CN219867985U - Structure for inhibiting thermoacoustic oscillation of gas turbine combustor - Google Patents

Abstract

The utility model discloses a structure for inhibiting thermoacoustic oscillation of a gas turbine combustor, which relates to the field of thermoacoustic oscillation of the gas turbine combustor. The utility model can effectively inhibit the thermoacoustic oscillation of the gas turbine combustor and reduce the influence of the thermoacoustic oscillation.

Description

Structure for inhibiting thermoacoustic oscillation of gas turbine combustor

Technical Field

The utility model relates to the field of suppressing thermoacoustic oscillations of a gas turbine combustor, in particular to a structure for suppressing thermoacoustic oscillations of a gas turbine combustor.

Background

The combustor is one of three core components of the gas turbine, fuel and air are mixed in the combustor and undergo severe combustion chemical reaction to form high-temperature and high-pressure fuel gas, and a power source spring is provided for turbine work. Wherein, thermoacoustic oscillation is a main factor in restricting the progress of the combustor and even the gas turbine to high efficiency, high temperature rise targets. Thermo-acoustic oscillations result from the coupling between flame heat release rate and pressure disturbances that affect the local instantaneous heat release rate, which in turn generates pressure disturbances that are delayed in time (phase) from the initial disturbance, and subsequently the pressure disturbance wave is reflected at the flame tube boundary, eventually forming a closed loop feedback loop.

When the rate of energy supplied to the sound field by the combustion process is greater than the dissipation of acoustic energy, large pressure fluctuations are caused, including circumferential, axial, radial and compound oscillations of different modes, which can cause flashback or flameout, leading to component ablation and even shutdown; when the resonance occurs with the structure, low-cycle or high-cycle fatigue of parts can be aggravated, the service life of the parts is shortened, and even the parts are invalid; the operation of the control system is interfered, and the operation safety of the combustion engine is endangered; therefore, how to suppress the thermo-acoustic oscillations of the gas turbine combustor is a problem that needs to be solved at present.

Disclosure of Invention

The utility model aims at: in order to solve the above-described problems, a structure for suppressing thermoacoustic oscillations of a gas turbine combustor is provided, which can effectively suppress thermoacoustic oscillations of the gas turbine combustor and reduce the influence of the thermoacoustic oscillations.

The technical scheme adopted by the utility model is as follows: the utility model provides a restrain structure of gas turbine combustor thermoacoustic vibration, includes outer pipeline and the inlayer ring canal that is located outer pipeline, and inlayer ring canal's length is the quarter of sound wave wavelength, form the resonant cavity between outer pipeline and the inlayer ring canal, the one end of resonant cavity is the ring cavity mouth that is used for business turn over sound wave, the other end of resonant cavity has the go-between that is used for connecting outer pipeline and inlayer ring canal.

Further, the axis of the inner collar is collinear with the axis of the outer conduit.

Further, the end surfaces of the connecting rings, which are positioned in the resonant cavity, are perpendicular to the axes of the inner ring pipe and the outer layer pipe.

Further, a plurality of cooling holes are formed in the outer layer pipeline and are communicated with the resonant cavity.

Further, a plurality of the cooling holes are circumferentially arrayed along the outer layer pipe.

Further, a plurality of the cooling holes are arrayed along the axis of the outer layer pipe.

A method of suppressing thermo-acoustic oscillations of a gas turbine combustor, the structure being applied, comprising the steps of:

s1: the installation is carried out by installing an annular cavity opening in the structure towards an excitation source;

s2: incident waves generated by the vibration source enter the resonant cavity through the annular cavity port;

s3: the vibration source generates incident waves which are reflected at the connecting ring position after entering the resonant cavity, so that reflected waves with the same frequency and opposite phase to the incident waves are formed;

s4: the reflected wave is superimposed on the incident wave, suppressing thermo-acoustic oscillations.

Further, adjusting the length of the inner collar suppresses incident waves of different frequencies.

Further, adjusting the diameter of the inner collar suppresses incident waves of different amplitudes and bandwidths.

Further, the mounting position of the adjustment structure suppresses incident waves generated by different excitation sources.

In summary, due to the adoption of the technical scheme, the beneficial effects of the utility model are as follows:

according to the utility model, the resonant cavity is sealed at one end formed by the outer layer pipeline and the inner layer ring pipe, thermoacoustic oscillation incident wave generated by the vibration source enters the resonant cavity and then is reflected, so that the same-frequency reflected wave with opposite phases is formed, and the reflected wave and the incident wave are mutually overlapped, so that the acoustic wave is mutually offset and vanished, or the amplitude of the incident acoustic wave is weakened, and the thermoacoustic oscillation is restrained.

Drawings

The utility model will now be described by way of example and with reference to the accompanying drawings in which:

FIG. 1 is an axial cross-sectional schematic view of a structure disclosed herein;

FIG. 2 is a schematic cross-sectional view taken in the direction A-A of FIG. 1;

the marks in the figure: 1-an outer layer pipeline; 11-cooling holes; 2-an inner collar; 3-connecting rings; 4-resonant cavity; 41-annulus orifice.

Detailed Description

All of the features disclosed in this specification, or all of the steps in a method or process disclosed, may be combined in any combination, except for mutually exclusive features and/or steps.

Any feature disclosed in this specification may be replaced by alternative features serving the same or equivalent purpose, unless expressly stated otherwise. That is, each feature is one example only of a generic series of equivalent or similar features, unless expressly stated otherwise.

Example 1

As shown in fig. 1-2, a structure for restraining thermoacoustic oscillation of a gas turbine combustor comprises an outer layer pipeline 1 and an inner layer loop pipe 2 positioned in the outer layer pipeline 1, wherein the length of the inner layer loop pipe 2 is one fourth of the wavelength of sound waves, a resonant cavity 4 is formed between the outer layer pipeline 1 and the inner layer loop pipe 2, one end of the resonant cavity 4 is a loop cavity opening 41 for entering and exiting the sound waves, the other end of the resonant cavity 4 is provided with a connecting ring 3 for connecting the outer layer pipeline 1 and the inner layer loop pipe 2, and the connecting ring 3 has the function of reflecting incident waves on one hand and is used for connecting the inner layer loop pipe 2 and the outer layer pipeline 1 on the other hand.

In this embodiment, the structure is installed with the ring cavity port 41 facing the vibration source direction in the flame tube, when sound waves are generated in the flame tube, and the sound waves in the flame tube enter the resonant cavity 4 through the ring cavity port 41, when the incident waves reach the closed end face of the resonant cavity 4 (i.e. the end face of the connecting ring 3 in this embodiment), the incident waves are reflected to generate reflected waves with the same frequency and opposite phase to the incident waves, the reflected waves and the incident waves are superimposed to cancel each other, and even if the incident waves and the reflected waves in adjacent frequency bands cannot be completely cancelled, the amplitude of the incident waves can be weakened to suppress thermoacoustic oscillation.

It should be noted that, through research, the natural frequency of the inner loop pipe 2 just enables the best noise elimination effect to be achieved when the frequency of the incident wave (i.e. resonance is enabled), and the axial length of the inner loop pipe 2 directly affects the natural frequency, so the axial length of the inner loop pipe 2 is calculated according to the frequency at the time of resonance, so that the effect of suppressing thermo-acoustic oscillation is best.

Example 2

Further embodiments are presented which can be implemented on the basis of example 1.

In a practical embodiment, the axis of the inner loop pipe 2 is collinear with the axis of the outer pipeline 1, so that the radial lengths of all the positions of the resonant cavity 4 are equal, the ratio of the area of the unit radian of any position in the resonant cavity 4 to the cross-sectional area of the main pipeline is equal, the same amplitude and bandwidth of the incident wave loss are ensured, and the effect of suppressing thermoacoustic oscillation is further improved.

In a practical embodiment, the end surfaces of the connecting ring 3 located in the resonant cavity 4 are perpendicular to the axes of the inner ring pipe 2 and the outer layer pipe 1, that is, the connecting ring 3 seals the resonant cavity 4 in a state perpendicular to the axis direction of the resonant cavity 4, so that incident waves can reach the end surface of the connecting ring 3 in a state perpendicular to the sealed end surface, reflected waves with the speed moving direction parallel and opposite to the incident wave moving direction can be generated, the superposition effect of the reflected waves and the incident waves is improved, and the effect of suppressing thermoacoustic oscillation is improved.

Example 3

Further embodiments are presented which can be implemented on the basis of any one of the embodiments of examples 1-2.

In a practical embodiment, the outer layer pipeline 1 is provided with a plurality of cooling holes 11, the cooling holes 11 are communicated with the resonant cavity 4, cold flow with low temperature (relative to high temperature in the combustion cylinder) can enter the resonant cavity 4 through the cooling holes 11 and then flow out of the annular cavity port 41, so that the cooling performance is improved by utilizing the cold flow; on the other hand, the cold flow can reduce the axial length increment of the inner ring pipe 2 caused by heat radiation, so that the axial length of the inner ring pipe 2 is ensured to be closer to the design length when in use, the natural frequency of the inner ring pipe 2 is directly influenced by the axial length of the inner ring pipe 2, and the effect of restraining the thermoacoustic oscillation is better when the natural frequency of the inner ring pipe 2 is closer to the frequency of the incident wave, namely, the effect of restraining the thermoacoustic oscillation is closer to the design requirement through the arrangement of the cooling holes 11.

In this embodiment, the cold flow is low temperature air.

Further, as shown in fig. 2, on the basis of the above embodiment, a plurality of cooling holes 11 are circumferentially arrayed along the outer layer pipe 1, so that cold flow can uniformly enter the resonant cavity 4 from the circumferential direction of the outer layer pipe 1, thereby achieving the purpose of uniformly cooling the resonant cavity 4 circumferentially; the cooling holes 11 are arrayed along the axis of the outer layer pipeline 1, so that cold flow can uniformly enter the resonant cavity 4 from the axial direction of the outer layer pipeline 1, and the purpose of uniformly cooling the resonant cavity 4 in the axial direction is achieved; the cooling is uniform in the circumferential direction and the axial direction, and the purpose of uniformly cooling the whole body is achieved.

A method of suppressing thermo-acoustic oscillations of a gas turbine combustor using the structure of any one of embodiments 1-3, comprising the steps of:

s1: the installation is carried out by installing the annular cavity port 41 in the structure towards the excitation source, and the incident wave generated by the excitation source enters the resonant cavity 4 in the direction vertical to the section of the resonant cavity 4;

s2: incident waves generated by the vibration source enter the resonant cavity 4 through the annular cavity port 41;

s3: the vibration source generates incident waves, the incident waves enter the resonant cavity 4 and then are reflected at the position of the connecting ring 3, and reflected waves with the same frequency and opposite phases with the incident waves are formed;

s4: the reflected wave is overlapped with the incident wave to inhibit thermo-acoustic oscillation;

while the steps S2-S4 are carried out, cold flow is introduced into the resonant cavity 4 through the cooling holes 11, so that on one hand, the cold flow cooling equipment improves the cooling performance; on the other hand, the cold flow reduces the axial deformation of the inner ring pipe 2 caused by high temperature, and ensures the effect of restraining thermoacoustic oscillation.

Further, adjusting the length of the inner loop 2 suppresses incident waves of different frequencies, specifically, adjusting the length of the inner loop 2 so as to adjust the natural frequency of the inner loop 2, further adjusting the resonance frequency of the inner loop 2 and the incident waves, wherein the frequency is the natural physical property of the waves, and the frequency of the waves cannot be changed due to resonance, so that adjusting the axial length of the inner loop 2 can suppress thermo-acoustic oscillation of different frequencies; the inner ring pipe 2 has an axial length of 44.17mm and a natural frequency of 3000Hz under the condition of 700K and a sound velocity of about 530m/s, and can inhibit thermoacoustic oscillation (incident wave) with the frequency of 3000 Hz; for another example, under the condition of 700K and sound velocity of about 530m/s, the axial length of the inner ring pipe 2 is 53mm, the natural frequency is 2500Hz, and thermoacoustic oscillation (incident wave) with the frequency of 2500Hz can be restrained; in another example, at a temperature of 700K and a sound velocity of about 530m/s, the inner collar 2 has an axial length of 66.25mm and a natural frequency of 2000Hz, and can suppress thermo-acoustic oscillations (incident waves) at a frequency of 2000 Hz.

Further, adjusting the diameter of the inner ring pipe 2 to restrain incident waves with different amplitudes and bandwidths; specifically, adjusting the diameter of the inner collar 2 actually adjusts the ratio of the cross-sectional area of the resonant cavity 4 to the cross-sectional area of the outer tube 1, thereby achieving the purpose of suppressing thermo-acoustic oscillations (incident waves) of different amplitudes and bandwidths. Specifically, the larger the ratio of the cross-sectional areas, the wider the frequency bandwidth of effective suppression, and the greater the control capability of the pulsation amplitude.

Further, the installation position of the adjusting structure suppresses incident waves generated by different excitation sources, and as different oscillation modes including axial, radial and circumferential modes exist in the combustor, various modes can be coupled, so that sound pressure distribution forms and characteristics at different positions of the combustor are greatly different, for example, only axial modes and no circumferential modes can exist at certain positions; therefore, the structure is mounted at different positions in the combustion cylinder, and the effect of suppressing different modes is different.

The utility model is not limited to the specific embodiments described above. The utility model extends to any novel one, or any novel combination, of the features disclosed in this specification, as well as to any novel one, or any novel combination, of the steps of the method or process disclosed.

Claims (6)

1. A structure for suppressing thermo-acoustic oscillations of a gas turbine combustor, characterized by: including outer pipeline (1) and be located inlayer ring canal (2) of outer pipeline (1), the length of inlayer ring canal (2) is the quarter of sound wave wavelength, form resonant cavity (4) between outer pipeline (1) and inlayer ring canal (2), the one end of resonant cavity (4) is for being used for business turn over ring coelent (41) of sound wave, the other end of resonant cavity (4) has go-between (3) that are used for connecting outer pipeline (1) and inlayer ring canal (2).

2. The structure for suppressing thermo-acoustic oscillations of a gas turbine combustor according to claim 1, wherein: the axis of the inner ring pipe (2) is collinear with the axis of the outer pipe (1).

3. The structure for suppressing thermo-acoustic oscillations of a gas turbine combustor according to claim 1, wherein: the end faces of the connecting ring (3) positioned in the resonant cavity (4) are perpendicular to the axes of the inner ring pipe (2) and the outer pipe (1).

4. A structure for suppressing thermo-acoustic oscillations of a gas turbine combustor according to any of claims 1-3, wherein: a plurality of cooling holes (11) are formed in the outer layer pipeline (1), and the cooling holes (11) are communicated with the resonant cavity (4).

5. The structure for suppressing thermo-acoustic oscillations of a gas turbine combustor according to claim 4, wherein: and a plurality of cooling holes (11) are circumferentially arrayed along the outer layer pipeline (1).

6. The structure for suppressing thermo-acoustic oscillations of a gas turbine combustor according to claim 4, wherein: a plurality of cooling holes (11) are arrayed along the axis of the outer layer pipeline (1).