JP6894358B2 - Exhaust duct - Google Patents

Description

The present invention relates to a high temperature duct containing a high temperature fluid such as an exhaust duct of a gas turbine.

As an exhaust duct for gas turbines, a heat insulating duct with heat insulating materials such as ceramic fiber, rock wool, and glass wool attached to the outer peripheral surface (atmospheric side surface) or inner peripheral surface (exhaust gas passage side) of the duct plate is known. Has been done. Such an exhaust duct is provided with an bleed pipe that guides a part (bleed air) of the atmosphere compressed by the air compressor at an appropriate time such as when the gas turbine is started. The bleed air pipe is configured so that one end side is inserted into the exhaust duct and the bleed air is introduced there.

JP-A-2010-203256

When introducing the bleed air into the exhaust duct, if the bleed air is directly injected, the inner surface of the exhaust duct (specifically, the plate or bolt holding the heat insulating material) may be damaged. As a countermeasure, a structure has been proposed in which the bleed air pipe is inserted deeply and the insertion portion of the bleed air pipe is bent so that the injection direction of the bleed air changes inside the exhaust duct (Patent Document 1). The insertion portion of the bleeding pipe is fixedly supported by the exhaust duct via a support structure using a support member.

However, the existence of such a support structure causes problems such as an increase in manufacturing cost and an increase in weight of the exhaust duct as a whole. Further, when the bleeding pipe is inserted deep into the exhaust duct, there is a concern that thermal stress damage may occur in the inserted portion due to the temperature difference between the inside and outside of the bleeding pipe. Further, there is a concern that the portion of the support structure installed in the exhaust duct may be damaged by thermal stress due to exposure to high-temperature exhaust gas.

The present invention has been made in view of the above circumstances, and the bleeding pipe is formed by being exposed to high temperature exhaust gas and damage to the inner peripheral surface of the duct plate due to bleeding while suppressing cost increase and weight increase. An object of the present invention is to provide an exhaust duct capable of avoiding the problem of damage to the support structure.

In order to solve the above problems, the present invention employs the following means.

(1) The exhaust duct according to one aspect of the present invention has a tubular shape in which exhaust flows as the mainstream, and is connected to a duct main body having an opening on a side wall from the outside and the duct by being connected to the opening of the duct main body from the outside. An bleeding pipe that guides bleeding toward the inside in the radial direction of the main body, a ceiling portion that faces the opening and is arranged so as to intersect the bleeding pipe that extends in the longitudinal direction inside the duct main body, and A cushion plate fixed to the side wall of the duct body and having a side portion for supporting the ceiling portion, and the ceiling portion is separated from the side wall of the duct body as it advances to the downstream side of the duct body. It extends in the direction of

(2) In the exhaust duct according to (1), the side wall of the duct body is arranged between an inner plate arranged on the inner peripheral surface side and an outer plate arranged on the outer peripheral surface side. It is preferable that the side portion of the cushioning plate is fixed to the heat insulating material side of the outer plate.

(3) In the ceiling portion of the exhaust duct according to any one of (1) or (2), the ceiling portion is placed in the thickness direction at a position away from a region intersecting with the bleeding pipe extending in the longitudinal direction. It is preferable that a through hole is provided through the ceiling.

(4) In the exhaust duct according to (2) , the side portion has a wall shape surrounding a space sandwiched between the ceiling portion and the side wall of the duct main body, and the side portion has the outer plate. It is preferable that a notch extending from the fixed position is provided.

(5) In the exhaust duct according to any one of (1) to (4), at least a part of the side portion of the cushioning plate has a rod shape connecting the ceiling portion and the side wall of the duct body. It is preferably composed of members.

(6) In the exhaust duct according to any one of (1) to (5), it is preferable that the shock absorber is formed by connecting a plurality of members.

(7) In the exhaust duct according to any one of (1) to (6), the duct main body has a plurality of openings on the side wall, and the ceiling portion is a plurality of the openings. It is preferable that they extend so as to face each other.

The exhaust duct of the present invention includes an bleed pipe that introduces bleed air into the duct body, and a cushioning plate that extends including an extension region thereof. This cushioning plate has a function of absorbing the impact caused by the introduction and then changing the direction of the introduced air to be guided in the direction along the side wall of the duct body. Furthermore, this buffer plate has a simpler structure than the conventional structure that requires equipment to route the bleeding pipe itself in the duct body and support it, which is required for weight reduction and its construction. Cost reduction can be realized. Therefore, since the exhaust duct of the present invention is provided with the cushioning plate, it is possible to avoid the problem that the bleed air directly hits the inner peripheral surface of the duct plate and causes damage, and the weight is reduced. It is possible to reduce the cost required for construction. Further, in the exhaust duct of the present invention, the support structure of the bleeding pipe is unnecessary, and the problem of damage thereof can be avoided.

It is a system diagram of the gas turbine provided with the exhaust duct which concerns on one Embodiment of this invention. (A) is a cross-sectional view schematically showing the configuration of the gas turbine of FIG. (B) is a cross-sectional view taken along the line α-α of the exhaust duct of FIG. (A) and (b) are an enlarged perspective view and a cross-sectional view of the shock absorber according to the first embodiment provided in the exhaust duct of FIG. 1 together with the peripheral configuration thereof. FIG. 3B is an enlarged cross-sectional view of the configuration of the connection portion between the buffer plate and the exhaust duct of FIG. 3 (b). (A), (b) is a perspective view and a cross-sectional view schematically showing the structure of the shock absorber according to the second embodiment. It is a perspective view which shows typically the structure of the shock absorbing plate which concerns on the modification of 2nd Embodiment. It is a perspective view which shows typically the structure of the cushioning plate which concerns on 3rd Embodiment. It is a perspective view which shows typically the structure of the cushioning plate which concerns on 4th Embodiment. (A), (b) is a perspective view and a cross-sectional view schematically showing the structure of the shock absorber according to the fifth embodiment. (A), (b) is a perspective view and a cross-sectional view schematically showing the structure of the shock absorber according to the sixth embodiment.

Hereinafter, the exhaust duct according to the embodiment to which the present invention is applied will be described in detail with reference to the drawings. In the drawings used in the following description, in order to make the features easier to understand, the featured parts may be enlarged for convenience, and the dimensional ratios of each component may not be the same as the actual ones. Absent. Further, the materials, dimensions, etc. exemplified in the following description are examples, and the present invention is not limited thereto, and the present invention can be appropriately modified without changing the gist thereof.

<First Embodiment>
[Exhaust duct configuration]
FIG. 1 is a system diagram of a gas turbine 10 provided with an exhaust duct 100 according to the first embodiment of the present invention. As shown in FIG. 1, the atmosphere filtered by the intake filter 104 is compressed by the air compressor 105 and then burned by the combustor 106 to become a high-temperature gas, which flows into the turbine 107. The air compressor 105, the combustor 106, the turbine 107, and the like constitute a simple single-screw gas turbine 10, and drives the generator 108. The exhaust gas (high temperature fluid) of the gas turbine 10 is discharged from the chimney 110 to the outside through the exhaust duct (high temperature duct) 100. Further, a part of the atmosphere compressed by the air compressor 105 is guided to the inside of the exhaust duct 100 via the bleeding pipe 102 at a predetermined timing such as when the gas turbine 10 is started.

FIG. 2A is a cross-sectional view schematically showing the configuration of a main part of the gas turbine 10 of FIG. FIG. 2B is a cross-sectional view taken along the line α-α of the exhaust duct 100 of FIG. The exhaust duct 100 has a tubular shape in which exhaust mainly flows as the mainstream, and is connected to the duct main body 101 having an opening 101H on the side wall from the outside and the opening 101H of the duct main body from the outside, and is connected in the radial direction of the duct main body 101. It is composed of an air extraction pipe 102 that guides air extraction toward the inside, and a cushioning plate (hood) 103 that is arranged inside the duct body 101 so as to cover the opening 101H.

3 (a) and 3 (b) are an enlarged perspective view and a cross section of the buffer plate 103 together with the configuration around the _{region R 1} including the buffer plate 103 provided in the exhaust duct 100 of FIG. 1, respectively. It is a figure. The cushioning plate 103 has a substantially plate-shaped ceiling portion 103A that faces the opening 101H, intersects the bleeding pipe 102 extending in the longitudinal direction 102L, and is arranged so as to extend in the exhaust gas flow direction 101L. There is. The ceiling portion 103A may have a flat plate shape or a curved shape. Further, the cushioning plate 103 is fixed to the side wall of the duct main body 101 and has a side portion 103B that supports the ceiling portion 103A.

A side portion 103B having a predetermined shape (here, a plate shape) is connected to an end portion of the ceiling portion 103A other than the downstream side of the exhaust gas (end portions 103a, 103b, 103c in FIG. 3A). Has been done. The ceiling portion 103A is fixed to the side wall of the duct main body 101 via the side portion 103B.

The ceiling portion 103A and the side portion 103B may be integrated or separate. The boundary portion between the ceiling portion 103A and the side portion 103B may have a shape that bends at a predetermined angle or a shape that bends smoothly in a plan view from the downstream side of the exhaust gas. Here, at the ends 103a and 103c, the boundary portion between the ceiling portion 103A and the side portion 103B has a bent shape, respectively, and the cushioning plate 103 has a substantially U-shape in a plan view from the downstream side. The case where it is is illustrated.

The side portion 103B is not connected to the end portion 103d, and the space surrounded by the duct main body 101 and the cushioning plate 103 is open. It is assumed that the opening area corresponds to the flow path area of the bleed air introduced from the bleed air pipe 102 and is equal to or larger than the flow path area of the bleed air pipe 102.

The extending direction of the ceiling portion 103A is not particularly limited, but from the viewpoint of reducing the pressure applied to the bleed air flowing in the flow path, the ceiling portion 103A advances to the downstream side so that the flow path area becomes large, and the duct main body 101 It is preferable that the opening extends in a direction away from the side wall on the side of the opening 101H.

Figure 4 is an enlarged cross-sectional view of a configuration of a connection portion R ₂ of the side wall of the buffer plate 103 and the duct body 101 in FIG. 3 (b). As shown in FIG. 4, the side walls of the duct main body 101 are the heat insulating material holding plate (inner plate) 101A arranged on the inner peripheral surface side (the side through which the exhaust gas passes) and the outer peripheral surface side (the side in contact with the outside air). It is composed of a duct plate (outer plate) 101B arranged in the above and a heat insulating material 101C arranged between the two. Examples of the heat insulating material 101C include ceramic fiber, rock wool, glass wool and the like. The heat insulating material 101C is fixed to the heat insulating material holding plate 101A and the duct plate 101B with bolts or the like.

The side portion 103B of the cushioning plate is fixed to the surface of the outer plate 101B on the heat insulating material 101C side by fillet welding or the like. In this case, the welded portion 103M is buried inside the heat insulating material 101C, so that it is less likely to receive thermal stress due to the ejection reaction force when the bleed air is ejected to the buffer plate 103, and the stability is improved. It has a structure.

The bleeding pipe 102 may have a protruding portion 102a extending inward from the opening 101H of the duct body. When the projecting portion 102a is provided, the diffusion of the bleed air introduced into the duct main body 101 can be suppressed, and the bleed air can be more reliably guided so as to collide with the ceiling portion 103A of the cushioning plate.

As described above, the exhaust duct according to the present embodiment includes an bleed pipe that introduces bleed air into the duct body, and a cushioning plate that extends including an extension region thereof. This cushioning plate has a function of absorbing the impact caused by the introduction and then changing the direction of the introduced air to be guided in the direction along the side wall of the duct body. Furthermore, this buffer plate has a simpler structure than the conventional structure that requires equipment to route the bleeding pipe itself in the duct body and support it, which is required for weight reduction and its construction. Cost reduction can be realized. Therefore, since the exhaust duct according to the present embodiment is provided with the cushioning plate, it is possible to avoid the problem that the bleed air directly hits the inner peripheral surface of the duct plate and causes damage, and the weight is reduced. , It is possible to reduce the cost required for the construction. Further, in the exhaust duct of the present invention, the support structure of the bleeding pipe is unnecessary, and the problem of damage thereof can be avoided.

<Second embodiment>
5 (a) and 5 (b) are an enlarged perspective view and a cross-sectional view of the shock absorber 203 provided in the exhaust duct according to the second embodiment of the present invention, together with the peripheral configuration thereof.

The cushioning plate 203 of the present embodiment is provided with a through hole 203H that penetrates the ceiling portion 203A in the thickness direction at a position away from the region intersecting the bleeding pipe 202 extending in the longitudinal direction 202L in the ceiling portion 203A. ing. Other configurations are the same as the configuration of the exhaust duct 100 of the first embodiment.

According to the exhaust duct of the present embodiment, the bleed air S introduced into the space surrounded by the cushioning plate 203 can be discharged not only from the opening 203D on the downstream side but also from the through hole 203H. Therefore, the directions of the ejection reaction force received by the cushioning plate 203 are dispersed, and the damage of the ejection reaction force applied to the fixed portion (welded portion) 203M of the cushioning plate 203 (side portion 203B) can be reduced, and as an exhaust facility. Reliability can be increased.

FIG. 6 is a cross-sectional view of the cushioning plate 213 according to the modified example of the second embodiment cut vertically in the longitudinal direction (direction in which bleed air flows). In this example, in the space surrounded by the cushioning plate 213, a perforated plate 214 having a plurality of through holes 214H is installed under the ceiling portion 213A. The number of perforated plates 214 is not particularly limited.

The perforated plate 214 can give a predetermined pressure loss to the bleed air that tries to pass through in the thickness direction thereof. Therefore, since the perforated plate 214 is installed as in this example, the bleed air flowing out from the through hole 213H of the ceiling portion receives more pressure loss. Since the ejection reaction force received by the buffer plate 213 is reduced by the amount of the pressure loss of the ejected bleed air, the damage of the ejection reaction force applied to the fixed portion 213M can be reduced, and the reliability as an exhaust facility can be reduced. Can be enhanced.

<Third Embodiment>
FIG. 7 is an enlarged perspective view of the cushioning plate 303 provided in the exhaust duct according to the third embodiment of the present invention, together with the configuration around the buffer plate 303.

In the cushioning plate 303 of the present embodiment, the side portion 303B has a wall shape surrounding the space sandwiched between the ceiling portion 303A and the side wall of the duct main body 301. A notch 305 extending from a position 303M fixed to the duct main body 301 (more specifically, an outer plate) is provided on the wall-shaped side portion 303B. FIG. 7 illustrates a case where the cutout portion 305 is provided on the side portion 303B extending along the flow of the bleed air S, but the side portion located on the opposite side (back side) of the flow of the bleed air S. It may be provided in 303B. The notch bottom (the portion on the duct body 301 side) of the notch 305 is preferably rounded. Other configurations are the same as the configuration of the exhaust duct 100 of the first embodiment.

The cushioning plate 303 inside the duct body 301 is easily exposed to high-temperature exhaust gas and easily expands in heat, whereas the outer plate of the duct body 301 fixing the cushioning plate 303 is covered with a heat insulating material. Hard to heat. Therefore, thermal stress is generated between the duct main body 301 and the cushioning plate 303 (side portion 303B) due to the difference in thermal elongation, and there is a possibility that the fixed portion (welded portion) 303M of both is damaged.

However, according to the exhaust duct of the present embodiment, in the notch 305 connected to the fixed portion, the heat elongation difference between the duct main body 301 and the cushioning plate 303 is absorbed by the notch, so that the welded portion Since the generation of thermal stress is suppressed, such a problem can be avoided.

<Fourth Embodiment>
FIG. 8 is an enlarged perspective view of the cushioning plate 403 provided in the exhaust duct according to the fourth embodiment of the present invention, together with the configuration around the buffer plate 403.

In the cushioning plate 403 of the present embodiment, at least a part of the side portion 403B of the cushioning plate is composed of a rod-shaped member connecting the ceiling portion 403A and the side wall of the duct main body 401. Since at least a part of the ceiling portion 403A is supported by a rod-shaped member, from the viewpoint of stability, the rod-shaped members are approximately the same at symmetrical positions across the center line C of the flow path of the bleed air S. It is preferable that the number of is arranged. FIG. 8 illustrates a case where the side portion 303B located on the opposite side (back side) of the flow of the bleed air S has a wall shape, but this portion may have a rod shape. Other configurations are the same as the configuration of the exhaust duct 100 of the first embodiment.

In the cushioning plate 403 of the present embodiment, a gap is formed between the ceiling portion 403A and the duct main body 401. Therefore, by using this gap, it is easy to implement the stage heating material or the like constituting the duct main body 301. Become.

<Fifth Embodiment>
FIG. 9A is an enlarged perspective view of the cushioning plate 503 provided in the exhaust duct according to the fifth embodiment of the present invention, together with the configuration around the buffer plate 503.

The cushioning plate 503 of the present embodiment is formed by connecting a plurality of members. That is, the cushioning plate 503 can be divided into a plurality of parts. Here, the case where four members are connected is illustrated, but the number of members to be connected is not limited. Other configurations are the same as the configuration of the exhaust duct 100 of the first embodiment.

9 (b) is a cross-sectional view taken along the line γ-γ of the buffer plate 503 of FIG. 9 (a), and shows a configuration example of a connecting portion between the members. The method of connecting the members is not particularly limited, but for example, one end side of the two members to be connected is overlapped with each other, the bolt 506 is passed through the overlapped portion from one side, and the bolt penetrated from the other side of the overlapped portion. This can be done by tightening the nut 507 to 506.

According to the exhaust duct of the present embodiment, in the connecting portion between the members constituting the cushioning plate 503, the difference in thermal elongation between the duct main body 501 and the cushioning plate 503 can be absorbed by the connecting portion, and the generation of thermal stress is suppressed. Therefore, the problem of damage to the fixed portion (welded portion) 503M described above can be avoided.

<Sixth Embodiment>
FIG. 10A is a perspective view schematically showing the configuration of the cushioning plate 603 and its surroundings according to the sixth embodiment. FIG. 10 (b) is a cross-sectional view taken along the line δ-δ of the configuration of the buffer plate 603 of FIG. 10 (a) and its surroundings.

In the present embodiment, the duct main body 601 has a plurality of openings 601H on the side wall, and the ceiling portion 603A extends so as to face any of the plurality of openings 601H. Other configurations are the same as the configuration of the exhaust duct 100 of the first embodiment.

According to the present embodiment, even when a plurality of bleed pipes are connected to the duct body, a buffer plate covering the plurality of openings can be installed in one construction (welding), and each of them can be installed. The number of man-hours can be reduced as compared with the case where one buffer plate is installed in each opening 601H.

100 ... Exhaust ducts 101, 201, 301, 401, 501 ... Duct body 101A ... Insulation material holding plate, 101B ... Duct plate 101C ... Insulation material 101H ... Opening 101L ... -Direction of exhaust flow 102, 212 ... Extraction pipe 102a ... Projection 102L ... Longitudinal direction of extraction pipe 103, 203, 213, 303, 403, 503 ... Buffer plates 103A, 203A, 303A, 403A, 503A ... Ceiling portions 103B, 203B, 213B, 303B, 403B, 503B ... Side portions 103M, 203M, 303M, 503M ... Welded portions 103a, 103b, 103c, 103d ... Edges of the ceiling portion Part 203D ... Opening 203H, 213H ... Through hole 214 ... Perforated plate 214H ... Through hole 305 ... Notch 506 ... Bolt 507 ... Nut C ... Center line S・ ・ ・ Extraction

Claims (7)

A duct body that has a tubular shape with exhaust as the mainstream and has an opening on the side wall,
An bleed pipe that is connected to the opening of the duct body from the outside and guides bleed air toward the inside in the radial direction of the duct body.
Inside the duct body, a ceiling portion is arranged so as to face the opening and intersect with the air extraction pipe extending in the longitudinal direction, and the ceiling portion is fixed to the side wall of the duct body to support the ceiling portion. With a cushioning plate with sides,
An exhaust duct characterized in that the ceiling portion extends in a direction away from the side wall of the duct body as it advances toward the downstream side of the duct body. The side wall of the duct body is composed of an inner plate arranged on the inner peripheral surface side, an outer plate arranged on the outer peripheral surface side, and a heat insulating material arranged between the two.
The exhaust duct according to claim 1, wherein the side portion of the cushioning plate is fixed to the heat insulating material side of the outer plate. Claim 1 or 2 is characterized in that, in the ceiling portion, a through hole penetrating the ceiling portion in the thickness direction is provided at a position away from a region intersecting with the air extraction pipe extending in the longitudinal direction. Exhaust duct described in any of. The side portion forms a wall shape surrounding the space sandwiched between the ceiling portion and the side wall of the duct body.
The exhaust duct according to claim 2 , wherein the side portion is provided with a notch portion extending from a position fixed to the outer plate. The invention according to any one of claims 1 to 4, wherein at least a part of the side portion of the cushioning plate is formed of a rod-shaped member connecting the ceiling portion and the side wall of the duct body. Exhaust duct. The exhaust duct according to any one of claims 1 to 5, wherein the cushioning plate is formed by connecting a plurality of members. The duct body has a plurality of openings in the side wall, and the duct body has a plurality of openings.
The exhaust duct according to any one of claims 1 to 6, wherein the ceiling portion extends so as to face any of the plurality of openings.

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