JP4174615B2 - Gas turbine combustor tail tube seal structure - Google Patents

Description

  The present invention relates to a transition piece seal structure for a gas turbine combustor. More specifically, the present invention relates to a transition structure for a tail tube seal of a gas turbine combustor that prevents leakage of compressed air to the turbine side at a connection portion between the tail tube of the combustor and the turbine.

  A gas turbine includes a compressor, a combustor, and a turbine. In the case of can-type and cannula-type combustor structures, a plurality of cylindrical combustors are arranged on the same circumference, and the combustion is performed. The vessel outlet is connected to an annular turbine inlet via a tail tube.

  In FIG. 9, the connection part of a gas turbine combustor and a turbine is shown with sectional drawing. As shown in FIG. 9, the connecting portion is generally composed of a tail cylinder 101 as a passage for sending combustion gas generated in a combustor (not shown) to the turbine side, a turbine inlet portion 102, and an outlet end portion of the tail cylinder 101. A flange 103 provided around, a nozzle support 105 that supports the transition piece 101 and the turbine vane 104, outer diameter side and inner diameter side flow path forming members 106 and 107 that form a turbine flow path, and the flange 103; Outer diameter side and inner diameter side annular seal members 108, 109 interposed between the flow path forming members 106, 107 are provided.

  Here, the compressed air from the compressor of the gas turbine is sent to a high-pressure chamber (not shown) formed around the tail cylinder 101, where the tail cylinder 101 is cooled and then sent to the combustor. However, a part of the exhaust is discharged from the high-pressure chamber to the turbine side through the pores 108a and 109a provided in the seal members 108 and 109. Thus, the transition piece outlet end portion 101a is cooled, and combustion gas that is likely to be generated in the flow path from the transition piece 101 to the turbine stationary blade 104 is prevented.

  However, in the connecting portion between the combustor and the turbine, the compressed air in the high-pressure chamber burns from the gaps between the tail cylinders 101 adjacent to each other in the circumferential direction, the gaps between the tail cylinders 101 and the annular seal members 108 and 109, and the like. Otherwise, it may leak to the turbine side (inside the turbine inlet portion 102) without contributing to cooling (see Patent Documents 1, 2, and 3 below). As a result, there arises a problem that output and engine performance are deteriorated.

As a result, in order to maintain the required output and engine performance, it is necessary to raise the combustion gas temperature. As a result, the amount of NOx (nitrogen oxide) emission increases, the combustor, the tail cylinder, etc. There arises a problem that each member has a short life.
JP 2004-156543 A JP 2004-301115 A JP 2000-136731 A

  The present invention has been made in view of the problems of the prior art, and prevents leakage of compressed air from the compressor to the turbine side to suppress a decrease in output and engine performance. As a result, NOx (nitrogen oxide) It is an object of the present invention to provide a tail tube seal structure for a gas turbine combustor that can suppress an increase in the discharge amount of the gas turbine combustor and prevent the life of each member from being shortened.

In the gas turbine combustor tail pipe seal structure according to the present invention, the periphery of the tail pipe outlet end portion is provided at a connection portion between the tail cylinder and the turbine inlet portion of the gas turbine combustor formed by annularly arranging a plurality of combustors. A transition piece seal structure of a gas turbine combustor provided with an annular seal member having a surface facing the surface, wherein a circumferential gap is formed between the facing surface of the annular seal member and the peripheral surface of the end portion of the transition piece outlet. A peripheral end seal member is provided at both ends of the outer diameter side and the inner diameter side of the tail tube outlet end so as to block the flow of compressed air flowing from the direction gap to the radial gap. And

  In the transition tube seal structure of the gas turbine combustor according to the present invention, the peripheral end seal member is formed to be bent along the annular seal member and to be bent in the radial direction from one end of the seal side. An L-shaped member including a locking claw, and the locking claw is fitted in a fitting groove formed on a surface of the annular seal member facing the peripheral surface of the tail tube outlet end, or an annular seal A deformed T-shaped member including a seal side curved so as to follow the member and a locking claw protruding from one side end of the seal side in the radial direction, the locking claw being an annular seal It is preferable that the member is fitted in a fitting groove formed on a surface facing the peripheral surface of the end portion of the transition piece outlet of the member.

  Moreover, in the transition piece seal structure of the gas turbine combustor according to the present invention, it is preferable that circumferential end seal members having the same shape are disposed at the four corners of the transition piece.

  Since the transition structure of the transition of the gas turbine combustor according to the present invention is configured as described above, leakage of compressed air to the turbine side at the connection between the transition and the turbine can be prevented, and output and engine performance are improved. An excellent effect is obtained.

  Further, since there is no decrease in the turbine inlet temperature due to leaked air, an increase in the combustion gas temperature can be suppressed, NOx (nitrogen oxide) can be reduced, and the life of parts such as the tail tube can be extended. An excellent effect is obtained.

  Hereinafter, although the present invention is explained based on an embodiment, referring to an accompanying drawing, the present invention is not limited only to this embodiment.

Embodiment 1
FIG. 1 is a schematic view showing a transition structure of a transition piece of a gas turbine combustor according to Embodiment 1 of the present invention. FIG. 2 shows a perspective view thereof.

  As shown in FIGS. 1 and 2, the seal structure U includes a tail tube 1 that is a passage for sending combustion gas from a gas turbine combustor (not shown) to the turbine, and a turbine inlet 2 that is an inflow passage for combustion gas on the turbine side. It is assumed that the connection part is sealed.

That is, the seal structure U has a surface facing the peripheral surface of the outlet end portion of the tail cylinder 1 so as to seal the connection portion between the combustion gas outlet opening 1 a of the tail cylinder 1 and the inlet opening 2 a of the turbine inlet portion 2. The annular seal members 3 ₁ , 3 ₂ are respectively disposed, and the outlet end of the tail tube 1 from the gap (see FIG. 3; hereinafter referred to as the circumferential gap) L1 between the outlet ends of the tail tubes 1 adjacent in the circumferential direction. The radial direction so as to block the flow of compressed air from the compressor that wraps around a gap L2 (see FIG. 3; hereinafter referred to as a radial gap) between the circumferential surface of the portion and the opposed surfaces of the annular seal members 3 ₁ , 3 ₂ . The plate-like seal members 4 and 4 are arranged at predetermined positions of the gap L2. In the present specification, the circumferential direction and the radial direction are defined based on the shape of the annular turbine inlet 2.

  That is, as shown in FIG. 3, the outlet openings 1 a of the tail cylinders 1 are substantially square and are arranged on the same circumference so as to face the inlet openings 2 a of the annular turbine inlet 2. Here, the fitting part 1b (refer FIG. 2) is provided in the circumferential direction both-sides edge of the exit opening 1a of the transition piece 1, The fitting part 1b of each transition piece 1 arranged in the circumferential direction is fitted, and each is fitted. The gap at the outlet end of the transition piece 1 is sealed. However, there is a slight gap L1 between the tail cylinders 1 arranged in the circumferential direction at locations other than the fitting portion 1b. As shown in FIG. 2, the circumferential gap L1 and the radial gap L2 communicate with each other. Therefore, the compressed air from the compressor leaks from the circumferential gap L1 to the turbine side via the radial gap L2. The radial gap L2 is provided so as to secure an air flow path for cooling the outlet end portion of the transition piece 1 as shown in the background art.

  Further, as described later, the annular seal member 3 is constituted by a divided body divided into a predetermined length (in the embodiment, a length corresponding to the circumferential length of the outlet end portion of the tail tube 1). (Refer to FIG. 4 and FIG. 5), compressed air leaks from the gap between the opposed end faces of each divided body into the radial gap L2.

  From these circumstances, in order to prevent leakage of compressed air to the turbine side, in the embodiment, the plate-like seal members 4 and 4 are provided at predetermined positions of the radial gap L2.

4 to 6 show the details of the annular seal member 3. Figure 4 is a two-sided view of an annular sealing member 3 ₁ of the outer diameter side, Fig 5 is a two-sided view of an annular sealing member 3 ₂ on the inner diameter side. FIG. 6 is a perspective view schematically showing the annular seal member.

  As shown in FIG. 1, the annular seal member 3 is retracted by a predetermined distance from the outer diameter side and inner diameter side end surfaces of the outlet opening 1 a of the tail tube 1 toward the inlet, and the outer diameter side of the outlet end portion of the tail tube 1 and A flange-like portion (hereinafter referred to as a transition piece flange) 5 provided on the inner diameter side and a part of the nozzle support 6 are configured, and a first stage turbine stationary blade (hereinafter simply referred to as a stationary blade) 7 is connected to the outer diameter side and It is interposed between the open ends 8a, 9a of the turbine flow path forming members 8, 9 supported from the inner diameter side.

  Here, as shown in FIG. 4 and FIG. 5, the annular seal member 3 is composed of each divided body cut into a predetermined length, and a main body 3 a (see FIG. 6) having a U-shaped cross section, and a main body A ridge 3b fitted on a groove 5a having a square cross section provided on one outlet surface perpendicular to the transition surface H of the transition piece 3a and extending in the circumferential direction on the outlet side of the root portion of the transition piece flange 5; The groove 3c is formed on the other outer surface of the main body 3a and is fitted to the end portions 8a, 9a of the turbine flow path forming members 8, 9.

  Further, as shown in FIG. 6, the annular seal member 3 has a locking groove 3 d that fits with a locking claw portion 4 b of the plate-like sealing member 4 described later, and a peripheral surface of the outlet end portion of the transition piece 1 of the main body 3 a. It is supposed that it is provided on the opposite surface H of the. 4 and 5, a portion denoted by reference numeral 3 e is a flange for fixing the annular seal member 3 to the tail tube 1, and a portion denoted by reference numeral 3 f is the annular seal member 3 and the tail tube 1. It is a flange for deciding the positional relationship.

  Next, the plate-like seal member 4 will be described.

  FIG. 7 shows details of the plate-like seal member 4. The plate-like seal member 4 is made of a heat-resistant material, and is fitted into a plate-like shape by fitting with a main body 4a and a locking groove 3d of the annular seal member 3 provided so that one end of the main body 4a is bent vertically. The member has an L-shaped cross section having a locking claw portion 4b for fixing the seal member 4. Here, it is preferable that the plate-like seal members 4 have the same size and shape in order to reduce the number of different parts and prevent assembly errors.

  Thus, as shown in FIGS. 2 and 3, such a plate-shaped sealing member 4 includes a circumferential gap L1 and a gap between the opposed end faces of each divided body of the annular sealing member 3 (hereinafter referred to as a circumferential gap L1 and the like). In order to prevent inflow of compressed air from the outer diameter side to the radial gap L2, the outer diameter side and the inner diameter side radial gap L2 are arranged at both ends in the circumferential direction of the outlet end portion of the transition piece 1. Accordingly, it is possible to prevent leakage of compressed air flowing into the turbine inlet 2 from the circumferential gap L1 and the like through the radial gap L2.

  Therefore, a decrease in output and engine performance due to leakage of compressed air to the turbine side is prevented, and there is no need to increase the combustion gas temperature in order to maintain a desired output level, and NOx (nitrogen oxide in the combustion gas is eliminated. ) Emissions can be reduced, and the life of each member such as the gas turbine combustor and the tail tube can be extended.

Embodiment 2
Next, Embodiment 2 of the present invention will be described with reference to FIG. The second embodiment is obtained by modifying the first embodiment, and is obtained by modifying the plate-like seal member 4. Since the remaining configuration of the second embodiment is the same as that of the first embodiment, detailed description thereof is omitted.

  That is, as shown in FIG. 8, the plate-shaped sealing member 4A according to the second embodiment is a T-shaped member having a deformed cross section in which the locking claw portion 4b is provided near one end of the main body 4a. Thus, by making the plate-shaped seal member 4A into a T-shaped cross-sectional deformation, the strength of the locking claw portion 4b can be increased, and the seal structure can be made more robust.

  As mentioned above, although this invention was demonstrated by each embodiment, this invention is not restricted to this, For example, instead of providing the latching groove | channel which fits the latching claw part of a plate-shaped seal member in an annular seal member In addition, it is also possible to provide the annular seal member facing surface on the outer diameter side and inner diameter side of the outlet end portion of the tail tube, that is, the peripheral surface of the outlet end portion. It is possible to achieve.

  The present invention can be applied to a connection portion between a gas turbine combustor and a turbine.

It is the schematic of the tail-tube seal structure of the gas turbine combustor which concerns on Embodiment 1 of this invention. It is a schematic perspective view of the seal structure. It is a schematic diagram which shows the principal part detail of the seal structure. It is a 2nd page figure which shows the detail of the annular seal member by the side of an outer diameter, The same (a) is a front view, The same (b) is a side view. It is a 2nd page figure which shows the detail of the annular seal member of an internal diameter side, The same (a) is a front view, The same (b) is a side view. It is the perspective view which modeled the annular seal member. It is a 2nd page figure which shows the detail of the plate-shaped sealing member of Embodiment 1, (a) is a front view, (b) is a side view. It is a 2nd page figure which shows the detail of the plate-shaped sealing member of Embodiment 2, (a) is a front view, (b) is a side view. It is a fragmentary sectional view which shows schematic structure of the seal structure of the tail cylinder of the conventional gas turbine combustor.

Explanation of symbols

U seal structure L1 circumferential gap L2 radial gap 1 tail cylinder 2 turbine inlet 3 annular seal member 4 plate-like seal member

Claims (4)

An annular seal member having a surface opposed to the peripheral surface of the end portion of the tail tube outlet is provided at a connection portion between the tail tube of the gas turbine combustor formed by arranging a plurality of combustors in a ring shape and the turbine inlet portion. A gas turbine combustor tail tube seal structure,
The outer diameter side of the tail tube outlet end and the gap between the facing surface of the annular seal member and the peripheral surface of the tail tube outlet end so as to block the flow of compressed air that goes from the circumferential gap to the radial gap and A tail tube seal structure for a gas turbine combustor, characterized in that a peripheral end seal member is disposed at both ends in the circumferential direction on the inner diameter side . The peripheral end seal member is an L-shaped member including a seal side that is curved so as to follow the annular seal member, and a locking claw that is bent in a radial direction from one end of the seal side,
The tail of the gas turbine combustor according to claim 1, wherein the engaging claw is fitted in a fitting groove formed on a surface of the annular seal member facing the peripheral surface of the end portion of the tail tube outlet. Tube seal structure. The peripheral end seal member is a deformed T-shaped member including a seal side that is curved so as to follow the annular seal member, and a locking claw that is formed to project from one side end of the seal side in the radial direction. ,
The tail of the gas turbine combustor according to claim 1, wherein the engaging claw is fitted in a fitting groove formed on a surface of the annular seal member facing the peripheral surface of the end portion of the tail tube outlet. Tube seal structure.   The tail end seal structure for a gas turbine combustor according to claim 1, wherein the peripheral end seal members having the same shape are disposed at four corners of the end case.

Images