WO2022193067A1

WO2022193067A1 - Combustion chamber for suppressing combustion oscillation, and combustor

Info

Publication number: WO2022193067A1
Application number: PCT/CN2021/080781
Authority: WO
Inventors: 韩啸; 韩猛; 林宇震; 周宇晨
Original assignee: 北京航空航天大学
Priority date: 2021-03-15
Filing date: 2021-03-15
Publication date: 2022-09-22

Abstract

A combustion chamber for suppressing combustion oscillation, and a combustor comprising the combustion chamber. The combustion chamber comprises: a pre-combustion stage, a main combustion stage, a combustion chamber body, and an anti-oscillation ring (7); the pre-combustion stage comprises a center body (1), and a pre-combustion stage swirler (2) and an inter-stage section (3) which are provided on the periphery of the center body (1); the main combustion stage is provide on the periphery of the pre-combustion stage; the main combustion stage comprises a main combustion stage swirler (4) and a main combustion stage outer ring (5); the combustion body comprises an end wall (6) and side walls (8); the end wall (6) is connected to the main combustion stage outer ring (5) and the side walls (8); the anti-oscillation ring (7) is fixed to the inner surface of the end wall (6) and/or an outlet end of the main combustion stage outer ring (5); and a flame channel (71) that is gradually expanded in a direction facing away from the main combustion stage is formed in the anti-oscillation ring (7). The combustion chamber has the advantages of low retrofit cost and a wide application range.

Description

Combustion chambers and burners for suppressing combustion oscillations

technical field

The present application relates to the technical field of energy and power, and in particular, to a combustion chamber and a burner for suppressing combustion oscillation.

Background technique

The way humans obtain energy and power is still mainly the burning of fossil fuels. In the related application equipment in the energy and power field, combustion oscillation is a common technical challenge in various types of burners, which are widely found in boilers, gas water heaters, gas turbines and other combustion devices. Especially under the increasingly strict emission requirements, in order to reduce the emission of pollutants dominated by nitrogen oxides (NOx), advanced combustion devices often use lean premixed combustion mode, and combustion devices are often in a state near flameout Work is very sensitive to external disturbances, and is easily affected by external disturbances, resulting in heat release rate fluctuations. When the heat release rate pulsation is coupled with the acoustics of the combustion system (which can be simply understood as meeting the Rayleigh criterion), it is easy to cause a large amount of heat release rate pulsation and pressure pulsation, which will affect the stable operation of the combustion device in light, and cause the combustion device in severe cases. Or the structural damage of other components will seriously threaten the operation safety of the entire system. Therefore, combustion oscillations must be avoided by modern advanced combustion devices.

In order to solve the problem of combustion oscillation, a variety of methods have been proposed to control combustion oscillation, which can be divided into two categories: active control and passive control. Active control is to use special monitors and active actuators to actively apply appropriate external excitation (for inlet air or fuel supply, etc.) according to the monitored signals such as pressure pulsation in the combustion system to suppress or eliminate the heat release rate. Coupling between pulsations and pressure oscillations (sound waves). However, this type of method requires additional control systems and execution devices, and also has high requirements on control algorithms, which will increase additional costs and have limited application scenarios. Passive control refers to the addition of fixed devices to the combustion system to suppress or eliminate combustion oscillations. Common types of acoustic components, such as Helmholtz resonators, can suppress combustion oscillations at specific frequencies. The disadvantage is that the volume is large, and it can only be effective for a specific frequency, so a lot of experiments and debugging need to be done in advance.

SUMMARY OF THE INVENTION

The present application aims to solve at least one of the technical problems existing in the prior art. Therefore, the present application proposes a combustion chamber for suppressing combustion oscillation, so as to suppress the occurrence of the phenomenon of combustion oscillation.

The application also proposes a burner.

The combustion chamber for suppressing combustion oscillation according to the embodiment of the first aspect of the present application includes:

a pre-combustion stage, the pre-combustion stage including a central body and a pre-combustion stage swirler and an interstage disposed on the periphery of the central body;

a main combustion stage, the main combustion stage is arranged on the periphery of the pre-combustion stage, and the main combustion stage includes a main combustion stage swirler and a main combustion stage outer ring;

a combustion chamber main body, comprising an end wall and a side wall, the end wall connecting the main combustion stage outer ring and the side wall;

an anti-vibration ring, fixed on the inner surface of the end wall of the end wall and/or the outer ring outlet end face of the outer ring of the main combustion stage, and the anti-vibration ring is formed in a direction facing away from the main combustion stage The flame channel is gradually expanding, the inlet end of the flame channel is butted with the outlet end of the main combustion stage, and the outlet end of the flame channel is communicated with the inner cavity of the combustion chamber main body.

In the prior art, combustion oscillation is generally suppressed by machining the end wall or the side wall of the combustion chamber to have a conical transition structure, while the combustion chamber described in the present application is at the end of the end wall. The same effect can be achieved by installing the anti-vibration ring on the inner surface of the wall and/or the outlet end face of the outer ring of the outer ring of the main combustion stage; compared with the combustion chamber of the prior art, the combustion chamber of the present application has a retrofit cost Low, the advantages of a wide range of applications.

According to an embodiment of the present application, the pre-stage, the main combustion stage, the combustion chamber main body and the anti-vibration ring are all arranged coaxially.

According to an embodiment of the present application, the inner wall of the anti-vibration ring is formed with a flow spoiler.

According to an embodiment of the present application, the spoiler includes a plurality of steps distributed along the axis of the central body, or,

The spoiler portion includes a plurality of annular spoiler grooves distributed along the axis of the central body, or,

The spoiler portion includes a longitudinal spoiler groove penetrating the inner wall along the axis direction of the central body, and the number of the longitudinal spoilers is plural and distributed along the circumference of the inner wall.

According to an embodiment of the present application, the cross section of the inlet end and the cross section of the outlet end are both circular, or both the cross section of the inlet end and the cross section of the outlet end are oval.

According to an embodiment of the present application, the interstage section includes an outlet end face of the interstage section, the main combustion stage swirler includes an outlet end face of the main combustion stage swirler, and the outlet end face of the interstage section is connected to the outer ring. The outlet end face is misaligned.

According to an embodiment of the present application, the outlet end surface of the outer ring and the inner surface of the end wall are coplanar.

According to an embodiment of the present application, the distance between the outlet end face of the main combustion stage swirler and the outlet end face of the interstage section along the axial direction of the central body is a first distance; the main combustion stage swirler The distance between the outlet end face and the outlet end face of the outer ring along the axial direction of the central body is a second interval, and the first interval is greater than the second interval.

According to an embodiment of the present application, the distance between the outlet end face of the main combustion stage swirler and the outlet end face of the interstage section along the axial direction of the central body is a first distance; the main combustion stage swirler The distance between the outlet end face and the outlet end face of the outer ring along the axial direction of the central body is a second pitch, and the first pitch is smaller than the second pitch.

A burner according to an embodiment of the second aspect of the present application includes the combustion chamber for suppressing combustion oscillation according to any one of the above embodiments, and the burner is a swirl cup structure burner, a multi-swirl burner or a center burner Staged burners.

Since the burner according to the embodiment of the present application includes the above-mentioned combustion chamber, it has all the technical effects of the above-mentioned combustion chamber, which will not be repeated here.

Additional aspects and advantages of the present application will be set forth, in part, from the following description, and in part will become apparent from the following description, or may be learned by practice of the present application.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

1 is a schematic diagram of a partial structure of a combustion chamber for suppressing combustion oscillation provided by an embodiment of the present application;

2 is a schematic diagram of a partial structure of a spoiler provided by an embodiment of the present application;

3 is a schematic diagram of a partial structure of another spoiler provided by an embodiment of the present application;

4 is a schematic diagram of a partial structure of still another spoiler provided by an embodiment of the present application;

5 is a schematic diagram of another partial structure of a combustion chamber for suppressing combustion oscillation provided by an embodiment of the present application;

FIG. 6 is a schematic diagram of another partial structure of a combustion chamber for suppressing combustion oscillation provided by an embodiment of the present application;

Reference number:

1. Center body; 2. Pre-combustion stage swirler; 3. Interstage section; 4. Main combustion stage swirler; 5. Main combustion stage outer ring; 6. End wall; 7. Anti-vibration ring; 71, Flame passage; 711, step; 712, annular spoiler groove; 713, longitudinal spoiler groove; 8, side wall; 9, main combustion stage flame; 10, pre-burning stage flame;

Detailed ways

The embodiments of the present application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the application, but not to limit the scope of the application.

In the description of the embodiments of the present application, it should be noted that the terms "center", "portrait", "horizontal", "top", "bottom", "front", "rear", "left" and "right" , "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, only for the convenience of describing this The application examples and simplified descriptions are not intended to indicate or imply that the indicated devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of the present application. Furthermore, the terms "first", "second", and "third" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

In the description of the embodiments of the present application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection, Or integral connection; it can be mechanical connection or electrical connection; it can be directly connected or indirectly connected through an intermediate medium. Those of ordinary skill in the art can understand the specific meanings of the above terms in the embodiments of the present application in specific situations.

In the embodiments of the present application, unless otherwise expressly specified and limited, the first feature "on" or "under" the second feature may be in direct contact with the first and second features, or the first and second features pass through the middle indirect contact with the media. Also, the first feature being "above", "over" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structures, materials, or features are included in at least one example or example of the embodiments of the present application. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other.

The embodiment of the present application provides a combustion chamber for suppressing combustion oscillation. As shown in FIG. 1 , the combustion chamber includes a pre-combustion stage, a main combustion stage, a combustion chamber main body and an anti-vibration ring 7 , and the pre-combustion stage includes a central body 1 and the pre-combustion stage swirler 2 and the interstage section 3 arranged on the periphery of the central body 1; the main combustion stage is arranged on the periphery of the pre-combustion stage, and the main combustion stage includes the main combustion stage swirler 4 and the main combustion stage outer ring 5 The main combustion chamber body includes an end wall 6 and a side wall 8, and the end wall 6 is connected to the main combustion stage outer ring 5 and the side wall 8; Outlet end, and the anti-vibration ring 7 is formed with a flame channel 71 that is gradually expanding in the direction away from the main combustion stage, the inlet end of the flame channel 71 is butted with the outlet end of the main combustion stage, and the outlet end of the flame channel 71 is connected The inner cavity of the combustion chamber body.

The anti-vibration ring 7 is formed with a flame channel 71 that gradually expands in the direction away from the main combustion stage. During operation, based on the Coanda effect, the unburned mixture of air and fuel entering the flame channel 71 will fit the flame. The channel 71 flows, so that the flame front will flow as close to the inner wall of the flame channel 71 as possible, thereby reducing the heat release rate pulsation, decoupling it from the combustion system acoustic system, and finally suppressing combustion oscillation.

In the prior art, combustion oscillation is generally suppressed by processing the end wall 6 or side wall 8 of the combustion chamber to have a conical transition structure, while the combustion chamber of the present application is only located at the outlet end face 11 and/or end wall of the outer ring. The same effect can be achieved by installing the anti-vibration ring 7 on the inner surface; compared with the combustion chamber of the prior art, the combustion chamber of the present application has the advantages of low modification cost and wide application range.

According to one of the embodiments of the present application, the anti-vibration ring 7 is connected with the end wall 6 and/or the main combustion stage outer ring 5 by means of integral processing, welding or fastener connection. Certainly, the connection manner between the anti-vibration ring 7 and the end wall 6 and/or the main combustion stage outer ring 5 is not limited by the examples herein.

According to one of the embodiments of the present application, the anti-vibration ring 7 is a hollow cylinder, a hollow truncated cone or a hollow cubic structure.

According to another embodiment of the present application, as shown in FIG. 1 , the shape of the anti-vibration ring 7 is similar to that of the flame channel 71 , and the anti-vibration ring 7 is a hollow circular truncated structure, and gradually expands in the direction away from the main combustion stage shape extension. The anti-vibration ring 7 designed in this way can reduce its thickness to the limit on the premise of ensuring the structural strength and thermal load, thereby reducing the weight of the combustion chamber.

According to one of the embodiments of the present application, as shown in FIG. 1 , the pre-stage, the main combustion stage, the combustion chamber main body and the anti-vibration ring 7 are all arranged coaxially.

According to one of the embodiments of the present application, the anti-vibration ring 7 extends in the axial direction of the central body 1 . It should be noted that the anti-vibration ring 7 may also extend in other directions, as long as the anti-vibration ring 7 has a flame channel 71 formed in the anti-vibration ring 7 which is gradually expanding in the direction away from the main combustion stage.

According to one of the embodiments of the present application, a spoiler is formed in the flame channel 71 .

The spoiler can change the flow trajectory of the flame front in the flame channel 71, and further improve the effect of the anti-vibration ring 7 in suppressing combustion oscillation.

The spoiler includes one or more of a step 711, an annular spoiler groove 712 and a longitudinal spoiler groove 713. Of course, the structure of the spoiler is not limited by the examples here, as long as the flame front can be changed in the flame passage. The flow trajectory in 71 is sufficient.

According to one of the embodiments of the present application, as shown in FIG. 2 , the spoiler includes a plurality of steps 711 distributed along the axial direction of the central body 1 . Based on the Coanda effect, the flame front is close to the step 711, and the step 711 interferes with the normal flow of the flame.

According to another embodiment of the present application, the length L _{1 of the step 711 parallel to the axial direction of the central body 1} =L ₀ /n; the length of the step 711 perpendicular to the axial direction of the central body 1 L ₂ =L ₀ /n/tanɑ ; wherein, L0 is the length of the flame channel 71 formed along the axis of the central body 1, and n is the number of steps 711.

According to another embodiment of the present application, as shown in FIG. 3 , the spoiler portion includes a plurality of annular spoiler grooves 712 distributed along the axial direction of the central body 1 . Based on the Coanda effect, the flame flows circumferentially around the annular spoiler groove 712 .

According to another embodiment of the present application, the width f and the height e of the annular spoiler groove 712 are both in the range of 2-10 mm.

According to another embodiment of the present application, as shown in FIG. 4 , the spoiler includes a plurality of longitudinal spoiler grooves 713 penetrating the flame channel 71 along the axial direction of the central body 1 , and the longitudinal spoiler grooves 713 are along the flame channel Circumferential distribution of 71. Based on the Coanda effect, the flame is divided at the entrance end of the flame channel 71 by the respective longitudinal spoiler grooves 713.

According to another embodiment of the present application, the depth of the longitudinal spoiler grooves 713 is in the range of 2-10 mm, and the width of the longitudinal spoiler grooves 713 is S=2π/2m, where m is the number of the longitudinal spoiler grooves 713 .

According to one of the embodiments of the present application, the cross section of the inlet end of the flame channel 71 and the cross section of the outlet end of the flame channel 71 are both circular, or the cross section of the inlet end of the flame channel 71 and the cross section of the outlet end of the flame channel 71 are circular All are oval. The cross section is circular or oval to satisfy the Coanda effect. Of course, the present application is not limited by the above examples, for example, the shape of the flame channel 71 may also be: the cross section of the inlet end is circular, and the shape of the cross section of the outlet end is oval.

According to another embodiment of the present application, when the cross section of the inlet end of the flame channel 71 is circular, the diameter of the cross section of the inlet end is 1-3 times the diameter D of the outlet end of the main combustion stage, and the channel side wall of the flame channel 71 The included angle α between the plane where the plane is located and the plane where the outlet end face 51 of the outer ring is located is in the range of 0-90°. The maximum channel length of the flame channel 71 is 3 times the diameter D of the outlet end of the main combustion stage.

When the cross section of the inlet end of the flame passage 71 is oval, the dimension of the long axis of the cross section of the inlet end is 1-3 times the diameter D of the outlet end of the main combustion stage, and the dimension of the short axis of the cross section of the inlet end is the size of the main combustion stage 1-3 times the diameter D of the outlet end.

According to one of the embodiments of the present application, as shown in FIG. 5 , when the anti-vibration ring 7 is fixed on the outlet end of the main combustion stage outer ring 5 and the inner surface of the end wall 6 , the main changes are the included angle α and the channel length L ₀ , different channel lengths L ₀ provide different attachment areas for the flame, thereby changing the flame shape and suppressing the combustion chamber oscillation; at the same time, the change of the included angle α, due to the Coanda effect, will cause the fluid to follow the channel wall of the flame channel 71 . Flow, and then change the physical expansion angle of the flow, and then change the flame opening angle and the relative position of the main combustion stage flame 9, so as to achieve the ability to change the flame shape and the combustion chamber oscillation.

According to one of the embodiments of the present application, as shown in FIG. 6 , the anti-vibration ring 7 is fixed on the inner surface of the end wall 6 , and the main variable is the distance between the side wall at the inlet of the flame channel 71 and the inner side wall of the outlet end face 11 of the outer ring. Difference L, different differences will lead to changes in the shape of the flame. As shown in Figure 6, when the difference L reaches a certain state, the main combustion stage flame 9 will have a double root state, which can play a beneficial role in the stability of the flame. In order to achieve the effect of suppressing oscillation. The pre-combustion stage flame 10 is generally stabilized at the two edge points of the interstage section 3 at the same time, and serves to provide a high temperature recirculation zone to keep the entire flame sustaining combustion.

According to one of the embodiments of the present application, the interstage section 3 includes an outlet end face of the interstage section, the main combustion stage swirler 4 includes an outlet end face of the main combustion stage swirler, and the main combustion stage outer ring 5 includes an outer ring outlet end face 11, The combustion chamber end wall 6 includes the inner surface of the end wall; the outlet end face of the interstage section and the outlet end face 11 of the outer ring are arranged in a staggered position.

The dislocation of the outlet end face of the interstage section and the outlet end face 11 of the outer ring can change the starting position of the inner and outer shear layers of the swirl flow, thereby affecting the flame position in the inner cavity of the combustion chamber main body, and realizing the regulation of combustion oscillation.

According to one of the embodiments of the present application, the outlet end surface 11 of the outer ring and the inner surface of the end wall are coplanar, so as to facilitate the installation of other equipment such as the anti-vibration ring 7 in the combustion chamber.

According to one of the embodiments of the present application, the distance between the outlet end face of the main combustion stage swirler and the outlet end face of the interstage section along the axis direction of the central body 1 is the first distance; the outlet end face of the main combustion stage swirler and the outlet of the outer ring The spacing distance between the end faces 11 along the axis of the center body 1 is the second spacing, the first spacing is greater than the second spacing, and the value of the first spacing is S. The separation distance of the direction is H, where S and H are both set values, and both can take values in the corresponding interval, and H/S≤1. Compared with the prior art, the length of the outer ring 5 of the main combustion stage designed in this way is shorter, so that the combustion chamber has a lighter weight while suppressing combustion oscillation.

According to another embodiment of the present application, the first distance is greater than the second distance, and the value of the second distance is S, and H/S≤1.

According to another embodiment of the present application, the first distance is smaller than the second distance, and the value of the first distance is S, and H/S≤1.

According to another embodiment of the present application, the first distance is smaller than the second distance, and the value of the second distance is S, and H/S≤1.

Another embodiment of the present application provides a burner, including the combustion chamber provided by any of the technical solutions of the present application.

According to one of the embodiments of the present application, the burners include, but are not limited to, conventional swirl cup burners, multi-swirl burners, and center stage burners.

The above embodiments are only used to illustrate the present application, but not to limit the present application. Although the present application has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that various combinations, modifications or equivalent replacements to the technical solutions of the present application do not depart from the spirit and scope of the technical solutions of the present application, and should cover within the scope of the claims of this application.

Claims

A combustion chamber for suppressing combustion oscillation, characterized in that it includes:

a pre-combustion stage, the pre-combustion stage comprising a central body (1) and a pre-combustion stage swirler (2) and an interstage (3) arranged on the periphery of the central body (1);

a main combustion stage, the main combustion stage is arranged on the periphery of the pre-combustion stage, and the main combustion stage includes a main combustion stage swirler (4) and a main combustion stage outer ring (5);

a combustion chamber main body, comprising an end wall (6) and a side wall (8), the end wall (6) connecting the main combustion stage outer ring (5) and the side wall (8);

An anti-vibration ring (7), the anti-vibration ring (7) is fixed on the inner surface of the end wall of the end wall (6) and/or the outer ring outlet end face (11) of the main combustion stage outer ring (5) , and the anti-vibration ring (7) is formed with a flame channel (71) that is gradually expanding in the direction away from the main combustion stage, and the inlet end of the flame channel (71) is connected to the main combustion stage. The outlet ends of the flame passages (71) are connected to the inner cavity of the combustion chamber main body.
The combustion chamber for suppressing combustion oscillation according to claim 1, wherein the pre-stage, the main combustion stage, the combustion chamber main body and the anti-vibration ring (7) are all arranged coaxially.
The combustion chamber for suppressing combustion oscillation according to claim 1, characterized in that a spoiler is formed on the inner wall of the anti-vibration ring (7).
The combustion chamber for suppressing combustion oscillation according to claim 3, wherein the spoiler comprises a plurality of steps (711) distributed along the axis direction of the central body (1), or,

The spoiler includes a plurality of annular spoiler grooves (712) distributed along the axis of the central body (1), or,

The spoiler portion includes a longitudinal spoiler groove (713) penetrating the inner wall along the axial direction of the central body (1), and the longitudinal spoilers are plural in number and distributed along the circumferential direction of the inner wall .
The combustion chamber for suppressing combustion oscillation according to any one of claims 2 to 4, wherein the cross-section of the inlet end and the cross-section of the outlet end are both circular, or the inlet end has a circular cross-section. The cross-section, as well as the cross-section of the outlet end, is elliptical.
The combustion chamber for suppressing combustion oscillation according to claim 5, characterized in that the interstage section (3) includes an outlet end face of the interstage section, and the main combustion stage swirler (4) includes a main combustion stage The outlet end face of the cyclone, the outlet end face of the interstage section and the outlet end face (11) of the outer ring are arranged in a staggered position.
The combustion chamber for suppressing combustion oscillation according to claim 6, wherein the outlet end surface of the outer ring and the inner surface of the end wall are coplanar.
The combustion chamber for suppressing combustion oscillation according to claim 7, characterized in that the main combustion stage swirler outlet end face and the interstage outlet end face are along the axial direction of the central body (1). The separation distance is the first distance; the separation distance between the outlet end face of the main combustion stage swirler and the outlet end face (11) of the outer ring along the axial direction of the central body (1) is the second distance, and the first The spacing is greater than the second spacing.
The combustion chamber for suppressing combustion oscillation according to claim 7, wherein the main combustion stage swirler outlet end face and the interstage section outlet end face are along the axis direction of the central body (1). The separation distance is the first distance; the separation distance between the outlet end face of the main combustion stage swirler and the outlet end face (11) of the outer ring along the axial direction of the central body (1) is the second distance, and the first The spacing is smaller than the second spacing.
A burner, characterized in that the burner comprises the combustion chamber for suppressing combustion oscillation according to any one of claims 1-9, and the burner is a swirl cup structure burner, a multi-swirl combustion burner or center stage burner.