Combustion chamber and pure hydrogen gas turbine having the same

Abstract

The present application relates to the technical field of gas turbine, in particular to a combustion chamber and a pure hydrogen gas turbine with the same. The combustion chamber comprises at least one set of nozzle assemblies, each of which comprises: a fuel flow channel comprising a flow channel body and a nozzle body arranged in sequence, an arc-shaped transition section being arranged between the flow channel body and the nozzle body, and an inner side wall of an outlet end of the nozzle body being obliquely arranged to form an outflow angle so that fuel gas forms an axial vortex at the outlet of the nozzle body; and an auxiliary gas flow channel which is sleeved and arranged outside the fuel flow channel. By utilizing the cooperation of the guide sharp angle and the air as the auxiliary gas on the inner wall and the outer periphery of the auxiliary gas flow channel, the hydrogen as the fuel gas generates an axial vortex at the nozzle body, the axial vortex develops downstream of the nozzle body, and the speed distribution of the axial vortex does not generate reverse axial speed, thereby avoiding the formation of a backflow area, reducing the risk of hydrogen flame backfire, and helping to reduce the generation of nitrogen oxides.

Description

Technical Field

[0001] This invention relates to the field of gas turbine technology, and more specifically to a combustion chamber and a pure hydrogen gas turbine having therein. Background Technology

[0002] Gas turbines, as highly efficient power plants, have wide applications in power generation, aviation, and industry. With the global energy structure transitioning towards a low-carbon model, hydrogen energy, due to its zero-carbon emission characteristics, has become an important alternative to fossil fuels. However, traditional gas turbine combustors are primarily designed for hydrocarbon fuels such as natural gas. Directly using pure hydrogen as fuel faces numerous challenges, necessitating the development of new combustion technologies adapted to the characteristics of hydrogen fuel to meet environmental requirements.

[0003] Existing pure hydrogen fuel combustors mostly employ micro-mixing combustion technology, suppressing backfire by reducing the fuel nozzle diameter and increasing the mixing rate. However, micro-mixing structures require numerous micro-nozzles, leading to complex manufacturing and high costs. Furthermore, increasing the fuel flow rate per orifice can easily disrupt diffusion combustion. Some designs also incorporate swirling devices to enhance mixing, but the backflow zone generated by the swirling exacerbates the risk of hydrogen flame backfire. Moreover, these devices are structurally complex, have significant pressure losses, and are difficult to adapt to the high diffusivity and low turbulence requirements of hydrogen fuel. Therefore, axial vortex mixing technology was considered. This not only avoids backflow but also simplifies the structural implementation. Thus, based on existing hydrogen fuel combustor structures, it can effectively balance the contradictory requirements of hydrogen combustion, namely, achieving rapid mixing of hydrogen and air to reduce local high temperatures and NO. x On the one hand, it generates heat, and on the other hand, it avoids the formation of backflow zones or high turbulence during the mixing process, thus preventing flame backfire and thermoacoustic oscillations. Summary of the Invention

[0004] In view of this, the present invention provides a combustion chamber and a pure hydrogen gas turbine having the same, to solve the problem that the existing hydrogen fuel combustion chamber structure cannot avoid the generation of backflow zone or high turbulence during rapid mixing.

[0005] In a first aspect, the present invention provides a combustion chamber comprising at least one set of nozzle assemblies, the nozzle assemblies comprising:

[0006] A fuel flow channel includes a flow channel body and a nozzle body arranged in sequence. An arc-shaped transition section is provided between the flow channel body and the nozzle body. The inner sidewall of the nozzle body outlet end is inclined away from the axis of the flow channel body to form an outlet angle. The outlet end of the nozzle body is formed with at least a pair of guide sharp corners so that the fuel gas forms at least one axial vortex at the outlet of the nozzle body.

[0007] A combustion-supporting gas flow channel is fitted and installed on the outside of the fuel flow channel.

[0008] During combustion, fuel gas is ejected from the fuel channel and combustion-supporting gas from the combustion-supporting gas channel. As the fuel gas passes the nozzle body, an axial vortex is formed under the influence of the guide angle and the inner wall of the nozzle body, before mixing with the combustion-supporting gas in the outer combustion-supporting gas channel. When a pure hydrogen gas turbine is used in the combustion chamber, hydrogen is used as the fuel gas. The maximum laminar flame velocity of hydrogen combustion in air is more than eight times that of a methane flame, making the hydrogen flame prone to backfire. By utilizing the guide angle in conjunction with the inner wall of the combustion-supporting gas channel and the surrounding air (which acts as the combustion-supporting gas), an axial vortex is generated at the nozzle body, achieving thorough mixing of hydrogen and air. The axial vortex develops downstream of the nozzle, and its velocity distribution does not generate a reverse axial velocity, avoiding the formation of a backflow zone, thus reducing the risk of hydrogen flame backfire and helping to reduce the generation of nitrogen oxides.

[0009] In one optional embodiment, multiple pairs of guide tips are provided. The inner side of the nozzle body between the guide tips of the same pair is a straight edge, while the inner side of the nozzle body between two adjacent guide tips of different pairs is a concave edge. By providing multiple pairs of guide tips and using a concave edge design between different pairs of guide tips, the flow direction of fuel gas can be effectively guided by the combination of multiple pairs of guide tips and multiple concave edges. This allows the fluid to form specific multi-channel axial vortex flow paths inside the nozzle, thereby enhancing the mixing effect of the fluid, improving the uniformity of fuel-air mixing, promoting the complete combustion reaction, and thus improving combustion efficiency, reducing the generation of incomplete combustion products, and reducing pollutant emissions.

[0010] In one optional embodiment, three pairs of guide tips are spaced apart and evenly arranged around the circumference of the fuel flow channel. This even arrangement of the three pairs of guide tips around the circumference of the fuel flow channel creates a symmetrical flow structure around the nozzle, enhancing fluid mixing and ensuring uniform mixing of fuel and air around the nozzle. This avoids incomplete combustion caused by uneven local mixing, improves combustion efficiency, and reduces emissions of pollutants such as nitrogen oxides.

[0011] In one optional embodiment, multiple sets of nozzle assemblies are arranged at intervals to form nozzle clusters, with multiple nozzle clusters spaced apart circumferentially, and the multiple nozzle clusters are arranged in a rotationally symmetrical manner. By arranging multiple sets of nozzle assemblies into nozzle clusters and setting multiple nozzle clusters at intervals circumferentially to form a rotationally symmetrical arrangement, a uniform flow field can be formed in the combustion chamber. This ensures uniform mixing of fuel and air in the combustion chamber, improves combustion efficiency, reduces the formation of local high-temperature zones, thereby reducing emissions of pollutants such as nitrogen oxides, while also improving the stability and reliability of the combustion chamber.

[0012] In one optional embodiment, two rows of nozzle assemblies are arranged radially within the same nozzle cluster. One straight edge of the outer nozzle assembly faces the axis of rotational symmetry between the multiple nozzle clusters, while one straight edge of the inner nozzle assembly faces away from the axis of rotational symmetry. This can guide the axial vortices output from the multiple nozzle assemblies to mutually reinforce each other, enhancing the mixing effect of the fuel gas and the combustion-supporting gas.

[0013] In one alternative embodiment, the nozzle clusters are arranged in a fan shape, and the central angle of one nozzle cluster is 50° to 70°.

[0014] In one optional embodiment, the width of the straight edge is not greater than the width of the concave edge, so that the concave edge has sufficient width to guide the flow direction of the fuel gas, ensuring that the fuel gas output from the nozzle body can generate an axial vortex with sufficient kinetic energy to ensure that the forward direction is not easily disturbed.

[0015] In one alternative implementation, multiple sets of nozzle assemblies are arranged in a ring.

[0016] In one optional embodiment, the inner side of the guide angle is rounded, which can reduce the flow resistance of the fluid inside the nozzle, allowing the fluid to pass through the nozzle more smoothly, enhancing the mixing effect of the fluid, promoting the full combustion reaction, improving combustion efficiency, reducing the generation of incomplete combustion products, and reducing the emission of pollutants such as nitrogen oxides, thereby improving the stability and reliability of the combustion chamber.

[0017] Secondly, the present invention also provides a pure hydrogen gas turbine having the combustion chamber described in the present invention. Since the pure hydrogen gas turbine includes a combustion chamber and has the same effects as a combustion chamber, it will not be described further here. Attached Figure Description

[0018] 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.

[0019] Figure 1 A schematic diagram of the nozzle assembly provided in an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the nozzle assembly provided in an embodiment of the present invention from another perspective.

[0021] Figure 3This is a schematic diagram of the flow direction of fuel gas at the outlet end of the nozzle assembly provided in an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the flow direction of fuel gas at the outlet end of the nozzle assembly provided in an embodiment of the present invention.

[0023] Figure 5 A schematic diagram of the combustion chamber provided for an embodiment of the present invention.

[0024] Figure 6 This is a structural schematic diagram of the combustion chamber from another angle, provided for an embodiment of the present invention.

[0025] Figure 7 A static temperature distribution cloud map of the nozzle assembly in the axial direction section provided for an embodiment of the present invention.

[0026] Figure 8 A schematic diagram of the temperature distribution of a nozzle assembly in cross-section provided for an embodiment of the present invention.

[0027] Explanation of reference numerals in the attached drawings: 1. Fuel flow channel; 101. Flow channel body; 102. Arc-shaped transition section; 103. Nozzle body; 1031. Guide angle; 1032. Straight edge; 1033. Concave edge; 2. Combustion-supporting gas flow channel. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0029] The following is combined Figures 1 to 8 The following describes embodiments of the present invention.

[0030] In a first aspect, the present invention provides a combustion chamber comprising at least one set of nozzle assemblies, the nozzle assemblies including a fuel flow channel 1 and a combustion-supporting gas flow channel 2.

[0031] like Figure 1 and Figure 2As shown, the fuel flow channel 1 includes a flow channel body 101 and a nozzle body 103 arranged sequentially. An arc-shaped transition section 102 is provided between the flow channel body 101 and the nozzle body 103 to accelerate the movement speed of the fuel gas upstream of the nozzle body 103 and increase the kinetic energy of the fuel gas. The inner sidewall of the outlet end of the nozzle body 103 is inclined away from the axis of the flow channel body to form an outlet angle α, so that the fuel gas forms an axial vortex at the outlet of the nozzle body 103. The combustion-supporting gas flow channel 2 is sleeved and installed on the outside of the fuel flow channel 1.

[0032] During combustion, fuel gas is ejected from fuel channel 1, and combustion-supporting gas is ejected from combustion-supporting gas channel 2. When the fuel gas reaches the nozzle body 103, an axial vortex is formed under the action of the guide angle 1031 and the inner wall of the nozzle body 103. This vortex then mixes with the combustion-supporting gas in the outer combustion-supporting gas channel 2. When a pure hydrogen gas turbine is used in the combustion chamber, hydrogen is used as the fuel gas. The maximum laminar flame velocity of hydrogen combustion in air is more than eight times that of a methane flame, making the hydrogen flame prone to backfire. By utilizing the guide angle 1031 in conjunction with the action of the inner wall of the combustion-supporting gas channel 2 and the surrounding air (which acts as the combustion-supporting gas), an axial vortex is generated at the nozzle body 103, achieving thorough mixing of hydrogen and air. The axial vortex develops downstream of the nozzle, and its velocity distribution does not generate a reverse axial velocity, avoiding the formation of a backflow zone. This reduces the risk of hydrogen flame backfire and helps reduce the generation of nitrogen oxides.

[0033] In one embodiment, multiple pairs of guide tips 1031 are provided. The inner side of the nozzle body 103 between the same pair of guide tips 1031 is a straight edge 1032, and the inner side of the nozzle body 103 between two adjacent guide tips 1031 of different pairs of guide tips 1031 is a concave edge 1033. By providing multiple pairs of guide tips 1031 and using concave edges 1033 between different pairs of guide tips 1031, the flow direction of fuel gas can be effectively guided by the combination of multiple pairs of guide tips 1031 and multiple concave edges 1033, so that the fluid forms a specific multi-stream axial vortex flow path inside the nozzle, thereby enhancing the mixing effect of the fluid, improving the uniformity of fuel-air mixing, promoting the complete combustion reaction, thereby improving combustion efficiency, reducing the generation of incomplete combustion products, and reducing pollutant emissions. The shape of the concave edge 1033 can be designed as an arc, a parabola, or other shapes suitable for guiding the fluid to optimize the fluid flow path and mixing effect. In some other embodiments, the number of guide tips 1031 can be set to two pairs, four pairs, or any other arbitrary number, and the specific number can be adjusted according to actual needs and design parameters.

[0034] In this embodiment, three pairs of guide tips 1031 are spaced apart and evenly arranged around the circumference of the fuel flow channel 1. This even arrangement of the three pairs of guide tips 1031 around the circumference of the fuel flow channel 1 creates a symmetrical flow structure around the nozzle, enhancing fluid mixing and ensuring uniform mixing of fuel and air around the nozzle. This avoids incomplete combustion caused by uneven local mixing, improves combustion efficiency, and reduces emissions of pollutants such as nitrogen oxides. In some other embodiments, the guide tips 1031 can be arranged non-uniformly, for example, at specific angular intervals, to optimize fluid mixing and combustion performance. Figure 3 and Figure 4 As shown, the flow pattern of the fuel gas after being output from the nozzle body 103 is as follows: the streamlines originating from the central fuel hole, i.e. inside the nozzle body 103, flare outwards downstream, and axial vortices are generated at the six guide cusps 1031 of the three outer straight edges 1032.

[0035] In one embodiment, such as Figure 5 and Figure 6 As shown, multiple nozzle assemblies are arranged at intervals to form nozzle clusters. These nozzle clusters are spaced apart circumferentially and arranged in a rotationally symmetrical manner. By arranging multiple nozzle assemblies into nozzle clusters and creating a rotationally symmetrical arrangement, a uniform flow field can be formed in the combustion chamber. This ensures uniform mixing of fuel and air within the combustion chamber, improves combustion efficiency, reduces the formation of localized high-temperature zones, thereby reducing emissions of pollutants such as nitrogen oxides, and simultaneously improving the stability and reliability of the combustion chamber. The number of nozzle clusters can be set to 3, 5, or more, and the specific number can be adjusted according to actual needs and design parameters.

[0036] In one embodiment, two rows of nozzle assemblies are arranged radially within the same nozzle cluster. One straight edge 1032 of the outer nozzle assembly faces the axis of rotational symmetry between the nozzle clusters, while one straight edge 1032 of the inner nozzle assembly faces away from the axis of rotational symmetry. This guides the axial vortices output from the multiple nozzle assemblies to reinforce each other, enhancing the mixing effect of the fuel gas and the combustion-supporting gas. In some other embodiments, the number of rows of nozzle assemblies can be three or more, with the specific number adjusted according to actual needs and design parameters. The orientation of the straight edge 1032 of the nozzle assembly can be adjusted; for example, the straight edge 1032 of the outer nozzle assembly can face or face away from the axis of rotational symmetry to optimize fluid mixing and combustion performance.

[0037] In one optional embodiment, the nozzle clusters are arranged in a fan shape, with the central angle α of one nozzle cluster being 50° to 70°. The central angle β of the nozzle cluster can be set to 40°, 60°, 80°, or other suitable angles, and the specific angle can be adjusted according to actual needs and design parameters. In this embodiment, five nozzle clusters are provided, and the central angle of the nozzle clusters can be set to 60°. The shape of the nozzle clusters can be designed as other shapes, such as rectangular, elliptical, etc., to optimize the structure of the combustion chamber and the fluid flow path. In the combustion chamber, a nozzle cluster is composed of three nozzle assemblies, and five nozzle clusters are provided at the head of the combustion chamber. In each nozzle assembly, hydrogen fuel is injected at the center, and air is injected in the small circles on the outer periphery of the nozzle assembly. Various cooling vents and an arc-shaped transition section 102 of a high-frequency thermoacoustic oscillation damper are arranged on the head panel. Therefore, this design not only ensures hydrogen fuel combustion but also provides panel cooling and noise reduction.

[0038] In one embodiment, the width of the straight edge 1032 is no greater than the width of the concave edge 1033, ensuring that the concave edge 1033 has sufficient width to guide the flow direction of the fuel gas. This guarantees that the fuel gas output from the nozzle body 103 can generate an axial vortex with sufficient kinetic energy to ensure that the forward direction is not easily disturbed. The width of the concave edge 1033 can be optimized, for example, by increasing the width of the concave edge 1033 to enhance the guiding effect of the fluid, or by decreasing the width of the concave edge 1033 to optimize the flow path of the fluid.

[0039] In one embodiment, multiple nozzle assemblies are arranged in a ring. This enables the fluid to form a uniform flow field within the combustion chamber, ensuring uniform mixing of fuel and air, improving combustion efficiency, reducing the formation of localized high-temperature zones, thereby reducing emissions of pollutants such as nitrogen oxides, and simultaneously improving the stability and reliability of the combustion chamber. The nozzle assemblies can also be designed in a non-ring arrangement, for example, arranged at specific angular intervals, to optimize fluid mixing and combustion performance.

[0040] In one embodiment, the guide angle 1031 has a rounded corner on its inner side, which reduces the flow resistance of the fluid inside the nozzle, allowing the fluid to pass through the nozzle more smoothly, enhancing the fluid mixing effect, promoting the complete combustion reaction, improving combustion efficiency, reducing the generation of incomplete combustion products, and simultaneously reducing the emission of pollutants such as nitrogen oxides, thereby improving the stability and reliability of the combustion chamber. The rounded corner on the inner side of the guide angle 1031 can be designed in other shapes, such as chamfers or parabolic shapes, to optimize the fluid flow path and mixing effect. The size of the rounded corner can be adjusted, for example, by increasing or decreasing the radius of the rounded corner, to optimize the fluid flow resistance and mixing effect.

[0041] The combustion chamber provided in this embodiment uses an axial vortex principle for nozzle structure design, effectively solving multiple technical problems faced by existing pure hydrogen gas turbine combustion chambers. Addressing the issue of nitrogen oxides easily generated during hydrogen combustion, an axial vortex is used to achieve thorough mixing of hydrogen and air. The axial vortex develops downstream of the nozzle, and its velocity distribution does not generate reverse axial velocity, avoiding the formation of a backflow zone, thereby reducing the risk of hydrogen flame flashback and helping to reduce nitrogen oxide formation. Figure 7 As shown, downstream of the nozzle body 103, fuel and air mix and burn. Cooling air is entrained towards the inner ring of the flame, lowering the central temperature and thus reducing pollution. The flame has an irregular shape in the lower left corner, which is beneficial for mode stability. To address the stability of hydrogen combustion, a Y-shaped nozzle design is used, placing hydrogen in the center of the nozzle and air on the outer side. Figure 8 As shown, this design allows hydrogen and air to mix rapidly and uniformly after the nozzle exit, improving combustion stability and avoiding flame instability caused by excessive turbulence, thus helping to reduce nitrogen oxide emissions. Considering the structural complexity and manufacturing cost of the combustion chamber, the Y-shaped nozzle design is simple and easy to manufacture. It can be integrally formed using technologies such as 3D printing, reducing manufacturing difficulty and cost. Simultaneously, the nozzle itself does not generate a significant pressure drop, only a small pressure drop in the downstream axial vortex region, which helps maintain a reasonable pressure distribution inside the combustion chamber, improving combustion efficiency and maintaining the exit velocity to prevent backfire. Regarding the combustion chamber head design, the reasonable arrangement of baffles and radiating cooling holes effectively reduces the radiation and conduction heat of the hydrogen-burning near-wall flame, improving the thermal efficiency and durability of the combustion chamber. Through the arrangement and combination of multiple Y-shaped nozzle bodies 103, annular combustion chambers or combustion chamber heads with single or multiple flame tubes can be flexibly constructed to meet the needs of gas turbines with different power outputs. The combustion chamber provided in this embodiment effectively solves the comprehensive technical problems of pure hydrogen gas turbine combustion chambers in preventing backfire, reducing NOx emissions, improving combustion stability, and simplifying structural design through an innovative axial vortex nozzle design, and has significant technical advantages and application prospects.

[0042] According to an embodiment of the present invention, in another aspect, a pure hydrogen gas turbine is also provided, having the combustion chamber described in the present invention. Because the pure hydrogen gas turbine includes a combustion chamber, during operation, fuel gas is ejected from fuel flow channel 1, and combustion-supporting gas is ejected from combustion-supporting gas flow channel 2. At the nozzle body 103, the fuel gas forms an axial vortex due to the action of the guide angle 1031 and the inner wall of the nozzle body 103. The axial vortex ensures thorough mixing of the fuel gas and combustion-supporting gas, avoiding the formation of a backflow zone and reducing the risk of hydrogen flame flashback. Simultaneously, the axial vortex helps reduce the generation of nitrogen oxides, improves combustion efficiency, reduces the generation of incompletely combusted products, and lowers pollutant emissions.

[0043] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A combustion chamber, characterized in that, Includes at least one set of nozzle assemblies, the nozzle assembly comprising: The fuel flow channel (1) includes a flow channel body (101) and a nozzle body (103) arranged sequentially. An arc-shaped transition section (102) is provided between the flow channel body (101) and the nozzle body (103). The inner sidewall of the nozzle body (103) outlet end is inclined away from the axis of the flow channel body to form an outlet angle. The outlet end of the nozzle body (103) is formed with at least a pair of guide sharp corners (1031) so that the fuel gas forms at least one axial vortex at the outlet of the nozzle body (103). Combustion-supporting gas flow channel (2) is sleeved and installed on the outside of the fuel flow channel (1); The guide tips (1031) are arranged in three pairs at intervals. The three pairs of guide tips (1031) are evenly arranged around the circumference of the fuel flow channel (1). The inner side of the nozzle body (103) between the same pair of guide tips (1031) is a straight side (1032), and the inner side of the nozzle body (103) between two adjacent guide tips (1031) of different pairs of guide tips (1031) is a concave side (1033).

2. The combustion chamber according to claim 1, characterized in that, Multiple sets of the nozzle assemblies are arranged at intervals to form a nozzle cluster, and the nozzle clusters are arranged at intervals along the circumference, and the multiple nozzle clusters are arranged in a rotationally symmetrical manner.

3. The combustion chamber according to claim 2, characterized in that, Two rows of nozzle assemblies are arranged radially within the same nozzle cluster. One straight edge (1032) of the outer nozzle assembly is oriented toward the axis of rotational symmetry between the multiple nozzle clusters, while one straight edge (1032) of the inner nozzle assembly is oriented away from the axis of rotational symmetry between the multiple nozzle clusters.

4. The combustion chamber according to claim 3, characterized in that, The nozzle clusters are arranged in a fan shape, and the central angle of one nozzle cluster is 50°~70°.

5. The combustion chamber according to claim 1, characterized in that, The width of the straight edge (1032) is not greater than the width of the concave edge (1033).

6. The combustion chamber according to claim 1, characterized in that, The multiple sets of nozzle assemblies are arranged in a ring.

7. The combustion chamber according to claim 1, characterized in that, The inner side of the guide sharp corner (1031) is provided with a rounded corner.

8. A pure hydrogen gas turbine, characterized in that, It has a combustion chamber as described in any one of claims 1 to 7.

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