A flame tube structure and its burner

Abstract

The present invention relates to a flame tube structure and its burner. The flame tube is arranged inside the burner, and the head of the burner extends into the interior of the front end of the flame tube. An array of concave tongue piece assemblies is axially provided on the flame tube, and each group of concave tongue piece assemblies is circumferentially arranged on the inner side of the flame tube wall. A partition plate and a sound cavity plate are arranged between the concave tongues of the concave tongue piece assembly. The side of the sound cavity plate facing the flame tube wall forms a cooling transition cavity, and the side facing the interior of the flame tube forms a sound cavity. The beneficial effects of the present invention are as follows: The combined design of the concave tongue being divided into a concave section and a straight section improves the cooling effect. In the concave section, the heat transfer effect is enhanced by increasing the heat transfer area, and in the straight section, due to the reduction in cross-sectional area, the flow velocity increases, enhancing the convective heat transfer effect. The space between two concave tongues is divided into a sound cavity and a cooling transition cavity by the sound cavity plate, making full use of the space. The sound cavity is used to absorb the energy of the pressure wave, and the cooling transition cavity is used to balance the cooling effect of the concave tongues in the circumferential direction.

Description

Technical Field

[0001] The present invention belongs to the technical field of combustion devices, and particularly relates to a flame tube structure and a burner thereof. Background Art

[0002] In order to reduce NOx emissions, ground gas turbines generally adopt lean combustion. In the lean combustion mode, fluctuations in fuel or air flow have a significant impact on combustion stability, which in turn affects the fluctuations in chemical reactions and heat release. When the phase difference between acoustic wave fluctuations and heat release rate fluctuations is less than 90°, the two will promote each other, causing greater fluctuations. When the fluctuation frequency is coupled with the natural frequency of the burner body, resonance will occur, seriously damaging the burner structure.

[0003] Currently, in order to solve the problem of unstable combustion, the measures usually taken are to improve nozzle design and improve the design of the combustion chamber body. Patent CN104896513B proposes a vibration-proof structure combining a sound lining and a sound cavity, which can significantly reduce the acoustic resistance and nonlinear effects in the combustion chamber, and overcome the transverse and longitudinal oscillating combustion in the combustion chamber. However, this structure completely covers the flame tube body, which has an adverse effect on the cooling design, gas volume distribution, and combustion organization of the flame tube. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a flame tube structure and a burner thereof.

[0005] Such a flame tube structure and a burner thereof include: a flame tube and a burner head. The flame tube is arranged inside the burner, and the burner head extends into the front end interior of the flame tube. The flame tube is axially provided with several groups of concave tongue piece assemblies, and each group of concave tongue piece assemblies is circumferentially arranged on the inner side of the flame tube wall.

[0006] The concave tongue piece assembly includes a concave tongue piece. The front end of the concave tongue piece is fixed on the flame tube wall, and the rear end is open. A cooling concave cavity is formed between the concave tongue piece and the flame tube wall. Flame tube cooling holes are provided on the flame tube wall corresponding to the cooling concave cavity. A partition plate and a sound cavity plate are arranged between the concave tongue pieces of adjacent concave tongue piece assemblies. The side of the sound cavity plate facing the flame tube wall forms a cooling transition cavity, and the side facing the interior of the flame tube forms a sound cavity.

[0007] Preferably, the concave tongue piece includes a concave section and a straight section. The straight section is located downstream of the concave section and is parallel to the flame tube wall. One side of the straight section is connected to the concave section by a rounded corner, and a cold air outlet is formed between the other side and the flame tube wall.

[0008] Preferably, the acoustic cavity plate is flush with the straight sections of two adjacent concave tongue pieces, and the front end of the acoustic cavity plate is fixed to the wall surface of the flame tube through a convex structure; the partition plate is in an arc shape, with the curved side of the partition plate fixed to the end of the concave section and the straight side fixed to the side of the acoustic cavity plate. The partition plate includes a first partition plate and a second partition plate, and the first partition plate and the second partition plate are respectively arranged on both sides of the acoustic cavity plate to partially enclose the ends of two adjacent concave sections.

[0009] Preferably, a cooling transition cavity is formed between the wall surface of the flame tube in the radial direction of the flame tube and the acoustic cavity plate, and the cooling transition cavity communicates with the cooling concave cavities on both sides in the circumferential direction of the flame tube; a sound cavity is formed on the side of the acoustic cavity plate facing the inside of the flame tube, and the sound cavity is located between the first partition plate and the second partition plate on both sides of the acoustic cavity plate.

[0010] Preferably, in the axial direction of the flame tube, the acoustic cavity plate and the concave tongue pieces are of equal length, and the length of the sound cavity in the axial direction of the flame tube is greater than the width of the sound cavity.

[0011] Preferably, the cross-sectional area of the cooling concave cavity in the concave section is larger than that in the straight section.

[0012] Preferably, the burner head includes a fuel inlet pipe, a fuel injection port is arranged at one end of the fuel inlet pipe extending into the flame tube, a primary swirler is sleeved outside the fuel injection port, and a secondary swirler is sleeved outside the primary swirler.

[0013] Preferably, the distance between two adjacent groups of concave tongue piece assemblies in the axial direction of the flame tube is 30 - 40 mm; several groups of concave tongue piece assemblies are arranged behind the end of the burner head, and the distance between the group of concave tongue piece assemblies closest to the front end of the flame tube and the front end of the flame tube is 50 - 80 mm.

[0014] The use method of this kind of flame tube structure and its burner includes the following steps:

[0015] Step 1: Part of the cold air coming from the compressor enters the flame tube through the burner head, and the other part enters the cooling concave cavity through the flame tube cooling holes on the wall surface of the flame tube;

[0016] Step 2: The cold air exchanges heat in the cooling concave cavity and then flows out of the concave tongue pieces along the axial direction of the flame tube;

[0017] Meanwhile, the cold air entering the flame tube through the burner head mixes with the fuel and burns, forming a pressure wave acting on the wall surface of the flame tube and the concave tongue piece assemblies, and the sound cavity absorbs part of the energy of the pressure wave.

[0018] Preferably, in Step 2, several concave tongue piece assemblies in the same group are connected through a cooling transition cavity, and the cold air flows circumferentially around the flame tube through the cooling transition cavity.

[0019] The beneficial effects of the present invention are:

[0020] 1) The present invention forms an array of cooling concave cavities through the concave tongue piece assembly, improving the cooling effect of the flame tube wall surface. The combined design of the concave tongue piece, which is divided into a concave section and a straight section, improves the cooling effect. In the concave section, the heat transfer effect is enhanced by increasing the heat transfer area. In the straight section, due to the reduction of the cross-sectional area, the flow velocity increases, enhancing the convective heat transfer effect and effectively suppressing the reflux of hot flue gas.

[0021] 2) The present invention divides the gap between two concave tongue pieces into a sound cavity and a cooling transition cavity through the sound cavity plate, making full use of the space. The sound cavity is used to absorb the pressure wave energy, and the cooling transition cavity is used to balance the cooling effect of the concave tongue pieces in the circumferential direction, providing the uniformity of the circumferential cooling effect and also playing a certain cooling role for the sound cavity, greatly improving the cooling effect.

[0022] 3) The present invention sets a sound cavity between the concave tongue pieces. After the pressure wave is generated in the combustion area, part of it will enter the sound cavity structure, changing the conduction of the pressure wave and absorbing part of the pressure wave energy, thus avoiding mutual promotion with the chemical reaction and improving the combustion stability. And because the sound cavity is narrow and long, and its length direction is parallel to the flow direction in the flame tube, it will not affect the flow in the flame tube when absorbing energy and can also play an additional combing role, further improving the stability of the flow combustion. Description of the Drawings

[0023] Figure 1 It is a schematic diagram of a burner structure;

[0024] Figure 2 It is a schematic diagram of the flame tube structure;

[0025] Figure 3 It is a schematic diagram of the structure of the concave tongue piece assembly on one side of the flame tube wall surface;

[0026] Figure 4 It is a schematic diagram of the structure of the concave tongue piece assembly on one side inside the flame tube.

[0027] Description of the reference numerals: Burner housing 1, Burner casing 11, Burner front plate 12, Flame tube 2, Flame tube front partition 21, Flame tube cooling holes 22, Flame tube wall surface 23, Concave tongue piece assembly 3, Concave tongue piece 31, Concave section 311, Straight section 312, First partition 32, Sound cavity plate 33, Second partition 34, Cooling concave cavity 35, Sound cavity 36, Cooling transition cavity 37, Burner head 4, Fuel inlet pipe 41, Fuel injection port 42, Primary swirler 43, Outer partition of the primary swirler 44, Secondary swirler 45, Outer partition of the secondary swirler 46. Detailed Embodiment

[0028] The present invention will be further described below in conjunction with embodiments. The description of the following embodiments is only for helping to understand the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0029] Embodiment 1

[0030] As an embodiment, as Figures 1 to 4 shown, this kind of flame tube structure and its burner include: a flame tube 2 and a burner head 4. The flame tube 2 is arranged inside the burner. The burner includes a burner casing 11 and a burner front plate 12. The flame tube 2 includes a flame tube front partition 21 and a flame tube wall surface 23.

[0031] The burner head 4 extends into the interior of the front end of the flame tube 2; a plurality of groups of concave tongue assemblies 3 are axially arranged on the flame tube 2, and each group of concave tongue assemblies 3 is circumferentially arranged inside the flame tube wall surface 23.

[0032] The concave tongue assembly 3 includes a concave tongue 31. The front end of the concave tongue 31 is fixed on the flame tube wall surface 23, and the rear end is open. A cooling concave cavity 35 is formed between the concave tongue 31 and the flame tube wall surface 23. Flame tube cooling holes 22 corresponding to the cooling concave cavity 35 are arranged on the flame tube wall surface 23. Each group of flame tube cooling holes 22 is composed of 3 rows of circumferentially uniformly distributed cooling holes, and each row of cooling holes is 60 - 100, and the adjacent two rows of cooling holes are arranged in a staggered manner.

[0033] As Figure 3 and Figure 4 shown, a partition board and a sound cavity board 33 are arranged between the concave tongues 31 of adjacent concave tongue assemblies 3. A cooling transition cavity 37 is formed on the side of the sound cavity board 33 facing the flame tube wall surface 23, and a sound cavity 36 is formed on the side facing the interior of the flame tube 2. The space occupied by a single cooling concave cavity 37 in the circumferential direction is 40°, and the space occupied by a single sound cavity 36 in the circumferential direction is 5°.

[0034] A cooling transition cavity 37 is formed between the flame tube wall surface 23 and the sound cavity board 33 in the radial direction of the flame tube 2. The cooling transition cavity 37 communicates with the cooling concave cavities 35 on both sides in the circumferential direction of the flame tube 2; a sound cavity 36 is formed on the side of the sound cavity board 33 facing the interior of the flame tube 2. The number of the sound cavities 36 is the same as that of the cooling transition cavities 37, and the positions are also corresponding. The sound cavity 36 is located between the first partition board 32 and the second partition board 34 on both sides of the sound cavity board 33.

[0035] In the present invention, the cavity plate 33 divides the gap between the two concave tongue pieces 31 into a sound cavity 36 and a cooling transition cavity 37. The sound cavity 36 can absorb the energy of part of the pressure wave, reducing the thermoacoustic oscillation effect inside the burner. The cooling transition cavity 37 is used to balance the cooling effect of the concave tongue pieces 31 on the ring upwards, making full use of the space. The cooling transition cavity 37 can not only connect the cooling airflows in the multi-segment cooling concave cavities 35 to make the cold air evenly distributed circumferentially, but also have a certain cooling effect on the sound cavity 36. The setting of this structure not only makes full use of the space, but also can improve the cooling effect of the flame tube wall surface 23 on the premise of reducing thermoacoustic oscillation, having a good application prospect.

[0036] Axially on the flame tube 2, the cavity plate 33 and the concave tongue pieces 31 are of the same length, and the length of the sound cavity 36 along the axial direction of the flame tube 2 is greater than the width of the sound cavity 36. It is relatively long and narrow, and the length direction is parallel to the flow direction inside the flame tube 2. Therefore, when absorbing energy, it hardly affects the flow inside the burner, and the sound cavity 36 can also play a certain "combing" role on the flow, so it is more conducive to improving the stability of flow combustion.

[0037] As Figure 1 shown, the burner head 4 includes a fuel inlet pipe 41. One end of the fuel inlet pipe 41 extending into the flame tube 2 is provided with a fuel injection port 42. A primary swirler 43 is sleeved outside the fuel injection port 42, and a secondary swirler 45 is sleeved outside the primary swirler 43. The primary swirler 43 has 6 straight blades, the secondary swirler 45 has 8 straight blades, the primary swirler 43 and the secondary swirler 45 have opposite swirl directions, and a primary swirler outer partition 44 and a secondary swirler outer partition 46 are respectively provided on the outside.

[0038] In this embodiment, five groups of concave tongue piece assemblies 3 are evenly distributed along the axial direction. In each group of concave tongue piece assemblies 3, 8 concave tongue piece groups 3 are evenly distributed circumferentially along the flame tube wall surface 23. Therefore, a total of 40 concave tongue piece assemblies 3 are distributed.

[0039] According to the structural characteristics of the burner, the incident sound wave of the pressure fluctuation mainly comes from the burner head 4. Therefore, the incident sound wave mainly acts on the middle and rear section areas of the flame tube 2. Considering the cooling requirement of the flame tube wall surface 23 of the burner comprehensively, in this embodiment, the distance between two adjacent groups of concave tongue piece assemblies 3 along the axial direction of the flame tube 2 is 30 - 40 mm; several groups of concave tongue piece assemblies 3 are arranged behind the end of the burner head 4, and the distance between the group of concave tongue piece assemblies 3 closest to the front partition 21 of the flame tube 2, that is, the most upstream one, and the front partition 21 of the flame tube 2 is 50 - 80 mm.

[0040] Embodiment Two

[0041] As another embodiment, this Embodiment Two proposes the specific structure of the concave tongue piece 31 in this flame tube structure and its burner on the basis of Embodiment One.

[0042] The concave tongue piece 31 includes a concave section 311 and a straight section 312. In the axial direction of the combustion chamber liner 2, the straight section 312 is arranged behind the concave section 311, that is, the straight section 312 is arranged downstream of the concave section 311. The straight section 312 is actually a strip-shaped arc plate, and its radian is parallel to the wall surface 23 of the combustion chamber liner. The "straight" means that the straight section 312 is straight in the cross-sectional shape of the cooling cavity 35. One side of the straight section 312 is connected to the concave section 311 by a fillet, and a cold air outlet is formed between the other side and the wall surface 23 of the combustion chamber liner.

[0043] The acoustic cavity plate 33 is flush with the straight sections 312 of two adjacent concave tongue pieces 31. Therefore, there is a gap between the acoustic cavity plate 33 and the wall surface 23 of the combustion chamber liner, and this gap is the cooling transition cavity 37. The cooling transition cavity 37 communicates with the cooling cavities 35 on both sides in the circumferential direction of the combustion chamber liner 2.

[0044] The front end of the acoustic cavity plate 33 is fixed on the wall surface 23 of the combustion chamber liner through a convex structure; matching the cross-sectional shape of the concave section 311, the partition is bow-shaped. The bent side of the partition is fixed at the end of the concave section 311, and the straight side is fixed on the side of the acoustic cavity plate 33. The partition includes a first partition 32 and a second partition 34, and the first partition 32 and the second partition 34 are respectively arranged on both sides of the acoustic cavity plate 33 to partially enclose the ends of two adjacent concave sections 311.

[0045] The cross-sectional area of the cooling cavity 35 in the concave section 311 is larger than that in the straight section 312. In this embodiment, the axial length of the concave section 311 is 5-10 mm, the concave section 311 is a semi-circular structure, and is connected to the straight section 312 through a fillet. The maximum radial distance between the concave section 311 and the wall surface 23 of the combustion chamber liner is 4-6 mm; the axial length of the straight section 312 is 5-10 mm, and the radial distance between the straight section 312 and the wall surface 23 of the combustion chamber liner is 1-3 mm.

[0046] It should be noted that the same or similar parts in this embodiment and Embodiment 1 can be referred to each other, and will not be elaborated in this application.

[0047] Embodiment 3

[0048] As another embodiment, this Embodiment 3 proposes a combustion chamber liner structure and a usage method of its burner on the basis of Embodiment 1 and Embodiment 2, including the following steps:

[0049] Step 1: Press cold air into the burner through a compressor. A part of the cold air enters the combustion chamber liner 2 through the burner head 4, and another part enters the cooling cavity 35 through the combustion chamber liner cooling holes 22 on the wall surface 23 of the combustion chamber liner.

[0050] Step 2: The cold air entering from the cooling holes 22 of the combustion chamber first enters the cooling cavity 35. The cold air exchanges heat within the cooling cavity 35. Since the first half of the cavity is a concave section 311, it can suck in the three rows of cooling air from a group of cooling holes 22 of the combustion chamber into the concave section 311, which not only increases the cooling air volume but also increases the effective heat exchange area between the cold air and the combustion chamber 2, enhancing the cooling effect of this section.

[0051] Several concave tongue piece assemblies 3 of the same group are connected through a cooling transition cavity 37. The cold air flows circumferentially around the combustion chamber 2 through the cooling transition cavity 37, enhancing the circumferential uniformity of the wall temperature distribution on the combustion chamber wall 23.

[0052] After the cooling cavity 35 is filled with the cooling air, the cooling air starts to flow towards the downstream straight section 312 and then flows out axially along the combustion chamber 2 from the concave tongue piece 31. Since the space enclosed by the straight section 312 and the combustion chamber wall 23 is relatively small, approximately 1 / 3 of the volume of the concave section 311, the outflow velocity of the cooling air flow in the straight section is greatly enhanced, improving the convective heat exchange effect of the straight section. And due to the increase in the flow velocity of the cooling air, the backflow of the hot flue gas can be limitedly avoided.

[0053] Embodiment 4

[0054] As another embodiment, this Embodiment 4 proposes a more specific structure of the combustion chamber and a usage method of its burner based on Embodiment 3.

[0055] In Step 2, while the cold air enters the cooling cavity 35 for heat exchange, another part of the cold air enters the cavity of the combustion chamber 2 from the burner head 4. The main - path fuel enters from the fuel inlet pipe 41 and is sprayed into the interior of the combustion chamber 2 from the fuel injection port 42, and is mixed and burned with the air coming from the primary swirler 43 and the secondary swirler 45. Part of the hot flue gas after combustion forms a pressure wave through convection, radiation, etc. and acts on the combustion chamber wall 23 and the concave tongue piece assembly 3.

[0056] The pressure wave transmitted from the upstream and the pressure wave coupled with the combustion reaction will be transmitted in multiple directions. Part of them will be transmitted into the acoustic cavity 36 between the concave tongue pieces 31. The setting of this acoustic cavity 36 can change the conduction and reflection of part of the pressure wave, absorb the energy of the pressure wave, thereby avoiding mutual coupling promotion with the combustion reaction, reducing the oscillating combustion in the burner, and improving the combustion stability.

[0057] It should be noted that the same or similar parts in this embodiment and Embodiment 3 can be referred to each other and will not be elaborated in this application.

[0058] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other.

Claims

1. A flame tube structure and its burner, characterized in that Comprising: A combustion chamber liner (2) and a burner head (4), the combustion chamber liner (2) is arranged inside the burner, and the burner head (4) extends into the interior of the front end of the combustion chamber liner (2); a plurality of groups of concave tongue assemblies (3) are axially arranged on the combustion chamber liner (2), and each group of concave tongue assemblies (3) is circumferentially arranged inside the wall surface (23) of the combustion chamber liner; The concave tongue assembly (3) includes a concave tongue (31), the front end of the concave tongue (31) is fixed on the wall surface (23) of the combustion chamber liner, the rear end is open, a cooling concave cavity (35) is formed between the concave tongue (31) and the wall surface (23) of the combustion chamber liner, and a combustion chamber liner cooling hole (22) is provided on the wall surface (23) of the combustion chamber liner corresponding to the cooling concave cavity (35). A partition plate and a sound cavity plate (33) are arranged between the concave tongues (31) of adjacent concave tongue assemblies (3) in the circumferential direction. The side of the sound cavity plate (33) facing the wall surface (23) of the combustion chamber liner forms a cooling transition cavity (37), and the side facing the interior of the combustion chamber liner (2) forms a sound cavity (36).

2. The flame tube structure and its burner according to claim 1, characterized in that, The concave tongue (31) includes a concave section (311) and a straight section (312), the straight section (312) is located downstream of the concave section (311), the straight section (312) is parallel to the wall surface (23) of the combustion chamber liner, one side of the straight section (312) is connected to the concave section (311) by a rounded corner, and a cold air outlet is formed between the other side and the wall surface (23) of the combustion chamber liner.

3. The flame tube structure and its burner according to claim 2, characterized in that, The sound cavity plate (33) is flush with the straight sections (312) of two adjacent concave tongues (31), and the front end of the sound cavity plate (33) is fixed on the wall surface (23) of the combustion chamber liner through a convex structure; the partition plate is bow-shaped, the curved side of the partition plate is fixed at the end of the concave section (311), and the straight side is fixed on the side of the sound cavity plate (33). The partition plate includes a first partition plate (32) and a second partition plate (34), and the first partition plate (32) and the second partition plate (34) are respectively arranged on both sides of the sound cavity plate (33) for partially closing the ends of two adjacent concave sections (311).

4. The flame tube structure and its burner according to claim 3, characterized in that, A cooling transition cavity (37) is formed between the wall surface (23) of the combustion chamber liner and the sound cavity plate (33) in the radial direction of the combustion chamber liner (2), and the cooling transition cavity (37) connects the cooling concave cavities (35) on both sides in the circumferential direction of the combustion chamber liner (2); the side of the sound cavity plate (33) facing the interior of the combustion chamber liner (2) forms a sound cavity (36), and the sound cavity (36) is located between the first partition plate (32) and the second partition plate (34) on both sides of the sound cavity plate (33).

5. The flame tube structure and its burner according to claim 4, characterized in that, In the axial direction of the combustion chamber liner (2), the sound cavity plate (33) is of the same length as the concave tongue (31), and the length of the sound cavity (36) along the axial direction of the combustion chamber liner (2) is greater than the width of the sound cavity (36).

6. The flame tube structure and its burner according to claim 2, characterized in that, The cross-sectional area of the cooling concave cavity (35) in the concave section (311) is larger than that in the straight section (312).

7. The flame tube structure and burner thereof according to claim 1, characterized in that: The burner head (4) includes a fuel inlet pipe (41), a fuel injection port (42) is provided at one end of the fuel inlet pipe (41) extending into the combustion chamber liner (2), a primary swirler (43) is sleeved outside the fuel injection port (42), and a secondary swirler (45) is sleeved outside the primary swirler (43).

8. The flame tube structure and its burner according to claim 1, characterized in that, The distance between two adjacent sets of concave tongue blade assemblies (3) in the axial direction of the flame tube (2) is 30 - 40 mm; several sets of concave tongue blade assemblies (3) are arranged behind the end of the burner head (4), and the distance from the set of concave tongue blade assemblies (3) closest to the front end of the flame tube (2) to the front end of the flame tube (2) is 50 - 80 mm.

9. The flame tube structure and the method of using the burner according to any one of claims 1 to 8, characterized in that, It includes the following steps: Step 1: Part of the cold air coming from the compressor enters the flame tube (2) through the burner head (4), and the other part enters the cooling cavity (35) through the flame tube cooling holes (22) on the flame tube wall surface (23); Step 2: The cold air exchanges heat in the cooling cavity (35), and then flows out of the concave tongue blade (31) along the axial direction of the flame tube (2); Meanwhile, the cold air entering the flame tube (2) through the burner head (4) mixes with the fuel and burns, forming a pressure wave acting on the flame tube wall surface (23) and the concave tongue blade assembly (3), and the acoustic cavity (36) absorbs part of the energy of the pressure wave.

10. The method of using the combustor and the flame tube structure according to claim 9, characterized in that, In Step 2, several concave tongue blade assemblies (3) in the same group are connected through a cooling transition cavity (37), and the cold air flows circumferentially around the flame tube (2) through the cooling transition cavity (37).

Images