WO2023030467A1

WO2023030467A1 - Combustion chamber having double fuel pipes and gas turbine

Info

Publication number: WO2023030467A1
Application number: PCT/CN2022/116638
Authority: WO
Inventors: 靳普; 刘慕华
Original assignee: 永旭腾风新能源动力科技（北京）有限公司
Priority date: 2021-09-03
Filing date: 2022-09-01
Publication date: 2023-03-09
Also published as: CN113701195A

Abstract

Disclosed in the present invention are a combustion chamber having double fuel pipes and a gas turbine. The combustion chamber comprises a flame tube, an igniter, a first swirler, a second swirler, a first fuel pipe, a second fuel pipe, and a housing; an inner cavity of the flame tube is sequentially divided into a primary combustion area, a secondary combustion area, and a mixing area from front to back; a plurality of mixing holes are formed in the side wall of the mixing area; the second swirler is provided at the front end of the flame tube and is coaxial with the flame tube; the first swirler is provided on a portion, close to an outlet end, in an inner hole of the second swirler and is coaxial with the second swirler; a gap is reserved between the outer side wall of the first swirler and the inner hole of the second swirler; the first fuel pipe penetrates through the front wall of the flame tube and is communicated with the first swirler; the second fuel pipe penetrates through the front wall of the flame tube and is communicated with the second swirler; the igniter extends into the primary combustion area from the side wall of the flame tube; the housing covers the flame tube; and an air channel is provided between the flame tube and the housing. According to the present invention, the double fuel pipes and the double swirlers are used, such that the fuel gas is fully mixed, and the fuel is fully and continuously combusted, thereby reducing the emission.

Description

Dual fuel tube combustor and gas turbine

technical field

The invention relates to a dual-fuel tube combustion chamber and a gas turbine, belonging to the technical field of gas turbines.

Background technique

As the main device that consumes natural gas energy, gas turbine is an indispensable power source in industrial production. As the level of gas turbines is getting higher and higher, gas turbines are constantly developing towards high efficiency and wide load adjustment range. The method to improve the cycle efficiency is mainly by increasing the combustion temperature and pressure. The diffusion combustor burning medium and low calorific value fuels is likely to cause the emission of nitrogen oxides to exceed the standard. Important performance goals for combustors.

Contents of the invention

Aiming at the above prior art, the present invention provides a combustor with dual fuel pipes and a gas turbine, which can fully burn fuel and reduce emissions.

The present invention is achieved through the following technical solutions:

A double-fuel tube combustor, including a flame tube, an igniter, a first swirler, a second swirler, a first fuel tube, a second fuel tube and a casing, and the inner cavity of the flame tube is from front to back (press in and out The flow direction of the gas is the front and rear directions, the air intake side is the front, and the air outlet side is the rear) is divided into the main combustion area, the secondary combustion area and the mixing area in turn, and a number of mixing holes are set on the side wall of the mixing area;

The second swirler is arranged at the front end of the flame tube and coaxial with it; the first swirler is arranged in the inner hole of the second swirler close to the outlet end and coaxial with it; the outer side of the first swirler There is a gap between the wall and the inner hole of the second cyclone;

The first fuel pipe passes through the front wall of the flame tube and leads into the first swirler, and the second fuel pipe passes through the front wall of the flame tube and leads into the second swirler;

The igniter extends into the main combustion zone from the side wall of the flame tube;

The housing cover is arranged outside the flame tube, and an air channel is provided between the flame tube and the shell, the air intake direction of the air channel is from the end of the flame tube to the front end, and the air outlet of the air channel communicates with the inlet of the second cyclone .

Further, a number of air holes are provided on the side walls of the main combustion zone and the secondary combustion area. The function of the air holes is to allow cold air to diffuse from the air holes to the inner wall of the flame cylinder and form an air film along the inner wall to cool the wall surface.

Further, at least one circle of air holes is arranged around the side walls of the main combustion zone and the secondary combustion zone.

Further, the air hole can be arranged obliquely, and its air intake direction is from the front end to the end of the combustion chamber, and the air intake direction is consistent with the flow direction of the combustion mixture gas, so as to avoid air flow blockage.

Further, the included angle between the air hole and the axis of the flame tube is 10°-80°.

Further, the air holes may be oblique cylindrical holes, stepped holes or convergent holes.

Further, at least one ring of mixing holes is arranged around the side wall of the mixing zone.

Further, the first fuel pipe can be threadedly connected with the flame cylinder, and its extending distance can be adjusted to prevent it from being burned.

Further, the igniter can be threadedly connected with the flame cylinder, and its extending distance can be adjusted to prevent it from being burnt out.

A gas turbine comprises the above-mentioned double-fuel pipe combustor, a rotating shaft, and a compressor, a turbine and a generator arranged on the rotating shaft.

The working process of the multi-fuel tube combustor is as follows: air enters from the air channel and enters the flame cylinder in the following ways, specifically:

① A part of the air enters the mixing area through the mixing hole;

② A part of the air enters the secondary combustion zone and the main combustion zone along the inner wall of the flame tube through the pores, forming a layer of air film attached to the wall, which plays the role of film cooling and cools the wall of the flame tube;

③ A part enters the second cyclone through the inlet of the second cyclone, and flows out from the swirl blades of the second cyclone;

④ A part flows in through the inlet of the inner hole of the second cyclone, and then flows out through the first cyclone and the gap.

Fuel enters from the first fuel pipe and sprays out from its nozzle, and forms a small swirl with the air flowing out of the first swirler at the outlet end of the first swirler; fuel enters the cavity of the second swirler from the second fuel pipe And it is discharged from the swirl vanes, and forms a large swirl flow at the outlet of the second swirler with the air flowing out of the second swirler.

Fuel and air form a swirling flow that can be further mixed fully, ignited by the igniter, and discharged from the tail end of the combustion chamber after being burned in the main combustion zone and the secondary combustion zone, and then passed into the turbine through the volute; the air entering the mixing hole can make the incomplete The burning fuel burns completely. The first fuel pipe ejects fuel with a relatively large equivalent, forming a continuous and stable flame core in the center of the flame tube, and the second fuel pipe feeds a large amount of fuel, which forms a strong mixed combustion flame with a large amount of air. When the carbon generated by the large swirl When too many nitrogen compounds cause the flame to go out, the persistent core will continue to ignite the burning flame.

Further, the fuel flow ratio between the first fuel pipe and the second fuel pipe is 1:3-9.

Further, the air flow of the air hole accounts for 5%-15% of the overall flow of the combustion chamber, the air flow of the mixing hole accounts for 39%-48% of the overall flow of the combustion chamber, and the air flow of the first fuel pipe Accounting for 2%-8% of the overall flow of the combustion chamber, the air flow of the second fuel pipe accounts for 35%-50% of the overall flow of the combustion chamber.

The double fuel pipe combustion chamber of the present invention adopts double fuel pipes and double swirlers, so that the fuel gas can be fully mixed, and the fuel can be fully and continuously burned, thereby reducing emissions. In the invention, air holes are arranged on the side wall of the flame tube, which can cool and protect the wall surface of the flame tube from being damaged by high-temperature air flow. The screw-in distance of the nozzle of the first fuel pipe and the igniter of the present invention can be adjusted through threaded connection to prevent from being burnt out.

Various terms and phrases used herein have their ordinary meanings known to those skilled in the art. If the mentioned terms and phrases are inconsistent with the known meanings, the meanings expressed in the present invention shall prevail.

Description of drawings

Figure 1: Schematic diagram of the structure of the dual-fuel tube combustor of the present invention.

Among them, 1. flame cylinder; 101. mixing hole; 102. air hole; 2. igniter; 3. second swirler; 4. first swirler; 5. first fuel pipe; 6. second fuel Tube; 7, shell; 701, air channel; S1: gap; A: air; B: fuel; C: hot air; D: small swirl; E: large swirl; the direction of the arrow indicates the airflow direction.

Detailed ways

The present invention will be further described below in conjunction with embodiment. However, the scope of the present invention is not limited to the following examples. Those skilled in the art can understand that various changes and modifications can be made to the present invention without departing from the spirit and scope of the present invention.

Example 1

A dual-fuel tube combustor, including a flame cylinder 1, an igniter 2, a first swirler 4, a second swirler 3, a first fuel tube 5, a second fuel tube 6 and a housing 7, as shown in Figure 1 As shown, the inner cavity of the flame cylinder 1 is divided into the main combustion zone, the secondary combustion zone and the mixing zone successively from the front to the back (according to the flow direction of the inlet and outlet gas as the front and rear directions, the inlet side is the front, and the gas outlet side is the rear). A circle of mixing holes 101 is set around the side wall, and a circle of air holes 102 is set around the side walls of the main combustion zone and the secondary combustion zone;

The second swirler 3 is arranged on the front end of the flame cylinder 1 and is coaxial with it; the first swirler 4 is arranged in the inner hole of the second swirler 3 near the outlet end and is coaxial with it; There is a gap S1 between the outer wall of the cyclone 4 and the inner hole of the second cyclone 3;

The first fuel pipe 5 passes through the front wall of the flame cylinder 1 and passes into the first swirler 4, and the second fuel pipe 6 passes through the front wall of the flame cylinder 1 and passes into the second swirler 3;

The igniter 2 extends into the main combustion zone from the side wall of the flame tube 1;

The housing 7 is covered outside the flame tube 1, and an air passage 701 is arranged between the flame tube 1 and the housing 7. The air intake direction of the air passage 701 is from the end of the flame tube 1 to the front end, and the air outlet of the air passage 701 is connected to the front end of the flame tube 1. The inlet of the second cyclone 3 is connected.

The air holes 102 can be arranged obliquely. The function of the air hole 102 is: when the cold air enters, it is diffused from the air hole 102 to the inner wall of the flame tube 1 and forms an air film along the inner wall to cool the wall surface; Consistent flow direction to avoid airflow blockage.

The included angle between the air hole 102 and the axis of the flame cylinder 1 is 10°-80°, such as 10°, 20°, 30°, 40°, 45°, 50°, 60°, 70°, 80°.

The air holes 102 may be oblique cylindrical holes, stepped holes or convergent holes.

The first fuel pipe 5 can be threadedly connected with the flame tube 1 . The effect of this arrangement is: because the position of the nozzle of the first fuel pipe 5 is close to the flame zone, so it can be regulated by threaded connection and stretches into the distance, to prevent from being burnt out.

The igniter 2 can be threadedly connected with the flame tube 1 . The effect of this setting is: because the position of igniter 2 is close to the high temperature area, so can adjust its stretching distance by threaded connection, to prevent from being burnt out.

The outlet at the end of the combustion chamber is connected to the inlet of the turbine (not shown) through a volute (not shown).

The working process of the multi-fuel tube combustor is as follows: air enters through the air channel 701 and enters the flame tube 1 in the following manner, specifically:

① A part of the air enters the mixing zone through the mixing hole 101;

② A part of the air enters the secondary combustion zone and the main combustion zone along the inner wall of the flame tube 1 through the air hole 102, forming a layer of air film attached to the wall, which plays the role of air film cooling and cools the wall surface of the flame tube 1;

③ A part enters the second cyclone 3 through the inlet of the second cyclone 3, and flows out from the swirl blades of the second cyclone 3;

④ A part flows in through the inlet of the inner hole of the second cyclone 3, and then flows out through the first cyclone 4 and the gap S1.

Fuel B enters from the first fuel pipe 5 and sprays out from its nozzle, and forms a small swirl D at the outlet end of the first swirler 4 with the air A flowing out of the first swirler 4; fuel B flows from the second fuel pipe 6 Enter the cavity of the second swirler 3 and discharge from the swirl blades, and form a large swirl E at the outlet of the second swirler 3 with the air A flowing out of the second swirler 3 .

Fuel B and air A form a swirling flow that can be further mixed fully, ignited by the igniter 2, and hot air C is discharged from the tail end of the combustion chamber after being burned in the main combustion zone and the secondary combustion zone, and enters the turbine through the volute; the mixing hole 101 The incoming air A can fully burn the incompletely burned fuel B. The first fuel pipe 5 ejects fuel B with a relatively large equivalent, forming a continuous and stable flame core in the center of the flame tube 1, and the second fuel pipe 6 leads a large amount of fuel B to form a strong mixed combustion flame with a large amount of air A. When too much carbon and nitrogen produced by the large swirl E causes the flame to go out, the continuous flame core will continue to ignite the combustion flame.

In specific applications, the fuel flow ratio between the first fuel pipe 5 and the second fuel pipe 6 can be controlled to be 1:3-9, such as 1:3, 1:4, 1:5, 1:6, 1:7,1 :8,1:9.

In specific applications, the air flow of the stomata can be controlled to account for 5% to 15% of the overall flow of the combustion chamber, the air flow of the mixing hole can be controlled to account for 39% to 48% of the overall flow of the combustion chamber, and the air flow of the first fuel pipe 5 can be controlled. Accounting for 2%-8% of the overall flow of the combustion chamber, the air flow of the second fuel pipe 6 is controlled to account for 35%-50% of the overall flow of the combustion chamber.

More specifically, the air flow of the control air hole accounts for 7% of the overall flow of the combustion chamber, the air flow of the control mixing hole accounts for 43% of the overall flow of the combustion chamber, and the air flow of the first fuel pipe 5 accounts for 5% of the overall flow of the combustion chamber. %, the air flow of the second fuel pipe 6 is controlled to account for 45% of the overall flow of the combustion chamber.

Example 2

A gas turbine comprises a double-fuel tube combustor with the structure shown in Embodiment 1, a rotating shaft, and a compressor, a turbine and a generator arranged on the rotating shaft.

Although the specific implementation of the present invention has been described above in conjunction with the examples, it is not intended to limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims

A dual-fuel tube combustion chamber is characterized in that it includes a flame tube, an igniter, a first swirler, a second swirler, a first fuel tube, a second fuel tube and a casing, and the inner cavity of the flame tube is from the front to the After that, it is divided into main combustion zone, secondary combustion zone and mixing zone in turn, and several mixing holes are set on the side wall of the mixing zone;

The second swirler is arranged at the front end of the flame tube and coaxial with it; the first swirler is arranged in the inner hole of the second swirler close to the outlet end and coaxial with it; the outer side of the first swirler There is a gap between the wall and the inner hole of the second cyclone;

The first fuel pipe passes through the front wall of the flame tube and leads into the first swirler, and the second fuel pipe passes through the front wall of the flame tube and leads into the second swirler;

The igniter extends into the main combustion zone from the side wall of the flame tube;

The housing cover is arranged outside the flame tube, and an air channel is provided between the flame tube and the shell, the air intake direction of the air channel is from the end of the flame tube to the front end, and the air outlet of the air channel communicates with the inlet of the second cyclone .
The dual-fuel tube combustion chamber according to claim 1, characterized in that: the side walls of the main combustion zone and the secondary combustion zone are provided with several air holes.
The dual fuel pipe combustion chamber according to claim 2, characterized in that: the air holes are arranged obliquely, and the air intake direction is from the front end to the end of the combustion chamber.
The dual-fuel tube combustion chamber according to claim 2 or 3, characterized in that: the angle between the air hole and the axis of the flame tube is 10°-80°;

And/or: the pores are oblique cylindrical pores, stepped pores or convergent pores.
The dual-fuel tube combustion chamber according to claim 1 or 2, characterized in that: at least one circle of air holes is arranged around the side walls of the main combustion zone and the secondary combustion zone;

And/or: at least one ring of mixing holes is arranged around the side wall of the mixing zone.
The dual-fuel tube combustor according to claim 1, wherein the first fuel tube is threadedly connected to the flame tube.
The dual-fuel tube combustion chamber according to claim 1, wherein the igniter is threadedly connected to the flame tube.
The dual-fuel-pipe combustor according to claim 1, characterized in that: the fuel flow ratio of the first fuel pipe and the second fuel pipe is 1:3-9.
The dual-fuel tube combustion chamber according to claim 2, characterized in that: the air flow of the air hole accounts for 5% to 15% of the overall flow of the combustion chamber, and the air flow of the mixing hole accounts for 39% of the overall flow of the combustion chamber % to 48%, the air flow of the first fuel pipe accounts for 2% to 8% of the overall flow of the combustion chamber, and the air flow of the second fuel pipe accounts for 35% to 50% of the overall flow of the combustion chamber.
A gas turbine comprising the dual-fuel tube combustor according to any one of claims 1-9.