An aircraft engine hybrid electric power system and its design method

Abstract

This application belongs to the technical field of aircraft engine power system design, and specifically relates to an aircraft engine hybrid electric power system and its design method. The design extracts power from the aviation engine by an in-built starter generator to supply power to drive the ducted fan, which can greatly increase the equivalent duct ratio of the power system, reduce the fuel consumption rate of the engine. In addition, the design uses high heat sink liquid hydrogen as a cooling medium to cool the motor equipment, which can effectively meet the requirements of the efficient operation of the power system. Moreover, the design uses a hydrogen fuel cell to generate electricity using gaseous hydrogen to supplement the power consumption demand of the power system, which can reduce the power load of the starter generator, achieve the comprehensive utilization of energy, and ensure the flight range and loiter time of the aircraft.

Description

Technical Field

[0001] This application belongs to the technical field of aircraft engine power system design, and particularly relates to an aircraft engine hybrid electric power system and its design method. Background Art

[0002] A high-bypass ratio turbofan engine is used as the power system on an aircraft. Usually, a reduction gearbox or an open rotor scheme is used to increase the bypass ratio. However, the design and heat dissipation of a reduction gearbox with a high transmission ratio are difficult, and the processing of the ultra-large size blades required for an open rotor is difficult. At the same time, it affects the power layout of the aircraft, making it difficult to significantly increase the bypass ratio, and the fuel consumption rate level of the engine is limited.

[0003] The aircraft engine hybrid electric power system extracts power from the engine for power generation to drive the ducted fan to operate, which can significantly increase the equivalent bypass ratio of the power system and reduce the fuel consumption rate level of the engine. However, there is a lack of an efficient motor equipment cooling scheme and it cannot meet the requirements of the efficient operation of the power system.

[0004] In view of the existence of the above technical defects, this application is proposed. Summary of the Invention

[0005] The purpose of this application is to provide an aircraft engine hybrid electric power system and its design method to overcome or mitigate at least one aspect of the known technical defects.

[0006] The technical solution of this application is as follows:

[0007] On the one hand, an aircraft engine hybrid electric power system is provided, including an engine, a starter / generator, a starter / generator cooler, a ducted fan, an electric motor, an electric motor cooler, an integrated energy management system, an integrated energy management system cooler, a booster pump, a liquid hydrogen storage tank, and a hydrogen fuel cell;

[0008] The engine includes a fan, a compressor, a main combustion chamber, a high-pressure turbine, a low-pressure turbine, and a nozzle arranged in sequence. Among them, the compressor and the high-pressure turbine are connected by a high-pressure shaft;

[0009] A starter / generator is arranged in the inner cavity of the engine. The starter / generator is sleeved on the front end of the high-pressure shaft, and a starter / generator cooler is arranged on the starter / generator. The starter / generator is connected to the integrated energy management system through a circuit;

[0010] An electric motor is arranged on the rotating shaft of the ducted fan, and an electric motor cooler is arranged on the electric motor. The electric motor is connected to the integrated energy management system through a circuit;

[0011] An integrated energy management system cooler is arranged on the integrated energy management system, and it has an energy storage function;

[0012] The booster pump is connected to the integrated energy management system through a circuit. Its inlet is connected to the liquid hydrogen storage tank through a pipeline, and its outlet is connected to the cold-side inlets of the generator cooler, motor cooler, and integrated energy management system cooler through pipelines.

[0013] The cold-side outlets of the generator cooler, motor cooler, and integrated energy management system cooler are connected to the hydrogen fuel cell through pipelines, and the hydrogen fuel cell is connected to the integrated energy management system through a circuit.

[0014] Optionally, in the above aircraft engine hybrid power system, when starting the engine, the integrated energy management system can set the starter-generator to the electric mode and supply power to the starter-generator to drive the high-pressure shaft to rotate. After the high-pressure shaft speed reaches the engine starting speed requirement, the engine is ignited to achieve engine start.

[0015] After the engine starts, the integrated energy management system can set the starter-generator to the power generation mode to enable the starter-generator to generate electricity driven by the high-pressure shaft. The electric energy generated by the starter-generator is transmitted to the integrated energy management system for storage. At the same time, the integrated energy management system can supply power to the motor to drive the ducted fan to work.

[0016] After the engine starts, the integrated energy management system can supply power to the booster pump to start the booster pump, and can control the start of the generator cooler, motor cooler, and integrated energy management system cooler. The liquid hydrogen stored in the liquid hydrogen storage tank is introduced into the generator cooler, motor cooler, and integrated energy management system cooler to cool the starter-generator, motor, and integrated energy management system. The liquid hydrogen absorbs heat and becomes gaseous hydrogen when flowing through the generator cooler, motor cooler, and integrated energy management system cooler, and the gaseous hydrogen flows into the hydrogen fuel cell for power generation, and the generated electric energy is transmitted to the integrated energy management system for storage.

[0017] Optionally, in the above aircraft engine hybrid power system, there are two sets of engines and their corresponding starter-generators and generator coolers.

[0018] On the other hand, a design method for an aircraft engine hybrid power system is provided to design the above aircraft engine hybrid power system, including:

[0019] Step 1: Based on the cruise fuel consumption rate index requirements of the aircraft engine hybrid power system and on the basis of the engine scheme performance parameters, perform a matching design of the equivalent bypass ratio to clarify the design indicators of the ducted fan. The design indicators of the ducted fan include the power demand of the ducted fan.

[0020] Step 2: According to the power requirement of the ducted fan, conduct a matching design for the power generation of the starter-generator. Considering that a hydrogen fuel cell provides part of the electric energy, specify the power generation of the starter-generator.

[0021] Step 3: According to the heat dissipation requirements of the starter-generator, motor, and integrated energy management system, design the starter-generator cooler, motor cooler, and integrated energy management system cooler, and calculate the supply flow rate of liquid hydrogen.

[0022] Step 4: According to the supply flow rate of liquid hydrogen, calculate the power requirement of the booster pump and the power generation of the hydrogen fuel cell.

[0023] Step 5: Determine whether the power generation of the starter-generator and hydrogen fuel cell meets the power requirements of the ducted fan and booster pump. If not, adjust the power generation of the starter-generator and repeat Steps 3 to 5 until the power generation of the starter-generator and hydrogen fuel cell meets the power requirements of the ducted fan and booster pump.

[0024] Optionally, in the above design method of the aircraft engine hybrid electric power system, it further includes:

[0025] Step 6: According to the cruise time / range, determine the working time of the starter-generator and ducted fan. Combining with the supply flow rate of liquid hydrogen, obtain the required carrying amount of liquid hydrogen and design the liquid hydrogen storage tank.

[0026] The present application has at least the following beneficial technical effects:

[0027] Provide an aircraft engine hybrid electric power system and its design method. Design to extract power from the aviation engine by an in-built starter-generator to supply power to drive the ducted fan, which can greatly increase the equivalent duct ratio of the power system, reduce the engine fuel consumption rate level, and design to use high heat sink liquid hydrogen as the cooling medium to cool the motor equipment, which can effectively meet the requirements of the power system for efficient operation. In addition, design to use a hydrogen fuel cell to generate electricity using gaseous hydrogen to supplement the power consumption demand of the power system, which can reduce the power load of the starter-generator, realize the comprehensive utilization of energy, and ensure the range and endurance of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of the aircraft engine hybrid electric power system provided by the embodiment of the present application;

[0029] Figure 2 is a schematic diagram of the design method of the aircraft engine hybrid electric power system provided by the embodiment of the present application;

[0030] Wherein:

[0031] 1 - Engine; 2 - Starter - generator; 3 - Starter - generator cooler; 4 - Ducted fan; 5 - Electric motor; 6 - Electric motor cooler; 7 - Integrated energy management system; 8 - Integrated energy management system cooler; 9 - Booster pump; 10 - Liquid hydrogen storage tank; 11 - Hydrogen fuel cell;

[0032] 12 - Compressor; 13 - Main combustion chamber; 14 - High - pressure turbine; 15 - Low - pressure turbine; 16 - Nozzle; 17 - High - pressure shaft; 18 - Fan.

[0033] To better illustrate this embodiment, some content in the drawings will be omitted, enlarged, or reduced, which is only for illustrative purposes and cannot be construed as a limitation to this application. Detailed implementation manners

[0034] To make the technical solutions and their advantages of this application clearer, the technical solutions of this application will be further described clearly and completely in conjunction with the drawings. It can be understood that the specific embodiments described herein are only part of the embodiments of this application, which are only used to explain this application rather than limit this application. It should be noted that for the convenience of description, only the parts related to this application are shown in the drawings, and other related parts can refer to the general design.

[0035] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application should be the ordinary meanings understood by those of ordinary skill in the field to which this application belongs. The "including" used in the description of this application means that the concept appearing before this word covers the concepts listed after this word and their equivalents, without excluding other related concepts.

[0036] In addition, the words indicating directions used in the description of this application are only used to represent relative directions or position relationships. When the absolute position of the object being described changes, its relative position relationship may also change accordingly. It should also be noted that unless otherwise clearly specified and limited, the "installation", "connection" and other similar words used in the description of this application should be understood in a broad sense. For example, connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. Those skilled in the art can understand their specific meanings in this application according to the specific situation.

[0037] An aircraft engine hybrid - electric power system, as Figure 1 shown, includes an engine 1, a starter - generator 2, a starter - generator cooler 3, a ducted fan 4, an electric motor 5, an electric motor cooler 6, an integrated energy management system 7, an integrated energy management system cooler 8, a booster pump 9, a liquid hydrogen storage tank 10, and a hydrogen fuel cell 11.

[0038] The engine 1 includes a fan 18, a compressor 12, a main combustion chamber 13, a high-pressure turbine 14, a low-pressure turbine 15, and a nozzle 16 arranged in sequence. Among them, the compressor 12 and the high-pressure turbine 14 are connected by a high-pressure shaft 17.

[0039] A starter-generator 2 is arranged in the inner cavity of the engine 1. The starter-generator 2 is sleeved on the front end of the high-pressure shaft 17 of the engine 1. A starter-generator cooler 3 is arranged on the starter-generator 2. The starter-generator 2 is connected to the integrated energy management system 7 through a circuit.

[0040] A motor 5 is arranged on the rotating shaft of the ducted fan 4. A motor cooler 6 is arranged on the motor 5. The motor 5 is connected to the integrated energy management system 7 through a circuit.

[0041] An integrated energy management system cooler 8 is arranged on the integrated energy management system 7, and it has an energy storage function.

[0042] A booster pump 9 is connected to the integrated energy management system 7 through a circuit. Its inlet is connected to a liquid hydrogen storage tank 10 through a pipeline, and its outlet is connected to the cold-side inlets of the starter-generator cooler 3, the motor cooler 6, and the integrated energy management system cooler 8 through pipelines.

[0043] The cold-side outlets of the starter-generator cooler 3, the motor cooler 6, and the integrated energy management system cooler 8 are connected to a hydrogen fuel cell 11 through pipelines. The hydrogen fuel cell 11 is connected to the integrated energy management system 7 through a circuit.

[0044] When starting the engine 1, the integrated energy management system 7 can set the starter-generator 2 to be in the electric mode and supply power to the starter-generator 2, so that the starter-generator 2 drives the high-pressure shaft 17 to rotate. After the rotational speed of the high-pressure shaft 17 reaches the engine starting speed requirement, the engine 1 is ignited to realize the starting of the engine 1.

[0045] After the engine 1 is started, the integrated energy management system 7 can set the starter-generator 2 to be in the power generation mode, so that the starter-generator 2 generates electricity driven by the high-pressure shaft 17. The electric energy generated by the starter-generator 2 is transmitted to the integrated energy management system 7 for storage. At the same time, the integrated energy management system 7 can supply power to the motor 5 to drive the ducted fan 4 to work.

[0046] After the engine 1 starts, when the temperatures of the starter-generator 2, the motor 5, and the integrated energy management system 7 reach the safety threshold, the integrated energy management system 7 can supply power to the booster pump 9 to start the booster pump 9, and control the starter-generator cooler 3, the motor cooler 6, and the integrated energy management system cooler 8 to start. The liquid hydrogen stored in the liquid hydrogen storage tank 10 is introduced into the starter-generator cooler 3, the motor cooler 6, and the integrated energy management system cooler 8 to cool the starter-generator 2, the motor 5, and the integrated energy management system 7. When the liquid hydrogen flows through the starter-generator cooler 3, the motor cooler 6, and the integrated energy management system cooler 8, it absorbs heat and turns into gaseous hydrogen, and the gaseous hydrogen flows into the hydrogen fuel cell 11 for power generation, and the generated electric energy is transmitted to the integrated energy management system 7 for storage.

[0047] In the aircraft engine hybrid power system disclosed in the above embodiment, there are two sets of the engine 1 and its corresponding starter-generator 2 and starter-generator cooler 3.

[0048] The aircraft engine hybrid power system disclosed in the above embodiment can carry out matching design by taking technical indicators such as cruise fuel consumption rate and cruise time / range as the traction, as Figure 2 shown.

[0049] Step 1: According to the cruise fuel consumption rate index requirement of the aircraft engine hybrid power system, based on the performance parameters of the engine 1 scheme, carry out the matching design of the equivalent bypass ratio, and clarify the design index of the bypass fan 4. The design index of the bypass fan 4 includes the power demand of the bypass fan 4.

[0050] Step 2: According to the power demand of the bypass fan 4, carry out the matching design of the power generation of the starter-generator 2, considering that the hydrogen fuel cell 11 provides a part of the electric energy, and specify the power generation of the starter-generator 2.

[0051] Step 3: According to the heat dissipation requirements of the starter-generator 2, the motor 5, and the integrated energy management system 7, design the starter-generator cooler 3, the motor cooler 6, and the integrated energy management system cooler 8, and calculate the supply flow rate of the liquid hydrogen.

[0052] Step 4: According to the supply flow rate of the liquid hydrogen, calculate the power demand of the booster pump 9 and the power generation of the hydrogen fuel cell 11.

[0053] Step 5: Judge whether the power generation of the starter-generator 2 and the hydrogen fuel cell 11 meets the power demand of the bypass fan 4 and the booster pump 9. If not, adjust the power generation of the starter-generator 2, and re-perform Steps 3 to 5 until the power generation of the starter-generator 2 and the hydrogen fuel cell 11 meets the power demand of the bypass fan 4 and the booster pump 9.

[0054] When the power demand of the ducted fan 4 and the booster pump 9 is exceeded, the power generation power of the starter-generator 2 is reduced; when the power demand of the ducted fan 4 and the booster pump 9 is not met, the power generation power of the starter-generator 2 is increased.

[0055] Adjusting the power generation power of the starter-generator 2 will affect the cooling and heat exchange power of the cooling system, and thus affect the power of the booster pump 9 and the power generation power of the hydrogen fuel cell 11. At the same time, it will also affect the engine 1 scheme, and thus affect the design indexes of the ducted fan 4. Therefore, when adjusting the power generation power of the starter-generator 2, the engine 1 scheme and the design indexes of the ducted fan 4 are also iteratively designed accordingly.

[0056] Step six: According to the cruise time / voyage, determine the working time of the starter-generator 2 and the ducted fan 4, and combine the supply flow rate of liquid hydrogen to obtain the required carrying amount of liquid hydrogen, and design the liquid hydrogen storage tank 10.

[0057] The aircraft engine hybrid electric power system and its design method disclosed in the above embodiments extract power from the aviation engine 1 by the built-in starter-generator 2 to supply power to drive the ducted fan 4, which can greatly improve the equivalent ducted ratio of the power system, reduce the fuel consumption rate level of the engine, and design to use liquid hydrogen with a high heat sink as a cooling medium to cool the motor equipment, which can effectively meet the requirements of the efficient operation of the power system. In addition, the design uses the hydrogen fuel cell 11 to generate electricity using gaseous hydrogen to supplement the power consumption demand of the power system, which can reduce the power load of the starter-generator 2, realize the comprehensive utilization of energy, and ensure the voyage and loitering time of the aircraft.

[0058] So far, the technical solutions of the present application have been described in conjunction with the preferred embodiments shown in the drawings. Those skilled in the art should understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without departing from the principle of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present application.

Claims

1. A method for designing a hybrid electric power system for an aircraft engine, for designing a hybrid electric power system for an aircraft engine, wherein the hybrid electric power system for an aircraft engine comprises an engine (1), a generator (2), a generator cooler (3), a ducted fan (4), an electric motor (5), an electric motor cooler (6), an integrated energy management system (7), an integrated energy management system cooler (8), a boost pump (9), a liquid hydrogen storage tank (10), and a hydrogen fuel cell (11); The engine (1) comprises a fan (18), a compressor (12), a main combustion chamber (13), a high-pressure turbine (14), a low-pressure turbine (15), and a nozzle (16) which are arranged in sequence, wherein: The compressor (12) and the high-pressure turbine (14) are connected via a high-pressure shaft (17); A generator (2) is arranged in the inner cavity of the engine (1), the generator (2) is sleeved on the front end of the high-pressure shaft (17), a generator cooler (3) is arranged on the generator (2), and the generator (2) is connected to the integrated energy management system (7) via a line; An electric motor (5) is disposed on the rotating shaft of the ducted fan (4), a motor cooler (6) is disposed on the electric motor (5), and the electric motor (5) is connected to an integrated energy management system (7) via a line; The integrated energy management system (7) is provided with an integrated energy management system cooler (8) having an energy storage function; The boost pump (9) is connected to the integrated energy management system (7) through a line, its inlet is connected to the liquid hydrogen storage tank (10) through a pipeline, and its outlet is connected to the generator cooler (3), the motor cooler (6), and the cold side inlet of the integrated energy management system cooler (8) through a pipeline; The cold side outlets of the generator cooler (3), the motor cooler (6), and the integrated energy management system cooler (8) are connected to the hydrogen fuel cell (11) through pipelines, and the hydrogen fuel cell (11) is connected to the integrated energy management system (7) through lines; The aircraft engine hybrid electric power system design method is characterized by comprising: Step 1: According to the cruise fuel consumption index requirement of the aircraft engine hybrid electric power system, on the basis of the performance parameters of the engine (1) scheme, an equivalent bypass ratio matching design is performed, and the design index of the ducted fan (4) is clarified. The design index of the ducted fan (4) includes the power requirement of the ducted fan (4); Step 2: According to the power requirement of the ducted fan (4), the power generation power of the generator (2) is matched and designed, and the power generation power of the generator (2) is given by considering that the hydrogen fuel cell (11) provides a part of the electric energy; Step 3: According to the heat dissipation requirements of the generator (2), the motor (5), and the integrated energy management system (7), the generator cooler (3), the motor cooler (6), and the integrated energy management system cooler (8) are designed, and the supply flow rate of liquid hydrogen is calculated; Step 4: Calculate the power requirement of the boost pump (9) and the power generation power of the hydrogen fuel cell (11) according to the supply flow rate of liquid hydrogen; Step 5: Determine whether the power generated by the generator (2) and the hydrogen fuel cell (11) meets the power requirements of the ducted fan (4) and the booster pump (9). If not, adjust the power generated by the generator (2) and repeat steps 3 to 5 until the power generated by the generator (2) and the hydrogen fuel cell (11) meets the power requirements of the ducted fan (4) and the booster pump (9).

2. The aircraft engine hybrid electric power system design method according to claim 1, characterized in that: Also includes: Step 6: According to the cruising time / range, determine the working time of the generator (2) and the ducted fan (4), combine the supply flow of liquid hydrogen, obtain the required amount of liquid hydrogen, and design the liquid hydrogen storage tank (10).

3. The aircraft engine hybrid electric power system design method according to claim 1, characterized in that: When starting an engine (1), the aircraft engine hybrid electric power system can set the starter generator (2) to an electric mode by using the integrated energy management system (7), and supply power to the starter generator (2), so that the starter generator (2) drives the high-voltage shaft (17) to rotate, and after the rotation speed of the high-voltage shaft (17) reaches the engine starting rotation speed requirement, the engine (1) is ignited to start the engine (1); An aircraft engine hybrid electric power system, after the engine (1) is started, can use an integrated energy management system (7) to set a starter generator (2) in a power generation mode, so that the starter generator (2) generates electricity under the drive of a high-voltage shaft (17), and the electric energy generated by the starter generator (2) is transmitted to the integrated energy management system (7) for storage. At the same time, the integrated energy management system (7) can supply power to an electric motor (5), so that the electric motor (5) drives a ducted fan (4) to work; After the engine (1) is started, the integrated energy management system (7) can supply power to the boost pump (9) to start the boost pump (9), and can control the starter generator cooler (3), the motor cooler (6), and the integrated energy management system cooler (8) to start. Liquid hydrogen stored in the liquid hydrogen storage tank (10) is passed into the starter generator cooler (3), the motor cooler (6), and the integrated energy management system cooler (8) to cool the starter generator (2), the motor (5), and the integrated energy management system (7). When the liquid hydrogen flows through the starter generator cooler (3), the motor cooler (6), and the integrated energy management system cooler (8), it absorbs heat and becomes gaseous hydrogen. The gaseous hydrogen flows into the hydrogen fuel cell (11) to generate electricity, and the generated electric energy is transmitted to the integrated energy management system (7) for storage.

4. The aircraft engine hybrid electric power system design method according to claim 1, characterized in that: In an aircraft engine hybrid electric power system, there are two groups of engines (1) and their corresponding generators (2) and generator coolers (3).

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