Nozzle with small branch

Abstract

This invention discloses a nozzle with a small support plate, comprising an air inlet section, a mixing section, and an outlet section arranged coaxially in sequence. A fuel inlet penetrating the sidewall of the mixing section is provided, and a protruding small support plate is provided within the sidewall of the mixing section, located upstream of the fuel inlet. By providing this small support plate, the mixing uniformity of fuel and air at the nozzle outlet is improved. Simultaneously, the flame of micro-mixed combustion is smaller, the flame distribution during combustion is more uniform, and the local high-temperature zone is reduced, thereby reducing NO₂ levels. x Emissions.

Description

Technical Field

[0001] This invention relates to the field of micro-mixing combustion technology, specifically to a nozzle with a small support plate. Background Technology

[0002] The main pollutants emitted by gas turbines are CO and NO. x In recent years, micro-hybrid combustion technology has become increasingly popular as a novel combustion technology because it can achieve ultra-low emissions of pollutants compared to other technologies. CO emissions have been effectively controlled with the improvement of combustion efficiency in the combustion chamber, so NO emissions are also significantly reduced. x This has become a major source of pollutant emissions from gas turbines, particularly thermal NOx. x NO emissions are temperature-related; however, improving gas turbine efficiency inevitably leads to an increase in combustion temperature, which in turn causes NO emissions to rise. x Emissions are increasing, so we should find ways to address NO. x The problem of increased emissions.

[0003] Studies have shown that NO x NO emissions are closely related to the uniformity of fuel and air mixing. Current nozzle designs employ air flowing axially along the nozzle and fuel flowing radially along the nozzle, mixing within the nozzle. Therefore, to reduce NO emissions... x To address the issue of emissions, improving the uniformity of air-fuel mixing at the nozzle outlet is a technical problem that needs to be solved in nozzle design. Summary of the Invention

[0004] Purpose of the invention: Based on the above problems, this invention provides a nozzle with a small support plate, aiming to improve the uniformity of air-fuel mixing at the nozzle outlet, thereby solving the problem of increased combustion temperature in gas turbines leading to NO emissions. x The problem of increased emissions.

[0005] Technical solution: A nozzle with a small support plate includes an air inlet section, a mixing section, and an outlet section arranged coaxially in sequence; a fuel inlet penetrating the side wall of the mixing section is provided, and a protruding small support plate is provided inside the side wall of the mixing section, with the small support plate located upstream of the fuel inlet; the bottom surface of the small support plate is a trapezoidal or a trapezoidal structure with an arc-shaped bottom edge, and the cross-section of the small support plate is triangular, with the end of the bottom surface that is in contact with the side wall of the mixing section being the wide end.

[0006] Furthermore, the bottom surface of the small support plate is located upstream of the fuel inlet, and the central axis of the bottom surface is located directly above the fuel inlet.

[0007] Furthermore, the top of the small support plate is pointed and extends inward at an angle from upstream to downstream.

[0008] Furthermore, the air inlet section, mixing section, and outlet section are all cylindrical inside. There are two fuel inlets, which are symmetrically distributed on opposite sides of the mixing section sidewall from the central axis. Each fuel inlet has a small support plate upstream. The bottom surface of the small support plate is a trapezoidal structure with an arc-shaped bottom edge, and the side connected to the mixing section sidewall is the bottom edge of the bottom surface.

[0009] Furthermore, the two small support plates are also symmetrically distributed on opposite sides of the mixing section sidewall from the central axis.

[0010] Furthermore, the inner diameter of the air inlet section is larger than the inner diameter of the mixing section, and the inner diameter of the outlet section is also larger than the inner diameter of the mixing section.

[0011] Furthermore, the internal cross-sections of the air inlet section, mixing section, and outlet section are all equilateral triangles. The mixing section has three inner surfaces, each with a fuel inlet. The three fuel inlets are evenly distributed along the central axis of the nozzle, and each fuel inlet has a small support plate upstream.

[0012] Furthermore, the three small support plates are also evenly distributed along the central axis of the nozzle.

[0013] Furthermore, the cross-sectional area of ​​the air inlet section is larger than that of the mixing section, and the cross-sectional area of ​​the outlet section is also larger than that of the mixing section.

[0014] Beneficial effects: Compared with the prior art, the nozzle with small support plates provided by this invention improves the uniformity of fuel and air mixing at the nozzle outlet. Simultaneously, the flame of micro-mixed combustion is smaller, the flame distribution is more uniform during combustion, and the local high-temperature zone is reduced, thereby reducing NO₂ levels. x Emissions. Attached Figure Description

[0015] Figure 1 This is a perspective view of the nozzle in Example 1;

[0016] Figure 2 This is a three-dimensional cross-sectional view of the nozzle in Example 1;

[0017] Figure 3 This is a schematic cross-sectional view of the nozzle in Embodiment 1;

[0018] Figure 4 This is a top view of the arrangement of small support plates in the nozzle of Embodiment 1;

[0019] Figure 5 A perspective view of the nozzle in Example 2;

[0020] Figure 6 A three-dimensional cross-sectional view of the nozzle in Example 2;

[0021] Figure 7Example 2: Top view of the arrangement of small support plates in the nozzle;

[0022] Figure 8 Example 2: A perspective view of the small support plate in the nozzle;

[0023] Figure 9 A simulation diagram of the molar concentration distribution along the axial direction H2 of the prototype nozzle;

[0024] Figure 10 This is a simulation diagram of the H2 molar concentration distribution at the cross section of the prototype nozzle aa.

[0025] Figure 11 A simulation diagram of the H2 molar concentration distribution at the outlet of the prototype nozzle;

[0026] Figure 12 This is a simulation diagram of the nozzle axial H2 molar concentration distribution in Example 1;

[0027] Figure 13 This is a simulation diagram of the H2 molar concentration distribution at section aa in Example 1;

[0028] Figure 14 This is a simulation diagram of the H2 molar concentration distribution at the nozzle outlet in Example 1;

[0029] Figure 15 A schematic diagram of the molar concentration distribution along the axial direction H2 of a triangular nozzle;

[0030] Figure 16 This is a simulation diagram of the H2 molar concentration distribution across the cross section of a triangular nozzle aa.

[0031] Figure 17 Simulation diagram of H2 molar concentration distribution at the outlet of a triangular nozzle;

[0032] Figure 18 This is a simulation diagram of the molar concentration distribution along the nozzle axis H2 in Example 2;

[0033] Figure 19 This is a simulation diagram of the H2 molar concentration distribution at the nozzle aa cross section in Example 2;

[0034] Figure 20 This is a simulation diagram of the H2 molar concentration distribution at the nozzle outlet in Example 2. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0036] Example 1

[0037] Please combine Figures 1 to 3As shown, this embodiment discloses a nozzle with a small support plate, used for mixing fuel and air in a gas turbine. The nozzle includes an air inlet section 10, a mixing section 20, and an outlet section 30 arranged coaxially in sequence. The air inlet section 10 has an inlet 1 for introducing air; the outlet section 30 has an outlet 4 for outputting the mixed gas. The interiors of the air inlet section 10, mixing section 20, and outlet section 30 are all cylindrical. A fuel inlet 3 penetrating the sidewall of the mixing section 20 is provided, meaning that air flows axially and fuel flows radially within the nozzle. A protruding small support plate 2 is provided inside the sidewall of the mixing section, with the bottom surface of the small support plate 2 located upstream of the fuel inlet 3 and its central axis directly above the fuel inlet 3. There are two fuel inlets 3, symmetrically distributed from their central axes on opposite sides of the mixing section sidewall; each fuel inlet 3 has a small support plate 2 upstream of it.

[0038] Combination Figure 4 As shown, since the sidewall of the mixing section 20 is an inner cylinder, the bottom surface of the small support plate 2 is a trapezoidal structure with an arc-shaped bottom edge, and the side connected to the sidewall of the mixing section 20 is the bottom edge of the bottom surface. The cross-section of the small support plate 2 is triangular, and the end of the bottom surface that is in contact with the sidewall of the mixing section is the wide end. The top of the small support plate 2 is a pointed tip and extends inward at an angle from upstream to downstream.

[0039] Example 2

[0040] Please combine Figures 5 to 7 As shown, this embodiment discloses another nozzle with a small support plate, including an air inlet section 10, a mixing section 20, and an outlet section 30 arranged coaxially in sequence. The internal cross-sections of the air inlet section 10, the mixing section 20, and the outlet section 30 are all equilateral triangles. The mixing section 20 has three inner surfaces, each with a fuel inlet 3. The three fuel inlets 3 are evenly distributed along the central axis of the nozzle, and each fuel inlet 3 has a small support plate 2 upstream. The three small support plates 2 are also evenly distributed along the central axis of the nozzle.

[0041] Please combine Figure 8 As shown, the bottom surface of the small support plate 2 is an isosceles trapezoid with an isosceles trapezoidal structure, and the side connected to the sidewall of the mixing section 20 is the bottom edge of the bottom surface. The cross-section of the small support plate 2 is triangular, and the end of the bottom surface that is in contact with the sidewall of the mixing section is the wide end. The top of the small support plate 2 is a pointed tip and extends inward from upstream to downstream.

[0042] For the two embodiments described above, simulation experiments were used to verify their technical effects. Comparative examples were also provided for comparison with the two embodiments. In this invention, Ansys Fluent software was used to simulate the mixing characteristics of the nozzle.

[0043] Please see Figures 9 to 11The diagram shows an experimental example of a conventional nozzle where the air inlet, mixing, and outlet sections all have cylindrical channels and no internal support plates. Figure 9 The molar concentration distribution along the axial direction H2 of the prototype nozzle; Figure 10 The molar concentration distribution of H2 at the cross section of the prototype nozzle aa; Figure 11 The H2 molar concentration distribution at the prototype nozzle outlet.

[0044] Please see Figures 12 to 14 The figure shown is an experimental illustration of the nozzle with a small support plate in Example 1. Figure 12 The nozzle axial H2 molar concentration distribution in Example 1; Figure 13 The molar concentration distribution of H2 at section aa in Example 1; Figure 14 The nozzle outlet H2 molar concentration distribution is shown in Example 1.

[0045] Please see Figures 15 to 17 The diagram shows an experimental setup where the air inlet, mixing, and outlet sections all have triangular cross-sections, and the nozzles lack internal support plates. Figure 15 The molar concentration distribution along the axial direction H2 of the triangular nozzle; Figure 16 The H2 molar concentration distribution across the cross section of the triangular nozzle aa; Figure 17 H2 molar concentration distribution at the outlet of the triangular nozzle.

[0046] Please see Figures 18 to 20 The image shown is an experimental illustration of the nozzle with a small support plate in Example 2. Figure 18 The molar concentration distribution along the nozzle axis H2 in Example 2; Figure 19 The H2 molar concentration distribution at the nozzle aa cross section in Example 2; Figure 20 The nozzle outlet H2 molar concentration distribution is shown in Example 2.

[0047] The mixing characteristics of the nozzle were simulated using Ansys Fluent software, and the uniformity of air-fuel mixing at the nozzle outlet section 4 was obtained. Compared with the nozzle outlet section without the small support plate, the uniformity of air-fuel mixing with the small support plate was significantly higher.

[0048] Table 1 below compares the mixing uniformity at the outlet of the prototype nozzle, the triangular nozzle without the small support plate, and the nozzles of Examples 1 and 2. The results show that the mixing uniformity at the nozzle outlet of Example 1 is as high as 0.98, and the mixing uniformity at the outlet of the triangular nozzle without the small support plate is 0.94, both significantly improved compared to the prototype nozzle. The mixing uniformity at the nozzle outlet cross-section of Example 2 is also as high as 0.98, showing a similar improvement compared to the triangular nozzle without the small support plate.

[0049] Table 1. Mixing uniformity of several nozzle outlet cross sections

[0050]

[0051] In summary, in embodiments one and two, the addition of small support plates within the mixing section improves the uniformity of air-fuel mixing at the nozzle outlet cross-section and reduces the high-temperature combustion zone, thereby reducing NO... x Emissions are reduced.

[0052] The above embodiments illustrate the working principle of the present invention in detail. It should be noted that any technical solutions obtained by reasoning and modifying the embodiments described in this invention without inventive effort should fall within the protection scope of the claims of this invention.

Claims

1. A nozzle with a small support plate, characterized in that, It includes an air inlet section (10), a mixing section (20), and an outlet section (30) arranged coaxially in sequence; the mixing section has a fuel inlet (3) that penetrates the side wall, and a protruding small support plate (2) is provided inside the side wall of the mixing section, and the small support plate (2) is located upstream of the fuel inlet (3); The bottom surface of the small support plate (2) is a trapezoidal or a trapezoidal structure with an arc-shaped bottom edge, and the cross-section of the small support plate (2) is triangular, with the end of the bottom surface that is in contact with the side wall of the mixing section being the wide end; The bottom surface of the small support plate (2) is located upstream of the fuel inlet (3) and the central axis of the bottom surface is located directly above the fuel inlet (3); the top of the small support plate (2) is a pointed tip and extends inward from upstream to downstream.

2. The nozzle with a small support plate according to claim 1, characterized in that, The air inlet section, mixing section and outlet section are all cylindrical inside. There are two fuel inlets (3) that are symmetrically distributed on opposite sides of the mixing section sidewall from the central axis. Each fuel inlet (3) has a small support plate (2) upstream. The bottom surface of the small support plate (2) is a trapezoidal structure with an arc-shaped bottom edge. The side connected to the mixing section sidewall is the bottom edge of the bottom surface.

3. The nozzle with a small support plate according to claim 2, characterized in that, Two small support plates (2) are also symmetrically distributed on opposite sides of the sidewall of the mixing section from the central axis.

4. The nozzle with a small support plate according to claim 2, characterized in that, The inner diameter of the air inlet section is larger than that of the mixing section, and the inner diameter of the outlet section is also larger than that of the mixing section.

5. The nozzle with a small support plate according to claim 1, characterized in that, The air inlet section, mixing section and outlet section have equilateral triangle cross sections. The mixing section has three inner surfaces, and each inner surface is provided with a fuel inlet (3). The three fuel inlets (3) are evenly distributed along the central axis of the nozzle. Each fuel inlet (3) has a small support plate (2) upstream.

6. The nozzle with a small support plate according to claim 5, characterized in that, The three small support plates (2) are also evenly distributed along the central axis of the nozzle.

7. The nozzle with a small support plate according to claim 5, characterized in that, The cross-sectional area of ​​the air inlet section is larger than that of the mixing section, and the cross-sectional area of ​​the outlet section is also larger than that of the mixing section.

8. The nozzle with a small support plate according to claim 1, characterized in that, It is used in gas turbines.

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