JPH08261414A - Fuel injector - Google Patents

Abstract

PURPOSE: To obtain fuel injector which can facilitate efficient atomization of fuel and vaporization thereof and can mix the fuel with air more uniformly. CONSTITUTION: A fuel jetting part 4 is provided inside a tubular nozzle body 2 of which one end side is made an inlet part 3 for introducing air. The other end side of the nozzle body 2 is made an outlet part 5 for injecting a mixture of fuel (b) and air (a). The fuel jetting part 4 has a fuel jetting port 7 provided in the nozzle body and jetting the fuel toward the outlet part side and a slope 9 guiding the fuel jetted from the fuel jetting port in the direction intersecting the axis of the nozzle body. A flat plane part 10 for forming a thin film which extends to the outlet part 5 side of the nozzle body and is parallel to the axis of the nozzle body continues to the top part of the slope 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device in a combustor of a gas turbine engine or an industrial gas turbine.

[0002]

2. Description of the Related Art For example, a plurality of gas turbine combustors are incorporated in a gas turbine or a combined cycle power plant, and a fuel injection device is provided in the gas turbine combustor. The fuel injected from this fuel injection device burns in the combustor, and the combustion gas is guided to the gas turbine to drive the gas turbine.

In this type of gas turbine plant, since the turbine thermal efficiency is improved by increasing the turbine inlet temperature, the turbine inlet temperature, that is, the outlet temperature of the gas turbine combustor is increased.

In a gas turbine combustor, NOx is used.
The main cause of this is the local combustion gas, which is caused by the fact that the fuel injected from the fuel injection device in the gas turbine combustor is sprayed into the combustion chamber with a large particle size as in diffusion combustion. There is a typical increase in temperature. NO
The x generation amount depends on the combustion gas temperature in the combustion region of the gas turbine combustor, and the larger the amount of fuel, the larger the amount of x generated.

As a means for suppressing the generation of NOx in a gas turbine combustor to a low level, a lean premixed combustion system in which fuel and air are mixed in advance in a lean fuel state and burned is known. This premixed combustion type gas turbine combustor reduces predominant mixing of main fuel as well as partial premixing of pilot fuel to reduce diffusion combustion with a large amount of NOx generation and to achieve low NOx. .

In recent gas turbine plants,
In order to further improve the efficiency of the gas turbine, it is sought to raise the combustion gas temperature in the gas turbine combustor.
With the increase in the combustion gas temperature, the demand for low NOx is further increasing. In order to achieve the target value for reducing NOx, diffusion combustion that produces a large amount of NOx is reduced, and the rest is premixed lean combustion that produces almost no NOx, thus promoting sufficient atomization and evaporation of fuel. Development of a fuel injection device is required.

[0007]

In the conventional fuel injection device, the fuel injection device has a design structure in which a relatively large amount of air is allowed to flow in order to sufficiently atomize the fuel and further dilute the fuel. There is a problem in that it becomes large in size and it is difficult to efficiently atomize the fuel and promote evaporation.

The present invention has been made in consideration of the above circumstances, and can efficiently promote atomization of the fuel, promote evaporation of the fuel, and make the fuel and the air more uniform. It is an object of the present invention to provide a fuel injection device that can be mixed, effectively promote the reduction of NOx, and ensure stable combustion.

[0009]

In order to achieve the above-mentioned object, the invention according to claim 1 is to inject a fuel into a cylindrical nozzle body having one end as an inlet for introducing air. And a fuel injection device in which the other end side of the nozzle body is an outlet portion for injecting a mixed fuel of fuel and air, wherein the fuel ejection portion is provided in the nozzle body and A fuel spout that spouts toward the outlet side,
And a slope for guiding the fuel injected from the fuel injection port in a direction intersecting with the axis of the nozzle body, and the top of the slope extends over the outlet side of the nozzle body, It is characterized in that a flat thin film forming plane portion parallel to the axis of the nozzle body is continuous.

According to a second aspect of the present invention, in the fuel injection device according to the first aspect, guide walls are provided on both sides of the slope, the guide walls being rising walls that gradually become wider toward the top of the slope. Characterize.

According to a third aspect of the present invention, in the fuel injection device according to the first aspect, a groove is provided between the fuel injection port and the slope to form a constant space.

According to a fourth aspect of the invention, in the fuel injection device according to the first aspect, the slope is 5 with respect to the axis of the nozzle body.
It is characterized by intersecting at an angle of more than a degree.

According to a fifth aspect of the present invention, in the fuel injection device according to the first aspect, a second step slope having a smaller angle of intersection with the nozzle body axis than the middle of the slope is provided. To do.

According to a sixth aspect of the present invention, in the fuel injection device according to the first to fifth aspects, the inner surface of the peripheral wall of the nozzle body is a flat surface, or a flat plate is inserted in the nozzle body along the axial direction. A flat surface or the surface of a flat plate is used as a flat portion for forming a fuel thin film, and a fuel jet port, a groove, a slope and a guide wall are provided on the peripheral wall or the flat plate of the nozzle body that constitutes the flat surface. To do.

According to a seventh aspect of the present invention, in the fuel injection device according to the sixth aspect, the fuel injection port, the groove, the slope or the guide wall is provided on the peripheral wall or the flat plate of the nozzle body forming the same flat portion for thin film formation. Or a plurality of flat plates are arranged in parallel along the radial direction of the nozzle body, and each of them is provided with a fuel injection port, a groove, a slope or a guide groove.

According to an eighth aspect of the present invention, in the fuel injection device according to the first to seventh aspects, the cross-sectional shape of the end portion of the flat plate on the inlet side is arcuate, or the thickness of the flat plate is on the outlet side. Toward the outlet of the flat plate so that the velocity of the mixed fuel is constant at all positions of the flat surface for thin film formation by making the thickness of the tip of the outlet as small as possible. It is characterized in that a protrusion whose cross-section changes along is provided.

[0017]

According to the fuel injection device of the present invention, the fuel is ejected from the fuel ejection port toward the slope, so that the fuel collides and is dispersed on the slope.

Further, the fuel is atomized by the shearing action with the air at the position where the slope contacts the flat surface. in this case,
When the angle of intersection of the slope with the axis of the nozzle body is 5 degrees or more, the shearing action is more effectively performed.

When the second slope is provided, the flow to the flat surface becomes smooth.

Next, the evaporation effect is promoted by forming a thin film on the flat surface portion.

Furthermore, when the guide wall is provided, a uniform thin film is formed downstream even on the slope. Furthermore, at the outlet, further atomization is achieved by the shearing action with air.

Further, when the groove is provided, the collision force of the fuel ejected from the fuel ejection port on the slope is increased, and the dispersion action is further promoted.

Furthermore, by providing a plurality of fuel injection ports, grooves, slopes, etc. in each direction in the nozzle body, and by rounding the thickness of the flat plate and the shape of the end portion, each of the above operations can be performed more effectively. be able to.

As described above, by combining a plurality of actions, it is possible to improve atomization of fuel more than a single action, more uniform mixing is obtained, and as a result, low NOx is obtained. Can be realized.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 (FIGS. 1 and 2) FIG. 1 is an axial sectional view from one side of a fuel injection device according to this embodiment, and FIG. 2 is an orthogonal sectional view of FIG. 1 (AA in FIG. 1). It is a line sectional view).

The fuel injection device 1 of this embodiment has an inlet portion 3 for introducing air a at one end of a cylindrical nozzle body 2. The nozzle body 2 has a spout 4 for the fuel b. On the other end side of the nozzle body 2, there is an outlet portion 5 for injecting a mixed fuel c of fuel b and air a.

The jet portion 4 of the fuel b is provided with a fuel passage portion 6 provided in the nozzle body 2 from a fuel supply source (not shown) for guiding the fuel b, and an outlet portion 5 along a direction parallel to the axis of the nozzle body 2.
The fuel jet port 7 for jetting the fuel b toward the side, and the fuel jetted from the fuel jet port 7 through the groove 8 at a constant interval and jetted at a predetermined angle with respect to the axial center of the nozzle body 2. and a slope 9 that guides in a direction intersecting at θ.

The top portion 9 of the slope 9 of the jet portion 4 of this fuel b
A flat thin film forming flat surface portion 10 parallel to the axis of the nozzle body 2 is provided from a to the outlet portion 5 side of the nozzle body 2.

On both sides of the sloped surface 9, guide walls 11 are provided which are rising walls which gradually widen toward the top side.

The intersection angle θ of the slope 9 with respect to the axis of the nozzle body 2 is set to an angle of 5 degrees or more.

In the present embodiment, the peripheral wall 2a of the nozzle body 2 is formed in a flat plate shape, and the flat surface of the inner surface thereof is the thin film forming flat surface portion 10. A fuel passage portion 6, a fuel injection port 7, a groove 8, a slope 9 and a guide wall 11 are provided inside the peripheral wall 2a.

In this embodiment having such a structure, the injected fuel is atomized by the airflow flowing from the inlet portion 3 of the nozzle body 2 and flowing in the internal space 12. That is, the fuel is guided from the external fuel supply device through the supply port 13 at the end of the fuel passage portion 6, and the fuel is further ejected from the fuel ejection port 6.

The fuel jetted from the fuel jet port 6 collides with the slope 9 having an angle of 5 degrees or more from the downstream groove 8.
The fuel b collides with and is dispersed on the slope 9. next,
The fuel b is air a at the position where the slope 9 and the flat surface 10 are in contact with each other.
Is subjected to a shearing action to be atomized.

Further, the rear flat surface portion 10 in contact with the slope 9 is provided.
In, the evaporation effect is promoted by forming a thin film. Further, at the outlet portion 5, the fuel b is the air a.
Further atomization is achieved by the shearing action of and.

Therefore, according to this embodiment, dispersion, shearing,
The effective combination of multiple actions of evaporation and thinning greatly promotes atomization of the fuel b, uniformizes the mixing with the air a, and achieves low NOx by good combustion without local combustion. The efficiency can be improved.

Embodiment 2 (FIG. 3) FIG. 3 shows another embodiment of the present invention.

In this embodiment, the jet portion 4 of the fuel b is provided on the flat plate 14 inserted in the central portion of the nozzle body 2 in parallel with the axis thereof.

An air passage 15 is provided on the back side of the fuel injection port 6, and an end portion 14a on the air flow inlet 3 side is an air a.
Has a circular arc-shaped cross-section so that it can easily flow.

A second step slope (α angle) 9b having a smaller crossing angle is formed in the middle of the slope (θ angle) 9.

According to the structure of the second embodiment, the flow of the fuel b becomes smooth due to the second slope 9b having the angle α. Further, the formation of the air passage 15 makes it possible to promote the lean dilution of the fuel. Further, by rounding the end surface of the flat plate 4 on the air inlet side, the flow of the air a is performed more smoothly.

Embodiment 3 (FIG. 4) FIG. 4 shows Embodiment 3 of the present invention.

In this embodiment, a plurality of ejection ports 7, which are the ejection portions 4 for the fuel b, grooves 8, slopes 9 and guide walls 11 are provided in the width direction of the same flat plate 14. The jet parts 4 have the same configuration.

According to the third embodiment having such a configuration, the air a flowing in the space 12 in the nozzle body 2 and the fuel b are mixed at a larger number of points, so that the homogenization is further promoted. .

Embodiment 4 (FIG. 5) FIG. 5 shows Embodiment 4 of the present invention.

In this embodiment, a plurality of flat plates 14 each having a jetting portion 4 for the fuel b are provided in the nozzle body 2 in a multistage combination. Each component is substantially the same as that in the first embodiment.

According to the fourth embodiment having such a configuration, a large amount of fuel can be mixed, and therefore it is suitable for a large-sized gas turbine combustor.

Embodiment 5 (FIG. 6) FIG. 6 shows Embodiment 5 of the present invention.

In this embodiment, the flat plate 14 is substantially the same as the fourth embodiment.
A plurality of plates are provided, but the plate thickness of the flat plate 14 at the outlet portion 5 is gradually reduced to minimize the thickness of the tip of the outlet portion 5.

According to the fifth embodiment having such a structure, the cross section of the flow path is expanded on the downstream side due to the change in the plate thickness of the flat plate 14 and the minimized thickness of the outlet side end 14b, and the evaporation and outlet side end It is possible to promote atomization in some parts.

Embodiment 6 (FIG. 7) FIG. 7 shows Embodiment 6 of the present invention.

This embodiment has substantially the same structure as that of the fourth embodiment, but in the space between the flat plates 14 on the outlet 5 side,
Protrusions 17 whose longitudinal cross section is changed are provided so that the mixed fuel has a constant velocity on any surface.

According to the structure of the sixth embodiment having such a structure, atomization of the fuel b at the outlet side end can be promoted.

Embodiment 7 (FIG. 8) FIG. 8 shows Embodiment 7 of the present invention.

In this embodiment, no groove is provided in the jet portion 4 for the fuel b, and the slope 9 is formed directly from the jet port 7.

The present invention can be applied not only to the fuel injection device in the pilot premix combustion section, but also to the fuel injection apparatus in the diffusion combustion section.

[0057]

As described in detail in the above embodiments of the present invention, the fuel is ejected from the fuel ejection port toward the slope, so that the fuel collides and is dispersed on the slope. Further, the fuel is atomized by the shearing action with the air at the position where it contacts the slope and the flat surface. In this case, when the angle of intersection of the slope with the axis of the nozzle body is 5 degrees or more, the shearing action is more effectively performed. Further, when the second slope is provided, the flow to the flat surface becomes smooth. Next, the evaporation effect is promoted by forming a thin film on the flat surface portion.

Further, when the guide wall is provided, a uniform thin film is formed downstream even on the slope. Furthermore, at the outlet, further atomization is achieved by the shearing action with air. In addition, when the groove is provided, the collision force of the fuel ejected from the fuel ejection port on the slope increases,
The dispersing action is further promoted. In addition, the fuel outlet,
By providing a plurality of grooves, slopes, etc. in each direction in the nozzle body, and by rounding the thickness and the end shape of the flat plate, each of the above operations can be performed more effectively.

As described above, by combining a plurality of actions, it is possible to improve atomization of the fuel more than a single action, more uniform mixing can be obtained, and as a result, low It is possible to achieve NOx conversion and efficiency improvement.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view showing a second embodiment of the present invention.

FIG. 4 is a sectional view showing a third embodiment of the present invention.

FIG. 5 is a sectional view showing Embodiment 4 of the present invention.

FIG. 6 is a cross-sectional view showing a fifth embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a sixth embodiment of the present invention.

FIG. 8 is a sectional view showing Embodiment 7 of the present invention.

[Explanation of symbols]

 1 Fuel Injector 2 Nozzle Body 3 Inlet 4 Outlet 5 Outlet 6 Fuel Passage 7 Fuel Outlet 8 Groove 9 Slope 9a Top 9b Second Stage Slope (α Angle) 10 Thin Film Forming Plane 11 Guide Wall 12 Internal Space 13 Supply Port 14 Flat Plate 14a End 14b Exit Side End 15 Air Passage 17 Protrusion a Air b Fuel c Mixed Fuel

Claims (8)

[Claims] 1. A fuel jet portion is provided inside a cylindrical nozzle body having one end as an inlet for introducing air, and
A fuel injection device in which the other end side of the nozzle body is an outlet part for injecting a mixed fuel of fuel and air, wherein the fuel jet part is provided in the nozzle body and directs the fuel to the outlet part side. It has a fuel ejection port which ejects toward it, and a slope which guides the fuel ejected from this fuel ejection port in a direction intersecting with the axial center of the nozzle body, and the top of the slope has the above-mentioned A fuel injection device, characterized in that a flat thin-film forming flat portion parallel to the axis of the nozzle body is continuous over the outlet side of the nozzle body. 2. The fuel injection device according to claim 1, wherein
A fuel injection device, characterized in that guide walls are provided on both sides of the slope, the guide walls being rising walls that gradually widen toward the top of the slope. 3. The fuel injection device according to claim 1, wherein
A fuel injection device characterized in that a groove is formed between the fuel injection port and the slope to form a constant space. 4. The fuel injection device according to claim 1, wherein
The fuel injection device characterized in that the sloped surface intersects the axis of the nozzle body at an angle of 5 degrees or more. 5. The fuel injection device according to claim 1, wherein
A fuel injection device characterized in that a second-stage slope whose angle of intersection with the nozzle body axis is smaller from the middle of the slope is provided. 6. The fuel injection device according to claim 1, wherein the inner surface of the peripheral wall of the nozzle body is a flat surface, or a flat plate is inserted in the nozzle body along the axial direction, and the flat surface or the surface of the flat plate. Is a flat portion for forming a thin film of fuel, and a fuel injection port, a groove, a slope and a guide wall are provided on the peripheral wall or the flat plate of the nozzle body forming the flat surface. 7. The fuel injection device according to claim 6,
Plural fuel injection ports, grooves, slopes or guide walls are arranged on the peripheral wall or flat plate of the nozzle body that constitutes the same flat surface for thin film formation, or plural flat plates are parallel in the radial direction of the nozzle body. And a fuel injection port, a groove, a slope, or a guide groove is provided in each of the fuel injection devices. 8. The fuel injection device according to claim 1, wherein the cross-sectional shape of the inlet side end of the flat plate is arcuate, or the thickness of the flat plate is gradually reduced toward the outlet side. To minimize the thickness of the tip of the outlet, or to change the cross section along the axial direction of the nozzle body on the outlet side of the flat plate so that the velocity of the mixed fuel is constant at all positions on the flat surface for thin film formation. A fuel injection device, characterized in that it is provided with a protrusion.