Liquid hydrogen tank for unmanned aerial vehicle with active thermal management and adaptive heat exchange system

Abstract

This invention relates to the field of hydrogen-powered drone technology, specifically to a liquid hydrogen cylinder for drones with active thermal management and an adaptive heat exchange system. The cylinder includes a cylinder body, a hydrogen storage box, a heating element, a heat exchange element, and a management system. The inner liner of the cylinder body provides a storage environment for liquid hydrogen, while a hydrogen supply channel on the outer shell stably supplies hydrogen to the drone's hydrogen fuel system. The hydrogen storage box within the interlayer is filled with a hydrogen storage alloy, which utilizes the hydrogen absorption and release properties of liquid hydrogen at low temperatures, using the hydrogen within the interlayer as a heat transfer medium to achieve controllable heat transfer. The flow guide and heat exchange element form a heat exchange assembly, utilizing the slipstream generated by the drone's propellers for passive heat exchange. The management system can communicate with the drone's flight control system, predicting hydrogen demand based on flight conditions and controlling the heating element accordingly. This enables controllable switching between heat conduction and insulation states within the interlayer, resolving the core contradiction between storage and vaporization in existing liquid hydrogen cylinders.

Description

Technical Field

[0001] This invention relates to the field of hydrogen-powered drone technology, and more specifically to a liquid hydrogen cylinder for drones with an active thermal management and adaptive heat exchange system. Background Technology

[0002] With the rapid development of the low-altitude economy, drones are increasingly being used in logistics delivery, agricultural plant protection, power line inspection, and emergency rescue. Endurance has become a core bottleneck restricting the improvement of drone's overall performance. Compared to traditional lithium batteries and high-pressure gaseous hydrogen energy, liquid hydrogen fuel, with its extremely high energy density and zero-emission characteristics, is widely recognized as the ideal energy solution for long-endurance drones.

[0003] However, liquid hydrogen needs to be stored in an ultra-low temperature environment of -253 degrees Celsius for a long time, which places extremely high demands on the thermal insulation performance of the storage tank; the drone platform is extremely sensitive to weight, and the lightweight design of the hydrogen storage system is a core prerequisite; at the same time, issues such as evaporation loss of liquid hydrogen, rapid refueling and safety of use also limit its large-scale application in the field of drones.

[0004] Currently, liquid hydrogen is typically stored in Dewar flasks. However, liquid hydrogen stored in Dewar flasks cannot meet the needs of drones. First, liquid hydrogen stored in Dewar flasks has a high evaporation loss rate, and the flask itself is quite heavy. In addition, liquid hydrogen vaporization often uses a combination of independent tube-fin heat exchangers and electric heaters, resulting in a bulky structure, slow response speed, and additional energy consumption, which reduces the drone's range. Furthermore, liquid hydrogen stored in Dewar flasks requires extremely high vacuum insulation to reduce heat intrusion during the storage phase, while the hydrogen supply phase requires rapid heat introduction to achieve liquid hydrogen vaporization and maintain the pressure inside the flask. The existing structure cannot meet both of these requirements.

[0005] In the prior art, for example, Chinese invention patent with authorization announcement number CN114542979B discloses a hydrogen supply system for drones. The published document uses a multi-stage pressure reducing valve to divert and output hydrogen, thereby achieving a stable hydrogen supply to multiple hydrogen fuel cell stacks. It also uses a solenoid valve to control the on / off of the hydrogen supply pipeline, reducing system weight and leakage points. However, the published document does not involve the core technologies of liquid hydrogen storage and vaporization, which means that existing hydrogen-powered drones using liquid hydrogen storage and supply systems still face a contradiction between storage and vaporization. Summary of the Invention

[0006] This invention provides a liquid hydrogen cylinder for drones with active thermal management and adaptive heat exchange system to solve the problem of the contradiction between storage and vaporization in existing liquid hydrogen cylinders for drones.

[0007] The present invention provides a liquid hydrogen cylinder for unmanned aerial vehicles with an active thermal management and adaptive heat exchange system, which adopts the following technical solution: A liquid hydrogen cylinder for unmanned aerial vehicles (UAVs) with active thermal management and adaptive heat exchange system includes a cylinder body, a hydrogen storage box, a heating element, a heat exchange element, and a management system.

[0008] The bottle body includes an inner liner and an outer shell, with a sealed interlayer between them. The inner liner stores liquid hydrogen, and the outer shell has a hydrogen supply channel connecting the interior of the inner liner to the external environment. Initially, the interlayer is set to a vacuum environment. A hydrogen storage box is located within the interlayer and is filled with a hydrogen storage alloy that can adsorb hydrogen at liquid hydrogen temperatures. A heating element heats the hydrogen storage box; when heated, the hydrogen storage alloy releases hydrogen, and when the temperature of the storage box decreases, the alloy adsorbs hydrogen again. A heat exchange assembly includes a flow guide and a heat exchanger. The heat exchanger is located on the outer shell, and the flow guide directs the airflow disturbed by the UAV propellers to the heat exchanger. A management system communicates with the UAV's flight control system, receives propeller speed or throttle signals, predicts hydrogen demand based on the received data, and adjusts the heating element and heat exchanger according to the predicted hydrogen demand.

[0009] Furthermore, the interlayer is filled with multiple layers of thermal insulation material, which consists of 30-40 layers of aluminum foil and glass fiber spacers stacked alternately, and the interlayer is initially set to a vacuum environment.

[0010] Furthermore, the hydrogen storage alloy is any one of lanthanum-nickel based hydrogen storage alloy, titanium-iron based hydrogen storage alloy, or mixed nickel-based hydrogen storage alloy.

[0011] Furthermore, the heating element is an electric heating film that is attached and fixed to the outer wall of the hydrogen storage box, or an electric heating wire built into the inside of the hydrogen storage box.

[0012] Furthermore, the heat exchanger includes multiple fins made of aluminum alloy, and the fins are fixedly connected to the outer shell by brazing.

[0013] Furthermore, the heat exchange component also includes a heat exchange plate, which is fixedly connected to the outer shell by brazing, and the heat exchange plate is connected to the UAV.

[0014] Furthermore, the flow guide includes a flow guide shroud and a damper adjustment mechanism. The flow guide shroud is fixedly installed below the UAV propeller and has a flow guide channel. The flow guide shroud can guide the wind disturbed by the propeller to the fins and the heat exchange plate. The damper adjustment mechanism is used to change the cross-sectional size of the flow guide channel.

[0015] Furthermore, the damper adjustment mechanism includes a baffle plate, the diameter of which is equal to the diameter of the flow channel, and the baffle plate is rotatably disposed within the flow channel; when the baffle plate rotates, it can adjust the amount of gas blown toward the fins and the heat exchange plate.

[0016] Furthermore, a pressure sensor is installed inside the inner liner, and the management system is able to receive data from the pressure sensor.

[0017] Furthermore, a vacuum gauge is installed inside the interlayer, and a temperature sensor is installed on the hydrogen storage box. The management system is capable of receiving data from the vacuum gauge and the temperature sensor.

[0018] The beneficial effects of this invention are as follows: This invention provides a liquid hydrogen cylinder for drones with an active thermal management and adaptive heat exchange system. It includes a cylinder body, a hydrogen storage box, a heating element, a heat exchange element, and a management system. The inner liner and outer shell cooperate to form a sealed interlayer cylinder structure, providing a safe and stable low-temperature storage environment for liquid hydrogen. Combined with the hydrogen supply channel on the outer shell, it can stably supply hydrogen to the drone's hydrogen fuel system. The hydrogen storage box, filled with a hydrogen storage alloy, utilizes the alloy's ability to adsorb hydrogen in the low-temperature liquid hydrogen environment and release hydrogen upon heating. The hydrogen in the interlayer can act as a heat transfer medium. The heat exchange assembly, composed of a flow guide and a heat exchange element, can directionally guide the airflow disturbed during drone propeller flight to the heat exchange element on the outer shell, fully utilizing the airflow generated by the drone's own flight to achieve passive heat exchange. This eliminates the need for additional power heat exchange equipment, effectively reducing the system's weight and energy consumption, and meeting the core requirement of lightweight drones. More importantly, the management system, which can communicate with the UAV flight control system, can acquire propeller speed or throttle signals in real time and predict the hydrogen demand of the UAV under different flight conditions. When the amount of hydrogen required by the UAV increases, the management system controls the heating element to increase the heating power of the hydrogen storage box. The hydrogen released from the hydrogen storage box acts as a good heat transfer medium. When the airflow disturbed by the propeller acts on the heat exchange element, the heat can be quickly transferred to the liquid hydrogen stored in the inner liner, causing the liquid hydrogen to vaporize rapidly. This causes the gas pressure inside the inner liner to rise rapidly, thereby increasing the amount of hydrogen supplied to the outside. Conversely, when the UAV needs to be shut down, the management system controls the heating element to stop heating the hydrogen storage box. The low temperature liquid hydrogen in the inner liner acts as a cold source, which can quickly cool the hydrogen storage box. The hydrogen storage alloy re-adsorbs hydrogen, causing the gas pressure inside the interlayer to drop sharply. This improves the thermal insulation performance of the interlayer and greatly slows down the volatilization of liquid hydrogen, thereby solving the contradiction between storage and vaporization in existing liquid hydrogen cylinders. Attached Figure Description

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

[0020] Figure 1 A schematic cross-sectional view of the front of a liquid hydrogen cylinder for a drone with an active thermal management and adaptive heat exchange system, provided for an embodiment of the present invention; Figure 2 This is a top view of a liquid hydrogen cylinder for unmanned aerial vehicles (UAVs) with an active thermal management and adaptive heat exchange system, provided as an embodiment of the present invention. Figure 3 A simplified structural diagram of a propeller integrated into a liquid hydrogen cylinder for a drone with an active thermal management and adaptive heat exchange system, provided as an embodiment of the present invention; Figure 4 A simplified logic diagram of a liquid hydrogen cylinder for a drone with an active thermal management and adaptive heat exchange system, provided as an embodiment of the present invention.

[0021] In the diagram: 1. Inner liner; 2. Interlayer; 3. Outer shell; 4. Hydrogen supply channel; 5. UAV; 6. Floodgate; 7. Heat exchange plate; 8. Fins; 9. Hydrogen storage box; 10. Hydrogen storage alloy; 11. Propeller; 20. Management system; 21. Vacuum gauge; 22. Temperature sensor; 23. Pressure sensor. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The serial numbers assigned to components in this document, such as "first," "second," etc., are merely used to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages). In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention.

[0024] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates 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 indicates that the first feature is at a lower horizontal level than the second feature.

[0025] like Figures 1 to 4 As shown in the figure, an embodiment of the present invention provides a liquid hydrogen cylinder for unmanned aerial vehicles with an active thermal management and adaptive heat exchange system, which includes a cylinder body, a hydrogen storage box 9, a heating element, a heat exchange element and a management system 20.

[0026] The bottle body consists of an inner liner 1 and an outer shell 3. The inner liner 1 is integrally formed from a low-temperature resistant, high-strength aluminum alloy using a spinning process, and can withstand the cryogenic environment of liquid hydrogen down to -253 degrees Celsius. The inner liner 1 has a storage chamber inside, which stores liquid hydrogen. The outer shell 3 is made of lightweight aluminum alloy and coaxially sleeved on the outside of the inner liner 1. A sealed interlayer 2 is formed between the outer wall of the inner liner 1 and the inner wall of the outer shell 3, providing thermal insulation protection for the inner liner 1. The outer shell 3 is provided with a hydrogen supply channel 4. One end of the hydrogen supply channel 4 is connected to the inside of the inner liner 1, and the other end is used to connect to the hydrogen fuel cell system of the drone 5, providing a stable supply of hydrogen to the fuel cell.

[0027] The hydrogen storage box 9 is made of thin-walled aluminum alloy and is fixedly installed inside the interlayer 2. Specifically, the hydrogen storage box 9 is fixedly installed on the outer wall of the inner liner 1. The inner cavity of the hydrogen storage box 9 is connected to the space of the interlayer 2. The hydrogen storage box 9 is filled with a hydrogen storage alloy 10 that can stably adsorb hydrogen at liquid hydrogen temperature. The hydrogen storage alloy 10 can adjust the hydrogen content in the interlayer 2 by absorbing and releasing hydrogen. In the initial state, the drone 5 is in a stopped state, and the interlayer 2 is set to a vacuum state.

[0028] A heating element is installed in conjunction with the hydrogen storage box 9 to heat the hydrogen storage box 9 and the hydrogen storage alloy 10 inside. When the heating element heats the hydrogen storage box 9, the temperature of the hydrogen storage alloy 10 rises, decomposing and releasing adsorbed hydrogen, thus increasing the hydrogen content in the interlayer 2. When the heating element stops heating and the hydrogen storage box 9 is cooled by the low-temperature environment of the inner liner 1, the hydrogen storage alloy 10 can re-adsorb hydrogen from the interlayer 2, achieving controllable adjustment of the hydrogen content in the interlayer 2. Initially, the interior of the interlayer 2 is in a vacuum state, and the liquid hydrogen stored inside the inner liner 1 will keep the hydrogen storage box 9 at a constant low temperature. Heat from the external environment cannot penetrate the interlayer 2 and act on the inner liner 1, thereby hindering the vaporization of liquid hydrogen. When the drone 5 needs to take off, the heating element is activated to heat the hydrogen storage box 9. The hydrogen storage alloy 10 stored inside the hydrogen storage box 9 releases hydrogen. When the hydrogen fills the interior of the interlayer 2, the hydrogen inside the interlayer 2 acts as a heat transfer medium to conduct heat. The heat from the external environment can be effectively transferred to the inner liner 1, causing the liquid hydrogen stored inside the inner liner 1 to vaporize. The vaporized liquid hydrogen is then transported to the hydrogen fuel cell of the drone 5 through the hydrogen supply channel 4.

[0029] The heat exchange assembly includes a flow guide and a heat exchanger. The heat exchanger is fixedly mounted on the outer surface of the outer shell 3 and is used to achieve heat exchange between the outer shell 3 and the external environment. The air inlet of the flow guide corresponds to the slipstream area of ​​the propeller 11 of the UAV 5, and the air outlet corresponds to the arrangement area of ​​the heat exchanger. It can guide the airflow disturbed by the rotation of the propeller 11 of the UAV 5 to the surface of the heat exchanger, and achieve passive heat exchange by utilizing the slipstream generated by the UAV 5 itself during flight. There is no need to set up additional power heat exchange equipment, which meets the requirements of UAV 5 for lightweight and low energy consumption.

[0030] The management system 20 is an electronic control system with a computing module. It establishes a real-time communication connection with the flight control system of the UAV 5 via a CAN bus. The management system 20 can receive the propeller speed or throttle signal transmitted by the flight control system. Based on the pre-stored flight conditions and hydrogen demand correspondence algorithm model, it predicts the current and future hydrogen demand of the UAV 5. At the same time, according to the predicted hydrogen demand, it outputs control signals to coordinate and regulate the heating power of the heating element and the heat exchange efficiency of the heat exchange components, so as to achieve adaptive matching between liquid hydrogen cylinder hydrogen supply and thermal management.

[0031] This invention discloses a liquid hydrogen cylinder for drones with active thermal management and adaptive heat exchange systems. The cylinder structure, formed by the inner liner 1 and outer shell 3 with a sealed interlayer 2, provides a safe and stable low-temperature storage environment for liquid hydrogen. Combined with the hydrogen supply channel 4 on the outer shell 3, it can stably supply hydrogen to the hydrogen fuel system of the drone 5. A hydrogen storage box 9 filled with hydrogen storage alloy 10 is located within the interlayer 2. Utilizing the properties of the hydrogen storage alloy 10—which adsorbs hydrogen in the low-temperature liquid hydrogen environment and releases hydrogen upon heating—the hydrogen within the interlayer 2 can act as a heat transfer medium. A heat exchange assembly composed of a flow guide and a heat exchanger can directionally guide the airflow disturbed by the drone 5's propeller 11 during flight to the heat exchanger on the outer shell 3, fully utilizing the airflow generated by the drone 5's own flight to achieve passive heat exchange. This eliminates the need for additional power heat exchange equipment, effectively reducing the system's weight and energy consumption, and meeting the core requirement of lightweight design for the drone 5. More importantly, the management system 20, which can communicate with the flight control system of the UAV 5, can acquire the propeller speed or throttle signal in real time, predict the hydrogen demand of the UAV 5 under different flight conditions in advance. When the amount of hydrogen required by the UAV 5 increases, the management system 20 controls the heating element to increase the heating power of the hydrogen storage box 9. The hydrogen released from the hydrogen storage box 9 serves as a good heat transfer medium. When the airflow disturbed by the propeller 11 acts on the heat exchange element, the heat can be quickly transferred to the liquid hydrogen stored inside the inner liner 1, promoting... The rapid vaporization of liquid hydrogen causes the internal pressure of the inner liner 1 to rise rapidly, thereby increasing the amount of hydrogen supplied to the outside. Conversely, when the drone 5 needs to be shut down, the management system 20 controls the heating element to stop heating the hydrogen storage box 9. The low-temperature liquid hydrogen in the inner liner 1 acts as a cold source, which can quickly cool down the hydrogen storage box 9. The hydrogen storage alloy 10 re-adsorbs hydrogen, causing the internal pressure of the interlayer 2 to drop sharply. This improves the thermal insulation performance of the interlayer 2 and greatly slows down the evaporation of liquid hydrogen, thus solving the contradiction between storage and vaporization in existing liquid hydrogen cylinders.

[0032] In one embodiment, the interlayer 2 is filled with multiple layers of thermal insulation material, which consists of 30-40 layers of aluminum foil and glass fiber spacers stacked alternately. The aluminum foil acts as a heat reflective layer, which can form multi-level reflection and blocking of ambient heat radiation, significantly reducing the radiative heat transfer from the outside to the inner liner 1. The glass fiber spacers act as interlayer support and thermal insulation medium, which can effectively reduce solid heat conduction between the layers. At the same time, after the interlayer 2 is assembled, it is evacuated by a high-vacuum unit to form an initial high-vacuum environment. The vacuum environment can eliminate gas convection heat transfer in the interlayer 2. Together with the multiple layers of thermal insulation material, it forms a high-insulation-performance vacuum multilayer thermal insulation system, which can reduce the daily evaporation rate of liquid hydrogen, reduce liquid hydrogen loss during storage, and extend the storage time of liquid hydrogen.

[0033] In one embodiment, the hydrogen storage alloy 10 is any one of a lanthanum-nickel based hydrogen storage alloy 10, a titanium-iron based hydrogen storage alloy 10, or a mixed nickel-based hydrogen storage alloy 10. Specifically, the lanthanum-nickel based hydrogen storage alloy 10 can be a LaNi5 alloy, which exhibits excellent reversibility of hydrogen absorption and desorption at liquid hydrogen temperatures, low hydrogen absorption equilibrium pressure, and good activation performance, enabling it to complete the hydrogen absorption and desorption state switch within 30 seconds, thus meeting rapid response hydrogen supply requirements. The titanium-iron based hydrogen storage alloy 10 is a TiFe-based hydrogen storage alloy 10, which has advantages such as low raw material cost, high volumetric hydrogen storage capacity, and long cycle life, making it suitable for long-term reusable applications of the UAV 5. The mixed nickel-based hydrogen storage alloy 10 can be a Mm-Ni based alloy (mixed rare earth-nickel based hydrogen storage alloy 10), which has a wider operating temperature range, good resistance to poisoning, and a wide adjustable range of hydrogen absorption and desorption rates, making it suitable for the pressure regulation requirements of the UAV 5 under complex flight conditions.

[0034] In one embodiment, the heating element is an electric heating film adhered to and fixed to the outer wall of the hydrogen storage box 9, or an electric heating wire built into the hydrogen storage box 9. When an electric heating film is used, a low-temperature resistant polyimide electric heating film is selected and fully adhered to the outer wall of the hydrogen storage box 9 using a high- and low-temperature resistant thermally conductive adhesive. This achieves uniform surface heating of the hydrogen storage box 9, resulting in good heating uniformity, convenient installation, and minimal space occupation within the interlayer 2, making it suitable for the limited installation environment of the interlayer 2. When an electric heating wire is used, a nickel-chromium alloy micro electric heating wire is selected and evenly arranged inside the hydrogen storage box 9 via an insulating ceramic support. This allows direct contact with the hydrogen storage alloy 10, resulting in higher heat conduction efficiency, faster heating response, and rapid temperature increase of the hydrogen storage alloy 10, enabling rapid hydrogen release. The power of both heating elements can be continuously and precisely controlled through the management system 20, accurately responding to heating requirements under different operating conditions.

[0035] In one embodiment, the heat exchanger includes multiple fins 8 made of high thermal conductivity aluminum alloy, possessing lightweight, high thermal conductivity, and corrosion resistance characteristics, suitable for the lightweight requirements of the drone 5 and its outdoor use environment. The multiple fins 8 are arranged parallel to each other at equal intervals, and one end of each fin 8 is fixedly connected to the outer surface of the shell 3 by a brazing process. Brazing forms a low thermal resistance metallurgical interface between the fins 8 and the shell 3, significantly reducing contact thermal resistance and improving heat transfer efficiency. The multi-fin structure significantly increases the contact heat exchange area between the bottle and the external airflow, enhancing convective heat transfer and improving the efficiency of passive heat transfer. Simultaneously, the shell 3 of the bottle directly serves as the heat exchange substrate, eliminating the need for a separate heat exchanger shell, thus achieving lightweight and integrated structure.

[0036] In one embodiment, the heat exchanger also includes a heat exchange plate 7, which is made of a high thermal conductivity aluminum alloy. One side of the heat exchange plate 7 is fixedly connected to the outer surface of the outer shell 3 by brazing, forming a low thermal resistance thermally conductive connection with the outer shell 3, which can further increase the overall heat exchange area and improve the heat exchange capacity. The other side of the heat exchange plate 7 is provided with standardized mounting holes adapted to the fuselage of the UAV 5, which can be directly fixed to the fuselage structure of the UAV 5 by high-strength bolts. This not only enables the stable installation of the liquid hydrogen tank on the UAV 5, but also eliminates the need for additional mounting brackets and further reduces the system weight. At the same time, the side of the heat exchange plate 7 is provided with an arc-shaped guide edge, which can regulate the airflow from the guide element, so that the airflow evenly covers the heat exchange surface of the fins 8, avoids the formation of airflow dead zones, and improves the uniformity and efficiency of heat exchange.

[0037] In one embodiment, the flow guide includes a flow guide shroud 6 and a damper adjustment mechanism, which are mounted below the propeller 11 of the UAV 5 via a fixed bracket. The interior of the flow guide shroud 6 forms a flow guide channel with openings at both ends. The air inlet of the flow guide channel faces the slip zone of the propeller 11, and the air outlet faces the arrangement area of ​​the fins 8 and the heat exchange plate 7. This can concentrate and collect the airflow generated by the rotation of the propeller 11 and guide it directionally to the surface of the fins 8 and the heat exchange plate 7, avoiding airflow dispersion and loss, and maximizing the utilization of the slip zone of the propeller 11 to achieve efficient heat exchange. The damper adjustment mechanism is located inside the flow guide channel, and its drive end is electrically connected to the management system 20. It can receive control signals from the management system 20 to change the effective flow cross-section of the flow guide channel, thereby adjusting the airflow rate blowing towards the heat exchanger through the flow guide channel, and realizing active adjustment of heat exchange efficiency.

[0038] In one embodiment, the damper adjustment mechanism includes a baffle plate, which is a circular plate with a diameter equal to the inner diameter of the guide channel. The two sides of the baffle plate are rotatably mounted on the inner wall of the guide channel via a rotating shaft. One end of the rotating shaft is connected to a drive motor, which is electrically connected to the management system 20. When the management system 20 outputs a control signal, the drive motor can drive the baffle plate to rotate around the rotating shaft, changing the angle between the baffle plate and the axis of the guide channel. When the baffle plate is perpendicular to the axis of the guide channel, the guide channel is completely closed, and no airflow passes through. When the baffle plate is parallel to the axis of the guide channel, the flow cross section of the guide channel is at its maximum, and the airflow is at its maximum. By adjusting the rotation angle of the baffle plate, the amount of gas blown towards the fins 8 and the heat exchange plate 7 can be continuously and accurately adjusted, achieving adaptive control of heat exchange efficiency and adapting to the heat exchange requirements under different flight conditions.

[0039] In one embodiment, a pressure sensor 23 is installed inside the inner liner 1. The pressure sensor 23 is a low-temperature resistant, high-precision piezoresistive pressure sensor, ensuring long-term stable operation in a liquid hydrogen cryogenic environment of -253 degrees Celsius, and real-time monitoring of the hydrogen pressure data inside the inner liner 1. The pressure sensor 23 is electrically connected to the management system 20 via a data cable, transmitting the real-time pressure data to the management system 20. The management system 20 can then combine the real-time pressure data of the inner liner 1 with the predicted hydrogen demand to more precisely control the heating power of the heating element.

[0040] Specifically, when the hydrogen pressure inside the inner liner 1 slowly increases, the management system 20 reduces the heating power of the heating element, causing the hydrogen storage alloy 10 to adsorb more hydrogen, increasing the vacuum degree of the interlayer 2, reducing the heat transfer from the outside to the inner liner 1, and thus reducing the evaporation of liquid hydrogen; when the pressure inside the inner liner 1 slowly decreases, the management system 20 increases the heating power of the heating element, causing the hydrogen storage alloy 10 to release hydrogen, reducing the vacuum degree of the interlayer 2, increasing the heat transfer from the outside to the inner liner 1, and thus increasing the evaporation of liquid hydrogen, maintaining the stability of the hydrogen supply pressure of the inner liner 1.

[0041] In one embodiment, a vacuum gauge 21 is installed inside the interlayer 2, which can detect the vacuum level data inside the interlayer 2 in real time. A temperature sensor 22 is fixedly installed on the outer wall of the hydrogen storage box 9, which can detect the temperature data of the hydrogen storage box 9 and the internal hydrogen storage alloy 10 in real time. Both the vacuum gauge 21 and the temperature sensor 22 are electrically connected to the management system 20 via data cables, which can transmit the real-time detected vacuum level data and temperature data to the management system 20. The management system 20 judges the thermal insulation performance of the interlayer 2 based on the vacuum level data, and can also combine the real-time temperature data of the hydrogen storage box 9 to precisely adjust the heating power of the heating element, so as to achieve fine control of the hydrogen absorption and desorption rate of the hydrogen storage alloy 10, ensure the accuracy and stability of the vacuum level adjustment of the interlayer 2, and ultimately achieve full-dimensional monitoring and control of the liquid hydrogen cylinder's operating status.

[0042] Furthermore, the management system 20 can coordinate and control various components to achieve adaptive operation according to different flight conditions of the UAV 5. Specifically, when the UAV 5 is in a stable cruise mode, the management system 20 controls the heating element to operate at low power, so that the interlayer 2 maintains a stable low vacuum and liquid hydrogen is vaporized by external heat conduction. At the same time, the opening of the guide channel is adjusted according to the speed of the propeller 11 to match the heat exchange power with the hydrogen supply demand and maintain a stable hydrogen supply pressure. When the UAV 5 is in a rapid acceleration or high climb rate mode, the management system 20 predicts a surge in hydrogen demand based on the throttle signal. It first increases the opening of the flow channel to enhance external heat exchange, while simultaneously increasing the heating power of the heating element, reducing the vacuum level of the interlayer 2, increasing heat transfer, and rapidly increasing the liquid hydrogen evaporation rate to meet peak hydrogen supply demand. When the UAV 5 is in a high-altitude hovering or low-temperature environment mode, the management system 20 continuously operates the heating element at low power to maintain a moderate hydrogen pressure in the interlayer 2, ensuring a stable basic hydrogen supply. At the same time, it increases the opening of the flow channel to maximize the use of limited airflow for heat exchange. When the UAV 5 is in a ground standby or long-term storage mode, the management system 20 controls the heating element to be completely shut off, and the hydrogen storage alloy 10 adsorbs the hydrogen in the interlayer 2, restoring the interlayer 2 to a high vacuum insulation state and minimizing the evaporation loss of liquid hydrogen.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A liquid hydrogen cylinder for unmanned aerial vehicles (UAVs) with an active thermal management and adaptive heat exchange system, characterized in that, include: The bottle body includes an inner liner and an outer shell, with a sealed interlayer between the inner liner and the outer shell; the inner liner stores liquid hydrogen, and the outer shell has a hydrogen supply channel that connects the interior of the inner liner to the external environment; the interlayer is initially set to a vacuum environment. A hydrogen storage box is disposed within the interlayer and is filled with a hydrogen storage alloy that can adsorb hydrogen at liquid hydrogen temperature. A heating element is used to heat the hydrogen storage box. After the hydrogen storage box is heated, the hydrogen storage alloy can release hydrogen. When the temperature of the hydrogen storage box decreases, the hydrogen storage alloy re-adsorbs hydrogen. A heat exchange assembly, comprising a flow guide and a heat exchanger, wherein the heat exchanger is disposed on the housing, and the flow guide is used to directionally guide the airflow disturbed by the UAV propeller to the heat exchanger. The management system is used to communicate with the flight control system of the UAV. The management system can receive propeller speed or throttle signals, predict hydrogen demand based on the received data, and regulate the heating element and the heat exchange element according to the predicted hydrogen demand.

2. The liquid hydrogen cylinder for UAVs with active thermal management and adaptive heat exchange system according to claim 1, characterized in that: The interlayer is filled with multiple layers of thermal insulation material, which consists of 30-40 layers of aluminum foil and glass fiber spacers stacked alternately. The interlayer is initially set to a vacuum environment.

3. A liquid hydrogen cylinder for unmanned aerial vehicles with an active thermal management and adaptive heat exchange system according to claim 1, characterized in that: The hydrogen storage alloy is any one of lanthanum-nickel based hydrogen storage alloy, titanium-iron based hydrogen storage alloy, or mixed nickel-based hydrogen storage alloy.

4. A liquid hydrogen cylinder for unmanned aerial vehicles with an active thermal management and adaptive heat exchange system according to claim 1, characterized in that: The heating element is an electric heating film that is attached to and fixed to the outer wall of the hydrogen storage box, or an electric heating wire built into the inside of the hydrogen storage box.

5. A liquid hydrogen cylinder for unmanned aerial vehicles with an active thermal management and adaptive heat exchange system according to claim 1, characterized in that: The heat exchanger includes multiple fins made of aluminum alloy, and the fins are fixedly connected to the outer shell by brazing.

6. A liquid hydrogen cylinder for unmanned aerial vehicles with an active thermal management and adaptive heat exchange system according to claim 5, characterized in that: The heat exchanger also includes a heat exchange plate, which is fixedly connected to the outer shell by brazing, and the heat exchange plate is connected to the UAV.

7. A liquid hydrogen cylinder for unmanned aerial vehicles with an active thermal management and adaptive heat exchange system according to claim 6, characterized in that: The airflow guide includes a shroud and a damper adjustment mechanism. The shroud is fixedly installed below the UAV propeller and has an airflow channel. The shroud can guide the wind disturbed by the propeller to the fins and the heat exchange plate. The damper adjustment mechanism is used to change the cross-sectional size of the airflow channel.

8. A liquid hydrogen cylinder for unmanned aerial vehicles with an active thermal management and adaptive heat exchange system according to claim 7, characterized in that: The damper adjustment mechanism includes a baffle plate, the diameter of which is equal to the diameter of the flow channel, and the baffle plate is rotatably disposed within the flow channel; when the baffle plate rotates, it can adjust the amount of gas blown toward the fins and the heat exchange plate.

9. A liquid hydrogen cylinder for unmanned aerial vehicles with an active thermal management and adaptive heat exchange system according to claim 1, characterized in that: A pressure sensor is installed inside the inner liner, and the management system is able to receive data from the pressure sensor.

10. A liquid hydrogen cylinder for unmanned aerial vehicles with an active thermal management and adaptive heat exchange system according to claim 1, characterized in that: A vacuum gauge is installed inside the interlayer, and a temperature sensor is installed on the hydrogen storage box. The management system is able to receive data from the vacuum gauge and the temperature sensor.

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