High-lift-limit and high-power-to-weight-ratio auxiliary power device and airplane

Abstract

The invention belongs to the technical field of aviation, and discloses a high-rise-limit and high-power-to-weight-ratio auxiliary power device and an airplane, and the device comprises an air inlet channel, a load air compressor, a core air compressor, a double-ring-cavity combustion chamber and a contra-rotating turbine; the load gas compressor and the core gas compressor are arranged at the downstream of the gas inlet channel, the load gas compressor introduces gas and supplies the gas to an environment control subsystem and a starting subsystem of the aircraft, the core gas compressor supercharges the gas flow of the gas inlet channel and then supplies the supercharged gas flow to the double-ring-cavity combustion chamber, and the double-ring-cavity combustion chamber provides power for the contra-rotating turbine; wherein the contra-rotating turbine comprises a front-row turbine rotor and a rear-row turbine rotor, the front-row turbine rotor and the rear-row turbine rotor are opposite in rotating direction, the front-row turbine rotor is coaxial with a rotating shaft of the core gas compressor, and the rear-row turbine rotor is coaxial with a rotating shaft of the load gas compressor. The device has the advantages of being compact, efficient and wide in stable working speed range, the aerodynamic performance and the power-to-weight ratio of the auxiliary power device at the high altitude can be improved, and the high-altitude flight requirement of an aircraft in the future is met.

Description

Technical Field

[0001] The invention belongs to the field of aviation technology, and relates to an auxiliary power device and an aircraft, and in particular to an auxiliary power device and an aircraft with a high ceiling and a high power-to-weight ratio. Background Art

[0002] The auxiliary power unit is a set of small engines installed on the aircraft that is independent of any external energy and is a self-contained system. It is used to provide auxiliary energy such as electricity and compressed air for starting the aircraft engine and ground maintenance. It plays an important role in improving the safety and autonomous security of the aircraft. There are more than a hundred products, with power ranging from tens of kilowatts to thousands of kilowatts. It has become an indispensable key airborne equipment for modern military and civilian aircraft.

[0003] Internationally, aviation powers such as the United States, Russia, and France attach great importance to auxiliary power units and have established their own professional research and development units for auxiliary power units. In China, although the development of auxiliary power units has made certain progress and basically meets the development needs of the third and fourth generation aircraft and barely supports the development of the fifth generation aircraft, there is still a lack of auxiliary power units with high ceilings and high power-to-weight ratios. With the increase in the flight envelope of future aircraft, the traditional auxiliary power unit structure layout will be difficult to meet, and there is an urgent need to innovate and develop the layout structure of the auxiliary power unit to improve the aerodynamic performance and power-to-weight ratio of the auxiliary power unit at high altitudes to meet the functional performance requirements of future aircraft.

[0004] As for the counter-rotating turbine technology, it was first proposed in the field of aeroengines. However, due to in-depth research, scholars have found that with the counter-rotating turbine, as the speed decreases, the low-pressure turbine inlet airflow angle deviates from the high-efficiency area, which can easily cause the efficiency of the counter-rotating turbine engine to drop sharply. Although in principle, the low-pressure turbine directly works by using the circumferential pre-swirl generated by the high-pressure turbine rotor outlet airflow, eliminating the guide vanes and reducing the weight of the parts, due to problems such as low efficiency at low reduced speeds, the counter-rotating turbine technology has not been widely used in engineering practice in the field of aeroengines. Compared with traditional aeroengines, the auxiliary power unit, as a secondary power source, often works at 90% to 115% of the reduced speed, and the speed working range is relatively narrow. The use of counter-rotating turbines is theoretically feasible and can further reduce the weight of the body, which is worth exploring and studying. Summary of the invention

[0005] In order to solve the problem that the existing auxiliary power unit structural layout has poor performance and cannot meet the functional performance requirements of future aircraft, the present invention provides a high-ceiling, high-power-to-weight ratio auxiliary power unit, which maximizes the aerodynamic performance and power-to-weight ratio of the auxiliary power unit at high altitudes and meets the functional performance requirements of future aircraft.

[0006] The technical solution of the present invention is as follows:

[0007] An auxiliary power unit with high ceiling and high power-to-weight ratio comprises an air inlet, a load compressor, a core compressor, a double-annular combustion chamber and a counter-rotating turbine; the load compressor and the core compressor are arranged downstream of the air inlet, the load compressor bleeds air to supply the environmental control subsystem and the starting subsystem of the aircraft, the core compressor pressurizes the airflow in the air inlet and then supplies it to the double-annular combustion chamber, and the double-annular combustion chamber provides power for the counter-rotating turbine; wherein the counter-rotating turbine comprises a front turbine rotor and a rear turbine rotor, the front turbine rotor and the rear turbine rotor rotate in opposite directions, the front turbine rotor is coaxial with the rotating shaft of the core compressor, and the rear turbine rotor is coaxial with the rotating shaft of the load compressor.

[0008] Furthermore, the load compressor includes an inlet guide vane and a load impeller, and the rear turbine rotor is coaxial with the load impeller.

[0009] Furthermore, the core compressor includes a centrifugal impeller with splitter blades and a tubular diffuser. The centrifugal impeller pressurizes the airflow from the air inlet duct, and the tubular diffuser decelerates and pressurizes the airflow. The front turbine rotor is coaxial with the centrifugal impeller.

[0010] Furthermore, the dual-annular combustion chamber drives the front turbine rotor.

[0011] Furthermore, the counter-rotating turbine also includes a turbine inlet guide vane, which controls the airflow from the double-annular combustion chamber to flow to the front turbine rotor, the front turbine rotor decompresses the airflow, and then controls the airflow to pass through the rear turbine rotor, the rear turbine rotor further decompresses the airflow, and finally controls the airflow to be discharged.

[0012] Furthermore, the dual-annular combustion chamber is divided into an outer annular cavity and an inner annular cavity; during the starting and slow running stages of the auxiliary power unit, fuel is only supplied to the outer annular cavity; under design conditions, fuel is supplied to both annular cavities at the same time, and the design conditions include ground maintenance conditions and maximum air bleed conditions.

[0013] Furthermore, the optimal operating condition of the counter-rotating turbine is designed to be within 90% to 115% of the converted speed, the pressure drop ratio of the front turbine rotor to the rear turbine rotor is 1.6:1 to 1.1:1, and the overall pressure drop ratio of the counter-rotating turbine is 4:1 to 9:1.

[0014] Furthermore, the inlet guide vanes of the load compressor adopt a variable curvature design, the inlet angle remains unchanged, and the outlet angle is adjusted by the joint drive of 1 to 3 motors; the variable angle of the air outlet of the load compressor is 0 to 90°, and the number of inlet guide vanes of the load compressor is 20 to 60; and 6 to 15 mm through holes are punched on 3 to 6 blades at different circumferential positions to facilitate borescope maintenance and inspection.

[0015] Furthermore, the number of splitter blades of the centrifugal impeller of the core compressor is 1 to 3; the casing of the centrifugal impeller is arranged with stabilizing holes, and the number of the stabilizing holes is 10 to 40.

[0016] Furthermore, the starter-generator is composed of a stator assembly, a rotor assembly, and a cooling assembly to realize the integration of power generation and starting functions of the auxiliary power unit, and the power generation capacity of the starter-generator is 0 to 1200 kW.

[0017] Further, the electronic controller is used to control the reverse operation of the dual shafts of the auxiliary power unit, and is provided with a health management and fault diagnosis module for real-time monitoring of the stable operation status of the auxiliary power unit under different working conditions;

[0018] Furthermore, the air inlet is formed by resin-based composite materials, the load compressor and the core compressor are formed by titanium-aluminum alloy; the double-annular combustion chamber is formed by metal-based composite materials; and the counter-rotating turbine is cast by high-temperature alloy to achieve light weight and long life requirements.

[0019] Furthermore, the power level of the auxiliary power unit is 100-1500kW.

[0020] Furthermore, an aircraft comprises any auxiliary power unit as described above.

[0021] The beneficial effects of the present invention are as follows:

[0022] The high-ceiling, high-power-to-weight ratio auxiliary power unit of the present invention has the advantages of being compact, efficient, and having a wide stable operating speed range, which is beneficial to improving the aerodynamic performance and power-to-weight ratio of the auxiliary power unit at high altitudes and meeting the high-altitude flight requirements of future aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solution of the implementation method of the patent of the present invention, the following is a brief introduction to the drawings required for use in the implementation method. It should be understood that the following drawings only show certain embodiments of the patent of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 is a schematic diagram of a conventional auxiliary power unit.

[0025] Figure 2 It is a structural diagram of the auxiliary power unit disclosed in the present invention.

[0026] Figure 3 Schematic diagram of a counter-rotating turbine disclosed in the present invention.

[0027] Among them, 1-inlet duct, 2-inlet guide vane, 3-load impeller, 4-centrifugal impeller, 5-wedge-shaped diffuser, 6-annular combustion chamber, 7-two-stage turbine, 8-exhaust section, 9-gearbox, 10-variable curvature adjustable blades, 11-tubular diffuser, 12-double annular combustion chamber, 13-counter-rotating turbine, 14-turbine inlet guide vane, 15-front row turbine rotor, 16-rear row turbine rotor. DETAILED DESCRIPTION

[0028] This section is an embodiment of the present invention, which is used to explain and illustrate the technical solution of the present invention. In the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate directions or positional relationships as given in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or case referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implying the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be interpreted in a broad sense, for example, it can be a fixed connection, a detachable connection or an integrated connection; it can be a mechanical connection or a point connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0031] Embodiment 1:

[0032] An auxiliary power unit with high ceiling and high power-to-weight ratio comprises an air inlet 1, a load compressor, a core compressor, a double-annular combustion chamber and a counter-rotating turbine 13; the load compressor and the core compressor are arranged downstream of the air inlet 1, the load compressor bleeds air to supply the environmental control subsystem and the starting subsystem of the aircraft, the core compressor pressurizes the airflow of the air inlet 1 and then supplies it to the double-annular combustion chamber 12, and the double-annular combustion chamber 12 provides power for the counter-rotating turbine 13; wherein the counter-rotating turbine 13 comprises a front turbine rotor 15 and a rear turbine rotor 16, the front turbine rotor 15 and the rear turbine rotor 16 rotate in opposite directions, the front turbine rotor 15 is coaxial with the rotating shaft of the core compressor, and the rear turbine rotor 16 is coaxial with the rotating shaft of the load compressor.

[0033] The load compressor includes an inlet guide vane and a load impeller 3 , and the rear turbine rotor 16 is coaxial with the load impeller 3 .

[0034] The core compressor includes a centrifugal impeller 4 with splitter blades and a tubular diffuser 11. The centrifugal impeller 4 pressurizes the airflow from the air inlet 1, and the tubular diffuser 11 decelerates and pressurizes the airflow; the front turbine rotor 15 is coaxial with the centrifugal impeller 4.

[0035] The double-annular combustion chamber 12 drives the front turbine rotor 15 .

[0036] The counter-rotating turbine 13 also includes a turbine inlet guide vane 14, which controls the airflow from the double-annular combustion chamber to flow to the front turbine rotor 15. The front turbine rotor decompresses the airflow and then controls the airflow to pass through the rear turbine rotor 16. The rear turbine rotor further decompresses the airflow and finally controls the airflow to be discharged.

[0037] The double-annular combustion chamber 12 is divided into an outer annular cavity and an inner annular cavity; during the auxiliary power unit starting and slow running stages, only the outer annular cavity is supplied with fuel; under design conditions, fuel is supplied to both annular cavities at the same time, and the design conditions include ground maintenance conditions and maximum air bleed conditions.

[0038] The optimal operating condition of the counter-rotating turbine 13 is designed to be within 90% to 115% of the converted speed, the pressure drop ratio of the front turbine rotor 15 to the rear turbine rotor 16 is 1.6:1 to 1.1:1, and the overall pressure drop ratio of the counter-rotating turbine 13 is 4:1 to 9:1.

[0039] The inlet guide vanes of the load compressor adopt a variable curvature design, the inlet angle remains unchanged, and the outlet angle is adjusted by the joint drive of 1 to 3 motors; the variable angle of the load compressor outlet is 0 to 90°, and the number of the inlet guide vanes of the load compressor is 20 to 60; and 6 to 15 mm through holes are punched on 3 to 6 blades at different circumferential positions to facilitate borescope maintenance and inspection.

[0040] The number of the splitter blades of the centrifugal impeller 4 of the core compressor is 1 to 3; the casing of the centrifugal impeller is arranged with stabilizing holes, and the number of the stabilizing holes is 10 to 40.

[0041] The starter-generator is composed of a stator assembly, a rotor assembly, and a cooling assembly to realize the integration of power generation and starting functions of the auxiliary power device. The power generation capacity of the starter-generator is 0 to 1200 kW.

[0042] An electronic controller is used to control the reverse operation of the dual shafts of the auxiliary power unit, and is equipped with a health management and fault diagnosis module to monitor the stable operation status of the auxiliary power unit under different working conditions in real time;

[0043] The air inlet 1 is formed by a resin-based composite material, the load compressor and the core compressor are formed by a titanium-aluminum alloy; the double-annular combustion chamber 12 is formed by a metal-based composite material; and the counter-rotating turbine is cast by a high-temperature alloy 13 to achieve light weight and long life requirements.

[0044] The power level of the auxiliary power unit is 100 to 1500kW.

[0045] An aircraft comprises any one of the auxiliary power units described above.

[0046] Embodiment 2:

[0047] The present invention aims to provide an auxiliary power unit and an aircraft, which have the advantages of being compact, efficient, stable and having a wide operating speed range, are conducive to improving the aerodynamic performance and power-to-weight ratio of the auxiliary power unit at high altitudes, reducing the fuel consumption rate of the aircraft, and meeting the high-altitude flight needs of future aircraft.

[0048] See also Figure 1 The conventional auxiliary power unit comprises an air inlet 1, an inlet adjustable blade 2, a load impeller 3, a centrifugal impeller 4, a wedge-shaped diffuser 5, an annular combustion chamber 6, a two-stage turbine 7, an exhaust section 8, and a gear box 9. The auxiliary power unit has a long axial length and a heavy weight.

[0049] See also Figure 2 and Figure 3 The auxiliary power unit disclosed in the present invention comprises an air inlet 1, a variable camber adjustable blade 10, a load impeller 3, a centrifugal impeller 4, a tubular diffuser 11, a double annular combustion chamber 12, a counter-rotating turbine 13, and an exhaust section 8; the counter-rotating turbine 13 comprises a turbine inlet guide vane 14, a front row turbine rotor 15, and a rear row turbine rotor 16, and the front row turbine rotor 15 and the rear row turbine rotor 16 rotate in opposite directions;

[0050] The starter-generator is arranged on the gearbox 9; the stator assembly of the starter-generator is wound around the circumference of the rotor assembly; the rotor assembly is connected to the gearbox through a spline shaft; the cooling assembly is located on the periphery of the stator assembly and is mainly cooled by lubricating oil; when the auxiliary power unit is started, the starter-generator is driven by an external power supply to drive the centrifugal impeller and the front turbine rotor to rotate coaxially; when the auxiliary power unit reaches a preset speed, the starter-generator starts to generate electricity to provide electrical energy for other equipment on the aircraft; it realizes the integrated design of the starter and the generator, effectively reducing the weight of the auxiliary power unit;

[0051] The above layout enables the auxiliary power unit to operate stably at an altitude of 0-18km, with less deterioration in aerodynamic performance under high-altitude and low Reynolds number conditions, strong high-altitude ignition capability, and improved auxiliary power unit fuel consumption rate and output shaft power characteristics.

[0052] The core compressor is composed of a centrifugal impeller with splitter blades and a compact tubular diffuser. The centrifugal impeller pressurizes the airflow from the air inlet, and the tubular diffuser decelerates and pressurizes the airflow.

[0053] The double-annular combustion chamber ignites and burns the airflow from the core compressor;

[0054] The counter-rotating turbine is composed of a turbine inlet guide vane, a front turbine rotor, and a rear turbine rotor. The front turbine rotor and the rear turbine rotor rotate in opposite directions. The turbine inlet guide vane controls the airflow from the double-annular combustion chamber to flow to the front turbine rotor. The front turbine rotor decompresses the airflow and then controls the airflow to pass through the rear turbine rotor. The rear turbine rotor decompresses the airflow again and finally controls the airflow to flow to the exhaust section.

[0055] The accessories include a gearbox, a starter generator, an electronic controller, an electric fuel regulator, etc.

[0056] Preferably, the load compressor inlet guide vane adopts a variable camber design, the inlet angle remains unchanged, and the outlet angle is adjusted by 1 to 3 motors. The variable angle is 60°, the number of blades is 35, and 8mm through holes are punched on 3 to 6 blades at different circumferential positions to facilitate borescope maintenance and inspection.

[0057] Preferably, the number of splitter blades of the centrifugal impeller of the core compressor is 1; the casing of the centrifugal impeller is arranged with stabilizing holes, and the number of stabilizing holes is 22.

[0058] Preferably, the dual-annular cavity combustion chamber is divided into an outer annular cavity and an inner annular cavity; during the starting and slow-running stages of the auxiliary power unit, only the outer annular cavity is supplied with oil. At this time, the oil-to-gas ratio of the outer annular cavity is high, the airflow velocity is low, and the combustion is maintained for a long time, which is beneficial to reducing pollutant emissions. It also makes it easy for the auxiliary power unit to start the block at high altitude and not prone to flameout. Under the designed operating conditions, oil is supplied to the two annular cavities at the same time. At this time, the oil-to-gas ratio is low, the airflow velocity is high, the combustion is maintained for a short time, and the pollutant emissions are low. At the same time, an electric fuel regulator is used to adjust the fuel rules of different operating conditions to enhance the high-altitude ignition capability.

[0059] Preferably, the counter-rotating turbine is designed to strictly ensure good performance within 90% to 115% of the converted speed, the pressure drop ratio of the front and rear rows of rotors is 1.5, and the total pressure drop ratio is 4.5.

[0060] Preferably, the starter-generator is composed of a stator assembly, a rotor assembly, and a cooling assembly to realize the integration of power generation and starting functions of the auxiliary power unit, and the starter-generator has a power generation capacity of 200kW.

[0061] Preferably, the electronic controller is used to control the reverse operation of the dual shafts of the auxiliary power unit, and is provided with a health management and fault diagnosis module for real-time monitoring of the stable operation state of the auxiliary power unit under different working conditions;

[0062] Preferably, the air inlet is formed by resin-based composite materials, the load compressor and the core compressor are formed by titanium-aluminum alloy; the double-annular combustion chamber is formed by metal-based composite materials; the counter-rotating turbine is cast by high-temperature alloy, and the exhaust section is formed by ceramic-based composite materials, so as to achieve light weight and long life requirements.

[0063] Preferably, the auxiliary power unit has a power level of 500 kW.

[0064] Preferably, an aircraft comprises any one of the auxiliary power units described above.

[0065] The above is only a specific embodiment of the present invention, and the present invention is described in detail. The unexplained part is a conventional technology. However, the protection scope of the present invention is not limited to this. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A high ceiling, high power-to-weight ratio auxiliary power unit, It is characterized in that The invention comprises an air inlet (1), a load compressor, a core compressor, a double annular combustion chamber and a counter-rotating turbine (13); the load compressor and the core compressor are arranged downstream of the air inlet (1); the load compressor bleeds air to supply the environmental control subsystem and the starting subsystem of the aircraft; the core compressor pressurizes the airflow of the air inlet (1) and supplies it to the double annular combustion chamber (12); the double annular combustion chamber (12) provides power for the counter-rotating turbine (13); wherein the counter-rotating turbine (13) comprises a front turbine rotor (15) and a rear turbine rotor (16); the front turbine rotor (15) and the rear turbine rotor (16) rotate in opposite directions; the front turbine rotor (15) is coaxial with the rotation axis of the core compressor; and the rear turbine rotor (16) is coaxial with the rotation axis of the load compressor.

2. A high ceiling, high power-to-weight ratio auxiliary power unit according to claim 1, It is characterized in that The load compressor comprises an inlet guide vane and a load impeller (3), and a rear turbine rotor (16) is coaxial with the load impeller (3).

3. A high ceiling, high power-to-weight ratio auxiliary power unit according to claim 1, It is characterized in that The core compressor comprises a centrifugal impeller (4) with splitter blades and a tubular diffuser (11). The centrifugal impeller (4) performs pressurization processing on the airflow from the air inlet (1), and the tubular diffuser (11) further reduces the speed and pressurizes the airflow. The front turbine rotor (15) is coaxial with the centrifugal impeller (4).

4. A high ceiling, high power-to-weight ratio auxiliary power unit according to claim 3, It is characterized in that The number of the splitter blades of the centrifugal impeller (4) of the core compressor is 1 to 3; the casing of the centrifugal impeller is arranged with stabilizing holes, and the number of the stabilizing holes is 10 to 40.

5. A high ceiling, high power-to-weight ratio auxiliary power unit according to claim 1, It is characterized in that The double-annular combustion chamber (12) drives the front turbine rotor (15).

6. A high ceiling, high power-to-weight ratio auxiliary power unit according to claim 1, It is characterized in that The counter-rotating turbine (13) further includes a turbine inlet guide vane (14), which controls the airflow from the double-annular combustion chamber to flow to the front turbine rotor (15), the front turbine rotor decompresses the airflow, and then controls the airflow to pass through the rear turbine rotor (16), the rear turbine rotor further decompresses the airflow, and finally controls the airflow to be discharged.

7. A high ceiling, high power-to-weight ratio auxiliary power unit according to claim 1, It is characterized in that The double-annular combustion chamber (12) is divided into an outer annular cavity and an inner annular cavity; during the auxiliary power unit starting and slow running stages, oil is only supplied to the outer annular cavity; under design operating conditions, oil is simultaneously supplied to the two annular cavities, and the design operating conditions include ground maintenance operating conditions and maximum air bleed operating conditions.

8. A high ceiling, high power-to-weight ratio auxiliary power unit according to claim 1, It is characterized in that The optimal operating condition of the counter-rotating turbine (13) is designed to be within a range of 90% to 115% of the converted speed, the pressure drop ratio of the front turbine rotor (15) to the rear turbine rotor (16) is 1.6:1 to 1.1:1, and the overall pressure drop ratio of the counter-rotating turbine (13) is 4:1 to 9:

1.

9. A high ceiling, high power-to-weight ratio auxiliary power unit according to claim 1, It is characterized in that The inlet guide vanes of the load compressor adopt a variable curvature design, the inlet angle remains unchanged, and the outlet angle is adjusted by the joint drive of 1 to 3 motors; the variable angle of the load compressor outlet is 0 to 90°, and the number of the inlet guide vanes of the load compressor is 20 to 60; and 6 to 15 mm through holes are punched on 3 to 6 blades at different circumferential positions to facilitate borescope maintenance and inspection.

10. An aircraft, It is characterized in that Use a high ceiling, high power-to-weight ratio auxiliary power unit as described in any one of claims 1-9.

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