An energy management method for a split fuel cell hybrid aircraft propulsion system based on flight phase

Abstract

The application relates to an energy management method of a split fuel cell composite aviation propulsion system based on a flight phase, belonging to the aviation propulsion field, and solves the problems of uncoordinated energy scheduling, insufficient dynamic response capability, large fuel cell operation fluctuation and insufficient fault tolerance reconstruction capability under abnormal working conditions of an existing split fuel cell composite aviation propulsion system. The method comprises the following steps: acquiring aircraft flight phase information, propulsion power demand information and system state information; determining a corresponding operation mode according to the flight phase; performing collaborative distribution and dynamic adjustment on the output power of a hydrogen fuel cell, the working parameters of a compressor, the hydrogen supply amount of a combustion chamber and the power generation power of an expansion power generation turbine according to the operation mode; and switching to an emergency mode and isolating and reconstructing the power of a fault branch when abnormal working conditions or branch faults occur. The method can improve the energy utilization efficiency, propulsion power response capability and operation stability of the system.

Description

Technical Field

[0001] This invention relates to the field of aviation propulsion technology, and specifically to an energy management method for a split-type fuel cell hybrid aviation propulsion system based on flight phases. Background Technology

[0002] With the increasing demands for green, electrified, and efficient aircraft development, hybrid aero-propulsion technology combining hydrogen fuel and electric propulsion has gradually become a research hotspot. To further break through the thermodynamic limits of traditional simple cycles and pursue ultimate propulsion efficiency, introducing complex thermodynamic cycle architectures into propulsion systems has become a cutting-edge development trend. By utilizing the enormous cooling capacity of high-pressure, cryogenic hydrogen or liquid hydrogen for compressor interstage cooling and using the exhaust gas from the expansion turbine to preheat the combustion chamber intake, compression power consumption can be significantly reduced, and fuel consumption can be greatly decreased. Therefore, integrating a high-pressure, cryogenic hydrogen storage and supply unit, a hydrogen fuel cell, a turbine power generation unit with intercooling and reheating capabilities, and an electric propulsion output unit to construct a split-type fuel cell hybrid aero-propulsion system has extremely high engineering application prospects and generational advantages.

[0003] However, this deep thermo-fluid coupling and complex system architecture present significant technical bottlenecks for existing energy management and control methods. Firstly, the requirements for propulsion power, power response speed, and system thermodynamic state vary greatly across different flight phases. During takeoff, climb, and in-flight start-up, the propulsion system needs to provide extremely high instantaneous output power and very fast dynamic response capabilities; during cruise, it demands extremely low hydrogen consumption and efficient and stable operation of the fuel cell. Using a uniform static energy distribution method is simply insufficient to manage the operational needs of such complex cyclic systems under multiple operating conditions.

[0004] Secondly, there are significant differences in dynamic response and deep energy coupling relationships among fuel cells, multi-stage compressors, intercoolers, regenerators, combustion chambers, and expansion turbines. Fuel cells are better suited to operation under relatively stable conditions. Directly tracking rapidly fluctuating loads can easily cause large output fluctuations and accelerate lifespan degradation. Furthermore, the introduction of intercoolers and regenerators significantly increases the system's thermal inertia, with airflow, intercooler heat exchange efficiency, regenerator thermal delay, and combustion chamber hydrogen supply all interacting and constraining each other. Without coordinated scheduling of electrical and thermal energy, propulsion response lag, compressor surge margin deterioration, and even localized thermal mismatch can easily occur.

[0005] Furthermore, while split-type propulsion systems offer advantages such as flexible configuration and high redundancy, their complex thermodynamic architectures still lack targeted energy management methods for rapidly isolating faults, reconfiguring power, and maintaining minimum safe propulsion capability in the event of abnormal operating conditions or branch circuit failures. Existing technologies primarily focus on power distribution in simple configurations, lacking systematic solutions for pattern recognition, energy scheduling, and abnormal reconfiguration control in highly thermally coupled split-type fuel cell hybrid aerospace propulsion systems across different flight phases.

[0006] Therefore, there is an urgent need for an energy management method that can combine flight phase identification, propulsion demand changes, and system status feedback to systematically and collaboratively control hydrogen fuel cells, low / high pressure compressors, intercooling and regenerating networks, combustion chambers, expansion turbines, and generator sets, so as to achieve efficient, stable, and safe operation of this complex system over a wide range of operating conditions. Summary of the Invention

[0007] This invention addresses the technical problems of existing split-type fuel cell hybrid aero-propulsion systems, including uncoordinated energy scheduling, insufficient dynamic response, large fluctuations in fuel cell operation, and insufficient fault-tolerant reconfiguration capabilities under abnormal conditions. Therefore, this invention proposes an energy management method for split-type fuel cell hybrid aero-propulsion systems based on flight phases. The invention achieves these technical problems through the following technical solution: Option 1: This invention proposes an energy management method for a split-type fuel cell hybrid aero-propulsion system based on the flight phase. The method is characterized by being implemented based on a fuel cell hybrid aero-propulsion system with a split-type arrangement. The system includes a high-pressure cryogenic hydrogen tank, a splitter, a hydrogen-space cooler, a hydrogen fuel cell, a low-pressure compressor, a high-pressure compressor, an electric motor, a combustion chamber, an expansion power generation turbine, a generator, and an exhaust gas regenerator. The method includes: Acquire information on the aircraft's flight phases, propulsion power requirements, and system status. The current operating mode of the propulsion system is determined based on the flight phase information. Based on the operating mode, propulsion power demand information, and system status information, the target allocation values ​​for hydrogen fuel cell output power, low-pressure compressor and high-pressure compressor operating parameters, combustion chamber hydrogen supply, and expansion turbine power generation are determined. The hydrogen fuel cell, electric motor, combustion chamber, expansion turbine and generator are coordinated and controlled according to the target allocation value so that the hydrogen fuel cell outputs electrical energy within the preset working range. The low-pressure compressor performs primary compression on the air entering the propulsion system. The primary compressed air exchanges heat with the low-temperature hydrogen from the high-pressure low-temperature hydrogen tank in the hydrogen-space cooler. The cooled and densified air enters the high-pressure compressor for secondary compression. The hydrogen, heated by absorbing heat from the air, is supplied to the combustion chamber. Secondary compressed air flows through the exhaust regenerator, absorbs heat from the exhaust of the expansion generator turbine, and then enters the combustion chamber. The combustion chamber causes the preheated compressed air and hydrogen to burn, generating a high-temperature, high-pressure working fluid. The expansion generator turbine uses this high-temperature, high-pressure working fluid to expand, perform work, and generate electricity. The exhaust gas after performing work is discharged after heat exchange through the exhaust regenerator, and the generator obtains the target power to meet the propulsion requirements. When an abnormal operating condition or a propulsion branch failure is detected, the system switches to emergency mode, isolates the faulty branch, and reconfigures the power of the remaining branches to meet the minimum safe propulsion requirements of the aircraft.

[0008] Furthermore, a preferred embodiment is provided, wherein the flight phase information of the aircraft includes at least one of the following: startup phase, takeoff phase, climb phase, cruise phase, descent phase, and emergency phase, and the operating mode is set to correspond one-to-one or partially correspond to the flight phase.

[0009] Furthermore, a preferred embodiment is provided, wherein the system status information includes at least one or more of the following: hydrogen fuel cell output power, hydrogen fuel cell temperature, hydrogen fuel cell health status, hydrogen supply status, low-pressure compressor and high-pressure compressor speeds, low-pressure compressor and high-pressure compressor compression parameters, hydrogen-space cooler heat exchange parameters, exhaust gas regenerator heat exchange parameters, combustion chamber outlet working fluid parameters, expansion turbine output status, and generator output status.

[0010] Furthermore, a preferred embodiment is provided, wherein the method for determining the current operating mode of the propulsion system based on the flight phase information is as follows: the current operating mode is determined by comparing the flight phase information with the propulsion power demand, the propulsion power demand change rate and system status information, and preset mode switching conditions.

[0011] Furthermore, a preferred embodiment is provided, wherein the method for determining the current operating mode based on the propulsion power demand change rate and system status information is as follows: When the rate of change of propulsion power demand exceeds a preset threshold, the rate of change of output power of the hydrogen fuel cell is limited so that the rapid power demand is borne by the combustion chamber heating branch or the expansion power generation branch.

[0012] Furthermore, a preferred embodiment is provided in which the hydrogen fuel cell is controlled to operate in a preset high-efficiency range during the cruise phase, and the hydrogen supply ratio in the combustion chamber is reduced, so that the hydrogen fuel cell can undertake the basic propulsion power output.

[0013] Furthermore, a preferred embodiment is provided, wherein the takeoff and climb phases further include steps of increasing the operating parameters of the low-pressure compressor and the high-pressure compressor and the hydrogen supply to the combustion chamber, in order to improve the power generation capacity of the expansion turbine and the output power of the propulsion system.

[0014] Furthermore, a preferred embodiment is provided, wherein the method for determining the target allocation value of the power generation of the expansion turbine based on the operating mode, propulsion power demand information, and system status information is as follows: The optimization objectives are to minimize the total hydrogen consumption of the system, maximize the propulsion efficiency, minimize the damage to the lifespan of the hydrogen fuel cell, and meet the propulsion power requirements. The constraints are to include at least one of the following: hydrogen fuel cell output constraints, low-pressure compressor operation constraints, high-pressure compressor operation constraints, hydrogen-space cooler thermodynamic constraints, exhaust gas regenerator thermodynamic constraints, combustion chamber operation constraints, expansion power generation turbine operation constraints, generator output constraints, and electric motor output constraints.

[0015] Furthermore, a preferred embodiment is provided, wherein the output constraints of the hydrogen fuel cell include at least an output power range constraint and an output power change rate constraint; the operating constraints of the low-pressure compressor and the high-pressure compressor include at least an upper speed limit constraint and a surge margin constraint; the operating constraints of the combustion chamber include at least an upper outlet temperature limit constraint; and the output constraints of the electric motor include at least a minimum safe propulsion power constraint.

[0016] Furthermore, a preferred embodiment is provided, in which the method of isolating the faulty branch and reconfiguring the power of the remaining branches includes shutting off the hydrogen supply path of the faulty branch or cutting off the power output path of the faulty branch, and redistributing the propulsion power according to the remaining available power of the remaining branches to maintain the minimum propulsion capability required for safe flight of the aircraft.

[0017] The advantages of this invention are: The energy management method of the split fuel cell hybrid aviation propulsion system based on flight phases described in this invention introduces an operation mode identification and switching mechanism based on flight phases. It can perform targeted energy scheduling of each functional unit according to the propulsion requirements and system status under different flight phases such as takeoff, climb, cruise, descent and emergency, thereby improving the adaptability of the propulsion system in a wide range of operating conditions.

[0018] The energy management method of the split fuel cell hybrid aviation propulsion system based on flight phase described in this invention limits the rate of change of hydrogen fuel cell output and makes the rapid power demand bear the combustion heating branch or expansion power generation branch. This helps to avoid the fuel cell directly bearing the rapid fluctuation load, improve the operating stability of the fuel cell and delay its performance degradation.

[0019] The energy management method of the split fuel cell hybrid aviation propulsion system based on the flight phase described in this invention realizes the coordinated control between fuel cell, compressor, electric motor, combustion chamber, expansion power generation turbine and generator. It can ensure the propulsion power response capability while taking into account the overall system efficiency, and is particularly beneficial to reduce hydrogen consumption during the cruise phase and improve output capability during the high power demand phase.

[0020] The energy management method of the split-type fuel cell hybrid aero-propulsion system based on flight phase described in this invention has the ability to isolate branches and reconfigure power under abnormal operating conditions. It can maintain minimum safe propulsion requirements when some propulsion branches fail, thereby enhancing the safety, fault tolerance and engineering application adaptability of the split-type fuel cell hybrid aero-propulsion system.

[0021] This invention is also applicable to a control method for the coordinated scheduling of multiple complex functional units, including high-pressure cryogenic hydrogen storage and supply, hydrogen fuel cell power generation, staged compression of low-pressure and high-pressure compressors, hydrogen-space cooler heat exchange and cooling, exhaust gas waste heat recovery from exhaust regenerator, combustion chamber combustion heating, expansion power generation turbine energy recovery, generator power generation, and electric motor propulsion output. It is particularly suitable for a split-type hydrogen-electric hybrid aviation propulsion system that takes into account the power response requirements during takeoff and climb, the extremely low hydrogen consumption operation during cruise, and the fault-tolerant reconfiguration requirements under abnormal operating conditions. Attached Figure Description

[0022] Figure 1 This is a schematic diagram illustrating the principle of the energy management method for the split-type fuel cell hybrid aviation propulsion system based on flight phases, as described in Implementation Method 1.

[0023] Figure 2 This is a flowchart illustrating the energy management method for the split-type fuel cell hybrid aviation propulsion system based on flight phases, as described in Implementation Method 1.

[0024] The components include: a high-pressure cryogenic hydrogen tank 1, a distributor 2, a hydrogen-space cooler 3, a hydrogen fuel cell 4, a low-pressure compressor 5, a high-pressure compressor 6, an electric motor 7, a combustion chamber 8, an expansion power generation turbine 9, a generator 10, and an exhaust gas regenerator 11. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them.

[0026] Implementation Method 1, see [link] Figure 1 This embodiment describes an energy management method for a split-type fuel cell hybrid aero-propulsion system based on the flight phase. The method is applied to this system. The overall structure of the propulsion system can be referred to... Figure 1 As shown, it mainly includes a high-pressure cryogenic hydrogen tank 1, a distributor 2, a hydrogen-space cooler 3, a hydrogen fuel cell 4, a low-pressure compressor 5, a high-pressure compressor 6, an electric motor 7, a combustion chamber 8, an expansion power generation turbine 9, a generator 10, and an exhaust gas regenerator 11.

[0027] In the physical architecture of this system, the fluid pipelines and energy interaction are meticulously designed: air from the outside first enters the low-pressure compressor 5 for primary compression; the heated air after primary compression enters the hydrogen-space cooler 3, where it exchanges heat with the low-temperature hydrogen from the high-pressure low-temperature hydrogen tank 1. After being cooled and densified, the air then enters the high-pressure compressor 6 for secondary compression; the secondary compressed air then flows through the exhaust gas regenerator 11, absorbs the waste heat from the turbine exhaust, and enters the combustion chamber 8. On the fuel side, the hydrogen output from the high-pressure low-temperature hydrogen tank 1 is divided into two paths by the splitter 2. One path is depressurized and regulated before being supplied to the hydrogen fuel cell 4 for power generation; the other path, acting as an ultra-low temperature cold source, first enters the hydrogen-space cooler 3 to absorb heat from the air for preheating, and then enters the combustion chamber 8 to mix and burn with the preheated high-pressure air. The generated high-temperature and high-pressure working fluid drives the expansion turbine 9 to do work, which in turn drives the generator 10 to generate electricity. The medium-temperature exhaust gas after doing work is cooled by heat exchange in the exhaust gas regenerator 11 and then discharged outside the machine. The electrical energy generated by the aforementioned hydrogen fuel cell 4 and generator 10 is aggregated through an integrated power network to drive the main propulsion motor 7.

[0028] In this embodiment, the propulsion system adopts a split-type arrangement, which can be configured as two or more independent or partially independent propulsion branches, each distributed in different locations such as the wing, fuselage, or tail. Each propulsion branch can share some fuel supply units and control units, or it can have its own corresponding compression, combustion, power generation, and propulsion output components. This split-type configuration improves the flexibility of the propulsion system layout and helps maintain the aircraft's basic propulsion capability even if a local branch malfunctions.

[0029] The core operating logic of this invention relies on the flight phase identification and energy management algorithm embedded in the controller. For specific control logic, please refer to... Figure 2The controller first acquires information on the aircraft's current flight phase, propulsion power requirements, and system status. The flight phase information can be provided by the flight control system, mission management system, or flight parameter identification module, and includes at least one of the following phases: start-up, takeoff, climb, cruise, descent, and emergency. The propulsion power requirements can be obtained from pilot commands, throttle commands, flight control law outputs, or mission profile requirements. The system status information includes at least one or more parameters such as hydrogen fuel cell output power, output voltage, output current, temperature, health status parameters, hydrogen supply pressure, flow rate, and valve status, compressor speed and compression parameters, combustion chamber hydrogen supply, combustion state, and outlet working fluid temperature and pressure, as well as the output power of the expansion turbine and the motor load status.

[0030] After acquiring the aforementioned parameters, the controller determines the current operating mode of the propulsion system based on flight phase information. Preferably, the operating mode corresponding to the flight phase can be modified by combining the magnitude of propulsion power demand, the rate of change of propulsion power demand, and system status information. For example, when the aircraft is in a ground preparation state and the propulsion power demand is low, it can be determined as the start-up mode; when the propulsion power demand increases significantly and the rate of change is high, it can be determined as the take-off mode or climb mode; when the propulsion power demand remains relatively stable and continuously meets preset conditions, it can be determined as the cruise mode; when a branch circuit fault, abnormal hydrogen supply, fuel cell overheating, or other abnormal operating conditions are detected, it switches to the emergency mode. The above mode switching conditions can be achieved by preset rules or by combining model prediction or optimization control methods for comprehensive judgment.

[0031] After determining the current operating mode, the controller determines the target allocation values ​​for the hydrogen fuel cell output power, compressor operating parameters, combustion chamber hydrogen supply, and expansion turbine power generation based on the operating mode, propulsion power requirements, and system status information. Preferably, the target allocation values ​​can be obtained through preset control rules, lookup tables, constraint optimization algorithms, or any combination thereof. During the target allocation process, at least one of the following can be used as optimization objectives: minimizing total system hydrogen consumption, maximizing propulsion efficiency, minimizing fuel cell lifespan damage, meeting propulsion power requirements, and improving system operational stability. Constraints include the fuel cell output power range and rate of change, compressor speed limit, combustion chamber outlet temperature limit, expansion turbine safe operating range, and motor minimum power.

[0032] When the system is in startup mode, the controller preferentially controls the hydrogen fuel cell to gradually establish a stable output, allowing the compressor to operate at a lower load to gradually establish airflow and compression conditions. After meeting the preset ignition conditions, the controller controls the combustion chamber to receive compressed air and hydrogen and enter the working state. Subsequently, the controller controls the expansion turbine to generate electricity, and gradually increases the generator output power according to propulsion requirements. In this way, sudden load changes in the propulsion system during startup can be avoided, improving the operational stability of the fuel cell and related functional components.

[0033] When the system is in takeoff and climb modes, the aircraft's propulsion power demand is high. The controller increases the compressor operating parameters and the hydrogen supply to the combustion chamber to raise the temperature and pressure of the working fluid at the combustion chamber outlet and enhance the power generation capacity of the expansion turbine, thus enabling the generator to achieve higher propulsion power. In this mode, the hydrogen fuel cell preferentially undertakes the basic electrical power output, while the additional rapidly changing power demand is jointly handled by the combustion heating branch and the expansion power generation branch. This avoids the fuel cell being in a state of rapid and large-scale adjustment for a long time, reducing the impact on the fuel cell's lifespan and stability.

[0034] When the system is in cruise mode, the aircraft's propulsion power demand is relatively stable. The controller preferentially keeps the hydrogen fuel cell operating within a preset high-efficiency range, allowing it to handle the basic propulsion power output, and appropriately reduces the proportion of hydrogen supplied to the combustion chamber and the load on the expansion turbine to reduce the total hydrogen consumption of the system and improve overall energy utilization efficiency. At this time, the compressor maintains compression parameters that match the flight altitude, flight speed, and propulsion requirements, ensuring that the combustion chamber and expansion turbine are within a stable operating range.

[0035] When the system is in descent mode, the propulsion power demand is relatively reduced, and the controller accordingly lowers the target output power of the hydrogen fuel cell, the compressor operating parameters, the hydrogen supply to the combustion chamber, and the power generation of the expansion turbine. Preferably, the fuel cell is kept operating in a higher efficiency range, and the system's thermal and mechanical loads are reduced to improve operational stability during the descent phase and reduce unnecessary energy consumption.

[0036] In this embodiment, to avoid the hydrogen fuel cell directly bearing rapidly fluctuating loads, when the rate of change in propulsion power demand exceeds a preset threshold, the controller limits the rate of change in the output power of the hydrogen fuel cell, keeping the fuel cell operating within a relatively stable power range. The rapidly changing power demand is compensated by the combustion chamber heating branch and / or the expansion power generation branch. This reduces the risk of performance degradation caused by frequent and significant adjustments to the fuel cell and improves the responsiveness of the propulsion system under dynamic operating conditions.

[0037] Furthermore, the controller can also adjust the target allocation values ​​based on environmental parameters such as flight altitude, flight speed, ambient temperature, and pressure. For example, under high-altitude, thin air conditions, the compressor's compression capacity can be increased or the hydrogen supply to the combustion chamber can be adjusted to maintain the working fluid parameters entering the expansion turbine within the target range; in low-temperature environments, the power build-up rate and hydrogen supply parameters during the start-up phase can be adjusted to improve the system's environmental adaptability.

[0038] When an abnormal operating condition or propulsion circuit failure is detected, the system switches to emergency mode. The abnormal operating conditions may include, but are not limited to, fuel cell overheating, abnormal output, insufficient hydrogen supply pressure, abnormal combustion, compressor failure, expansion turbine failure, and generator or propulsion unit failure. In emergency mode, the controller isolates the faulty circuit, for example, by shutting down the hydrogen supply path, cutting off the power output path, or stopping the operation of related components in the faulty circuit; simultaneously, it reallocates propulsion power based on the remaining available power in the other circuits, ensuring the aircraft maintains the minimum propulsion capability required for safe flight. Preferably, during power reallocation, meeting the minimum safe propulsion requirements is prioritized, while also considering the temperature, speed, and output power limitations of the remaining circuits.

[0039] For example, in one specific embodiment, when the aircraft transitions from the cruise phase to the climb phase, the system detects an increase in propulsion power demand. The controller accordingly increases the compressor speed, increases the hydrogen supply to the combustion chamber, and boosts the power output of the expansion turbine, while maintaining the hydrogen fuel cell at a preset high-efficiency operating range to output basic power. When a hydrogen supply anomaly is detected in a propulsion branch, the controller immediately shuts off the hydrogen supply valve for that branch and reallocates the output power of other branches to ensure the aircraft still possesses basic propulsion capabilities. Therefore, the energy management method described in this invention not only adapts to changes in propulsion demand during different flight phases but also enables rapid fault tolerance and power reconfiguration in abnormal situations.

[0040] Those skilled in the art will understand that the above description is merely a preferred embodiment of the present invention, and the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. This is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0041] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if these modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include these modifications and modifications.

Claims

1. An energy management method for a split-type fuel cell hybrid aero-propulsion system based on flight phases, characterized in that, The method is based on a fuel cell composite aerospace propulsion system with a split arrangement. The system includes a high-pressure cryogenic hydrogen tank (1), a splitter (2), a hydrogen-space cooler (3), a hydrogen fuel cell (4), a low-pressure compressor (5), a high-pressure compressor (6), an electric motor (7), a combustion chamber (8), an expansion power generation turbine (9), a generator (10), and an exhaust gas regenerator (11). The method includes: Acquire information on the aircraft's flight phases, propulsion power requirements, and system status. The current operating mode of the propulsion system is determined based on the flight phase information. Based on the operating mode, propulsion power demand information and system status information, the target allocation values ​​for the output power of the hydrogen fuel cell (4), the operating parameters of the low-pressure compressor (5) and the high-pressure compressor (6), the hydrogen supply of the combustion chamber (8) and the power generation of the expansion power generation turbine (9) are determined. The hydrogen fuel cell (4), electric motor (7), combustion chamber (8), expansion power generation turbine (9) and generator (10) are coordinated and controlled according to the target allocation value, so that the hydrogen fuel cell (4) outputs electrical energy within the preset working range. The low-pressure compressor (5) performs primary compression on the air entering the propulsion system. The primary compressed air exchanges heat with the low-temperature hydrogen from the high-pressure low-temperature hydrogen tank (1) in the hydrogen-space cooler (3). The cooled and densified air enters the high-pressure compressor (6) for secondary compression. The hydrogen gas, heated by absorbing heat from the air, is supplied to the combustion chamber (8); the secondary compressed air flows through the exhaust heat regenerator (11) and absorbs the exhaust heat from the expansion power generation turbine (9) before entering the combustion chamber (8). The combustion chamber (8) causes the preheated compressed air and hydrogen to burn to generate a high-temperature and high-pressure working fluid. The expansion power generation turbine (9) uses the high-temperature and high-pressure working fluid to expand, do work, and generate electricity. The exhaust gas after doing work is discharged after heat exchange through the exhaust heat regenerator (11). The generator (10) obtains the target power to meet the propulsion requirements. When an abnormal operating condition or a propulsion branch failure is detected, the system switches to emergency mode, isolates the faulty branch, and reconfigures the power of the remaining branches to meet the minimum safe propulsion requirements of the aircraft.

2. The energy management method for a split-type fuel cell hybrid aero-propulsion system based on flight phases according to claim 1, characterized in that, The flight phase information of the aircraft includes at least one of the following: startup phase, takeoff phase, climb phase, cruise phase, descent phase, and emergency phase. The operating mode is set to correspond one-to-one or partially to the flight phase.

3. The energy management method for a split-type fuel cell hybrid aero-propulsion system based on flight phases according to claim 1, characterized in that, The system status information includes at least one or more of the following: hydrogen fuel cell (4) output power, hydrogen fuel cell (4) temperature, hydrogen fuel cell (4) health status, hydrogen supply status, low-pressure compressor (5) and high-pressure compressor (6) speed, low-pressure compressor (5) and high-pressure compressor (6) compression parameters, hydrogen-space cooler (3) heat exchange parameters, exhaust regenerator (11) heat exchange parameters, combustion chamber (8) outlet working fluid parameters, expansion power generation turbine (9) output status, and generator (10) output status.

4. The energy management method for a split-type fuel cell hybrid aero-propulsion system based on flight phases according to claim 1, characterized in that, The method for determining the current operating mode of the propulsion system based on the flight phase information is as follows: based on the flight phase information and combined with the magnitude of propulsion power demand, the rate of change of propulsion power demand and system status information, the current operating mode is determined by comparing it with preset mode switching conditions.

5. The energy management method for a split-type fuel cell hybrid aero-propulsion system based on flight phases according to claim 4, characterized in that, The method for determining the current operating mode based on the rate of change in propulsion power demand and system status information is as follows: When the rate of change of propulsion power demand exceeds a preset threshold, the rate of change of output power of hydrogen fuel cell (4) is limited so that the rapid power demand is borne by the heating branch of combustion chamber (8) or the expansion power generation branch.

6. The energy management method for a split-type fuel cell hybrid aero-propulsion system based on flight phases according to claim 2, characterized in that, During the cruise phase, the hydrogen fuel cell (4) is controlled to operate in a preset high-efficiency range, and the hydrogen supply ratio of the combustion chamber (8) is reduced so that the hydrogen fuel cell (4) can bear the basic propulsion power output.

7. The energy management method for a split-type fuel cell hybrid aero-propulsion system based on flight phases according to claim 2, characterized in that, The takeoff and climb phases also include steps to increase the operating parameters of the low-pressure compressor (5) and the high-pressure compressor (6) and the hydrogen supply to the combustion chamber (8) to improve the power generation capacity of the expansion turbine (9) and the output power of the propulsion system.

8. The energy management method for a split-type fuel cell hybrid aero-propulsion system based on flight phases according to claim 1, characterized in that, The method for determining the target allocation value of the power generation of the expansion turbine (9) based on the operating mode, propulsion power demand information, and system status information is as follows: The optimization objectives are: minimum total hydrogen consumption, maximum propulsion efficiency, minimum lifespan damage of hydrogen fuel cell (4), and propulsion power meeting requirements. The constraints are: output constraint of hydrogen fuel cell (4), operation constraint of low-pressure compressor (5), operation constraint of high-pressure compressor (6), thermal constraint of hydrogen-space cooler (3), thermal constraint of exhaust gas regenerator (11), operation constraint of combustion chamber (8), operation constraint of expansion power generation turbine (9), output constraint of generator (10), and output constraint of electric motor (7).

9. The energy management method for a split-type fuel cell hybrid aero-propulsion system based on flight phases as described in claim 8, characterized in that, The output constraints of the hydrogen fuel cell (4) include at least the output power range constraint and the output power change rate constraint. The operating constraints of the low-pressure compressor (5) and the high-pressure compressor (6) include at least the speed limit constraint and the surge margin constraint. The operating constraints of the combustion chamber (8) include at least the outlet temperature limit constraint. The output constraints of the electric motor (7) include at least the minimum safe propulsion power constraint.

10. The energy management method for a split-type fuel cell hybrid aero-propulsion system based on flight phases as described in claim 8, characterized in that, Methods for isolating a faulty branch and reconfiguring the power of the remaining branches include shutting off the hydrogen supply path of the faulty branch or cutting off the electrical output path of the faulty branch, and redistributing propulsion power based on the remaining available power of the remaining branches to maintain the minimum propulsion capability required for safe flight of the aircraft.

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