Novel combustion chamber damping system capable of adjusting working frequency

Abstract

The utility model provides a novel combustion chamber shock absorption system capable of adjusting working frequency. The novel combustion chamber shock absorption system comprises a plurality of single shock absorbers distributed at intervals and adjusting connecting assemblies arranged between every two adjacent single shock absorbers. Each single shock absorber comprises a lower air inlet pipe and an upper shock absorption cavity which are communicated with each other, and the upper shock absorption cavity is provided with a connecting interface communicated with the shock absorption inner cavity at the joint of the adjusting connecting assembly; each adjusting connecting assembly comprises a connecting pipe, a plurality of adjusting inserting grooves formed in the connecting pipe and adjusting partition plates detachably inserted into the adjusting inserting grooves, and the ends of the connecting pipes are connected with the upper damping cavity through connecting ports of the single shock absorbers. The volume of the shock absorption inner cavity of each single shock absorber is independently adjusted by inserting the adjusting partition plates into the different adjusting slots of each connecting pipe, so that the working frequency of each single shock absorber is independently adjusted, the universality of parts is improved, and the time cost and the economic cost of research, development, production, manufacturing and installation are greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of gas turbine technology, and in particular to a novel combustion chamber vibration reduction system with adjustable operating frequency. Background Technology

[0002] Thermoacoustic oscillations are one of the main factors hindering the advancement of gas turbines towards higher efficiency and higher temperature. Thermoacoustic oscillations originate from the coupling effect between the flame heat release rate and pressure disturbances. Pressure disturbances affect the local instantaneous heat release rate, and conversely, changes in the heat release rate generate pressure disturbances with a certain time (phase) delay from the initial disturbance. Subsequently, the pressure disturbance wave is reflected at the flame tube boundary, ultimately forming a closed-loop feedback loop. Thermoacoustic oscillations can cause backfire or flameout, leading to component ablation and even shutdown. When the thermoacoustic oscillation frequency of the combustion system resonates with the structural frequency, it exacerbates low-cycle or high-cycle fatigue of components, thereby shortening component lifespan and even causing component failure. Ultimately, it interferes with the operation of the combustion system control system, jeopardizing the safe operation of the gas turbine. Therefore, how to suppress thermoacoustic oscillations in the gas turbine combustion system is a problem that needs to be solved.

[0003] In existing gas turbine design systems, passively suppressing thermoacoustic oscillations is a common method. A common passive suppression approach is to install vibration dampers (or Helmholtz dampers) at specific locations within the gas turbine combustion system to reduce pulses and vibrations within the combustion chamber; for example, Figure 1 The diagram shows a conventional annular combustor for a gas turbine. Several annularly spaced burners 10 are mounted at the head of the combustor, and individual Helmholtz dampers 20 are mounted between adjacent burners 10. All burners 10 and individual Helmholtz dampers 20 are fixed to burner inserts 30 at the head of the combustor. The individual Helmholtz dampers 20 suppress thermoacoustic vibrations. The structure of a conventional individual Helmholtz damper 20 is as follows: Figure 2 As shown, the single-unit Helmholtz damper 20 includes a lower intake pipe 21 and an upper damping chamber 22. The lower intake pipe 21 is fixedly installed on the burner insert 30, and the upper damping chamber 22 is a cylindrical closed structure with only an interface connected to the lower intake pipe 21. During the combustion of the gas in the combustion chamber, when heat release occurs at a certain frequency and intensity, ultimately leading to thermoacoustic oscillations, the high-temperature gas in the combustion chamber enters from the lower intake pipe 21 of the single-unit Helmholtz damper 20 and flows into the upper damping chamber 22, where it is ultimately damped. However, this existing gas turbine design system has the following defects.

[0004] 1. When designing and developing individual shock absorbers, the damping effect of the individual shock absorber and the final damping effect on the whole machine can sometimes be quite different due to the limitations of its mechanical structure layout. This is because it is difficult to adjust the operating frequency of current mainstream shock absorbers. Once the overall effect of the machine is poor, the shock absorber will need to be redesigned and manufactured, which results in high research and development costs.

[0005] 2. When designing individual shock absorbers and their arrangement, they are generally developed based on the thermoacoustic oscillation frequency corresponding to the main hazardous working conditions. This means that if the working conditions change during operation, such as peak-shaving conditions or differences between winter and summer conditions, the shock absorber's working effect will be weakened because it is difficult to adjust its working frequency.

[0006] 3. After the development of the new generation of gas turbines, the higher output power and higher heat load will also cause the frequency of thermoacoustic oscillations in the unit to change. When upgrading the old model of gas turbine, the original shock absorber may be weakened or even lose its effect because it is difficult to adjust its operating frequency, resulting in a certain degree of waste. Utility Model Content

[0007] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a novel combustion chamber damping system with adjustable operating frequency, which achieves adjustable operating frequency by adjusting the volume of the upper damping chamber of the individual damper.

[0008] To achieve the above objectives, this utility model provides a novel combustion chamber vibration damping system with adjustable operating frequency, which is used to be mounted on the burner insert at the head of the combustion chamber. The novel combustion chamber vibration damping system includes several spaced individual vibration dampers and an adjustable connection assembly disposed between two adjacent individual vibration dampers.

[0009] Each of the aforementioned individual shock absorbers includes a communicating lower air intake pipe and an upper shock absorber chamber. The lower air intake pipe is fixed in the burner insert and is used to connect to the combustion chamber. The upper shock absorber chamber is provided with a shock absorber inner cavity. The upper shock absorber chamber has a connection interface communicating with the shock absorber inner cavity at the connection of the adjustment connection assembly.

[0010] Each set of the adjustment connection components includes a connecting pipe, several adjustment slots that are opened in the connecting pipe and spaced apart along the extension direction of the connecting pipe, an adjustment partition that is detachably inserted into each adjustment slot, and a sealing and locking component that is detachably assembled on the outer periphery of each adjustment slot. The end of the connecting pipe is connected to the upper shock absorption chamber via the connection interface of the single shock absorber.

[0011] The volume of the damping cavity of each individual shock absorber can be independently adjusted by inserting adjusting baffles into different adjusting slots in each of the connecting pipes.

[0012] Furthermore, the burner insert is equipped with several burners, and a single shock absorber is disposed between two adjacent burners.

[0013] Furthermore, several of the burners are arranged in a ring, the novel combustion chamber damping system is arranged around the periphery of the burners, and several of the individual dampers are also arranged in a ring.

[0014] Furthermore, the adjusting partition is a circular, fully enclosed partition;

[0015] When the fully enclosed partition is inserted into the adjustment slot, the fully enclosed partition blocks the connecting pipe at that location.

[0016] Furthermore, the adjusting partition is a semi-circular, semi-enclosed partition.

[0017] Furthermore, the adjusting partition is a circular, perforated partition with several through holes.

[0018] Furthermore, the single-unit shock absorber is a Helmholtz single-unit shock absorber.

[0019] Furthermore, the sealing and locking component includes an upper sealing ring and a lower sealing ring that surround the outer periphery of the connecting pipe, and the two ends of the upper sealing ring and the lower sealing ring are connected by bolts.

[0020] As described above, the novel combustion chamber vibration damping system with adjustable operating frequency involved in this utility model has the following beneficial effects:

[0021] This application achieves independent adjustment of the damping cavity volume of each individual shock absorber by inserting adjusting baffles into different adjusting slots in each connecting pipe, thereby enabling independent adjustment of the operating frequency of each individual shock absorber. Based on the characteristic of independently adjustable operating frequencies of each individual shock absorber, the operating frequency of the new combustion chamber damping system is adjustable and has a large operating frequency range, thus increasing the versatility of components. In this way, whether for research and development, operating condition adjustment, or gas turbine upgrades, the effective operating frequency (i.e., effective damping frequency) of each individual shock absorber can be adjusted by changing the position of the adjusting baffles, eliminating the need to develop separate individual shock absorbers for the required operating frequencies, thereby significantly improving the time and economic costs of research and development, production, manufacturing, and installation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of an annular combustion chamber in an existing gas turbine. The diagram is a top view.

[0023] Figure 2 for Figure 1 A schematic diagram of the structure of a single-unit Helmholtz shock absorber.

[0024] Figure 3 This is a top view of the structure of a gas turbine annular combustion chamber equipped with the novel combustion chamber vibration damping system with adjustable operating frequency of this application.

[0025] Figure 4 This is a structural schematic diagram of the novel combustion chamber vibration damping system with adjustable operating frequency according to this application.

[0026] Figure 5 for Figure 4 Exploded view.

[0027] Figure 6 for Figure 4 A schematic diagram of the structure of a single-unit shock absorber.

[0028] Figure 7a This is a schematic diagram of the structure of the first embodiment of the adjustable partition in this application.

[0029] Figure 7b This is a schematic diagram of the structure of the second embodiment of the adjustable partition in this application.

[0030] Figure 7c This is a schematic diagram of the structure of the adjusting partition in Embodiment 3 of this application.

[0031] Figure 8 This is a schematic diagram illustrating the application of the novel combustion chamber vibration damping system with adjustable operating frequency according to the present application.

[0032] Figure 9 This is a schematic diagram illustrating the application of the novel combustion chamber vibration damping system with adjustable operating frequency as described in Embodiment 2 of this application.

[0033] Figure 10 This is a schematic diagram illustrating the application of the novel combustion chamber vibration damping system with adjustable operating frequency as described in Embodiment 3 of this application.

[0034] Figure 11 This diagram illustrates a comparison of the vibration reduction effects of the novel combustion chamber vibration reduction system with adjustable operating frequency in this application and the single vibration damper with non-adjustable operating frequency in the prior art on a certain burner under two different operating conditions.

[0035] Component designation explanation

[0036] 10. Burner

[0037] 20-unit Helmholtz shock absorber

[0038] 21. Lower air intake pipe of a single Helmholtz shock absorber

[0039] 22 Upper damping chamber of a single Helmholtz shock absorber

[0040] 30 Burner inserts

[0041] 40 Single-unit shock absorber

[0042] 41 Lower air intake pipe

[0043] 42 Upper damping chamber

[0044] 43 Connection Interface

[0045] 50 Adjustable connection components

[0046] 51 Connecting pipe

[0047] 52 Adjustment slot

[0048] 53 Adjusting the partition

[0049] 531 Fully Enclosed Partition

[0050] 532 Semi-enclosed partition

[0051] 533 Perforated partition

[0052] 54 Sealing and fixing upper ring

[0053] 55 Sealing and fixing lower ring

[0054] 61 First Adjustment Slot

[0055] 62 Second Adjustment Slot

[0056] 63 Third Adjustment Slot

[0057] 64 Fourth Adjustment Slot Detailed Implementation

[0058] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0059] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings of this specification are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the content disclosed herein. They are not intended to limit the implementation conditions of this utility model and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by this utility model, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of implementation of this utility model.

[0060] It should also be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or may be connected to an intermediary component. When a component is referred to as being "connected to" another component, it can be directly connected to the other component or indirectly connected to the other component through an intermediary component.

[0061] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0062] like Figure 3 and Figure 4 As shown, this utility model provides a novel combustion chamber vibration damping system with adjustable operating frequency, used for mounting on a burner insert 30 at the head of the combustion chamber. The burner insert 30 is equipped with several burners 10. The novel combustion chamber vibration damping system includes several spaced-apart individual vibration dampers 40 and an adjusting connection assembly 50 disposed between adjacent individual vibration dampers 40. The arrangement of the individual vibration dampers 40 and the several burners 10 is such that one individual vibration damper 40 is disposed between every two adjacent burners 10.

[0063] like Figures 4 to 6 As shown, each individual shock absorber 40 includes a connected lower air intake pipe 41 and an upper shock-absorbing chamber 42, with the adjusting connection assembly 50 connected to the upper shock-absorbing chamber 42. The lower air intake pipe 41 is fixed in the burner insert 30, thereby fixing the individual shock absorber 40 in the burner insert 30; the end of the lower air intake pipe 41 away from the upper shock-absorbing chamber 42 is connected to the combustion chamber, forming a damping block structure in the damping system. The upper shock-absorbing chamber 42 has a damping inner cavity, which forms a spring structure in the damping system. In particular, the upper shock-absorbing chamber 42 is a non-enclosed structure, that is: the upper shock-absorbing chamber 42 has a connection interface 43 at its connection with the adjusting connection assembly 50, and the connection interface 43 communicates with the damping inner cavity.

[0064] like Figure 4 and Figure 5As shown, each set of adjustment connection components 50 includes a connecting pipe 51, several adjustment slots 52 that are opened in the connecting pipe 51 and spaced apart along the extension direction of the connecting pipe 51, adjustment partitions 53 that are detachably inserted into each adjustment slot 52, and sealing and locking components that are detachably assembled on the outer periphery of each adjustment slot 52. The end of the connecting pipe 51 is connected to the upper damping chamber 42 via the connection interface 43 of the single shock absorber 40, thereby realizing the communication between the connecting pipe 51 and the damping chamber. When the adjustment partition 53 is inserted into the adjustment slot 52, the adjustment partition 53 is fixed in the adjustment slot 52 by the sealing and locking components. At this time, the adjustment partition 53 can completely isolate the connecting pipe 51 at its insertion point, or it can not completely isolate the connecting pipe 51 at its insertion point, but change the partition surface of the connecting pipe 51 at that point. Therefore, by inserting adjustment baffles 53 into different adjustment slots 52 of each connecting pipe 51, the volume of the part of the connecting pipe 51 that is connected to the damping cavity of each individual shock absorber 40 can be independently adjusted, thereby independently adjusting the volume of the damping cavity of each individual shock absorber 40.

[0065] When the combustion gas burns in the combustion chamber, generating heat release at a certain frequency and intensity, ultimately leading to thermoacoustic oscillations, the high-temperature combustion gas in the combustion chamber enters from the lower intake pipe 41 of the individual shock absorber 40 and flows into the upper damping chamber 42 of the individual shock absorber 40, where it is ultimately damped. The volume of the damping cavity of the individual shock absorber 40 is strongly correlated with its effective operating frequency. Specifically, the formula for calculating the effective operating frequency f of the individual shock absorber 40 is:

[0066]

[0067] In the above formula, c is the speed of sound; A is the cross-sectional area of ​​the unit damper 40 connected to the combustion chamber, which is the cross-sectional area of ​​the lower intake pipe 41; L is the length of the pipe connecting the unit damper 40 to the combustion chamber, which is the length of the lower intake pipe 41; and V is the volume of the damping cavity of the unit damper 40. Therefore, the effective operating frequency f of the unit damper 40 is proportional to the 1 / 2 power of the volume V of the damping cavity of the unit damper 40.

[0068] Based on the strong correlation between the effective operating frequency f of the individual shock absorber 40 and the volume V of its damping cavity, this application achieves independent adjustment of the damping cavity volume of each individual shock absorber 40 by inserting adjusting baffles 53 into different adjusting slots 52 of each connecting pipe 51. This, in turn, enables independent adjustment of the operating frequency of each individual shock absorber 40, thus making the operating frequency of the novel combustion chamber damping system of this application adjustable and having a large operating frequency range, increasing the versatility of the components. Compared to the existing individual shock absorbers 40 with non-adjustable operating frequencies, the novel combustion chamber damping system with adjustable operating frequencies of this application has the following beneficial effects.

[0069] 1. Based on the increased operating frequency range, when the overall performance is poor, the shock absorber's performance is weakened due to changes in operating conditions, or when upgrading old gas turbines, the operating frequency can be adjusted to match the performance, eliminating the need to develop separate individual shock absorbers with the required operating frequency 40, thus reducing R&D costs.

[0070] 2. Based on the adjustable operating frequency, the gas turbine can suppress thermoacoustic oscillations under different operating conditions.

[0071] 3. Based on the adjustable operating frequency, it effectively compensates for the differences between the operation of individual shock absorbers (40 units) and the overall system, increases the versatility of components, eliminates the need to develop shock absorbers separately for different gas turbine models, and reduces R&D costs.

[0072] In summary, the novel adjustable-frequency combustion chamber vibration damping system disclosed in this application can adjust the effective operating frequency of each individual vibration damper 40 by changing the position of the adjusting baffle 53, whether for the research and development process, operating condition adjustment, or gas turbine upgrade and transformation, thus greatly improving the time and economic costs of research and development, production, manufacturing and installation.

[0073] Furthermore, the novel combustion chamber damping system with adjustable operating frequency described in this application operates in annular combustion chambers or annular tube combustion chambers. Figure 3 In the view shown, the novel combustion chamber damping system acts on the annular combustion chamber; based on this, several burners 10 are arranged in a ring, the novel combustion chamber damping system is arranged around the periphery of the several burners 10, and several individual dampers 40 are also arranged in a ring, preferably arranged circumferentially along the outer wall of the combustion chamber.

[0074] Furthermore, since the shape of the damping cavity of the individual shock absorber 40 generally does not affect the effective operating frequency of the individual shock absorber 40, the external shape of the upper damping chamber 42 of the individual shock absorber 40 can be selected in various ways, such as circular, square, or polygonal, and can be designed according to actual needs. In addition, the cross-sectional area A and the length L of the lower air intake pipe 41 will affect the effective operating frequency of the individual shock absorber 40. Therefore, in some other embodiments, different types of individual dampers can be constructed by setting lower air intake pipes 41 with different cross-sectional areas A or lengths L. Combined with changing the volume V of the damping cavity of the individual shock absorber 40, the damping effect of the novel combustion chamber damping system can be modified.

[0075] Furthermore, the individual shock absorber 40 is a Helmholtz individual shock absorber, but other types of shock absorbers can also be selected. In addition, the several individual shock absorbers 40 arranged circumferentially on the outer wall of the combustion chamber can be of the same type or different types of shock absorbers.

[0076] Furthermore, there are various types of adjusting baffles 53, and three preferred embodiments of adjusting baffles 53 are provided below.

[0077] Adjustable partition 53 Example 1: Figure 7a As shown, the adjusting partition 53 is a circular, fully enclosed partition 531. When the fully enclosed partition 531 is inserted into the adjusting slot 52, the fully enclosed partition 531 blocks the connecting pipe 51 at that location, completely isolating the annular cavity of the connecting pipe 51 on both sides of the fully enclosed partition 531.

[0078] Adjusting partition 53 Example 2: Figure 7b As shown, the adjusting baffle 53 is a semi-circular, semi-enclosed baffle 532. When the semi-circular, semi-enclosed baffle 532 is inserted into the adjusting slot 52, the semi-enclosed baffle 532 does not block the connecting pipe 51 at that location, but changes the partition surface of the connecting pipe 51 at the location of the semi-enclosed baffle 532, that is, changes the partition surface of the connection between the adjacent damping inner cavity at that location.

[0079] Adjusting partition 53 Example 3: Figure 7c As shown, the adjusting partition 53 is a circular, perforated partition 533 with several through holes. Similar to the second embodiment of the adjusting partition 53, when the circular perforated partition 533 with through holes is inserted into the adjusting slot 52, the perforated partition 533 does not block the connecting pipe 51 at that location, but changes the partition surface of the connecting pipe 51 at the location of the perforated partition 533, that is, changes the partition surface of the connection between the adjacent shock-absorbing inner cavity at that location.

[0080] Preferably, the adjusting baffles 53 fixedly installed in the same connecting pipe 51 can be of the same type or different types; only one adjusting baffle 53 or several adjusting baffles 53 can be installed in the same connecting pipe 51.

[0081] Furthermore, such as Figure 4 and Figure 5 As shown, the sealing and locking components include an upper sealing ring 54 and a lower sealing ring 55 that encircle the outer periphery of the connecting pipe 51. The two ends of the upper sealing ring 54 and the lower sealing ring 55 are connected by bolts. Preferably, in the adjusting slot 52, the adjusting baffle 53 can be omitted, but the upper sealing ring 54 and the lower sealing ring 55 can be installed. In this case, the upper sealing ring 54 and the lower sealing ring 55 will seal the adjusting slot 52 at that location, allowing the high-temperature gas to flow smoothly through the adjusting slot 52 of the connecting pipe 51. Alternatively, in the adjusting slot 52, the adjusting baffle 53, the upper sealing ring 54, and the lower sealing ring 55 can also be omitted, allowing the high-temperature gas to flow directly into the outer periphery of the connecting pipe 51, which is also the diffuser section of the compressor in the gas turbine.

[0082] In the aforementioned novel combustion chamber vibration damping system with adjustable operating frequency, the number and position of the slots 52 on the connecting pipe 51 are determined based on actual needs. The fixing position and type of the adjusting baffle 53 are also determined based on actual needs. For example, the adjusting baffle 53 can be fixed at the connecting interface 43 of the individual shock absorber 40, or it can be fixed in the adjusting slot 52 of the connecting pipe 51. The number of slots and the number and type of adjusting baffles 53 installed on the connecting pipe 51 between any two adjacent individual shock absorbers 40 can be the same or different. By using different types of adjusting baffles 53, fixing adjusting baffles 53 at different positions, not installing adjusting baffles 53, not installing the sealing upper ring 54 and sealing lower ring 55, etc., the closure and connection of the internal channels of the connecting pipe 51 can be achieved, ultimately adjusting the effective operating frequency of the novel combustion chamber vibration damping system.

[0083] The following provides three preferred embodiments of a novel combustion chamber damping system.

[0084] Example 1 of the novel combustion chamber vibration damping system Figure 8 As shown, each connecting pipe 51 has three adjustment slots 52, which are sequentially designated as the first adjustment slot 61, the second adjustment slot 62, and the third adjustment slot 63. The first adjustment slot 61 and the third adjustment slot 63 are side slots near the individual shock absorber 40, while the second adjustment slot 62 is a central slot. A fully enclosed partition 531, a sealing upper ring 54, and a sealing lower ring 55 are fixedly installed at both the first adjustment slot 61 and the third adjustment slot 63. In this way, the damping effect of the multiple individual shock absorbers 40 is consistent.

[0085] Example 2 of the novel combustion chamber vibration damping system, such as Figure 9 As shown, each connecting pipe 51 has three adjustment slots 52, which are sequentially designated as the first adjustment slot 61, the second adjustment slot 62, and the third adjustment slot 63. The first adjustment slot 61 and the third adjustment slot 63 are side slots near the individual shock absorber 40, while the second adjustment slot 62 is a central slot. A fully enclosed partition 531, a sealing upper ring 54, and a sealing lower ring 55 are fixedly installed at the second adjustment slot 62. Only the sealing upper ring 54 and the sealing lower ring 55 are fixedly installed at the first adjustment slot 61 and the third adjustment slot 63. In this way, the volume of the damping cavity of the several individual shock absorbers 40 increases by approximately 30%, thereby increasing the operating frequency.

[0086] Example 3 of the novel combustion chamber vibration damping system Figure 9As shown, each connecting pipe 51 has four adjustment slots 52. The four adjustment slots 52 are, in order, the first adjustment slot 61, the second adjustment slot 62, the third adjustment slot 63 and the fourth adjustment slot 64. The first adjustment slot 61 and the fourth adjustment slot 64 are side slots close to the single shock absorber 40, and the second adjustment slot 62 and the third adjustment slot 63 are middle slots.

[0087] Furthermore, comparing the vibration damping effect of assembling a single-unit vibration damper 40 with a non-adjustable operating frequency in a burner 10 with that of the novel combustion chamber vibration damping system with an adjustable operating frequency as described in this application under two different operating conditions, the results are as follows: Figure 11 As shown, Figure 11 The horizontal axis represents the dimensionless oscillation frequency. Figure 11 The vertical axis represents the growth rate, which characterizes the probability that thermoacoustic oscillations will be excited; the larger the growth rate, the greater the probability that thermoacoustic oscillations will be excited. Figure 11 The three circled regions are S1, S2 and S3 from left to right. Region S1 represents the first-order circumferential frequency of the combustion chamber, region S2 represents the second-order circumferential frequency of the combustion chamber, and region S3 represents the third-order circumferential frequency of the combustion chamber. Figure 11 In the diagram, black ● indicates the case without a shock absorber under operating condition 1; black ◆ indicates the case with a single shock absorber 40 of the prior art whose operating frequency is not adjustable under operating condition 1; and black ▲ indicates the case with the novel combustion chamber vibration damping system of this application whose operating frequency is adjustable under operating condition 1. Red ● indicates the case without a shock absorber under operating condition 2; red ◆ indicates the case with a single shock absorber 40 of the prior art whose operating frequency is not adjustable under operating condition 2; and red ▲ indicates the case with the novel combustion chamber vibration damping system of this application whose operating frequency is adjustable under operating condition 2. Figure 11 It is known that the original single-unit shock absorber 40, with its non-adjustable operating frequency, was developed under operating condition 1 with the goal of suppressing second-order frequency oscillations. While it does have a significant suppression effect on the second-order frequency in operating condition 1, its suppression effect at the first and third-order frequencies in operating condition 1 is almost negligible, and its suppression effect on operating condition 2 is also poor. However, the novel combustion chamber damping system with adjustable operating frequency of this application has a significant suppression effect on the circumferential first-order frequency, circumferential second-order frequency, and circumferential third-order frequency under both operating conditions 1 and 2.

[0088] In summary, this utility model effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0089] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A novel combustion chamber vibration damping system with adjustable operating frequency, for mounting on a burner insert (30) at the head of the combustion chamber, characterized in that: The novel combustion chamber damping system includes several spaced individual dampers (40) and an adjustable connection assembly (50) located between two adjacent individual dampers (40); Each of the individual shock absorbers (40) includes a lower intake pipe (41) and an upper shock absorber chamber (42) that are connected. The lower intake pipe (41) is fixed in the burner insert (30) and is used to connect to the combustion chamber. The upper shock absorber chamber (42) is provided with a shock absorber cavity. The upper shock absorber chamber (42) has a connection interface (43) that communicates with the shock absorber cavity at the connection with the adjustment connection assembly (50). Each of the aforementioned adjustment connection assemblies (50) includes a connecting pipe (51), several adjustment slots (52) that are opened in the connecting pipe (51) and spaced apart along the extension direction of the connecting pipe (51), an adjustment partition (53) that is detachably inserted into each adjustment slot (52), and a sealing locking component that is detachably assembled on the outer periphery of each adjustment slot (52). The end of the connecting pipe (51) is connected to the upper shock absorption chamber (42) via the connection interface (43) of the single shock absorber (40). The volume of the damping cavity of each individual shock absorber (40) can be independently adjusted by inserting an adjusting baffle (53) into a different adjusting slot (52) of each of the connecting pipes (51).

2. The novel combustion chamber vibration damping system with adjustable operating frequency according to claim 1, characterized in that: The burner insert (30) is equipped with several burners (10), and a single shock absorber (40) is arranged between two adjacent burners (10).

3. The novel combustion chamber vibration damping system with adjustable operating frequency according to claim 2, characterized in that: Several burners (10) are arranged in a ring, and the novel combustion chamber damping system is arranged around the burners (10). Several individual dampers (40) are also arranged in a ring.

4. The novel combustion chamber vibration damping system with adjustable operating frequency according to claim 1, characterized in that: The adjusting baffle (53) is a circular, fully enclosed baffle (531); When the fully enclosed partition (531) is inserted into the adjustment slot (52), the fully enclosed partition (531) blocks the connecting pipe (51) at that location.

5. The novel combustion chamber vibration damping system with adjustable operating frequency according to claim 1, characterized in that: The adjusting baffle (53) is a semi-circular, semi-enclosed baffle (532).

6. The novel combustion chamber vibration damping system with adjustable operating frequency according to claim 1, characterized in that: The adjusting baffle (53) is a circular, perforated baffle (533) with several through holes.

7. The novel combustion chamber vibration damping system with adjustable operating frequency according to claim 1, characterized in that: The single-unit shock absorber (40) is a Helmholtz single-unit shock absorber.

8. The novel combustion chamber vibration damping system with adjustable operating frequency according to claim 1, characterized in that: The sealing and locking component includes an upper sealing and fixing ring (54) and a lower sealing and fixing ring (55) that surround the outer periphery of the connecting pipe (51), and the two ends of the upper sealing and fixing ring (54) and the lower sealing and fixing ring (55) are connected by bolts.

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