Combustion chamber and burner

Abstract

The present invention relates to the field of energy and power technology, and provides a combustion chamber and a burner, wherein the combustion chamber comprises: a pre-combustion stage, a main combustion stage and a combustion chamber body; the pre-combustion stage comprises a center body and a pre-combustion stage swirler and an interstage section arranged on the periphery of the center body, and the interstage section comprises an interstage section outlet end face; the main combustion stage is arranged on the periphery of the pre-combustion stage, and the main combustion stage comprises a main combustion stage swirler and a main combustion stage outer ring, and the main combustion stage swirler comprises a main combustion stage swirler outlet end face, and the main combustion stage outer ring comprises an outer ring outlet end face; the combustion chamber body comprises an end wall and a side wall, and the end wall connects the main combustion stage outer ring and the side wall, and the end wall comprises an end wall inner surface; the interstage section outlet end face is staggered with the outer ring outlet end face. The present invention changes the starting position of the inner and outer shear layers of the swirl flow by staggering the internal structure of the combustion chamber, thereby affecting the flame position in the inner cavity of the combustion chamber body, and realizing the regulation of combustion oscillation.

Description

Technical Field

[0001] The invention relates to the field of energy and power technology, in particular to a combustion chamber and a burner. Background Art

[0002] The combustion of fossil fuels is still the main way for humans to obtain energy and power. Among various types of combustion devices, combustion oscillation is a common technical challenge, which is widely present in boilers, gas water heaters, gas turbines and other combustion devices. Especially under increasingly stringent emission requirements, in order to reduce the emission of pollutants mainly composed of nitrogen oxides (NOx), advanced combustion devices mostly use lean oil premixed combustion technology. The combustion devices often operate in a working state close to flameout, which is very sensitive to external disturbances and easily affected by external disturbances, resulting in heat release rate pulsation. When the heat release rate pulsation in the burner is coupled with the acoustics of the combustion system (which can be simply understood as satisfying the Rayleigh criterion), it is easy to cause large heat release rate pulsation and pressure pulsation. The large pressure pulsation and heat release pulsation in the burner will cause structural damage to the burner, further affecting the stable operation and safe operation of the combustion system. Therefore, combustion oscillation is something that modern advanced combustion devices must try their best to avoid.

[0003] In order to solve the combustion oscillation problem of the burner, a variety of methods have been proposed and applied to control combustion oscillation. According to different principles, they 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 excitations (such as inlet air or fuel supply) according to the pressure pulsation and other signals monitored in the combustion system, so as to suppress or eliminate the coupling between heat release rate pulsation and pressure oscillation (sound wave). However, this type of method requires additional control systems and actuators, and has high requirements for control algorithms, which will increase additional costs and have limited applicable scenarios. Passive control refers to adding certain 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 of specific frequencies. The disadvantage is that it is large in size and is only effective for specific frequencies, requiring a lot of experiments and debugging in advance. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a combustion chamber to suppress the occurrence of combustion oscillation.

[0005] The invention also provides a burner.

[0006] A combustion chamber according to an embodiment of the first aspect of the present invention comprises:

[0007] A pre-combustion stage, the pre-combustion stage comprising a center body, a pre-combustion stage swirler and an inter-stage section arranged on the periphery of the center body, the inter-stage section comprising an inter-stage section outlet end face;

[0008] A main combustion stage is arranged at the periphery of the pre-combustion stage, the main combustion stage comprises a main combustion stage swirler and a main combustion stage outer ring, the main combustion stage swirler comprises a main combustion stage swirler outlet end face, and the main combustion stage outer ring comprises an outer ring outlet end face;

[0009] A combustion chamber body, comprising an end wall and a side wall, wherein the end wall connects the main combustion stage outer ring and the side wall, and the end wall comprises an end wall inner surface;

[0010] The outlet end face of the interstage section is staggered with the outlet end face of the outer ring.

[0011] According to the combustion chamber of an embodiment of the present invention, the interstage outlet end face and the outer ring outlet end face are staggered, which can change the starting positions of the inner and outer shear layers of the swirl flow, thereby affecting the flame position in the inner cavity of the combustion chamber body, thereby achieving regulation of combustion oscillations.

[0012] According to one embodiment of the present invention, the spacing 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 center body is a first spacing; the spacing distance between the outlet end face of the main combustion stage swirler and the outlet end face of the outer ring along the axial direction of the center body is a second spacing, and the first spacing is greater than the second spacing.

[0013] According to one embodiment of the present invention, the spacing 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 center body is a first spacing; the spacing distance between the outlet end face of the main combustion stage swirler and the outlet end face of the outer ring along the axial direction of the center body is a second spacing, and the first spacing is smaller than the second spacing.

[0014] According to one embodiment of the present invention, the value of the first spacing or the value of the second spacing is S, the spacing distance between the interstage outlet end face and the outer ring outlet end face along the axial direction of the center body is H, and H / S≤1.

[0015] According to one embodiment of the present invention, the outer ring outlet end surface and the end wall inner surface are coplanar.

[0016] According to one embodiment of the present invention, the combustion chamber also includes a vibration suppression device, which is fixed to the inner surface of the end wall and / or the outer ring outlet end face, and the vibration suppression device forms a flame channel that gradually expands along the direction away from the main combustion stage, the inlet end of the flame channel is connected to the outlet end of the main combustion stage, and the outlet end of the flame channel is connected to the inner cavity of the combustion chamber body.

[0017] According to one embodiment of the present invention, the cross-section of the inlet end of the flame channel and the cross-section of the outlet end of the flame channel are both circular, or the cross-section of the inlet end of the flame channel and the cross-section of the outlet end of the flame channel are both elliptical.

[0018] According to an embodiment of the present invention, a spoiler is formed in the flame channel.

[0019] According to one embodiment of the present invention, the spoiler comprises a plurality of steps distributed along the axis direction of the central body, or,

[0020] The spoiler comprises a plurality of annular spoiler grooves distributed along the axial direction of the central body, or,

[0021] The spoiler portion includes a plurality of longitudinal spoiler grooves penetrating the flame channel along the axial direction of the central body, and the longitudinal spoiler grooves are distributed along the circumference of the flame channel.

[0022] The burner according to the embodiment of the second aspect of the present invention comprises the combustion chamber described in any one of the above embodiments, and the burner comprises a swirl cup structure burner, a multi-swirl burner or a central staged burner.

[0023] The burner according to the embodiment of the present invention includes the above-mentioned combustion chamber and thus has all the technical effects of the above-mentioned combustion chamber, which will not be described in detail here.

[0024] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a schematic diagram of a local structure of a combustion chamber provided by an embodiment of the present invention;

[0027] Figure 2 is another schematic diagram of a partial structure of a combustion chamber provided by an embodiment of the present invention;

[0028] Figure 3 is another schematic diagram of a partial structure of a combustion chamber provided by an embodiment of the present invention;

[0029] Figure 4is another schematic diagram of a partial structure of a combustion chamber provided by an embodiment of the present invention;

[0030] Reference numerals:

[0031] 1. Center body; 2. Pre-combustion stage cyclone; 3. Interstage section; 31. Interstage section outlet end face; 4. Main combustion stage cyclone; 41. Main combustion stage cyclone outlet end face; 5. Main combustion stage outer ring; 51. Outer ring outlet end face; 6. End wall; 61. Inner surface of end wall; 7. Side wall. DETAILED DESCRIPTION

[0032] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0033] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0034] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0035] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" 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 higher in level 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 is lower in level than the second feature.

[0036] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0037] like Figures 1 to 4 As shown, an embodiment of the present invention provides a combustion chamber, comprising: a pre-combustion stage, a main combustion stage and a combustion chamber body, the pre-combustion stage comprising a center body 1 and a pre-combustion stage swirler 2 and an interstage section 3 arranged on the periphery of the center body 1, the interstage section 3 comprising an interstage section outlet end face 31; the main combustion stage is arranged 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 main combustion stage swirler 4 comprises a main combustion stage swirler outlet end face 41, and the main combustion stage outer ring comprises an outer ring outlet end face 51; the combustion chamber body comprises an end wall 6 and a side wall 7, the end wall 6 connects the main combustion stage outer ring 5 and the side wall 7, and the end wall 6 comprises an end wall inner surface 61; the interstage section outlet end face 31 is staggered with the outer ring outlet end face 51.

[0038] The interstage outlet end face 31 and the outer ring outlet end face 51 are staggered, which 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 body and achieving regulation of combustion oscillation.

[0039] According to one embodiment of the present invention, Figure 1 As shown, the distance between the main combustion stage swirler outlet end face 41 and the interstage section outlet end face 31 along the axis of the center body 1 is the first distance; the distance between the main combustion stage swirler outlet end face 41 and the outer ring outlet end face 51 along the axis of the center body 1 is the second distance, the first distance is greater than the second distance, the value of the first distance is S, and the distance between the interstage section outlet end face 31 and the outer ring outlet end face 51 along the axis of the center body 1 is H, where S and H are both set values, and can be taken in the corresponding range, H / S≤1. Compared with the prior art, the length of the main combustion stage outer ring 5 of this embodiment is shorter, so that the combustion chamber has a lighter weight while suppressing combustion oscillation.

[0040] According to another embodiment of the present invention, Figure 2 As shown, the first spacing is greater than the second spacing, the value of the second spacing is S, and H / S≤1.

[0041] According to another embodiment of the present invention, Figure 3 As shown, the first spacing is smaller than the second spacing, the value of the first spacing is S, and H / S≤1.

[0042] According to another embodiment of the present invention, Figure 4 As shown, the first spacing is smaller than the second spacing, the value of the second spacing is S, and H / S≤1.

[0043] According to one embodiment of the present invention, Figures 1 to 4 As shown, the outer ring outlet end face 51 and the end wall inner surface 61 are coplanar, so as to facilitate the installation of other equipment such as vibration suppression devices in the combustion chamber. Of course, the outer ring outlet end face 51 and the end wall inner surface 61 can also be staggered.

[0044] According to one embodiment of the present invention, the combustion chamber also includes a vibration suppression device, which is fixed to the outer ring outlet end face 51 and / or the end wall inner surface 61, and the vibration suppression device forms a flame channel that gradually expands along the direction away from the main combustion stage, the inlet end of the flame channel is connected to the outlet end of the main combustion stage, and the outlet end of the flame channel is connected to the inner cavity of the combustion chamber body.

[0045] Since the vibration suppression device forms a gradually expanding flame channel 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 will flow along the flame channel, so that the flame front will flow as close to the inner wall of the flame channel as possible, thereby reducing the heat release rate pulsation, decoupling it from the acoustic system of the combustion system, and ultimately suppressing combustion oscillations.

[0046] According to one embodiment of the present invention, the vibration suppression device is a hollow cylinder, a hollow frustum or a hollow cube structure.

[0047] According to one embodiment of the present invention, the vibration suppression device is similar in shape to the flame channel, is a hollow truncated cone structure, and extends in a gradually expanding shape in the direction away from the main combustion stage. The vibration suppression device designed in this way can reduce its thickness to the limit while ensuring the structural strength and heat load, thereby reducing the weight of the combustion chamber.

[0048] According to one embodiment of the present invention, the cross section of the inlet end of the flame channel and the cross section of the outlet end of the flame channel are both circular, or the cross section of the inlet end of the flame channel and the cross section of the outlet end of the flame channel are both elliptical. The cross section is circular or elliptical to satisfy the Coanda effect.

[0049] According to another embodiment of the present invention, when the cross section of the inlet end of the flame channel is circular, the diameter of the cross section of the inlet end is 1-3 times the diameter of the main combustion stage outlet end, and the angle ɑ between the plane where the channel side wall of the flame channel is located and the plane where the outer ring outlet end face 51 is located is in the range of 0-90°. The maximum channel length of the flame channel is 3 times the diameter of the main combustion stage outlet end.

[0050] When the cross section of the inlet end of the flame channel is elliptical, the major axis dimension of the cross section of the inlet end is 1-3 times the diameter of the main combustion stage outlet end, and the minor axis dimension of the cross section of the inlet end is 1-3 times the diameter of the main combustion stage outlet end.

[0051] According to one embodiment of the present invention, a spoiler is formed in the flame channel. The spoiler refers to a structure that can change the flow trajectory of the flame front in the flame channel. The setting of the spoiler further improves the effect of the vibration suppression device in suppressing combustion oscillations.

[0052] The structure of the spoiler is not limited, and may be, for example, in the form of one or more of a step, an annular spoiler groove, and a longitudinal spoiler groove.

[0053] According to another embodiment of the present invention, the spoiler includes a plurality of steps distributed along the axis of the central body 1. Based on the Coanda effect, the flame front approaches the steps, and the steps interfere with the normal flow of the flame.

[0054] According to another embodiment of the present invention, the spoiler comprises a plurality of annular spoiler grooves distributed along the axial direction of the central body 1. Based on the Coanda effect, the flame flows in a circle around the annular spoiler grooves.

[0055] According to another embodiment of the present invention, the spoiler comprises a plurality of longitudinal spoiler grooves penetrating the flame channel along the axial direction of the central body 1, and the longitudinal spoiler grooves are distributed along the circumference of the flame channel. Based on the Coanda effect, the flame is diverted by each longitudinal spoiler groove at the inlet end of the flame channel.

[0056] Another embodiment of the present invention provides a burner, comprising a combustion chamber provided by any technical solution of the present invention.

[0057] According to one embodiment of the present invention, the burner includes a swirl cup structure burner, a multi-swirl burner or a center-staged burner. Of course, the specific type of the burner is not limited to the examples given here.

[0058] The above embodiments are only used to illustrate the present invention, but not to limit the present invention. Although the present invention is described in detail with reference to the embodiments, it should be understood by those skilled in the art that various combinations, modifications or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and should be included in the scope of the claims of the present invention.

Claims

1. A combustion chamber, characterized in that: include: A pre-combustion stage, the pre-combustion stage comprising a center body (1), a pre-combustion stage swirler (2) and an inter-stage section (3) arranged on the periphery of the center body (1), the inter-stage section (3) comprising an inter-stage section outlet end surface (31); A main combustion stage is arranged at the periphery of the pre-combustion stage, the main combustion stage comprising a main combustion stage swirler (4) and a main combustion stage outer ring (5), the main combustion stage swirler (4) comprising a main combustion stage swirler outlet end face (41), and the main combustion stage outer ring (5) comprising an outer ring outlet end face (51); A combustion chamber body, comprising an end wall (6) and a side wall (7), wherein the end wall (6) connects the main combustion stage outer ring (5) and the side wall (7), and the end wall (6) comprises an end wall inner surface (61); A vibration suppression device, the vibration suppression device is fixed to the inner surface (61) of the end wall and / or the outer ring outlet end surface (51), and the vibration suppression device forms a flame channel that is gradually expanded in a direction away from the main combustion stage, the inlet end of the flame channel is connected to the outlet end of the main combustion stage, and the outlet end of the flame channel is connected to the inner cavity of the combustion chamber body; The cross section of the inlet end of the flame channel and the cross section of the outlet end of the flame channel are both circular, or the cross section of the inlet end of the flame channel and the cross section of the outlet end of the flame channel are both elliptical; a flow spoiler is formed in the flame channel; The spoiler comprises a plurality of steps distributed along the axial direction of the central body (1), or, The spoiler portion comprises a plurality of annular spoiler grooves distributed along the axial direction of the central body (1), or, The spoiler portion comprises a plurality of longitudinal spoiler grooves penetrating the flame channel along the axial direction of the central body (1), and the longitudinal spoiler grooves are distributed along the circumference of the flame channel; The interstage outlet end surface (31) and the outer ring outlet end surface (51) are arranged in a staggered manner.

2. The combustion chamber according to claim 1, characterized in that The spacing distance between the main combustion stage swirler outlet end face (41) and the interstage section outlet end face (31) along the axial direction of the center body (1) is a first spacing distance; the spacing distance between the main combustion stage swirler outlet end face (41) and the outer ring outlet end face (51) along the axial direction of the center body (1) is a second spacing distance, and the first spacing is greater than the second spacing.

3. The combustion chamber according to claim 1, characterized in that The spacing distance between the main combustion stage swirler outlet end face (41) and the interstage section outlet end face (31) along the axial direction of the center body (1) is a first spacing distance; the spacing distance between the main combustion stage swirler outlet end face (41) and the outer ring outlet end face (51) along the axial direction of the center body (1) is a second spacing distance, and the first spacing is smaller than the second spacing.

4. The combustion chamber according to claim 2 or 3, characterized in that The value of the first spacing or the value of the second spacing is S, the spacing distance between the interstage outlet end face (31) and the outer ring outlet end face (51) along the axial direction of the center body (1) is H, and H / S≤1.

5. The combustion chamber according to claim 4, characterized in that The outer ring outlet end surface (51) and the end wall inner surface (61) are coplanar.

6. A burner, characterized in that: It comprises the combustion chamber described in any one of claims 1 to 5, wherein the burner is a swirl cup structure burner, a multi-swirl burner or a center-staged burner.

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