Heat-electricity coupling driven indirect cooling and heat regeneration mixed exhaust turbofan engine

Abstract

The invention provides a heat-electricity coupling driven indirect cooling and heat regeneration mixed exhaust turbofan engine, and belongs to the technical field of aero-engines, the heat-electricity coupling driven indirect cooling and heat regeneration mixed exhaust turbofan engine comprises an engine body, and an indirect cooling and heat regeneration heat exchange system, a transmission system and an electric propulsion system are arranged in the engine body; the electric propulsion system is connected with the transmission system and drives the transmission system to do work, the transmission system and the electric propulsion system are both arranged at the middle section position of the engine body, and the indirect cooling heat regeneration heat exchange system is arranged at the head section position and the tail section position of the engine body. According to the heat-electricity coupling driven intercooling regenerative mixed exhaust turbofan engine, the solid oxide fuel cell is introduced, so that the thermodynamic cycle effective work of the engine is increased, the overall energy utilization rate of a propulsion system is remarkably improved, an optimal power supply degree design value interval is provided, and the power supply degree design value interval is optimized. And a design reference basis is provided for reasonable thermal-electric energy distribution of the corresponding propulsion system configuration in the design stage.

Description

Technical Field

[0001] The present invention relates to an intercooled recuperated mixed-flow turbofan engine driven by thermal-electric coupling, belonging to the technical field of aeroengines. Background Art

[0002] With the continuous improvement of the living standards of human beings and the increasing attention of the international community to environmental protection and energy conservation, future civil aircraft have put forward higher requirements for the "four properties" (safety, economy, comfort, and environmental protection). Currently, the mainstream of the currently active civil aircraft is high-subsonic civil aircraft, and its defects such as long transoceanic flight time and reduced comfort caused by its slow flight speed make it difficult to meet the future demand for rapid travel. The emergence of supersonic civil aircraft can greatly improve this problem. Therefore, supersonic civil aircraft have become one of the important directions for the future development of the world's civil aircraft.

[0003] The requirements of supersonic civil aircraft for power plants are "four lows and one high", namely low sonic boom, low noise, low emissions, low fuel consumption, and high thrust for supersonic cruise. Currently, large bypass ratio turbofan engines are generally selected to provide power for the currently active subsonic civil aircraft in the world. However, the large lateral dimension and frontal area caused by the large bypass ratio characteristics of this engine configuration make it unsuitable for supersonic flight. In addition, whether it is a turbojet engine or a small bypass ratio turbofan engine, the high-speed airflow ejected from its nozzle will cause relatively large flight noise, and significantly reduce the propulsion efficiency, with a relatively high fuel consumption rate and unsatisfactory economy in the subsonic state. In recent years, with the development of various technologies such as turbine materials and blade cooling, the realization of non-afterburning supersonic cruise has become possible. At the same time, in order to achieve better high-speed performance, medium bypass ratio turbofan engines have increasingly attracted the attention of researchers.

[0004] (1) In 2010, NASA in the United States achieved a cruise of a 16 km, 1.6 Ma airliner using a medium bypass ratio non-afterburning dual-rotor turbofan engine in the "N+2" stage of the CST program, and reduced noise through throttling during the takeoff stage.

[0005] (2) In 2018, GE in the United States launched the Affinity engine as the power plant for the supersonic business jet AS2 jointly developed by Airbus in France and Aerion in the United States. The engine configuration is a two-shaft medium bypass ratio turbofan engine. For the low-pressure rotor, it has a 2-stage wide-chord integral bladed disk fan and a 2-stage low-pressure turbine, and for the high-pressure rotor, it has a 9-stage high-pressure compressor and a single-stage high-pressure turbine, and can achieve a 1.4 Ma supersonic cruise.

[0006] (3) In 2022, Boom Company in the United States cooperated with Kratos Company to develop the "Symphony" engine for its "Overture" supersonic airliner. The "Overture" airliner is equipped with 4 engines, achieving a supersonic cruise of 1.7 Ma and a range of 7,871 km. The "Symphony" engine is a dual-rotor medium bypass ratio turbofan engine, and its design features include: an axisymmetric supersonic inlet, a single-stage fan with a low-noise design, a high-pressure turbine with passive cooling, no afterburner, and a variable-geometry low-noise nozzle.

[0007] Based on the above research findings, regarding the key technical difficulties existing in the power plants of supersonic civil aircraft, countries around the world have carried out research for many years and proposed and verified various solutions. However, the current development of mixed-exhaust turbofan technology has not fully overcome the inherent contradiction among "low noise", "low fuel consumption" and "low emissions": the mainstream method of reducing the exhaust velocity still takes increasing the bypass ratio as the core goal, but the insufficient specific thrust of supersonic cruise caused by this requires increasing the turbine inlet temperature for compensation, which may lead to further deterioration of fuel consumption and emissions. At the same time, due to the strong coupling between the high-pressure and low-pressure rotors of traditional mixed-exhaust turbofan engines, their adaptability to wide flight condition changes is relatively poor, and it is impossible to optimize the wide range of operating points under a single condition. Summary of the Invention

[0008] The present invention provides an intercooled recuperated mixed-exhaust turbofan engine driven by thermoelectric coupling to solve the problems raised in the above background technology, aiming to further save energy, reduce emissions and reduce noise in civil aircraft power, and improve the inherent contradiction among "low noise", "low fuel consumption" and "low emissions".

[0009] To achieve the above object, the present invention provides an intercooled recuperated mixed-exhaust turbofan engine driven by thermoelectric coupling, including an engine body. An intercooled recuperated heat exchange system, a transmission system and an electric propulsion system are arranged inside the engine body. The electric propulsion system is connected to the transmission system and drives the transmission system to do work. Both the transmission system and the electric propulsion system are arranged at the middle section position of the engine body, and the intercooled recuperated heat exchange system is arranged at the front section and the rear section positions of the engine body.

[0010] Preferably, a fan, a high-pressure compressor, a main combustion chamber, a high-pressure turbine, a low-pressure turbine, a mixer and a main nozzle are sequentially arranged inside the engine body.

[0011] Preferably, the intercooled recuperated heat exchange system includes an intercooler and a recuperator. The recuperator is arranged at the outlet of the low-pressure turbine, and the intercooler is arranged at the inlet of the high-pressure compressor.

[0012] Preferably, the cold sources of the intermediate cooling heat exchanger and the regenerative heat exchanger are both liquid hydrogen.

[0013] Preferably, the electric propulsion system includes an electric motor, an energy transmission circuit, and a solid oxide fuel cell. The solid oxide fuel cell is disposed between the high-pressure compressor and the main combustion chamber. The solid oxide fuel cell converts the chemical energy in the hydrogen fuel into electrical energy and inputs the electrical energy into the electric motor through the energy transmission circuit.

[0014] Preferably, the transmission system is a gearbox, which internally is provided with two input shafts, an output shaft, and a plurality of mechanical gears; the output shaft is a high-pressure compressor shaft, on which a compressor rotor is provided. The two input shafts are respectively a motor shaft and a high-pressure turbine shaft, on which a high-pressure turbine rotor is provided, and a motor rotor is provided on the motor shaft;

[0015] The motor rotor and the high-pressure turbine rotor are both connected to the compressor rotor through the gearbox and drive it to do work.

[0016] Preferably, an inner flow path and an outer flow path are provided inside the engine body.

[0017] Preferably, the solid oxide fuel cell is a high-temperature cell with an operating temperature of 800°C - 1100°C.

[0018] Therefore, the present invention adopts the above-mentioned intercooled regenerative mixed-exhaust turbofan engine driven by thermal-electric coupling, and has the following beneficial effects:

[0019] (1) Compared with the traditional hydrogen energy intercooled regenerative medium bypass ratio mixed-exhaust turbofan engine, the introduction of SOFC in this device increases the effective work of the engine's thermodynamic cycle, significantly improves the overall energy utilization rate of the propulsion system, and provides an optimal power supply design value range, providing a design reference basis for the reasonable thermal-electric energy distribution of the corresponding propulsion system configuration in the design stage.

[0020] (2) On the premise of ensuring the same other design parameters and achieving the same thrust, the present invention can achieve a lower fuel consumption rate and a smaller engine inlet flow rate compared with the traditional scheme, corresponding to better economy during flight.

[0021] (3) Due to the introduction of the intercooling heat exchanger in this device, the outlet temperature of the high-pressure compressor can be satisfied by pre-cooling the inlet air flow of the compressor, so the deterioration of the engine performance caused by the reduction of rotation and throttling can be delayed. As the flight speed increases, the thrust is increased, the fuel consumption rate is reduced, and at the same time, the flight speed range is expanded.

[0022] (4) During the implementation of thrust throttling by this device, the power supply degree gradually increases, and the temperature before the turbine monotonically decreases, achieving better cruise economy and higher working reliability of turbine components compared with traditional configurations.

[0023] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Brief Description of the Drawings

[0024] Figure 1 It is a schematic diagram of the HIR-SOFC-MTF configuration of a hydrogen-cooled intercooled recuperated mixed-exhaust turbofan engine with thermoelectric coupling drive in an embodiment of the present invention;

[0025] Figure 2 It is a schematic diagram of the key cross-section numbering of the HIR-SOFC-MTF configuration in an embodiment of a thermoelectric coupling drive intercooled recuperated mixed-exhaust turbofan engine of the present invention;

[0026] Figure 3 It is a schematic diagram of the intercooled recuperated heat exchange system module in an embodiment of a thermoelectric coupling drive intercooled recuperated mixed-exhaust turbofan engine of the present invention;

[0027] Figure 4 It is a comparison diagram of the thermodynamic cycles of the baseline and advanced schemes in an embodiment of a thermoelectric coupling drive intercooled recuperated mixed-exhaust turbofan engine of the present invention;

[0028] Figure 5 It is a comparison diagram of the energy utilization effects of the baseline and advanced schemes in an embodiment of a thermoelectric coupling drive intercooled recuperated mixed-exhaust turbofan engine of the present invention;

[0029] Reference Numerals: 101 - Fan; 102 - Intercooler; 103 - High-pressure Compressor; 104 - Solid Oxide Fuel Cell; 105 - Main Combustion Chamber; 106 - High-pressure Turbine; 107 - Low-pressure Turbine; 108 - Recuperator; 109 - Mixer; 110 - Main Nozzle; 111 - Transmission System; 112 - Electric Motor; 113 - Low-pressure Rotor; 114 - Compressor Rotor; 115 - Electric Motor Rotor; 116 - High-pressure Turbine Rotor. Embodiment Modes

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. Embodiments

[0032] Please refer toFigures 1-5 , the present invention provides a heat-electricity coupled-driven intermediate cooling and recuperative mixed-flow turbofan engine. Taking the traditional mixed-flow turbofan engine as the carrier, this embodiment proposes a heat-electricity coupled-driven hydrogen energy intermediate cooling and recuperative medium bypass ratio mixed-flow turbofan engine configuration HIR-SOFC-MTF that integrates the advantages of mixed-flow turbofan, intermediate cooling and recuperation, and fuel cell hybrid propulsion. It includes an engine body, and an intermediate cooling and recuperative heat exchange system, a transmission system 111, and an electric propulsion system are arranged inside the engine body. The electric propulsion system is connected to the transmission system 111 and drives the transmission system 111 to do work. Both the transmission system 111 and the electric propulsion system are arranged at the middle section position of the engine body, and the intermediate cooling and recuperative heat exchange system is arranged at the head section and the tail section positions of the engine body.

[0033] Inside the engine body, there are a fan 101, a high-pressure compressor 103, a main combustion chamber 105, a high-pressure turbine 106, a low-pressure turbine 107, a mixer 109, and a main nozzle 110 arranged in this way. The above structure is the structure of a traditional mixed-flow turbofan engine, and the traditional mixed-flow turbofan engine is a mature technology in the art. Therefore, the connection relationship of the above structure will not be elaborated here, and its position in the engine body can be referred to Figure 1 .

[0034] The intermediate cooling and recuperative heat exchange system includes an intercooler 102 and a recuperator 108. The recuperator 108 is arranged at the outlet of the low-pressure turbine 107, and the intercooler 102 is arranged at the inlet of the high-pressure compressor 103. The cold sources of both the intercooler 102 and the recuperator 108 are liquid hydrogen.

[0035] To facilitate the description of the thermodynamic process, the key flow path sections of the HIR-SOFC-MTF configuration are numbered, as Figure 2 shown: The mixed-flow turbofan engine used as the carrier has an outer bypass duct, and its adjustable geometric components are relatively limited, including the main nozzle throat area (A8) and the main nozzle outlet area (A9). The air flow passing through the mixed-flow turbofan engine enters from the inlet duct, is first compressed and pressurized by the fan 101, and then is divided into two paths: The first path flows through the intercooler 102, the high-pressure compressor 103, the solid oxide fuel cell 104, the combustion chamber 105, the high- and low-pressure turbines 106, and the recuperator 108 in the core duct; the other path enters the outer bypass duct. The two paths of air flow are mixed in the mixer 109 after the recuperator 108, and after the mixing is completed, they expand and accelerate from the same tail nozzle and are discharged at high speed to generate reaction thrust.

[0036] To balance the energy efficiency under both low-speed and high-speed flight conditions, this solution still adopts a high total pressure ratio design under low-speed conditions to ensure high efficiency at low speeds. Under high-speed conditions, the idea of precooling heat exchange is introduced, and "intercooling heat exchange" is used to reconcile the contradictions of insufficient energy efficiency and excessive heat exchange power in the high-speed section. The key reason for the insufficient high-speed energy efficiency is that the temperature at the compressor outlet exceeds the limit, which will cause problems such as insufficient blade strength of the compressor components or a sharp decline in component performance whether the engine reduces its speed or not. In the mainstream precooling heat exchange solutions, all the inlet airflows of the engine are cooled, which will lead to extremely high heat exchange power requirements for the heat exchanger, and its design size, weight, and total pressure loss will all increase sharply. This solution selects a mixed-flow turbofan engine as the carrier and adopts targeted intercooling heat exchange by taking advantage of the characteristics of the bypass airflow diversion. Since the temperature drop achieved by heat exchange of the bypass airflow of the fan cannot solve the problem of the excessive temperature at the compressor outlet, to avoid wasting heat exchange power, the intercooling heat exchanger is placed behind the core to specifically cool the airflow entering the core.

[0037] Considering the relatively limited installation space in the engine flow path, the intercooling heat exchanger 102 is arranged in front of the high-pressure compressor 103, and the recuperative heat exchanger 108 is arranged behind the low-pressure turbine 107. The specific structural form (including but not limited to plate heat exchangers, cross-flow / counter-flow cross-flow tube bundles, finned tube bundles, etc.) can be determined according to actual performance requirements and design constraints, and it is mainly responsible for the heat enthalpy energy exchange and transfer between part of the engine heat flow and the cold source liquid hydrogen.

[0038] The specific working principle is as follows Figure 3 As shown in the figure: The heat source input of the intercooling heat exchanger 102 is the heat flow that enters the core flow path from the outlet of the fan 101. The heat flow undergoes a temperature drop through heat exchange in the heat exchanger and enters the high-pressure compressor 103 for further pressurization after the heat exchange in the heat exchanger is completed; the heat source input of the recuperative heat exchanger 108 is the core flow path heat flow that flows out from the outlet of the low-pressure turbine 107. The heat flow undergoes a temperature drop through heat exchange in the heat exchanger and enters the mixer 109 to be mixed with the bypass flow path airflow after the heat exchange in the heat exchanger is completed. The cold sources of both the intercooling heat exchanger 102 and the recuperative heat exchanger 108 are liquid hydrogen. The liquid hydrogen is pumped out from the hydrogen storage tank and enters the heat exchanger to absorb the heat released by the heat source, thereby increasing the temperature and enthalpy value. After the heat exchange is completed, it carries the heat into the SOFC to participate in the electrochemical reaction or enters the main combustion chamber to participate in combustion. At the same time, the unreacted fuel in the SOFC also enters the main combustion chamber 105 to participate in combustion.

[0039] The electric propulsion system includes an electric motor (Motor) 112, an energy transmission circuit (Circuit), and a solid oxide fuel cell (SOFC) 104. The solid oxide fuel cell 104 is arranged between the high-pressure compressor 103 and the main combustion chamber 105. The solid oxide fuel cell 104 converts the chemical energy in the hydrogen fuel into electrical energy and inputs the electrical energy into the electric motor 112 through the energy transmission circuit.

[0040] The transmission system 111 is a gearbox that realizes the transmission of torque and mechanical power through the meshing of mechanical gears. It includes two input shafts, an output shaft and several mechanical gears inside. The input shafts are the motor 112 shaft and the high-pressure turbine 106 shaft respectively. A high-pressure turbine rotor is arranged on the high-pressure turbine shaft, and a motor rotor is arranged on the motor shaft. The output shaft is the high-pressure compressor 103 shaft, and a compressor rotor is arranged on the high-pressure compressor shaft. The motor rotor and the high-pressure turbine rotor are both connected to the compressor rotor through the gearbox and drive it to do work.

[0041] The SOFC converts the chemical energy in the hydrogen fuel into electrical energy through an electrochemical reaction and inputs it into the motor 112 through a transmission circuit. The motor 112 inputs mechanical energy into the transmission system 111 under the drive of electrical energy. The motor rotor 115, the high-pressure turbine rotor 116 and the compressor rotor 114 are connected through the gearbox and output shaft work together to drive the compressor rotor 114 to rotate and drive the compression component to do work. To better illustrate this embodiment, a new concept - power supply degree P ratio,ele is introduced in this configuration, which is used to characterize the proportion of electric work in the compression work consumed by the compressor, and its variation range is [0, 1].

[0042] The solid oxide fuel cell (SOFC) 104 used in the present invention belongs to a high-temperature battery, and its typical operating temperature is 800 - 1100 °C. The total temperature of the air flow at the compressor outlet is relatively close to this range, but the temperature of the liquid hydrogen only passing through the intercooling heat exchanger 102 still has a certain gap from this range, and it is necessary to increase its temperature as much as possible to make it close to this index. At the same time, the total exhaust temperature at the outlet of the low-pressure turbine 107 is relatively high. Directly discharging the gas at the turbine outlet into the atmosphere will cause a large amount of waste of exhaust heat. If the gas at the turbine outlet is used to preheat the liquid hydrogen after intercooling, it can not only realize the reuse of exhaust heat but also improve the working environment of the fuel cell; at the same time, after the fuel in the main combustion chamber is preheated, the fuel injection amount in the combustion chamber 105 can also be reduced, improving the energy utilization rate. Based on the above analysis, a regenerative heat exchanger 108 is arranged behind the low-pressure turbine 107 in this scheme, using the hot gas at the outlet of the low-pressure turbine 107 as the heat source and the liquid hydrogen as the cold source to heat the liquid hydrogen entering the SOFC and the main combustion chamber 105, improving the energy utilization rate of the propulsion system.

[0043] The hybrid propulsion system established in this embodiment is developed based on a gas turbine engine. By embedding the energy supply method of thermoelectric coupling to drive the high-pressure rotor into the propulsion system, and by flexibly adjusting the proportion of electrical work in the compression work consumption of the high-pressure rotor, the aerodynamic and thermal loads of the high-pressure turbine components can be effectively alleviated under different working conditions, the working environment of the turbine components can be improved, and thus the component life can be extended; it can also achieve the matching of different working speeds of the high and low pressures and adaptively adjust the working loads and working points of each component. At the same time, by adjusting the proportion of electrical work, a wider adjustment range of the working state of the propulsion system can be achieved, and the performance potential of the propulsion system can be maximally exerted within the envelope. The method of thermoelectric coupling drive also has the potential to further reduce fuel consumption, emissions, and noise.

[0044] The engine body adopts a medium bypass ratio mixed-exhaust turbofan, and the engine body is a new supersonic power configuration. The advantage of using a medium bypass ratio mixed-exhaust turbofan engine as a carrier is also that it can fully inherit its comprehensive performance advantages in the low-speed and transonic stages and take into account the thrust and specific fuel consumption requirements under different working conditions. The relatively high bypass ratio of the medium bypass ratio turbofan engine can ensure low noise during takeoff and low fuel consumption during cruise, and at the same time, the appropriate size will not increase the flight resistance too much.

[0045] The beneficial effects of the embodiments of the present invention are verified as follows:

[0046] First, the benefits of the HIR-SOFC-MTF configuration (hereinafter referred to as the advanced solution) compared with the traditional configuration are analyzed from the perspective of the thermodynamic cycle. The hydrogen intercooled recuperated medium bypass ratio mixed-exhaust turbofan engine with a traditional structure (HIR-MTF configuration, hereinafter referred to as the baseline solution) is selected as the baseline configuration for comparison.

[0047] To illustrate the influence of the introduction of SOFC on the thermodynamic process of the engine working in the intercooled heat exchange mode, Figure 4 shows the ideal Brayton cycle T-s diagram description of the HIR-MTF configuration and the HIR-SOFC-MTF configuration under the same design point parameters. Figure 4 The numbers in Figure 2corresponds to the key section numbers. For the HIR-MTF cycle, 0→2 represents the intake compression process, 2→21 represents the compression within the low-pressure compressor component, 21→22 represents the intercooling heat release process of the core engine airflow, and 22→3 represents the compression process within the high-pressure compressor 103 component; the combustion process occurs at 3→4 within the combustion chamber 105, followed by the turbine expansion process corresponding to 4→5, 5→51 represents the heat release process of the regenerator for the core engine airflow, and 51→64 represents the mixing and heat release within the mixer 109 of the core engine airflow; finally, 64→9 represents the nozzle expansion, and 9→0 represents the release of exhaust heat into the atmosphere. Compared with the HIR-MTF cycle, due to the addition of the SOFC, the HIR-SOFC-MTF configuration introduces an endothermic process of 3→32, and at the same time, the expansion degree of the 4→5 process weakens. From Figure 4 it can be seen that the introduction of the SOFC increases the effective work of the engine's thermodynamic cycle.

[0048] In addition, two indicators, efficiency and the fuel consumption rate of the propulsion system, are selected to evaluate the energy utilization effects of the baseline and advanced schemes under the same design parameters. As Figure 5 shown: It can be seen that the introduction of the SOFC significantly improves the overall energy utilization rate of the propulsion system. However, for fuel economy, as the designed power supply degree increases, the improvement effect of fuel economy becomes more obvious. There is an optimal designed power supply degree range. Within this range, the fuel economy of the advanced scheme is better than that of the baseline scheme. Beyond this range, the fuel economy of the advanced scheme is inferior to that of the baseline scheme. This provides a design reference basis for the reasonable thermal-electric energy distribution of the propulsion system configuration corresponding to the advanced scheme during the design stage.

[0049] To further illustrate the advantages of the patent solution, component-level overall performance simulation models of two different configurations are established for engine performance calculation and comparison. During the comparison, the advanced scheme and the baseline scheme adopt the same component design level parameters and at the same time meet the same constraint conditions, such as considering the maximum outlet temperature T t3 that the compressor blade strength can withstand under the existing technology is not higher than 973K, and the surge margins SM Fan and SM HPC both need to be maintained above 15%, the engine pressure ratio EPR is greater than 1, and the relative physical speed N H of the high-pressure rotor does not exceed 1.05.

[0050]

[0051] In terms of the selection of the baseline design point, the thrust and fuel consumption rate of the engine used by the first-generation supersonic airliner, the "Concorde", are taken as reference indicators, and the engine operating condition is the ground take-off condition: 0 km, 0.302 Ma, 10K. The off-design point calculation condition is the supersonic cruise condition: 16.154 km, 5K. Starting from the cruise speed of the "Concorde", 2 Ma, the flight Mach number is gradually increased until the constraint conditions cannot be met, and the working speed range of the baseline scheme and the advanced scheme can be obtained. In terms of the control law setting, the baseline scheme will initially keep the relative physical speed of the control low pressure at 1 unchanged, and try to keep the engine in a high-thrust state. When the outlet temperature of the high-pressure compressor exceeds the limit, the engine state is adjusted by reducing the relative physical speed of the low pressure to reduce the outlet temperature of the high-pressure compressor. For the advanced scheme, when the outlet temperature of the high-pressure compressor exceeds the limit, the relative physical speed of the low pressure remains unchanged, and the power supply is adjusted to reduce the outlet temperature of the high-pressure compressor. At the same time, considering the loss of the SOFC to the air flow, the advanced scheme also considers the 5% total pressure loss caused by the air flow passing through the SOFC during the calculation.

[0052] Table 1 Comparison of Design Point Performance Parameters between Baseline Scheme and Advanced Scheme

[0053]

[0054] Table 1 shows the comparison of the design point performance parameters between the baseline scheme and the advanced scheme under the condition of ensuring the same target thrust at the ground take-off design point. It can be seen that on the premise of ensuring the same other design parameters, to achieve the same thrust, the advanced scheme can achieve a lower fuel consumption rate and a smaller engine inlet flow rate compared with the baseline scheme, corresponding to better economy during the flight.

[0055] Table 2 Calculation Results of the Overall Performance of the Baseline Scheme during Supersonic Flight

[0056] Ma <![CDATA[N1]]> F (daN) sfc (kg / (daN·h)) EPR <![CDATA[T t4 (K)]]> <![CDATA[W a (kg / s)]]> 2 1 4202.4175 0.38817 1.3372 1895.1755 226.6961 2.1 1 4523.769 0.39795 1.2996 1919.8448 249.8359 2.2 1 4787.7134 0.41034 1.2484 1936.2345 275.4213 2.3 1 5148.6028 0.41965 1.2143 1958.5368 305.6085 2.4 1 5528.4914 0.42905 1.1814 1980.488 338.9613 2.5 1 5924.2585 0.43876 1.1502 2001.591 375.896 2.6 1 6358.3313 0.44895 1.1222 2023.752 417.1856 2.7 0.9757 6206.6488 0.46552 1.0687 2004.6383 455.3631 2.8 0.9392 5603.8323 0.48991 1.0062 1954.5706 493.2622

[0057] Table 3 Calculation Results of the Overall Performance of the Advanced Scheme during Supersonic Flight

[0058] Ma <![CDATA[N1]]> F (daN) sfc (kg / (daN·h)) EPR <![CDATA[T t4 (K)]]> <![CDATA[W a (kg / s)]]> 2 1 4802.1353 0.34863 1.6655 1896.209 229.9741 2.1 1 5161.2396 0.35769 1.6151 1922.7213 254.2845 2.2 1 5537.3906 0.36676 1.5656 1947.6156 281.092 2.3 1 5933.1412 0.37579 1.5174 1971.6056 310.5807 2.4 1 6360.6982 0.38488 1.4719 1996.2335 343.1547 2.5 1 6830.4012 0.39385 1.4302 2021.3158 379.3555 2.6 1 7460.0936 0.4031 1.3943 2083.769 419.0273 2.7 0.98 8117.1842 0.41611 1.3358 2264.7763 452.019 2.8 0.935 7288.5917 0.43157 1.2367 2177.1759 483.5044 2.9 0.9 6849.4462 0.44813 1.1636 2163.1827 520.3102 3 0.86 5854.0397 0.47348 1.0856 2063.6868 557.857 3.1 0.83 5023.9167 0.50895 1.022 1996.4796 599.3968

[0059] Tables 2 and 3 show the overall performance calculation results of the baseline and advanced schemes under the above constraints and control laws in the supersonic flight condition. It can be seen that for the baseline scheme, when the flight Mach number reaches 2.7, the rotation speed is reduced to ensure that the outlet temperature of the high-pressure compressor does not exceed the limit. As the flight Mach number further increases, the throttling depth becomes deeper. Finally, when the flight Mach number is 2.8, the calculation ends because the EPR is close to 1. Therefore, the maximum flight speed range of the baseline scheme is 2.8 Ma. For the advanced scheme, due to the introduction of the intercooling heat exchanger, the outlet temperature of the high-pressure compressor can meet the constraints by pre-cooling the inlet air flow of the compressor. Therefore, the deterioration of the engine performance caused by rotation speed reduction and throttling can be delayed. As the flight speed increases, the improvement effects of the advanced scheme compared with the baseline scheme in terms of thrust and fuel consumption are gradually enhanced. At the maximum flight speed of 2.8 Ma of the baseline scheme, the thrust of the advanced scheme is increased by 30.06%, the specific fuel consumption is reduced by 11.91%, and the flight speed range is also extended from 2.8 Ma to 3.1 Ma.

[0060] Table 4 Overall performance calculation results of the advanced scheme for constant mass flow throttling in supersonic cruise condition

[0061]

[0062]

[0063] Table 4 shows the overall performance calculation results of the advanced scheme during the throttling process in the supersonic cruise condition. Different from the baseline scheme, the new scheme can achieve the goal of constant mass flow throttling of the propulsion system by adjusting the power supply degree while keeping the relative physical rotation speed of the low-pressure rotor basically unchanged and assisting with the adjustment of the adjustable geometry of the nozzle throat area A8. During the throttling process, the same relative rotation speed of the low-pressure rotor can be matched with different relative rotation speeds of the high-pressure rotor, realizing the "decoupling" of the rotation speeds of the high-pressure and low-pressure rotors that cannot be achieved by traditional configurations. This throttling method has lower inlet duct overboard resistance compared with the traditional rotation speed reduction throttling. The installation loss of the propulsion system increases relatively gently with the increase of the throttling depth, reducing the specific fuel consumption of the propulsion system. It can be seen from the table that during the throttling process of achieving 14% thrust reduction in the advanced scheme, the specific fuel consumption is reduced by 19.33%, and the engine specific fuel consumption decreases monotonically with the increase of the throttling depth. Correspondingly, the power supply degree gradually increases during the throttling process, and the turbine inlet temperature decreases monotonically, achieving better cruise economy and higher working reliability of the turbine components compared with the traditional configuration.

[0064] Therefore, the present invention adopts the above-mentioned intercooled recuperated mixed-flow turbofan engine driven by thermo-electric coupling, and conducts a coupled design of the intercooler / recuperator heat exchanger, SOFC and the mixed-flow turbofan engine, so as to further save energy, reduce emissions and noise of civil aircraft power, and improve the inherent contradiction among "low noise", "low fuel consumption" and "low emissions".

[0065] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A regenerative mixed-flow turbofan engine with intercooling driven by thermoelectric coupling, characterized in that: It includes an engine body, and an intercooled recuperative heat exchange system, a transmission system and an electric propulsion system are arranged inside the engine body. The electric propulsion system is connected to the transmission system and drives the transmission system to do work. Both the transmission system and the electric propulsion system are arranged at the middle section position of the engine body, and the intercooled recuperative heat exchange system is arranged at the head section and the tail section positions of the engine body.

2. A regenerative intercooled mixed-flow turbofan engine driven by thermoelectric coupling according to claim 1, characterized in that: Inside the engine body, a fan, a high-pressure compressor, a main combustion chamber, a high-pressure turbine, a low-pressure turbine, a mixer and a main nozzle are sequentially arranged.

3. The intercooled recuperated mixed-flow turbofan engine driven by thermoelectric coupling according to claim 2, characterized in that: The intercooled recuperative heat exchange system includes an intercooler and a recuperator. The recuperator is arranged at the outlet of the low-pressure turbine, and the intercooler is arranged at the inlet of the high-pressure compressor.

4. A regenerative mixed-flow turbofan engine with intermediate cooling and thermal-electric coupling drive according to claim 3, characterized in that: The cold sources of the intercooler and the recuperator are both liquid hydrogen.

5. A regenerative bypass turbofan engine with an intercooler driven by thermoelectric coupling according to claim 4, characterized in that: The electric propulsion system includes an electric motor, an energy transmission circuit and a solid oxide fuel cell. The solid oxide fuel cell is arranged between the high-pressure compressor and the main combustion chamber. The solid oxide fuel cell converts the chemical energy in the hydrogen fuel into electrical energy and inputs the electrical energy into the electric motor through the energy transmission circuit.

6. A regenerative intercooled mixed-flow turbofan engine driven by thermoelectric coupling, as claimed in claim 5, wherein: The transmission system is a gearbox, and two input shafts, an output shaft and several mechanical gears are arranged inside it. The output shaft is the high-pressure compressor shaft, and a compressor rotor is arranged on the high-pressure compressor shaft. The two input shafts are respectively the motor shaft and the high-pressure turbine shaft. A high-pressure turbine rotor is arranged on the high-pressure turbine shaft, and a motor rotor is arranged on the motor shaft. The motor rotor and the high-pressure turbine rotor are both connected to the compressor rotor through the gearbox and drive it to do work.

7. A regenerative bypass turbofan engine with intercooling and recuperation driven by thermoelectric coupling, characterized in that: An inner duct and an outer duct are arranged inside the engine body.

8. A regenerative intercooled mixed-flow turbofan engine driven by thermoelectric coupling, characterized in that: The solid oxide fuel cell is a high-temperature battery, and its working temperature is 800°C - 1100°C.

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