CN110440292B

CN110440292B - Combustor of combustion chamber of gas turbine

Info

Publication number: CN110440292B
Application number: CN201910683359.6A
Authority: CN
Inventors: 张善军; 马宏宇; 邵志强
Original assignee: AECC Shenyang Engine Research Institute
Current assignee: AECC Shenyang Engine Research Institute
Priority date: 2019-07-26
Filing date: 2019-07-26
Publication date: 2020-12-01
Anticipated expiration: 2039-07-26
Also published as: CN110440292A

Abstract

The application belongs to the technical field of aero-engine design, and relates to a combustor of a combustion chamber of a gas turbine.A fuel conveying pipeline of the combustor comprises an innermost secondary fuel gas pipe, and a secondary sleeve, an inner pipe and an outer pipe which are sequentially sleeved along the radial direction, wherein a main mixing channel is formed between the inner pipe and the outer pipe, and a main swirler is arranged in the main mixing channel; the secondary sleeve is connected with the inner wall of the inner pipe through a Venturi pipe, a secondary mixing channel is formed between the secondary sleeve and the secondary fuel gas pipe, a secondary swirler is arranged in the secondary mixing channel, and a secondary fuel spray rod extends into the secondary mixing channel from the secondary fuel gas pipe; the secondary fuel gas pipe is internally sleeved with an espin fuel gas pipe, and fuel is sprayed into the flame tube of the combustion chamber through an espin fuel nozzle. The two-stage axial swirler, the three-stage fuel nozzle and the Venturi structure are arranged to realize pre-mixing combustion of fuel, the grading effect of the head of the combustion chamber is optimized, low NOx emission is realized, the ignition performance of the combustor is improved, and the complexity of a fuel system is reduced.

Description

Combustor of combustion chamber of gas turbine

Technical Field

The application belongs to the technical field of aero-engine design, and particularly relates to a combustor of a gas turbine combustor.

Background

In accordance with the regulations of the environmental requirements, one of the key requirements for gas turbine combustors at present is that stable and low-emission (mainly for NOx) combustion can be performed over a wide range from a partial load state to a rated load. For the most mature lean premixed low emission combustion technology at present, the existing combustors achieve the requirement of low NOx emission by feeding fuel and air into the combustion zone of the combustor for low temperature combustion after premixing. However, since the combustion temperature is low at the time of partial load, a large amount of unburned hydrocarbon fuel and unburned CO are generated, and there are problems such as combustion shock, difficulty in ignition, and flameout.

The existing combustor has the technical scheme that at least one swirler and at least two paths of fuel are arranged, the fuel and air are premixed and then enter a combustion zone of the combustor to be combusted, only a secondary fuel nozzle is started when the load is lower than a preset load, and a primary fuel nozzle is started when the load is higher than the preset load, namely the fuel is graded.

The prior art mainly has the following defects:

1. difficulty in ignition: the existing low-emission combustor burner has the defects that the proportion of air participating in the ignition process of the combustor is too high, so that the ignition of the combustor is difficult, the ignition boundary is narrow, and even the ignition is unsuccessful.

2. The control system is complex: the existing low-emission combustor has more fuel grades, so that a control system is complicated.

3. The safe operation risk is high: due to the complexity of the control system, safe operation accidents caused by problems of the control system are easy to occur.

Disclosure of Invention

In order to solve one of the above problems, the present application provides a combustor burner of a gas turbine, comprising a fuel pipe disposed at an inlet of a combustor basket, the fuel pipe being coaxial with the combustor, wherein the fuel pipe comprises a secondary fuel pipe coaxial with the fuel pipe, and a secondary sleeve, an inner pipe and an outer pipe radially sleeved outside the secondary fuel pipe in sequence, wherein,

a main mixing channel is formed between the inner pipe and the outer pipe, one end of the main mixing channel is connected with a main fuel spray rod, the other end of the main mixing channel is connected with a combustion chamber flame tube, and a main swirler is arranged in the main mixing channel;

the secondary sleeve comprises a secondary swirler outer sleeve positioned at the front section and a venturi pipe positioned at the rear section along the axial direction, the tail end of the venturi pipe is connected with the tail end of the inner pipe, a secondary mixing channel is formed between the secondary sleeve and the secondary fuel gas pipe, a secondary swirler is arranged between the secondary swirler outer sleeve and the secondary fuel gas pipe in the secondary mixing channel, the front end of the secondary fuel gas pipe is provided with a secondary fuel inlet, the rear end of the secondary fuel gas pipe is closed, and a secondary fuel spray rod extends into the secondary mixing channel along the radial direction at the upstream of the secondary swirler;

the secondary fuel gas pipe is internally sleeved with an on-duty fuel gas pipe, the front end of the on-duty fuel gas pipe is provided with an on-duty fuel inlet, and the rear end of the on-duty fuel gas pipe extends to the closed end of the secondary fuel gas pipe and sprays fuel to the combustion chamber flame tube through an on-duty fuel nozzle arranged on the closed end.

Preferably, the closed rear end of the secondary fuel gas pipe extends axially rearwardly to or beyond the throat of the venturi.

Preferably, the primary cyclone has a lower swirl strength than the secondary cyclone.

Preferably, the angle of the blades of the primary swirler is 0-30 degrees off the axis of the fuel pipe, and the angle of the blades of the secondary swirler is 40-65 degrees off the axis of the fuel pipe.

Preferably, the primary swirler has an effective flow area greater than that of the secondary swirler.

Preferably, the effective flow area of the main-stage cyclone is 3-5 times of that of the secondary-stage cyclone.

Preferably, the included angle between the expansion section of the Venturi tube and the axis of the combustor is 10-30 degrees.

Preferably, the included angle between the speed direction of the fuel sprayed out of the main-stage fuel spray rod and the axis of the burner is 45-90 degrees.

Preferably, the included angle between the speed direction of the fuel sprayed by the secondary fuel spray rod and the axis of the burner is 45-90 degrees.

Preferably, the other end of the primary fuel lance is connected through a cap of the combustion chamber to a primary fuel inlet located outside the combustion chamber.

The grading effect of the combustion chamber head is optimized, the ignition performance of the combustor is improved while low NOx emission is achieved, and the complexity of a fuel system is reduced.

Drawings

FIG. 1 is a schematic cross-sectional view of a gas turbine combustor of the present application.

The system comprises a primary swirler, a secondary swirler, a 3 primary fuel spray rod, a 4 secondary fuel spray rod, a 5-Venturi tube, a 6-duty fuel nozzle, a 7-duty fuel gas tube, an 8-secondary fuel gas tube, a 9-duty fuel inlet, a 10-secondary fuel inlet, an 11-primary fuel inlet, a 12-fuel nozzle plate, a 13-combustion chamber casing, a 14-combustion chamber flame tube and a 15-secondary swirler outer sleeve.

Detailed Description

In order to make the implementation objects, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the accompanying drawings in the embodiments of the present application. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all embodiments of the present application. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present application, and should not be construed as limiting the present application. All other embodiments obtained by a person of ordinary skill in the art without any inventive work based on the embodiments in the present application are within the scope of protection of the present application. Embodiments of the present application will be described in detail below with reference to the drawings.

The application provides a combustor, as shown in fig. 1, which mainly comprises a main-stage swirler 1, an auxiliary-stage swirler 2, an auxiliary-stage swirler jacket 15, a main-stage fuel spray rod 3, an auxiliary-stage fuel spray rod 4, a venturi tube 5, an on-duty fuel nozzle 6, an on-duty fuel gas pipe 7, an auxiliary-stage fuel gas pipe 8, an on-duty fuel inlet 9, an auxiliary-stage fuel inlet 10, a main-stage fuel inlet 11 and a fuel nozzle disc 12. The method specifically comprises the following steps:

the combustor comprises a combustor casing 13 in which a combustor basket 14 is disposed coaxially with the combustor, the combustor casing having a closure at a front end thereof, the closure being configured as a fuel nozzle plate 13, a fuel pipe extending from the fuel nozzle plate 13 to the combustor basket 14 for delivering fuel, air or a mixture thereof to the combustor.

The fuel pipe is coaxial with the combustion chamber, the fuel pipe comprises an innermost secondary fuel pipe 8 arranged at the axis position of the fuel pipe, and a secondary sleeve, an inner pipe and an outer pipe are sequentially sleeved outside the secondary fuel pipe 8 along the radial direction outwards.

A main mixing channel is formed between the inner pipe and the outer pipe, one end of the main mixing channel is connected with a main fuel spray rod 3, the other end of the main mixing channel is connected with a combustion chamber flame tube 14, and a main swirler 1 is arranged in the main mixing channel.

The secondary sleeve comprises a secondary swirler outer sleeve 15 positioned at the front section and a venturi tube 5 positioned at the rear section along the axial direction, the tail end of the venturi tube 5 is connected with the tail end of the inner tube, a secondary mixing channel is formed between the secondary sleeve and the secondary fuel gas tube 8, a secondary swirler 2 is arranged between the secondary swirler outer sleeve 15 and the secondary fuel gas tube 8 in the secondary mixing channel, a secondary fuel inlet 10 is arranged at the front end of the secondary fuel gas tube 8, the rear end of the secondary fuel gas tube is closed, and a secondary fuel spray rod 4 extends into the secondary mixing channel along the radial direction at the upstream of the secondary swirler 2 by the secondary fuel gas tube 8;

the auxiliary fuel gas pipe 8 is internally sleeved with an on-duty fuel gas pipe 7, the front end of the on-duty fuel gas pipe 7 is provided with an on-duty fuel inlet 9, the rear end of the on-duty fuel gas pipe extends to the closed end of the auxiliary fuel gas pipe 8, and fuel is sprayed to the combustion chamber flame tube 14 through an on-duty fuel nozzle 6 arranged on the closed end.

In the present application, the front end and the rear end, or the upstream and the downstream, refer to that the upstream corresponds to the front end and the downstream corresponds to the rear end with respect to the flow direction of the fuel or the air.

In the application, the secondary swirler 2 is fixed on the secondary fuel gas pipe 8; the secondary fuel spray rod 4 is arranged at the upstream of the secondary swirler 2 and is communicated with a secondary fuel gas pipe 8; the on-duty fuel gas pipe 7 and the secondary fuel gas pipe 8 are coaxially arranged, one end of the on-duty fuel gas pipe and one end of the secondary fuel gas pipe are connected with the on-duty fuel nozzle 6, and the other end of the on-duty fuel gas pipe and the one end of the secondary fuel gas pipe are connected with the on-duty fuel inlet 9; the secondary fuel inlet 10 is arranged on the secondary fuel gas pipe 8 and communicated with the secondary fuel gas pipe; the main-stage fuel inlet 11 is fixed on the fuel nozzle disc 12 and is communicated with the main-stage fuel spray rod 3 through the fuel nozzle disc 12; the fuel nozzle plate 12 is fixed on the combustion chamber casing 13; the parts are fixedly connected by welding or bolts. In addition, the main mixing channel with the main swirler 1 is connected to the combustor basket 14 by plugging, i.e. in fig. 1 the tube overlaps the inlet of the basket.

The utility model provides a combustor has set up two-stage axial swirler, tertiary fuel nozzle/spray lance and venturi structure and has realized the premixed combustion of fuel, reduces combustion temperature and realizes low NOx burning to "conceal the backward flow district" and the promotion of ignition performance is stabilized in setting up of fuel nozzle on duty through the venturi structure formation. Wherein: the swirl strength of the main-stage swirler 1 is lower than that of the secondary-stage swirler 2, the blade angle of the main-stage swirler 1 is 0-30 degrees, the blade angle of the secondary-stage swirler 2 is 40-65 degrees, the effective flow area of the main-stage swirler 1 is larger than that of the secondary-stage swirler 2, the effective flow area of the main-stage swirler 1 is 3-5 times of that of the secondary-stage swirler 2, the structure of the Venturi tube 5 comprises a contraction section, a throat and an expansion section, wherein the throat is a region with the smallest cross-sectional area, the axial position of the cross-sectional area of the throat is flush with the axial position of the on-duty fuel nozzle 6, or the axial position of the on-duty fuel nozzle 6 is positioned at the downstream of the section of the throat of the dune 5, the included angle between the expansion section of the Venturi 5 and the axis of the combustor is 10-30 degrees, the main-stage fuel spray lance 3 is positioned at the upstream of the main-stage swirler 1 and is used for realizing the pre-mixing, the secondary fuel spray rod 4 is located on the upstream of the secondary swirler 2 and used for pre-mixing secondary fuel and air flowing through the secondary swirler 2, the included angle between the speed direction of the fuel sprayed by the primary fuel spray rod 3 and the secondary fuel spray rod 4 and the axis of the combustor is 45-90 degrees, the duty fuel nozzle 6 is located on the downstream of the secondary swirler 2, and the included angle between the fuel spraying speed direction of the duty fuel nozzle 6 and the axis of the combustor is 0-45 degrees. The burner is supplied with fuel from the starting to a certain intermediate load only by the secondary fuel spray rod 4 and the duty fuel nozzle 6, and is supplied with fuel from the secondary fuel spray rod 4, the duty fuel nozzle 6 and the main fuel spray rod 3 from a certain intermediate load to the maximum load, so that the fuel switching process is simple, the control system is simple, and the operation safety is high.

This application is through the setting of "hiding the backward flow district" and the fuel nozzle on duty that design venturi structure formed, when realizing low NOx and stable combustion, the ignition performance of combustor is better. On the other hand, the fuel control system is simpler, the fuel switching process is simple, the equipment cost and the operation cost are lower, and the operation safety of the combustor is higher.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A combustor burner of a gas turbine, comprising a fuel pipe disposed at an inlet of a combustor basket (14), the fuel pipe being coaxial with the combustor, characterized in that the fuel pipe comprises a secondary fuel pipe (8) coaxial with the fuel pipe, and a secondary sleeve, an inner pipe and an outer pipe sequentially sleeved outward in a radial direction from the secondary fuel pipe (8), wherein,

a main mixing channel is formed between the inner pipe and the outer pipe, one end of the main mixing channel is connected with a main fuel spray rod (3), the other end of the main mixing channel is connected with a combustion chamber flame tube (14), and a main swirler (1) is arranged in the main mixing channel;

a secondary mixing channel is formed between the secondary sleeve and the secondary fuel gas pipe (8), the secondary sleeve comprises a secondary swirler outer sleeve (15) located at the front section in the axial direction and a venturi tube (5) located at the rear section, a gap is formed between the swirler outer sleeve (15) and the inner pipe, the rear end of the swirler outer sleeve is fixed at the tail end of the inner pipe through the venturi tube (5), a secondary swirler (2) is arranged between the secondary swirler outer sleeve (15) and the secondary fuel gas pipe (8) in the secondary mixing channel, a secondary fuel inlet (10) is arranged at the front end of the secondary fuel gas pipe (8), the rear end of the secondary fuel gas pipe is closed, and a secondary fuel spray rod (4) extends into the secondary mixing channel along the radial direction at the upstream of the secondary swirler (2) of the secondary fuel gas pipe (8);

the auxiliary fuel gas pipe (8) is internally sleeved with an on-duty fuel gas pipe (7), the front end of the on-duty fuel gas pipe (7) is provided with an on-duty fuel inlet (9), the rear end of the on-duty fuel gas pipe extends to the closed end of the auxiliary fuel gas pipe (8), and fuel is sprayed to a combustion chamber flame tube (14) through an on-duty fuel nozzle (6) arranged on the closed end.

2. A gas turbine combustor burner as claimed in claim 1, wherein the closed aft end of the secondary fuel gas tube (8) extends axially aft to or beyond the throat of the venturi tube (5).

3. A gas turbine combustor burner as in claim 1, wherein the primary swirler (1) has a lower swirl strength than the secondary swirler (2).

4. A gas turbine combustor burner as in claim 3, wherein the primary swirler (1) has a vane angle that is 0 to 30 degrees off the fuel tube axis and the secondary swirler (2) has a vane angle that is 40 to 65 degrees off the fuel tube axis.

5. A gas turbine combustor burner as in claim 1, wherein the effective flow area of the primary swirler (1) is larger than the effective flow area of the secondary swirler (2).

6. A gas turbine combustor burner as in claim 5, wherein the effective flow area of the primary swirler (1) is 3-5 times the effective flow area of the secondary swirler (2).

7. A gas turbine combustor burner as in claim 1, wherein the divergent section of the venturi tube (5) is at an angle of 10-30 degrees to the burner axis.

8. The gas turbine combustor burner of claim 1, wherein the velocity direction of the fuel sprayed from the main fuel spray lance (3) forms an angle of 45 to 90 degrees with the axis of the burner.

9. The gas turbine combustor burner of claim 1, wherein the speed direction of the fuel sprayed from the secondary fuel spray lance (4) forms an angle of 45 to 90 degrees with the axis of the burner.

10. A gas turbine combustor burner as claimed in claim 1, characterised in that the other end of the primary fuel lance (3) is connected through the combustor cap to a primary fuel inlet (11) located outside the combustor.