Hybrid power turboshaft engine and working method

Abstract

The invention discloses a hybrid power turboshaft engine and a working method, the engine comprises a core machine system and a fuel cell power supply system, and the core machine system comprises an air inlet channel, an air compressor, a main combustion chamber, a gas turbine and a power turbine; the fuel cell power supply system comprises a liquid ammonia storage tank, a fuel pump, a liquid ammonia decomposer, a pressure reducing valve, a heat exchanger and a proton exchange membrane fuel cell. According to the invention, a hybrid power form of combining a turbine power system and a fuel cell power system is adopted, so that the output power of the turboshaft engine is ensured, and meanwhile, the proton exchange membrane fuel cell provides electric energy for airborne electric equipment of the engine; the problems that the electric power requirement of an existing turboshaft engine is gradually improved, power of storage batteries such as lithium batteries is insufficient, and electric power is difficult to extract from a power turbine are solved. Meanwhile, the ammonia working medium serves as power generation fuel, the energy conversion efficiency of the aviation turboshaft engine is improved, and energy consumption is reduced.

Description

Technical Field

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

[0002] In recent years, driven by the strong demand for helicopter power and supported by major engine development programs, aero-turboshaft engines have been continuously developing towards more compact structures, higher performance, and lower energy consumption. Based on the basic turboshaft engine configuration, turboshaft engine systems are optimized by adopting new processes, materials, and technologies, or by improving aerodynamic design, increasing turbine inlet temperature, increasing flow rate, and altering component structures. This has led to the development of a series of turboshaft engines that meet the diverse applications and power requirements of different helicopters.

[0003] However, on the one hand, with the improvement of engine system cycle parameters, especially the increase in turbine inlet temperature and flow rate, the exhaust heat loss of turboshaft engines also increases rapidly, and the engine energy utilization rate decreases, which affects its efficiency and flight range. On the other hand, the power demand of turboshaft engines is gradually increasing, and the existing battery capacity can no longer meet the power demand of the new generation of helicopters, making it difficult to extract power from the power turbine. In addition, with the rapid growth of the aviation industry, air transport will become one of the main sources of greenhouse gas emissions in the future transportation sector, and the environmental problems it brings have received more attention, posing new requirements for the next generation of aircraft in terms of fuel consumption and pollution emissions.

[0004] Therefore, providing a hybrid 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 hybrid turboshaft engine and its operating method to reduce greenhouse gas emissions from turboshaft engines and solve problems such as the difficulty in further improving the thermal efficiency of turboshaft engine systems, serious waste heat loss from exhaust gas, and the rapid increase in the power demand of airborne equipment.

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

[0007] A hybrid turboshaft engine includes a core engine system and a fuel cell power supply system. The core engine system includes an intake duct, a compressor, a main combustion chamber, a gas turbine, and a power turbine. The fuel cell power supply system includes a liquid ammonia storage tank, a fuel pump, a liquid ammonia decomposer, a pressure reducing valve, a heat exchanger, and a proton exchange membrane fuel cell. The outlet of the intake duct is connected to the inlet of the compressor, the outlet of the compressor is connected to the air inlet of the main combustion chamber, the outlet of the main combustion chamber is connected to the inlet of the gas turbine, the gas turbine and the compressor are connected via a rotor shaft drive, the outlet of the gas turbine is connected to the inlet of the power turbine, and the gas outlet of the power turbine is connected to the gas inlet of the liquid ammonia decomposer. The outlet of the liquid ammonia storage tank is connected to the inlet of the fuel pump, the outlet of the fuel pump is connected to the inlet of the ammonia fuel channel of the liquid ammonia decomposer, the outlet of the ammonia fuel channel of the liquid ammonia decomposer is connected to the inlet of the pressure reducing valve and the fuel inlet of the main combustion chamber, the outlet of the pressure reducing valve is connected to the inlet of the fuel channel of the heat exchanger, the outlet of the fuel channel of the heat exchanger is connected to the anode inlet of the proton exchange membrane fuel cell, the outlet channel of the compressor interstage bleed air is connected to the inlet of the air channel of the heat exchanger, the outlet of the air channel of the heat exchanger is connected to the cathode inlet of the proton exchange membrane fuel cell, and the cathode outlet and anode outlet of the proton exchange membrane fuel cell are connected to the tail nozzle.

[0008] Furthermore, the fuel pump is electrically connected to the proton exchange membrane fuel cell.

[0009] A method for operating a hybrid turboshaft engine includes the following steps: Outside the engine, incoming air enters the intake duct, is decelerated and diffused to form a uniform airflow, and then enters the compressor for pressurization. Inside the compressor, some air is pressurized in a single stage and flows from the compressor's bleed port into the heat exchanger, and then into the cathode of the proton exchange membrane fuel cell. The main air enters the main combustion chamber and is fully mixed with the fuel before combustion. The resulting high-temperature gas first drives the gas turbine to do work, providing power for the compressor. After it finishes doing work, it continues to do work in the power turbine to provide lift for the aircraft. The gas that has finished doing work in the power turbine enters the liquid ammonia decomposer. Inside the engine, liquid ammonia in the liquid ammonia storage tank is pumped and pressurized by the fuel pump and enters the liquid ammonia decomposer. In the liquid ammonia decomposer, the liquid ammonia is first heated and phased into ammonia gas. After being heated by the fuel gas and catalyzed by the catalyst, it decomposes into hydrogen and nitrogen. Part of the high-temperature mixture directly enters the main combustion chamber to participate in combustion, while the other part is pressured to 3-4 times the local gas pressure by the pressure reducing valve and then enters the heat exchanger. The high-temperature ammonia fuel decomposed gas exchanges heat with the bleed gas extracted from the compressor and then enters the anode of the proton exchange membrane fuel cell. Inside a proton exchange membrane fuel cell, hydrogen reacts with air to produce water, and the generated electricity supplies the electrical devices of the core system. The anode outlet of the proton exchange membrane fuel cell is a mixture of undecomposed ammonia, a small amount of unreacted hydrogen, and nitrogen produced by the decomposition of ammonia. The cathode outlet is unreacted air. Both gases are introduced into the tail nozzle and discharged to the outside atmosphere under the deceleration and pressurization of the tail nozzle.

[0010] Furthermore, the heat exchange structure of the liquid ammonia decomposer adopts a wall-type heat exchange.

[0011] Furthermore, the ammonia fuel channel of the liquid ammonia decomposer includes a liquid ammonia phase change section and an ammonia catalytic decomposition section. The inner wall of the ammonia catalytic decomposition section is coated with a catalyst that promotes the cracking reaction of ammonia fuel. The catalyst is a ruthenium-based catalyst, and catalyst supports CNFs and Al2O3 and co-catalyst KOH are added.

[0012] Furthermore, the gas produced from the power turbine, along with the gas produced from the cathode and anode outlets of the proton exchange membrane fuel cell, is fed into the catalytic combustion chamber to burn unreacted combustible gases, thereby increasing the temperature of the gas.

[0013] Therefore, the present invention provides a hybrid turboshaft engine and its operating method, and compared with the prior art, the present invention has the following beneficial effects: 1) Combining turbine power systems with fuel cell power systems and applying them to turboshaft engines can significantly improve the thermal efficiency of turboshaft engines and enhance the overall energy level of the engines; 2) The chemical heat sink of ammonia fuel is used to recover and reuse the waste heat of the turboshaft engine exhaust gas and the unreacted hydrogen and ammonia in the fuel cell, converting the low heat energy in the exhaust gas into electrical energy and chemical energy, thereby improving the energy quality of the turboshaft engine system and improving the energy utilization rate of the turboshaft engine system. 3) Replacing traditional jet fuel with ammonia fuel (green aviation power fuel) significantly reduces the concentration of greenhouse gases in the exhaust of turboshaft engine systems, thereby reducing the carbon emissions of the engine and conforming to the development plan for carbon emission reduction in aviation. 4) By using fuel cells for power supply, the problems of insufficient capacity of existing batteries and the complexity of transmission structure caused by extracting electrical power from the engine core are effectively solved, simplifying the engine's power supply system and having certain significance for promoting the development of future advanced turboshaft engine design. Attached Figure Description

[0014] 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.

[0015] Figure 1 The attached figure is a structural schematic diagram of a hybrid turboshaft engine provided by the present invention. Detailed Implementation

[0016] 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.

[0017] like Figure 1As shown in the figure, this invention discloses a hybrid turboshaft engine, including a core engine system 1 and a fuel cell power supply system 2. The core engine system 1 includes an intake duct 11, a compressor 12, a main combustion chamber 13, a gas turbine 14, and a power turbine 15. The fuel cell power supply system 2 includes a liquid ammonia storage tank 21, a fuel pump 22, a liquid ammonia decomposer 23, a pressure reducing valve 24, a heat exchanger 25, and a proton exchange membrane fuel cell 26. The inlet of the intake duct 11 is connected to the outside atmosphere, the outlet of the intake duct 11 is connected to the inlet of the compressor 12, the outlet of the compressor 12 is connected to the air inlet of the main combustion chamber 13, the outlet of the main 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, and the gas outlet of the power turbine 15 is connected to... The gas inlet of the liquid ammonia decomposer 23 is connected; the outlet of the liquid ammonia storage tank 21 is connected to the inlet of the fuel pump 22, the outlet of the fuel pump 22 is connected to the ammonia fuel channel inlet of the liquid ammonia decomposer 23, the ammonia fuel channel outlet of the liquid ammonia decomposer 23 is connected to the inlet of the pressure reducing valve 24 and the fuel inlet of the main combustion chamber 13, the outlet of the pressure reducing valve 24 is connected to the fuel channel inlet of the heat exchanger 25, the fuel channel outlet of the heat exchanger 25 is connected to the anode inlet of the proton exchange membrane fuel cell 26, the outlet channel of the bleed air between the 12 stages of the compressor is connected to the air channel inlet of the heat exchanger 25, the air channel outlet of the heat exchanger 25 is connected to the cathode inlet of the proton exchange membrane fuel cell 26, and the cathode outlet and anode outlet of the proton exchange membrane fuel cell 26 are connected to the tail nozzle, respectively; the fuel pump 22 is electrically connected to the proton exchange membrane fuel cell 26. This invention employs a hybrid power system combining a turbine power system and a fuel cell power system. While ensuring the output power of the turboshaft engine, the proton exchange membrane fuel cell 26 provides electrical energy for the engine's onboard electrical equipment. This addresses the problems of the increasing power demand of existing turboshaft engines, insufficient power of lithium batteries and other storage batteries, and difficulties in extracting electrical power from the power turbine 15. Simultaneously, using ammonia as the working fluid for power generation increases the hydrogen storage density of the fuel and reduces the fuel storage volume. By recovering the waste heat from the exhaust gas, the ammonia fuel is cracked to produce hydrogen, which is then used as a reactant in the fuel cell, thus improving the system's energy utilization efficiency. This is significant for promoting the development of green aviation power.

[0018] 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, dashed lines at connection points represent gas transmission pipelines, and double solid lines represent power transmission.

[0019] This invention also discloses a method for operating a hybrid turboshaft engine, comprising the following steps: Outside the engine, incoming air enters the intake duct 11, is decelerated and diffused to form a uniform airflow, and then enters the compressor 12 for pressurization. Inside the compressor 12, some air undergoes single-stage pressurization and flows from the compressor 12's bleed port into the heat exchanger 25, and then into the cathode of the proton exchange membrane fuel cell 26. The main airflow enters the main combustion chamber 13 and is fully mixed with the fuel for combustion. The resulting high-temperature gas first drives the gas turbine 14 to do work, providing power for the compressor 12. After doing work, it continues to enter the power turbine 15 to do work, providing lift for the aircraft. During this process, the power turbine 15 can directly drive the reducer to drive the rotor to do work, or it can be connected to a generator to generate electricity and drive the rotor to work using an electric drive method. The gas that has finished doing work in the power turbine 15 enters the liquid ammonia decomposer 23. Inside the engine, liquid ammonia in the liquid ammonia storage tank 21 is pumped and pressurized by the fuel pump 22 and enters the liquid ammonia decomposer 23. In this embodiment, the heat exchange structure of the liquid ammonia decomposer 23 adopts a wall-type heat exchange. The high-temperature gas flowing out from the outlet of the power turbine 15 is the heat source for the heat exchange process, and the liquid ammonia is the cold source for the heat exchange process. Inside the liquid ammonia decomposer 23, in this embodiment, the ammonia fuel channel of the liquid ammonia decomposer 23 includes a liquid ammonia phase change section and an ammonia catalytic decomposition section. The inner wall of the ammonia catalytic decomposition section is coated with a catalyst that promotes the cracking reaction of ammonia fuel. The liquid ammonia is first heated and phase-changes into ammonia gas, and then decomposes into hydrogen and nitrogen gas after being heated by the gas and catalyzed by the catalyst. The resulting high-temperature mixture is partially fed directly into the main combustion chamber 13 for combustion, while the other part, under the action of the pressure reducing valve 24, is reduced to 3-4 times the local atmospheric pressure and then enters the heat exchanger 25. The high-temperature ammonia fuel decomposition gas exchanges heat with the bleed gas extracted from the compressor 12, and then enters the anode of the proton exchange membrane fuel cell 26. In this process, on the one hand, the decomposition reaction of liquid ammonia fuel will absorb heat and recover the waste heat of the turboshaft engine exhaust gas, which can improve the energy utilization rate of the turboshaft engine. On the other hand, the engine uses the decomposition of liquid ammonia fuel to produce hydrogen, which provides reactants for the proton exchange membrane fuel cell, increases the hydrogen storage density of the fuel, and reduces the fuel volume. Inside the proton exchange membrane fuel cell 26, hydrogen reacts with air to produce water, and the generated electricity supplies the electrical devices of the core machine system 1. The anode outlet of the proton exchange membrane fuel cell 26 is a mixture of undecomposed ammonia, a small amount of unreacted hydrogen, and nitrogen produced by the decomposition of ammonia. The cathode outlet is unreacted air. Both gases are introduced into the tail nozzle and discharged to the outside atmosphere under the deceleration and pressurization of the tail nozzle.

[0020] Specifically, the catalyst is a ruthenium-based catalyst, with the addition of catalyst supports CNFs and Al2O3, as well as the co-catalyst KOH, to improve catalyst performance.

[0021] To further optimize the technical solution of the present invention, the gas produced from the power turbine 15, the gas produced from the cathode outlet of the proton exchange membrane fuel cell 26 (nitrogen and unreacted oxygen), and the gas produced from the anode outlet (water vapor, nitrogen, ammonia and some unreacted hydrogen) are all introduced into the catalytic combustion chamber to burn the unreacted combustible gas, thereby increasing the temperature of the gas and improving the decomposition rate of ammonia fuel in the liquid ammonia decomposer 23.

[0022] 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.

[0023] 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 hybrid turboshaft engine, characterized in that, The system includes a core engine system and a fuel cell power supply system. The core engine system includes an air intake, a compressor, a main combustion chamber, a gas turbine, and a power turbine. The fuel cell power supply system includes a liquid ammonia storage tank, a fuel pump, a liquid ammonia decomposer, a pressure reducing valve, a heat exchanger, and a proton exchange membrane fuel cell. 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 main combustion chamber, the outlet of the main combustion chamber is connected to the inlet of the gas turbine, the gas turbine and the compressor are connected via a rotor shaft drive, the outlet of the gas turbine is connected to the inlet of the power turbine, and the gas outlet of the power turbine is connected to the gas inlet of the liquid ammonia decomposer. The liquid ammonia storage tank... The outlet of the storage tank is connected to the inlet of the fuel pump, the outlet of the fuel pump is connected to the inlet of the ammonia fuel channel of the liquid ammonia decomposer, the outlet of the ammonia fuel channel of the liquid ammonia decomposer is connected to the inlet of the pressure reducing valve and the fuel inlet of the main combustion chamber, the outlet of the pressure reducing valve is connected to the inlet of the fuel channel of the heat exchanger, the outlet of the fuel channel of the heat exchanger is connected to the anode inlet of the proton exchange membrane fuel cell, the outlet channel of the compressor interstage bleed air is connected to the inlet of the air channel of the heat exchanger, the outlet of the air channel of the heat exchanger is connected to the cathode inlet of the proton exchange membrane fuel cell, and the cathode outlet and anode outlet of the proton exchange membrane fuel cell are connected to the tail nozzle.

2. A hybrid turboshaft engine according to claim 1, characterized in that, The fuel pump is electrically connected to the proton exchange membrane fuel cell.

3. The operating method of a hybrid turboshaft engine as described in claim 1 or 2, characterized in that, Includes the following steps: Outside the engine, incoming air enters the intake duct, is decelerated and diffused to form a uniform airflow, and then enters the compressor for pressurization. Inside the compressor, some air is pressurized in a single stage and flows from the compressor's bleed port into the heat exchanger, and then into the cathode of the proton exchange membrane fuel cell. The main air enters the main combustion chamber and is fully mixed with the fuel before combustion. The resulting high-temperature gas first drives the gas turbine to do work, providing power for the compressor. After it finishes doing work, it continues to do work in the power turbine to provide lift for the aircraft. The gas that has finished doing work in the power turbine enters the liquid ammonia decomposer. Inside the engine, liquid ammonia in the liquid ammonia storage tank is pumped and pressurized by the fuel pump and enters the liquid ammonia decomposer. In the liquid ammonia decomposer, the liquid ammonia is first heated and phased into ammonia gas. After being heated by the fuel gas and catalyzed by the catalyst, it decomposes into hydrogen and nitrogen. Part of the high-temperature mixture directly enters the main combustion chamber to participate in combustion, while the other part is pressured to 3-4 times the local gas pressure by the pressure reducing valve and then enters the heat exchanger. The high-temperature ammonia fuel decomposed gas exchanges heat with the bleed gas extracted from the compressor and then enters the anode of the proton exchange membrane fuel cell. Inside a proton exchange membrane fuel cell, hydrogen reacts with air to produce water, and the generated electricity supplies the electrical devices of the core system. The anode outlet of the proton exchange membrane fuel cell is a mixture of undecomposed ammonia, a small amount of unreacted hydrogen, and nitrogen produced by the decomposition of ammonia. The cathode outlet is unreacted air. Both gases are introduced into the tail nozzle and discharged to the outside atmosphere under the deceleration and pressurization of the tail nozzle.

4. The working method according to claim 3, characterized in that, The heat exchange structure of the liquid ammonia decomposer adopts a wall-type heat exchange.

5. The working method according to claim 3, characterized in that, The ammonia fuel channel of the liquid ammonia decomposer includes a liquid ammonia phase change section and an ammonia catalytic decomposition section. The inner wall of the ammonia catalytic decomposition section is coated with a catalyst that promotes the cracking reaction of ammonia fuel. The catalyst is a ruthenium-based catalyst, and catalyst supports CNFs and Al2O3 and co-catalyst KOH are added.

6. The working method according to claim 3, characterized in that, The gas produced from the power turbine, along with the gas produced from the cathode and anode outlets of the proton exchange membrane fuel cell, is fed into the catalytic combustion chamber to burn unreacted combustible gases and increase the temperature of the gas.

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