JPH04292712A - gas turbine combustor - Google Patents

Abstract

PURPOSE:To eliminate a need for an external actuator, to reduce a cost, and to improve reliability by a method wherein flow rate of air at the inlet of a burner and a swirl angle are changed according to a change in the shape of a temperature deforming member. CONSTITUTION:In a gas turbine combustor provided with an air swirler 13 having an indoor blade 7 arranged in a manner to surround a fuel injection valve 3, the inclination angels of the guide blades 7 are simultaneously changed through a link mechanism by change in the shape of a temperature deforming member of a shape memory alloy or a bimetal which is arranged in the vicinity of the guide blade 7 and the shape of which is changed through sensing of the temperature of air passing through the guide blade 7. This constitution decreases the area of a passage for air passing through the guide blade 7 and increase a swirl angle of air when an air temperature is low and a gas turbine output is low and increases the area of the air passage and decreases the swirl angle of air when an air temperature is high and a gas turbine output is high.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a combustor for a gas turbine such as a jet engine, and in particular to a combustor that emits a small amount of polluting exhaust substances such as unburned hydrocarbons, carbon monoxide, nitrogen oxides, and black smoke. Regarding.

0002

2. Description of the Related Art Gas turbine combustors tend to emit a large amount of unburned hydrocarbons and carbon monoxide when the output is low, and nitrogen oxides and black smoke when the output is high. In order to reduce the emissions of these polluting exhaust substances, it is effective to control the combustion conditions in the primary combustion region of the combustor. That is, at low power, the amount of fuel injected is small, so the amount of primary air flowing through the air swirler is correspondingly reduced, and a strong swirl is applied to cause appropriate turbulence in the airflow, thereby increasing the flame propagation speed. Conversely, when the output is high, the amount of fuel injected is large, so the flow rate of the primary air passing through the air swirler is correspondingly increased, the strength of the air swirl is suppressed, and the residence time is increased. Less is better.

[0003] For example, Japanese Patent Application Laid-Open No. 57/1987 discloses a system in which the above-mentioned combustion state is controlled by adjusting the movement of the blades of the air swirler surrounding the fuel nozzle of the combustor.
There is -87537. In this invention, the air swirler includes a fixed first element consisting of an annular plate having a plurality of radially extending openings, and an air swirler adjacent to the upstream side of the first element and rotatable in the circumferential direction. It consists of a second element arranged in the same direction as the first element and has a similar shape to the first element, and by rotating the second element relative to the first element, the air volume and rotation angle of the primary air can be adjusted. It has become.

Furthermore, the temperature inside the combustion chamber is detected and the opening degree of a cover installed in front of the air swirler is adjusted based on the signal (US Patent 4,04).
1,694), the air swirler is divided into one for primary air and one for secondary air, and air is constantly supplied to the primary air swirler, and the secondary air swirler is used only when the temperature of the inlet air is above a certain value. In order to fully open the entrance opening, it is opened and closed by a bimetallic device (U.S. Patent 4,606,190
) etc.

[0005]

Problems to be Solved by the Invention Of the prior art as described above, the invention disclosed in Japanese Patent Application Laid-Open No. 57-87537 has the following problems.

[0006] Since an actuator is provided outside the combustor and the second element is rotated via a link mechanism, the amount of air flowing through the air swirler and the swirling angle are adjusted, so an external actuator is not required. This increases cost and weight, and the link mechanism is complicated, making it difficult to seal the air in the penetrating parts, and the links tend to get caught, resulting in a lack of reliability. Furthermore, since each gas turbine usually has ten to several dozen air swirlers, it is impossible to operate all the air swirlers with one actuator.

Next, U. S. Patent 4,041,
In addition to the same problem as above, the invention disclosed in No. 694 does not adjust the swirling angle of the air passing through the air swirler, so it does not solve the problem at low output.

Next, U. S. Patent 4,606,
In the invention disclosed in No. 190, the amount of secondary air is adjusted by a bimetal sensitive to its temperature.
There is no way to adjust the turning angle of the air.

The present invention has been made in view of the problems of the prior art, and provides a gas turbine combustor that can adjust the amount and swirl angle of incoming air from an air swirler without the need for an external actuator. The purpose is to

0010

[Means for Solving the Problems] In order to achieve the above object, the gas turbine combustor of the present invention is arranged to surround a fuel injection valve that supplies fuel to a combustion chamber in the combustor for flame stabilization. In a gas turbine combustor equipped with an air swirler having a large number of guide vanes, the inclination of the guide vanes is controlled by a temperature deformable member that is placed near the guide vanes and whose shape changes depending on the temperature of the air passing through the guide vanes. By changing the angles all at once, when the air temperature is low, the passage area of the air passing through the guide vanes is small and the turning angle of the air is large, and when the air temperature is high, the air passage area is large and the turning angle of the air is large. It is characterized by being made smaller.

[0011]

[Function] When the load is small, the gas turbine has a small temperature rise due to the compressor, so the temperature of the air entering the combustor is low; when the load is large, the temperature rise due to the compressor is large, so the temperature of the air entering the combustor is low. The temperature of the incoming air is high.

The temperature deformable member placed near the guide vane changes its shape in response to the temperature of the air passing through it, and also changes the inclination angle of the guide vane through a required link as a driving source for moving the guide vane. change all at once.

[0013] When the output is low and the air temperature is low, the amount of fuel injected is small, so the inclination angle of the guide vane is increased. This narrows the area of the air passage and gives it a strong swirl, which increases the flame propagation speed, improves flame holding, and suppresses the generation of unburned hydrocarbons and carbon monoxide.

On the other hand, when the output is high and the air temperature is high, the amount of fuel injected is large, so the inclination angle of the guide vanes is increased. This increases the area of the air passage and reduces the swirl angle, resulting in lower fuel concentration in the combustion region, shorter residence time, and less nitrogen oxide and black smoke.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a gas turbine combustor according to the present invention, FIG. 2 is a sectional view taken along the line II--II in FIG. 1, and FIG. 3 is a sectional view taken along the line III--III in FIG.

The figure shows a so-called annular type combustor. In the figure, 1 is a combustor case, which is approximately cylindrical and consists of a combustor outer case 1a and a combustor inner case 1b that are arranged concentrically, and 1a and 1b form an annular space. .

A combustor liner 2 is disposed concentrically within the combustor case 1, forming an annular combustion chamber 26. Upstream of the combustion chamber 26, a large number of combustion injection valves 3 are arranged at equal intervals in the circumferential direction. A partition plate 4 is provided downstream of the injection valve 3 from the combustor liner 2 toward the inside of the combustion chamber 26 to form an upstream end of the combustion chamber 26 .

The partition plate 4 is provided with a truncated conical projection 4a facing toward the fuel injection valve 3, and has an inward groove 4b at its top.
He is holding 3.

The air swirler 13 is fitted and fixed to the cylindrical tip member of the fuel injection valve 3, and is located on the inner cylinder 9 having a flange portion 9a facing the combustion chamber 26, and on the downstream side of the inner cylinder 9, An annular lower plate 5b facing the portion 9a, a cylindrical body 5a having a flange 5c arranged in line on the downstream side of the lower plate 5b, and a cylindrical body 5a having a flange 5c arranged in line on the downstream side of the lower plate 5b; A large number of guide blades 7 are arranged at equal intervals, and an upper plate 6 is rotatably fitted on the outside of the flange portion 9a and is arranged so as to sandwich the guide blades between the lower plate 5b. Consisting of

The flange 5c of the cylindrical body 5a is held so as to be fixed within the groove 4b of the partition plate 4.

The lower plate 5b and the flange portion 9a of the inner cylinder 9 are connected by four U-shaped supports 8 so as to straddle the outside of the guide vane 7. The upper plate 6 is in sliding contact with the inside of the support 8.

The upper plate 6 is an annular disc, and slits 18 corresponding to the number of guide vanes 7 and opening outward are radially bored therein.

The guide blade 7 is provided with pin-shaped projections 14 at its three corners, two of which are located at the outer and inner ends of the blade toward the top plate 6, and one is located at the bottom. It is provided at the inner end of the blade toward the plate 5b.

The lower plate 5b is provided with the same number of round holes 5d into which one of the protrusions 14 is loosely fitted as the guide vanes 7, and the round hole 9b is located at a position facing the flange portion 9a of the cylinder 9 and the round hole 5d. is provided, and one of the projections 14 is loosely fitted therein.

Furthermore, a projection 14 at the outer end of the guide vane 7 is accommodated within the slit 18 of the upper plate 6. Reference numeral 17 denotes a stopper protruding from the upper plate 6.

10 is a temperature deformable member formed in a spiral shape and made of bimetal or shape memory alloy. The outer end of the temperature deformable member 10 is provided with a metal fitting 1 protruding from the upper plate 6.
5 with a machine screw 16, and the inner end is fixed to the inner cylinder 9 with a machine screw 19.

Next, the operation will be explained. In FIG. 1, the air flow from the compressor (not shown) outlet, indicated by arrow 11, is
A part of it flows into the air swirler 13 through the guide vane 7 as shown by the arrow.

The air flow 12 flows into the air swirler 13 at an air flow rate corresponding to the passage area determined by the minimum spacing between the guide vanes 7 and at a swirling angle corresponding to the inclination angle θ of the guide vanes, and is caused by primary combustion. It is supplied as air for use.

[0030] When the gas turbine is at low power, less work is done by the compressor and therefore the temperature of the air stream 11 is also lower. When the temperature of the airflow 11 is low, the temperature deformable member 10 maintains its original shape before deformation, and this state is shown in the upper diagram (a) of FIG.
Shown below. At this time, the guide vane 7 is in the state shown in the upper diagram (a) of FIG. 3, that is, the state in which the inclination angle θ with respect to the radial direction of the air swirler 13 is large.

When the inclination angle θ is large, the minimum distance between the guide vanes 7 becomes small as shown by the arrow 21 in FIG. The flow is restricted and becomes a strong swirling flow as shown by arrow 23. Therefore, in the primary combustion region within the combustion chamber 26, the fuel concentration is excessively high, and stable combustion is obtained due to the strong swirling flow, and the generation of unburned hydrocarbons and carbon monoxide is suppressed.

On the other hand, when the gas turbine has a high output, the amount of work done by the compressor is large, and therefore the temperature of the air stream 11 is also high. When the temperature of the air flow 11 increases, the temperature deformable member 10 senses the temperature by itself, and uses its own deforming force to move the upper plate 6 toward the arrow 20 as shown in the lower part (b) of FIG.
Rotate until the stopper 17 hits the support 8 as shown in the figure.

[0033] Then, the guide vane 7 is shown in the lower diagram (b) of Fig. 3.
In such a state, that is, when the inclination angle is 0, the guide vanes 7 point toward the center, the minimum interval between the guide vanes 7 becomes the maximum as shown by the arrow 24, and the passage area also becomes the maximum. The airflow flowing into the air swirler 13 loses its swirling component, as shown by arrow 25, and its amount increases. Therefore, at high output, the fuel concentration is diluted in the primary combustion region within the combustion chamber 26 and the residence time is short, suppressing the generation of nitrogen oxides and black smoke.

It should be noted that the present invention is not limited to the above-described embodiment, and may be modified, for example, as follows. That is, the temperature deformable member 10 is not spiral-shaped but may have another shape. Furthermore, although the airflow passing through the guide vanes 7 flows inward from the outside in the radial direction of the air swirler in this embodiment, it may also flow in the axial direction of the air swirler. good. In this case, the inclination angle of the guide vane 7 means the angle with the axial direction, and when the output is low, the angle between the axial direction and the vane may be increased, and when the output is high, the angle between the axial direction and the vane may be decreased.

[0035]

[Effects of the Invention] As described above, the gas turbine combustor of the present invention has the following effects in reducing nitrogen oxides, unburned hydrocarbons, carbon monoxide, and black smoke, which are harmful components in exhaust gas. be. (1) Since the temperature deformable member itself, such as bimetal or shape memory alloy, serves as both the temperature sensor and the drive source for moving the device, there is no need for any other unique sensors or external actuators, which reduces costs accordingly. can be achieved. (2) As mentioned above, since no unique sensor or external actuator is required, the overall weight is light, and there is no need to worry about problems such as abrasion of moving parts, seal leakage, or snagging, and it is highly reliable.

[Brief explanation of drawings]

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

FIG. 2 is a sectional view taken along the line II-II in FIG. 1;

FIG. 3 is a sectional view taken along the line III-III in FIG. 1;

[Explanation of symbols]

3 Fuel injection valve 7 Guide vane 10 Temperature deformation member 13 Air swirler 26 Combustion chamber θ　　　　Inclination angle of guide vane

Claims (1)

[Claims] 1. A gas turbine combustor equipped with an air swirler having a large number of guide vanes arranged for flame stabilization surrounding a fuel injection valve that supplies fuel to a combustion chamber in the combustor, wherein the guide vane When the air temperature is low, the inclination angle of the guide vanes is changed all at once by a temperature deformable member that changes its shape depending on the temperature of the air passing through the guide vanes when the air temperature is low. A gas turbine combustor characterized in that the air passage area is small and the air swirling angle is large, and when the air temperature is high, the air passage area is large and the air swirling angle is small.