CN102878580B - Lean premixed combustion chamber for gas turbine - Google Patents

Abstract

A lean premixed combustor of a gas turbine: a flame tube is fixed inside the casing, and a number of round holes for air are opened on the rear wall of the casing; an igniter mounting seat for installing an igniter is provided on the side of the casing; A variable-diameter swirl cup is installed, and the nozzle swirler assembly is connected to the inlet of the swirl cup through the casing; the center of the nozzle body is the duty fuel introduction pipe, and the outer ring is the premixed fuel introduction pipe; the swirler assembly The rear cover of the premixed fuel chamber is connected with the inner side of the blade installation base to form a premixed fuel chamber; the outer side of the blade installation base is fixed with a plurality of blades, and each blade has a blind hole along the axial direction. Multiple premixed fuel injection holes; the premixed fuel enters the premixed fuel cavity from the premixed fuel introduction pipe, and enters the swirler channel through the blind holes on the vanes and the premixed fuel injection holes on the vanes to complete the mixing with air . The invention makes the fuel and air mix evenly, and is beneficial to reduce the _NOx emission of the combustion chamber.

Description

A gas turbine lean premix combustor

technical field

The invention belongs to the technical field of gas turbines, and in particular relates to a lean premixed combustion premixed fuel injection structure applied to a gas turbine combustor and a lean premixed combustor adopting the structure.

Background technique

At present, the main problem faced by the gas turbine combustor is to reduce the emission of pollutants, especially NO _X. As a mature dry low NO _x technology, lean premixed combustion has been widely used. The so-called lean premixed combustion is to pre-mix fuel and air upstream of the combustion chamber to avoid a region where the ratio of fuel and air is close to the chemically proper ratio. In this way, the combustion zone is in a state of excess air, so the flame temperature is reduced, thereby greatly reducing the generation of thermal _NOx . The key to reducing NO _x emissions in lean premixed combustion technology is to achieve uniform mixing of fuel and air in the shortest possible time. The fuel and air are mixed uniformly, and there is no local high-concentration area of fuel, so there will be no local high-temperature area, so that the generation of a large amount of NO _X can be suppressed. In addition, the fuel cannot stay in the mixing area for too long, otherwise tempering and self-ignition will occur, which will affect the safe operation of the combustion chamber. With the development of gas turbine technology, the inlet air temperature of the combustion chamber is getting higher and higher, and this problem is becoming more and more serious. In addition, since the ignition delay time of hydrogen is much shorter than that of conventional natural gas fuel under the same conditions, it is easier for fuels with high hydrogen content to self-ignite in the premix channel when lean premixed combustion is used.

The gas turbine combustor usually uses a swirler at the head to form a central recirculation zone to stabilize the flame. When the lean premixed combustion technology is used, the fuel is usually injected upstream of the swirler, and the fuel is mixed with the air during the passage of the swirler. of blending. The disadvantage of this method is that under the influence of the upstream incoming air, the fuel jet will cause the fuel to accumulate in a certain area, and the uniform mixing with the air cannot be achieved. The flow rate of incoming air and fluctuations in the direction of flow also affect the mixing effect of fuel and air.

Contents of the invention

The object of the present invention is to provide a gas turbine lean premix combustor to improve the mixing effect of premixed fuel and air in the gas turbine lean premix combustor and reduce _NOx emissions.

In order to achieve the above object, the gas turbine lean premixed combustor provided by the present invention, its main structure includes:

A casing (1), the casing (1) is fixed with a flame cylinder (2), and two channels of air are formed between the casing and the flame cylinder;

The rear wall of the casing (1) is provided with a number of circular holes (11) leading to the air; the side of the casing (1) is provided with an igniter mounting seat (17) for installing the igniter (5);

A variable-diameter swirl cup (45) is installed inside the flame tube (2), and the inlet diameter of the swirl cup (45) is smaller than the outlet diameter; the nozzle swirler assembly (3) is connected to the The inlet of the swirl cup (45);

The center of the rotating nozzle body (34) in the nozzle swirler assembly (3) is the duty fuel introduction pipe (38), and the top of the duty fuel introduction pipe (38) is the duty nozzle (33), and the duty nozzle (33) The outer side of the outlet end is a chamfered cone surface, and a plurality of round holes are processed along the circumference of the chamfered cone surface as fuel injection holes (310); the outer ring of the on-duty fuel introduction pipe (38) is a premixed fuel introduction pipe (39). One end of the premixed fuel introduction pipe (39) is connected to the swirler assembly (35), and the side of the premixed fuel introduction pipe (39) is provided with a premixed fuel hole (303);

The back cover (304) of the premixed fuel chamber of the swirler assembly (35) is connected with the inner side of the blade installation base (305) to form a premixed fuel chamber (307); the outer side of the blade installation base (305) is fixed with multiple blades (306), a swirler channel (31) with equal cross-section along the flow direction and an included angle with the radial direction is formed between each blade (306); each blade (306) has a blind hole (308) along the axial direction, Each blind hole (308) is aligned with the opening (309) on the vane installation base (305); multiple premixed fuel injection holes (32) are provided on the two side walls of each vane (306), and each vane (306) The premixed fuel injection hole (32) communicates with the blind hole (308) of the vane (306); the premixed fuel enters the premixed fuel cavity (307) from the premixed fuel introduction pipe (39), and passes through the vane (306) The blind hole (308) of the swirler vane and the premixed fuel injection hole (32) on the vane (306) enter the swirler channel (31) to complete the mixing with air.

In the lean premixed combustor of the gas turbine, shallow grooves with the same cross-sectional shape as the swirler blades (306) are provided on the outside of the blade mounting base (305), and the blades (306) are embedded in the shallow grooves and fixed by welding.

In the gas turbine lean premixed combustor, the equal cross-sectional area of the swirler channel (31) depends on the air flow entering the flame tube (2) through the swirler channel (31); the swirler channel (31) The size of the radial angle depends on the required swirl strength.

In the lean premixed combustion chamber of the gas turbine, a flange (12) is provided in the middle of the casing (1), through which the gas turbine body and the lean premixed combustion chamber of the gas turbine are connected together.

In the gas turbine lean premixed combustor, the total area of the circular holes (11) at the tail of the casing (1) is greater than twice the cross-sectional area (6) of the two channels.

In the lean premixed combustor of the gas turbine, the outer side of the vane installation base (305) is provided with notches having the same cross-sectional shape as the vanes (306), and each vane (306) is embedded in a notch and fixed.

In the lean premixed combustion chamber of the gas turbine, the inlet of the swirl cup (45) is a straight pipe section, and the transition is an outlet with a large diameter.

The lean premixed combustion chamber of the gas turbine, wherein the igniter (5) is fixed on the mounting seat (17) of the casing through threads, and passes through the casing (1), the flame tube (2) and the swirl cup in sequence (45), the ignition head of the igniter (5) is located at the inside of the swirl cup, discharges and ignites the fuel after electrification.

The biggest feature of the present invention is that the swirler channel has multiple rows of fuel injection holes on the surface along the axial direction of the vane, and these holes are connected with the premixed fuel channel of the nozzle to form the injection channel of the premixed fuel. The premixed fuel is injected and mixed with air in the swirler channel. The advantage of this premixed fuel injection method is that it can ensure the uniform mixing of fuel and air, which is beneficial to reduce the _NOx emission of the combustion chamber. Stability of combustor fuel blends without causing changes in combustor _NOx emissions.

Description of drawings

Fig. 1 is a longitudinal sectional view of a gas turbine lean premixed combustor of the present invention.

FIG. 2A is an enlarged schematic view of the structure of the casing in FIG. 1 , and FIG. 2B is a side view and a front view of FIG. 2A .

Fig. 3A is an enlarged schematic view of the structure of the flame cylinder in Fig. 1, and Fig. 3B is a side view of Fig. 3A.

FIG. 4 is a perspective view of the nozzle swirler assembly in FIG. 1 .

Fig. 5 is a longitudinal sectional view of the nozzle swirler assembly in Fig. 1 .

Fig. 6 is a longitudinal sectional view of the swirl cup assembly in Fig. 1 .

Explanation of main component symbols in the attached drawings:

1 receiver;

2 flame tube, 20 top cover of flame tube, 201 end section of flame tube, 202 cylindrical section outside the tapered section, 203 first section of flame tube, 204 igniter insertion hole on flame tube, 21 mixing hole, 22 cylinder body Air film cooling holes, 23 cooling holes on the top cover of the flame tube, 24 outlet of the flame tube, 25 cylinder body of the flame tube, 26 big hole in the center of the top cover of the flame tube, 27 small holes around the big hole in the center of the top cover of the flame tube, 28 inside of the flame tube Ring, 29 circular passages;

3 Nozzle Swirl Assembly, 31 Swirl Passage, 32 Premixed Fuel Injection Hole on Blade Wall, 33 Duty Nozzle, 34 Swivel Nozzle Body, 35 Swirl Assembly, 36 Swirl Mounting Nut, 37 Swirl Install gasket, 38 Duty nozzle fuel inlet pipe, 39 Premixed fuel inlet pipe; 301 Fuel road isolation sleeve, 302 Premixed fuel road annular channel, 303 Premixed fuel inlet, 304 Premixed fuel chamber rear cover, 305 Swirler vane mounting base, 306 swirler vane, 307 swirler premixed fuel cavity, 308 swirler vane blind hole, 309 blade mounting base opening, 310 duty nozzle fuel injection hole;

4 swirl cup assembly, 41 swirl cup inlet, 42 swirl cup outlet, 43 swirl cup mount, 44 swirl cup mount screw hole, 45 swirl cup, 46 igniter socket;

5. Igniter; 6. Annular secondary channel; 7. Double-headed stud; 8. Gasket; 9. Nut; 10. Washer; 11. Round hole; ; 16 through holes; 17 igniter mount; 18 screws.

Detailed ways

The technical problem to be solved by the invention is to improve the mixing effect of premixed fuel and air in a gas turbine lean premixed combustor, and reduce _NOx emissions.

Technical scheme of the present invention is realized like this:

A cylindrical gas turbine combustor for burning gaseous fuel, comprising five parts in total, including a casing, a flame cylinder, a nozzle swirler assembly, a swirl cup assembly and an igniter.

The combustion chamber is generally divided into two layers, the outer side is the casing, and the inner side is the flame tube. A secondary channel of air is formed between the casing and the flame tube. There are a large number of circular holes on the wall of the rear of the casing, and the air from the compressor enters the secondary channel through these circular holes. The total area of the circular holes will be greater than twice the cross-sectional area of the two passages, to ensure that the total pressure loss of the combustion chamber mainly occurs in the flame tube and the swirler, rather than these circular holes on the casing. These round holes play the role of rectifying the air from the compressor, eliminating the circumferential inhomogeneity of the incoming air and the disturbance of the large vortex, ensuring the uniformity of the air intake of the flame tube, thereby improving the outlet temperature of the combustion chamber distributed. A flange is welded in the middle of the casing, through which the combustion chamber and the gas turbine body are assembled together. There is a large hole in the center of the case end cap for the nozzle to be inserted. There are four screw holes evenly distributed along the circumference outward from the large central hole, which are used to screw in the screws for fixing the nozzle. There are four blind holes evenly distributed along the circumference outwards, and the outer side is close to the blind holes are four through holes, which are used to insert the studs connecting the flame tube and the casing. After the double-ended stud passes through the end cover from the inside of the end cover, fix it with a nut with a lock washer, and smash the lock washer into the blind hole with a tool to prevent the nut from loosening. There is a hole on the side of the casing near the end cover and an igniter mounting seat is welded for installing the igniter.

The flame cylinder is a cylindrical thin-walled part, including a top cover and a cylinder body. There is a large hole in the center of the top cover, which is used to install the swirl cup. There are 4 small holes along the circumference around the big hole, which are used to insert studs to fix the swirl cup assembly; there are a large number of air inlet holes in the rest, through which some air enters the flame tube to cool the swirl cup . The barrel is welded in multiple sections, and the side of the first section has a hole corresponding to the mounting seat of the receiver igniter for inserting the igniter. Except for the first section, a large number of small holes are opened along the circumference of the upstream end of each section, and a ring is welded on the inside to form an annular passage with the cylinder, and the air entering through the small holes on the wall of the cylinder flows through the annular passage to form Air film cooling reduces the temperature of the wall surface of the flame tube. There are 4 to 6 large holes along the circumference in the middle part of the penultimate section. The air entering through the row of holes is mixed with the high-temperature flue gas from the head to reduce the temperature. The last section of the flame tube is contracted from a straight section through a tapered section to a straight section with a smaller diameter, which serves as the outlet of the flame tube and is inserted into the volute for connecting the combustion chamber and the turbine when it is assembled with the gas turbine. A cylindrical section is welded outside the tapered section to increase the rigidity of the outlet section.

Nozzle swirler assembly consists of nozzle body, swirler assembly, duty nozzle, mounting nut and gasket.

The nozzle body includes duty fuel introduction pipe, premixed fuel introduction pipe and fuel road isolation sleeve.

The fuel road isolation sleeve is a pipe fitting with a step processed at one end. It is first welded with the fuel introduction pipe on duty, and then welded with the premixed fuel introduction pipe to form an annular passage, and the premixed fuel enters the annulus from the side opening. Empty, flow to cyclone assembly.

The swirler assembly consists of the rear cover of the premixed fuel chamber, the blade installation base and several swirler blades. The rear cover of the premixed fuel chamber is welded with the blade mounting base to form the premixed fuel chamber, and the swirler blades are welded on the blade mounting base. The edges of the swirler blades are rounded to reduce flow loss. A blind hole is opened in the swirler vane along the axial direction, and the opening is aligned with the opening on the vane mounting base, and several small holes are opened on both sides of the vane along the axial direction of the central hole of the vane as premixed fuel injection holes. The premixed fuel injection holes are evenly distributed along the axial direction of the vane to ensure the uniformity of fuel distribution. The premixed fuel enters the annular space and the premixed fuel chamber sequentially from the premixed fuel introduction pipe, then leads to the axial blind hole on the blade, and finally enters the swirler channel through the premixed fuel injection hole on the side of the blade. Mixing with air is done in the tank channel.

The external thread of the thin end of the premixed fuel chamber rear cover is matched with the internal thread of the thin end of the premixed fuel pipe. The nozzle body and the swirler assembly are connected together through this thread. Gaskets between the rear covers of the mixed fuel chambers provide a seal to prevent leakage of the premixed fuel.

A number of shallow grooves (the same as the number of blades) are processed on the outside of the blade installation base, which are the same as the cross-sectional shape of the blades, and the blades are embedded in them during welding to facilitate blade positioning and ensure blade position accuracy. After the blade is welded on the substrate, a channel with equal cross-section along the flow direction and a certain angle with the radial direction is formed. The channel is for the air entering the combustor head to achieve the mixing of premixed fuel and air, and to form a swirl flow downstream.

The on-duty nozzle is located in the center of the nozzle assembly, and one end is machined with an internal thread to match the on-duty fuel introduction pipe. The outer side of the outlet end is chamfered, and a number of circular holes are processed along the circumference on the chamfered cone surface as fuel injection holes. The centerline of the circular holes forms a certain angle with the center of the nozzle.

The nozzle body and the swirler are connected by threads. When assembling with the casing, the two parts are disassembled first, and the nozzle body is inserted from the outside of the casing end cover, while the swirler is installed from the inside of the end cover and connected to the nozzle. The bodies are assembled together.

When assembling the nozzle swirler assembly with the casing, first assemble the mounting nut, the duty nozzle and the nozzle body, then insert it from the outside of the end cover of the combustion chamber, and fix the mounting nut on the end cover with four screws, and rotate the nozzle body The depth of the nozzle inserted into the combustion chamber can be adjusted to facilitate the cooperation with the flame tube. Then install the swirler assembly to the nozzle body inside the end cap.

The swirl cup assembly is composed of a swirl cup and a swirl cup mount, which are welded together. There are four threaded holes on the outer side of the swirl cup mounting seat along the circumference. A hole is opened on the side of the swirl cup at a position corresponding to the penetration hole of the igniter of the flame tube, through which the igniter is inserted and discharged to ignite the fuel at this position. The swirl cup assembly is installed into the large hole in the center of the top cover inside the flame tube, and a gasket is placed outside the top cover, and the studs pass through the threaded holes of the gasket, the top cover of the flame tube and the swirl cup assembly in turn. Secure the swirl cup assembly to the flame tube top cover by tightening the studs.

The igniter is fixed on the mounting seat of the casing by threads, and passes through the casing, the flame tube and the swirl cup in turn. The ignition head leaks inside the swirl cup, and discharges to ignite the fuel after power on.

The nozzle swirler assembly includes two fuel injection channels for premixing and duty. The on-duty fuel path is in the center of the nozzle and is injected through the on-duty nozzle. Its function is to form a diffusion combustion flame in the center of the swirler to achieve stable combustion under low load. The premixed fuel path is on the outside and is connected with the central hole of the radial swirler vane. Several premixed fuel injection holes communicated with the central hole are opened on both sides of the vane, and the premixed fuel is injected into the swirler channel through the premixed fuel injection holes. The premixed fuel injection holes are evenly distributed along the axial direction of the vane, which ensures the uniformity of fuel distribution. After the air enters the swirler channel, the flow is accelerated, and it is not easily affected by the fluctuation of the upstream air flow, thereby ensuring the stability of fuel and air mixing. The radial swirl is a channel of equal cross-sectional area, one end is threadedly connected with the nozzle body, and the other end fits with the swirl cup mounting seat installed on the top cover of the flame tube to form a closed radial swirl device channel. The premixed fuel and the air passing through the swirler are uniformly mixed during the flow in the swirler channel, and then enter the swirler cup installed at the head of the flame tube. The inlet of the swirl cup is a straight pipe section, and then transitions into a large-diameter outlet. Under the action of the swirler, a stable flame in the recirculation zone is formed in the center of the expansion section of the swirl cup.

The air from the compressor enters the two passages from the rear end of the casing, flows from the back to the front, and enters the flame tube through the mixing holes on the flame tube, the film cooling holes and the swirler at the head in turn, and in the process The wall of the flame tube is cooled by convection. The amount of air passing through the film cooling hole is determined according to the flame temperature and the allowable working temperature of the wall of the flame tube, the amount of air passing through the swirler is determined according to the required average temperature of the main combustion zone and the amount of fuel, and the rest of the air enters through the mixing hole .

The flame tube and the receiver are connected together by 4 studs. One end of the stud is threaded through a spacer spacer, and the top cover of the flame tube is screwed into the screw hole of the swirl cup mount. The other end protrudes out of the casing and is fixed with a nut. The nozzle-swirler assembly is fixed on the casing, and the insertion depth can be adjusted by rotating the nozzle body until the end face of the swirler vane is against the swirl cup mounting seat.

The present invention will be described in detail below in conjunction with the accompanying drawings. The specific structure of the single cylindrical combustion chamber of the present invention is shown in FIG. 1 , and mainly includes five parts: casing 1 , flame tube 2 , nozzle swirler assembly 3 , swirl cup assembly 4 and igniter 5 .

(1) Overall structure

As shown in Figure 1, the air from the compressor enters the circular two-way channel 6 between the casing 1 and the flame tube 2 from the round hole 11 opened at the rear of the casing 1 and flows to the head, passing through the doped holes on the flame tube 2 in turn. The mixing hole 21 , the cylinder film cooling hole 22 and the swirler channel 31 enter the flame cylinder 2 . The fuel is injected in two ways. About 90% of the fuel is sprayed into the swirler channel 31 through the opening 32 on the wall of the swirler vane, and mixed with air in the swirler channel 31; The duty nozzle 33 is injected to form a diffusion combustion for stabilizing the flame. The mixture of fuel and air enters the inlet 41 of the swirl cup from the channel of the swirler, and then reaches the outlet 42 of the swirl cup to form a sudden expansion, and forms a central backflow at the outlet 42 of the swirl cup under the swirling action of the swirler, ensuring Stable combustion. The high-temperature flue gas generated at the outlet 42 of the swirl cup is then mixed with the air from the cooling hole 23 on the top cover of the flame tube, the film cooling hole 22 and the mixing hole 21 of the tube body, and then flows out from the outlet 24 of the flame tube.

The flame tube 2 and the casing 1 are connected together by four studs 7 . One end of the double-ended stud passes through a gasket 8 and the top cover 20 of the flame tube, and is screwed into the screw hole 44 of the swirl cup mounting seat 43 . The other end stretches out of the casing and is fixed with a nut 9 and a washer 10 . The nozzle swirler assembly 3 is fixed on the casing 1 , and the insertion depth can be adjusted by rotating the nozzle body 34 until the end surface of the swirler vane abuts on the swirl cup mounting seat 43 .

(2) Receiver

2A and 2B are structural diagrams of the casing. There are a large number of round holes 11 on the rear wall of the casing (1), and the air from the compressor enters the secondary passage through these round holes. A flange 12 is welded in the middle of the casing, through which the combustion chamber and the gas turbine body are assembled together. The large hole 13 in the center of the casing end cover is used to insert the nozzle. There are four screw holes 14 evenly distributed along the circumference outward from the large central hole, which are used for screwing in screws 18 for fixing the nozzle. There are four blind holes 15 evenly distributed along the circumference outwards, and the outside is close to the blind holes are four through holes 16, which are used to insert the studs 7 connecting the flame tube 2 and the casing 1. After the double-ended stud 7 passes the end cover from the inside of the end cover, it is fixed with a nut 9 with a lock washer 10, and the lock washer is smashed into the blind hole 15 with a tool to prevent the nut 9 from loosening. The casing side has a hole near the end cover end and is welded with an igniter mount 17 for installing the igniter 5 .

(3) flame tube

3A and 3B are structural views of the flame cylinder. The flame tube is a cylindrical thin-walled part, including a top cover 20 and a cylinder body 25 . There is a large hole 26 in the center of the top cover 20 for installing the swirl cup. There are four small holes 27 along the circumference around the large hole, which are used to insert studs 7 to fix the swirl cup assembly 4 . The remaining part has a large number of air intake holes 23, and a part of air enters the flame tube through these holes and is used for cooling the swirl cup 45. The cylinder body 25 of the flame cylinder is welded in multiple sections, wherein the side of the first section 203 is provided with an igniter insertion hole 204 at a position corresponding to the mounting seat of the casing igniter. Except for the first section, a large number of small holes 22 are opened at the upstream end of each section along the circumference, and a ring 28 is welded on the inside to form an annular channel 29 with the cylinder, through which the air entering through the small holes 22 on the wall of the cylinder flows through. The annular channel 29 forms film cooling to reduce the temperature of the wall surface of the flame tube. There are six mixing holes 21 along the circumference in the middle part of the penultimate section, and the air entering through the row of holes is mixed with the high-temperature flue gas from the head to reduce the temperature. The last section 201 of the flame tube is contracted from a straight section through a tapered section to a straight section with a smaller diameter, which serves as the outlet of the flame tube and is inserted into the volute for connecting the combustion chamber and the turbine when assembling with the gas turbine. A cylindrical section 202 is welded outside the tapered section to increase the rigidity of the outlet section.

(4) Nozzle swirler assembly

Figure 4 and Figure 5 are a front view and a longitudinal sectional view of the nozzle swirler assembly, respectively. The nozzle swirler assembly is composed of a nozzle body 34 , a swirler assembly 35 , a duty nozzle 33 , a mounting nut 36 and a gasket 37 .

The rotary nozzle body 34 includes an on-duty fuel introduction pipe 38 , a premixed fuel introduction pipe 39 and a fuel passage isolation sleeve 301 .

The fuel path isolation sleeve 301 is a pipe fitting with a step processed at one end. It is first welded together with the on-duty fuel introduction pipe 38, and then welded with the premixed fuel introduction pipe 39 to form a premixed fuel annular passage 302. The premixed fuel The premixed fuel inlet 303 from the side enters the annulus passage and flows to the swirler assembly 35 .

The swirler assembly 35 includes a premix fuel chamber rear cover 304 , a vane mounting base 305 and twelve swirler vanes 306 . The rear cover 304 of the premixed fuel chamber is welded together with the vane mounting base 305 to form a premixed fuel chamber 307 . The outer side of the blade installation base 305 is processed with 12 shallow grooves having the same cross-sectional shape as the blade, and the blade 306 is embedded in it during welding to facilitate blade positioning and ensure blade position accuracy. After the blade 306 is welded on the base body 305, a channel 31 with a constant section along the flow direction and a certain angle with the radial direction is formed. The channel allows the air entering the head of the combustor to pass through, realize the mixing of premixed fuel and air, and form a swirl flow downstream. The edges of the swirler blades 306 are rounded to reduce flow loss. The swirler blade 306 has a blind hole 308 along the axial direction, the blind hole 308 is aligned with the opening 309 on the blade mounting base, and five small holes 32 are respectively opened on both sides of the blade along the axial direction of the blade center hole, as a premixed Fuel injection holes. The premixed fuel injection holes 32 are evenly distributed along the axial direction of the vane to ensure the uniformity of fuel distribution. The premixed fuel enters the premixed fuel circuit annular passage 302 and the premixed fuel chamber 307 in turn from the premixed fuel introduction pipe 39, then leads to the axial blind hole 308 on the blade, and finally passes through the premixed fuel injection hole on the side of the blade 32 into the cyclone channel 31 to complete the mixing with air.

The external thread of the thin end of the premixed fuel chamber rear cover is matched with the internal thread of the thin end of the premixed fuel pipe. The nozzle body and the swirler assembly are connected together through this thread. The gasket 37 between the rear covers of the mixed fuel chamber is sealed to prevent leakage of the premixed fuel.

The duty nozzle 33 is located at the center of the nozzle assembly 34 , and one end is processed with an internal thread to match the duty fuel introduction pipe 38 . The outer side of the outlet end is chamfered, and 12 circular holes are processed along the circumference on the chamfered cone surface as fuel injection holes 310, and the centerline of the circular holes forms an included angle of 30-45° with the center of the nozzle.

(5) Swirl cup assembly

Fig. 6 is a longitudinal sectional view of the swirl cup assembly. The swirl cup assembly 4 is composed of a swirl cup 45 and a swirl cup mount 43, which are welded together. Four screw holes 44 are arranged on the outside of the swirl cup mounting seat along the circumference. A hole 46 is opened on the side of the swirl cup at a position corresponding to the penetration hole of the igniter of the flame tube, through which the igniter 5 is inserted and discharged to ignite the fuel at this position.

The swirl cup assembly 4 is installed in the large hole 26 in the center of the top cover inside the flame tube 2, and a gasket 8 is placed outside the top cover, and the studs 7 pass through the gasket 8, the top cover 24 of the flame tube and the swirl cup assembly in sequence. The screw hole 44 of the cup assembly is used to fix the swirl cup assembly 7 on the flame tube top cover 24 by tightening the stud 7 .

(6) Igniter

The igniter 5 is fixed on the mounting seat 17 of the casing by threads, and passes through the casing 1, the flame tube 2 and the swirl cup 45 in sequence, and the ignition head is exposed inside the swirl cup, and discharges to ignite the fuel after electrification (see Figure 1 ).

Claims (7)

1. A gas turbine lean premixed combustor, its main structure comprising: A casing (1), the casing (1) is fixed with a flame cylinder (2), and an annular two-way air passage is formed between the casing and the flame cylinder. The round holes (11), through which the air from the compressor enters the annular secondary channel, these round holes rectify the air from the compressor, eliminating the circumferential inhomogeneity of the incoming air and the large vortex Disturbance, improving the outlet temperature distribution of the combustion chamber; The side of the casing (1) is provided with an igniter mounting seat (17) for installing the igniter (5); A variable-diameter swirl cup (45) is installed in the flame tube (2), and the inlet diameter of the swirl cup (45) is smaller than the outlet diameter; the nozzle swirler assembly (3) is connected to the the inlet of the swirl cup (45); The center of the nozzle body (34) in the nozzle swirler assembly (3) is the duty fuel introduction pipe (38), the top of the duty fuel introduction pipe (38) is the duty nozzle (33), and the outlet of the duty nozzle (33) The outer side of the end is a chamfered cone surface, and a plurality of circular holes are processed along the circumference of the chamfered cone surface as the duty nozzle fuel injection hole (310); the outer ring of the duty fuel introduction pipe (38) is a premixed fuel introduction pipe (39), One end of the premixed fuel introduction pipe (39) is connected to the swirler assembly (35), and the side of the premixed fuel introduction pipe (39) is provided with a premixed fuel inlet (303); The premixed fuel chamber rear cover (304) of the swirler assembly (35) is connected with the inner side of the blade installation base (305) to form a premixed fuel chamber (307); the outer side of the blade installation base (305) is fixed with a plurality of blades (306), a swirler channel (31) with equal cross-section along the flow direction and an included angle with the radial direction is formed between each blade (306); each blade (306) has a swirler blade blind hole along the axial direction (308), each swirler vane blind hole (308) is aligned with the opening (309) on the vane mounting base (305); each vane (306) two side walls are provided with a plurality of premixed fuel injection holes (32 ), the premixed fuel injection hole (32) on each blade (306) communicates with the swirler blade blind hole (308) of the blade (306); the premixed fuel enters the premixed fuel from the premixed fuel introduction pipe (39) The fuel cavity (307) enters the swirler channel (31) through the swirler vane blind hole (308) on the vane (306) and the premixed fuel injection hole (32) on the vane (306), completing the interaction with the air Blend. 2. The gas turbine lean premixed combustor according to claim 1, wherein the outer side of the blade mounting base (305) is provided with a shallow groove having the same cross-sectional shape as the swirler blade (306), and each blade (306) is embedded Welded in a shallow groove. 3. The gas turbine lean premix combustor according to claim 1, wherein the equal cross-sectional area of the swirler passage (31) depends on the air flow entering the flame tube (2) through the swirler passage (31); The size of the included radial angle of the flow device channel (31) depends on the required swirl strength. 4. The gas turbine lean premix combustor according to claim 1, wherein a flange (12) is provided in the middle of the casing (1), through which the gas turbine body is connected with the gas turbine lean premix combustor together. 5. The gas turbine lean premixed combustor according to claim 1, wherein the total area of the circular holes (11) at the rear of the casing (1) is greater than twice the cross-sectional area (6) of the two passages. 6. The gas turbine lean premixed combustor according to claim 1, wherein the inlet of the swirl cup (45) is a straight pipe section, and transitions to an outlet with a large diameter. 7. The gas turbine lean premixed combustor according to claim 1, wherein the igniter (5) is fixed on the mount (17) of the casing by threads, and passes through the casing (1), the flame tube ( 2) and swirl cup (45), the ignition head of igniter (5) is located at swirl cup inboard, discharges and ignites fuel after electrification.