Combustor and combustion instability suppression method thereof

Abstract

The present disclosure provides a combustor comprising: a combustion chamber suitable for combustion of premixed gas; the premixing pipe is coaxial with the combustion chamber, communicates with the combustion chamber and is suitable for introducing premixed gas into the combustion chamber in the first axial direction of the combustion chamber; the first restraining assembly is suitable for enabling the premixed gas to generate a first turbulent vortex in the premixing pipe and a second turbulent vortex in the combustion chamber, adjusting the relative time delay between the first turbulent vortex and the second turbulent vortex and changing the axial flow field distribution of the premixed gas in the combustion chamber; and the second suppression assembly is adjustably mounted on the side wall of the combustion chamber and is suitable for introducing air into the combustion chamber to enable the air to form a third turbulent vortex in the combustion chamber so as to change radial and circumferential flow field distribution of premixed gas in the combustion chamber and suppress combustion oscillation.

Description

Technical Field

[0001] At least one embodiment of the present disclosure relates to the field of energy and power technology, and in particular, to a burner and a method for suppressing combustion instability thereof. Background Art

[0002] Combustion instability is a major challenge in the development of advanced gas turbine combustors, rocket engines, and aircraft engine afterburners. In particular, in lean premixed combustion systems that aim to reduce NOx emissions, the problem of combustion instability is particularly serious. Thermoacoustic instability originates from the dynamic coupling between multiple physical fields such as non-steady-state heat release field, pressure field, and flow field, and usually manifests as high-amplitude acoustic pressure and heat release oscillations. Such oscillations cause periodic heat loads on the combustion chamber wall, which in turn induces mechanical vibrations, affects engine performance, and may even cause the flame to flash back, blow out, and ultimately damage the combustion chamber structure.

[0003] At present, the methods of suppressing thermoacoustic instability can be divided into two methods: passive suppression and active suppression. Passive suppression refers to reducing the sensitivity of the combustion process to acoustic interference by optimizing the burner structure and air distribution method, or absorbing acoustic energy by adding a silencer, thereby suppressing the amplification of acoustic waves. Passive suppression methods are usually only applicable to a single frequency in a specific combustion chamber, and are mostly developed for a certain type of burner, with a long development cycle and high cost. Active suppression suppresses thermoacoustic instability through a control system composed of sensors, controllers, and actuators. Taking into account factors such as economy, reliability, and R&D cycle, active control is considered to have good prospects in suppressing thermoacoustic instability in actual combustion systems.

[0004] In the related art, the actuators commonly used in active control technology include dynamic speakers and fuel regulating valves. Dynamic speakers adjust the pressure disturbance in the combustion chamber, thereby changing the thermoacoustic oscillation characteristics to suppress combustion instability. However, since the actual combustion system is in a high temperature and high pressure environment, dynamic speakers cannot be directly applied, and if higher power is to be achieved, the speaker volume will become very large, and it is not suitable for systems with flexible fuel types. The fuel regulating valve changes the heat release fluctuations of the combustion system by adjusting the fuel supply, thereby suppressing its coupling with the sound pressure. However, fuel regulating valves rarely have the performance requirements of wide-band response and high linearity, and even if they do, they are very expensive. Summary of the invention

[0005] In view of this, the present disclosure provides a burner and a method for suppressing combustion instability thereof, which can suppress combustion oscillation.

[0006] As one aspect of an embodiment of the present disclosure, a burner is provided, comprising: a combustion chamber suitable for combustion of a premixed gas; a premixing tube coaxial with the combustion chamber and connected to the combustion chamber, suitable for introducing premixed gas into the combustion chamber in a first axial direction of the combustion chamber; a first suppression component suitable for causing the premixed gas to generate a first turbulent vortex in the premixing tube and a second turbulent vortex in the combustion chamber, and adjusting the relative time delay between the first turbulent vortex and the second turbulent vortex to change the axial flow field distribution of the premixed gas in the combustion chamber; and a second suppression component adjustably mounted on the side wall of the combustion chamber, suitable for introducing air into the combustion chamber so that the air forms a third turbulent vortex in the combustion chamber, so as to change the radial and circumferential flow field distribution of the premixed gas in the combustion chamber and suppress combustion oscillations.

[0007] According to an embodiment of the present disclosure, the first suppression component includes: a connecting rod coaxially inserted into the premixing tube, and a blunt body is provided at the end of the connecting rod close to the combustion chamber; a first swirler is slidably installed between the connecting rod and the premixing tube along the axial direction of the connecting rod, and the premixed gas generates a first turbulent vortex through the first swirler, and the premixed gas that generates the first turbulent vortex generates the second turbulent vortex in the combustion chamber under the action of the blunt body; an adjustment unit is suitable for adjusting the distance between the first swirler and the blunt body, changing the relative time delay between the first turbulent vortex and the second turbulent vortex, so as to suppress combustion oscillations.

[0008] According to an embodiment of the present disclosure, at least a portion of the first cyclone is made of ferromagnetic material; the adjustment unit includes: a magnetic member, which is arranged on the outer surface of the premixing tube; and a position regulator, which is suitable for driving the magnetic member to translate along the first axial direction, so that the magnetic member drives the first cyclone to slide through magnetic force, thereby adjusting the distance between the first cyclone and the blunt body.

[0009] According to an embodiment of the present disclosure, the first swirler includes: a hub, which is slidably mounted on the connecting rod; a plurality of first swirl blades, which are arranged between the outer surface of the hub and the inner surface of the premixing tube, and are inclined relative to the first axial direction and the first radial direction of the hub, so that the premixed gas generates the first turbulent vortex first swirl blades.

[0010] According to an embodiment of the present disclosure, the second suppression assembly includes: at least one pair of second swirlers, each pair of second swirlers is arranged at both radial ends of the combustion chamber, and each of the second swirlers is configured to pass the air toward the flame generated by the combustion of the premixed gas, and cause the air to generate the third turbulent vortex in the combustion chamber.

[0011] According to an embodiment of the present disclosure, each of the second swirlers includes: a barrel portion, a first end of which is open, and a second end of which is sealed and extends into the combustion chamber; a tubular portion, which extends from the inner wall of the combustion chamber toward a direction close to the flame, is coaxial with the barrel portion and is arranged at intervals on the periphery of the barrel portion; and a plurality of second swirl blades, which are connected between the tubular portion and the barrel portion, and are inclined relative to the second axial direction and the second radial direction of the barrel portion; wherein a plurality of through holes are formed on the barrel portion between the plurality of second swirl blades and the inner wall of the combustion chamber, and air from the outside flows in through the first end of the barrel portion, passes through the plurality of through holes, and is disturbed by the plurality of second swirl blades to generate the third turbulent vortex in the combustion chamber.

[0012] As another aspect of the embodiments of the present disclosure, a method for suppressing combustion instability of any of the above-mentioned burners is provided, comprising:

[0013] The premixed gas is introduced into the combustion chamber through the premixing pipe and ignited, so that the premixed gas generates a first flame in the combustion chamber;

[0014] Air is introduced into the combustion chamber through a second suppression component, and the air forms a third turbulent vortex in the combustion chamber, thereby changing the radial and circumferential flow field distribution in the combustion chamber, and causing the combustion of the premixed gas in the combustion chamber to change from a first flame to a second flame;

[0015] When the sound pressure amplitude of the second flame exceeds a preset value, the flow rate of the air introduced is adjusted to keep the sound pressure amplitude below the preset value.

[0016] According to an embodiment of the present disclosure, before the premixed gas is introduced into the combustion chamber through the premixing pipe and ignited, the process further includes:

[0017] The premixed gas is introduced into the combustion chamber through the premixing pipe and ignited, so that the premixed gas generates a third flame in the combustion chamber;

[0018] Obtain a dynamic pressure spectrum diagram of the third flame to determine a first characteristic dimension of the first swirler and a second characteristic dimension of the second swirler of the second suppression assembly, wherein the first characteristic dimension is a dimension of a first swirl blade of the first swirler in a first axial direction of the hub, and the second characteristic dimension is a dimension of a plurality of second swirl blades of the second swirler in a second axial direction of the barrel.

[0019] According to an embodiment of the present disclosure, the combustion instability suppression method further includes:

[0020] When the flow rate is adjusted multiple times and the sound pressure amplitude of the second flame still exceeds the preset value, obtaining a second dynamic pressure spectrum diagram of the second flame to obtain a deviation between the sound pressure amplitude of the second flame and the preset value according to the second dynamic pressure spectrum diagram; and

[0021] The distance between the first swirler and the blunt body in the first suppression assembly is adjusted according to the deviation to change the relative time delay between the first turbulent vortex generated by the first swirler and the second turbulent vortex generated by the blunt body, thereby changing the axial flow field distribution of the premixed gas in the combustion chamber so that the sound pressure is always lower than the preset value.

[0022] According to an embodiment of the present disclosure, adjusting the distance between the first swirler and the bluff body in the first suppression assembly according to the deviation includes:

[0023] Calculating the offset of the first swirler in the axial direction according to the deviation includes:

[0024] u(t)=K p e(t)+K i +K d ;

[0025] Among them, u(t) is the offset; is the deviation; t represents time; K p is the proportional gain, K p The value range of K is 1.0-3.0; i is the integral gain, K i The value range of K is 0.1-0.5; d is the differential gain, K d The value range of is 0.01-0.5;

[0026] The adjustment assembly drives the first swirler to translate along the axial direction in response to the offset.

[0027] According to the burner of the embodiment of the present disclosure, the optimization and improvement of combustion stability is achieved by coordinated regulation of the multi-dimensional flow field. Specifically, the first suppression component is used to generate the first turbulent vortex and the second turbulent vortex in the premixed gas introduced into the combustion chamber. By adjusting the relative time delay between the generation of the first turbulent vortex and the second turbulent vortex, the axial flow field distribution of the premixed gas in the combustion chamber is changed, the synchronous coupling between the axial sound field in the combustion chamber and the turbulent vortex disturbance formed by the first suppression component is destroyed, and the amplitude of the combustion oscillation is reduced. At the same time, the turbulent disturbance generated by the first suppression component enhances the turbulent intensity of the premixed gas, making the fuel and air mixed more evenly. This homogenization significantly reduces the intensity of local overheating areas and high heat release areas, and reduces the driving effect of these areas on the acoustic modes from the root, thereby suppressing the occurrence of combustion instability, and further reducing the risk of flame blowout, flashback and increased emissions. A flow rate of is injected into the combustion chamber through the second suppression component. a The air can be adjusted to have a flow rate so that the air forms a third turbulent vortex in the combustion chamber, which can change the radial and circumferential flow field distribution in the combustion chamber, thereby changing the coupling between the pressure field in the combustion chamber and the radial and circumferential velocity fields, destroying the positive feedback mechanism between the heat release rate fluctuation and the sound pressure, thereby suppressing radial and circumferential combustion instability in a wider range. The turbulent disturbance provided by the third turbulent vortex makes the heat release of the premixed gas more uniform, improves the combustion efficiency in the combustion chamber, and further reduces the combustion oscillation amplitude of the burner. Through the cooperation of the first suppression component and the second suppression component, the axial, radial and circumferential flow fields in the combustion chamber are adjusted, the combustion oscillation is suppressed, and the stability, safety and environmental protection performance of the burner are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0029] Figure 1 Schematically shows an axial cross-sectional view of a burner system according to an embodiment of the present disclosure;

[0030] Figure 2 Schematically shows Figure 1 A cutaway perspective schematic diagram of a burner system is shown;

[0031] Figure 3 Schematically showing a side view of a bluff body and a first swirler according to an embodiment of the present disclosure;

[0032] Figure 4 The schematic diagram schematically shows the principle of a bluff body forming a second turbulent vortex according to an embodiment of the present disclosure;

[0033] Figure 5A perspective view of a first cyclone according to an embodiment of the present disclosure is schematically shown;

[0034] Figure 6 A perspective view of a second cyclone according to an embodiment of the present disclosure is schematically shown;

[0035] Figure 7 A cross-sectional perspective view of a second cyclone according to an embodiment of the present disclosure is schematically shown;

[0036] Figure 8 A perspective view schematically showing the internal structure of a second cyclone according to an embodiment of the present disclosure; and

[0037] Fig. 9 A flowchart of a combustion instability suppression method according to an embodiment of the present disclosure is schematically shown.

[0038] The following are the descriptions of the reference numerals:

[0039] 1. Combustion chamber; 2. Premixing tube; 3. First suppression assembly; 31. Blunt body; 32. First swirler; 321. Hub; 322. First swirl blade; 33. Adjustment unit; 331. Magnetic member; 332. Position regulator; 34. Connecting rod; 4. Second swirler; 41. Cylinder body; 411. Through hole; 42. Tube-shaped portion; 43. Second swirl blade; 5. Pressure sensor; 6. Pressure data acquisition system; 7. Controller; 8. PID controller; 9. First turbulent vortex; 10. Second turbulent vortex; 11. Third turbulent vortex; 12. Flame. DETAILED DESCRIPTION

[0040] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0041] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0042] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0043] When using expressions such as "at least one of A, B, and C, etc.", it should generally be interpreted as the meaning of the expression generally understood by those skilled in the art. For example, "a system having at least one of A, B, and C" should include but not be limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc. When using expressions such as "at least one of A, B, or C, etc.", it should generally be interpreted as the meaning of the expression generally understood by those skilled in the art. For example, "a system having at least one of A, B, or C" should include but not be limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.

[0044] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only reference directions of the drawings and are not intended to limit the scope of protection of the present disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or configurations will be omitted when they may cause confusion in the understanding of the present disclosure.

[0045] In the process of realizing the present disclosure, it was found that by actively applying appropriate external excitations and changing the dynamic characteristics of the flame, the inherent instability of the flame can be reduced within a wider working range, thereby decoupling the heat release pulsation and the system sound pressure and suppressing the thermoacoustic instability. This type of active control method that directly acts on the flow field structure in the combustion chamber has the characteristics of strong adaptability and low cost, can be widely applied to various types of fuels, and shows the advantages of high efficiency, simplicity and practicality in improving the stability of the combustion system. However, in existing combustion systems, there are few technologies that suppress thermoacoustic instability by actively adjusting the flow field characteristics of the combustion chamber.

[0046] Figure 1 The axial cross-sectional view of the burner system according to the embodiment of the present disclosure is schematically shown. Figure 2 Schematically shows Figure 1 The burner system is shown in a cutaway perspective view. Figure 1 and Figure 2 In the figures, the burners shown are all cross-sectional views.

[0047] As one aspect of the embodiments of the present disclosure, a burner is provided. Figure 1 and Figure 2As shown, the burner includes a combustion chamber 1, a premixing tube 2, a first suppression assembly 3, and a second suppression assembly. The combustion chamber 1 is suitable for providing premixed gas to burn and generate flames 12. The premixing tube 2 is coaxial with the combustion chamber 1 and communicated with the combustion chamber 1. The premixing tube 2 is suitable for introducing premixed gas into the combustion chamber 1 in the first axial direction of the combustion chamber 1. The first suppression assembly 3 is suitable for causing the premixed gas introduced into the combustion chamber 1 to generate a first turbulent vortex 9 in the premixing tube 2, and a second turbulent vortex 10 in the combustion chamber 1, and to adjust the relative time delay between the first turbulent vortex 9 and the second turbulent vortex 10, so as to change the axial flow field distribution of the premixed gas in the combustion chamber 1. The second suppression assembly is adjustably mounted on the side wall of the combustion chamber 1, and is suitable for introducing air into the combustion chamber 1 so that the air forms a third turbulent vortex 11 in the combustion chamber 1, so as to change the radial and circumferential flow field distribution of the premixed gas in the combustion chamber 1 and suppress combustion oscillation.

[0048] According to the burner of the embodiment of the present disclosure, the first suppression component 3 is used to generate the first turbulent vortex 9 and the second turbulent vortex 10 in the premixed gas introduced into the combustion chamber 1. By adjusting the relative time delay between the generation of the first turbulent vortex 9 and the second turbulent vortex 10, the axial flow field distribution of the premixed gas in the combustion chamber 1 is changed, the synchronous coupling between the axial sound field in the combustion chamber 1 and the turbulent vortex disturbance formed by the first suppression component 3 is destroyed, and the amplitude of the combustion oscillation is reduced. a The air is captured and the air forms a third turbulent vortex 11 in the combustion chamber 1, which can change the radial and circumferential flow field distribution of the combustion chamber 1, and then change the coupling between the pressure field and the radial and circumferential velocity fields in the combustion chamber 1, destroying the positive feedback mechanism between the heat release rate fluctuation and the sound pressure, thereby suppressing radial and circumferential combustion instability in a wider range. The turbulent disturbance provided by the third turbulent vortex 11 makes the heat release of the premixed gas more uniform, improves the combustion efficiency in the combustion chamber 1, and further reduces the combustion oscillation amplitude of the burner. Through the cooperation of the first suppression component 3 and the second suppression component, the axial, radial and circumferential flow fields in the combustion chamber 1 are adjusted to achieve the suppression of combustion oscillations.

[0049] According to an embodiment of the present disclosure, the premixed gas is a combustible gas, such as natural gas, a mixture of methane and air, a mixture of hydrogen and air, etc., which is not limited here.

[0050] According to an embodiment of the present disclosure, a pressure sensor 5 is provided on the inner wall of the combustion chamber 1. The pressure sensor 5 is suitable for collecting the sound pressure pulsation signal of the flame 12 in the combustion chamber 1, so as to obtain the pulsation main frequency of the flame 12 and the pulsation amplitude corresponding to the pulsation main frequency according to the sound pressure pulsation signal. When the pulsation amplitude is less than or equal to the preset value, it is judged that the combustion is in a stable state.

[0051] In an illustrative embodiment, the external pressure data acquisition system 6 acquires the acoustic pressure pulsation signal detected by the pressure sensor 5. The processor (such as a computer, CPU, etc.) has a host computer pressure data acquisition and analysis software. The host computer pressure data acquisition and analysis software obtains the acoustic pressure characteristics of the flame 12 through fast Fourier transform (FFT). The acoustic pressure characteristics include a time domain diagram of the dynamic pressure change over time and a spectrum diagram of the dynamic pressure. The pulsation main frequency f of the acoustic pressure pulsation signal can be extracted through the spectrum diagram of the dynamic pressure. b The pulsation amplitude P corresponding to the main frequency b .

[0052] According to the embodiment of the present disclosure, the sound pressure amplitude of the flame in the combustion chamber 1 can be adjusted by adjusting the flow rate of the air introduced into the second suppression assembly.

[0053] According to the embodiments of the present disclosure, the flame sound pressure amplitude can be obtained by the pressure sensor 5 to determine whether the flame is in a stable combustion state, or the flame shape can be observed and the sound emitted by the flame can be listened to to determine whether the flame is in a stable combustion state.

[0054] In an illustrative embodiment, the wall of the combustion chamber 1 may be made of high temperature resistant quartz glass to facilitate observation of the flame morphology.

[0055] like Figure 1 and Figure 2 As shown, the combustion chamber 1 is divided into an end wall, a combustion section and a contraction section in sequence. The end wall is located at Figure 1 At the lower end of the combustion chamber 1 from the perspective shown, the combustion section is a tubular structure, and the radius of the contraction section gradually decreases from bottom to top.

[0056] Figure 3 A side view of a bluff body and a first swirler according to an embodiment of the present disclosure is schematically shown.

[0057] According to the embodiments of the present disclosure, Figures 1 to 3 As shown, the first suppression assembly 3 includes a connecting rod 34, a first swirler 32 and an adjustment unit 33. The connecting rod 34 is coaxially inserted into the premixing tube 2, and a bluff body 31 is provided at the end of the connecting rod 34 close to the combustion chamber 1. The first swirler 32 is slidably installed between the connecting rod 34 and the premixing tube 2 along the axial direction of the connecting rod 34. The premixed gas generates a first turbulent vortex 9 through the first swirler 32, and the premixed gas that generates the first turbulent vortex 9 generates a second turbulent vortex 10 in the combustion chamber 1 under the action of the bluff body 31. The adjustment unit 33 is suitable for adjusting the distance between the first swirler 32 and the bluff body 31, changing the relative time delay between the first turbulent vortex 9 and the second turbulent vortex 10, so that the shedding frequency of the first turbulent vortex 9 acting on the second turbulent vortex 10 is mismatched with the natural frequency of the axial sound pressure mode in the combustion chamber 1, so as to suppress combustion oscillation.

[0058] In such an embodiment, the axial position of the first swirler 32 is actively adjusted by the adjustment unit 33, and the first turbulent vortex 9 generated by the first swirler 32 interferes with the second turbulent vortex 10 generated by the bluff body 31, so that the shedding frequency of the second turbulent vortex 10 formed by the bluff body 31 no longer matches the natural frequency of the axial sound pressure mode in the combustion chamber 1, thereby destroying the synchronous coupling between the axial sound field in the combustion chamber 1 and the turbulent vortex disturbance formed by the bluff body 31, and reducing the amplitude of the combustion oscillation. At the same time, the turbulent disturbance generated by the first swirler 32 enhances the turbulent intensity of the premixed gas, makes the fuel and air mix more evenly, reduces the intensity of the local overheating area and the high heat release area, and thus reduces the driving effect of these areas on the sound pressure mode.

[0059] According to an embodiment of the present disclosure, the regulating unit 33 may drive the first cyclone 32 to move in response to an offset calculated by an external proportional integral derivative (PID) controller. It is understood that the PID controller 8 may be integrated into the controller 7 or independently provided.

[0060] In an illustrative embodiment, after adjusting (once or multiple times) the flow rate of air entering the combustion chamber 1 through the second suppression component, if the sound pressure amplitude in the combustion chamber 1 still exceeds the preset value, the processor obtains the dynamic pressure map of the flame in the combustion chamber 1 based on the sound pressure pulsation signal, obtains the sound pressure amplitude of the flame based on the dynamic pressure map, and calculates the deviation between the sound pressure amplitude and the preset value, and the PID controller 8 calculates the offset distance (offset) between the first swirler 32 and the blunt body 31 in the first suppression component 3 based on the deviation.

[0061] Figure 4 The schematic diagram schematically shows the principle of a bluff body forming a second turbulent vortex according to an embodiment of the present disclosure.

[0062] According to the embodiments of the present disclosure, Figure 4 As shown, the bluff body 31 has a frustum shape with a radius gradually expanding in the direction toward the combustion chamber 1 , and an annular gap is provided between the bluff body 31 and the inner wall of the premixing tube 2 for the premixed gas to pass through.

[0063] According to an embodiment of the present disclosure, at least a portion of the first cyclone 32 is made of ferromagnetic material. Figure 1 and Figure 2 As shown, the adjustment unit 33 includes a magnetic member 331 and a position regulator 332. The magnetic member 331 is arranged on the outer surface of the premixing tube 2, and the position regulator 332 is suitable for driving the magnetic member 331 to translate along the axial direction of the premixing tube 2, so that the magnetic member 331 drives the first cyclone 32 to slide through the magnetic force, thereby adjusting the distance between the first cyclone 32 and the bluff body 31.

[0064] In an illustrative embodiment, a slide groove extending in the axial direction is formed on the outer surface of the premixing tube 2. The magnetic member 331 is driven by the position regulator 332 to translate in the axial direction in the slide groove, and the slide groove provides guidance for the translation of the magnetic member 331.

[0065] In an illustrative embodiment, the position regulator 332 may be a linear drive motor, which is mounted on the outside of the premixing tube 2 through a mounting bracket, and the magnetic member 331 is mounted on the driving end of the linear drive motor, and moves along the axial direction of the premixing tube 2 under the guidance of the slideway following the driving end. In an illustrative embodiment, the magnetic member 331 may be a magnet.

[0066] Figure 5 A perspective view of a first cyclone according to an embodiment of the present disclosure is schematically shown.

[0067] According to the embodiments of the present disclosure, Figure 5 As shown, the first swirler 32 includes a hub 321 and a plurality of first swirl blades 322. The hub 321 is slidably sleeved on the connecting rod 34, and the plurality of first swirl blades 322 are arranged between the outer surface of the hub 321 and the inner surface of the premixing tube, and are arranged obliquely relative to the axial direction and radial direction of the hub, and are configured to generate a first turbulent vortex 9 in the premixed gas.

[0068] According to an embodiment of the present disclosure, the hub 321 and at least one of the plurality of first swirl blades 322 are made of ferromagnetic material, so that the first swirler 32 can move in the axial direction of the premixing tube 2 following the magnetic member 331 arranged on the outer surface of the premixing tube 2 .

[0069] According to the embodiments of the present disclosure, Figure 3 As shown, the first swirl blades 322 are inclined to the axial direction and radial direction of the hub 321 and are arranged between the inner wall of the premixing tube 2 and the hub 321 .

[0070] In an exemplary embodiment, the airflow outlet angle θ of the first swirl blade is 1 The range of is 0° to 30°, for example, 0°, 10°, 15° or 30°. The number of the first swirl blades can be 6 to 16 (for example, 6, 8, 10, 13 or 16), and they are evenly arranged between the inner wall of the premixing tube 2 and the hub 321. The hub 321 is hollow and can be sleeved on the connecting rod 34.

[0071] According to the embodiments of the present disclosure, Figure 1 and Figure 2As shown, the second suppression assembly includes at least one pair of second swirlers 4, each pair of second swirlers 4 is arranged at both radial ends of the combustion chamber 1, and each second swirler 4 is configured to introduce air toward the flame generated by the combustion of the premixed gas, and cause the air to generate a third turbulent vortex 11 in the combustion chamber 1.

[0072] In such an embodiment, the second swirler 4 installed on the wall of the combustion chamber 1 injects a flow rate of 1000 μm into the combustion chamber 1 perpendicularly or obliquely to the axis of the combustion chamber 1. a The air injected into the combustion chamber 1 increases the turbulence intensity of the flow field, enhances the mixing efficiency of air and fuel, and thus optimizes the combustion process. In addition, the injected air disturbs the acoustic mode in the combustion chamber 1, breaks the thermal-acoustic coupling, and suppresses combustion instability. At the same time, this airflow injection method can also improve the uniformity of temperature distribution in the combustion chamber 1, reduce the heat load of the local high-temperature area, and extend the service life of the combustion chamber 1. The flow rate injected into the combustion chamber 1 through the second suppression component is a The injected air can effectively cool the overheated combustion chamber 1 wall.

[0073] According to an embodiment of the present disclosure, a plurality of pairs of second swirlers 4 may be evenly distributed along the axial direction of the combustion chamber 1 .

[0074] In an illustrative embodiment, the second suppression assembly may include 1 pair, 2 pairs, 3 pairs, 4 pairs or 5 pairs of second cyclones 4 .

[0075] According to the embodiment of the present disclosure, the suppression of the flame in the combustion chamber 1 in the circumferential direction and the radial direction can be adjusted by adjusting the flow rate of the air introduced into the second swirler 4 .

[0076] In an illustrative embodiment, the suppression of the flame in the combustion chamber 1 in the circumferential and radial directions can be adjusted by adjusting the angle of the second swirler 4 toward the flame.

[0077] In an illustrative embodiment, a first mounting port and a second mounting port are provided on the wall surface of the combustion chamber 1, the second swirler 4 is embedded in the first mounting port, and the pressure sensor 5 is embedded in the second mounting port, which simplifies the installation of the second swirler 4 and the pressure sensor 5 and reduces their loss.

[0078] In an illustrative embodiment, the collection frequency of the pressure sensor 5 can be 50kHz, which is used to collect low-frequency and high-frequency pressure oscillations in the combustion chamber 1. The pressure measurement point is located in the middle of the two second swirlers 4 close to the end wall of the combustion chamber 1 and is installed in the second mounting port. The head of the pressure sensor 5 is flush with the inner wall of the combustion chamber 1.

[0079] According to the embodiment of the present disclosure, the second swirler 4 injects a flow rate into the combustion chamber 1 of a The direction of the air can be injected perpendicularly or obliquely to the axis of the combustion chamber 1.

[0080] Figure 6 A perspective view of a second cyclone according to an embodiment of the present disclosure is schematically shown. Figure 7 A cross-sectional perspective view of a second cyclone according to an embodiment of the present disclosure is schematically shown. Figure 8 The internal structure of the second cyclone according to the embodiment of the present disclosure is schematically shown in a three-dimensional diagram. Figure 8 The tubular portion 42 is not shown.

[0081] According to the embodiments of the present disclosure, Figures 6 to 8 As shown, each second swirler 4 includes a barrel portion 41, a tubular portion 42 and a plurality of second swirl blades 43. The first end of the barrel portion 41 is open, and the second end of the tubular portion is blocked and extends into the combustion chamber 1. The tubular portion 42 extends from the inner wall of the combustion chamber 1 toward the direction close to the flame, and is coaxial with the barrel portion 41 and is sleeved on the outer periphery of the barrel portion 41 at intervals. A plurality of second swirl blades 43 are connected between the tubular portion 42 and the barrel portion 41, and are arranged obliquely relative to the second axial direction and the second radial direction of the barrel portion 41. Among them, a plurality of through holes 411 are formed on the barrel portion 41 between the second swirl blades 43 and the inner wall of the combustion chamber 1, and air from the outside flows in through the first end of the barrel portion 41, passes through the plurality of through holes 411, and is disturbed by the plurality of second swirl blades 43, and generates a third turbulent vortex 11 in the combustion chamber 1.

[0082] According to an embodiment of the present disclosure, the diameter of the first mounting opening is larger than the outer diameter of the barrel portion 41 and smaller than the outer diameter of the tubular portion 42. An end of the barrel portion 41 extending out of the combustion chamber 1 may be formed with an external thread structure to mount the second swirler 4 on the wall surface of the combustion chamber 1 through a locking member threadedly coupled to the external thread.

[0083] According to an embodiment of the present disclosure, the second swirl blade 43 may include a plurality of second swirl blades, which are inclined to the axis of the barrel portion 41 and arranged in a spiral shape, so that the air passes through the plurality of second swirl blades to generate a third turbulent vortex 11, thereby changing the radial and circumferential flow field distribution of the combustion chamber 1 and suppressing combustion oscillations.

[0084] In an exemplary embodiment, the airflow outlet angle θ of the second swirl blade is 2The angle of the second swirl blades is 0° to 40°, for example, 0°, 10°, 15°, 20°, 30° or 40°. The number of the second swirl blades is 6 to 16 (for example, 6, 8, 10, 13 or 16) and they are evenly arranged between the tubular portion 42 and the barrel portion 41. The barrel portion 41 is evenly arranged with 1 to 5 circles of air injection holes (through holes 411) along the circumferential direction near the inner wall of the combustion section (located on the barrel portion 41 between the second swirl blades 43 and the inner wall of the combustion chamber 1). The diameter of the air injection holes is the diameter D of the barrel portion 41 of the second swirler 4. w of ~ .

[0085] In such an embodiment, through the coordinated layout of the adjustable air flow outlet angle of 0°~40° and 6~16 blades, combined with 1~5 circles of circumferential injection holes, a swirl field and an air curtain are formed, which can effectively suppress combustion oscillation and reduce CO / NOx emissions; multiple circles of air injection holes (through holes 411) accurately control the air flow distribution and reduce the thermal stress in the high temperature zone. Combined with the modular blade configuration, it can take into account both combustion stability and structural reliability.

[0086] In such an embodiment, at least one pair of second swirlers 4 is installed at both ends of the radial direction of the combustion section wall surface to inject a flow rate of a The air is symmetrically distributed along the axis of the combustion section to ensure uniform and stable combustion in all parts of the combustion chamber 1. This arrangement can evenly disturb the flow field in the combustion chamber 1, avoiding excessive local turbulence or flow field disorder caused by asymmetric airflow distribution, thereby improving the stability of the combustion process and effectively suppressing combustion instability.

[0087] According to the embodiment of the present disclosure, air is introduced into the second swirler 4 installed on the wall of the combustion chamber 1, and at least one pair of second swirlers 4 is installed at both ends of the radial direction of the wall of the combustion chamber 1. The air first passes through the barrel 41, and then is ejected through the multiple through holes 411 on the barrel 41 and passes through the multiple second swirl blades to form the third turbulent vortex 11 with a spiral trajectory, and is ejected into the combustion chamber 1. The third turbulent vortex 11 can effectively cool the overheated wall of the combustion chamber 1.

[0088] According to an embodiment of the present disclosure, the second swirlers 4 may be symmetrically arranged in one or more pairs along the axial direction along the wall of the combustion chamber 1, and the installation position and number of the second swirlers 4 are determined by the combustion disturbance form. The direction of the axis of the second swirler 4 may be perpendicular to the combustion section wall of the combustion chamber 1, or at a certain angle to the combustion section wall.

[0089] According to the burner of the embodiment of the present disclosure, the axial position of the first swirler 32 in the premixing tube 2 can be actively adjusted by the PID controller 8 and the position regulator 332, so as to change the relative time delay τ between the first turbulent vortex 9 generated by the first swirler 32 and the second turbulent vortex 10 generated by the blunt body 31. d This relative time delay τ d The change in the turbulent vortexes generated by the two and the mutual interference of the turbulent vortices generated by the two change the time scale and distribution characteristics of the shedding of the second turbulent vortex 10 generated by the blunt body 31, so that the shedding frequency of the second turbulent vortex 10 generated by the blunt body 31 no longer matches the natural frequency of the axial sound pressure mode in the combustion chamber 1, thereby destroying the synchronous coupling between the sound field in the combustion chamber 1 and the disturbance of the second turbulent vortex 10 generated by the blunt body 31. By weakening this positive feedback mechanism, the amplitude of the combustion oscillation is reduced. At the same time, the turbulent disturbance generated by the first swirler 32 enhances the turbulent intensity of the premixed gas, making the fuel and air mix more evenly. This homogenization significantly reduces the intensity of local overheating areas and high heat release areas, and reduces the driving effect of these areas on the acoustic mode from the root, thereby suppressing the occurrence of combustion instability, thereby reducing the risk of flame blowout, flashback and increased emissions, and improving the stability, safety and environmental protection performance of the combustion system.

[0090] In an illustrative embodiment, a premixed gas is introduced through a premixing tube 2 into a sealed combustion chamber 1 where the first swirler 32 and the second suppression assembly are not installed and ignited, so that the premixed gas generates a third flame in the combustion chamber 1. The first characteristic size of the first swirler 32 and the second characteristic size of the multiple second swirlers 4 of the second suppression assembly are determined by acquiring a dynamic pressure spectrum of the third flame.

[0091] By acquiring the sound pressure pulsation information of the third flame, a time domain diagram of the dynamic pressure change of the third flame over time and a spectrum diagram of the dynamic pressure are obtained. According to the spectrum diagram of the dynamic pressure of the third flame, the pulsation main frequency of the third flame and the amplitude corresponding to the main frequency are determined.

[0092] The characteristic dimension D of the first cyclone 32 f1 (like Figure 3 shown) meet:

[0093] ≈0.2~0.6(1)

[0094] in, is the Strouhal number, D f1 is the characteristic size of the first cyclone 32, f b The pulsation frequency of the third flame, m is the flow rate of the premixed gas introduced into the premixing tube 2.

[0095] The characteristic dimension D of the second cyclone 4 f2 (like Figure 8 shown) meet:

[0096] ≈0.2~0.6(2);

[0097] in, is the Strouhal number, D f2 is the characteristic size of the second cyclone 4, f b The pulsation frequency of the third flame, a is the flow rate of the incoming air.

[0098] Further, a first spoiler having a first characteristic size is mounted on the connecting rod 34, and a second spoiler having a second characteristic size is mounted on the first mounting port of the combustion chamber 1. Premixed gas is introduced into the combustion chamber 1 through the premixing pipe 2 and ignited to burn the premixed gas in the combustion chamber 1. Air is introduced into the combustion chamber 1 through a plurality of second spoilers.

[0099] When the sound pressure amplitude in the combustion chamber 1 is higher than a preset value (e.g., 50 Pa), the flow rate of the air introduced can be adjusted. a , so that the sound pressure amplitude in the combustion chamber 1 is less than or equal to the preset value.

[0100] Adjusting the air flow rate a If the sound pressure amplitude in the combustion chamber 1 still cannot be made less than or equal to the preset value, the pulsation main frequency f of the sound pressure pulsation signal of the current flame is extracted by the upper computer pressure data acquisition and analysis software through fast Fourier transform (FFT). b The amplitude P corresponding to the main frequency b , the main pulsation frequency f of the extracted combustion chamber 1 sound pressure signal b And the amplitude P corresponding to the main frequency b Passed as input parameter to PID controller 8 for error calculation:

[0101] e(t)=P b -P s (3);

[0102] Where e(t) is the error, t is the time, that is, the current moment when the control system is running; P s It is the maximum permissible sound pressure amplitude in the combustion chamber 1, ie, the preset value.

[0103] P s It can be set to 50 Pa, and can be adjusted according to the amplitude P bGet the real-time sound pressure amplitude in combustion chamber 1 and the set value P s The deviation e(t) between them.

[0104] Based on the calculated error e(t), the offset u(t) is calculated using the PID control algorithm:

[0105] u(t)=K p e(t)+K i +K d (4);

[0106] Among them, K p is the proportional gain, K p The value range is 1.0-3.0; K i is the integral gain, K i The value range is 0.1-0.5; K d is the differential gain, K d The value range is 0.01-0.5, and t is time.

[0107] The calculated offset u(t) is transmitted to the position regulator 332, and the position regulator 332 is used to adjust the axial position of the first cyclone 32 to change the distance L between the first cyclone 32 and the bluff body 31. c , thereby changing the relative time delay τ between the first turbulent vortex 9 and the second turbulent vortex 10 d , so that the shedding frequency of the second turbulent vortex 10 generated by the bluff body 31 no longer matches the natural frequency of the axial sound pressure mode in the combustion chamber 1, thereby destroying the synchronous coupling between the sound field in the combustion chamber 1 and the disturbance of the second turbulent vortex 10 generated by the bluff body 31.

[0108] According to the embodiment of the present disclosure, the pressure sensor 5 is used to measure the acoustic pressure characteristics in the combustion chamber 1, and the air flow rate into the second swirler 4 installed on the wall of the combustion section is changed according to the acoustic pressure characteristics in the combustion chamber 1. a The PID controller 8 sends a control signal to the position regulator 332 to adjust the axial distance L between the center of the first cyclone 32 in the premixing tube 2 and the upper end surface of the bluff body 31. c Finally, the purpose of suppressing combustion instability is achieved. Practice has found that the burner has the effect of suppressing oscillation for stratified swirl flames, single swirl flames, micro-mixed flames, combustible premixed / diffused gases and combustible premixed / diffused liquids, and has good versatility.

[0109] The burner provided in the embodiment of the present disclosure can reduce the coupling between the flame in the combustion chamber 1 and the system sound pressure, thereby achieving the purpose of suppressing combustion instability and solving the problems of poor adaptability, high cost and insufficient adaptability to different fuels of existing active suppression technologies in industrial applications.

[0110] The flow rate injected into the combustion chamber 1 through the second swirler 4 installed on the wall of the combustion chamber 1 is a The air is discharged and the acoustic pressure characteristics in the combustion chamber 1 after the position of the first swirler 32 in the premixing tube 2 are adjusted. The direction of the second swirler 4 and its injection velocity into the combustion section are changed according to the acoustic pressure characteristics. a and the axial distance L between the center of the first cyclone 32 in the premixing tube 2 and the upper end surface of the bluff body 31 c , to achieve the purpose of suppressing combustion oscillation. Among them, the sound pressure characteristics include a time domain diagram of the dynamic pressure change over time obtained according to the sound pressure pulsation signal and a spectrum diagram of the dynamic pressure.

[0111] Compared with traditional dynamic speakers, the burner provided by the present invention has the characteristics of high pressure resistance and can operate reliably in the high-pressure harsh environment of the combustion system. The burner has a relatively low cost, strong applicability, and is compatible with different types of fuels, further improving the economy and flexibility in practical engineering applications. Practice has also found that the device has a significant oscillation suppression effect on stratified swirl flames, single swirl flames, micro-mixed flames, combustible premixed / diffused gases and combustible premixed / diffused liquids, and has good versatility.

[0112] The burner provided by the present disclosure adopts an active control method that directly acts on the flow field structure of the combustion chamber 1, without relying on complex acoustic dampers, and has the advantages of high efficiency, simplicity and practicality. The method significantly improves the combustion efficiency, effectively suppresses combustion instability, avoids excessive temperature in the combustion chamber 1, realizes efficient and safe operation of the combustion system, and provides a practical solution for suppressing combustion instability in modern combustion systems.

[0113] Fig. 9 A flowchart of a combustion instability suppression method according to an embodiment of the present disclosure is schematically shown.

[0114] As another aspect of the embodiments of the present disclosure, a method for suppressing combustion instability of any of the above-mentioned burners is provided, such as Fig. 9 As shown, the combustion instability suppression method includes operations S910 to S930.

[0115] In operation S910 , the premixed gas is introduced into the combustion chamber 1 through the premixing pipe 2 and ignited, so that the premixed gas generates a first flame in the combustion chamber 1 .

[0116] In operation S920, air is introduced into the combustion chamber 1 through the second suppression component, and the air forms a third turbulent vortex 11 in the combustion chamber 1, thereby changing the radial and circumferential flow field distribution in the combustion chamber 1, and changing the combustion of the premixed gas in the combustion chamber 1 from the first flame to the second flame.

[0117] In operation S930, when the sound pressure amplitude of the second flame exceeds a preset value, the flow rate of the introduced air is adjusted to keep the sound pressure amplitude below the preset value.

[0118] According to the combustion instability suppression method of the embodiment of the present disclosure, active control technology is used to directly act on the flow field structure of the combustion chamber 1, without relying on complex acoustic dampers, and it has the characteristics of high efficiency, simplicity and practicality. It improves the combustion efficiency, effectively suppresses combustion instability, avoids excessive temperature of the combustion chamber 1, realizes efficient and safe operation of the combustion system, and provides a practical solution for suppressing combustion instability in modern combustion systems.

[0119] In an illustrative embodiment, a preset value matching the burner can be determined according to the structure of the burner. The preset value can include any one of 50Pa, 100Pa, 200Pa, etc., which is not limited here.

[0120] The sound pressure amplitude of the second flame can be acquired by the processor through the pressure sensor 5 .

[0121] According to an embodiment of the present disclosure, before the premixed gas is introduced into the combustion chamber 1 through the premixing pipe 2 and ignited, the process further includes:

[0122] After the first swirler 32 and the second suppression assembly are removed and the mounting hole for mounting the second suppression assembly is sealed, the premixed gas is introduced through the premixing pipe 2 and ignited, so that the premixed gas generates a third flame in the combustion chamber 1;

[0123] Obtain a dynamic pressure spectrum diagram of the third flame to determine the first characteristic dimension of the first swirler 32 and the second characteristic dimension of the multiple second swirlers 4 of the second suppression assembly, wherein the first characteristic dimension is the dimension of the multiple first swirler blades of the first swirler in the first axial direction of the hub, and the second characteristic dimension is the dimension of the multiple second swirler blades of the second swirler in the second axial direction of the barrel.

[0124] In such an embodiment, the dynamic pressure spectrum of the third flame can be obtained based on the sound pressure pulsation signal obtained by the pressure sensor 5, and the sound pressure properties of the third flame can be obtained based on the dynamic pressure spectrum, and the sound pressure properties include the pulsation amplitude and the main frequency corresponding to the pulsation amplitude.

[0125] Then, the second characteristic size D of the second cyclone 4 can be determined according to the main frequency in the acquired sound pressure attribute.f2 and a first characteristic dimension D of the first swirler 32 f1 , so that the turbulent vortex shedding frequency generated by the first swirler 32 and the second swirler 4 can effectively interfere with the flow field, that is, can effectively interfere with the coupling between the flame and the acoustic mode;

[0126] The amplitude of the sound pressure attribute is obtained, and a control signal can be sent to the position regulator 332 through the PID controller 8 to adjust the axial distance L between the center of the first swirler 32 in the premixing tube 2 and the upper end surface of the bluff body 31 c , to change the relative time delay τ between the turbulent vortex generated by the first swirler 32 and the turbulent vortex generated by the bluff body 31 d , adjust the convection interference effect between them, so that they produce destructive interference on combustion instability, thereby achieving the purpose of suppressing combustion instability.

[0127] According to an embodiment of the present disclosure, the combustion instability suppression method further includes:

[0128] When the flow rate is adjusted multiple times and the sound pressure amplitude of the second flame still exceeds the preset value, a second dynamic pressure spectrum of the second flame is obtained to obtain a deviation between the sound pressure amplitude of the second flame and the preset value according to the second dynamic pressure spectrum;

[0129] The distance between the first swirler 32 and the blunt body 31 in the first suppression assembly 3 is adjusted according to the deviation to change the relative time delay between the first turbulent vortex 9 generated by the first swirler 32 and the second turbulent vortex 10 generated by the blunt body 31, thereby changing the axial flow field distribution of the premixed gas in the combustion chamber 1 so that the sound pressure is always lower than the preset value.

[0130] According to an embodiment of the present disclosure, adjusting the distance between the first cyclone 32 and the bluff body 31 in the first suppression assembly 3 according to the deviation includes:

[0131] Calculating the offset of the first swirler 32 in the axial direction according to the deviation includes:

[0132] u(t)=K p e(t)+K i +K d (5);

[0133] Among them, u(t) is the offset; is the deviation; t represents time; K p is the proportional gain, K p The value range of K is 1.0-3.0; i is the integral gain, K i The value range of K is 0.1-0.5; dis the differential gain, K d The value range of is 0.01-0.5;

[0134] The adjustment assembly drives the first swirler 32 to translate in the axial direction in response to the offset.

[0135] According to the embodiment of the present disclosure, when the unsteady heat release generated by the premixed gas injected into the combustion chamber 1 through the premixing pipe 2 during the combustion process is coupled with the inherent acoustic mode in the combustion chamber 1, the combustion chamber 1 will be driven to spontaneously form sustainable combustion instability. The combustion instability suppression method provided by the embodiment of the present disclosure uses the second swirler 4 to inject a flow rate of a The air moves in a spiral shape around the axis of the second swirler 4 to form a third turbulent vortex 11. The third turbulent vortex 11 generated by the second swirler 4 can change the radial and circumferential flow field distribution of the combustion chamber 1, and produce an interference effect on the flow structure in the combustion chamber 1 by introducing additional turbulent disturbances. This interference effect destroys the positive feedback mechanism between the heat release rate fluctuation and the sound pressure by changing the coupling relationship between the pressure field and the radial and circumferential velocity fields, thereby suppressing radial and circumferential combustion instabilities over a wide range. In addition, turbulent disturbances enhance the mixing effect of the combustion process and make heat release more uniform, thereby significantly improving the combustion efficiency in the combustion chamber 1 and further reducing the amplitude of thermoacoustic oscillations in the combustion system.

[0136] In addition, the PID controller 8 and the position regulator 332 jointly actively adjust the axial position of the first swirler 32 in the premixing tube 2 to change the relative time delay τ between the turbulent vortex generated by the first swirler 32 and the turbulent vortex generated by the bluff body 31. d This relative time delay τ d The change in the turbulent vortices and the mutual interference of the turbulent vortices generated by the two change the time scale and distribution characteristics of the turbulent vortex shedding generated by the blunt body 31, so that the turbulent vortex shedding frequency generated by the blunt body 31 no longer matches the natural frequency of the axial sound pressure mode in the combustion chamber 1, thereby destroying the synchronous coupling between the sound field in the combustion chamber 1 and the turbulent vortex disturbance generated by the blunt body 31. By weakening this positive feedback mechanism, the amplitude of the combustion oscillation is significantly reduced. At the same time, the turbulent disturbance generated by the first swirler 32 enhances the turbulent intensity of the premixed gas, making the fuel and air mix more evenly. This homogenization significantly reduces the intensity of local overheating areas and high heat release areas, and reduces the driving effect of these areas on the acoustic mode from the root, thereby suppressing the occurrence of combustion instability, thereby reducing the risk of flame blowout, flashback and increased emissions, and improving the stability, safety and environmental protection performance of the combustion system.

[0137] In an illustrative embodiment, first, the first swirler 32 is not installed in the premixing tube 2, the second swirler 4 is not installed on the wall of the combustion chamber 1, and the first installation port for installing the second swirler 4 is blocked by a blocking device. The blocking device is a high-temperature stainless steel metal round block that matches the shape and size of the first installation port (for example, it can be round, and the diameter is consistent with the diameter of the second installation port), and the thickness of the metal round block is consistent with the thickness of the wall of the combustion chamber 1.

[0138] The flow rate at the inlet of premixing tube 2 is m The premixed gas is ignited, and the pressure sensor 5 installed on the wall of the combustion chamber 1 is used to measure the sound pressure pulsation signal in the combustion chamber 1. The pressure data acquisition system 6 connected to the pressure sensor 5 synchronously collects the sound pressure data, and the upper computer data acquisition control software in the processor connected to the pressure data acquisition system 6 is used to display the time domain diagram of the dynamic pressure change over time in the combustion chamber 1 and the spectrum diagram of the dynamic pressure in real time. The spectrum analysis is obtained by the fast Fourier transform (FFT) method, and the pulsation main frequency f of the flame is obtained according to the spectrum diagram. b The amplitude P corresponding to the main frequency b .

[0139] Ensure that Pb>50 Pa (preset value). If P b ≤50 Pa, then the flow velocity at the inlet of the premixing tube 2 is continuously adjusted so that P b >50 Pa. When Pb>50 Pa, maintain the target flow rate of the premixed gas. m The size remains unchanged.

[0140] According to the pulsation frequency f b The first characteristic dimension D of the first cyclone 32 is calculated as follows: f1 :

[0141] ≈0.2~0.6(6).

[0142] According to the pulsation frequency f b The second characteristic dimension D of the second cyclone 4 is calculated as follows: f2 :

[0143] ≈0.2~0.6(7).

[0144] The first cyclone 32 is mounted on the connecting rod 34 from the air inlet end of the premixing pipe 2, the obstruction of the first installation opening is removed, and the second cyclone 4 is installed in the first installation opening.

[0145] Target flow rate mThe premixed gas is ignited and injected through the second cyclone 4 at a flow rate of a If the sound pressure amplitude of the flame exceeds the preset value at this time, the sound pressure amplitude of the flame can be changed by adjusting the flow rate of the air passed through the second spoiler to make the sound pressure amplitude of the flame less than or equal to the preset value.

[0146] After adjusting the flow rate of the incoming air, if the flame sound pressure amplitude still exceeds the preset value, the host computer pressure data acquisition and analysis software on the processor will extract the main frequency f of the sound pressure signal of the combustion chamber 1 b And the amplitude P corresponding to the main frequency b Passed as input parameter to PID controller 8 for error calculation:

[0147] e(t)=P b -P s (8);

[0148] Default value P s =50 Pa, and then the deviation e(t) between the real-time sound pressure amplitude in the combustion chamber 1 and the set value is obtained.

[0149] The offset is calculated using the PID controller 8 algorithm based on the calculated error e(t): u(t)=K p e(t)+K i +K d (9);

[0150] Among them, K p The value ranges from 1.0 to 3.0; K i The value is 0.1-0.5; K d The value range is 0.01-0.5.

[0151] The calculated offset u(t) is transmitted to the position regulator 332 , and the position regulator 332 is used to adjust the axial position of the first swirler 32 .

[0152] According to the burner and the method for suppressing combustion instability of the embodiment of the present disclosure, air with a certain flow rate is injected into the combustion section by the second swirler 4 installed on the wall of the combustion section, and the axial position adjustment of the first swirler 32 in the premixing tube 2 is combined to form an active control closed loop. The sound pressure pulsation signal in the combustion section is collected by the pressure sensor 5, and the main frequency and amplitude of the sound pressure signal are analyzed in real time by fast Fourier transform (FFT), and it is input into the PID controller 8 for error calculation and feedback control. The axial position of the first swirler 32 is adjusted according to the feedback, and the flow field structure is accurately adjusted to suppress combustion instability. It can not only reduce the sound pressure amplitude in the combustion chamber 1 and suppress combustion instability, but also improve the combustion efficiency and avoid thermal damage caused by excessive local temperature, thereby ensuring the safe and stable operation of the combustion system. This technology based on active flow field regulation has the advantages of high efficiency, flexibility and strong applicability, and provides strong support for the optimization design of modern combustion systems.

[0153] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. The scope of the present disclosure is defined by the attached claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A burner, characterized in that: include: A combustion chamber adapted for combustion of premixed gas; A premixing tube, coaxial with the combustion chamber and in communication with the combustion chamber, adapted to introduce premixed gas into the combustion chamber in a first axial direction of the combustion chamber; a first suppression component, adapted to cause the premixed gas to generate a first turbulent vortex in the premixing tube and a second turbulent vortex in the combustion chamber, and to adjust a relative time delay between the first turbulent vortex and the second turbulent vortex to change an axial flow field distribution of the premixed gas in the combustion chamber; and The second suppression component is adjustably mounted on the side wall of the combustion chamber and is suitable for introducing air into the combustion chamber so that the air forms a third turbulent vortex in the combustion chamber to change the radial and circumferential flow field distribution of the premixed gas in the combustion chamber and suppress combustion oscillations.

2. The burner according to claim 1, characterized in that The first suppression component comprises: A connecting rod is coaxially inserted into the premixing tube, and a blunt body is provided at an end of the connecting rod close to the combustion chamber; A first swirler is slidably installed between the connecting rod and the premixing tube along the axial direction of the connecting rod, the premixed gas generates a first turbulent vortex through the first swirler, and the premixed gas that generates the first turbulent vortex generates a second turbulent vortex in the combustion chamber under the action of the bluff body; The regulating unit is adapted to adjust the distance between the first swirler and the bluff body, and change the relative time delay between the first turbulent vortex and the second turbulent vortex to suppress combustion oscillation.

3. The burner according to claim 2, characterized in that At least a portion of the first cyclone is made of ferromagnetic material; The adjustment unit comprises: A magnetic member, arranged on the outer surface of the premixing tube; The position regulator is adapted to drive the magnetic member to translate along the first axial direction, so that the magnetic member drives the first cyclone to slide through magnetic force, thereby adjusting the distance between the first cyclone and the bluff body.

4. The burner according to claim 2 or 3, characterized in that: The first cyclone comprises: A wheel hub is slidably mounted on the connecting rod; A plurality of first swirl blades are arranged between the outer surface of the hub and the inner surface of the premixing tube and are arranged obliquely relative to the first axial direction and the first radial direction of the hub. The first swirl blades cause the premixed gas to generate the first turbulent vortex.

5. The burner according to any one of claims 1 to 3, characterized in that: The second suppression component comprises: At least one pair of second swirlers, each pair of second swirlers is arranged at both radial ends of the combustion chamber, and each second swirler is configured to pass the air toward the flame generated by the combustion of the premixed gas, and cause the air to generate the third turbulent vortex in the combustion chamber.

6. The burner according to claim 5, characterized in that Each of the second cyclones comprises: A barrel portion, wherein a first end of the barrel portion is open, and a second end of the tube portion is blocked and extends into the combustion chamber; a tubular portion, the tubular portion extending from the inner wall of the combustion chamber toward the direction close to the flame, and being coaxial with the cylindrical portion and sleeved on the outer periphery of the cylindrical portion at intervals; and A plurality of second swirl blades connected between the tubular portion and the barrel portion and arranged obliquely relative to a second axial direction and a second radial direction of the barrel portion; Among them, a plurality of through holes are formed on the cylinder portion located between the plurality of second swirl blades and the inner wall of the combustion chamber. Air from the outside flows in through the first end of the cylinder portion, passes through the plurality of through holes, and after being disturbed by the plurality of second swirl blades, the third turbulent vortex is generated in the combustion chamber.

7. A method for suppressing combustion instability of a burner according to any one of claims 1 to 6, characterized in that: include: The premixed gas is introduced into the combustion chamber through the premixing pipe and ignited, so that the premixed gas generates a first flame in the combustion chamber; Air is introduced into the combustion chamber through a second suppression component, and the air forms a third turbulent vortex in the combustion chamber, thereby changing the radial and circumferential flow field distribution in the combustion chamber, and causing the combustion of the premixed gas in the combustion chamber to change from a first flame to a second flame; When the sound pressure amplitude of the second flame exceeds a preset value, the flow rate of the air introduced is adjusted to keep the sound pressure amplitude below the preset value.

8. The method for suppressing combustion instability according to claim 7, characterized in that: Before the premixed gas is introduced into the combustion chamber through the premixing pipe and ignited, the method further comprises: The premixed gas is introduced into the combustion chamber through the premixing pipe and ignited, so that the premixed gas generates a third flame in the combustion chamber; Obtain a dynamic pressure spectrum diagram of the third flame to determine a first characteristic dimension of the first swirler and a second characteristic dimension of the second swirler of the second suppression assembly, wherein the first characteristic dimension is a dimension of a first swirl blade of the first swirler in a first axial direction of the hub, and the second characteristic dimension is a dimension of a plurality of second swirl blades of the second swirler in a second axial direction of the barrel.

9. The method for suppressing combustion instability according to claim 7, characterized in that: Also includes: When the flow rate is adjusted multiple times and the sound pressure amplitude of the second flame still exceeds the preset value, a second dynamic pressure spectrum of the second flame is obtained to obtain a deviation between the sound pressure amplitude of the second flame and the preset value according to the second dynamic pressure spectrum; as well as The distance between the first swirler and the blunt body in the first suppression assembly is adjusted according to the deviation to change the relative time delay between the first turbulent vortex generated by the first swirler and the second turbulent vortex generated by the blunt body, thereby changing the axial flow field distribution of the premixed gas in the combustion chamber so that the sound pressure is always lower than the preset value.

10. The method for suppressing combustion instability according to claim 9, characterized in that: The step of adjusting the distance between the first cyclone and the bluff body in the first suppression assembly according to the deviation comprises: Calculating the offset of the first swirler in the axial direction according to the deviation includes: u(t)=K p e(t)+K i +K d ; Among them, u(t) is the offset; is the deviation; t represents the time; K p is the proportional gain, K p The value range of K is 1.0-3.0; i is the integral gain, K i The value range of K is 0.1-0.5; d is the differential gain, K d The value range of is 0.01-0.5; The adjustment assembly drives the first swirler to translate along the axial direction in response to the offset.

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