Aircraft engine hybrid electric power system and design method thereof

Abstract

The invention belongs to the technical field of design of aircraft engine power systems, and particularly relates to an aircraft engine hybrid electric power system and a design method thereof. A built-in generator is designed to extract power from an aero-engine and supply power to drive a ducted fan, so that the equivalent bypass ratio of the power system can be greatly improved, and the power efficiency is improved. According to the present invention, the oil consumption level of the engine is reduced, the high heat sink liquid hydrogen is adopted as the cooling medium to cool the motor equipment so as to effectively meet the efficient work requirement of the power system, the hydrogen fuel cell is adopted to generate power by using the gas hydrogen so as to supplement the power consumption requirement of the power system, and the power load of the generator can be reduced; the comprehensive utilization of energy is realized, and the voyage and the airborne time of the aircraft are ensured.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft engine power system design, and specifically relates to an aircraft engine hybrid electric power system and a design method thereof. Background Art

[0002] Aircraft use high bypass ratio turbofan engines as their power systems, and usually use a reduction gearbox or open rotor solution to increase the bypass ratio. However, the design and heat dissipation of high transmission ratio reduction gearboxes are difficult, and the oversized blades required for open rotors are difficult to process, which also affects the aircraft's power layout, making it difficult to achieve a significant increase in the bypass ratio, and limiting the engine's fuel consumption rate.

[0003] The aircraft engine hybrid-electric power system extracts power from the engine to generate electricity and drive the ducted fan to operate, which can greatly improve the power system equivalent bypass ratio and reduce the engine fuel consumption level. However, the lack of an efficient motor equipment cooling solution cannot meet the needs of efficient operation of the power system.

[0004] This application is proposed in view of the above-mentioned technical defects. Summary of the invention

[0005] The purpose of the present application is to provide an aircraft engine hybrid-electric power system and a design method thereof to overcome or alleviate at least one of the known technical deficiencies.

[0006] The technical solution of this application is: 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 boost pump, a liquid hydrogen storage tank, and a hydrogen fuel cell; The engine includes a fan, a compressor, a main combustion chamber, a high-pressure turbine, a low-pressure turbine, and a nozzle, which are arranged in sequence, wherein the compressor and the main combustion chamber are connected by a high-pressure shaft; A generator is arranged in the inner cavity of the engine, the generator is sleeved on the front end of the high-voltage shaft, a generator cooler is arranged on the generator, and the generator is connected to the integrated energy management system through a line; An electric motor is arranged on the rotating shaft of the ducted fan, a motor cooler is arranged on the electric motor, and the electric motor is connected to the integrated energy management system through a line; An integrated energy management system cooler is provided on the integrated energy management system and has an energy storage function; The booster pump is connected to the integrated energy management system through a line, its inlet is connected to the liquid hydrogen storage tank through a pipeline, and its outlet is connected to the cold side inlet of the generator cooler, the motor cooler, and the integrated energy management system cooler through a pipeline; The cold side outlets of the generator cooler, the motor cooler and the 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 lines.

[0007] Optionally, in the above-mentioned aircraft engine hybrid electric power system, when starting the engine, the integrated energy management system can be used to set the starter generator to an electric mode, and power the starter generator, so that the starter generator drives the high-voltage shaft to rotate, and after the high-voltage shaft speed reaches the engine starting speed requirement, the engine is ignited to start the engine; After the engine is started, the integrated energy management system can be used to set the starter generator to a power generation mode, so that the starter generator generates electricity driven by the high-voltage shaft, and 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 electric motor, so that the electric motor drives the ducted fan to work; After the engine is started, the integrated energy management system can supply power to the boost pump to start the boost pump, and can control the starter generator cooler, the electric motor cooler, and the integrated energy management system cooler to start the liquid hydrogen stored in the liquid hydrogen storage tank, and pass the liquid hydrogen stored in the liquid hydrogen storage tank into the starter generator cooler, the electric motor cooler, and the integrated energy management system cooler to cool the starter generator, the electric motor, and the integrated energy management system. When the liquid hydrogen flows through the starter generator cooler, the electric motor cooler, and the integrated energy management system cooler, it absorbs heat and becomes gaseous hydrogen. The gaseous hydrogen flows into the hydrogen fuel cell to generate electricity, and the generated electrical energy is transmitted to the integrated energy management system for storage.

[0008] Optionally, in the above-mentioned aircraft engine hybrid-electric power system, there are two groups of engines and their corresponding generators and generator coolers.

[0009] On the other hand, a method for designing a hybrid electric power system of an aircraft engine is provided, which is used to design the hybrid electric power system of the aircraft engine, comprising: Step 1: According to the cruise fuel consumption index requirements of the aircraft engine hybrid power system, on the basis of the engine solution performance parameters, the equivalent bypass ratio matching design is carried out, and the design index of the ducted fan is clarified. The design index of the ducted fan includes the power demand of the ducted fan; Step 2: According to the power requirement of the ducted fan, the power generation of the generator is matched and designed, and the power generation of the generator is given by considering that the hydrogen fuel cell provides part of the power; Step 3: According to the heat dissipation requirements of the generator, motor and integrated energy management system, design the generator cooler, motor cooler and integrated energy management system cooler, and calculate the supply flow rate of liquid hydrogen; Step 4: Calculate the power requirement of the booster pump and the power generation of the hydrogen fuel cell according to the supply flow of liquid hydrogen; Step 5: Determine whether the power generation of the generator and hydrogen fuel cell meets the power requirements of the ducted fan and booster pump. If not, adjust the power generation of the generator and repeat steps 3 to 5 until the power generation of the generator and hydrogen fuel cell meets the power requirements of the ducted fan and booster pump.

[0010] Optionally, the above-mentioned aircraft engine hybrid electric power system design method further includes: Step 6. Determine the working time of the generator and ducted fan based on the cruising time / range, and calculate the required amount of liquid hydrogen to be carried based on the supply flow of liquid hydrogen, and design the liquid hydrogen storage tank.

[0011] This application has at least the following beneficial technical effects: Provided are an aircraft engine hybrid electric power system and a design method thereof. The system is designed to extract power from the aircraft engine through a built-in starter generator to power and drive the duct fan, which can significantly improve the equivalent bypass ratio of the power system and reduce the engine fuel consumption rate. The system is designed to use liquid hydrogen with a high heat sink as a cooling medium to cool the motor equipment, which can effectively meet the needs of efficient operation of the power system. In addition, the system is designed to use hydrogen fuel cells to generate electricity using gaseous hydrogen to supplement the power 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 of the aircraft and its airborne time. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic diagram of a hybrid electric power system for an aircraft engine provided in an embodiment of the present application; Figure 2 is a schematic diagram of a design method for a hybrid electric power system of an aircraft engine provided in an embodiment of the present application; in: 1-engine; 2-generator; 3-generator cooler; 4-ducted fan; 5-motor; 6-motor cooler; 7-integrated energy management system; 8-integrated energy management system cooler; 9-boost pump; 10-liquid hydrogen storage tank; 11-hydrogen fuel cell; 12-compressor; 13-main combustion chamber; 14-high-pressure turbine; 15-low-pressure turbine; 16-nozzle; 17-high-pressure shaft; 18-fan.

[0013] In order to better illustrate the present embodiment, some contents of the drawings may be omitted, enlarged or reduced, which is only used for illustrative purposes and should not be construed as limiting the present application. DETAILED DESCRIPTION

[0014] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be described in further detail in detail and in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design.

[0015] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application should be the common meanings understood by those skilled in the art in the field to which this application belongs. The term "include" used in the description of this application means that the concepts appearing before the term include the concepts listed after the term and their equivalents, without excluding other related concepts.

[0016] In addition, the words indicating orientation used in the description of this application are only used to indicate relative directions or positional relationships. When the absolute position of the object being described changes, its relative positional relationship may also change accordingly. It should also be noted that, unless otherwise clearly specified and limited, the words "installation", "connection" and other similar words used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Technical personnel in the field can understand its specific meaning in this application according to the specific circumstances.

[0017] An aircraft engine hybrid electric power system, such as Figure 1 As shown, it 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 boost pump 9, a liquid hydrogen storage tank 10, and a hydrogen fuel cell 11.

[0018] 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 , which are arranged in sequence. The compressor 12 and the main combustion chamber 13 are connected via a high-pressure shaft 17 .

[0019] 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 of the engine 1. A generator cooler 3 is arranged on the generator 2. The generator 2 is connected to the integrated energy management system 7 through a line.

[0020] An electric motor 5 is arranged on the rotating shaft of the ducted fan 4 , a motor cooler 6 is arranged on the electric motor 5 , and the electric motor 5 is connected to an integrated energy management system 7 through a line.

[0021] The integrated energy management system cooler 8 is provided on the integrated energy management system 7 and has an energy storage function.

[0022] 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 cold side inlet of the generator cooler 3, the motor cooler 6, and the integrated energy management system cooler 8 through a pipeline.

[0023] 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.

[0024] When starting the engine 1, the integrated energy management system 7 can set the starter generator 2 to the electric mode and supply power to the starter generator 2 so that the starter generator 2 drives the high-voltage shaft 17 to rotate. After the speed of the high-voltage shaft 17 reaches the engine starting speed requirement, the engine 1 is ignited to start the engine 1.

[0025] After the engine 1 is started, the integrated energy management system 7 can set the starter generator 2 to a power generation mode, so that the starter generator 2 generates electricity under the drive of the high-voltage 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, so that the motor 5 drives the ducted fan 4 to work.

[0026] After the engine 1 is started, when the temperature of the starter generator 2, the motor 5 and the integrated energy management system 7 reaches a safety threshold, the integrated energy management system 7 can supply power to the boost pump 9 to start the boost pump 9, and control the starter generator cooler 3, the motor cooler 6 and the integrated energy management system cooler 8 to start, and pass the liquid hydrogen stored in the liquid hydrogen storage tank 10 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 electrical energy is transmitted to the integrated energy management system 7 for storage.

[0027] In the aircraft engine hybrid electric power system disclosed in the above embodiment, there are two groups of engines 1 and their corresponding generators 2 and generator coolers 3.

[0028] The aircraft engine hybrid power system disclosed in the above embodiment can be designed to match the cruise fuel consumption rate and cruise time / range and other technical indicators for traction. Figure 2 shown.

[0029] Step 1: According to the cruise fuel consumption index requirements of the aircraft engine hybrid-electric power system, on the basis of the performance parameters of the engine 1 scheme, the equivalent bypass ratio is matched and designed, and the design index of the ducted fan 4 is clarified. The design index of the ducted fan 4 includes the power demand of the ducted fan 4.

[0030] Step 2: According to the power requirement of the ducted fan 4, the power generation of the generator 2 is matched and designed. Considering that the hydrogen fuel cell 11 provides part of the electrical energy, the power generation of the generator 2 is given.

[0031] 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.

[0032] 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.

[0033] Step 5: Determine whether the power generation of 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 generation of the generator 2 and repeat steps 3 to 5 until the power generation of the generator 2 and the hydrogen fuel cell 11 meets the power requirements of the ducted fan 4 and the booster pump 9.

[0034] When the power demand of the ducted fan 4 and the booster pump 9 is exceeded, the power generation power of the 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 generator 2 is increased.

[0035] Adjusting the power generation power of the generator 2 will affect the cooling and heat exchange power of the cooling system, and further affect the power of the boost pump 9 and the power generation power of the hydrogen fuel cell 11. It will also affect the engine 1 scheme, and further affect the design indicators of the ducted fan 4. Therefore, when adjusting the power generation power of the generator 2, the design indicators of the engine 1 scheme and the ducted fan 4 are also iteratively designed accordingly.

[0036] Step 6: Determine the working time of the generator 2 and the ducted fan 4 according to the cruising time / range, and calculate the required carrying amount of liquid hydrogen in combination with the supply flow of liquid hydrogen, and design the liquid hydrogen storage tank 10.

[0037] The aircraft engine hybrid electric power system and design method disclosed in the above-mentioned embodiment are designed to extract power from the aircraft engine 1 with the built-in generator 2 to power the ducted fan 4, which can greatly improve the equivalent bypass ratio of the power system and reduce the engine fuel consumption level. It is also designed to use liquid hydrogen with high heat sink as a cooling medium to cool the motor equipment, which can effectively meet the needs of efficient operation of the power system. In addition, the hydrogen fuel cell 11 is designed to use gaseous hydrogen to generate electricity to supplement the power system's electricity demand, which can reduce the power load of the generator 2, realize the comprehensive utilization of energy, and ensure the aircraft's range and its airborne time.

[0038] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles 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 fall within the scope of protection of the present application.

Claims

1. An aircraft engine hybrid electric power system, characterized in that: It includes 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 booster 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 main combustion chamber (13) 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) via pipelines, and the hydrogen fuel cell (11) is connected to the integrated energy management system (7) via lines.

2. The aircraft engine hybrid electric power system according to claim 1, characterized in that: When starting the engine (1), the integrated energy management system (7) can be used to set the starter generator (2) to an electric mode, and to 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); After the engine (1) is started, the integrated energy management system (7) can be used to set the starter generator (2) to a power generation mode, so that the starter generator (2) generates electricity under the drive of the 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 the electric motor (5), so that the electric motor (5) drives the 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.

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

4. A method for designing a hybrid electric power system for an aircraft engine, used to design the hybrid electric power system for an aircraft engine according to claim 3, characterized in that: include: 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).

5. The aircraft engine hybrid electric power system design method according to claim 4, 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).

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