A gas turbine compound propulsion power generation system with anode cycle fuel cell

Abstract

A gas turbine compound propulsion power generation system with an anode cycle fuel cell belongs to the field of aircraft power generation and propulsion technology. The present invention solves the problem of low power generation efficiency of existing aircraft taking power from the engine main shaft or carrying a small turbine engine. The low-pressure turbine and the low-pressure compressor are coaxially fixed, the high-pressure turbine and the high-pressure compressor are coaxially fixed, the outlet of the fuel tank is connected to the inlet of the reformer and the inlet of the combustion chamber respectively through a fuel pump, the low-pressure compressor is connected to the high-pressure compressor, the high-pressure turbine is connected to the low-pressure turbine, the outlet of the high-pressure compressor is connected to the inlet of the reformer and the inlet of the cathode respectively, the outlet of the cathode is connected to the inlet of the combustion chamber, the outlet of the combustion chamber is connected to the inlet of the high-pressure turbine, the outlet of the reformer is connected to the inlet of the anode, the inlet of the anode is connected to the inlet of the cooler and the inlet of the combustion chamber respectively through a diverter, and the outlet of the cooler and the inlet of the reformer are connected through a high-temperature pump.

Description

Technical Field

[0001] The invention relates to a gas turbine compound propulsion power generation system with an anode circulation fuel cell, belonging to the technical field of aircraft power generation and propulsion. Background Art

[0002] More-electric and all-electric aircraft have high controllability and high comfort, and are one of the mainstream development directions of aircraft at present. As the power system gradually replaces the aircraft's onboard mechanical and hydraulic systems, and the power of onboard equipment gradually increases, the electric power fraction of more-electric and all-electric aircraft gradually increases (the electric power fraction is defined as the ratio of the aircraft's onboard equipment to the total power, and the total power is the sum of the aircraft's onboard equipment and the propulsion power). The electric power fraction of large commercial aircraft continues to increase with the development of aircraft models, and the electric power fraction of some military drones can reach as high as 20%. Traditional aircraft onboard electrical energy generally comes from gas turbine main shaft power or carries a small turbine generator. The existing mature aircraft power generation methods all have to go through the Brayton cycle for power generation. Limited by the thermal efficiency of the Carnot cycle, the aircraft power generation efficiency and thermal efficiency are relatively low, with a power generation efficiency of about 20% to 40% and an aircraft thermal efficiency of about 35%. At a high electric power fraction, the low power generation efficiency increases the aircraft's fuel consumption rate, which seriously reduces the aircraft's performance. Therefore, with the development trend of more-electric and all-electric aircraft, the electrical power fraction of aircraft is constantly increasing, and there is an urgent need for a high-efficiency, low-fuel-consumption power generation method.

[0003] Solid oxide fuel cells (SOFC) have the advantages of high efficiency (generally greater than 50%), direct use of hydrocarbon fuels, no need for precious metal catalysts, no liquid electrolytes, low pollutant emissions, and low noise. They have been widely studied as power systems for drones and commuter aircraft. SOFC exhaust gas has a high temperature and contains unreacted fuel. It is a high-grade energy source and can be used in conjunction with a gas turbine to improve the overall thermal efficiency of the system. Therefore, the fuel cell gas turbine hybrid cycle has been a hot topic in recent years for research on airborne high-efficiency power generation cycles. The U.S. Air Force developed a propane SOFC drone in 2012. Compared with other battery power sources, its flight time can be increased from 2 hours to 8 hours.

[0004] Existing aircraft power generation systems generally draw power from the engine main shaft or carry a small turbine engine to generate electricity, resulting in low efficiency and unable to adapt to the development direction of high electric power fraction multi-electric / all-electric aircraft. Summary of the invention

[0005] The present invention aims to solve the problem of low power generation efficiency of existing aircraft taking power from the engine main shaft or carrying a small turbine engine, and further provides a gas turbine compound propulsion power generation system with an anode cycle fuel cell.

[0006] The technical solution adopted by the present invention to solve the above technical problems is:

[0007] A gas turbine compound propulsion power generation system with an anode cycle fuel cell, which includes a fuel cell system and an aircraft propulsion system, wherein the fuel cell system includes a fuel tank, a fuel pump, a solid oxide fuel cell stack, a cooler, a high temperature pump and a reformer, and the solid oxide fuel cell stack includes an anode, an electrolyte and a cathode.

[0008] The aircraft propulsion system comprises a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine and a low-pressure turbine, wherein the low-pressure turbine and the low-pressure compressor are coaxially fixedly connected, and the high-pressure turbine and the high-pressure compressor are coaxially fixedly connected,

[0009] The outlet of the fuel tank is connected to the inlet of the reformer and the inlet of the combustion chamber through a fuel pump.

[0010] The low-pressure compressor is connected to the high-pressure compressor, the high-pressure turbine is connected to the low-pressure turbine, the outlet of the high-pressure compressor is connected to the inlet of the reformer and the inlet of the cathode respectively, the outlet of the cathode is connected to the inlet of the combustion chamber, and the outlet of the combustion chamber is connected to the inlet of the high-pressure turbine.

[0011] The outlet of the reformer is connected to the inlet of the anode, the inlet of the anode is connected to the inlet of the cooler and the inlet of the combustion chamber through a diverter, and the outlet of the cooler is connected to the inlet of the reformer through a high-temperature pump.

[0012] Furthermore, the reformer is provided with a fuel inlet, an air inlet, an anode tail gas inlet and a gas outlet, the fuel tank is connected to the fuel inlet of the reformer through a fuel pump, the cooler is connected to the anode tail gas inlet of the reformer through a high-temperature pump, the high-pressure compressor is connected to the air inlet of the reformer, and the gas outlet of the reformer is connected to the inlet of the anode.

[0013] Furthermore, the low-pressure compressor and the low-pressure turbine are fixedly connected via a first connecting shaft, and the high-pressure compressor and the high-pressure turbine are fixedly connected via a second connecting shaft, and the first connecting shaft and the second connecting shaft are coaxial shafts that are rotatably connected.

[0014] Compared with the prior art, the present invention has the following effects:

[0015] The solid oxide fuel cell group is connected to the combustion chamber, and the high temperature tail gas of the fuel cell is introduced into the combustion chamber through a pipeline. The tail gas of the fuel cell and the fuel are mixed and burned in the combustion chamber and then enter the turbine to perform work, thereby realizing the cascade utilization of energy.

[0016] This application combines the two systems of aircraft propulsion and metal-supported solid oxide fuel cells. After the high-efficiency fuel cell and gas turbine are combined, the power generation efficiency can reach 50%, and the thermal efficiency of the composite system can reach 45%, saving energy. At the same time, this application provides sufficient electrical energy and propulsion work for the aircraft without completely eliminating excessive mass penalties;

[0017] The fuel cell anode cycle constructed in the present application realizes partial recycling of water by passing a portion of the fuel cell anode exhaust gas into a cooler, which is then cooled by external air and pressurized by a high-temperature pump before entering a reformer. This can reduce the total amount of water carried by 60%, thereby reducing to a certain extent the mass penalty caused by the aircraft carrying a large amount of water due to hydrogen production through steam reforming. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the principle of this application;

[0019] Figure 2 This is a schematic diagram of the structure of this application. DETAILED DESCRIPTION

[0020] Specific implementation method 1: Combination Figures 1-2 The present embodiment is described as a gas turbine compound propulsion power generation system with an anode cycle fuel cell, which includes a fuel cell system and an aircraft propulsion system, wherein the fuel cell system includes a fuel tank 1, a fuel pump 2, a solid oxide fuel cell stack 3, a cooler 4, a high temperature pump 5 and a reformer 6, and the solid oxide fuel cell stack 3 includes an anode 3-1, an electrolyte 3-2 and a cathode 3-3,

[0021] The aircraft propulsion system comprises a low-pressure compressor 7, a high-pressure compressor 8, a combustion chamber 9, a high-pressure turbine 10 and a low-pressure turbine 11, wherein the low-pressure turbine 11 is coaxially fixedly connected to the low-pressure compressor 7, and the high-pressure turbine 10 is coaxially fixedly connected to the high-pressure compressor 8.

[0022] The outlet of the fuel tank 1 is connected to the inlet of the reformer 6 and the inlet of the combustion chamber 9 through the fuel pump 2.

[0023] The low-pressure compressor 7 is connected to the high-pressure compressor 8, the high-pressure turbine 10 is connected to the low-pressure turbine 11, the outlet of the high-pressure compressor 8 is connected to the inlet of the reformer 6 and the inlet of the cathode 3-3 respectively, the outlet of the cathode 3-3 is connected to the inlet of the combustion chamber 9, and the outlet of the combustion chamber 9 is connected to the inlet of the high-pressure turbine 10.

[0024] The outlet of the reformer 6 is connected to the inlet of the anode 3-1, and the inlet of the anode 3-1 is connected to the inlet of the cooler 4 and the inlet of the combustion chamber 9 through the diverter 14, and the outlet of the cooler 4 is connected to the inlet of the reformer 6 through the high-temperature pump 5. The air is compressed by the low-pressure compressor 7 and the high-pressure compressor 8 in turn to provide high-pressure air for the combustion chamber 9; the fuel tank 1 divides the fuel into two paths through the fuel pump 2, respectively providing fuel for the reformer 6 and the combustion chamber 9; the reformer 6 delivers the gas to the anode 3-1 of the solid oxide fuel cell group 3 after reforming, and the high-temperature tail gas generated by the anode 3-1 of the solid oxide fuel cell group 3 is delivered to the combustion chamber 9; the solid oxide system fuel cell passes a part of the anode tail gas into the cooler 4 through the diverter 14, and after being cooled by air, it increases the pressure through the high-temperature pump 5 and enters the reformer 6, providing water resources for the reforming hydrogen production of the reformer 6, and realizing partial recycling of water.

[0025] The cooler 4, the high temperature pump 5, and the reformer 6 constitute the anode cycle of the fuel cell system;

[0026] The present application adopts the method of producing hydrogen by water reforming hydrocarbon fuels to provide the solid oxide fuel cell with the hydrogen required for the reaction, so the aircraft carries a certain amount of water resources. The water carried by the aircraft can be sprayed through the array nozzles arranged at the front of the air inlet. The water droplets mix with the air in the air inlet and evaporate, thereby reducing the air temperature in front of the compressor and thus reducing the power consumption of the compressor, thereby improving the engine specific power. The engine specific power can be increased by 5% to 10%; at the same time, the water droplets injected into the air inlet evaporate and are compressed by the compressor and then passed into the reformer 6, which can provide water vapor for the reformer 6.

[0027] The solid oxide fuel cell group 3 is connected to the combustion chamber 9, and the high temperature exhaust gas of the fuel cell is introduced into the combustion chamber 9 through a pipeline. The exhaust gas of the fuel cell and the fuel are mixed and burned in the combustion chamber 9 and then enter the turbine to perform work, thereby realizing the cascade utilization of energy.

[0028] This application is adapted to the development needs of all-electric aircraft propulsion and power generation systems with high electrical power fraction, high power-to-weight ratio, high efficiency, low fuel consumption rate, and more. On the basis of fully considering the utilization of SOFC exhaust gas, improving the thermal efficiency of the propulsion system, and reducing the weight of carried water, a gas turbine compound propulsion and power generation system with an anode cycle fuel cell is proposed.

[0029] This application combines the two systems of aircraft propulsion and metal-supported solid oxide fuel cells. After the high-efficiency fuel cell and gas turbine are combined, the power generation efficiency can reach 50%, and the thermal efficiency of the composite system can reach 45%, saving energy. At the same time, this application provides sufficient electrical energy and propulsion work for the aircraft without completely eliminating excessive mass penalties;

[0030] The fuel cell anode cycle constructed in the present application realizes partial recycling of water by passing a part of the exhaust gas from the fuel cell anode 3-1 into the cooler 4, which is then pressurized by the high-temperature pump 5 and enters the reformer 6 after being cooled by the external air. This can reduce the total amount of water carried by 60%, thereby reducing to a certain extent the mass penalty caused by the aircraft carrying a large amount of water due to hydrogen production through steam reforming.

[0031] The reformer 6 is provided with a fuel inlet, an air inlet, an anode tail gas inlet and a gas outlet. The fuel tank 1 is connected to the fuel inlet of the reformer 6 through a fuel pump 2, the cooler 4 is connected to the anode tail gas inlet of the reformer 6 through a high-temperature pump 5, the high-pressure compressor 8 is connected to the air inlet of the reformer 6, and the gas outlet of the reformer 6 is connected to the anode inlet.

[0032] The low-pressure compressor 7 and the low-pressure turbine 11 are fixedly connected via a first connecting shaft 12, and the high-pressure compressor 8 and the high-pressure turbine 10 are fixedly connected via a second connecting shaft 13. The first connecting shaft 12 and the second connecting shaft 13 are coaxial shafts that are rotatably connected.

Claims

1. A gas turbine compound propulsion power generation system with an anode cycle fuel cell, characterized in that: It comprises a fuel cell system and an aircraft propulsion system, wherein the fuel cell system comprises a fuel tank (1), a fuel pump (2), a solid oxide fuel cell stack (3), a cooler (4), a high temperature pump (5) and a reformer (6), and the solid oxide fuel cell stack (3) comprises an anode (3-1), an electrolyte (3-2) and a cathode (3-3). The aircraft propulsion system comprises a low-pressure compressor (7), a high-pressure compressor (8), a combustion chamber (9), a high-pressure turbine (10) and a low-pressure turbine (11), wherein the low-pressure turbine (11) and the low-pressure compressor (7) are coaxially fixedly connected, and the high-pressure turbine (10) and the high-pressure compressor (8) are coaxially fixedly connected. The outlet of the fuel tank (1) is connected to the inlet of the reformer (6) and the inlet of the combustion chamber (9) respectively through the fuel pump (2). The low-pressure compressor (7) is connected to the high-pressure compressor (8), the high-pressure turbine (10) is connected to the low-pressure turbine (11), the outlet of the high-pressure compressor (8) is connected to the inlet of the reformer (6) and the inlet of the cathode (3-3), the outlet of the cathode (3-3) is connected to the inlet of the combustion chamber (9), and the outlet of the combustion chamber (9) is connected to the inlet of the high-pressure turbine (10). The outlet of the reformer (6) is connected to the inlet of the anode (3-1), the inlet of the anode (3-1) is respectively connected to the inlet of the cooler (4) and the inlet of the combustion chamber (9) through a flow divider (14), the outlet of the cooler (4) and the inlet of the reformer (6) are connected through a high-temperature pump (5); the reformer (6) is provided with a fuel inlet, an air inlet, an anode tail gas inlet and a gas outlet, the fuel tank (1) is connected to the fuel inlet of the reformer (6) through a fuel pump (2), the cooler ( 4) The high-temperature pump (5) is connected to the anode tail gas inlet of the reformer (6), the high-pressure compressor (8) is connected to the air inlet of the reformer (6), and the gas outlet of the reformer (6) is connected to the anode inlet; the low-pressure compressor (7) and the low-pressure turbine (11) are fixedly connected by a first connecting shaft (12), and the high-pressure compressor (8) and the high-pressure turbine (10) are fixedly connected by a second connecting shaft (13), and the first connecting shaft (12) and the second connecting shaft (13) are coaxial shafts connected in rotation.

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