Low-emission combustion chamber head structure with V-shaped blade tail end

Abstract

The invention discloses a low-emission combustion chamber head structure adopting a V-shaped blade tail end, relates to the technical field of graded low-pollution combustion chambers of gas turbines, and solves the problem that the combustion stability is poor due to the fact that the combustion chamber head structure is short in service life and uneven in outlet airflow. Wherein the on-duty stage consists of a swirler, a venturi tube and a centrifugal nozzle; the main combustion stage is composed of an oblique radial swirler, a swirl vane, a V-shaped tail end vane, an annular oil collecting cavity and a direct injection type nozzle. An oblique radial swirler is used in the main combustion stage, and the axial length of the head of the swirler can be reduced while the swirling strength is guaranteed. According to the main combustion stage, a discrete multi-point direct injection type nozzle is adopted for initial pressure atomization, then fuel oil liquid drop crushing and mixing are enhanced through a V-shaped tail end structure, fuel oil is fully premixed in a rotational flow channel, pollutant emission can be greatly reduced, and then ultralow emission is achieved; the combustion chamber head structure is integrally designed and is convenient to replace and maintain.

Description

Technical Field

[0001] The invention relates to the technical field of staged low-pollution combustion chambers for gas turbines, and in particular to a low-emission combustion chamber head structure using a V-shaped blade tail end. Background Art

[0002] The source of gas turbine pollutant emissions comes from the combustion chamber, so the development of low-pollution combustion technology is the key to reducing gas turbine pollution emissions. The main pollutants in the combustion chamber include nitrogen oxides, carbon monoxide and unburned hydrocarbons, among which the most important is to reduce the amount of nitrogen oxides generated. In the combustion chamber, the thermal nitrogen oxide generation mechanism plays a dominant role, so reducing the combustion temperature in the combustion zone is one of the effective means to reduce the amount of nitrogen oxides generated. Lean oil combustion technology can effectively reduce the combustion temperature in the combustion zone, thereby reducing the amount of nitrogen oxides generated. The ability of advanced low-emission combustion chambers to reduce pollution emissions is largely due to the technical design of advanced head organization combustion. For lean oil low-emission combustion chambers, due to the need for air partitioning and fuel staged combustion, most advanced low-emission combustion chamber nozzles are mainly composed of duty class nozzles (centrifugal) and main combustion stage (direct injection) nozzles. For lean oil combustion technology, foreign researchers have proposed lean oil premixed preevaporation combustion technology and conducted extensive research on it. This technology can effectively control the combustion temperature in the main combustion zone and has great potential in reducing nitrogen oxides.

[0003] GE's TAPS combustor has applied for a number of US patents, including US6453660B1, US6381964B1, US6389815B1, etc. The technical solution proposed in the low-emission combustor head patent is: the duty class is composed of a centrifugal nozzle, a two-stage axial swirler, a venturi and a sleeve, and the main combustion stage is composed of a direct-injection nozzle and one or two stages of radial swirl. The large nozzle of the head is composed of a single-oil centrifugal nozzle of the duty class and a direct-injection nozzle of the main combustion stage. Beijing University of Aeronautics and Astronautics and China Gas Turbine Research Institute have also applied for a variety of patents for lean oil partially premixed preevaporation combustion chambers, such as patents CN101169252A, CN101275751A, CN101275750A, CN202032612U, CN202032613U and CN202082953U. NOx is one of the pollutants that gas turbine combustor designers need to focus on. In the combustion chamber, NOx is mainly determined by the flame temperature in the combustion zone and the residence time of the gas. At present, low-pollution combustion chambers use center-staged lean oil premixing and preevaporation technology to reduce pollution emissions. The head of this low-emission combustion chamber is divided into a duty class and a main combustion stage surrounding the duty class. The head needs to mix the fuel and air well to obtain a good low-emission effect. The fuel and air need to be mixed within a limited space. The existing technology mostly uses fuel transverse jets to obtain good atomization and mixing effects, but the jet penetration depth of the transverse jet is greatly related to the momentum ratio of the fuel to air. The transverse jet penetration depth of the gas turbine under different operating conditions is different, which will cause uneven radial distribution of the fuel and the fuel atomization effect deviates from the design requirements, resulting in high pollution emissions, incomplete combustion and other problems. Summary of the invention

[0004] In view of the above problems of uneven radial distribution of fuel in existing combustion chambers, poor fuel atomization effect, high pollution emissions, incomplete combustion, etc., the present invention aims to provide a low-emission combustion chamber head structure using a V-shaped blade tail end.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A low-emission combustion chamber head structure with a V-shaped blade tail end, which includes: a main combustion stage, a duty stage, a heat shield 12 and a flame tube 13. The main combustion stage and the duty stage are coaxially arranged, the duty stage and the front end middle of the main combustion stage are connected, the rear end outer edge of the main combustion stage and the flame tube 13 are connected through the heat shield 12, and the rear end of the main combustion stage, the heat shield 12 and the flame tube 13 together form a combustion chamber; the main combustion stage is used to spray fuel into the combustion chamber.

[0007] The above-mentioned low-emission combustion chamber head structure using the V-shaped blade tail end also includes: a fuel conduit 11, one fuel conduit 11 is used to transport fuel to the duty class, and the other fuel conduit 11 is used to transport fuel to the main combustion stage.

[0008] The above-mentioned low-emission combustion chamber head structure adopts a V-shaped blade tail end, wherein the value class includes: a value swirler inner ring 7 and a centrifugal nozzle 10, the centrifugal nozzle 10 is installed inside the rear end of the value swirler inner ring 7, and a fuel duct 11 is connected to the front end of the value swirler inner ring 7.

[0009] In the above-mentioned low-emission combustion chamber head structure using a V-shaped blade tail end, a plurality of purge channels 9 are opened along the circumferential direction at the front end of the swirler inner ring 7, and the plurality of purge channels 9 are all connected to the combustion chamber.

[0010] The above-mentioned low-emission combustion chamber head structure adopts a V-shaped blade tail end, wherein the main combustion stage includes: a main combustion stage outer ring 1 and a main combustion stage inner ring 5, the main combustion stage outer ring 1 and the main combustion stage inner ring 5 are coaxially arranged, the rear end outer edge of the main combustion stage outer ring 1 and the flame tube 13 are connected through a heat insulation shield 12, the main combustion stage inner ring 5 is provided with a main combustion stage annular oil collecting chamber 6, and another fuel duct 11 is connected to the main combustion stage annular oil collecting chamber 6.

[0011] The above-mentioned low-emission combustion chamber head structure adopts a V-shaped blade tail end, wherein the value class also includes: swirl blades 8, the inner wall of the main combustion stage inner ring 5 and the rear end outer wall of the value swirler inner ring 7 are connected by multiple swirl blades 8, and the multiple swirl blades 8 are arranged at equal intervals around the axis of the value swirler inner ring 7.

[0012] The above-mentioned low-emission combustion chamber head structure adopts a V-shaped blade tail end, wherein the main combustion stage also includes: main combustion stage swirl blades 2 and main combustion stage V-shaped tail end blades 3, the outer wall of the main combustion stage inner ring 5 and the inner wall of the main combustion stage outer ring 1 are connected by multiple main combustion stage swirl blades 2 and multiple main combustion stage V-shaped tail end blades 3, multiple main combustion stage swirl blades 2 are arranged at equal intervals in the circumferential direction around the axis of the swirler inner ring 7, multiple main combustion stage V-shaped tail end blades 3 are arranged at equal intervals in the circumferential direction around the axis of the swirler inner ring 7, and a main combustion stage V-shaped tail end blade 3 is provided between any two adjacent main combustion stage swirl blades 2.

[0013] The above-mentioned low-emission combustion chamber head structure adopts a V-shaped blade tail end, wherein a first swirl passage is provided in the swirl blade 8, one end of the first swirl passage is connected to the interior of the swirler inner ring 7, and the other end of the first swirl passage is connected to the main combustion stage annular oil collecting chamber 6.

[0014] The above-mentioned low-emission combustion chamber head structure adopts a V-shaped blade tail end, wherein a second swirl passage is provided in the main combustion stage swirl blade 2, and the second swirl passage is connected to the main combustion stage annular oil collecting chamber 6; at least one main combustion stage fuel injection hole 4 is provided on the main combustion stage swirl blade 2, and the third passage and the combustion chamber are connected through the main combustion stage fuel injection hole 4; any two adjacent main combustion stage V-shaped tail end blades 3 are surrounded to form a V-shaped groove, and each main combustion stage fuel injection hole 4 is located in a V-shaped groove.

[0015] The above-mentioned low-emission combustion chamber head structure adopts a V-shaped blade tail end, wherein a plurality of cooling holes distributed along the circumferential direction are provided on the heat insulation screen 12, the angle between the axis of the cooling holes and the axis of the duty class is 0° to 30°, the diameter of the cooling holes is 0.4 to 0.6 mm, and the number is 150 to 300.

[0016] Due to the adoption of the above technology, the present invention has the following positive effects compared with the prior art:

[0017] (1) The main combustion stage of the present invention adopts an oblique radial swirler and lean oil premixing and preevaporation technology. The oblique radial swirler combines the advantages of low flow resistance of the axial swirler and short axial length of the radial swirler. The main combustion stage swirl blades and the main combustion stage V-shaped tail blades are arranged in an alternating manner, and a recirculation vortex is formed downstream of the main combustion stage V-shaped tail blades. The main combustion stage fuel injection holes are arranged in the V-shaped grooves of the V-shaped tail blades. The main combustion stage fuel is sprayed from the main combustion stage fuel injection holes into the recirculation vortex formed downstream of the V-shaped tail blades. The sharp wedges on both sides of the V-shaped blades form a speed difference to enhance the breakup of fuel droplets. The recirculation vortex enhances the mixing of the atomized fuel downstream of the nozzle. The downstream injection mode effectively avoids the collision of the commonly used transverse jet fuel droplets with the swirler wall structure, resulting in the aggregation of oil droplets. At the same time, the uniformity of the main combustion stage outlet airflow is ensured, which is conducive to uniform combustion.

[0018] (2) The present invention adopts a design in which the tail of the venturi expansion section is flush with the height of the inner ring of the main combustion stage. The interstage section of an aircraft engine usually has a step structure with a height of about 3 to 5 mm. The step recirculation zone formed by the interstage section structure helps to widen the lean flameout limit range. Since the lean flameout limit range requirements of the gas turbine combustion chamber are lower than those of the aircraft engine combustion chamber, there is no need to form a step recirculation zone. The design of the present invention can avoid the formation of a step recirculation zone, reduce resistance loss, and also avoid the high temperature zone formed by the step recirculation zone from ablation on the interstage section and the outlet of the inner ring of the main combustion stage, thereby extending the service life of the head.

[0019] (3) The present invention adopts the concept of staged combustion, with the pre-combustion stage providing a stable fire source and the main combustion stage achieving low-pollution combustion, thereby ensuring the stability of the combustion chamber while reducing pollution emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1It is a structural schematic diagram of an integrated head of a low-emission combustion chamber head structure adopting a V-shaped blade tail end of the present invention.

[0021] Figure 2 It is a structural schematic diagram of an integrated fuel nozzle of the present invention that adopts a low-emission combustion chamber head structure with a V-shaped blade tail end.

[0022] Figure 3 yes Figure 2 A partial enlarged view of .

[0023] Figure 4 It is a schematic diagram of the assembly of an integrated head and a flame tube of a low-emission combustion chamber head structure using a V-shaped blade tail end of the present invention.

[0024] In the attached figure: 1. Main combustion stage outer ring; 2. Main combustion stage swirl blade; 3. Main combustion stage V-shaped tail blade; 4. Main combustion stage oil injection hole; 5. Main combustion stage inner ring; 6. Main combustion stage annular oil collecting chamber; 7. Value swirler inner ring; 8. Swirl blade; 9. Purge flow channel; 10. Centrifugal nozzle; 11. Fuel duct; 12. Heat shield; 13. Flame tube. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0026] Please refer to Figures 1 to 4 As shown, a low-emission combustion chamber head structure with a V-shaped blade tail end is shown, which includes: a main combustion stage, a duty stage, a heat shield 12 and a flame tube 13. The main combustion stage and the duty stage are coaxially arranged, the duty stage and the front end middle of the main combustion stage are connected, the rear end outer edge of the main combustion stage and the flame tube 13 are connected through the heat shield 12, and the rear end of the main combustion stage, the heat shield 12 and the flame tube 13 together form a combustion chamber; the main combustion stage is used to inject fuel into the combustion chamber.

[0027] Furthermore, in a preferred embodiment, it also includes: a fuel conduit 11, one fuel conduit 11 is used to transport fuel to the duty class, and the other fuel conduit 11 is used to transport fuel to the main combustion stage.

[0028] Furthermore, in a preferred embodiment, the fuel tank comprises: a swirler inner ring 7 and a centrifugal nozzle 10, wherein the centrifugal nozzle 10 is installed inside the rear end of the swirler inner ring 7, and a fuel conduit 11 is connected to the front end of the swirler inner ring 7.

[0029] Furthermore, in a preferred embodiment, a plurality of purge channels 9 are circumferentially opened at the front end of the swirler inner ring 7, and the plurality of purge channels 9 are all connected to the combustion chamber.

[0030] Furthermore, in a preferred embodiment, the main combustion stage includes: a main combustion stage outer ring 1 and a main combustion stage inner ring 5, the main combustion stage outer ring 1 and the main combustion stage inner ring 5 are coaxially arranged, the rear end outer edge of the main combustion stage outer ring 1 and the flame tube 13 are connected through a heat insulation screen 12, a main combustion stage annular oil collecting chamber 6 is provided in the main combustion stage inner ring 5, and another fuel duct 11 is connected to the main combustion stage annular oil collecting chamber 6.

[0031] Furthermore, in a preferred embodiment, the value stage also includes: swirl blades 8, the inner wall of the main combustion stage inner ring 5 and the rear end outer wall of the value swirler inner ring 7 are connected by multiple swirl blades 8, and the multiple swirl blades 8 are arranged circumferentially around the axis of the value swirler inner ring 7 at equal intervals.

[0032] Furthermore, in a preferred embodiment, the main combustion stage also includes: main combustion stage swirl blades 2 and main combustion stage V-shaped tail end blades 3, the outer wall of the main combustion stage inner ring 5 and the inner wall of the main combustion stage outer ring 1 are connected through multiple main combustion stage swirl blades 2 and multiple main combustion stage V-shaped tail end blades 3, the multiple main combustion stage swirl blades 2 are arranged at equal intervals in the circumferential direction around the axis of the swirler inner ring 7, the multiple main combustion stage V-shaped tail end blades 3 are arranged at equal intervals in the circumferential direction around the axis of the swirler inner ring 7, and a main combustion stage V-shaped tail end blade 3 is provided between any two adjacent main combustion stage swirl blades 2.

[0033] Furthermore, in a preferred embodiment, a first swirl passage is provided in each swirl blade 8 , one end of the first swirl passage is connected to the interior of the swirler inner ring 7 , and the other end of the first swirl passage is connected to the main combustion stage annular oil collecting chamber 6 .

[0034] Furthermore, in a preferred embodiment, a second swirl passage is provided in the main combustion stage swirl blade 2, and the second swirl passage is connected to the main combustion stage annular oil collecting chamber 6; at least one main combustion stage fuel injection hole 4 is provided on the main combustion stage swirl blade 2, and the third passage and the combustion chamber are connected through the main combustion stage fuel injection hole 4; any two adjacent main combustion stage V-shaped tail blades 3 are surrounded to form a V-shaped groove, and each main combustion stage fuel injection hole 4 is located in a V-shaped groove.

[0035] Furthermore, in a preferred embodiment, the heat insulation shield 12 is provided with a plurality of cooling holes distributed along the circumferential direction, the angle between the axis of the cooling holes and the axis of the duty class is 0° to 30°, the diameter of the cooling holes is 0.4 to 0.6 mm, and the number of the cooling holes is 150 to 300.

[0036] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation and protection scope of the present invention.

[0037] The present invention also has the following implementation modes on the basis of the above:

[0038] In a further embodiment of the present invention, the present invention discloses a low-emission combustion chamber head structure using a V-shaped blade tail end. It is composed of a duty class, a main combustion stage and other structures, wherein the duty class is composed of a swirler, a venturi and a centrifugal nozzle 10; the main combustion stage is composed of an oblique radial swirler, a main combustion stage swirl blade 2, a main combustion stage V-shaped tail blade 3, a main combustion stage annular oil collecting chamber 6, and a main combustion stage injection hole 4, and the main combustion stage injection hole 4 is a straight-injection nozzle. The oblique radial swirler of the main combustion stage is composed of a main combustion stage outer ring 1, a main combustion stage swirl blade 2, and a main combustion stage inner ring 5. The oblique radial swirler combines the advantages of radial and axial swirlers, and can reduce the axial length of the swirler head while ensuring the swirl strength. The main combustion stage uses a discrete multi-point direct-injection nozzle for initial pressure atomization, and then uses a V-shaped tail end structure to enhance the breakup and mixing of fuel droplets. The fuel is fully premixed downstream of the main combustion stage V-shaped tail end blade 3, which can significantly reduce pollutant emissions and achieve ultra-low emissions. The combustion chamber head structure is made into an integrated design for easy replacement and maintenance.

[0039] In a further embodiment of the present invention, the present invention proposes a low-emission combustion chamber head structure with a V-shaped blade tail end, which can enable the combustion chamber to operate stably and efficiently within the entire operating range, effectively suppressing the occurrence of combustion instability. At the same time, this solution has the advantages of compact structure, smooth operating transition, good uniformity of outlet temperature field, wide operating range, good combustion stability, low emissions, strong load adaptability, and can be used on both light and heavy gas engines.

[0040] In a further embodiment of the present invention, Figure 1 and Figure 2 1 shows a cross-sectional view of a low emission combustion chamber head structure using a V-shaped blade tail according to an embodiment of the present invention. Figure 1 and Figure 2 As shown, a direct / centrifugal nozzle and a central graded structure are adopted, the main combustion stage injection hole 4 is a direct nozzle, and the centrifugal nozzle is a centrifugal nozzle 10, wherein the main combustion stage includes: a main combustion stage outer ring 1, a main combustion stage swirl blade 2, a main combustion stage V-shaped tail blade 3, a main combustion stage injection hole 4, a main combustion stage inner ring 5, and a main combustion stage annular oil collecting cavity 6; the value class includes a value swirler inner ring 7, a swirl blade 8, a purge flow channel 9, and a centrifugal nozzle 10; the head structure also includes a fuel duct 11 and a heat shield 12. The duty class is connected to the main combustion stage through the main combustion stage inner ring 5 and is concentric with the main combustion stage; the main combustion stage swirl blades 2 and the main combustion stage V-shaped tail blades 3 are arranged alternately, and a return vortex is formed downstream of the main combustion stage V-shaped tail blades 3. The main combustion stage injection holes 4 are arranged in the V-shaped grooves of the V-shaped tail blades. The main combustion stage fuel is sprayed from the main combustion stage injection holes 4 into the return vortex formed downstream of the V-shaped tail blades, and is fully mixed with the air in the main combustion stage premixing channel after being ejected through the main combustion stage injection holes 4; the duty class fuel forms oil mist through the centrifugal nozzle 10 and is diffusely burned at the duty class outlet;

[0041] In a further embodiment of the present invention, the main combustion stage adopts an oblique radial swirler structure, having 8 to 16 main combustion stage swirl blades 2 with a thickness of 1.0 to 4.0 mm evenly distributed along the circumferential direction, and 8 to 16 main combustion stage V-shaped tail end blades 3 with a thickness of 3.0 to 8.0 mm evenly distributed along the circumferential direction, and the tail end V-shaped angle is 45° to 120°. The main combustion stage swirl blades 2 and the main combustion stage V-shaped tail end blades 3 are arranged alternately and the number is the same. The main combustion stage swirl blades 2 are longer in axial length than the main combustion stage V-shaped tail end blades 3, and the swirl number is 0.5 to 1.5, which is used to form swirl air; the angle between the main combustion stage swirler inlet and the center line direction of the combustion chamber is 30° to 60°, the swirler spacing is 25 to 35 mm, and the axial length is 50 to 60 mm.

[0042] In a further embodiment of the present invention, the duty class swirler has 8 to 12 swirl blades 8 with a thickness of 2 to 10 mm evenly distributed along the circumferential direction, and the swirl number is 0.5 to 1.5, which is used to form a strong swirl. The swirl intensity is calculated by an empirical formula. Experiments have shown that the strong swirl obtained by adopting this blade arrangement can effectively improve the combustion efficiency under low operating conditions. The blade thickness is obtained according to the effective flow area of ​​the duty class swirler, and the flow area is obtained according to the distribution ratio of the air flow of the duty class.

[0043] In a further embodiment of the present invention, the duty-class centrifugal nozzle 10 has a spray cone angle of 60° to 90°. If the spray cone angle is too small, the atomization effect is poor. If the spray cone angle is too large, the fuel droplets will hit the contraction section of the main combustion stage inner ring 5, causing the droplets to splash upstream; the main combustion stage fuel injection hole 4 is a straight nozzle, and the main combustion stage fuel injection hole 4 is arranged in the V-shaped groove of the main combustion stage V-shaped tail end blade 3. The main combustion stage fuel injection hole 4 is arranged at a height of 10% to 90% of the V-shaped groove. Each main combustion stage V-shaped tail end blade 3 is arranged with 1 to 2 main combustion stage fuel injection holes 4. The diameter of the main combustion stage fuel injection hole 4 is 0.01 to 0.8 mm. The number and diameter of the nozzles of the main combustion stage fuel injection hole 4 are selected according to the fuel flow rate of the combustion chamber design working conditions. The angle between the injection direction and the axial direction is 0° to 30°. The injection direction is the same as the swirling air direction. If the injection angle is too large, the fuel will splash onto the main combustion stage inner ring 5, causing coking. The main combustion stage fuel injection hole 4 is supplied with oil through the annular oil collecting cavity. The main combustion stage annular oil collecting cavity 6 is placed on the main combustion stage inner ring 5. The radial width of the oil collecting cavity ring is 2 to 6 mm, and the axial length is 20 to 35 mm. The main combustion stage fuel accounts for 50% to 100% of the total fuel volume. The axial distance between the main combustion stage fuel injection hole 4 and the swirler outlet is 10 to 20 mm. Sufficient axial distance can ensure that the fuel and air are fully mixed. Under the action of the V-shaped groove, a vortex is formed downstream of the blade. The main combustion stage fuel injection hole 4 using this structural scheme can spray fuel into the vortex formed downstream of the V-shaped groove. Compared with directly injecting fuel into the downstream air, the disturbance and shearing effect of the vortex can enhance the mixing effect of fuel and air.

[0044] In a further embodiment of the present invention, the main combustion stage, the duty stage, the fuel duct 11, and the heat insulation screen 12 constitute a low-emission combustion chamber head structure, and the heat insulation screen 12 is gap-matched with the flame tube 13; the heat insulation screen 12 has cooling holes distributed along the circumferential direction for passing the cooling airflow, and the angle between the axis of the cooling hole and the center line of the combustion chamber is 10°~30°, the diameter of the hole is 0.4~0.6mm, and the number is 150~300. The smaller angle can obtain a uniform cooling air film on the heat insulation screen 12 to prevent the heat insulation screen 12 from being ablated by high temperature, and the diameter and number of the holes are adjusted according to the cooling air flow that can be allocated to the combustion chamber.

[0045] In a further embodiment of the present invention, the working principle of the present invention is: the main combustion stage adopts the lean oil partial premixing preevaporation combustion technology, the main combustion stage swirl blades 2 and the main combustion stage V-shaped tail blades 3 are arranged in an alternating manner, and a recirculation vortex is formed downstream of the main combustion stage V-shaped tail blades 3, and the main combustion stage injection holes 4 are arranged in the V-shaped grooves of the main combustion stage V-shaped tail blades 3. The main combustion stage fuel is sprayed from the main combustion stage injection holes 4 into the recirculation vortex formed downstream of the main combustion stage V-shaped tail blades 3. The sharp wedges on both sides of the main combustion stage V-shaped tail blades 3 form a speed difference to enhance the breakup of fuel droplets, and the recirculation vortex enhances the mixing of the atomized fuel downstream of the nozzle, and after being ejected through the main combustion stage injection holes 4, it is fully mixed with the air in the main combustion stage premixing channel, which can greatly reduce the emissions of pollutants such as NOx, UHC, CO and smoke particles; the main combustion stage swirl blades 2 and the main combustion stage V-shaped tail blades 3 are arranged in an V-shaped groove of the main combustion stage V-shaped tail blades 3. The design of the vortex cyclone takes into account the prevention of flashback and spontaneous combustion. By using an inclined radial cyclone, the equivalent flow area of ​​the inclined section is controlled to be larger than the equivalent flow area of ​​the straight section, so that the main combustion stage air flow has an acceleration effect, combining the advantages of the low flow resistance of the axial cyclone and the short axial length of the radial cyclone; the duty class adopts a diffusion combustion mode to ensure the stable operation of the combustion chamber under low working conditions, while enhancing the ignition performance of the combustion chamber; the design of the combustion chamber head takes into account the intake uniformity and the main combustion stage fuel aerodynamic atomization and head assembly and disassembly issues. The flame tube 13 and the head clearance match, the integrated head nozzle structure does not need to disassemble the flame tube 13 during installation and maintenance, and the clearance fit makes it possible to separate the head and the flame tube 13 without the help of tools, which has high practical value. NOx emissions can be kept below 50ppm within the 0.5-1.0 working condition.

[0046] In a further embodiment of the present invention, the main combustion stage of the present invention adopts an oblique radial swirler and lean oil premixing and preevaporation technology. The oblique radial swirler combines the advantages of low flow resistance of the axial swirler and short axial length of the radial swirler. The main combustion stage swirl blades 2 and the main combustion stage V-shaped tail blades 3 are arranged alternately, and a recirculation vortex is formed downstream of the main combustion stage V-shaped tail blades 3. The main combustion stage injection hole 4 is arranged in the V-shaped groove of the main combustion stage V-shaped tail blade 3. The main combustion stage fuel is sprayed from the main combustion stage injection hole 4 into the recirculation vortex formed downstream of the main combustion stage V-shaped tail blade 3. The sharp wedges on both sides of the main combustion stage V-shaped tail blade 3 form a speed difference to enhance the breakage of fuel droplets, and the recirculation vortex enhances the mixing of the atomized fuel downstream of the nozzle. The downstream injection mode effectively avoids the collision of the commonly used transverse jet fuel droplets with the swirler wall structure, resulting in the aggregation of oil droplets, while ensuring the uniformity of the main combustion stage outlet airflow, which is conducive to uniform combustion.

[0047] In a further embodiment of the present invention, the present invention adopts a design in which the tail of the venturi expansion section is highly flush with the main combustion stage inner ring 5. The interstage section of the aircraft engine usually has a step structure with a height of about 3 to 5 mm. The step reflux zone is formed by the interstage section structure, which helps to widen the lean flameout limit range. Since the lean flameout limit range requirements of the gas turbine combustion chamber are lower than those of the aircraft engine combustion chamber, there is no need to form a step reflux zone. The design of the present invention can avoid the formation of a step reflux zone, reduce resistance loss, and also avoid the high temperature zone formed by the step reflux zone from ablation of the interstage section and the outlet of the main combustion stage inner ring 5, thereby extending the service life of the head.

[0048] In a further embodiment of the present invention, the present invention adopts the concept of staged combustion, the pre-combustion stage provides a stable fire source, and the main combustion stage achieves low-pollution combustion, which can ensure the stability of the combustion chamber while reducing pollution emissions.

[0049] In a further embodiment of the present invention, the fuel enters the duty class centrifugal nozzle 10 after entering from the fuel pipe 11. The fuel is atomized to form oil mist under the action of the centrifugal nozzle 10 and enters the combustion chamber for combustion. The fuel pipe 11 and the duty class centrifugal nozzle 10 are connected by threads. The centrifugal nozzle 10 can be removed separately for replacement. The connecting thread size is smaller than the outer diameter of the pipe of the fuel pipe 11 and the centrifugal nozzle 10. The inner diameter size of the pipe at the connection can be selected according to the selected thread size to reduce the processing difficulty. The internal pipeline structure of the centrifugal nozzle 10 is selected according to the working conditions and equipment conditions.

[0050] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A low emission combustion chamber head structure using a V-shaped blade tail end, characterized in that: include: A main combustion stage, a duty stage, a heat shield (12) and a flame tube (13), wherein the main combustion stage and the duty stage are coaxially arranged, the duty stage and the front end middle of the main combustion stage are connected, the rear end outer edge of the main combustion stage and the flame tube (13) are connected via the heat shield (12), and the rear end of the main combustion stage, the heat shield (12) and the flame tube (13) are enclosed to form a combustion chamber; the main combustion stage is used to inject fuel into the combustion chamber.

2. The low emission combustion chamber head structure using a V-shaped blade tail end according to claim 1, characterized in that: Also includes: A fuel conduit (11), one fuel conduit (11) is used to transport fuel to the duty class, and the other fuel conduit (11) is used to transport fuel to the main combustion stage.

3. The low emission combustion chamber head structure using a V-shaped blade tail end according to claim 2, characterized in that: The fuel tank comprises: a cyclone inner ring (7) and a centrifugal nozzle (10). The centrifugal nozzle (10) is installed inside the rear end of the cyclone inner ring (7), and a fuel pipe (11) is connected to the front end of the cyclone inner ring (7).

4. The low emission combustion chamber head structure using a V-shaped blade tail end according to claim 3, characterized in that: A plurality of purge flow channels (9) are provided at the front end of the cyclone inner ring (7) along the circumferential direction, and the plurality of purge flow channels (9) are all connected to the combustion chamber.

5. The low emission combustion chamber head structure using a V-shaped blade tail end according to claim 4, characterized in that: The main combustion stage comprises: a main combustion stage outer ring (1) and a main combustion stage inner ring (5), the main combustion stage outer ring (1) and the main combustion stage inner ring (5) are coaxially arranged, the rear end outer edge of the main combustion stage outer ring (1) and the flame tube (13) are connected through a heat insulation screen (12), a main combustion stage annular oil collecting chamber (6) is arranged in the main combustion stage inner ring (5), and another fuel pipe (11) is connected to the main combustion stage annular oil collecting chamber (6).

6. The low emission combustion chamber head structure using a V-shaped blade tail end according to claim 5, characterized in that: The duty stage further comprises: swirl blades (8); the inner wall of the main combustion stage inner ring (5) and the rear end outer wall of the swirler inner ring (7) are connected via a plurality of swirl blades (8); and the plurality of swirl blades (8) are arranged at equal intervals in the circumferential direction around the axis of the swirler inner ring (7).

7. The low emission combustion chamber head structure using a V-shaped blade tail end according to claim 5, characterized in that: The main combustion stage further comprises: main combustion stage swirl blades (2) and main combustion stage V-shaped tail blades (3); the outer wall of the main combustion stage inner ring (5) and the inner wall of the main combustion stage outer ring (1) are connected via a plurality of main combustion stage swirl blades (2) and a plurality of main combustion stage V-shaped tail blades (3); the plurality of main combustion stage swirl blades (2) are arranged at equal intervals in the circumferential direction around the axis of the swirler inner ring (7); the plurality of main combustion stage V-shaped tail blades (3) are arranged at equal intervals in the circumferential direction around the axis of the swirler inner ring (7); and a main combustion stage V-shaped tail blade (3) is provided between any two adjacent main combustion stage swirl blades (2).

8. The low emission combustion chamber head structure using a V-shaped blade tail end according to claim 6, characterized in that: A first swirl passage is provided in each swirl blade (8), one end of the first swirl passage is connected to the interior of the swirler inner ring (7), and the other end of the first swirl passage is connected to the main combustion stage annular oil collecting chamber (6).

9. The low emission combustion chamber head structure using a V-shaped blade tail end according to claim 7, characterized in that: A second swirl passage is provided in the main combustion stage swirl blade (2), and the second swirl passage is connected to the main combustion stage annular oil collecting chamber (6); at least one main combustion stage oil injection hole (4) is provided on the main combustion stage swirl blade (2), and the third passage is connected to the combustion chamber through the main combustion stage oil injection hole (4); any two adjacent main combustion stage V-shaped tail blades (3) are surrounded to form a V-shaped groove, and each main combustion stage oil injection hole (4) is located in a V-shaped groove.

10. The low emission combustion chamber head structure using a V-shaped blade tail end according to claim 1, characterized in that: The heat insulation screen (12) is provided with a plurality of cooling holes distributed along the circumferential direction, the angle between the axis of the cooling holes and the axis of the duty class is 0° to 30°, the diameter of the cooling holes is 0.4 to 0.6 mm, and the number of the cooling holes is 150 to 300.

Images