A wide fuel-adaptable nozzle suitable for hydrogen fuel

Abstract

The present application aims to provide a wide fuel-adaptable nozzle suitable for hydrogen fuel, belonging to the field of gas turbine nozzle. The present application designs a structure of micro fuel hole inserted into a micro premixing channel, ensuring that the premixed air and gaseous fuel propagate in the same direction, and the premixed air prevents the gaseous fuel from contacting the inner wall of the channel, preventing boundary layer tempering; the premixing channel has a swirl angle, which can effectively prevent tempering; the outlet surface of the micro premixing section is designed as a concave surface as a whole, ensuring ignition reliability and improving combustion stability; a radial staging strategy is adopted, meeting the efficient, stable and low-emission combustion of different working conditions. In addition, the present application designs the micro premixing channel in a split body, which has the characteristics that only the small part of the micro premixing section outlet section needs to be replaced, so that the whole machine can meet the combustion of pure natural gas fuel, pure hydrogen fuel, natural gas and hydrogen mixed fuel, greatly saving time and having good economy.

Description

Technical Field

[0001] The present invention relates to a nozzle, specifically a hydrogen fuel nozzle. Background Technology

[0002] Hydrogen fuel cell gas turbines have broad application prospects in future energy systems. They have good scalability and can adapt to different hydrogen production capacities and energy storage methods to meet the needs of applications such as hydrogen power generation, ship propulsion, and pipeline transportation. They are a feasible solution for achieving low-carbon and distributed energy applications.

[0003] Hydrogen fuel differs from commonly used fuels like natural gas in gas turbines. Its unique diffusion and combustion characteristics present a series of challenges to combustion chamber operation, including backfire, spontaneous combustion, nitrogen oxide emissions, and thermoacoustic oscillations. Therefore, preventing backfire and efficiently organizing the combustion field to achieve efficient, stable, and low-emission combustion in hydrogen fuel combustion chambers is of paramount importance in the engineering application of hydrogen fuel gas turbines, thus necessitating a suitable nozzle for hydrogen fuel. Summary of the Invention

[0004] The purpose of this invention is to provide a wide fuel adaptability nozzle suitable for hydrogen fuel that can meet the usage requirements of pure natural gas fuel, pure hydrogen fuel, and mixed fuels of natural gas and hydrogen, while ensuring that the performance of the combustion chamber meets the overall performance requirements of the gas turbine under different operating conditions.

[0005] The objective of this invention is achieved as follows:

[0006] This invention discloses a wide fuel adaptability nozzle suitable for hydrogen fuel, characterized by comprising an interface portion, a bend portion, a fuel path portion, and a micro-premixing channel, wherein the interface portion, bend portion, fuel path portion, and micro-premixing channel are sequentially connected; the interface portion is respectively provided with a liquid fuel inlet, an auxiliary atomizing air inlet, a primary gas fuel inlet, and a secondary gas fuel inlet; the bend portion is respectively provided with a liquid fuel orifice, an auxiliary atomizing air ring channel, a primary gas fuel orifice, and a secondary gas fuel orifice; the fuel path portion is respectively provided with a diesel path, an auxiliary atomizing air path, a primary gas fuel path, and a secondary gas fuel path; and the liquid fuel inlet... The diesel fuel circuit is connected to the diesel fuel circuit. The auxiliary atomizing air interface is connected to the auxiliary atomizing air circuit through the auxiliary atomizing air loop. The primary gas fuel interface is connected to the primary gas fuel circuit through the primary gas fuel port. The secondary gas fuel interface is connected to the secondary gas fuel circuit through the secondary gas fuel port. A liquid fuel cyclone separator is installed at the end of the diesel fuel circuit. The fuel circuit section is provided with fuel micropores, which include an inner ring and an outer ring. The inner ring is connected to the primary gas fuel circuit, and the outer ring is connected to the secondary gas fuel circuit. Each fuel micropore corresponds to a micro premixing channel, which includes a micro premixing channel inlet section and a micro premixing channel outlet section.

[0007] The present invention may also include:

[0008] 1. The inlet section of the micro premixed channel is parallel to the fuel micropores, the outlet section of the micro premixed channel is at an angle to the inlet section of the micro premixed channel, and the inlet section of the micro premixed channel and the outlet section of the micro premixed channel are connected by bolts.

[0009] 2. The outlet section of the micro-premixed channel adopts a concave design.

[0010] 3. Install nozzle cooling holes on the outside of the micro-premix channel.

[0011] 4. When using liquid fuel, only the fuel circuit and the auxiliary atomizing air circuit are started. The fuel enters through the liquid fuel cyclone located on the central axis, and the auxiliary atomizing air enters through the channel outside the fuel cyclone, is compressed, and enters the combustion chamber together with the liquid fuel.

[0012] 5. When using gaseous fuel, start the primary gaseous fuel circuit and the secondary gaseous fuel circuit. The gaseous fuel enters the fuel micropores from the primary gaseous fuel circuit and the secondary gaseous fuel circuit respectively according to the set ratio, so as to realize the radial grading of fuel.

[0013] The advantages of this invention are as follows: It achieves efficient and stable combustion of hydrogen fuel. Through the liquid fuel path and auxiliary atomized air path, it ensures a high success rate for engine start-up. The structure of inserting fuel micropores into the micro-premixed channel evenly divides the fuel and premixed air into several small portions, forming several small flames, controlling the combustion field temperature. Furthermore, the premixed air surrounds the hydrogen fuel in the center, effectively preventing backfire and reducing nitrogen oxide emissions. The micro-premixed channel is designed with a bend to further prevent backfire. The premixed channel outlet section is designed with a concave surface to promote the formation of a recirculation zone and improve combustion stability. The radial grading strategy achieves the formation of a stable flame with a suitable temperature in the combustion chamber under different gas turbine operating conditions, avoiding the generation of large amounts of nitrogen oxides due to excessively high temperatures in local combustion zones caused by concentrated fuel injection and uneven fuel-air mixing. By replacing a single small component in the premixed channel outlet section, combustion zones with different swirl intensities can be formed, thus matching different fuels such as pure hydrogen, pure natural gas, and mixtures of natural gas and hydrogen, achieving wide fuel adaptability, convenience, efficiency, and high economy. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention;

[0015] Figure 2 This is a top view of the present invention;

[0016] Figure 3 This is a cross-sectional view of AA.

[0017] Figure 4 This is a sectional view of BB;

[0018] Figure 5This is a schematic diagram of fuel micropores and micro-premixed channels;

[0019] Figure 6 View of the fuel and premixed air outlet directions. Detailed Implementation

[0020] The invention will now be described in more detail with reference to the accompanying drawings:

[0021] Combination Figure 1-6 The present invention mainly includes, for example, Figure 1 Micro premixed channel inlet section 1 and micro premixed channel outlet section 2; Figure 4 The diesel circuit 11, auxiliary atomizing air circuit 12, primary gas fuel circuit 13, secondary gas fuel circuit 14, fuel micropores 15, and micro premixing channel 16 are included.

[0022] The liquid fuel circuit can introduce liquid fuel during gas turbine startup, instability, or accidental flameout, improving ignition success rate and combustion stability. Gas fuel path 13 and gas fuel path 14 employ a radial staged strategy, allowing for independent supply to the combustion chamber according to operating conditions. Gas fuel path 13 is located at the nozzle center; under low operating conditions, only gas fuel path 13 is supplied to ensure combustion efficiency and stability. Under high operating conditions, gas fuel path 13 and gas fuel path 14 are supplied simultaneously, forming a uniformly composed premixed air, improving combustion zone temperature uniformity and reducing nitrogen oxide formation. Fuel micropores 15 and micro-premixing channels 16 form a separate micro-premixing unit; several micro-premixing units uniformly mix gaseous fuel and premixed air. The fuel is divided into several portions, forming several individual small flames to prevent backfire and localized overheating. Fuel micropores 15 are inserted into the micro-premixed channel 16, allowing premixed air to envelop the gaseous fuel and propagate downstream, preventing the gaseous fuel from contacting the wall and preventing hydrogen fuel from burning upstream along the boundary layer, further preventing backfire. The front section of the micro-premixed channel 16 is parallel to the fuel micropores 15, while the rear section is designed with a certain angle, changing the flow direction within the channel to prevent backfire. Furthermore, the premixed channel enters the combustion chamber at a certain angle, forming a stable recirculation zone within the combustion chamber, ensuring combustion stability. The outlet section 2 of the micro-premixed channel adopts a concave angle design, which also promotes the formation of a stable recirculation zone within the combustion chamber, further enhancing combustion chamber stability. In addition, by simply changing the outlet section 2 of the micro-premixed channel, different swirl angles and concavities can be designed for the micro-premixed outlet section 2, creating combustion zones with different recirculation intensities, adapting to various fuels such as pure hydrogen fuel, pure natural gas fuel, and mixed natural gas and hydrogen fuels, making it convenient and efficient.

[0023] Liquid fuel enters through liquid fuel inlet 5, then through liquid fuel orifice 9, propagates along diesel path 11 at the center of the nozzle, and finally enters the combustion chamber. Atomizing air enters through auxiliary atomizing air inlet 3, passes through auxiliary atomizing air loop 8, enters auxiliary atomizing air path 12, and finally enters the combustion chamber, serving to atomize the liquid fuel, promote its combustion, and achieve the purpose of gas turbine start-up and stable operation of liquid fuel.

[0024] The primary and secondary gaseous fuels employ a radial staged strategy, allowing for separate supply of gaseous fuels. Primary gaseous fuel enters through primary gaseous fuel inlet 6, then through primary fuel orifice 10 located in the inner ring, into the primary gaseous fuel path 13 in the inner ring of the nozzle. Secondary gaseous fuel enters through secondary gaseous fuel inlet 4, then through secondary gaseous fuel orifice 7 located in the inner ring, into the secondary gaseous fuel path 14 in the outer ring of the nozzle. Under low operating conditions, only primary gaseous fuel is supplied, concentrating the fuel in the center of the combustion chamber, ensuring sufficient fuel distribution and combustion stability. As operating conditions increase, the total fuel demand rises. To avoid excessive fuel in one stage, leading to excessively high temperatures in the main combustion zone and increased nitrogen oxide emissions, some fuel is supplied through the secondary gaseous fuel path. This achieves uniform distribution of gaseous fuel and premixed air, with the central flame igniting the secondary fuel, thus achieving low emissions under high operating conditions.

[0025] Each fuel micro-orifice 15 is equipped with a micro-premixed fuel channel 16, which evenly divides the fuel and premixed air into several small portions, forming several small flames, controlling the combustion field temperature, effectively preventing backfire, and reducing nitrogen oxide emissions. The outlet of the fuel micro-orifice 15 is flush with the inlet of the micro-premixed fuel channel 16, and the gaseous fuel and premixed air propagate in the same direction. The fuel micro-orifice 15 is inserted into the micro-premixed fuel channel 16, ensuring that the premixed air surrounds the gaseous fuel as it propagates downstream, preventing the gaseous fuel from contacting the inner wall of the premixed channel 16 and preventing boundary layer backfire.

[0026] When using liquid fuel, only the fuel line 11 and the auxiliary atomizing air line 12 are activated. The fuel enters through the liquid fuel cyclone separator 19 located on the central axis, and the auxiliary atomizing air enters through the channel outside the fuel cyclone separator 19. It is compressed and enters the combustion chamber together with the liquid fuel. The auxiliary atomizing air and the fuel are mixed together, which promotes the breaking and atomization of the fuel.

[0027] When using gaseous fuel, the primary gas fuel path 13 and the secondary gas fuel path 14 are activated. The gaseous fuel enters the fuel micropores 15 from the primary gas fuel path 13 and the secondary gas fuel path 14 in a certain proportion. The fuel micropores 15 are divided into inner and outer rings. The inner ring micropores are for the same primary gas, while the outer ring micropores are for the secondary gas, thus realizing radial grading of the fuel. Low emissions can be achieved by adjusting the ratio of the primary and secondary gas.

[0028] The micro-premixed channel is divided into two parts: the inlet section 1 and the outlet section 2. The inlet section 1 is parallel to the fuel micropores 15, while the outlet section 2 is at an angle to the inlet section 1 to further prevent backfire. Furthermore, the outlet section 2 adopts a concave design to enhance the recirculation zone strength, prevent combustion instability and flameout under low operating conditions, and improve combustion stability.

[0029] The micro-premixed channel inlet section 1 and micro-premixed channel outlet section 2 are connected and fixed by fixing bolts 17, making disassembly and replacement of the micro-premixed channel outlet section 2 extremely convenient. Hydrogen fuel and natural gas fuel have significantly different combustion characteristics, such as laminar flame propagation speed, and therefore require different flow field organization methods in their combustion chambers. This patent allows for the creation of combustion zones with varying swirl intensities simply by replacing the micro-premixed channel outlet section 2 and designing different swirl angles and outlet surface concavity. This enables the matching of different fuels, such as pure hydrogen, pure natural gas, and mixtures of natural gas and hydrogen, achieving wide fuel adaptability. Furthermore, the replacement process is quick, simple, and efficient, offering a degree of economic advantage.

[0030] like Figure 6 As shown, several nozzle cooling holes 18 are arranged on the outer ring of the nozzle. Cooling air prevents the flame from contacting the nozzle wall, reduces the nozzle wall temperature, extends the nozzle life, and improves the nozzle reliability.

Claims

1. A wide fuel adaptability nozzle suitable for hydrogen fuel, characterized in that: The system includes an interface section, a bend section, a fuel path section, and a micro-premixing channel. These sections are sequentially connected. The interface section is equipped with a liquid fuel inlet, an auxiliary atomizing air inlet, a primary gas fuel inlet, and a secondary gas fuel inlet. The bend section is equipped with a liquid fuel port, an auxiliary atomizing air loop, a primary gas fuel port, and a secondary gas fuel port. The fuel path section is equipped with a diesel fuel path, an auxiliary atomizing air path, a primary gas fuel path, and a secondary gas fuel path. The liquid fuel inlet is connected to the diesel fuel path via the liquid fuel port. The atomizing air interface is connected to the auxiliary atomizing air path through the auxiliary atomizing air loop. The primary gas fuel interface is connected to the primary gas fuel path through the primary gas fuel orifice. The secondary gas fuel interface is connected to the secondary gas fuel path through the secondary gas fuel orifice. A liquid fuel cyclone separator is installed at the end of the diesel path. The fuel path section is provided with fuel micropores, which include an inner ring and an outer ring. The inner ring is connected to the primary gas fuel path, and the outer ring is connected to the secondary gas fuel path. Each fuel micropore corresponds to a micro premixing channel, which includes a micro premixing channel inlet section and a micro premixing channel outlet section. The inlet section of the micro premixed channel is parallel to the fuel micropores, the outlet section of the micro premixed channel is at an angle to the inlet section of the micro premixed channel, and the inlet section of the micro premixed channel and the outlet section of the micro premixed channel are connected by bolts.

2. A wide fuel adaptability nozzle suitable for hydrogen fuel according to claim 1, characterized in that: The outlet section of the micro-premixed channel adopts a concave design.

3. A wide fuel adaptability nozzle suitable for hydrogen fuel according to claim 1, characterized in that: A nozzle cooling hole is provided outside the micro-premix channel.

4. A wide fuel adaptability nozzle suitable for hydrogen fuel according to claim 1, characterized in that: When using liquid fuel, only the fuel circuit and the auxiliary atomizing air circuit are activated. The fuel enters through the liquid fuel swirler located on the central axis, and the auxiliary atomizing air enters through the channel outside the fuel swirler, is compressed, and enters the combustion chamber together with the liquid fuel.

5. A wide fuel adaptability nozzle suitable for hydrogen fuel according to claim 1, characterized in that: When using gaseous fuel, the primary and secondary gaseous fuel paths are activated. The gaseous fuel enters the fuel micropores from both the primary and secondary gaseous fuel paths according to the set ratio, thus achieving radial grading of the fuel.

6. A wide fuel adaptability nozzle suitable for hydrogen fuel according to claim 1, characterized in that: Fuel micropores and micro-premixed channels form individual micro-premixed units. Several micro-premixed units evenly distribute gaseous fuel and premixed air into several portions, forming several individual small flames to prevent backfire and local overheating.

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