Liquid hydrogen supply system for hydrogen-powered unmanned aerial vehicle

Abstract

The invention relates to the technical field of liquid hydrogen supply, and discloses a liquid hydrogen supply system for a hydrogen-powered unmanned aerial vehicle, which comprises an interstage heat exchanger, a vaporizer, a gaseous hydrogen storage tank and an exhaust nozzle heat exchanger which are sequentially connected, the interstage heat exchanger is distributed between centrifugal compressor stages of the unmanned aerial vehicle, and the vaporizer is connected with the interstage heat exchanger through a circulating pipeline; the vaporizer is arranged in a countercurrent manner, the exhaust nozzle heat exchanger is arranged on an exhaust nozzle of the unmanned aerial vehicle, a heat exchange pipeline of the exhaust nozzle heat exchanger extends into the gaseous hydrogen storage tank, and a heat exchange medium in the interstage heat exchanger is subjected to phase change between stages of a gas compressor and is evaporated upwards to enter the vaporizer, so that liquid hydrogen enters the gaseous hydrogen storage tank after being vaporized into hydrogen in the vaporizer; the phase change working medium in the exhaust nozzle heat exchanger brings heat of the exhaust nozzle into the gaseous hydrogen storage tank through the heat exchange pipeline, so that hydrogen in the gaseous hydrogen storage tank is heated and finally sprayed into the combustion chamber through the pipeline to be uniformly mixed with air, and the control cost in the liquid hydrogen vaporization process in the liquid hydrogen supply system can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid hydrogen supply, and in particular to a liquid hydrogen supply system for a hydrogen-powered unmanned aerial vehicle. Background Art

[0002] The UAV turbofan engine sucks in a large amount of air through the adjustable leading edge air inlet. After being pressurized by the rotor of a multi-stage axial flow or centrifugal compressor, its pressure and temperature gradually increase to form a high-temperature and high-pressure gas. Finally, after entering the combustion chamber, it is mixed with the fuel. The fuel amount and air mixing ratio are controlled by precise fuel injectors to ensure that the fuel burns quickly and completely in the combustion chamber to produce high-temperature and high-pressure combustion gas. The high-temperature and high-pressure combustion gas expands and drives the turbine blades to rotate. The turbine is divided into a high-pressure turbine and a low-pressure turbine. The high-pressure turbine directly drives the compressor, while the low-pressure turbine may drive the fan or other accessories.

[0003] The turbofan engines currently in use use aviation fuel, which can be directly injected into the combustion chamber and mixed with air. However, as energy conservation, emission reduction, and green environmental protection gradually become the mainstream, new alternative energy sources need to be found. The energy density of liquid hydrogen is much higher than that of aviation fuel, and it is a clean energy. Therefore, hydrogen energy has become the preferred fuel for the new generation of aircraft. However, liquid hydrogen cannot be used directly as fuel at present. It needs to be heated by a heat exchanger and converted into hydrogen before entering the combustion chamber and mixing with air. During the combustion process, the combustion chamber of a hydrogen-powered engine needs to mix hydrogen at a certain temperature and pressure with air for combustion, heat the liquid hydrogen to its boiling point (-252.87℃), convert it into gas, and continue to heat it to room temperature. This process requires a high-temperature heat source.

[0004] In the relevant hydrogen-powered engine design, the heat exchanger is placed at the tail nozzle, and the heat of the tail nozzle is used to directly vaporize the liquid hydrogen. Although this structure improves the energy utilization efficiency, the temperature of the tail nozzle is constantly changing with the flight changes. Therefore, if the high-temperature heat source of the tail nozzle is used, an additional control system is required to control the progress of heat exchange, resulting in a high additional cost for the control system. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a liquid hydrogen supply system for a hydrogen-powered UAV, which can reduce the control cost of the liquid hydrogen vaporization process in the liquid hydrogen supply system.

[0006] The present invention provides a liquid hydrogen supply system for a hydrogen-powered unmanned aerial vehicle, comprising: an interstage heat exchanger, a vaporizer, a gaseous hydrogen storage tank and a tail nozzle heat exchanger connected in sequence, the interstage heat exchanger is distributed between stages of a centrifugal compressor of the unmanned aerial vehicle, the vaporizer is connected to the interstage heat exchanger through a circulation pipeline, the vaporizer is arranged in countercurrent, the tail nozzle heat exchanger is arranged on the tail nozzle of the unmanned aerial vehicle, the heat exchange pipeline of the tail nozzle heat exchanger extends into the gaseous hydrogen storage tank, the heat exchange medium in the interstage heat exchanger undergoes phase change between the compressor stages and evaporates upward into the vaporizer, so that the liquid hydrogen is vaporized into hydrogen in the vaporizer and then enters the gaseous hydrogen storage tank, the phase change working medium in the tail nozzle heat exchanger brings the heat of the tail nozzle into the gaseous hydrogen storage tank through the heat exchange pipeline, so that the hydrogen in the gaseous hydrogen storage tank is heated, and finally sprayed into a combustion chamber through a pipeline and evenly mixed with air.

[0007] Optionally, the interstage heat exchanger is in the shape of a double-layer circular ring with inner and outer layers nested.

[0008] Optionally, a plurality of guide vanes are arranged between the double-layer circular rings of the interstage heat exchanger, one end of the guide vane abuts against the outer circular ring, and the other end of the guide vane abuts against the inner circular ring.

[0009] Optionally, heat sinks are arranged on the inner circumference of the outer ring of the inter-stage heat exchanger.

[0010] Optionally, the vaporizer and the gaseous hydrogen storage tank are connected via an inclined pipeline, and one end of the inclined pipeline connected to the vaporizer is lower than one end of the inclined pipeline connected to the gaseous hydrogen storage tank.

[0011] Optionally, an annular pipeline is provided in the combustion chamber, and a plurality of air outlet holes are evenly distributed on the annular pipeline, and hydrogen enters the annular pipeline and is ejected through the air outlet holes.

[0012] Optionally, the vaporizer is connected to a liquid hydrogen pump and a liquid hydrogen storage tank in sequence, and the liquid hydrogen is stored in the liquid hydrogen storage tank and is input into the vaporizer through the liquid hydrogen pump when needed.

[0013] The technical solution provided by the embodiment of the present invention has the following advantages compared with the prior art:

[0014] A liquid hydrogen supply system for a hydrogen-powered UAV provided in an embodiment of the present invention places an inter-stage heat exchanger between the centrifugal compressor stages of the UAV, and uses a step-by-step heating method to bring the high-temperature air between the centrifugal compressor stages into the vaporizer. Through the preheater, evaporator and superheater in the vaporizer, the liquid hydrogen is heated from liquid to gaseous, and then enters the gaseous hydrogen storage tank through a pipeline. The gaseous hydrogen storage tank contains a heat exchange pipeline, and the heat of the tail nozzle is brought into the gaseous hydrogen storage tank by using a phase change working fluid through the tail nozzle heat exchanger, so that the hydrogen in the gaseous hydrogen storage tank is heated, and finally the heated hydrogen is added to the combustion chamber to be mixed with air and then burned. By bringing the heat of the high-temperature gas between the stages of the engine's centrifugal compressor to the vaporizer to heat the liquid hydrogen, on the one hand, the compression efficiency of the centrifugal compressor can be improved and the power consumed by compression can be reduced. On the other hand, it can also provide the high-temperature heat source required by the vaporizer, which not only improves the energy utilization efficiency, but also improves the efficiency of the compressor. When the engine thrust increases, a large amount of hydrogen is required as a combustion working fluid, and the vaporizer requires more heat. At the same time, the air flow through the compressor will also increase, which can also provide more heat, thereby achieving heat balance. The amount of hydrogen required by the engine is positively correlated with the engine thrust, so the relevant control costs can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic structural diagram of a liquid hydrogen supply system for a hydrogen-powered UAV provided in an embodiment of the present invention;

[0016] Figure 2 A schematic structural diagram of an interstage heat exchanger provided in an embodiment of the present invention.

[0017] Description of reference numerals:

[0018] 1. Air inlet; 2. Impeller; 3. Interstage heat exchanger; 4. Vaporizer; 5. Liquid hydrogen pump; 6. Liquid hydrogen storage tank; 7. Combustion chamber; 8. Turbine; 9. Gaseous hydrogen storage tank; 10. Tail nozzle; 11. Tail nozzle heat exchanger; 12. Guide vane; 13. Heat sink. DETAILED DESCRIPTION

[0019] A specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation.

[0020] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the technical solutions of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0021] In the relevant hydrogen-powered engine design, the heat exchanger is placed at the tail nozzle, and the heat of the tail nozzle is used to directly vaporize the liquid hydrogen. Although this structure improves the energy utilization efficiency, the temperature of the tail nozzle is constantly changing with the flight changes. Therefore, if the high-temperature heat source of the tail nozzle is used, an additional control system is required to control the progress of heat exchange, resulting in a high additional cost for the control system.

[0022] To this end, an embodiment of the present invention provides a liquid hydrogen supply system for a hydrogen-powered UAV, which can reduce the control cost of the liquid hydrogen vaporization process in the liquid hydrogen supply system.

[0023] To further understand the overall solution of the present invention, the following first describes the relevant components of the drone involved in the embodiment of the present invention:

[0024] Centrifugal compressor: The working principle of the centrifugal compressor is based on the dynamic interaction between high-speed airflow and the working impeller and fixed blades. When the gas flows through the impeller 2, the gas is subjected to the centrifugal force due to the rotation of the impeller 2 and generates pressure. At the same time, the gas also gains speed. Subsequently, the gas passes through the diffuser to slow down the speed, further increasing the pressure of the gas.

[0025] Combustion chamber 7: Located between the compressor and the turbine 8, it is responsible for converting the chemical energy of the fuel into thermal energy through combustion. The high-temperature and high-pressure combustion gas formed drives the turbine 8 to do work, thereby providing power for the aircraft engine.

[0026] Turbine 8: converts most of the energy of the high-temperature, high-pressure combustion gas flowing out of the combustion chamber 7 into mechanical work, so that the turbine 8 rotates at high speed and generates large power, which is output by the turbine shaft. The mechanical work output by the turbine can be used to drive the compressor.

[0027] Isothermal compression: Isothermal compression refers to a compression method in which the temperature of gas or substance remains unchanged during the compression process.

[0028] At least one embodiment of the present invention provides a liquid hydrogen supply system for a hydrogen-powered UAV, comprising: an interstage heat exchanger, a vaporizer, a gaseous hydrogen storage tank and a tail nozzle heat exchanger connected in sequence, the interstage heat exchanger is distributed between the stages of the centrifugal compressor of the UAV, the vaporizer is connected to the interstage heat exchanger through a circulation pipeline, the vaporizer is countercurrently arranged, the tail nozzle heat exchanger is arranged on the tail nozzle of the UAV, the heat exchange pipeline of the tail nozzle heat exchanger extends into the gaseous hydrogen storage tank, the heat exchange medium in the interstage heat exchanger undergoes a phase change between the compressor stages and evaporates upward into the vaporizer, so that the liquid hydrogen is vaporized into hydrogen in the vaporizer and then enters the gaseous hydrogen storage tank, the phase change working fluid in the tail nozzle heat exchanger brings the heat of the tail nozzle into the gaseous hydrogen storage tank through the heat exchange pipeline, so that the hydrogen in the gaseous hydrogen storage tank is heated, and finally sprayed into the combustion chamber through the pipeline and evenly mixed with the air.

[0029] In the liquid hydrogen supply system for a hydrogen-powered UAV provided by the above-mentioned embodiment of the present invention, by bringing the heat of the high-temperature gas between the stages of the centrifugal compressor of the engine to the vaporizer to heat the liquid hydrogen, on the one hand, the compression efficiency of the centrifugal compressor can be improved and the power consumed by compression can be reduced. On the other hand, it can also provide the high-temperature heat source required by the vaporizer, which not only improves the energy utilization efficiency, but also improves the efficiency of the compressor. When the engine thrust increases, a large amount of hydrogen is required as a combustion working medium, and the vaporizer requires more heat. At the same time, the air flow through the compressor will also increase, which can also provide more heat, thereby achieving heat balance. The amount of hydrogen required by the engine is positively correlated with the thrust of the engine, so the relevant control costs can be reduced.

[0030] The present invention is described below by several specific embodiments. In order to keep the following description of the embodiments of the present invention clear and concise, the detailed description of known functions and known components may be omitted. When any component of the embodiments of the present invention appears in more than one accompanying drawings, the component may be represented by the same reference numeral in each of the accompanying drawings.

[0031] refer to Figure 1 , Figure 1 A three-dimensional schematic diagram of a liquid hydrogen supply system for a hydrogen-powered UAV provided in an embodiment of the present invention, such as Figure 1As shown, an embodiment of the present invention provides a liquid hydrogen supply system for a hydrogen-powered UAV, comprising: an interstage heat exchanger 3, a vaporizer 4, a gaseous hydrogen storage tank 9 and a tail nozzle heat exchanger 11 connected in sequence, the interstage heat exchanger 3 is distributed between the centrifugal compressor stages of the UAV, the vaporizer 4 is connected to the interstage heat exchanger 3 through a circulation pipeline, the vaporizer 4 is countercurrently arranged, the tail nozzle heat exchanger 11 is arranged on the tail nozzle 10 of the UAV, and the heat exchange pipeline of the tail nozzle heat exchanger 11 extends into the gaseous hydrogen storage tank 9. The heat exchange medium in the interstage heat exchanger 3 undergoes a phase change between the compressor stages and evaporates upward into the vaporizer 4, so that the liquid hydrogen is vaporized into hydrogen in the vaporizer 4 and then enters the gaseous hydrogen storage tank 9. The phase change working fluid in the tail nozzle heat exchanger 11 brings the heat of the tail nozzle into the gaseous hydrogen storage tank 9 through the heat exchange pipeline, so that the hydrogen in the gaseous hydrogen storage tank 9 is heated, and finally sprayed into the combustion chamber 7 through the pipeline and evenly mixed with the air.

[0032] exist Figure 1 At the lower end of the diagram, air enters from the air inlet 1, passes through the impeller 2 and the interstage heat exchanger 3, enters the second stage compressor, and then enters the combustion chamber 7, where it is mixed with hydrogen and burned, thereby ejecting high-temperature gas to drive the turbine 8, and finally ejected from the tail nozzle 10 at high speed to give the aircraft thrust. At the upper end of the diagram, when necessary, liquid hydrogen is input into the vaporizer 4, which includes a preheater, an evaporator and a heat exchanger. The liquid hydrogen is vaporized into hydrogen in the vaporizer 4, enters the gaseous hydrogen storage tank 9 through a pipeline, and is heated by heat exchange in the gaseous hydrogen storage tank 9, and finally sprayed into the combustion chamber 7 through a pipeline and evenly mixed with the air. The vaporizer 4 adopts a countercurrent arrangement and enters the interstage heat exchanger 3 through a pipeline. The interstage heat exchanger 3 is installed between the compressor stages. During this process, the heat exchange medium undergoes a phase change. The medium that undergoes a phase change evaporates upward, and the medium that does not undergo a phase change flows downward along the pipeline. The heat exchange medium coming out of the interstage heat exchanger 3 enters the vaporizer 4 in a countercurrent manner along the pipeline, and serves as a heat source to heat up and vaporize the liquid hydrogen. After the heat exchange, the heat exchange medium that has changed into a liquid state leaves the vaporizer 4, and returns to the interstage heat exchanger 3 along the pipeline to absorb heat and change phase. The heat exchange medium absorbs heat in the interstage heat exchanger 3 because the impeller 2 compresses the air, which causes the gas to heat up. The interstage heat exchanger 3 can absorb excess heat, allowing the compression process to tend to isothermal compression, thereby improving the compression efficiency of the compressor. A heat exchange pipeline is arranged in the gaseous hydrogen storage tank 9. After the phase change working fluid passes through the tail nozzle heat exchanger 11, it absorbs the heat of the ejected high-temperature gas and brings it back to the gaseous hydrogen storage tank 9, which will heat up the hydrogen and make the high-temperature hydrogen more efficiently utilized in the combustion chamber 7. After the gas in the tail nozzle 10 is cooled by absorbing heat, the infrared thermal signal can also be reduced. In this process, the heat between stages is only used to vaporize liquid hydrogen, and the heat of the tail nozzle 10 is only used to heat up the hydrogen. This will greatly reduce the difficulty of control system design, and the additional gaseous hydrogen storage tank 9 can more conveniently dispatch the hydrogen usage, so that it can be used in various emergencies.

[0033] A liquid hydrogen supply system for a hydrogen-powered UAV provided in an embodiment of the present invention places an inter-stage heat exchanger between the centrifugal compressor stages of the UAV, and uses a step-by-step heating method to bring the high-temperature air between the centrifugal compressor stages into the vaporizer. Through the preheater, evaporator and superheater in the vaporizer, the liquid hydrogen is heated from liquid to gaseous, and then enters the gaseous hydrogen storage tank through a pipeline. The gaseous hydrogen storage tank contains a heat exchange pipeline, and the heat of the tail nozzle is brought into the gaseous hydrogen storage tank by using a phase change working fluid through the tail nozzle heat exchanger, so that the hydrogen in the gaseous hydrogen storage tank is heated, and finally the heated hydrogen is added to the combustion chamber to be mixed with air and then burned. By bringing the heat of the high-temperature gas between the stages of the engine's centrifugal compressor to the vaporizer to heat the liquid hydrogen, on the one hand, the compression efficiency of the centrifugal compressor can be improved and the power consumed by compression can be reduced. On the other hand, it can also provide the high-temperature heat source required by the vaporizer, which not only improves the energy utilization efficiency, but also improves the efficiency of the compressor. When the engine thrust increases, a large amount of hydrogen is required as a combustion working fluid, and the vaporizer requires more heat. At the same time, the air flow through the compressor will also increase, which can also provide more heat, thereby achieving heat balance. The amount of hydrogen required by the engine is positively correlated with the engine thrust, so the relevant control costs can be reduced.

[0034] refer to Figure 2 , Figure 2 A schematic diagram of the structure of an interstage heat exchanger provided in an embodiment of the present invention is shown in FIG. Figure 2 As shown, the inter-stage heat exchanger 3 is in the shape of a double-layer circular ring with inner and outer layers nested.

[0035] The interstage heat exchanger 3 in the embodiment of the present invention needs to be placed between the stages of the centrifugal compressor, and the pipelines of the interstage heat exchanger 3 form a circle, and the phase change medium flows in the middle. The UAV will involve various attitude adjustments during flight. When the UAV makes a large-scale attitude adjustment, the heat exchange medium in the interstage heat exchanger 3 will be insufficiently heated due to the acceleration in all directions. The interstage heat exchanger 3 is arranged in a circular ring shape, so that sufficient heat exchange can still be performed when the UAV is adjusted. Figure 2 In the figure, the arrow at the lower end is the inlet of the phase-change medium, and the arrow at the upper end is the outlet of the phase-change medium. The phase-change medium in the interstage heat exchanger 3 flows in from the bottom, and is in the liquid phase at this time, and flows upward along the channel of the tube wall. In this process, the phase-change medium absorbs the heat of the air in the pipeline, so that the phase-change medium vaporizes from the liquid phase to the gas phase. The gas phase phase-change medium flows upward along the wall surface and finally leaves the interstage heat exchanger 3. The liquid phase will continue to flow in the interstage heat exchanger 3 under the action of gravity and cannot leave the interstage heat exchanger 3 through the outlet. The air passes between the inner ring and the outer ring of the interstage heat exchanger 3.

[0036] Specifically, a plurality of guide vanes 12 are arranged between the double-layer circular rings of the interstage heat exchanger 3, one end of the guide vane 12 abuts against the outer circular ring, and the other end of the guide vane 12 abuts against the inner circular ring, thereby guiding the air to flow into the next-stage compressor.

[0037] Specifically, heat sinks 13 are arranged on the inner circumference of the outer ring of the inter-stage heat exchanger 3, and the outer ring is filled with heat sinks 13 so as to guide the heat to the outer heat exchange channel.

[0038] Reference again Figure 1 The vaporizer 4 and the gaseous hydrogen storage tank 9 are connected by an inclined pipeline, and one end of the inclined pipeline connected to the vaporizer 4 is lower than the other end of the inclined pipeline connected to the gaseous hydrogen storage tank 9. The vaporizer 4 adopts a countercurrent arrangement and enters the interstage heat exchanger 3 through a pipeline. The interstage heat exchanger 3 is installed between the compressor stages. During this process, the heat exchange medium undergoes a phase change, the medium that undergoes a phase change evaporates upward, and the medium that does not undergo a phase change flows downward along the inclined pipeline, ensuring that the heat exchange medium undergoes a phase change and becomes gaseous.

[0039] In the embodiment of the present invention, an annular pipeline is provided in the combustion chamber 7, and a plurality of air outlet holes are evenly distributed on the annular pipeline. After the hydrogen enters the annular pipeline, it is ejected through the air outlet holes. In the combustion chamber 7, the hydrogen passes through the annular pipeline, and the pipeline is covered with small holes, so that the hydrogen can be evenly mixed into the air to achieve the purpose of mixing with the dynamic flow rate. The uniform distribution can make the hydrogen and air gases more complete during combustion.

[0040] Specifically, the vaporizer 4 is connected to a liquid hydrogen pump 5 and a liquid hydrogen storage tank 6 in sequence. The liquid hydrogen is stored in the liquid hydrogen storage tank 6 and is input into the vaporizer 4 through the liquid hydrogen pump 5 when needed. In the present invention, after the liquid hydrogen is gasified into gaseous hydrogen, it will first be introduced into the gaseous hydrogen storage tank 9, and will not be directly introduced into the combustion chamber 7. In the gaseous hydrogen storage tank 9, the heat of the tail nozzle 10 will be used to heat the gaseous hydrogen, so that it can enter the combustion chamber 7 later for more efficient combustion, and at the same time, the amount of gaseous hydrogen used can be more conveniently dispatched to cope with various emergencies.

[0041] The overall effects of the embodiments of the present invention are as follows:

[0042] 1. Use the heat generated by the impeller to compress the air to heat the vaporizer, so that liquid hydrogen can be converted into hydrogen, thereby providing fuel for the engine.

[0043] 2. With the change of engine thrust, the heat required by the vaporizer and the heat provided by the centrifugal compressor stage can basically achieve heat balance, and no additional control system is needed to control the liquid hydrogen vaporization process.

[0044] 3. The heat exchange between the stages of the multi-stage compressor is specifically used to vaporize the liquid hydrogen in the vaporizer, and a gaseous hydrogen storage tank is set up to store the hydrogen that has passed through the vaporizer. The heat exchange pipeline is built into the gaseous hydrogen storage tank to heat the hydrogen.

[0045] The compression heat released by the compressor is used to vaporize liquid hydrogen into hydrogen, avoiding the use of additional energy to vaporize liquid hydrogen. It also simplifies the complexity of the equipment to a certain extent. At the same time, the compressor can slow down the temperature rise and is closer to isothermal compression, thereby improving energy utilization efficiency.

[0046] When the engine thrust increases, the consumption of hydrogen increases, and the vaporizer requires more heat. At this time, the air flow through the compressor will also increase accordingly. The heat exchange medium can absorb more heat from the compressor stages, thus achieving heat self-balance.

[0047] Adding a gaseous hydrogen storage tank and setting up a heat exchange pipeline in it can make more efficient use of the heat from the tail nozzle and also make it more convenient to schedule and control the amount of hydrogen used.

[0048] In the present invention, after liquid hydrogen is vaporized into hydrogen, it will first be introduced into a gaseous hydrogen storage tank, rather than directly into the combustion chamber. In the hydrogen storage tank, the heat of the tail nozzle will be used to heat the hydrogen so that it can enter the combustion chamber for more efficient combustion. At the same time, the amount of hydrogen used can be more conveniently scheduled to deal with various emergencies.

[0049] The above inventions are only several specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A liquid hydrogen supply system for a hydrogen-powered UAV, characterized in that: The invention comprises an interstage heat exchanger (3), a vaporizer (4), a gaseous hydrogen storage tank (9) and a tail nozzle heat exchanger (11) which are connected in sequence, wherein the interstage heat exchanger (3) is distributed between the stages of the centrifugal compressor of the unmanned aerial vehicle, the vaporizer (4) is connected to the interstage heat exchanger (3) via a circulation pipeline, the vaporizer (4) is arranged in countercurrent, the tail nozzle heat exchanger (11) is arranged on the tail nozzle (10) of the unmanned aerial vehicle, and the heat exchange pipeline of the tail nozzle heat exchanger (11) extends into the gaseous hydrogen storage tank (9); The heat exchange medium in the interstage heat exchanger (3) undergoes a phase change between the compressor stages and evaporates upward into the vaporizer (4), causing the liquid hydrogen to be vaporized into hydrogen in the vaporizer (4) and then enter the gaseous hydrogen storage tank (9). The phase change medium in the tail nozzle heat exchanger (11) brings the heat of the tail nozzle into the gaseous hydrogen storage tank (9) through the heat exchange pipeline, causing the hydrogen in the gaseous hydrogen storage tank (9) to heat up, and finally is sprayed into the combustion chamber (7) through the pipeline to be evenly mixed with the air.

2. A liquid hydrogen supply system for a hydrogen-powered UAV as claimed in claim 1, characterized in that: The inter-stage heat exchanger (3) is in the shape of a double-layer circular ring with inner and outer layers nested.

3. A liquid hydrogen supply system for a hydrogen-powered UAV as claimed in claim 2, characterized in that: A plurality of guide vanes (12) are arranged between the double-layer circular rings of the interstage heat exchanger (3), one end of the guide vane (12) abuts against the outer circular ring, and the other end of the guide vane (12) abuts against the inner circular ring.

4. A liquid hydrogen supply system for a hydrogen-powered UAV as claimed in claim 2, characterized in that: Heat sinks (13) are arranged on the inner circumference of the outer circular ring of the inter-stage heat exchanger (3).

5. A liquid hydrogen supply system for a hydrogen-powered UAV as claimed in claim 1, characterized in that: The vaporizer (4) and the gaseous hydrogen storage tank (9) are connected via an inclined pipeline, and one end of the inclined pipeline connected to the vaporizer (4) is lower than one end of the inclined pipeline connected to the gaseous hydrogen storage tank (9).

6. A liquid hydrogen supply system for a hydrogen-powered UAV as claimed in claim 1, characterized in that: An annular pipeline is arranged in the combustion chamber (7), and a plurality of gas outlet holes are evenly distributed on the annular pipeline. After hydrogen enters the annular pipeline, it is ejected through the gas outlet holes.

7. A liquid hydrogen supply system for a hydrogen-powered UAV as claimed in claim 1, characterized in that: The vaporizer (4) is connected in sequence to a liquid hydrogen pump (5) and a liquid hydrogen storage tank (6); liquid hydrogen is stored in the liquid hydrogen storage tank (6) and is input into the vaporizer (4) through the liquid hydrogen pump (5) when needed.

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