Dry-type low-pollution combustion chamber nozzle structure capable of being used for complete machine operation

Abstract

The utility model discloses a dry-type low-pollution combustion chamber nozzle structure capable of being used for complete machine operation. An existing radial premixing nozzle integrated with a diffusion path cannot well solve the problem of spatial arrangement of an air inlet path, so that an air inlet pipeline needs to be welded to an external flange, and the external flange is large in size. The nozzle assembly comprises a nozzle head connected with a gas compressor casing and a boss connected with gas pipelines, an inner premixing connector and an outer premixing connector are arranged on the central axis of the boss, and a diffusion path connector is arranged on the right side of the axis of the boss. The extruder is welded on the nozzle assembly through a rivet, and air is freely distributed into the extruder; the small circular cover plate is connected to the nozzle assembly by welding; the large circular cover plate is connected to the nozzle assembly in a welded mode. The semicircular cover plate is connected to the nozzle assembly in a welded mode. The dry-type low-pollution combustion chamber nozzle is used for complete machine operation.

Description

TECHNICAL FIELD

[0001] The utility model relates to a dry type low pollution combustor nozzle structure for whole machine operation. BACKGROUND

[0002] Gas turbine has the characteristics of compact structure, light weight, low maintenance cost, short starting time, etc. and can be widely used in distributed power generation field. With the increasingly strict environmental protection requirements, the pollution emission of gas turbine is more and more strict at home and abroad, especially the NOX emission in the flue gas of gas turbine is clearly required. Reducing NOX pollution emission is very important for gas turbine.

[0003] In the design of small gas turbine combustor, there are mainly two ways for low pollution emission combustion nozzle type: the first way is to spray diluent, generally water or steam, before the gas turbine combustor nozzle to reduce the temperature of the combustion area and reduce NOX emission, but it will bring adverse effects such as combustion chamber, turbine blade fouling, reducing the efficiency of the unit, shortening the service life of high temperature parts, etc.; the second way is to use premixed combustion, generally axial structure, but the axial size requirement is large, the swirling blade is difficult to process, in addition, due to the coaxial structure, the radial distribution of speed and fuel concentration is not easy to be uniform, and the generation of NOx pollution is high at low load. A small amount of combustor has radial premixed nozzle structure, but due to the compact structure, generally without central diffusion nozzle, the combustion is not stable, and problems such as backfire and oscillation easily occur. The radial premixed nozzle integrated with diffusion path cannot well solve the space arrangement problem of the inlet path, resulting in that the inlet pipe needs to be welded on the external flange, and the external flange occupies a large volume and occupies external space, so it can only be used for single cylinder component test of combustor, and cannot be applied to whole machine test and whole machine operation. SUMMARY

[0004] The utility model aims at providing a dry type low pollution combustor nozzle structure for whole machine operation.

[0005] The above purpose is realized by the following technical scheme:

[0006] A dry type low pollution combustor nozzle structure for whole machine operation, which comprises a nozzle assembly, a small round cover plate, a large round cover plate, a semicircular cover plate, a presser, a cup-shaped part, a horn-shaped part, an inner premixing interface, a diffusion path interface and an outer premixing interface.

[0007] The nozzle assembly comprises a nozzle head connected with a compressor casing and a boss connected with each gas pipeline, the inner premixing interface and the outer premixing interface are arranged on the central axis of the boss, and the diffusion path interface is arranged on the right side of the boss axis.

[0008] The presser is welded on the nozzle assembly by rivets, and air is freely distributed into the presser.

[0009] The small round cover plate is connected to the nozzle assembly by welding;

[0010] The large round cover plate is connected to the nozzle assembly by welding;

[0011] The semicircular cover plate is connected to the nozzle assembly by welding.

[0012] The nozzle assembly further comprises a nozzle shell, a spline separating the inner and outer premix gas paths, inner premix swirl vanes, outer premix swirl vanes, a partition forming a gas collection chamber of each gas path, and an outer ring connected to a flame tube.

[0013] The nozzle assembly further comprises a presser located at a central position of the nozzle assembly, wherein the presser is composed of a nozzle tube and a nozzle outlet, and the nozzle tube and the nozzle outlet are connected together by welding.

[0014] The nozzle assembly further comprises a horn-shaped piece in a horn shape, wherein the horn-shaped piece has a plurality of circular fuel through holes uniformly distributed at an end of the horn-shaped piece, and the end surface of the horn-shaped piece is welded to the nozzle assembly to form an inner premix air passage, and the horn-shaped piece is welded to the cup-shaped piece to mainly form an outer premix air passage.

[0015] The nozzle assembly is connected to the presser by welding, and the presser, the cup-shaped piece, and the horn-shaped piece jointly form the outer premix air passage.

[0016] The nozzle assembly further comprises an outer ring having N4 air small holes uniformly distributed thereon.

[0017] The presser is in an I-shaped form, and has a plurality of rows of cooling small holes at an end surface thereof.

[0018] The small round cover plate is divided into two halves, and is connected to the nozzle assembly by welding to form a diffusion path gas collection chamber.

[0019] The large round cover plate is divided into two halves, and is connected to the nozzle assembly by welding to form an inner premix path gas collection chamber.

[0020] The dry low-pollution combustion chamber nozzle structure that can be used for whole machine operation, the semicircular cover plate is divided into upper and lower halves, which are connected to the nozzle assembly by welding to form an external premixing path gas collecting cavity therewith. Beneficial effects

[0021] 1. The utility model integrates the diffusion path and the premixing path together, and can be applied to the whole machine test and whole machine operation of small gas turbines, thereby improving the stability of premixed combustion and reducing the concentration of pollutant emissions.

[0022] 2. This new design integrates all gas paths into the nozzle housing, eliminating external flanges and other connection devices, allowing direct connection to the compressor casing. While ensuring combustion performance, it addresses the challenges of traditional dry, low-pollution nozzles in small gas turbines, such as unstable combustion, substandard pollutant emissions, the need for external pipe connections, and the inability to connect directly to the casing, which restricts their application to the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a front view of the utility model;

[0024] Figure 2 It is a rear view of the utility model;

[0025] Figure 3 It is a top view of the utility model;

[0026] Figure 4 It is a right side view of the utility model;

[0027] Figure 5 This is a cross-sectional view a of the nozzle of the present invention;

[0028] Figure 6 This is a cross-sectional view b of the nozzle of the present invention;

[0029] Figure 7 It is a three-dimensional diagram of the utility model;

[0030] Figure 8 yes Figure 6 AA section view;

[0031] Figure 9 yes Figure 6 BB section view;

[0032] Figure 10 yes Figure 8 GG section view;

[0033] Figure 11 It is a cross-sectional view of the inner premixing swirl blade;

[0034] Figure 12 It is a cross-sectional view of the external premixing swirl blade;

[0035] Figure: 1, nozzle assembly; 2, small round cover plate; 3, large round cover plate; 4, half round cover plate; 5, spout; 6, nozzle; 7, cup-shaped piece; 8, horn-shaped piece; 9, inner premix interface; 10, diffusion path interface; 11, inner premix swirler vane; 12, outer premix swirler vane; 13, air large hole; 14, air small hole; 15, nozzle head; 16, boss; 17, nozzle shell; 18, spline; 21, partition; 22, outer ring; 23, rivet; 24, compression piece; 1-1, inner premix channel; 1-2, inner premix path plenum; 1-3, inner premix plenum small hole; 1-5, fuel small hole; 1-6, inner premix air channel; 2-1, outer premix channel; 2-2, inner premix plenum; 2-3, small hole; 2-4, outer premix fuel gas channel; 2-5, outer premix path plenum; 2-7, swirler channel; 2-8, fuel small hole; 2-9, outer premix air channel; 3-1, diffusion channel; 3-2, diffusion path plenum; 3-3, diffusion path plenum small hole; 3-4, front diffusion path plenum; 3-5, front end fuel small hole; 4-1, air channel; 4-2, nozzle small hole; 5-1, cooling air cavity; 5-2, cooling small hole. DETAILED DESCRIPTION

[0036] Reference Figures 1-12 A dry low pollution combustor nozzle structure for whole machine operation, which consists of: nozzle assembly 1, small round cover plate 2, large round cover plate 3, half round cover plate 4, pressure expeller, cup-shaped piece 7, horn-shaped piece 8, inner premix interface 9, diffusion path interface 10 and outer premix interface 11;

[0037] The nozzle assembly 1 includes a nozzle head 15 connected with the compressor casing and a boss 16 connected with each gas pipeline, the boss 16 center axis is arranged with the inner premix interface 9 and the outer premix interface 11, and the right side of the boss axis is arranged with the diffusion path interface 10;

[0038] The nozzle assembly 1 mainly includes the nozzle head 15 connected with the compressor casing, the nozzle head is uniformly arranged with N1 bolt holes; the boss 16 connected with each gas pipeline, the boss 16 center axis is arranged with the inner premix interface 9 and the outer premix interface 11, and the right side of the boss axis is arranged with the diffusion path interface 10; the nozzle shell 17 containing each fuel path channel, the shell is T-shaped, and the upper part has a central air purge path air large hole 13; the spline 18 isolating the inner and outer premix gas paths; the inner premix swirler vane 11, N2 vanes are uniformly arranged; the outer premix swirler vane 12, N3 vanes are uniformly arranged; the partition 21 constituting each gas path plenum; the outer ring 22 connected with the flame tube, the outer ring 22 is uniformly arranged with N4 air small holes 14.

[0039] The small round cover plate 2 is divided into upper and lower halves, and is connected to the nozzle assembly 1 by welding to form a diffusion path plenum.

[0040] The large circular cover plate 3 is divided into two halves, an upper half and an lower half, which are connected to the nozzle assembly 1 by welding to form an inner premixing path gas collecting cavity therewith.

[0041] The semicircular cover plate 4 is divided into two halves, an upper half and an lower half, which are connected to the nozzle assembly 1 by welding to form an external premixing channel gas collecting cavity therewith.

[0042] The extruder is located in the center of the nozzle and is mainly composed of a nozzle pipe 5 and a nozzle 6. The nozzle pipe 5 and the nozzle 6 are connected together by welding. The extruder is welded to the nozzle assembly 1 by rivets 23. Air is freely distributed into the extruder.

[0043] The cup-shaped member 7 is cup-shaped and is mainly used to form a diffusion path. There are several rows of small holes on the side of the cup to play a rectifying role. Through welding with the nozzle assembly 1 and the pressing member 8, an irregular front diffusion path gas collection chamber 3-4 is formed.

[0044] The trumpet-shaped member 8 is trumpet-shaped and primarily serves to disperse the flame, lowering the temperature in the central area and reducing pollutant emissions. The end of the trumpet-shaped member 8 has several evenly distributed circular fuel holes 3-5. It is welded to the end surface and the nozzle assembly 1, primarily forming the inner premixed air passages 1-6. It is welded to the cup-shaped member 7, primarily forming the outer premixed air passages 2-9.

[0045] The clamping element 9 is I-shaped, with several rows of cooling holes 5-2 evenly spaced on its end surface at angles to the wall. These holes primarily cool the nozzle end face through air, reducing corner recirculation and the risk of corner tempering. The clamping element 9 is welded to the nozzle assembly 1. Together with the cup-shaped element 7 and the trumpet-shaped element 8, they form the external premixed air passage 2-9.

[0046] The internal premixing gas enters the internal premixing channel 1-1 through the internal premixing interface 9 and then enters the internal premixing gas collecting chamber 1-2, enters the internal premixing swirl blade 11 through the internal premixing gas collecting chamber small hole 1-3, and is then ejected through the fuel small hole 1-5 on the blade to mix with the air in the internal premixing air channel 1-6 to form a mixed gas and enter the combustion area.

[0047] The external premixing gas enters the external premixing channel 2-1 through the external premixing interface 11 and then enters the internal premixing gas collecting chamber 2-2, then passes through the small hole 2-3 on the internal premixing swirl blade 11 to enter the external premixing gas channel 2-4, enters the external premixing gas collecting chamber 2-5, and then enters the channel 2-7 on the external premixing swirl blade 12 into the fuel small hole 2-8 on the external premixing swirl blade to be ejected, mixed with the air in the external premixing air channel 2-9 to form a mixed gas, and enters the combustion area.

[0048] The diffusion path gas enters the diffusion channel 3-1 through the diffusion path interface 10 and enters the diffusion path gas collecting chamber 3-2, then passes through the diffusion path gas collecting chamber small hole 3-3 and the inner premixing swirler blade 11 to enter the front diffusion path gas collecting chamber 3-4, and then passes through the fuel small hole 3-5 at the front end of the trumpet-shaped member 8, and finally ejected into the combustion area.

[0049] The central air purge path is an air path that enters the extruder through the large air hole 13 on the nozzle assembly 1, passes through the air channel 4-1 and finally enters the combustion area through the nozzle small hole 4-2.

[0050] The nozzle end face cooling path is an air path, which enters the cooling air cavity 5 - 1 through the air holes 14 on the nozzle assembly 1 and enters the combustion area through the cooling holes 5 - 2 on the pressing piece 9 .

[0051] The design of this utility model was derived after one-dimensional, three-dimensional, and thermal life analysis. The advantage of this nozzle lies in its integrated diffusion and premixing paths, making it suitable for use in small gas turbine complete unit testing and full unit operation. This improves the stability of premixed combustion while reducing pollutant emissions. During full-temperature, full-pressure testing, the nozzle demonstrated the following specific values: OTDF no more than 0.15, RTDF no more than 0.10, total pressure recovery coefficient within 95%, and pollutant emissions no more than 50 mg / Nm³ (at 15% O₂).

[0052] The present invention is mainly used in the testing and operation of small gas turbine complete machines. Under the condition of ensuring the basic combustion parameters, full consideration is given to using the diffusion path for combustion during ignition and low operating conditions to ensure stable combustion. Under high operating conditions, the premixing path is used to reduce the pollutant emission value. The premixing path is divided into an internal premixing path and an external premixing path. The internal premixing path is mainly used to improve the stability under high operating conditions, and can be used to adjust the central combustion temperature and reduce pollutant emissions. The present invention provides a dry low-pollution nozzle that can be used for a small gas turbine complete machine. The various gas paths are integrated into the nozzle housing, eliminating external flanges and other connecting devices, and can be directly connected to the compressor casing. Under the condition of ensuring combustion performance, the present invention solves the problems of traditional dry low-pollution nozzles of small gas turbines, such as unstable combustion, substandard pollutant emissions, the need for external pipe connection, and the inability to be directly connected to the casing, which cannot be applied to the complete machine.

[0053] The fuel of the nozzle is natural gas. The whole nozzle includes five channels, diffusion channel, inner premixing channel, outer premixing channel, center air purge channel and nozzle end face cooling channel. The diffusion channel is mainly used for ignition and low load working condition, the premixing two channels are mainly used for high load working condition and adjusting the pollutant emission by adjusting the inner and outer premixing gas ratio. The center air purge channel mainly cools the center of the nozzle by air. The nozzle end face cooling channel mainly cools the nozzle end face by air and reduces the problem of corner backflow area, reduces the probability of corner backfire.

Claims

1. A dry low-pollution combustion chamber nozzle structure that can be used for whole-machine operation, characterized by: The components include: nozzle assembly, small circular cover plate, large circular cover plate, semicircular cover plate, extruder, cup-shaped part, trumpet-shaped part, internal premixing interface, diffusion path interface and external premixing interface; The nozzle assembly includes a nozzle head connected to the compressor casing and a boss connected to each gas pipeline. The inner premixing interface and the outer premixing interface are arranged on the central axis of the boss, and the diffusion path interface is arranged on the right side of the boss axis. The extruder is welded to the nozzle assembly by rivets, and air is freely distributed into the extruder; The small circular cover plate is connected to the nozzle assembly by welding; The large circular cover plate is connected to the nozzle assembly by welding; The semicircular cover plate is connected to the nozzle assembly by welding.

2. The dry low-pollution combustion chamber nozzle structure that can be used for whole-machine operation according to claim 1 is characterized by: The nozzle assembly also includes a nozzle shell, splines for isolating inner and outer premixed air paths, inner premixed swirl blades, outer premixed swirl blades, partitions forming gas collecting cavities of each air path, and an outer ring connected to the flame tube.

3. The dry low-pollution combustion chamber nozzle structure that can be used for whole-machine operation according to claim 2 is characterized by: The extruder is located at the center of the nozzle assembly and is composed of a nozzle pipe and a nozzle. The nozzle pipe and the nozzle are connected together by welding.

4. The dry low-pollution combustion chamber nozzle structure that can be used for whole-machine operation according to claim 3 is characterized by: The trumpet-shaped part is trumpet-shaped, and has a number of circular evenly distributed fuel through holes at the end of the trumpet-shaped part. Its end face is welded together with the nozzle assembly to form an inner premixed air channel, and is welded together with the cup-shaped part to mainly form an outer premixed air channel.

5. The dry low-pollution combustion chamber nozzle structure that can be used for whole-machine operation according to claim 4 is characterized by: The nozzle assembly is connected to the pressing piece by welding, and the pressing piece, the cup-shaped piece and the trumpet-shaped piece together form an external premixed air channel.

6. The dry low-pollution combustion chamber nozzle structure that can be used for whole-machine operation according to claim 5 is characterized by: N4 air holes are evenly distributed on the outer ring.

7. The dry low-pollution combustion chamber nozzle structure applicable to the whole machine operation according to claim 6 is characterized by: The pressing piece is in an I-shape, and has a plurality of rows of cooling holes on its end surface.

8. The dry low-pollution combustion chamber nozzle structure applicable to whole-machine operation according to claim 7 is characterized by: The small circular cover plate is divided into two halves, the upper and lower halves, which are connected to the nozzle assembly by welding to form a diffusion path gas collecting cavity therewith.

9. The dry low-pollution combustion chamber nozzle structure applicable to whole-machine operation according to claim 8, characterized in that: The large circular cover plate is divided into two halves, the upper and lower halves, which are connected to the nozzle assembly by welding to form an inner premixing path gas collecting cavity therewith.

10. The dry low-pollution combustion chamber nozzle structure applicable to whole machine operation according to claim 9, characterized in that: The semicircular cover plate is divided into two halves, an upper halves and an lower halves, which are connected to the nozzle assembly by welding to form an external premixing path gas collecting cavity therewith.

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