A hydrogen fuel turbine engine

Abstract

This invention proposes a hydrogen fuel turbine engine, including an air intake, a compressor, a hydrogen combustion chamber, a turbine, an exhaust nozzle, and a hydrogen storage device. The hydrogen combustion chamber is supplied with hydrogen via a hydrogen supply pipe, which is installed in an air supply pipe to form an air supply unit. The hydrogen storage device is connected to the hydrogen supply pipe. The air compressed by the compressor enters the hydrogen combustion chamber and is split into two paths. One path directly enters the interior of the flame tube through air holes on the flame tube wall, while the other path is split into multiple paths and connected to the air pipe. The air supply unit enters from the rear end of the flame tube and extends to the front of the flame tube. The hydrogen supply pipe and the air pipe respectively spray hydrogen and air towards the head of the flame tube, where air and hydrogen are mixed and combusted at constant pressure in the flame tube. This invention incorporates an air pipe outside the hydrogen supply pipe. On one hand, this introduces more gas, which lowers the temperature of the main combustion zone in the combustion chamber and reduces the generation of nitrogen oxides. On the other hand, the air pipe can also serve as a heat insulation pipe, effectively reducing the surface temperature of the hydrogen supply pipe. Simultaneously, the air inside the pipe impacts the flame tube head, which not only lowers the temperature of the head panel but also generates a complex vortex structure at the flame tube head, further enhancing the mixing of hydrogen and air. The inconsistent natural frequencies of the vortices prevent thermal oscillation problems.

Description

Technical Field

[0001] This invention relates to a hydrogen fuel turbine engine, belonging to the field of new energy and power technology. Background Technology

[0002] A turbine engine is an engine that extracts kinetic energy from a fluid passing through it using rotating components. It typically uses aviation kerosene as fuel. With increasing global warming and frequent extreme weather events, developing clean and green energy has become a global consensus. In 2023, the aviation industry accounted for 3% of global carbon emissions, highlighting the immense pressure on the aviation sector to decarbonize.

[0003] Currently, common technological routes for decarbonizing the aviation industry include sustainable aviation fuel (SAF), electric propulsion technology (including hybrid electric propulsion technology), and hydrogen fuel engines. Sustainable aviation fuel refers to aviation fuel synthesized from waste oils, organic waste, non-food crops, or carbon dioxide. Using sustainable aviation fuel can reduce carbon dioxide emissions by 75-90%, but its current price is 2-4 times that of aviation kerosene, and its production can only meet 0.1% of the civil aviation market's demand, resulting in problems of excessively high costs and insufficient production capacity. Electric propulsion technology refers to the technology of using electricity to drive fans or rotors to generate thrust. Currently, all-electric propulsion technology is limited by the low energy density and power density of batteries, resulting in shorter ranges and generally weaker carrying capacities for all-electric aircraft. Hybrid electric propulsion technology is considered a more feasible solution in the short to medium term. Although its overall efficiency is high, it still uses aviation kerosene as fuel, making carbon emissions unavoidable.

[0004] The main difference between hydrogen fuel and aviation kerosene lies in the flame propagation speed. Hydrogen has a much higher flame speed, approximately six times that of aviation kerosene, which can easily lead to backfire. Additionally, hydrogen combustion produces a higher adiabatic flame temperature, about 120K higher than aviation kerosene. At this higher combustion temperature, NOx formation increases dramatically. Therefore, it is necessary to prevent backfire and reduce NOx formation.

[0005] Currently, hydrogen combustion in aero-engines generally employs clustered micro-mixing combustion technology. This technology uses numerous injection units with characteristic dimensions on the millimeter scale, each of which can be considered a miniature combustion chamber where hydrogen and air mix and burn, forming multiple small-scale diffusion flames. Compared to traditional injection methods, this technology uses high-speed jets instead of the swirling flow of traditional combustion chambers, resulting in higher injection velocities than the flame propagation speed of hydrogen, significantly reducing the risk of backfire. However, its combustion organization is diffusion combustion, and its combustion is relatively complete, leading to higher flame temperatures and consequently higher NOx emissions. Most importantly, clustered micro-mixing combustion technology consists of a series of small-scale flames, making it highly susceptible to high-frequency combustion instabilities, which can cause severe thermoacoustic oscillations. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a hydrogen fuel turbine engine that overcomes thermal vibration and prevents backfire, thereby achieving the green and low-carbon transformation of aero engines.

[0007] The technical solution of this invention is as follows: A hydrogen fuel turbine engine includes an air intake, a compressor, a hydrogen combustion chamber, a turbine, a tail nozzle, and a hydrogen storage device. The hydrogen combustion chamber is supplied with hydrogen via a hydrogen supply pipe, which is installed in an air pipe to form an air supply unit. The hydrogen storage device is connected to the hydrogen supply pipe. Air compressed by the compressor enters the hydrogen combustion chamber and is split into two paths. One path directly enters the interior of the flame tube through air holes on the flame tube wall, while the other path is split into multiple paths and connected to the air pipe. The air supply unit enters from the rear end of the flame tube and extends to the front of the flame tube. The hydrogen supply pipe and the air pipe respectively spray hydrogen and air towards the head of the flame tube, where air and hydrogen are mixed and combusted at constant pressure in the flame tube.

[0008] The beneficial effects of this invention compared to the prior art are as follows:

[0009] (1) The present invention sets an air pipe outside the hydrogen supply pipe. On the one hand, more air is introduced, which can reduce the temperature of the main combustion zone of the combustion chamber and reduce the generation of nitrogen oxides. On the other hand, the air pipe can be used as a heat insulation pipe, which can effectively reduce the temperature of the surface of the hydrogen supply pipe. At the same time, the air inside the pipe impacts the head of the flame tube, which can reduce the temperature of the head panel and generate a complex vortex structure at the head of the flame tube, further enhancing the mixing of hydrogen and air. The inconsistent natural frequency of the vortex avoids the problem of thermal oscillation.

[0010] (2) The present invention adopts a diffusion combustion organization method, which does not premix hydrogen with air, thus avoiding the problem of backfire;

[0011] (3) The hydrogen supply direction of this invention is opposite to that of the mainstream, which enhances the mixing of hydrogen and air and improves combustion efficiency;

[0012] (4) The hydrogen fuel of the present invention has stable and efficient combustion, and its combustion products do not contain carbon, but only water and some nitrogen oxides, which is more environmentally friendly than aviation kerosene.

[0013] (5) By adopting mature components such as air compressors and turbines of turbine engines, this invention reduces the design difficulty of the entire engine and shortens the design cycle.

[0014] (6) Due to the high calorific value of hydrogen fuel (120MJ / kg, which is about three times that of aviation kerosene), the specific impulse of aviation hydrogen turbine engines of the same size class can be greatly improved, which has outstanding advantages in the fields of general aviation and civil aviation. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the engine principle of the present invention;

[0016] Figure 2 This is a schematic diagram of the hydrogen combustion chamber principle of the present invention;

[0017] Figure 3 This is an example of the arrangement of hydrogen supply pipes and air pipes according to the present invention. Detailed Implementation

[0018] The present invention will now be described in detail with reference to specific examples and accompanying drawings.

[0019] The present invention is as follows Figure 1 , 2 As shown, a hydrogen fuel cell turbine engine is provided, including an air intake, a compressor, a hydrogen combustion chamber, a turbine, an exhaust nozzle, and a hydrogen storage device. The hydrogen combustion chamber supplies hydrogen via a hydrogen supply pipe, which is installed within an air supply pipe to form an air supply unit. Multiple air supply units are evenly distributed circumferentially inside the flame tube. The hydrogen storage device is connected to the hydrogen supply pipe. Air compressed by the compressor enters the hydrogen combustion chamber and is split into two paths: one path directly enters the flame tube through air holes in the flame tube wall, and the other path is split into multiple paths connected to the air pipe. The air supply units enter from the rear end of the flame tube and extend to the front end. The hydrogen supply pipe and the air pipe respectively spray hydrogen and air towards the head of the flame tube, where air and hydrogen are mixed and combusted at constant pressure within the flame tube.

[0020] The hydrogen supply pipe of this invention enters from the rear end of the flame tube and extends to the front of the flame tube, spraying hydrogen towards the head of the flame tube. The hydrogen flow direction is opposite to the mainstream, which increases the dwell time and improves the mixing efficiency.

[0021] This invention employs a diffusion combustion method, where hydrogen is mixed with air and combusted within the flame tube. Since hydrogen and air are not premixed, there is no backfire issue. To improve combustion efficiency, the hydrogen supply direction is opposite to the mainstream direction to enhance hydrogen-air mixing.

[0022] To avoid directly exposing the hydrogen supply pipe to high temperatures, this invention adds an air pipe outside the hydrogen supply pipe. This serves two purposes: firstly, it introduces more gas, reducing the temperature of the main combustion zone in the combustion chamber and decreasing nitrogen oxide formation; secondly, it acts as a heat insulation pipe, effectively lowering the surface temperature of the hydrogen supply pipe. Simultaneously, the air inside the air pipe impacts the flame tube head, reducing the temperature of the head panel and generating both hydrogen and air vortices at the flame tube head, further enhancing the mixing of hydrogen and air. The different natural frequencies of the two vortices prevent thermal oscillation problems.

[0023] Furthermore, the present invention as follows Figure 3 As shown, multiple gas supply units are installed in the hydrogen combustion chamber flame tube. Each gas supply unit consists of a hydrogen supply pipe and an air pipe, which are coaxially arranged, with the hydrogen supply pipe located at the center.

[0024] Furthermore, the hydrogen supply pipe is made of stainless steel, and the air pipe is made of high-temperature alloy.

[0025] Furthermore, the pressure of the hydrogen ejected from the hydrogen supply pipe is at least one order of magnitude greater than the pressure of the air ejected from the air pipe.

[0026] Furthermore, the hydrogen storage device includes a hydrogen storage cylinder, a regulating valve, and an adjustable nozzle ejector. Hydrogen is stored in the hydrogen storage cylinder, and the flow rate and pressure of the hydrogen are regulated by the regulating valve and the adjustable nozzle ejector. The pressure of the hydrogen storage cylinder is generally not less than 70 MPa.

[0027] Furthermore, the compressor of this invention is a single-stage diagonal-flow compressor, and the turbine is a single-stage axial-flow turbine.

[0028] Furthermore, the engine main shaft is supported by two ball bearings, which are lubricated with lubricating oil. The lubricated oil then enters the combustion chamber for combustion.

[0029] Furthermore, an electric igniter is installed on the head panel of the hydrogen combustion chamber flame tube of the present invention.

[0030] The working principle of this invention is as follows: Figure 1 , 2 As shown, the incoming air passes through the intake duct, is compressed in the compressor, and then splits into two paths. One path enters the flame tube directly through the air holes on the wall of the hydrogen combustion chamber flame tube, while the other path is split into multiple paths and injected into the flame tube in the opposite direction through the air pipe. In the flame tube, it undergoes constant-pressure combustion with hydrogen. The high-temperature gas after combustion expands and does work in the turbine, and finally expands and accelerates in the nozzle before entering the atmosphere to generate thrust.

[0031] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0032] The parts of this invention not described in detail are techniques known to those skilled in the art.

Claims

1. A hydrogen fuel cell turbine engine, comprising an intake manifold, a compressor, a hydrogen combustion chamber, a turbine, an exhaust nozzle, and a hydrogen storage device, characterized in that: The hydrogen combustion chamber is supplied with hydrogen via a hydrogen supply pipe, which is installed in the air pipe to form a gas supply unit. The hydrogen storage device is connected to the hydrogen supply pipe. The air compressed by the compressor enters the hydrogen combustion chamber and is split into two paths. One path enters the interior of the flame tube directly through the air holes on the flame tube wall, and the other path is split into multiple paths and connected to the air pipe. The gas supply unit enters from the rear end of the flame tube and extends to the front of the flame tube. The hydrogen supply pipe and the air pipe spray hydrogen and air respectively towards the head of the flame tube. In the flame tube, the air and hydrogen are mixed for constant pressure combustion.

2. A hydrogen fuel turbine engine according to claim 1, characterized in that: The gas supply units are evenly distributed circumferentially inside the flame tube of the hydrogen combustion chamber, and the hydrogen supply pipe and air pipe are coaxially arranged, with the hydrogen supply pipe located at the center.

3. A hydrogen fuel turbine engine according to claim 2, characterized in that: The hydrogen supply pipe is made of stainless steel, and the air pipe is made of high-temperature alloy.

4. A hydrogen fuel turbine engine according to claim 2, characterized in that: The hydrogen pressure ejected from the hydrogen supply pipe is at least one order of magnitude greater than the air pressure ejected from the air pipe.

5. A hydrogen fuel turbine engine according to claim 2, characterized in that: The hydrogen storage device includes a hydrogen storage cylinder, a regulating valve, and an adjustable nozzle ejector. Hydrogen is stored in the hydrogen storage cylinder, and the flow rate and pressure of the hydrogen are regulated by the regulating valve and the adjustable nozzle ejector.

6. A hydrogen fuel turbine engine according to claim 2, characterized in that: The compressor is a single-stage diagonal-flow compressor.

7. A hydrogen fuel turbine engine according to claim 2, characterized in that: The turbine is a single-stage axial flow turbine.

8. A hydrogen fuel turbine engine according to claim 2, characterized in that: The main shaft of the hydrogen fuel turbine engine is supported by two ball bearings, which are lubricated with lubricating oil. The lubricated oil then enters the combustion chamber for combustion.

9. A hydrogen fuel turbine engine according to claim 2, characterized in that: An electric igniter is installed on the head panel of the hydrogen combustion chamber flame tube.

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