A swirl nozzle, nozzle assembly and combustion chamber

Abstract

This application discloses a swirling nozzle, comprising: a tube body having a premixing chamber; an annular swirling fuel chamber and a central air inlet at the air inlet end; multiple radial swirling holes on the outer wall of the tube body; multiple swirling fuel channels within the tube wall near the annular swirling fuel chamber, each swirling fuel channel corresponding to one of the radial swirling holes; a main combustion stage swirling fuel hole in the tube wall between each swirling fuel channel and its corresponding radial swirling hole, the main combustion stage swirling fuel hole connecting the corresponding swirling fuel channel and the radial swirling hole; multiple main combustion stage axial fuel holes on the annular cavity wall facing the premixing chamber, each main combustion stage axial fuel hole connecting the premixing chamber and the annular swirling fuel chamber. The air entering from the central air inlet and the mixed gas within the radial swirling holes have a velocity difference, and upon encountering each other, they can form a shear flow. This shear flow can reduce the size of the high-temperature recirculation zone in the central region of the swirling nozzle, thereby reducing the risk of backfire.

Description

Technical Field

[0001] This application relates to the field of gas turbine technology, and in particular to a swirling nozzle, nozzle assembly and combustion chamber. Background Technology

[0002] In the field of gas turbines, the application of high-hydrogen fuels (such as coal-to-syngas) is becoming increasingly widespread. However, as a medium-calorific-value fuel, high-hydrogen syngas has a relatively fast laminar flame propagation speed during combustion. Therefore, backfire is prone to occur during combustion when high-hydrogen fuels are used. Summary of the Invention

[0003] This application proposes a swirling nozzle, nozzle assembly, and combustion chamber, aiming to solve the problem of backfire in the nozzles of gas turbines when using high-hydrogen-content syngas fuel for combustion in the prior art.

[0004] This application provides a swirling nozzle, comprising:

[0005] The tube body is hollow to form a premixing chamber, and the tube body is provided with an air inlet and an air outlet; The air inlet end is provided with an annular swirling fuel chamber and a central air inlet; the annular swirling fuel chamber is separated from the premixing chamber and surrounds the central air inlet; the central air inlet is used to allow air to enter; The outer wall of the pipe near the air inlet end is provided with a plurality of radial swirl holes, each radial swirl hole is distributed along the circumference of the pipe, and each radial swirl hole is connected to the premixing chamber; The tube body has multiple swirling fuel channels in the tube wall near the annular swirling fuel chamber. Each swirling fuel channel corresponds to each radial swirling hole, and each swirling fuel channel is connected to the corresponding annular swirling fuel chamber. Each swirling fuel channel and its corresponding radial swirling orifice are provided with a main combustion stage swirling fuel orifice in the pipe wall, and the main combustion stage swirling fuel orifice is connected to the corresponding swirling fuel channel and the radial swirling orifice; The annular swirling fuel chamber has multiple main combustion stage axial fuel holes on its annular cavity wall facing the premixing chamber, and each of the main combustion stage axial fuel holes is connected to the premixing chamber and the annular swirling fuel chamber.

[0006] In the embodiments of this application, each of the main combustion stage axial fuel holes corresponds one-to-one with each of the radial swirl holes, and in the radial direction of the tube body, each main combustion stage axial fuel hole is located downstream of the outlet direction of its corresponding radial swirl hole.

[0007] In this embodiment of the application, the amount of air entering the swirl nozzle from each radial swirl hole is 75%-95% of the total amount of air entering the swirl nozzle.

[0008] In the embodiments of this application, the swirl coefficient of each radial swirling hole is between 0.4 and 0.6.

[0009] In this embodiment, each radial swirling hole is a rounded rectangular hole, and the length direction of the radial swirling hole is parallel to the length direction of the tube body; the length of each radial swirling hole in the axial direction of the swirling nozzle does not exceed 1 / 4 of the length of the swirling nozzle.

[0010] In this embodiment of the application, a truncated cone is provided on the side of the annular swirl fuel chamber facing the premixing chamber, the truncated cone protrudes towards one side of the premixing chamber, and the central air inlet passes through the truncated cone and communicates with the premixing chamber; In the radial direction of the tube body, each of the main combustion stage axial fuel holes is located between the truncated cone and the inner wall of the tube body.

[0011] In this embodiment of the application, the outer wall of the pipe body located at the air outlet end is provided with a plurality of cooling holes, and each cooling hole is distributed along the circumference of the pipe body.

[0012] This application also proposes a nozzle assembly, which includes a standby nozzle and a plurality of swirling nozzles as described in the above embodiments; Each of the swirling nozzles surrounds the duty nozzle in the circumferential direction, and the air outlet end of each of the swirling nozzles and the air outlet end of the duty nozzle are located on the same spatial plane. The duty nozzle is provided with a duty fuel passage and a duty air passage, with the duty fuel passage surrounding the duty air passage; The outlet end of the duty nozzle is provided with a duty air hole and a duty fuel hole. The duty air hole is connected to the duty air passage, and the duty fuel hole is connected to the duty fuel passage. A duty cyclone separator is provided on the outer wall of the outlet end of the duty nozzle.

[0013] In this embodiment of the application, the nozzle assembly further includes a nozzle disk, on which a main combustion stage fuel chamber and a duty fuel chamber are provided. The main combustion stage fuel chamber surrounds the duty fuel chamber. The main combustion stage fuel chamber is used to connect to the main combustion stage fuel pipeline of the gas turbine, and the duty fuel chamber is used to connect to the duty fuel pipeline of the gas turbine. The duty fuel channel of the duty nozzle is connected to the duty fuel chamber, and the annular swirling fuel chamber of each swirling nozzle is connected to the main combustion stage fuel chamber.

[0014] This application also proposes a combustion chamber comprising the nozzle assembly described in the above embodiments.

[0015] The swirl nozzle in this embodiment of the application, by providing a radial swirl hole at the air inlet end, enables the air entering from the radial swirl hole and the fuel entering from the swirl fuel hole of the main combustion stage to be mixed for the first time. After the mixed gas enters the premixing chamber, it can be mixed for the second time with the fuel entering from the axial fuel hole of the main combustion stage, and further uniformly mixed during the flow towards the air outlet end. For high-hydrogen-content fuels, uniform premixing can significantly reduce the size of the local high-temperature zone during combustion, thereby reducing the formation of nitrogen oxides. In addition, there is a velocity difference between the jet air entering from the central inlet and the mixed gas after the second mixing. Therefore, when the mixed gas after the second mixing meets the jet air, a shear flow can be formed. The shear flow can reduce the size of the high-temperature recirculation zone in the central region of the swirl nozzle outlet, thereby reducing the risk of backfire. Moreover, after the fuel and air are first mixed in the radial swirl orifice, they enter the premixing chamber in a radial swirl manner. Compared with the axial swirl, the mixed gas after radial swirl has a larger axial velocity, which makes the mixed gas flowing out of the outlet end have a larger axial velocity, thus also helping to avoid backfire. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a swirling nozzle in one embodiment of this application; Figure 2 This is a cross-sectional view of a swirling nozzle in one embodiment of this application; Figure 3 This is a cross-sectional view of the swirling nozzle in one embodiment of this application from another direction; Figure 4 This is a schematic diagram of the structure of a swirling nozzle in another embodiment of this application; Figure 5 This is another cross-sectional view of the swirling nozzle in one embodiment of this application; Figure 6 This is a schematic diagram of the nozzle assembly in one embodiment of this application; Figure 7 This is a schematic diagram of the structure of the duty nozzle in one embodiment of this application; Figure 8 This is a cross-sectional view of a duty nozzle in one embodiment of this application; Figure 9 This is a schematic diagram of the nozzle disc structure in one embodiment of this application; Figure 10 This is a cross-sectional view of the nozzle disk in one embodiment of this application; Figure 11 This is a cross-sectional view of the combustion chamber in one embodiment of this application; Figure 12 This is a schematic diagram of the fairing structure in one embodiment of this application.

[0018] Explanation of reference numerals in the attached figures: 100-Swirl nozzle, 101-Premixing chamber, 102-Annular swirling fuel chamber, 103-Central air inlet, 104-Main combustion stage fuel inlet, 105-Swirl fuel channel, 106-Main combustion stage swirling fuel orifice, 107-Radial swirling orifice, 108-Main combustion stage axial fuel orifice, 109-Frustum, 110-Cooling hole, 120-Stationary nozzle, 121-Stationary fuel channel, 12 2-Stay-at-home air passage, 123-Stay-at-home air port, 124-Stay-at-home fuel port, 125-Stay-at-home cyclone separator, 126-Nozzle disc, 127-Main combustion stage fuel chamber, 128-Stay-at-home fuel chamber, 129-Main combustion stage fuel inlet pipe, 130-Flame tube, 131-Film plate, 132-Flame tube, 140-Casing, 150-Fairing, 151-Fairing orifice, 160-Transition section.

[0019] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0022] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0023] like Figure 1 , Figure 2 , Figure 3 As shown in the figure, this application provides a swirling nozzle 100, including: a tube body, wherein the tube body is hollow to form a premixing chamber 101, and the tube body is provided with an air inlet end and an air outlet end; The air inlet end is provided with an annular swirling fuel chamber 102 and a central air inlet 103. The annular swirling fuel chamber 102 is separated from the premixing chamber 101 and surrounds the central air inlet 103. The central air inlet 103 is used to allow air to enter. The outer wall of the pipe body near the air inlet end is provided with a plurality of radial swirl holes 107, each radial swirl hole 107 is distributed along the circumference of the pipe body, and each radial swirl hole 107 is connected to the premixing chamber 101. The tube body is provided with a plurality of swirling fuel channels 105 in the tube wall near the annular swirling fuel chamber 102. Each swirling fuel channel 105 corresponds one-to-one with each radial swirling hole 107, and each swirling fuel channel 105 is connected to the corresponding annular swirling fuel chamber 102. Each swirling fuel channel 105 is provided with a main combustion stage swirling fuel hole 106 in the pipe wall between itself and its corresponding radial swirling hole 107. The main combustion stage swirling fuel hole 106 connects the corresponding swirling fuel channel 105 and the radial swirling hole 107. The annular swirling fuel chamber 102 has a plurality of main combustion stage axial fuel holes 108 on its annular cavity wall facing the premixing chamber 101, and each of the main combustion stage axial fuel holes 108 is connected to the premixing chamber 101 and the annular swirling fuel chamber 102.

[0024] like Figure 1 , Figure 2 , Figure 3 As shown, the swirl nozzle 100 in this embodiment can be used in gas turbines that use high-hydrogen-content fuels such as coal-to-syngas as fuel.

[0025] like Figure 1As shown in this embodiment, the swirl nozzle 100 is generally tubular, with a hollow interior forming a premixing chamber 101 for premixing fuel and air. The tube has two ends, an inlet and an outlet. Figure 1 , Figure 2 In the orientation shown, the left side of the pipe body is the air inlet end of the swirl nozzle 100, and the right side of the pipe body is the air outlet end of the swirl nozzle 100.

[0026] like Figure 1 , Figure 2 As shown in this embodiment, the annular swirl fuel chamber 102 is located at the inlet end of the swirl nozzle 100. The cavity of the annular swirl fuel chamber 102 is approximately cylindrical and coaxially arranged with the tube body. A central air inlet 103 is provided at the center of the cavity of the annular swirl fuel chamber 102, and the central air inlet 103 connects from the outside of the cavity of the annular swirl fuel chamber 102 to the premixing chamber 101 inside the tube body. After the swirl nozzle 100 is installed on the gas turbine, the annular swirl fuel chamber 102 is used to connect with the main combustion stage fuel pipeline of the gas turbine. For example, multiple main combustion stage fuel inlets 104 can be provided on the side of the annular swirl fuel chamber 102 away from the premixing chamber 101, and each main combustion stage fuel inlet 104 can be connected to the main combustion stage fuel pipeline of the gas turbine. The central air inlet 103 is used to supply air into the premixing chamber 101 of the swirl nozzle 100.

[0027] Figure 1 , Figure 2 As shown in the embodiment of this application, a plurality of radial swirl holes 107 are provided on the outer side wall of the pipe body near the air inlet end. Each radial swirl hole 107 is evenly distributed in the circumference of the pipe body. Each radial swirl hole 107 is in the same position in the axial direction of the pipe body. Each radial swirl hole 107 penetrates the side wall of the pipe body and communicates with the premixing chamber 101 inside.

[0028] like Figure 1 , Figure 2 , Figure 3 As shown in this embodiment, the swirling fuel channel 105 is located inside the tube sidewall and at a position corresponding to the annular swirling fuel cavity 102. Each swirling fuel channel 105 starts from the annular swirling fuel cavity 102 and extends axially along the tube inside the tube sidewall. Each swirling fuel channel 105 corresponds one-to-one with each radial swirling hole 107. For example, swirling fuel channels 105 can be provided on the tube wall between two adjacent radial swirling holes 107. Moreover, for each set of swirling fuel channels 105 and radial swirling holes 107, multiple main combustion stage swirling fuel holes 106 are also provided in the tube wall between the swirling fuel channels 105 and the radial swirling holes 107. Each main combustion stage swirling fuel hole 106 is connected to its corresponding swirling fuel channel 105 and radial swirling hole 107.

[0029] like Figure 4 , Figure 5 As shown in the embodiment of this application, the main combustion stage axial fuel hole 108 connects the annular swirling fuel chamber 102 and the premixing chamber 101. Each main combustion stage axial fuel hole 108 is uniformly arranged around the tube body on the annular cavity wall of the annular swirling fuel chamber 102 facing the premixing chamber 101. The orientation of each main combustion stage axial fuel hole 108 is parallel to the axial direction of the tube body.

[0030] like Figure 4 As shown in the embodiment of this application, each main combustion stage axial fuel hole 108 corresponds one-to-one with each radial swirl hole 107, and in the radial direction of the tube body, each main combustion stage axial fuel hole 108 is located downstream of the outlet direction of its corresponding radial swirl hole 107.

[0031] When the swirl nozzle 100 of this application is installed on a gas turbine, the outlet end of the swirl nozzle 100 is connected to the flame tube. The air entering the swirl nozzle 100 can be divided into two parts. One part of the air can enter the premixing chamber 101 from the central air inlet 103 at the air inlet end, and the other part can enter the premixing chamber 101 from each radial swirl hole 107 at the air inlet end. The main combustion stage fuel first enters the annular swirl combustion chamber 102, and then enters the premixing chamber 101 in two parts. One part enters each swirl fuel channel 105 from the annular swirl fuel chamber 102, and then enters the premixing chamber 101 through each radial swirl hole 107 based on each main combustion stage swirl fuel hole 106. The other part enters the premixing chamber 101 from the annular swirl fuel chamber 102 based on each main combustion stage axial fuel hole 108.

[0032] In this embodiment, the main combustion stage fuel is diverted through the annular swirl fuel chamber 102 to each swirl fuel channel 105, and then precisely injected into the corresponding radial swirl orifice 107 through the main combustion stage swirl fuel orifice 106. It can be mixed for the first time with the air entering the radial swirl orifice 107. After the first mixing, the mixed gas enters the premixing chamber 101 after swirling through the radial swirl orifice 107. Each radial swirl orifice 107 is provided with a main combustion stage axial fuel orifice 108 in the outlet direction. Therefore, after the mixed gas flowing out of each radial swirl orifice 107 enters the premixing chamber 101, it can be mixed for the second time with the fuel injected by the corresponding main combustion stage axial fuel orifice 108. After the second mixing, the mixed gas continues to flow from the premixing chamber 101 towards the outlet end of the swirl nozzle 100.

[0033] In addition, the air entering from the central air inlet 103 enters the premixing chamber 101 in the form of a jet. Moreover, each radial swirl orifice 107 is located on the side of the air inlet end. That is, the mixed gas after the second mixing is still a certain distance away from the outlet end of the swirl nozzle 100. Therefore, as the mixed gas after the second mixing flows towards the outlet end, it can be further mixed with the jet air entering from the central air inlet 103 in the premixing chamber 101. This makes the fuel and air mix more evenly, ensuring that the high hydrogen fuel can burn completely, significantly reducing the size of the local high temperature zone during the combustion of high hydrogen fuel, and thus reducing the generation of nitrogen oxides.

[0034] In addition, there is a velocity difference between the jet air entering from the central air inlet 103 and the mixed gas after the second mixing. Therefore, when the mixed gas after the second mixing meets the jet air, a shear flow can be formed. The shear flow can reduce the size of the high-temperature backflow zone in the central region of the swirl nozzle 100 outlet, thereby reducing the risk of backfire.

[0035] In addition, after the high hydrogen fuel and air are first mixed in the radial swirling orifice 107, they enter the premixing chamber 101 in a radial swirling manner. Compared with the axial swirling, the mixed gas after radial swirling has a larger axial velocity, which makes the axial velocity of the mixed gas that finally flows out from the outlet end larger, thus also helping to avoid backfire.

[0036] like Figure 1 As shown in the embodiment of this application, the amount of air entering the swirl nozzle 100 from each radial swirl hole 107 is 75%-95% of the total amount of air entering the swirl nozzle 100.

[0037] The air entering the swirl nozzle 100 is mainly divided into two parts: one part enters from each radial swirl hole 107, and the other part enters from the central air inlet hole 103.

[0038] Each radial swirl orifice 107 is the main air channel for premixing. The proportion of air entering from each radial swirl orifice 107 is set at 75%-95% to ensure that the vast majority of air enters through the radial swirl orifice 107. This ensures that the vast majority of air can undergo the first mixing with the fuel injected from the main combustion stage swirl fuel orifice 106 in the radial swirl orifice 107 before entering the premixing chamber 101, thus ensuring that the fuel and air have sufficient contact volume and contact time.

[0039] In this embodiment, a central air inlet is provided to ensure that the air entering through the central air inlet 103 can form a high-speed axial jet, ensuring that the mixed gas flowing out from the outlet has a high axial velocity, thereby preventing backfire. In addition, the proportion of air entering through the central air inlet 103 is set to 5%-20%, which can avoid insufficient premixing due to excessive air entering through the central air inlet 103.

[0040] In the embodiments of this application, the swirl coefficient of each of the radial swirling holes 107 is between 0.4 and 0.6.

[0041] In this embodiment, the swirl coefficient of the radial swirl orifice 107 is set between 0.4 and 0.6, enabling the radial swirl orifice 107 to create a swirl effect on the fuel and air, but only a weak swirl effect. This reduces the tangential momentum ratio of the mixed gas and prevents a large-scale low-pressure backflow zone from forming at the outlet end of the swirl nozzle 100 during strong swirl, thus preventing the flame from being absorbed and backflowed by the backflow zone. Furthermore, the lower swirl coefficient also reduces the axial kinetic energy loss of the mixed gas, ensuring a higher axial ejection velocity, so that the flow velocity of the mixed gas is always higher than the flame propagation velocity, thereby preventing backfire. Additionally, the moderate weak swirl ensures that the mixed gas flowing out of the radial swirl orifice 107 can be shear-mixed with the jet air from the central air inlet 103, ensuring premixing uniformity, avoiding the generation of localized high-temperature combustion zones, and reducing nitrogen oxide emissions.

[0042] like Figure 1 As shown in the embodiment of this application, each of the radial swirl holes 107 is a rounded rectangular hole, and the length direction of the radial swirl hole 107 is parallel to the length direction of the tube body; the length of each radial swirl hole 107 in the axial direction of the swirl nozzle 100 does not exceed 1 / 4 of the length of the swirl nozzle 100.

[0043] In this embodiment, the radial swirl orifice 107 is configured as a rounded rectangular orifice, with its length parallel to the length of the pipe body. This means the interface through which air enters from the radial swirl orifice 107 is elongated, limiting the lateral deflection of the airflow and preventing excessive tangential angular velocity in the mixed gas exiting the radial swirl orifice 107. Furthermore, setting the length of the rounded rectangular orifice to no more than 1 / 4 of the pipe body length allows for a shorter swirl path in the mixed gas within the radial swirl orifice 107, preventing the formation of strong vortices and swirling currents, and ensuring that the mixed gas exiting each radial swirl orifice 107 maintains a weak swirling state. On the other hand, it also reduces axial kinetic energy loss in the mixed gas exiting each radial swirl orifice 107, maintaining a higher axial flow velocity and thus preventing the formation of a low-pressure backflow zone at the outlet.

[0044] In this embodiment, by coordinating the air intake ratio parameters of the radial swirling orifice 107 and the central air intake orifice 103, as well as the shape and length parameters of the radial swirling orifice 107 and the swirling coefficient parameters of the swirling orifice, it is possible to ensure that the fuel and air are moderately sheared and mixed to achieve uniform premixed low-NOx combustion, while also effectively maintaining a high axial velocity at the outlet end of the swirling nozzle 100. This ensures that the axial velocity of the mixed gas flowing out of the outlet end is greater than the propagation speed of the laminar flame of high-hydrogen fuel, thereby avoiding backfire.

[0045] like Figure 4 As shown, the annular swirl fuel chamber 102 has a truncated cone 109 on its side facing the premixing chamber 101. The truncated cone 109 protrudes towards one side of the premixing chamber 101, and the central air inlet 103 passes through the truncated cone 109 and communicates with the premixing chamber 101. In the radial direction of the tube body, each of the main combustion stage axial fuel holes 108 is located between the truncated cone 109 and the inner wall of the tube body.

[0046] like Figure 4 As shown in this embodiment, the truncated cone 109 protrudes from the side of the annular swirling fuel chamber 102 toward the premixing chamber 101 and toward the premixing chamber 101. The central air inlet 103 passes through the annular swirling fuel chamber 102 and the truncated cone 109. For the air entering from the central air inlet 103, the part of the central air inlet 103 located inside the truncated cone 109 can converge and guide the air entering from the central air inlet 103, ensuring that the air entering from the central air inlet 103 can maintain high-speed axial direct injection, thereby strengthening the central air jet and reducing the central low-pressure area.

[0047] In addition, such as Figure 2 , Figure 5 As shown, the truncated cone 109 passes over each radial swirl hole 107 in the axial direction of the tube body. Therefore, the conical surface of the truncated cone 109 can also isolate the mixed gas flowing in from the radial swirl holes 107, preventing the mixed gas flowing in from the radial swirl holes 107 from interfering with the central air jet too early. Instead, it is mixed again with the fuel injected from the axial fuel hole 108 of the main combustion stage and then smoothly enters the premixing chamber 101 along the conical surface of the truncated cone 109.

[0048] like Figure 1 , Figure 2 , Figure 5 As shown in the embodiment of this application, the outer wall of the pipe body at the air outlet end is provided with a plurality of cooling holes 110, and each cooling hole 110 is distributed along the circumference of the pipe body.

[0049] Cooling holes 110, which connect to the premixing chamber 101, are provided on the outer wall of the outlet end of the pipe. Cooling air can be introduced into the premixing chamber 101 through each cooling hole 110. After entering the premixing chamber 101 through each cooling hole 110, the cooling air can form a cooling airflow film on the outer wall of the outlet end of the swirl nozzle 100, which can effectively reduce the wall temperature of the outlet end of the swirl nozzle 100 and avoid high-temperature ablation damage. In addition, after entering the premixing chamber 101 through each cooling hole 110, the cooling air can be blown radially inward along the pipe at the outlet end, thereby eliminating the flashback path on the inner wall of the pipe at the outlet end and avoiding boundary layer flashback.

[0050] The swirl nozzle 100 in this embodiment of the application, by providing a radial swirl hole 107 at the air inlet end, enables the air entering from the radial swirl hole 107 and the fuel entering from the main combustion stage swirl fuel hole 106 to be mixed for the first time to form a mixed gas. After the mixed gas enters the premixing chamber 101, it can be mixed for the second time with the fuel entering from the main combustion stage axial fuel hole 108, and further uniformly mixed during the flow towards the air outlet end. For high-hydrogen-content fuels, uniform premixing can significantly reduce the size of the local high-temperature zone during combustion, thereby reducing the generation of nitrogen oxides. In addition, there is a velocity difference between the jet air entering from the central air inlet 103 and the flow rate of the mixed gas after the second mixing. Therefore, when the mixed gas after the second mixing meets the jet air, a shear flow can be formed. The shear flow can reduce the size of the high-temperature backflow zone in the central region of the outlet of the swirl nozzle 100, thereby reducing the risk of backfire. Moreover, after the fuel and air are first mixed in the radial swirl orifice 107, they enter the premixing chamber 101 in a radial swirl manner. Compared with the axial swirl, the mixed gas after radial swirl has a larger axial velocity, which makes the mixed gas flowing out from the outlet end have a larger axial velocity, thus also helping to avoid backfire.

[0051] like Figure 6 , Figure 7 , Figure 8 As shown, this application also proposes a nozzle assembly, which includes a duty nozzle 120 and a plurality of swirling nozzles 100 as described in any of the above embodiments. Each of the swirling nozzles 100 surrounds the duty nozzle 120 in the circumferential direction, and the air outlet of each of the swirling nozzles 100 and the air outlet of the duty nozzle 120 are located on the same spatial plane. The duty nozzle 120 is provided with a duty fuel passage 121 and a duty air passage 122, wherein the duty fuel passage 121 surrounds the duty air passage 122; The outlet end of the duty nozzle 120 is provided with a duty air hole 123 and a duty fuel hole 124. The duty air hole 123 is connected to the duty air passage 122, and the duty fuel hole 124 is connected to the duty fuel passage 121. A duty vortex 125 is provided on the outer wall of the outlet end of the duty nozzle 120.

[0052] like Figure 6 As shown in the embodiment of this application, the duty nozzle 120 is located at the center of the nozzle assembly, and each swirl nozzle 100 is uniformly surrounding the duty nozzle 120. After the nozzle assembly is installed on the gas turbine, the outlet end of each swirl nozzle 100 and the outlet end of the duty nozzle 120 are located on the same spatial plane, and both are connected to the flame tube of the gas turbine.

[0053] like Figure 8 As shown in the embodiment of this application, the duty fuel channel 121 is an annular channel, and the duty fuel channel 121 surrounds the duty air channel 122. The duty fuel channel 121 and the duty air channel 122 are coaxially arranged. This surrounding layout can realize the stratified output of fuel and air, provide a structural basis for diffusion combustion, and ensure that a stable flame can be formed at the outlet end of the duty nozzle 120.

[0054] In addition, such as Figure 7 , Figure 8 As shown, the swirler 125 on the outer wall of the outlet end of the swirler nozzle 120 can be an axial swirler or a radial swirler. The air passing through the swirler nozzle 120 consists of two parts: one part enters from the swirler air passage 122 and exits from the swirler nozzle 120; the other part is swirled by the swirler 125 at the outlet end of the swirler nozzle 120 and then exits from the swirler nozzle 120.

[0055] The duty air hole 123 is located in the central area of ​​the outlet end of the duty nozzle 120 and is connected to the duty air channel 122. The air entering from the duty air channel 122 can be sprayed into the flame tube by each duty air hole 123. The axial direct air can provide sufficient oxygen for diffusion combustion on the one hand, and form a central air column on the other hand, which is conducive to stabilizing the flame root and preventing flame deviation.

[0056] The duty fuel holes 124 are evenly distributed around the circumference of the outlet end of the duty nozzle 120. Each duty fuel hole 124 surrounds the outside of the duty air hole 123. After the fuel in the duty fuel channel 121 is sprayed outward in a diffused manner through the duty fuel holes 124, it gradually mixes with the air sprayed out of the duty air hole 123 on the outside of the outlet end of the duty nozzle 120, which can form a stable diffusion flame. This diffusion flame is not affected by low operating conditions and low equivalence ratio, so it can maintain stable combustion throughout the process, thereby providing a reliable ignition source for the premixed mixture sprayed by each swirl nozzle 100 around it.

[0057] In addition, most of the air passing through the duty nozzle 120 is swirled by the duty cyclone separator 125 at the outlet end and then ejected from the duty nozzle 120. The swirled air can slightly guide the fuel ejected from the outlet end of the duty nozzle 120, so that the fuel and air are mixed evenly and can play a role in stabilizing the flame.

[0058] In this embodiment, when the nozzle assembly is installed on a gas turbine, each swirl nozzle 100 can work in conjunction with the standby nozzle 120 to form a staged combustion mode. For example, under low operating conditions, the gas turbine load is low, the fuel supply is small, and the premixed gas equivalence ratio output by the swirl nozzle 100 is too low to burn stably independently. At this time, the standby nozzle 120 can work to form a continuous and stable ignition source through diffusion combustion, ensuring stable combustion under low operating conditions. Under high operating conditions, the swirl nozzle 100 can work in conjunction with the standby nozzle 120. The swirl nozzle 100 outputs a premixed gas mixture, which achieves stable premixed combustion under the ignition of the diffusion flame of the standby nozzle 120, thereby achieving low nitrogen oxide emissions. At the same time, the diffusion flame of the standby nozzle 120 can effectively suppress the thermoacoustic oscillations that may be generated by premixed combustion, improving the combustion stability under all operating conditions.

[0059] like Figure 6 , Figure 9 , Figure 10 As shown in the embodiment of this application, the nozzle assembly further includes a nozzle disk 126, on which a main combustion stage fuel chamber 127 and a duty fuel chamber 128 are provided. The main combustion stage fuel chamber 127 surrounds the duty fuel chamber 128. The main combustion stage fuel chamber 127 is connected to the main combustion stage fuel pipeline of the gas turbine, and the duty fuel chamber 128 is connected to the duty fuel pipeline of the gas turbine. The duty fuel passage 121 of the duty nozzle 120 is connected to the duty fuel chamber 128, and the annular swirl fuel chamber 102 of each swirl nozzle 100 is connected to the main combustion stage fuel chamber 127.

[0060] like Figure 9 , Figure 10As shown in the embodiment of this application, the nozzle disk 126 is generally disc-shaped, and the nozzle disk 126 is provided with a main combustion stage fuel chamber 127 and a duty fuel chamber 128. The main combustion stage fuel chamber 127 is annular, and the duty fuel chamber 128 is hollow cylindrical. The main combustion stage fuel chamber 127 surrounds the outside of the duty fuel chamber 128.

[0061] like Figure 11 As shown in this embodiment, each swirl nozzle 100 can be mounted on the nozzle disk 126 circumferentially. During installation, the annular swirl fuel chamber 102 of each swirl nozzle 100 is connected to the main combustion stage fuel chamber 127. For example, each swirl nozzle 100 has multiple main combustion stage fuel inlets 104 on the side away from the premixing chamber 101. When installing the swirl nozzle 100, a main combustion stage fuel inlet pipe 129 can be provided at each main combustion stage fuel inlet 104. One end of each main combustion stage fuel inlet pipe 129 is connected to the main combustion stage fuel chamber 127, and the other end is connected to the corresponding main combustion stage fuel inlet 104.

[0062] When installing the duty nozzle 120, the duty fuel passage 121 of the duty nozzle 120 can be sealed and connected to the duty fuel chamber 128, while the duty air passage 122 passes through the duty fuel chamber 128.

[0063] In this embodiment, the main combustion stage fuel chamber 127 is used to connect to the main combustion stage fuel pipeline of the gas turbine and serves as the fuel supply main chamber of the swirl nozzle 100. It can receive fuel from the gas turbine and buffer and stabilize the fuel to ensure that the fuel pressure entering each swirl nozzle 100 is uniform and the flow rate is stable, thus providing a stable fuel basis for the premixed combustion of the swirl nozzle 100.

[0064] In this embodiment, the duty fuel chamber 128 is used to connect to the duty fuel pipeline of the gas turbine and is specifically used to supply fuel to the duty nozzle 120. It is sealed and connected to the duty fuel channel 121 of the duty nozzle 120, and can independently deliver fuel to the duty nozzle 120, thereby realizing the individual control of the duty nozzle 120.

[0065] The nozzle assembly in this embodiment includes the swirling nozzle 100 described in any of the above embodiments, and therefore has all the beneficial effects of the swirling nozzle 100, which will not be elaborated here. In addition, the nozzle assembly in this embodiment also includes a standby nozzle 120, which can not only maintain a stable central flame, but also cooperate with each swirling nozzle 100 to match different working conditions.

[0066] like Figure 11 As shown, this application also proposes a combustion chamber that includes the nozzle assembly described in any of the above embodiments.

[0067] like Figure 11 As shown in this embodiment, the flame tube 130 is located inside the casing 140, the nozzle assembly is mounted on the casing 140 of the gas turbine, and the outlet ends of each swirl nozzle 100 and the standby nozzle 120 are connected to the inlet end of the flame tube 130. The outlet end of the flame tube 130 is provided with a transition section 160, and a shunting shield 150 is provided between the casing 140 and the transition section 160. The shunting shield 150 is provided with a rectifying hole 151, so that air can enter the casing 140 evenly after passing through the rectifying hole 151, ensuring that the air... Air can enter each swirl nozzle 100 evenly. After the air enters the casing 140 through the rectifier hole 151, part of the air enters each swirl nozzle 100 through the radial swirl hole 107, part of the air enters the swirl nozzle 100 through the central air inlet hole 103, part of the air enters the swirl nozzle 100 through the cooling hole 110, and part of the air enters the duty swirler 125 of the duty nozzle 120.

[0068] In this embodiment, the flame tube 130 is also provided with a connecting tube 132 to facilitate connecting with other flame tubes 130.

[0069] like Figure 11 As shown in this embodiment, the rectifying holes 151 on the shroud 150 can be arranged in three rows. Each rectifying hole 151 in the same row is arranged circumferentially around the shroud 150, and the rectifying holes 151 in the same row are at the same axial position on the shroud 150. Two rows can be arranged on the inclined section of the shroud 150, and the other row can be arranged on the bushing of the shroud 150. Furthermore, in practical applications, the combustion chamber is installed at a certain angle, causing air to tend to accumulate at the bottom of the cavity between the flame tube 130 and the shroud 150, resulting in a larger air volume at the bottom than in the upper region. Therefore, for each row of rectifying holes 151, it is possible to omit the rectifying holes 151 at the bottom of the shroud 150, or to arrange fewer rectifying holes 151, thereby preventing a further increase in the bottom air intake and ensuring a uniform circumferential air distribution in the flame tube 130.

[0070] Additionally, an air film plate 131 can be installed at the air inlet end of the flame tube 130. The air outlet ends of the duty nozzle 120 and each swirl nozzle 100 pass through the air film plate 131 and are connected to the flame tube 130. The air film plate 131 can prevent the flame from burning the nozzle. Furthermore, through holes can be provided on the air film plate 131, allowing air entering the casing 140 to enter the flame tube 130 through the through holes on the air film plate 131.

[0071] In addition, in this embodiment, an impact cooling structure can be provided on the outer wall of the flame tube 130. After air enters the casing 140 through the rectifier hole 151, it comes into contact with the impact cooling structure as it flows toward the nozzle assembly, thereby cooling the flame tube 130. For example, the impact cooling structure can have protrusions on the flame tube 130 to increase the contact area between the outer wall of the flame tube 130 and the air, thus also achieving a cooling effect.

[0072] The combustion chamber in this application embodiment includes the nozzle assembly described in any of the above embodiments, and therefore has all the beneficial effects of the above nozzle assembly, which will not be elaborated here.

[0073] The above description is merely an optional embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the inventive concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A swirl nozzle (100) characterized by, include: The tube body is hollow to form a premixing cavity (101), and the tube body is provided with an air inlet and an air outlet; The air inlet end is provided with an annular swirling fuel chamber (102) and a central air inlet (103); the annular swirling fuel chamber (102) is separated from the premixing chamber (101) and surrounds the central air inlet (103); the central air inlet (103) is used to allow air to enter; The outer wall of the pipe near the air inlet end is provided with a plurality of radial swirl holes (107), each radial swirl hole (107) is distributed along the circumference of the pipe, and each radial swirl hole (107) is connected to the premixing chamber (101). The tube body is provided with a plurality of swirling fuel channels (105) in the tube wall near the annular swirling fuel chamber (102). Each swirling fuel channel (105) corresponds one-to-one with each radial swirling hole (107), and each swirling fuel channel (105) is connected to the corresponding annular swirling fuel chamber (102). Each swirling fuel channel (105) is provided with a main combustion stage swirling fuel hole (106) in the pipe wall between itself and its corresponding radial swirling hole (107). The main combustion stage swirling fuel hole (106) is connected to the corresponding swirling fuel channel (105) and the radial swirling hole (107). The annular swirling fuel chamber (102) has a plurality of main combustion stage axial fuel holes (108) on its annular cavity wall facing the premixing chamber (101), and each of the main combustion stage axial fuel holes (108) is connected to the premixing chamber (101) and the annular swirling fuel chamber (102).

2. The swirl nozzle (100) of claim 1, characterized in that Each of the main combustion stage axial fuel holes (108) corresponds one-to-one with each of the radial swirl holes (107), and in the radial direction of the tube body, each main combustion stage axial fuel hole (108) is located downstream of the outlet direction of its corresponding radial swirl hole (107).

3. The swirl nozzle (100) of claim 1, wherein The amount of air entering the swirl nozzle (100) from each radial swirl hole (107) is 75%-95% of the total amount of air entering the swirl nozzle (100).

4. The swirl nozzle (100) of claim 1, wherein The swirl coefficient of each of the radial swirling holes (107) is between 0.4 and 0.

6.

5. The swirl nozzle (100) of claim 1, wherein Each of the radial swirling holes (107) is a rounded rectangular hole, and the length direction of the radial swirling hole (107) is parallel to the length direction of the tube body; the length of each radial swirling hole (107) in the axial direction of the swirling nozzle (100) does not exceed 1 / 4 of the length of the swirling nozzle (100).

6. The swirl nozzle (100) of claim 1, wherein The annular swirl fuel chamber (102) has a truncated cone (109) on its side facing the premixing chamber (101). The truncated cone (109) protrudes towards one side of the premixing chamber (101), and the central air inlet (103) passes through the truncated cone (109) and communicates with the premixing chamber (101). In the radial direction of the tube body, each of the main combustion stage axial fuel holes (108) is located between the truncated cone (109) and the inner wall of the tube body.

7. The swirl nozzle (100) of claim 1, wherein The pipe body has multiple cooling holes (110) on the outer wall of the outlet end, and each cooling hole (110) is distributed along the circumference of the pipe body.

8. A nozzle assembly characterized by, The nozzle assembly includes a standby nozzle (120) and a plurality of swirling nozzles (100) as described in any one of claims 1-7. Each of the swirling nozzles (100) surrounds the duty nozzle (120) in the circumferential direction, and the air outlet of each of the swirling nozzles (100) and the air outlet of the duty nozzle (120) are located on the same spatial plane. The duty nozzle (120) is provided with a duty fuel passage (121) and a duty air passage (122), wherein the duty fuel passage (121) surrounds the duty air passage (122). The outlet end of the duty nozzle (120) is provided with a duty air hole (123) and a duty fuel hole (124). The duty air hole (123) is connected to the duty air passage (122), and the duty fuel hole (124) is connected to the duty fuel passage (121). A duty vortex (125) is provided on the outer wall of the outlet end of the duty nozzle (120).

9. The nozzle assembly of claim 8, wherein, The nozzle assembly further includes a nozzle disk (126), on which a main combustion stage fuel chamber (127) and a duty fuel chamber (128) are provided. The main combustion stage fuel chamber (127) surrounds the duty fuel chamber (128). The main combustion stage fuel chamber (127) is used to connect to the main combustion stage fuel pipeline of the gas turbine, and the duty fuel chamber (128) is used to connect to the duty fuel pipeline of the gas turbine. The duty fuel passage (121) of the duty nozzle (120) is connected to the duty fuel chamber (128), and the annular swirling fuel chamber (102) of each swirling nozzle (100) is connected to the main combustion stage fuel chamber (127).

10. A combustion chamber, characterized by The combustion chamber includes the nozzle assembly as described in claim 8 or 9.

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