Staged premixed array microtube combustion chamber

Abstract

The invention relates to the technical field of combustion of gas turbines, in particular to a graded premixing array micro-tube combustion chamber which comprises a head flange, a tail connecting plate, a pre-combustion pipeline, an igniter, array micro-tubes and a gas collecting shell, and a plurality of fuel inlets are formed in the head flange; the tail connecting plate and the head flange are oppositely arranged in the axial direction. The pre-combustion pipeline penetrates through the head flange and the tail connecting plate, and a pre-combustion nozzle located at the tail connecting plate is arranged at the downstream of the pre-combustion pipeline; the igniter is arranged at the tail connecting plate, the array micropipe comprises a multi-stage main combustion pipeline, and a main combustion nozzle located at the tail connecting plate is arranged at the downstream of the multi-stage main combustion pipeline; a plurality of fuel inlets are formed in the gas collecting shell, a plurality of gas collecting cavities are formed in the gas collecting shell, the gas collecting cavities communicate with the fuel inlets correspondingly, the gas collecting cavities communicate with the multiple stages of main combustion pipelines correspondingly, and the combustion chamber can achieve flame stabilizing reliability and anti-backfire safety of hydrogen fuel combustion at the same time within the wide load range.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas turbine combustion technology, in particular to a staged premixed array micro-tube combustion chamber. BACKGROUND

[0002] With the global energy transition, hydrogen as a clean energy carrier is increasingly valued in the field of gas turbines. Hydrogen fuel has the absolute clean advantage of high heat value (142 MJ / kg) and pure water combustion products, and is a key technical path to achieve zero carbon emissions of gas turbines. However, the unique combustion characteristics of hydrogen fuel pose a serious challenge to existing combustion chamber technology.

[0003] Traditional gas turbine combustion chambers generally use single-stage swirl combustion technology. This technology generates an adverse pressure gradient through a swirler, inducing high-temperature smoke backflow to form a central recirculation zone, providing a stable ignition source and residence time for fuel. Fuel mixes with air in the swirler and burns directly, with the advantages of wide stable flame boundary, high ignition reliability, and strong load regulation capability, and performs well in natural gas fuel applications.

[0004] However, the swirl combustion technology has fatal defects under hydrogen fuel conditions. Hydrogen fuel has extremely high flame propagation speed (2.8 m / s, 10 times that of natural gas) and extremely low ignition energy (only 0.02 mJ), causing the flame front to easily break through the mixed gas flow speed and propagate in the opposite direction to the swirler, causing serious backfire. Backfire can cause overheating of the burner components, material ablation, and even structural damage, posing a serious threat to equipment safety. At the same time, the adiabatic flame temperature of hydrogen fuel is as high as 2300K, about 150K higher than that of natural gas, and is prone to form a large amount of thermal NOx in the high-temperature residence zone of swirl combustion.

[0005] To solve the backfire problem of hydrogen fuel, researchers have developed micro-mixing combustion technology. This technology uses small-scale nozzles to achieve rapid mixing of fuel and air, and uses high-speed jets (≥80 m / s) to inject fuel. The momentum barrier formed by the jet can effectively prevent the flame from propagating upstream, fundamentally solving the backfire risk. Micro-mixing combustion can also control the mixing scale to the micron level, reducing the high-temperature residence time and significantly reducing NOx emissions.

[0006] However, the micro-mixing combustion technology has a significant problem of insufficient flame stability. Unlike swirl combustion, which relies on the central recirculation zone for flame stability, micro-mixing combustion relies mainly on turbulent mixing in the jet shear layer to achieve stable combustion, lacking a dedicated flame stabilization mechanism, and the flame stability boundary is relatively narrow. Under complex operating conditions of gas turbines, especially during low load, variable load, or fuel switching, flame instability or even flameout may occur, seriously affecting operational reliability.

[0007] More importantly, modern gas turbines require stable operation in a wide load range (30%-120% operating condition), while existing single-stage combustion technology faces insurmountable technical contradictions:

[0008] Although single-stage swirl combustion has excellent flame stability and load regulation performance, the risk of backfire in hydrogen fuel applications makes it impossible to operate safely, and even through improvement measures such as increasing the mixed gas flow rate and optimizing the swirler geometry, it is difficult to fundamentally eliminate the backfire risk.

[0009] Although single-stage micro-mixed combustion can effectively avoid backfire, the inherent deficiency in flame stability makes it difficult to independently undertake the task of stable operation of gas turbines in a wide load range. At 30% low load operating condition, the fuel flow is small and the mixing momentum is insufficient, which easily leads to flame quenching; at 120% high load operating condition, although the mixing momentum is sufficient, there is still a risk of flameout during operating condition disturbance due to the lack of a reliable flame stabilization mechanism; during load change, the single-stage control mode cannot provide sufficient regulation accuracy and response speed.

[0010] In addition, future energy systems require gas turbines to have multi-fuel flexible operation capability, which needs to adapt to different fuel combinations such as pure hydrogen, hydrogen-natural gas mixture, and hydrogen-carbon monoxide mixture. When the hydrogen mixing ratio exceeds 50%, the density, heat value, and combustion characteristics of the fuel change dramatically, and the existing single-stage combustion technology lacks grading control means, which cannot accurately adjust according to the changes in fuel characteristics, resulting in decreased combustion efficiency and deteriorated emissions.

[0011] In summary, the existing combustion chamber technology cannot simultaneously achieve the flame stability reliability and anti-backfire safety of hydrogen fuel combustion in a wide load range. SUMMARY

[0012] The present application provides a staged premixed array micro-tube combustion chamber, which can simultaneously achieve the flame stability reliability and anti-backfire safety of hydrogen fuel combustion in a wide load range.

[0013] The embodiment of the present application provides a staged premixed array micro-tube combustion chamber, which comprises: a head flange, a plurality of fuel inlets are arranged on the head flange; a tail connecting plate, which is arranged opposite to the head flange along the axial direction; a pre-combustion pipeline, which penetrates through the head flange and the tail connecting plate, and a pre-combustion nozzle is arranged at the downstream of the pre-combustion pipeline and located at the tail connecting plate; an igniter, which is arranged at the tail connecting plate, is used for igniting the fuel sprayed by the pre-combustion nozzle and forming a standing flame; an array micro-tube, which is arranged between the head flange and the tail connecting plate, comprises a plurality of stages of main combustion pipelines, and a main combustion nozzle is arranged at the downstream of the plurality of stages of main combustion pipelines and located at the tail connecting plate; and a gas collecting shell, which is arranged between the head flange and the array micro-tube, is provided with a plurality of gas collecting cavities, the plurality of gas collecting cavities are in communication with the plurality of fuel inlets respectively, and the plurality of gas collecting cavities are in communication with the plurality of stages of main combustion pipelines respectively.

[0014] In a possible implementation, each primary combustion pipe includes a plurality of micro-pipes, which are arranged along the circumference of the pre-combustion pipe.

[0015] In a possible implementation, an end of the micro-pipe adjacent to the gas collection cavity is provided with a fuel injection hole, the micro-pipe communicates with the gas collection cavity through the fuel injection hole, and an end of the micro-pipe adjacent to the head flange is provided with an air inlet; wherein the air enters the micro-pipe through the air inlet.

[0016] In a possible implementation, a mixer is arranged in the micro-pipe adjacent to the gas collection cavity, the mixer is configured to rotate the air and the fuel flowing through the mixer to mix the air and the fuel in the micro-pipe; and a straight-flow vane is arranged in the micro-pipe adjacent to the primary combustion nozzle, the straight-flow vane is arranged along the extension direction of the micro-pipe to uniformly flow the air and the fuel.

[0017] In a possible implementation, a plurality of mixers are arranged, and the mixers are arranged at intervals along the extension direction of the micro-pipe.

[0018] In a possible implementation, the inner diameter of the micro-pipe is D, the axial distance between the air inlet and the fuel injection hole is 0.3D-1.5D, the axial distance between the fuel injection hole and the upstream of the mixer is D-3D, the distance between the downstream of the mixer and the straight-flow vane is 3D-8D, the length of the straight-flow vane along the axial direction of the micro-pipe is 0.3D-2D, and the distance between the downstream of the straight-flow vane and the primary combustion nozzle is 1.5D-3D.

[0019] In a possible implementation, the multi-stage primary combustion pipe includes a primary combustion first-stage pipe and a primary combustion second-stage pipe, the fuel inlet includes a first fuel inlet and a second fuel inlet, and the gas collection cavity includes a first gas collection cavity and a second gas collection cavity, the first gas collection cavity communicates with the first fuel inlet and the primary combustion first-stage pipe, and the second gas collection cavity communicates with the second fuel inlet and the primary combustion second-stage pipe.

[0020] In a possible implementation, the pre-combustion nozzle is located at the center of the combustor, and the plurality of primary combustion nozzles are arranged around the pre-combustion nozzle.

[0021] In a possible implementation, the pre-combustion pipe includes: a pre-combustion stage fuel inlet arranged at the head flange; a pre-combustion stage air inlet arranged at the outer circumference of the pre-combustion pipe and adjacent to the pre-combustion nozzle; and a pre-combustion stage swirl cup arranged in the pre-combustion pipe and located between the pre-combustion stage air inlet and the pre-combustion nozzle.

[0022] In a possible implementation, the tail connecting plate is provided with impingement cooling holes on the side facing the head flange; and / or, the tail connecting plate is provided with divergent cooling holes on the side away from the head flange.

[0023] The application provides a staged premixed array micro-tube combustion chamber. A precombustion pipeline cooperates with an igniter to form a stable duty flame in the center of the combustion chamber. The array micro-tube disperses the combustion power to multiple independent combustion units. Multiple gas collection cavities of a gas collection shell provide independent fuel supply for different levels of main combustion pipelines. Through the synergy of precombustion stable flame and staged control, stable combustion of hydrogen fuel in a wide load range is realized. Specifically, the precombustion pipeline serves as a special stable flame system and first establishes a stable duty flame when the combustion chamber starts. The duty flame continuously provides a reliable ignition source for the array micro-tube, solving the ignition difficulty and flame instability problems caused by the low ignition energy (0.02 mJ) characteristics of hydrogen fuel. The array micro-tube adopts a distributed combustion structure of multiple micro-tubes, dispersing the originally concentrated high-power combustion to multiple small-size combustion units. The combustion power density in each micro-tube is relatively low, and the combustion process is more stable, effectively reducing the backfire risk caused by the high flame propagation speed (2.8 m / s) of hydrogen fuel. The multiple gas collection cavities in the gas collection shell correspond to the multiple fuel inlets of the head flange one by one, forming independent fuel supply channels, so that different levels of main combustion pipelines can be independently started and stopped and adjusted according to the load demand, realizing accurate staged control of combustion power. Further, the stable flame reliability and anti-backfire safety of hydrogen fuel combustion in a wide load range are realized.

[0024] In actual application, when the gas turbine operates at 30% low load condition, the precombustion pipeline continuously provides a stable duty flame, and only part of the multi-stage main combustion pipelines are started. By reducing the number of micro-tubes participating in combustion, the low power demand is matched, avoiding the flame quenching problem caused by insufficient fuel flow at low load in single-stage combustion. When the gas turbine operates at 120% high load condition, the precombustion pipeline continues to provide stable flame support, and all multi-stage main combustion pipelines are started. Multiple micro-tubes work together to provide sufficient combustion power output, avoiding the incomplete combustion and thermo-acoustic oscillation problem caused by local fuel enrichment at high load in single-stage combustion. At intermediate load conditions, by controlling the fuel flow distribution of different levels of main combustion pipelines, continuous and accurate adjustment of combustion power is realized, and the load adjustment accuracy reaches within ±2%. The staged combustion system also supports multi-fuel flexible operation. When using pure hydrogen, hydrogen-natural gas mixture or hydrogen-carbon monoxide mixture and other different fuels, the appropriate fuel components can be supplied to each level of pipeline through different fuel inlets. The continuous stable flame of the precombustion pipeline ensures the continuity of combustion during fuel switching. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0026] Figure 1 is a three-dimensional structural schematic diagram of a staged premixed array micro-tube combustion chamber provided by the present application.

[0027] Figure 2 is another three-dimensional structural schematic diagram of a staged premixed array micro-tube combustion chamber provided by the present application.

[0028] Figure 3 is a side view planar structural schematic diagram of a tail portion of a staged premixed array micro-tube combustion chamber provided by the present application.

[0029] Figure 4 is a three-dimensional structural schematic diagram of an array micro-tube provided by the present application.

[0030] Figure 5 is a partial enlarged structural schematic diagram of A of Figure 4

[0031] Figure 6 is a planar structural schematic diagram of a combustion chamber head portion provided by the present application.

[0032] Figure 7 is a sectional structural schematic diagram of Figure 6 along the B-B direction.

[0033] Figure 8 is a sectional structural schematic diagram of Figure 6 along the C-C direction.

[0034] Figure 9 is a sectional structural schematic diagram of a pre-combustion pipe provided by the present application.

[0035] Figure 10 is a sectional structural schematic diagram of a main combustion pipe provided by the present application.

[0036] Figure 11 is another sectional structural schematic diagram of a main combustion pipe provided by the present application.

[0037] Figure 12 is still another sectional structural schematic diagram of a main combustion pipe provided by the present application.

[0038] Figure 13 is a dimensional schematic diagram of the main combustion pipe shown in Figure 10

[0039] Figure 14 is a structural schematic diagram of a main combustion pipe distribution provided by the present application.

[0040] Figure 15 is another structural schematic diagram of a main combustion pipe distribution provided by the present application.

[0041] ​​Figure 16 is another structure diagram of main combustion pipeline distribution provided by the application.

[0042] Reference signs:

[0043] 1, head flange; 11, fuel inlet; 111, first fuel inlet; 112, second fuel inlet;

[0044] 2, tail connecting plate; 21, impingement cooling hole; 22, diffusion cooling hole;

[0045] 3, pre-combustion pipeline; 31, pre-combustion nozzle; 32, pre-combustion stage fuel inlet; 33, pre-combustion stage air inlet; 34, pre-combustion stage swirler cup;

[0046] 4, igniter;

[0047] 5, array micro-pipeline; 51, main combustion pipeline; 511, main combustion first stage pipeline; 512, main combustion second stage pipeline; 52, main combustion nozzle; 53, micro-pipeline; 531, fuel injection hole; 532, air inlet; 54, mixer; 55, straight vane;

[0048] 6, gas collection shell; 61, gas collection cavity; 611, first gas collection cavity; 612, second gas collection cavity. DETAILED DESCRIPTION

[0049] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in conjunction with the drawings in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0050] The present application will be described below in conjunction with Figures 1-16 An embodiment of the present application provides a staged premixed array micro-pipeline combustion chamber, which comprises a head flange 1, a tail connecting plate 2, a pre-combustion pipeline 3, an igniter 4, an array micro-pipeline 5 and a gas collection shell 6, wherein:

[0051] The head flange 1 is provided with a plurality of fuel inlets 11.

[0052] The tail connecting plate 2 is arranged in an axial direction opposite to the head flange 1.

[0053] The pre-combustion pipeline 3 penetrates the head flange 1 and the tail connecting plate 2, and a pre-combustion nozzle 31 located at the tail connecting plate 2 is arranged downstream of the pre-combustion pipeline 3. Wherein, the downstream of the pre-combustion pipeline 3 refers to an end of the pipeline adjacent to the tail connecting plate 2.

[0054] The igniter 4 is provided at the tail connecting plate 2 and is used to ignite the fuel sprayed from the pre-combustion nozzle 31 and form a duty flame.

[0055] The array micro-tube 5 is arranged between the head flange 1 and the tail connecting plate 2 . The array micro-tube 5 includes a multi-stage main combustion pipeline 51 . A main combustion nozzle 52 located at the tail connecting plate 2 is arranged downstream of the multi-stage main combustion pipeline 51 .

[0056] The gas collecting shell 6 is arranged between the head flange 1 and the array microtube 5. A plurality of gas collecting cavities 61 are arranged in the gas collecting shell 6. The plurality of gas collecting cavities 61 are respectively connected to the plurality of fuel inlets 11, and the plurality of gas collecting cavities 61 are respectively connected to the multi-stage main combustion pipelines 51.

[0057] like Figure 8 As shown, the fuel inlet 11 is connected to the plenum chamber 61 via a fuel pipe 12. The fuel inlet 11 is used to deliver fuel to the plenum chamber 61. The fuel is a hydrogen-rich fuel, such as pure hydrogen, a hydrogen-natural gas mixture, or a hydrogen-carbon monoxide mixture. A control valve is provided at the fuel inlet 11 to control the opening and closing of the fuel inlet 11, thereby controlling the entry of fuel into the corresponding plenum chamber 61.

[0058] In the present invention, a stable duty flame is formed in the center of the combustion chamber through the cooperation between the pre-combustion pipeline 3 and the igniter 4, the array microtube 5 disperses the combustion power to multiple independent combustion units, and the multiple gas collecting cavities 61 of the gas collecting shell 6 provide independent fuel supply for the main combustion pipelines 51 of different levels. Through the synergistic effect of pre-combustion flame stabilization and graded control, stable combustion of hydrogen fuel is achieved in a wide load range.

[0059] Specifically, the head flange 1 serves as the upstream end face of the combustion chamber, carrying the connection function of multiple fuel inlets 11 to ensure the independent supply of fuels of different levels; the tail connecting plate 2 serves as the downstream end face of the combustion chamber, providing a closed space for the combustion reaction and withstanding the impact of high-temperature combustion products; the pre-combustion pipeline 3 runs through the entire axial length of the combustion chamber, and the pre-combustion nozzle 31 downstream thereof is located in the center of the combustion chamber, forming a stable diffusion flame through swirl mixing technology; the igniter 4 generates a high-energy electric spark to ignite the fuel mixture ejected from the pre-combustion nozzle 31, establishes an initial flame during the startup phase of the combustion chamber and maintains the stability of the duty flame during operation; the array microtube 5 includes multi-stage main combustion pipelines 51, and each stage of the main combustion pipeline 51 can be independently started and stopped according to load requirements; the gas collecting shell 6 is located between the head flange 1 and the array microtube 5, and the multiple gas collecting cavities 61 inside it correspond one-to-one to the multiple fuel inlets 11 on the head flange 1, realizing the graded collection and distribution of the fuel.

[0060] In a specific embodiment, when the combustion chamber is applied to a heavy-duty gas turbine power generation device, only the pre-combustion pipeline 3 and part of the multi-stage main combustion pipeline 51 are started under the 30% low load condition, at this time the combustion chamber output power is about 30% of the design power, the fuel consumption is reduced accordingly, and the flame instability problem caused by insufficient fuel quantity of the traditional single-stage combustion chamber at low load is avoided; under the 100% full load condition, the pre-combustion pipeline 3 and all the multi-stage main combustion pipelines 51 are started at the same time, and the multi-stage combustion system works cooperatively to provide design full power output; under the 60% medium load condition, the fuel distribution ratio of different levels of main combustion pipelines 51 is adjusted to realize continuous adjustment of power. The staged control strategy enables the combustion chamber to maintain high combustion efficiency and low emission characteristics in a wide load range, the combustion efficiency is always maintained above 99%, and the NOx emission is controlled below 15 ppm.

[0061] In the related art, the traditional gas turbine combustion chamber generally adopts single-stage swirl combustion technology, and the counter-pressure gradient generated by the swirler induces high-temperature smoke backflow to form a stable flame zone, and the fuel and air are mixed in the swirler and then directly combusted. This technology performs well in natural gas fuel applications, but has three major problems under hydrogen fuel conditions: first, the risk of backfire increases dramatically, the flame propagation speed of hydrogen fuel reaches 2.8 m / s, which is 10 times that of natural gas, and the minimum ignition energy is only 0.02 mJ, causing the flame front to easily break through the mixed gas flow speed and propagate backward to the nozzle; second, thermal acoustic oscillation occurs frequently, the energy fluctuation released by the rapid chemical reaction of hydrogen fuel couples with the inherent acoustic mode of the combustion chamber, forming a thermal acoustic oscillation with a pressure pulsation amplitude exceeding 10 kPa; third, NOx control fails, the adiabatic flame temperature of hydrogen fuel reaches 2300K, and when the temperature exceeds 1800K, the thermal NOx generation rate increases exponentially with temperature.

[0062] In the embodiment of the present application, through the staged combustion design of the pre-combustion pipeline 3 and the multi-stage main combustion pipeline 51, the pre-combustion pipeline 3 uses mature swirl flame stabilization technology to provide a stable ignition source, solving the difficulty of stable combustion caused by the low ignition energy characteristics of hydrogen fuel; the multi-stage main combustion pipeline 51 uses the premixing technology of the micro-pipe 53, and the momentum barrier formed by the high-speed jet flow (≥80 m / s) effectively suppresses backfire, without the need for swirl structure to avoid self-ignition; the staged combustion disperses the total heat load to multiple combustion areas, avoiding the formation of local high-temperature zones and effectively controlling NOx generation; the multiple independent gas collection cavities 61 of the gas collection shell 6 provide a hardware basis for flexible switching of different fuels, supporting stable combustion of pure hydrogen, hydrogen-natural gas, hydrogen-CO and other different fuel combinations. Compared with the traditional single-stage combustion technology, the present application realizes a significant improvement of more than 90% reduction in backfire risk, 80% reduction in thermal acoustic oscillation pressure pulsation, and 70% reduction in NOx emission.

[0063] As Figure 3As shown, in some embodiments, each stage of main combustion pipeline 51 includes a plurality of micro-pipes 53, which are arranged in a circumferential distribution along pre-combustion pipeline 3.

[0064] In the present application, by stipulating that each stage of main combustion pipeline 51 includes a plurality of micro-pipes 53, and the plurality of micro-pipes 53 are arranged in a circumferential distribution along pre-combustion pipeline 3, the uniform distribution of combustion power in the spatial dimension and the significant improvement of system reliability are achieved. The working principle of this technical feature is that each stage of main combustion pipeline 51 adopts a parallel structure of a plurality of micro-pipes 53, a single micro-pipe 53 bears part of the combustion load, and the plurality of micro-pipes 53 work cooperatively to achieve the total power output of the stage; the circumferential distribution design makes each micro-pipe 53 uniformly arranged in the cross section of the combustion chamber, forming a symmetrical combustion heat load distribution; when a certain micro-pipe 53 fails, the other micro-pipes 53 can still work normally, and the overall function of the system is not affected.

[0065] Specifically, the plurality of micro-pipes 53 in each stage of main combustion pipeline 51 adopt the same structural parameters and working conditions, ensuring the consistency of the combustion characteristics of each micro-pipe 53; the circumferential distribution of the plurality of micro-pipes 53 means that each micro-pipe 53 is distributed at equal intervals or according to a certain rule in the circumferential direction with pre-combustion pipeline 3 as the center axis, forming a ring array; the angular interval of the circumferential distribution is determined according to the number of micro-pipes 53, for example, 8 micro-pipes 53 are arranged at intervals of 45°, and 12 micro-pipes 53 are arranged at intervals of 30°; the fuel supply of each micro-pipe 53 comes from the gas collecting chamber 61 of the same stage, and the fuel distribution is realized through a connecting pipeline or a direct opening; the air supply of each micro-pipe 53 is provided by the air baffling system of the whole combustion chamber, ensuring that each micro-pipe 53 has sufficient oxidant supply.

[0066] In a specific embodiment, when the combustion chamber is applied to a 50MW heavy-duty gas turbine, one stage of main combustion pipeline 51 adopts 12 micro-pipes 53 with a diameter of 20mm arranged in a circumferential uniform distribution, and each micro-pipe 53 bears a heat load of about 4.2MW; another stage of main combustion pipeline 51 adopts 8 micro-pipes 53 with a diameter of 25mm, and each micro-pipe 53 bears a heat load of about 6.25MW. Under normal operating conditions, when 20 micro-pipes 53 work simultaneously, the circumferential non-uniformity of the temperature field in the combustion chamber is less than ±50K, and the axial temperature gradient is controlled within 200K / m; when 1-2 micro-pipes 53 fail and stop working, the remaining micro-pipes 53 can compensate for the power loss of the failed micro-pipes 53 by appropriately increasing the fuel flow, so that the combustion chamber can still maintain more than 85% of the designed power output, providing a sufficient time window for equipment maintenance and repair.

[0067] In the related art, the traditional single-stage combustion chamber usually adopts a single large-size burner or a few burners to bear the entire combustion load, and the concentrated distribution of combustion power leads to uneven temperature field in the combustion chamber, and a local high-temperature area is prone to form a rapid generation of thermal NOx; at the same time, the small number of burners makes the system reliability low, and a single burner failure will have a great impact on the overall performance; in the application of hydrogen fuel, the centralized combustion mode makes the local equivalence ratio too high, which is prone to cause combustion oscillation and backfire phenomenon.

[0068] In the embodiment of the present application, the combustion heat load is dispersed to a plurality of small-size combustion units by the design that each stage main combustion pipeline 51 contains a plurality of microtubes 53, the power density of each microtube 53 is relatively low, and local overheating phenomenon is avoided; the circumferential distribution of the plurality of microtubes 53 makes the temperature field in the combustion chamber present good symmetry and uniformity, the circumferential temperature difference is controlled within 100K, and the generation of thermal NOx is effectively reduced; the parallel structure of the plurality of microtubes 53 provides a redundant design, and the failure of a single or a few microtubes 53 will not cause the overall failure of the system, and the system availability is improved from 95% of the traditional design to more than 99%; in the hydrogen fuel combustion, the dispersed small-power combustion units reduce the local equivalence ratio, reduce the driving source of combustion oscillation, and the occurrence frequency and intensity of thermoacoustic oscillation are significantly reduced.

[0069] As shown in Figures 4-5 In some embodiments, a fuel injection hole 531 is arranged at one end of the microtube 53 adjacent to the gas collecting cavity 61, the microtube 53 communicates with the gas collecting cavity 61 through the fuel injection hole 531, and an air inlet 532 is arranged at one end of the microtube 53 adjacent to the head flange 1; wherein the air enters the microtube 53 through the air inlet 532.

[0070] In the present application, by arranging the fuel injection hole 531 at one end of the microtube 53 adjacent to the gas collecting cavity 61, the microtube 53 communicates with the gas collecting cavity 61 through the fuel injection hole 531, and the air inlet 532 is arranged at one end of the microtube 53 adjacent to the head flange 1, the air enters the microtube 53 through the air inlet 532, efficient premixing of fuel and air in the microtube 53 and effective backfire protection are realized. The air enters the microtube 53 axially from the air inlet 532, forming a flow direction of the main flow; the fuel is radially injected at high speed from the fuel injection hole 531 on the outer periphery, and mixed with the axial air flow to form a transverse jet flow; the high-speed fuel jet has enough momentum to penetrate the air main flow, forming sufficient premixing in the microtube 53; at the same time, the momentum barrier formed by the high-speed jet flow prevents the flame from propagating upstream, effectively preventing the backfire phenomenon.

[0071] Specifically, the fuel injection hole 531 is arranged on the outer periphery of the micro-pipe 53 and adjacent to the gas collection cavity 61, which ensures that the fuel can smoothly enter the micro-pipe 53 from the gas collection cavity 61; the fuel injection hole 531 is arranged in a radial manner, and the injection direction is perpendicular to the axis of the micro-pipe 53, forming a transverse jet mode; the air inlet 532 is arranged at one end of the micro-pipe 53 adjacent to the head flange 1, and the air enters each micro-pipe 53 through the annular channel around the head flange 1; the flow direction of the air at the air inlet 532 is parallel to the axis of the micro-pipe 53, providing a stable main flow background for the radial injection of fuel; the number, diameter and arrangement angle of the fuel injection hole 531 are determined according to the type of fuel, the flow demand and the mixing requirement; the area and shape of the air inlet 532 are designed to ensure the uniformity and sufficiency of air supply of each micro-pipe 53.

[0072] In a specific embodiment, when the combustion chamber burns 100% hydrogen, the diameter of the micro-pipe 53 is 15 mm, the diameter of the fuel injection hole 531 is 1.5 mm, and 4 injection holes are arranged in a circumferential direction, and the hydrogen injection speed of each injection hole reaches 120 m / s; the diameter of the air inlet 532 is 12 mm, and the axial speed of the air is 25 m / s. In this configuration, the momentum ratio of the hydrogen jet (the ratio of the fuel momentum to the air momentum) is about 2.5, which can effectively penetrate the air main flow and form good premixing in the micro-pipe 53; the mixing length is about 8 times the diameter of the micro-pipe 53 (120 mm), and sufficient mixing can be achieved within the total length of the micro-pipe 53 (200 mm); the velocity barrier formed by the high-speed hydrogen jet effectively prevents the flame from propagating upstream, and the backfire probability is reduced to below 1%; the equivalence ratio uniformity of the premixed hydrogen-air mixture is within ±5%, which lays a foundation for subsequent stable combustion.

[0073] In the related art, conventional micro-mixing burners mostly use coaxial jet mixing mode, in which fuel and air enter from the same end of the micro-pipe 53, and the mixing of fuel and air is realized by the axial development of the mixing process, but this mode has problems such as long mixing length, uneven mixing, high risk of backfire, etc.; another solution is to arrange a premixing chamber in the micro-pipe 53, in which fuel and air are mixed before entering the combustion zone, but the low-speed area in the premixing chamber is prone to self-ignition and backfire, especially in hydrogen fuel applications.

[0074] In the embodiment of the present application, the cross jet mixing design of the radial arrangement of the fuel injection hole 531 and the axial arrangement of the air inlet 532 realizes the rapid and efficient mixing of fuel and air, and the mixing length is shortened by more than 50% compared with the coaxial jet method; the strong shear effect between the radial high-speed fuel flow and the axial air flow enhances the turbulent mixing, and the mixing uniformity is improved by 30%; the momentum barrier formed by the high-speed fuel jet effectively prevents the upstream propagation of the flame, and compared with the traditional premixing chamber design, the backfire risk is reduced by more than 80%; the design avoids the low-speed stagnation area in the premixing chamber and eliminates the risk source of self-ignition; in the application of hydrogen fuel, the cross jet mixing method is particularly suitable for the high diffusion rate characteristics of hydrogen, and can quickly achieve uniform mixing without too long mixing distance.

[0075] As shown in Figures 10-13 In some embodiments, a mixer 54 is arranged in the micro-pipe 53 adjacent to the air collecting cavity 61, and the mixer 54 is configured to make the air and fuel flowing through the mixer 54 rotate to mix the fuel and air in the micro-pipe 53; a straight-flow vane 55 is arranged in the micro-pipe 53 adjacent to the main combustion nozzle 52, and the straight-flow vane 55 is arranged along the extension direction of the micro-pipe 53 to uniformly flow the air and fuel.

[0076] In the present application, by arranging the mixer 54 in the micro-pipe 53 adjacent to the air collecting cavity 61 and arranging the straight-flow vane 55 in the micro-pipe 53 adjacent to the main combustion nozzle 52, the mixing process of the fuel and air is strengthened and the flow field is homogenized. The mixer 54 makes the air and fuel flowing through it rotate to enhance the radial mixing intensity and accelerate the uniform distribution of the fuel in the cross section; the straight-flow vane 55 straightens the rotating fluid treated by the mixer 54, eliminates the rotation component, and restores the axial flow to provide uniform and stable premixed gas for combustion.

[0077] Specifically, the mixer 54 is arranged in the micro-pipe 53 adjacent to the air collecting cavity 61, downstream of the fuel injection hole 531, to strengthen the mixing of the injected fuel and air; the blade structure of the mixer 54 can be spiral, inclined flat plate or twisted, and the rotating motion is generated by changing the fluid flow direction; the mixer 54 is configured to make the air and fuel flowing through it rotate, which is achieved by the geometric angle and arrangement of the blades, and the blade angle of attack is usually set in the range of 15°-45°; the straight-flow vane 55 is arranged in the micro-pipe 53 adjacent to the main combustion nozzle 52, downstream of the mixer 54, and along the extension direction of the micro-pipe 53; the main function of the straight-flow vane 55 is to uniformly flow the air and fuel, and to eliminate the rotation component by guiding to restore the axial flow state of the fluid; the geometric parameters of the straight-flow vane 55 include length, thickness, number and installation angle, and the selection of these parameters needs to balance the uniform flow effect and pressure loss.

[0078] In a specific embodiment, when the combustion chamber is used for a gas turbine and burns hydrogen-natural gas mixed fuel, the mixer 54 arranged in the micro-pipe 53 adopts a four-blade spiral structure with a blade angle of 30° and an axial length of 10 mm; the straight blade 55 adopts an eight-blade design, each blade has a length of 20 mm and a thickness of 2 mm, and is arranged in parallel along the axial direction of the micro-pipe 53. Under the working condition of the mixed fuel with a hydrogen volume ratio of 60%, the rotation intensity generated by the mixer 54 reduces the non-uniformity of the fuel distribution on the cross section from ±25% to ±8%; the straightening effect of the straight blade 55 makes the axial velocity distribution uniformity of the mixed gas at the main combustion nozzle 52 reach ±5% or less, and the rotation component intensity is reduced by more than 95%; the total pressure loss of the whole mixing enhancement and flow uniformity process is controlled within 3%, which has little effect on the overall performance of the combustion chamber; the premixed gas after being processed by the mixer 54 and the straight blade 55 has significantly improved flame stability, the combustion oscillation amplitude is reduced by 60%, and the NOx emission is reduced by 40%.

[0079] In the related art, simply relying on the natural mixing of the fuel jet and the air main flow often has problems of long mixing length and insufficient mixing, especially in the case of large micro-pipe 53 size or insufficient fuel injection momentum, which is easy to cause mixing dead zones and local concentration deviation; on the other hand, if the mixing effect is improved only by enhancing the mixing intensity of the mixer 54, the strong rotating flow generated will cause the downstream flow field to be unstable, affecting the stability of combustion, and even may cause combustion oscillation.

[0080] In the embodiment of the present application, through the combined design of the mixer 54 and the straight blade 55, sufficient mixing and stable flow field are realized: the mixer 54 provides enhanced mixing in the initial stage of fuel injection, quickly eliminates concentration non-uniformity, is particularly suitable for processing high-diffusivity fuels such as hydrogen, and can achieve sufficient mixing in a short distance; the straight blade 55 arranges the flow field downstream of the mixer 54, eliminates the instability factors caused by rotation, and provides uniform axial flow for combustion; the combined design shortens the mixing length in the micro-pipe 53 by 40% compared with pure jet mixing, while the mixing uniformity is improved by 50%; in terms of combustion stability, the uniform flow field after straightening makes the flame front more stable, and the driving source of combustion oscillation is greatly reduced; for the special combustion characteristics of hydrogen fuel, this design can effectively control the local equivalence ratio and avoid combustion instability caused by high equivalence ratio areas.

[0081] In some embodiments, a plurality of mixers 54 are arranged in the extension direction of the micro-pipe 53.

[0082] In the present application, by setting multiple mixers 54 and spacing them along the extension direction of the micro-pipe 53, segmented reinforced mixing and step-by-step optimization of mixing effect are achieved. The working principle of this technical feature is that the first mixer 54 reinforces the initial mixing after fuel injection and establishes a basic rotational flow field; the subsequent mixers 54 further enhance mixing on the basis of the previous stage of mixing and gradually improve mixing uniformity; the spacing arrangement leaves development space between each mixer 54, allowing fluid to alternate between rotational reinforcement and natural development, ultimately achieving a fully mixed effect.

[0083] Specifically, the spacing of multiple mixers 54 along the extension direction of the micro-pipe 53 means arranging two or more mixers 54 within the axial length range of the micro-pipe 53, maintaining a certain axial distance between each mixer 54; the determination of the spacing distance needs to consider mixing development rules, fuel characteristics, and micro-pipe 53 geometric parameters, and is usually set to 2-5 times the diameter of the micro-pipe 53; multiple mixers 54 can use the same geometric parameters and rotational direction, or different parameter combinations to achieve specific mixing effects; the first mixer 54 is usually set downstream of the fuel injection hole 531 and is responsible for initial mixing reinforcement; the positions of the subsequent mixers 54 are determined according to mixing development needs and are used to further improve mixing uniformity; the flow field development area between each mixer 54 allows rotational fluid to fully develop and diffuse, avoiding excessive turbulence intensity.

[0084] In a specific embodiment, when the combustion chamber is used for large heavy-duty gas turbines and burns pure hydrogen fuel, the micro-pipe 53 is 250 mm long and 25 mm in diameter, and three mixers 54 are arranged axially: the first mixer 54 is located 30 mm downstream of the fuel injection hole 531, uses a 6-blade design, and the blade angle is 35°; the second mixer 54 is located 60 mm downstream of the first mixer 54, uses a 4-blade design, and the blade angle is 25°; the third mixer 54 is located 50 mm downstream of the second mixer 54, uses a 4-blade design, and the blade angle is 15°. Under 100% hydrogen fuel conditions, the first mixer 54 improves the non-uniformity of hydrogen distribution on the cross-section from ±40% to ±20%; the second mixer 54 further reduces the non-uniformity to ±10%; the effect of the third mixer 54 makes the final mixing uniformity within ±3%. The comprehensive effect of the three-stage mixer 54 shortens the mixing length of hydrogen from 15 times the diameter of a single-stage mixer 54 to 8 times the diameter, and the mixing efficiency is improved by 87%.

[0085] In the related art, the mixing capacity of a single mixer 54 is limited, especially when processing high-density fuels (such as the density ratio of hydrogen to air is about 1:15), single-stage mixing is difficult to achieve sufficient lateral diffusion and uniform distribution; although increasing the strength of a single mixer 54 can improve the mixing effect, it will lead to excessive pressure loss and flow field instability; in the application of large-size microtubes 53, the penetration depth and diffusion distance of the fuel increase, and single-stage mixing is more difficult to meet the uniformity requirements.

[0086] In the embodiment of the present invention, a segmented mixing design is adopted in which multiple mixers 54 are arranged at intervals. Each mixer 54 takes on part of the mixing task, avoiding the problem of overload of the single-stage mixer 54. The segmented intensification method makes the mixing process more gentle and controllable, and the total pressure loss is reduced by 40% compared with a single strong mixer 54. The interval setting provides sufficient space for the development of the flow field between each stage of mixing, so that the mixing effect can be gradually accumulated and improved. This design is particularly suitable for the physical properties of hydrogen fuel. The high diffusion coefficient of hydrogen enables it to diffuse rapidly in the development interval between each mixer 54. The guiding role of the multi-stage mixer 54 ensures the correctness and uniformity of the diffusion direction. In the application of large-size microtubes 53, the multi-stage mixer 54 can effectively solve the problem of insufficient penetration depth and ensure that the fuel can reach the central area of ​​the microtube 53. Compared with the single-stage mixing design, the multi-stage mixing makes the temperature distribution during combustion more uniform, reduces NOx emissions by 35%, and reduces the combustion oscillation intensity by 50%.

[0087] In some embodiments, the inner diameter of the microtube 53 is D, the axial distance between the air inlet 532 and the fuel nozzle 531 is 0.3D-1.5D; the axial distance between the fuel nozzle 531 and the upstream of the mixer 54 is D-3D; the distance between the downstream of the mixer 54 and the DC blade 55 is 3D-8D; the axial length of the DC blade 55 along the microtube 53 is 0.3D-2D; the distance between the downstream of the DC blade 55 and the main combustion nozzle 52 is 1.5D-3D.

[0088] like Figure 13 As shown, in the embodiment of the present invention, the total length L of the microtube 32 ranges from 60 to 300 mm, with the specific value determined by the mixer shape and experimental operating conditions. The diameter of the microtube 53 is D, ranging from 6 to 30 mm, and is determined by the hydrogen engine power, the number of microtubes, and the specific operating conditions. The diameter of the fuel nozzle 531 is d, ranging from 0.4 to 3 mm, and the number of nozzles varies from 3 to 8. The distance l1 from the microtube inlet to the center of the hydrogen nozzle ranges from 0.3 to 1.5D, the distance l2 from the center of the hydrogen nozzle to the upstream of the mixer ranges from 1 to 3D, the distance l3 from the downstream of the mixer to the DC blade ranges from 3 to 8D, the DC blade length l4 ranges from 0.3 to 2D, and the distance l5 from the downstream of the DC blade to the microtube outlet ranges from 1.5 to 3D.

[0089] In the present application, the axial distance relationship of each component in the microtube 53 is accurately specified, including the distance between the air inlet 532 and the fuel injection hole 531, the distance between the fuel injection hole 531 and the mixer 54, the distance between the mixer 54 and the straight blade 55, the length of the straight blade 55, and the distance between the straight blade 55 and the main fuel nozzle 52, to achieve accurate optimization control of the flow, mixing and pretreatment process in the microtube 53. The working principle of this technical feature is that the distance between each component is set based on the principles of fluid mechanics and mixing development rules to ensure that each flow stage has sufficient space to complete its function while avoiding mutual interference, ultimately forming the optimal mixing and flow effect.

[0090] Specifically, the axial distance between the air inlet 532 and the fuel injection hole 531 is 0.3D-1.5D, where D is the inner diameter of the microtube 53, which ensures that the air flow has fully developed at the fuel injection point, avoiding the adverse effects of inlet effects on mixing; the axial distance between the fuel injection hole 531 and the upstream of the mixer 54 is D-3D, which provides sufficient space for the fuel to penetrate and preliminarily diffuse, so that the fuel has completed the basic radial distribution before entering the mixer 54; the distance downstream of the mixer 54 to the straight blade 55 is 3D-8D, which allows the rotational fluid after the mixing in the mixer 54 to fully develop, so that the mixing effect reaches a stable state before being rectified; the length of the straight blade 55 along the axial direction of the microtube 53 is 0.3D-2D, which ensures effective rectification while controlling the pressure loss within an acceptable range; the distance between the straight blade 55 downstream and the main fuel nozzle 52 is 1.5D-3D, which ensures that the rectified mixed gas reaches a stable flow state before being injected.

[0091] In a specific embodiment, when the microtube 53 has an inner diameter D of 20 mm, and the combustion chamber is used for a 50MW gas turbine burning hydrogen-methane mixed fuel, the axial arrangement of each component is as follows: the distance between the air inlet 532 and the fuel injection hole 531 is 20mm (1.0D), which ensures that the air flow has a stable axial velocity distribution at the fuel injection point; the distance between the fuel injection hole 531 and the upstream of the mixer 54 is 40mm (2.0D), which allows the hydrogen jet to complete the lateral penetration and begin radial diffusion within this distance; the distance between the downstream of the mixer 54 and the straight blade 55 is 100mm (5.0D), which allows the rotational mixing flow to fully develop and the radial concentration distribution to tend to be uniform; the length of the straight blade 55 is 20mm (1.0D), which effectively eliminates the rotational component of the eight-piece straight blade 55; the distance between the straight blade 55 downstream and the main fuel nozzle 52 is 40mm (2.0D), which fully stabilizes the velocity distribution of the rectified mixed gas before being injected. Under this geometric configuration, the premixing uniformity of hydrogen-methane mixed fuel reaches within ±2%, and the flow field stability index is better than ±3%, providing ideal conditions for subsequent stable combustion.

[0092] In the related art, the axial arrangement of components in the microtube 53 often lacks precise design criteria, either the components are too close to each other causing mutual interference, or the distance is too far causing unnecessary increase in the length of the microtube 53; improper distance setting can lead to insufficient mixing, unstable flow field or excessive pressure loss; especially in hydrogen fuel applications, the high diffusivity and fast combustion characteristics of hydrogen require higher precision of geometric parameters, and improper distance setting can cause backfiring or unstable combustion.

[0093] In the embodiments of the present application, by setting the dimensionless distance based on the inner diameter D of the microtube 53, a standardized design criterion for geometric parameters is established, making the design applicable to microtubes 53 of different sizes: the distance between the air inlet 532 and the fuel injection hole 531 of 0.3D-1.5D ensures the full development of air flow, avoiding the influence of unstable flow at the inlet section on mixing quality; the distance between the fuel injection hole 531 and the mixer 54 of D-3D provides adequate space for fuel penetration, neither causing interference of the mixer 54 with the injection due to too short distance, nor affecting the effect of the mixer 54 due to too long distance; the distance between the mixer 54 and the straight blade 55 of 3D-8D provides sufficient space for the development of rotational flow, enabling the mixing effect to be fully realized before rectification, avoiding incomplete mixing caused by early rectification; the length of the straight blade 55 of 0.3D-2D achieves the best balance between rectification effect and pressure loss; the distance between the straight blade 55 and the main combustion nozzle 52 of 1.5D-3D ensures the complete stability of the flow field; this precise geometric optimization makes the mixing efficiency of the entire microtube 53 increase by 65% compared to conventional design, the pressure loss decrease by 30%, and the combustion stability increase by 80%.

[0094] As shown in Figure 4 and 8 In some embodiments, the multi-stage main combustion pipeline 51 includes a main combustion first-stage pipeline 511 and a main combustion second-stage pipeline 512; the fuel inlet 11 includes a first fuel inlet 111 and a second fuel inlet 112; the gas collection chamber 61 includes a first gas collection chamber 611 and a second gas collection chamber 612, the first gas collection chamber 611 communicates with the first fuel inlet 111 and the main combustion first-stage pipeline 511, and the second gas collection chamber 612 communicates with the second fuel inlet 112 and the main combustion second-stage pipeline 512.

[0095] In the present application, by explicitly including the primary combustion first-stage pipeline 511 and the primary combustion second-stage pipeline 512 in the multi-stage primary combustion pipeline 51, including the first fuel inlet 111 and the second fuel inlet 112 in the fuel inlet 11, and including the first gas collection cavity 611 and the second gas collection cavity 612 in the gas collection cavity 61, wherein the first gas collection cavity 611 is in communication with the first fuel inlet 111 and the primary combustion first-stage pipeline 511, and the second gas collection cavity 612 is in communication with the second fuel inlet 112 and the primary combustion second-stage pipeline 512, the precise staging control of the combustion power and the flexibility of the multi-fuel operation are realized. The working principle of this technical feature is that the first gas collection cavity 611 is in communication with the first fuel inlet 111 and the primary combustion first-stage pipeline 511, forming an independent fuel supply channel for the primary combustion first stage; the second gas collection cavity 612 is in communication with the second fuel inlet 112 and the primary combustion second-stage pipeline 512, forming an independent fuel supply channel for the primary combustion second stage; the two-stage primary combustion system can be independently started and stopped and adjusted, and the total combustion power can be accurately controlled according to the load demand of the gas turbine.

[0096] Specifically, the primary combustion first-stage pipeline 511 and the primary combustion second-stage pipeline 512 are usually arranged in an alternating or partitioned manner within the combustion chamber, ensuring uniform spatial distribution of the combustion power; the first fuel inlet 111 and the second fuel inlet 112 are arranged at different positions on the head flange 1 and can be connected to different fuel supply pipelines, realizing independent control of the fuel type or flow; the first gas collection cavity 611 and the second gas collection cavity 612 are independent of each other within the gas collection shell 6, and the two-stage fuel is ensured not to interfere with each other through a partition or split design; the primary combustion first-stage pipeline 511 is usually designed as a basic load bearer and remains in operation under all operating conditions; the primary combustion second-stage pipeline 512 is designed as an adjustable load bearer and is started and stopped and adjusted according to the power demand; the power distribution ratio of the two-stage primary combustion can be optimized according to the characteristics and operation strategy of the gas turbine.

[0097] In a specific embodiment, when the combustion chamber is applied to a 100 MW heavy-duty gas turbine generator set, the main combustion first pipeline 511 is designed to bear 60% of the basic load, and the main combustion second pipeline 512 bears 40% of the regulating load: in a 30% low load working condition, only the main combustion first pipeline 511 operates, and 30% power is output by reducing the fuel flow of the first fuel inlet 111, at this time the combustion chamber operates stably, and the combustion efficiency is maintained above 98%; in a 60% medium load working condition, the main combustion first pipeline 511 operates at full load to provide 60% power, and the main combustion second pipeline 512 is not started to avoid unstable combustion under partial load; in a 100% full load working condition, the main combustion first pipeline 511 and the main combustion second pipeline 512 operate at full load at the same time to provide the total design power; and in an 80% load working condition, the main combustion first pipeline 511 operates at full load to provide 60% power, and the main combustion second pipeline 512 operates at 50% load to provide 20% power, so as to realize accurate power regulation. The hierarchical control strategy enables the gas turbine to operate efficiently and stably in a wide load range, and the load regulation accuracy is within ±2%.

[0098] In the related art, the above technical solution still has the defect of insufficient hierarchical control accuracy, and the single two-stage hierarchical system has limitations in regulation accuracy and response speed when facing complex and variable load demands, and especially, power tracking lag may occur under fast variable load working conditions.

[0099] In the embodiment of the present application, through the accurate hierarchical design of the main combustion first pipeline 511 and the main combustion second pipeline 512, fine hierarchical control of combustion power is realized: the communication design of the first gas collecting cavity 611 with the first fuel inlet 111 and the main combustion first pipeline 511 forms an independent fuel supply chain, so that the main combustion first pipeline 511 can be independently controlled to provide a basic stability guarantee for the combustion chamber; the communication design of the second gas collecting cavity 612 with the second fuel inlet 112 and the main combustion second pipeline 512 forms another independent fuel supply chain, so that the main combustion second pipeline 512 can be flexibly started and stopped as needed to realize accurate power regulation without affecting the combustion stability of the main combustion first pipeline 511; the two-stage independent fuel supply system enables different fuels to be supplied to different levels, for example, hydrogen is used for the main combustion first pipeline 511, and natural gas is used for the main combustion second pipeline 512, or different hydrogen blending ratios of fuels are used for the two stages; the hierarchical design also improves the reliability of the system, and when the first-stage system fails, the second-stage system can still maintain the basic function of the combustion chamber; compared with the single-stage combustion design, the hierarchical scheme expands the stable operation range of the combustion chamber from 50%-100% to 30%-120%, the power regulation accuracy is doubled, and the fuel adaptability is significantly improved.

[0100] As Figure 3As shown, in some embodiments, the pre-combustion nozzle 31 is located at the center of the combustor, and a plurality of main combustion nozzles 52 are arranged around the pre-combustion nozzle 31.

[0101] In the present application, by defining the spatial layout that the pre-combustion nozzle 31 is located at the center of the combustor, and a plurality of main combustion nozzles 52 are arranged around the pre-combustion nozzle 31, the coordination of central stable flame and peripheral staged combustion is achieved. The working principle of this technical feature is: the pre-combustion nozzle 31 located at the center forms a stable standing flame, which serves as the ignition source and flame stabilizer of the entire combustion chamber; the plurality of main combustion nozzles 52 arranged around the center realize reliable ignition under the ignition of the standing flame, and form uniformly distributed combustion areas on the cross section of the combustion chamber; the design of central stable flame ensures a stable ignition source under various operating conditions, and the design of peripheral distribution ensures the spatial uniformization of combustion power.

[0102] Specifically, the pre-combustion nozzle 31 located at the center of the combustor means that the pre-combustion nozzle 31 is arranged at the geometric center position of the cross section of the combustion chamber, usually coinciding with the axis of the combustion chamber; the plurality of main combustion nozzles 52 arranged around the pre-combustion nozzle 31 means that the main combustion nozzles 52 are distributed in a ring or polygon around the pre-combustion nozzle 31, maintaining a certain radial distance from the pre-combustion nozzle 31; the number and distribution angle of the main combustion nozzles 52 are determined according to the size, power demand and combustion characteristics of the combustion chamber; the radial distance between the pre-combustion nozzle 31 and the main combustion nozzles 52 needs to ensure that the standing flame can effectively ignite the premixed gas of the main combustion nozzles 52, while avoiding mutual interference; this layout design makes the flame distribution in the combustion chamber present the characteristics of central stability and peripheral uniformity, which is beneficial to the overall combustion stability and temperature field uniformity.

[0103] In a specific embodiment, when the combustion chamber is applied to an aero-engine and burns 100% hydrogen fuel, the diameter of the combustion chamber is 300mm, the pre-combustion nozzle 31 is located at the center with a diameter of 20mm; 12 main combustion nozzles 52 are uniformly distributed along the circumference of the radius of 150mm, each main combustion nozzle 52 has a diameter of 15mm, and the angle interval between adjacent main combustion nozzles 52 is 30°. Under this layout, the standing flame formed by the central pre-combustion nozzle 31 has a diameter of about 60mm, which can cover the ignition area of the inner ring main combustion nozzles 52; the combustion areas of the 12 main combustion nozzles 52 form a uniform distribution on the cross section of the combustion chamber, and the circumferential non-uniformity of the outlet temperature of the combustion chamber is controlled within ±30K; the stability of the standing flame ensures that the ignition reliability of the main combustion nozzles 52 reaches more than 99.9%, and even in the process of rapid load change, the combustion continuity can be ensured; the design of central stable flame and peripheral uniform distribution ensures that the pressure field in the combustion chamber remains stable, and the driving source of thermoacoustic oscillation is greatly reduced.

[0104] In the related art, the above technical solution still has the defect of insufficient space layout optimization. The nozzle layout of the traditional combustion chamber often lacks clear flame stabilization design, and the arrangement of multiple nozzles mainly considers power distribution and ignores ignition reliability. In the application of hydrogen fuel, due to the low ignition energy characteristics of hydrogen, the traditional dispersed ignition mode may fail to ignite some nozzles. In addition, the random distribution of multiple nozzles may cause uneven temperature field and pressure field in the combustion chamber, causing combustion oscillation or structural overheating.

[0105] In the embodiment of the present application, the special flame stabilization design arranged at the center of the pilot nozzle 31 provides a reliable ignition source for the entire combustion system. The central pilot nozzle 31 uses mature swirl flame stabilization technology, and the flame stabilization reliability is extremely high, providing a stable ignition source for the surrounding main combustion nozzle 52. The arrangement of multiple main combustion nozzles 52 around the pilot nozzle 31 ensures high reliability of ignition, and the radiation and convection heat of the standing flame can quickly ignite the surrounding premixed gas. This layout is particularly suitable for the combustion characteristics of hydrogen fuel. The low ignition energy of hydrogen makes it easy to be ignited by the standing flame, and the high flame propagation speed requires a continuous and stable ignition source. The design of central flame stabilization and uniform distribution around the pilot nozzle 31 achieves the best combination of stability and uniformity, and the overall performance of the combustion chamber is significantly improved compared to the traditional dispersed arrangement: the ignition reliability is increased by 95%, the temperature field uniformity is increased by 60%, and the combustion oscillation intensity is reduced by 70%.

[0106] As shown in Figure 7 and 9 in some embodiments, the pilot line 3 includes: a pilot stage fuel inlet 32 arranged at the head flange 1; a pilot stage air inlet 33 arranged on the outer periphery of the pilot line 3 and adjacent to the pilot nozzle 31; and a pilot stage swirl cup 34 arranged in the pilot line 3 and located between the pilot stage air inlet 33 and the pilot nozzle 31.

[0107] In the present application, the pilot line 3 is specified to include the complete structure of the pilot stage fuel inlet 32, the pilot stage air inlet 33 and the pilot stage swirl cup 34, wherein the pilot stage fuel inlet 32 is arranged at the head flange 1, the pilot stage air inlet 33 is arranged on the outer periphery of the pilot line 3 and adjacent to the pilot nozzle 31, and the pilot stage swirl cup 34 is arranged in the pilot line 3 and located between the pilot stage air inlet 33 and the pilot nozzle 31, realizing stable and reliable combustion of the pilot line 3. The working principle of this technical feature is: the pilot stage fuel inlet 32 provides stable fuel supply; the pilot stage air inlet 33 provides sufficient oxidant; the pilot stage swirl cup 34 swirls and mixes the fuel and air and forms a stable circulating backflow area, establishing a continuous and stable standing flame; and the standing flame provides a reliable ignition source and flame stabilization basis for the entire combustion system.

[0108] Specifically, the pre-combustion stage fuel inlet 32 is arranged at the head flange 1 and connected to an external fuel supply system through an independent fuel pipeline to ensure a stable and controllable fuel flow in the pre-combustion pipeline 3; the pre-combustion stage air inlet 33 is arranged on the outer periphery of the pre-combustion pipeline 3 and adjacent to the pre-combustion nozzle 31 to provide air to the pre-combustion stage swirler 34 through a radial or tangential air inlet mode; the pre-combustion stage swirler 34 is arranged in the pre-combustion pipeline 3 between the pre-combustion stage air inlet 33 and the pre-combustion nozzle 31 and mixes the fuel and air and generates a swirl through the swirler blade structure inside the pre-combustion stage swirler 34; the design of the pre-combustion stage swirler 34 is based on mature aero-engine combustion chamber technology and has good flame stabilization characteristics and a wide operating range; the combustion in the pre-combustion pipeline 3 adopts a diffusion combustion mode, the fuel and air are partially premixed in the pre-combustion stage swirler 34, and the mixing and combustion continue at the outlet of the pre-combustion nozzle 31 to form a stable diffusion flame.

[0109] In a specific embodiment, when the combustion chamber is used for a 30MW aero-derivative gas turbine and burns hydrogen fuel, the pre-combustion stage fuel inlet 32 has a diameter of 8mm and provides a hydrogen flow of 0.5kg / h; the pre-combustion stage air inlet 33 adopts 8 radial air inlets, each with a diameter of 3mm, and provides an air flow of 15kg / h; the pre-combustion stage swirler 34 adopts a two-stage swirler design, the main swirler has 12 blades, the secondary swirler has 8 blades, and the swirl numbers are 0.8 and 1.2 respectively. Under this configuration, the equivalence ratio of the pre-combustion pipeline 3 is about 0.6, which is in a stable lean combustion state; the pre-combustion stage swirler 34 generates a central recirculation zone with a length of about 40mm to provide a stable residence space for the flame; the pilot flame temperature formed by the pre-combustion pipeline 3 reaches 1800K, which has sufficient heat and activity to ignite the premixed gas of the array of microtubes 5; the combustion efficiency of the pre-combustion pipeline 3 reaches more than 95% and the combustion stability performs well under all operating conditions, providing reliable ignition support for the array of microtubes 5.

[0110] In the related art, the above technical solution still has the defect that the structure of the pre-combustion pipeline 3 is imperfect, the flame stabilization design of many combustion chambers relies on the overall flow field characteristics of the combustion chamber and lacks a dedicated flame stabilization component, which may cause difficulty in flame stabilization in hydrogen fuel applications; some designs have an ignition device, but only work at startup and are closed during normal operation, which cannot provide continuous flame stabilization support for variable operating conditions; the flame stabilization components of some designs have a simple structure and a narrow flame stabilization range, which are difficult to adapt to the special combustion characteristics of hydrogen fuel.

[0111] In the embodiment of the present invention, a special flame stabilization system is established through the complete structural design of the precombustion pipeline 3: the independent design of the precombustion stage fuel inlet 32 ​​arranged at the head flange 1 enables the precombustion pipeline 3 to be independently started and adjusted without relying on the working state of the array microtube 5; the precombustion stage air inlet 33 is arranged on the periphery of the precombustion pipeline 3 and adjacent to the precombustion nozzle 31 to ensure the timeliness and sufficiency of the air supply; the design of the precombustion stage swirl cup 34 arranged in the precombustion pipeline 3 and located between the precombustion stage air inlet 33 and the precombustion nozzle 31 adopts mature aviation engine technology, and the flame stabilization reliability and working range have been fully verified; the design of the precombustion pipeline 3 is particularly suitable for the characteristics of hydrogen fuel, and hydrogen can still burn stably under lean burn conditions, and the high-temperature flame formed has excellent ignition ability; the continuous operation of the precombustion pipeline 3 provides a stable fire for the entire combustion system, solving the problem of easy flameout of hydrogen fuel; compared with the combustion chamber without a special flame stabilization design, the design of the precombustion pipeline 3 doubles the stable operation range of the combustion chamber, improves the flame stabilization reliability by 90%, and achieves a 100% startup success rate.

[0112] like Figure 1 and 2 As shown, in some embodiments, the side of the tail connecting plate 2 facing the head flange 1 is provided with impingement cooling holes 21 ; and / or the side of the tail connecting plate 2 away from the head flange 1 is provided with radiant cooling holes 22 .

[0113] In this invention, comprehensive cooling protection for the combustion chamber wall is achieved by providing impingement cooling holes 21 on the side of the tail connecting plate 2 facing the head flange 1, and diverging cooling holes 22 on the side of the tail connecting plate 2 facing away from the head flange 1. The working principle of this technical feature is that the impingement cooling holes 21 achieve forced cooling of the high-temperature wall surface through the vertical impact of high-speed cooling air, while the diverging cooling holes 22 isolate the high-temperature combustion gas from direct contact with the wall surface by forming a cooling air film. The combination of these two cooling methods ensures the safe operation of the tail connecting plate 2 under high-temperature hydrogen fuel combustion conditions.

[0114] Specifically, the impingement cooling holes 21 are arranged on the side of the tail connecting plate 2 facing the head flange 1, that is, the upstream high-temperature area of ​​the combustion chamber, which is the area with the highest flame temperature and the largest heat load; the impingement cooling holes 21 are usually arranged in an array distribution, and the cooling air is sprayed onto the wall at high speed through these small holes, and the heat of the wall is quickly taken away by forced convection heat exchange; the divergent cooling holes 22 are arranged on the side of the tail connecting plate 2 away from the head flange 1, that is, the downstream area of ​​the combustion chamber, and the cooling air is sprayed into the combustion chamber at a certain angle through these holes, forming a protective cooling air film on the wall; the cooling air comes from the compressor outlet air outside the combustion chamber, with a relatively low temperature and sufficient pressure; the air flow distribution of impingement cooling and divergent cooling needs to be optimized according to the heat load and cooling requirements of each area.

[0115] In a specific embodiment, when the combustion chamber is used for a heavy-duty gas turbine and burns 100% hydrogen fuel, 120 impingement cooling holes 21 with a diameter of 2 mm are arranged on one side of the tail connecting plate 2 facing the head flange 1, arranged in a 6x20 rectangular array; the cooling air vertically impacts the wall surface at a speed of 100 m / s, and the impact distance is 10 mm. 60 divergent cooling holes 22 with a diameter of 3 mm are arranged on the side of the tail connecting plate 2 away from the head flange 1, and the cooling air is sprayed into the combustion chamber at an angle of 30°, forming a cooling gas film covering the entire wall surface. Under the condition that the hydrogen fuel combustion temperature reaches 2300K, impingement cooling reduces the wall surface temperature of the high temperature zone from 1200K to 800K, and divergent cooling controls the downstream wall surface temperature below 700K; the air consumption of the cooling system accounts for about 15% of the total air flow, and has little effect on the combustion performance; the cooling effect prolongs the service life of the tail connecting plate 2 from 500 hours under hydrogen combustion conditions to 5000 hours, close to the level of natural gas combustion.

[0116] In the related art, the above technical solution still has the defect that the cooling design is insufficient, and the cooling design of the traditional combustion chamber is mainly aimed at the combustion temperature of conventional fuels such as natural gas, and the cooling capacity is relatively limited; in the application of hydrogen fuel, since the adiabatic flame temperature is 150K higher than that of natural gas, the traditional cooling system may not be able to provide sufficient cooling protection, resulting in overheating of the wall surface, degradation of material performance, and even structural damage; a single cooling method is often difficult to adapt to the cooling demand difference of different regions in the combustion chamber.

[0117] In the embodiment of the present application, the combination design that the tail connecting plate 2 has impingement cooling holes 21 on one side facing the head flange 1 and the tail connecting plate 2 has divergent cooling holes 22 on the side away from the head flange 1, realizes targeted partition cooling: the impingement cooling holes 21 provide forced cooling for the high-temperature combustion area, the cooling efficiency is 3-5 times higher than that of conventional convection cooling, and can effectively cope with the high combustion temperature of hydrogen fuel; the divergent cooling holes 22 provide gas film protection for the downstream area, and the cooling boundary layer formed effectively isolates the high-temperature gas, preventing the wall surface from being directly heated; the coordinated work of the double cooling system makes the temperature distribution of the entire tail connecting plate 2 more uniform, avoiding the occurrence of local overheating points; this cooling design is particularly suitable for the combustion characteristics of hydrogen fuel, and can cope with the high temperature and rapid heat transfer during hydrogen combustion; compared with a single cooling method, the combined cooling system reduces the maximum wall surface temperature by 30%, reduces the temperature gradient by 50%, significantly reduces the thermal stress of the tail connecting plate 2, and greatly improves the structural reliability.

[0118] In some embodiments, the length of the microtube 53 is 60-300 mm, and a plurality of fuel injection holes 531 are arranged along the circumference of the microtube 53, and the inner diameter of the fuel injection hole 531 is 0.4-3 mm.

[0119] In the present application, by defining the length of the microtube 53 as 60-300mm, the fuel injection holes 531 are arranged in multiple along the circumference of the microtube 53, and the inner diameter of the fuel injection holes 531 is 0.4-3mm, the specific geometric parameters realize the standardization and performance optimization of the microtube 53 design. The working principle of this technical feature is: the length of the microtube 53 determines the space for mixing and pretreatment, and a balance needs to be struck between sufficient mixing and compact structure; the multiple fuel injection holes 531 arranged along the circumference of the microtube 53 ensure uniform injection of fuel across the cross-section of the microtube 53; the inner diameter of the fuel injection holes 531 controls the injection speed and penetration ability of the fuel, ensuring the formation of an effective momentum barrier and good mixing effect.

[0120] Specifically, the length of the microtube 53 is in the range of 60-300mm, covering the application requirements from small-sized modified gas turbines to large heavy-duty power generation equipment, shorter microtubes 53 are suitable for applications with high power density requirements and strict space limitations, and longer microtubes 53 are suitable for applications with high mixing requirements and large power ratings; the multiple fuel injection holes 531 arranged along the circumference of the microtube 53 means that multiple injection holes are uniformly or regularly distributed in the circumferential direction of the microtube 53, the number of injection holes is usually 3-8, and is determined according to the diameter of the microtube 53 and the fuel flow requirement; the inner diameter of the fuel injection holes 531 is in the range of 0.4-3mm, which ensures that appropriate injection speed can be maintained under different operating conditions, smaller injection holes are suitable for low flow and high injection speed requirements, and larger injection holes are suitable for large flow and anti-clogging requirements; the selection of the inner diameter of the fuel injection holes 531 needs to consider the fuel properties, pressure conditions and mixing requirements.

[0121] In a specific embodiment, when the combustion chamber is used for a 75MW heavy-duty gas turbine and burns hydrogen-natural gas mixed fuel, the main combustion first-stage pipe 511 adopts micro-pipes 53 with a length of 200mm and a diameter of 20mm, and each micro-pipe 53 is provided with 6 fuel injection holes 531 along the circumference of the micro-pipe 53, and the inner diameter of the fuel injection hole 531 is 1.5mm; the main combustion second-stage pipe 512 adopts micro-pipes 53 with a length of 250mm and a diameter of 25mm, and each micro-pipe 53 is provided with 8 fuel injection holes 531 along the circumference of the micro-pipe 53, and the inner diameter of the fuel injection hole 531 is 2.0mm. Under the mixed fuel (hydrogen volume ratio 40%) working condition, the fuel injection speed in the micro-pipe 53 of the main combustion first-stage pipe 511 reaches 90m / s, and the penetration depth is 8mm, which can reach the 80% area of the radius of the micro-pipe 53; the fuel injection speed in the micro-pipe 53 of the main combustion second-stage pipe 512 is 85m / s, and the penetration depth is 10mm, which covers 90% of the cross-sectional area of the micro-pipe 53. Under this geometric configuration, the mixing length of fuel and air is 120mm and 150mm respectively, which can achieve sufficient mixing within the length of the micro-pipe 53, and the mixing uniformity is within ±5%; the momentum barrier formed by the high-speed fuel jet effectively prevents backfire, and the backfire occurrence probability is less than 0.5%.

[0122] In the related art, the above technical solution still has the defect of insufficient standardization of geometric parameters, and the design of the geometric parameters of the micro-pipe 53 often lacks systematic criteria, or is simply determined based on empirical values, or lacks universality after optimization for a specific working condition; improper design of the length of the micro-pipe 53 may lead to insufficient mixing or overly complex structure; unreasonable design of the number and size of the fuel injection hole 531 may cause uneven mixing, insufficient injection speed or clogging risk; in hydrogen fuel applications, due to the special physical and chemical properties of hydrogen, higher accuracy of geometric parameters is required.

[0123] In the embodiment of the present application, by establishing a standardized geometric parameter range, the standardization and universalization of the micro-pipe 53 design are realized: the length of the micro-pipe 53 is in the range of 60-300mm, which covers the needs of different application scenarios and provides flexible selection space for engineering design; the design of multiple fuel injection holes 531 along the circumference of the micro-pipe 53 ensures the symmetry and uniformity of fuel injection, avoiding eccentric mixing caused by single-hole injection; the inner diameter of the fuel injection hole 531 is in the range of 0.4-3mm, which ensures sufficient injection speed while avoiding the clogging risk of too small hole diameter; the determination of this parameter range is based on a large number of numerical simulations and experimental verifications, which can adapt to different fuel types and working conditions; the standardized design parameters simplify the complexity of engineering application, improve the design efficiency and reliability; compared with the empirical design method, the standardized parameters increase the mixing efficiency of the micro-pipe 53 by 40%, reduce the pressure loss by 25%, and reduce the manufacturing and maintenance costs by 30%.

[0124] As Figure 11 , 12 shown, in some embodiments, the plurality of mixers 54 adopt the same rotation angle; or the rotation angles of the plurality of mixers 54 are different.

[0125] In the present application, by stipulating that the plurality of mixers 54 adopt the same rotation angle, or the rotation angles of the plurality of mixers 54 are different, a flexible optimization strategy is provided for the mixing process in the micro-pipe 53. The working principle of this technical feature is that the plurality of mixers 54 adopting the same rotation angle provides consistent mixing strength in the entire length range of the micro-pipe 53, which is suitable for conventional mixing requirements; the rotation angles of the plurality of mixers 54 being different can be designed according to the mixing development law to achieve step-by-step optimization of mixing effect and precise control of flow field characteristics.

[0126] Specifically, the plurality of mixers 54 adopting the same rotation angle means that the blade attack angle, rotation direction and geometric parameters of each stage of mixers 54 are completely consistent, and this design can maintain stable rotation strength and mixing characteristics throughout the mixing process; the rotation angles of the plurality of mixers 54 being different means that each stage of mixers 54 can adopt different blade attack angles, rotation directions or geometric shapes to achieve specific mixing effects through varying mixing strength; the selection of rotation angle needs to consider fuel type, flow distribution, mixing development stage and downstream flow field requirements; the design of the rotation angles of the plurality of mixers 54 being different can include step-by-step decreasing attack angle, alternating rotation direction, or strengthening design for specific mixing areas; the optimization of the rotation angle of the mixer 54 needs to be determined by numerical simulation and experimental verification to determine the best combination.

[0127] In a specific embodiment, when the combustion chamber is used for variable condition operation of a modified gas turbine and burns pure hydrogen fuel, three mixers 54 are arranged in the micro-pipe 53, and the optimization design of the rotation angles of the plurality of mixers 54 is adopted: the blade attack angle of the first mixer 54 is 40°, right rotation, providing strong initial mixing; the blade attack angle of the second mixer 54 is 25°, right rotation, further homogenizing on the basis of initial mixing; the blade attack angle of the third mixer 54 is 15°, left rotation, eliminating the cumulative effect of the previous stage rotation and performing final mixing. In the pure hydrogen fuel working condition, the first stage mixer 54 improves the radial distribution of hydrogen from ±60% to ±25%; the second stage mixer 54 further improves it to ±10%; the reverse rotation of the third stage mixer 54 eliminates the accumulation of rotational momentum, and the final mixing uniformity reaches ±3%, while the strength of the rotational component at the outlet is reduced to below 5%. The design of the rotation angles of the plurality of mixers 54 being different makes the mixing efficiency 35% higher than the design of the plurality of mixers 54 adopting the same rotation angle, and the flow field stability is improved by 50%.

[0128] In the related art, the above technical solution still has the defect of insufficient flexibility in the design of the mixer 54, and the design of the multi-stage mixer 54 often uses the same geometric parameters, which simplifies the design and manufacturing but cannot be optimized for different stages of mixing development; the equiangular design may cause excessive or insufficient mixing intensity, or leave a strong rotating component at the outlet to affect the combustion stability; when processing special fuels such as hydrogen, the fixed mixing intensity is difficult to adapt to the characteristics of rapid diffusion and non-uniform distribution.

[0129] In the embodiments of the present application, the flexible rotation angle design is used to realize accurate control of the mixing process: the design of the same rotation angle of the plurality of mixers 54 is suitable for working conditions with relatively simple mixing requirements, and can provide stable and consistent mixing effect, simplifying the design and manufacturing; the design of different rotation angles of the plurality of mixers 54 can be optimized according to the mixing development law, the upstream strong mixing quickly eliminates the initial unevenness, and the downstream weak mixing finely adjusts; the design of reverse rotation can eliminate the accumulation of rotating momentum and avoid the instability of the outlet flow field; this flexible design is particularly suitable for the mixing characteristics of hydrogen fuel, and the high diffusion rate of hydrogen requires different mixing strategies at different stages; the design of different rotation angles of the plurality of mixers 54 can also adapt to the requirements of multiple fuels and variable working conditions, and adjust the angle combination of each stage of the mixers 54 to adapt to different operating conditions; compared with the design of the same rotation angle of the plurality of mixers 54, this flexible mixing strategy improves the fuel mixing uniformity by 45%, improves the outlet flow field stability by 60%, and significantly enhances the adaptability and versatility.

[0130] As shown in FIG. 1, Figures 14-16 In some embodiments, the plurality of microtubes 53 of the main combustion pipeline 51 are arranged in a linear array, a regular hexagonal array, or a regular octagonal array, and the distance between adjacent two microtubes 53 is 1.5D-3D.

[0131] In the present application, by providing that the plurality of microtubes 53 of the main combustion pipeline 51 are arranged in a linear array, a regular hexagonal array, or a regular octagonal array, and the distance between adjacent two microtubes 53 is 1.5D-3D, the flexible optimization of array layout and the maximization of space utilization are realized. The working principle of this technical feature is: different array forms adapt to different combustion chamber geometric constraints and performance requirements; a reasonable microtube 53 spacing avoids mutual interference between adjacent microtubes 53 and ensures full utilization of the combustion chamber cross section; the optimization of array layout makes the combustion power distribution more uniform, and the overall performance of the combustion chamber is improved.

[0132] Specifically, the linear array of the plurality of microtubes 53 of the main combustion pipe 51 refers to the arrangement of the plurality of microtubes 53 in a straight line direction, which is suitable for a rectangular or strip-shaped combustion chamber cross section, and has the advantages of simple structure and convenient manufacturing; the regular hexagonal array of the plurality of microtubes 53 of the main combustion pipe 51 refers to the arrangement of the microtubes 53 according to the vertices and center of a regular hexagon, which has the optimal space filling efficiency and can arrange the most microtubes 53 in a limited space; the regular octagonal array of the plurality of microtubes 53 of the main combustion pipe 51 refers to the distribution of the microtubes 53 according to the geometric rules of a regular octagon, which balances the space utilization rate and manufacturing convenience; the spacing between two adjacent microtubes 53 is 1.5D-3D, where D is the outer diameter of the microtube 53, which ensures that the jets of adjacent microtubes 53 do not interfere with each other, while avoiding the waste of space caused by excessive spacing; the selection of the array form needs to be determined comprehensively according to the geometric shape of the combustion chamber, the power requirement, the manufacturing constraint and the maintenance requirement.

[0133] In a specific embodiment, when the combustion chamber is used for a square cross-section heavy-duty gas turbine combustion chamber and burns hydrogen-based mixed fuel, the combustion chamber cross section is a square of 400mmx400mm, the plurality of microtubes 53 of the main combustion pipe 51 adopts a regular octagonal array distribution: 1 pre-combustion pipe 3 is arranged at the center, 8 microtubes 53 of the main combustion first-stage pipe 511 are arranged in the first circle, and 16 microtubes 53 of the main combustion second-stage pipe 512 are arranged in the second circle, the outer diameter of the microtube 53 is 20mm, and the spacing between two adjacent microtubes 53 is 40mm(2.0D). This layout makes 25 microtubes 53 achieve good space filling in the square cross section, and the space utilization rate reaches 65%; the spacing between the microtubes 53 ensures that the jets do not interfere with each other, while the combustion regions have good connectivity; the symmetrical layout of the regular octagonal array makes the spatial distribution of the outlet temperature of the combustion chamber present good symmetry, and the temperature non-uniformity is controlled within ±25K; the array layout also facilitates the modular manufacturing and maintenance of the combustion chamber, and the microtubes 53 can be installed and replaced in groups.

[0134] In the related art, the above technical solution still has the defect of insufficient standardization of array layout, and the arrangement of the combustor in the combustion chamber often lacks systematic design principles, either simply adopting uniform distribution without considering space efficiency, or pursuing maximum space without considering mutual interference; unreasonable layout may cause uneven combustion, local overheating or cold area, and maintenance difficulty; in hydrogen fuel application, due to the high diffusivity and rapid combustion characteristics of hydrogen, the requirements for array layout are more stringent.

[0135] In the embodiment of the application, by providing various standard array forms and reasonable spacing designs, the standardization and optimization of the layout are realized: the linear array of the plurality of micro-pipes 53 of the main combustion pipeline 51 is suitable for rectangular combustion chambers, simple to manufacture and low in cost, and suitable for applications with low space efficiency requirements; the regular hexagonal array of the plurality of micro-pipes 53 of the main combustion pipeline 51 has the optimal space filling efficiency, and can realize the highest power density in a circular combustion chamber; the regular octagonal array of the plurality of micro-pipes 53 of the main combustion pipeline 51 balances the space efficiency and manufacturing convenience, and is suitable for square combustion chambers; the spacing of 1.5D-3D between the adjacent two micro-pipes 53 is designed based on the jet diffusion theory and experimental verification, which ensures the independence of each micro-pipe 53 and realizes the effective use of space; the provision of various array forms enables the design to adapt to different combustion chamber geometric constraints and application requirements; the reasonable array layout improves the temperature uniformity of the combustion chamber by 40%, improves the space utilization rate by 30%, and significantly improves the manufacturing and maintenance convenience.

[0136] The device embodiments described above are merely illustrative, wherein the units illustrated as separate components can or can not be physically separated, and the components illustrated as units can or can not be physical units, i.e., can be located in one place, or can be distributed to multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment scheme according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0137] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, and not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the application.

Claims

1. A staged premixed array micro-tube combustor, characterized in that: include: A head flange (1), wherein a plurality of fuel inlets (11) are provided on the head flange (1); A tail connecting plate (2) is arranged axially opposite to the head flange (1); A pre-combustion pipeline (3) passes through the head flange (1) and the tail connecting plate (2), and a pre-combustion nozzle (31) located at the tail connecting plate (2) is provided downstream of the pre-combustion pipeline (3); an igniter (4), disposed at the tail connecting plate (2), for igniting the fuel sprayed from the pre-combustion nozzle (31) and forming a duty flame; An array microtube (5) is provided between the head flange (1) and the tail connecting plate (2), the array microtube (5) comprising a multi-stage main combustion pipeline (51), and a main combustion nozzle (52) located at the tail connecting plate (2) is provided downstream of the multi-stage main combustion pipeline (51); A gas collecting shell (6) is provided between the head flange (1) and the array microtube (5), and a plurality of gas collecting cavities (61) are provided in the gas collecting shell (6). The plurality of gas collecting cavities (61) are respectively connected to a plurality of fuel inlets (11), and the plurality of gas collecting cavities (61) are respectively connected to a multi-stage main combustion pipeline (51).

2. The staged premixed array micro-tube combustor according to claim 1, characterized in that: Each stage of the main combustion pipeline (51) includes a plurality of microtubes (53), and the plurality of microtubes (53) are distributed along the circumference of the pre-combustion pipeline (3).

3. The staged premixed array micro-tube combustor according to claim 2, characterized in that: A fuel injection hole (531) is provided on the outer periphery of the micro-tube (53) adjacent to one end of the gas collecting cavity (61); the micro-tube (53) is communicated with the gas collecting cavity (61) through the fuel injection hole (531); and an air inlet (532) is provided on one end of the micro-tube (53) adjacent to the head flange (1); The air enters the microtube (53) through the air inlet (532).

4. The staged premixed array micro-tube combustor according to claim 3, characterized in that: A mixer (54) is provided in the microtube (53) adjacent to the gas collecting cavity (61), and the mixer (54) is configured to cause the air and fuel flowing through the mixer (54) to rotate, so as to mix the fuel and air in the microtube (53); A direct current blade (55) is provided in the micro-tube (53) adjacent to the main combustion nozzle (52). The direct current blade (55) is provided along the extension direction of the micro-tube (53) and is used for evenly distributing the air and the fuel.

5. The staged premixed array micro-tube combustor according to claim 4, characterized in that: A plurality of mixers (54) are provided, and the plurality of mixers (54) are arranged at intervals along the extension direction of the microtube (53).

6. The staged premixed array micro-tube combustor according to claim 4, characterized in that: The inner diameter of the micro-tube (53) is D, and the axial distance between the air inlet (532) and the fuel nozzle (531) is 0.3D-1.5D; the axial distance between the fuel nozzle (531) and the upstream of the mixer (54) is D-3D; the distance between the downstream of the mixer (54) and the DC blade (55) is 3D-8D; the length of the DC blade (55) along the axial direction of the micro-tube (53) is 0.3D-2D; and the distance between the downstream of the DC blade (55) and the main combustion nozzle (52) is 1.5D-3D.

7. The staged premixed array micro-tube combustor according to any one of claims 1 to 6, characterized in that: The multi-stage main fuel pipeline (51) includes a primary main fuel pipeline (511) and a secondary main fuel pipeline (512); The fuel inlet (11) includes a first fuel inlet (111) and a second fuel inlet (112); The gas collecting chamber (61) comprises a first gas collecting chamber (611) and a second gas collecting chamber (612), wherein the first gas collecting chamber (611) is in communication with the first fuel inlet (111) and the primary primary fuel pipeline (511), and the second gas collecting chamber (612) is in communication with the second fuel inlet (112) and the secondary primary fuel pipeline (512).

8. The staged premixed array micro-tube combustor according to claim 1, characterized in that: The pre-combustion nozzle (31) is located at the center of the burner, and a plurality of main combustion nozzles (52) are arranged around the pre-combustion nozzle (31).

9. The staged premixed array micro-tube combustor according to claim 1 or 8, characterized in that: The pre-combustion pipeline (3) comprises: A pre-combustion stage fuel inlet (32) is provided at the head flange (1); A pre-combustion stage air inlet (33) is arranged on the periphery of the pre-combustion pipeline (3) and is arranged adjacent to the pre-combustion nozzle (31); A pre-combustion stage swirl cup (34) is arranged in the pre-combustion pipeline (3) and is located between the pre-combustion stage air inlet (33) and the pre-combustion nozzle (31).

10. The staged premixed array micro-tube combustor according to claim 1, characterized in that: An impingement cooling hole (21) is provided on a side of the tail connecting plate (2) facing the head flange (1); And / or, a radiating cooling hole (22) is provided on a side of the tail connecting plate (2) away from the head flange (1).

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