A fuel cell electric booster jet propulsion system employing fuel pre-cooling

Abstract

This invention proposes a fuel cell electric supercharged jet propulsion system employing fuel precooling, belonging to the field of aerospace systems. It solves the problems of complex structure in precooled turbine engines, difficulty in matching the compressor or pump with the turbine, poor engine performance under varying operating conditions, and low efficiency. It includes a precooler, with its hot-end inlet connected to the intake outlet and its hot-end outlet connected to the compressor inlet; a first splitter, with its inlet connected to the compressor outlet and one outlet connected to the combustion chamber inlet; the cathode outlet of the solid oxide fuel cell system connected to the combustion chamber inlet; a first high-speed motor coaxial with the compressor; a liquid hydrogen storage tank, with its outlet connected to the hydrogen pump inlet; and one outlet of the hydrogen pump connected to the cold-end inlet of the precooler via a first valve; the first, second, and third high-speed motors are all electrically connected to the solid oxide fuel cell system. It is primarily used in propulsion systems.

Description

Technical Field

[0001] This invention belongs to the field of aviation systems, and in particular relates to a fuel cell electric supercharged jet propulsion system employing fuel precooling. Background Technology

[0002] The engine is a key component in the development of near-space hypersonic vehicles capable of horizontal takeoff and landing and two-stage-to-orbit space transportation systems, and pre-cooled combined engines have been a significant development direction. By arranging a pre-cooling heat exchanger at the compressor inlet and utilizing fuel to cool the incoming flow, the compressor inlet air temperature can be significantly reduced, thereby greatly reducing compressor power consumption and improving engine cycle efficiency. However, pre-cooled engines, such as the SABRE engine, employ aero-gas turbine technology, where the turbine and compressor operate in a coupled manner, resulting in a complex structure. Furthermore, they are limited by the Carnot cycle, leading to low system efficiency.

[0003] A fuel cell is a device that directly converts the chemical energy of fuel into electrical energy, is not limited by the Carnot cycle, and has high power generation efficiency. High-temperature solid oxide fuel cells, in particular, operate at high temperatures and have advantages such as a wide range of fuel applications, long service life, and low maintenance costs. Combining high-efficiency fuel cell technology with electric supercharging technology for application in jet propulsion systems holds great potential.

[0004] Most existing pre-cooled turbine engines have complex structures, making it difficult to match the compressor or pump with the turbine. This results in poor performance under varying operating conditions and correspondingly low efficiency. Summary of the Invention

[0005] In view of this, the present invention aims to propose a fuel cell electric supercharged jet propulsion system with fuel precooling to solve the problems of complex structure of precooled turbine engines, difficulty in matching compressors or pumps with turbines, poor performance under varying engine operating conditions, and low operating efficiency.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a fuel cell electric booster jet propulsion system employing fuel pre-cooling, comprising:

[0007] The precooler has its hot-end inlet connected to the outlet of the intake duct, and its hot-end outlet connected to the inlet of the compressor.

[0008] The first splitter has an inlet connected to the outlet of the compressor, one outlet connected to the inlet of the combustion chamber, and another outlet connected to the cathode inlet of the solid oxide fuel cell system. The cathode outlet of the solid oxide fuel cell system is connected to the inlet of the combustion chamber. The compressor is equipped with a first high-speed motor coaxial with it.

[0009] The liquid hydrogen storage tank has its outlet connected to the inlet of a hydrogen pump. One outlet of the hydrogen pump is connected to the cold end inlet of a precooler via a first valve. The cold end outlet of the precooler is connected to the inlet of a second distributor via a third valve. The other outlet of the hydrogen pump is connected to the inlet of a regenerative cooling channel coupled to the outer wall of the combustion chamber via a second valve. The hydrogen pump is equipped with a second high-speed motor coaxial with it. The outlet of the regenerative cooling channel is connected to the inlet of the second distributor via a fourth valve. One outlet of the second distributor is connected to the inlet of a third distributor, and the other outlet is connected to the inlet of the combustion chamber. One outlet of the third distributor is connected to the anode inlet of the solid oxide fuel cell system, and the other outlet is connected to the cooling channel inlet of the solid oxide fuel cell system. Both the anode outlet and the cooling channel outlet of the solid oxide fuel cell system are connected to the inlet of the combustion chamber.

[0010] The liquid oxygen storage tank has its outlet connected to the oxygen pump inlet via a fifth valve. The oxygen pump outlet is connected to the inlet of the fourth splitter. The oxygen pump is equipped with a third high-speed motor coaxial with it. One outlet of the fourth splitter is connected to the cathode inlet of the solid oxide fuel cell system, and the other outlet is connected to the combustion chamber inlet. The first, second, and third high-speed motors are all electrically connected to the solid oxide fuel cell system.

[0011] Furthermore, the size of the air intake port of the air intake duct is adjustable.

[0012] Furthermore, the precooler is a partitioned heat exchanger.

[0013] Furthermore, the first high-speed motor, the second high-speed motor, and the third high-speed motor are all DC motors.

[0014] Furthermore, the outlet flow rates of the first, second, third, and fourth splitters are adjustable.

[0015] Furthermore, the solid oxide fuel cell system includes multiple metal-supported solid oxide fuel cell stacks, and each metal-supported solid oxide fuel cell stack includes multiple metal-supported solid oxide fuel cells connected in series.

[0016] Furthermore, the cathode inlet of the solid oxide fuel cell system is air or oxygen.

[0017] Furthermore, the combustion chamber is equipped with a nozzle.

[0018] Furthermore, the nozzle is a contraction / expansion tail nozzle.

[0019] Furthermore, the nozzle throat area and outlet area are adjustable.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. This system directly converts chemical energy into electrical energy through a solid oxide fuel cell to drive a high-speed motor to pressurize air, thus avoiding the complex coupling problem between the turbine and compressor or pump in traditional pre-cooled turbine engines.

[0022] 2. This system eliminates the traditional turbine, which not only simplifies the engine's structural design but also solves the problems of difficult matching between the two and poor performance under varying operating conditions;

[0023] 3. This system uses liquid hydrogen as a coolant and fuel. In intake mode, it significantly reduces the air temperature entering the compressor, increases the compression ratio and combustion efficiency, and thus improves the overall efficiency and thrust output of the engine.

[0024] 4. This system efficiently converts chemical energy into electrical energy by setting up a solid oxide fuel cell. The compressor and pump are directly driven by an electric motor to pressurize the working fluid, resulting in less energy loss, effectively increasing the system's pressure ratio and significantly improving the system's working efficiency. Attached Figure Description

[0025] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 This is a schematic diagram illustrating the principle of a fuel cell electric booster jet propulsion system employing fuel pre-cooling, as described in this invention.

[0027] 1. Inlet; 2. Precooler; 3. Compressor; 4. First high-speed motor; 5. First distributor; 6. First valve; 7. Second valve; 8. Third valve; 9. Fourth valve; 10. Second distributor; 11. Third distributor; 12. Solid oxide fuel cell system; 13. Combustion chamber; 14. Regenerative cooling channel; 15. Nozzle; 16. Liquid hydrogen storage tank; 17. Hydrogen pump; 18. Second high-speed motor; 19. Liquid oxygen storage tank; 20. Fifth valve; 21. Oxygen pump; 22. Third high-speed motor; 23. Fourth distributor. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments.

[0029] It should be noted that the descriptions of "left," "right," "left side," "right side," "upper part," "lower part," "top," and "bottom" in this invention are defined based on the orientation or positional relationships shown in the accompanying drawings. They are merely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the described structure must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] In the description of this invention, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] Referring to the accompanying drawings, this embodiment describes a fuel cell electric booster jet propulsion system employing fuel pre-cooling, comprising:

[0032] The precooler 2 has its hot end inlet connected to the outlet of the intake duct 1, and its hot end outlet connected to the inlet of the compressor 3.

[0033] The first splitter 5 has an inlet connected to the outlet of the compressor 3, one outlet connected to the inlet of the combustion chamber 13, and another outlet connected to the cathode inlet of the solid oxide fuel cell system 12. The cathode outlet of the solid oxide fuel cell system 12 is connected to the inlet of the combustion chamber 13. The compressor 3 is equipped with a first high-speed motor 4 coaxial with it.

[0034] A liquid hydrogen storage tank 16 has its outlet connected to the inlet of a hydrogen pump 17. One outlet of the hydrogen pump 17 is connected to the cold end inlet of a precooler 2 via a first valve 6. The cold end outlet of the precooler 2 is connected to the inlet of a second distributor 10 via a third valve 8. The other outlet of the hydrogen pump 17 is connected to the inlet of a regeneration cooling channel 14 coupled to the outer wall of the combustion chamber 13 via a second valve 7. The hydrogen pump 17 is equipped with a second high-speed motor 18 coaxial with it. The outlet of the regeneration cooling channel 14 is connected to the inlet of the second distributor 10 via a fourth valve 9. One outlet of the second distributor 10 is connected to the inlet of a third distributor 11, and the other outlet is connected to the inlet of the combustion chamber 13. One outlet of the third distributor 11 is connected to a solid oxide fuel... The anode inlet of the battery system 12 is connected to the other outlet, which is connected to the cooling channel inlet of the solid oxide fuel cell system 12. Both the anode outlet and the cooling channel outlet of the solid oxide fuel cell system 12 are connected to the inlet of the combustion chamber 13. As for the regenerative cooling channel 14, it is mainly formed by coupling a shell to the outside of the combustion chamber 13. The regenerative cooling channel 14 is mainly for reusing the heat of the combustion chamber 13. The fixed form and the specific form of the pipe can be selected according to the actual situation. In order to improve the heat utilization rate and extend the flow channel, corresponding baffles can be set inside the regenerative cooling channel 14 to extend the path of the working fluid movement and the heat transfer area, thereby obtaining the best heat exchange effect.

[0035] The liquid oxygen storage tank 19 has its outlet connected to the inlet of the oxygen pump 21 via the fifth valve 20. The outlet of the oxygen pump 21 is connected to the inlet of the fourth distributor 23. The oxygen pump 21 is equipped with a third high-speed motor 22 coaxial with it. One outlet of the fourth distributor 23 is connected to the cathode inlet of the solid oxide fuel cell system 12, and the other outlet is connected to the inlet of the combustion chamber 13. The first high-speed motor 4, the second high-speed motor 18, and the third high-speed motor 22 are all electrically connected to the solid oxide fuel cell system 12.

[0036] Based on the above approach, the turbine structure is eliminated, fundamentally simplifying the design. This avoids the complex coupling issues between the turbine and compressor or pump found in traditional pre-cooled turbine engines, and also solves the problems of difficult matching and poor performance under varying operating conditions. Simultaneously, using liquid hydrogen as both coolant and fuel significantly reduces the air temperature entering the compressor during intake mode, increasing the compression ratio and combustion efficiency, thereby improving the engine's overall efficiency and thrust output. Directly driving the compressor and pump with a high-speed electric motor to pressurize the working fluid results in minimal energy loss, effectively increasing the system's dry pressure ratio and significantly improving system efficiency.

[0037] In this embodiment, the size of the air intake port of the air intake duct 1 is adjustable. This ensures that the engine's air mass flow rate meets a preset value while effectively compressing the incoming airflow.

[0038] In this embodiment, the precooler 2 is a partition wall heat exchanger. The internal heat exchange channels can be arranged in a serpentine tube bundle or an involute pattern, depending on the actual needs. Existing technologies can be used. Other layouts that facilitate heat exchange of the medium can also be selected, all within the spirit of this invention.

[0039] In this embodiment, the first high-speed motor 4, the second high-speed motor 18, and the third high-speed motor 22 are all DC motors. The solid oxide fuel cell system 12 supplies power to the first high-speed motor 4, the second high-speed motor 18, and the third high-speed motor 22, enabling them to drive corresponding components, thereby increasing gas pressure and achieving electric boosting.

[0040] In this embodiment, the outlet flow rates of the first splitter 5, the second splitter 10, the third splitter 11, and the fourth splitter 23 are adjustable. By controlling and adjusting the splitting ratio, adjustments can be made according to the corresponding operating conditions, thereby achieving optimal operating status based on the overall operating conditions.

[0041] In this embodiment, the solid oxide fuel cell system 12 includes a plurality of metal-supported solid oxide fuel cell stacks, and each metal-supported solid oxide fuel cell stack includes a plurality of metal-supported solid oxide fuel cells connected in series.

[0042] In this embodiment, the cathode inlet of the solid oxide fuel cell system 12 is either air or oxygen. The appropriate feedstock can be selected based on actual needs.

[0043] In this embodiment, the combustion chamber 13 is equipped with a nozzle 15. The nozzle 15 is a contraction / expansion tail nozzle. The throat area and exit area of ​​the nozzle 15 are adjustable. Thus, by adjusting, maximum thrust can be obtained within a certain range and under certain operating conditions.

[0044] This system has two operating modes: air-breathing propulsion and liquid hydrogen / liquid oxygen rocket propulsion.

[0045] When the propulsion system operates in intake mode, air from the environment is initially compressed through intake duct 1 and then enters precooler 2. In precooler 2, the air exchanges heat with cryogenic fuel. Afterward, the air enters compressor 3, which is connected to the first high-speed motor 4 via a shaft. The first high-speed motor 4 drives compressor 3 to pressurize the air. The air outlet of compressor 3 is piped into the first splitter 5, which divides the air into two paths: one path enters combustion chamber 13, and the other path enters the cathode inlet of solid oxide fuel cell system 12. The cathode exhaust gas from the solid oxide fuel cell system 12 enters combustion chamber 13. At this time, first valve 6 and third valve 8 are open, while second valve 7, fourth valve 9, and fifth valve 20 are closed. Liquid hydrogen stored in liquid hydrogen storage tank 16 is pressurized by hydrogen pump 17 and enters the cold end inlet of precooler 2 through first valve 6. Liquid hydrogen absorbs heat in the precooler 2. The hydrogen gas at the cold end outlet of the precooler 2 enters the second splitter 10 through the third valve 8. The second splitter 10 divides the hydrogen gas into two paths: one path directly enters the combustion chamber 13, and the other path enters the third splitter 11. One path of hydrogen gas from the outlet of the third splitter 11 enters the anode inlet of the solid oxide fuel cell system 12. The anode tail gas after the reaction in the solid oxide fuel cell system 12 enters the combustion chamber 13. The other path of hydrogen gas from the outlet of the third splitter 11 enters the cooling channel inlet of the solid oxide fuel cell system 12. The hydrogen gas acts as a cooling gas to cool the solid oxide fuel cell system 12. The outlet of the cooling channel is connected to the inlet of the combustion chamber 13. Finally, the air, hydrogen gas and fuel cell tail gas that enter the combustion chamber are mixed and burned in the combustion chamber 13. The high-temperature gas is accelerated through the nozzle 15 and then discharged to generate thrust.

[0046] When the propulsion system operates in liquid hydrogen / liquid oxygen rocket mode, the air intake duct 1 is closed, the second valve 7, the fourth valve 9, and the fifth valve 20 are open, and the first valve 6 and the third valve 8 are closed. The liquid hydrogen stored in the liquid hydrogen tank 16 is pressurized by the hydrogen pump 17 and enters the inlet of the regeneration cooling channel 14 through the second valve 7. The liquid hydrogen absorbs heat in the regeneration cooling channel 14 and cools the throat and other parts of the nozzle 15. The hydrogen gas from the outlet of the regeneration cooling channel 14 enters the second splitter 10 through the fourth valve 9. The second splitter 10 divides the hydrogen gas into two paths: one path directly enters the combustion chamber 13, and the other path enters the third splitter 11. One path of hydrogen gas from the outlet of the third splitter 11 enters the anode inlet of the solid oxide fuel cell system 12. The anode exhaust gas after the reaction in the solid oxide fuel cell system 12 enters the combustion chamber 13, and the other path of hydrogen gas from the outlet of the third splitter 11 enters the combustion chamber 13. Hydrogen gas is introduced into the cooling channel inlet of the solid oxide fuel cell system 12. The cooling channel outlet is connected to the inlet of the combustion chamber 13. Liquid oxygen in the liquid oxygen storage tank 19 flows through the fifth valve 20 into the oxygen pump 21. After being pressurized by the oxygen pump 21, it enters the fourth distributor 23. The fourth distributor 23 has two outlets. One outlet is connected to the cathode inlet of the solid oxide fuel cell system 12, and the other outlet is connected to the inlet of the combustion chamber 13. The hydrogen pump 17 is connected to the second high-speed motor 18 through a shaft, and the oxygen pump 21 is connected to the third high-speed motor 22 through a shaft. Both motors are directly powered by the solid oxide fuel cell system 12. Finally, the oxygen, hydrogen and fuel cell exhaust gas introduced into the combustion chamber 13 are mixed and burned. The high-temperature gas is accelerated through the nozzle 15 and discharged, generating thrust.

[0047] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A fuel cell electric supercharged jet propulsion system employing fuel pre-cooling, characterized in that: include: The precooler (2) has its hot end inlet connected to the outlet of the intake duct (1) and its hot end outlet connected to the inlet of the compressor (3). The first splitter (5) has an inlet connected to the outlet of the compressor (3), one outlet connected to the inlet of the combustion chamber (13), and another outlet connected to the cathode inlet of the solid oxide fuel cell system (12). The cathode outlet of the solid oxide fuel cell system (12) is connected to the inlet of the combustion chamber (13). The compressor (3) is equipped with a first high-speed motor (4) coaxial with it. A liquid hydrogen storage tank (16) has its outlet connected to the inlet of a hydrogen pump (17). One outlet of the hydrogen pump (17) is connected to the cold end inlet of the precooler (2) via a first valve (6). The cold end outlet of the precooler (2) is connected to the inlet of the second distributor (10) via a third valve (8). The other outlet of the hydrogen pump (17) is connected to the inlet of a regeneration cooling channel (14) coupled to the outer wall of the combustion chamber (13) via a second valve (7). The hydrogen pump (17) is equipped with a second high-speed motor (18) coaxial with it. The outlet of the regeneration cooling channel (14) is... The inlet of the second splitter (10) is connected to the fourth valve (9). One outlet of the second splitter (10) is connected to the inlet of the third splitter (11), and the other outlet is connected to the inlet of the combustion chamber (13). One outlet of the third splitter (11) is connected to the anode inlet of the solid oxide fuel cell system (12), and the other outlet is connected to the cooling channel inlet of the solid oxide fuel cell system (12). The anode outlet and the cooling channel outlet of the solid oxide fuel cell system (12) are both connected to the inlet of the combustion chamber (13). The liquid oxygen storage tank (19) has its outlet connected to the inlet of the oxygen pump (21) via the fifth valve (20). The outlet of the oxygen pump (21) is connected to the inlet of the fourth splitter (23). The oxygen pump (21) is equipped with a third high-speed motor (22) coaxial with it. One outlet of the fourth splitter (23) is connected to the cathode inlet of the solid oxide fuel cell system (12), and the other outlet is connected to the inlet of the combustion chamber (13). The first high-speed motor (4), the second high-speed motor (18), and the third high-speed motor (22) are all electrically connected to the solid oxide fuel cell system (12).

2. The fuel cell electric booster jet propulsion system with fuel precooling according to claim 1, characterized in that: The size of the air inlet of the air intake (1) is adjustable.

3. A fuel cell electric booster jet propulsion system employing fuel pre-cooling according to claim 1 or 2, characterized in that: The precooler (2) is a partitioned heat exchanger.

4. A fuel cell electric booster jet propulsion system with fuel precooling according to claim 3, characterized in that: The first high-speed motor (4), the second high-speed motor (18) and the third high-speed motor (22) are all DC motors.

5. A fuel cell electric booster jet propulsion system employing fuel pre-cooling according to claim 1, 2, or 4, characterized in that: The outlet flow rates of the first splitter (5), the second splitter (10), the third splitter (11) and the fourth splitter (23) are adjustable.

6. A fuel cell electric booster jet propulsion system employing fuel pre-cooling according to claim 5, characterized in that: The solid oxide fuel cell system (12) includes multiple metal-supported solid oxide fuel cell stacks, each of which includes multiple metal-supported solid oxide fuel cells connected in series.

7. A fuel cell electric booster jet propulsion system employing fuel pre-cooling according to claim 5, characterized in that: The cathode inlet of the solid oxide fuel cell system (12) is air or oxygen.

8. A fuel cell electric booster jet propulsion system employing fuel pre-cooling according to claim 1, 2, 4, 6 or 7, characterized in that: The combustion chamber (13) is equipped with a nozzle (15).

9. A fuel cell electric booster jet propulsion system employing fuel pre-cooling according to claim 8, characterized in that: The nozzle (15) is a contraction / expansion tail nozzle.

10. A fuel cell electric booster jet propulsion system employing fuel pre-cooling according to claim 9, characterized in that: The throat area and outlet area of ​​the nozzle (15) are adjustable.

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