Thermo-acoustic oscillation passive control axial staged combustion chamber

Abstract

The invention discloses a thermo-acoustic oscillation passive control axial grading combustion chamber which comprises a fuel gas distribution pipe, a head gas distribution cavity, a cooling end plate, a weak rotation micro-mixing on-duty nozzle, a direct injection micro-mixing main combustion nozzle, an axial grading nozzle, a flame tube, a flow guide bushing and an outer casing. Due to the combustion arrangement of head micro-mixing combustion and axial staged combustion, fuel gas distribution is optimized; the ignition / load-per-liter combustion stability of the combustion chamber is realized through the weak-rotation micro-mixing on-duty nozzle; the axial grading nozzle adopts a lobe structure to enhance fuel and air mixing; the cooling hole structure of the axial grading nozzle is optimized, and the effect of restraining thermo-acoustic oscillation is achieved; and the opening positions of the axial grading windward side and leeward side cooling holes are improved, so that flame lifting under the high-hydrogen-content fuel is realized. According to the axial grading combustion chamber arrangement mode, the residence time of smoke in a high-temperature area is shortened, NOx pollutant emission of the combustion chamber is reduced, and the requirement for efficient, stable and low-emission operation under the condition of high-hydrogen-content fuel is integrally met.

Description

Technical Field

[0001] The invention relates to the technical field of gas turbines, and in particular to an axially staged combustion chamber with passive control of thermoacoustic oscillation. Background Art

[0002] Fuel applicability, wide load regulation, and high efficiency, stability, and low emissions are the main development directions of gas turbines. Hydrogen fuel, as a green energy source, can effectively reduce carbon emissions, but hydrogen fuel puts forward more stringent requirements on the safety and emissions of the combustion chamber, especially the thermoacoustic oscillation characteristics are more obvious. Multi-nozzle array combustion is one of the most promising combustion technologies. Under high hydrogen content fuel, it increases the jet nozzle speed to reduce the risk of nozzle flashback while shortening the overall length of the combustion chamber to achieve the requirements of controlling pollutant emissions. However, the combustion organization of high-speed jets makes the combustion chamber ignition and load increase process combustion chamber stability problematic. The axial staged combustion method can effectively broaden the load regulation range of the combustion chamber, shorten the residence time of high-temperature flue gas in the combustion chamber to control pollutant emissions, and change the spatial position of the flame in the combustion chamber, thereby realizing the control of the thermoacoustic oscillation of the combustion chamber, but the nozzle cooling problem in the outlet area of ​​the axial staged nozzle needs to be solved. Therefore, it is urgent to explore a new design scheme for passive control of thermoacoustic oscillation in the axial staged combustion chamber. Summary of the invention

[0003] In order to at least partially solve at least one of the above-mentioned technical problems, the present invention provides an axially staged combustion chamber with passive control of thermoacoustic oscillation, which optimizes fuel gas distribution through the combustion organization mode of head micro-mixing combustion and axial staged combustion to achieve the combustion stability of the gas turbine combustion chamber under high hydrogen content fuel; weak swirl micro-mixing duty nozzles are used to achieve the ignition / load increase combustion stability of the combustion chamber, and the radial non-equidistant arrangement of direct injection micro-mixing main combustion nozzle combination is used to enhance the overall load of the combustion chamber and enhance the combustion stability through the local reflow zone; axially staged nozzles are added, and the lobe structure is used to enhance the fuel-air mixing performance, and the position of the heat release zone is adjusted to change the thermoacoustic oscillation characteristics of the combustion chamber; the cooling hole structure of the axially staged nozzle is optimized to form a Helmholtz resonator of a specific frequency band to achieve the effect of suppressing thermoacoustic oscillation; the opening position of the axially staged windward and leeward cooling holes is improved to achieve flame lifting under high hydrogen content fuel and ensure the safety of the combustion chamber. The thermoacoustic oscillation suppression effect of the combustion chamber under high hydrogen content fuel is achieved by optimizing the fuel gas distribution mode, the radial arrangement of the micro-mixing nozzles, the axially staged combustion arrangement, and the axially staged nozzle cooling hole structure. The axially graded combustion chamber arrangement shortens the residence time of flue gas in the high-temperature zone, reduces the NOx pollutant emissions from the combustion chamber, and overall meets the requirements of efficient, stable and low-emission operation under high-hydrogen fuel.

[0004] In order to achieve the above object, the present invention adopts the following technical scheme:

[0005] A thermoacoustic oscillation passively controlled axially staged combustion chamber, comprising a fuel distribution pipe, a head distribution cavity, a cooling end plate, a weak swirl micro-mixing duty nozzle, a direct injection micro-mixing main combustion nozzle, an axially staged nozzle, a flame tube, a guide bushing and an outer casing;

[0006] The fuel distribution pipe is arranged at the head and middle of the combustion chamber, and is used for partitioned and graded fuel distribution of different fuels;

[0007] The head gas distribution cavity is arranged at the rear end of the fuel gas distribution pipe of the combustion chamber head, used for further uniform gas distribution of air and fuel, and is welded to the fuel gas distribution pipe of the combustion chamber head;

[0008] The cooling end plate is used to cool the head of the combustion chamber. The circumference of the cooling end plate is connected to the flame tube through a retaining spring. The cooling end plate is provided with mounting holes for the weak swirl micro-mixing service nozzle and the direct injection micro-mixing main combustion nozzle, which are used for the installation and positioning of the weak swirl micro-mixing service nozzle and the direct injection micro-mixing main combustion nozzle;

[0009] One end of the weak swirl and micro-mixing nozzle is installed on the head gas distribution cavity, and the other end of the weak swirl and micro-mixing nozzle is connected to the cooling end plate;

[0010] The direct injection mild-mix main combustion nozzles are radially arranged in stages and zones on the cooling end plate;

[0011] One end of the axial grading nozzle is mounted on the outer casing via a flange, and the other end of the axial grading nozzle is connected to the flame tube via a multi-cooling chamber floating ring of the axial grading nozzle, and the axial grading nozzle is evenly distributed along the circumference of the flame tube;

[0012] One end of the flame tube is connected to the cooling end plate;

[0013] The guide bushing is clamped and installed in position by the head gas distribution cavity and the outer casing, and the guide bushing and the flame tube form an air flow channel;

[0014] The outer casing and the head gas distribution cavity are installed and positioned.

[0015] Furthermore, the fuel distribution pipe includes a main combustion stage fuel distribution pipe A, a duty stage fuel distribution pipe, a main combustion stage fuel distribution pipe B and an axially graded fuel distribution pipe. The duty stage fuel distribution pipe is used for the fuel supply of the weak swirl micro-mixing duty nozzle. The main combustion stage fuel distribution pipe A and the main combustion stage fuel distribution pipe B are used for the fuel supply of the central area and the surrounding area of ​​the direct injection micro-mixing main combustion nozzle. The axially graded fuel distribution pipe is used for the fuel supply of the axially graded nozzle. The fuel distribution pipe at the head of the combustion chamber is integrally formed with the head distribution cavity by a brazing process.

[0016] The duty class nozzle fuel distribution pipe and the main combustion stage fuel distribution pipe A share a fuel buffer cavity, and the cavity is distributed through a metal plate. At the same time, multiple fuel distribution branch pipes are added to further increase the uniformity of fuel distribution.

[0017] Furthermore, the main combustion stage fuel distribution pipe B adopts a plurality of distribution pipes evenly distributed along the circumferential direction to increase the flexibility of fuel distribution; the axially graded fuel distribution pipe adopts a ring pipe and a distribution branch pipe to increase the uniformity of fuel distribution.

[0018] Furthermore, the head gas distribution cavity includes a head air gas distribution cavity, a head fuel gas distribution cavity and a gas distribution cavity metal plate, and the whole cavity is divided into multiple areas by the gas distribution cavity metal plate, and the whole cavity is printed and formed in one piece by a brazing process;

[0019] The head air distribution cavity distributes air evenly through a three-stage air distribution plate, wherein the first-stage air distribution plate and the second-stage air distribution plate are arranged axially, and the third-stage air distribution plate is arranged circumferentially. Air distribution holes are evenly distributed on the three-stage air distribution plate, and the aperture and number of the air distribution holes on the air distribution plates at each level decrease along the air flow. The multi-cavity structure of the head air distribution cavity can form a sound absorption effect of a porous plate, which is beneficial to control the thermoacoustic instability of the combustion chamber;

[0020] The head fuel distribution cavity is divided into a main combustion stage fuel distribution cavity A and a main combustion stage fuel distribution cavity B by a central metal plate, and the uniformity and flexibility of fuel distribution are increased by fuel cavity partitioning.

[0021] Furthermore, the cooling end plate is spaced apart from the front metal plate of the head air distribution cavity by a certain height, and air enters along the circumferential direction.

[0022] Furthermore, the weak swirl micro-mixing service nozzles are evenly distributed in the radial direction of the cooling end plate, and the center distance of the weak swirl micro-mixing service nozzles is S1; the weak swirl micro-premixing service nozzles include swirl blades, a mixing tube and a central fuel supply pipe, and the outer diameter of the mixing tube is , the inner diameter is ; The swirl blade angle is ,and The distance between the swirl blade and the nozzle outlet is L z2 , and 3 ≤L z2 ≤5 The central fuel supply pipe is designed with non-uniform diameters, and its intake side diameter is ,and , the diameter of the outlet side is ,and ; The length of the center fuel pipe expansion section is L z1 , and 1 / 2L z2 ≤L z1≤2 / 3L z2 ; The diameter change angle of the central fuel supply pipe is ,and The mixing tube outlet is designed as a cone-bowl, and its outlet semi-expansion angle is ,and The central fuel supply pipe has N fuel holes evenly distributed along the circumferential direction near the nozzle outlet area, N ≥ 6, the fuel passes through the fuel hole at V2, and V2 ≥ 160 m / s; the opening direction of the fuel hole has two angles, the angle along the radial direction is ,and , the angle along the axial direction is ,and ; The distance between the fuel hole and the nozzle outlet is L z3 , and 1mm≤L z3 ≤5mm.

[0023] Furthermore, the axially graded nozzle also includes a lobe-type nozzle, which controls the emission of pollutants in the combustion chamber by developing a vortex system of orthogonal vortices and streamwise vortices to achieve rapid mixing of a non-swirl structure. The distance between the axially graded nozzle and the cooling end plate is L1, the length of the flame tube is L2, and 1 / 2L2≤L1≤4 / 5L2. The multi-cooling cavity floating ring adopts a Helmholtz resonator cooling cavity design.

[0024] Furthermore, the direct injection micro-mixing main combustion nozzle is evenly arranged in a square in the central area of ​​the cooling end plate, the center distance of the direct injection micro-mixing main combustion nozzle is S2, and the area close to the flame tube wall is circumferentially symmetrically distributed to increase the combustion chamber load. A gap is left between the direct injection micro-mixing main combustion nozzle and the mounting hole of the cooling end plate to form a cooling hole for cooling the direct injection micro-mixing main combustion nozzle. The distance between the outlet of the direct injection micro-mixing main combustion nozzle and the cooling end plate is H. j , and 5mm≤H j ≤15mm.

[0025] Furthermore, the flame tube adopts rib cooling and air film cooling structure.

[0026] Furthermore, the air flow passage ensures that the air velocity satisfies 30m / s≤V1≤60m / s, thereby ensuring the cooling and air distribution of the flame tube.

[0027] It can be seen from the above technical solutions that the thermoacoustic oscillation passively controlled axial staged combustion chamber of the present invention has at least one or part of the following beneficial effects:

[0028] (1) The fuel distribution pipe and the head distribution cavity are designed as one piece by brazing process, which ensures the design accuracy and improves the uniformity of the distribution. The multi-cavity orifice plate structure has the effect of silencing and absorbing sound, reducing the thermal acoustic instability of the combustion chamber.

[0029] (2) The primary combustion zone uses a combination of a weak swirl micro-mixing service nozzle and a direct injection micro-mixing main combustion nozzle. By controlling the swirl number and size of the service nozzle, it is ensured that the service nozzle will not affect the flow field and flame morphology of the direct injection micro-mixing main combustion nozzle, thereby ensuring the stability of combustion during the ignition and load increase of the combustion chamber;

[0030] (3) The axial staged combustion method effectively broadens the range of combustion chamber load adjustment, changes the spatial distribution of the heat release area in the combustion chamber, modulates the interaction between fuel and flame, and thus controls the thermoacoustic oscillation characteristics of the combustion chamber;

[0031] (4) The air film cooling structure of the axially graded nozzle adopts the structural design of the Helmholtz resonator. While cooling the outlet of the axially graded nozzle, it effectively controls the thermoacoustic oscillation of the combustion chamber and ensures the safe and stable operation of the combustion chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic structural diagram of an axially staged combustion chamber passively controlled by thermoacoustic oscillation according to an embodiment of the present invention;

[0033] Figure 2 It is a right view of the axially staged combustion chamber for passive control of thermoacoustic oscillation according to an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of the weak swirl micro-mixing nozzle structure;

[0035] Figure 4 Schematic diagram of the structure of the axially graded nozzle.

[0036] The meanings of the reference numerals are as follows:

[0037] 100-Axially staged combustion chamber with passive control of thermoacoustic oscillations;

[0038] 110- fuel distribution pipe; 111- main combustion stage fuel distribution pipe A;

[0039] 112-duty class fuel distribution pipe; 113-main combustion class fuel distribution pipe B;

[0040] 114-axially graded fuel distribution pipe; 120-head distribution cavity;

[0041] 121-head air distribution chamber; 122-head fuel distribution chamber;

[0042] 123-air distribution cavity metal plate; 124-front metal plate;

[0043] 125-first-level air distribution plate; 126-second-level air distribution plate;

[0044] 127- three-stage air distribution plate; 130- cooling end plate;

[0045] 140-weak swirl micro-mixing nozzle; 141-swirl blade;

[0046] 142-mixing pipe; 143-central fuel supply pipe;

[0047] 150-direct injection mild-mix main combustion nozzle; 160-axial staged nozzle;

[0048] 161-lobe type nozzle; 162-multi-cooling chamber floating ring;

[0049] 170-flame tube; 180-guide bushing;

[0050] 190 - outer receiver;

[0051] D zw -Outer diameter of mixing tube; D zn -Inner diameter of the mixing tube;

[0052] D zf - Diameter of the central fuel supply pipe on the air inlet side; D zd - Diameter of the central fuel supply pipe on the outlet side;

[0053] L1-the length of the flame tube; L2-the distance between the axial grading nozzle and the cooling end plate;

[0054] L z1 - Length of the expanded section of the central fuel pipe; L z2 - Distance between swirl blade and nozzle outlet;

[0055] L z3 -The distance between the fuel hole and the nozzle outlet;

[0056] H j -The distance between the outlet of the direct injection mild-mix main combustion nozzle and the cooling end plate;

[0057] S1-the center distance of the weak swirl mild mixing duty nozzle; S2-the center distance of the direct injection mild mixing main combustion nozzle;

[0058] -Swirl blade angle; -The angle of change in the diameter of the central fuel supply pipe;

[0059] - outlet semi-expansion angle; - radial angle of the fuel holes;

[0060] - axial direction of the fuel holes;

[0061] V 1- Air velocity; V 2- The speed at which fuel passes through the fuel holes. DETAILED DESCRIPTION

[0062] In order to effectively solve the problem of thermoacoustic oscillation in the combustion chamber of a gas turbine under high-hydrogen-content fuel, the present invention adopts the combustion organization mode of head micro-mixing combustion and axial staged combustion, optimizes fuel gas distribution, adopts weak-swirl micro-mixing duty nozzle to achieve the ignition / load-increasing combustion stability of the combustion chamber, and radially arranges a combination of direct-injection micro-mixing main combustion nozzles at non-equidistant intervals to enhance the overall load of the combustion chamber and enhances the combustion stability through a local reflow zone. An axially staged nozzle is added, and a lobe structure is adopted to enhance the fuel-air mixing performance. At the same time, the position of the heat release zone is adjusted to change the thermoacoustic oscillation characteristics of the combustion chamber, the cooling hole structure of the axially staged nozzle is optimized, and a Helmholtz resonator of a specific frequency band is formed to achieve the effect of suppressing thermoacoustic oscillation, and the opening positions of the axially staged windward and leeward cooling holes are improved to achieve flame lift under high-hydrogen-content fuel and ensure the safety of the combustion chamber. By optimizing the fuel distribution method, radial arrangement of the micro-mixing nozzle, axial staged combustion arrangement, and axial staged nozzle cooling hole structure modeling, the present invention can achieve efficient and stable combustion under high hydrogen content fuel in the combustion chamber. The axially staged combustion chamber arrangement shortens the residence time of the flue gas in the high temperature zone and reduces the NOx pollutant emissions in the combustion chamber, thereby achieving the overall requirements of efficient, stable and low emission operation under high hydrogen content fuel.

[0063] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. It should be noted in advance that the directional terms mentioned in the embodiments of the present invention, such as "upper", "lower", "front", "back", "left", "right", etc., are only referenced to the directions of the accompanying drawings and are not intended to limit the scope of protection of the present invention.

[0064] In an exemplary embodiment of the present invention, Figures 1 to 4 As shown, the present invention provides an axially staged combustion chamber 100 with passive control of thermoacoustic oscillation, comprising: a fuel distribution pipe 110, a head distribution cavity 120, a cooling end plate 130, a weak-swirl micro-mixing service nozzle 140, a direct-injection micro-mixing main combustion nozzle 150, an axially staged nozzle 160, a flame tube 170, a guide bushing 180, and an outer casing 190.

[0065] The fuel distribution pipe 110 includes a main combustion stage fuel distribution pipe A 111, a duty stage fuel distribution pipe 112, a main combustion stage fuel distribution pipe B 113 and an axially graded fuel distribution pipe 114. The head distribution cavity 120 includes a head air distribution cavity 121, a head fuel distribution cavity 122 and a distribution metal plate 123. The weak swirl micro-mixing duty nozzle 140 includes a swirl vane 141, a mixing tube 142 and a central fuel supply pipe 143. The axially graded nozzle 160 includes a lobe-type nozzle 161 and a multi-cooling chamber floating ring 162.

[0066] The various components of the thermoacoustic oscillation passive control of axial staged combustion in this embodiment are described in detail below.

[0067] like Figure 1 As shown, in the thermoacoustic oscillation passively controlled axially staged combustion chamber 100, air is fed in countercurrently, enters through the annular channel formed by the flame tube 170 and the guide bushing 180, and enters the flame tube 170 in five parts, including: film cooling air of the flame tube 170, combustion air of the axially staged nozzle 160, cooling air of the axially staged nozzle 160, cooling air of the cooling end plate 130, and combustion air through the head gas distribution cavity 120. The combustion air of the axially staged nozzle 160 accounts for 20% of the total air volume, and the film cooling air of the flame tube 170 and the cooling air of the cooling end plate 130 account for 15% of the total air volume. Figure 1 In the figure, V1 is the air velocity. The fuel distribution pipe 110 and the head distribution cavity 120 are combined by machining and brazing processes to ensure the machining accuracy of the fuel holes of the weak-swirl micro-mixing duty nozzle 140 and the fuel holes of the direct-injection micro-mixing main combustion nozzle 150; the head distribution cavity 120 is divided into the head air distribution cavity 121 and the head fuel distribution cavity 122 by a multi-layer distribution metal plate 123, and the brazing process can ensure the sealing of the fuel head fuel distribution cavity 122. The head distribution cavity 120 is connected to the outer casing 190 by bolts, and the guide bushing 180 is clamped and positioned by the head distribution cavity 120 and the outer casing 190.

[0068] The outer casing 190 is provided with a mounting base for the axially graded nozzle 160, and the axially graded nozzle 160 is connected and fixed to the outer casing 190 by screws. The cooling end plate 130 is connected to the head gas distribution cavity 120 by screws, which facilitates the subsequent disassembly and replacement of the cooling end plate 130. The flame tube 170 is fixed to the cooling end plate 130 by a retaining spring, and the flame tube 170 and the guide bushing 180 are installed and positioned by connecting the thrust block and the thrust groove. The multi-cooling chamber floating ring 162 of the axially graded nozzle 160 is arranged flush with the inner diameter of the flame tube 170, and the mounting hole on the flame tube 170 is larger than the outer diameter of the multi-cooling chamber floating ring 162, so as to ensure the relative position of the axially graded nozzle 160 under thermal deformation. The axially graded nozzle 160 is evenly distributed along the circumference of the flame tube 170. Preferably, the number of the axially graded nozzles 160 is greater than 4, and the number of the axially graded nozzles 160 is related to the axially graded combustion load ratio, and ensures the uniformity of the combustion chamber outlet temperature. The axially graded fuel gas distribution pipe 114 is used for supplying fuel to the axially graded nozzle 160 . The axially graded fuel gas distribution pipe 114 adopts a ring pipe and a gas distribution branch pipe to increase the uniformity of fuel gas distribution.

[0069] Among them, the duty class fuel distribution pipe 112 is connected with the weak swirl micro-mixing duty nozzle 140 for its fuel supply. The duty class nozzle fuel distribution pipe 112 and the main combustion stage fuel distribution pipe A 111 share a fuel buffer cavity, and the cavity is distributed through a metal plate. At the same time, multiple fuel distribution branch pipes are added to be connected to the central fuel supply pipe 143 of the weak swirl micro-mixing duty nozzle 140 to further increase the uniformity of fuel distribution.

[0070] Among them, the head air distribution cavity 120 is divided into multiple areas by the metal plate 123, including the head air distribution cavity 121 and the head fuel distribution cavity 122, wherein the head fuel distribution cavity 122 includes the main combustion stage fuel distribution cavity A and the main combustion stage fuel distribution cavity B, and the whole is printed and formed in one piece by brazing process to ensure the air tightness of the head fuel distribution cavity 122, and increase the uniformity and flexibility of fuel distribution by fuel cavity partitioning. The head air distribution cavity 121 distributes air evenly through three levels of air distribution plates (primary air distribution plate 125, secondary air distribution plate 126, tertiary air distribution plate 127), the primary air distribution plate 125 and the secondary air distribution plate 126 are arranged along the axial direction, the tertiary air distribution plate 127 is arranged along the circumferential direction, and the air distribution holes are evenly distributed on the tertiary air distribution plates, and the aperture and number of the air distribution holes on the air distribution plates at each level decrease along the air flow. The multi-cavity structure of the head air distribution cavity 121 can form a porous plate sound absorption effect, which is beneficial to controlling the thermoacoustic instability of the combustion chamber.

[0071] Among them, the cooling end plate 130 is separated from the front metal plate 124 of the head air distribution cavity 120 by a certain height, and the air enters along the circumferential direction, which can isolate the high temperature of the combustion chamber, prevent the high-temperature flue gas from directly contacting the head fuel air distribution cavity 120, and ensure the safety of the combustion chamber.

[0072] More specifically, if Figure 1 , Figure 2 and Figure 3 As shown, the air inlet end of the mixing tube 142 of the weak swirl micro-mixing service nozzle 140 is integrated with the head gas distribution cavity 120 by brazing, and the air outlet end of the mixing tube 142 of the weak swirl micro-mixing service nozzle 140 is connected with the cooling end plate 130. The weak swirl micro-mixing service nozzle 140 is radially uniformly distributed on the cooling end plate 130, and the center distance of the weak swirl micro-mixing service nozzle 140 is S1, which expands the stable combustion range and meets the passive fuel control requirements.

[0073] Among them, Figure 2 As shown, the direct injection micro-mixing main combustion nozzle 150 is arranged in radial stages and zones along the cooling end plate 130, wherein the direct injection micro-mixing main combustion nozzle 150 is evenly arranged in a square shape in the central area of ​​the cooling end plate 130, and the center distance of the direct injection micro-mixing main combustion nozzle is S2, and the fuel in this part is supplied by the main combustion stage fuel distribution pipe A 111, and the area near the wall of the flame tube 170 is circumferentially symmetrically distributed to increase the load of the combustion chamber, and the fuel in this part is supplied by the main combustion stage fuel distribution pipe B 113, and the main combustion stage fuel distribution pipe B 113 uses multiple distribution pipes evenly distributed along the circumference to increase the flexibility of fuel distribution. A gap is left between the mounting holes of the direct injection micro-mixing main combustion nozzle 150 and the cooling end plate 130 to form a cooling hole for cooling the outlet wall of the direct injection micro-mixing main combustion nozzle 150, and the distance between the outlet of the direct injection micro-mixing main combustion nozzle 150 and the cooling end plate 130 is H. j , and 5mm≤H j ≤15mm, to prevent cooling air from directly contacting the flame and affecting the stability of combustion.

[0074] More specifically, if Figure 3 As shown, the weak swirl micro premixing service nozzle 140 mainly includes a swirl blade 141, a mixing tube 142 and a central fuel supply pipe 143. The outer diameter of the mixing tube is , the inner diameter is , a swirl blade 141 is used to achieve a weak swirl effect; the angle of the swirl blade 141 is ,and The distance between the swirl blade 141 and the nozzle outlet is L z2 , and 3 ≤L z2 ≤5 The central fuel supply pipe 143 is designed with non-uniform diameters, and its intake side diameter is ,and , the diameter of the outlet side is ,and The length of the expansion section of the central fuel supply pipe 143 is L z1 , and 1 / 2L z2 ≤L z1 ≤2 / 3L z2 , ensuring that the inlet velocity of the weak swirl micro-mixing duty nozzle 140 is small and the outlet velocity is high, which is beneficial to enhance the mixing of air and fuel and reduce the risk of fuel burning near the central fuel supply pipe 143; the diameter change angle of the central fuel supply pipe 143 is ,and , reducing the increase in pressure loss caused by flow channel changes; the outlet of the mixing tube 142 is designed to be similar to a cone bowl, and its outlet semi-expansion angle is ,and The central fuel supply pipe 143 has N fuel holes evenly distributed along the circumferential direction near the nozzle outlet area, N ≥ 6, the speed of the fuel passing through the fuel hole is V2, and V2 ≥ 160 m / s; the opening direction of the fuel hole has two angles, the radial angle is ,and , the angle along the axial direction is ,and , the distance between the fuel hole and the nozzle outlet is L z3 , and 1mm≤L z3 ≤5mm, the ignition of the integral combustion chamber and the combustion stability of the load increase are achieved through weak rotation and blunt body flame stabilization.

[0075] More specifically, if Figure 4 As shown, the axially graded nozzle 160 includes a lobe-type nozzle 161 and a multi-cooling chamber floating ring 162. The lobe-type nozzle 161 realizes rapid mixing of non-swirl structure through the development of vortex systems of orthogonal vortices and streamwise vortices, thereby controlling the emission of pollutants in the combustion chamber. The distance between the axially graded nozzle 160 and the cooling end plate 130 is L1, and the length of the flame tube is L2, and 1 / 2L2≤L1≤4 / 5L2, which ensures the residence time of high-temperature flue gas in the combustion chamber to control NOx and CO emissions. The multi-cooling chamber floating ring 162 adopts a Helmholtz resonator cooling cavity design, which reduces the possibility of thermal acoustic oscillation of the combustion chamber while ensuring the cooling and safety of the axially graded nozzle 160.

[0076] In this embodiment, the air velocity of the weak-swirl micro-mixing service nozzle, the direct-injection main combustion nozzle and the axial-staged nozzle is set to 60 m / s-120 m / s, the fuel passes through the fuel hole at 160 m / s-300 m / s, the air velocity V1 of the annular air channel formed by the guide bushing and the flame tube is 30 m / s-60 m / s, the combustion chamber outlet temperature is 1400°C-1800°C, and the hydrogen content can be arbitrarily mixed within 100%.

[0077] So far, the composition of the thermoacoustic oscillation passively controlled axial staged combustion chamber according to the embodiment of the present invention has been introduced.

[0078] It should be noted that the implementation methods not shown or described in the drawings or the text of the specification are all forms known to ordinary technicians in the relevant technical field and are not described in detail. In addition, the above definitions of each element are not limited to the various specific structures and shapes mentioned in the embodiments, and ordinary technicians in the field can simply change or replace them.

[0079] It should also be noted that the present invention can provide demonstrations of parameters including specific values, but these parameters do not need to be exactly equal to the corresponding values, but can be approximated to the corresponding values ​​within an acceptable error tolerance or design constraint; the above-mentioned embodiments can be mixed and matched with each other or with other embodiments based on design and reliability considerations, that is, the technical features in different embodiments can be freely combined to form more embodiments.

[0080] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A thermoacoustic oscillation passively controlled axially staged combustion chamber, characterized in that: It includes fuel distribution pipe, head distribution cavity, cooling end plate, weak swirl micro-mixing duty nozzle, direct injection micro-mixing main combustion nozzle, axial staged nozzle, flame tube, guide bushing and outer casing; The fuel distribution pipe is arranged at the head and middle of the combustion chamber, and is used for partitioned and graded fuel distribution of different fuels; The head gas distribution cavity is arranged at the rear end of the fuel gas distribution pipe of the combustion chamber head, used for further uniform gas distribution of air and fuel, and is welded to the fuel gas distribution pipe of the combustion chamber head; The cooling end plate is used to cool the head of the combustion chamber. The circumference of the cooling end plate is connected to the flame tube through a retaining spring. The cooling end plate is provided with mounting holes for the weak swirl micro-mixing service nozzle and the direct injection micro-mixing main combustion nozzle, which are used for the installation and positioning of the weak swirl micro-mixing service nozzle and the direct injection micro-mixing main combustion nozzle; One end of the weak swirl and micro-mixing nozzle is installed on the head gas distribution cavity, and the other end of the weak swirl and micro-mixing nozzle is connected to the cooling end plate; The direct injection mild-mix main combustion nozzles are radially arranged in stages and zones on the cooling end plate; One end of the axial grading nozzle is mounted on the outer casing via a flange, and the other end of the axial grading nozzle is connected to the flame tube via a multi-cooling chamber floating ring of the axial grading nozzle, and the axial grading nozzle is evenly distributed along the circumference of the flame tube; One end of the flame tube is connected to the cooling end plate; The guide bushing is clamped and installed in position by the head gas distribution cavity and the outer casing, and the guide bushing and the flame tube form an air flow channel; The outer casing and the head gas distribution cavity are installed and positioned.

2. The thermoacoustic oscillation passively controlled axially staged combustion chamber according to claim 1, characterized in that: The fuel distribution pipe includes a main combustion stage fuel distribution pipe A, a duty stage fuel distribution pipe, a main combustion stage fuel distribution pipe B and an axially graded fuel distribution pipe. The duty stage fuel distribution pipe is used for the fuel supply of the weak swirl micro-mixing duty nozzle. The main combustion stage fuel distribution pipe A and the main combustion stage fuel distribution pipe B are used for the fuel supply of the central area and the surrounding area of ​​the direct injection micro-mixing main combustion nozzle. The axially graded fuel distribution pipe is used for the fuel supply of the axially graded nozzle. The fuel gas distribution pipe of the combustion chamber head and the gas distribution cavity of the head are integrally formed by brazing process; The duty class nozzle fuel distribution pipe and the main combustion stage fuel distribution pipe A share a fuel buffer cavity, and the cavity is distributed through a metal plate. At the same time, multiple fuel distribution branch pipes are added to further increase the uniformity of fuel distribution.

3. The thermoacoustic oscillation passively controlled axially staged combustion chamber according to claim 2, characterized in that: The main combustion stage fuel distribution pipe B adopts a plurality of distribution pipes evenly distributed along the circumference to increase the flexibility of fuel distribution; the axially graded fuel distribution pipe adopts a ring pipe and a distribution branch pipe to increase the uniformity of fuel distribution.

4. The thermoacoustic oscillation passively controlled axially staged combustion chamber according to claim 1, characterized in that: The head gas distribution cavity comprises a head air gas distribution cavity, a head fuel gas distribution cavity and a gas distribution cavity metal plate, the whole cavity is divided into multiple areas by the gas distribution cavity metal plate, and the whole cavity is printed and formed in one piece by a brazing process; The head air distribution cavity distributes air evenly through a three-stage air distribution plate, wherein the first-stage air distribution plate and the second-stage air distribution plate are arranged axially, and the third-stage air distribution plate is arranged circumferentially. Air distribution holes are evenly distributed on the three-stage air distribution plate, and the aperture and number of the air distribution holes on the air distribution plates at each level decrease along the air flow. The multi-cavity structure of the head air distribution cavity can form a sound absorption effect of a porous plate, which is beneficial to control the thermoacoustic instability of the combustion chamber; The head fuel distribution cavity is divided into a main combustion stage fuel distribution cavity A and a main combustion stage fuel distribution cavity B by a central metal plate, and the uniformity and flexibility of fuel distribution are increased by fuel cavity partitioning.

5. The thermoacoustic oscillation passively controlled axially staged combustion chamber according to claim 1, characterized in that: The cooling end plate is spaced a certain height from the front metal plate of the head air distribution cavity, and air enters along the circumferential direction.

6. The thermoacoustic oscillation passively controlled axially staged combustion chamber according to claim 1, characterized in that: The weak swirl micro-mixing service nozzles are evenly distributed in the radial direction of the cooling end plate, and the center distance of the weak swirl micro-mixing service nozzles is S1; the weak swirl micro-premixing service nozzles include swirl blades, a mixing tube and a central fuel supply pipe, and the outer diameter of the mixing tube is , the inner diameter is ; The swirl blade angle is ,and The distance between the swirl blade and the nozzle outlet is L z2 , and 3 ≤L z2 ≤5 The central fuel supply pipe is designed with non-uniform diameters, and its intake side diameter is ,and , the diameter of the outlet side is ,and ; The length of the central fuel pipe expansion section is L z1 , and 1 / 2L z2 ≤L z1 ≤2 / 3L z2 ; The diameter change angle of the central fuel supply pipe is ,and The mixing tube outlet is designed as a cone-bowl, and its outlet semi-expansion angle is ,and The central fuel supply pipe has N fuel holes evenly distributed along the circumferential direction near the nozzle outlet area, N ≥ 6, the fuel passes through the fuel hole at V2, and V2 ≥ 160 m / s; the opening direction of the fuel hole has two angles, the angle along the radial direction is ,and , the angle along the axial direction is ,and ; The distance between the fuel hole and the nozzle outlet is L z3 , and 1mm≤L z3 ≤5mm.

7. The thermoacoustic oscillation passively controlled axially staged combustion chamber according to claim 1, characterized in that: The axially graded nozzle also includes a lobe-type nozzle, which controls the emission of pollutants in the combustion chamber by realizing rapid mixing of non-swirl structures through the development of vortex systems of orthogonal vortices and streamwise vortices. The distance between the axially graded nozzle and the cooling end plate is L1, the length of the flame tube is L2, and 1 / 2L2≤L1≤4 / 5L2. The multi-cooling cavity floating ring adopts a Helmholtz resonator cooling cavity design.

8. The thermoacoustic oscillation passively controlled axially staged combustion chamber according to claim 1, characterized in that: The direct injection micro-mixed main combustion nozzle is evenly arranged in a square in the central area of ​​the cooling end plate. The center distance of the direct injection micro-mixed main combustion nozzle is S2. The area close to the flame tube wall adopts a circumferential symmetrical distribution to increase the combustion chamber load. A gap is left between the direct injection micro-mixed main combustion nozzle and the mounting hole of the cooling end plate to form a cooling hole for cooling the direct injection micro-mixed main combustion nozzle. The distance between the outlet of the direct injection micro-mixed main combustion nozzle and the cooling end plate is H. j , and 5mm≤H j ≤15mm.

9. The thermoacoustic oscillation passively controlled axially staged combustion chamber according to claim 1, characterized in that: The flame tube adopts rib cooling and air film cooling structure.

10. The thermoacoustic oscillation passively controlled axially staged combustion chamber according to claim 1, characterized in that: The air flow channel ensures that the air velocity satisfies 30m / s≤V1≤60m / s, thereby ensuring the cooling and air distribution of the flame tube.

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