Combustor with axial adjustment of oxidizer swirl

Abstract

The application discloses a combustor with axial adjustment of oxidant rotational flow degree, which adopts a coaxial sealed chamber structure, and sequentially comprises a fuel chamber, an oxidant chamber and a mixing chamber from bottom to top; high-efficiency mixing of fuel and oxidant is realized through a nozzle assembly with square multilayer array distribution in the oxidant chamber; each nozzle assembly is integrated with a rotatable oxidant direct flow component, axial rotational flow generating components of multiple single rotational flow channels and a fuel delivery shaft sleeve; continuous adjustment of the rotational flow degree of the oxidant under different working conditions is realized by switching single rotational flow channels with different rotational flow angles; and the mixing uniformity is significantly improved, local high temperature is inhibited and NOx emission is reduced by matching the double-channel pre-rotation design of fuel and oxidant and the variable cross-section mixed gas injection channel.

Description

Technical Field

[0001] This invention relates to a burner, specifically an axially adjustable burner for oxidant swirl, belonging to the field of gas turbine technology. Background Technology

[0002] As a highly efficient power plant, the performance of a gas turbine depends heavily on the combustion efficiency and stability of its combustion chamber. The combustion chamber plays a crucial role in mixing fuel and oxidizer, igniting the fuel, and releasing energy; its design directly impacts the overall thermal efficiency, emissions levels, and operational reliability of the gas turbine. However, traditional combustion chambers often suffer from uneven fuel mixing and poor flame stability, leading to the formation of excessive nitrogen oxides (NOx) in localized high-temperature zones. x Pollutants such as carbon monoxide (CO) and other pollutants can cause significant performance fluctuations, especially when switching between multiple fuels or operating under varying conditions. Patent CN119196719A discloses a burner that achieves tangential adjustment of air swirl intensity within the range of 0-65° through the combined adjustment of air guide components and tangential swirl components. However, tangential swirl has certain limitations in practical applications: on the one hand, its mixing uniformity is limited by the swirl angle adjustment range; on the other hand, in space-constrained burners, tangential swirl is prone to failing to achieve ideal swirl intensity due to the swirl channel length and flow dissipation, leading to a decrease in mixing effect and combustion stability.

[0003] In comparison, axial swirl exhibits certain advantages. Within a certain scale range, axial swirl allows for a wider range of adjustable swirl angles, resulting in more uniform mixing and more stable flame residence. Based on these advantages, developing a burner with a wider oxidizer swirl range and axial adjustment is of great significance for improving combustion chamber performance and achieving optimal combustion results under different combustion requirements. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a burner with axially adjustable oxidant swirl. This design, through an innovative structure, achieves flexible adjustment of the axial swirl over a wider range, enabling the combustion chamber to adapt to different fuel characteristics and operating conditions, thereby improving combustion efficiency, reducing pollutant emissions, and enhancing the stability and adaptability of the system.

[0005] To achieve the above objectives, this oxidizer burner with axially adjustable oxidizer swirl comprises, from bottom to top, a fuel chamber, an oxidizer chamber, and a mixing chamber, all coaxially sealed and spaced apart. The fuel chamber and oxidizer chamber are separated by an upper partition for the fuel chamber and a lower partition for the oxidizer chamber, and the oxidizer chamber and mixing chamber are separated by an upper partition for the oxidizer chamber and a lower partition for the mixing chamber. Multiple nozzle assemblies are fixedly arranged within the oxidizer chamber, forming a symmetrical, square, multi-layered array structure relative to the center of the oxidizer chamber. The fuel chamber is provided with a lower partition for the fuel chamber, a fuel input channel, and an upper partition for the fuel chamber. The oxidizer chamber is provided with a lower partition for the oxidizer chamber, an oxidizer input channel, and an upper partition for the oxidizer chamber. The mixing chamber is provided with a lower partition for the mixing chamber and a mixture injection channel. Its distinguishing feature is that… The combustion nozzle assembly includes a fuel delivery bushing, an oxidizer direct current unit, and an axial swirl generating unit. The oxidizer direct current unit and the axial swirl generating unit are coaxially arranged outside the fuel delivery bushing, and from bottom to top, they are the oxidizer direct current unit and the axial swirl generating unit.

[0006] The oxidant DC component is a through-hole bushing structure with an internal through hole. An oxidant DC channel is opened on it, and multiple small through holes are opened on the outer periphery of the oxidant DC channel.

[0007] The axial swirl generator has a through-hole bushing structure with a through hole inside. The upper end of the axial swirl generator is connected to the oxidant chamber by a threaded seal. The lower end of the axial swirl generator has a multi-stage axial swirl channel with a spiral structure that runs through the axial swirl generator. Each multi-stage axial swirl channel has a single swirl channel with a different axial swirl angle. The outer circumference of each single swirl channel has multiple sets of threaded holes. The lower end of the single swirl channel is connected to the upper end of the oxidant DC channel of the oxidant DC component, and the upper end opening faces the mixed gas injection channel.

[0008] The fuel delivery bushing is a blind-hole bushing structure with an internal coaxial blind hole located at the bottom end of the fuel delivery bushing. The bottom end of the fuel delivery bushing is connected to the upper partition of the fuel chamber by a threaded seal. The blind hole of the fuel delivery bushing forms a fuel channel, and a radial fuel injection hole is opened on the side of the fuel delivery bushing near the mixture injection channel.

[0009] As a further improvement of the present invention, the fuel chamber has multiple fuel input channels arranged around the central axis of the burner, and the fuel input channels have a certain degree of swirl. The oxidant chamber has multiple oxidant input channels arranged around the central axis of the burner, and the oxidant input channels have a certain degree of swirl.

[0010] As a further improvement of the present invention, the mixing chamber's gas injection channel is composed of a contraction pipe section with a variable cross-section and a straight pipe section with a constant cross-section.

[0011] As a further improvement of the present invention, multiple multi-stage axial vortex channels of the axial vortex generating component are arranged around the central axis of the axial vortex generating component, and the vortex intensity of the single vortex channel built into the multi-stage axial vortex channel increases or decreases sequentially in the clockwise direction.

[0012] As a further improvement of the present invention, the swirl angle of a single swirling channel is in the range of 0-70°, and the number of multi-stage axial swirling channels is affected by the swirl intensity of the single swirling channel.

[0013] As a further improvement of the present invention, the small through hole of the oxidant DC component and the threaded hole of the axial vortex generator component are connected in a sealed manner by fixing bolts.

[0014] As a further improvement of the present invention, by rotating the oxidant DC component, the small through holes are made coaxial with different threaded holes in the same group, thereby realizing the connection between the oxidant DC channel and different single swirling channels in the multi-stage axial swirling channel, and thus realizing the adjustment of the swirling degree of the nozzle assembly.

[0015] As a further improvement of the present invention, the radial fuel injection holes of the fuel delivery bushing are arranged on the same horizontal line.

[0016] As a further improvement of the present invention, the top end of the fuel delivery bushing is flush with the top end of the straight section of the mixture injection channel.

[0017] As a further improvement of the present invention, a perforated plate is provided between the oxidant DC component in the oxidant chamber and the upper partition of the fuel chamber.

[0018] Compared with existing technologies, this oxidant swirl-adjustable burner has the following advantages: 1. In terms of improving fuel adaptability, for nozzles with adjustable oxidant swirl intensity, the swirl intensity requirements under different operating conditions can be achieved by combining the adjustment of the direct oxidant component and the axial swirl generating component according to the fuel characteristics of different fuels, thereby improving the fuel adaptability of the burner under different operating conditions.

[0019] 2. In terms of enhancing the uniformity of the mixed airflow, the present invention employs a perforated plate, which allows the oxidant to enter the nozzle assembly in a more uniform manner, thereby generating an axial rotating airflow with a specific swirl degree through the axial swirl generating component. This rotating airflow is more fully mixed with the jet fuel in the mixed gas injection channel.

[0020] 3. In reducing NO xIn terms of emissions, the variable cross-section design of the contraction section of the air-fuel injection channel helps to increase the jet velocity of the air-fuel mixture in the straight section, further shortening the residence time in the high-temperature recirculation zone of the combustion chamber and reducing NO. x emission.

[0021] 4. In terms of improving combustion efficiency, both the fuel input channel and the oxidant input channel have a certain degree of swirl. This pre-selection design allows the fuel and oxidant to form a pre-swirl before entering the combustion zone, further enhancing the mixing effect between the two. This allows the combustion reaction to proceed more evenly, avoiding high temperatures and incomplete combustion caused by local over-oxygen or oxygen-deficient combustion, thereby improving combustion efficiency. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall two-dimensional cross-sectional structure of the present invention; Figure 2 This is a schematic diagram of the overall three-dimensional structure of the present invention; Figure 3 This is an overall top view of the invention; Figure 4 This is one of the three-dimensional structural schematic diagrams of the nozzle assembly of the present invention (the angles of the single swirling channels are 15°, 30°, and 45° respectively). Figure 5 This is the second three-dimensional structural schematic diagram of the nozzle assembly of the present invention (the angles of the single swirling channels are 60° and 70° respectively). Figure 6 This is a top view of the axial swirl generating component of the present invention (the angles of the single swirl channels are 15°, 30°, and 45° respectively). Figure 7 This is a top view of the axial swirl generating component of the present invention (the angles of the single swirl channels are 60° and 70° respectively). Figure 8 This is a top view of the DC oxidant component of the present invention; In the diagram: 1-Fuel chamber, 11-Lower baffle of fuel chamber, 12-Fuel input channel, 13-Upper baffle of fuel chamber, 2-Oxidant chamber, 21-Lower baffle of oxidant chamber, 22-Oxidant input channel, 23-Upper baffle of oxidant chamber, 3-Mixing chamber, 31-Lower baffle of mixing chamber, 32-Mixed gas injection channel, 321-Contraction pipe section, 322-Straight pipe section, 4-Nozzle assembly, 41-Fuel delivery bushing, 411-Fuel channel, 412-Radial fuel injection hole, 42-Oxidant DC component, 421-Oxidant DC channel, 422-Small through hole, 43-Axial swirl generator component, 431-Multi-stage axial swirl channel, 432-Threaded hole, 5-Fixing bolt, 6-Perforated plate. Detailed Implementation

[0023] The invention will be further described below with reference to the accompanying drawings. like Figure 1 As shown, this oxidizer burner with axially adjustable oxidizer swirl has a fuel chamber 1, an oxidizer chamber 2, and a mixing chamber 3 arranged coaxially and sealed from bottom to top. The fuel chamber 1 and the oxidizer chamber 2 are separated by an upper baffle 13 and a lower baffle 21, while the oxidizer chamber 2 and the mixing chamber 3 are separated by an upper baffle 23 and a lower baffle 31. Multiple nozzle assemblies 4 are fixedly installed within the oxidizer chamber 2, such as... Figure 3 As shown, multiple nozzle assemblies 4 are arranged in a square multi-layer array structure with symmetry relative to the oxidant chamber 2.

[0024] The fuel chamber 1 is provided with a lower baffle 11, multiple fuel input channels 12 with a certain degree of swirl are evenly arranged around the central axis of the fuel tank, and an upper baffle 13. Fuel enters the fuel chamber 1 through the fuel input channels 12 in the form of a rotating airflow.

[0025] The oxidant chamber 2 is provided with a lower oxidant chamber baffle 21, multiple oxidant input channels 22 with a certain degree of swirl evenly arranged around the central axis of the fuel unit, and an upper oxidant chamber baffle 23. The oxidant enters the oxidant chamber 2 through the oxidant input channels 22 in the form of a rotating airflow.

[0026] The mixing chamber 3 is provided with a lower partition 31 and a mixed gas injection channel 32. The mixed gas injection channel 32 is composed of a lower constriction pipe section 321 and an upper straight pipe section 322.

[0027] like Figure 4 As shown, the combustion nozzle assembly 4 includes a fuel delivery bushing 41, an oxidant direct current component 42, and an axial swirl generating component 43. The oxidant direct current component 42 and the axial swirl generating component 43 are coaxially arranged outside the fuel delivery bushing 41, and from bottom to top, they are the oxidant direct current component 42 and the axial swirl generating component 43.

[0028] The oxidant DC component 42 is a through-hole bushing structure with internal through holes. Multiple sets of oxidant DC channels 421 are formed on it, penetrating the oxidant DC component 42. These multiple sets of oxidant DC channels 421 are evenly arranged around the central axis of the oxidant DC component 42. For example... Figure 6 As shown, the outer periphery of the oxidant DC channel 421 has multiple small through holes 422.

[0029] The axial vortex generating component 43 has a through-hole bushing structure with a through hole inside. The upper end of the axial vortex generating component 43 is connected to the upper partition plate 23 of the oxidant chamber by a threaded seal. The lower end of the axial vortex generating component 43 has a multi-stage axial vortex channel 431 that penetrates the axial vortex generating component 43 and has a spiral structure. The multi-stage axial vortex channel 431 contains single vortex channels with different axial vortex angles. The number of single vortex channels in the same group of multi-stage axial vortex channels 431 is affected by their vortex angle. The axial vortex angle of a single vortex channel refers to the angle between the central axis of its outlet flow channel and the plane perpendicular to the outlet surface. The vortex angle range of the single vortex channel of the axial vortex generating component 43 is 0-70°. The outer periphery of the multi-stage axial vortex channel 431 has multiple sets of threaded holes 432. The number of sets is the same as the number of small through holes 422 on the oxidant direct flow component 42. The number of threaded holes 432 in the same group is the same as the number of single vortex channels in the multi-stage axial vortex channel 431. The lower end of the single swirl channel is connected to the upper end of the oxidant DC channel 421 of the oxidant DC component 42, and the cross-sectional area of ​​the oxidant DC channel 42 on the connecting surface is slightly smaller than the cross-sectional area of ​​the single swirl channel on the connecting surface; the upper opening faces the mixed gas injection channel 32. In this embodiment, as... Figure 4 , 6 As shown, the multi-stage axial swirling channel 431 contains three individual swirling channels, with swirling angles of 30°, 45°, and 60° respectively in the clockwise direction; Figure 5 , 7 As shown, the number of individual swirling channels in the multi-stage axial swirling channel 431 is two, and the swirling angles are 60° and 70° respectively in the clockwise direction.

[0030] The fuel delivery bushing 41 is a blind hole bushing structure with a blind hole coaxially arranged inside, and the opening is located at the bottom end of the fuel delivery bushing 41. The bottom end of the fuel delivery bushing 41 is connected to the upper partition plate 13 of the fuel chamber by a threaded seal. The blind hole of the fuel delivery bushing 41 forms a fuel channel 411, and a radial fuel injection hole 412 is opened on the side of the fuel delivery bushing 41 near the mixture injection channel 32.

[0031] The working principle of this oxidizer with axially adjustable swirl is as follows: Rotating gaseous fuel is supplied to the fuel chamber 1 through the fuel input channel 11. The fuel flows through the fuel channel 411 of the fuel delivery sleeve 41 extending into the fuel chamber 1 to the radial fuel injection hole 412, and is injected into the front end of the contraction section 321 of the mixture injection channel 32 through the radial fuel injection hole 412. Rotating gaseous oxidizer is supplied to the oxidizer chamber 2 through the oxidizer input channel. The oxidizer passes sequentially through the perforated plate 6, the oxidizer direct flow channel 421 of the oxidizer direct flow component 42, and the single swirl channel of the axial swirl generating component 43 into the front end of the contraction section 321 of the mixture injection channel 32. Under the action of the single swirl channel, the oxidizer with a certain swirl degree entering the front end of the contraction section 321 is initially mixed with the fuel entering the front end of the contraction section 321 at the same time. The mixed gas after the initial mixing passes through the rear end of the contraction section 321 and the straight pipe section 322 for further mixing to achieve better mixing uniformity. The mixed gas after the second mixing enters the combustion chamber for combustion. Multiple nozzle assemblies 3 are symmetrical about the center of the oxidant chamber 2 and form a square multi-layer array structure. The nozzle assembly 4 arranged in the center of the oxidant chamber 2 is the central nozzle. Multiple nozzles arranged at a set interval around the central nozzle are the inner layer nozzles. Based on the central axis of the oxidant chamber 2, the nozzle in the layer with the farthest distance is the outermost layer nozzle. The oxidant DC component 42 and the axial swirl generating component 43 are jointly adjusted according to different working conditions to obtain the required oxidant swirl degree.

[0032] To facilitate thorough mixing of fuel and oxidant, as a further improvement of the present invention, the mixing chamber 3's gas injection channel 32 is composed of a contraction section 321 with a variable cross-section and a straight section 322 with a constant cross-section, with the contraction section 321 located at the lower end of the straight section 322. The inner surface of the contraction section 321 with a variable cross-section can turbulentize the airflow, thereby facilitating thorough mixing of fuel and oxidant.

[0033] To increase the inlet velocity of the air-fuel mixture entering the combustion chamber, as a further improvement of the present invention, the diameter of the constriction pipe section 321 decreases sequentially from the front end to the rear end, thereby achieving a greater air-fuel mixture velocity in the straight pipe section 322, ultimately increasing the inlet velocity into the combustion chamber.

[0034] To achieve a wider range of oxidant swirl regulation effects, as a further improvement of the present invention, multiple multi-stage axial swirl channels 431 of the axial swirl generating component 43 are arranged around the central axis of the axial swirl generating component 43. The swirl intensity of a single swirl channel built into the multi-stage axial swirl channel 431 increases or decreases sequentially in a clockwise direction, and the swirl angle range of a single swirl channel is 0-70°.

[0035] To achieve precise control of the nozzle swirl, as a further improvement of the present invention, a rotating structure is provided between the oxidant direct current component 42 and the axial swirl generating component 43. The rotating structure consists of a small through-hole 422 in the oxidant direct current component 42, a threaded hole 432 in the axial swirl generating component 43, and a fixing bolt 5. Multiple threaded holes 432 are provided in the same group. After determining the target swirl angle, the small through-hole 422 and the corresponding threaded hole 432 of the single swirl channel are coaxially engaged, and then a fixing bolt 5 of the same specification is used for a sealing connection, thereby achieving communication between the oxidant direct current channel 421 and the target single swirl channel. In practical applications, a rubber gasket can be placed at the interface between the oxidant direct current component 42 and the axial swirl generating component 43 for further sealing.

[0036] To achieve better mixing effect, as a further improvement of the present invention, the outlet area of ​​the radial fuel injection hole 412 is much smaller than the outlet area of ​​the single swirl channel of the multi-stage axial swirl channel 431. The oxidant enters the front end of the contraction section 321 of the mixed gas injection channel 32 in different directions along the single swirl channel. At the same time, the gaseous fuel jetted out through the radial fuel injection hole 412 can impact the swirling oxidant at a larger jet velocity, thereby improving the mixing effect of fuel and oxidant.

[0037] To achieve a more uniform airflow into the nozzle assembly, as a further improvement of the present invention, a perforated plate 6 is provided between the oxidant direct flow component 42 in the oxidant chamber 2 and the upper partition plate 13 of the fuel chamber. The perforated plate 6 with different pore diameters and pore spacing can be provided according to different situations.

[0038] This axially adjustable oxidant swirl burner, through a combined adjustment mechanism of the oxidant direct flow component and the axial swirl generation component, can improve the multi-fuel adaptability of the combustion system, achieve efficient fuel combustion, and reduce pollutant emissions.

Claims

1. A burner with axial adjustment of oxidant swirl, comprising a fuel chamber (1), an oxidant chamber (2), and a mixing chamber (3) arranged coaxially and sealed from bottom to top; the fuel chamber (1) and the oxidant chamber (2) are separated by an upper partition plate (13) of the fuel chamber and a lower partition plate (21) of the oxidant chamber, and the oxidant chamber (2) and the mixing chamber (3) are separated by an upper partition plate (23) of the oxidant chamber and a lower partition plate (31) of the mixing chamber, and multiple nozzle assemblies (4) are fixedly arranged inside the oxidant chamber (2). Furthermore, multiple nozzle assemblies (4) are arranged in a square multi-layer array structure with central symmetry relative to the oxidant chamber (2); the fuel chamber (1) is provided with a lower fuel chamber partition (11), a fuel input channel (12), and an upper fuel chamber partition (13); the oxidant chamber (2) is provided with a lower oxidant chamber partition (21), an oxidant input channel (22), and an upper oxidant chamber partition (23); the mixing chamber (3) is provided with a lower mixing chamber partition (31) and a mixed gas injection channel (32); characterized in that, The combustion nozzle assembly (4) includes a fuel delivery bushing (41), an oxidant direct current component (42), and an axial swirl generating component (43). The oxidant direct current component (42) and the axial swirl generating component (43) are coaxially arranged outside the fuel delivery bushing (41). From bottom to top, they are the oxidant direct current component (42) and the axial swirl generating component (43). The oxidant DC component (42) is a through-hole bushing structure with through holes inside, and an oxidant DC channel (421) is opened on it, which penetrates the oxidant DC component (42). Multiple small through holes (422) are opened on the outer periphery of the oxidant DC channel (421). The axial swirl generating component (43) has a through-hole bushing structure with a through hole inside. The upper end of the axial swirl generating component (43) is connected to the oxidant chamber (2) by a threaded seal. The lower end of the axial swirl generating component (43) is provided with a multi-stage axial swirl channel (431) that runs through the axial swirl generating component (43) and has a spiral structure. The multi-stage axial swirl channel (431) has a single swirl channel with different axial swirl angles. Multiple sets of threaded holes (432) are opened on its outer periphery. The lower end of the single swirl channel is connected to the upper end of the oxidant direct current channel (421) of the oxidant direct current component (42). The upper end opening faces the mixed gas injection channel (32). The fuel delivery bushing (41) is a blind hole bushing structure with a blind hole coaxially arranged inside, and the opening is located at the bottom end of the fuel delivery bushing (41). The bottom end of the fuel delivery bushing (41) is connected to the upper partition (13) of the fuel chamber by a threaded seal. The blind hole of the fuel delivery bushing (41) forms a fuel channel (411), and a radial fuel injection hole (412) is opened on the side of the fuel delivery bushing (41) near the mixture injection channel (32).

2. The burner with axial adjustment of oxidant swirl according to claim 1, characterized in that, The fuel input channels (12) of the fuel chamber (1) are arranged around the central axis of the burner, and the fuel input channels (12) have a certain degree of swirl. The oxidant input channels (22) of the oxidant chamber (2) are arranged around the central axis of the burner, and the oxidant input channels (22) have a certain degree of swirl.

3. The burner with axial adjustment of oxidant swirl according to claim 1, characterized in that, The gas injection channel (32) of the mixing chamber (3) is composed of a contraction tube section (321) with a variable cross-section and a straight tube section (322) with a constant cross-section, and the contraction tube section (321) is located at the lower end of the straight tube section (322).

4. The burner with axial adjustment of oxidant swirl according to claim 1, characterized in that, The axial vortex generating component (43) has multiple multi-stage axial vortex channels (431) arranged around the central axis of the axial vortex generating component (43). The vortex intensity of the single vortex channel built into the multi-stage axial vortex channel (431) increases or decreases sequentially in the clockwise direction.

5. The burner with axial adjustment of oxidant swirl according to claim 1 or 4, characterized in that, The swirl angle of a single swirl channel ranges from 0 to 70°, and the number of multi-stage axial swirl channels (431) is affected by the swirl intensity of the single swirl channel.

6. The burner with axial adjustment of oxidant swirl according to claim 1, characterized in that, The small through hole (422) of the oxidant DC component (42) and the threaded hole (432) of the axial vortex generator component (43) are sealed together by fixing bolts (5).

7. The burner with axial adjustment of oxidant swirl according to claim 1, characterized in that, By rotating the oxidant DC component (42), the small through hole (422) is made coaxial with the threaded hole (432) of different types in the same group, thereby realizing the connection between the oxidant DC channel (421) and the different single swirling channels in the multi-stage axial swirling channel (431), and thus realizing the adjustment of the swirling degree of the nozzle assembly (4).

8. The burner with axial adjustment of oxidant swirl according to claim 1, characterized in that, The radial fuel injection holes (412) of the fuel delivery bushing (41) are arranged in multiple ways on the same horizontal line.

9. The burner with axial adjustment of oxidant swirl according to claim 1, 3, or 8, characterized in that, The top end of the fuel delivery bushing (41) is flush with the top end of the straight section (322) of the mixture injection channel (32).

10. The burner with axial adjustment of oxidant swirl according to claim 1, characterized in that, A perforated plate (6) is provided between the oxidant DC component (42) in the oxidant chamber (2) and the upper partition plate (13) of the fuel chamber.

Images