the metal foils are the same but the current flows in opposite directions, which achieves the effect of magnetic field cancellation. At the same time, the electric heater leads are close to each other and twisted together. The insulating layer material is generally an insulating material such as polyimide. The etched metal foil material should be a non-magnetic metal material (such as copper).

[0044] When attaching electric heaters to the surface of satellite structures and equipment, silicone rubber curing is generally used for fixation. However, when attaching electric heaters to curved surfaces, the surface bending strength of a double-layer single-loop electric heater is higher than that of a single-layer heater. Using silicone rubber can cause the heater to not adhere properly to the curved surface, resulting in gaps between the heater and the object being attached. This can lead to localized overheating of the heater when it is powered on, posing a safety hazard of burnout. To address this, notches can be created on the side of the electric heater based on parameters such as the curvature of the surface and the heater's configuration. This allows the double-layer single-loop electric heater to be fixed securely to the curved surface, thus eliminating the safety hazard of localized overheating.

[0045] The wires connecting the electric heaters should be twisted-pair wires connected to another pair of twisted-pair wires in a localized area. The connection area should be small enough. The connection should be made in series and parallel according to the design requirements. The connection method can be welding or crimping. Single-wire wiring should be avoided during connection to prevent electromagnetic interference signals from being generated when the electric heater is powered on and off.

[0046] In addition to electric heaters, the thermal control subsystem will also be equipped with temperature sensing elements to monitor the local temperature of the spacecraft. The design of the back-end wires of the temperature sensing elements can refer to the design of the wires between the electric heaters mentioned above, and the wiring is also done in a twisted pair manner.

[0047] For the wires of the electric heater and temperature sensing element, a shielding layer can be used for protection according to design requirements, and the shielding layer should be grounded at the same potential as the satellite.

[0048] Based on the above, the electromagnetic cleanroom design method for electric heaters provided in this embodiment may include:

[0049] S11, A notch feature is provided on the side of the double-layer single-circuit electric heater so that the double-layer single-circuit electric heater can be fixed to the curved surface in a close manner;

[0050] S12, for the wires connecting the double-layer single-circuit electric heaters and the rear wires of the temperature element, a structure is adopted in which twisted-pair wires are connected to another pair of twisted-pair wires in a local area to prevent the electric heater from generating electromagnetic interference signals when the power is turned on and off.

[0051] In some preferred embodiments, the above-mentioned S11, which involves providing a notch feature on the side of the double-layer single-loop electric heater, may further include:

[0052] S111, the basic configuration of the electric heater is designed according to the surface development formula, and the electric heater is set as a trapezoidal structure with arc-shaped top and bottom sides; where, as Figure 2 As shown, the dimensional parameters of the electric heater are defined as follows:

[0053] The radius of curvature of the surface on which the electric heater is located The unit is mm;

[0054] The radius of the arc at the top edge of the electric heater The unit is mm;

[0055] The radius of the arc at the bottom edge of the electric heater The unit is mm;

[0056] The angle formed by the left and right sides of the electric heater , unit °;

[0057] Electric heater height The unit is mm;

[0058] The heater notch shape is defined as an isosceles triangle structure; where the base length of the isosceles triangle structure is... (Unit: mm), side length is (Unit: mm);

[0059] S112, Design of the notch size for the electric heater:

[0060] The following parameters are introduced to represent the shape characteristics of the heater dimensions:

[0061] shape factor The unit is mm / °, and the formula is as follows: The height of the electric heater. The angle formed by the left and right sides of the electric heater;

[0062] Average radius factor In the formula, The radius of the arc at the top edge of the electric heater. The radius of the arc at the bottom edge of the electric heater. Let be the radius of curvature of the surface where the electric heater is located;

[0063] Current position radius factor ;

[0064] when When smaller, the electric heater has a short or wide angle, a relatively "short and stout" shape, and a smaller difference in curvature between its edges and the spherical surface, resulting in a good fit; when... When the size is large, the electric heater is "tall and thin", with significant side bending, and is prone to warping.

[0065] when When the surface is small, the electric heater is located near the top of the curved surface; the curvature is large, but the size is small, making it less prone to warping at the top edge. When the curvature is large, the electric heater is located near the bottom of the curved surface. The curvature is small but the size is large, and the top or bottom edge needs to release stress.

[0066] Set threshold and ,in, Used to characterize the slenderness of an electric heater; To characterize the position of the electric heater on the spherical surface; based on experience in electric heater manufacturing processes and implementation processes, The preferred value is 1.5 to 2.5. The preferred value is 0.4 to 0.6.

[0067] First, the number and location of triangular notches are designed based on the current shape characteristics of electric heaters:

[0068] like Therefore, the current electric heater does not need to have any triangular notches;

[0069] like and Therefore, the electric heater needs to have a triangular notch at the bottom edge and in the middle of each of the two sides, for a total of three notches;

[0070] like and Therefore, the electric heater needs to have a triangular notch at the top edge, bottom edge, and the middle of both sides, for a total of four notches;

[0071] Secondly, the radius factor of the current position where the triangular notch is located is determined according to the requirements. and the shape factor of electric heaters Set the notch shape parameters for: The notch shape parameters shape factor and current position radius factor Coupling is used as a deformation driving factor to describe the relationship between edge warping and notch size: The larger the size, the more severe the edge warping, and the larger the required notch size.

[0072] Define the dimensions of each triangular notch. (Base plate length) (Side length), set shape reference parameters (Empirical data) , The calculation is described in the following form:

[0073]

[0074] In the formula, the shape reference parameter They represent:

[0075] Units The changes in the dimensions of the bottom and sides of the notch caused by the change reflect the combined effects of the stiffness of the electric heater material, the bonding process of the silicone rubber, and the surface curvature on the deformation sensitivity; if the electric heater material is softer, the slope will decrease; if the material is harder or the bonding requirements are higher, the slope will increase.

[0076] Indicates when The theoretical notch size when =0 (i.e., when the shape is extremely short and wide and located at the top of the curved surface) should actually be zero. When the size is small, the actual notch size is 0 (no notch needs to be made). Therefore Setting it to a negative value indicates that the notch size is from It only begins to grow linearly when it exceeds a certain critical value.

[0077] Furthermore, in a specific application example, given the materials and bonding method, The value ranges from 1.0 to 1.2. The value ranges from 3.0 to 3.4. The value ranges from approximately -12 to -10. The value ranges from approximately -45 to -40. The specific value depends on the threshold. and The choice.

[0078] In some preferred embodiments, S12 above, for the wires connecting the double-layer single-loop electric heaters and the rear-end wires of the temperature element, adopts a structure in which twisted-pair wires are simultaneously connected to another pair of twisted-pair wires in a local area, and may further include:

[0079] S121, as Figure 3 As shown, a method of connecting one pair of twisted-pair wires to another pair of twisted-pair wires in a localized area is employed. Specifically, the wires with the same current direction in the two pairs of twisted-pair wires to be connected are connected in series or parallel in a localized area. The resulting twisted-pair wire then becomes a new twisted-pair wire and is connected to other twisted-pair wires in the same way in the localized area, and so on. The connection area should be less than or equal to a set area threshold to ensure it is small enough. The connection is performed in series or parallel according to design requirements. The connection method can be welding or crimping. Single-wire wiring should be avoided during connection to prevent electromagnetic interference signals generated when the electric heater is powered on and off.

[0080] S122, a shielding layer is installed on the outside of the conductor for protection, and the shielding layer is grounded at the same potential as the satellite.

[0081] Furthermore, in the electromagnetic cleanroom design for multi-layer thermal insulation components, the implementation method is as follows.

[0082] For multi-layered thermal insulation components in spacecraft, electromagnetic cleanliness is primarily reflected in the equipotential characteristics of these components. Based on this, the electromagnetic cleanliness design method for multi-layered thermal insulation components provided in this embodiment may include:

[0083] S21, A grounding network is set on the surface of the multi-layer thermal insulation component, requiring that the distance from any point on the surface of the multi-layer thermal insulation component to the nearest grounding point is no greater than GL, in meters; where:

[0084] S211, such as Figure 4 As shown, the grounding area background template is set according to GL. This template is an array background with three circles of radius GL as the common point and the center of the circle as the features.

[0085] S212, draw the outer boundary drawing of the multi-layer thermal insulation component, and mark the inner boundary of the multi-layer thermal insulation component on the drawing. The distance from the inner boundary to the outer boundary of the multi-layer thermal insulation component is GL, thus forming the drawing of the multi-layer thermal insulation component.

[0086] S213, overlay the multi-layer thermal insulation component drawing onto the grounding area background template, select a suitable position and angle, and determine the boundary grounding point and internal grounding point; the determination logic is as follows:

[0087] The three circular points within the outer boundary of the multi-layer thermal insulation component are used as the internal grounding point;

[0088] The center of the circle located between the inner boundary and the outer boundary of the multi-layer thermal insulation component is taken as the boundary grounding point;

[0089] Both the internal grounding point and the boundary grounding point are used as the grounding points of the multi-layer thermal insulation component to determine the grounding location;

[0090] After determining the grounding location, internal grounding wires are used to connect the grounding points. The connection method can be designed in series and parallel according to the grounding location. External grounding wires are designed and led out as required for equipotential grounding with the satellite to form the final equipment.

[0091] S22, After determining the grounding location, the design for each grounding point within the multi-layer thermal insulation assembly is as follows:

[0092] S221, multi-layer thermal insulation components typically include several parts such as secondary surface mirrors, spacer layers, and reflective layers. The spacer layer is generally an insulating material, such as polyester mesh, and the reflective layer is generally a conductive material, such as double-sided aluminized polyester film. A certain area of ​​the spacer layer needs to be removed from each layer at the location of the grounding point so that there is no insulating material blocking the reflective layers below the grounding point.

[0093] S222 uses a conductive secondary surface mirror. The outer surface is an ITO (indium oxide) conductive coating, and the inner surface is a metal layer. The ITO layer and the metal layer have conductive properties.

[0094] S223 uses a metal rivet structure that runs through and presses together multiple layers of heat insulation components, allowing each reflective layer to make conductive contact with the other layers. At the same time, the reflective layer makes conductive contact with the inner surface metal layer of the conductive secondary surface mirror. The metal rivets should be made of non-magnetic metal materials, such as aluminum alloy.

[0095] S224, when the number of spacer layers and reflective layers is small (e.g., less than or equal to a set threshold m, m is preferably 5), metal foil may not be provided; when the number of layers is large (e.g., greater than a set threshold n, n is preferably 10), metal foil may be provided to make the degree of compression adjustable. The material should be a non-magnetic material, such as aluminum foil or copper foil. Metal foil is inserted into each or part of the reflective layers, and when the rivet structure is pressed, the metal foil and each reflective layer make conductive contact.

[0096] S23, the fixing device for the multi-layer thermal insulation component adopts a "pin-card" form. The card can be made of a composite conductive material, such as copper-doped polyimide; when the pin adopts an adhesive base form, the pin can be made of the same material as the card and is glued with conductive silicone rubber; when the pin adopts a screw base form, the pin must be made of a non-magnetic metal material, such as titanium alloy.

[0097] Through the design of S21, S22, and S23, the cross-section and inner and outer surfaces of the multi-layer thermal insulation component are integrated to achieve an equipotential effect, thus meeting electromagnetic cleanliness requirements. For example... Figure 5 As shown.

[0098] In some preferred embodiments, the above method may further include:

[0099] S3, electromagnetic cleanroom design for thermal control equipment in propulsion systems; where:

[0100] The heating strip in the pipeline is designed to consist of polyimide insulating tape and metal wires, with the metal wires being routed in a folded-back manner.

[0101] A polyimide material layer is applied to the surface of the gas cylinder's thermal conductive film, and a grounding point is set up with a grounding wire led out to be grounded at the same potential as the satellite;

[0102] The high-temperature heat shield near the main thruster is designed using carbon fiber-ceramic composite material with conductive properties to form an equipotential structure.

[0103] An aluminum foil heat-insulating cloth is placed between the secondary surface mirror and the internal multi-layer unit in the multi-layer heat insulation assembly near the small thruster, and the aluminum foil heat-insulating cloth is made into conductive contact with the secondary surface mirror and the reflective layer.

[0104] Furthermore, in the electromagnetic cleanroom design for propulsion system thermal control equipment, the implementation method is as follows.

[0105] In addition to the electromagnetic cleanroom design mentioned above for electric heaters and multi-layer insulation components, electromagnetic cleanroom design is also required for thermal control equipment in propulsion systems. Therefore, the electromagnetic cleanroom design method for thermal control equipment in propulsion systems provided in this embodiment may include:

[0106] S31, Pipeline heating element:

[0107] Similar to the aforementioned electric heater design, the heating element in the pipeline consists of polyimide insulating tape and metal wires. The metal wires are laid out in a folded-back configuration, which generates current in both directions and weakens the electromagnetic interference caused by the heating element being energized. A specific example is... Figure 7 As shown in the figure, this is a single-loop heating belt. In the figure, 21 is a metal wire, 22 is an insulating layer, the positive line and the return line are exited on the same side, and 20 is the characteristic of the heating metal wire folding back.

[0108] S32, Gas cylinder heat-conducting film:

[0109] The gas cylinders in the propulsion system are usually metal pressure vessels with carbon fiber material wrapped around them. During the filling test on the ground, the cylinders will undergo significant deformation in the axial and circumferential directions. Therefore, the electric heater cannot be directly attached to the cylinder body. The solution is to attach the electric heater to a heat-conducting film. The heat-conducting film is usually a flexible carbon-based composite material. In order to avoid generating excess material, polyimide material must be attached to the surface of the heat-conducting film.

[0110] Based on the above design, the thermally conductive film with polyimide is an isolated conductor, requiring a grounding point to be specially set on the thermally conductive film and a grounding wire to be led out to be grounded at the same potential as the satellite.

[0111] S33, High-temperature heat shield near the main thruster:

[0112] Commonly used high-temperature heat shields contain stainless steel and other metal materials, which have a significant impact on the electromagnetic environment. In electromagnetically clean systems, non-magnetic molybdenum foil can be used instead of stainless steel. The outer surface of high-temperature heat shields is usually made of silicon-based materials, which have no conductive properties. They can be replaced with carbon fiber-ceramic composite materials that have conductive properties to achieve an equipotential effect.

[0113] S34, multi-layer thermal insulation assembly near the small thruster:

[0114] For the multi-layer heat insulation components near the small thruster, aluminum foil heat insulation cloth needs to be added between the secondary surface mirror and the internal multi-layer unit. The aluminum foil heat insulation cloth should be in conductive contact with the secondary surface mirror and the reflective layer, and be pressed and fixed by a rivet structure.

[0115] Based on the same inventive concept, an embodiment of the present invention also provides an electromagnetically clean spacecraft thermal control device, which is designed using the electromagnetic clean design method provided in the above-described embodiment of the present invention; wherein:

[0116] The double-layer single-loop electric heater has a notch feature on its side; the connecting wires between the double-layer single-loop electric heaters and the rear wires of the temperature element all adopt a structure in which one pair of twisted wires is connected to another pair of twisted wires in a local area.

[0117] The surface of the multi-layer thermal insulation component is provided with a grounding point network, and each grounding point in the multi-layer thermal insulation component adopts an integrated equipotential grounding design.

[0118] In some preferred embodiments, the aforementioned spacecraft thermal control device may further include:

[0119] In the propulsion system, the pipeline heating tape is composed of polyimide insulating tape and metal wires, with the metal wires being routed in a folded-back manner;

[0120] A polyimide material layer is applied to the surface of the gas cylinder's thermal conductive film, and a grounding point is set up with a grounding wire leading out to be grounded at the same potential as the satellite;

[0121] The high-temperature heat shield near the main thruster is made of carbon fiber-ceramic composite material with conductive properties to form an equipotential structure.

[0122] An aluminum foil heat-insulating cloth is provided between the secondary surface mirror and the internal multi-layer unit in the multi-layer heat insulation assembly near the small thruster. The aluminum foil heat-insulating cloth is in conductive contact with the secondary surface mirror and the reflective layer.

[0123] It should be noted that each part of the device provided by the present invention can be implemented using the corresponding steps in the method. Those skilled in the art can refer to the technical solution of the method to realize the composition of the device. That is, the embodiments in the method can be understood as preferred examples of constructing the device, and will not be elaborated here.

[0124] The technical solution provided by the above embodiments of the present invention will be further described in detail below with reference to a specific application example.

[0125] This specific application example addresses the problem of unclear design methods for actual spacecraft thermal control equipment under electromagnetic cleanliness requirements in existing technologies. Through the technical solutions provided in the above embodiments of the present invention, the specificity and standardization of thermal control equipment design methods are verified, making implementation more operational and providing greater guidance.

[0126] This specific application example uses the design of the tank hemispherical electric heater in the SMILE satellite's large thrust system as an example. The three-layer hemispherical heater of the tank has the following shape: Figure 6 As shown.

[0127] 1. The storage tank has a hemispherical surface with a radius of 365mm, and a double-layer single-circuit electric heating element is attached to the hemispherical surface.

[0128] 2. Three types of electric heaters are set up according to the latitude of the hemisphere. These three types of electric heaters are arranged on the surface of the upper, middle and lower layers of the hemisphere. The angles of these three layers to the center of the hemisphere are 33°, 28° and 28° respectively. From the side, the arc lengths of these three layers on the hemisphere are approximately 212mm, 181mm and 181mm. The number of electric heaters in the upper, middle and lower layers are 8, 16 and 16 respectively. After each electric heater is expanded outward by 16-18mm, the electric heaters will cover the outer surface area of ​​the hemisphere.

[0129] 3. Based on the above input conditions, design the shape of the electric heater and the design of each heater notch:

[0130] (1) The top layer is similar to a trapezoid with arcs on the top and bottom. The radius of the arc on the top is 110mm, the radius of the arc on the bottom is 170mm, the angle between the left and right sides is 44°, and the height of the trapezoid is 60mm. According to the formula for the notch of the electric heater mentioned above, the electric heater does not need to have notches on its four sides.

[0131] (2) The middle layer of electric heater is also similar to a trapezoid, with arcs at the top and bottom; the radius of the upper arc is 170mm, the radius of the lower arc is 315mm, the angle between the left and right sides is 21°, and the height of the trapezoid is 145mm. According to the aforementioned formula for electric heater notches, the electric heater needs to have three notches at the bottom and two sides. The triangular notches on the two sides of the electric heater have a base length of 15mm and a side length of 25mm; the triangular notches on the bottom of the electric heater have a base length of 23mm and a side length of 30mm.

[0132] (3) The bottom layer of electric heater is also similar to a trapezoid, with arcs at the top and bottom; the radius of the upper arc is 315mm, the radius of the lower arc is 460mm, the angle between the left and right sides is 18°, and the height of the trapezoid is 145mm. According to the above formula for electric heater notches, the electric heater needs to have four notches on the bottom, top, and two sides. The triangular notches on the two sides of the electric heater have a base length of 20mm and a side length of 38mm; the triangular notch on the bottom side of the electric heater has a base length of 29mm and a side length of 39mm; the triangular notch on the top side of the electric heater has a base length of 19mm and a side length of 28mm.

[0133] The electromagnetic cleanliness design method for spacecraft thermal control equipment provided in the above embodiments of the present invention reduces the electromagnetic signals generated when the heating circuit is energized or de-energized by designing an electromagnetic cleanliness design for a double-layer single-loop electric heater; a double-layer single-loop electric heater configuration with a curved surface is designed to better fit the electric heater to the curved surface, eliminating potential risks; the electric heater's guide wires are twisted in a pair to suppress electromagnetic stray signals; for the electromagnetic cleanliness design of multi-layer thermal insulation components, a surface grounding layout design method is adopted, and a cross-sectional conductive grounding method for multi-layer thermal insulation components is proposed. Through the above methods, the overall equipotential effect of the multi-layer thermal insulation components is significantly enhanced, achieving the electromagnetic cleanliness effect of the thermal control equipment; the electromagnetic cleanliness design for the propulsion system pipeline heating belt, gas cylinder heat-conducting film, high-temperature heat insulation screen near the main thruster, and multi-layer thermal insulation components near the small thruster further achieves the electromagnetic cleanliness effect of the thermal control equipment. The electromagnetically clean spacecraft thermal control equipment and its electromagnetic clean design method provided in the above embodiments of the present invention have had a positive impact on the field of spacecraft thermal control technology, and have played a technological driving role in the next generation of deep space exploration missions, especially in the in-situ detection of space particles and high-precision magnetic field measurement.

[0134] Any matters not covered in the above embodiments of the present invention are well-known in the art.

[0135] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A method for electromagnetic cleanliness design of spacecraft thermal control equipment, characterized in that, include: Electromagnetic clean design for electric heaters; a notch is provided on the side of the double-layer single-loop electric heater so that it can be fixed to the curved surface; the wires connecting the double-layer single-loop electric heaters and the rear wires of the temperature element are all connected by a structure in a local area between one pair of twisted wires and another pair of twisted wires to prevent electromagnetic interference signals from being generated when the electric heater is powered on and off. Electromagnetic cleanroom design for multi-layer thermal insulation components; wherein, a grounding point network is set on the surface of the multi-layer thermal insulation components, and after determining the grounding location, an integrated equipotential grounding design is carried out for each grounding point in the multi-layer thermal insulation components; in: The notch feature on the side of the double-layer single-loop electric heater includes: The electric heater is configured as a trapezoidal structure, with both the top and bottom sides of the trapezoid being arc-shaped; The notch shape of the electric heater is defined as an isosceles triangle structure; where the base length of the isosceles triangle structure is... The side length is ; The shape factor, average radius factor, and current position radius factor are introduced to represent the shape characteristics of the electric heater's dimensions; where: shape factor In the formula, The height of the electric heater. The angle formed by the left and right sides of the electric heater; Average radius factor In the formula, The radius of the arc at the top edge of the electric heater. The radius of the arc at the bottom edge of the electric heater. Let be the radius of curvature of the surface where the electric heater is located; Current position radius factor ; Set threshold and ,in, Used to characterize the slenderness of an electric heater; This is used to characterize the position of the electric heater on the spherical surface; Based on the shape characteristics of the current electric heater, the number and location of the notches in the electric heater are designed as follows: like Therefore, the current electric heater does not need to have any openings made; like and The electric heater has three notches, one at the bottom and one at the middle of each of the two sides. like and The electric heater has four notches: one at the top edge, one at the bottom edge, and one at the middle of each of the two sides. Set the current position radius factor of the gap location as needed. and the shape factor of electric heaters Set the notch shape parameters for: The notch shape parameters shape factor and current position radius factor Coupling is used as a deformation driving factor to describe the relationship between edge warping and notch size; Set shape reference parameters The size characteristics of the notch , They are respectively: In the formula, Units The change in the dimensions of the bottom and side edges of the notch caused by the change. Indicates when The theoretical notch size at that time.

2. The electromagnetic cleanliness design method for spacecraft thermal control equipment according to claim 1, characterized in that, The wires connecting the double-layer single-loop electric heaters and the rear-end wires of the temperature element all adopt a structure in which one pair of twisted-pair wires is connected to another pair of twisted-pair wires in a local area, including: Connect the wires with the same current direction in a local area of ​​the two pairs of twisted wires that need to be connected in series or in parallel. Then, use the resulting twisted wire as a new twisted wire to connect with other twisted wires in the same way in the local area, and so on. The connection area is less than or equal to the set area threshold, and the connection method is welding or crimping. A shielding layer is installed on the outside of the conductor, and the shielding layer is grounded at the same potential as the satellite.

3. The electromagnetic clean design method for spacecraft thermal control equipment according to claim 1, characterized in that, The process of setting a grounding point network on the surface of the multi-layer thermal insulation component, and after determining the grounding location, performing an integrated equipotential grounding design for each grounding point within the multi-layer thermal insulation component, includes: A grounding point network is set on the surface of the multi-layer thermal insulation component, wherein the distance from any point on the surface of the multi-layer thermal insulation component to the nearest grounding point is not greater than a set threshold GL, and the grounding location is determined. After determining the grounding location, an integrated equipotential grounding design is implemented for each grounding point within the multi-layer thermal insulation assembly; The multi-layer thermal insulation components are fixed using a pin-and-card structure, thereby achieving integrated equipotential grounding of the cross-section and inner and outer surfaces of the multi-layer thermal insulation components as a whole.

4. The electromagnetic cleanliness design method for spacecraft thermal control equipment according to claim 3, characterized in that, The step of setting a grounding point network on the surface of the multi-layer thermal insulation component, wherein the distance from any point on the surface of the multi-layer thermal insulation component to the nearest grounding point is not greater than a set threshold GL, and determining the grounding location includes: A grounding area background template is set according to a set threshold GL. The template is an array background featuring three circles of radius GL that meet at a common point and their center. Draw the outer boundary drawing of the multi-layer thermal insulation component, and mark the inner boundary of the multi-layer thermal insulation component on the drawing. The distance from the inner boundary to the outer boundary of the multi-layer thermal insulation component is GL, thus forming the drawing of the multi-layer thermal insulation component. Overlay the drawings of the multi-layer thermal insulation component onto the background template of the grounding area, determine the boundary grounding point and the internal grounding point according to the following determination logic, and design the wiring: The three circular points within the outer boundary of the multi-layer thermal insulation component are used as the internal grounding point; The center of the circle located between the inner boundary and the outer boundary of the multi-layer thermal insulation component is taken as the boundary grounding point; Both the internal grounding point and the boundary grounding point are used as the grounding points of the multi-layer thermal insulation component to determine the grounding location; After determining the grounding location, internal grounding wires are used to connect the grounding points, and external grounding wires are led out for equipotential grounding with the satellite.

5. The electromagnetic cleanliness design method for spacecraft thermal control equipment according to claim 3, characterized in that, After determining the grounding location, an integrated equipotential grounding design is implemented for each grounding point within the multi-layer thermal insulation assembly, including: Remove the spacer layer of a set area at each layer where the grounding point is located, so that there is no insulating material blocking the reflection layers below the grounding point; A conductive secondary surface mirror is used as the outer layer of the multilayer thermal insulation component. Its outer surface is an ITO conductive coating and its inner surface is a metal layer. The ITO conductive coating and the metal layer have conductive properties. The non-magnetic metal material rivet structure runs through and presses together multiple layers of heat insulation components, allowing the reflective layers to make conductive contact with each other, while the reflective layers make conductive contact with the inner surface metal layer of the conductive secondary surface mirror. When the number of spacer layers and reflective layers is less than or equal to the set threshold m, no non-magnetic metal foil is set; when the number of spacer layers and reflective layers is greater than the set threshold n, non-magnetic metal foil is set in each or part of the reflective layers so that the degree of compression is adjustable, and the non-magnetic metal foil makes conductive contact with each reflective layer when the rivet structure is pressed.

6. The electromagnetic clean design method for spacecraft thermal control equipment according to claim 3, characterized in that, The pin-card structure includes: The card is made of a composite conductive material; The pin is made from any of the following materials: When the pin adopts the form of an adhesive base, the pin is made of the same material as the card and is bonded with conductive silicone rubber; When the pin adopts a screw-in base, the pin must be made of non-magnetic metal material.

7. The electromagnetic clean design method for spacecraft thermal control equipment according to any one of claims 1-6, characterized in that, Also includes: Electromagnetic cleanroom design for thermal control equipment in propulsion systems includes: The heating strip in the pipeline is designed to consist of polyimide insulating tape and metal wires, with the metal wires being routed in a folded-back manner. A polyimide material layer is applied to the surface of the gas cylinder's thermal conductive film, and a grounding point is set up with a grounding wire led out to be grounded at the same potential as the satellite; The high-temperature heat shield near the main thruster is designed using carbon fiber-ceramic composite material with conductive properties to form an equipotential structure. An aluminum foil heat-insulating cloth is placed between the secondary surface mirror and the internal multi-layer unit in the multi-layer heat insulation assembly near the small thruster, and the aluminum foil heat-insulating cloth is made into conductive contact with the secondary surface mirror and the reflective layer.

8. An electromagnetically clean spacecraft thermal control device, characterized in that, The double-layer single-loop electric heater has a notch on its side; the connecting wires between the double-layer single-loop electric heaters and the rear wires of the temperature element all adopt a structure in which one pair of twisted wires is connected to another pair of twisted wires in a local area; the surface of the multi-layer heat insulation component is provided with a grounding point network, and each grounding point in the multi-layer heat insulation component adopts an integrated equipotential grounding design. in: The double-layer single-loop electric heater has a notch feature on its side, including: The electric heater is configured as a trapezoidal structure, with both the top and bottom sides of the trapezoid being arc-shaped; The notch shape of the electric heater is defined as an isosceles triangle structure; where the base length of the isosceles triangle structure is... The side length is ; The shape factor, average radius factor, and current position radius factor are introduced to represent the shape characteristics of the electric heater's dimensions; where: shape factor In the formula, The height of the electric heater. The angle formed by the left and right sides of the electric heater; Average radius factor In the formula, The radius of the arc at the top edge of the electric heater. The radius of the arc at the bottom edge of the electric heater. Let be the radius of curvature of the surface where the electric heater is located; Current position radius factor ; Set threshold and ,in, Used to characterize the slenderness of an electric heater; This is used to characterize the position of the electric heater on the spherical surface; Based on the shape characteristics of the current electric heater, the number and location of the notches in the electric heater are designed as follows: like Therefore, the current electric heater does not need to have any openings made; like and The electric heater has three notches, one at the bottom and one at the middle of each of the two sides. like and The electric heater has four notches: one at the top edge, one at the bottom edge, and one at the middle of each of the two sides. Set the current position radius factor of the gap location as needed. and the shape factor of electric heaters Set the notch shape parameters for: The notch shape parameters shape factor and current position radius factor Coupling is used as a deformation driving factor to describe the relationship between edge warping and notch size; Set shape reference parameters The size characteristics of the notch , They are respectively: In the formula, Units The change in the dimensions of the bottom and side edges of the notch caused by the change. Indicates when The theoretical notch size at that time.

9. The electromagnetically clean spacecraft thermal control equipment according to claim 8, characterized in that, Also includes: In the propulsion system: The pipeline heating tape is composed of polyimide insulating tape and metal wires, with the metal wires being routed in a folded-back manner. A polyimide material layer is applied to the surface of the gas cylinder's thermal conductive film, and a grounding point is set up with a grounding wire leading out to be grounded at the same potential as the satellite; The high-temperature heat shield near the main thruster is made of carbon fiber-ceramic composite material with conductive properties to form an equipotential structure. An aluminum foil heat-insulating cloth is provided between the secondary surface mirror and the internal multi-layer unit in the multi-layer heat insulation assembly near the small thruster. The aluminum foil heat-insulating cloth is in conductive contact with the secondary surface mirror and the reflective layer.

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