A wide hydrogen fraction combustor for a gas turbine and method of use

Abstract

This invention discloses a wide hydrogen blending ratio burner suitable for gas turbines and its usage method, including a first-stage blending pipe, a second-stage blending pipe, an air ejector, a burner body, a fuel pipe, and an ejector nozzle. The main air participating in gas turbine combustion enters the main air chamber through an air inlet, a small portion of the air enters the ejector air chamber, and most of the air, after being mixed with fuel through the second-stage blending pipe, enters the downstream combustion chamber for combustion. The fuel participating in gas turbine combustion is injected into the first-stage blending pipe through the fuel pipe and the ejector nozzle after depressurization and acceleration. The high-speed ejected fuel gas creates a suction effect on the air entering the ejector air chamber. The sucked-in ejector air and fuel are continuously mixed in the first-stage blending pipe, then enter the fuel chamber, where they are further mixed. Finally, the fuel gas is injected into the second-stage blending pipe through a fuel injection hole, where it mixes with the mainstream air entering the second-stage blending pipe. After mixing, the mixture enters the combustion chamber for combustion and heat release.

Description

Technical Field

[0001] This invention belongs to the field of thermal power generation technology, specifically relating to a wide hydrogen-doping ratio burner suitable for gas turbines and its usage method. Background Technology

[0002] The energy system is currently undergoing a rapid transformation towards cleaner and lower-carbon energy. Traditional gas turbines, as core power equipment in fields such as electricity, aviation, and shipbuilding, have long relied on fossil fuels such as natural gas and heavy oil, accounting for over 15% of global energy-related carbon emissions. Hydrogen, as an energy carrier, produces only water during combustion and emits no greenhouse gases such as carbon dioxide, making it a truly clean energy source. Applying hydrogen to gas turbines, enabling power generation or mechanical power generation through hydrogen blending or pure hydrogen combustion, can effectively reduce dependence on fossil fuels, contributing to the transformation of the energy structure towards low-carbon and carbon-free energy, and meeting the urgent needs of countries worldwide in addressing climate change and fulfilling their emission reduction commitments.

[0003] Compared to traditional gas turbines, hydrogen-blended or pure hydrogen gas turbines present new challenges and demands in terms of combustion technology, material properties, and system design. For example, the combustion characteristics of hydrogen differ significantly from those of natural gas; its rapid combustion speed, high flame temperature, and susceptibility to backfire necessitate the development of novel burners and combustion control technologies. For high-blended or pure hydrogen gas turbines, micro-mixing combustion technology is currently the primary approach. This technology transforms the traditional large-scale flame into multiple micro-scale flames, enhancing the local mixing intensity of air and fuel and improving mixing uniformity. This eliminates the need for a recirculation zone to stabilize the flame, shortening the residence time of high-temperature gas in the high-temperature zone and reducing the formation of thermal NOx. However, micro-mixing burners generally suffer from high flow resistance, flame detachment or extinction during variable operating conditions of the gas turbine, and thermoacoustic unstable combustion, all of which require further research and verification. Summary of the Invention

[0004] This invention provides a wide hydrogen-doping ratio burner suitable for gas turbines and its usage method, aiming to overcome the shortcomings of traditional gas turbines.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A wide hydrogen blending ratio burner suitable for gas turbines includes a first-stage blending pipe, a second-stage blending pipe, a fuel chamber, an air ejector, a burner body, an air inlet, a main air chamber, a burner mounting flange, a fuel pipe, an ejector nozzle, an ejector air inlet, an ejector air chamber, and a fuel injection port. The first-stage mixing tube, air ejector, burner body, burner mounting flange, fuel pipe, and ejector nozzle are arranged aligned along their central axis. The ejector nozzle is connected to the fuel pipe. Both ends of the air ejector are connected to the fuel pipe and the first-stage mixing tube, respectively. An ejector air chamber is formed between the air ejector and the ejector nozzle, and ejector air inlets are evenly arranged circumferentially on the wall of the air ejector. The same end of the fuel chamber is connected to the first-stage mixing tube and the cylindrical burner body, respectively. The burner mounting flange is connected to the burner body. The air inlet is located on the cylindrical wall of the burner body near the burner mounting flange. The second-stage mixing tube passes through the fuel chamber, and its central axis is parallel to that of the first-stage mixing tube. The fuel injection orifice is located at the end of the second-stage mixing tube.

[0006] A further improvement of the present invention is that the ejector nozzle adopts a convergent ejector nozzle with a convergence ratio of 0.7 to 0.85.

[0007] A further improvement of the present invention is that the air ejector adopts a cylindrical cavity air ejector.

[0008] A further improvement of the present invention is that the air intake hole is a square shape.

[0009] A further improvement of the present invention is that the inner diameter of the second-stage mixing tube is designed to be 2~6 mm.

[0010] A further improvement of the present invention is that the diameter ratio of the first-stage mixing tube to the second-stage mixing tube is 3 to 5.

[0011] A further improvement of the present invention is that the diameter of the ejector air inlet is 5~10mm, and the number of them arranged evenly in the circumferential direction is 4~16.

[0012] A further improvement of the present invention is that the diameter of the fuel injection holes is 0.2~1mm and the number is 2~4.

[0013] A further improvement of this invention is that after the air and fuel are mixed, they are injected into the combustion chamber through the second-stage mixing pipe by injection. There is no swirler structure, so no backflow zone is formed in the combustion chamber. The inner diameter of the second-stage mixing pipe is designed to be 2~6 mm. The tiny channel leads to a significant increase in the contact area between the flame and the pipe wall. The heat of the flame is quickly absorbed by the pipe wall, which can prevent backfire of the hydrogen-blended fuel.

[0014] A method of using a wide hydrogen-doping ratio burner suitable for gas turbines includes: The main air participating in the combustion of the gas turbine enters the main air chamber through the air inlet on the burner body. A small portion of the air enters the ejector air chamber through the ejector air inlet, while most of the air mixes with the fuel injected from the fuel injection port through the second-stage mixing pipe before entering the downstream combustion chamber for combustion. The fuel participating in the combustion of the gas turbine is injected into the first-stage mixing pipe through the fuel pipe after being depressurized and accelerated by the ejector nozzle. The high-speed ejected fuel gas creates a suction effect on the air entering the ejector air chamber. The drawn-in ejector air and fuel are continuously mixed in the first-stage mixing pipe before entering the fuel chamber, where they are further mixed. Finally, the fuel gas is injected into the second-stage mixing pipe through the fuel injection port, where it mixes with the mainstream air entering the second-stage mixing pipe. After mixing, the mixture enters the combustion chamber for combustion and heat release.

[0015] Compared with the prior art, the present invention has at least the following beneficial technical effects: The fuel tube of this invention is designed with a converging ejector nozzle at its end, which effectively increases the fuel injection velocity. The high-speed ejected fuel, under the influence of viscous forces between gas molecules, draws in the air entering the air ejector and mixes with the drawn-in air in the first-stage mixing tube. It is then further mixed in the large-space fuel chamber, and finally injected through the fuel injection hole into the second-stage mixing tube for final mixing with the mainstream air. This innovative structure, combining ejection, mixing, fuel chamber, and remixing, cleverly utilizes the principle that the average molecular weight of fuel increases after mixing with air, thereby enhancing penetration ability. This improves the penetration force of the fuel gas when mixing with the mainstream air in the second-stage mixing tube. After the first-stage mixing, because the molecular weight of the ejected air is greater than that of the fuel gas, the inertial force of the fuel gas is significantly increased after incorporating the larger air molecules. This allows the fuel gas to reach the center of the second-stage mixing tube better after being ejected from the fuel injection hole, resulting in better mixing with the mainstream air and improving the uniformity of fuel-air mixing.

[0016] If the traditional structure of directly injecting fuel into the mixing tube from the fuel injection hole is adopted, the small molecular weight of the fuel will result in insufficient penetration. Most of the fuel gas will stick close to the wall of the mixing tube and will have difficulty reaching the center of the mixing tube, resulting in a lack of fuel in the middle of the mixing tube and uneven mixing of fuel and air. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1This is a central cross-sectional view of a wide hydrogen-doping ratio burner suitable for gas turbines according to the present invention; Figure 2 This is an isometric drawing of a wide hydrogen-doping ratio burner suitable for gas turbines according to the present invention; Figure 3 This is a three-dimensional cross-sectional view of the center section of a wide hydrogen-doping ratio burner suitable for gas turbines according to the present invention.

[0019] Explanation of reference numerals in the attached figures: 1. First-stage mixing pipe; 2. Second-stage mixing pipe; 3. Fuel chamber; 4. Air ejector; 5. Burner body; 6. Air inlet; 7. Main air chamber; 8. Burner mounting flange; 9. Fuel pipe; 10. Ejector nozzle; 11. Ejector air inlet; 12. Ejector air chamber; 13. Fuel injection hole. Detailed Implementation

[0020] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0021] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0025] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0026] It should also be understood that the term “and / or” as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0027] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0028] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0029] Example 1 like Figures 1 to 3As shown, the present invention provides a wide hydrogen blending ratio burner suitable for gas turbines, comprising: a first-stage blending pipe 1, a second-stage blending pipe 2, a fuel chamber 3, an air ejector 4, a burner body 5, an air inlet 6, a main air chamber 7, a burner mounting flange 8, a fuel pipe 9, an ejector nozzle 10, an ejector air inlet 11, an ejector air chamber 12, and a fuel injection port 13.

[0030] The first-stage mixing pipe 1, air ejector 4, burner body 5, burner mounting flange 8, fuel pipe 9, and ejector nozzle 10 are arranged with their central axes aligned. The ejector nozzle 10 is connected to the fuel pipe 9. Both ends of the air ejector 4 are connected to the fuel pipe 9 and the first-stage mixing pipe 1, respectively. An ejector air cavity 12 is formed between the air ejector 4 and the ejector nozzle 10. The ejector air inlet holes 11 are evenly arranged circumferentially on the wall of the air ejector 4. The same end of the fuel cavity 3 is connected to the first-stage mixing pipe 1 and the cylindrical burner body 5, respectively. The burner mounting flange 8 is connected to the burner body 5. The air inlet hole 6 is opened on the cylindrical wall of the burner body 5 near the burner mounting flange 8. The second-stage mixing pipe 2 passes through the fuel cavity 3, and the central axis of the second-stage mixing pipe 2 is parallel to the central axis of the first-stage mixing pipe 1. The fuel injection hole 13 is opened at the end of the second-stage mixing pipe 2.

[0031] In this embodiment, the ejector nozzle 10 is a convergent ejector nozzle.

[0032] In this embodiment, the air ejector 4 is a cylindrical cavity air ejector.

[0033] In this embodiment, the air intake 6 is a square air intake.

[0034] In this embodiment, the ejector nozzle 10 is a convergent ejector nozzle with a convergence ratio of 0.7 to 0.85.

[0035] In this embodiment, the inner diameter of the second-stage mixing tube 2 is designed to be 2~6 mm.

[0036] In this embodiment, the diameter ratio of the first-stage mixing pipe 1 to the second-stage mixing pipe 2 is 3 to 5.

[0037] In this embodiment, the diameter of the ejector air inlet 11 is 5~10mm, and the number of them arranged evenly in the circumferential direction is 4~16.

[0038] In this embodiment, the diameter of the fuel injection holes 13 is 0.2~1mm, and the number is 2~4.

[0039] In this embodiment, after the air and fuel are mixed, they are injected into the combustion chamber through the second-stage mixing pipe 2 by injection. There is no swirler structure, so no backflow zone is formed in the combustion chamber. The inner diameter of the second-stage mixing pipe 2 is designed to be 2~6mm. The small channel will increase the contact area between the flame and the pipe wall, and the heat of the flame will be quickly absorbed by the pipe wall, which can prevent the backfire of the hydrogen-blended fuel.

[0040] Example 2 like Figures 1 to 3 As shown, the present invention provides a method for using a wide hydrogen-doping ratio burner suitable for gas turbines, comprising: The main air participating in the combustion of the gas turbine enters the main air chamber 7 through the air inlet 6 on the burner body 5. A small portion of the air enters the ejector air chamber 12 through the ejector air inlet 11. Most of the air is mixed with the fuel injected from the fuel injection port 13 through the second-stage mixing pipe 2 and then enters the downstream combustion chamber for combustion. The fuel participating in the combustion of the gas turbine is injected into the first-stage mixing pipe 1 through the fuel pipe 9 and the ejector nozzle 10 after depressurization and acceleration. Due to the viscosity of the gas, the high-speed ejected fuel gas forms a suction effect on the air entering the ejector air chamber 12. The drawn-in ejector air and fuel are continuously mixed in the first-stage mixing pipe 1, and then enter the fuel chamber 3, where they are further mixed. Finally, they are injected into the second-stage mixing pipe 2 through the fuel injection port 13 and mixed with the mainstream air entering the second-stage mixing pipe 2. After mixing, the mixture enters the combustion chamber for combustion and heat release.

[0041] In this invention, the main air enters the main air chamber through air inlets on the burner body, while a small portion of the air enters the ejector air chamber through ejector air inlets. This separate introduction method allows for precise control of the amount of air entering different zones according to the needs of different combustion stages, providing a suitable environment for main combustion and the initial mixing of fuel and air. Most of the air is mixed with the fuel injected from the fuel injection orifice through a second-stage mixing pipe. This design ensures that the mainstream air and fuel are in full contact before entering the combustion chamber, increasing mixing time and improving mixing uniformity. This contributes to more stable and efficient combustion, reduces localized over-rich or over-lean conditions, and lowers pollutant emissions from incomplete combustion.

[0042] In this invention, fuel is injected into the first-stage mixing tube after being depressurized and accelerated through a fuel pipe and ejector nozzle. The depressurization and acceleration process not only alters the fuel's flow state, causing it to be ejected at high speed, but also improves atomization before ejection, increasing the fuel's surface area and facilitating faster and more thorough mixing with air. Due to the viscous force of the gas, the high-speed ejected fuel gas exerts a suction effect on the air entering the ejector air chamber. This ejection method requires no additional power equipment; it relies solely on the flow characteristics of the fuel gas itself to draw in air, simplifying the system structure and reducing energy consumption and cost. Simultaneously, the drawn-in ejector air and fuel are continuously mixed within the first-stage mixing tube, further enhancing the mixing effect.

[0043] In this invention, fuel and ejector air are initially mixed in the first-stage mixing tube before entering the fuel chamber, where they are further mixed. Finally, the mixture is injected through the fuel injection hole into the second-stage mixing tube to mix with the mainstream air. This multi-stage mixing design enables gradual and thorough mixing of fuel and air, resulting in a more refined and uniform mixing process. Each stage of mixing further optimizes the mixing ratio and uniformity based on the previous stage, ultimately providing a highly uniform fuel-air mixture to the combustion chamber, contributing to efficient, stable, and low-pollution combustion. Multi-stage mixing allows for better control of temperature distribution and reaction rate during combustion, reducing combustion fluctuations and the formation of localized high-temperature zones. This helps reduce nitrogen oxides (NOx). x The generation of pollutants such as ) meets increasingly stringent environmental protection requirements, while improving combustion efficiency and equipment operational stability.

[0044] In summary, the present invention has the following advantages: 1. The burner in this invention adopts an air ejector structure, which can divide the air participating in combustion into mainstream air and a small portion of ejector air, thereby achieving two-stage mixing of fuel and air and significantly improving the mixing effect of fuel and air.

[0045] 2. The fuel nozzle in this invention is designed with a convergent ejector nozzle at the end. It utilizes the viscous force between gas molecules to draw in the ejector air by increasing the fuel injection speed. After the fuel gas is mixed with the drawn air, the inertial penetration of the fuel gas is enhanced due to the inclusion of large molecular weight air molecules, which helps to improve the uniformity of mixing between the fuel and the mainstream air.

[0046] 3. In this invention, the inner diameter of the second-stage mixing tube of the burner is designed to be 2~6mm. The tiny channel increases the contact area between the flame and the tube wall, and the heat of the flame is quickly absorbed by the tube wall. That is, the heat loss rate is greater than the heat release rate of the flame itself, which causes the flame temperature to drop rapidly below the ignition point of the fuel. The flame cannot continue to spread in the tiny channel. Therefore, the burner of this invention has a good backfire prevention function and can be used for the combustion of gaseous fuels with different hydrogen volume ratios.

[0047] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0048] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A wide hydrogen-doping ratio burner suitable for gas turbines, characterized in that, It includes a first-stage mixing pipe, a second-stage mixing pipe, a fuel chamber, an air ejector, a burner body, an air inlet, a main air chamber, a burner mounting flange, a fuel pipe, an ejector nozzle, an ejector air inlet, an ejector air chamber, and a fuel injection port; The first-stage mixing tube, air ejector, burner body, burner mounting flange, fuel pipe and ejector nozzle are arranged aligned with the central axis; the ejector nozzle is connected to the fuel pipe. The air ejector is connected to the fuel pipe and the first-stage mixing pipe at both ends, respectively; an ejector air chamber is formed between the air ejector and the ejector nozzle, and the ejector air inlet holes are evenly arranged circumferentially on the wall of the air ejector; the same end of the fuel chamber is connected to the first-stage mixing pipe and the cylindrical burner body, respectively; the burner mounting flange is connected to the burner body; the air inlet holes are opened on the cylindrical wall of the burner body near the burner mounting flange; the second-stage mixing pipe passes through the fuel chamber, and the central axis of the second-stage mixing pipe is parallel to the central axis of the first-stage mixing pipe; the fuel injection hole is opened at the end of the second-stage mixing pipe.

2. A wide hydrogen-doping ratio burner suitable for gas turbines according to claim 1, characterized in that, The ejector nozzle is a convergent ejector nozzle with a convergence ratio of 0.7 to 0.

85.

3. A wide hydrogen-doping ratio burner suitable for gas turbines according to claim 1, characterized in that, The air ejector is a cylindrical cavity air ejector.

4. A wide hydrogen-doping ratio burner suitable for gas turbines according to claim 1, characterized in that, The air intake is square.

5. A wide hydrogen-doping ratio burner suitable for gas turbines according to claim 1, characterized in that, The inner diameter of the second-stage mixing tube is designed to be 2~6 mm.

6. A wide hydrogen-doping ratio burner suitable for gas turbines according to claim 1, characterized in that, The diameter ratio of the first-stage mixing pipe to the second-stage mixing pipe is 3 to 5.

7. A wide hydrogen-doping ratio burner suitable for gas turbines according to claim 1, characterized in that, The diameter of the ejector air inlet is 5~10mm, and the number of them is 4~16, which are evenly arranged in the circumference.

8. A wide hydrogen-doping ratio burner suitable for gas turbines according to claim 1, characterized in that, The diameter of the fuel injection holes is 0.2~1mm, and the number is 2~4.

9. A wide hydrogen-doping ratio burner suitable for gas turbines according to claim 1, characterized in that, After the air and fuel are mixed, they are injected into the combustion chamber through the second-stage mixing pipe. No backflow zone is formed in the combustion chamber. The inner diameter of the second-stage mixing pipe is designed to be 2~6 mm. The tiny channel greatly increases the contact area between the flame and the pipe wall. The heat of the flame is quickly absorbed by the pipe wall, which can prevent backfire of the hydrogen-blended fuel.

10. A method of using a wide hydrogen-doping ratio burner suitable for a gas turbine according to any one of claims 1 to 9, characterized in that, include: The main air participating in the combustion of the gas turbine enters the main air chamber through the air inlet on the burner body. A small portion of the air enters the ejector air chamber through the ejector air inlet, while most of the air mixes with the fuel injected from the fuel injection port through the second-stage mixing pipe before entering the downstream combustion chamber for combustion. The fuel participating in the combustion of the gas turbine is injected into the first-stage mixing pipe through the fuel pipe after being depressurized and accelerated by the ejector nozzle. The high-speed ejected fuel gas creates a suction effect on the air entering the ejector air chamber. The drawn-in ejector air and fuel are continuously mixed in the first-stage mixing pipe before entering the fuel chamber, where they are further mixed. Finally, the fuel gas is injected into the second-stage mixing pipe through the fuel injection port, where it mixes with the mainstream air entering the second-stage mixing pipe. After mixing, the mixture enters the combustion chamber for combustion and heat release.

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