Airborne liquid hydrogen fuel cell power system and fixed-wing unmanned aerial vehicle

Abstract

The invention discloses an airborne liquid hydrogen fuel cell power system and a fixed-wing unmanned aerial vehicle, and belongs to the technical field of new energy power systems, the airborne liquid hydrogen fuel cell power system comprises a liquid hydrogen storage and supply module, a hydrogen fuel cell module, a lithium battery module, an airborne equipment module and a motor module; according to the airborne liquid hydrogen fuel cell power system, liquid hydrogen is used as an energy source, a fuel cell is used as a cruising power form of stable power output, a small lithium battery is used for supplementing power supply when an unmanned aerial vehicle takes off, so that the instantaneous high-power requirement is met, and the unmanned aerial vehicle is charged by the fuel cell in the descending stage; through high-energy-density liquid hydrogen storage and efficient power demand matching, the cruising ability of the airborne liquid hydrogen fuel cell power system can be effectively improved, and the long-time and long-distance flight task demand of the unmanned aerial vehicle is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy power systems, and in particular relates to an airborne liquid hydrogen fuel cell power system and a fixed-wing unmanned aerial vehicle. Background Art

[0002] In recent years, drone technology has developed rapidly. Traditional aviation manufacturers, professional drone manufacturers, start-ups and innovation teams are actively involved in research and development, and are constantly exploring the application of drones in civil fields such as urban transportation and logistics, agricultural plant protection, surveying and inspection, emergency rescue, and military missions such as reconnaissance and strike, and communication relay. Most existing drones use traditional fuel and lithium batteries as energy sources. The carbon emissions of fuel drones in a wide range of applications in various general aviation scenarios run counter to the dual carbon goals. Lithium battery drones are limited by the current technical level of batteries and future room for improvement, and have a low power-to-weight ratio, which limits their in-depth application in scenarios requiring long-endurance missions.

[0003] In view of the limitations of traditional fuel engines and lithium battery power systems in UAV applications, people have begun to explore more environmentally friendly and efficient forms of energy and power for UAVs. Hydrogen is a clean energy source, and cryogenic liquid hydrogen has an extremely high energy density (about 38.8kWh / kg), which is more than three times that of traditional aviation fuel (about 12kWh / kg) and dozens of times that of lithium batteries (200-250Wh / kg). Compared with fuel engines, hydrogen fuel cell power has only water as the reaction product, and has the characteristics of low vibration and low noise. Compared with lithium battery power, it has high energy density, strong low temperature adaptability, no obvious infrared characteristics, and long life. In summary, liquid hydrogen fuel cell power system has significant advantages as a new type of energy and power solution for fixed-wing UAVs. Summary of the invention

[0004] In view of the deficiencies in the above-mentioned background technology, the present invention aims to provide an airborne liquid hydrogen fuel cell power system and a fixed-wing UAV, which solve the problem that traditional fuel and lithium battery power systems have limitations in UAV applications.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is as follows: Provided is an airborne liquid hydrogen fuel cell power system, which includes a liquid hydrogen storage and supply module, a hydrogen fuel cell module, a lithium battery module, an airborne equipment module and a motor module; The liquid hydrogen storage and supply module comprises a liquid hydrogen storage tank, a gas hydrogen buffer tank and a heat exchanger which are interconnected; The hydrogen fuel cell module includes a stack master controller and at least one group of fuel cell stacks, each group of the fuel cell stacks is matched with a group of BOP components, the fuel cell stack is electrically connected to the stack controller and the current converter; the current converter is used to convert the low-voltage current generated by the hydrogen fuel cell module into a high-voltage current; the stack controller is electrically connected to the stack master controller via a communication line; The heat exchanger is connected to the fuel cell stack through a gas-hydrogen pipeline and a solenoid valve; The lithium battery module includes a lithium battery controller and at least one lithium battery group electrically connected to the lithium battery controller, and the current converter is electrically connected to the lithium battery controller; The airborne equipment module includes an airborne power supply, a power supply controller, a flight control system and a low-voltage junction box; the lithium battery pack is electrically connected to the airborne power supply through the lithium battery controller and the power supply controller; the low-voltage junction box is electrically connected to the battery stack master controller and the battery stack controller; The motor module includes a plurality of drive motors, each of which is electrically connected to a motor controller, and each of which is electrically connected to a lithium battery pack, an onboard power supply, and a hydrogen fuel cell module; the drive motor is used to drive the propeller to rotate; The battery stack master controller, battery stack controller, lithium battery controller, power supply controller and motor controller are all electrically connected to the flight control system through communication lines.

[0006] Furthermore, the airborne liquid hydrogen fuel cell power system also includes an interface module, which includes a hydrogen filling port, a high-voltage charging port and a low-voltage charging port; the hydrogen filling port is connected to the liquid hydrogen storage tank to realize the filling of liquid hydrogen into the liquid hydrogen storage tank. The high-voltage charging port is electrically connected to the lithium battery pack through the charging cable and the lithium battery controller, and an external charging device can charge the lithium battery pack through the high-voltage charging port. The low-voltage charging port is electrically connected to the airborne power supply through the charging cable and the power supply controller, and an external charging device can charge the airborne power supply through the low-voltage charging port.

[0007] Furthermore, the hydrogen filling port is connected to the liquid hydrogen storage tank through a detachable liquid hydrogen filling valve pipeline. The detachable liquid hydrogen filling valve pipeline has a cutoff point. After the liquid hydrogen storage tank is filled with liquid hydrogen, the liquid hydrogen filling valve pipeline can be detached to reduce the weight on the aircraft and increase the cruising range of the drone.

[0008] Furthermore, the liquid hydrogen storage tank is a structure with a vacuum layer sandwiched between an inner and outer tank; a liquid level gauge, an electric heater, an anti-sway baffle and a gas-liquid separator are arranged inside the liquid hydrogen storage tank; the liquid level gauge is used to monitor the remaining liquid hydrogen inside the liquid hydrogen storage tank; the electric heater is used to control the hydrogen evaporation supply speed of the liquid hydrogen storage tank; the anti-sway baffle is used to prevent liquid hydrogen swaying caused by aircraft vibration and impact loads, and alleviate hydrogen flow fluctuations; the gas-liquid separator is used to prevent liquid hydrogen swaying from blocking the hydrogen outlet.

[0009] Furthermore, the gas hydrogen buffer tank is used to alleviate the hydrogen flow fluctuation caused by aircraft vibration and impact load. The gas hydrogen buffer tank is set close to the liquid hydrogen storage tank, and the low temperature characteristics of gas hydrogen are used to reduce the volume mass of the gas hydrogen buffer tank, saving available space and payload on the aircraft. The gas hydrogen buffer tank is equipped with a safety exhaust valve pipeline to prevent overpressure of the storage tank during the filling process and on-board use. The heat exchanger allows the hydrogen entering the fuel cell stack to reach the optimal reaction temperature. An electromagnetic pressure reducing valve is installed on the gas hydrogen pipeline between the outlet end of the heat exchanger and the fuel cell stack, and the electromagnetic pressure reducing valve is used to ensure the stability of the hydrogen supply pressure.

[0010] Furthermore, the hydrogen fuel cell module includes two groups of fuel cell stacks arranged in parallel. The fuel cell stack has a redundant design, which serves as an emergency backup and improves the stability of the hydrogen fuel cell module.

[0011] The present invention also provides a fixed-wing UAV, which is equipped with the airborne liquid hydrogen fuel cell power system of the present application.

[0012] Furthermore, the response characteristics of hydrogen fuel cell modules and lithium battery modules are different. The power output of hydrogen fuel cell modules is stable but the response is slow, while the response speed of lithium battery modules is fast but the energy density is insufficient.

[0013] When the fixed-wing UAV is in the cruising stage, the hydrogen fuel cell module works to supply power to the motor module; when the fixed-wing UAV is in the take-off stage, the hydrogen fuel cell module and the lithium battery module work together to supply power to the motor module; when the fixed-wing UAV is in the descent stage, the hydrogen fuel cell module works to supply power to the motor module and charge the lithium battery module, thereby realizing the complementary advantages of hydrogen fuel cells and lithium batteries, thereby achieving efficient allocation and utilization of energy.

[0014] The beneficial effects of the present invention are as follows: 1. An airborne liquid hydrogen fuel cell power system in the present invention uses liquid hydrogen as an energy source and a fuel cell as a cruise power form with stable power output, supplemented by a small lithium battery to supply power when the UAV takes off to meet instantaneous high power requirements, and accepts fuel cell charging during the descent phase. Through high-energy-density liquid hydrogen storage and efficient power demand matching, the endurance of the airborne liquid hydrogen fuel cell power system can be effectively improved.

[0015] 2. The airborne liquid hydrogen fuel cell power system of the present invention realizes the efficient utilization of the energy on board the UAV, which can not only significantly improve the endurance, but also reduce carbon emissions, and solves the problem of limitations of traditional fuel engines and lithium battery power systems in UAV applications. It can be used for long-term and long-distance flight mission scenarios such as patrolling in vast areas, rugged terrain, and inconvenient transportation areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the principle of an airborne liquid hydrogen fuel cell power system.

[0017] Among them, 1. Liquid hydrogen storage and supply module; 11. Liquid hydrogen storage tank; 12. Gas hydrogen buffer tank; 13. Heat exchanger; 2. Hydrogen fuel cell module; 21. Stack master controller; 22. Fuel cell stack; 23. Stack controller; 24. Current converter; 3. Lithium battery module; 31. Lithium battery pack; 32. Lithium battery controller; 4. Airborne equipment module; 41. Airborne power supply; 42. Power controller; 43. Flight control system; 44. Low voltage junction box; 5. Motor module; 51. Drive motor; 52. Motor controller; 53. Propeller; 6. Interface module; 61. Hydrogen refueling port; 62. High-voltage charging port; 63. Low-voltage charging port. DETAILED DESCRIPTION

[0018] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0019] like Figure 1 As shown, the present invention provides an airborne liquid hydrogen fuel cell power system, which includes a liquid hydrogen storage and supply module 1, a hydrogen fuel cell module 2, a lithium battery module 3, an airborne equipment module 4 and a motor module 5; the liquid hydrogen storage and supply module 1 includes a liquid hydrogen storage tank 11, a gas hydrogen buffer tank 12 and a heat exchanger 13 that are interconnected.

[0020] The hydrogen fuel cell module 2 includes a stack master controller 21 and at least one group of fuel cell stacks 22. Each group of the fuel cell stacks 22 is matched with a group of BOP components. The fuel cell stacks 22 are electrically connected to the stack controller 23 and the current converter 24. The BOP component refers to an auxiliary device responsible for processing the hydrogen, air, thermal management and other tasks required for the operation of the fuel cell stack. The function of the BOP component is to ensure that the fuel cell stack can operate under optimal conditions, thereby improving the performance and efficiency of the entire fuel cell system. The BOP component belongs to the prior art, and its components and principles are not described in detail here. The current converter 24 is used to convert the low-voltage current generated by the hydrogen fuel cell module 2 into a high-voltage current; the stack controller 23 is electrically connected to the stack master controller 21.

[0021] The heat exchanger 13 is connected to the fuel cell stack 22 through a gas-hydrogen pipeline and a solenoid valve.

[0022] The lithium battery module 3 includes a lithium battery controller 32 and at least one lithium battery group 31 electrically connected to the lithium battery controller 32 , and the current converter 24 is electrically connected to the lithium battery controller 32 .

[0023] The airborne equipment module 4 includes an airborne power supply 41, a power supply controller 42, a flight control system 43 and a low-voltage junction box 44. The lithium battery pack 31 is electrically connected to the airborne power supply 41 through the lithium battery controller 32 and the power supply controller 42; the low-voltage junction box 44 is electrically connected to the battery stack master controller 21 and the battery stack controller 23; The motor module 5 includes multiple drive motors 51, each of which is electrically connected to a motor controller 52, and each of which is electrically connected to the lithium battery pack 31, the onboard power supply 41 and the hydrogen fuel cell module 2; the drive motor 51 is used to drive the propeller 53 to rotate; the stack master controller 21, the stack controller 23, the lithium battery controller 32, the power supply controller 42 and the motor controller 52 are all electrically connected to the flight control system 43 via communication lines.

[0024] An airborne liquid hydrogen fuel cell power system in the present invention uses liquid hydrogen as an energy source and a fuel cell as a cruise power form with stable power output. It is supplemented by a small lithium battery to supply power when the UAV takes off to meet instantaneous high power requirements, and is charged by the fuel cell during the descent phase. Through high-energy-density liquid hydrogen storage and efficient power demand matching, the endurance of the airborne liquid hydrogen fuel cell power system can be effectively improved to meet the long-term and long-distance flight mission requirements of the UAV.

[0025] Preferably, but not limited to, the airborne liquid hydrogen fuel cell power system further includes an interface module 6, which includes a hydrogen filling port 61, a high-voltage charging port 62, and a low-voltage charging port 63; the hydrogen filling port 61 is connected to the liquid hydrogen storage tank 11 to realize the filling of liquid hydrogen into the liquid hydrogen storage tank 11; the high-voltage charging port 62 is electrically connected to the lithium battery pack 31 through the charging cable and the lithium battery controller 32, and an external charging device can charge the lithium battery pack 31 through the high-voltage charging port 62. The low-voltage charging port 63 is electrically connected to the airborne power supply 41 through the charging cable and the power supply controller 42, and an external charging device can charge the airborne power supply 41 through the low-voltage charging port 63.

[0026] As a specific configuration of the liquid hydrogen storage and supply module 1, the hydrogen filling port 61 is connected to the liquid hydrogen storage tank 11 through a detachable liquid hydrogen filling valve pipeline. The detachable liquid hydrogen filling valve pipeline has a cutoff point. After the liquid hydrogen storage tank 11 is filled with liquid hydrogen, the liquid hydrogen filling valve pipeline can be detached to reduce the weight on board and increase the cruising range of the drone.

[0027] The liquid hydrogen storage tank 11 is a structure with a vacuum layer sandwiched between an inner and outer tank; a liquid level gauge, an electric heater, an anti-sway baffle and a gas-liquid separator are arranged inside the liquid hydrogen storage tank 11; the liquid level gauge is used to monitor the remaining liquid hydrogen inside the liquid hydrogen storage tank 11; the electric heater is used to control the hydrogen evaporation supply speed of the liquid hydrogen storage tank 11; the anti-sway baffle is used to prevent liquid hydrogen swaying caused by aircraft vibration and impact loads, and alleviate hydrogen flow fluctuations; the gas-liquid separator is used to prevent liquid hydrogen swaying from blocking the hydrogen outlet.

[0028] The gas hydrogen buffer tank 12 is used to alleviate the fluctuation of hydrogen flow caused by aircraft vibration and impact load. The gas hydrogen buffer tank 12 is arranged close to the liquid hydrogen storage tank 11, and the low temperature characteristics of gas hydrogen are used to reduce the volume mass of the gas hydrogen buffer tank 12, saving the available space and payload on the aircraft. The gas hydrogen buffer tank 12 is provided with a safety exhaust valve pipeline to prevent the tank from overpressure during the filling process and the use process on the aircraft. The heat exchanger 13 allows the hydrogen entering the fuel cell stack 22 to reach the optimal reaction temperature. An electromagnetic pressure reducing valve is provided on the gas hydrogen pipeline between the outlet end of the heat exchanger 13 and the fuel cell stack 22, and the electromagnetic pressure reducing valve is used to ensure the stability of the hydrogen supply pressure.

[0029] Specifically, the hydrogen fuel cell module 2 includes two groups of fuel cell stacks 22 arranged in parallel. The fuel cell stacks 22 are designed to be redundant, that is, they play an emergency backup role and improve the stability of the hydrogen fuel cell module 2.

[0030] The present invention also provides a fixed-wing UAV, which is equipped with the airborne liquid hydrogen fuel cell power system of the present application.

[0031] Furthermore, the hydrogen fuel cell module 2 and the lithium battery module 3 have different response characteristics. The hydrogen fuel cell module 2 has a stable power output but a slow response, while the lithium battery module 3 has a fast response speed but insufficient energy density.

[0032] When the fixed-wing UAV is in the cruising stage, the hydrogen fuel cell module 2 works to supply power to the motor module 5; when the fixed-wing UAV is in the take-off stage, the hydrogen fuel cell module 2 and the lithium battery module 3 work together to supply power to the motor module 5; when the fixed-wing UAV is in the descent stage, the hydrogen fuel cell module 2 works to supply power to the motor module 5 and to charge the lithium battery module 3, thereby realizing the complementary advantages of the hydrogen fuel cell module 2 and the lithium battery module 3, thereby achieving efficient allocation and utilization of energy, which can not only significantly improve the endurance, but also reduce carbon emissions, and solve the problem of limitations of traditional fuel and lithium battery power systems in UAV applications, and can be used for mission scenarios such as patrols in vast areas, rugged terrain, and inconvenient transportation areas.

Claims

1. An airborne liquid hydrogen fuel cell power system, characterized in that: It includes liquid hydrogen storage and supply module, hydrogen fuel cell module, lithium battery module, airborne equipment module and motor module; The liquid hydrogen storage and supply module comprises a liquid hydrogen storage tank, a gas hydrogen buffer tank and a heat exchanger which are interconnected; The hydrogen fuel cell module includes a stack master controller and at least one group of fuel cell stacks, each group of the fuel cell stacks is matched with a group of BOP components, the fuel cell stack is electrically connected to the stack controller and the current converter; the current converter is used to convert the low-voltage current generated by the hydrogen fuel cell module into a high-voltage current; the stack controller is electrically connected to the stack master controller via a communication line; The heat exchanger is connected to the fuel cell stack through a gas-hydrogen pipeline and a solenoid valve; The lithium battery module includes a lithium battery controller and at least one lithium battery group electrically connected to the lithium battery controller, and the current converter is electrically connected to the lithium battery controller; The airborne equipment module includes an airborne power supply, a power supply controller, a flight control system and a low-voltage junction box; the lithium battery pack is electrically connected to the airborne power supply through the lithium battery controller and the power supply controller; the low-voltage junction box is electrically connected to the battery stack master controller and the battery stack controller; The motor module includes a plurality of drive motors, each of which is electrically connected to a motor controller, and each of which is electrically connected to a lithium battery pack, an onboard power supply, and a hydrogen fuel cell module; the drive motor is used to drive the propeller to rotate; The battery stack master controller, battery stack controller, lithium battery controller, power supply controller and motor controller are all electrically connected to the flight control system through communication lines.

2. The airborne liquid hydrogen fuel cell power system according to claim 1, characterized in that: It also includes an interface module, which includes a hydrogen refueling port, a high-voltage charging port and a low-voltage charging port; the hydrogen refueling port is connected to the liquid hydrogen storage tank; the high-voltage charging port is electrically connected to the lithium battery pack through a charging cable and the lithium battery controller; the low-voltage charging port is electrically connected to the onboard power supply through a charging cable and the power controller.

3. The airborne liquid hydrogen fuel cell power system according to claim 2, characterized in that: The hydrogen filling port is connected to the liquid hydrogen storage tank through a detachable liquid hydrogen filling valve pipeline.

4. The airborne liquid hydrogen fuel cell power system according to claim 1, characterized in that: The liquid hydrogen storage tank is a structure with a vacuum layer sandwiched between inner and outer tanks; a liquid level gauge, an electric heater, an anti-sway baffle and a gas-liquid separator are arranged inside the liquid hydrogen storage tank.

5. The airborne liquid hydrogen fuel cell power system according to claim 1, characterized in that: The gas hydrogen buffer tank is arranged close to the liquid hydrogen storage tank, and a safety exhaust valve pipeline is arranged on the gas hydrogen buffer tank; an electromagnetic pressure reducing valve is arranged on the gas hydrogen pipeline between the outlet end of the heat exchanger and the fuel cell stack.

6. The airborne liquid hydrogen fuel cell power system according to claim 1, characterized in that: The hydrogen fuel cell module includes two groups of fuel cell stacks arranged in parallel.

7. A fixed-wing UAV, characterized in that: It comprises an airborne liquid hydrogen fuel cell power system as described in any one of claims 1 to 6.

8. The fixed-wing UAV according to claim 7, characterized in that: When the fixed-wing UAV is in the cruising stage, the hydrogen fuel cell module works to supply power to the motor module; when the fixed-wing UAV is in the take-off stage, the hydrogen fuel cell module and the lithium battery module work together to supply power to the motor module; when the fixed-wing UAV is in the descent stage, the hydrogen fuel cell module works to supply power to the motor module and charge the lithium battery module.

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