Thermal management method for a single high-heat dissipation machine based on a heat pipe network

Abstract

The present invention provides a thermal management method for a single machine with high heat dissipation based on a heat pipe network, which includes the following steps: Step 1: Combining the heat dissipation and temperature indicators of the single machine, calculate the heat dissipation area required for the single machine's heat dissipation, and directly install the single machine on the heat dissipation surface; Step 2: Form a heat pipe network by embedding heat pipes in the heat dissipation surface and attaching heat pipes outside the heat dissipation surface to efficiently transfer the heat at the bottom of the single machine to the entire heat dissipation surface; Step 3: Arrange externally attached heat pipes on the top surface of the single machine to overlap with the embedded heat pipes arranged in the mounting plate and incorporate them into the heat pipe network of the heat dissipation surface; Step 4: Paste heating sheets on the surface of the single machine to achieve heat compensation under low-temperature conditions of the single machine. The present invention realizes the heat dissipation of a single machine with high heat dissipation based on a heat pipe network, and realizes the heat compensation of the single machine under low-temperature conditions by pasting heating sheets on the surface of the single machine. The thermal management method of the single machine with high heat dissipation of the present invention is based on a heat pipe network and has the characteristics of high reliability, high efficiency and high heat dissipation capacity.

Description

Technical Field

[0001] The present invention relates to the field of thermal control technology, and in particular to a thermal management method for a single machine with large heat consumption based on a heat pipe network. Background Art

[0002] In aerospace thermal control design, single units with large heat consumption are generally arranged on the heat dissipation surface, and their heat is dissipated by pre-buried heat pipes in the heat dissipation surface. However, with the high integration and multifunctional requirements of satellites, there are more and more single units with large heat consumption, especially communication satellites, which have the characteristics of large heat consumption single units and large payloads. Some single units have heat consumption reaching kW level and require long-term operation. Satellites are limited by the carrying capacity and the size envelope of the fairing, and their available heat dissipation surface is limited, and they cannot dissipate heat through deployable radiators based on fluid circuits or loop heat pipes. Therefore, how to improve the efficiency of the heat dissipation surface through thermal control design has become a problem that must be solved. Since heat pipes have no moving parts and rely on phase change for heat dissipation, they have strong heat transfer capacity and reliable operation, and are widely used in the field of aerospace thermal control. However, no matter how strong the heat transfer capacity of a single heat pipe is, it only plays the role of heat conduction. Only after the formation of a heat pipe network can it play the role of both heat conduction and efficient heat dissipation.

[0003] The patent document with publication number CN105744804A discloses a temperature control system for a single machine with high heat consumption and high stability, including: a single machine, a heater, a multi-layer insulation component and a fluid circuit system, wherein the fluid circuit system includes a drive pump, a cold plate, a radiator, a liquid reservoir and a pipeline. The non-heat-generating surface of the single machine is attached with a heater and covered with a multi-layer insulation component. The heat source surface of the single machine is fixedly connected to the cold plate, and the components of the fluid circuit are connected by pipelines to form a closed loop. When the single machine is working, the non-heat source surface of the single machine is heated and temperature-controlled by the heater partition program; the heat source surface of the single machine is temperature-controlled by coupling heat transfer through the fluid circuit. When the single machine is not working, the fluid circuit stops working, the heat transfer is blocked, and the single machine heater is heated by program control to maintain it within the temperature control range. However, the drive pump of the system in the patent document has moving parts, and the reliability of the system is not high.

[0004] The patent document with publication number CN106304778A discloses an integrated thermal control method for a single machine with large space heat consumption and transient operation, wherein the integrated thermal control method for a single machine with large space heat consumption and transient operation adopts a phase change energy storage device and a phase change energy storage material, wherein the phase change energy storage material is filled in the phase change energy storage device, and the phase change energy storage device and at least one single machine with large heat consumption and transient operation adopt an integrated design. However, the patent document is only applicable to single machines with large instantaneous heat consumption, and is not suitable for single machines or single machines that work for a long time. Summary of the invention

[0005] Aiming at the defects in the prior art, the purpose of the present invention is to provide a thermal management method for a large heat dissipation single machine based on a heat pipe network.

[0006] A thermal management method for a large heat dissipation single machine based on a heat pipe network provided by the present invention includes the following steps:

[0007] Step 1: Combining the heat dissipation and temperature indexes of the single machine, calculating the heat dissipation area required for the single machine heat dissipation, and directly installing the single machine on the heat dissipation surface;

[0008] Step 2: Forming a heat pipe network by embedding heat pipes in the heat dissipation surface and attaching heat pipes outside the heat dissipation surface to efficiently transfer the heat at the bottom of the single machine to the entire heat dissipation surface;

[0009] Step 3: Arranging externally attached heat pipes on the top surface of the single machine to lap them with the embedded heat pipes arranged in the mounting plate and incorporate them into the heat pipe network of the heat dissipation surface;

[0010] Step 4: Pasting heating sheets on the surface of the single machine to achieve heat compensation under low temperature conditions of the single machine.

[0011] Preferably, in the step 1, a heat conductive filler should be filled between the single machine and the heat dissipation surface to reduce the contact thermal resistance.

[0012] Preferably, in the step 2, a heat conductive filler should be filled between the externally attached heat pipe and the heat dissipation surface to reduce the contact thermal resistance.

[0013] Preferably, in the step 2, a heat conductive filler should be filled between the externally attached heat pipe and the single machine and between the externally attached heat pipe and the heat dissipation surface to reduce the contact thermal resistance.

[0014] Preferably, in the step 2, the embedded heat pipes and the externally attached heat pipes are bent or fin-removed according to the layout form.

[0015] Preferably, in the step 2, an insulating film is padded between the externally attached heat pipe and the single machine.

[0016] Preferably, the two sides of the insulating film are filled with heat conductive filler.

[0017] Preferably, in the step 2, a thermal control coating with a low solar absorptance and a high hemispherical emissivity is sprayed or pasted on the non-mounting surface of the externally attached heat pipe.

[0018] Preferably, in the step 2, the externally attached heat pipe is fixed to the mounting surface by screws or clamps.

[0019] Preferably, the fixed spacing of the externally attached heat pipe along the heat pipe direction is 100 - 150 mm.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. A thermal management method for a high heat dissipation single machine based on a heat pipe network forms a heat pipe network through heat pipe selection, three-dimensional layout, and heat dissipation surface planning to meet the heat dissipation requirements of short-term or long-term operation of a high heat dissipation single machine, and realizes heat compensation for the low-temperature working condition of the single machine through a heater;

[0022] 2. A thermal management method for a high heat dissipation single machine based on a heat pipe network, and the entire design relies on the heat pipe network formed by heat pipes. The heat pipe itself has no moving parts and relies on phase change for heat dissipation, which not only ensures the heat transfer and heat dissipation capabilities of the system but also has high reliability;

[0023] 3. A thermal management method for a high heat dissipation single machine based on a heat pipe network. The bottom and top surfaces of the single machine are incorporated into the same heat pipe network. Therefore, the entire single machine has good temperature uniformity;

[0024] 4. A thermal management method for a high heat dissipation single machine based on a heat pipe network effectively improves the utilization efficiency of the heat dissipation surface through the layout of the heat pipe network, thereby improving the heat dissipation capacity of the satellite platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] By reading the detailed description of the non-restrictive embodiments with reference to the following drawings, other features, objects, and advantages of the present invention will become more apparent:

[0026] Figure 1 is a schematic structural diagram of a specific embodiment of the present invention;

[0027] Figure 2 is a single machine temperature data diagram of the high-temperature working condition of the whole satellite thermal test in an embodiment of the present invention.

[0028] Heat pipes 4 embedded in the heat dissipation surface of the high heat dissipation single machine 1

[0029] Heat dissipation surface 2 Heat pipes 5 externally attached to the heat dissipation surface

[0030] Heat pipes 3 embedded in the bottom surface of the single machine Heat pipes 6 externally attached to the top surface of the single machine DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those of ordinary skill in the art can make several changes and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0032] As Figure 1 shown, a thermal management method for a high heat dissipation single machine based on a heat pipe network provided by the present invention includes the following steps:

[0033] Step 1: Combine the heat consumption and temperature index of the single unit, calculate the heat dissipation area required for the single unit's heat dissipation through calculation, and directly install the single unit on the heat dissipation surface. In Step 1, a heat-conducting filler should be filled between the single unit and the heat dissipation surface to reduce the contact thermal resistance;

[0034] Step 2: Form a heat pipe network by embedding heat pipes in the heat dissipation surface and attaching heat pipes outside the heat dissipation surface to efficiently transfer the heat at the bottom of the single unit to the entire heat dissipation surface. In Step 2, a heat-conducting filler should be filled between the attached heat pipe and the heat dissipation surface to reduce the contact thermal resistance. In Step 2, a heat-conducting filler should be filled between the attached heat pipe and the single unit and between the attached heat pipe and the heat dissipation surface to reduce the contact thermal resistance. In Step 2, the embedded heat pipes and the attached heat pipes should be bent or fin-removed according to the layout form. In Step 2, an insulating film should be padded between the attached heat pipe and the single unit, and the two sides of the insulating film should be filled with a heat-conducting filler. In Step 2, a thermal control coating with a low solar absorptance and a high hemispherical emissivity should be sprayed or pasted on the non-installation surface of the attached heat pipe. In Step 2, the attached heat pipe should be fixed to the installation surface by screws or clamps, and the fixed spacing of the attached heat pipe along the heat pipe direction is 100 - 150 mm;

[0035] Step 3: Arrange attached heat pipes on the top surface of the single unit to lap with the embedded heat pipes arranged in the mounting plate and incorporate the heat of the single unit into the heat pipe network of the heat dissipation surface;

[0036] Step 4: Paste heating sheets on the surface of the single unit to achieve heat compensation under low-temperature conditions of the single unit.

[0037] In the preferred example, the size of the heat dissipation surface and the layout of the heat pipes need to be calculated in combination with the heat consumption and temperature index of the single unit, and the single unit should be directly installed on the heat dissipation surface; for single units with high heat consumption, heat pipes are embedded at the bottom of the single unit to conduct the heat at the bottom of the single unit out, and attached heat pipes are arranged outside the heat dissipation surface to form a heat pipe network to transfer and distribute its heat to the entire heat dissipation surface. The embedded heat pipes and the attached heat pipes can be appropriately bent and fin-removed according to the layout form, but the heat transfer capacity after bending still meets the heat transfer requirements of the single unit; for single units with high heat consumption, attached heat pipes are arranged on the top surface of the single unit to conduct the heat on the top surface of the single unit out, and the heat on its top surface is dissipated by lapping with the embedded heat pipes in the heat dissipation surface and ensuring the temperature uniformity of the entire single unit; if the single unit has electrical insulation requirements, an insulating film with a certain thickness should be padded between the attached heat pipe and the single unit. Among them, the two sides of the insulating film are filled with a heat-conducting filler to ensure both electrical insulation and reduce the thermal resistance between the heat pipe and the installation surface; the selection of the thermal control coating for the heat dissipation surface should be determined through analysis and calculation to ensure that its heat dissipation capacity meets the requirements; generally, a thermal control coating with a low solar absorptance and a high hemispherical emissivity is sprayed or pasted on the non-installation surface of the attached heat pipe to ensure the dissipation of its heat; generally, the attached heat pipe is fixed to the installation surface by screws or clamps, and the fixed spacing along the heat pipe direction is generally 100 - 150 mm; the heater is directly pasted on the surface of the single unit to improve the heating efficiency and achieve heat compensation for the single unit under low-temperature conditions.

[0038] In the preferred embodiment, the heat pipe should be selected according to the heat to be transferred actually required. Generally, a double-hole aluminum ammonia channel heat pipe is selected to improve the reliability of the whole system. The heat distributed on each heat pipe shall not exceed its maximum heat transfer capacity, and generally at least 30% margin shall be reserved. On the basis of meeting the design specifications, the heat pipe can be appropriately bent and the fins can be trimmed, but the heat transfer capacity of the heat pipe after bending shall be able to meet the heat transfer requirements.

[0039] In the preferred embodiment, the heat dissipation surface should generally be a high thermal conductivity skin + honeycomb sandwich structure, which can not only reduce the weight of the system but also meet the embedding requirements of the heat pipe. Generally, it is an Al skin + Al honeycomb structure. The heat dissipation surface needs to be sprayed or pasted with a low solar absorptance thermal control coating to ensure its heat dissipation requirements. The selection of the thermal control coating and the size of the heat dissipation surface both need to be determined by calculation.

[0040] In the preferred embodiment, the heat pipes embedded in the heat dissipation surface should be selected as the type of heat pipes that are double-sidedly attached to the skin of the heat dissipation surface. On the one hand, it reduces the thermal resistance of the inner and outer skins. On the other hand, it is necessary to form a heat pipe network with the heat pipes externally attached to the heat dissipation surface; the heat pipes externally attached to the heat dissipation surface are externally attached on the side of the heat dissipation surface facing the cold air to avoid interference with the heat pipes externally attached to the top surface of the single machine, which affects the layout of the heat pipe network and further affects the heat dissipation efficiency of the heat dissipation surface; for the overlapping method of the externally attached heat pipes and the heat pipes embedded in the heat dissipation surface, generally, the heat pipes are bent and overlapped with the heat pipes embedded in the heat dissipation surface by 300 - 500 mm. The fin removal operation can be carried out on the bent section as needed, and it is fixed along the direction by screws or clamps.

[0041] In the preferred embodiment, the insulating film is a non-conductive insulating thin film, and polyimide film can be selected; the heat-conducting filler is heat-conducting silicone grease RKTL-DRZ-1 or indium foil; the heating sheet is pasted on the surface of the single machine with silicone rubber to realize the thermal compensation of the single machine under low-temperature conditions.

[0042] Example:

[0043] As Figure 1 shown, the embodiment of the present invention discloses a thermal management method for a large heat dissipation single machine based on a heat pipe network.

[0044] The heat dissipation of a certain single machine of a communication satellite is 1250 W. The single machine works long-term during the whole orbit except during the eclipse period when it does not work. The weight resources of the whole satellite are tense, and the layout of the payload and the single machine is compact. It is impossible to use other expandable radiators based on fluid loops or loop heat pipes for heat dissipation. Therefore, it is necessary to adopt the thermal management method for a large heat dissipation single machine based on the heat pipe network of the present invention to realize the temperature control during the whole mission cycle.

[0045] First, according to the overall satellite thermal simulation analysis, the required heat dissipation area is approximately 4 m². Seven I-shaped double-hole 30 mm × 24.1 mm aluminum-ammonia channel heat pipes are embedded at the bottom heat dissipation surface position of the single unit, six I-shaped double-hole 30 mm × 24.1 mm aluminum-ammonia channel heat pipes are embedded at other positions of the heat dissipation surface, six I-shaped double-hole 40 mm × 14.1 mm aluminum-ammonia channel heat pipes are pasted on the outside of the heat dissipation surface, and four I-shaped double-hole 40 mm × 14.1 mm aluminum-ammonia channel heat pipes are pasted on the outside of the top surface of the single unit and incorporated into the heat pipe network of the heat dissipation surface for heat dissipation. The heat pipes pasted on the outside of the top surface of the single unit are fixed to the top surface of the single unit and the joint between the heat dissipation surface and the embedded heat pipes at a spacing of 100 mm using screws.

[0046] Secondly, OSR sheets are pasted on the heat dissipation surface, and the non-installation surface of the externally pasted heat pipes is sprayed with antistatic low solar absorptance and high hemispherical emissivity thermal control white paint;

[0047] Finally, thin-film electric heating sheets are pasted on the side of the single unit to improve the heating efficiency. The heating circuit is designed with 1 main and 1 standby, with a compensation power consumption of 350 W. Through the feedback of the temperature measurement points on the side of the single unit and the setting of the temperature control threshold, the self-closed loop realizes the thermal compensation of the single unit under low-temperature conditions.

[0048] The working temperature index of the high heat dissipation single unit is -15°C to 55°C for the top surface and -15°C to 55°C for the bottom surface, and the storage temperature index is -40°C to 70°C. From Figure 2 the temperature curve, it can be found that during the thermal balance test, the temperature of the single unit meets the index requirements and there is a certain design margin. The maximum temperature difference between the top surface and the bottom surface of the single unit is 2°C, and the temperature consistency is good. The thermal management method of the high heat dissipation single unit based on the heat pipe network of the present invention has successfully realized the thermal management of the kW-level high heat dissipation single unit.

[0049] The present invention realizes the heat dissipation of the high heat dissipation single unit based on the heat pipe network, and realizes the thermal compensation of the single unit under low-temperature conditions by pasting heating sheets on the surface of the single unit. The thermal management method of the high heat dissipation single unit of the present invention is based on the heat pipe network and has the characteristics of high reliability, high efficiency and high heat dissipation capacity.

[0050] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0051] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A thermal management method for a single machine with high heat dissipation based on a heat pipe network, characterized in that, it includes the following steps: Step 1: Combine the heat dissipation and temperature indicators of the single machine, calculate the heat dissipation area required for the single machine to dissipate heat, and directly install the single machine on the heat dissipation surface; Step 2: Form a heat pipe network by embedding heat pipes in the heat dissipation surface and attaching heat pipes outside the heat dissipation surface, and efficiently transfer the heat at the bottom of the single machine to the entire heat dissipation surface; Step 3: Arrange attached heat pipes on the top surface of the single machine, and lap them with the embedded heat pipes arranged in the heat dissipation surface and incorporate them into the heat pipe network of the heat dissipation surface; Step 4: Paste heating sheets on the surface of the single machine to achieve heat compensation under low-temperature conditions of the single machine; In the said Step 2, the embedded heat pipes and the attached heat pipes are bent or fin-removed according to the layout form; In the said Step 2, an insulating film is padded between the attached heat pipes and the single machine; Both sides of the insulating film are filled with heat-conducting fillers; In the said Step 2, the non-installation surface of the attached heat pipe is sprayed or pasted with a thermal control coating with a low solar absorptance and a high hemispherical emissivity; In the said Step 2, the attached heat pipes are fixed to the heat dissipation surface by screws or clamps, and the fixing pitch of the attached heat pipes along the heat pipe direction is 100 - 150 mm; The heat pipes selected are double-hole aluminum ammonia channel heat pipes, and the heat distributed on each heat pipe does not exceed its maximum heat transfer capacity, with at least 30% margin left; The heat dissipation surface is a structure composed of a skin and a honeycomb sandwich; The embedded heat pipes are double-sidedly adhered to the skin of the heat dissipation surface; Attached heat pipes are arranged on the side of the heat dissipation surface facing the cold air; The lapping method of the attached heat pipes and the embedded heat pipes is: bending the attached heat pipes and lapping them with the embedded heat pipes for 300 - 500 mm.

2. The thermal management method for a single machine with high heat dissipation based on a heat pipe network according to claim 1, characterized in that, in the said Step 2, heat-conducting fillers should be filled between the attached heat pipes and the heat dissipation surface to reduce the contact thermal resistance.

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