Aero-engine with embedded high-temperature and high-speed motor and cooling method of high-temperature and high-speed motor

Abstract

The aero-engine comprises a high-pressure shaft, a low-pressure compressor supported by the high-pressure shaft, the high-temperature and high-speed motor and a high-pressure compressor, the high-temperature and high-speed motor is located between the low-pressure compressor and the high-pressure compressor, the high-temperature and high-speed motor comprises a machine shell, a stator and a rotor, and the stator and the rotor are located in the machine shell; a plurality of through holes are formed in the front end face and the rear end face of the machine shell, the through holes in the front end face communicate the interior of the high-temperature and high-speed motor with an air outlet of the low-pressure air compressor, and the through holes in the rear end face communicate the interior of the high-temperature and high-speed motor with an air inlet of the high-pressure air compressor. The high-temperature and high-speed motor is arranged in the aero-engine, air generated in the axial direction in the operation process of the engine is directly used for cooling through the through holes in the motor shell, an additional air source is not needed, the structure is simple, and the cooling effect is good. Cooling air increases the temperature of a combustion air inlet of a combustion chamber through temperature rise in the motor, combustion efficiency can be improved, and aviation fuel is saved.

Description

Technical Field

[0001] The present invention relates to a more-electric aircraft / more-electric engine, and in particular to an aero-engine with an embedded high-temperature and high-speed motor and a cooling method for the high-temperature and high-speed motor. Background Art

[0002] In order to improve the performance of future aircraft in terms of safety, cleanliness and quietness, the existing technology is actively conducting research on aircraft engine electrification and "multi-electric engines". The main solution to realize the concept of multi-electric engines is to install the motor directly on the high-pressure shaft of the aircraft engine to eliminate the auxiliary gearbox between the aircraft engine shaft and the motor, which has the advantages of significantly simplifying engine maintenance, reducing the overall size of the aircraft engine, reducing the weight of the aircraft engine by about 15% to 20%, improving the fuel efficiency of the aircraft engine, and realizing direct electric starting of the aircraft engine. In the existing technology, a high-temperature and high-speed starter / generator installed on the high-pressure shaft of the aircraft engine has been developed based on a high-coercive force permanent magnet motor. The motor can provide a torque of 350Nm at a speed of 4800r / min in starting mode and a power of 150k at a speed of 9000r / min in generator mode. However, considering the complexity of the oil cooling technology used in this motor, its large weight (the mass of the stator and rotor is 88 kg) and overall size will reduce its efficiency in the engine, the concept of installing an outer rotor permanent magnet motor (magnetic system based on Halbach array) as a high-temperature and high-speed starter / generator on the high-pressure shaft of the engine was proposed. The reason for using the Halbach array is that the back of the rotor is made of titanium, which is part of the engine. The advantage of the design is that the outer rotor can be directly cooled by the external air, allowing an acceptable operating temperature for the permanent magnets. As a follow-up study, a new design scheme for installing a high-temperature starter / generator on the high-pressure shaft was proposed. Not only the basic materials for making the motor were selected and verified, but also the developed design scheme was optimized by multi-criteria using genetic algorithms and Pareto methods. However, the main difficulty in installing a starter / generator on the high-pressure shaft of the engine is the ambient temperature conditions of the high-pressure shaft and the high degree of integration of the motor. The starter / generator should operate as a single system with the engine. In order to avoid engine accidents, it is necessary to improve the safety of the starter / generator. Therefore, in addition to the requirements for traditional starters / generators, starters / generators installed on high-voltage shafts must have additional requirements to ensure their heat resistance and safety. These additional requirements generally include: reliable operation at an ambient temperature of 300°C; maximum efficiency of more than 90%; minimum weight and overall size; stable operation under high-intensity and high-vibration conditions of mechanical, thermal, electromagnetic loads and overloads; because the starter / generator is coaxial with the high-voltage rotor, the starter / generator meets the applicability and reliability of high-speed operation. However, existing motor technology can no longer meet the high-temperature (300°C) working environment requirements of aircraft engines.

[0003] The survey found that there is little research on efficient cooling technology for high-temperature and high-speed motors based on the structure of aircraft engine systems. When a high-temperature and high-speed motor is integrated into the engine as a starter / generator, it is the core of the engine power system. However, in addition to having excellent high-temperature resistance, each component of the aircraft engine system should be compatible with advanced cooling methods. The cooling media commonly used in aircraft engines mainly include air, mechanical lubricating oil and fuel (aviation kerosene). However, aviation kerosene generally produces coking at around 150°C and is not suitable for use in high-temperature environments of 300°C. Summary of the invention

[0004] Purpose of the invention: In view of the above shortcomings, the present invention provides an aircraft engine with an embedded high-temperature and high-speed motor and a cooling method for the high-temperature and high-speed motor with good cooling effect.

[0005] Technical solution: To solve the above problems, the present invention adopts an aircraft engine with an embedded high-temperature and high-speed motor, including a high-pressure shaft and a low-pressure compressor, a high-temperature and high-speed motor, and a high-pressure compressor supported by the high-pressure shaft, wherein the high-temperature and high-speed motor is located between the low-pressure compressor and the high-pressure compressor, and the high-temperature and high-speed motor includes a casing, a stator and a rotor located in the casing, the rotor is fixedly sleeved on the high-pressure shaft, and the stator is sleeved on the outside of the rotor; a plurality of through holes are arranged on the front end face and the rear end face of the casing, the through holes on the front end face connect the interior of the high-temperature and high-speed motor with the air outlet of the low-pressure compressor, and the through holes on the rear end face connect the interior of the high-temperature and high-speed motor with the air inlet of the high-pressure compressor.

[0006] Furthermore, the through holes on the front and rear faces of the high-temperature high-speed motor are evenly arranged in the circumferential direction. The through holes are cylindrical holes. The through holes on the front face of the housing correspond to the through holes on the rear face of the housing one by one, and the axis of the through holes on the front face coincides with the axis of the corresponding through holes on the rear face. The axis of the through holes on the front and rear faces of the housing passes through the gap between the stator and the rotor of the high-temperature high-speed motor.

[0007] Furthermore, the aircraft engine also includes a fan located at the front end of the low-pressure compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine and a tail nozzle located at the rear end of the high-pressure compressor.

[0008] The present invention also adopts a cooling method for the high-temperature and high-speed motor of the aircraft engine, wherein part of the air that has passed through the low-pressure compressor to increase the flow and pressure is introduced into the interior of the casing through the through hole on the front end face of the high-temperature and high-speed motor casing. After cooling the high-temperature and high-speed motor, the air is heated and returned to the inlet of the high-pressure compressor from the through hole on the rear end face of the high-temperature and high-speed motor casing.

[0009] Furthermore, the air introduced from the through hole on the front end surface of the casing flows through the gap between the stator and the rotor of the high-temperature and high-speed motor, and then flows out from the through hole on the rear end surface of the casing.

[0010] Beneficial effect: Compared with the prior art, the significant advantage of the present invention is that the high-temperature, high-speed motor is placed in the entire aircraft engine system to study its cooling scheme, and the cooling medium (air) commonly used in the engine is directly used for cooling by "using local materials". The huge flow of air generated in the axial direction during the operation of the aircraft engine is directly used for unconventional cooling. The cooling air is directly introduced from the turbofan engine compressor air path through the through holes on the motor casing, and no additional air source is required. The structure is simple and the cooling effect is good, providing a solution support for the stable operation of the motor in a high-temperature environment. After flowing through the inside of the motor, the cooling air will return to the outlet of the high-pressure compressor, which has little effect on the engine thrust. The high-temperature, high-speed motor is used as a heat storage body in the combustion chamber of the aircraft engine. When the cooling air enters the motor from the compressor, it is heated and then returns to the compressor outlet. This increases the inlet temperature of the combustion chamber combustion air, which can improve combustion efficiency and save aviation fuel.

[0011] The high-temperature, high-speed motor is embedded in the aircraft engine as a starter / generator to achieve direct electric starting of the engine, eliminating the drive shaft and auxiliary gearbox (AGB) between the traditional aircraft engine shaft and the motor, effectively reducing the weight and overall size of the engine. The high-temperature, high-speed motor is highly integrated with the engine and operates as a single system, using the high speed on the high-pressure shaft to more efficiently convert mechanical energy to electrical energy. The high-temperature, high-speed motor can meet the requirements of reliable operation at an ambient temperature of 300°C, with a maximum efficiency of more than 90%. It can not only work stably under high-intensity and high-vibration conditions of mechanical, thermal, electromagnetic loads and overloads, but also operate safely under high-speed (15183r / min) conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the air system of a CFM56 aircraft engine in the prior art.

[0013] Figure 2 It is a schematic diagram of the cooling scheme of an aircraft engine with an embedded high-temperature and high-speed motor in the present invention.

[0014] Figure 3 It is a schematic diagram of the flow path of cooling air inside the high-temperature and high-speed motor in the present invention. DETAILED DESCRIPTION

[0015] like Figure 1As shown in the figure, the CFM56 aircraft engine is a twin-rotor turbofan engine, and the total cooling air flow accounts for 14% of the total flow of the core engine. It is mainly composed of 6 cooling air routes to form a complex air system. The first cooling air route is led from the opening on the inner wall of the intermediate casing between the high and low pressure compressors through a duct to the cavity A between the rear bearing of the low pressure compressor and the front bearing of the high pressure compressor.

[0016] like Figure 2 As shown, an aircraft engine with an embedded high-temperature and high-speed motor in this embodiment includes a fan 100, a low-pressure compressor 200, a high-temperature and high-speed motor 300, a high-pressure compressor 400, a combustion chamber 500, a high-pressure turbine 600, a low-pressure turbine 700 and a tail nozzle 800. A high-pressure shaft 900 supports the low-pressure compressor 200, the high-temperature and high-speed motor 300 and the high-pressure compressor 400. The high-temperature and high-speed motor 300 is located between the low-pressure compressor 200 and the high-pressure compressor 300.

[0017] like Figure 3 As shown, the high-temperature high-speed motor 300 includes a housing 301, a stator 302 and a rotor 305 located in the housing 301, a winding 303 is provided on the stator 302, the rotor 305 is fixedly sleeved on the high-pressure shaft 900, the stator 302 is sleeved on the outside of the rotor 305, and the housing is connected to the high-pressure shaft 900 through a bearing 304. A plurality of through holes are provided on the front and rear faces of the housing 301, and the through holes on the front and rear faces of the high-temperature high-speed motor are uniformly arranged in the circumferential direction, and the through holes are cylindrical holes, and the through holes on the front face of the housing correspond to the through holes on the rear face of the housing one by one, and the axis of the through holes on the front face coincides with the axis of the corresponding through holes on the rear face, and the axis of the through holes on the front and rear faces of the housing pass through the gap between the stator and the rotor of the high-temperature high-speed motor, and the through holes on the front face connect the interior of the high-temperature high-speed motor with the air outlet of the low-pressure compressor, and the through holes on the rear face connect the interior of the high-temperature high-speed motor with the air inlet of the high-pressure compressor. The cooling air enters the motor through a circumferentially uniform array of cylindrical holes (inner diameter 10 mm) at one end of the motor, first cooling the motor end wall, and then cooling the motor through the air gap between the rotor and the stator. The cooled air flows out through the circumferentially uniformly arranged cylindrical holes at the other end and returns to the high-pressure compressor inlet.

[0018] The high-temperature, high-speed motor is embedded in the aircraft engine as a starter / generator to achieve direct electric starting of the engine, eliminating the transmission shaft and auxiliary gearbox (AGB) between the traditional aircraft engine shaft and the motor, effectively reducing the engine weight and overall size.

[0019] The high-temperature, high-speed motor is specifically located at the front end of the high-pressure shaft of the aircraft engine. The high-temperature, high-speed motor is highly integrated with the engine and operates as a single system, utilizing the high speed on the high-pressure shaft to more efficiently convert mechanical energy into electrical energy.

[0020] The high-temperature, high-speed motor can operate reliably at an ambient temperature of 300°C, with a maximum efficiency of over 90%. It can not only work stably under high-intensity and high-vibration conditions of mechanical, thermal, electromagnetic loads and overloads, but also operate safely at high speeds (15183r / min).

[0021] Based on the powerful application background of high-temperature and high-speed motors in MEA, AEA and MEE, the motor is placed in the entire aircraft engine system to study its cooling solution. The motor is cooled directly using the commonly used cooling medium (air) of the engine, which is perfectly compatible with the advanced cooling method of aircraft engines.

[0022] Directly utilizing the huge flow of air generated in the axial direction during the operation of the aircraft engine for unconventional cooling has the following advantages: (1) The cooling air is directly introduced from the No. 1 air path of the turbofan engine compressor without the need for an additional air source; (2) The cooling air flows through the motor and then returns to the high-pressure compressor inlet, which has little effect on the engine thrust; (3) The high-temperature and high-speed motor is used as a heat storage body in the combustion chamber of the aircraft engine. This not only increases the combustion air inlet temperature of the combustion chamber, but also improves combustion efficiency and saves aviation fuel.

Claims

1. An aircraft engine with a built-in high-temperature and high-speed motor, characterized in that: It includes a high-pressure shaft and a low-pressure compressor supported by the high-pressure shaft, a high-temperature high-speed motor, and a high-pressure compressor. The high-temperature high-speed motor is located between the low-pressure compressor and the high-pressure compressor. The high-temperature high-speed motor includes a casing, a stator and a rotor located in the casing. The rotor is fixedly sleeved on the high-pressure shaft, and the stator is sleeved on the outside of the rotor. A plurality of through holes are arranged on the front end face and the rear end face of the casing. The through holes on the front end face connect the interior of the high-temperature high-speed motor with the air outlet of the low-pressure compressor, and the through holes on the rear end face connect the interior of the high-temperature high-speed motor with the air inlet of the high-pressure compressor.

2. The aircraft engine according to claim 1, characterized in that: The through holes on the front end face and the rear end face of the high-temperature high-speed motor are evenly arranged in the circumferential direction.

3. The aircraft engine according to claim 2, characterized in that: The through hole is a cylindrical hole.

4. The aircraft engine according to claim 2, characterized in that: The through holes on the front end surface of the housing correspond to the through holes on the rear end surface of the housing one by one, and the axes of the through holes on the front end surface coincide with the axes of the corresponding through holes on the rear end surface.

5. The aircraft engine according to claim 4, characterized in that: The axes of the through holes on the front and rear surfaces of the casing pass through the gap between the stator and the rotor of the high-temperature and high-speed motor.

6. The aircraft engine according to claim 1, characterized in that: Also included is a fan located at the front end of the low-pressure compressor.

7. The aircraft engine according to claim 2, characterized in that: It also includes a combustion chamber located at the rear end of the high-pressure compressor, a high-pressure turbine, a low-pressure turbine and a tail nozzle.

8. A method for cooling a high-temperature, high-speed motor of an aircraft engine according to claim 1, characterized in that: Part of the air that has increased its flow and pressure through the low-pressure compressor is introduced into the casing through the through hole on the front end face of the high-temperature and high-speed motor casing. After cooling the high-temperature and high-speed motor, the air is heated and returns to the inlet of the high-pressure compressor from the through hole on the rear end face of the high-temperature and high-speed motor casing.

9. The cooling method according to claim 1, characterized in that: The air introduced from the through hole on the front end face of the casing flows through the gap between the stator and the rotor of the high-temperature and high-speed motor, and then flows out from the through hole on the rear end face of the casing.

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