JPH08284688A - Gas turbine and gas turbine combustion device - Google Patents

Abstract

PURPOSE: To reduce cooling air amount led to flow into a connecting part between a combustor liner and a tail cylinder, and sufficiently cool a plate spring body and the end part of the combustor liner. CONSTITUTION: A cooling hole 9 which is communicated outside and inside of the liner 1 is opened to a combustor inner 1 covered with a plate spring body 8 in a fitting part between the combustor liner 1 and a tail cylinder 4, and a hood 10 is arranged inside the cooling hole 9 so as to form a channel which is approximately in parallel with the inner wall of the combustor liner 1. A side from the top part of the plate spring body 8 to the combustor liner 1 is formed in such a way that, for example, the width of a slit 8s is widened so as to diminish fluid resistance, and a side from the top part of the plate spring body 8 to the tail cylinder side 4 is formed in such a way that, for example, the width of the slit 8s is diminished as much as possible so as to increase the fluid resistance.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to gas turbines and gas turbine combustion systems.

[0002]

2. Description of the Related Art Conventionally, a gas turbine combustion apparatus that is generally adopted has a combustion chamber R as shown in FIG.
The combustor liner 1 forming the
Is provided with a fuel supply device 2 at one end side thereof, and a tail cylinder 4 for guiding the high temperature combustion gas to the moving blades 3 is provided at the other end portion thereof.

In the figure, 5 is a compressor driven by a gas turbine, which supplies combustion air and cooling air for cooling high-temperature members such as the combustor liner 1, the transition piece 4, the rotor blades 3 and the stator blades 6. Supply. The arrows show the flow of air.

Combustion in the combustion device is carried out in the combustion chamber R by the fuel supplied from the fuel supply device 2 and the combustion air supplied from the compressor 5, and the burned high temperature gas flows from the combustor liner 1 to the transition piece 4 And the rotor blade 3 on the rotor side via the stator blades 6.
Given to.

The cooling of the combustor liner 1 and the transition piece 4 by the cooling air is performed by heat exchange with the cooling air flowing on the outer peripheral surface of the combustor liner 1 and the transition piece 4, and from the cooling holes previously provided in the combustion liner 1 and the transition piece 4. It is performed by air A ₁ and A ₂ flowing into the liner 1 and the transition piece 4.

A transition piece 4 is provided at one end of the combustor liner 1, that is, at the downstream end of the hot gas flow (indicated by the arrow W), and the two are connected to each other. Although the two are connected, they are not completely fixed like welding or bolting, but are joined by loose fitting.

That is, although the combustor liner 1 and the transition piece 4 are heated to a high temperature and thermally expand and contract, their thermal expansion and contraction amounts are different from each other, and a stress escape route is required between them to avoid thermal stress fracture. is there.

FIGS. 6 and 7 are enlarged views of this joint portion, and a curved leaf spring body 8 is interposed between the combustor liner 1 and the transition piece 4 fitted together.

That is, the outer peripheral surface of the combustor liner 1 is provided with a leaf spring body 8 which is manufactured by bending a thin plate in an arc shape and is interposed in a compressed state. A large number of elongated slits 8s are cut in the arc-shaped portion of the leaf spring body 8 in the axial direction of the combustor liner 1 so as to have a spring action, and the non-slit side is spotted on the outer peripheral wall surface of the combustor liner 1. It is fixed by welding. Reference numeral 7 indicates the welding point.

Since the outer diameter of the leaf spring body 8 is fed larger than the inner diameter of the tail tube 4, the inner wall of the tail tube 4 near the top of the leaf spring body 8 is inserted into the tail tube 4. And the reaction force acts on the leaf spring according to the magnitude of the spring constant of the leaf spring body 8.

The fitting connection between the combustor liner 1 and the transition piece 4 is formed in this way, so that the combustor liner 1 can slide in the axial direction, allow elongation due to thermal expansion, and generate thermal stress. Has been reduced. Further, the vibration of the combustor liner 1 is suppressed by the spring action of the leaf spring body 8.

The combustor liner 1 and the transition piece 4 are cooled by the cooling air as described above. Of course, the leaf spring body 8 and the combustor liner 1 inside the leaf spring body 8 are also heated to a high temperature. It is also necessary to cool the combustor liner 1 inside the leaf spring body 8, and it is necessary to flow cooling air to the portion of the leaf spring body 8.

The leaf spring body 8 is provided with a slit 8s,
Cooling air flows through this portion, but most of it only flows through the slits 8s from the combustor liner 1 side to the transition piece 4 side in a short-circuited manner, and the main body of the leaf spring body 8 and the combustor inside the leaf spring body 8 are short-circuited. A small amount of cooling air flows along the liner 1 and substantially contributes to the cooling of the leaf spring body 8 and the combustor liner 1 inside the leaf spring body 8. For this reason, in order to keep the leaf spring body 8 and the combustor liner 1 inside the leaf spring body 8 below the allowable temperature, the width of the slit 8s must be widened, and an unnecessarily large amount of cooling air flows in to cause combustion. The amount of air used is reduced accordingly. The method of reducing the cooling air and turning the cooling air to the combustion air is to reduce the width of the slit as much as possible, or, as described in Japanese Utility Model Laid-Open No. 63-71433, use an arc-shaped leaf spring body 8. It is used by stacking two sheets and shifting them so that the slits do not overlap.

In this system, the leaf spring body 8 has a slit 8s.
Is formed, which acts sufficiently as a spring and substantially prevents the inflow of cooling air.

[0015]

In this combustion apparatus, there is almost no inflow of air from the fitting portion, and the combustion air can be increased accordingly. However, the leaf spring body hardly touches the cooling air, the leaf spring body becomes hot and the spring reaction force changes, and similarly, the combustor liner inside the leaf spring body also becomes hot and a part of the liner deforms. Or, it causes stress fracture.

An object of the present invention is to provide a gas turbine combustor in which the amount of cooling air flowing through the joint between the combustor liner and the transition piece is small and the leaf spring body and the end of the combustor liner are sufficiently cooled. It is in.

[0017]

In order to achieve the above object, the present invention provides a flow passage communicating from the outside to the inside of a liner in an inner combustor liner covered with a leaf spring body, and the flow passage is provided in the flow passage. Adjusting the air flow rate, e.g. by providing a number of air holes, at least near the outlet of the flow path being substantially parallel to the inner wall of the liner over the entire inner circumference of the combustor liner,
Further, the liner side from the top of the leaf spring body has, for example, the width of the slit increased to reduce the fluid resistance, and the tail tube side from the top of the leaf spring body has the width of the slit made as small as possible, or the leaf spring. A protrusion plate or the like fixed to either one of the body and the transition piece is provided.

[0018]

In this structure, the air that has flowed into the gap between the leaf spring body and the combustor liner from the outside of the combustor liner through the slit having a larger width on the liner side than the top of the leaf spring body is used. After taking heat from the inside of the leaf spring body, it passes through a flow path provided so as to communicate from the outside to the inside of the combustor liner inside the leaf spring body, and then flows out into the combustor liner. Since the vicinity of the outlet of the flow path is almost parallel to the inner wall of the liner over the entire inner circumference of the liner, the air flowing into the liner flows in a film shape along the inner wall of the liner so as to cover the entire inner wall, and the leaf spring body and combustion Prevents the combustor liner from being directly exposed to hot combustion gases and draws heat from the leaf spring body and the combustor liner. In addition, the cooling air flow rate is suppressed to a necessary minimum by adjusting the opening area of a large number of cooling holes provided in the flow path.

On the other hand, on the tail tube side from the top of the leaf spring body, the width of the slit is made as narrow as possible, and a protruding plate or the like is provided in the flow path between the leaf spring body and the tail tube. The air flowing into the transition piece through the slit from the gap of the combustor liner becomes a fluid resistance, and the flow rate is significantly reduced.

Therefore, the amount of cooling air is small, and the leaf spring body and the combustor liner are sufficiently cooled.

Further, in the gas turbine provided with the combustion device thus formed, the combustion air is increased, so that the combustion temperature can be lowered and the NOx can be reduced.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. FIG. 1 shows a fitting portion in which the combustor liner 1 is loosely fitted to the transition piece 4.

On the downstream end of the combustor liner 1, that is, on the outer peripheral surface of the end to which the transition piece 4 is joined, a leaf spring body 8 made by bending a thin plate into an arc shape is attached as in the prior art. .
A large number of elongated slits 8s are cut in the axial direction of the combustor liner 1 in the arc-shaped portion of the leaf spring body 8, and the combustor liner 1
Is spot-welded to the outer peripheral surface. The width of the slit 8s is made larger on the liner 1 side than on the top of the leaf spring body 8 and as small as possible on the transition piece 4 side.

The outer diameter of the leaf spring body 8 is formed larger than the inner diameter of the tail cylinder 4, and the leaf spring body 8 elastically contacts the inner wall of the tail barrel 4 near the top of the leaf spring body 8 and has a spring constant of the leaf spring body 8. A reaction force acts on the leaf spring body 8 according to the size.

The inner combustor liner 1 covered with the leaf spring body 8 is provided with a large number of cooling holes 9 in the circumferential direction which communicate the outer side and the inner side of the combustor liner 1. Further, inside the cooling hole 9, a shelter 10 that extends substantially parallel to the inner wall of the combustor liner 1 is provided on the downstream side of the combustor liner 1 over the entire circumference of the combustor line 1. A flow path is formed over the circumference and substantially parallel to the inner wall of the combustor liner 1.

Since the leaf spring body 8 is elastically in contact with the inner wall of the transition piece 4, the combustor liner 1 is slidable in the axial direction and allows expansion due to thermal expansion in the axial direction.
The action of the leaf spring bodies 8 suppresses the vibration of the combustor liner 1.

The cooling air A (shown by an arrow) is used for the leaf spring body 8.
8s with a wider width on the combustor liner 1 side from the top of the
After that, the gas flows from the outside of the combustor liner 1 into the gap between the leaf spring body 8 and the combustor liner 1, and flows toward the cooling holes 9 provided in the circumferential direction of the combustor liner 1 while spreading in the circumferential direction. . At this time, heat is taken from the leaf spring body 8 and the combustor liner 1 to cool them. However, since the flow spreads in the circumferential direction, the cooling does not become significantly uneven in the circumferential direction.

The cooling air A which has passed through the cooling holes 9 has a mound 10
Collide with the inner wall of the combustor liner 1 and spread over the entire circumferential direction of the flow path formed by the mound 10, and flow into the combustor liner 1. Since the flow passage is formed substantially parallel to the inner wall of the combustor liner 1 over the entire inner circumference of the combustor liner 1, the cooling air A flows in a film shape along the inner wall so as to cover the entire inner wall of the liner 1. . As a result, the leaf spring body 8 and the combustor liner 1 are prevented from being directly exposed to high-temperature combustion gas,
Heat can be taken from the leaf spring body 8 and the combustor liner 1.

Further, the width of the slit 8s on the combustor liner 1 side from the top of the leaf spring body 8 is sufficiently large, and the cooling air A passes through the slit 8s and comes from the outside of the combustor liner 1 to the leaf spring body 8.
Since the fluid resistance when flowing into the gap between the burner liner 1 and the combustor liner 1 is small, the cooling air A is changed by changing the opening area of the cooling holes 9 provided in the circumferential direction of the combustor liner 1.
The flow rate can be adjusted, and by appropriately selecting the opening area of the cooling holes 9, the flow rate of the cooling air A can be suppressed to the necessary minimum. By the way, the passage area of the slit 8s on the combustor liner 1 side of the top of the leaf spring body 8 through which the cooling air A passes needs to be at least the opening area of the cooling hole 9 or more, and preferably twice or more.

On the other hand, from the top of the leaf spring body 8 to the tail tube 4 side,
Since the width of the slit 8s is made as small as possible, there is almost no gap and the fluid resistance becomes large. Therefore, the slit 8s passes through the slit 8s in this portion and flows into the transition piece 4 through the gap between the leaf spring body 8 and the combustor liner 1. The cooling air A that is generated is suppressed.

As described above, according to the combustion apparatus, the cooling air A flowing from the outside of the combustor liner 1 to the inside of the transition piece 4 through the leaf spring body 8 can be minimized, and the combustion liner 1 It is possible to suppress an increase in the temperature of the combustor liner 1 in the vicinity of the end portion on the side of the transition piece 4, thereby reducing thermal stress and preventing the strength of the material from decreasing.

The cooling hole 9 is provided closer to the tail cylinder 4 than the position of the combustor liner 1 corresponding to the top of the leaf spring body 8.

Further, in the embodiment, the cooling holes 9 are arranged in only one row in the axial direction of the combustor liner 1, but the effect is the same even if two or more rows are provided.

In the above description, the width of the slit 8s on the combustor liner 1 side from the top of the leaf spring body 8 is increased to reduce the fluid resistance of that portion. For example, as shown in FIG. The leaf spring body 8 may be removed from the top of the leaf spring body 8 on the side of the combustor liner 1 to further reduce the fluid resistance.

By reducing the width of the slit 8s on the tail cylinder 4 side from the top of the leaf spring body 8, the cooling air A flowing into the tail cylinder 4 through the gap between the leaf spring body 8 and the combustor liner 1 is suppressed. However, if the reduction of the cooling air A is still insufficient, it is conceivable to further increase the fluid resistance of this portion.

In FIG. 3, another arcuate leaf spring body 8'is used by stacking another leaf spring body 8'on the tail cylinder 4 side from the top of the leaf spring body 8.
The slits 8s were installed so as not to overlap each other. In this case, the slits 8s are closed by the other leaf spring bodies 8, the cooling air A hardly flows, and the slits 8s sufficiently function as springs.

In FIG. 4, the fine wire group 11 is fixed to the inner wall of the transition piece 4 corresponding to the rear end of the leaf spring body 8. Fine wire group 1
1 extends toward the rear end surface of the leaf spring body 8, and the tip side, that is, the inner diameter side, is slightly smaller than the outer diameter of the rear end portion of the leaf spring body 8. That is, the wire is a little longer than this play gap.

For this reason, the thin wire group 11 fills the annular portion between the inner wall near the inlet of the transition piece 4 and the rear end of the leaf spring body 8 without any gap, and elastically contacts the rear end of the leaf spring body 8. Become. The combustor liner 1 is then axially slidable and the cooling air A is further reduced.

Of course, conversely, the thin wire group 11 may be fixed to the leaf spring body 8 and elastically contact the inner wall of the transition piece 4.

In FIG. 5, the projection group 12 or the projection plate 12 (the projections 12 in the circumferential direction of the liner 1 are continuously formed into a plate shape on the inner wall of the transition piece 4 corresponding to the rear end of the leaf spring body 8. Have been fixed). The projection group 12 or the projection plate 12 projects toward the rear end of the leaf spring body 8, and its tip side, that is, the inner diameter side, is slightly larger than the outer diameter of the rear end portion of the leaf spring body 8. . That is, the protrusion is slightly shorter than the play gap. Therefore, the projection group 12 or the projection plate 12 reduces the gap between the inner wall near the inlet of the transition piece 4 and the rear end of the leaf spring body 8. Also,
Since the leaf spring body 8 and the projection group 12 or the projection plate 12 do not come into contact with each other, the combustor liner 1 can slide in the axial direction, and the cooling air A can be further reduced.

Also in this case, of course, conversely, the projection group 12 or the projection plate 12 may be fixed to the leaf spring body 8.

[0042]

According to the present invention, in the fitting portion, the inner combustor liner covered by the leaf spring body is provided with a large number of cooling holes in the circumferential direction for communicating the outer side and the inner side of the combustor liner. Inside the hole, so as to form a flow path substantially parallel to the inner wall of the combustor liner over the entire inner surface of the combustor liner,
Since the yard extending to the downstream side of the combustor liner is provided, the cooling air flows along the inner wall so as to cover the entire inner wall of the combustor liner, and the leaf spring body and the combustor liner are directly exposed to the hot combustion gas. Prevents and removes heat from leaf springs and combustor liners.

Further, since the fluid resistance of the air flowing into the gap between the leaf spring body and the combustor liner from the outside of the combustor liner on the combustor liner side from the top of the leaf spring body is made small, the cooling air flow rate is equal to that of the cooling holes. It can be minimized by making the opening area appropriate.

Further, since the fluid resistance of the air flowing out into the transition piece from the gap between the leaf spring element on the tail tube side of the top of the leaf spring element and the combustor liner is increased, the cooling air passing through this portion has a flow rate. Is significantly reduced.

Therefore, it is possible to obtain such a gas turbine combustion apparatus in which the amount of cooling air is small and the leaf spring body and the combustor liner are sufficiently cooled.

Further, in the gas turbine provided with the combustion device thus formed, the combustion air is increased, so that the combustion temperature can be lowered and the NOx can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a gas turbine combustion apparatus of the present invention, showing a fitting portion between a combustor liner and a transition piece.

FIG. 2 is a cross-sectional view showing another embodiment of the gas turbine combustion apparatus of the present invention, showing a fitting portion between a combustor liner and a transition piece.

FIG. 3 is an explanatory view showing another embodiment of the gas turbine combustion apparatus of the present invention and showing a fitting portion between a combustor liner and a transition piece.

FIG. 4 is a cross-sectional view showing another embodiment of the gas turbine combustion apparatus of the present invention, showing a fitting portion between a combustor liner and a transition piece.

FIG. 5 is a cross-sectional view showing another embodiment of the gas turbine combustion apparatus of the present invention, showing a fitting portion between a combustor liner and a transition piece.

FIG. 6 is a partially cutaway side view showing a fitting portion between a combustor liner and a transition piece of a conventional gas turbine combustion apparatus.

FIG. 7 is a partially cutaway side view showing a fitting portion between a combustor liner and a transition piece of a conventional gas turbine combustion apparatus.

FIG. 8 is a cross-sectional view showing the periphery of a conventional gas turbine combustion device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Combustor liner, 4 ... Tail tube, 8 ... Leaf spring body, 8s ... Slit, 9 ... Cooling hole, 10 ... Side, 11 ... Fine wire group, 12 ...
A group of protrusions or a protrusion plate.

Front Page Continuation (72) Inventor Kaichi Moritomo 3-1-1, Saiwaicho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi Works

Claims (7)

[Claims] 1. A combustor liner forming a combustion chamber, a cylinder body loosely connected to an end of the combustor liner, and a clearance gap between the cylinder body and the combustor liner. In a gas turbine combustor including an intervening leaf spring body that maintains the play gap at a predetermined value, an outer side and an inner side of the combustor liner in the circumferential direction of the combustor liner covered by the leaf spring body. A gas turbine characterized in that a large number of cooling holes that communicate with each other are provided, and further that an inner wall of the combustor liner is provided with a predetermined distance inside the cooling holes and that is substantially parallel to the inner wall. Combustion device. 2. A large number of elongated slits are provided in the curved portion of the leaf spring body in the axial direction of the combustor liner, and the width of the slits is made larger on the combustor liner side than the top portion of the leaf spring body. The gas turbine combustion apparatus according to claim 1, wherein the leaf spring body is made as small as possible on the cylinder side from the top. 3. A plurality of elongated slits in the axial direction of the combustor liner are provided in the curved portion of the leaf spring body, and the leaf spring body is deleted from the top of the leaf spring body on the combustor liner side. The gas turbine combustion device according to claim 1, wherein the width of the slit is made as small as possible on the cylinder side from the top of the leaf spring body. 4. A further leaf spring body having a plurality of elongated slits provided in a curved portion in the axial direction of the combustor liner is provided on the cylindrical body side from the top of the leaf spring body, The gas turbine combustion apparatus according to claim 2, wherein the slit and the slit of the leaf spring body do not overlap each other. 5. The gas turbine combustion according to claim 2 or 3, wherein the loose gap is provided with a group of fine wires arranged so that one end thereof is fixed to one side wall surface and the other end is in contact with the facing wall surface. apparatus. 6. A projection group or a projection plate, the one end of which is fixed to one wall surface and the other end of which is arranged so as not to contact the opposite wall surface, in the loose gap. Gas turbine combustion equipment. 7. A combustion device, a combustor liner forming a combustion chamber, a tubular body loosely fitted to the hot gas downstream end side of the combustor liner, the tubular body and the tubular body. In a gas turbine having a leaf spring body arranged in a loose clearance of a combustor liner and keeping the loose clearance at a predetermined value, the combustion is performed in a circumferential direction of the combustor liner covered with the flat spring body. A large number of cooling holes that connect the inside and the outside of the burner liner are provided, and further, an inner wall of the combustor liner is provided at a predetermined distance inside the cooling holes, and a plate-like plate that is substantially parallel to the inner wall is provided. A gas turbine characterized by that.