Axial staged combustion lobe nozzle of combustion chamber

Abstract

The invention relates to the technical field of gas turbines, and particularly discloses a combustion chamber axial staged combustion lobe nozzle which comprises a lobe nozzle body, and the lobe nozzle body comprises a fuel air inlet channel, an air inlet channel, a mixing channel, a lobe structure and a mounting flange. An air inlet channel is formed in the top of the lobe nozzle, a fuel inlet channel is connected to the side face of the lobe nozzle, a mixing channel is formed in the lobe nozzle, a lobe structure is arranged in the mixing channel, and the lobe structure is used for forming a vortex system beneficial to improving mixing of air and fuel. According to the axial grading nozzle, the mixing performance of fuel and air can be improved, the nozzle outlet flame lifting and wall face cooling effects are improved, the operation load of a combustion chamber is adjusted, and therefore the effects of reducing emission of pollutants in the combustion chamber, improving the safety and reliability of the axial grading nozzle and widening the thermal load adjusting range are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of gas turbines, in particular to an axially graded combustion lobe nozzle for a combustion chamber. Background Art

[0002] The outlet temperature of the gas turbine combustion chamber is an important factor in further improving the efficiency of the gas turbine. However, directly increasing the outlet temperature of the combustion chamber will increase the emission of pollutants, which is contrary to the increasingly stringent environmental standards in the world. The axial staged combustion technology of fuel has great potential in reducing pollutant emissions and regulating the load of the combustion chamber. At the same time, the mixing characteristics of fuel and air in the combustion chamber are also crucial to pollutant emissions. The traditional swirl structure can be used in the lean premixed combustion technology to improve the mixing effect of fuel and air. Due to the existence of the recirculation zone, it is easy to flash back after using hydrogen-rich fuel. The development of the vortex system in the vortex-free structure can also achieve rapid mixing. The lobe nozzle can significantly improve the mixing performance due to the petal-shaped folds at the top and is used in different application scenarios in important fields such as aerospace. The application of the lobe nozzle in the axial staged combustion chamber can improve the mixing of fuel and air, thereby improving the combustion efficiency and reducing the emission of pollutants. The uniform development of the premixed gas downstream of the lobe avoids the occurrence of flashback. However, the flow organization and structural design of the fuel and air in the lobe nozzle need to be considered in depth. For this purpose, a lobe nozzle for axial staged combustion of the combustion chamber is provided. Summary of the invention

[0003] The purpose of the present invention is to provide an axially graded combustion lobe nozzle for a combustion chamber in view of the defects of the prior art, so as to solve the problems raised by the above-mentioned background technology.

[0004] To achieve the above-mentioned object, the present invention provides the following technical solutions: a combustion chamber axially graded combustion lobe nozzle, comprising a lobe nozzle, the lobe nozzle comprising a fuel intake channel, an air intake channel, a mixing channel, a lobe structure and a mounting flange; the top of the lobe nozzle is provided with an air intake channel, the side of the lobe nozzle is connected with the fuel intake channel, the interior of the lobe nozzle is provided with a mixing channel, the interior of the mixing channel is provided with a lobe structure, and the lobe structure is used to form a vortex system that is beneficial to improving the mixing of air and fuel;

[0005] The fuel inlet passage comprises a fuel inlet pipe, a fuel annular cavity and a fuel distribution pipe; the fuel distribution pipe is connected and fixed to the lobe structure, and the fuel annular cavity is arranged at one end of the inner part of the fuel inlet pipe; the fuel enters the fuel annular cavity from the fuel inlet pipe, and then enters the lobe structure through a plurality of fuel distribution pipes evenly distributed in the circumferential direction;

[0006] The air intake passage comprises a primary air distribution structure and a secondary air distribution structure; the air enters the lobe nozzle mixing passage after being rectified and speed-regulated by the primary air distribution structure and the secondary air distribution structure;

[0007] The mixing channel includes a straight flow section, a mixing development section, a mixing contraction section, a mixing outlet section and an air film channel;

[0008] A plurality of air film channels are evenly arranged on the wall surfaces of the straight flow section, the mixing development section, the mixing contraction section and the mixing outlet section, which are used for cooling the mixing contraction section of the lobe nozzle and lifting the flame after axial staged combustion;

[0009] The lobe structure includes a straight section, a lobe section, a trailing edge section, a fuel interlayer, a fuel hole and a supporting rib;

[0010] The straight section is connected to the fuel distribution pipe to provide a fuel channel for the fuel interlayer, and its length is L1; the lobe section is composed of a number of petals with the wave crest facing outward, the number of petals is n1, and n1 ≥ 3, and the length of the lobe section is L2; ​​the trailing edge section is streamlined to avoid the formation of a rear step flow at the trailing edge, and the length of the trailing edge section is L3;

[0011] As a preferred technical solution of the present invention, the number of the fuel inlet pipes is one or more, and the cross-sectional shape of the fuel distribution pipe is an elliptical streamline, which rectifies the external duct air while distributing the fuel to reduce the pressure loss; the speed of the fuel flow in the fuel inlet pipe is v f1 , and 40m / s≤v f1 ≤80m / s, the cross-sectional area of ​​the fuel inlet pipe is A f1 The velocity of the fuel flow in the fuel ring cavity is v f2 , and 20m / s≤v f2 ≤60m / s, the cross-sectional area of ​​the fuel ring cavity is A f2 , and A f1 <A f2 ; The cross-sectional shape of the fuel distribution pipe is an elliptical streamline, and the velocity of the fuel flow in the fuel distribution pipe is v f3 , and 60m / s≤v f3 ≤120m / s, the cross-sectional area of ​​the fuel distribution pipe is A f3 .

[0012] As a preferred technical solution of the present invention, the first-level air distribution structure evenly arranges a plurality of ad1 The total area of ​​the gas distribution holes is A ad1 The secondary air distribution structure is evenly arranged with several diameters D ad2 The total area of ​​the gas distribution holes is A ad2 , and D ad1 >D ad2 , Aad1 >A ad2 The primary air distribution structure and the secondary air distribution structure are used to make the air entering the lobe nozzle flow evenly. The air sources of the lobe nozzle include: air entering from between the combustion chamber casing and the flame tube, air entering from between the combustion chamber casing and the guide sleeve, and separate air supply.

[0013] As a preferred technical solution of the present invention, the straight rectifying section is connected to the secondary air distribution structure, and its inner diameter is D1, and 20mm≤D1≤120mm, and its length is L1+L2, and L1+L2≥20mm; the mixing development section is located after the straight rectifying section, and is used to provide a mixing development area for the air and fuel of the lobe nozzle, and its inner diameter is D1, and its length is L3; the mixing contraction section is located after the mixing development section, and is used to adapt the outlet velocity of the axial graded nozzle to the velocity of the mainstream flue gas in the combustion chamber to meet the jet momentum ratio; its contraction curve is the Vito-Sinsky curve, and the contraction process of the mixed gas is uniform and stable; its inner diameter at the inlet is D1, the diameter at the outlet is D2, and the length is L4; the mixing outlet section is located after the mixing contraction section, and its inner diameter is D2, and 10mm≤D2≤80mm, and the length is L5;

[0014] The mixing development section, mixing contraction section and mixing outlet section are the distances where the fuel and air of the lobe nozzle are actually mixed, and their lengths are L3+L4+L5, and L3+L4+L5≥0.5×D2.

[0015] As a preferred technical solution of the present invention, the air film channel is inletted by the air inside the combustion chamber, the air flow direction of the air film channel outlet is the same as the mixed air flow direction, the cross-sectional shape of the air film channel is a "capsule shape", and the total area is A c , total area of ​​air film channel A c It accounts for 2-10% of the air intake area of ​​the axial grading nozzle and is used to control the air velocity in the air film channel to be no greater than the outlet velocity of the lobe nozzle.

[0016] As a preferred technical solution of the present invention, the straight section and the flat section divide the air entering the lobe nozzle into an inner channel and an outer channel, and the inlet cross-sectional area of ​​the inner channel is A. in The cross-sectional area of ​​the outer duct entrance is A out The area ratio of the outer duct to the inner duct is A out / A in , and 0.2≤A out / A in ≤5; Support ribs are arranged inside the fuel interlayer to improve the strength of the lobe structure; the gap between the fuel interlayer is D f , and 0.5mm≤D f ≤2mm, D fis a constant value or a variable value; the diameter of the support rib is D zcl , the number is n2, and 0.5mm≤D zcl ≤2mm, n1≤n2≤5n1; the support ribs are evenly arranged to ensure the strength of the lobe structure and the flow rate and speed of the fuel in the fuel interlayer; the speed of the fuel flow in the fuel interlayer is v f4 , and 20m / s≤v f4 ≤60m / s, the cross-sectional area of ​​the fuel interlayer is A f4 , and A f3 f4 ; Set the mixed gas jet velocity v of the axial staged combustion lobe nozzle m 40m / s~150m / s;

[0017] The fuel hole is arranged at the connection between the lobe section and the trailing edge section. The outflow direction of the fuel hole includes the inner channel and the outer duct of the lobe structure. The area of ​​the fuel holes on the inner channel and the outer duct is proportional to the air area of ​​the inner channel and the outer duct. The equivalent ratio of the outer duct is Φ out , the equivalent ratio of the internal Dao is Φ in , and Φ out ≤Φ in ; Used to achieve stable combustion after axial classification and mainstream smoke mixing; the fuel hole is located in the area where the vortex system interacts after the lobe, the diameter of the fuel hole is D, and 0.5mm≤D≤3mm, the fuel jet velocity v of the fuel hole f The speed is 120m / s to 300m / s, the number of rows of the fuel holes arranged in the air flow direction in the lobe is 1-5 rows; the mixing unevenness of the fuel and air at the lobe nozzle outlet is less than 0.05;

[0018] The straight section, the lobe section and the trailing edge section of the lobe structure form the fuel interlayer, and the fuel supplied by the fuel distribution pipe enters the fuel hole through the fuel interlayer to mix with the air; wherein the inner side inclination angle of the lobe section is θ in and the outer inclination angle is θ out , and 10°≤θ in ≤30°, 10°≤θ out ≤30°.

[0019] As a preferred technical solution of the present invention, the lobe structure and the mixing channel are processed jointly by additive manufacturing technology and mechanical processing technology. The straight section, lobe section, trailing edge section, support ribs and the main body of the mixing channel are completed by additive manufacturing technology, and then the surface is mechanically processed to reduce the roughness of the contact surface between the lobe structure and the air, reduce the flow resistance, and avoid low speed on the contact surface; the fuel hole is processed by mechanical processing technology to ensure the dimensional accuracy of the fuel hole and the actual flow rate of the fuel. ​

[0020] As a preferred technical solution of the present invention, the mixing channel and the lobe structure in the lobe nozzle jointly form different air flow areas, including an air development area, a velocity direction change area, a cross jet mixing area, a vortex system development and contraction area, and a mixed air rectification area;

[0021] The air that passes through the air intake passage and then enters the mixing passage is divided into inner duct air and outer duct air; the inner duct air includes an inner duct air development area, an inner duct velocity direction change area and an inner duct cross jet mixing area; the outer duct air includes an outer duct air development area, an outer duct velocity direction change area and an outer duct cross jet mixing area;

[0022] The flow rates of the inner and outer duct air are distributed according to the area ratio A2 / A1 of the outer duct to the inner duct. The air in the inner duct air development area develops stably in the straight section and then changes its air speed direction after passing through the inner duct speed direction change area; the air in the outer duct air development area develops stably outside the straight section and then changes its air speed direction after passing through the outer duct speed direction change area.

[0023] After the fuel in the fuel interlayer flows out from the outlet of the fuel hole, it forms cross jets with the air in the inner duct of the lobe and the air in the outer duct of the lobe, forming an inner duct fuel-air mixed gas in the inner duct cross jet mixing area; in the outer duct cross jet mixing area, the outer duct fuel-air mixed gas, due to the change in the direction of the inner and outer duct air velocities, the inner duct fuel-air mixed gas and the outer duct fuel-air mixed gas produce relative displacement in the vortex development and contraction area, forming a stream vortex and an orthogonal vortex. The formation and development of the stream vortex and the orthogonal vortex improve the mixing effect of the fuel and air; at the same time, it rectifies the development of the mixed gas in the inner and outer ducts of the lobe nozzle. The stream vortex and the orthogonal vortex are constantly broken during the development process, which rapidly improves the mixing uniformity of the fuel and air, and reduces the mixing unevenness of the fuel and air to below 0.05 within a limited distance.

[0024] As a preferred technical solution of the present invention, the outer shell of the lobe nozzle is integrated with the mounting flange, and the lobe nozzle is connected and fastened to the axially staged combustion chamber through the mounting flange.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The axially graded combustion lobe nozzle can achieve rapid and uniform mixing of fuel and air within a limited mixing distance, while promoting effective mixing of the nozzle mixed gas and mainstream flue gas, thereby improving combustion efficiency and helping to control the generation of combustion pollutants.

[0027] (2) During the development of the mixed gas in the mixing contraction section and the mixing outlet section of the axially staged combustion lobe nozzle, the process of the flow vortex and the orthogonal vortex breaking is accompanied by the interaction of the vortex system, which can provide a uniform mixing stage for the mixing of fuel and air and at the same time increase the jet velocity of the axially staged nozzle.

[0028] (3) Arranging air film channels in the nozzle straightening section, mixing development section, mixing contraction section and mixing outlet section can provide cooling effect for the mixing contraction section and mixing outlet section at the nozzle outlet, while improving the flame lift after combustion of the axially graded nozzle mixed gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of an axially graded combustion lobe nozzle for a combustion chamber according to an embodiment of the present invention;

[0030] Figure 2 It is a cross-sectional view of a mixing channel and a lobe structure of an axially graded combustion lobe nozzle for a combustion chamber of the present invention;

[0031] Figure 3 It is an axonometric cross-sectional view of a mixing channel of an axially graded combustion lobe nozzle of a combustion chamber of the present invention;

[0032] Figure 4 It is a structural schematic diagram of the lobe structure of the present invention;

[0033] Figure 5 It is a structural schematic diagram of the petal structure and fuel hole of the lobe nozzle of the present invention;

[0034] In the above drawings, the meanings of the reference numerals are as follows:

[0035] 100-lobe nozzle; 110-fuel intake channel; 111-fuel intake pipe; 112-fuel annular cavity; 113-fuel distribution pipe; 120-air intake channel; 121-primary air distribution structure; 122-secondary air distribution structure; 130-mixing channel; 131-rectifier straight section; 132-mixing development section; 133-mixing contraction section; 134-mixing outlet section; 135-air film channel; 140-lobe structure; 141-straight section; 142-lobe section; 143-trailing edge section; 144-fuel interlayer; 145-fuel hole; 146-support rib; 150-mounting flange;

[0036] R10-air development area; R11-connotational air development area;

[0037] R12-outer duct air development area; R20-speed direction change area;

[0038] R21-the area where the velocity direction of the inner channel changes; R22-the area where the velocity direction of the outer channel changes;

[0039] R30-cross jet mixing area; R31-internal channel cross jet mixing area;

[0040] R32-external duct cross jet mixing area; R40-mixed gas vortex system development and contraction area;

[0041] R50-mixed gas rectification straight section area;

[0042] A f1 - Cross-sectional area of ​​the fuel inlet pipe; A f2 - Cross-sectional area of ​​the fuel distribution chamber;

[0043] A f3 - Cross-sectional area of ​​the fuel distribution pipe; A f4 - Cross-sectional area of ​​the fuel interlayer;

[0044] A c -Total area of ​​air film channel; A in -Internal air inlet cross-sectional area;

[0045] A out - Cross-sectional area of ​​the air inlet of the outer duct; A2 / A1-area ratio of the outer duct to the inner duct;

[0046] A ad1 -Total area of ​​the air distribution holes of the primary air distribution structure; A ad2 -Total area of ​​the air distribution holes of the secondary air distribution structure;

[0048] D ad1 - Diameter of the air distribution hole of the first-stage air distribution structure; D ad2 -Diameter of the air distribution holes of the secondary air distribution structure; D1-inner diameter of the entrance of the straight section / mixing development section / mixing contraction section;

[0049] D2-mixing contraction section outlet / mixing outlet section inner diameter; D f - fuel interlayer gap;

[0050] D zcl -Support rib diameter; D-fuel hole diameter;

[0051] L1-straight section length; L2-lobe section length;

[0052] L3-length of the mixing development section; L4-length of the mixing contraction section;

[0053] L5- the length of the mixing and closing section; L1+L2- the length of the straight rectifier section;

[0054] L3+L4+L5-the distance where the fuel and air are actually mixed in the lobe nozzle;

[0055] n1-number of petals; n2-number of supporting ribs;

[0056] v f1 - velocity of the fuel flow in the fuel inlet pipe; v f2 - the velocity of the fuel flow in the fuel distribution chamber;

[0057] v f3 - the velocity of the fuel flow in the fuel distribution pipe; v f4 - the velocity of the fuel flow in the fuel interlayer;

[0058] v f - fuel jet velocity at the fuel hole; v m - Mixed gas jet velocity;

[0059] θ in - the inner tilt angle of the petals of the lobe segment; θ out - The outer inclination angle of the petals of the lobe segment;

[0060] Φ out -Equivalence ratio of the bypass duct; Φ in -Equivalence ratio of the inner Dao. DETAILED DESCRIPTION

[0061] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0062] like Figures 1 to 5 As shown, the present invention provides an axially staged combustion lobe nozzle for a combustion chamber, wherein the lobe nozzle 100 includes a fuel intake passage 110 (i.e., a fuel intake pipe 111, a fuel ring cavity 112 and a fuel distribution pipe 113), an air intake passage 120 (i.e., a primary air distribution structure 121 and a secondary air distribution structure 122), a mixing passage 130 (i.e., a straight rectifying section 131, a mixing development section 132, a mixing contraction section 133, a mixing outlet section 134 and an air film passage 135), a lobe structure 140 (i.e., a straight section 141, a lobe section 142, a trailing edge section 143, a fuel interlayer 144, a fuel hole 145 and a support rib 146) and a mounting flange 150.

[0063] The various components of the axially staged combustion lobe nozzle of this embodiment are described in detail below.

[0064] like Figure 1-Figure 3As shown, the combustion chamber has an axially graded combustion lobe nozzle. The air enters the lobe nozzle mixing channel 130 after being rectified and regulated by the primary air distribution structure 121 and the secondary air distribution structure 122. The primary air distribution structure 121 is evenly arranged with a plurality of diameters D ad1 The total area of ​​the gas distribution holes is A ad1 The secondary air distribution structure 122 evenly arranges a number of ad2 The total area of ​​the gas distribution holes is A ad2 , and D ad1 >D ad2 , A ad1 >A ad2 , so as to ensure that the air flowing into the lobe nozzle is uniform. The sources of air for the lobe nozzle include but are not limited to: air entering from between the combustion chamber casing and the flame tube, air entering from between the combustion chamber casing and the guide bushing, and separate air supply. The fuel enters the fuel ring cavity 112 from the fuel inlet pipe 111. The number of fuel inlet pipes 111 is 1 or more. Then, it passes through a number of fuel distribution pipes 113 evenly distributed circumferentially and enters the fuel interlayer 144 formed by the internal space of the straight section 141, the lobe section 142 and the trailing edge section 143. The cross-sectional shape of the fuel distribution pipe 113 is an elliptical streamline. While distributing the fuel, it rectifies the external duct air to reduce pressure loss. The velocity of the fuel flow in the fuel inlet pipe 111 is v f1 , and 40m / s≤v f1 ≤80m / s, the cross-sectional area of ​​the fuel inlet pipe is A f1 The velocity of the fuel flow in the fuel ring cavity 112 is v f2 , and 20m / s≤v f2 ≤60m / s, the cross-sectional area of ​​the fuel ring cavity 112 is A f2 , and A f1 <A f2 The cross-section of the fuel distribution pipe is an elliptical streamline, and the velocity of the fuel flowing in the fuel distribution pipe is v f3 , and 60m / s≤v f3 ≤120m / s, the cross-sectional area of ​​the fuel distribution pipe is A f3 .

[0065] Among them, the lobe structure 140 and the mixing channel 130 are processed jointly by additive manufacturing technology and mechanical processing technology. The straight section 141, the lobe section 142, the trailing edge section 143, the support rib 146 and the main body of the mixing channel 130 are completed by additive manufacturing technology, and then the surface is mechanically processed to reduce the roughness of the contact surface of the lobe structure 140 with the air, reduce the flow resistance, and avoid low speed on the contact surface; the fuel hole 145 is processed by mechanical processing technology to ensure the dimensional accuracy of the fuel hole 145 and the actual flow rate of the fuel.

[0066] More specifically, Figure 1-Figure 3 As shown, in the lobe nozzle, the mixing channel 130 and the lobe structure 140 together form different air flow areas, including an air development area R10, a velocity direction change area R20, a cross jet mixing area R30, a vortex development and contraction area R40, and a mixed air rectification area R50. The air that passes through the air intake channel 120 and then enters the mixing channel 130 is divided into inner duct air, inner duct air development area R11, inner duct velocity direction change area R21 and inner duct cross jet mixing area R31, and outer duct air, outer duct air development area R12, outer duct velocity direction change area R22 and outer duct cross jet mixing area R32. The flow rates of the inner and outer duct air are distributed according to the area ratio A2 / A1 of the outer duct to the inner duct. The air in the inner duct air development area R11 develops stably in the straight section 141 and then changes its air speed direction after passing through the inner duct speed direction changing area R21; the air in the outer duct air development area R12 develops stably outside the straight section 141 and then changes its air speed direction after passing through the outer duct speed direction changing area R22. After the fuel in the fuel interlayer 144 flows out from the outlet of the fuel hole 145, it forms cross jets with the inner duct air and the outer duct air of the lobe, forming inner duct fuel-air mixed gas in the inner duct cross jet mixing area R31; in the outer duct cross jet mixing area R32, the outer duct fuel-air mixed gas, due to the change in the direction of the inner and outer duct air speeds, the inner duct fuel-air mixed gas and the outer duct fuel-air mixed gas produce relative displacement in the vortex system development and contraction area, forming vortex systems such as flow vortex and orthogonal vortex. The formation and development of the vortex system improves the mixing effect of fuel and air. At the same time, the inner and outer duct mixed gas development and rectification of the lobe nozzle inner and outer duct mixed gas, the vortex system is constantly broken during the development process, which makes the mixing uniformity of fuel and air rapidly improved, and reduces the mixing unevenness of fuel and air to below 0.05 within a limited distance.

[0067] In this embodiment, if Figure 1-Figure 3 As shown, the mixing channel 130 includes a straight rectifying section 131, a mixing development section 132, a mixing contraction section 133, a mixing outlet section 134, and an air film channel 135, and the lobe structure 140 includes a straight section 141, a lobe section 142, a trailing edge section 143, a fuel interlayer 144, a fuel hole 145, and a support rib 146.

[0068] Among them, the straight section 131 is connected to the secondary air distribution structure 122, and its inner diameter is D1, and 20mm≤D1≤120mm, and its length is L1+L2, and L1+L2≥20mm; the mixing development section 132 is located after the straight section 131, and provides a mixing development area for the air and fuel of the lobe nozzle, and its inner diameter is D1 and its length is L3; the mixing contraction section 133 is located after the mixing development section 132, and is an axial graded nozzle outlet velocity that adapts to the velocity of the mainstream smoke in the combustion chamber to meet the jet momentum ratio; Its contraction curve is the Vito-Sinsky curve, and the contraction process of the mixed gas is uniform and smooth; its inner diameter at the inlet is D1, the diameter at the outlet is D2, and the length is L4; the mixing outlet section 134 is located after the mixing contraction section 133, its inner diameter is D2, and 10mm≤D2≤80mm, and its length is L5; the mixing development section 132, the mixing contraction section 133 and the mixing outlet section 134 are the actual mixing distances of the lobe nozzle fuel and air, and its length is L3+L4+L5, and L3+L4+L5≥0.5×D2.

[0069] The rectifier straight section 131 and the flat section 141 divide the air entering the lobe nozzle into an inner channel and an outer channel. The inlet cross-sectional area of ​​the inner channel is A. in The cross-sectional area of ​​the outer duct entrance is A out The area ratio of the outer duct to the inner duct is A out / A in , and 0.2≤A out / A in ≤5. A support rib 146 is arranged inside the fuel interlayer 144 to improve the strength of the lobe structure 140; the gap of the fuel interlayer 144 is D f , and 0.5mm≤D f ≤2mm, D f is a constant value or a variable value; the diameter of the support rib 146 is D zcl , the number is n2, and 0.5mm≤D zcl ≤2mm, n1≤n2≤5n1; the support ribs 146 are evenly arranged to ensure the strength of the lobe structure 140 and the flow rate and speed of the fuel in the fuel interlayer 144; the speed of the fuel flow in the fuel interlayer 144 is v f4 , and 20m / s≤v f4 ≤60m / s, the cross-sectional area of ​​the fuel interlayer is A f4 , and A f3 f4 ;

[0070] In this embodiment, the mixed gas jet velocity v of the axial staged combustion lobe nozzle is set m The jet velocity v of the fuel in the fuel hole 145 is 40m / s to 150m / s. f ​The speed is 120m / s to 300m / s, and the mixing unevenness of fuel and air at the outlet of the lobe nozzle is less than 0.05.

[0071] In order to protect the safety of the nozzle under high temperature conditions and adjust the lifting height of the axial staged combustion flame, a number of air film channels 135 are evenly arranged on the wall of the straight section 131, the mixing development section 132, the mixing contraction section 133 and the mixing outlet section 134. The air film channels 135 are inlet by the air inside the combustion chamber. The air flow direction of the air film channel 135 outlet is the same as the flow direction of the mixed air. It is used for cooling the mixing contraction section of the lobe nozzle and lifting the flame after the axial staged combustion. The cross-sectional shape of the air film channel 135 is a "capsule shape" with a total area of ​​A. c , total area of ​​air film channel 135 A c It accounts for 2-10% of the air intake area of ​​the axial grading nozzle, so as to control the air velocity in the air film channel not to be greater than the outlet velocity of the lobe nozzle.

[0072] In this embodiment, if Figure 4 and Figure 5 As shown, the common internal passage of the straight section 141, lobe section 142 and trailing edge section 143 of the lobe structure 140 forms the fuel interlayer 144. The fuel supplied by the fuel distribution pipe enters the fuel hole 145 through the fuel interlayer 144 and is mixed with the air.

[0073] The inner tilt angle of the lobe segment 142 is θ in and the outer inclination angle is θ out , and 10°≤θ in ≤30°, 10°≤θ out ≤30°, the lobe section 142 is composed of a plurality of petals with wave crests facing outward, the number of petals is n1, and n1 ≥ 3; the trailing edge section 143 is streamlined to avoid the formation of a rear step flow at the trailing edge;

[0074] The fuel holes 145 are arranged at the connection between the lobe section 142 and the trailing edge section 143. The number of rows of the fuel holes 145 arranged in the air flow direction is 1-5 rows. The fuel holes are located in the area where the vortex system behind the lobe interacts. The diameter of the fuel holes is D, and 0.5mm≤D≤3mm. The outflow direction of the fuel holes 145 includes the inner duct and the outer duct of the lobe structure 140. The area of ​​the fuel holes 145 on the inner and outer ducts is proportional to the air area of ​​the inner and outer ducts. The equivalent ratio of the fuel to the air in the outer duct of the lobe nozzle is Φ out , the equivalent ratio of fuel to air is Φ in , and Φ out ≤Φ in , thereby achieving stable combustion after axial classification and mixing with mainstream smoke.

[0075] In summary, the axially graded combustion lobe nozzle 100 of the combustion chamber of the present invention, in order to achieve rapid and uniform mixing of fuel and air in a limited space, fully utilizes the characteristics of the lobe structure 140 and its trailing edge fold formation to improve the development of the mixing vortex system, and at the same time, under the action of multiple fuel holes 145 and air cross jets, the mixing unevenness at the lobe nozzle outlet is greatly reduced. Finally, a mixing contraction section 133 and a mixing outlet section 134 are added to the outlet of the nozzle mixing channel 130 to form a vortex system development contraction area R40 and a rectifier straight section area R50, so that the mixed gas of the axially graded nozzle is uniformly contracted and stably developed. Therefore, the present invention can achieve rapid mixing of fuel and air in a limited distance while ensuring that the occupied space is small, thereby meeting the requirements of stable and sufficient combustion and pollutant emissions of the axially graded combustion chamber.

[0076] The above embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Claims

1. A combustion chamber axially staged combustion lobe nozzle, comprising a lobe nozzle (100), characterized in that: The lobe nozzle (100) comprises a fuel intake passage (110), an air intake passage (120), a mixing passage (130), a lobe structure (140) and a mounting flange (150); the top of the lobe nozzle (100) is provided with an air intake passage (120); the side of the lobe nozzle (100) is connected to the fuel intake passage (110); the interior of the lobe nozzle (100) is provided with a mixing passage (130); the interior of the mixing passage (130) is provided with a lobe structure (140); the lobe structure (140) is used to form a vortex system that is beneficial to improving the mixing of air and fuel; The fuel intake passage (110) comprises a fuel intake pipe (111), a fuel annular cavity (112) and a fuel distribution pipe (113); the fuel distribution pipe (113) is connected and fixed to the lobe structure (140), and the fuel annular cavity (112) is arranged at one end inside the fuel intake pipe (111); the fuel enters the fuel annular cavity (112) from the fuel intake pipe (111), and then enters the lobe structure (140) through a plurality of fuel distribution pipes (113) evenly distributed in the circumferential direction; The air intake channel (120) comprises a primary air distribution structure (121) and a secondary air distribution structure (122); the air enters the lobe nozzle mixing channel (130) after being rectified and speed-regulated by the primary air distribution structure (121) and the secondary air distribution structure (122); The mixing channel (130) comprises a straight flow section (131), a mixing development section (132), a mixing contraction section (133), a mixing outlet section (134) and an air film channel (135); a plurality of air film channels (135) are evenly arranged on the wall surfaces of the straight flow section (131), the mixing development section (132), the mixing contraction section (133) and the mixing outlet section (134) for cooling the mixing contraction section of the lobe nozzle and lifting the flame after axial staged combustion; The lobe structure (140) comprises a straight section (141), a lobe section (142), a trailing edge section (143), a fuel interlayer (144), a fuel hole (145) and a supporting rib (146); the straight section (141) is connected to the fuel distribution pipe (113) to provide a fuel channel for the fuel interlayer (144), and the length thereof is L1; the lobe section (142) is composed of a plurality of petals with the wave crest facing outward, the number of petals is n1, and n1 is ≥3, and the length of the lobe section (142) is L2; ​​the trailing edge section (143) is streamlined to avoid the formation of a rear step flow at the trailing edge, and the length of the trailing edge section (143) is L 3。 2. The combustion chamber axially staged combustion lobe nozzle according to claim 1, characterized in that: The number of the fuel inlet pipes (111) is one or more, and the cross-sectional shape of the fuel distribution pipe (113) is an elliptical streamline, which rectifies the external bypass air while distributing the fuel to reduce the pressure loss; the speed of the fuel flow in the fuel inlet pipe (111) is v f1 , and 40m / s≤v f1 ≤80m / s, the cross-sectional area of ​​the fuel inlet pipe is A f1 The velocity of the fuel flow in the fuel ring cavity (112) is v f2 , and 20m / s≤v f2 ≤60m / s, the cross-sectional area of ​​the fuel ring cavity (112) is A f2 , and A f1 <A f2 The cross-sectional shape of the fuel distribution pipe (113) is an elliptical streamline, and the velocity of the fuel flow in the fuel distribution pipe is v f3 , and 60m / s≤v f3 ≤120m / s, the cross-sectional area of ​​the fuel distribution pipe is A f3 .

3. The combustion chamber axially staged combustion lobe nozzle according to claim 2, characterized in that: The primary air distribution structure (121) is evenly arranged with a plurality of ad1 The total area of ​​the gas distribution holes is A ad1 The secondary air distribution structure (122) is evenly arranged with a plurality of diameters D ad2 The total area of ​​the gas distribution holes is A ad2 , and D ad1 >D ad2 , A ad1 >A ad2 The primary air distribution structure (121) and the secondary air distribution structure (122) are used to make the air entering the lobe nozzle (100) flow evenly. The air sources of the lobe nozzle (100) include: air entering from between the combustion chamber casing and the flame tube, air entering from between the combustion chamber casing and the guide bushing, and separate air supply.

4. The combustion chamber axially staged combustion lobe nozzle according to claim 3, characterized in that: The straight rectifying section (131) is connected to the secondary air distribution structure (122), and has an inner diameter of D1, and 20 mm ≤ D1 ≤ 120 mm, and a length of L1 + L2, and L1 + L2 ≥ 20 mm; the mixing development section (132) is located after the straight rectifying section (131), and is used to provide a mixing development area for the air and fuel of the lobe nozzle, and has an inner diameter of D1 and a length of L3; the mixing contraction section (133) is located after the mixing development section (132), and is used to adapt the outlet velocity of the axially graded nozzle to the velocity of the mainstream smoke in the combustion chamber, so as to meet the jet momentum ratio; Its contraction curve is the Vito-Sinsky curve, and the contraction process of the mixed gas is uniform and stable; The inner diameter at the inlet is D1, the diameter at the outlet is D2, and the length is L4; the mixing outlet section (134) is located after the mixing contraction section (133), the inner diameter is D2, and 10mm≤D2≤80mm, and the length is L5; The mixing development section (132), the mixing contraction section (133) and the mixing outlet section (134) are the distances of the actual mixing of the fuel and the air in the lobe nozzle, and their lengths are L3+L4+L5, and L3+L4+L5≥0.5×D2.

5. The combustion chamber axially staged combustion lobe nozzle according to claim 4, characterized in that: The air film channel (135) is inletted with air from the combustion chamber. The air flow direction at the outlet of the air film channel (135) is the same as the flow direction of the mixed air. The cross-sectional shape of the air film channel (135) is a "capsule shape" with a total area of ​​A. c , the total area A of the air film channel (135) c It accounts for 2-10% of the air intake area of ​​the axial grading nozzle and is used to control the air velocity in the air film channel to be no greater than the outlet velocity of the lobe nozzle.

6. The combustion chamber axially staged combustion lobe nozzle according to claim 1, characterized in that: The rectifying straight section (131) and the flat section (141) divide the air entering the lobe nozzle into an inner channel and an outer channel. The inlet cross-sectional area of ​​the inner channel is A. in The cross-sectional area of ​​the duct entrance is A out The area ratio of the outer duct to the inner duct is A out / A in , and 0.2≤A out / A in ≤5; a support rib (146) is arranged inside the fuel interlayer (144) to improve the strength of the lobe structure (140); the gap between the fuel interlayer (144) is D f , and 0.5mm≤D f ≤2mm, D f is a constant value or a variable value; the diameter of the support rib (146) is D zcl , the number is n2, and 0.5mm≤D zcl ≤2mm, n1≤n2≤5n1; the support ribs (146) are evenly arranged to ensure the strength of the lobe structure (140) and the flow rate and speed of the fuel in the fuel interlayer (144); the speed of the fuel flow in the fuel interlayer (144) is v f4 , and 20m / s≤v f4 ≤60m / s, the cross-sectional area of ​​the fuel interlayer is A f4 , and A f3 f4 ; Set the mixed gas jet velocity v of the axial staged combustion lobe nozzle m 40m / s~150m / s;​ The fuel hole (145) is arranged at the connection between the lobe section (142) and the trailing edge section (143); the outflow direction of the fuel hole (145) includes the inner channel and the outer duct of the lobe structure; the areas of the fuel holes on the inner channel and the outer duct are proportional to the air areas of the inner channel and the outer duct; the equivalent ratio of the outer duct is Φ out , the equivalent ratio of the internal Dao is Φ in , and Φ out ≤Φ in ; Used to achieve stable combustion after axial classification and mainstream smoke mixing; the fuel hole (145) is located in the area where the vortex system behind the lobe interacts, the diameter of the fuel hole (145) is D, and 0.5mm≤D≤3mm, the fuel jet velocity v of the fuel hole (145) f The speed is 120m / s to 300m / s, the number of rows of the fuel holes (145) arranged in the air flow direction in the lobe is 1 to 5 rows; the mixing unevenness of the fuel and air at the lobe nozzle outlet is less than 0.05; The straight section (141), the lobe section (142) and the trailing edge section (143) of the lobe structure (140) form a common internal channel of the fuel interlayer (144). The fuel supplied by the fuel distribution pipe (113) enters the fuel hole (145) through the fuel interlayer (144) and is mixed with the air. The inner side inclination angle of the lobe section (142) is θ in and the outer inclination angle is θ out , and 10°≤θ in ≤30°, 10°≤θ out ≤30°.

7. The combustion chamber axially staged combustion lobe nozzle according to claim 6, characterized in that: The lobe structure (140) and the mixing channel (130) are processed by additive manufacturing technology and mechanical processing technology. The straight section (141), the lobe section (142), the trailing edge section (143), the support rib (146) and the main body of the mixing channel (130) are completed by additive manufacturing technology, and then the surface is processed by mechanical processing, so as to reduce the roughness of the contact surface of the lobe structure (140) and the air, reduce the flow resistance, and avoid low speed on the contact surface; the fuel hole (145) is processed by mechanical processing technology to ensure the dimensional accuracy of the fuel hole (145) and the actual flow rate of the fuel.

8. The combustion chamber axially staged combustion lobe nozzle according to claim 7, characterized in that: The mixing channel (130) and the lobe structure (140) in the lobe nozzle jointly form different air flow regions, including an air development region (R10), a velocity direction change region (R20), a cross jet mixing region (R30), a vortex system development and contraction region (R40), and a mixed air rectification region (R50); The air that passes through the air intake channel (120) and then enters the mixing channel (130) is divided into inner duct air and outer duct air; the inner duct air includes an inner duct air development area (R11), an inner duct velocity direction change area (R21) and an inner duct cross jet mixing area (R31); the outer duct air includes an outer duct air development area (R12), an outer duct velocity direction change area (R22) and an outer duct cross jet mixing area (R32); The flow rates of the inner and outer duct air are distributed according to the area ratio A2 / A1 of the outer duct to the inner duct. The air in the inner duct air development area (R11) develops stably in the straight section (141) and then changes its air speed direction after passing through the inner duct speed direction change area (R21); the air in the outer duct air development area (R12) develops stably outside the straight section (141) and then changes its air speed direction after passing through the outer duct speed direction change area (R22). After the fuel in the fuel interlayer (144) flows out from the outlet of the fuel hole (145), it forms cross jets with the inner duct air of the lobe and the outer duct air of the lobe, forming an inner duct fuel-air mixed gas in the inner duct cross jet mixing area (R31); in the outer duct cross jet mixing area (R32), the outer duct fuel-air mixed gas, due to the change in the direction of the inner and outer duct air velocities, the inner duct fuel-air mixed gas and the outer duct fuel-air mixed gas produce relative displacement in the vortex system development and contraction area, forming a stream vortex and an orthogonal vortex. The formation and development of the stream vortex and the orthogonal vortex improve the mixing effect of the fuel and air; at the same time, the inner and outer duct mixed gas of the lobe nozzle are rectified, and the stream vortex and the orthogonal vortex are continuously broken during the development process, which makes the mixing uniformity of the fuel and air rapidly improved, and the mixing unevenness of the fuel and air is reduced to below 0.05 within a limited distance.

9. The combustion chamber axially staged combustion lobe nozzle according to claim 1, characterized in that: The outer shell of the lobe nozzle (100) and the mounting flange (150) are integrated, and the lobe nozzle (100) is connected and fastened to the axial staged combustion chamber via the mounting flange (150).

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