An unmanned aerial vehicle hydrogen fuel cell system, control method and unmanned aerial vehicle

Abstract

The application discloses an unmanned aerial vehicle hydrogen fuel cell system, a control method and an unmanned aerial vehicle, and belongs to the technical field of unmanned aerial vehicle fuel cells. The system comprises a control unit, a hydrogen supply unit, a fuel cell unit and a power management unit. The control unit is in communication connection with the hydrogen supply unit, the fuel cell unit and the power management unit. The hydrogen supply unit is in communication with the fuel cell unit. The fuel cell unit is electrically connected with the power management unit. The power management unit is used for providing electric energy for the unmanned aerial vehicle. The hydrogen supply unit comprises a storage tank, a reactor and a purification cooler. The storage tank is used for storing solid or liquid hydrogen production reactants. The storage tank is in communication with the reactor. The reactor is in communication with the purification cooler. The purification cooler is in communication with the gas inlet of the fuel cell unit. The system has the characteristics of stable hydrogen release, controllable hydrogen production rate, instant hydrogen supply and high energy density, and solves the problems of traditional fuel cell transportation difficulty, air charging difficulty and poor flexibility.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology for unmanned aerial vehicles (UAVs), and more particularly to a hydrogen fuel cell system and control method for UAVs. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] Unmanned Aerial Vehicles (UAVs), also known as drones, are unmanned aircraft controlled by radio remote control equipment and their own program control devices, or operated autonomously, either completely or intermittently, by an onboard computer. Currently, there are many types of drones both domestically and internationally, with wide applications and rapid development. Users are not only concerned with the aircraft's size, flight altitude, and speed, but also with parameters such as lightweight design and endurance.

[0004] In the context of global energy and resource scarcity and the promotion of a low-carbon economy, achieving truly low energy consumption, low pollution, and low emissions through innovative technologies and mechanisms is urgently needed. Therefore, replacing traditional fuel-powered systems with clean energy sources, such as hydrogen energy, is one of the most important development directions for unmanned aerial vehicle (UAV) power systems.

[0005] Fuel cells are clean power systems that convert chemical energy into electrical energy through the reaction of hydrogen and oxygen. The reactant hydrogen has a high energy density, and the product is water, which produces no pollution and ensures the flight performance of drones. Currently, the hydrogen source for fuel cells used in drones is mainly high-pressure hydrogen cylinders. However, high-pressure hydrogen cylinders generally need to be filled to 35 MPa, and their mass storage efficiency is generally no higher than 5%, which presents problems such as difficulty in transportation, difficulty in filling, and poor flexibility. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a hydrogen fuel cell system, control method, and drone for unmanned aerial vehicles (UAVs). By employing solid-state hydrogen storage, the hydrogen fuel cell system is optimized, increasing the flight time of UAVs using the hydrogen fuel cell system and improving their performance.

[0007] In a first aspect, the present invention provides a hydrogen fuel cell system for unmanned aerial vehicles;

[0008] A hydrogen fuel cell system for unmanned aerial vehicles (UAVs) includes a control unit, a hydrogen supply unit, a fuel cell unit, and a power management unit.

[0009] The control unit is communicatively connected to the hydrogen supply unit, the fuel cell unit, and the power management unit, respectively. The hydrogen supply unit is connected to the fuel cell unit, and the fuel cell unit is electrically connected to the power management unit. The power management unit is used to provide power to the UAV.

[0010] The hydrogen supply unit includes a storage tank, a reactor, and a purification cooler. The storage tank is used to store solid or liquid hydrogen production reactants. The storage tank is connected to the reactor, the reactor is connected to the purification cooler, and the purification cooler is connected to the air inlet of the fuel cell unit.

[0011] Furthermore, the fuel cell unit includes a fuel cell stack, an exhaust valve, and a fan; the fuel cell stack is connected to a purification cooler through an air inlet, the fan is used to provide power for oxygen to flow into the fuel cell stack and heat to flow out of the fuel cell stack, and the exhaust valve is used to discharge unreacted hydrogen and some of the generated water from the fuel cell stack.

[0012] Furthermore, the power management unit includes a DC / DC converter and a lithium battery. The fuel cell unit is electrically connected to the DC / DC converter, and the fuel cell unit powers the drone through the DC / DC converter. The lithium battery is used to power the drone.

[0013] Furthermore, the reactor is equipped with a pressure sensor, a first temperature sensor, and a first liquid level sensor; the storage tank is equipped with a second liquid level sensor; the fuel cell unit is equipped with a voltage acquisition device, a current acquisition device, and a second temperature sensor; a metering pump is installed between the storage tank and the reactor; an air inlet valve is installed between the purification cooler and the fuel cell unit; and a fan and an exhaust valve are installed inside the fuel cell unit.

[0014] The pressure sensor, the first temperature sensor, the first liquid level sensor, the second liquid level sensor, the voltage acquisition device, the current acquisition device, and the second temperature sensor are all communicatively connected to the control unit. The control unit is also communicatively connected to the metering pump, the air inlet valve, the fan, and the exhaust valve.

[0015] Preferably, the system also includes a drone alarm, and the control unit is communicatively connected to the drone alarm.

[0016] Furthermore, the hydrogen production reactants are a mixture of sodium borohydride aqueous solution and solid catalyst, water and solid sodium borohydride, and a catalyst mixture or a catalyst solution and solid sodium borohydride mixture.

[0017] Furthermore, a hydrogen storage buffer tank is provided between the purification cooler and the fuel cell unit.

[0018] Secondly, the present invention provides a control method for a hydrogen fuel cell system of an unmanned aerial vehicle;

[0019] A control method for a hydrogen fuel cell system for unmanned aerial vehicles, comprising:

[0020] The system acquires liquid level, temperature, and pressure information within the hydrogen supply unit. Based on this information, it sends control signals to the hydrogen supply unit to control its operating status and generate hydrogen.

[0021] The system acquires the drone's operating status, as well as the current, voltage, and temperature information of the fuel cell unit. Based on these information, it sends signals to the fuel cell unit to enable it to generate electricity from hydrogen.

[0022] Based on the current and voltage information of the fuel cell unit, the power of the fuel cell unit is calculated; the voltage and current of the power management unit are obtained, and the power of the fuel cell unit is compared with the system power. When the voltage of the power management unit is greater than the preset voltage threshold and the current is less than the preset current threshold, if the power of the fuel cell unit is less than the system power, the power management unit and the fuel cell unit are controlled to supply power to the UAV system; if the power of the fuel cell unit is greater than the system power, the fuel cell unit is controlled to supply power to the lithium battery in the power management unit and the UAV system.

[0023] Furthermore, the intake airflow, exhaust valve opening interval, exhaust valve start time, and fan speed of the fuel cell unit are controlled according to the drone's status.

[0024] Thirdly, the present invention provides an unmanned aerial vehicle (UAV);

[0025] An unmanned aerial vehicle (UAV) includes the aforementioned UAV hydrogen fuel cell system.

[0026] The technical solution provided by this invention has at least the following technical effects or advantages:

[0027] 1. The technical solution provided by this invention uses chemical hydrogen storage as the hydrogen supply system for drones, which has the characteristics of stable hydrogen release, controllable hydrogen production rate, instant hydrogen supply, and high energy density; it is simple to replenish, has a long flight time, and a high safety factor. Compared with traditional high-pressure gas cylinders, it avoids problems such as difficult transportation, difficult filling, and poor flexibility.

[0028] 2. The technical solution provided by this invention does not require gas tanks, high pressure, or high-pressure hydrogen sources. It can effectively couple hydrogen production systems, fuel cell systems, power systems, and drone systems, meeting the application needs of drones in multiple scenarios, such as scenarios where hydrogen sources are scarce or refueling is inconvenient. Attached Figure Description

[0029] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0030] Figure 1 This is a schematic diagram of the system architecture provided in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of information collection provided in an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the control connection provided in an embodiment of the present invention;

[0033] The distances or dimensions between parts have been exaggerated to show their positions; the diagram is for illustrative purposes only. Detailed Implementation

[0034] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0035] Example 1

[0036] Combination Figures 1-3 This embodiment proposes a hydrogen fuel cell system for unmanned aerial vehicles (UAVs). The system includes a control unit, a hydrogen supply unit, a fuel cell unit, and a power management unit. The control unit is communicatively connected to the hydrogen supply unit, the fuel cell unit, and the power management unit to send control signals to control the operating status of these units. The hydrogen supply unit is connected to the fuel cell unit, where internal reactions produce hydrogen that is then transferred to the fuel cell unit. Inside the fuel cell unit, hydrogen reacts with oxygen to generate electricity. The fuel cell unit is electrically connected to the power management unit, which converts the electrical energy to provide power to the UAV.

[0037] Furthermore, the hydrogen supply unit includes a storage tank, a reactor, and a purification cooler; the fuel cell unit includes a fuel cell stack, an exhaust valve, and a fan; the fuel cell stack is connected to the purification cooler via an air inlet, the fan provides power for oxygen to flow into the fuel cell stack and heat to flow out of the fuel cell stack, and the exhaust valve is used to discharge unreacted hydrogen and some of the generated water from the fuel cell stack. The storage tank is used to store solid or liquid hydrogen production reactants. The storage tank is connected to the reactor via a pipeline, and a metering pump is installed on the pipeline between the storage tank and the reactor to deliver the hydrogen production reactants to the reactor; the reactor is connected to the purification cooler via a pipeline, and the purification cooler is connected to the air inlet via a pipeline. An air inlet valve is installed at the air inlet to deliver the purified hydrogen from the purification cooler to the fuel cell unit.

[0038] The fuel cell stack is electrically connected to a DC / DC converter, which powers the drone. The DC / DC converter is also electrically connected to a lithium battery, which powers the drone.

[0039] Furthermore, a pressure sensor, a first temperature sensor, and a first liquid level sensor are installed inside the reactor. The pressure sensor collects pressure information inside the reactor, the first temperature sensor collects temperature information inside the reactor, and the first liquid level sensor collects liquid level information inside the reactor. A second liquid level sensor is installed inside the storage tank, and a voltage acquisition device, a current acquisition device, and a second temperature sensor are installed inside the fuel cell unit. The second liquid level sensor collects liquid level information inside the storage tank, the voltage acquisition device collects voltage information of the fuel cell stack, the current acquisition device collects current information of the fuel cell stack, and the second temperature sensor collects temperature information inside the fuel cell unit. The pressure sensor, the first temperature sensor, the first liquid level sensor, the second liquid level sensor, the voltage acquisition device, the current acquisition device, and the second temperature sensor are all communicatively connected to the control unit. The control unit is also communicatively connected to the metering pump, the intake valve, the fan, and the exhaust valve. Based on the collected information, the control unit controls the operating status of the metering pump, the intake valve, the fan, and the exhaust valve.

[0040] The specific process is as follows:

[0041] Under the control unit, the hydrogen supply unit controls the metering pump to start. When the pressure inside the reactor Pr < Pr-min, the metering pump enters the reactor at a preset flow rate L-set. When the pressure inside the reactor Pr > Pr-max, the metering pump stops working. During this process, the liquid level Hc in the storage tank is always greater than the preset minimum liquid level Hc-min, the liquid level Hr in the reactor is always lower than the maximum preset liquid level Hr-max, and the reactor temperature is always lower than the maximum preset temperature Tr-max.

[0042] Hydrogen generated by the hydrogen supply unit enters the fuel cell stack through the inlet valve at a preset inlet flow rate Gset and pressure P. The control unit outputs the corresponding inlet flow rate G, exhaust valve opening interval / time T / t, and fan speed Fv according to the UAV status to control the working status of the inlet valve, exhaust valve, and fan. During this process, the fuel cell voltage UFC is always greater than UFC-min, the fuel cell current IFC is always less than IFC-max, and the stack temperature TFC is always lower than the maximum preset temperature TFC-max.

[0043] Under the control unit's operation, when the fuel cell stack power is greater than the system power, the fuel cell stack powers the drone through a DC / DC converter and charges the lithium battery through the DC / DC converter. When the fuel cell stack power is less than the system power, the lithium battery powers the drone, and the fuel cell stack powers the drone through the DC / DC converter. During this process, the lithium-ion battery voltage ULi is always greater than ULi-min.

[0044] Furthermore, it also includes a drone alarm, with the control unit communicating with the drone alarm.

[0045] If one or more parameters of the liquid level sensor, temperature sensor, pressure sensor, current and voltage acquisition device, and drone alarm device malfunction and cannot be adjusted, each unit will enter an emergency state, and the drone will return to base, land, or terminate its operation under the power of the lithium battery.

[0046] In this embodiment, the fuel cell stack is a proton exchange membrane cathode open air-cooled fuel cell reactor. The hydrogen production reactants are a catalyst solution and solid sodium borohydride. The catalyst solution is placed in a storage tank, and the solid sodium borohydride is placed in the reactor. The control unit is a control chip commonly used in the prior art.

[0047] Example 2

[0048] This embodiment provides a control method for a drone hydrogen fuel cell system, based on the aforementioned drone hydrogen fuel cell system, including the following steps:

[0049] S1. Start the system. The lithium battery powers the entire system. The control unit checks the hydrogen supply unit, fuel cell unit, power management unit, and drone to determine if each unit is in normal working order. If so, proceed to S2.

[0050] S2. The control unit acquires the liquid level, temperature and pressure information in the hydrogen supply unit, and sends a control signal to the hydrogen supply unit to control the working state of the hydrogen supply unit in order to generate hydrogen.

[0051] Specifically, the control unit acquires pressure information inside the reactor from the pressure sensor, temperature information inside the reactor from the first temperature sensor, liquid level information inside the reactor from the first liquid level sensor, and liquid level information inside the storage tank from the second liquid level sensor. It then compares these information with preset thresholds within the control unit. When the reactor pressure (Pr) is less than the preset minimum pressure threshold (Pr-min), the liquid level in the storage tank is greater than the preset minimum liquid level, the reactor liquid level is lower than the maximum preset liquid level, and the reactor temperature is lower than the minimum preset temperature, a control signal is sent to the metering pump to control it to deliver material to the reactor at a preset flow rate (L-set). When the reactor pressure (Pr) is greater than the preset maximum pressure threshold (Pr-max), a control signal is sent to stop the metering pump.

[0052] The hydrogen production reactants react in the reactor to produce hydrogen gas, which is then purified by a cooling purifier.

[0053] S3. Acquire the drone's output power, the fuel cell unit's current, voltage, and temperature information, and send a signal to the fuel cell unit based on the drone's output power, the fuel cell unit's current, voltage, and temperature information, so that the fuel cell unit can obtain hydrogen to generate electricity.

[0054] Specifically, the control unit acquires current information from the fuel cell stack collected by the current acquisition device, voltage information from the fuel cell stack collected by the voltage acquisition device, and temperature information from the fuel cell stack collected by the second temperature sensor. When the fuel cell stack voltage UFC is greater than UFC-min, the fuel cell current IFC is less than IFC-max, and the stack temperature TFC is lower than the maximum preset temperature TFC-max, the control unit sends a control signal to control the intake valve to deliver hydrogen into the fuel cell stack at a preset intake flow rate Gset and pressure P.

[0055] Based on the drone's status, the corresponding air intake flow rate G is output, and the fan is controlled to rotate at a speed Fv. Under the action of the fan, air enters the fuel cell stack from the cathode channel, providing oxygen for the fuel cell stack reaction and carrying away some of the heat of the fuel cell system. The opening interval / time T / t of the exhaust valve is controlled, and unreacted hydrogen and some of the generated water leave the fuel cell unit with the exhaust valve.

[0056] S4. Based on the voltage and current of the fuel cell stack, calculate the power of the fuel cell stack, obtain the voltage of the lithium-ion battery, and compare the power of the fuel cell unit with the system power. If the power of the fuel cell stack is less than the system power, control the lithium battery to power the drone, and control the fuel cell stack to power the drone through a DC / DC converter. If the power of the fuel cell stack is greater than the system power, control the fuel cell stack to power the drone through a DC / DC converter, and charge the lithium battery through the DC / DC converter. During this process, the lithium-ion battery voltage ULi is always greater than the preset voltage threshold ULi-min.

[0057] The system power is the power used by the drone, which is the lithium battery charging power plus the drone power.

[0058] Example 3

[0059] Based on the above-described UAV hydrogen fuel cell system, this invention also provides a UAV equipped with the UAV hydrogen fuel cell system described in the above embodiments and executing the UAV hydrogen fuel cell system control method described in the above embodiments. Since the above-described UAV hydrogen fuel cell system has the above-described technical effects, please refer to the above embodiments for the technical effects of the UAV using the above-described UAV hydrogen fuel cell system.

[0060] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A hydrogen fuel cell system for unmanned aerial vehicles (UAVs), characterized in that, It includes a control unit, a hydrogen supply unit, a fuel cell unit, and a power management unit; The control unit is communicatively connected to the hydrogen supply unit, the fuel cell unit, and the power management unit, respectively. The hydrogen supply unit is connected to the fuel cell unit, and the fuel cell unit is electrically connected to the power management unit. The power management unit is used to provide power to the UAV. The hydrogen supply unit includes a storage tank, a reactor, and a purification cooler. The storage tank is used to store solid and liquid hydrogen production reactants. The storage tank is connected to the reactor, the reactor is connected to the purification cooler, and the purification cooler is connected to the air inlet of the fuel cell unit. The fuel cell unit includes a fuel cell stack, an exhaust valve, and a fan; the fuel cell stack is connected to a purification cooler through an air inlet, the fan is used to provide power for oxygen to flow into the fuel cell stack and heat to flow out of the fuel cell stack, and the exhaust valve is used to discharge unreacted hydrogen and some of the generated water from the fuel cell stack. The reactor is equipped with a pressure sensor, a first temperature sensor, and a first liquid level sensor; the storage tank is equipped with a second liquid level sensor; the fuel cell unit is equipped with a voltage acquisition device, a current acquisition device, and a second temperature sensor; a metering pump is installed between the storage tank and the reactor; an air inlet valve is installed between the purification cooler and the fuel cell unit; and a fan and an exhaust valve are installed inside the fuel cell unit. The pressure sensor, the first temperature sensor, the first liquid level sensor, the second liquid level sensor, the voltage acquisition device, the current acquisition device, and the second temperature sensor are all communicatively connected to the control unit. The control unit is also communicatively connected to the metering pump, the air inlet valve, the fan, and the exhaust valve.

2. The unmanned aerial vehicle hydrogen fuel cell system as described in claim 1, characterized in that, The power management unit includes a DC / DC converter and a lithium battery. The fuel cell unit is electrically connected to the DC / DC converter, and the fuel cell unit powers the drone through the DC / DC converter. The lithium battery is used to power the drone.

3. The unmanned aerial vehicle hydrogen fuel cell system as described in claim 1, characterized in that, It also includes a drone alarm, and the control unit is communicatively connected to the drone alarm.

4. The unmanned aerial vehicle hydrogen fuel cell system as described in claim 1, characterized in that, The hydrogen production reactants are a mixture of sodium borohydride aqueous solution and solid catalyst, a mixture of water and solid sodium borohydride and catalyst, or a mixture of catalyst solution and solid sodium borohydride.

5. The unmanned aerial vehicle hydrogen fuel cell system as described in claim 1, characterized in that, A hydrogen storage buffer tank is provided between the purification cooler and the fuel cell unit.

6. A control method for a drone hydrogen fuel cell system, applied to the drone hydrogen fuel cell system according to any one of claims 1-5, characterized in that, include: The system acquires liquid level, temperature, and pressure information within the hydrogen supply unit. Based on this information, it sends control signals to the hydrogen supply unit to control its operating status and generate hydrogen. The system acquires the drone's operating status, as well as the current, voltage, and temperature information of the fuel cell unit. Based on these information, it sends signals to the fuel cell unit to enable it to generate electricity from hydrogen. The power of the fuel cell unit is calculated based on the current and voltage information of the fuel cell unit. The voltage and current of the power management unit are acquired, and the power of the fuel cell unit is compared with the system power. When the voltage of the power management unit is greater than a preset voltage threshold and the current is less than a preset current threshold, if the power of the fuel cell unit is less than the system power, the power management unit and the fuel cell unit are controlled to supply power to the UAV system; if the power of the fuel cell unit is greater than the system power, the fuel cell unit is controlled to supply power to the lithium battery in the power management unit and the UAV system.

7. The control method for a UAV hydrogen fuel cell system as described in claim 6, characterized in that, The intake airflow, exhaust valve opening interval, exhaust valve start time, and fan speed of the fuel cell unit are controlled according to the drone's status.

8. A drone, characterized in that, Including the unmanned aerial vehicle hydrogen fuel cell system as described in any one of claims 1-5.

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