Auxiliary power units and aircraft having them

Abstract

This invention relates to the field of auxiliary power technology, and discloses an auxiliary power device and an aircraft having the same, comprising: a compressed air system; a piping system having an air inlet, a first air outlet, a second air outlet, and a third air outlet, all three of which are connected to the air inlet. The air inlet is connected to the compressed air system, the first air outlet is adapted to be connected to the aircraft's main engine, and the second air outlet is adapted to be connected to the aircraft's environmental control system; a fuel cell, the inlet of which is connected to the third air outlet; and a control system for controlling the air flow rates at the first, second, and third air outlets. The auxiliary power device of this invention, by incorporating a fuel cell, reduces the amount of compressed air discharged into the atmosphere, improves energy utilization, and avoids energy waste.

Description

Technical Field

[0001] This invention relates to the field of auxiliary power technology, and more specifically to auxiliary power devices and aircraft having the same. Background Technology

[0002] An auxiliary power unit (APU) is a self-contained power unit used in aircraft that does not rely on any external energy source. Often referred to as the aircraft's "second power plant," it is a crucial functional subsystem. It provides compressed air to the starter motor that powers the aircraft's main engines, as well as to the aircraft's environmental control system, and simultaneously provides power to the aircraft.

[0003] In related technologies, once the main engine of an aircraft has started, the auxiliary power unit does not need to continue supplying compressed air to the starter motor of the main engine. This portion of compressed air will be discharged into the atmosphere through the exhaust nozzle of the auxiliary power unit, resulting in energy waste. Summary of the Invention

[0004] In view of this, the present invention provides an auxiliary power unit and an aircraft having the same, in order to solve the problem of energy waste.

[0005] In a first aspect, the present invention provides an auxiliary power device, comprising: a compressed air system; a piping system having an air inlet, a first air outlet, a second air outlet, and a third air outlet, wherein the first air outlet, the second air outlet, and the third air outlet are all connected to the air inlet, the air inlet is connected to the compressed air system, the first air outlet is adapted to be connected to the main engine of an aircraft, and the second air outlet is adapted to be connected to the environmental control system of the aircraft; a fuel cell, wherein the inlet of the fuel cell is connected to the third air outlet; and a control system for controlling the air flow rate of the first air outlet, the air flow rate of the second air outlet, and the air flow rate of the third air outlet.

[0006] Beneficial effects: By installing a fuel cell, after the main engine starts, the compressed air generated by the compressor system can flow through the pipeline system to the environmental control system and the fuel cell, reducing the amount of compressed air generated by the compressor system discharged into the atmosphere, improving energy utilization, and avoiding energy waste.

[0007] In one alternative embodiment, the auxiliary power unit further includes an energy storage system electrically connected to the fuel cell.

[0008] Beneficial effects: The energy storage system is used to store the electrical energy generated by the fuel cell, which on the one hand ensures the stability of the output voltage, and on the other hand stores the excess electrical energy to avoid energy waste.

[0009] In one optional embodiment, the auxiliary power unit further includes: a combustion chamber connected to the compression system and provided with a cooling channel; and an exhaust pipe having an inlet end and an outlet end disposed opposite to each other, the inlet end being connected to the outlet of the fuel cell and the outlet end being connected to the cooling channel.

[0010] Beneficial effects: The exhaust gas generated by the fuel cell can flow into the cooling channel through the exhaust gas pipe, which cools the combustion chamber and improves the utilization rate of the fuel cell exhaust gas.

[0011] In one optional embodiment, the fuel cell is constructed in a ring shape, and there are multiple exhaust pipes, with multiple air inlets spaced apart circumferentially along the fuel cell and multiple air outlets spaced apart circumferentially along the combustion chamber.

[0012] Beneficial effects: On the one hand, it can increase the air flow between the fuel cell and the combustion chamber, resulting in high cooling efficiency of the combustion chamber; on the other hand, it can ensure the uniformity of circumferential cooling of the combustion chamber and avoid local heat concentration in the combustion chamber.

[0013] In one alternative embodiment, the combustion chamber and the fuel cell are connected to opposite sides of the compressor, with the end of the fuel cell facing away from the compression system connected to the air inlet, and the outer peripheral surface of the combustion chamber connected to the air outlet.

[0014] Beneficial effects: On the one hand, it can avoid interference between the exhaust gas pipeline and the compressor system, and the layout of the compressor system, combustion chamber, fuel cell and exhaust gas pipeline is more reasonable. On the other hand, the outer circumference of the combustion chamber is connected to the exhaust end. Compared with connecting the end of the combustion chamber away from the compressor system to the exhaust end, it can shorten the size of the exhaust gas pipeline, reduce costs and save space.

[0015] In one alternative embodiment, the central axis of the combustion chamber and the central axis of the fuel cell are aligned.

[0016] Beneficial effects: The combustion chamber and fuel cell do not need to be misaligned in the radial direction of the fuel cell (i.e., the radial direction of the combustion chamber), which can ensure that multiple exhaust pipes are the same size, which is beneficial to the production and manufacturing of exhaust pipes. In addition, the combustion chamber and fuel cell as a whole occupy little space in the radial direction of the fuel cell, thus improving space utilization.

[0017] In one optional embodiment, the auxiliary power unit further includes: an exhaust device communicating with the exhaust port of the combustion chamber; and a fuel heat exchanger connected to the combustion chamber and the fuel cell, and exchanging heat with the exhaust device, wherein the fuel heat exchanger is used to deliver fuel to the combustion chamber and the fuel cell.

[0018] Beneficial effects: The fuel heat exchanger absorbs the heat from the exhaust gas generated in the combustion chamber to heat the fuel, realizing energy recovery and utilization, improving energy efficiency, reducing energy consumption, and gasifying the fuel. The fuel reacts more fully in the combustion chamber and fuel cell, producing less exhaust gas and achieving a higher degree of cleanliness.

[0019] In one optional embodiment, the auxiliary power unit further includes: a first control valve connected between the fuel cell and the fuel heat exchanger and electrically connected to the control system, the control system controlling the opening degree of the first control valve; and a second control valve connected between the combustion chamber and the fuel heat exchanger and electrically connected to the control system, the control system controlling the opening degree of the second control valve.

[0020] Beneficial effects: The control system can control the opening of the first control valve and the second control valve according to the aircraft's operating status. This ensures that the fuel cell and combustion chamber have sufficient fuel and that the auxiliary power unit works normally. It also prevents excessive fuel supply, which could lead to fuel waste and incomplete combustion, thereby improving fuel utilization and reducing air pollution.

[0021] In a second aspect, the present invention also provides an aircraft comprising: a main engine, an environmental control system, and a fuel storage system; the auxiliary power unit described in the first aspect embodiment of the present invention, wherein a first air outlet of the piping system is connected to the main engine, a second air outlet of the piping system is connected to the environmental control system, and the fuel cell is connected to the fuel storage system.

[0022] Beneficial effects: By installing a fuel cell, after the main engine starts, the compressed air generated by the compressor system can flow through the pipeline system to the environmental control system and the fuel cell, reducing the amount of compressed air generated by the compressor system discharged into the atmosphere, improving energy utilization, and avoiding energy waste.

[0023] In one alternative embodiment, the aircraft further includes a third control valve connected between the fuel cell and the fuel storage system and connected to the control system, the control system controlling the opening degree of the third control valve.

[0024] Beneficial effects: The control system can control the opening of the third control valve according to the amount of fuel required by the auxiliary power unit. This ensures that the fuel cell and combustion chamber have sufficient fuel and that the auxiliary power unit can work normally. It also prevents excessive fuel supply, which could lead to fuel waste and incomplete combustion. This improves fuel utilization and reduces air pollution. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is one of the structural schematic diagrams of an aircraft according to an embodiment of the present invention;

[0027] Figure 2 This is a second schematic diagram of the structure of an aircraft according to an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the connection structure of the fuel cell, the compressor system and the combustion chamber of the auxiliary power device according to an embodiment of the present invention.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Auxiliary power unit; 2. Main engine; 3. Environmental control system; 4. Fuel storage system; 5. Third control valve; 6. Aircraft;

[0031] 100. Compressed air system; 110. First compressor; 120. Second compressor;

[0032] 200. Piping system; 201. Air inlet; 202. First air outlet; 203. Second air outlet; 204. Third air outlet;

[0033] 300. Fuel cells;

[0034] 400. Control system; 410. Four-way valve;

[0035] 500. Electric accessory system;

[0036] 600. Energy storage system;

[0037] 700, Combustion chamber; 710, Turbine;

[0038] 800. Exhaust gas duct; 810. Inlet end; 820. Outlet end;

[0039] 900. Exhaust device; 910. Fuel heat exchanger; 911. First control valve; 912. Second control valve. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] The following is combined with Figures 1 to 3 The following describes embodiments of the present invention.

[0042] According to an embodiment of the present invention, in one aspect, an auxiliary power unit 1 is provided, which includes a compressed air system 100, a pipeline system 200, a fuel cell 300, and a control system 400.

[0043] The pipeline system 200 is provided with an air inlet 201, a first air outlet 202, a second air outlet 203 and a third air outlet 204. The first air outlet 202, the second air outlet 203 and the third air outlet 204 are all connected to the air inlet 201. The air inlet 201 is connected to the compressed air system 100. The first air outlet 202 is adapted to be connected to the main engine 2 of the aircraft 6. The second air outlet 203 is adapted to be connected to the environmental control system 3 of the aircraft 6. The environmental control system 3 is used to regulate the air usage status inside the aircraft 6.

[0044] The inlet of the fuel cell 300 is connected to the third outlet 204. The control system 400 is connected to the pipeline system 200, and the control system 400 is used to control the gas flow rate of the first outlet 202, the second outlet 203 and the third outlet 204.

[0045] Among them, the fuel cell 300 can be a hydrogen fuel cell, and the main engine 2 of the aircraft 6 can use hydrogen fuel. This not only ensures that the fuel of the fuel cell 300 and the main engine 2 are consistent, but also eliminates the need for the aircraft 6 to store two types of fuel, reducing the storage space required for fuel. Furthermore, since there is no combustion process in the hydrogen fuel cell 300, there is almost no generation of nitrogen oxides (NOx), which can avoid carbon emissions and greatly reduce the pollution of the auxiliary power unit 1 to the atmosphere.

[0046] By setting up the fuel cell 300, after the main engine 2 starts, the compressed air generated by the compressor system 100 can flow through the pipeline system 200 to the environmental control system 3 and the fuel cell 300, reducing the amount of compressed air generated by the compressor system 100 discharged into the atmosphere, improving energy utilization, and avoiding energy waste.

[0047] Specifically, when the main engine 2 of the aircraft 6 starts, the control system 400 can control the air flow of the first outlet 202 to be at its maximum and the air flow of the third outlet 204 to be at its minimum. The compressed air pressurized by the compressor system 100 is prioritized for use by the starter of the main engine 2, and the remaining compressed air can be supplied to the environmental control system 3. After the main engine 2 starts, the control system 400 can control the air flow of the first outlet 202 to be at its minimum (at this time, the air flow of the first outlet 202 can be 0 or close to 0). The air flow of the second outlet 203 and the air flow of the third outlet 204 are adjusted according to the actual air demand. The compressed air pressurized by the compressor system 100 is prioritized for supply to the environmental control system 3 to ensure the air demand in the aircraft 6. The remaining compressed air is supplied to the fuel cell 300. After the compressed air enters the fuel cell 300, it reacts with the fuel in the presence of a catalyst to generate electricity.

[0048] For example, the piping system 200 may include a four-way valve 410, the four ports of which are respectively connected to the air inlet 201, the first air outlet 202, the second air outlet 203 and the third air outlet 204. The control system 400 is connected to the four-way valve 410, and by controlling the opening degree of the four ports of the four-way valve 410, the air flow rate of the first air outlet 202, the air flow rate of the second air outlet 203 and the air flow rate of the third air outlet 204 are controlled.

[0049] For example, when the main engine 2 of the aircraft 6 starts, the opening of the four-way valve 410 connected to the first exhaust port 202 can be increased, and the opening of the four-way valve 410 connected to the third exhaust port 204 can be decreased or closed; after the main engine 2 starts, the opening of the four-way valve 410 connected to the first exhaust port 202 can be decreased or closed.

[0050] In addition, by setting up the fuel cell 300, the auxiliary power unit 1 can generate electricity, which can provide electrical energy for the aircraft 6, and share the power generation pressure of the main engine 2. Furthermore, the fuel cell 300 uses the remaining compressed air of the compressed air system 100 to generate electricity, thus improving the intake conditions of the fuel cell 300 and increasing its efficiency. Compared with the auxiliary power units in related technologies that convert the thermal energy of fuel into mechanical energy and then into electrical energy, the auxiliary power unit 1 in this embodiment of the invention has fewer energy conversion steps and higher overall efficiency.

[0051] In one embodiment, such as Figure 1 and Figure 2 As shown, the auxiliary power unit 1 also includes an energy storage system 600, which is connected to the fuel cell 300. That is, the electrical energy generated by the fuel cell 300 is delivered to the energy storage system 600, which is used to store the electrical energy generated by the fuel cell 300.

[0052] The energy storage system 600 can provide power to the electrical equipment inside the aircraft 6. On the one hand, the output voltage is highly stable, ensuring the stable operation of the electrical equipment inside the aircraft 6 and reducing the probability of fluctuations and damage to the electrical equipment inside the aircraft 6. On the other hand, the energy storage system 600 can store the excess electrical energy generated by the fuel cell 300 for subsequent use, thereby adjusting the amount of electrical energy output, avoiding energy waste, and improving energy utilization.

[0053] For example, the auxiliary power unit 1 also includes an electric accessory system 500. The energy storage system 600 is connected to the electric accessory system 500. The electric accessory system 500 can be used to provide auxiliary power to the aircraft 6, or the electric accessory system 500 can provide auxiliary power to the auxiliary power unit 1. For example, the electric accessory system 500 is connected to the turbine 710 to drive the turbine 710 to rotate, ensuring the stability of the main engine 2 startup.

[0054] In one embodiment, such as Figure 1 and Figure 2 As shown, the auxiliary power unit 1 also includes a combustion chamber 700 and an exhaust gas duct 800.

[0055] Combustion chamber 700 is connected to compression system 100 and is provided with cooling channel (not shown in the figure). Exhaust duct 800 has an inlet end 810 and an outlet end 820 arranged opposite to each other. Inlet end 810 is connected to outlet of fuel cell 300 and outlet end 820 is connected to cooling channel.

[0056] Specifically, the compressed air that does not participate in the power generation reaction of the fuel cell 300 and the water vapor generated by the reaction of the fuel cell 300 can enter the cooling channel through the exhaust pipe 800 to cool the combustion chamber 700, thereby reducing the probability of the combustion chamber 700 being damaged due to high temperature, reducing the cooling cost of the combustion chamber 700, and improving the utilization rate of the exhaust gas of the fuel cell 300.

[0057] Additionally, the air compression system 100 may include a first compressor 110 and a second compressor 120. The first compressor 110 is connected to the piping system 200, and the second compressor 120 is connected to the combustion chamber 700, which is used to drive the turbine 710 to rotate.

[0058] The airflow entering the intake duct is divided into two streams. The first stream enters the first compressor 110 and is pressurized by the first compressor 110. The compressed air is used to supply air to the main engine 2, the environmental control system 3, and the fuel cell 300 during startup. The control system 400 adjusts the air flow to the main engine 2, the environmental control system 3, and the fuel cell 300 in real time according to the demand for compressed air.

[0059] The second stream enters the second compressor 120, is pressurized by the second compressor 120, flows to the combustion chamber 700 and turbine 710, and then the airflow is ejected from the tail nozzle, which is the part of the APU that generates power.

[0060] In this way, the auxiliary power unit 1 can meet the bleed air requirements while avoiding large changes in rotation speed, thereby ensuring the service life of the auxiliary power unit 1.

[0061] In one embodiment, such as Figures 1-3 As shown, the fuel cell 300 is constructed in a ring shape, which increases its output power. For example, the output power of the ring-shaped fuel cell 300 can be increased by approximately 20%-50%. Multiple exhaust gas pipes 800 are included. Increasing the number of exhaust gas pipes 800 increases the flow rate of exhaust gas between the fuel cell 300 and the combustion chamber 700. This ensures that the exhaust gas in the fuel cell 300 is collected and discharged in a timely manner, preventing exhaust gas accumulation. It also ensures that the combustion chamber 700 exchanges heat with sufficient exhaust gas, improving the cooling efficiency of the combustion chamber 700.

[0062] Multiple air inlets 810 are spaced circumferentially along the fuel cell 300, allowing exhaust gases from various areas within the fuel cell 300 to more easily move to the exhaust gas duct 800, preventing exhaust gas accumulation in localized areas within the fuel cell 300. Furthermore, multiple air outlets 820 are spaced circumferentially along the combustion chamber 700, ensuring that all areas within the combustion chamber 700 are cooled, preventing excessively rapid temperature increases due to localized temperature build-up in the combustion chamber 700.

[0063] In addition, since the fuel cell 300 is annular, the intake end 810 can be evenly arranged along the circumference of the fuel cell 300. The amount of exhaust gas in the multiple exhaust pipes 800 is roughly the same, and the cooling effect on each area in the combustion chamber 700 is roughly the same. Therefore, it can be ensured that each area of ​​the combustion chamber 700 is sufficiently cooled.

[0064] Furthermore, since the exhaust gas (air and water vapor) produced by the fuel cell 300 has a certain temperature, it can reduce the hydrogen consumption rate of the auxiliary power unit 1.

[0065] In one embodiment, such as Figures 1-3 As shown, the combustion chamber 700 and the fuel cell 300 are connected to opposite sides of the compressor system 100. The fuel cell 300 can be installed in the compressor system 100 via a flange. The combustion chamber 700 and the compressor system 100 can have a certain gap. The combustion chamber 700 and the compressor system 100 are connected by a structure such as connecting ribs to ensure that the combustion chamber 700 is inlet.

[0066] This ensures the stability of the relative positions of the compressor system 100, combustion chamber 700, and fuel cell 300, and reduces the probability of vibration in the exhaust pipe 800.

[0067] The end of the fuel cell 300 facing away from the compressor system 100 is connected to the air inlet 810, and the end of the fuel cell 300 facing the compressor system 100 can be connected to the compressor system 100, shortening the size of the pipeline system 200, reducing costs, and saving space. The outer peripheral surface of the combustion chamber 700 is connected to the air outlet 820, and multiple exhaust pipes 800 can be arranged around the compressor system 100.

[0068] In this way, on the one hand, the exhaust pipe 800 and the compressor system 100 can be prevented from interfering with each other, and the layout of the compressor system 100, combustion chamber 700, fuel cell 300 and exhaust pipe 800 is more reasonable. On the other hand, the outer circumference of the combustion chamber 700 is connected to the exhaust end 820. Compared with connecting the end of the combustion chamber 700 facing away from the compressor system 100 to the exhaust end 820, the size of the exhaust pipe 800 can be shortened, the cost can be reduced and space can be saved.

[0069] In one embodiment, such as Figure 3 As shown, the central axis of the combustion chamber 700 and the central axis of the fuel cell 300 are arranged to coincide. For example, both the combustion chamber 700 and the fuel cell 300 are connected to the first compressor 110, and the central axis of the first compressor 110, the central axis of the combustion chamber 700 and the central axis of the fuel cell 300 are arranged to coincide.

[0070] In this way, the combustion chamber 700 and the fuel cell 300 do not need to be misaligned in the radial direction of the fuel cell 300 (that is, in the radial direction of the combustion chamber 700), which can ensure that the multiple exhaust pipes 800 are the same size, which is beneficial to the production and manufacturing of the exhaust pipes 800. Furthermore, the combustion chamber 700 and the fuel cell 300 together occupy little space in the radial direction of the fuel cell 300, thus improving space utilization.

[0071] In one embodiment, such as Figures 1-3 As shown, the auxiliary power unit 1 also includes an exhaust device 900 and a fuel heat exchanger 910.

[0072] The exhaust device 900 is connected to the outlet of the combustion chamber 700, and the exhaust gas generated in the combustion chamber 700 is discharged through the exhaust device 900. The fuel heat exchanger 910 is connected to the combustion chamber 700 and the fuel cell 300 respectively. The fuel heat exchanger 910 exchanges heat with the exhaust device 900 and is used to deliver fuel to the combustion chamber 700 and the fuel cell 300.

[0073] Specifically, the aircraft 6 has a fuel storage system 4, which stores liquid fuel. A fuel heat exchanger 910 is connected to the fuel storage system 4, and the liquid fuel in the fuel storage system 4 flows into the fuel heat exchanger 910. Since the fuel heat exchanger 910 exchanges heat with the exhaust device 900, the fuel heat exchanger 910 can absorb the heat of the exhaust gas in the exhaust device 900 to preheat and vaporize the liquid fuel. In this way, the vaporized fuel burns more completely in the combustion chamber 700, reducing NOx (nitrogen oxides) emissions. The vaporized fuel also reacts more completely in the fuel cell 300, resulting in less exhaust gas and higher energy utilization.

[0074] Therefore, the fuel heat exchanger 910 absorbs the heat from the exhaust gas generated in the combustion chamber 700 to heat the fuel, thereby realizing energy recovery and utilization, improving energy efficiency, reducing energy consumption, and gasifying the fuel. The fuel reacts more fully in the combustion chamber 700 and the fuel cell 300, resulting in less exhaust gas and a higher degree of cleanliness.

[0075] In one embodiment, Figure 1 As shown, the auxiliary power unit 1 also includes a first control valve 911 and a second control valve 912. The first control valve 911 and the second control valve 912 can be solenoid valves.

[0076] The first control valve 911 is connected between the fuel cell 300 and the fuel heat exchanger 910, and is electrically connected to the control system 400, which controls the opening degree of the first control valve 911. The second control valve 912 is connected between the combustion chamber 700 and the fuel heat exchanger 910, and is electrically connected to the control system 400, which controls the opening degree of the second control valve 912.

[0077] By adjusting the opening of the first control valve 911 and the second control valve 912, the proportion of fuel flowing from the fuel heat exchanger 910 to the fuel cell 300 and the combustion chamber 700 can be adjusted, thereby controlling the power generation of the fuel cell 300 and the heat generated by the combustion chamber 700. For example, when the power in the aircraft 6 is low or the remaining energy storage space of the energy storage system 600 is large, the opening of the first control valve 911 can be increased. When the power in the aircraft 6 is sufficient or the remaining energy storage space of the energy storage system 600 is small, the opening of the first control valve 911 can be decreased. When the main engine 2 is started, the opening of the second control valve 912 can be increased. After the main engine 2 is started, the opening of the second control valve 912 can be decreased.

[0078] By setting the first control valve 911 and the second control valve 912, the control system 400 can control the opening degree of the first control valve 911 and the second control valve 912 according to the working state of the aircraft 6. This ensures that the fuel cell 300 and the combustion chamber 700 have sufficient fuel and that the auxiliary power unit 1 can work normally. It also prevents excessive fuel supply, which could lead to fuel waste and incomplete combustion, thereby improving fuel utilization and reducing air pollution.

[0079] According to an embodiment of the present invention, in another aspect, an aircraft 6 is also provided, such as Figure 1 and Figure 2 As shown, aircraft 6 includes a main engine 2, an environmental control system 3, a fuel storage system 4, and an auxiliary power unit 1. The first exhaust port 202 of the piping system 200 is connected to the main engine 2, the second exhaust port 203 of the piping system 200 is connected to the environmental control system 3, and the fuel cell 300 is connected to the fuel storage system 4. Aircraft 6 can be an airplane, airship, etc.

[0080] For example, the main engine 2 may include a turbine starter connected to the first exhaust port 202 of the piping system 200. The turbine starter may be fueled with hydrogen to reduce carbon emissions and lower atmospheric pollution. The environmental control system 3 is used to ensure that the aircraft's cabin and equipment bay have the appropriate environment required for the normal operation of the occupants and equipment.

[0081] Since the fuel for the main engine 2, the fuel for the fuel cell 300, and the fuel for the combustion chamber 700 can all be hydrogen fuel, the fuel storage system 4 can store only one type of fuel, which is beneficial for saving space.

[0082] By setting up the fuel cell 300, after the main engine 2 starts, the compressed air generated by the compressor system 100 can flow through the pipeline system 200 to the environmental control system 3 and the fuel cell 300, reducing the amount of compressed air generated by the compressor system 100 discharged into the atmosphere, improving energy utilization, and avoiding energy waste.

[0083] In addition, by setting up the fuel cell 300, the auxiliary power unit 1 can generate electricity, which can provide electrical energy for the aircraft 6, and share the power generation pressure of the main engine 2. Furthermore, the fuel cell 300 uses the remaining compressed air of the compressed air system 100 to generate electricity, thus improving the intake conditions of the fuel cell 300 and increasing its efficiency. Compared with the auxiliary power units in related technologies that convert the thermal energy of fuel into mechanical energy and then into electrical energy, the auxiliary power unit 1 in this embodiment of the invention has fewer energy conversion steps and higher overall efficiency.

[0084] In one embodiment, such as Figure 1As shown, aircraft 6 also includes a third control valve 5, which is connected between fuel cell 300 and fuel storage system 4. The third control valve 5 is connected to control system 400, which controls the opening degree of the third control valve 5. The third control valve 5 can be a solenoid valve, and control system 400 controls the opening degree of the third control valve 5 via an electrical signal.

[0085] By setting a third control valve 5, the control system 400 can control the opening degree of the third control valve 5 according to the amount of fuel required by the auxiliary power unit 1. This ensures that the fuel cell 300 and the combustion chamber 700 have sufficient fuel to ensure the normal operation of the auxiliary power unit 1, while also preventing excessive fuel supply, fuel waste, and incomplete fuel combustion. This improves fuel utilization and reduces air pollution.

[0086] The following description, with reference to the accompanying diagram, illustrates the operation of aircraft 6:

[0087] The intake air is divided into two streams. The first stream flows to the first compressor 110 of the compression system 100. The compressed air, after being pressurized by the first compressor 110, flows into the pipeline system 200 through the intake port 201. The compressed air distribution in the pipeline system 200 is divided into two cases: First, when the main engine 2 needs to be started, the control system 400 adjusts the opening of the four-way valve 410 to make the air flow rate of the first outlet 202 larger and the air flow rate of the third outlet 204 smaller, so that the compressed air is preferentially supplied to the turbine starter of the main engine 2 to ensure the rapid start of the main engine 2. The remaining compressed air is supplied to the ring. Control system 3; secondly, when the main engine 2 does not need to be started, the control system 400 adjusts the opening of the four-way valve 410 to make the air flow of the first outlet 202 smaller (at this time, the air flow of the first outlet 202 can be 0 or close to 0), and the air flow of the second outlet 203 and the third outlet 204 appropriate, so that the compressed air is preferentially supplied to the environmental control system 3 to ensure the needs of the aircraft 6. The remaining compressed air is supplied to the fuel cell 300 for power generation. The electrical energy of the fuel cell 300 is transferred to the energy storage system 600 for storage. The energy storage system 600 can supply power to the electric accessory system 500.

[0088] The second stream flows to the second compressor 120 of the air compressor system 100. The compressed air after being boosted by the second compressor 120 flows to the combustion chamber 700 and the turbine 710 to assist the power unit 1 in generating power.

[0089] The fuel in the fuel storage system 4 flows to the fuel cell 300 and the combustion chamber 700 through the fuel heat exchanger 910. The exhaust gas from the combustion chamber 700 is discharged through the exhaust device 900. The fuel heat exchanger 910 exchanges heat with the exhaust device 900 to absorb the temperature of the exhaust gas in the exhaust device 900 to vaporize the liquefied fuel in the fuel heat exchanger 910.

[0090] The water vapor and ungenerated air produced after the reaction in the fuel cell 300 flow through the exhaust pipe 800 to the cooling pipe of the combustion chamber 700 to cool the combustion chamber 700 and the turbine 710.

[0091] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An auxiliary power device, characterized in that, include: The air compression system (100) includes a first compressor (110) and a second compressor (120); The pipeline system (200) is provided with an air inlet (201), a first air outlet (202), a second air outlet (203) and a third air outlet (204). The first air outlet (202), the second air outlet (203) and the third air outlet (204) are all connected to the air inlet (201). The air inlet (201) is connected to the first compressor (110). The first air outlet (202) is adapted to be connected to the main engine (2) of the aircraft (6). The second air outlet (203) is adapted to be connected to the environmental control system (3) of the aircraft (6). A fuel cell (300), wherein the inlet of the fuel cell (300) is connected to the third outlet (204); The control system (400) is used to control the air flow rate of the first air outlet (202), the air flow rate of the second air outlet (203) and the air flow rate of the third air outlet (204); The combustion chamber (700) is connected to the second compressor (120) and is provided with cooling channels for driving the turbine (710) to rotate; The exhaust gas duct (800) has an inlet end (810) and an outlet end (820) arranged opposite to each other. The inlet end (810) is connected to the outlet of the fuel cell (300), and the outlet end (820) is connected to the cooling channel. Compressed air in the fuel cell (300) that does not participate in the power generation reaction of the fuel cell (300) and water vapor generated by the reaction of the fuel cell (300) enter the cooling channel through the exhaust gas duct (800) to cool the combustion chamber (700). An exhaust device (900) is connected to the outlet of the combustion chamber (700); A fuel heat exchanger (910) is connected to the combustion chamber (700) and the fuel cell (300) and exchanges heat with the exhaust device (900). The fuel heat exchanger (910) is used to supply fuel to the combustion chamber (700) and the fuel cell (300). The airflow entering the intake duct is divided into two streams. The first stream enters the first compressor (110), and is pressurized by the first compressor (110) to supply air to the main engine (2), the environmental control system (3), and the fuel cell (300) during startup. The control system (400) adjusts the air flow to the main engine (2), the environmental control system (3), and the fuel cell (300) in real time according to the demand for compressed air. The second stream enters the second compressor (120), is pressurized by the second compressor (120), flows to the combustion chamber (700) and the turbine (710), and then the airflow is ejected from the tail nozzle.

2. The auxiliary power device according to claim 1, characterized in that, Also includes: An energy storage system (600) is electrically connected to the fuel cell (300).

3. The auxiliary power device according to claim 1 or 2, characterized in that, The fuel cell (300) is constructed in a ring shape, and there are multiple exhaust pipes (800). Multiple air inlets (810) are arranged at intervals along the circumference of the fuel cell (300), and multiple air outlets (820) are arranged at intervals along the circumference of the combustion chamber (700).

4. The auxiliary power device according to claim 3, characterized in that, The combustion chamber (700) and the fuel cell (300) are connected to opposite sides of the compressor system (100). The end of the fuel cell (300) facing away from the compressor system (100) is connected to the air inlet (810), and the outer peripheral surface of the combustion chamber (700) is connected to the air outlet (820).

5. The auxiliary power device according to claim 4, characterized in that, The central axis of the combustion chamber (700) and the central axis of the fuel cell (300) are aligned.

6. The auxiliary power device according to claim 1 or 2, characterized in that, Also includes: A first control valve (911) is connected between the fuel cell (300) and the fuel heat exchanger (910) and is electrically connected to the control system (400), which controls the opening degree of the first control valve (911). The second control valve (912) is connected between the combustion chamber (700) and the fuel heat exchanger (910) and is electrically connected to the control system (400), which controls the opening degree of the second control valve (912).

7. An aircraft, characterized in that, include: Main engine (2), environmental control system (3) and fuel storage system (4); The auxiliary power unit (1) according to any one of claims 1 to 6, wherein the first outlet (202) of the pipeline system (200) is connected to the main engine (2), the second outlet (203) of the pipeline system (200) is connected to the environmental control system (3), and the fuel cell (300) is connected to the fuel storage system (4).

8. The aircraft according to claim 7, characterized in that, Also includes: The third control valve (5) is connected between the fuel cell (300) and the fuel storage system (4) and is connected to the control system (400), which controls the opening degree of the third control valve (5).

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