Unmanned aerial vehicle power system and energy supply method

Abstract

This invention proposes a drone power system, specifically relating to the field of hydrogen energy technology. The drone power system includes a liquid hydrogen storage and supply system, which comprises a liquid hydrogen storage tank, a gas phase hydrogen supply component, a liquid phase hydrogen supply component, a self-pressurizing pipeline, and a fuel cell. The gas phase hydrogen supply component includes a gas phase hydrogen supply pipeline and a gas phase heating coil, and the liquid phase hydrogen supply component includes a liquid phase hydrogen supply pipeline and a liquid phase heating coil. A self-pressurizing pipeline connects the bottom and top of the liquid hydrogen storage tank. The liquid phase heating coil and the gas phase heating coil are used for heat exchange with air and to heat the liquid hydrogen and hydrogen gas. This invention utilizes a self-pressurizing pipeline to pressurize the liquid hydrogen storage tank, eliminating the need for internal electric heating and maintenance without opening the vacuum layer, resulting in a simpler structure.

Description

Technical Field

[0001] This invention relates to the field of hydrogen energy technology, and in particular to unmanned aerial vehicle (UAV) power systems and power supply methods. Background Technology

[0002] Drones have been applied to various scenarios such as power line inspection, emergency rescue, logistics transportation, and long-endurance surveying. Currently, the main way to power drones is with lithium batteries, but lithium batteries have many drawbacks such as poor endurance, sharp drop in discharge efficiency at low temperatures, long recharging time, and low payload.

[0003] Against this backdrop, liquid hydrogen drones have emerged due to their unique advantages. Liquid hydrogen has a high energy density, which can support drones to achieve long-endurance flights of hundreds or even thousands of kilometers, far exceeding the level of lithium battery models. Moreover, its combustion products are only water vapor, which can achieve zero carbon emissions throughout the entire life cycle, perfectly meeting the needs of green aviation development.

[0004] While liquid hydrogen drones have many advantages, the low temperature of liquid hydrogen means that stored liquid hydrogen needs to be brought back to room temperature before it can be fed into fuel cells to generate the power required by the drone. Liquid hydrogen also needs to absorb a lot of heat energy to return to room temperature. An unsuitable hydrogen supply system can lead to lag in response and affect the performance of the drone. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a power system and energy supply method for unmanned aerial vehicles (UAVs).

[0006] This invention is achieved through the following technical solution: This invention proposes an unmanned aerial vehicle (UAV) power system including a liquid hydrogen storage and supply system. The liquid hydrogen storage and supply system comprises a liquid hydrogen storage tank, a gas phase hydrogen supply assembly, a self-pressurizing pipeline, a liquid phase hydrogen supply assembly, and a fuel cell, wherein: The gas phase hydrogen supply assembly includes a gas phase hydrogen supply pipeline and a gas phase heating coil. The liquid phase hydrogen supply assembly includes a liquid phase hydrogen supply pipeline and a liquid phase heating coil. The top of the liquid hydrogen storage tank is sequentially connected to the gas phase hydrogen supply pipeline, the gas phase heating coil, and the fuel cell. The bottom of the liquid hydrogen storage tank is sequentially connected to the liquid phase hydrogen supply pipeline, the liquid phase heating coil, and the fuel cell. One end of the self-pressurizing pipeline is connected to the top of the liquid hydrogen storage tank, and the other end is connected to the end of the liquid phase hydrogen supply pipeline near the storage tank. The liquid phase heating coil and the gas phase heating coil are used to exchange heat with air and heat the liquid hydrogen and hydrogen gas.

[0007] Furthermore, a manual shut-off valve is installed on the self-pressurizing pipeline.

[0008] Furthermore, a heater can be installed on the self-pressurizing heating pipeline to enhance the pressurization capacity, and the portion of the self-pressurizing heating pipeline near the liquid hydrogen storage tank is covered with insulation material.

[0009] Furthermore, the liquid phase heating coil and the gas phase heating coil are made of aluminum tubing.

[0010] Furthermore, a gas phase pipeline on / off solenoid valve is provided between the gas phase heating coil and the fuel cell, and a liquid phase pipeline on / off solenoid valve is provided between the liquid phase coil and the fuel cell.

[0011] Furthermore, it also includes PID controllers, two of which are used to control the duty cycle of the liquid phase pipeline on / off solenoid valve and the gas phase pipeline on / off solenoid valve, respectively.

[0012] Furthermore, it also includes a pressure sensor installed inside the liquid hydrogen storage tank, which is used to monitor the pressure of the liquid hydrogen storage tank and input the signal to the PID controller.

[0013] Furthermore, it also includes a motor and a lithium battery, the fuel cell and the lithium battery being connected to the motor, the motor being used to provide driving force for the drone.

[0014] Furthermore, a method for supplying power to a drone propulsion system includes the following steps: Close the solenoid valve on / off of the gas phase pipeline, open the manual shut-off valve of the self-pressurizing pipeline, and the liquid hydrogen is heated through the self-pressurizing pipeline and turned into gaseous hydrogen before being input into the gas phase zone of the liquid hydrogen storage tank to achieve pressurization of the liquid hydrogen storage tank. At the same time, the liquid hydrogen enters the liquid phase heating coil through the liquid phase hydrogen supply pipeline to reheat to room temperature and supply fuel cell power generation to drive the drone. When the pressure in the liquid hydrogen storage tank rises above the set pressure, the gas phase pipeline on / off solenoid valve is opened. The PID controller receives the pressure difference detected by the pressure sensor inside the liquid hydrogen storage tank and controls the duty cycle of the gas phase pipeline on / off solenoid valve to achieve stable pressure control of the liquid hydrogen storage tank.

[0015] Furthermore, it also includes: When the drone requires increased power, the PID controller increases the duty cycle of the liquid phase pipeline on / off valve and increases the hydrogen supply of the liquid phase hydrogen supply pipeline, so as to increase the output power of the fuel cell to balance the demand of the drone. When the power required by the drone decreases, the PID controller controls the on / off solenoid valve of the liquid phase pipeline to reduce the duty cycle and reduce the hydrogen supply of the liquid phase hydrogen supply pipeline, so as to reduce the output power of the fuel cell to balance the demand of the drone. When the power of the drone changes suddenly during takeoff and landing, the output power of the fuel cell is adjusted and balanced with the drone's needs through lithium batteries.

[0016] The beneficial effects of this invention are: (1) The UAV power system proposed in this invention is equipped with gas phase hydrogen supply pipeline and liquid phase hydrogen supply pipeline and has corresponding gas phase heating coil and liquid phase heating coil. The pressure of the storage tank is controlled by adjusting the flow of the self-pressurizing pipeline and the gas-liquid pipeline. There is no need to arrange electric heating in the liquid hydrogen storage tank. Compared with the electric heating pressurization in the liquid hydrogen storage tank, there is no need to open the vacuum layer for maintenance, and the structure is simpler.

[0017] (2) The UAV power system proposed in this invention does not contain bulky components such as cryogenic regulating valves and hydrogen cylinders, and the overall system weight is lower. At the same time, the pressure and power control of the liquid hydrogen touch control system can be realized through gas phase on / off solenoid valves and liquid phase on / off solenoid valves, which is simpler.

[0018] (3) The easily damaged components of the UAV power system proposed in this invention, such as the gas phase on / off solenoid valve, the liquid phase on / off solenoid valve, the self-pressurization pipeline, the gas phase hydrogen supply pipeline, and the liquid phase hydrogen supply pipeline, are all located outside the liquid hydrogen storage tank, making maintenance more convenient.

[0019] (4) The UAV power system proposed in this invention uses PID control to control the opening and closing of the gas phase hydrogen supply pipeline and the liquid phase hydrogen supply pipeline, which can better control the hydrogen supply from the storage tank to the fuel cell and is less likely to cause the storage tank to overpressure and waste hydrogen. Attached Figure Description

[0020] Figure 1 This is a structural diagram of the unmanned aerial vehicle (UAV) power system of the present invention; Figure 2 This is a diagram of the power supply control method for the UAV power system of the present invention; In the diagram: 1. Liquid hydrogen storage tank; 2. Liquid phase hydrogen supply pipeline; 3. Liquid phase heating coil; 4. Liquid phase pipeline on / off solenoid valve; 5. Gas phase hydrogen supply pipeline; 6. Gas phase heating coil; 7. Gas phase pipeline on / off solenoid valve; 8. Manual shut-off valve; 9. Self-pressurizing pipeline; 10. Pressure sensor; 11. Fuel cell; 12. Lithium battery; 13. Motor.

[0021] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] To more clearly and completely illustrate the technical solution of the present invention, the present invention will be further described below with reference to the accompanying drawings.

[0023] Please refer to Figures 1-2 This invention proposes a drone power system including a liquid hydrogen storage and supply system. The liquid hydrogen storage and supply system includes a liquid hydrogen storage tank 1, a gas phase hydrogen supply component, a self-pressurizing pipeline, a liquid phase hydrogen supply component, and a fuel cell 11, wherein: The gas phase hydrogen supply assembly includes a gas phase hydrogen supply pipeline 5 and a gas phase heating coil 6. The liquid phase hydrogen supply assembly includes a liquid phase hydrogen supply pipeline 2 and a liquid phase heating coil 3. The top of the liquid hydrogen storage tank 1 is connected in sequence to the gas phase hydrogen supply pipeline 5, the gas phase heating coil 6 and the fuel cell 11. The bottom of the liquid hydrogen storage tank 1 is connected in sequence to the liquid phase hydrogen supply pipeline 2, the liquid phase heating coil 3 and the fuel cell 11. One end of the self-pressurizing pipeline 9 is connected to the top of the liquid hydrogen storage tank 1, and the other end is connected to the end of the liquid phase hydrogen supply pipeline 2 near the storage tank. The liquid phase heating coil 3 and the gas phase heating coil 6 are used to exchange heat with air and heat the liquid hydrogen and hydrogen gas.

[0024] Specifically, liquid hydrogen storage tank 1 is used to store liquid hydrogen. Gas phase hydrogen supply pipeline 5 and liquid phase hydrogen supply pipeline 2 are used to supply hydrogen and liquid hydrogen to fuel cell 11, respectively. Self-pressurization pipeline 9 is used to absorb ambient heat to vaporize liquid hydrogen and pass the vaporized hydrogen into the gas phase zone of liquid hydrogen storage tank 1 to achieve self-pressurization of liquid hydrogen storage tank 1. There is no need to install electric heating in liquid hydrogen storage tank. Gas phase heating coil 6 and liquid phase heating coil 3 heat liquid hydrogen and hydrogen to a suitable temperature by exchanging heat with air and then deliver them to fuel cell 11. Fuel cell 11 provides power to the drone through liquid hydrogen and hydrogen.

[0025] Furthermore, a manual shut-off valve 8 is installed on the self-pressurizing pipeline 9.

[0026] Specifically, the manual shut-off valve 8 on the self-pressurizing pipeline 9 can be selected and set for convenient on / off control or canceled to reduce counterweight, depending on the actual situation.

[0027] Furthermore, a heater can be installed on the self-pressurizing heating pipeline to increase the pressurization rate, and the section of the self-pressurizing heating pipeline near the liquid hydrogen storage tank 1 is covered with insulation material.

[0028] Specifically, lightweight insulation materials can be selected based on actual conditions to reduce heat leakage. The heater heats the self-pressurizing heating pipeline. The heater can be selected and set according to actual conditions, such as canceling the heater to reduce the counterweight or setting the heater to increase the pressurization speed.

[0029] Furthermore, the liquid phase heating coil 3 and the gas phase heating coil 6 are made of aluminum tubes.

[0030] Specifically, the liquid phase heating coil 3 and the gas phase heating coil use ambient air as a heating source, which can save heating energy.

[0031] Furthermore, a gas phase pipeline on / off solenoid valve 7 is provided between the gas phase heating coil 6 and the fuel cell 11, and a liquid phase pipeline on / off solenoid valve 4 is provided between the liquid phase coil and the fuel cell 11.

[0032] Specifically, the gas phase pipeline on / off solenoid valve 7 is used to control the duty cycle of the gas phase hydrogen supply component, and the liquid phase pipeline on / off solenoid valve 4 is used to control the duty cycle of the liquid phase hydrogen supply component. The output power of the fuel cell 11 is adjusted by switching the two solenoid valves on and off, which is consistent with the needs of the UAV.

[0033] Furthermore, it also includes PID controllers, with two PID controllers used to control the duty cycle of the liquid phase pipeline on / off solenoid valve 4 and the gas phase pipeline on / off solenoid valve 7, respectively.

[0034] Specifically, the liquid phase pipeline on / off solenoid valve 4 and the gas phase pipeline on / off solenoid valve 7 have their corresponding PID controllers. When the drone starts to take off, the difference between the output power of the fuel cell 11 and the power required by the drone is used as a feedback signal and input to the PID controller. The PID controller adjusts the output duty cycle signal to control the opening degree of the liquid phase pipeline on / off solenoid valve 4, so as to adjust the output power of the fuel cell 11 to be consistent with the needs of the drone.

[0035] Furthermore, it also includes a pressure sensor 10 installed inside the liquid hydrogen storage tank 1. The pressure sensor 10 is used to monitor the pressure of the liquid hydrogen storage tank 1 and input the signal to the PID controller.

[0036] Specifically, when the pressure in liquid hydrogen storage tank 1 rises to a level greater than the set pressure of liquid hydrogen storage tank 1, the gas phase pipeline on / off solenoid valve 7 opens, and the gas phase hydrogen supply pipeline 5 supplies a certain amount of hydrogen to fuel cell 11. The pressure sensor 10 detects the pressure difference between the pressure detected and the pressure set in liquid hydrogen storage tank 1, and inputs it as a feedback signal to the PID controller. After adjustment by the PID controller, the duty cycle signal is output to control the duty cycle of the gas phase pipeline on / off valve, thereby adjusting the amount of hydrogen supplied by the gas phase hydrogen supply pipeline 5 to achieve pressure stability in liquid hydrogen storage tank 1.

[0037] In one embodiment, when hydrogen is supplied to the gas phase hydrogen supply line 5, the output power of the fuel cell 11 will increase. At this time, the PID controller of the liquid phase hydrogen supply line 2 will reduce the duty cycle of the liquid phase pipeline on / off solenoid valve 4 to reduce the amount of hydrogen supplied to the liquid phase pipeline, thereby achieving a balance between the output power of the fuel cell 11 and the demand of the drone. Conversely, when the amount of hydrogen supplied to the gas phase hydrogen supply line 5 decreases, the PID controller of the liquid phase hydrogen supply line 2 will increase the duty cycle of the liquid phase pipeline on / off solenoid valve 4 to achieve a balance between the output power and the demand.

[0038] Furthermore, it also includes a motor 13 and a lithium battery 12. The fuel cell 11 and the lithium battery 12 are connected to the motor 13, which is used to provide driving force for the drone.

[0039] Specifically, the motor 13 provides driving force for the drone, and the lithium battery 12 can adjust the power demand and the output power of the fuel cell 11 to compensate for the difference in power demand when the liquid hydrogen storage and supply system is not timely.

[0040] Furthermore, a method for supplying power to a drone propulsion system includes the following steps: Close the solenoid valve 7 for opening and closing the gas phase pipeline, open the manual shut-off valve 8 for the self-pressurizing pipeline 9, and the liquid hydrogen is heated through the self-pressurizing pipeline 9 and turned into gaseous hydrogen before being input into the gas phase zone of the liquid hydrogen storage tank 1 to achieve pressurization of the liquid hydrogen storage tank. At the same time, the liquid hydrogen enters the liquid phase heating coil 3 through the liquid phase hydrogen supply pipeline 2 to be reheated to room temperature to supply the fuel cell 11 to generate electricity and drive the drone. When the pressure in liquid hydrogen storage tank 1 rises above the set pressure, the gas phase pipeline on / off solenoid valve 7 is opened. The PID controller receives the pressure difference detected by the pressure sensor 10 inside liquid hydrogen storage tank 1 and controls the duty cycle of the gas phase pipeline on / off solenoid valve 7 to achieve stable pressure control of the storage tank.

[0041] When the drone requires an increase in the output power of fuel cell 11, the PID controller increases the duty cycle of the liquid phase pipeline on / off valve to increase the output power of fuel cell 11 to balance the drone's demand. When the drone requires a smaller output power from fuel cell 11, the PID controller controls the liquid phase pipeline to switch the solenoid valve 4 to reduce the duty cycle, thereby reducing the output power of fuel cell 11 to balance the drone's demand. When the power changes suddenly during takeoff and landing of the drone, the output power of the fuel cell 11 is adjusted and balanced with the drone's needs by the lithium battery 12.

[0042] Of course, the present invention may have many other embodiments. Based on this embodiment, other embodiments obtained by those skilled in the art without any creative effort are all within the scope of protection of the present invention.

Claims

1. A power system for an unmanned aerial vehicle (UAV), characterized in that, The system includes a liquid hydrogen storage and supply system, comprising a liquid hydrogen storage tank, a gas phase hydrogen supply assembly, a self-pressurizing pipeline, a liquid phase hydrogen supply assembly, and a fuel cell, wherein: The gas phase hydrogen supply assembly includes a gas phase hydrogen supply pipeline and a gas phase heating coil. The liquid phase hydrogen supply assembly includes a liquid phase hydrogen supply pipeline and a liquid phase heating coil. The top of the liquid hydrogen storage tank is sequentially connected to the gas phase hydrogen supply pipeline, the gas phase heating coil, and the fuel cell. The bottom of the liquid hydrogen storage tank is sequentially connected to the liquid phase hydrogen supply pipeline, the liquid phase heating coil, and the fuel cell. One end of the self-pressurizing pipeline is connected to the top of the liquid hydrogen storage tank, and the other end is connected to the end of the liquid phase hydrogen supply pipeline near the storage tank. The liquid phase heating coil and the gas phase heating coil are used to exchange heat with air and heat the liquid hydrogen and hydrogen gas.

2. The UAV power system according to claim 1, characterized in that, It also includes a self-pressurizing pipeline, which is equipped with a manual shut-off valve.

3. The UAV power system according to claim 2, characterized in that, A heater is installed on the self-pressurizing heating pipeline, and the portion of the self-pressurizing heating pipeline near the liquid hydrogen storage tank is covered with insulation material.

4. The UAV power system according to claim 1, characterized in that, The liquid phase heating coil and the gas phase heating coil are made of aluminum tubing.

5. The unmanned aerial vehicle (UAV) power system according to claim 1, characterized in that, A gas phase pipeline on / off solenoid valve is provided between the gas phase heating coil and the fuel cell, and a liquid phase pipeline on / off solenoid valve is provided between the liquid phase coil and the fuel cell.

6. The UAV power system according to claim 5, characterized in that, It also includes PID controllers, two of which are used to control the duty cycle of the liquid phase pipeline on / off solenoid valve and the gas phase pipeline on / off solenoid valve, respectively.

7. The UAV power system according to claim 6, characterized in that, It also includes a pressure sensor installed inside the liquid hydrogen storage tank, which is used to monitor the pressure of the liquid hydrogen storage tank and input the signal to the PID controller.

8. The unmanned aerial vehicle power system according to claim 1, characterized in that, It also includes a motor and a lithium battery, the fuel cell and the lithium battery being connected to the motor, which is used to provide driving force for the drone.

9. A power supply method for an unmanned aerial vehicle (UAV) power system, applied to the UAV power system as described in any one of claims 1-8, comprising the following steps: Close the solenoid valve on / off of the gas phase pipeline, open the manual shut-off valve of the self-pressurizing pipeline, and the liquid hydrogen is heated through the self-pressurizing pipeline and turned into gaseous hydrogen before being input into the gas phase zone of the liquid hydrogen storage tank to achieve pressurization of the liquid hydrogen storage tank. At the same time, the liquid hydrogen enters the liquid phase heating coil through the liquid phase hydrogen supply pipeline to reheat to room temperature and supply fuel cell power generation to drive the drone. When the pressure in the liquid hydrogen storage tank rises above the set pressure, the gas phase pipeline on / off solenoid valve is opened. The PID controller receives the pressure difference detected by the pressure sensor inside the liquid hydrogen storage tank and controls the duty cycle of the gas phase pipeline on / off solenoid valve to achieve stable pressure control of the liquid hydrogen storage tank.

10. The unmanned aerial vehicle power system according to claim 9, characterized in that, Also includes: When the drone requires increased power, the PID controller increases the duty cycle of the liquid phase pipeline on / off valve to increase the hydrogen supply of the liquid phase hydrogen supply pipeline, thereby increasing the output power of the fuel cell to balance the demand of the drone. When the power required by the drone decreases, the PID controller controls the on / off solenoid valve of the liquid phase pipeline to reduce the duty cycle and reduce the hydrogen supply of the liquid phase hydrogen supply pipeline, so as to reduce the output power of the fuel cell to balance the demand of the drone. When the power of the drone changes suddenly during takeoff and landing, the output power of the fuel cell is adjusted and balanced with the drone's needs through lithium batteries.

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