Fuel cell and gas turbine hybrid cycle power generation system and working method therefor

Abstract

The present invention relates to the field of aviation power of clean energy, and disclosed is a fuel cell and gas turbine hybrid cycle power generation system, comprising a fuel tank, a gas turbine subsystem, a fuel cell subsystem, a control subsystem, and an electric power system. In a first working mode, fuel from the fuel tank enters the gas turbine subsystem, and the gas turbine subsystem converts energy after fuel combustion into electric power and stores the electric power in the electric power system. In a second working mode, fuel from the fuel tank enters the fuel cell subsystem, and the fuel cell subsystem converts chemical energy of the fuel into electric power and stores the electric power in the electric power system; and remaining anode waste and cathode waste then enter the gas turbine subsystem for combustion, and energy after the combustion is converted into electric power and stored in the electric power system. The control subsystem switches between the two working modes. The power generation system architecture of the present invention has a fuel utilization rate increased by more than 43% compared with a conventional gas turbine engine system, saves 75% of fuel consumption under a same power generation demand, directly outputs matched electric power on the basis of power supply demand required by onboard equipment, and satisfies the demand for real-time adjustment of large fluctuations in aircraft electric load.

Description

A hybrid cycle power generation system combining fuel cell and gas turbine and its operating method Technical Field

[0001] This invention belongs to the field of clean energy aviation power, and relates to an aviation hybrid cycle power generation system, specifically to a fuel cell and gas turbine hybrid cycle power generation system and its working method. Background Technology

[0002] With the rise of clean energy, "green aviation" is receiving increasing attention from countries around the world, especially given the International Air Transport Association's (IATA) "Carbon Emissions Roadmap," which aims to achieve net-zero carbon emissions by 2050. All-electric aircraft place higher demands on the power generation capacity of aviation gas turbine engines. Traditional gas turbine engines, which use aviation kerosene, have low thermoelectric efficiency and cannot meet the requirements for green and environmentally friendly operation. Currently, there are concepts for aircraft using liquid hydrogen as fuel; however, the storage conditions for liquid hydrogen are demanding, making it difficult to design an environment on an aircraft that meets the requirements for liquid hydrogen storage.

[0003] One approach has been to use fuel cells to generate electricity and improve fuel efficiency. However, fuel cell power generation systems have slow start-up and low power-to-weight ratios. Although they can improve fuel efficiency, the increase in fuel consumption due to increased weight usually outweighs the fuel savings resulting from improved fuel efficiency. Preliminary solutions based on hybrid cycle systems combining fuel cells and gas turbine engines have been developed and applied in oil refineries and thermal power plants. However, these systems are complex in structure, bulky, and have limited power ratings, making them unsuitable for the aviation propulsion field.

[0004] The hybrid power generation system proposed in CN202110988387.6 uses a low-temperature fuel cell with an operating temperature of 160-200℃. The fuel cell has a complex internal structure, including a fuel dehydrogenation device. Only oxygen and hydrogen undergo an electrochemical reaction inside the fuel cell. The exhaust gas temperature at the fuel cell outlet is 80-100℃, and the exhaust gas contains many components, including methylcyclohexane gasoline, products from diesel dehydrogenation, residual hydrogen, oxygen, and water vapor. Due to its low efficiency, it cannot provide sufficient energy to power aircraft equipment.

[0005] The pressurized fuel cell-internal combustion engine hybrid power system proposed in CN201910439432.5 adopts the internal combustion engine mode, with a crankshaft and connecting rod structure connected to the generator through a gearbox. It has low conversion efficiency and is only suitable for small power generation, which is obviously not applicable to the use of all-electric aircraft.

[0006] The hydrogen fuel-based system provided by CN201810664951.7 has an engine that emits a large amount of waste heat and the exhaust contains a large amount of pollutants, which does not meet the requirements of an all-electric aircraft; in addition, the architecture is complex and the power-to-weight ratio is low. Summary of the Invention

[0007] To address the aforementioned issues, a novel dual-mode system architecture with high power-to-weight ratio, high thermoelectric efficiency, and low pollution is proposed. This architecture features a superior flight envelope and can operate stably and efficiently in high and low temperature and high-altitude environments.

[0008] The technical solution of the present invention is as follows:

[0009] A hybrid cycle power generation system combining a fuel cell and a gas turbine includes a fuel tank, a gas turbine subsystem, a fuel cell subsystem, a control subsystem, and an electrical system. In a first operating mode, fuel from the fuel tank enters the gas turbine subsystem, where the combustion energy is converted into electrical energy and stored in the electrical system. In a second operating mode, fuel from the fuel tank enters the fuel cell subsystem, where the chemical energy is converted into electrical energy and stored in the electrical system. The remaining anode and cathode waste then re-enter the gas turbine subsystem for combustion, where the combustion energy is converted back into electrical energy and stored in the electrical system. The control subsystem switches between the two operating modes.

[0010] Furthermore, the gas turbine subsystem includes a combustion chamber, a compressor, a starter / generator, and a turbine. The inlet of the combustion chamber is connected to the fuel tank, the cathode outlet of the fuel cell subsystem, and the anode outlet of the fuel cell subsystem. The outlet of the combustion chamber is connected to the turbine. The turbine connects to and drives the compressor and the starter / generator. The high-pressure air generated by the compressor enters the combustion chamber or the cathode inlet of the fuel cell subsystem after being selected by the control subsystem. The starter / generator is connected to the power system.

[0011] Furthermore, it also includes a primary heat exchanger. The exhaust gas emitted from the rear end of the turbine passes through the hot end of the primary heat exchanger, while the high-pressure air generated by the compressor passes through the cold end of the primary heat exchanger before entering the control subsystem.

[0012] Furthermore, the control subsystem includes a controller, an auxiliary fuel control valve, and a bypass control valve. The controller connects to and controls the auxiliary fuel control valve, the bypass control valve, the starter / generator, and the electrical system. The auxiliary fuel control valve is located in the fuel passage between the fuel tank and the combustion chamber. The bypass control valve selects between the compressor and the combustion chamber, or between the compressor and the cathode inlet of the fuel cell subsystem.

[0013] Furthermore, the fuel cell subsystem includes a reformer, a solid oxide fuel cell, a high-temperature pump, and a secondary heat exchanger. The fuel tank is connected to the cold end of the reformer, and the cold end of the reformer is connected to the inlet of the high-temperature pump. The outlet of the high-temperature pump is connected to the anode inlet of the solid oxide fuel cell. The compressor selects the cathode inlet of the solid oxide fuel cell through the control subsystem. The power generation end of the solid oxide fuel cell is connected to the power system. The anode outlet of the solid oxide fuel cell passes through the hot end of the reformer and the hot end of the secondary heat exchanger before connecting to the combustion chamber. The cathode outlet of the solid oxide fuel cell is directly connected to the combustion chamber.

[0014] Furthermore, the cold end of the secondary heat exchanger is equipped with a pressure swing adsorption molecular sieve to separate nitrogen and oxygen from the air. The nitrogen is discharged into the surrounding atmosphere, while the oxygen is connected to the cathode inlet of the solid oxide fuel cell.

[0015] Furthermore, the cold end of the reformer is equipped with a catalyst, which is a high-temperature fuel catalyst that catalyzes the fuel into a mixture of hydrogen and other combustible gases.

[0016] Furthermore, the fuel is one or more of aviation kerosene, natural gas, methanol, and ethanol.

[0017] A method for operating a fuel cell and gas turbine hybrid cycle power generation system: Using the aforementioned fuel cell and gas turbine hybrid cycle power generation system, when the gas turbine engine operates in start-up and stable mode alone, it enters the first operating mode. The controller sends a start signal to the starter / generator, simultaneously controlling the bypass control valve to connect the combustion chamber and compressor, and also sends a signal to open the auxiliary fuel control valve. At this time, the gas turbine engine subsystem starts, and air is drawn in at the compressor inlet, cooling the starter / generator through the suction effect. Simultaneously, the compressed air at the compressor outlet, after heating, directly enters the combustion chamber to mix with fuel and ignite. The high-temperature, high-pressure gas drives the turbine to perform work, and the rotor speed increases rapidly. When the rotor speed reaches the cut-off speed, the controller sends a control signal to disconnect the power input switch of the starter / generator, disconnecting the output torque of the starter / generator. As the gas turbine engine speed continues to increase to idle speed, the controller sends a load loading signal to the starter / generator, and the starter / generator begins to output electrical energy to supply the power system. Simultaneously, the high-temperature exhaust gas discharged after the turbine is cooled and released into the surrounding atmosphere.

[0018] A method for operating a fuel cell and gas turbine hybrid cycle power generation system is disclosed. Using the aforementioned fuel cell and gas turbine hybrid cycle power generation system, when the system is operating in stable mode, it enters a second operating mode. The controller sends a signal to control the bypass control valve to select the compressor and fuel cell subsystems, while simultaneously closing the auxiliary fuel control valve. At this time, the gas turbine subsystem draws in air from the compressor inlet, using the suction effect to cool the starter / generator. Simultaneously, the compressed air from the compressor outlet, after heating, enters the pressure swing adsorption molecular sieve in the secondary heat exchanger, achieving nitrogen and oxygen separation. The nitrogen is then discharged into the surrounding atmosphere. Oxygen is introduced into the cathode inlet of the solid oxide fuel cell, where it reacts with the fuel introduced into the anode inlet to generate electrical energy, which is stored in the power system. The residual oxygen at the cathode outlet of the solid oxide fuel cell and the residual fuel at the anode outlet of the solid oxide fuel cell exchange heat through the reformer and the secondary heat exchanger before directly entering the combustion chamber for combustion. The resulting high-temperature and high-pressure gas drives the turbine of the gas turbine engine to rotate, which drives the coaxial compressor and the starter generator to work. The controller sends a start / generator load signal, and the starter / generator begins to output electrical energy for storage in the power system. The exhaust gas from the turbine outlet of the gas turbine engine is cooled and discharged into the surrounding atmosphere.

[0019] The beneficial effects of this invention are as follows:

[0020] 1. The novel dual-mode fuel cell and gas turbine engine hybrid cycle power generation system architecture of the present invention improves the fuel utilization rate by more than 43% compared with the traditional gas turbine engine system, and saves 75% of fuel consumption under the same power generation demand.

[0021] 2. The novel dual-mode fuel cell and gas turbine engine hybrid cycle power generation system architecture of the present invention is equipped with a fuel reformer, a power regulator, and a battery, which can directly output matching power according to the power supply requirements of airborne equipment and meet the requirements of real-time adjustment of large fluctuations in aircraft electrical load.

[0022] 3. The novel dual-mode fuel cell and gas turbine engine hybrid cycle power generation system architecture of the present invention includes a control system and adjustment mechanism that match the system architecture, enabling the system to operate in dual modes and meet the power needs of high-altitude flight and ground maintenance.

[0023] 4. This invention offers exceptional economic benefits and significant energy-saving and emission-reduction value for applications with harsh operating conditions and high power demands, particularly for all-electric aircraft requiring extremely high power for high-altitude flight and relatively low power for ground maintenance. Furthermore, this solution can also be applied to other energy generation systems, demonstrating good versatility, economy, and environmental friendliness.

[0024] 5. Compared to CN202110988387.6, this invention employs a high-temperature solid oxide fuel cell. The internal stack reaction temperature of the fuel cell is (1000~1200)℃, and the exhaust gas discharged from the fuel cell outlet contains only hydrogen, oxygen, and water vapor at a temperature of (600~800)℃, exhibiting extremely high thermal efficiency. Compared to CN201910439432.5, this invention boasts extremely high power generation and higher thermal energy utilization. The engine of this invention is a gas turbine structure, with the compressor, turbine, and generator coaxial, resulting in a compact structure. Compared to CN201810664951.7, the exhaust waste heat of this invention heats the fuel and compressed air, and the exhaust gas is discharged only after heat exchange. The engine only burns hydrogen, producing only water vapor as a byproduct, with no pollutants. Compared to the above solutions, this invention, through switching between different operating modes, allows the energy system to operate in different modes, adapting to different electricity demands and energy reserves, thus supporting different flight requirements of all-electric aircraft. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this invention, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 is a schematic diagram of the architecture of the novel dual-mode fuel cell and gas turbine engine hybrid cycle power generation system of the present invention.

[0027] Among them, 1-fuel tank, 2-fuel pump, 3-reformer, 4-auxiliary fuel control valve, 5-primary heat exchanger, 6-turbine, 7-high temperature pump, 8-solid oxide fuel cell, 9-secondary heat exchanger, 10-combustion chamber, 11-power regulator, 12-battery, 13-starter / generator, 14-compressor, 15-controller, 16-bypass control valve. Embodiments of the present invention

[0028] This section describes embodiments of the present invention, used to explain and illustrate the technical solutions of the present invention. Unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0029] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating directions or positional relationships, are given in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or device referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include more than one of those features. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integrated connections; they can refer to mechanical connections or point connections; they can refer to direct connections or indirect connections 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] Example 1:

[0032] A novel dual-mode fuel cell and gas turbine engine hybrid cycle power generation system is characterized by comprising a fuel tank 1, a fuel pump 2, a reformer 3, an auxiliary fuel control valve 4, a primary heat exchanger 5, a turbine 6, a high-temperature pump 7, a solid oxide fuel cell 8, a secondary heat exchanger 9, a combustion chamber 10, a power regulator 11, a battery 12, a starter / generator 13, a compressor 14, a controller 15, and a bypass control valve 16. The turbine 6, starter / generator 13, and compressor 14 rotate coaxially at high speed. The high-pressure air output from the compressor 14 is heated by the primary heat exchanger 5 and then split into two paths via the bypass control valve: one path supplies the combustion chamber, and the other path, after being heated by the secondary heat exchanger 9, supplies the solid oxide fuel cell 8. The secondary heat exchanger 9 contains multiple layers of pressure swing adsorption molecular sieves to separate oxygen and nitrogen in the compressed air, thereby generating high-purity oxygen (O2).

[0033] Solid oxide fuel cells (SOFCs) operate at temperatures between 800°C and 900°C, therefore requiring preheating to this temperature for effective use. The high-temperature pump (7), powered by battery electricity, operates after system startup and when the battery's energy storage reaches the required level, ensuring the fuel entering the SOFC reaches its operating temperature.

[0034] The secondary exchanger 9 contains a multi-layered honeycomb-shaped pressure swing adsorption molecular sieve to separate oxygen and nitrogen in compressed air, thereby generating high-purity oxygen (O2) to supply the solid oxide fuel cell 8.

[0035] This invention has two modes: a standalone gas turbine engine start-up and stable operation mode, and a stable operation mode of a hybrid cycle power generation system of fuel cell and gas turbine engine.

[0036] The turbine 6, starter / generator 13, and compressor 14 are coaxial; the starter / generator 13 is located at the front end of the compressor 14, and can effectively utilize the air suction effect of the compressor 14 during air intake to cool and dissipate heat from the starter / generator 13.

[0037] When the system starts, the controller 15 sends a start signal to the starter / generator 13 and an opening signal to the auxiliary fuel control valve 4. When the gas turbine engine speed reaches the ignition speed, the fuel injected into the combustion chamber 10 is ignited and burned. The high-temperature and high-pressure gas drives the turbine 6 to do work, and the speed increases rapidly. When the speed reaches the cut-off speed, the controller 15 sends a control signal to disconnect the power input switch of the starter / generator 13. As the gas turbine engine speed continues to increase to the idle speed, the controller sends a load signal to the starter / generator 13 to start generating electricity to supply the battery 12. At the same time, the high-temperature exhaust gas discharged after the turbine 6 is heated by the compressed air at the outlet of the compressor 14 through the primary heat exchanger 5, further reducing the exhaust gas temperature.

[0038] When the internal temperature of the solid oxide fuel cell 8 reaches 800℃-900℃ and the energy is balanced, the controller 13 sends a control signal to close the auxiliary fuel control valve 4, cutting off the fuel output channel from the reformer 3 to the combustion chamber 10.

[0039] The system operates stably. The residual H2 and CO in the exhaust gas at the anode outlet are approximately 800°C. After being mixed, cooled, and reformed by the reformer 3, the temperature is approximately 600°C. It then enters the combustion chamber 10 of the gas turbine engine GT, where it mixes and burns with the compressed air from the compressor 14 outlet and the residual O2 from the cathode of the solid oxide fuel cell 8. The high-temperature, high-pressure gas drives the turbine 6 to do work, and the generator 13 outputs electrical energy to the battery 12. At the same time, the controller 15 converts the voltage of the electrical energy generated by the solid oxide fuel cell 8 through the power regulator 11 and outputs it to the battery 12. Meanwhile, the high-temperature exhaust gas from the gas turbine engine is heated by the compressed air at the compressor 14 outlet through the primary heat exchanger 5, and the temperature is further reduced before it is discharged.

[0040] Example 2:

[0041] A novel fuel cell and gas turbine engine hybrid cycle power generation system is disclosed, wherein the aircraft fuel system supplies fuel to the fuel cell and gas turbine engine hybrid cycle power generation system, and the fuel cell and gas turbine engine hybrid cycle power generation system provides electrical energy to the aircraft load system. The system is characterized in that it includes a gas turbine engine subsystem, a fuel cell subsystem, and a control and energy storage system.

[0042] The gas turbine engine subsystem includes a starter / generator 13, a compressor 14, a combustion chamber 10, and a turbine 6;

[0043] The fuel cell subsystem includes a solid oxide fuel cell 8, a reformer 3, and a high-temperature pump 7;

[0044] The control and energy storage system includes an auxiliary fuel control valve 4, a controller 15, a battery 12, and a power regulator 11;

[0045] The starter / generator 13, compressor 14, and turbine 6 are arranged coaxially in sequence. The inlet of compressor 14 is connected to the atmosphere, and the outlet of compressor 14 is connected to the cold air inlet of primary heat exchanger 5. After passing through bypass control valve 16, one path enters combustion chamber 10 for combustion, and the other path connects to secondary heat exchanger 9 to separate oxygen (O2) through molecular sieves, which is then connected to the cathode of solid oxide fuel cell 8. When the fuel cell and gas turbine hybrid cycle power generation system is working, compressor 14 draws in air from the inlet, generates compressed air, and supplies it to solid oxide fuel cell 8. The anode inlet of solid oxide fuel cell 8 is connected to the supply line of high-temperature pump 7, and the anode outlet of solid oxide fuel cell 8 is connected to the fuel line of reformer 3. The cathode outlet of solid oxide fuel cell 8... The inlet is connected to the gas path of the combustion chamber 10; the outlet of the combustion chamber 10 is connected to the turbine 6; the fuel cell and gas turbine engine hybrid cycle power generation system includes two power generation units: a starter / generator 13 and a solid oxide fuel cell 8. These two power generation units are connected to the power regulator 11. The electrical energy is converted by the power regulator 11 into the voltage and current required by the airborne equipment and stored in the airborne battery 12; a fuel pump 2 is provided between the airborne fuel system and the fuel cell subsystem, and an auxiliary fuel control valve 4 is provided between the airborne fuel system and the combustion chamber 10; the controller 15 is connected to the auxiliary fuel valve 4 via a cable. The controller 15 can adjust the opening of the fuel valve 16 and the auxiliary fuel valve 4 to adjust the fuel supply between the fuel cell subsystem and the combustion chamber 10.

[0046] The hybrid cycle power generation system of fuel cell and gas turbine engine is equipped with a reformer 3, a primary heat exchanger 5, and a secondary heat exchanger 9 for heat exchange. When the hybrid cycle power generation system of fuel cell and gas turbine engine uses kerosene, natural gas, methanol, ethanol, etc. as fuel, a reforming device is provided between the fuel pump 2 and the solid oxide fuel cell 8. After the fuel is reformed by the reformer 3 to produce hydrogen, it is supplied to the solid oxide fuel cell 8 by the high-temperature pump 7. In order to ensure the stable operating temperature of the solid oxide fuel cell 8, the compressed air of the compressor 14 is preheated to a specific temperature by the primary heat exchanger 5 and the secondary heat exchanger 9 before entering the fuel cell.

[0047] The fuel cell and gas turbine hybrid cycle power generation system is also equipped with a bypass control valve 16 and an auxiliary fuel control valve 4. The controller 15 controls the opening and closing of the bypass control valve 16 and the auxiliary fuel control valve 4 through control signals, thereby controlling the stable mode of the fuel cell and gas turbine hybrid cycle power generation system and the start-up and stable mode of the gas turbine engine alone.

[0048] When the gas turbine engine is operating in standalone start-up and stable mode, controller 15 sends a start signal to starter / generator 13. Simultaneously, controller 15 signals to open the bypass control valve 16 connecting to combustion chamber 10, and signals to open the auxiliary fuel control valve 4 connecting to combustion chamber 10, allowing pressurized fuel to be directly introduced into combustion chamber 10 via fuel lines. At this time, the gas turbine engine subsystem starts, and air is drawn into compressor 14. The suction effect cools starter / generator 13, while the compressed air from compressor 14 outlet is heated by primary heat exchanger 5 and then directly enters combustion chamber 10 after passing through bypass control valve 16. Fuel is mixed, ignited, and burned. The high-temperature, high-pressure gas drives the turbine 6 to do work, and the rotor speed increases rapidly. When the rotor speed reaches the cut-off speed, the controller 15 sends a control signal to disconnect the power input switch of the starter / generator 13, thus disconnecting the output torque of the starter / generator 13. The speed of the gas turbine engine continues to increase to the idle speed, and the controller 15 sends a load loading signal to the starter / generator 13. The starter / generator 13 begins to output electrical energy to the power regulator 11, which is then stored in the battery 12 after power regulation and conversion. At the same time, the high-temperature exhaust gas discharged from the turbine 6 is heated by the primary heat exchanger 5 to the compressed air at the outlet of the compressor 14 before being discharged into the surrounding atmosphere.

[0049] When the fuel cell and gas turbine engine hybrid cycle power generation system is operating in stable mode, the controller 15 sends a signal to close the valve connecting the bypass control valve 16 and the combustion chamber 10, and simultaneously closes the valve connecting the auxiliary fuel control valve 4 and the combustion chamber 10. At this time, the gas turbine engine subsystem draws in air from the compressor 14 inlet, using the suction effect to cool the starter / generator 13. Simultaneously, the compressed air from the compressor 14 outlet is heated by the primary heat exchanger 5, and after passing through the bypass control valve 16, enters the pressure swing adsorption molecular sieve in the secondary heat exchanger 9, achieving the separation of nitrogen (N2) and oxygen (O2) from the air. The nitrogen (N2) is discharged into the surrounding atmosphere, while the oxygen (O2) is connected to the cathode inlet of the solid oxide fuel cell 8, where it reacts electrochemically with the fuel connected to the anode inlet. The generated electrical energy is stored in the battery 12 after being regulated and converted by the power regulator 11. The residual oxygen O2 at the cathode outlet of the solid oxide fuel cell 8 and the residual fuel at the anode outlet of the solid oxide fuel cell 8 are reformed by the reformer 3 and heat-exchanged by the secondary heat exchanger 9 before directly entering the combustion chamber 10 for combustion. The generated high-temperature and high-pressure gas drives the turbine 6 of the gas turbine engine to rotate, which drives the coaxial compressor 14 and the starter generator 13 to work. The controller 15 sends a load signal to the starter / generator 13, and the starter / generator 13 starts to output electrical energy to the power regulator 11. After being regulated and converted by the power regulator, the electrical energy is stored in the battery 12. The exhaust gas at the outlet of the turbine 6 of the gas turbine engine is cooled by the primary heat exchanger 5 and then discharged into the surrounding atmosphere.

[0050] The electrical energy output from the starter / generator 13 and the solid oxide fuel cell 8 is converted into ±270V DC power by the power regulator 11 and supplied to the aircraft's electrical equipment.

[0051] Example 3:

[0052] A novel fuel cell and gas turbine engine hybrid cycle power generation system, wherein an airborne fuel system supplies fuel to the fuel cell and gas turbine engine hybrid cycle power generation system, and the fuel cell and gas turbine engine hybrid cycle power generation system provides energy to an all-electric or multi-electric aircraft load system, characterized in that the system includes a gas turbine subsystem, a fuel cell subsystem, and a control and energy storage system;

[0053] The gas turbine engine subsystem includes a starter / generator 13, a compressor 14, a combustion chamber 10, and a turbine 6;

[0054] The fuel cell subsystem includes a solid oxide fuel cell 8, a reformer 3, and a high-temperature pump 7;

[0055] The control and energy storage system includes an auxiliary fuel control valve 4, a controller 15, a battery 12, and a power regulator 11;

[0056] The starter / generator 13, compressor 14, and turbine 6 are arranged coaxially in sequence. The inlet of compressor 14 is connected to the atmosphere, and the outlet of compressor 14 is connected to the cold air inlet of primary heat exchanger 5. After passing through bypass control valve 16, one path enters combustion chamber 10 for combustion, and the other path connects to secondary heat exchanger 9 to separate oxygen (O2) through molecular sieves, which is then connected to the cathode of solid oxide fuel cell 8. When the fuel cell and gas turbine hybrid cycle power generation system is working, compressor 14 draws in air from the inlet, generates compressed air, and supplies it to solid oxide fuel cell 8. The anode inlet of solid oxide fuel cell 8 is connected to the supply line of high-temperature pump 7, and the anode outlet of solid oxide fuel cell 8 is connected to the fuel line of reformer 3. The cathode outlet of solid oxide fuel cell 8... The inlet is connected to the gas path of the combustion chamber 10; the outlet of the combustion chamber 10 is connected to the turbine 6; the fuel cell and gas turbine engine hybrid cycle power generation system includes two power generation units: a starter / generator 13 and a solid oxide fuel cell 8. These two power generation units are connected to the power regulator 11. The electrical energy is converted by the power regulator 11 into the voltage and current required by the airborne equipment and stored in the airborne battery 12; a fuel pump 2 is provided between the airborne fuel system and the fuel cell subsystem, and an auxiliary fuel control valve 4 is provided between the airborne fuel system and the combustion chamber 10; the controller 15 is connected to the auxiliary fuel valve 4 via a cable. The controller 15 can adjust the opening of the fuel valve 16 and the auxiliary fuel valve 4 to adjust the fuel supply between the fuel cell subsystem and the combustion chamber 10.

[0057] The hybrid cycle power generation system of fuel cell and gas turbine engine is equipped with a reformer 3, a primary heat exchanger 5, and a secondary heat exchanger 9 for heat exchange. When the hybrid cycle power generation system of fuel cell and gas turbine engine uses kerosene as fuel, a reforming device is provided between the fuel pump 2 and the solid oxide fuel cell 8. After the fuel is reformed by the reformer 3 to produce hydrogen, it is supplied to the solid oxide fuel cell 8 by the high-temperature pump 7. In order to ensure the stable operating temperature of the solid oxide fuel cell 8, the compressed air of the compressor 14 is preheated to a specific temperature by the primary heat exchanger 5 and the secondary heat exchanger 9 before entering the fuel cell.

[0058] The fuel cell and gas turbine engine hybrid cycle power generation system is also equipped with a bypass control valve 16 and an auxiliary fuel control valve 4. The controller 15 controls the opening and closing of the bypass control valve 16 and the auxiliary fuel control valve 4 through control signals, thereby controlling the stable operating mode of the fuel cell and gas turbine engine hybrid cycle power generation system, and the start-up and stable operating mode of the gas turbine engine alone.

[0059] When the gas turbine engine is in standby start-up and stable operation mode, controller 15 sends a start signal to starter / generator 13. Simultaneously, controller 15 signals to open the bypass control valve 16 connecting to combustion chamber 10, and signals to open the auxiliary fuel control valve 4 connecting to combustion chamber 10, allowing pressurized fuel to be directly introduced into combustion chamber 10 via fuel lines. At this time, the gas turbine engine subsystem starts, and air is drawn in at compressor 14, cooling starter / generator 13 through the suction effect. Simultaneously, compressed air from compressor 14 outlet is heated by primary heat exchanger 5 and then directly enters combustion chamber 10 after passing through bypass control valve 16. Fuel is mixed, ignited, and burned. The high-temperature, high-pressure gas drives the turbine 6 to do work, and the rotor speed increases rapidly. When the rotor speed reaches the cut-off speed, the controller 15 sends a control signal to disconnect the power input switch of the starter / generator 13, thus disconnecting the output torque of the starter / generator 13. The speed of the gas turbine engine continues to increase to the idle speed, and the controller 15 sends a load loading signal to the starter / generator 13. The starter / generator 13 begins to output electrical energy to the power regulator 11, which is then stored in the battery 12 after power regulation and conversion. At the same time, the high-temperature exhaust gas discharged from the turbine 6 is heated by the primary heat exchanger 5 to the compressed air at the outlet of the compressor 14 before being discharged into the surrounding atmosphere.

[0060] When the fuel cell and gas turbine engine hybrid cycle power generation system is in stable operating mode, the controller 15 sends a signal to close the valve connecting the bypass control valve 16 and the combustion chamber 10, and simultaneously closes the valve connecting the auxiliary fuel control valve 4 and the combustion chamber 10. At this time, the gas turbine engine subsystem draws in air from the compressor 14 inlet, using the suction effect to cool the starter / generator 13. Simultaneously, the compressed air from the compressor 14 outlet is heated by the primary heat exchanger 5, and after passing through the bypass control valve 16, enters the pressure swing adsorption molecular sieve in the secondary heat exchanger 9, achieving the separation of nitrogen (N2) and oxygen (O2) from the air. The nitrogen (N2) is discharged into the surrounding atmosphere, while the oxygen (O2) is connected to the cathode inlet of the solid oxide fuel cell 8, where it reacts electrochemically with the fuel connected to the anode inlet. The generated electrical energy is stored in the battery 12 after being regulated and converted by the power regulator 11. The residual oxygen O2 at the cathode outlet of the solid oxide fuel cell 8 and the residual fuel at the anode outlet of the solid oxide fuel cell 8 are reformed by the reformer 3 and heat-exchanged by the secondary heat exchanger 9 before directly entering the combustion chamber 10 for combustion. The generated high-temperature and high-pressure gas drives the turbine 6 of the gas turbine engine to rotate, which drives the coaxial compressor 14 and the starter generator 13 to work. The controller 15 sends a load signal to the starter / generator 13, and the starter / generator 13 starts to output electrical energy to the power regulator 11. After being regulated and converted by the power regulator, the electrical energy is stored in the battery 12. The exhaust gas at the outlet of the turbine 6 of the gas turbine engine is cooled by the primary heat exchanger 5 and then discharged into the surrounding atmosphere.

[0061] The electrical energy output from the starter / generator 13 and the solid oxide fuel cell 8 is converted into ±270V DC power by the power regulator 11 and supplied to the aircraft's electrical equipment.

[0062] This invention relates to a novel dual-mode fuel cell and gas turbine engine hybrid cycle power generation system, comprising a gas turbine subsystem, a fuel cell subsystem, and a control and energy storage system. The system includes two operating modes: a standalone gas turbine engine start-up and stabilization mode, and a fuel cell-gas turbine engine hybrid cycle power generation system stabilization mode.

[0063] Please refer to Figure 1 for the standalone gas turbine engine start-up and stabilization modes. The fuel cell subsystem requires specific temperature, pressure, and fuel supply conditions to operate stably. Under special conditions such as system start-up and shutdown, the system can only operate in standalone gas turbine engine start-up and stabilization modes.

[0064] During startup, when the gas turbine engine is operating in standalone startup and stable mode, controller 15 sends a startup signal to starter / generator 13. Simultaneously, controller 15 signals to open the bypass control valve 16 connecting to combustion chamber 10, and signals to open the auxiliary fuel control valve 4 connecting to combustion chamber 10, allowing pressurized fuel to be directly introduced into combustion chamber 10 via fuel lines. At this time, the gas turbine engine subsystem starts, and air is drawn into compressor 14. The suction effect cools starter / generator 13, while the compressed air from compressor 14 outlet is heated by primary heat exchanger 5 and then directly enters combustion chamber 10 after passing through bypass control valve 16. The gas turbine engine mixes with fuel and ignites for combustion. The high-temperature, high-pressure gas drives the turbine 6 to do work, and the rotor speed increases rapidly. When the rotor speed reaches the cut-off speed, the controller 15 sends a control signal to disconnect the power input switch of the starter / generator 13, thus disconnecting the output torque of the starter / generator 13. The speed of the gas turbine engine continues to increase to the idle speed, and the controller 15 sends a load loading signal to the starter / generator 13. The starter / generator 13 begins to output electrical energy to the power regulator 11, which is then stored in the battery 12 after power regulation and conversion. At the same time, the high-temperature exhaust gas discharged from the turbine 6 is heated by the primary heat exchanger 5 to the compressed air at the outlet of the compressor 14 before being discharged into the surrounding atmosphere.

[0065] Please refer to Figure 1. When the fuel cell and gas turbine engine hybrid cycle power generation system is operating in stable mode, the controller 15 sends a signal to close the valve connecting the bypass control valve 16 and the combustion chamber 10, and simultaneously closes the valve connecting the auxiliary fuel control valve 4 and the combustion chamber 10. At this time, the gas turbine engine subsystem draws in air from the compressor 14 inlet, using the suction effect to cool the starter / generator 13. Simultaneously, the compressed air from the compressor 14 outlet is heated by the primary heat exchanger 5, and after passing through the bypass control valve 16, enters the pressure swing adsorption molecular sieve in the secondary heat exchanger 9, achieving the separation of nitrogen (N2) and oxygen (O2) from the air. The nitrogen (N2) is discharged into the surrounding atmosphere, while the oxygen (O2) is connected to the cathode inlet of the solid oxide fuel cell 8, where it is electrolyzed with the fuel connected to the anode inlet. The chemical reaction generates electrical energy, which is then stored in the battery 12 after being regulated and converted by the power regulator 11. The residual oxygen O2 at the cathode outlet of the solid oxide fuel cell 8 and the residual fuel at the anode outlet of the solid oxide fuel cell 8 are reformed by the reformer 3 and heat-exchanged by the secondary heat exchanger 9 before directly entering the combustion chamber 10 for combustion. The resulting high-temperature and high-pressure gas drives the turbine 6 of the gas turbine engine to rotate, which in turn drives the coaxial compressor 14 and the starter generator 13 to work. The controller 15 sends a load signal to the starter / generator 13, and the starter / generator 13 begins to output electrical energy to the power regulator 11. After being regulated and converted by the power regulator, the electrical energy is stored in the battery 12. Meanwhile, the exhaust gas from the turbine 6 outlet of the gas turbine engine is cooled by the primary heat exchanger 5 and then discharged into the surrounding atmosphere.

[0066] The above description is merely a specific embodiment of the present invention, providing a detailed description of the invention. Parts not covered herein are conventional techniques. However, the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A hybrid cycle power generation system combining a fuel cell and a gas turbine, characterized in that, It includes a fuel tank (1), a gas turbine subsystem, a fuel cell subsystem, a control subsystem, and an electrical system; in the first working mode, the fuel in the fuel tank (1) enters the gas turbine subsystem, and the gas turbine subsystem converts the energy after the fuel combustion into electrical energy and stores it in the electrical system; in the second working mode, the fuel in the fuel tank (1) enters the fuel cell subsystem, and the fuel cell subsystem converts the chemical energy of the fuel into electrical energy and stores it in the electrical system, and the remaining anode waste and cathode waste enter the gas turbine subsystem for combustion, and the energy after the fuel combustion is converted into electrical energy and stored in the electrical system; the control subsystem switches between the two working modes.

2. The fuel cell and gas turbine hybrid cycle power generation system according to claim 1, characterized in that, The gas turbine subsystem includes a combustion chamber (10), a compressor (14), a starter / generator (13), and a turbine (6). The inlet of the combustion chamber (10) is connected to the fuel tank (1), the cathode outlet of the fuel cell subsystem, and the anode outlet of the fuel cell subsystem, respectively. The outlet of the combustion chamber (10) is connected to the turbine (6). The turbine (6) connects to and drives the compressor (14) and the starter / generator (13) to operate. The high-pressure air generated by the compressor (14) enters the combustion chamber or the cathode inlet of the fuel cell subsystem after being selected by the control subsystem. The starter / generator (13) is connected to the power system.

3. The fuel cell and gas turbine hybrid cycle power generation system according to claim 2, characterized in that, It also includes a primary heat exchanger (5). The exhaust gas emitted from the rear end of the turbine (6) passes through the hot end of the primary heat exchanger (5), and the high-pressure air generated by the compressor (14) passes through the cold end of the primary heat exchanger (5) before entering the fuel cell subsystem.

4. The fuel cell and gas turbine hybrid cycle power generation system according to claim 2, characterized in that, The control subsystem includes a controller (15), an auxiliary fuel control valve (4), and a bypass control valve (16). The controller (15) connects to and controls the auxiliary fuel control valve (4), the bypass control valve (16), the starter / generator (13), and the power system. The auxiliary fuel control valve (4) is located in the fuel passage between the fuel tank (1) and the combustion chamber (10). The bypass control valve (16) selects between the compressor (14) and the combustion chamber (10), or between the compressor (14) and the cathode inlet of the fuel cell subsystem.

5. A fuel cell and gas turbine hybrid cycle power generation system according to claim 4, characterized in that, The fuel cell subsystem includes a reformer (3), a solid oxide fuel cell (8), a high-temperature pump (7), and a secondary heat exchanger (9). The fuel tank (1) is connected to the cold end of the reformer (3). The cold end of the reformer (3) is connected to the inlet of the high-temperature pump (7). The outlet of the high-temperature pump (7) is connected to the anode inlet of the solid oxide fuel cell (8). The compressor (14) selects the cathode inlet of the solid oxide fuel cell (8) through the control subsystem. The power generation end of the solid oxide fuel cell (8) is connected to the power system. The anode outlet of the solid oxide fuel cell (8) passes through the hot end of the reformer (3) and the hot end of the secondary heat exchanger (9) before connecting to the combustion chamber (10). The cathode outlet of the solid oxide fuel cell (8) is directly connected to the combustion chamber (10).

6. A fuel cell and gas turbine hybrid cycle power generation system according to claim 5, characterized in that, The cold end of the secondary heat exchanger (9) is equipped with a pressure swing adsorption molecular sieve to separate nitrogen and oxygen in the air. Nitrogen is discharged into the surrounding atmospheric environment, and oxygen is connected to the cathode inlet of the solid oxide fuel cell (8).

7. A fuel cell and gas turbine hybrid cycle power generation system according to claim 5, characterized in that, The reformer (3) has a catalyst in its cold end. The catalyst is a high-temperature fuel catalyst that catalyzes the fuel into a mixture of hydrogen and other combustible gases.

8. A fuel cell and gas turbine hybrid cycle power generation system according to claim 7, characterized in that, The fuel is one or more of aviation kerosene, natural gas, methanol, and ethanol.

9. A method for operating a hybrid cycle power generation system combining a fuel cell and a gas turbine, characterized in that, The fuel cell and gas turbine hybrid cycle power generation system as described in any one of claims 4-8 is characterized in that, when the gas turbine engine operates in start-up and stable mode alone, it enters the first operating mode. The controller sends a start-up signal to the starter / generator, simultaneously controls the bypass control valve to connect the combustion chamber and the compressor, and sends a signal to open the auxiliary fuel control valve. At this time, the gas turbine engine subsystem starts, and air is drawn in at the compressor inlet. The starter / generator is cooled by the suction effect. At the same time, the compressed air at the compressor outlet is heated and directly enters the combustion chamber to mix with fuel and ignite. The high-temperature and high-pressure gas drives the turbine to do work, and the rotor speed increases rapidly. When the rotor speed reaches the cut-off speed, the controller sends a control signal to disconnect the power input switch of the starter / generator, thus disconnecting the output torque of the starter / generator. The gas turbine engine speed continues to increase to the idle speed, and the controller sends a load loading signal to the starter / generator. The starter / generator begins to output electrical energy to supply the power system. At the same time, the high-temperature exhaust gas discharged after the turbine is cooled and discharged into the surrounding atmosphere.

10. A method for operating a hybrid cycle power generation system combining a fuel cell and a gas turbine, characterized in that, The fuel cell and gas turbine hybrid cycle power generation system as described in any one of claims 5-8 is characterized in that, when the fuel cell and gas turbine hybrid cycle power generation system is operating in stable mode, it enters a second operating mode. The controller sends a signal to control the bypass control valve to select the compressor and fuel cell subsystem, while simultaneously closing the auxiliary fuel control valve. At this time, the gas turbine subsystem draws in air from the compressor inlet, using the suction effect to dissipate heat from the starter / generator. Simultaneously, the compressed air from the compressor outlet, after being heated, enters the secondary heat exchanger for heat exchange and then connects to the cathode of the solid oxide fuel cell. Fuel connected to the anode inlet undergoes an electrochemical reaction to generate electrical energy, which is stored in the electrical energy system. Residual oxygen at the cathode outlet of the solid oxide fuel cell and residual fuel at the anode outlet of the solid oxide fuel cell exchange heat through a reformer and a secondary heat exchanger before directly entering the combustion chamber for combustion. The resulting high-temperature, high-pressure gas drives the turbine of the gas turbine engine to rotate, which in turn drives the coaxial compressor and starter generator to work. The controller sends a starter / generator load signal, and the starter / generator begins to output electrical energy for storage in the electrical energy system. Meanwhile, the exhaust gas from the turbine outlet of the gas turbine engine is cooled and discharged into the surrounding atmosphere.

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