Axial staged combustion two-stage nozzle and combustor

Abstract

The invention provides an axial staged combustion two-stage nozzle and a combustor, and relates to the technical field of axial staged combustion nozzles, the axial staged combustion two-stage nozzle comprises a nozzle body part and a first side surrounding part, the nozzle body part comprises a premixing section used for premixing air and fuel, the premixing section is provided with a first side plate facing a first direction and is provided with a spraying opening, and the first side plate is provided with a second side plate facing a second direction; the first direction is orthogonal to the extension direction of the premixing section; the first side surrounding part is located on the outer side of the first side plate, a first interlayer cavity is defined by the first side surrounding part and the first side plate, the first side surrounding part is provided with a first air inlet and a cooling hole which are communicated with the first interlayer cavity, and the cooling hole is formed adjacent to the spraying opening; and the cooling holes and the spraying ports are positioned on the same side of the premixing section along the extending direction of the premixing section. According to the invention, the cooling effect on the metal wall surface at the downstream backflow area of the secondary jet flow can be enhanced by additionally arranging the diverging cooling hole structure, so that the overtemperature risk of the local metal wall surface is effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of axial staged combustion nozzle, in particular to an axial staged combustion two-stage nozzle and a combustor. BACKGROUND

[0002] The axial staged combustion technology is to arrange a two-stage nozzle on the wall surface of a flame tube, and to mix the two-stage combustible mixture with the first-stage combustion products in a cross jet manner to organize combustion, so as to effectively inhibit the emission of thermal NOx in a high initial temperature gas turbine.

[0003] However, the cross jet manner in the related art will form a low-speed area downstream of the two-stage nozzle due to the existence of a horseshoe vortex and a vertical wake vortex, and the backflow has a large amount of high-temperature combustion products, so that the temperature of the area is extremely high, which easily leads to overheating of the nearby metal wall surface, and affects the safe and reliable operation of the combustor. SUMMARY

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

[0005] To this end, an embodiment of one aspect of the present application proposes an axial staged combustion two-stage nozzle, which can effectively reduce the risk of local metal wall surface overheating by adding a divergent cooling hole structure to strengthen the cooling effect of the metal wall surface at the backflow area downstream of the two-stage jet.

[0006] An embodiment of another aspect of the present application proposes a combustor.

[0007] According to an axial staged combustion two-stage nozzle of an embodiment of the present application, the nozzle body part includes a premixing section for premixing air and fuel, the premixing section has a first side plate facing a first direction and is provided with a nozzle outlet, the first direction is orthogonal to the extension direction of the premixing section; the first side wall part is located outside the first side plate and surrounds a first interlayer cavity with the first side plate, the first side wall part is provided with a first air inlet and a cooling hole communicating with the first interlayer cavity, the cooling hole is arranged adjacent to the nozzle outlet, and the cooling hole and the nozzle outlet are located on the same side of the premixing section along the extension direction thereof.

[0008] The axial staged combustion two-stage nozzle according to the embodiment of the present application can form a first interlayer cavity outside the nozzle body part by cooperation of the first side wall and the first side plate, wherein the first air inlet is used to fill cooling air into the first interlayer cavity, and the cooling hole is used to spray the cooling air to form a divergent cooling hole structure at a position adjacent to the ejection port of the two-stage nozzle, and if the two-stage nozzle is arranged on the wall surface of the flame tube, due to the influence of the cross jet structure characteristics, there will be a vortex structure formed by backflow on the leeward side of the two-stage nozzle (i.e. the side facing away from the airflow direction in the flame tube), and the backflow is high-temperature combustion products, so that the local temperature is too high and exceeds the allowable use temperature of the metal, so the first side wall is arranged on the leeward side of the two-stage nozzle, so that after the cooling air is sprayed into the combustion chamber of the flame tube through the cooling hole, an air film can be formed between the backflow area downstream of the two-stage combustible mixture jet and the inner wall surface of the flame tube, and the local cooling capacity is strengthened, thereby solving the problem of overheating of the metal wall surface downstream of the two-stage nozzle, and compared with the related art, the present application can strengthen the cooling effect of the metal wall surface at the backflow area downstream of the two-stage jet by adding the divergent cooling hole structure, so as to effectively reduce the risk of local metal wall surface overheating.

[0009] In some embodiments, the premixing section further has a premixing channel in communication with the ejection port, and an inner wall surface of the premixing channel includes a wall surface of the first side plate facing away from the first side wall, and the first side plate is provided with a mixing air hole in communication with the premixing channel and the first interlayer cavity.

[0010] In some embodiments, in a projection plane formed by the first direction and the extension direction of the premixing section, a projection of a central axis of at least one of the cooling hole and the mixing air hole and a projection of a central axis of the ejection port form an included angle.

[0011] In some embodiments, each of the cooling hole and the mixing air hole has a plurality of and is arranged at intervals.

[0012] In some embodiments, a normal projection area of the first air inlet along its extension direction is S, a sum of normal projection areas of all the cooling holes along their extension directions is S1, a sum of normal projection areas of all the mixing air holes along their extension directions is S2, and S>S1+S2.

[0013] In some embodiments, the nozzle body part further includes a fuel distribution section arranged at an end of the premixing section facing away from the first side wall;

[0014] The fuel distribution section has a fuel distribution cavity and is provided with a fuel inlet in communication with the fuel distribution cavity, and an end of the premixing section facing away from the first side wall is further provided with a second air inlet, and the second air inlet and the fuel distribution cavity are both in communication with the premixing channel.

[0015] According to an embodiment of the present application, a combustor comprises a flame tube having a combustion chamber, and a secondary nozzle. The secondary nozzle is any of the above-mentioned embodiments, and the nozzle body part of the secondary nozzle is arranged on the flame tube, and the nozzle outlet and the cooling hole are both in communication with the combustion chamber.

[0016] According to an embodiment of the present application, the combustor is designed with a secondary nozzle having a divergent cooling hole structure adjacent to the nozzle outlet position, which can strengthen the cooling effect of the metal wall surface at the downstream recirculation zone of the secondary jet, effectively reducing the risk of local metal wall surface overheating. Compared with the related art, the combustor using the secondary nozzle can strengthen the cooling capacity of the local overheated metal wall surface, so as to match the combustion characteristics of high-reactivity fuels such as hydrogen-rich and pure hydrogen, and has good operation safety and reliability.

[0017] In some embodiments, the combustor further comprises a flow guide bushing arranged on the flame tube, an air flow channel is formed between the inner circumferential surface of the flow guide bushing and the outer circumferential surface of the flame tube, at least part of the first side wall is located in the air flow channel, and the first air inlet is in communication with the air flow channel.

[0018] In some embodiments, the premixing section further has a second side plate arranged opposite to the first side plate along the first direction.

[0019] The secondary nozzle further comprises a second side wall located outside the second side plate and surrounding the second side plate to form a second interlayer cavity, and at least part of the second side wall is located in the air flow channel.

[0020] In some embodiments, the cross-sectional outer contour of each of the first side wall and the second side wall can be semicircular, sector-shaped or irregular, and the cross section is orthogonal to the extension direction of the premixing section.

[0021] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a sectional view of an axial staged combustion secondary nozzle according to an embodiment of the present application.

[0023] Figure 2 is a bottom view of an axial staged combustion secondary nozzle according to an embodiment of the present application.

[0024] Figure 3 is Figure 2 is a partial enlarged view of position A in FIG.

[0025] Figure 4 is a structural schematic view of a first perspective of a combustor according to an embodiment of the present application.

[0026] Figure 5 is Figure 4 a side structural schematic view of

[0027] Figure 6 is a structural schematic view of a second perspective of a combustor according to an embodiment of the present application.

[0028] Figure 7 is a sectional structural schematic view of a combustor according to an embodiment of the present application.

[0029] Reference Signs:

[0030] 10, combustor;

[0031] 100, secondary nozzle;

[0032] 200, flame tube;

[0033] 300, flow guide bushing;

[0034] 1, nozzle body portion; 11, premix section; 111, first side plate; 112, injection port; 113, premix passage; 114, mixing air hole; 115, second air inlet; 116, second side plate; 12, fuel distribution section; 121, fuel distribution cavity; 122, fuel inlet;

[0035] 2, first side wall portion; 21, first interlayer cavity; 22, first air inlet; 23, cooling hole;

[0036] 3, combustion chamber;

[0037] 4, air flow passage. DETAILED DESCRIPTION

[0038] Embodiments of the present application are described in detail below with reference to the attached drawings. The embodiments described below are examples of the present application, and are intended to explain the present application, and should not be understood as limiting the present application.

[0039] As Figures 1 to 3As shown, the axial staged combustion two-stage nozzle 100 of the embodiment of the present application comprises a nozzle body part 1 and a first side wall part 2, the nozzle body part 1 comprises a premixing section 11 for premixing air and fuel, the premixing section 11 has a first side plate 111 facing a first direction and is provided with a nozzle exit 112, the first direction is orthogonal to the extension direction of the premixing section 11; the first side wall part 2 is located outside the first side plate 111 and forms a first interlayer cavity 21 with the first side plate 111, the first side wall part 2 is provided with a first air inlet 22 and a cooling hole 23 communicating with the first interlayer cavity 21, the cooling hole 23 is arranged adjacent to the nozzle exit 112, and the cooling hole 23 and the nozzle exit 112 are located on the same side of the premixing section 11 along the extension direction thereof.

[0040] The axial staged combustion two-stage nozzle 100 according to the embodiment of the present application can form the first interlayer cavity 21 outside the nozzle body part 1 by cooperation of the first side wall part 2 and the first side plate 111, wherein the first air inlet 22 is used to fill cooling air in the first interlayer cavity 21, and the cooling hole 23 is used to spray cooling air to form the divergent cooling hole 23 structure adjacent to the nozzle exit 112 on the two-stage nozzle 100, if the two-stage nozzle 100 is arranged on the wall surface of the flame tube 200, due to the influence of the cross jet structure characteristics, there will be vortex structure formed by backflow on the leeward side of the two-stage nozzle 100 (i.e. the side facing away from the airflow direction in the flame tube 200), and the backflow is high-temperature combustion products, so that the local temperature is too high and exceeds the allowable temperature of the metal, therefore, the first side wall part 2 is located on the leeward side of the two-stage nozzle 100, so that after the cooling air is sprayed into the combustion chamber 3 of the flame tube 200 through the cooling hole 23, an air film can be formed between the backflow area downstream of the two-stage combustible mixture jet and the inner wall surface of the flame tube 200, the local cooling capacity is strengthened, the problem of over-temperature of the metal wall surface downstream of the two-stage nozzle 100 is solved, and therefore, compared with the related art, the present application can strengthen the cooling effect of the metal wall surface in the backflow area downstream of the two-stage jet by adding the divergent cooling hole 23 structure, so as to effectively reduce the risk of over-temperature of the local metal wall surface.

[0041] Specifically, the nozzle 112 is used to spray a well-mixed fuel-air mixture. The nozzle 112 can be located at the end of the premixing section 11. The first side enclosure 2 can be integrally formed with the nozzle body 1 to simplify the manufacturing process and improve production efficiency. The extension direction of the first interlayer cavity 21 can be consistent with the extension direction of the premixing section 11. The first air inlet 22 can be opened on the side of the first side enclosure 2 away from the first side plate 111. For example, as shown in the figure, the first air inlet 22 is not limited to a rectangular opening. The specific shape of the first air inlet 22 can be designed according to the actual usage requirements of the secondary nozzle 100, and is not limited here. Both the first air inlet 22 and the cooling hole 23 are in communication with the outside. The cooling hole 23 can be opened on the wall of the first side enclosure 2 adjacent to the nozzle 112. The wall of the first side enclosure 2 adjacent to the nozzle 112 can be flush with the nozzle 112 in the extension direction of the premixing section 11.

[0042] Understandably, integrating the cooling hole 23 into the secondary nozzle 100 using the first side enclosure 2 structure can effectively avoid the inability to add the divergent cooling hole 23 to the wall of the flame tube 200 near the nozzle outlet 112 due to the influence of the nozzle assembly structure, thus solving the problem of local overheating wall cooling of the flame tube 200 and ensuring the service life of the secondary nozzle 100 and the flame tube 200.

[0043] like Figure 1 As shown, in some embodiments, the premixing section 11 further includes a premixing channel 113, which communicates with the nozzle 112. The inner wall of the premixing channel 113 includes a first side plate 111 facing away from the wall of the first side enclosure 2. The first side plate 111 is provided with a mixing air hole 114, which communicates the premixing channel 113 and the first interlayer cavity 21. In other words, the mixing air hole 114 extends from the wall of the first side plate 111 adjacent to the wall of the first side enclosure 2 to the wall facing away from the first side enclosure 2, or the mixing air hole 114 penetrates the first side plate 111 to communicate the premixing channel 113 and the first interlayer cavity 21.

[0044] It is understandable that by adopting the mixed air hole 114 structure, the mixing uniformity of the local combustion-air mixture in the secondary jet can be adjusted, so that an appropriate amount of air is injected into the premixing channel 113 through the mixed air hole 114, so that a combustion-air mixture with a lower equivalence ratio is formed in the area near the leeward side of the secondary nozzle 100 inside the premixing channel 113 (that is, the wall surface of the first side plate 111 away from the first side enclosure 2), which can effectively improve the backfire resistance.

[0045] Specifically, the inner wall surface of the premixing channel 113 is the inner wall surface (or inner profile surface) of the premixing section 11 used to form the premixing channel 113. The end of the premixing channel 113 can form the nozzle 112.

[0046] It should be noted that although the as uniform as possible equivalence ratio distribution at the ejection port 112 is conducive to reducing the generation of NOx, there is a high temperature zone caused by backflow on the leeward side of the secondary nozzle 100 due to the rapid mixing of the secondary jet and the air main flow, and there is a greater risk of backfire on the windward side of the secondary nozzle 100. When the secondary nozzle 100 burns fuel with stronger reactivity, the backfire problem will be more prominent. However, by additionally providing appropriate mixing air holes 114 on the leeward side wall (i.e. the first side plate 111) of the secondary nozzle 100, the local equivalence ratio of the fuel-air mixture adjacent to the leeward side of the secondary nozzle 100 at the ejection port 112 can be reduced, thereby effectively improving the backfire prevention capability of the secondary nozzle 100.

[0047] As shown in FIG. 1, in some embodiments, the central axis of at least one of the cooling hole 23 and the mixing air hole 114 forms an angle with the central axis of the ejection port 112 on the projection plane formed by the first direction and the extension direction of the premixing section 11. Figures 1 to 3

[0048] It can be understood that the angle between the central axis of the cooling hole 23 and the central axis of the ejection port 112 can be adjusted according to cooling requirements, or the angle between the central axis of the mixing air hole 114 and the central axis of the ejection port 112 can be adjusted according to actual conditions to control the air mixing effect.

[0049] In addition, in addition to the way of adjusting the central axis direction of the mixing air hole 114 alone, the jet depth and mixing effect of the mixing air can also be controlled by adjusting the hole diameter of the mixing air hole 114 alone or simultaneously.

[0050] For example, the central axis of the cooling hole 23 can form an angle of 0° with the central axis of the ejection port 112, or in other words, the cooling hole 23 can be a normal hole of the end face of the ejection port 112, and the central axis of the mixing air hole 114 can form an angle of 45° with the central axis of the ejection port 112.

[0051] Specifically, the central axis of at least one of the cooling hole 23 and the mixing air hole 114 forms an angle with the central axis of the ejection port 112 on the projection plane formed by the first direction and the extension direction of the premixing section 11; or the central axis of the cooling hole 23 forms an angle with the central axis of the ejection port 112 on the projection plane formed by the first direction and the extension direction of the premixing section 11; or the central axis of the mixing air hole 114 forms an angle with the central axis of the ejection port 112 on the projection plane formed by the first direction and the extension direction of the premixing section 11.

[0052] As shown in FIG. 1, in some embodiments, each of the cooling hole 23 and the mixing air hole 114 has multiple and is arranged at intervals. Figures 1 to 3 As shown in FIG. 1, in some embodiments, each of the cooling hole 23 and the mixing air hole 114 has multiple and is arranged at intervals.​

[0053] It can be understood that the arrangement of the plurality of cooling holes 23 can further ensure the cooling effect on the over-temperature position of the metal wall surface downstream of the secondary nozzle 100 according to actual cooling needs, thereby improving the cooling efficiency. Similarly, the design of the plurality of air mixing holes 114 can ensure the air mixing effect according to actual conditions, thereby improving the mixing efficiency.

[0054] Specifically, the plurality of cooling holes 23 can be arranged at equal intervals on the wall surface of the first side wall 2 adjacent to the ejection port 112, so as to achieve uniform cooling of the over-temperature position of the metal wall surface downstream of the secondary nozzle 100. The plurality of air mixing holes 114 can be arranged at equal intervals on the first side plate 111, so as to achieve uniform mixing of the fuel-air mixture and the mixed air in the premixing channel 113 near the region on the leeward side of the secondary nozzle 100.

[0055] It should be noted that the specific arrangement structure, number, etc. of the cooling holes 23 and the air mixing holes 114 can be designed according to requirements, and the actual use conditions are used as the criterion, which will not be expanded here.

[0056] As shown in Figure 1 some embodiments, the first air inlet 22 has a projection area S along its extension direction, the sum of the projection areas of all the cooling holes 23 along their extension directions is S1, and the sum of the projection areas of all the air mixing holes 114 along their extension directions is S2. S > S1 + S2, that is, the area of the first air inlet 22 is greater than the total area of all the cooling holes 23 and all the air mixing holes 114.

[0057] It can be understood that in actual application, the air flow entering the first interlayer cavity 21 can be adjusted by adjusting the total area of the cooling holes 23 and the air mixing holes 114, and the distribution ratio of the cooling air and the mixed air can be adjusted by adjusting the area ratio of the two.

[0058] As shown in Figure 1 some embodiments, the nozzle body part 1 further comprises a fuel distribution section 12, and the fuel distribution section 12 is arranged at one end of the premixing section 11 away from the first side wall 2.

[0059] The fuel distribution section 12 has a fuel distribution cavity 121 and is provided with a fuel inlet 122 communicating with the fuel distribution cavity 121. The one end of the premixing section 11 away from the first side wall 2 is further provided with a second air inlet 115, and the second air inlet 115 and the fuel distribution cavity 121 are both in communication with the premixing channel 113.

[0060] It can be understood that air can be introduced into the nozzle body part 1 through the second air inlet 115, and fuel can be introduced into the nozzle body part 1 through the fuel inlet 122, so that the two are fully mixed in the premixing passage 113 to form a fuel-air mixture, and the fuel-air mixture enters the combustion chamber 3 of the flame tube 200 through the injection outlet 112 to be combusted.

[0061] Specifically, the fuel distribution section 12 and the premixing section 11 can be coaxial and integrally formed. The premixing flow channel and the fuel distribution cavity 121 can be sequentially sleeved from the inside to the outside. The fuel inlet 122 can be located on the windward side of the secondary nozzle 100. The second air inlet 115 can be arranged opposite the injection outlet 112 in the extension direction of the premixing section 11.

[0062] In addition, a fuel distribution structure can be arranged in the fuel distribution cavity 121 to ensure the mixing effect of the fuel gas flow entering the premixing passage 113 and the air introduced by the second air inlet 115, wherein the fuel distribution structure can adopt the prior art in the field, which will not be specifically expanded here.

[0063] As shown in the drawings, Figures 4 to 7 A burner 10 according to an embodiment of the present application includes a flame tube 200 and a secondary nozzle 100. The flame tube 200 has a combustion chamber 3. The secondary nozzle 100 is the secondary nozzle 100 according to any of the above embodiments. The nozzle body part 1 of the secondary nozzle 100 is arranged on the flame tube 200. The injection outlet 112 and the cooling hole 23 are both in communication with the combustion chamber 3.

[0064] According to the burner 10 of the embodiment of the present application, the secondary nozzle 100 is designed to have a divergent cooling hole 23 structure at a position adjacent to the injection outlet 112. The cooling effect on the metal wall surface at the recirculation zone downstream of the secondary jet can be enhanced, so as to effectively reduce the risk of local metal wall surface overheating. Therefore, compared with the related art, the burner 10 using the secondary nozzle 100 can enhance the cooling capacity at the local overheated metal wall surface, so as to match the combustion characteristics of high-reactivity fuels such as hydrogen-rich fuel and pure hydrogen, and the operation safety and reliability are good.

[0065] Specifically, the airflow direction in the flame tube 200 can be from the windward side of the secondary nozzle 100 to the leeward side of the secondary nozzle 100. The injection outlet 112 of the nozzle body part 1 can be connected to the peripheral wall surface of the flame tube 200 by welding. The wall surface of the first side wall part 2, in which the cooling hole 23 is arranged, can be connected to the peripheral wall surface of the flame tube 200.

[0066] As shown in the drawings, Figures 4 to 7 In some embodiments, the burner 10 further includes a flow guide bushing 300, which is sleeved on the flame tube 200. An air flow channel 4 is formed between the inner peripheral surface of the flow guide bushing 300 and the outer peripheral surface of the flame tube 200. At least part of the first side wall part 2 is located in the air flow channel 4. The first air inlet 22 is in communication with the air flow channel 4.

[0067] It can be understood that the cooling air provided by the air flow channel 4 for the first interlayer cavity 21 does not need to additionally increase the cooling source, further simplifies the overall structure of the combustor 10, and reduces the cost.

[0068] In addition, by additionally arranging the first interlayer cavity 21 on the leeward side of the secondary nozzle 100, operability is provided for optimizing the outer shape surface of the premixing channel 113 of the secondary nozzle 100, so as to improve the flow field of the air in the air flow channel 4 between the flow guide bushing 300 and the flame tube 200, and effectively improve the wake generated by the air between the flow guide bushing 300 and the flame tube 200 after flowing around the secondary nozzle 100, reduce the volume of the low-speed backflow area downstream of the secondary nozzle 100, and weaken the influence of the secondary nozzle 100 on the air distribution uniformity of the primary combustion chamber 3.

[0069] It should be noted that generally, the outer shape surface of the premixing section 11 is determined by the inner shape surface, and the inner shape surface is optimized according to the speed distribution, fuel and air mixing effect, flow loss and other factors, and the wall thickness is increased after being determined to be the outer shape surface. Therefore, the outer shape surface of the premixing section 11 is usually a simple geometric shape, such as a rectangle in the present application. Since the premixing section 11 appears as a bluff body in the annular channel (i.e., the air flow channel 4) composed of the inner circumferential surface of the flow guide bushing 300 and the outer circumferential surface of the flame tube 200, when high-speed air flows through such a bluff body, large-scale vortices will be generated on the leeward side of the bluff body, which not only increases the local flow loss, but also affects the air distribution in the annular channel downstream of the bluff body, and further affects the air flow distribution uniformity between the nozzles of the primary combustor 10, thereby adversely affecting the combustion performance. However, it is difficult to optimize the configuration of the windward side of the bluff body (i.e., the leeward side of the secondary nozzle 100) based on the original structure of the secondary nozzle 100. Simply increasing the wall thickness of the windward side of the bluff body to provide design space for the optimized shape surface not only increases the weight of the equipment and the cost, but also causes the downstream of the secondary nozzle 100 to be unable to be cooled, greatly increasing the risk of metal overheating. By increasing the air interlayer (i.e., the first interlayer cavity 21) and enhancing the local cooling (i.e., the cooling hole 23), not only can the metal overheating be avoided, but also sufficient design space can be provided for optimizing the shape surface of the windward side of the bluff body.

[0070] Specifically, the inner circumferential surface of the flow guide bushing 300 and the outer circumferential surface of the flame tube 200 define an annular channel, i.e., the air flow channel 4. The air flow direction in the air flow channel 4 can be from the leeward side of the secondary nozzle 100 to the windward side of the secondary nozzle 100. The first air inlet 22 can be located entirely in the air flow channel 4. The first air inlet 22 can be directly opposite the air flow direction, i.e., the first air inlet 22 faces the leeward side of the secondary nozzle 100.

[0071] As shown in FIG. 1, the first interlayer cavity 21 is arranged on the leeward side of the secondary nozzle 100, and the first air inlet 22 is arranged on the inner circumferential surface of the flow guide bushing 300. Figure 7As shown, in some embodiments, the premixing section 11 further has a second side plate 116, which is arranged opposite to the first side plate 111 along a first direction.

[0072] The secondary nozzle 100 also includes a second side enclosure (not shown in the figure), which is located outside the second side plate 116 and forms a second interlayer cavity with the second side plate 116. At least a portion of the second side enclosure is located in the air flow channel 4.

[0073] It is understandable that when the secondary nozzle 100 is arranged on the wall of the flame tube 200, and the first side enclosure 2 is located on the leeward side of the secondary nozzle 100, the second side enclosure can be located on the windward side of the secondary nozzle 100. Similarly, similar to the function of the first side enclosure 2, the second side enclosure can provide sufficient design space for optimizing the leeward side profile of the blunt body, and further adjust the outer profile of the premixing section 11 of the secondary nozzle 100 according to the aerodynamic conditions.

[0074] Specifically, the extension direction of the second interlayer cavity can be consistent with the extension direction of the premixing section 11.

[0075] like Figures 4 to 7 As shown, in some embodiments, the outer contour of the cross-section of each of the first side enclosure 2 and the second side enclosure can be a semi-circle, a fan shape or an irregular shape, and the cross-section is orthogonal to the extension direction of the premixing section 11. For example, the cross-section can include, but is not limited to, rounded corners, semi-circles, fan shapes, multiple curves and other configurations, in order to optimize the structure of the recirculation zone after turbulence.

[0076] Therefore, compared with related technologies, the present invention has the following technical effects:

[0077] 1. By adding divergent cooling holes 23, the present invention can enhance the cooling effect in the downstream recirculation zone of the secondary jet, effectively reducing the risk of local metal overheating;

[0078] 2. By adding the mixing air hole 114, the present invention can control the equivalence ratio of the combustible mixture on the leeward side of the secondary jet, effectively improving the backfire resistance of the axial staged combustion nozzle.

[0079] 3. By adding an air jacket, the present invention provides operability for optimizing the outer surface of the nozzle premixing channel 113, which can improve the flow field in the air channel 4 formed by the guide bushing 300 and the flame tube 200 to a certain extent and improve aerodynamic performance.

[0080] In the description of the application, it is to be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the devices or elements indicated thereby must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0081] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated thereby. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0082] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or in communication with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication or interaction relationship of two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0083] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0084] In this disclosure, the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" mean that a particular feature, structure, material, or characteristic is included in at least one embodiment or example of the present disclosure. The illustrative appearances of the above-mentioned terms in various places in the specification are not necessarily referred to the same embodiment or example. Moreover, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. Furthermore, the terminology "comprising" is used in the disclosure as comprising but not limited to, that is, it is open-ended and does not exclude the presence of additional features, structures, materials, or characteristics.

[0085] Although the embodiments of the present disclosure have been shown and described above, it is understood that the above-described embodiments are exemplary, and are not to be interpreted as limiting the present disclosure, and the ordinary skilled in the art can make changes, modifications, replacements, and variations to the above-described embodiments within the scope of the present disclosure.

Claims

1. An axially staged combustion two-stage nozzle characterized by, The nozzle body part comprises a premixing section for premixing air and fuel, the premixing section having a first side plate facing a first direction orthogonal to the extension direction of the premixing section and being provided with a spray outlet; and a first side wall part located outside the first side plate and surrounding the first side plate to form a first interlayer cavity, the first side wall part being provided with a first air inlet communicating with the first interlayer cavity and cooling holes, the cooling holes being arranged adjacent to the spray outlet, and the cooling holes and the spray outlet being located on the same side of the premixing section along the extension direction thereof. The premixing section further has a premixing channel communicating with the spray outlet, and the inner wall surface of the premixing channel comprises the wall surface of the first side plate facing away from the first side wall part, the first side plate being provided with mixing air holes communicating the premixing channel and the first interlayer cavity.

2. The axially staged combustion two-stage nozzle of claim 1, wherein, In the projection plane formed by the first direction and the extension direction of the premixing section, the projection of the central axis of at least one of the cooling holes and the mixing air holes forms an angle with the projection of the central axis of the spray outlet.

3. The axially staged combustion two-stage nozzle of claim 2, wherein, Each of the cooling holes and the mixing air holes has a plurality of and is arranged at intervals.

4. The axially staged combustion two-stage nozzle of claim 2, wherein, The normal projection area of the first air inlet along the extension direction thereof is S, the sum of the normal projection areas of all the cooling holes along the extension direction thereof is S1, the sum of the normal projection areas of all the mixing air holes along the extension direction thereof is S2, and S>S1+S2.

5. The axially staged combustion two-stage nozzle of claim 4, wherein, The nozzle body part further comprises a fuel distribution section arranged at the end of the premixing section facing away from the first side wall part; 6. The axially staged combustion two-stage nozzle of claim 2, wherein, The fuel distribution section has a fuel distribution cavity and is provided with a fuel inlet communicating with the fuel distribution cavity, and the end of the premixing section facing away from the first side wall part is further provided with a second air inlet, the second air inlet and the fuel distribution cavity both communicating with the premixing channel. The flame tube has a combustion chamber; and 7. A burner characterized by, The secondary nozzle is the secondary nozzle according to any one of claims 1-6, the nozzle body part of the secondary nozzle being arranged on the flame tube, the spray outlet and the cooling holes both communicating with the combustion chamber. A flow guide bushing is further included, the flow guide bushing being sleeved on the flame tube, an air flow channel being formed between the inner circumferential surface of the flow guide bushing and the outer circumferential surface of the flame tube, at least part of the first side wall part being located in the air flow channel, and the first air inlet communicating with the air flow channel. The premixing section further has a second side plate, the second side plate being arranged opposite to the first side plate along the first direction; The secondary nozzle further comprises a second side wall part located outside the second side plate and surrounding the second side plate to form a second interlayer cavity, at least part of the second side wall part being located in the air flow channel.

8. The burner of claim 7, wherein The cross-sectional outer contour of each of the first side wall part and the second side wall part can be semicircular, sector-shaped or irregular, and the cross-section is orthogonal to the extension direction of the premixing section.

9. The burner of claim 8, wherein ​ ​ 10. The burner of claim 9, wherein ​

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