Variable diameter heat pipe cooling structure and aircraft

Abstract

This application relates to a variable-diameter heat pipe cooling structure and an aircraft. The variable-diameter heat pipe cooling structure includes an electric drive bay, a cooler, and a heat dissipation shroud. A heat transfer medium circulates between the heat sources in the cooler and the electric drive bay to transfer heat from the electric drive bay to the cooler. One end of the heat dissipation shroud is fitted onto the outer periphery of the cooler along its own axial direction, and the other end extends towards the windward side of the aircraft. An airflow channel is formed between the heat dissipation shroud and the electric drive bay, allowing airflow to flow through the airflow channel to the cooler for heat dissipation. The heat dissipation shroud is attached to and tightly fitted to the side wall of the cooler, allowing heat from the cooler to be transferred to the atmosphere through the heat dissipation shroud. The variable-diameter heat pipe cooling structure and aircraft provided by this application solve the problems of significantly increasing the volume and weight of the cabin and the low heat dissipation efficiency of the cooling structure of the electric drive system.

Description

Technical Field

[0001] This application relates to the field of aircraft technology, and in particular to a variable diameter heat pipe heat dissipation structure and an aircraft. Background Technology

[0002] In existing rotorcraft, the cooling of the rotor (propeller) electric drive system (which can be simply understood as an electric drive system that integrates motors, reducers, controllers, etc. into one unit) mainly utilizes oil coolers for single-phase oil cooling. The oil cooler is usually located inside the rotor nacelle and is wrapped on the outside of the rotor nacelle skin. In addition, an auxiliary electric fan is also installed inside the rotor nacelle to cool the oil cooler.

[0003] However, this configuration has two drawbacks. First, the auxiliary electric fan significantly increases the size and weight of the rotorcraft's cabin. Second, when the electric drive system is operating at high power consumption, the combination of the electric fan and the cooler makes it difficult to quickly dissipate heat from the electric drive system; in other words, the heat dissipation efficiency cannot meet the requirements. Summary of the Invention

[0004] Therefore, it is necessary to provide a variable diameter heat pipe cooling structure and aircraft to solve the problems that the existing cooling structure of electric drive system will significantly increase the size and weight of the cabin and have low heat dissipation efficiency.

[0005] The variable diameter heat pipe cooling structure provided in this application includes an electric drive compartment, a cooler, and a heat dissipation shroud. The heat transfer medium can circulate between the heat source in the cooler and the electric drive compartment to transfer the heat in the electric drive compartment to the cooler. One end of the heat dissipation shroud is fitted onto the outer periphery of the cooler along its own axis, and the other end extends toward the windward side of the aircraft. A guide channel is formed between the heat dissipation shroud and the electric drive compartment. Airflow can flow through the guide channel to the cooler to dissipate heat from the cooler. The heat dissipation shroud is attached to the side wall of the cooler and fits tightly with the side wall of the cooler so that the heat of the cooler can be transferred to the atmospheric environment through the heat dissipation shroud.

[0006] In one embodiment, the heat dissipation shroud includes a fixed part and a variable diameter part. The heat dissipation shroud is installed and connected to the cooler through the fixed part, and the variable diameter part is movably connected to the end of the fixed part near the windward side of the aircraft. The variable diameter heat pipe heat dissipation structure can expand or shrink the diameter of the variable diameter part to increase or decrease the flow area of ​​the air duct.

[0007] In one embodiment, the variable diameter section includes a first sidewall and a second sidewall. The first sidewall is the inner ring sidewall of the variable diameter section, and the second sidewall is the outer ring sidewall of the variable diameter section. The coefficient of thermal expansion of the first sidewall is greater than that of the second sidewall. When the variable diameter section is in the initial state, the end of the variable diameter section away from the fixed part is in an inwardly curved state that is closer to the electric drive compartment. When the heat of the electric drive compartment is transferred to the variable diameter section, the end of the variable diameter section away from the fixed part can gradually change from the inwardly curved state to the outwardly expanded state. The outwardly expanded state is the state in which the end of the variable diameter section away from the fixed part is curved in the direction away from the electric drive compartment.

[0008] In one embodiment, the heat dissipation shroud includes a plurality of heat dissipation fins arranged sequentially along its circumference. Each heat dissipation fin includes a fixed section and a variable diameter section. The fixed sections of adjacent heat dissipation fins are fixedly connected to form an annular fixed part, and the variable diameter section is movably connected to the end of the fixed section near the windward side of the aircraft. The heat dissipation shroud also includes a controller, an adjustment motor, and an adjustment arm. The body of the adjustment motor is mounted on the fixed section, and one end of the adjustment arm is fixedly connected to the output end of the adjustment motor and the other end is connected to the variable diameter section. Alternatively, the body of the adjustment motor is mounted on the variable diameter section, and one end of the adjustment arm is fixedly connected to the output end of the adjustment motor and the other end is connected to the fixed section. The controller can control the adjustment motor to drive the adjustment arm to rotate forward or backward, so as to tilt the end of the variable diameter section away from the fixed section toward the direction of approaching or away from the electric drive bay.

[0009] In one embodiment, at least some of the heat sinks are provided with an adjustment motor and an adjustment arm. The three heat sinks arranged in sequence are defined as the first sink, the second sink, and the third sink. One end of the second sink along the circumference of the heat dissipation shroud overlaps the side of the first sink away from the electric drive compartment, and the other end of the second sink along the circumference of the heat dissipation shroud overlaps the side of the third sink near the electric drive compartment.

[0010] In one embodiment, the variable diameter section is hinged to one end of the fixed section via a hinge shaft; alternatively, the heat sink may also include a flexible connecting section, through which the variable diameter section is connected to the fixed section.

[0011] In one embodiment, the variable diameter heat pipe cooling structure further includes a temperature sensor and a wind speed sensor. The temperature sensor is located in one or more of the electric drive compartment, cooler, and heat dissipation shroud. The controller can adjust the tilt angle of the variable diameter section relative to the fixed section by adjusting the motor according to the temperature value measured by the temperature sensor, so as to adjust the total windward area of ​​the variable diameter section. The wind speed sensor is located on the fixed surface of the aircraft. The controller can adjust the tilt angle of the variable diameter section relative to the fixed section by adjusting the wind speed value measured by the wind speed sensor, so as to adjust the flow area of ​​the air guide channel.

[0012] In one embodiment, the fixed part is provided with an evaporation chamber, the variable diameter part is provided with a condensation chamber, the evaporation chamber is connected to the condensation chamber, and a liquid working fluid is provided in the evaporation chamber. When the liquid working fluid in the evaporation chamber absorbs heat and vaporizes, the gaseous working fluid can enter the condensation chamber and condense and liquefy. Furthermore, the liquefied working fluid can flow back from the condensation chamber to the evaporation chamber.

[0013] In one embodiment, the cooler includes an inlet manifold, an outlet manifold, and flat tubes. The inlet manifold is located at one end of the outer periphery of the cooler, and the outlet manifold is located at the other end of the outer periphery of the cooler. The two ends of the multiple flat tubes are respectively connected to the inlet manifold and the outlet manifold. Adjacent flat tubes are spaced apart to form a heat dissipation gap for airflow. A heat dissipation duct is fitted onto the outer periphery of the inlet manifold and the outlet manifold.

[0014] In one embodiment, the heat dissipation shroud and the sidewall of the cooler are welded together, or the heat dissipation shroud and the sidewall of the cooler are connected by thermal grease, or the heat dissipation shroud and the sidewall of the cooler are integrally formed.

[0015] This application also provides an aircraft that includes the variable diameter heat pipe heat dissipation structure described in any of the above embodiments.

[0016] Compared with existing technologies, the variable-diameter heat pipe cooling structure and aircraft provided in this application, specifically, allow oncoming airflow to enter the cooler area through the air guide channel during flight. Guided by the heat dissipation shroud, the airflow accelerates across the cooler surface, carrying away the heat transferred by the heat transfer medium. The heat transfer medium inside the cooler absorbs heat generated by the electric drive bay's heat source and then flows through the cooler's fins under the drive of the circulating pump, undergoing forced convection heat exchange with the high-speed airflow. The close contact between the heat dissipation shroud and the cooler sidewall forms a continuous heat conduction path, allowing some heat to be directly radiated to the external environment through the shroud. Furthermore, the axial extension design of the heat dissipation shroud effectively captures the kinetic energy of the airflow in the flight direction, preventing energy loss due to airflow detours.

[0017] Compared to existing technologies, which rely on electric fans for forced convection, requiring additional power and increasing structural weight, this solution converts flight kinetic energy into cooling airflow through a heat dissipation shroud structure, eliminating the need for an additional power unit. Traditional oil coolers are enclosed within the cabin, dissipating heat only through a limited surface area; this solution externalizes the cooler and integrates it with the airflow guide structure, significantly increasing the effective heat dissipation area. In existing technologies, the heat dissipation components and airflow channels are separate designs; this solution achieves a synergistic effect of heat conduction and airflow guidance through the tight fit between the heat dissipation shroud and the cooler.

[0018] Through the above technical solution, this application achieves passive and efficient heat dissipation for the aircraft's electric drive system. Utilizing the natural airflow generated by the aircraft's motion instead of an electric fan effectively reduces system weight and energy consumption. The directional guidance of the airflow channel improves airflow utilization, ensuring a stable, high-speed flow field on the cooler surface. The triple function of the heat dissipation shroud enhances structural rigidity, expands the heat dissipation path through heat conduction, and concentrates the oncoming airflow passing through the shroud onto the cooler, maintaining efficient and stable heat dissipation performance under complex flight conditions. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of a variable diameter heat pipe heat dissipation structure according to an embodiment of this application;

[0021] Figure 2 A partial cross-sectional view of a variable diameter heat pipe heat dissipation structure according to an embodiment of this application;

[0022] Figure 3 A partial structural schematic diagram of a variable diameter heat pipe heat dissipation structure according to an embodiment of this application;

[0023] Figure 4 for Figure 3 A cross-sectional view of the structure shown;

[0024] Figure 5 A partial cross-sectional view of the heat dissipation shroud provided in this application according to an embodiment;

[0025] Figure 6 A schematic diagram of the structure of a heat dissipation shroud according to an embodiment of this application;

[0026] Figure 7 for Figure 6 A magnified view of point Q shown.

[0027] Reference numerals: 100, electric drive compartment; 110, electric drive housing; 120, electric drive unit; 200, cooler; 210, liquid inlet manifold; 220, liquid outlet manifold; 230, flat tube; 240, heat dissipation gap; 250, fin; 300, propeller; 400, air guide shroud; 500, heat dissipation air guide shroud; 510, air guide channel; 520, fixed part; 521, evaporation chamber; 530, variable diameter part; 531, first side wall; 532, second side wall; 533, condensation chamber; 540, heat dissipation fin; 541, fixed section; 542, variable diameter section; 543, first fin; 544, second fin; 545, third fin; 550, adjusting motor; 560, adjusting arm; 570, retaining ring. Detailed Implementation

[0028] Please see Figures 1-7 This application provides a variable diameter heat pipe heat dissipation structure for cooling the electric drive system of various aircraft such as UAVs. The variable diameter heat pipe heat dissipation structure includes an electric drive compartment 100, a cooler 200, a heat dissipation shroud 500, a propeller 300, and a flow guide 400. The electric drive compartment 100 includes an electric drive housing 110 and an electric drive device 120. The electric drive device 120 is the power source for driving the propeller 300 to rotate. The electric drive device 120 is installed in the electric drive housing 110, which is cylindrical or flat cylindrical in shape. The electric drive device 120 mainly includes a drive motor, a reducer, and a controller. Among them, the stator of the drive motor generates the most heat. Therefore, the cooler 200 mainly cools the stator of the drive motor. Of course, it can also cool other heat sources (including but not limited to IGBT modules, SiC MOSFETs, reducers, controllers, and other parts of the drive motor). The fairing 400 is located at the front end of the electric drive bay 100 (that is, the front end of the aircraft, the end closest to the windward side), and serves to reduce wind resistance and protect the front-end components (including various sensors). The propeller 300 is connected to the output end of the electric drive bay 100 so that the electric drive unit 120 can drive the propeller 300 to rotate.

[0029] The cooler 200 is installed on the leeward side of the electric drive compartment 100. The heat transfer medium circulates between the cooler 200 and the heat source of the electric drive compartment 100 to transfer heat from the electric drive compartment 100 to the cooler 200. The cooler 200 refers to a heat exchange device arranged outside the electric drive compartment 100, which can be a finned radiator, fixed to the surface of the electric drive compartment 100 by welding or bolting. Specifically, the working principle of the cooler 200 is as follows: The heat transfer medium directly or indirectly contacts the heat source (such as the stator winding of the drive motor, IGBT module, or semiconductor power switching devices like SiCMOSTET) within the electric drive bay 100, absorbing the heat generated by the heat source. Then, the heat transfer medium (mainly heat transfer oil, but can also be deionized water, ethylene glycol aqueous solution, or other novel heat transfer media) is pumped into the cooler 200. Furthermore, the cooler 200 can utilize the oncoming airflow generated during flight or the airflow generated by the propeller 300 to dissipate a portion of the heat in the heat transfer medium into the atmosphere. The cooled heat transfer medium is then circulated back into the heat source within the electric drive bay 100 to continue absorbing heat. It should be noted that in this application, only a portion of the heat from the cooler 200 is dissipated into the atmosphere through the above method; the remaining heat can also be transferred through the heat dissipation duct 500.

[0030] Specifically, such as Figures 2-4 As shown, one end of the heat dissipation duct 500 is fitted onto the outer periphery of the cooler 200 along its own axis, and the other end extends toward the windward side of the aircraft, that is, the other end extends toward the direction close to the propeller 300. Furthermore, an annular air duct 510 is formed between the heat dissipation duct 500 and the electric drive nacelle 100. The airflow generated during the flight of the aircraft or the airflow generated by the propeller 300 can flow through the air duct 510 to the cooler 200 and pass through the heat dissipation gaps 240 between the flat tubes 230 of the cooler 200 to dissipate heat from the cooler 200.

[0031] Furthermore, the heat dissipation shroud 500 is attached to the side wall of the cooler 200 and tightly fitted to the side wall of the cooler 200, so that the heat of the cooler 200 can be transferred to the atmosphere through the heat dissipation shroud 500. Tight fit refers to the physical contact between the heat dissipation shroud 500 and the side wall of the cooler 200, which can be achieved through an interference fit or a flexible snap-fit ​​structure to ensure efficient heat conduction at the contact surface. Specifically, the heat dissipation shroud 500 and the side wall of the cooler 200 are welded together, or connected by thermal grease, or integrally formed (including but not limited to integral turning, integral stamping, integral casting, and 3D printing). This solution directly establishes the thermal interface between the cooler 200 and the heat dissipation shroud 500 through welding, thermal grease, or integral forming, eliminating the need for additional heat dissipation devices such as fans, simplifying the structure, shortening the heat transfer path, and improving heat dissipation efficiency.

[0032] Specifically, during flight, the oncoming airflow enters the cooler 200 area through the air guide duct 510. Guided by the heat dissipation shroud 500, the airflow accelerates and flows across the surface of the cooler 200, carrying away the heat transferred by the heat transfer medium. The heat transfer medium inside the cooler 200 absorbs the heat generated by the heat source in the electric drive bay 100 and, driven by the circulation pump, flows through the fins 250 of the cooler 200, undergoing forced convection heat exchange with the high-speed airflow. The close contact between the heat dissipation shroud 500 and the sidewall of the cooler 200 forms a continuous heat conduction path, allowing some heat to be directly radiated to the external environment through the heat dissipation shroud 500. Furthermore, the axial extension design of the heat dissipation shroud 500 effectively captures the kinetic energy of the airflow in the flight direction, preventing energy loss caused by airflow detours.

[0033] Compared to existing technologies, which rely on electric fans for forced convection, requiring additional power and increasing structural weight, this solution converts flight kinetic energy into cooling airflow through the heat dissipation shroud 500 structure, eliminating the need for an additional power unit. Traditional oil coolers are enclosed within the cabin, dissipating heat only through a limited surface area. This solution, however, externalizes the cooler 200 and integrates it with the airflow guide structure, significantly increasing the effective heat dissipation area and fully utilizing the airflow passing through the heat dissipation shroud 500 for cooling. In existing technologies, the heat dissipation components and airflow channels are separate designs; this solution achieves a synergistic effect of heat conduction and airflow guidance through the tight fit between the heat dissipation shroud 500 and the cooler 200.

[0034] Through the above technical solution, this application achieves passive and efficient heat dissipation for the aircraft's electric drive system. Utilizing the natural airflow generated by the aircraft's motion instead of an electric fan effectively reduces system weight and energy consumption. The directional guiding effect of the airflow channel 510 improves airflow utilization, ensuring a stable, high-speed flow field on the surface of the cooler 200. The triple function of the heat dissipation shroud 500 enhances structural rigidity, expands the heat dissipation path through heat conduction, and concentrates the oncoming airflow passing through the shroud 400 onto the cooler 200, maintaining efficient and stable heat dissipation performance under complex flight conditions.

[0035] In one embodiment, such as Figure 3 As shown, the cooler 200 includes an inlet manifold 210, an outlet manifold 220, and a flat tube 230. Both the inlet manifold 210 and the outlet manifold 220 are arc-shaped. Of course, the inlet manifold 210 and the outlet manifold 220 can also be polygonal, which can be adjusted according to the specific situation. An inlet manifold 210 is located at one end of the outer periphery of the cooler 200, and an outlet manifold 220 is located at the other end of the outer periphery of the cooler 200. Multiple flat tubes 230 are arranged in parallel, with their ends connected to the inlet manifold 210 and the outlet manifold 220, respectively. The heat-conducting medium in the inlet manifold 210 enters the outlet manifold 220 through the multiple flat tubes 230. Adjacent flat tubes 230 are spaced apart to form heat dissipation gaps 240 for airflow. To further enhance heat dissipation, the heat dissipation gaps 240 are also provided with multiple fins 250 spaced apart along the length of the flat tubes 230. A heat dissipation hood 500 is fitted onto the outer periphery of the inlet manifold 210 and the outlet manifold 220, allowing heat from the cooler 200 to be transferred to the heat dissipation hood 500 through the outer walls of the inlet manifold 210 and the outlet manifold 220.

[0036] Specifically, the heat transfer medium flows from the inlet manifold 210 into the flat tube 230, transferring heat from the electric drive bay 100's heat source to the flat tube 230's wall. During flight, external airflow enters the heat dissipation gap 240 through the airflow channel 510 formed by the heat dissipation shroud 500, directly washing away heat from the surface of the flat tube 230. Because the flat tubes 230 are arranged in parallel and spaced intervals, the airflow can flow evenly along the length of the flat tubes 230, avoiding localized airflow blockage. The design of the heat dissipation shroud 500 covering both the inlet manifold 210 and the outlet manifold 220 allows the cooler 200 to be entirely incorporated into the airflow channel 510, enabling the airflow to simultaneously act on the manifold surface for auxiliary heat dissipation. Furthermore, it allows the heat from the cooler 200 to be rapidly transferred to the heat dissipation shroud 500 through the inlet manifold 210 and the outlet manifold 220.

[0037] Through the above technical solutions, this application achieves a significant improvement in the heat dissipation efficiency of the cooler 200. The direct contact area between the flat tube 230 and the airflow is increased, and the flow resistance is reduced. At the same time, eliminating the electric fan structure reduces the weight of the aircraft. The peripheral arrangement of the inlet and outlet liquid collection chambers 210 and 220 makes the overall structure of the cooler 200 more compact and the heat transfer efficiency higher. The double-wrapped design of the heat dissipation shroud 500 further optimizes the airflow path, making it more suitable for the heat dissipation requirements under high-speed flight conditions of the aircraft.

[0038] In other embodiments, the cooler 200 is annular and sleeved on the outer periphery of the electric drive compartment 100, the flat tube 230 is arc-shaped (circular or semi-circular, etc.), the liquid inlet manifold 210 and the liquid outlet manifold 220 are respectively disposed at both ends of the flat tube 230, and the heat dissipation duct 500 is sleeved on the outer periphery of the flat tube 230.

[0039] In one embodiment, such as Figures 4-7 As shown, the heat dissipation hood 500 includes a fixed part 520 and a variable diameter part 530. The heat dissipation hood 500 is installed and connected to the cooler 200 through the fixed part 520. The variable diameter part 530 is movably connected to the end of the fixed part 520 near the windward side. Furthermore, the variable diameter heat pipe heat dissipation structure can expand or shrink the diameter of the variable diameter part 530 to increase or decrease the flow area of ​​the air duct 510.

[0040] Specifically, when the aircraft is in high-speed flight, the airflow pressure on the windward side increases. At this time, the variable diameter section 530 can automatically expand under the action of external airflow, thereby increasing the flow area of ​​the air guide channel 510 and allowing more airflow to enter the surface of the cooler 200 to enhance heat dissipation. When the aircraft is in a low-speed or hovering state, the variable diameter section 530 can contract to reduce the passage of ineffective airflow and avoid excessive heat dissipation leading to energy loss. Furthermore, the diameter adjustment of the variable diameter section 530 can be triggered by thermal expansion, mechanical drive, or aerodynamic pressure. For example, when the temperature of the cooler 200 rises, the variable diameter section 530 expands outward due to heat to enhance heat dissipation capacity.

[0041] Compared with existing technologies, this solution achieves active or passive adjustment of the flow area of ​​the air guide channel 510 through the adjustable diameter section 530, which can adapt to the heat dissipation requirements under different flight conditions and avoid the weight and volume problems caused by adding an electric fan. Through the above technical solution, this application solves the problem of the mismatch between the heat dissipation efficiency of traditional heat dissipation structures and flight conditions. By dynamically adjusting the flow area of ​​the air guide channel 510, heat dissipation efficiency can be autonomously optimized without the need for an auxiliary electric fan, while reducing the overall weight and space occupation of the aircraft cabin.

[0042] In one embodiment, the inner and outer sides of the variable diameter portion 530 have different coefficients of thermal expansion. Specifically, for example... Figure 5As shown, the variable diameter section 530 includes a first sidewall 531 and a second sidewall 532. The first sidewall 531 and the second sidewall 532 surround and form the variable diameter section 530. The first sidewall 531 is disposed at one end of the variable diameter section 530 near the axis of the electric drive compartment 100, that is, the first sidewall 531 is the inner ring sidewall of the variable diameter section 530. The second sidewall 532 is disposed at one end of the variable diameter section 530 away from the axis of the electric drive compartment 100, that is, the second sidewall 532 is the outer ring sidewall of the variable diameter section 530. Furthermore, the coefficient of thermal expansion of the first sidewall 531 is greater than the coefficient of thermal expansion of the second sidewall 532.

[0043] like Figure 6 and Figure 7 As shown, when the electric drive compartment 100 stops operating, that is, when no heat is transferred from the electric drive compartment 100 to the variable diameter section 530 of the heat dissipation duct 500, the variable diameter section 530 is in its initial state, and the end of the variable diameter section 530 away from the fixed part 520 is bent inward toward the direction closer to the electric drive compartment 100. Figure 3 and Figure 4 As shown, when the electric drive compartment 100 starts operating and continuously generates heat, that is, when the heat from the electric drive compartment 100 is transferred to the variable diameter section 530 of the heat dissipation duct 500, as the temperature of the variable diameter section 530 rises, the end of the variable diameter section 530 away from the fixed section 520 can gradually change from an inward state to an outward state. The outward state is characterized by the end of the variable diameter section 530 away from the fixed section 520 being bent in a direction away from the electric drive compartment 100. Clearly, as heat is transferred and the temperature rises, the variable diameter section 530 gradually changes from an inward state to an intermediate state (vertically positioned) and then to an outward state.

[0044] Specifically, its working principle is as follows: When the electric drive compartment 100 is not running (low temperature state), the variable diameter section 530 is in an inward state (bending towards the electric drive compartment 100). This is because the first sidewall 531 has a larger coefficient of thermal expansion, thus contracting more and causing the entire section to bend inward. When the electric drive compartment 100 is running and generating heat (high temperature state), heat is transferred to the variable diameter section 530, and the first sidewall 531 expands more than the second sidewall 532, causing the variable diameter section 530 to bend outward, forming an outward expansion state. This design can be used to automatically adjust the shape of the heat dissipation shroud 500 to respond to temperature changes in the electric drive compartment 100, thereby optimizing heat dissipation efficiency.

[0045] Specifically, when the heat generated by the heat source inside the electric drive compartment 100 is transferred to the heat dissipation shroud 500 through the cooler 200, the heat is further conducted to the variable diameter section 530. Since the coefficient of thermal expansion of the first sidewall 531 is higher than that of the second sidewall 532, during the temperature rise, the radial expansion of the first sidewall 531 is greater than that of the second sidewall 532, causing the end of the variable diameter section 530 to gradually expand outward from its initial inward-facing state. As the outward expansion increases, the cross-sectional area of ​​the air duct 510 increases, allowing more airflow to enter the duct for forced convection cooling of the cooler 200. When the temperature decreases, the contraction of the first sidewall 531 is greater than that of the second sidewall 532, and the end of the variable diameter section 530 returns to its inward-facing state, preventing excessive heat dissipation and energy loss.

[0046] Compared with existing technologies, this solution achieves adaptive airflow area adjustment through the difference in thermal expansion coefficients, responding to temperature changes without the need for additional drive devices. This reduces structural complexity and avoids the weight increase caused by electric fans. Through the above technical solution, this application solves the problems of large size and weight and limited heat dissipation efficiency in traditional heat dissipation structures. The self-adjusting characteristics of the variable diameter section 530 can dynamically optimize the flow capacity of the airflow channel 510 according to the real-time temperature of the electric drive compartment 100, rapidly improving heat dissipation efficiency under high-temperature conditions and maintaining reasonable heat dissipation intensity under low-temperature conditions, thereby achieving a balance between heat dissipation performance and energy consumption without the need for additional auxiliary equipment.

[0047] To ensure that the variable diameter section 530 can undergo significant bending deformation, the first sidewall 531 and the second sidewall 532 need to be made of common materials with significantly different coefficients of thermal expansion. Specifically, the first sidewall 531 is an aluminum sheet (e.g., aluminum alloy 6061 or 3003), with a coefficient of thermal expansion of approximately 0.000023 / ℃ (in the range of 20℃ to 100℃). Aluminum has a high coefficient of thermal expansion, is easy to process, and is lightweight, making it suitable as a material for the first sidewall 531. Alternatively, the first sidewall 531 can also be a zinc-containing metal sheet, with a coefficient of thermal expansion of 0.000036 / ℃. The second sidewall 532 is a low-carbon steel sheet (e.g., A36 steel or 1045 steel), with a coefficient of thermal expansion of approximately 0.000012 / ℃ (in the range of 20℃ to 100℃). Low-carbon steel has a low coefficient of thermal expansion, high strength, and durability, making it suitable as a material for the second sidewall 532. Of course, the second sidewall 532 can also be a metal plate containing tungsten, with tungsten having a thermal expansion coefficient of 0.0000045 / ℃.

[0048] Clearly, the difference in the coefficients of thermal expansion between the first sidewall 531 (aluminum) and the second sidewall 532 (steel) is approximately 0.000011 / ℃, which is sufficient to produce significant bending deformation when the temperature changes. For example, when the temperature rises by 50℃, the bending displacement of the variable diameter portion 530 is sufficient to ensure that the variable diameter portion 530 changes from an inward state to an outward state.

[0049] When manufacturing the variable diameter section 530, the first sidewall 531 and the second sidewall 532 need to be tightly joined by welding, brazing, or mechanical means to ensure consistency in heat conduction and deformation. For more precise control, this application also performed finite element analysis (FEA) to simulate the deformation behavior.

[0050] In one embodiment, such as Figure 6 and Figure 7 As shown, the heat dissipation shroud 500 includes a plurality of heat dissipation fins 540 arranged sequentially along its circumference. Each heat dissipation fin 540 includes a fixed section 541 and a variable diameter section 542. The fixed sections 541 of adjacent heat dissipation fins 540 are fixedly connected to form an annular fixed portion 520. All variable diameter sections 542 constitute the entire variable diameter portion 530. The variable diameter section 542 is movably connected to the end of the fixed section 541 near the windward side. Specifically, in one embodiment, the variable diameter section 542 is hinged to one end of the fixed section 541 via a hinge shaft, but it is not limited to this. In other embodiments, a flexible connecting section is provided between the variable diameter section 542 and the fixed section 541. That is, the heat dissipation fin 540 also includes a flexible connecting section (not shown in the figure). The variable diameter section 542 is connected to the fixed section 541 through the flexible connecting section. Specifically, the material of the flexible connecting section can be rubber, silicone, or other flexible materials, which are not listed here.

[0051] Specifically, when a hinged shaft connection is used, the variable diameter section 542 can rotate around the hinged shaft axis, changing its tilt angle through mechanical drive or thermal expansion, thereby adjusting the flow area of ​​the air guide channel 510. When a flexible connection section is used, a continuous elastic connection is formed between the variable diameter section 542 and the fixed section 541. Under temperature changes or airflow impact, the flexible connection section absorbs stress through its own deformation, causing the variable diameter section 542 to undergo adaptive bending deformation. Both connection methods can avoid the stress concentration problem caused by rigid connections, while ensuring the structural stability of the heat dissipation hood 500 under high-temperature conditions.

[0052] Furthermore, the heat dissipation duct 500 also includes a controller (not shown), an adjusting motor 550, and an adjusting arm 560. The controller is electrically connected to the adjusting motor 550. The body of the adjusting motor 550 is mounted on the fixed section 541. One end of the adjusting arm 560 is fixedly connected to the output end of the adjusting motor 550. It should be noted that the adjusting motor 550 may also integrate a reducer so that the output shaft of the adjusting motor 550 is connected to the adjusting arm 560 through the reducer. The other end of the adjusting arm 560 is connected to the variable diameter section 542. Specifically, in one embodiment, the variable diameter section 542 is provided with a retaining ring 570. One end of the adjusting arm 560 is fixedly sleeved on the output end of the adjusting motor 550, and the other end is movably inserted through the retaining ring 570 and the through hole formed by the variable diameter section 542, so that the variable diameter section 542 can swing relative to the fixed section 541 in different directions through the side wall of the through hole. That is, the controller can control the regulating motor 550 to drive the regulating arm 560 to rotate forward or backward, so as to drive the end of the variable diameter section 542 away from the fixed section 541 to tilt towards or away from the electric drive compartment 100, thereby expanding or shrinking the diameter of the entire variable diameter section 530, and thus increasing or decreasing the flow area of ​​the air guide channel 510.

[0053] It should be noted that in another embodiment, the body of the regulating motor 550 is mounted on the variable diameter section 542, one end of the regulating arm 560 is fixedly connected to the output end of the regulating motor 550, and the other end is connected to the fixed section 541. In this case, the reaction force of the fixed section 541 can also drive the variable diameter section 542 to swing in different directions.

[0054] Specifically, the fixed sections 541 of multiple heat sinks 540 are connected by welding or bolts to form a fixed part 520, providing a basic support structure for the air duct 510. The variable diameter section 542 is movably connected to the fixed section 541 via a hinge shaft or flexible connecting section. When the regulating motor 550 drives the regulating arm 560 to rotate, the end of the variable diameter section 542 tilts. For example, when the controller detects an increase in the temperature of the electric drive compartment 100, the regulating motor 550 drives the variable diameter section 542 to tilt outward to expand the flow area of ​​the air duct 510, thereby increasing the heat dissipation efficiency of the airflow to the cooler 200. Conversely, when the aircraft is in a low wind speed environment, the regulating motor 550 drives the variable diameter section 542 to contract inward to reduce airflow dissipation and maintain heat dissipation efficiency.

[0055] Compared with existing technologies, this solution achieves active adjustment of the flow area of ​​the air duct 510 through the movable variable diameter section 542 and the motor drive system. It can adapt to the heat dissipation requirements under different flight conditions without relying on an additional fan, effectively reducing the size and weight of the cabin. This structure can also automatically adjust the angle of the variable diameter section 542 according to real-time temperature or wind speed signals to ensure that the electric drive system can obtain optimized heat dissipation conditions under different operating conditions.

[0056] Furthermore, in one embodiment, as Figure 6 and Figure 7 As shown, at least some of the heat sinks 540 are equipped with an adjustment motor 550 and an adjustment arm 560. The three heat sinks 540 arranged in sequence are defined as the first 543, the second 544, and the third 545. That is, the second 544 is located between the first 543 and the third 545. Specifically, one end of the second 544 along the circumference of the heat dissipation shroud 500 overlaps with the side of the first 543 away from the electric drive compartment 100, and the other end of the second 544 along the circumference of the heat dissipation shroud 500 overlaps with the side of the third 545 near the electric drive compartment 100. In other words, the adjacent heat sinks 540 are partially overlapped.

[0057] Specifically, the first fin 543, the second fin 544, and the third fin 545 are arranged sequentially along the circumference of the heat dissipation shroud 500. One end of the second fin 544 overlaps the outer surface of the first fin 543, and the other end overlaps the inner surface of the third fin 545. When the adjusting motor 550 drives the adjusting arm 560 to tilt the variable diameter section 542, the overlapping structure can maintain the relative position stability between the heat dissipation fins 540, preventing gaps from appearing between adjacent heat dissipation fins 540 due to the angle adjustment of the variable diameter section 542. During high-speed flight of the aircraft, the overlapping structure can withstand the impact force of airflow, preventing the heat dissipation fins 540 from shifting or deforming. Furthermore, by setting up the overlapping structure, only one adjusting motor 550 is needed to achieve the synchronous inward and outward expansion of all heat dissipation fins 540, greatly improving control efficiency.

[0058] Compared with existing technologies, this solution uses a double-layer overlapping design to form staggered and overlapping sealing surfaces between the heat sinks 540. Even if the angle of the variable diameter section 542 changes, the integrity and airtightness of the air guide channel 510 can still be maintained. The overlapping structure further enhances the mechanical strength of the heat sinks 540, avoids structural failure caused by high-speed airflow impact, and reduces the use of auxiliary fixing parts 520, thereby reducing the complexity and weight of the overall structure.

[0059] In one embodiment, the variable-diameter heat pipe cooling structure further includes a temperature sensor (not shown) and a wind speed sensor (not shown). The temperature sensor and wind speed sensor are electrically connected to a controller. The temperature sensor is located in one or more of the electric drive bay 100, cooler 200, and heat dissipation duct 500. The controller can control the regulating motor 550 to adjust the tilt angle of the variable-diameter section 542 relative to the fixed section 541 based on the temperature value measured by the temperature sensor, thereby adjusting the windward area of ​​the variable-diameter section 530. The wind speed sensor is located on a fixed surface of the aircraft (a surface that does not rotate), specifically on the windward side of the fairing 400, the outside of the electric drive bay 100, or the heat dissipation duct 500. The controller can control the regulating motor 550 to adjust the tilt angle of the variable-diameter section 542 relative to the fixed section 541 based on the wind speed value measured by the wind speed sensor, thereby adjusting the flow area of ​​the air duct 510.

[0060] Specifically, temperature sensors collect real-time temperature data from the electric drive compartment 100, cooler 200, or heat dissipation shroud 500. When the temperature rises, the controller drives the regulating motor 550 to increase the tilt angle of the variable diameter section 542, thereby expanding the windward area of ​​the variable diameter section 530 to enhance heat dissipation. When the temperature drops, the controller controls the regulating motor 550 to decrease the tilt angle to reduce the heat dissipation intensity. Simultaneously, a wind speed sensor detects the external airflow velocity. If the wind speed is high, the controller drives the regulating motor 550 to reduce the flow area of ​​the air duct 510 to avoid excessive heat dissipation; if the wind speed is low, the flow area is expanded to improve heat dissipation efficiency. Temperature and wind speed data are analyzed collaboratively by the controller to achieve dynamic balance adjustment.

[0061] Compared with existing technologies, this solution uses a dual feedback mechanism of temperature and wind speed to enable the flow area of ​​the air guide channel 510 and the windward area of ​​the variable diameter section 530 to adapt to the actual heat dissipation needs in real time. This avoids the size and weight problems caused by electric fans and solves the shortcomings of insufficient efficiency of a single heat dissipation mode.

[0062] In one embodiment, such as Figure 4 and Figure 5 As shown, the fixed part 520 is provided with an evaporation chamber 521, and the variable diameter part 530 is provided with a condensation chamber 533. The evaporation chamber 521 is connected to the condensation chamber 533. The evaporation chamber 521 is provided with a liquid working fluid. When the liquid working fluid in the evaporation chamber 521 absorbs heat and vaporizes (the heat comes from the cooler 200), the gaseous working fluid can enter the condensation chamber 533 and condense and liquefy through the variable diameter part 530. After that, the liquefied working fluid can flow back from the condensation chamber 533 to the evaporation chamber 521 by gravity or liquid suction core.

[0063] It should be noted that the working fluid is a thermally conductive but non-electrically conductive insulating liquid. Specifically, the working fluid can be various refrigerants such as R1233ZD(E) or ethanol. Specifically, the boiling point of R1233ZD(E) is about 18.3℃, and the boiling point of ethanol is about 78℃.

[0064] Specifically, when the temperature of the cooler 200 rises due to the heat generated by the electric drive compartment 100, the evaporation chamber 521 of the fixed part 520 absorbs heat, causing the internal liquid working fluid to vaporize. The gaseous working fluid enters the condensation chamber 533 of the variable diameter part 530 through the connecting channel. In the condensation chamber 533, the gaseous working fluid exchanges heat with the external atmospheric environment and gradually liquefies. The released heat is rapidly transferred to the outside through the heat dissipation structure of the variable diameter part 530. The liquefied working fluid flows back to the evaporation chamber 521 under gravity or capillary action, forming a continuous heat transfer cycle. This process does not rely on an external power unit. The active transfer of heat from the fixed part 520 to the variable diameter part 530 is achieved through the phase change of the working fluid. At the same time, the expansion or contraction of the variable diameter part 530 can adjust the heat dissipation area of ​​the condensation chamber 533, further optimizing the heat dissipation efficiency.

[0065] Compared with the prior art, this solution uses the phase change heat transfer mechanism of the evaporation chamber 521 and the condensation chamber 533 to quickly transfer heat from the fixed part 520 to the variable diameter part 530. Combined with the diameter adjustment capability of the variable diameter part 530, the heat dissipation area is dynamically controlled, which reduces the dependence on auxiliary heat dissipation equipment and achieves efficient passive heat dissipation through working fluid circulation.

[0066] Through the above technical solution, this application can significantly reduce the volume and weight of the heat dissipation structure of the electric drive system, while improving heat dissipation efficiency by utilizing the phase change heat transfer principle, which is particularly suitable for the thermal management requirements of aircraft under high power consumption conditions. The autonomous circulation mechanism of the working fluid avoids external energy consumption, and the combination of the condensation chamber 533 and the variable diameter section 530 structure further enhances the heat dissipation capacity and adaptability to operating conditions.

[0067] This application also provides an aircraft that includes the variable diameter heat pipe heat dissipation structure described in any of the above embodiments.

[0068] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

[0070] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0071] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0072] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0073] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0074] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0075] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

Claims

1. A variable diameter heat pipe heat dissipation structure, characterized in that, It includes an electric drive compartment (100), a cooler (200) and a heat dissipation duct (500), and the heat transfer medium can circulate between the cooler (200) and the heat source of the electric drive compartment (100) to transfer the heat in the electric drive compartment (100) to the cooler (200). The heat dissipation hood (500) is fitted onto the outer periphery of the cooler (200) at one end along its own axis, and extends toward the windward side of the aircraft at the other end. A guide channel (510) is formed between the heat dissipation hood (500) and the electric drive cabin (100). Airflow can flow through the guide channel (510) to the cooler (200) to dissipate heat from the cooler (200). The heat dissipation hood (500) is attached to the side wall of the cooler (200) and tightly fitted to the side wall of the cooler (200) so that the heat of the cooler (200) can be transferred to the atmospheric environment through the heat dissipation hood (500). The heat dissipation shroud (500) includes a fixed part (520) and a variable diameter part (530). The heat dissipation shroud (500) is installed and connected to the cooler (200) through the fixed part (520). The variable diameter part (530) is movably connected to the end of the fixed part (520) near the windward side of the aircraft. The variable diameter heat pipe heat dissipation structure can expand or shrink the diameter of the variable diameter part (530) to increase or decrease the flow area of ​​the air guide channel (510). The fixed part (520) is provided with an evaporation chamber (521), and the variable diameter part (530) is provided with a condensation chamber (533). The evaporation chamber (521) is connected to the condensation chamber (533). The evaporation chamber (521) is provided with a liquid working medium. When the liquid working medium in the evaporation chamber (521) absorbs heat and vaporizes, the gaseous working medium can enter the condensation chamber (533) and condense and liquefy. Furthermore, the liquefied working medium can flow back from the condensation chamber (533) to the evaporation chamber (521).

2. The variable diameter heat pipe heat dissipation structure according to claim 1, characterized in that, The variable diameter section (530) includes a first sidewall (531) and a second sidewall (532). The first sidewall (531) is the inner ring sidewall of the variable diameter section (530), and the second sidewall (532) is the outer ring sidewall of the variable diameter section (530). The coefficient of thermal expansion of the first sidewall (531) is greater than that of the second sidewall (532). When the variable diameter section (530) is in the initial state, the end of the variable diameter section (530) away from the fixed part (520) is bent inward toward the electric drive compartment (100). When the heat of the electric drive compartment (100) is transferred to the variable diameter section (530), the end of the variable diameter section (530) away from the fixed part (520) can gradually change from the inward state to the outward state. The outward state is the state in which the end of the variable diameter section (530) away from the fixed part (520) is bent inward toward the electric drive compartment (100).

3. The variable diameter heat pipe heat dissipation structure according to claim 1, characterized in that, The heat dissipation shroud (500) includes a plurality of heat dissipation fins (540) arranged sequentially along its circumference. Each heat dissipation fin (540) includes a fixed section (541) and a variable diameter section (542). The fixed sections (541) of adjacent heat dissipation fins (540) are fixedly connected to form a ring-shaped fixed part (520). The variable diameter section (542) is movably connected to the end of the fixed section (541) near the windward side of the aircraft. The heat dissipation shroud (500) also includes a controller, an adjusting motor (550), and an adjusting arm (560). The body of the adjusting motor (550) is installed on the fixed section (541). One end of the adjusting arm (560) is fixedly connected to the output end of the adjusting motor (550), and the other end is connected to the variable diameter section (542). Alternatively, the body of the adjusting motor (550) is installed on the variable diameter section (542), and one end of the adjusting arm (560) is fixedly connected to the output end of the adjusting motor (550), and the other end is connected to the fixed section (541). The controller can control the regulating motor (550) to drive the regulating arm (560) to rotate forward or reverse, so as to cause the end of the variable diameter section (542) away from the fixed section (541) to tilt towards or away from the electric drive compartment (100).

4. The variable diameter heat pipe heat dissipation structure according to claim 3, characterized in that, At least some of the heat sinks (540) are provided with the adjustment motor (550) and the adjustment arm (560). The three heat sinks (540) arranged in sequence are defined as the first piece (543), the second piece (544) and the third piece (545). The second piece (544) overlaps one end of the heat dissipation shroud (500) on the side of the first piece (543) away from the electric drive compartment (100), and the other end of the second piece (544) overlaps the side of the third piece (545) close to the electric drive compartment (100).

5. The variable diameter heat pipe heat dissipation structure according to claim 3, characterized in that, The variable diameter section (542) is hinged to one end of the fixed section (541) via a hinge shaft, or the heat sink (540) further includes a flexible connecting section, and the variable diameter section (542) is connected to the fixed section (541) via the flexible connecting section.

6. The variable diameter heat pipe heat dissipation structure according to claim 3, characterized in that, It also includes a temperature sensor and a wind speed sensor. The temperature sensor is disposed in one or more of the electric drive compartment (100), the cooler (200) and the heat dissipation duct (500). The controller can control the regulating motor (550) to adjust the tilt angle of the variable diameter section (542) relative to the fixed section (541) according to the temperature value measured by the temperature sensor, so as to adjust the total windward area of ​​the variable diameter section (530). The wind speed sensor is installed on the fixed surface of the aircraft. The controller can control the regulating motor (550) to adjust the tilt angle of the variable diameter section (542) relative to the fixed section (541) according to the wind speed value measured by the wind speed sensor, so as to adjust the flow area of ​​the air guide channel (510).

7. The variable diameter heat pipe heat dissipation structure according to claim 1, characterized in that, The cooler (200) includes an inlet manifold (210), an outlet manifold (220), and flat tubes (230). The inlet manifold (210) is located at one end of the outer periphery of the cooler (200), and the outlet manifold (220) is located at the other end of the outer periphery of the cooler (200). The two ends of the multiple flat tubes (230) are respectively connected to the inlet manifold (210) and the outlet manifold (220). Adjacent flat tubes (230) are spaced apart to form heat dissipation gaps (240) for airflow. The heat dissipation hood (500) is sleeved on the outer periphery of the inlet manifold (210) and the outlet manifold (220).

8. The variable diameter heat pipe heat dissipation structure according to claim 1, characterized in that, The heat dissipation hood (500) and the side wall of the cooler (200) are welded together, or the heat dissipation hood (500) and the side wall of the cooler (200) are connected by thermal grease, or the heat dissipation hood (500) and the side wall of the cooler (200) are integrally formed.

9. An aircraft, characterized in that, It includes the variable diameter heat pipe heat dissipation structure as described in any one of claims 1-8.

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