Premix micro-mix injector and combustor

Abstract

The application provides a premixed micro-mixing nozzle and a combustor, relates to the technical field of low emission combustion of gas turbines, and comprises a pipe body, the pipe body is provided with a spray hole and a mixing flow channel extending in a first direction, the mixing flow channel has an inlet and an outlet opposite to each other in the first direction, one of the spray hole and the inlet is used for passing air, and the other is used for passing fuel, and the spray hole is located between the inlet and the outlet in the first direction; the spray hole is multiple and is arranged in a circumferential interval of the mixing flow channel, the spray hole has a first end and a second end arranged oppositely, the first end of the spray hole is formed on a circumferential wall of the pipe body, the second end of the spray hole is communicated with the mixing flow channel, and the second end of part of the spray holes is closer to a central axis of the mixing flow channel than the second end of the rest of the spray holes. The application can realize multi-point injection of air or fuel in the radial direction of the pipe body, increase the contact area of the fuel and the air, make the mixing performance of the two in the radial direction better, improve the combustion efficiency, and reduce the emission of pollutants.

Description

Technical Field

[0001] This application relates to the field of low-emission combustion technology for gas turbines, and in particular to a premixed micro-mixing nozzle and burner. Background Technology

[0002] Premixed and micro-mixed combustion technology combines the characteristics of premixing and micro-mixing. It can achieve premixing of fuel and air in the burner, and improve the premixing uniformity by reducing the premixing scale through small-scale (millimeter-level) nozzles, thereby improving combustion efficiency and reducing pollutant emissions.

[0003] In related technologies, premixed and micro-mixed burners use circular pipes as premixing channels. Swirling flow is generated through inclined pipes or the addition of cyclones. Air and fuel gas enter the circular pipe via transverse or coaxial jets for mixing. Transverse jet mixing can create localized turbulence and vortex structures in the circular pipe flow field, which is beneficial for rapid mixing of air and fuel. However, the mixing degree of this method is relatively weak in the radial direction, easily forming localized areas of uneven mixing. Coaxial jet mixing can achieve a more uniform mixing effect, but the mixing process of air and fuel gas mainly occurs in the interphase boundary layer region, resulting in lower mixing efficiency and a longer mixing time. Therefore, both transverse and coaxial jet mixing methods based on circular pipes have drawbacks and limitations in terms of fuel and air mixing effects. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, one embodiment of the present invention proposes a premixed micro-mixing nozzle, which can realize multi-point injection of air or fuel in the radial direction of the nozzle body, increase the contact area between fuel and air, and make the mixing performance of the two in the radial direction better, so as to improve combustion efficiency and reduce pollutant emissions.

[0006] Another embodiment of the present invention provides a premixed micro-mixed burner.

[0007] According to an embodiment of the present invention, a premixed micro-mixing nozzle includes a pipe body, the pipe body having a nozzle and a mixing channel extending along a first direction, the mixing channel having an inlet and an outlet opposite to each other along the first direction, one of the nozzle and the inlet being used to introduce air and the other being used to introduce fuel, the nozzle being located between the inlet and the outlet in the first direction;

[0008] The nozzles are multiple and arranged at intervals along the circumference of the mixing channel. Each nozzle has a first end and a second end arranged opposite to each other. The first end of the nozzle is formed on the circumferential wall of the tube body, and the second end of the nozzle communicates with the mixing channel. The second end of some nozzles is closer to the central axis of the mixing channel than the second end of the other nozzles.

[0009] According to an embodiment of the present invention, the premixed micro-mixing nozzle has an inlet and an outlet arranged opposite to each other along a first direction on the mixing channel, allowing air or fuel to enter the mixing channel in an axial jet manner. The nozzles arranged circumferentially on the mixing channel can inject fuel or air into the mixing channel in a transverse jet manner, and rapidly mix with the axial jet medium in the mixing channel, thus achieving the mixing of air and fuel. At the same time, because the second ends of some of the nozzles are closer to the central axis of the mixing channel than the second ends of the other nozzles, that is, at the same cross-sectional position of the mixing channel, the second ends of the multiple nozzles are distributed on concentric circles of different diameters in the mixing channel, thus forming a multi-point injection in the radial direction of the premixed micro-mixing nozzle, which is more conducive to the mixing of fuel and air. Compared with related technologies, this application can improve the problem of poor mixing effect at the same radial point injection in the transverse jet mixing method. By injecting air or fuel at multiple points in the radial direction of the pipe, the contact area between fuel and air is increased, resulting in better mixing performance of the two in the radial direction, thereby improving combustion efficiency and reducing pollutant emissions.

[0010] In some embodiments, the nozzles are arranged in at least one row at intervals along the first direction, and in the at least one row of nozzles, the second end of some nozzles is closer to the central axis of the mixing channel than the second end of the remaining nozzles, and the distance from the second end of all nozzles in the remaining rows to the central axis of the mixing channel is equal.

[0011] In some embodiments, the premixed micro-mixing nozzle further includes a plurality of protruding ridges extending along the first direction, the plurality of protruding ridges being arranged at intervals along the circumference of the nozzle body on the inner peripheral wall of the nozzle body and together with the inner peripheral wall of the nozzle body to form the mixing channel.

[0012] In some embodiments, the spacing between any two adjacent protrusions is equal, and the outer contour of the cross-section of the protrusion includes a first arc segment and a second arc segment connected end to end; or, the outer contour of the cross-section of the protrusion is a polygon.

[0013] In some embodiments, the mixing channel includes a first segment and a second segment connected sequentially along the first direction, the inlet and the second end of the nozzle are both formed on the first segment, the outlet is formed on the second segment, the convex ridge is located on the first segment, and the cross-sectional area of ​​the first segment gradually decreases along the direction from the inlet toward the outlet.

[0014] In some embodiments, the second segment includes a necked portion and a tail portion, the first segment, the necked portion and the tail portion are arranged sequentially and smoothly connected along the first direction, the outlet is formed in the tail portion, the cross-sectional area of ​​the necked portion gradually decreases and then gradually increases along the direction from the inlet to the outlet, and the minimum cross-sectional area of ​​the necked portion is smaller than the minimum cross-sectional area of ​​the first segment.

[0015] In some embodiments, the cross-sectional area of ​​the tail remains constant along the direction from the inlet to the outlet, and the outline of the cross-section of the tail may be circular.

[0016] In some embodiments, the convex rib has a first wall surface and a second wall surface opposite each other in a direction from the outer peripheral wall of the tube toward the inner peripheral wall, the first wall surface being connected to the inner peripheral wall of the tube, the distance between the first wall surface and the second wall surface gradually decreasing in a direction from the inlet toward the outlet, and the second wall surface adjacent to the second segment being flush with the inner peripheral wall of the tube at the corresponding position.

[0017] In some embodiments, the first segment of the mixing channel extends spirally along the first direction.

[0018] In some embodiments, the outer peripheral wall of the tube has the same structure as the mixing channel.

[0019] In some embodiments, the premixed micro-mixing nozzle is formed using an additive manufacturing process.

[0020] According to an embodiment of the present invention, a premixed micro-mixed burner includes a housing, a supply pipe, and a premixed micro-mixed nozzle.

[0021] The housing has a receiving cavity, and the supply pipe is connected to the receiving cavity and is used to supply air or fuel;

[0022] Wherein, the premixed micro-mixing nozzle is the premixed micro-mixing nozzle described in any of the above embodiments, the premixed micro-mixing nozzle is installed on the housing and at least partially located in the accommodating cavity, and the nozzle orifice of the premixed micro-mixing nozzle is in communication with the accommodating cavity.

[0023] According to embodiments of the present invention, the premixed and micro-mixed burner employs a premixed and micro-mixed nozzle capable of achieving multi-point injection of air or fuel in the radial direction of the nozzle body, thereby enabling the premixed and micro-mixed burner to have good premixing performance, high combustion efficiency, and reduced pollutant emissions.

[0024] In some embodiments, the premixed micro-mixing nozzles are arranged in a parallel array.

[0025] In some embodiments, on a projection plane perpendicular to the height direction of the housing, at the connection between the supply pipe and the housing, the central axis of the projection of the supply pipe is tangent to the projection of the inner peripheral wall of the housing, and the height direction of the housing is consistent with the first direction.

[0026] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of a premixed micro-mixing nozzle according to an embodiment of the present invention.

[0028] Figure 2 yes Figure 1 A cross-sectional view of the premixed and micromixed nozzle along the first direction.

[0029] Figure 3 yes Figure 1 A cross-sectional view of the premixed and micromixed nozzle along the first direction at the nozzle position.

[0030] Figure 4 This is a schematic diagram of the structure of a premixed micro-mixed burner according to an embodiment of the present invention.

[0031] Figure 5 yes Figure 4 A cross-sectional structural diagram.

[0032] Figure 6 yes Figure 4 A top-view structural diagram.

[0033] Reference numerals: 1. Tube body, 11. First section, 12. Second section, 121. Neck section, 122. Tail section, 2. Nozzle, 3. Inlet, 4. Outlet, 5. Rib, 6. Shell, 61. Receptacle, 7. Supply tube. Detailed Implementation

[0034] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0035] like Figures 1 to 3 As shown, an embodiment of the premixed micro-mixing nozzle of the present invention includes a pipe body 1. The pipe body 1 is provided with a nozzle 2 and a mixing channel extending along a first direction. The mixing channel has an inlet 3 and an outlet 4 opposite to each other along the first direction. One of the nozzle 2 and the inlet 3 is used to introduce air, and the other is used to introduce fuel, so that air or fuel can be injected into the mixing channel in an axial jet manner from the inlet 3. The nozzle 2 is located between the inlet 3 and the outlet 4 in the first direction.

[0036] Multiple nozzles 2 are arranged at intervals along the circumference of the mixing channel. Each nozzle 2 has a first end and a second end arranged opposite to each other. The first end of the nozzle 2 is formed on the circumferential wall of the tube body 1, and the second end of the nozzle 2 communicates with the mixing channel, so that the nozzles 2 are arranged radially on the outer circumference of the mixing channel. The second ends of some nozzles 2 are closer to the central axis of the mixing channel than the second ends of the others, so that multiple nozzles 2 are distributed at different radial positions at different distances from the central axis of the mixing channel at the same axial position.

[0037] According to an embodiment of the present invention, the premixed micro-mixing nozzle has an inlet 3 and an outlet 4 arranged opposite to each other along a first direction on the mixing channel, allowing air or fuel to enter the mixing channel in an axial jet manner. Meanwhile, the nozzles 2 arranged circumferentially in the mixing channel can inject fuel or air into the mixing channel in a transverse jet manner, and rapidly mix with the axial jet medium within the mixing channel, achieving the mixing of air and fuel. Simultaneously, because the second ends of some of the nozzles 2 are closer to the central axis of the mixing channel than the second ends of the others, that is, during mixing... At the same cross-sectional location of the flow channel, the second ends of multiple nozzles 2 are distributed on concentric circles of different diameters in the mixing flow channel. Therefore, multi-point injection is formed in the radial direction of the premixed micro-mixing nozzle, which is more conducive to the mixing of fuel and air. Compared with related technologies, this application can improve the problem of poor mixing effect at the same radial point injection in the transverse jet mixing mode. By injecting air or fuel at multiple points in the radial direction of the pipe body 1, the contact area between fuel and air is increased, so that the mixing performance of the two in the radial direction is better, thereby improving combustion efficiency and reducing pollutant emissions.

[0038] Specifically, the first direction (e.g., refer to the appendix) Figure 1 The direction e1 in the diagram can be the axial direction of the pipe body 1. The cross-section of the mixing channel is the cross-section of the mixing channel after it has been cut along a direction perpendicular to the first direction. The mixing channel has an open structure at both ends, with one end being the inlet 3 and the other end being the outlet 4, and both the inlet 3 and the outlet 4 are located at the ends of the pipe body 1. To further ensure the uniformity of fuel and air mixing, multiple nozzles 2 can be arranged at equal intervals along the circumference of the mixing channel. The nozzles 2 extend from the outer circumferential wall of the pipe body 1 toward the mixing channel. The first end of the nozzle 2 is the air or fuel injection end, and the second end of the nozzle 2 is the air or fuel discharge end. The cross-sectional area of ​​the nozzle 2 can remain constant, gradually increase, gradually decrease, or change accordingly along the direction from the first end to the second end. The specific design of the cross-sectional area of ​​the nozzle 2, the number of nozzles 2, and their distribution in the circumferential and axial directions are based on the actual injection requirements and will not be elaborated here.

[0039] It is understandable that the second end of some nozzles 2 is closer to the central axis of the mixing channel than the second end of the other nozzles 2. That is, among the multiple nozzles 2 distributed at intervals on the same cross section, the distance between the second end of some nozzles 2 and the central axis of the mixing channel is smaller than the distance between the second end of the other nozzles 2 and the central axis of the mixing channel. This allows multiple injection points at different distances from the center to be formed in the radial direction of the mixing channel.

[0040] Therefore, compared to the transverse jet method in related technologies, which involves jet mixing when the distance between the second end of all nozzles 2 and the centerline of the mixing channel is equal, resulting in a weaker mixing degree in the radial direction and a tendency to form localized uneven mixing regions in the radial direction (i.e., the mixing degree of the transverse jet medium is inconsistent with that of the axial jet medium in regions far or near the center of the mixing channel due to the influence of jet velocity, etc.), and the coaxial jet method in related technologies (i.e., air and fuel are both injected from the inlet 3 for mixing), where the mixing process mainly occurs in the boundary layer region between the two media, resulting in low mixing efficiency and long mixing time, this application adopts a combination of axial and transverse jets, and the transverse jet can be injected at multiple points at the same cross-sectional position, so as to avoid the defects of the aforementioned two methods and achieve rapid and sufficient mixing of fuel and air.

[0041] like Figure 1 and Figure 3 As shown, in some embodiments, the nozzles 2 are arranged in at least one row and spaced apart along a first direction. In at least one row of nozzles 2, the second end of some nozzles 2 is closer to the central axis of the mixing channel than the second end of the other nozzles 2. The distances from the second ends of all nozzles 2 in the other rows to the central axis of the mixing channel are equal (not shown in the figure).

[0042] By using multiple rows of nozzles 2 spaced apart along the first direction, the axial mixing of air and fuel in the mixing channel can be enhanced. At the same time, in conjunction with the structure of multiple nozzles 2 forming a multi-point injection in the radial direction, the spatial uniformity of the premixed gas (i.e., the mixed medium formed by air and fuel) is further improved.

[0043] Specifically, any two adjacent rows of nozzles 2 can be arranged at equal or unequal intervals along the first direction. The specific arrangement can be designed according to the flow rate or concentration of air and fuel in the mixing channel, so as to ensure the uniformity of the premixed gas mixing in the axial direction.

[0044] like Figure 1 As shown, in some embodiments, the premixed micro-mixing nozzle further includes a plurality of protruding ribs 5 extending along a first direction. The plurality of protruding ribs 5 are arranged at intervals along the circumference of the pipe body 1 on the inner peripheral wall of the pipe body 1 and together with the inner peripheral wall of the pipe body 1, they form a mixing channel.

[0045] The convex rib 5, in conjunction with the inner circumferential wall of the tube body 1, forms a mixing channel structure with a non-circular cross-sectional profile. Compared to the circular mixing channel in related technologies, the mixing channel structure in this application allows the transverse jet medium to have multiple injection positions in the radial direction of the mixing channel, increasing the contact area between fuel and air, thereby improving the uniformity of fuel and air mixing.

[0046] Specifically, multiple protruding ridges 5 can be arranged at equal or unequal intervals along the circumference of the tube body 1. The protruding ridges 5 can be integrally formed with the inner circumferential wall of the tube body 1. Any two adjacent protruding ridges 5 and the inner circumferential wall of the tube body 1 together define a groove structure.

[0047] It is understandable that the second end of some nozzles 2 can be formed on the wall surface of the protruding ridge 5 near the central axis of the mixing channel, while the second end of the remaining nozzles 2 can be formed on the inner peripheral wall of the tube body 1, thereby achieving the purpose that the second end of some nozzles 2 is closer to the central axis of the mixing channel than the second end of the remaining nozzles 2.

[0048] like Figure 1 As shown, in some embodiments, the spacing between any two adjacent protruding ridges 5 is equal to further ensure the uniformity of fuel and air mixing and reduce the difficulty of production and processing. The outer contour of the cross-section of the protruding ridge 5 includes a first arc segment and a second arc segment connected end to end, or the outer contour of the cross-section of the protruding ridge 5 is a polygon.

[0049] Specifically, the outline of the cross-section of the mixing channel is not limited to a closed waveform; that is, the outline of the cross-section of the mixing channel is a closed line formed by multiple peaks and troughs alternating circumferentially. Taking the arrangement of nozzles 2 at peaks and troughs as an example, the second end of some nozzles 2 can be formed at the trough, while the second end of the remaining nozzles 2 is formed at the peak. This allows the transverse jet medium to have two injection positions in the radial direction: "inner" and "outer" (the trough is "inner," and the peak is "outer"), which is more conducive to the mixing of fuel and air. For example, the waveform structure of the outline of the cross-section of the mixing channel is not limited to a sine wave (i.e., the outer contour of the cross-section of the convex ridge 5 includes the first and second arc segments connected end to end) or a square wave (i.e., the outer contour of the cross-section of the convex ridge 5 is rectangular). The injection position of nozzles 2 in the radial direction can be adjusted by changing the waveform structure, the number of peaks, increasing or decreasing the waveform amplitude, etc., to meet actual usage requirements.

[0050] In addition, the outer contour of the cross-section of the convex rib 5 can also be irregular in shape, specifically designed to ensure the degree of mixing of the premixed gas in the mixing channel, which will not be elaborated here.

[0051] like Figure 1 and Figure 2As shown, in some embodiments, the mixing channel includes a first section 11 and a second section 12 connected sequentially along a first direction. The second ends of the inlet 3 and the nozzle 2 are both formed on the first section 11, the outlet 4 is formed on the second section 12, the protrusion 5 is located on the first section 11, and the cross-sectional area of ​​the first section 11 gradually decreases along the direction from the inlet 3 toward the outlet 4.

[0052] The first section 11 of the mixing channel is designed as a tapered structure, which gradually weakens the radial expansion of the fluid, causing the fluid to gradually converge towards the center of the mixing channel. This strengthens the interaction and flow mixing between fuel and air. At the same time, the cross-sectional area of ​​the mixing channel gradually decreases, which gradually increases the flow velocity of the premixed gas to form a high-speed jet at the outlet 4. This reduces the risk of backfire when the premixed micro-mixing nozzle is used in the burner to a certain extent.

[0053] Specifically, both the first segment 11 and the second segment 12 extend along a first direction. The protruding rib 5 is integrally formed on the first segment 11. The inlet 3 is formed at the end of the first segment 11 opposite to the second segment 12. The length of the protruding rib 5 is less than or equal to the length of the first segment 11, and the protruding rib 5 and at least a portion of the inner peripheral wall of the tube body 1 together define the first segment 11 of the mixing channel.

[0054] like Figure 2 As shown, in some embodiments, the second segment 12 includes a necked portion 121 and a tail portion 122. The first segment 11, the necked portion 121 and the tail portion 122 are arranged sequentially and smoothly connected along a first direction, and are connected sequentially. The outlet 4 is formed in the tail portion 122. The cross-sectional area of ​​the necked portion 121 gradually decreases and then gradually increases along the direction from the inlet 3 toward the outlet 4. The minimum cross-sectional area of ​​the necked portion 121 is smaller than the minimum cross-sectional area of ​​the first segment 11.

[0055] Since premixed and micro-mixed combustion is prone to backfire, especially for pure hydrogen or hydrogen-rich fuels, a necking section is added to the tail end 122 of the premixed and micro-mixed nozzle to further reduce the risk of backfire.

[0056] Specifically, the outlet 4 is formed at the end of the tail 122 away from the necked portion 121.

[0057] like Figure 2 As shown, in some embodiments, the cross-sectional area of ​​the tail 122 remains constant along the direction from the inlet 3 to the outlet 4, and the outline of the cross-section of the tail 122 can be circular. Of course, the specific structure of the tail 122 can also be designed according to actual needs, which will not be elaborated here.

[0058] like Figures 1 to 3As shown, in some embodiments, the ridge 5 has a first wall surface and a second wall surface facing each other along the direction from the outer peripheral wall of the tube body 1 toward the inner peripheral wall. The first wall surface is connected to the inner peripheral wall of the tube body 1. The distance between the first wall surface and the second wall surface gradually decreases along the direction from the inlet 3 toward the outlet 4. The second wall surface adjacent to the second segment 12 is flush with the inner peripheral wall of the tube body 1 at the corresponding position. That is, the ridge 5 structure is flush with the inner peripheral wall of the tube body 1 when it is adjacent to the second segment 12 and no longer protrudes from the inner peripheral wall of the tube body 1, so that the amplitude of the peaks and troughs of the mixing channel gradually decreases until they disappear.

[0059] like Figure 2 As shown, in some embodiments, the first section 11 of the mixing channel extends spirally in a first direction, that is, at least a portion of the inner wall of the premixed micro-mixing nozzle rotates circumferentially, so that the entire pipe wall is spiral.

[0060] The mixing channel adopts a spiral extension structure along the first direction, which can induce the fluid to form a swirling effect in the mixing channel, increasing the contact area between air and fuel, thereby achieving more thorough mixing and improving mixing efficiency.

[0061] like Figures 1 to 3 As shown, in some embodiments, the outer peripheral wall of the tube body 1 has the same structure as the mixing channel, that is, the shape of the outer peripheral wall of the tube body 1 is the same as the shape of the mixing channel, so as to facilitate the processing of the premixed micro-mixing nozzle.

[0062] Specifically, the outer peripheral wall of tube 1 is coaxial with the mixing channel.

[0063] Of course, when the structure of the outer peripheral wall of the tube body 1 is different from that of the mixing channel, the outline of the cross-section of the outer peripheral wall of the tube body 1 may not be limited to one of the following: circle, triangle and polygon (not shown in the figure).

[0064] In some embodiments, the premixed micro-mixing nozzle is formed using an additive manufacturing process.

[0065] To improve the manufacturing efficiency, shorten the manufacturing cycle, and reduce the production cost of the premixed micro-mixed nozzle of this application, additive manufacturing technology is used to process the premixed micro-mixed nozzle, so as to integrate the various parts, components, and components of the premixed micro-mixed nozzle as much as possible, so as to make it have better reliability and structural stability.

[0066] like Figure 1As shown, it should be noted that the premixed micro-mixing nozzle of this application improves the problem of weak radial mixing of fuel and air through the corrugated surface and nozzle arrangement 2. The spiral wall surface enhances the turbulent mixing of air and fuel through swirling induction. The tapered pipe diameter structure enhances the interaction between air and fuel by limiting the radial expansion of the premixed gas. At the same time, the risk of backfire is reduced by reducing the pipe diameter and adding a necking section. Therefore, the designed premixed micro-mixing nozzle, through its corrugated surface and spiral tapered structure, relies on hydrodynamic effects to further enhance the mixing degree of fuel and air. Compared with the traditional circular pipe structure, it can achieve better mixing effect and higher mixing efficiency, thereby improving the temperature field distribution and achieving lower pollutant emissions.

[0067] like Figures 4 to 6 As shown, a premixed micro-mixed burner according to an embodiment of the present invention includes a housing 6, a supply pipe 7, and a premixed micro-mixed nozzle.

[0068] The housing 6 has a receiving cavity 61, and the supply pipe 7 is connected to the receiving cavity 61 and is used to supply air or fuel.

[0069] The premixed micro-mixing nozzle is any of the premixed micro-mixing nozzles described above. The premixed micro-mixing nozzle is mounted on the housing 6 and is at least partially located in the accommodating cavity 61. The nozzle orifice 2 of the premixed micro-mixing nozzle is connected to the accommodating cavity 61.

[0070] According to an embodiment of the present invention, the premixed micro-mixed burner employs a premixed micro-mixed nozzle that enables multi-point injection of air or fuel in the radial direction of the tube body 1, thereby giving the premixed micro-mixed burner good premixing performance, high combustion efficiency, and low pollutant emissions.

[0071] Specifically, the premixed micro-mixing nozzle can be completely placed in the accommodating cavity 61, with its inlet 3 flush with the top wall of the housing 6 and its outlet 4 flush with the bottom wall of the housing 6.

[0072] like Figure 4 As shown, in some embodiments, there are multiple premixed micro-mixing nozzles arranged in a parallel array.

[0073] Specifically, the multiple premixed micro-mixing nozzles are not limited to a matrix arrangement, ring arrangement, honeycomb arrangement, or diamond arrangement. By changing the position and spacing between the premixed micro-mixing nozzles, the interaction between the jets of multiple premixed micro-mixing nozzles can be controlled, thereby improving the flow field structure, achieving better mixing of fuel and air, and reducing pollutant emissions from the premixed micro-mixing burner.

[0074] like Figures 4 to 6As shown, in some embodiments, at the connection between the supply pipe 7 and the housing 6 on the projection plane in the vertical height direction of the housing 6, the central axis of the projection of the supply pipe 7 is tangent to the projection of the inner peripheral wall of the housing 6. This reduces the flow loss of fluid at the connection point, allowing the high-speed fluid to maintain its original pressure and flow velocity, thus ensuring the subsequent flow performance of the high-speed fluid. The height direction of the housing 6 is consistent with the first direction.

[0075] Specifically, there are multiple supply pipes 7 arranged at equal intervals along the circumference of the housing 6.

[0076] Taking the air intake 3 of the premixed micro-mixing nozzle as an example, compressed air enters the mixing channel from the top wall of the shell 6, forming a high-speed air mainstream with swirling flow. The fuel gas flow enters the accommodating cavity 61 tangentially through the supply pipe 7 and is injected into the air mainstream in a transverse jet manner through the nozzle 2 on the premixed micro-mixing nozzle. Under the induction of the wave-shaped tapered wall of the premixed micro-mixing nozzle, the fuel and air are turbulently mixed, forming a swirling premixed gas, which is ejected from the outlet 4 of the premixed micro-mixing nozzle. Because the fuel and air are quickly and fully mixed in the premixed micro-mixing nozzle, it can effectively avoid the generation of local high-temperature zones in the combustion chamber, reduce the formation of nitrogen oxides (NOx), and reduce pollutant emissions. At the same time, the good mixing degree of fuel and air in the premixed micro-mixing nozzle also makes the combustion stability of the premixed micro-mixing burner better, which can reduce combustion fluctuations and reduce the formation of high-temperature combustion zones, thereby helping to reduce NOx emissions.

[0077] 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 are not intended to 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.

[0078] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0079] 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 connection that allows communication between them; 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, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0080] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0081] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0082] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A premixed micro-mixing nozzle, characterized in that, The device includes a pipe body, which has a nozzle and a mixing channel extending in a first direction. The mixing channel has an inlet and an outlet opposite to each other in the first direction. One of the nozzle and the inlet is used to introduce air, and the other is used to introduce fuel. The nozzle is located between the inlet and the outlet in the first direction. The nozzles are multiple and arranged at intervals along the circumference of the mixing channel. Each nozzle has a first end and a second end arranged opposite to each other. The first end of the nozzle is formed on the peripheral wall of the tube body, and the second end of the nozzle communicates with the mixing channel. The second end of some nozzles is closer to the central axis of the mixing channel than the second end of the other nozzles. The nozzles are arranged in at least one row and spaced apart along the first direction. In the at least one row of nozzles, the second end of some nozzles is closer to the central axis of the mixing channel than the second end of the other nozzles. The distance from the second end of all nozzles in the other rows to the central axis of the mixing channel is equal. The premixed micro-mixing nozzle also includes a plurality of protruding ridges extending along the first direction. The plurality of protruding ridges are arranged at intervals along the circumference of the nozzle body on the inner peripheral wall of the nozzle body and together with the inner peripheral wall of the nozzle body, they form the mixing channel. And / or, the spacing between any two adjacent protruding edges is equal, the outer contour of the cross-section of the protruding edge includes a first arc segment and a second arc segment connected end to end, or, the outer contour of the cross-section of the protruding edge is a polygon.

2. The premixed micro-mixing nozzle according to claim 1, characterized in that, The mixing channel includes a first section and a second section connected sequentially along the first direction. The inlet and the second end of the nozzle are both formed on the first section, and the outlet is formed on the second section. The convex ridge is located on the first section, and the cross-sectional area of ​​the first section gradually decreases along the direction from the inlet to the outlet.

3. The premixed micro-mixing nozzle according to claim 2, characterized in that, The second segment includes a necked portion and a tail portion. The first segment, the necked portion, and the tail portion are arranged sequentially and smoothly connected along the first direction. The outlet is formed in the tail portion. The cross-sectional area of ​​the necked portion gradually decreases and then gradually increases along the direction from the inlet to the outlet. The minimum cross-sectional area of ​​the necked portion is smaller than the minimum cross-sectional area of ​​the first segment. And / or, the cross-sectional area of ​​the tail remains constant along the direction from the inlet to the outlet, and the outline of the cross-section of the tail is circular.

4. The premixed micro-mixing nozzle according to claim 2, characterized in that, The protruding rib has a first wall surface and a second wall surface that are opposite each other in the direction from the outer peripheral wall of the tube towards the inner peripheral wall. The first wall surface is connected to the inner peripheral wall of the tube. The distance between the first wall surface and the second wall surface gradually decreases in the direction from the inlet towards the outlet. The second wall surface adjacent to the second segment is flush with the inner peripheral wall of the tube at the corresponding position.

5. The premixed micro-mixing nozzle according to claim 2, characterized in that, The first section of the mixing channel extends spirally along the first direction.

6. The premixed micro-mixing nozzle according to any one of claims 1-5, characterized in that, The premixed micro-mixing nozzle is formed using additive manufacturing technology.

7. A premixed micro-mixed burner, characterized in that, include: A housing and a supply pipe, the housing having a receiving cavity, the supply pipe communicating with the receiving cavity and for supplying air or fuel; and A premixed micro-mixing nozzle, wherein the premixed micro-mixing nozzle is the premixed micro-mixing nozzle according to any one of claims 1-6, the premixed micro-mixing nozzle is mounted on the housing and at least partially located in the receiving cavity, and the nozzle orifice of the premixed micro-mixing nozzle communicates with the receiving cavity.

8. The premixed micro-mixed burner according to claim 7, characterized in that, The premixed micro-mixing nozzles are arranged in a parallel array.

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