JP2571636B2 - Variable air mechanism of gas turbine combustor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustor used for a gas turbine such as a gas turbine engine for a vehicle, and more particularly, to a passage area of an air passage communicating with a pre-evaporation space near a combustion injection nozzle. It relates to a variable air variable mechanism.

To reduce the discharged from the prior art gas turbine NO _x, provided with a space for pre-evaporation in the vicinity of the fuel injection nozzle, the amount of air flowing here adjusted according to the load,
2. Description of the Related Art A gas turbine combustor has been proposed in which a substantial air-fuel ratio of a main combustion region is kept constant or within a narrow range over a wide load range.

FIG. 5 shows a combustor described in SAE paper 820175 as an example. A fuel injection nozzle 33 is attached to one end of a substantially cylindrical combustor main body 32 that defines a combustion chamber 31. A pre-evaporation space 34 for performing pre-mixing and pre-evaporation is provided in front of the fuel injection nozzle 33. An air-conditioning sleep 35 is provided so as to surround the pre-evaporation space 34.

The air adjusting sleeve 35 is described in detail in FIGS.
As shown in the figure, a fixed-side sleeve 36 on which a number of swirler vanes 36a are erected, and a cylindrical wall 37a fitted on the outer periphery of the swirler vane 36a, and a number of openings 37b are cut out in the cylindrical wall 37a. The movable sleeve 37 is configured to rotate within a predetermined angle range by an actuator (not shown) via a gear 38.

In other words, a large number of air passages 3 between the swirler vanes 36a
9 can be appropriately adjusted by rotating the movable side sleeve 37.

In the above configuration, air flows from the outer peripheral side to the inner peripheral side of the swirler vanes 36a in the respective air passages 39. On the side, since the passage opening area is narrowed by the cylindrical wall 37a, indecency such as separation easily occurs immediately after the inflow of each air passage 39. Therefore, there has been a problem that the strength and the flow coefficient of the swirl generated by the swirler vanes 36a are unstablely changed depending on the amount of the throttle.

Further, as another conventional example, an elongate passage is formed between the movable blade and the fixed blade as in the technique described in Japanese Utility Model Laid-Open No. 60-154718, and the passage is formed by the rotation of the movable blade. There is also provided one that makes the opening area variable. However, in this conventional example, since the movable blade is formed substantially in an L shape and has a large mass, the turning resistance of the movable blade is increased.

Also, when the rotating blade and the fixed blade are combined, the side surface of the fixed blade protrudes greatly from the side surface of the movable blade. Therefore, when the passage has the maximum opening area,
There is a possibility that a sufficient air volume cannot be obtained due to the flow resistance of the air at the projecting portion of the fixed blade.

Means for Solving the Problems The present invention has been devised in view of the above-mentioned conventional problems, and has a pre-evaporation space near a fuel injection nozzle, and surrounds the outer periphery of the pre-evaporation space. In the air variable mechanism of the gas turbine combustor, the annular fixed-side block ring and the movable-side block ring are arranged to face each other, and the movable-side block ring is configured to be rotatable at a fixed angle. On the movable side block ring, a large number of elongated fan-shaped first protrusions are provided substantially radially, while on the fixed side block ring, an approximately L-shaped first protrusion is combined so as to cover one side surface and the outer peripheral surface of the first protrusion. The second protruding piece is provided substantially radially, and the outer peripheral surface of the first protruding piece is formed so as to be slidably rotatable with the inner peripheral surface of the second protruding piece facing the other, and the other side surface of the first protruding piece is formed. On the side Between the second projecting pieces to the inner peripheral with the outlet side to form a plurality of air passages becomes throat portion, the second when fully opened the air passage
The edge of the L-shaped tip of the projection is substantially aligned with the radial extension of the other side surface of the first projection.

Operation In the above configuration, a large number of air passages are formed substantially radially by combining the fixed block ring and the movable block ring. In this air passage, air flows from the outer peripheral side to the inner peripheral side of the block ring,
When the movable side block ring is rotated, the passage cross-sectional area of each air passage formed between the first protrusion and the second protrusion is reduced. Here, since the inner peripheral outlet side is the throat portion having the smallest passage cross-sectional area, disturbance such as peeling hardly occurs even when the passage cross-sectional area is narrowed. In addition, the present invention
Since the first protruding piece formed into an elongated fan shape has a smaller mass than the second protruding piece formed substantially in an L-shape, the turning resistance of the first protruding piece at the time of turning is reduced, and the transient response is reduced. The performance is improved.

Since a large gap is not formed between the outer peripheral surface of the first protrusion and the inner peripheral surface of the second protrusion that are in sliding contact with each other, leakage of air from both is prevented, and Appropriate air can be supplied to the evaporation space. further,
Since the L-shaped end of the second projection piece was substantially coincident with the radial extension of the other side surface of the first projection piece, the first projection piece was moved to the second projection piece.
When combined with the protruding piece, the L-shaped end of the second protruding piece does not protrude into the air passage, so that the air flow resistance can be suppressed.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view showing a main part of a combustor for a gas turbine according to the present invention, in which a heat insulating material 2 is disposed on an inner peripheral side of a substantially cylindrical casing 1 and a casing. An end plate 3 is attached so as to close one end. At the center of the end plate 3,
A fuel injection nozzle 4 is attached, and a baffle cylinder 5 is attached by a bolt 6 so as to surround the fuel injection nozzle 4.

In addition, a pre-evaporation space 7 is provided in the center of the inside of the casing 1.
Is formed coaxially with the fuel injection nozzle 4. The downstream side of the pre-evaporation tube 8 is
It communicates with a combustion space (not shown). The space between the heat insulating material 2 and the pre-evaporation pipe 8 forms an air passage 9 for introducing combustion air.

The base end of the pre-evaporation tube 8 is expanded in a flange shape, and an annular fixed-side block ring 10 is formed integrally therewith. More specifically, the fixed side block ring 10 includes a circular flange portion 11 extending perpendicular to the axis of the pre-evaporation tube 8, and a plurality of second projection pieces formed substantially radially on the flange surface of the flange portion 11. 12 (see FIG. 3).

On the other hand, an annular movable block ring 13 is rotatably fitted to the outer periphery of the baffle cylinder 5. The movable block ring 13 has a flange portion 14 facing the fixed block ring 10, and a large number of first protrusions 15 combined with the second protrusions 12 are provided on the flange surface in a substantially radial manner. Is formed.

The cylindrical portion 13a on the base end side of the movable side block ring 13
Is formed to be relatively thick. As shown in FIG. 2, spring receiving holes 16 are recessed at three places, and a coil spring 17 is disposed in a compressed state. The movable spring block ring 13 is constantly pressed toward the fixed block ring 10 by the coil spring 17, and the entire pre-evaporation tube 8 is supported between the movable pre-evaporation tube 8 and a downstream end (not shown). And, between the movable side block ring 13 and the fixed side block ring 10,
The outer periphery of the louver 18 is clamped and fixed. A tip 19 made of a solid lubricating material such as carbon is interposed at one end of the coil spring 17 in contact with the end plate 3 so as not to impair the smooth rotation of the movable block ring 13. .

Further, at two positions of the cylindrical portion 13a of the movable side block ring 13, pivots 20 made of bolts are provided, and as shown in FIG.
Are connected at one end.

The other end of the push-pull rod 21 is linked to an actuator (not shown), so that the movable block ring 13 rotates by a predetermined angle.

FIGS. 3 and 4 show the first projection 15 and the second projection 12 respectively.
The first protrusions 15 provided on the movable side block ring 13 each have an elongated fan shape, and are formed slightly inclined with respect to the radial direction so as to function as swirlers. . Also fixed block ring
Each of the second protrusions 12 provided on the 10 has a substantially L-shape that covers one side surface 15a and the outer peripheral surface 15b of the first protrusion 15 and is also slightly inclined with respect to the radial direction. Is formed. Further, the outer peripheral surface 15b of the first projection piece 15
Are slidably and rotatably arranged on the inner peripheral surface of the bent front end portion 12b of the second protruding piece 12, so that a large gap is not formed between the two.

Therefore, in a state where the first projection piece 15 and the second projection piece 12 are combined, as shown in FIG.
A large number of air passages 22 are formed between the other side surface 15c of the first protrusion 15 and the side surface 12a of the second protrusion 12. The air passage 22 is also inclined by a constant angle α with respect to the radial direction, and a swirling flow is generated in the pre-evaporation tube 8 by the air flow from the outer peripheral side to the inner peripheral side. Each of the air passages 22 has an elongated fan shape, and the inner peripheral outlet side is a throat portion 22a having the smallest passage cross-sectional area. Then, the first projection piece 15 and the second
When the protruding piece 12 is combined with the protruding piece 12, the edge 12c of the bent front end portion 12b of the second protruding piece 12 forms the other side face 15c of the first protruding piece 15.
Is formed so as to substantially coincide with a radial extension line X of.

When the movable block ring 13 rotates with respect to the fixed block ring 10, the air passage 22 formed between the first projection piece 15 and the second projection piece 12 narrows as shown in FIG. As a result, the amount of air flowing in is suppressed. FIG. 4 shows a state in which the movable block ring 13 is rotated by the maximum angle θ to minimize the passage area.

Here, in the above configuration, the cross-sectional area of the air passage 22 is reduced as a whole, and the basic shape of the throat portion 22a on the inner peripheral outlet side does not change. Therefore, even in the state where the cross-sectional area of the passage is narrowed, the flow of the air in each air passage 22 is very uniform, and the generation of separation, turbulence, and the like due to the local narrowing is suppressed. Therefore, unnecessary loss does not occur, and the intensity of the swirling flow generated in the pre-evaporation tube 8 can be made very stable.

The gap 23 (see FIG. 4) generated by the separation between the first projection piece 15 and the second projection piece 12 is closed by the outer peripheral wall of the second projection piece 12 on the outer peripheral side on the air inlet side. So
No problem.

Advantageous Effects of the Invention As is apparent from the above description, according to the variable air mechanism for a gas turbine combustor according to the present invention, a large number of air passages formed by combining a fixed block ring and a movable block ring are formed. The inner peripheral outlet side becomes the throat part, and each air passage is narrowed as a whole with the rotation of the movable side block ring, so that separation and turbulence of the air flow can be prevented, and the swirl flow generated in the pre-evaporation space The strength can be made very stable. Moreover, in the present invention, the slender fan-shaped first projection piece has a smaller mass than the L-shaped bent second projection piece, and the first projection piece having the smaller mass is rotated. In addition, the rotational resistance is reduced, and the transient response is improved.

Further, since the outer peripheral surface of the first protrusion is formed so as to be slidable and rotatable with the inner peripheral surface of the second protrusion, there is no large gap between the two protrusions. Supply amount can be controlled with high precision.

Further, since the L-shaped end of the second projection piece substantially coincides with the radial extension of the other side face of the first projection piece, when the first projection piece is combined with the second projection piece, the second projection piece has the second shape. Since the edge of the L-shaped tip of the projection does not protrude into the air passage, the flow resistance of the air flowing through the air passage can be suppressed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a main part of a gas turbine combustor according to the present invention, FIG. 2 is a cross-sectional view taken along the line II-II, and FIG. 3 is a cross-sectional view taken along the same line III-III. FIG. 4 is a sectional view similar to FIG. 3 showing a state in which the air passage is narrowed, FIG. 5 is a sectional view showing an example of a conventional gas turbine combustor, and FIG. FIG. 7 is a cross-sectional view showing a fixed-side sleeve, FIG. 7 is a plan view of the same, and FIG. 8 is a cross-sectional view showing a conventional movable-side sleeve. 4 ... fuel injection nozzle, 8 ... pre-evaporation tube, 10 ... fixed side block ring, 12 ... second projection piece, 12b ... tip part, 1
2c ... edge, 13 ... movable block ring, 15 ... first
Projection piece, 15b ... outer peripheral surface, 17 ... coil spring, 22
... air passage, X ... extension line.

Claims (1)

(57) [Claims] 1. A pre-evaporation space is provided near a fuel injection nozzle, and an annular fixed side block ring and a movable side block ring are arranged to face each other so as to surround an outer periphery of the pre-evaporation space. In the air variable mechanism of a combustor for a gas turbine, wherein the movable block ring is configured to be rotatable at a fixed angle, the movable block ring is provided with a plurality of elongated fan-shaped first protrusions substantially in a radial manner. The fixed block ring is provided with a substantially L-shaped second projection piece that is combined with the first projection piece so as to cover one side surface and the outer peripheral surface thereof, and the outer peripheral surface of the first projection piece is formed by the second projection. A throat portion is formed between the other side surface of the first protruding piece and the second protruding piece opposing the side surface, the throat portion being formed so as to be slidable and rotatable on the opposing inner peripheral surface of the piece. Many air vents A second passage when the air passage is fully opened.
An air variable mechanism for a combustor for a gas turbine, characterized in that an edge of an L-shaped tip portion of the projection piece substantially coincides with a radial extension of the other side face of the first projection piece.