Double-rotor turboshaft engine and working method

Abstract

The invention discloses a double-rotor turboshaft engine and a working method, the engine comprises a core engine system and a fuel supply system, the core engine system comprises an air inlet channel, an air compressor, a combustion chamber, a gas turbine, a power turbine, a main rotor speed reducer and a main rotor; the fuel supply system comprises an ammonia fuel storage tank, a fuel pump, a first-stage heat regenerator, a second-stage heat regenerator, a hot ammonia turbine, an auxiliary rotor wing speed reducer and an auxiliary rotor wing. High-temperature mixed gas obtained after ammonia decomposition drives the auxiliary rotor wings to do work, the temperature and pressure of a working medium are reduced, then secondary heat regeneration is conducted, the utilization rate of the system for engine tail gas waste heat is increased, the heat efficiency of the system is improved, the overall energy utilization level of the engine is improved, and the transmission structure of the turboshaft engine is simplified; the engine weight is reduced, and the power-to-weight ratio of the engine is increased.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, specifically to a twin-rotor turboshaft engine and its operating method. Background Technology

[0002] Currently, with the increasing demand for advanced aero-engine technology and improved engine economy, turboshaft engines are gradually developing towards higher thrust-to-weight ratio, lower emissions, lower fuel consumption, and higher efficiency.

[0003] However, the chemical regenerative cycle in existing turboshaft engines often suffers from insufficient heat exchange due to limited fuel mass flow rate, which restricts the thermal efficiency of the engine system and the improvement of helicopter range. Furthermore, with the increase in helicopter power demand, the number of rotors loaded on the engine system increases accordingly, the transmission system becomes more complex, and the power-to-weight ratio of the system is reduced, bringing new challenges to the design of high-efficiency turboshaft engines. For example, in turboshaft engines with main and auxiliary rotors, the auxiliary rotor also extracts power from the power turbine, which will lead to a complex transmission structure and a large engine mass.

[0004] Therefore, providing a dual-rotor turboshaft engine and its operating method is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a dual-rotor turboshaft engine and its operating method to solve the problems of insufficient regeneration and underutilization of exhaust waste heat caused by the small fuel mass flow rate when using fuel as the regeneration medium in existing turboshaft engines with chemical regeneration, thereby improving the overall efficiency of the engine system; at the same time, it solves the problems of complex transmission structure and large engine mass caused by the auxiliary rotor extracting power from the power turbine in turboshaft engines with main and auxiliary rotors, thereby reducing engine weight and improving engine power-to-weight ratio.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A twin-rotor turboshaft engine includes a core engine system and a fuel supply system. The core engine system includes an air inlet, a compressor, a combustion chamber, a gas turbine, a power turbine, a main rotor reduction gearbox, and a main rotor. The fuel supply system includes an ammonia fuel tank, a fuel pump, a first-stage regenerator, a second-stage regenerator, a hot ammonia turbine, an auxiliary rotor reduction gearbox, and an auxiliary rotor. The outlet of the air inlet is connected to the inlet of the compressor, the outlet of the compressor is connected to the air inlet of the combustion chamber, the fuel inlet of the combustion chamber is connected to the cold working fluid outlet of the second-stage regenerator, the outlet of the combustion chamber is connected to the inlet of the gas turbine, the gas turbine and the compressor are connected via a rotor shaft drive, and the outlet of the gas turbine is connected to the main rotor. The inlet of the power turbine is connected to the main rotor, the outlet of the power turbine is connected to the inlet of the working fluid of the secondary regenerator, the outlet of the working fluid of the secondary regenerator is connected to the inlet of the working fluid of the primary regenerator, and the outlet of the working fluid of the primary regenerator is connected to the tail nozzle; the power turbine is driven by the main rotor reducer; the outlet of the ammonia fuel storage tank is connected to the inlet of the fuel pump, the outlet of the fuel pump is connected to the inlet of the cold working fluid of the primary regenerator, the outlet of the cold working fluid of the primary regenerator is connected to the inlet of the hot ammonia turbine, and the outlet of the hot ammonia turbine is connected to the inlet of the cold working fluid of the secondary regenerator; the hot ammonia turbine is driven by the auxiliary rotor reducer.

[0008] A method for operating a dual-rotor turboshaft engine includes the following steps: Air from the atmosphere enters the intake duct, and after friction against the intake duct walls, it forms a low-speed, uniform airflow. This airflow then enters the compressor, where it is pressurized and fed into the combustion chamber. There, it mixes thoroughly with the gaseous fuel and combusts to form high-temperature combustion gas. This combustion gas then enters the gas turbine to perform work, which in turn drives the compressor. After completing its work in the gas turbine, the combustion gas enters the power turbine, which rotates the power turbine. The power turbine, through its rotor shaft, drives the gears in the main rotor's reduction gear to rotate, changing the rotational speed and then driving the main rotor to perform work, thus providing lift for the aircraft. After the combustion gas finishes working in the power turbine, it enters the working medium passage in the second-stage regenerator to provide heat energy for the chemical reaction of the fuel and the temperature rise. After the first heat exchange, the combustion gas will continue to enter the working medium passage in the first-stage regenerator to provide heat energy for the phase change of liquid ammonia, the decomposition of ammonia and the temperature rise. After that, the combustion gas discharged from the working medium passage in the first-stage regenerator will finally enter the tail nozzle. After being diffused and expanded in the tail nozzle, it will be discharged into the atmosphere. The main components of the exhaust gas are water vapor, oxygen and nitrogen. When the engine is running, the ammonia fuel in the ammonia fuel tank is pressurized and drawn into the cold working fluid passage of the first-stage regenerator after being heated by the high-temperature combustion gas. After being heated, it will first vaporize into ammonia gas. Then, under the catalytic action of the catalyst, some of the ammonia gas will decompose into nitrogen gas and hydrogen gas. The resulting high-temperature and high-pressure mixture will enter the hot ammonia turbine together to expand and do work. The hot ammonia turbine will then drive the auxiliary rotor gearbox to rotate through the rotor shaft, thereby driving the auxiliary rotor to rotate and providing power for the aircraft's flight and turning. After the mixed gas passes through the hot ammonia turbine, its temperature and pressure will drop. The low-temperature mixed gas will enter the cold working fluid channel of the secondary regenerator. After being heated by the fuel gas and catalyzed by the catalyst, the remaining ammonia will continue to decompose into hydrogen and nitrogen. Then, the high-temperature mixed gas will flow out of the secondary regenerator and into the combustion chamber. The fuel components entering the combustion chamber include hydrogen, nitrogen and some undecomposed ammonia.

[0009] Therefore, the present invention provides a dual-rotor turboshaft engine and its operating method. Compared with the prior art, the present invention has the following beneficial effects: 1) By using fuel decomposition gas to drive a thermal ammonia turbine to do work, multi-stage chemical regeneration of the engine system can be achieved, which solves the problems of insufficient heat exchange and underutilization of exhaust waste heat caused by the small fuel mass flow rate in the chemical regeneration turboshaft engine system, and can further improve the overall efficiency of the engine system. 2) By using fuel decomposition gas to drive the hot ammonia turbine to rotate the auxiliary rotor, the auxiliary rotor is prevented from extracting power from the power turbine, which simplifies the transmission structure of the turboshaft engine, helps to reduce engine weight, and improves the engine power-to-weight ratio. 3) It can realize the replacement of traditional fossil fuels with green aviation power fuels, which significantly reduces the concentration of carbon dioxide in the exhaust of the engine system, reduces the carbon emissions of the engine, and is in line with the development goal of carbon emission reduction. 4) It achieves the coupling of the Brayton cycle and the regenerative cycle, and converts the low-grade thermal energy in the exhaust gas into mechanical energy and chemical energy, thereby improving the energy quality of the turboshaft engine system and thus improving the efficiency of the turboshaft engine system, which is of certain significance in the field of aero-engines. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0011] Figure 1 The attached figure is a structural schematic diagram of a dual-rotor turboshaft engine provided by the present invention. Detailed Implementation

[0012] 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, and 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.

[0013] like Figure 1 As shown in the figure, this invention discloses a dual-rotor turboshaft engine, including a core engine system 1 and a fuel supply system 2. The core engine system 1 includes an air intake 11, a compressor 12, a combustion chamber 13, a gas turbine 14, a power turbine 15, a main rotor reducer 16, and a main rotor 17. The fuel supply system 2 includes an ammonia fuel storage tank 21, a fuel pump 22, a first-stage regenerator 23, a second-stage regenerator 24, a hot ammonia turbine 25, an auxiliary rotor reducer 26, and an auxiliary rotor 27. The inlet of the air intake 11 is connected to the outside atmosphere, the outlet of the air intake 11 is connected to the inlet of the compressor 12, the outlet of the compressor 12 is connected to the air intake of the combustion chamber 13, the fuel inlet of the combustion chamber 13 is connected to the cold working fluid outlet of the second-stage regenerator 24, and the outlet of the combustion chamber 13 is connected to the inlet of the gas turbine 14. The gas turbine 14 and the compressor 12 are connected by a rotor shaft drive. The outlet of the gas turbine 14 is connected to the inlet of the power turbine 15. The outlet of the power turbine 15 is connected to the inlet of the working fluid of the secondary regenerator 24. The outlet of the working fluid of the secondary regenerator 24 is connected to the inlet of the working fluid of the primary regenerator 23. The outlet of the working fluid of the primary regenerator 23 is connected to the tail nozzle and vents to the atmosphere. The power turbine 15 is driven by the main rotor 17 through the main rotor reducer 16. The outlet of the ammonia fuel storage tank 21 is connected to the inlet of the fuel pump 22. The outlet of the fuel pump 22 is connected to the inlet of the cold working fluid of the primary regenerator 23. The outlet of the cold working fluid of the primary regenerator 23 is connected to the inlet of the hot ammonia turbine 25. The outlet of the hot ammonia turbine 25 is connected to the inlet of the cold working fluid of the secondary regenerator 24. The hot ammonia turbine 25 is driven by the auxiliary rotor 27 through the auxiliary rotor reducer 26. The fuel pump 22 extracts shaft power from the hot ammonia turbine 25 to maintain the normal operation of the fuel pump 22. This invention uses the high-temperature mixture after ammonia decomposition to drive the auxiliary rotor 27 to do work, reducing the temperature and pressure of the working fluid, and then performing secondary reheating, thereby improving the system's utilization rate of the engine exhaust waste heat, improving the system's thermal efficiency, enhancing the overall energy utilization level of the engine, and simplifying the transmission structure of the turboshaft engine, which is conducive to reducing engine weight and improving the engine's power-to-weight ratio.

[0014] It is understood that the connection mentioned in this implementation can be achieved through pipelines or by direct mechanical connection, as long as the gas or liquid is connected. In the diagram, solid lines represent air transmission pipelines, dashed lines represent fuel transmission pipelines, and dashed lines at connection points represent gas transmission pipelines.

[0015] This invention also discloses a method for operating a dual-rotor turboshaft engine, comprising the following steps: Air from the atmosphere enters the intake duct 11 and forms a low-speed, uniform airflow after friction against the walls of the intake duct 11. This airflow then enters the compressor 12, where it is pressurized. The high-pressure gas then enters the combustion chamber 13 and mixes thoroughly with the gaseous fuel in the combustion chamber 13. The resulting high-temperature combustion gas enters the gas turbine 14 to perform work and drives the compressor 12. After performing work in the gas turbine 14, the combustion gas enters the power turbine 15, which rotates the power turbine 15. The power turbine 15 drives the gears of the main rotor reducer 16 through the rotor shaft, changing the rotational speed and then driving the main rotor 17 through the rotor shaft to perform work, providing lift for the aircraft. The gas that finishes working in the power turbine 15 will enter the working medium passage in the secondary regenerator 24 to provide heat energy for the chemical reaction of the fuel and the temperature rise. After the first heat exchange, the gas will continue to enter the working medium passage in the primary regenerator 23 to provide heat energy for the phase change of liquid ammonia, the decomposition of ammonia and the temperature rise. After that, the gas discharged from the working medium passage in the primary regenerator 23 will finally enter the tail nozzle. After being diffused and expanded in the tail nozzle, it will be discharged into the atmosphere. The main components of the exhaust gas are water vapor, oxygen and nitrogen. When the engine is running, the ammonia fuel in the ammonia fuel tank 21 is pressurized and drawn in by the fuel pump 22 and enters the cold working fluid channel of the first-stage regenerator 23. After being heated by the high-temperature combustion gas, it will first vaporize into ammonia gas. Then, under the catalytic action of the catalyst, a portion of the ammonia gas decomposes into nitrogen and hydrogen gas to improve the combustion performance, thermal expansion performance and work capacity of the fuel. The resulting high-temperature and high-pressure mixture will enter the hot ammonia turbine 25 together to expand and do work. The hot ammonia turbine 25 then drives the auxiliary rotor reducer 26 to rotate through the rotor shaft, which in turn drives the auxiliary rotor 27 to rotate, providing power for the flight and turning of the aircraft (the auxiliary rotor reducer 26 has gears of different sizes, and the rotation speed of the auxiliary rotor 27 can be changed by the meshing of the gears). This can prevent the auxiliary rotor 27 from extracting shaft work from the power turbine 15 and increase the output power of the main rotor 17. After the mixed gas passes through the hot ammonia turbine 25 and performs work, its temperature and pressure will decrease. The low-temperature mixed gas will enter the cold working fluid channel of the secondary regenerator 24. The temperature difference between the low-temperature mixed gas and the high-temperature gas that has finished performing work in the power turbine 15 will increase, thereby improving the heat exchange of the secondary regenerator 24 and increasing the system's utilization rate of exhaust gas waste heat. After being heated by the gas and catalyzed by the catalyst, the remaining ammonia will continue to decompose to generate hydrogen and nitrogen. That is, the ammonia that has not been decomposed in the primary regenerator 23 will undergo secondary decomposition, increasing the proportion of hydrogen in the fuel and improving the combustion performance of the fuel. Afterward, the high-temperature mixed gas will flow out of the secondary regenerator 24 and enter the combustion chamber 13. The fuel components entering the combustion chamber 13 include hydrogen, nitrogen, and some undecomposed ammonia.

[0016] Specifically, the cold working fluid channel of the first-stage regenerator 23 is divided into two sections: a phase change channel and a fuel decomposition channel. The inner wall of the fuel decomposition channel is coated with a catalyst that promotes the decomposition reaction of ammonia fuel. The inner wall of the cold working fluid channel of the second-stage regenerator 24 is also coated with a catalyst that promotes the decomposition reaction of ammonia fuel. All catalysts are ruthenium-based catalysts, and catalyst supports CNFs and Al2O3 and co-catalyst KOH are added to improve catalyst performance.

[0017] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0018] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A twin-rotor turboshaft engine, characterized in that, The system includes a core engine system and a fuel supply system. The core engine system includes an air intake, a compressor, a combustion chamber, a gas turbine, a power turbine, a main rotor gearbox, and a main rotor. The fuel supply system includes an ammonia fuel tank, a fuel pump, a first-stage regenerator, a second-stage regenerator, a hot ammonia turbine, an auxiliary rotor gearbox, and an auxiliary rotor. The outlet of the air intake is connected to the inlet of the compressor, the outlet of the compressor is connected to the air inlet of the combustion chamber, the fuel inlet of the combustion chamber is connected to the cold working fluid outlet of the second-stage regenerator, the outlet of the combustion chamber is connected to the inlet of the gas turbine, the gas turbine and the compressor are connected via a rotor shaft drive, and the outlet of the gas turbine is connected to the power turbine. The inlet of the power turbine is connected to the inlet of the secondary regenerator, the outlet of the secondary regenerator is connected to the inlet of the primary regenerator, and the outlet of the primary regenerator is connected to the tail nozzle. The power turbine is driven by the main rotor through the main rotor reducer. The outlet of the ammonia fuel storage tank is connected to the inlet of the fuel pump, the outlet of the fuel pump is connected to the inlet of the primary regenerator, the outlet of the primary regenerator is connected to the inlet of the hot ammonia turbine, and the outlet of the hot ammonia turbine is connected to the inlet of the secondary regenerator. The hot ammonia turbine is driven by the auxiliary rotor through the auxiliary rotor reducer.

2. The operating method of a twin-rotor turboshaft engine as described in claim 1, characterized in that, Includes the following steps: Air from the atmosphere enters the intake duct, and after friction against the intake duct walls, it forms a low-speed, uniform airflow. This airflow then enters the compressor, where it is pressurized and fed into the combustion chamber. There, it mixes thoroughly with the gaseous fuel and combusts to form high-temperature combustion gas. This combustion gas then enters the gas turbine to perform work, which in turn drives the compressor. After completing its work in the gas turbine, the combustion gas enters the power turbine, which rotates the power turbine. The power turbine, through its rotor shaft, drives the gears in the main rotor's reduction gear to rotate, changing the rotational speed and then driving the main rotor to perform work, thus providing lift for the aircraft. After the combustion gas finishes working in the power turbine, it enters the working medium passage in the second-stage regenerator to provide heat energy for the chemical reaction of the fuel and the temperature rise. After the first heat exchange, the combustion gas will continue to enter the working medium passage in the first-stage regenerator to provide heat energy for the phase change of liquid ammonia, the decomposition of ammonia and the temperature rise. After that, the combustion gas discharged from the working medium passage in the first-stage regenerator will finally enter the tail nozzle. After being diffused and expanded in the tail nozzle, it will be discharged into the atmosphere. The main components of the exhaust gas are water vapor, oxygen and nitrogen. When the engine is running, the ammonia fuel in the ammonia fuel tank is pressurized and drawn into the cold working fluid passage of the first-stage regenerator after being heated by the high-temperature combustion gas. After being heated, it will first vaporize into ammonia gas. Then, under the catalytic action of the catalyst, some of the ammonia gas will decompose into nitrogen gas and hydrogen gas. The resulting high-temperature and high-pressure mixture will enter the hot ammonia turbine together to expand and do work. The hot ammonia turbine will then drive the auxiliary rotor gearbox to rotate through the rotor shaft, thereby driving the auxiliary rotor to rotate and providing power for the aircraft's flight and turning. After the mixed gas passes through the hot ammonia turbine, its temperature and pressure will drop. The low-temperature mixed gas will re-enter the cold working fluid channel of the secondary regenerator. After being heated by the fuel gas and catalyzed by the catalyst, the remaining ammonia will continue to decompose into hydrogen and nitrogen. Then, the high-temperature mixed gas will flow out of the secondary regenerator and into the combustion chamber. The fuel components entering the combustion chamber include hydrogen, nitrogen and some undecomposed ammonia.

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