Main rotor and tail rotor separation all-hydrogen hybrid power propulsion system suitable for heavy long-voyage helicopter

Abstract

The utility model relates to a main rotor and tail rotor separation all-hydrogen hybrid power propelling system suitable for a heavy long-voyage helicopter. The main rotor and tail rotor separation all-hydrogen hybrid power propelling system comprises a gas conveying pipeline system, a fuel cell driving system, a turboshaft engine propelling system, a low-temperature liquid hydrogen cooling system and the like. The full hydrogen and main tail rotor separation technology is applied to the heavy long-voyage helicopter, a full hydrogen hybrid power system in which a hydrogen fuel turboshaft engine system and a hydrogen fuel cell system are coupled is provided, driving power of a main propeller and driving power of a tail propeller are separated, the tail propeller is independently driven by a fuel cell, and the total hydrogen and main tail rotor separation technology is applied to the heavy long-voyage helicopter. The utility model realizes the application of total hydrogen and main tail rotor separation in heavy long-range helicopters without increasing excessive equipment redundancy, omits a mechanical transmission mechanism of a tail propeller, improves the reliability, has the advantages of energy conservation, environmental protection, high safety performance, light weight, flexible control and the like, and has a wide application prospect.

Description

Technical Field

[0001] The utility model belongs to the technical field of helicopter power systems, and relates to a main and tail rotor separation full hydrogen hybrid power propulsion system suitable for heavy-duty long-range helicopters. Background Art

[0002] Helicopters are a corner of the transportation field. Due to their characteristics of hovering in the air and low take-off requirements, they play an important role in daily life and military. However, existing helicopters usually consume gasoline or kerosene fuel, which consumes a lot of oil resources. As oil resources gradually decrease, the power system of helicopters also needs to choose a wider secondary energy source - hydrogen energy as fuel.

[0003] Existing research focuses on hydrogen-powered pure electric small and medium-sized helicopters. For example, in the alcohol-hydrogen electric aircraft disclosed in CN204991857U, hydrogen is prepared by methanol steam reforming, and high-purity hydrogen is obtained by a membrane separation device plated with palladium-silver alloy. The high-purity hydrogen is generated by the power generation system and supplied to the motor to drive the aircraft to fly; for example, in the composite power electric helicopter disclosed in CN109250124A, electricity is generated by a water hydrogen machine (hydrogen fuel cell system) to supply the motor and fan to operate, drive the rotor and jet mechanism to provide helicopter power. The above schemes can achieve good performance improvement and reduce oil consumption. However, existing research does not consider the full hydrogen power system of heavy-duty long-range helicopters. In view of the low energy density of hydrogen fuel cells, for pure electric heavy-duty long-range helicopters, the weight of the battery to be carried is large, resulting in short endurance and short range, and the inability to complete the navigation mission. Therefore, the application of the full hydrogen hybrid propulsion system combining traditional engines with fuel cells in heavy-duty long-range helicopters is more promising.

[0004] At the same time, the main propeller with a tail rotor is a common configuration of existing helicopters. On the one hand, the tail rotor generates lateral force to balance the lateral torque of the main propeller, and on the other hand, it provides heading control. In existing helicopters, most of the engine power is transmitted to the main propeller through the main reduction mechanism to drive the main propeller to rotate, and a small part is transmitted to the tail propeller through an additional reduction mechanism and a longer transmission mechanism to drive the tail propeller to rotate. Due to the large difference between the output speed of the engine, the speed of the main propeller and the speed of the tail propeller, it is necessary to add an additional reduction mechanism for the tail propeller. Because of the layout of the engine, a longer transmission mechanism is required to transmit the power of the engine to the tail propeller, which further increases the weight, mechanical loss and system complexity of the helicopter. Therefore, research on separating the main and tail rotors is also a hot topic.

[0005] In addition, hydrogen energy has been gradually applied to power fields such as automobiles and gas turbine power generation, and the technology is also constantly being explored and transformed. However, due to its special physical and chemical properties, the application of hydrogen energy in aviation power fields such as helicopters is quite difficult. Utility Model Content

[0006] The purpose of the utility model is to provide a main tail rotor separation full hydrogen hybrid propulsion system suitable for heavy-duty long-range helicopters, so as to realize the application of full hydrogen and main tail rotor separation in heavy-duty long-range helicopters without adding too much equipment redundancy, eliminate the mechanical transmission mechanism of the tail rotor, and improve reliability and control flexibility.

[0007] The purpose of the utility model can be achieved through the following technical solutions:

[0008] In one aspect, the utility model provides a main tail rotor separation full hydrogen hybrid propulsion system suitable for a heavy-duty long-range helicopter, comprising:

[0009] A hydrogen fuel cell subsystem for providing electrical energy;

[0010] Liquid hydrogen storage tank, which is used to provide hydrogen required for the reaction;

[0011] A turboshaft engine propulsion subsystem, comprising an air inlet, a starter motor, a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine, a power turbine, a main propeller and a tail nozzle, wherein the air inlet is connected to the low-pressure compressor, the low-pressure compressor is also connected to the high-pressure compressor through an air delivery pipeline, the high-pressure compressor is also connected to the cathode inlet of the hydrogen fuel cell subsystem and the combustion chamber through an air delivery pipeline, the gas outlet of the combustion chamber is also connected to the high-pressure turbine, the low-pressure turbine, the power turbine and the tail nozzle in sequence through an exhaust gas delivery pipeline, the power turbine is also coupled to the main propeller motor through a reduction assembly, and together drive the main propeller to rotate;

[0012] The hydrogen fuel cell subsystem also supplies power to a tail rotor motor that drives the tail rotor to rotate.

[0013] Furthermore, the high-pressure turbine and the high-pressure compressor are connected via a high-pressure connecting shaft, and the low-pressure turbine, the starter motor and the low-pressure compressor are connected via a low-pressure connecting shaft.

[0014] Furthermore, the low-pressure connecting shaft is nested in the high-pressure connecting shaft.

[0015] Furthermore, the anode outlet of the hydrogen fuel cell subsystem is also connected to the combustion chamber via a circulation delivery pipeline, and the liquid hydrogen storage tank is also connected to the combustion chamber via a hydrogen inlet pipeline;

[0016] The cathode outlet of the hydrogen fuel cell subsystem is also connected to the low-pressure compressor via a circulation transmission pipeline.

[0017] Furthermore, it also includes a low-temperature liquid hydrogen cooling subsystem, which includes an oil tank, a circulation pump and a heat exchanger that are connected in sequence through an oil delivery pipeline to form a circulation, and the oil delivery pipeline and the hydrogen supply pipeline connected to the liquid hydrogen storage tank perform heat exchange at the heat exchanger.

[0018] Furthermore, the oil delivery pipeline also passes through and cools operating components including the tail rotor motor, hydrogen fuel cell system and main rotor motor.

[0019] Furthermore, the hydrogen fuel cell subsystem is composed of a number of hydrogen fuel cells stacked and connected in series, each hydrogen fuel cell has a cathode channel and an anode channel, and the cathode channels of all hydrogen fuel cells are also collectively connected to the cathode inlet and outlet of the hydrogen fuel cell subsystem, and the anode channels of all hydrogen fuel cells are also collectively connected to the anode inlet and outlet of the hydrogen fuel cell subsystem.

[0020] Furthermore, the reduction assembly includes an internal reducer and a main reducer, the power turbine is connected to the internal reducer, and couples power with the main propeller motor in the main reducer to jointly drive the main propeller.

[0021] Furthermore, the hydrogen fuel cell subsystem is also connected to an inverter, and then electrically connected to the airborne system, the main propeller motor, the tail propeller motor and the starter motor through cables.

[0022] On the other hand, the utility model also provides a main tail rotor separation full hydrogen hybrid propulsion method suitable for a heavy-duty long-range helicopter, which is based on any of the main tail rotor separation full hydrogen hybrid propulsion methods described above, and the propulsion method includes a quick start mode, an engine single drive mode, a fuel cell single drive mode and a parallel drive mode, wherein:

[0023] When the main and tail rotor separation full hydrogen hybrid propulsion system is in the rapid start mode, the cathode inlet of the hydrogen fuel cell subsystem supplies external high-pressure air, the hydrogen fuel cell subsystem first runs and outputs electrical energy to drive the starter motor and the main propeller motor, the starter motor quickly starts the turboshaft engine (i.e., the turboshaft engine propulsion subsystem) to reach the idle speed, the power turbine outputs mechanical energy coupled with the mechanical energy of the main propeller motor, and together drives the main propeller to rotate;

[0024] When the main and tail rotor separation full hydrogen hybrid propulsion system is in the engine-only drive mode, the main propeller is driven by the turboshaft engine alone, and the tail propeller is directly driven by the tail rotor motor;

[0025] When the main and tail rotor separation full hydrogen hybrid propulsion system is in the fuel cell single drive mode, the hydrogen fuel cell subsystem directly supplies power to the main propeller motor and the tail propeller motor, and outputs power to drive the main propeller and the tail propeller respectively;

[0026] When the main and tail rotors are separated and the full hydrogen hybrid propulsion system is in parallel drive mode, the turboshaft engine enters the rated operating condition, providing sufficient power for the main propeller to rotate, and the hydrogen fuel cell subsystem supplies power to the tail rotor motor and drives the tail propeller to work.

[0027] Or the turboshaft engine enters full-load condition, the hydrogen fuel cell subsystem outputs electrical energy to drive the main propeller motor and the tail propeller motor, the main propeller motor and the power turbine provide sufficient power for the main propeller, and the tail propeller motor outputs power to drive the tail propeller to work.

[0028] Compared with the prior art, the utility model has at least the following advantages:

[0029] 1. The utility model proposes a main tail rotor separation full hydrogen hybrid propulsion system suitable for heavy-duty long-range helicopters, which solves the application of full hydrogen in heavy-duty long-range helicopters, and there is no prior art at present.

[0030] 2. The utility model proposes a low-temperature liquid hydrogen cooling system, which uses the energy of liquid hydrogen for cooling and uses the heat of mechanical parts to heat the liquid hydrogen to gasify it into hydrogen, which is then sent to the combustion chamber and the anode of the fuel cell. Through the multi-stage utilization and circulation of energy, the operating efficiency of the system is improved, and the system quality and operating costs are reduced.

[0031] 3. The utility model adopts the main tail rotor separation technology, the fuel cell drives the tail rotor motor to rotate, and drives the tail propeller to rotate through direct mechanical connection. Directly controlled by the fuel cell, the redundant and cumbersome mechanical transmission mechanism is eliminated, the complexity of the system is reduced, the system quality is reduced, and the system life is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a configuration diagram of the power system of a traditional helicopter;

[0033] Figure 2 This is the configuration diagram of the power system of a fully hydrogen helicopter with the main and tail rotors separated;

[0034] Figure 3 This is a schematic diagram of the helicopter's main and tail rotor separation full hydrogen hybrid propulsion system;

[0035] Figure 4 This is a schematic diagram of the cryogenic liquid hydrogen cooling system of the all-hydrogen hybrid;

[0036] Figure 5 It is a schematic diagram of a shell and tube heat exchanger;

[0037] Description of the markings in the figure:

[0038] 1-intake; 2-low-pressure compressor; 3-high-pressure compressor; 4-hydrogen fuel cell subsystem; 5-combustion chamber; 6-high-pressure turbine; 7-low-pressure turbine; 8-power turbine; 9-tail nozzle; 10-inner reducer; 11-main reducer; 12-main propeller; 13-inverter; 14-tail propeller; 15-turboshaft engine propulsion subsystem; 16-oil tank; 17-circulating pump; 18-heat exchanger; 19-liquid hydrogen storage tank; 20-onboard system; 21-starting motor; 22-tail propeller motor; 23-main propeller motor; 24-traditional transmission mechanism. DETAILED DESCRIPTION

[0039] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0040] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "vertical", "circumferential", "radial", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0041] In the following implementation manners or examples, unless otherwise specified, functional components or structures are conventional components or conventional structures used in the art to achieve corresponding functions.

[0042] In order to realize the application of full hydrogen and main tail rotor separation in heavy-duty long-range helicopters without adding too much equipment redundancy, the utility model provides a main tail rotor separation full hydrogen hybrid propulsion system suitable for heavy-duty long-range helicopters. The structure of the system can be seen in Figures 2 to 3 As shown in the following, including:

[0043] A hydrogen fuel cell subsystem 4, which is used to provide electrical energy;

[0044] A liquid hydrogen storage tank 19, which is used to provide hydrogen required for the reaction;

[0045] A turboshaft engine propulsion subsystem 15, comprising an air inlet 1, a starter motor 21, a low-pressure compressor 2, a high-pressure compressor 3, a combustion chamber 5, a high-pressure turbine 6, a low-pressure turbine 7, a power turbine 8, a main propeller 12 and a tail nozzle 9, wherein the air inlet 1 is connected to the low-pressure compressor 2, the low-pressure compressor 2 is also connected to the high-pressure compressor 3 through an air delivery pipeline, the high-pressure compressor 3 is also connected to the cathode inlet of the hydrogen fuel cell subsystem 4 and the combustion chamber 5 through an air delivery pipeline, the gas outlet of the combustion chamber 5 is also connected to the high-pressure turbine 6, the low-pressure turbine 7, the power turbine 8 and the tail nozzle 9 in sequence through an exhaust gas delivery pipeline, the power turbine 8 is also coupled to the main propeller motor 23 through a reduction assembly, and together drives the main propeller 12 to rotate;

[0046] The hydrogen fuel cell subsystem 4 also supplies power to the tail rotor motor 22 that drives the tail rotor 14 to rotate.

[0047] In some specific embodiments, the high-pressure turbine 6 is connected to the high-pressure compressor 3 via a high-pressure connecting shaft, and the low-pressure turbine 7, the starter motor 21 and the low-pressure compressor 2 are connected via a low-pressure connecting shaft.

[0048] In a more specific embodiment, the low-pressure connecting shaft is nested in the high-pressure connecting shaft.

[0049] In some specific embodiments, the anode outlet of the hydrogen fuel cell subsystem 4 is further connected to the combustion chamber 5 via a circulation delivery pipeline, and the liquid hydrogen storage tank 19 is further connected to the combustion chamber 5 via a hydrogen inlet pipeline;

[0050] The cathode outlet of the hydrogen fuel cell subsystem 4 is also connected to the low-pressure compressor 2 through a circulation pipeline. The cathode outlet gas of the hydrogen fuel subsystem 4 is mixed with the cooled air and then sent to the low-pressure compressor 2 for further pressurization.

[0051] In some specific implementations, please refer to Figure 4 As shown, the main tail rotor separation full hydrogen hybrid propulsion system also includes a low-temperature liquid hydrogen cooling subsystem, which includes an oil tank 16, a circulation pump 17 and a heat exchanger 18 that are sequentially connected and circulated through an oil delivery pipeline, and the oil delivery pipeline and the hydrogen supply pipeline connected to the liquid hydrogen storage tank 19 perform heat exchange at the heat exchanger 18. After the heat exchange, the liquid hydrogen changes into gasified hydrogen, and then is transported to the anode and combustion chamber 5 of the hydrogen fuel cell subsystem 4 through the corresponding hydrogen supply pipeline.

[0052] In a more specific embodiment, the oil delivery pipeline also passes through and cools the operating parts including the tail rotor motor 22, the hydrogen fuel cell system and the main rotor motor 23. After the oil in the oil tank 16 is heat-exchanged with liquid hydrogen at the heat exchanger 18, the obtained low-temperature oil is transported through the oil delivery pipeline to cool the mechanical operating parts, and then circulates back to the oil tank 16. At the same time, it can also have the function of lubricating the mechanical parts.

[0053] In some specific embodiments, the hydrogen fuel cell subsystem 4 is composed of a number of hydrogen fuel cells stacked in series, each hydrogen fuel cell has a cathode channel and an anode channel, and the cathode channels of all hydrogen fuel cells are also connected to the cathode inlet and outlet of the hydrogen fuel cell subsystem 4, and the anode channels of all hydrogen fuel cells are also connected to the anode inlet and outlet of the hydrogen fuel cell subsystem 4.

[0054] In some specific embodiments, the reduction assembly includes an internal reducer 10 and a main reducer 11, the power turbine 8 is connected to the internal reducer, and couples power with the main propeller motor 23 in the main reducer 11 to jointly drive the main propeller 12.

[0055] In some specific embodiments, the hydrogen fuel cell subsystem 4 is also connected to the inverter 13, and the output DC power is converted into AC power by the inverter 13, and then electrically connected to the airborne system 20, the main propeller motor 23, the tail propeller motor 22 and the starter motor 21 through cables. In addition, the turboshaft engine is arranged on the top of the helicopter cabin to drive the main propeller 12 to rotate, and the hydrogen fuel cell system is arranged at the rear of the helicopter cabin. This arrangement effectively simplifies the mechanical transmission mechanism of the tail propeller 14, improves reliability, and reduces the weight of the power system.

[0056] The above embodiments may be implemented individually or in any combination of two or more.

[0057] The above implementation is described in more detail below in conjunction with Example 1.

[0058] Embodiment 1:

[0059] Figure 1 This is the configuration diagram of the traditional helicopter power system. Figure 2 : is a configuration diagram of the main tail rotor separation full hydrogen helicopter power system of this embodiment, Figure 3 This is a schematic diagram of the helicopter's main tail rotor separation full hydrogen hybrid propulsion system. Figure 4 This is a schematic diagram of the low-temperature liquid hydrogen cooling system of the all-hydrogen hybrid. Figure 5 It is a schematic diagram of a shell and tube heat exchanger 18. The system includes a gas pipeline subsystem, a hydrogen fuel cell subsystem 4, a turboshaft engine propulsion subsystem 15, and a cryogenic liquid hydrogen cooling subsystem.

[0060] like Figure 1 , Figure 2 As shown, this embodiment uses a hydrogen fuel cell system coupled with a turboshaft engine propulsion system to replace the traditional turboshaft engine system, saving the complex and inefficient traditional transmission mechanism 24, using cable transmission, increasing the response speed, and facilitating efficient control; the full hydrogen hybrid system uses liquid hydrogen cooling, efficiently utilizing the energy of liquid hydrogen, and at the same time, due to the hydrogen fuel cell system, the multi-energy system adapts to more complex working conditions and critical situations;

[0061] like Figure 3 As shown, the gas pipeline system can connect the hydrogen fuel cell subsystem 4 and the turboshaft engine propulsion subsystem 15 in the following manner:

[0062] The gas pipeline system is mainly divided into hydrogen pipeline, air pipeline, circulation pipeline and tail gas pipeline.

[0063] The hydrogen delivery pipeline includes a first hydrogen delivery pipeline, a second hydrogen delivery pipeline, and a third hydrogen delivery pipeline; the air delivery pipeline includes a first air delivery pipeline, a second air delivery pipeline, a third air delivery pipeline, and a fourth air delivery pipeline; the reflux delivery pipeline includes a first reflux delivery pipeline and a second reflux delivery pipeline; the tail gas delivery pipeline includes a first tail gas delivery pipeline, a second tail gas delivery pipeline, a third tail gas delivery pipeline, and a fourth tail gas delivery pipeline;

[0064] One end of the first hydrogen delivery pipeline is connected to the outlet of the heat exchanger 18, and the other end is connected to the inlet of the three-way valve; one end of the second hydrogen delivery pipeline is connected to the first outlet of the three-way valve, and the other end is connected to the anode inlet of the hydrogen fuel cell subsystem 4; one end of the third hydrogen delivery pipeline is connected to the second outlet of the three-way valve, and the other end is connected to the combustion chamber 5; the cathode outlet of the hydrogen fuel cell subsystem 4 is connected to one end of the first reflux delivery pipeline, and the other end is connected to the interstage of the low-pressure compressor 2; one end of the second reflux delivery pipeline is connected to the anode outlet of the hydrogen fuel cell, and the other end is connected to the combustion chamber 5.

[0065] The anode outlet gas of the hydrogen fuel cell subsystem 4 and the hydrogen that does not participate in the reaction are transported to the combustion chamber 5 for continued combustion, saving energy, wherein: the cathode tail gas is composed of cooled unused nitrogen, excess oxygen and water, a product of the electrochemical reaction; the anode tail gas is composed of excess hydrogen and water, a product of the electrochemical reaction.

[0066] The air inlet 1 is connected to the low-pressure compressor 2 through a first air delivery pipeline; the low-pressure compressor 2 is connected to the high-pressure compressor 3 through a second air delivery pipeline; the high-pressure compressor 3 is connected to the cathode inlet of the hydrogen fuel cell subsystem 4 through a third air delivery pipeline, and is connected to the combustion chamber 5 through a fourth air delivery pipeline.

[0067] The combustion chamber 5 is connected to the high-pressure turbine 6 through the first exhaust gas delivery pipeline; the high-pressure turbine 6 is connected to the low-pressure turbine 7 through the second exhaust gas delivery pipeline; the low-pressure turbine 7 is connected to the power turbine 8 through the third exhaust gas delivery pipeline; the power turbine 8 is connected to the tail nozzle 9 through the fourth exhaust gas delivery pipeline.

[0068] The turboshaft engine propulsion subsystem 15 includes an air inlet 1, a low-pressure compressor 2, a high-pressure compressor 3, a combustion chamber 5, a high-pressure turbine 6, a low-pressure turbine 7 and a power turbine 8; wherein: the high-pressure turbine 6 is coaxial with the high-pressure compressor 3 (high-pressure connecting shaft), the low-pressure turbine 7 is coaxial with the low-pressure compressor 2 (low-pressure connecting shaft), and the low-pressure connecting shaft is nested in the high-pressure connecting shaft. The high-pressure compressor 3 and the low-pressure compressor 2 compress the air and then burn with hydrogen in the combustion chamber 5 to produce a chemical reaction. The gas after combustion enters the high-pressure turbine 6, the low-pressure turbine 7, and the power turbine 8 through the tail gas pipeline in turn to perform work, and finally is discharged into the atmosphere through the tail nozzle 9. The high-pressure turbine 6 drives the high-pressure compressor 3 through the shaft, the low-pressure turbine 7 drives the low-pressure compressor 2 through the shaft, and the power turbine 8 is decelerated through the internal reducer 10, thereby driving the main propeller 12 connected to the main reducer 11 to rotate.

[0069] In this embodiment, the hydrogen fuel cell subsystem 4 and the combustion chamber 5 of the turboshaft engine directly use hydrogen as fuel.

[0070] like Figure 3 The main and tail rotor separation principle of the helicopter is shown. The power turbine 8 of the turboshaft engine is mechanically connected to the reducer 10 in the body, and the rotation of the turbine is transmitted through the gears in the reducer, the speed is reduced, the torque is increased, and it is transmitted to the main reducer 11 on the main propeller 12; the main reducer 11 converts the axial output work into radial output work and transmits it to the main propeller 12, reducing the speed of the shaft, increasing the torque of the shaft, and driving the main propeller 12 of the helicopter to rotate; the turboshaft engine of this embodiment drives the main propeller 12 alone, and no mechanical transmission components such as the tail propeller 14 are set, and the power is transmitted to the tail propeller 14, accessories, etc. according to the power and torque requirements.

[0071] The fuel cell drive system is mainly a hydrogen fuel cell system 4, which is mainly composed of multiple hydrogen fuel cells stacked in series. The air and hydrogen entering the fuel cell stack are distributed to each cell. In this embodiment, multiple fuel cells are connected in series to obtain a high-voltage and high-power fuel cell system. Each fuel cell plate has air and hydrogen channels, which are supplied through a pipeline system. The air and hydrogen supplied to the fuel cell system are first distributed to the cathode channel and anode channel on each fuel cell plate, and then the cathode and anode channels of each fuel cell stack distribute the air and hydrogen to each fuel cell. The hydrogen fuel cell subsystem 4 is connected to the inverter 13, which converts the output direct current into alternating current, and transmits the alternating current to the airborne system 20, the starting motor 21 of the turboshaft engine, the main propeller motor 23 and the tail propeller motor 22, and the circulating pump 17. The starting motor 21 is connected to the low-pressure compressor 2, and the tail propeller motor 22 is directly connected to the tail propeller 14. The turboshaft engine is started by the starting motor 21, and the tail propeller motor 22 directly drives the tail propeller 14 to rotate. In this way, redundant mechanical transmission mechanisms are eliminated and the system complexity is reduced.

[0072] like Figure 4 The liquid hydrogen cooling principle is shown. The liquid hydrogen storage tank 19 is made of multiple layers of thermal insulation and protection materials, and stores liquid hydrogen fuel inside, with the temperature maintained at or below 20.35K. Liquid hydrogen flows from the storage tank into the heat exchanger 1818, as shown in FIG. Figure 5 As shown, the heat exchanger 18 may be a commonly used shell and tube heat exchanger 18, which is composed of a series of tube bundles, which are fixed on the tube sheet, and the tube bundle and the tube sheet are encapsulated in the shell. There are heads at both ends of the shell, and the oil flows into the tube bundle from the inlet and flows out from the outlet on the other side; the liquid hydrogen flows into the inlet of the connecting pipe of the shell, and the hydrogen flows out at the outlet on the other side. The oil and liquid hydrogen in the tube bundle do not mix with each other, and heat is only exchanged through the tube wall. There are baffles on the tube wall to enhance heat exchange. Liquid hydrogen flows in from the bottom of the outer shell of the heat exchanger 18. The outer shell of the heat exchanger 18 is composed of multiple layers of thermal insulation materials. The liquid hydrogen fills the interior of the heat exchanger 18. Due to heat exchange with the high-temperature oil in the tube bundle, the liquid hydrogen at the outlet is gasified into hydrogen and supplied to the combustion chamber 5 of the turboshaft engine and the anode of the hydrogen fuel cell subsystem 4; and the low-temperature oil after heat exchange is sent to the cooling of the main propeller motor 23, the tail propeller motor 22, the hydrogen fuel cell subsystem 4, the starting motor 21 and the main reducer 11 through the oil delivery pipeline for cooling. The cooled high-temperature oil enters the internal tube bundle of the heat exchanger 18, and fully exchanges heat with the liquid hydrogen in the internal tube bundle. The tube wall is composed of a material that is resistant to low temperatures and has low thermal resistance. The oil lowers its temperature inside the heat exchanger 18 and continues to cool the motor and other components.

[0073] Refer to the following Figure 3 Describe in detail the working process and working mode of the main tail rotor separation full hydrogen hybrid propulsion system for helicopters:

[0074] According to the different working conditions of the helicopter, the main tail rotor separation full hydrogen hybrid propulsion system for the helicopter has the following working modes: quick start mode, engine single drive mode, fuel cell single drive mode, parallel drive mode.

[0075] 1) Quick Start Mode

[0076] When the hybrid power system is in the quick start mode, which is applicable to the start of a helicopter, the cathode of the fuel cell is supplied by external high-pressure air, the fuel cell runs first, and then the fuel cell outputs electrical energy to drive the starter motor 21 of the turboshaft engine and the main propeller motor 23 on the main reducer 11. The starter motor 21 quickly starts the turboshaft engine to make the engine reach the idle speed. The output mechanical energy of the power turbine 8 is coupled with the mechanical energy of the main propeller motor 23 through the main reducer 11 to drive the main propeller 12 to rotate. At the same time, the output electrical energy of the hydrogen fuel cell subsystem 4 is also supplied to the airborne system 20, the tail rotor motor 22 and the circulating pump 17 of the cooling system, and the cooling system starts to circulate.

[0077] 2) Engine-only driving mode

[0078] When the hybrid power system is in the engine-only drive mode, this mode is suitable for the normal level flight of the helicopter, that is, when flying at basically the same altitude, the turboshaft engine alone drives the main propeller 12 to rotate, and the hydrogen fuel cell subsystem 4 only drives the tail rotor motor 22 to rotate, and the tail rotor motor 22 directly drives the tail rotor 14 to rotate.

[0079] 3) Fuel cell single drive mode

[0080] When the hybrid power system is in the fuel cell-only drive mode, this mode is suitable for when the helicopter requires less power, such as when the helicopter lands smoothly, and when the turboshaft engine fails and stops in the air, the fuel cell will directly power the tail rotor motor 22 and the main rotor motor 23. The power output by the main rotor motor 23 drives the main propeller 12 to work through the main reducer 11, and the power output by the tail rotor motor 22 directly drives the tail propeller 14 to work. In the event of a failure, in order to ensure the safety of the helicopter, the fuel cell supplies the starter motor 21, which tries to restart the turboshaft engine while driving the main propeller 12 and the tail propeller 14 to provide a certain lift for the helicopter to ensure its safe landing.

[0081] 4) First parallel drive mode

[0082] When the hybrid power system is in the first parallel drive mode, this mode is suitable for the rapid maneuvering condition of the helicopter and can improve the maneuverability of the helicopter. The turboshaft engine enters the rated condition, provides sufficient power for the main propeller 12, and the fuel cell drives the tail rotor motor 22. The power output by the tail rotor motor 22 drives the tail rotor 14 to work.

[0083] 5) Second parallel drive mode

[0084] When the hybrid power system is in the second parallel drive mode, this mode is suitable for emergency maneuvering conditions of the helicopter and can significantly improve the maneuverability of the helicopter. The turboshaft engine enters the full load condition, and the electric energy output by the hydrogen fuel cell subsystem 4 jointly drives the main propeller motor 23 and the tail propeller motor 22. The main propeller motor 23 and the power turbine 8 provide sufficient power for the main rotor, and the power output by the tail propeller motor 22 drives the tail propeller 14 to work.

[0085] This embodiment can solve the problem of achieving full hydrogen and main tail rotor separation in heavy-duty long-range helicopter applications without adding too much extra equipment. The main tail rotor separation full hydrogen hybrid propulsion system has the advantages of energy saving and environmental protection, high safety performance, light weight, flexible control, etc.

[0086] The above description of the embodiments is to facilitate the understanding and use of the utility model by those skilled in the art. It is obvious that those familiar with the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the utility model is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the utility model without departing from the scope of the utility model should be within the scope of protection of the utility model.

Claims

1. A main and tail rotor separation full hydrogen hybrid propulsion system suitable for heavy-duty long-range helicopters, characterized in that: include: A hydrogen fuel cell subsystem for providing electrical energy; Liquid hydrogen storage tank, which is used to provide hydrogen required for the reaction; A turboshaft engine propulsion subsystem, comprising an air inlet, a starter motor, a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine, a power turbine, a main propeller and a tail nozzle, wherein the air inlet is connected to the low-pressure compressor, the low-pressure compressor is also connected to the high-pressure compressor through an air delivery pipeline, the high-pressure compressor is also respectively connected to the cathode inlet of the hydrogen fuel cell subsystem and the combustion chamber through an air delivery pipeline, the air outlet of the combustion chamber is also connected to the high-pressure turbine, the low-pressure turbine, the power turbine and the tail nozzle in sequence through an exhaust gas delivery pipeline, the power turbine is also coupled to the main propeller motor through a reduction assembly, and together drive the main propeller to rotate; The hydrogen fuel cell subsystem also supplies power to a tail rotor motor that drives the tail rotor to rotate.

2. The main and tail rotor separation full hydrogen hybrid propulsion system suitable for heavy-duty long-range helicopters according to claim 1, characterized in that: The high-pressure turbine is connected to the high-pressure compressor via a high-pressure connecting shaft, and the low-pressure turbine, the starter motor and the low-pressure compressor are connected to each other via a low-pressure connecting shaft.

3. The main and tail rotor separation full hydrogen hybrid propulsion system suitable for heavy-duty long-range helicopters according to claim 2, characterized in that: The low-pressure connecting shaft is nested in the high-pressure connecting shaft.

4. The main tail rotor separation full hydrogen hybrid propulsion system suitable for a heavy-duty long-range helicopter according to claim 1, characterized in that: The anode outlet of the hydrogen fuel cell subsystem is also connected to the combustion chamber via a circulation delivery pipeline, and the liquid hydrogen storage tank is also connected to the combustion chamber via a hydrogen inlet pipeline; The cathode outlet of the hydrogen fuel cell subsystem is also connected to the low-pressure compressor via a circulation transmission pipeline.

5. The main and tail rotor separation full hydrogen hybrid propulsion system suitable for heavy-duty long-range helicopters according to claim 1, characterized in that: It also includes a low-temperature liquid hydrogen cooling subsystem, which includes an oil tank, a circulation pump and a heat exchanger that are sequentially connected through an oil delivery pipeline to form a circulation, and the oil delivery pipeline and the hydrogen supply pipeline connected to the liquid hydrogen storage tank perform heat exchange at the heat exchanger.

6. The main and tail rotor separation full hydrogen hybrid propulsion system suitable for heavy-duty long-range helicopters according to claim 5, characterized in that: The oil delivery pipeline also passes through and cools operating components including the tail rotor motor, hydrogen fuel cell system and main rotor motor.

7. The main tail rotor separation full hydrogen hybrid propulsion system suitable for a heavy-duty long-range helicopter according to claim 1, characterized in that: The hydrogen fuel cell subsystem is composed of a number of hydrogen fuel cells stacked in series, each of which is provided with a cathode channel and an anode channel, and the cathode channels of all hydrogen fuel cells are collectively connected to the cathode inlet and outlet of the hydrogen fuel cell subsystem, and the anode channels of all hydrogen fuel cells are collectively connected to the anode inlet and outlet of the hydrogen fuel cell subsystem.

8. The main and tail rotor separation full hydrogen hybrid propulsion system suitable for a heavy-duty long-range helicopter according to claim 1, characterized in that: The reduction assembly includes an internal reducer and a main reducer. The power turbine is connected to the internal reducer and couples power with the main propeller motor in the main reducer to jointly drive the main propeller.

9. The main and tail rotor separation full hydrogen hybrid propulsion system suitable for a heavy-duty long-range helicopter according to claim 1, characterized in that: The hydrogen fuel cell subsystem is also connected to an inverter, and then electrically connected to an airborne system, a main propeller motor, a tail propeller motor and a starter motor via cables.

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