JP2007225180A - Combustor wall structure for gas turbine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combustor wall structure of a gas turbine reduced in required cooling air volume capable of being used even at high temperatures of 1700-1800°C. <P>SOLUTION: This combustor wall structure K of the gas turbine has an inner wall 20 composed of inner wall segments 20A densely arranged on an outer wall. The inner wall segment 20A is equipped with a heat-resistant block 30, a holding member 40 holding the heat-resistant blocks 30, and a cover member 50 having a sleeve 53 having a protrusion 53a on the inner face for covering the holding member 40. A clearance L1 is formed between the sleeve 53 and the heat resistant block 30. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a combustor wall structure of a gas turbine. More specifically, the present invention relates to a combustor wall structure of a gas turbine in which necessary cooling air is reduced.

  Conventionally, the combustion chamber side of the liner forming the combustor wall of the gas turbine is generally made of a heat-resistant alloy and cooled by cooling air. FIG. 10 shows the main part of an example of such a liner, and FIG. 11 shows the downstream end thereof.

  As shown in FIG. 10, the liner 100 has a double wall structure in which a slight gap 130 is provided between the outer wall 110 and the inner wall 120, and a number of the liners 100 provided on the burner side of the outer wall 110. A portion of the combustion air flowing outside the liner 100 is supplied as cooling air from the cooling holes 111 of the liner 100 to cool the inner wall 120 and can be used even at a high temperature of about 1300 ° C. at the combustion chamber BR outlet. It is said that. The cooling air used for this cooling is discharged from the exhaust port (see FIG. 11) 140 at the downstream end of the liner 100 to the combustion chamber BR, mixed with the combustion gas, and supplied to the downstream turbine.

  However, when realizing a highly efficient gas turbine, it is necessary to set the temperature of the outlet of the combustion chamber BR to a high temperature of about 1700 ° C to 1800 ° C. On the other hand, it is necessary to secure a large amount of combustion air from the demand for reducing nitrogen oxide emissions, and it is necessary to use the air conventionally used for cooling the liner 100 for the combustion of the fuel. The cooling air supplied to the liner 100 is reduced.

  However, if the cooling air supplied to the liner 100 decreases, the material temperature of the liner 100 becomes higher than the heat resistance temperature, and there arises a problem that it becomes impossible to use it under a predetermined temperature condition.

  In response to this problem, the inventors shall apply ceramics (eg, MGC (Melt-Growth Composites)) that can withstand ultra-high temperatures to the inner wall of the combustor liner, thereby A gas turbine combustor wall structure has been proposed in which a gas turbine combustor can be used in an extremely high temperature field with little air cooling (see Japanese Patent Application No. 2005-29978).

  However, in the wall structure according to the above proposal, the ceramic is held on the liner outer wall in such a state that the ceramic is sandwiched from both sides by the metal cover member, and the ceramic is cracked by the restraint of the ceramic by the cover member. This may cause another problem.

  In addition, the cover member is air-cooled, and when the ceramic comes into contact with the cover member, an excessive thermal stress is generated in the ceramic, which may cause a problem that the ceramic is cracked.

  The present invention has been made in view of the problems of the prior art, and the required amount of cooling air is reduced. Further, the present invention can be used even at a high temperature of about 1700 ° C. to 1800 ° C., and has high durability. The purpose is to provide a wall structure.

  The combustor wall structure of the gas turbine of the present invention is a gas turbine combustor wall structure having a double wall structure of an outer wall and an inner wall, and the inner wall has inner wall segments mounted on the outer wall in a dense arrangement. And the inner wall segment includes a heat-resistant block, a holding member that holds the heat-resistant block, and a cover member that covers the holding member, and the holding member is formed with a holding piece facing inward. The cover member has a sleeve portion that closes an open end of the holding member that is the lip groove steel shape, and is held by the sleeve portion and the holding member. A gap is provided between the block ends.

  In the combustor wall structure of the gas turbine of the present invention, it is preferable that a protrusion is provided on the inner surface of the sleeve portion.

  Further, in the combustor wall structure of the gas turbine of the present invention, it is preferable that a cooling hole for cooling the inner wall segment is disposed on the outer wall.

  Therefore, the combustor wall structure of the gas turbine is provided in the combustor of the gas turbine.

  According to the present invention, restraint of the heat-resistant block by the cover member during operation is avoided, and the generated thermal stress at the time of contact between the heat-resistant block and the cover member is greatly reduced, and there is no possibility that the heat-resistant block is cracked. Effect.

  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.

  1 and 2 show a combustor wall structure (hereinafter simply referred to as a wall structure) of a gas turbine according to an embodiment of the present invention. FIG. 1 is a partial side view of the combustor wall along the flow direction of the combustion gas, and FIG. 2 is a partial development view of the combustor wall.

  As shown in FIGS. 1 and 2, the wall structure K is composed of a double wall structure of an outer wall 10 and an inner wall 20, and the inner wall 20 is constituted by an inner wall segment 20A, and the inner wall segment 20A is bolted to the outer wall 10.・ It is supposed to be nut-fastened. The required number of inner wall segments 20A is arranged on the inner surface of the outer wall 10 in a dense arrangement.

  The outer wall 10 is a cylindrical member made of a heat-resistant alloy conventionally used as an outer wall of a liner. A bolt insertion hole 11 for inserting a bolt provided in an inner wall segment 20 </ b> A (described later) is formed in the outer wall 10 in a predetermined arrangement, and a part of combustion air flowing outside the outer wall 10. Is used as cooling air, and the required number of cooling holes 12 for impingement cooling of the inner wall segment 20A, more specifically, the holding member 40 and the cover member 50 are formed therethrough.

  As shown in FIGS. 3 to 8, the inner wall segment 20 </ b> A includes a heat-resistant block 30, a holding member 40 that holds the heat-resistant block 30, and a cover member 50 that covers the side opening end 40 a of the holding member 40. It is supposed to be.

  The heat resistant block 30 is formed by laminating a high temperature resistant gas ceramic layer 31, a refractory ceramic layer 32, and a heat insulating material layer 33 in this order from the combustion chamber BR side. Here, the provision of the refractory ceramic layer 32 and the heat insulating material layer 33 increases the heat transfer resistance between the upper part of the holding member 40 that is air-cooled and the high temperature resistant gas ceramic layer 31, and the high temperature resistant gas ceramic layer 31. This is to prevent cracking due to the temperature difference.

  The high temperature resistant gas ceramic layer 31 is a plate-like body made of, for example, MGC (Melt-Growth Composites) ceramic 31a having a heat resistance of about 1700 ° C., and its cross-sectional shape is an inverted trapezoid. (See FIG. 9). As a result, while the contact of the holding member 40 with the lip (holding piece) 45 is in a state close to a line contact, that is, the heat-resistant block 30 is held while reducing the contact area by using a pair of side surfaces as inclined surfaces, The surface 31b of the hot gas ceramic layer 31 can be protruded from the lip 45 toward the combustion chamber BR.

  In addition, the cross-sectional shape is not limited to the above, and any cross-sectional shape may be used as long as the surface 31b of the high temperature resistant gas ceramic layer 31 can protrude toward the combustion chamber BR while reducing the contact area. For example, the corner may be chamfered.

  The refractory ceramic layer 32 is a plate-like body having a heat resistance of about 1500 ° C., for example. The reason why the refractory ceramic layer 32 is provided is to prevent the MGC ceramic 31a from reacting with the heat insulating material and deteriorating. Therefore, if the high temperature resistant gas ceramic layer 31 is made of a material that does not react with the heat insulating material, the refractory ceramic layer 32 may not be provided.

  The heat insulating material layer 33 is a rectangular parallelepiped made of glass wool having cushioning properties, for example. By providing the heat insulating material layer 33 having the cushioning property, the thermal expansion of the high temperature resistant gas ceramic layer 31 and the refractory ceramic layer 32 is absorbed, and damage due to the thermal stress is prevented.

  The holding member 40 is formed by bending a plate made of a heat-resistant alloy such as Hastelloy X (trade name) into a wide lip groove steel shape and holding the heat-resistant block 30 therein. At the center of the upper surface 41 (the surface facing the outer wall 10) 41 of this holding member 40, a flat headed bolt 42 hangs down with the bolt part 43 facing outward. The height of the flat head 44 is adjusted such that a predetermined gap is formed between the outer wall 10 of the cover member 50 and impingement cooling of the holding member 40 and the cover member 50 can be performed.

  Here, the holding member 40 holds the lips (holding pieces) 45 and 45 in contact with the pair of inclined surfaces 31c and 31c (see FIG. 9) of the high temperature resistant gas ceramic layer 31 from both sides.

  In addition, a heat-resistant coating 47 (see FIGS. 4 and 5) is applied to the tip portion including the lip (holding piece) 45, that is, the holding portion 46. In FIG. 4, the hatched portion indicates the coating portion of the holding member 40.

  The material of the heat resistant coating 47 is, for example, a zirconia / yttria composite. By applying the heat resistant coating 47, the thermal shock between the holding portion 46 and the high temperature resistant gas ceramic is mitigated, and the high temperature resistant gas ceramic layer 31 is prevented from being damaged. In this case, as shown in FIG. 7, the lip 45 is appropriately provided with a notch 45a to reduce the contact area between the high temperature resistant gas ceramic layer 31 and the lip 45, thereby further preventing damage due to thermal shock. It is done.

  The cover member 50 is formed by bending a plate made of a heat-resistant alloy such as Hastelloy X (trade name) into a wide groove steel shape. A through hole 52 through which the flat head 44 of the flat head bolt 42 is inserted is formed at the center of the upper surface (surface facing the outer wall 10) 51 of the cover member 50. The cover member 50 is attached to the holding member 40 so that the sleeve portion 53 closes the side opening end 40 a of the holding member 40.

  Here, as shown in FIG. 4, between the sleeve portion 53 of the cover member 50 that is impingement cooled and the pair of opposing side surfaces 31 d and 31 d of the heat resistant block 30, more specifically, the high temperature resistant gas ceramic layer 31. In order to avoid significant contact between the opposing side surface 31d and the sleeve portion 53, gaps L1 and L1 are provided. Specifically, the gap L1 is a gap that does not allow the high-temperature resistant gas ceramic layer 31 to come into contact with the opposing side surface 31d and a protrusion 53a described later during operation. That is, if a large gap is provided, the cooling air and the combustion gas easily flow in, so the minimum gap is set.

  Further, inside the sleeve portion 53, in order to prevent the displacement of the heat-resistant block 30 due to the gap L1, as shown in FIGS. 3 and 4, a predetermined portion of the sleeve portion 53 that faces the facing surfaces 31d and 31d is provided. For example, the protrusions 53a and 53a are provided in the vicinity of both ends of the end of the sleeve portion 53 with a projecting amount shorter than the gap L1. Here, the protrusions 53 a and 53 a are not clearly shown in the figure, but may be coated similarly to the heat resistant coating 47 of the holding portion 46.

  That is, if the heat-resistant block 30 moves within the holding member 40 and the opposing surfaces 31d and 31d and the sleeve portion 53 of the cover member 50 come into substantial contact, the temperature gradient on the surface of the high-temperature resistant gas ceramic layer 31 increases. In addition, excessive thermal stress may occur and the high temperature resistant gas ceramic layer 31 may crack. Accordingly, in order to minimize the contact area between the high-temperature gas-resistant ceramic layer 31 and the cover member 50 in such a case, the protrusions 53a and 53a are provided at the opposing positions of the two materials, and the heat insulation is enhanced on the protrusion 53a. It is supposed to be coated for. Accordingly, it is possible to suppress the temperature gradient generated in the high temperature resistant gas ceramic layer 31 when the high temperature resistant gas ceramic layer 31 and the cover member 50 are in contact with each other, thereby avoiding damage to the high temperature resistant gas ceramic layer 31.

  Thus, in the combustor wall structure K of the present embodiment, the heat-resistant block 30 having the high-temperature resistant gas ceramic layer 31 is held by the holding member 40, and the open end 40 a of the holding member 40 is covered by the cover member 50. Since the inner wall 20 is composed of the inner wall segment 20A, the heat resistance is improved and the ratio of the required cooling air amount to the intake air amount can be reduced from about 15% to several percent of the conventional amount. .

  In addition to this, gaps L1 and L1 are provided between the sleeve portion 53 of the cover member 50 and the pair of opposing side surfaces 31d and 31d of the high-temperature resistant gas ceramic layer 31 of the heat-resistant block 30, thereby The high temperature resistant gas ceramic layer 31 is prevented from being restrained to prevent the high temperature resistant gas ceramic layer 31 from being damaged such as cracking, and the impingement cooled cover member 50 and the high temperature resistant gas ceramic layer 31 are in contact with each other. It is possible to keep the state of the high-temperature resistant gas ceramic layer 31 healthy by suppressing the occurrence of thermal stress in the high-temperature resistant gas ceramic layer 31 due to the temperature gradient caused by this, and thereby causing cracks in the high-temperature resistant gas ceramic layer 31. It becomes possible.

  Further, since the protrusion 53a is provided at a position where the cover member 50 faces the high temperature resistant gas ceramic layer 31, the high temperature resistant gas ceramic layer 31 and the cover member 50 are moved by the movement of the heat resistant block 30 within the holding member 40. When contacted, the contact area is reduced, and furthermore, by applying a heat-insulating coating to the protrusion 53a, the temperature gradient generated in the high-temperature resistant gas ceramic layer 31 when both materials are in contact is reduced, and the It becomes possible to keep the state of the high temperature gas ceramic layer 31 healthy for a long time. Therefore, the durability of the wall structure K can be improved.

  Therefore, the combustor wall structure K of the present embodiment can be applied to the combustor wall of a high efficiency gas turbine.

  The present invention can be applied to a combustor of a high efficiency gas turbine.

It is a partial side view along the flow direction of the combustion gas of the combustor wall of the gas turbine which concerns on one Embodiment of this invention. It is a partial expanded view of the combustor wall. It is a disassembled perspective view of the inner wall segment of the combustor wall. FIG. 3 is an arrow B view of FIG. 2. It is arrow C figure of FIG. It is the DD sectional view taken on the line of FIG. It is an arrow E figure of FIG. It is the FF sectional view taken on the line of FIG. It is a 2nd page figure of a high temperature-resistant gas ceramic layer. FIG. 2 is a view corresponding to FIG. 1 of a conventional combustor liner. It is arrow A figure of FIG.

Explanation of symbols

K Combustor wall structure L1 Crevice BR Combustion chamber 10 Outer wall 11 Bolt insertion hole 12 Cooling hole 20 Inner wall 20A Inner wall segment 30 Heat resistant block 31 High temperature gas ceramic layer 32 Refractory ceramic layer 33 Heat insulating material layer 40 Holding member 40a Open end 42 With flat head Bolt 45 Lip (holding piece)
45a Notch 47 Heat resistant coating 50 Cover member 52 Through hole 53 Sleeve 53a Protrusion

Claims (4)

A gas turbine combustor wall structure having a double wall structure of an outer wall and an inner wall,
The inner wall consists of inner wall segments mounted on the outer wall in a dense arrangement,
The inner wall segment includes a heat-resistant block, a holding member that holds the heat-resistant block, and a cover member that covers the holding member,
The holding member is a lip channel steel having a holding piece formed inward,
The cover member has a sleeve portion that closes an opening end of the holding member that is the lip groove steel shape,
A combustor wall structure of a gas turbine, wherein a gap is provided between the sleeve portion and an end portion of the heat-resistant block held by the holding member.   The combustor wall structure of a gas turbine according to claim 1, wherein a projection is provided on an inner surface of the sleeve portion.   The combustor wall structure for a gas turbine according to claim 1, wherein cooling holes for cooling the inner wall segments are disposed on the outer wall.   A combustor for a gas turbine, comprising the combustor wall structure for a gas turbine according to any one of claims 1 to 3.

Images