JP4773985B2 - Gas turbine combustor, support legs - Google Patents

Description

  The present invention relates to a combustor of a gas turbine, and more particularly to a support leg thereof.

The combustor of the gas turbine is arranged in an annular shape with respect to the center of the shaft in the passenger compartment, and feeds high temperature gas obtained by burning fuel into the turbine.
As shown in FIG. 4, in such a combustor, the fuel injected from the fuel nozzle 1 is ignited in the inner cylinder 2 to form a combustion flame, and the combustion gas passes through the tail cylinder 3 and the turbine section 4. It is sent to. Here, in the transition piece 3, the combustion gas reaches a high temperature of 1500 to 1600 ° C., for example, and the transition piece 3 is thermally expanded. As shown in FIG. 5, in order to allow thermal expansion of the transition piece 3, the end section 3 a on the downstream side in the flow direction of the combustion gas is fixed to the first stage stationary blade 4 a of the turbine section 4. Thus, the deformation of the transition piece 3 in the axial direction due to thermal expansion concentrates on the end portion 3b on the upstream side in the flow direction of the transition piece 3. The tail cylinder 3 is also deformed (enlarged) in the radial direction by thermal expansion. For this reason, the end portion 3b on the upstream side in the flow direction of the tail tube 3 is aligned with the end portion of the inner tube 2 along the flow direction of the combustion gas (hereinafter referred to as the length direction as appropriate). Even when it expands and contracts and is deformed in the radial direction, it is connected via a leaf spring-like seal member 5 so that the sealed state with the inner cylinder 2 can always be maintained.

Further, a support structure for the tail cylinder 3 for allowing thermal expansion of the tail cylinder 3 has been conventionally employed (see, for example, Patent Document 1).
The end 3b on the upstream side in the flow direction of the transition piece 3 is supported in the casing 7 by the support legs 6 so as to allow deformation in the longitudinal direction and deformation in the radial direction of the transition piece 3 at the outer periphery thereof. ing. The support leg 6 includes an upper support member 8 connected to the outer peripheral surface of the tail cylinder 3, and a lower support member 9 having a base end fixed to the vehicle compartment 7 and a distal end connected to the upper support member 8. Is done.
The upper support member 8 is formed of a leaf spring in which both end portions 8b and 8b are arranged in a substantially U shape or a substantially V shape with respect to the central portion 8a connected to the lower support member 9, and both end portions 8b , 8b are elastically deformed to absorb thermal deformation in the radial direction of the transition piece 3.
The lower support member 9 has a plate-like support plate 9 a, and the support plate 9 a has an in-plane direction perpendicular to the axial direction of the tail tube 3 with the thickness direction of the support plate 9 a coinciding with the length direction of the tail tube 3. Are arranged. The support plate 9a is elastically deformed in the thickness direction to absorb thermal deformation in the length direction of the tail tube 3.

Japanese Utility Model Publication No. 61-34365

However, the conventional support structure for the transition piece 3 has the following problems.
First, high frequency vibration generated by the operation of the combustor is input to the upper support member 8 made of a leaf spring in the lateral direction, which may cause fatigue fracture. For this reason, ingenuity to avoid local concentration of stress is made by processing so as not to damage the surface of the upper support member 8, increasing the surface roughness, or rounding the acute angle portion. It was. Conventionally, the upper support member 8 has been made of an alloy material mainly composed of nickel and having high heat resistance and corrosion resistance. However, such a material has a high material cost in the first place and is difficult to process. For this reason, there has been a problem that the processing for increasing the surface roughness or rounding the acute angle portion is also costly.
The present invention has been made based on such a technical problem, and an object of the present invention is to provide a gas turbine combustor and a support leg that can reliably support the tail cylinder of the combustor at a low cost. And

The gas turbine combustor according to the present invention, which has been made for this purpose, includes a combustor body that generates combustion gas by mixing and combusting air and fuel compressed by a compressor, and a downstream side of the combustor body. And a tail tube that feeds combustion gas to the turbine section. The tail tube has a downstream end fixed to the turbine portion, an upstream end connected to the combustor body so as to be relatively movable in the axial direction of the tail tube, and supported by a support leg in the gas turbine casing. The support legs are plate-like elastically deformed in the direction of the combined vector of the thermal deformation in the axial direction of the tail cylinder and the thermal deformation in the radial direction when the combustion gas generated in the combustor body passes through the tail cylinder. It has an elastic deformation part, and this elastic deformation part inclines with respect to the surface orthogonal to the axis line of a tail cylinder.
When the combustion gas generated in the combustor body passes through the transition piece and is sent to the turbine section, the transition piece is thermally deformed by the heat of the combustion gas. Since the downstream end of the transition piece is fixed to the turbine section, this thermal deformation is concentrated on the upstream end portion of the transition piece that is connected to the combustor body so as to be relatively movable in the axial direction. At this time, if the transition tube of the gas turbine combustor is supported by the support leg having the inclined elastic deformation portion as described above, the deformation of the transition tube in the axial direction and the radial direction generated at the upstream end portion of the transition tube. This deformation is absorbed by the elastic deformation of the elastic deformation portion of the support leg.

The elastic deformation portion may be provided with an inclination angle θ on the downstream side in the flow direction of the combustion gas with the base end portion on the tail tube side as the center with respect to the plane orthogonal to the axis of the tail tube. The inclination angle θ is set based on the deformation amount ΔL in the axial direction of the transition piece and the deformation amount ΔR in the radial direction of the transition piece when the combustion gas generated in the combustor body passes through the transition piece,
θ = tan ⁻¹ (ΔR / ΔL)
It can also be.

Further, it is also preferable that the elastically deforming portion of the support leg is disposed with the tip end portion on the tail tube side being offset to the downstream side in the combustion gas flow direction with respect to the base end portion on the gas turbine casing side. The offset amount S at that time is
S = (ΔL ² + ΔR ² ) ^0.5 / 2
Is preferable.
Thereby, what is called a cold offset can be provided to the elastic deformation part of a support leg.

Moreover, this invention can also be used as the support leg for fixing the tail cylinder for sending the combustion gas produced | generated with the combustor of the gas turbine to a turbine part to a gas turbine compartment. The support leg includes a base end portion fixed to the gas turbine casing, a tip end portion fixed to a tail cylinder for feeding combustion gas generated by the combustor to the turbine portion, and a base end portion and a tip end portion. And an elastically deformable portion that is elastically deformable in response to thermal deformation of the tail tube when combustion gas generated in the combustor passes through the inside of the tail tube. Then, the elastically deforming portion is formed so as to be inclined by an inclination angle θ with respect to the surface perpendicular to the axis of the tail tube, with the base end portion as the center, in the combustion gas flow direction, when attached to the tail tube. The inclination angle θ is obtained when ΔL is a deformation amount in the axial direction of the transition piece when the combustion gas generated in the combustor passes through the transition piece, and ΔR is a deformation amount in the radial direction of the transition piece.
θ = tan ⁻¹ (ΔR / ΔL)
It is characterized by being.
The gas turbine combustor of the present invention as described above can be configured by fixing the tail cylinder to the gas turbine casing using such support legs. Such a support leg can be applied not only to a new gas turbine but also to an existing gas turbine.

  According to the present invention, the support leg at the upstream end of the combustor's tail tube is provided to be inclined with respect to the axis of the tail tube by a predetermined inclination angle θ, so that the combustion gas generated in the combustor can be reduced. The deformation in the axial direction and the radial direction of the tail tube due to heat can be absorbed only by the elastic deformation portion of the support leg. Therefore, a leaf spring-like support member for absorbing the deformation in the radial direction of the transition piece as in the prior art becomes unnecessary, and the cost of the support leg can be reduced. In addition, since the tail cylinder can be supported only by the elastically deforming portion, the support rigidity of the tail cylinder is improved as compared with the conventional configuration using a plate spring-like support member, and the vibration of the combustor that can be caused by combustion vibration is effectively achieved. It becomes possible to suppress.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.
FIG. 1 is a view for explaining a support structure of a combustor in the present embodiment.
As shown in FIG. 1, the gas turbine 10 is provided with an air intake port 11, a compressor 12, a combustor (combustor body) 13, and a turbine unit 14 from the upstream side to the downstream side of the air flow. ing.
The air taken in from the air intake 11 is compressed by the compressor 12 and is sent to the combustor 13 as high-temperature and high-pressure compressed air. In the combustor 13, gas fuel such as natural gas or liquid fuel such as light oil or light heavy oil is supplied to the compressed air to burn the fuel, thereby generating high-temperature and high-pressure combustion gas. This high-temperature and high-pressure combustion gas is injected into the turbine section 14 and expands in the turbine section 14 to rotate the turbine section 14. The generator connected to the main shaft 15 of the gas turbine 10 is driven by the rotational energy of the turbine unit 14.

The combustor 13 ignites the fuel ejected from the fuel nozzle 21 to heat the compressed air from the compressor 12 and generate combustion gas. The combustor 13 is provided with an inner cylinder 22 that forms a combustion gas flow path downstream of the fuel nozzle 21. On the further downstream side of the inner cylinder 22 of the combustor 13, a tail cylinder 23 is provided that forms a flow path for sending combustion gas that has passed through the inner cylinder 22 to the turbine section 14.
Here, the combustor 13 including the fuel nozzle 21 and the inner cylinder 22 is fixed to the housing 16 of the gas turbine 10.

On the other hand, the transition piece 23 has a tapered shape in which the inner diameter gradually decreases from the upstream side to the downstream side in the flow direction of the combustion gas, and the downstream end in the flow direction of the combustion gas is fixed to the turbine portion 14 by the fixing bracket 25. It is fixed to the first stage stationary blade 14a. Further, as shown in FIG. 2, the upstream end portion of the transition piece 23 is supported by the casing 17 of the gas turbine 10 by the support leg 30.
The support leg 30 is bolted to a fixed base 17a formed on the surface of the vehicle compartment 17 at the base end 30a, and is bolted to a mounting base 23a formed on the outer peripheral surface of the tail cylinder 23. Yes. A flexible plate (elastic deformation portion) 31 having flexibility is provided between the base end portion 30a and the distal end portion 30b. In the present embodiment, for example, two flexible plates 31 are provided in parallel with a gap therebetween. Here, the number of flexible plates 31 may be one, or may be three or more. These flexible plates 31 are set to have a thickness and a width that can sufficiently support the load of the tail cylinder 23. The flexible plate 31, against the plane perpendicular to the axis of the transition piece 23 is formed so as to be positioned in a predetermined tilt angle θ only inclined plane.

Here, the inclination angle θ is set based on the ratio between the amount of deformation ΔL in the axial direction and the amount of deformation ΔR in the radial direction due to the thermal expansion of the tail tube 23 when the combustion gas passes through the tail tube 23. Since the downstream end of the transition piece 23 is fixed to the stationary blade 14a, the displacement of the thermal expansion deformation in the axial direction of the transition piece 23 due to the heat of the combustion gas occurs at the upstream end, which is the amount of deformation described above. ΔL. The temperature of the combustion gas generated in the combustor 13 is 1500 to 1600 ° C. Even if the ambient temperature fluctuates according to seasonal fluctuations, installation environment, etc., the deformation amount ΔL in the axial direction of the tail cylinder 23 and the radial direction The ratio of the deformation amount ΔR is substantially constant. Here, the deformation amount ΔL in the axial direction and the deformation amount ΔR in the radial direction of the transition piece 23 are relative differences from the thermal deformation that similarly occurs in the passenger compartment 17.
Therefore, in the transition piece 23, based on the deformation amount ΔL in the axial direction and the deformation amount ΔR in the radial direction in the temperature region when the combustion gas is generated in the combustor 13,
θ = tan ⁻¹ (ΔR / ΔL)
The inclination angle θ is set so that

With such a configuration, when the tail tube 23 is displaced by thermal expansion, the support leg 30 absorbs the displacement by the elastic deformation of the flexible plate 31. The flexible plate 31, since the inclined against the plane perpendicular to the axis of the tilt angle θ only transition piece 23, the distal end portion of the flexible plate 31 has a deformation in the axial direction of the transition piece 23, deformation in the radial direction Is displaced in a direction substantially along the direction of the combined vector V. Thereby, both the deformation in the axial direction and the deformation in the radial direction of the tail cylinder 23 are absorbed by the elastic deformation of the flexible plate 31.

In this way, the support legs 30 of the upstream end of the transition piece 23 of the combustor 13, against the plane perpendicular to the axis of the transition piece 23, by providing with an inclination by the inclination angle θ a predetermined combustion The deformation of the transition piece 23 due to the heat of the combustion gas generated in the vessel 13 can be absorbed only by the flexible plate 31. Therefore, the plate spring-like upper support member 8 (see FIG. 5) is not required as in the prior art, and the cost of the support leg 30 can be reduced. In addition, as a result, the support rigidity of the tail cylinder 23 is improved as compared with the conventional configuration using the upper support member 8, and vibration of the combustor 13 that can be caused by combustion vibration can be effectively suppressed.

By the way, the support leg 30 can be configured as follows.
That is, as shown in FIG. 3, the flexible plate (elastically deforming portion) 31 ′ of the support leg 30 ′ is curved in a substantially S shape at the intermediate portion in the longitudinal direction, and is formed at the base end portion 31 a ′ on the vehicle compartment 17 side. On the other hand, a predetermined offset amount with respect to a surface (surface on which the flexible plate 31 of FIG. 2 is located) on which the distal end portion 31b ′ on the tail tube 23 side passes through the proximal end portion 31a ′ and is inclined by the inclination angle θ described above. A configuration in which only S is offset may be employed.
Here, the offset amount S is based on the deformation amount ΔL in the axial direction and the deformation amount ΔR in the radial direction due to the thermal expansion of the transition piece 23,
S = (ΔL ² + ΔR ² ) ^0.5 / 2
Set to be.
The tip portion 30b ′ of the support leg 30 ′ is displaced by the deformation amount ΔL in the axial direction and the deformation amount ΔR in the radial direction by the thermal expansion of the tail tube 23. Therefore, when an offset of 1/2 of the composite vector V is set at the distal end portion 31b ′ of the flexible plate 31 ′, the base end portion 30a ′ of the support leg 30 ′ is caused by the elastic deformation of the flexible plate 31 ′ of the support leg 30 ′. The load acting on the bolt for fixing the to the casing 17 is reduced. As a result, it is possible to improve the durability of the mounting portion of the support leg 30 ′ in the compartment 17.

In the above embodiment, the configuration of the gas turbine 10 has been described. However, the configuration of each part of the gas turbine 10 can be changed as appropriate within the scope of the gist of the present invention.
In addition to this, as long as it does not depart from the gist of the present invention, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate.

It is a figure which shows schematic structure of the gas turbine in this Embodiment. It is the side view and sectional drawing which show the support leg of a combustor. It is a figure which shows the other example of a support leg. It is a figure which shows the combustor using the conventional support leg. It is the side view and sectional drawing which show the conventional support leg.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Gas turbine, 12 ... Compressor, 13 ... Combustor (combustor main body), 14 ... Turbine part, 17 ... Car compartment, 23 ... Tail tube, 30 ... Supporting leg, 31, 31 '... Flexible plate (elastic deformation) Part), 31a '... proximal end part, 31b' ... distal end part

Claims (4)

A combustor body that generates combustion gas by mixing and combusting air and fuel compressed by a compressor;
A tail tube that is arranged downstream of the combustor body and feeds the combustion gas into the turbine section;
With
The tail tube has a downstream end fixed to the turbine unit, and an upstream end connected to the combustor body so as to be relatively movable in the axial direction of the tail tube and supported by the gas turbine casing. Supported by legs,
The support leg is elastically deformed in the direction of a combined vector of thermal deformation in the axial direction and thermal deformation in the radial direction of the tail tube when the combustion gas generated in the combustor body passes through the tail tube. A gas turbine combustor having a plate-like elastic deformation portion, wherein the elastic deformation portion is inclined with respect to a plane orthogonal to the axis of the tail tube. The elastic deformation portion is provided to be inclined by an inclination angle θ on the downstream side in the flow direction of the combustion gas with a base end portion on the tail tube side as a center with respect to a surface orthogonal to the axis of the tail tube,
The inclination angle θ represents ΔL as a deformation amount in the axial direction of the transition piece when the combustion gas generated in the combustor main body passes through the transition piece, and a deformation amount in the radial direction of the transition piece as a result. When ΔR,
θ = tan ⁻¹ (ΔR / ΔL)
The gas turbine combustor according to claim 1, wherein: The elastic deformation portion is arranged such that the tip portion on the tail tube side is offset by an offset amount S on the downstream side in the flow direction of the combustion gas with respect to the base end portion on the gas turbine casing side,
The offset amount S is
S = (ΔL ² + ΔR ² ) ^0.5 / 2
The gas turbine combustor according to claim 1, wherein the gas turbine combustor is a gas turbine combustor. A support leg for fixing a tail tube for sending combustion gas generated by a combustor of a gas turbine to a turbine section in a gas turbine casing,
A base end fixed to the gas turbine casing;
A tip portion fixed to a transition piece for sending combustion gas generated in the combustor to a turbine portion;
An elastically deformable portion that is formed between the base end portion and the tip end portion and is elastically deformable in accordance with thermal deformation of the tail tube when the combustion gas generated by the combustor passes through the inside of the tail tube; ,
Have
The elastically deforming portion is attached to the transition piece so as to be inclined by an inclination angle θ with respect to a surface perpendicular to the axis of the transition piece, with the base end portion as a center and downstream of the combustion gas flow direction. Formed into
The inclination angle θ is defined as ΔL as a deformation amount in the axial direction of the transition piece when the combustion gas generated in the combustor passes through the transition piece, and ΔR as a deformation amount in the radial direction of the transition piece. When
θ = tan ⁻¹ (ΔR / ΔL)
The support leg characterized by being.

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