Thermoacoustic oscillation passive control axial staged combustor

Abstract

The application discloses a kind of passive control axial staging combustion chamber of thermoacoustic oscillation, including fuel gas distribution pipe, head gas distribution cavity, cooling end plate, weakly swirling micro-mixing value class nozzle, direct injection micro-mixing main combustion nozzle, axial staging nozzle, flame tube, flow guide bushing and outer casing.The combustion arrangement of head micro-mixing combustion and axial staging combustion optimizes fuel gas distribution;Weakly swirling micro-mixing value class nozzle realizes the ignition / load increase combustion stability of combustion chamber;Axial staging nozzle uses lobe structure to enhance fuel air mixing;Optimize the structure of axial staging nozzle cooling hole, achieve the effect of inhibiting thermoacoustic oscillation;Improve the opening position of axial staging windward side and leeward side cooling hole to realize flame lifting under high hydrogen content fuel.The axial staging combustion chamber arrangement of the application shortens the residence time of flue gas in high temperature zone, reduces the NOx pollutant emission of combustion chamber, and overall meets the requirements of high-efficiency stable low-emission operation under high hydrogen content fuel.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas turbine, in particular to a thermoacoustic oscillation passive control axial staged combustor. BACKGROUND

[0002] Fuel applicability, wide load regulation and high efficiency and stable low emission are the main development direction of gas turbine. Hydrogen fuel as green energy can effectively reduce carbon emissions, but hydrogen fuel puts forward more stringent requirements for the safety and emission of the combustor, especially the thermoacoustic oscillation characteristics. Multi-nozzle array combustion is one of the most potential combustion technologies, which can improve the jet nozzle speed under high hydrogen-containing fuel to reduce the nozzle backfire risk, shorten the length of the overall combustor to meet the requirements of controlling pollutant emissions, but the combustion organization mode of high-speed jet flow makes the combustor stability exist problems in the process of ignition and load increase. Axial staged combustion can effectively broaden the load regulation range of the combustor, shorten the residence time of high-temperature flue gas in the combustor to control pollutant emissions, and change the spatial position of the flame in the combustor, thereby realizing the control of the combustor thermoacoustic oscillation, but the nozzle cooling problem of the axial staged nozzle outlet area needs to be solved. Therefore, it is urgent to explore a new design scheme of thermoacoustic oscillation passive control axial staged combustor. SUMMARY

[0003] To at least partially solve at least one of the above-mentioned technical problems, the present application provides a thermoacoustic oscillation passive control axial staged combustor, which realizes the combustion stability of the gas turbine combustor under high hydrogen-containing fuel by optimizing the fuel distribution through the combustion organization mode of head micro-mixed combustion and axial staged combustion; realizes the ignition / load increase combustion stability of the combustor by using weakly rotating micro-premixed value service nozzle; enhances the overall load of the combustor and the combustion stability by using the combination of radial non-equidistant arrangement straight injection micro-mixed main combustion nozzle group and local backflow area; increases the axial staged nozzle, uses the lobe structure to enhance the fuel air mixing performance, adjusts the heat release zone position to change the thermoacoustic oscillation characteristics of the combustor; optimizes the cooling hole structure of the axial staged nozzle to form a Helmholtz resonator of a specific frequency band to achieve the effect of suppressing thermoacoustic oscillation; improves the opening position of the cooling holes on the axial staged windward side and leeward side to realize the flame lifting under high hydrogen-containing fuel and ensure the safety of the combustor. By optimizing the fuel distribution mode, the radial arrangement of the micro-mixed nozzle, the axial staged combustion arrangement, and the structure of the axial staged nozzle cooling hole, the effect of suppressing the thermoacoustic oscillation of the combustor under high hydrogen-containing fuel is realized. Through the axial staged combustor arrangement mode, the residence time of the flue gas in the high temperature zone is shortened, the NOx pollutant emission of the combustor is reduced, and the overall requirements of high efficiency, stable and low emission operation under high hydrogen-containing fuel are met.

[0004] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0005] A passive control axial staging combustion chamber of thermoacoustic oscillation, comprising a fuel distribution pipe, a head distribution cavity, a cooling end plate, a weakly swirling micro-premixed pilot nozzle, a direct injection micro-mixed main combustion nozzle, an axial staging nozzle, a flame tube, a flow guide bushing and an outer casing;

[0006] The fuel distribution pipe is arranged at the head and middle positions of the combustion chamber for zoned and staged fuel distribution of different fuels;

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

[0008] The cooling end plate is used for cooling the head of the combustion chamber, the circumferential direction of the cooling end plate is connected with the flame tube through a clasp, and mounting holes of the weakly swirling micro-premixed pilot nozzle and the direct injection micro-mixed main combustion nozzle are arranged on the cooling end plate for installation and positioning of the weakly swirling micro-premixed pilot nozzle and the direct injection micro-mixed main combustion nozzle;

[0009] One end of the weakly swirling micro-premixed pilot nozzle is mounted on the head distribution cavity, and the other end of the weakly swirling micro-premixed pilot nozzle is connected with the cooling end plate;

[0010] The direct injection micro-mixed main combustion nozzle is arranged radially and zonally on the cooling end plate;

[0011] One end of the axial staging nozzle is mounted with the outer casing through a flange, and the other end of the axial staging nozzle is connected with the flame tube by using a floating ring of multiple cooling cavities of the axial staging nozzle, and the axial staging nozzle is uniformly distributed along the circumferential direction of the flame tube;

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

[0013] The flow guide bushing is clamped and positioned by the head distribution cavity and the outer casing, and the flow guide bushing forms an air flow channel with the flame tube;

[0014] The outer casing is mounted and positioned with the head distribution cavity.

[0015] Further, the fuel distribution pipe comprises a main combustion stage fuel distribution pipe A, a pilot stage fuel distribution pipe, a main combustion stage fuel distribution pipe B and an axial staging fuel distribution pipe, the pilot stage fuel distribution pipe is used for fuel supply of the weakly swirling micro-premixed pilot nozzle, the main combustion stage fuel distribution pipe A and the main combustion stage fuel distribution pipe B are used for fuel supply of the central region and the surrounding region of the direct injection micro-mixed main combustion nozzle, and the axial staging fuel distribution pipe is used for fuel supply of the axial staging nozzle; the fuel distribution pipe at the head of the combustion chamber is integrally formed with the head distribution cavity by using a brazing process;

[0016] The on-duty class nozzle fuel distribution pipe and the main combustion stage fuel distribution pipe A share a fuel buffer cavity, the cavity is distributed by a metal plate, and a plurality of fuel distribution branch pipes are further added to further increase the uniformity of fuel distribution.

[0017] Further, the main combustion stage fuel distribution pipe B adopts a plurality of distribution pipes uniformly distributed in the circumferential direction to increase the flexibility of fuel distribution; and the axial staged fuel distribution pipe adopts a ring pipe and a distribution branch pipe to increase the uniformity of fuel distribution.

[0018] Further, the head distribution cavity includes a head air distribution cavity, a head fuel distribution cavity and a distribution cavity metal plate, the overall cavity is divided into a plurality of regions by the distribution cavity metal plate, and the overall is integrally formed by a brazing process;

[0019] The head air distribution cavity uniformly distributes air through three-stage air distribution plates, wherein the first-stage air distribution plate and the second-stage air distribution plate are arranged in the axial direction, and the third-stage air distribution plate is arranged in the circumferential direction; the third-stage air distribution plate is uniformly provided with air distribution holes; the hole diameter and the number of the air distribution holes on the air distribution plates decrease along the air flow direction; the multi-cavity structure of the head air distribution cavity can form the sound absorption effect of a multi-hole plate, which is conducive to controlling the thermal-acoustic 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 center metal plate, and the fuel cavity is divided into zones to increase the uniformity and flexibility of fuel distribution.

[0021] Further, the cooling end plate is separated from the front metal plate of the head distribution cavity by a certain height, and air enters in the circumferential direction.

[0022] Further, the weak-rotation micro-premixed on-duty nozzles are uniformly distributed in the radial direction of the cooling end plate, and the center distance of the weak-rotation micro-premixed on-duty nozzles is S1; the weak-rotation micro-premixed on-duty nozzles include a swirl vane, a mixing pipe and a center fuel supply pipe, the outer diameter of the mixing pipe is , the inner diameter is , the angle of the swirl vane is , and , the distance between the swirl vane and the nozzle outlet is L z2 , and 3 ≤ L z2 ≤ 5 ; the center fuel supply pipe is designed as a non-equal-diameter pipe, the diameter of the inlet side is , and , the diameter of the outlet side is , and ; and the length of the expansion section of the center fuel pipe is L z1 , and 1 / 2 L z2 ≤ L z1≤ 2 / 3L z2 ; the diameter variation angle of the central fuel supply pipe is , and ; the outlet of the mixing pipe is designed as a conical bowl, and the outlet half-expansion angle is , and ; the central fuel supply pipe is provided with N fuel holes which are uniformly distributed in the circumferential direction near the nozzle outlet region, N≥6, fuel passes through the fuel holes at V2, and V2≥160 m / s; the opening direction of the fuel holes has two angles, the angle in the radial direction is , and , and the angle in the axial direction is , and ; the distance between the fuel holes and the nozzle outlet is L z3 , and 1mm≤L z3 ≤5mm.

[0023] Further, the axial staged combustor further comprises a lobe type nozzle, the lobe type nozzle controls the emission of pollutants in the combustion chamber by realizing rapid mixing of the non-swirl structure through the vortex system development of the orthogonal vortex and the flow vortex, the distance between the axial staged combustor and the cooling end plate is L1, the length of the flame tube is L2, and 1 / 2L2≤L1≤4 / 5L2, and the multi-cooling cavity floating ring adopts a Helmholtz resonator cooling cavity design.

[0024] Further, the direct injection micro-mixing main fuel nozzle is uniformly arranged in a square in the central region of the cooling end plate, the center distance of the direct injection micro-mixing main fuel nozzle is S2, the circumferential symmetric distribution is adopted near the wall surface region of the flame tube to increase the load of the combustion chamber, a gap is left between the installation hole of the direct injection micro-mixing main fuel nozzle and the cooling end plate to form a cooling hole for cooling the direct injection micro-mixing main fuel nozzle, and the distance between the outlet of the direct injection micro-mixing main fuel nozzle and the cooling end plate is H j , and 5mm≤H j ≤15mm.

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

[0026] Further, the air flow channel ensures that the air speed satisfies 30m / s≤V1≤60m / s, so as to ensure the cooling and air distribution of the flame tube.

[0027] From the above technical solutions, the thermoacoustic oscillation passive control axial staged combustor has at least one or part of the following beneficial effects:

[0028] (1) Fuel distribution pipe and head distribution cavity adopt brazing process integrated design, ensure the design precision, improve the uniformity of distribution, multi-cavity orifice plate structure has the effect of sound absorption and sound absorption, reduces the thermal acoustic instability of combustion chamber;

[0029] (2) The first stage combustion zone adopts weak rotation micro-premixed value class nozzle and direct injection micro-mixed main fuel nozzle combination, through controlling the swirl number and size of the value class nozzle to ensure that the value class nozzle will not affect the flow field and flame shape of the direct injection micro-mixed main fuel nozzle, ensure the stability of combustion during the ignition and load increasing process of the combustion chamber;

[0030] (3) The axial staged combustion mode effectively widens the load regulation range of the combustion chamber, changes the spatial distribution of the combustion chamber heat release zone, modulates the interaction of fuel and flame, thereby controlling the thermal acoustic oscillation characteristics of the combustion chamber;

[0031] (4) The gas film cooling structure of the axial staged nozzle adopts the structure design of Helmholtz resonator, which effectively controls the thermal acoustic oscillation of the combustion chamber while cooling the outlet of the axial staged nozzle, and ensures the safe and stable operation of the combustion chamber. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is a structure schematic view of the thermal acoustic oscillation passive control axial staged combustion chamber of the embodiment of the present application;

[0033] Figure 2 It is a right view of the thermal acoustic oscillation passive control axial staged combustion chamber of the embodiment of the present application;

[0034] Figure 3 It is a structure schematic view of the weak rotation micro-premixed value class nozzle;

[0035] Figure 4 It is a structure schematic view of the axial staged nozzle.

[0036] Among them, the meaning of the reference signs is as follows:

[0037] 100-thermal acoustic oscillation passive control axial staged combustion chamber;

[0038] 110-fuel distribution pipe; 111-main fuel distribution pipe A of the value class;

[0039] 112-value class fuel distribution pipe; 113-main fuel distribution pipe B of the value class;

[0040] 114-axial staged fuel distribution pipe; 120-head distribution cavity;

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

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

[0043] 125 - first-stage air distribution panel; 126 - second-stage air distribution panel

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

[0045] 140 - weakly-swirling micro-premixed pilot nozzle; 141 - swirl vane

[0046] 142 - mixing tube; 143 - center fuel supply tube

[0047] 150 - straight-injection micro-mixed main fuel nozzle; 160 - axial staging nozzle

[0048] 161 - lobe-type nozzle; 162 - multi-cooled-cavity floating ring

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

[0050] 190 - outer case

[0051] D zw - mixing tube outer diameter; D zn - mixing tube inner diameter

[0052] D zf - center fuel supply tube intake side diameter; D zd - center fuel supply tube discharge side diameter

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

[0054] L z1 - length of center fuel tube expansion section; L z2 - distance between swirl vane and nozzle exit

[0055] L z3 - distance between fuel hole and nozzle exit

[0056] H j - distance between straight-injection micro-mixed main fuel nozzle exit and cooling end plate

[0057] S1 - center distance of weakly-swirling micro-premixed pilot nozzle; S2 - center distance of straight-injection micro-mixed main fuel nozzle

[0058] - swirl vane angle - center fuel supply tube diameter change angle

[0059] - exit half-expansion angle - radial angle of fuel hole

[0060] - axial direction of the fuel hole;

[0061] V 1- air velocity; V 2- velocity of the fuel through the fuel hole. DETAILED DESCRIPTION

[0062] The present application effectively solves the problem of thermal acoustic oscillation of a gas turbine combustor under high hydrogen-containing fuel, adopts a combustion organization mode of head micro-mixed combustion and axial staging combustion, optimizes fuel distribution, adopts a weakly swirling micro-premixed value scheduling nozzle to realize ignition / load-up combustion stability of the combustor, adopts a radial non-equidistant arrangement of straight injection micro-mixed main fuel nozzle combination to enhance overall load of the combustor and to enhance combustion stability through a local backflow area, increases axial staging nozzles, adopts a lobe structure to enhance fuel-air mixing performance, adjusts a heat release zone position to change thermal acoustic oscillation characteristics of the combustor, optimizes a cooling hole structure of the axial staging nozzle, forms a Helmholtz resonator of a specific frequency band, and achieves the effect of suppressing thermal acoustic oscillation, and improves opening positions of the cooling holes on the windward side and the leeward side of the axial staging to realize flame lifting under high hydrogen-containing fuel, and ensures safety of the combustor. By optimizing the fuel distribution mode, the radial arrangement of the micro-mixed nozzle, the axial staging combustion arrangement, and the structure and modeling of the cooling hole of the axial staging nozzle, the present application can realize efficient and stable combustion of the combustor under high hydrogen-containing fuel, and the axial staging combustor arrangement shortens the residence time of flue gas in the high-temperature zone, reduces the NOx pollutant emission of the combustor, and overall meets the requirements of efficient, stable and low-emission operation under high hydrogen-containing fuel.

[0063] To make the objects, technical solutions and advantages of the present application clearer, further detailed description will be made to the present application with reference to the specific embodiments and the accompanying drawings. It should be noted in advance that the directions mentioned in the embodiments of the present application, such as "up", "down", "front", "back", "left", "right", etc., are only the directions of the accompanying drawings, and are not used to limit the protection scope of the present application.

[0064] In an exemplary embodiment of the present application, as shown in Figures 1 to 4 Fig. 1, the present application provides a thermal acoustic oscillation passive control axial staging combustor 100, which comprises a fuel distribution pipe 110, a head distribution cavity 120, a cooling end plate 130, a weakly swirling micro-premixed value scheduling nozzle 140, a straight injection micro-mixed main fuel nozzle 150, an axial staging nozzle 160, a flame tube 170, a flow guide bushing 180, and an outer casing 190.

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

[0066] The following describes in detail each component of the embodiment of the passive control of thermoacoustic oscillation axial staging combustion.

[0067] As shown in Figure 1 The passive control of thermoacoustic oscillation axial staging combustion chamber 100, the air uses the reverse flow intake, enters through the annular passage composed of the flame tube 170 and the flow guide bushing 180, and is divided into five parts to enter the flame tube 170, including: the film cooling air of the flame tube 170, the combustion air of the axial staging nozzle 160, the cooling air of the axial staging nozzle 160, the cooling air of the cooling end plate 130, and the combustion air through the head distribution chamber 120. The combustion air of the axial staging nozzle 160 accounts for 20% of the total air quantity, and the film cooling air of the flame tube 170 and the cooling air of the cooling end plate 130 together account for 15% of the total air quantity. Figure 1 In the formula, V1 is the air speed.

[0068] In the formula, the fuel distribution pipe 110 and the head distribution chamber 120 are combined by machining and brazing process, so as to ensure the machining precision of the fuel holes of the weak swirl micro-premixed duty nozzle 140 and the direct injection micro-mixed main combustion nozzle 150; the head distribution chamber 120 divides the head into the head air distribution chamber 121 and the head fuel distribution chamber 122 by the multi-layer distribution metal plate 123, and adopts the brazing process to ensure the sealing of the head fuel distribution chamber 122. The head distribution chamber 120 is connected with the outer casing 190 by bolts, and the flow guide bushing 180 is clamped and positioned by the head distribution chamber 120 and the outer casing 190.

[0069] The outer casing 190 has an installation base of the axial staged nozzle 160, which is connected and fixed to the outer casing 190 by screws. The cooling end plate 130 and the head air distribution cavity 120 are connected together by screws, facilitating 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 snap spring, and the flame tube 170 and the flow guide bushing 180 are installed and positioned by the connection mode of the thrust block and the thrust groove. The multi-cooling cavity floating ring 162 of the axial staged nozzle 160 is arranged in the same plane as the inner diameter of the flame tube 170, and the installation hole on the flame tube 170 is larger than the outer diameter of the multi-cooling cavity floating ring 162, which ensures the relative position of the axial staged nozzle 160 under thermal deformation. The axial staged nozzles 160 are uniformly distributed along the circumference of the flame tube 170. Preferably, the number of axial staged nozzles 160 is greater than 4, the number of axial staged nozzles 160 is related to the axial staged combustion load ratio, and the uniformity of the combustion chamber outlet temperature is ensured. The axial staged fuel distribution pipe 114 is used for fuel supply of the axial staged nozzle 160, and the axial staged fuel distribution pipe 114 adopts the mode of ring pipe and air distribution branch pipe to increase the uniformity of fuel distribution.

[0070] Among them, the value class fuel distribution pipe 112 communicates with the weak rotation micro-premixed value nozzle 140, and is used for fuel supply thereof. The value class fuel distribution pipe 112 and the main combustion class fuel distribution pipe A 111 share a fuel buffer cavity, and the cavity is distributed by a metal plate. At the same time, a plurality of fuel distribution branch pipes are connected with the central fuel supply pipe 143 of the weak rotation micro-premixed value nozzle 140, further increasing the uniformity of fuel distribution.

[0071] Among them, the head air distribution cavity 120 divides the whole cavity into multiple areas through the air distribution cavity metal plate 123, including the head air distribution cavity 121 and the head fuel distribution cavity 122. The head fuel distribution cavity 122 includes the main combustion class fuel distribution cavity A and the main combustion class fuel distribution cavity B, and the whole is integrally formed by brazing process, ensuring the air tightness of the head fuel distribution cavity 122, and increasing the uniformity and flexibility of fuel distribution by fuel cavity partition. The head air distribution cavity 121 uniformly distributes air through three levels of air distribution plates (first air distribution plate 125, second air distribution plate 126, and third air distribution plate 127). The first air distribution plate 125 and the second air distribution plate 126 are arranged along the axial direction, and the third air distribution plate 127 is arranged along the circumferential direction. The third air distribution plate is uniformly distributed with air distribution holes, and the hole diameter and the number of air distribution holes on the third air distribution plate decrease along the air flow direction. The multi-cavity structure of the head air distribution cavity 121 can form the sound absorption effect of the perforated plate, which is conducive to controlling the thermal-acoustic instability of the combustion chamber.

[0072] The cooling end plate 130 is spaced apart from the front metal plate 124 of the head air distribution cavity 120 by a certain height, air enters along the circumference, which can isolate the high temperature of the combustion chamber, prevent the high temperature flue gas from directly contacting the head air distribution cavity 120, and ensure the safety of the combustion chamber.

[0073] More specifically, as shown in Figure 1 , Figure 2 and Figure 3 , the air inlet end of the mixing pipe 142 of the weakly swirling micro-premixed pilot nozzle 140 is integrally processed with the head air distribution cavity 120 by brazing, the air outlet end of the mixing pipe 142 of the weakly swirling micro-premixed pilot nozzle 140 is connected with the cooling end plate 130, the weakly swirling micro-premixed pilot nozzles 140 are uniformly distributed radially on the cooling end plate 130, and the center distance of the weakly swirling micro-premixed pilot nozzles 140 is S1, which expands the stable combustion range and meets the passive fuel control requirements.

[0074] More specifically, as shown in Figure 2 , the direct injection micro-mixed main fuel nozzle 150 is arranged in a radial hierarchical partition along the cooling end plate 130, wherein the direct injection micro-mixed main fuel nozzle 150 is uniformly arranged in a square in the central region of the cooling end plate 130, and the center distance of the direct injection micro-mixed main fuel nozzle is S2, the fuel of this part is supplied by the main fuel stage fuel distribution pipe A 111, and the circumferentially symmetrical distribution is adopted near the wall surface region of the flame tube 170 to increase the load of the combustion chamber, the fuel of this part is supplied by the main fuel stage fuel distribution pipe B 113, the main fuel stage fuel distribution pipe B 113 adopts a plurality of distribution pipes uniformly distributed along the circumference to increase the flexibility of fuel distribution. A gap is left between the mounting hole of the direct injection micro-mixed main fuel nozzle 150 and the cooling end plate 130 to form a cooling hole for cooling the outlet wall surface of the direct injection micro-mixed main fuel nozzle 150, and the distance between the outlet of the direct injection micro-mixed main fuel nozzle 150 and the cooling end plate 130 is H j , and 5mm≤H j ≤15mm, which prevents the cooling air from directly contacting the flame and affecting the stability of combustion.

[0075] More specifically, as shown in Figure 3 , the weakly swirling micro-premixed pilot nozzle 140 mainly includes a swirling vane 141, a mixing pipe 142 and a central fuel supply pipe 143, the outer diameter of the mixing pipe is , the inner diameter is , and the swirling vane 141 is used to achieve a weak swirling effect; the angle of the swirling vane 141 is , and , the distance between the swirling vane 141 and the nozzle outlet is L z2 , and 3 ≤L z2 ≤5 ; the central fuel supply pipe 143 is designed as a non-equal diameter, the diameter of the inlet side is , and with an outlet diameter of 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 , which ensures that the inlet velocity of the weakly swirling micro-premixed pilot nozzle 140 is small and the outlet velocity is high, which is conducive to enhancing the mixing of air and fuel and reducing the risk of fuel burning near the central fuel supply pipe 143; the angle of change in the diameter of the central fuel supply pipe 143 is , and , which reduces the increase in pressure loss caused by the change in the flow passage; the outlet of the mixing pipe 142 is designed as a conical bowl, and the outlet half-expansion angle is , and ; the central fuel supply pipe 143 is uniformly distributed with N fuel holes in the circumferential direction near the nozzle outlet region, N≥6, and the fuel velocity through the fuel holes is V2, and V2≥160 m / s; the opening direction of the fuel holes has two angles, the radial angle is , and , and the axial angle is , and , and the distance between the fuel holes and the nozzle outlet is L z3 , and 1mm≤L z3 ≤5mm, and the ignition and load-up combustion stability of the overall combustion chamber is realized by weak swirling and flame stabilization by a bluff body.

[0076] More specifically, as shown in Figure 4 , the axial staged nozzle 160 includes a lobed nozzle 161 and a multi-cooling-cavity floating ring 162, the lobed nozzle 161 realizes rapid mixing through the development of orthogonal vortex and streamwise vortex vortex systems, thereby controlling the emission of pollutants in the combustion chamber. The distance between the axial staged 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-cavity floating ring 162 adopts a Helmholtz resonator cooling cavity design, which ensures the cooling and safety of the axial staged nozzle 160 while reducing the possibility of thermoacoustic oscillation of the combustion chamber.

[0077] In this embodiment, the air velocity of the weakly swirling micro-premixed pilot nozzle, the direct-injection main fuel nozzle, and the axial staged nozzle is 60 m / s-120 m / s, the fuel velocity through the fuel holes is 160 m / s-300 m / s, the air velocity V1 of the annular air passage formed by the flow guide bushing and the flame tube is 30 m / s-60 m / s, the combustion chamber outlet temperature is 1400℃-1800℃, and the hydrogen content can be mixed by any amount within 100%.

[0078] So far, the composition of the thermoacoustic oscillation passive control axial staged combustor of the embodiment of the present application is introduced.

[0079] It should be noted that the implementation not shown or described in the drawings or the specification is the form known by the ordinary skilled in the art, and is not described in detail. In addition, the definition of each element described above is not limited to the various specific structures, shapes mentioned in the embodiment, and the ordinary skilled in the art can make simple changes or replacements.

[0080] It should also be noted that the present application can provide examples of parameters containing specific values, but these parameters do not necessarily equal the corresponding values, but can be approximately equal to the corresponding values within the acceptable error tolerance or design constraints; the above embodiments can be mixed and used 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.

[0081] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A thermoacoustic oscillation passively controlled axial staged combustion chamber, characterized in that, It includes fuel distribution pipe, head distribution chamber, cooling end plate, weak swirl micro-premixed duty nozzle, direct injection micro-mixed main combustion nozzle, axial staged nozzle, flame tube, flow guide bushing and outer casing; The fuel distribution pipe is located at the head and middle of the combustion chamber and is used for zoned and graded fuel distribution of different fuels. The head air distribution chamber is located at the rear end of the fuel air distribution pipe at the head of the combustion chamber, and is used for further uniform distribution of air and fuel. It is welded to the fuel air distribution pipe at the head of the combustion chamber. The cooling end plate is used to cool the head of the combustion chamber. The circumferential direction of the cooling end plate is connected to the flame tube by a retaining ring. The cooling end plate is provided with mounting holes for the weak swirl micro-premixed duty nozzle and the direct injection micro-mixed main combustion nozzle for installation and positioning. One end of the weak vortex micro premixed duty nozzle is installed on the head gas distribution chamber, and the other end of the weak vortex micro premixed duty nozzle is connected to the cooling end plate; The direct injection micro-hybrid main combustion nozzles are arranged radially in graded zones on the cooling end plate; One end of the axial grading nozzle is installed to 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. The axial grading nozzles are evenly distributed along the circumference of the flame tube. One end of the flame tube is connected to the cooling end plate; The flow guide bushing is clamped and positioned by the head air distribution chamber and the outer casing, and the flow guide bushing forms an air flow channel with the flame tube; The outer casing is installed and positioned with the head air distribution chamber; The weak swirl micro-premixing nozzles are radially evenly distributed on the cooling end plate, and the center-to-center distance between the nozzles is S1. Each weak swirl micro-premixing nozzle includes swirl vanes, a mixing tube, and a central fuel supply tube, and the outer diameter of the mixing tube is... The inner diameter is The angle of the swirl blades 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 a non-uniform diameter, and its intake side diameter is [missing information]. ,and Its outlet diameter is ,and The length of the expansion section of the central fuel pipe is L. z1 And 1 / 2L z2 ≤L z1 ≤2 / 3L z2 The diameter of the central fuel supply pipe changes at an angle of [value missing]. ,and The mixing pipe outlet adopts a conical-bowl shape design, and its outlet half-expansion angle is... ,and The central fuel supply pipe has N fuel holes evenly distributed circumferentially near the nozzle outlet area, where N ≥ 6. Fuel passes through these fuel holes at a rate of V2, where V2 ≥ 160 m / s. The opening direction of each fuel hole has two angles, with the radial angle being... ,and The angle along the axial direction is ,and The distance from the fuel orifice to the nozzle outlet is L. z3 And 1mm≤L z3 ≤5mm.

2. The thermoacoustic oscillation passively controlled axial 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 fuel distribution pipe, a main combustion stage fuel distribution pipe B, and an axial stage fuel distribution pipe. The duty fuel distribution pipe is used for fuel supply to the weak swirl micro-premixed duty nozzle. The main combustion stage fuel distribution pipe A and the main combustion stage fuel distribution pipe B are used for fuel supply to the central and surrounding areas of the direct injection micro-mixed main combustion nozzle. The axial stage fuel distribution pipe is used for fuel supply to the axial stage nozzle. The fuel distribution pipe at the head of the combustion chamber is integrally formed with the head distribution cavity by brazing. The duty fuel distribution pipe and the main combustion stage fuel distribution pipe A share a fuel buffer chamber, which is distributed by a metal plate. At the same time, multiple fuel distribution branches are added to further increase the uniformity of fuel distribution.

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

4. The thermoacoustic oscillation passively controlled axial staged combustion chamber according to claim 1, characterized in that, The head air distribution chamber includes a head air distribution chamber, a head fuel distribution chamber, and a distribution chamber metal plate. The overall chamber is divided into multiple areas by the distribution chamber metal plate, and the whole is printed as a single piece using a brazing process. The head air distribution chamber distributes air evenly through a three-stage air distribution plate. The first-stage and second-stage air distribution plates are arranged axially, while the third-stage air distribution plate is arranged circumferentially. Air distribution holes are evenly distributed on the third-stage air distribution plate. The diameter and number of air distribution holes on each stage of the air distribution plate decrease along the air flow direction. The multi-cavity structure of the head air distribution chamber can form a perforated plate sound absorption effect, which is beneficial to controlling the thermal and acoustic instability of the combustion chamber. The head fuel distribution chamber is divided into a main combustion stage fuel distribution chamber A and a main combustion stage fuel distribution chamber B by a central metal plate. The fuel chamber partitioning increases the uniformity and flexibility of fuel distribution.

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

6. The thermoacoustic oscillation passively controlled axial staged combustion chamber according to claim 1, characterized in that, The axial staged nozzle also includes a lobed nozzle. The lobed nozzle achieves rapid mixing of non-swirling structures through the development of orthogonal vortices and flow vortices to control the emission of pollutants from the combustion chamber. The distance between the axial staged 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 chamber floating ring adopts a Helmholtz resonator cooling chamber design.

7. The thermoacoustic oscillation passively controlled axial staged combustion chamber according to claim 1, characterized in that, The direct-injection micro-hybrid main combustion nozzles are arranged in a square and uniform manner in the central area of ​​the cooling end plate. The center-to-center distance between the direct-injection micro-hybrid main combustion nozzles is S2. They are circumferentially symmetrically distributed near the flame tube wall to increase the combustion chamber load. A gap is left between the mounting holes of the direct-injection micro-hybrid main combustion nozzles and the cooling end plate, forming cooling holes for cooling the direct-injection micro-hybrid main combustion nozzles. The distance between the outlet of the direct-injection micro-hybrid main combustion nozzle and the cooling end plate is H. j And 5mm≤H j ≤15mm.

8. The thermoacoustic oscillation passively controlled axial staged combustion chamber according to claim 1, characterized in that, The flame tube employs a rib cooling and film cooling structure.

9. The thermoacoustic oscillation passively controlled axial staged combustion chamber according to claim 1, characterized in that, The airflow channel ensures that the air velocity meets the requirement of 30m / s≤V1≤60m / s, thereby ensuring the cooling and gas distribution of the flame tube.

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