A hybrid supersonic engine using ammonia as the working fluid

Abstract

The present invention provides a hybrid supersonic engine using ammonia as the working fluid, which includes an engine body and an air inlet, a precooler, a fuel pump, a compressor, a fuel turbine, a combustion chamber, a nozzle and an electric motor that are matched and arranged in the engine body; the nozzle is arranged on one side of the combustion chamber, and the airflow generated by combustion in the combustion chamber is ejected from the nozzle; the hybrid supersonic engine further includes a fuel cell and a storage battery arranged in the engine body. By pre-cooling the oncoming air inhaled by the engine during high-speed flight, the present invention not only greatly reduces the power required by the compressor, but also pre-heats the reactants for the chemical reactions of the fuel cell and the combustion chamber, achieving multiple benefits and enabling the entire hybrid system solution to be closed; at the same time, the fuel cell in the storage battery - the combustion of ammonia fuel in the combustion chamber is organically integrated to form a hybrid system, making the power more diverse and capable of meeting the power requirements of the aircraft at various flight stages.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft engine manufacturing, and particularly relates to a hybrid supersonic engine using ammonia as a working medium. Background Art

[0002] For wide-range high-speed flight within the atmosphere, combined power can achieve relatively high performance at a relatively low cost. In a typical flight mission, it generally needs to go through different stages such as takeoff, climb, cruise, and descent, and the demand for instantaneous energy varies greatly during these processes. When providing a single type of fuel engine for the above flight mission, it is often necessary to take into account the maximum power output condition, which will inevitably cause waste and inefficiency to a certain extent. The higher requirements for the working ability in a larger airspace and a wider speed range make the entire combined power system have to operate in a larger off-design range, and the design difficulty increases sharply. Although the research on advanced combined power technology continues to be very popular, most of it focuses on turbines, rockets, ramjets that rapidly and violently release the chemical energy of fuel and convert it into mechanical energy, and their organic combinations. Many problems still need to be solved, such as how to improve the total energy conversion efficiency as much as possible, how to achieve the adaptability, high reliability, and component matching of the engine to large-span off-design conditions, and how to multi-objective optimize the performance of the complex non-linear system of the engine. Especially when long range and long loiter time are additional constraints presented to designers, the challenge of the problem is further increased.

[0003] On the other hand, from the perspective of green and sustainable development, the policy requirements for energy conservation and emission reduction are becoming increasingly strict, and the necessity and urgency of carbon reduction and efficiency improvement in the aerospace industry are very prominent. Therefore, for high-speed, supersonic, and even hypersonic aircraft, developing a carbon-free, green, environmentally friendly, and efficient power system solution should become one of the future design goals.

[0004] In view of the two major demands of effectively breaking through the development bottleneck of wide-range combined power and energy conservation and emission reduction, it is urgent to expand the types of combined power elementary engines with good technical development potential, continuously optimize the combination method and cooperation working mode of elementary engines in combination with the usage scenarios, while achieving efficient, clean, high-speed, and wide-range propulsion, effectively reducing the design difficulty of individual components, reducing the number of components, and improving the robustness of the entire power system.

[0005] Here, an air-breathing hybrid power system of "battery - fuel cell - internal combustion engine" with ammonia as the main working medium is proposed to achieve the above purpose. In addition, in order to perform more efficient wide-range combined power comprehensive energy management, technologies such as fuel regenerative cooling, turbine-less, and fuel-air precooling are integrated and used.

[0006] Currently, in the field of supersonic / hypersonic (Mach number above 5) air-breathing aerospace engines, there is no carbon-free green hybrid power solution.

[0007] The combination of battery and fuel cell has been proven to have good complementarity in the ground transportation industry. This pure electric combination has been initially applied to low-speed aircraft, but there are two major obstacles that must be solved for high-speed aerospace flight scenarios. One is the mismatch between the relatively low power density of fuel cells and the high power demand of high-speed flight. The other is how to effectively convert electrical energy into mechanical energy and propulsion under supersonic flight conditions. The net power demand for high-speed flight can be reflected by the product of flight resistance and speed. Compared with subsonic flight, the drag coefficient of supersonic flight is larger, and the speed is several times higher. Therefore, the power demand can be an order of magnitude or more larger. Although the efficiency of some types of fuel cells can exceed 60%, leading that of internal combustion engines which is only a little over 40%, the power density of the current best solid oxide fuel cell stack is at least one order of magnitude smaller than that of traditional energy conversion components such as turbines and internal combustion engines. Batteries or capacitors with larger power density have relatively small energy density. Generally speaking, relying solely on electricity cannot meet the requirements of long-term supersonic / hypersonic flight of aircraft. It is necessary to combine with an internal combustion engine to form a hybrid power system to meet the above-mentioned wide-range and high-efficiency flight requirements. When constructing a new hybrid power system, on the one hand, it is necessary to control the cost power consumption as much as possible, such as the power for driving the compressor. On the other hand, it is necessary to carry out simplification and comprehensive optimization at the system level to achieve "multiple functions in one component" of the core components, while reducing the number of auxiliary components, connecting parts and the additional weight, volume and losses they bring. The efficiency advantage of fuel cells compared with traditional internal combustion engines of about 20% can be fully utilized. In the past, for the application research of using SOFC to construct power components, hydrogen and hydrocarbons were used as the targets more often. There are still carbon emission problems in the fuel cell technology of reforming hydrocarbon fuels to produce hydrogen. Hydrogen has problems such as low density, harsh technical requirements for high pressure and low temperature in its use conditions, and hydrogen embrittlement.

[0008] In summary, it is necessary to further innovate the existing technology. Summary of the Invention

[0009] In view of the technical problems existing in the above background technology, the present invention proposes a hybrid supersonic engine using ammonia as the working medium. By pre-cooling the incoming air inhaled by the engine during high-speed flight, it not only greatly reduces the power required by the compressor, but also pre-heats the reactants for the chemical reactions in the fuel cell and the internal combustion chamber, achieving multiple benefits and closing the entire hybrid power system solution. At the same time, a hybrid power system is formed by the organic integration of battery - ammonia fuel cell - internal combustion engine, making the power more diverse and capable of meeting the power requirements of the aircraft at various flight stages.

[0010] To solve the above technical problems, a hybrid supersonic engine using ammonia working fluid provided by the present invention includes an engine body, and an air inlet, a pre-cooler, a fuel pump, a compressor, a fuel turbine, a combustion chamber, a nozzle and an electric motor which are arranged in the engine body in a matching manner; a cooling structure is arranged on the outer wall of the combustion chamber; the nozzle is arranged on one side of the combustion chamber in a matching manner, and the airflow generated by combustion in the combustion chamber is ejected from the nozzle; the hybrid supersonic engine further includes a fuel cell and a storage battery arranged in the engine body;

[0011] The air inlet is used for introducing high-speed oncoming air into the interior of the engine body;

[0012] The feed end of the fuel pump is connected to the discharge port of the fuel storage tank through a fuel pipeline to pump the liquid ammonia fuel in the fuel storage tank into the cooling channel of the pre-cooler to pre-cool the oncoming air of the air inlet;

[0013] The power input end of the compressor is connected to the power output end of the electric motor in a matching manner, and the power output end of the compressor is connected to a fuel turbine in a matching manner;

[0014] The pre-cooler is filled with the liquid ammonia output by the fuel pump as a coolant to pre-cool the high-speed oncoming air coming from the air inlet, and at the same time the liquid ammonia also absorbs heat and rises in temperature; the fuel cell is supplied with the pre-cooled air coming out of the pre-cooler;

[0015] The pre-cooler passes the ammonia that has absorbed heat and risen in temperature into the cooling structure on the outer wall of the combustion chamber through a discharge pipeline to thermally protect the wall surface of the combustion chamber, and at the same time the ammonia is further pre-heated by the combustion chamber; a part of the pre-heated ammonia is passed into the fuel cell through a discharge pipeline to react with the supplied pre-cooled air to generate electricity, and the reaction products are passed into the inner cavity of the combustion chamber for efficient combustion, and another part of the pre-heated ammonia fuel is used as supplementary fuel to selectively drive the fuel turbine to do work and finally enter the inner cavity of the combustion chamber; in the inner cavity of the combustion chamber, the reactants of the fuel cell, the pressurized air supplied by the compressor and a part of the ammonia fuel pre-heated by the combustion chamber are combusted sufficiently together to generate power;

[0016] The fuel cell is electrically connected to the storage battery and the electric motor respectively; the fuel pump and the compressor are driven by the electric motor; the electric energy generated by the fuel cell is supplied to the electric motor, and if there is surplus electric energy, it enters the storage battery for storage; the electric motor is also electrically connected to the storage battery so that the electric motor can be powered by one of the fuel cell and the storage battery or both at the same time.

[0017] In the hybrid supersonic engine using ammonia working fluid, a heat exchange structure is arranged in the wall surface of the combustion chamber.

[0018] The hybrid supersonic engine using ammonia as the working fluid, wherein: during the subsonic flight phase of the aircraft to achieve a long loiter time, the hybrid supersonic engine can use the fuel cell and the battery to supply power to the motor simultaneously, so that the motor drives the propeller to achieve long loiter flight of the aircraft.

[0019] The hybrid supersonic engine using ammonia as the working fluid, wherein: when the aircraft takes off, there is a large demand for instantaneous output power, and the hybrid supersonic engine can supply power to the motor solely through the battery.

[0020] The hybrid supersonic engine using ammonia as the working fluid, wherein: during the low and medium subsonic cruise phase of the aircraft, the hybrid supersonic engine can preheat the fuel cell to the operating temperature through the battery. After the fuel cell is fully started, it can rely on the electric energy output to supply the motor, and can also charge the battery through the remaining power of the fuel cell to achieve range extension.

[0021] The hybrid supersonic engine using ammonia as the working fluid, wherein: when the aircraft needs to end subsonic cruise, the aircraft using the hybrid supersonic engine can perform first-stage and second-stage separation. In the first stage, the battery drives the propeller to return and land to achieve autonomous power recovery. After that, the battery can be charged or replaced on the ground and undergo simple maintenance, and then it can be combined with the new second stage to prepare for the next flight mission, realizing the repeatability of the first stage; when the aircraft needs to accelerate from subsonic cruise to high subsonic until the ammonia fuel in the combustion chamber ignites, the fuel cell operates at full load and has no remaining power output; the second stage after safe separation is achieved by the hybrid combination of the battery, the fuel cell and the combustion of ammonia fuel in the combustion chamber to achieve transonic, supersonic and even hypersonic flight; the combustion of ammonia fuel in the combustion chamber provides direct power for the aircraft during the supersonic flight phase, while the fuel cell provides the electric energy required for the compressor and fuel pump.

[0022] The hybrid supersonic engine using ammonia as the working fluid, wherein: during the low supersonic section of the aircraft, the thermodynamic cycle of the hybrid supersonic engine is that the fuel cell supplies power to the fuel pump; when the power required to drive the compressor is at a relatively low design pressure ratio, it can be completely provided by the fuel cell; if the compressor pressure ratio demand is relatively high, a part of the electric energy is provided by the remaining power of the fuel cell. When the fuel cell operates at full load and still cannot provide enough power to drive the compressor, the remaining insufficient gap can be jointly completed by using the high-temperature ammonia expansion cycle working mode after inter-stage cooling of the compressor, combustion chamber and nozzle regeneration cooling with ammonia fuel.

[0023] The hybrid supersonic engine using ammonia as the working fluid, wherein: during the supersonic flight stage with higher speeds of the aircraft, the hybrid supersonic engine pumps liquid ammonia fuel as a coolant into the pre-cooler through the fuel pump to pre-cool the high-speed oncoming air from the inlet, so that the temperature of the oncoming air compressed by the inlet increases slightly and the density remains relatively large, thereby significantly reducing the power required for the compressor during supersonic flight; the role of the liquid ammonia fuel in the cooling structures of the pre-cooler and the outer wall of the combustion chamber is to pre-heat the reactants for the fuel cell; the pre-cooler is also the pre-heater for the fuel in the fuel cell.

[0024] Adopting the above technical solution, the present invention has the following beneficial effects:

[0025] By pre-cooling the oncoming air inhaled by the engine during high-speed flight with fuel, the present invention not only significantly reduces the power required for the compressor, but also pre-heats the reactants for the fuel cell and the chemical reaction in the combustion chamber, achieving multiple benefits and closing the entire hybrid system solution; at the same time, the hybrid system is composed of the organic integration of the battery fuel cell and the combustion of ammonia fuel in the combustion chamber, realizing more diverse power and meeting the power requirements of the aircraft at various flight stages. Description of the Drawings

[0026] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is the principle configuration diagram of the hybrid supersonic engine using ammonia as the working fluid of the present invention;

[0028] Notes:

[0029] IN - Inlet, PC - Pre-cooler, FP - Fuel Pump, CP - Compressor, FT - Fuel Turbine, CB - Combustion Chamber, HE - Heat Exchanger, NZ - Nozzle, FC - Fuel Cell, BAT - Battery, M - Motor. Specific Embodiments

[0030] The following will clearly and completely describe the technical solutions of the present invention with reference to the drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0031] The present invention will be further explained and illustrated below in conjunction with specific embodiments.

[0032] As Figure 1 shown, a hybrid supersonic engine using ammonia working fluid provided in this embodiment includes an engine body and an intake duct IN, a precooler PC, a fuel pump FP, a compressor CP, a fuel turbine FT, a combustion chamber CB, a heat exchanger HE, a nozzle NZ, a fuel cell FC, a battery BAT, and a motor M that are matched and arranged on the engine body.

[0033] The intake duct IN is matched and arranged at the head of the engine body, and is used to introduce high-speed oncoming air into the engine body.

[0034] The feed end of the fuel pump FP is connected to the discharge port of the fuel storage tank fuel, and the discharge end pumps the liquid ammonia fuel in the fuel storage tank fuel into the precooler PC through a fuel pipeline.

[0035] The precooler PC is matched and connected to the air outlet side of the intake duct IN; the precooler PC is filled with ammonia output by the fuel pump FP as a coolant to pre-cool the high-speed oncoming air entering from the intake duct IN, so that the temperature of the oncoming air compressed by the intake duct IN increases limitedly and the density is still large, thereby greatly reducing the power required by the compressor CP during the supersonic flight of the aircraft.

[0036] The fuel cell FC is matched and arranged on the air outlet side of the precooler PC, and the pre-cooled air coming out of the precooler PC is introduced into it; a heat exchange structure HE, that is, a number of heat exchange holes, is provided in the wall of the combustion chamber CB; the fuel cell FC passes the products of ammonia fuel and air into the inner cavity of the combustion chamber CB through a pipeline for combustion reaction, and heat exchange is carried out in a number of heat exchange holes in the wall of the combustion chamber CB. The fuel cell FC is electrically connected to the battery BAT and the motor M respectively; the fuel pump FP and the compressor CP are driven by the motor M; the electric energy generated by the fuel cell FC is supplied to the motor M, and if there is surplus electric energy, it is passed into the battery BAT for storage.

[0037] The pre-cooler PC is filled with liquid ammonia output by the fuel pump FP as a coolant to pre-cool the high-speed oncoming air from the intake duct IN. At the same time, the liquid ammonia also absorbs heat and heats up. The pre-cooler PC passes the ammonia that has absorbed heat and heated up into the cooling structure on the outer wall of the combustion chamber CB through the discharge pipeline to provide thermal protection for the wall surface of the combustion chamber CB. At the same time, the ammonia is further pre-heated by the combustion chamber CB. A part of the pre-heated ammonia passes through the discharge pipeline into the fuel cell FC to react with the pre-cooled air introduced and generate electricity, and the reaction products are introduced into the inner cavity of the combustion chamber CB for efficient combustion. Another part of the pre-heated ammonia fuel is used as supplementary fuel to selectively drive the fuel turbine FT to do work and finally enter the inner cavity of the combustion chamber CB. In the inner cavity of the combustion chamber CB, the reactants of the fuel cell FC, the pressurized air introduced by the compressor CP, and a part of the ammonia fuel pre-heated by the combustion chamber CB are combusted sufficiently together to generate power.

[0038] The battery BAT and the motor M are arranged in a matching manner on one side of the fuel cell FC. Among them, the motor M is also electrically connected to the battery BAT so that the motor M can be powered by one of the fuel cell FC and the battery BAT or both at the same time.

[0039] The power input end of the compressor CP is connected to the power output end of the motor M in a matching manner, and the power output end of the compressor CP is connected to a fuel turbine FT in a matching manner. Among them, the fuel turbine FT is rotated passively by the airflow generated by combustion in the combustion chamber CB on the one hand and is rotated by the compressor CP on the other hand.

[0040] The nozzle NZ is arranged in a matching manner on one side of the combustion chamber CB, and the airflow generated by combustion in the combustion chamber CB is ejected from the nozzle NZ.

[0041] Based on the new understanding in the current academic community that the performance of ammonia fuel cells is comparable to that of methane and even hydrogen fuel cells, ammonia is used as the main working medium in the present invention to realize the above idea. However, due to the difficulty of ammonia ignition and the low flame propagation speed, using pure ammonia itself as the sole fuel for an internal combustion engine to achieve sufficient combustion and generate thrust is a bottleneck problem that must be solved. After ammonia decomposition, due to the presence of hydrogen in the products, efficient injection, mixing, and combustion can be achieved, which can not only greatly increase the flame propagation speed and flame stabilization range, reduce the ignition difficulty, but also effectively shorten the size and weight of the combustion chamber. The ammonia fuel SOFC actually highly integrates the catalytic cracker and the catalytic electrochemical reactor. Through good design and technological iteration, reaction self-sustainment can even be achieved. Its anode products naturally contain ammonia-hydrogen mixtures, which are very conducive to subsequent organization of wide-range and efficient combustion, and the aforementioned problems are solved.

[0042] The core principle of the air-breathing hybrid power system of "battery - fuel cell - internal combustion engine" with ammonia as the main working medium proposed by the present invention is as follows:

[0043] Inlet IN, precooler PC, fuel pump FP, compressor CP, fuel turbine FT, combustion chamber CB, nozzle NZ, motor M, fuel cell FC, and battery BAT;

[0044] To achieve a long loiter time during the subsonic flight phase, it is possible to consider using only the "battery BAT - fuel cell FC" part to drive the motor M to drive the propeller, achieving high specific impulse and high fuel economy. During takeoff, a large instantaneous output power is required, and the battery BAT can supply power to the motor M. The theoretical capacity of the battery BAT only needs to slightly exceed the sum of the energies required during the takeoff phase. The power demand during the medium and low subsonic cruise phase is significantly lower than that during the takeoff period. Therefore, the battery BAT can be used to preheat the fuel cell FC to the operating temperature. After the fuel cell FC is fully started, the electric energy output by the fuel cell FC can be used to drive the motor, and the remaining power of the fuel cell FC can also be used to charge the battery BAT to achieve range extension.

[0045] When it is necessary to end the subsonic cruise, the aircraft with a hybrid power system can perform first-stage and second-stage separation. The first stage is driven by the partially charged battery BAT to drive the propeller, and the return flight and landing achieve autonomous power recovery. Then, it can be charged or replaced on the ground. After simple maintenance, it can be combined with a new second stage to prepare for the next flight mission, realizing the reusable first stage. To reduce the dead weight of the aircraft, the above method of separating most of the power batteries has achieved a significant reduction in load for transonic and supersonic flights. When it is necessary to accelerate from subsonic cruise to high subsonic until the ammonia fuel in the combustion chamber CB ignites, the fuel cell FC can be made to operate at full load with no remaining power output. The second stage after safe separation is a hybrid power combination of the battery BAT, fuel cell FC, and combustion of ammonia fuel in the combustion chamber CB to achieve transonic, supersonic, and even hypersonic flight. The ammonia fuel in the combustion chamber CB provides direct power during the supersonic flight phase, while the fuel cell FC provides the power required for other components such as the compressor CP and fuel pump FP. In this way, at least complex components such as the gas generator and turbine can be omitted, and the system level is simplified and optimized once again.

[0046] In the low hypersonic speed range (e.g., Mach number 1.2 - 2.5), for the thermodynamic cycle of the engine operation, the fuel cell FC powers the fuel pump FP. When the design pressure ratio is relatively low, the power required to drive the compressor CP can be fully provided by the fuel cell FC; if a higher pressure ratio is needed, a part of it is provided by the remaining power of the fuel cell FC. When the fuel cell FC operates at full load and still cannot provide enough power to drive the compressor CP, the remaining insufficient power gap can be jointly completed by using the high-temperature ammonia expansion cycle working mode after the inter-stage cooling of the compressor CP, the combustion chamber CB, and the regenerative cooling of the nozzle CB with ammonia fuel, but in this case, a fuel turbine FT needs to be introduced. Since the ignition and combustion of pure ammonia are more difficult than those of hydrocarbon fuels, it has always been a hot and difficult research topic. However, due to the introduction of the ammonia-fueled fuel cell FC, the main product contains hydrogen with excellent combustion performance, which well solves this problem.

[0047] In the higher-speed supersonic speed range (e.g., Mach number greater than 2.5), ammonia is used as a coolant to pre-cool the high-speed oncoming air, so that the temperature of the oncoming air compressed by the inlet IN increases limitedly, and the density is still relatively large, thus significantly reducing the power required for the compressor CP during supersonic flight. The main role of ammonia in the cooling structures on the outer walls of the air pre-cooler PC and the combustion chamber CB is to pre-heat the reactants for the fuel cell FC. The pre-cooler PC is also the pre-heater for the fuel in the fuel cell FC, combining the two functions into one, achieving system-level integration and optimization. Then, the fuel cell FC generates electricity to drive the compressor CP and the fuel pump FP. The product mixture of the fuel cell FC that may contain unreacted fuel is introduced into the combustion chamber CB, and fully combusted with the pressurized air and another part of the fuel to generate thrust in the form of an internal combustion engine. It can be chosen to directly discharge a part of the waste gas (pollution-free components) of the product of the fuel cell FC that is not needed into the atmosphere. After pre-cooling, a part of the fuel that absorbs heat and increases in temperature enters the fuel cell FC, and enters the combustion chamber CB in the form of a mixture of components such as ammonia, hydrogen, nitrogen, and water, serving as the core combustion zone for ignition and flame stabilization, and at the same time generating electricity for the whole machine to use; another part serves as supplementary fuel and can selectively drive the fuel turbine FT or directly enter the combustion chamber CB, flexibly matching with the core combustion zone to generate the power required for high-speed flight.

[0048] By pre-cooling the oncoming air inhaled by the engine during high-speed flight, the present invention not only significantly reduces the power required for the compressor, but also pre-heats the reactants for the fuel cell and the chemical reactions in the internal combustion chamber, achieving multiple benefits and closing the entire hybrid power system solution; at the same time, by organically integrating the battery - ammonia fuel cell - internal combustion engine, a hybrid power system is formed, making the power more diverse and capable of meeting the power requirements of the aircraft at various flight stages.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hybrid supersonic engine using ammonia as a working medium, comprising an engine body and an inlet duct (IN), a precooler (PC), a fuel pump (FP), a compressor (CP), a fuel turbine (FT), a combustion chamber (CB), a nozzle (NZ) and a motor (M) matched and arranged in the engine body; the outer wall of the combustion chamber (CB) is provided with a cooling structure; the nozzle (NZ) is matched and arranged on one side of the combustion chamber (CB), and the airflow generated by combustion in the combustion chamber (CB) is ejected from the nozzle (NZ); characterized in that: The hybrid supersonic engine further comprises a fuel cell (FC) and a battery (BAT) disposed in the engine body; The air inlet (IN) is used to introduce high-speed incoming air into the engine body; The feed end of the fuel pump (FP) is connected to the discharge port of the fuel storage tank (fuel) through a fuel pipeline to pump the liquid ammonia fuel in the fuel storage tank (fuel) into the cooling channel of the precooler (PC) to precool the incoming air of the intake duct (IN); The power input end of the compressor (CP) is matched and connected with the power output end of the motor (M), and the power output end of the compressor (CP) is matched and connected with a fuel turbine (FT); The precooler (PC) is filled with liquid ammonia output by the fuel pump (FP) as a coolant to precool the high-speed incoming air from the intake duct (IN), and the liquid ammonia also absorbs heat and heats up; the fuel cell (FC) is fed with the precooled air from the precooler (PC); The precooler (PC) passes the ammonia after absorbing heat and heating into the cooling structure of the outer wall of the combustion chamber (CB) through the discharge pipe to provide thermal protection for the wall surface of the combustion chamber (CB), and the ammonia is further preheated by the combustion chamber (CB); a part of the preheated ammonia is passed into the fuel cell (FC) through the discharge pipe to react with the precooled air introduced to generate electricity, and the reaction products are passed into the inner cavity of the combustion chamber (CB) for efficient combustion, and another part of the preheated ammonia fuel can be used as a supplementary fuel to selectively drive the fuel turbine (FT) to do work and finally enter the inner cavity of the combustion chamber (CB); in the inner cavity of the combustion chamber (CB), the reactants of the fuel cell (FC) are fully burned together with the pressurized air introduced by the compressor (CP) and a part of the ammonia fuel preheated by the combustion chamber (CB) to generate power; The fuel cell (FC) is electrically connected to the battery (BAT) and the electric motor (M) respectively; the fuel pump (FP) and the compressor (CP) are driven by the electric motor (M); the electric energy generated by the fuel cell (FC) is supplied to the electric motor (M), and if there is surplus electric energy, it enters the battery (BAT) for storage; the electric motor (M) is also electrically connected to the battery (BAT), so that the electric motor (M) can be powered by one of the fuel cell (FC) and the battery (BAT) or both at the same time.

2. The hybrid supersonic engine using ammonia as claimed in claim 1, characterized in that: A heat exchange structure (HE) is provided in the wall of the combustion chamber (CB).

3. The hybrid supersonic engine using ammonia as claimed in claim 1, characterized in that: In order to achieve a long hovering time in the subsonic flight phase of the aircraft, the hybrid supersonic engine can use the fuel cell (FC) and the battery (BAT) to simultaneously power the electric motor (M), so that the electric motor (M) drives the propeller to achieve long hovering flight of the aircraft.

4. The hybrid supersonic engine using ammonia as a working medium according to claim 1, characterized in that: When the aircraft takes off, the demand for instantaneous output power is relatively large, and the hybrid supersonic engine can supply power to the electric motor (M) solely through the battery (BAT).

5. The hybrid supersonic engine using ammonia as claimed in claim 1, characterized in that: During the low-subsonic cruise phase of the aircraft, the hybrid supersonic engine can preheat the fuel cell (FC) to the operating temperature through the battery (BAT), and after the fuel cell (FC) is fully started, the electric energy output by the fuel cell (FC) can be used to supply the electric motor (M), and the battery (BAT) can also be charged with the surplus power of the fuel cell (FC) to achieve range extension.

6. The hybrid supersonic engine using ammonia as a working medium according to claim 1, characterized in that: When the aircraft needs to end subsonic cruise, the aircraft using the hybrid supersonic engine can separate the first stage and the second stage, the first stage is driven by the battery (BAT) to drive the propeller, and the return landing is performed to realize autonomous power recovery. After that, the battery (BAT) can be charged or replaced on the ground and simply maintained before it can be combined with a new second stage to prepare for the next flight mission, thereby realizing the repeatability of the first stage; when the aircraft needs to accelerate from subsonic cruise to high subsonic speed until the ammonia fuel in the combustion chamber (CB) is ignited, the fuel cell (FC) works at full load and has no residual power output; after safe separation, the second stage is realized by a hybrid power combination of the battery (BAT), the fuel cell (FC) and the combustion of ammonia fuel in the combustion chamber (CB) to realize transonic, supersonic and even hypersonic flight; the combustion of ammonia fuel in the combustion chamber (CB) provides direct power for the aircraft in the supersonic flight stage, and the fuel cell (FC) provides the electric energy required by the compressor (CP) and the fuel pump (FP).

7. The hybrid supersonic engine using ammonia as a working medium according to claim 1, characterized in that: When the aircraft is in the low supersonic section, the thermodynamic cycle of the hybrid supersonic engine is powered by the fuel cell (FC) for the fuel pump; the power for driving the compressor (CP) can be completely provided by the fuel cell (FC) when the design pressure ratio value is low; if the pressure ratio requirement of the compressor (CP) is high, part of the electric energy is provided by the remaining power of the fuel cell (FC), and when the fuel cell (FC) is working at full capacity and is still insufficient to provide the power required to drive the compressor (CP), the remaining shortfall can be completed by combining the high-temperature ammonia expansion cycle working mode after the interstage cooling of the compressor (CP) and the regenerative cooling of the combustion chamber (CB) and the nozzle (NZ) using ammonia fuel.

8. The hybrid supersonic engine using ammonia as a working medium according to claim 1, characterized in that: When the aircraft is in a supersonic section with a higher speed, the hybrid supersonic engine pumps liquid ammonia fuel as a coolant into the precooler (PC) through the fuel pump (FP) to precool the high-speed incoming air from the inlet (IN), so that the temperature of the incoming air compressed by the inlet (IN) increases only slightly and the density is still relatively large, thereby greatly reducing the power required by the compressor (CP) during supersonic flight; the role of the liquid ammonia fuel in the cooling structure of the precooler (PC) and the outer wall of the combustion chamber (CB) is to preheat the reactants for the fuel cell (FC); the precooler (PC) is also a preheater for the fuel in the fuel cell (FC).

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