JP2010025006A - Exhaust diffuser of gas turbine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust diffuser of a gas turbine for lengthening the service life by restraining thermal stress with an economical and simple structure, without requiring study of a design change in a gas turbine facility. <P>SOLUTION: The exhaust diffuser of the gas turbine is arranged in an exhaust flue part for exhausting exhaust gas 2 of the gas turbine to an external part, and is composed of an outside cylinder body 1, an inside cylinder body 4A and a strut 5 arranged between these cylinder bodies. The strut 5 is a hollow cylindrical body having a cooling passage for connecting the outside cylinder body 1 and the inside cylinder body 4A. Joining members 6B and 6A having the peripheral edge joined to the outside cylinder body 1 and/or the inside cylinder body 4A, are arranged on the opening end of the strut 5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an exhaust diffuser of a gas turbine, and more particularly, to an exhaust diffuser of a gas turbine in which cooling air passes through a strut provided between an outer cylinder and an inner cylinder constituting the exhaust diffuser.

  In general, gas turbine equipment includes a compressor that compresses intake air to obtain compressed air for combustion, a combustor that burns compressed air from the compressor together with fuel, and generates high-temperature and high-pressure combustion gas, and the combustion And a turbine that obtains the rotational power of the rotor by the combustion gas from the vessel. Further, in order to restore the static pressure of the combustion gas after driving the rotor, the exhaust flue portion connected to the combustion gas outlet of the turbine is provided with an exhaust diffuser having a double cylindrical structure, for example.

Such an exhaust diffuser includes, for example, an outer cylinder that also serves as a casing through which combustion gas passes, an inner cylinder disposed inside the casing, and a hollow strut provided radially between the cylinders at intervals in the circumferential direction. In this type of exhaust diffuser, since cooling air flows into the strut, the outer surface and the inner tube of the outer cylinder that communicate with the inner surface of the strut and the outer and inner ends of the strut, respectively. The inner surface of the body is exposed to this cooling air. On the other hand, the outer surface of the strut, the inner surface of the outer cylinder, and the outer surface of the inner cylinder are exposed to about 650 ° C. exhaust gas.

  As a result, thermal stress due to the temperature difference between the inner and outer surfaces is generated in the strut, the outer cylinder, and the inner cylinder. For this reason, if this thermal stress is repeated by starting and stopping of the gas turbine, thermal fatigue damage occurs in the welded portion that is a connecting portion between the strut and the outer and inner cylinders. Furthermore, when this thermal fatigue damage progresses, a large crack that penetrates the thickness of the outer and inner cylinders is caused.

  In response to such a problem, by making the strut thickness thicker than the casing (outer cylinder), the responsiveness to thermal deformation of the strut is lowered and the heat of the casing (outer cylinder) is relatively reduced. Improved responsiveness of deformation, thereby suppressing excessive thermal stress between the strut and the casing (outer cylinder) caused by the difference in thermal expansion due to the temperature difference, and extending the life of the device There are some (for example, refer to Patent Document 1).

JP 2008-31871 A

  However, in the strut structure described in Patent Document 1 described above, since the strut is formed thicker than the casing (outer cylinder), the weight of the strut increases. As a result, it may be necessary to study a design change of the gas turbine facility from the viewpoint of strength. Further, for example, when welding the strut and the casing (outer cylinder), it is necessary to increase the amount of welding, which may increase the repair cost as well as the manufacturing cost.

  For this reason, there is a need for a gas turbine exhaust diffuser that can improve performance with an economical and simple structure without requiring examination of design changes of these gas turbine facilities.

  The present invention has been made on the basis of the above-mentioned matters, and its object is to reduce the thermal stress with an economical and simple structure without extending the design of the gas turbine equipment and to extend the service life. Another object is to provide an exhaust diffuser for a gas turbine.

  (1) In order to achieve the above object, the present invention is provided in an exhaust flue for exhausting exhaust gas of a gas turbine to the outside, and has an outer cylinder, an inner cylinder, and struts provided between these cylinders. In the exhaust diffuser of a gas turbine, the strut is a hollow cylindrical body having a cooling passage that connects the outer cylindrical body and the inner cylindrical body, and the outer cylindrical body is disposed at an opening end of the strut. And / or the joining member which has the periphery joined to the said inner side cylinder is provided.

  (2) In the above (1), preferably, the joining member is located on an opening end side of the strut in an exhaust gas passage formed by an inner surface of the outer cylinder and an outer surface of the inner cylinder. It shall be provided.

  (3) In the above (1), preferably, the joining member is provided on the opening end side of the strut on the outer surface of the outer cylinder and the inner surface of the inner cylinder, and the peripheral edge of the one joining member And the outer surface of the outer cylinder, the periphery of the other joining member, and the inner surface of the inner cylinder.

  (4) In the above (1), preferably, the joining member is on the opening end side of the strut in the exhaust gas flow path formed by the inner surface of the outer cylinder and the outer surface of the inner cylinder. It is provided and welded to the periphery of said one joining member, the inner surface of the said outer cylinder, and the periphery of said other joining member, and the outer surface of the said inner cylinder.

  (5) In any one of the above (1) to (4), preferably, the joining member is provided only on the opening end side of the strut in the inner cylindrical body.

  (6) In any one of the above (1) to (4), preferably, the joining member is provided only on the opening end side of the strut in the outer cylindrical body.

  (7) In any one of the above (1) to (6), preferably, the joining member is an annular body.

  (8) In any one of the above (1) to (6), preferably, the joining member is a protruding body.

  According to the present invention, since the weld toe portion of the strut is not present in the same cross section in the gas turbine exhaust diffuser thickness direction, the stress concentration portion due to thermal expansion caused by the temperature difference between the exhaust gas and the cooling air is eliminated. Superposition can be avoided. As a result, it is possible to improve the strength of the exhaust diffuser against thermal fatigue damage that occurs from the weld toe as a starting point, and to extend the life of the exhaust diffuser by suppressing thermal stress with an economical and simple structure. Can do.

Embodiments of an exhaust diffuser for a gas turbine according to the present invention will be described below with reference to the drawings.
FIG. 1 is a side view of a gas turbine provided with a first embodiment of a gas turbine exhaust diffuser of the present invention in a partial cross section. In FIG. 1, a turbine section 52 of a gas turbine 100 includes a cylindrical turbine casing 1 that accommodates the whole, a shroud (not shown) that is installed in a plurality of stages in the axial direction on the inner peripheral side of the casing 1, and A plurality of stationary blades 50 that are engaged and supported by the shrouds of each stage and are installed in a ring shape, and a plurality of rotor blades 51 that are arranged between the stationary blades 50 of each stage are arranged in a ring shape on the outer periphery. And a turbine rotor 55 installed individually. The gas turbine 100 also compresses the intake air a to obtain compressed air for combustion and cooling, and burns the compressed air from the compressor 53 together with fuel to generate high-temperature and high-pressure combustion gas. And a combustor 54. In addition, the exhaust flue portion connected to the combustion gas outlet of the turbine portion 52 is provided with an exhaust diffuser 3 on the outer peripheral side and an exhaust diffuser 4 on the inner peripheral side of a double cylindrical structure.

  The exhaust diffuser 4 on the inner peripheral side includes an inner cylinder 4 </ b> A inside the casing 1. A bearing housing 11a is provided in the space 12 in the inner cylindrical body 4A so as to be vertically divided into two. A bearing 11 that rotatably supports the turbine rotor 55 is provided in the bearing housing 11a. The bearing housing 11a is supported by the inner cylinder 4A via a support member 11b. Further, the rear shaft end of the turbine rotor 55 is disposed so as to coincide with the rear shaft end of the bearing housing 11a. A concentric disk-shaped partition plate 11c is provided at the axially front end of the exhaust diffuser 4 on the inner peripheral side and the bearing housing 11a. The exhaust diffuser 3 on the outer peripheral side includes a casing 1, an inner cylindrical body 4 </ b> A disposed inside the casing 1, and hollow struts 5 provided radially between the casing 1 and the inner cylindrical body 4 </ b> A in the circumferential direction. Has been.

  The combustion gas H generated at the combustion device 54 and having a combustion temperature of about 1300 ° C. is injected to the moving blade 51 through the stationary blade 50 and drives the turbine section 52. Thereafter, the combustion gas H that has driven the turbine section 52 becomes the exhaust gas 2 at about 650 ° C., and is discharged to the outside of the gas turbine 100 through the exhaust diffusers 3 and 4 constituting the exhaust flue section.

  Next, a detailed configuration of the exhaust diffusers 3 and 4 in the exhaust flue portion described above will be described with reference to FIGS. 2 is a cross-sectional view showing a first embodiment of an exhaust diffuser of a gas turbine of the present invention, FIG. 3 is a longitudinal front view of the exhaust diffuser on the outer peripheral side as viewed from the arrow III-III in FIG. 4 is a longitudinal front view of the exhaust diffuser on the outer peripheral side viewed from the arrow IV-IV in FIG. 3, and FIG. 5 is a sectional view of the strut of the exhaust diffuser on the outer peripheral side viewed from the arrow V-V in FIG. FIG. 6 is a perspective view of a strut constituting the gas turbine exhaust diffuser of the present invention shown in FIG. In these drawings, the same reference numerals as those shown in FIG.

  The exhaust diffuser 3 on the outer peripheral side in the exhaust flue portion forms an exhaust gas flow path portion 7 through which the exhaust gas 2 of the gas turbine 100 passes between the inner surface of the casing 1 and the outer peripheral surface of the inner cylinder 4A. Yes. In this example, three struts 5 are provided at equal intervals around the rotor rotation axis between the casing 1 and the outer peripheral surface of the inner cylindrical body 4A as shown in FIG. Since the strut 5 is disposed so as to cross the flow path 7 of the exhaust gas 2 of the gas turbine 100, the strut 5 is shown in FIG. 5 in order to reduce the resistance of the strut 5 to the flow of the exhaust gas 2. As described above, the cross section of the hollow cylindrical body is streamlined.

  As shown in FIGS. 3, 4, and 6, the strut 5 is provided with colored joints 6 </ b> A and 6 </ b> B on the outer periphery of the inner opening end and the outer opening end. The joined bodies 6A and 6B have a dimension of a diameter LD larger than the diameter D of the insertion hole of the strut 5 provided in the casing 1 and the inner cylinder 4A. The joined bodies 6 </ b> A and 6 </ b> B may be attached to the strut 5 by welding or an adhesive, or may be formed integrally with the strut 5 in advance.

  When connecting the strut 5 to the casing 1 and the inner cylinder 4A, for example, when using the strut 5 in which the joined body 6B is integrally formed in advance on the outer peripheral portion of one (outside) opening end of the strut 5, first, The other open end of the strut 5 is inserted into a hole provided in the casing 1 and a hole provided in the inner cylinder 4A, and protrudes to the inner side of the inner cylinder 4A. After the inner joined body 6A is fitted and attached to the outer peripheral portion of the other opening end of the strut 5 protruding inside the inner tubular body 4A, the corner between the peripheral edge of the joined body 6A and the inner side surface of the inner tubular body 4A. A welded portion 10A is formed at the portion, and the periphery of the joined body 6A and the inner cylindrical body 4A are joined.

  Next, a welded portion 10B is formed at the corner between the periphery of the joined body 6B and the outer surface of the casing 1, and the periphery of the joined body 6B and the casing 1 are joined.

  Next, a welded portion 9A is provided at the corner between the outer peripheral surface of the inner diameter side of the strut 5 and the outer surface of the inner cylindrical body 4A, the outer peripheral surface of the outer diameter side of the strut 5 and the inner surface of the casing 1. The welded portion 9B is applied to each corner. As a result, the joined body 6 </ b> A applied to the strut 5 is disposed inside the inner cylindrical body 4 </ b> A, and the joined body 6 </ b> B is disposed outside the casing 1. The welds 9A, 9B, 10A, and 10B for welding and fixing the strut 5 and the joined bodies 6A and 6B to the inner cylinder 4A and the casing 1 are provided on the cooling air flow path side through which the cooling air 8 of the gas turbine 100 passes. There are four welded portions, that is, two welded portions on the exhaust gas side on the exhaust gas passage portion side through which the exhaust gas 2 of the gas turbine 100 passes.

  And as shown in FIG.3 and FIG.4, these welding toe parts do not exist in the same cross section of the thickness direction of the casing 1 and the inner side cylinder 4A, as shown in FIG.3 and FIG.4, and the welding parts 9A, 9B, 10A, 10B, The strut 5 is arranged with a deviation outward with respect to the radial direction of the strut 5.

  According to the first embodiment of the exhaust diffuser of the gas turbine of the present invention described above, the toe ends of the welds 9A, 9B, 10A, 10B are the same cross section in the thickness direction of the casing 1 and the inner cylinder 4A. Therefore, it is possible to avoid the superposition of stress concentration portions due to thermal expansion caused by the temperature difference between the exhaust gas 2 and the cooling air 8. As a result, it is possible to improve the strength of the exhaust diffusers 3 and 4 against thermal fatigue damage that occurs from the weld toe as a starting point, and to suppress the thermal stress with an economical and simple structure, thereby reducing the exhaust diffusers 3 and 4. Long life can be achieved.

  Further, according to the present embodiment, the strength of the connecting portion can be equalized with the same welding amount as the conventional welding amount, and the occurrence of cracks that are thermal fatigue damage of the welding portion as described above is suppressed. it can. As a result, exhaust gas leakage caused by wall cracks in the exhaust diffusers 3 and 4 can be reduced, and an increase in the atmospheric temperature of the inner peripheral exhaust diffuser inner surface 12 and an increase in the atmospheric temperature of the gas turbine enclosure can be prevented. The reliability of gas turbine equipment can be improved.

  Furthermore, since the occurrence of thick through cracks in the exhaust diffuser 3 on the outer peripheral side and the exhaust diffuser 4 on the inner peripheral side can be suppressed, repair welding work at the time of periodic inspection of the gas turbine equipment can be reduced. As a result, the economic efficiency of the gas turbine facility can be improved.

  Further, since the conventional attachment of the strut 5 to the exhaust diffuser 3 on the outer peripheral side and the exhaust diffuser 4 on the inner peripheral side is a punch-through structure, temporary welding is required. Since the strut 5 in the present embodiment is provided with the collar-like joined bodies 6A and 6B, the radial positioning is facilitated and the workability can be improved.

  Further, since the collar-like joined bodies 6A and 6B are installed outside the exhaust diffuser 3 on the outer peripheral side and inside the exhaust diffuser 4 on the inner peripheral side, the outer periphery of the welded portions 9A and 9B on the exhaust gas side is caused by thermal stress. Even if a large crack that penetrates through the wall thickness of the exhaust diffuser 3 on the side and the exhaust diffuser 4 on the inner peripheral side occurs, the sealing performance of the exhaust gas flow path portion 7 is maintained by the collar-shaped joined bodies 6A and 6B. As a result, no leakage of the exhaust gas 2 to the outside of the exhaust gas flow path portion 7 occurs, and an increase in the atmospheric temperature of the inner surface 12 of the exhaust diff user inner space 12 and an increase in the atmospheric temperature of the gas turbine enclosure are prevented. The reliability of the equipment can be improved.

  FIGS. 7 and 8 show a second embodiment of the exhaust diffuser of the gas turbine of the present invention. FIG. 7 is a longitudinal front view of a strut portion used in the exhaust diffuser of the gas turbine of the present invention. These are the perspective views of the strut used for the exhaust diffuser of the gas turbine of this invention shown in FIG. 7 and 8, the same reference numerals as those shown in FIGS. 3 to 6 are the same or corresponding parts, and the description thereof is omitted.

  In the present embodiment, the collar-like joined bodies 6A and 6B provided on the strut 5 are provided on the opening end side of the strut 5 so that they are located on the exhaust gas 2 side, that is, the exhaust gas flow path portion 7 side. It is. The strut 5 is connected to the casing 1 and the inner cylindrical body 4A by welding the inner surface of the casing 1 and the outer periphery of one joined body 6B with a welded portion 9B, and connecting the outer surface of the inner cylindrical body 4A to the other side. The outer periphery of the joined body 6A is welded and connected by the welding portion 9A. Next, the outer surface of the casing 1, the inner surface of the inner cylinder 4 </ b> A and the connecting portion on the cooling air flow path side of the strut 5 are welded and connected by welding portions 10 </ b> B and 10 </ b> A.

  According to the second embodiment of the inner and outer peripheral wall connection structure of the gas turbine exhaust diffuser of the present invention, the same effects as those of the first embodiment described above can be obtained.

  9 and 10 show a third embodiment of the exhaust diffuser of the gas turbine of the present invention. FIG. 9 is a longitudinal front view of a strut portion used in the exhaust diffuser of the gas turbine of the present invention. These are the perspective views of the struts used for the exhaust diffuser of the gas turbine of this invention shown in FIG. 9 and 10, the same reference numerals as those shown in FIGS. 3 to 6 are the same or corresponding parts, and the description thereof is omitted.

  In the present embodiment, the joined bodies 6A and 6B are formed separately from the struts 5 and provided at the one side opening end and the other side opening end of the strut 5, respectively. As shown in FIG. 9, the joined bodies 6 </ b> A and 6 </ b> B have a height dimension T so as to protrude from the end face of each open end of the strut 5. Therefore, in order to connect the strut 5 to the casing 1 and the inner cylinder 4A, first, the strut 5 is inserted into the hole provided in the casing 1 and the hole provided in the inner cylinder 4A, and the strut 5 protrudes outside the casing 1. The joined bodies 6B and 6A are fitted into the inner portion and the protruding portion toward the inner side of the inner cylindrical body 4A. Next, a welded portion 13A is formed at the corner between the inner peripheral edge of the joined body 6A and the end face of the one-side opening end of the strut 5, and the joined body 6A and the strut 5 are joined. Similarly, a welded portion 13B is formed at the corner between the inner peripheral edge of the joined body 6B and the end face of the other opening end of the strut 5 to join the joined body 6B and the strut 5 together.

  Next, a welded portion 10A is formed at the corner between the outer peripheral edge of the joined body 6A and the inner side surface of the inner cylindrical body 4A, and the outer peripheral edge of the joined body 6A and the inner cylindrical body 4A are joined.

  Next, the welding part 10B is formed in the corner part of the outer periphery of the joined body 6B and the outer surface of the casing 1, and the outer periphery of the joined body 6B and the casing 1 are joined. As a result, the joined body 6 </ b> A applied to the strut 5 is disposed inside the inner cylindrical body 4 </ b> A, and the joined body 6 </ b> B is disposed outside the casing 1. The welded portions 10A, 10B, 13A, 13B for welding and fixing the struts 5 and the joined bodies 6A, 6B to the inner cylinder 4A and the casing 1 are all cooling air flow passage portions through which the cooling air 8 of the gas turbine 100 passes. There will be 4 places on the side.

  And as shown in FIG. 9, welding part 10A, 10B, 13A, 13B does not have these welding toe parts in the same cross section of the thickness direction of the casing 1 and the inner side cylinder 4A. It is arranged with a deviation outward from the radial direction.

  According to the third embodiment of the exhaust diffuser of the gas turbine of the present invention, the same effect as that of the first embodiment described above can be obtained, and the thickness T of the joined bodies 6A and 6B can be increased. By providing, the intensity | strength of a connection part can be made equivalent by the same welding amount as the conventional welding amount. Further, the welded portions 10A, 10B, 13A, and 13B can all be the cooling air side welded portion 10. As a result, the toe ends of the welded portions 10A, 10B, 13A, and 13B do not exist in the same cross section in the thickness direction of the casing 1 and the inner cylindrical body 4A, so that the exhaust diffusers 3 and 4 and the strut 5 are connected. In addition to avoiding the superposition of stress concentration parts due to thermal expansion that occurs in the part, the thermal fatigue damage of the welded part caused by the temperature difference between the exhaust gas 2 and the cooling air 8 is suppressed, and the inner peripheral exhaust diffuser inner surface space due to exhaust gas leakage 12 atmosphere temperature rise and gas turbine enclosure atmosphere temperature rise can be prevented.

  11 and 12 show a fourth embodiment of the exhaust diffuser of the gas turbine of the present invention. FIG. 11 is a longitudinal front view of a strut portion used in the exhaust diffuser of the gas turbine of the present invention. These are the perspective views of the strut used for the exhaust diffuser of the gas turbine of this invention shown in FIG. 11 and 12, the same reference numerals as those shown in FIGS. 3 to 6 are the same or corresponding parts, and the description thereof is omitted.

  This embodiment is basically the same as the third embodiment, except that the joined bodies 6A and 6B are arranged on the opening side between the outer surface side of the inner cylindrical body 4A in the strut 5 and the inner surface side of the casing 1, That is, they are provided on the exhaust gas flow path side. Therefore, the connection between the strut 5 and the casing 1 and the inner cylinder 4A is, for example, by first inserting the strut 5 into a hole provided in the casing 1 and connecting the joints 6A and 6B to the projecting portion of the strut 5 toward the inside of the casing 1. Fit in. Next, the end of the strut 5 is inserted into a hole provided in the inner cylinder 4A, and the joined bodies 6A and 6B are arranged at positions where they contact the outer surface of the inner cylinder 4A and the inner surface of the casing 1, respectively.

  Next, a welded portion 13A is formed at the corner between the inner peripheral edge of the joined body 6A and the outer peripheral surface of the strut 5 on the inner diameter side, and the joined body 6A and the strut 5 are joined. Similarly, a welded portion 13B is formed at the corner between the inner peripheral edge of the joined body 6B and the outer peripheral surface of the outer diameter side end of the strut 5 to join the joined body 6B and the strut 5 together.

  Next, a welded portion 9A is formed at the corner between the outer peripheral edge of the joined body 6A and the outer surface of the inner cylindrical body 4A, and the outer peripheral edge of the joined body 6A and the inner cylindrical body 4A are joined.

  Next, a welded portion 9B is formed at the corner between the outer peripheral edge of the joined body 6B and the inner side surface of the casing 1, and the outer peripheral edge of the joined body 6B and the casing 1 are joined. As a result, the joined body 6 </ b> A applied to the strut 5 is disposed outside the inner cylindrical body 4 </ b> A, and the joined body 6 </ b> B is disposed inside the casing 1. The welded portions 9A, 9B, 13A, and 13B for welding and fixing the strut 5 and the joined bodies 6A and 6B to the inner cylinder 4A and the casing 1 are all exhaust gas passage portions through which the exhaust gas 2 of the gas turbine 100 passes. There will be 4 places on the side.

  As shown in FIG. 11, the welded ends 9A, 9B, 13A, 13B are not present in the same cross section in the thickness direction of the casing 1 and the inner cylindrical body 4A. It is arranged with a deviation outward from the radial direction.

  According to the fourth embodiment of the exhaust diffuser of the gas turbine of the present invention, the same effects as those of the third embodiment described above can be obtained.

  FIGS. 13 and 14 show a fifth embodiment of the exhaust diffuser of the gas turbine of the present invention. FIG. 13 is a longitudinal sectional front view of a strut portion used in the exhaust diffuser of the gas turbine of the present invention. These are the perspective views of the strut used for the exhaust diffuser of the gas turbine of this invention shown in FIG. In FIGS. 13 and 14, the same reference numerals as those shown in FIGS. 3 to 6 are the same or corresponding parts, and the description thereof is omitted.

  This embodiment is basically the same as the first to fourth embodiments, but the joined body 6A is provided only on the inner surface side of the inner cylindrical body 4A.

  According to the fifth embodiment of the exhaust diffuser of the gas turbine of the present invention, the same effects as those of the first to fourth embodiments described above can be obtained, and the cost and work involved in manufacturing the strut 5 can be obtained. The amount can be reduced, and the economic efficiency of the gas turbine equipment can be improved.

  Note that the joined body 6 </ b> A can be provided only on the outer surface side of the casing 1.

  FIGS. 15 and 16 show a sixth embodiment of the exhaust diffuser of the gas turbine of the present invention. FIG. 15 is a longitudinal front view of a strut portion used in the exhaust diffuser of the gas turbine of the present invention. These are the perspective views of the strut used for the exhaust diffuser of the gas turbine of this invention shown in FIG. In FIGS. 15 and 16, the same reference numerals as those shown in FIGS. 3 to 6 are the same or corresponding parts, and the description thereof is omitted.

  This embodiment is basically the same as the first to fifth embodiments, but the joined body 6A is a partial protrusion having a C dimension outside the outer dimension D of the strut 5. Is.

  According to the fifth embodiment of the inner and outer peripheral wall connection structure of the gas turbine exhaust diffuser of the present invention, the same effects as those of the first to fifth embodiments described above can be obtained, and the strut 5 can be manufactured. The associated costs and workload can be reduced, and the economics of the gas turbine equipment can be improved.

It is a side view showing the gas turbine provided with a 1st embodiment of the gas turbine exhaust diffuser of the present invention in a partial section. 1 is a cross-sectional view showing a first embodiment of an exhaust diffuser of a gas turbine of the present invention. FIG. 3 is a longitudinal front view of an exhaust diffuser on the outer peripheral side as viewed from the direction of arrows III-III in FIG. 2. FIG. 4 is a longitudinal front view of the exhaust diffuser on the outer peripheral side viewed from the direction of arrows IV-IV in FIG. 3. It is sectional drawing of the strut of the exhaust diffuser of the outer peripheral side seen from the VV arrow of FIG. It is a perspective view of the strut which comprises the gas turbine exhaust diffuser of this invention shown in FIG. It is a vertical front view of the strut part used for 2nd Embodiment of the exhaust diffuser of the gas turbine of this invention. It is a perspective view of the strut used for the exhaust diffuser of the gas turbine of this invention shown in FIG. It is a vertical front view of the strut part used for 3rd Embodiment of the exhaust diffuser of the gas turbine of this invention. It is a perspective view of the strut used for the exhaust diffuser of the gas turbine of this invention shown in FIG. It is a vertical front view of the strut part used for 4th Embodiment of the exhaust diffuser of the gas turbine of this invention. It is a perspective view of the strut used for the exhaust diffuser of the gas turbine of this invention shown in FIG. It is a vertical front view of the strut part used for 5th Embodiment of the exhaust diffuser of the gas turbine of this invention. It is a perspective view of the strut used for the exhaust diffuser of the gas turbine of this invention shown in FIG. It is a vertical front view of the strut part used for 6th Embodiment of the exhaust diffuser of the gas turbine of this invention. It is a perspective view of the strut used for the exhaust diffuser of the gas turbine of this invention shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Casing 2 Exhaust gas 3 Exhaust diffuser 4 of outer peripheral side Exhaust diffuser 4A of inner peripheral side Inner cylinder 5 Strut 6A Joint body (inner diameter side)
6B joined body (outer diameter side)
7 Exhaust gas flow path 8 Cooling air 9A Exhaust gas side welded part (inner diameter side)
9B Exhaust gas side weld (outer diameter side)
10A Cooling air side weld (inner diameter side)
10B Cooling air side weld (outer diameter side)
100 gas turbine

Claims (8)

In the exhaust diffuser of the gas turbine, which is provided in the exhaust flue portion for discharging the exhaust gas of the gas turbine to the outside, and includes an outer cylinder, an inner cylinder, and a strut provided between these cylinders,
The strut is a hollow cylindrical body having a cooling passage connecting the outer cylindrical body and the inner cylindrical body,
An exhaust diffuser for a gas turbine, wherein a joint member having a peripheral edge joined to the outer cylinder and / or the inner cylinder is provided at an opening end of the strut. The exhaust diffuser of a gas turbine according to claim 1,
The exhaust gas turbine according to claim 1, wherein the joining member is provided on an opening end side of the strut in an exhaust gas passage formed by an inner surface of the outer cylinder and an outer surface of the inner cylinder. Diffuser. The exhaust diffuser of a gas turbine according to claim 1,
The joining member is provided on the opening end side of the strut on the outer surface of the outer cylinder and the inner surface of the inner cylinder,
An exhaust diffuser for a gas turbine, wherein welding is performed on a peripheral edge of the one joining member and the outer side surface of the outer cylindrical body, and a peripheral edge of the other joining member and an inner side surface of the inner cylindrical body. The exhaust diffuser of a gas turbine according to claim 1,
The joining member is provided on the opening end side of the strut in an exhaust gas flow path formed by an inner surface of the outer cylinder and an outer surface of the inner cylinder,
An exhaust diffuser for a gas turbine, wherein welding is performed on a peripheral edge of the one joining member and an inner surface of the outer cylinder, and a peripheral edge of the other joining member and an outer surface of the inner cylinder. The exhaust diffuser for a gas turbine according to any one of claims 1 to 4,
The exhaust diffuser of a gas turbine, wherein the joining member is provided only on the opening end side of the strut in the inner cylindrical body. The exhaust diffuser for a gas turbine according to any one of claims 1 to 4,
The exhaust diffuser of a gas turbine, wherein the joining member is provided only on the opening end side of the strut in the outer cylindrical body. In the exhaust diffuser of the gas turbine according to any one of claims 1 to 6,
The exhaust diffuser of a gas turbine, wherein the joining member is an annular body. In the exhaust diffuser of the gas turbine according to any one of claims 1 to 6,
The exhaust diffuser of a gas turbine, wherein the joining member is a protruding body.

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