The present invention relates to a hollow curved plate having a hollow part formed inside, a manufacturing method of the same and a combustor of a gas turbine which uses this hollow curved plate.
It has been practiced to cool a combustor by feeding a cooling medium to a hollow part of a hollow curved plate. For instance, a combustor of a gas turbine is known, in which a combustor basket and a transition piece are formed by hollow curved plates, and cooling air is fed to the hollow part of this hollow curved plate to cool the combustor.
For instance, described in Patent Literature 1 is to manufacture a combustor basket of a gas turbine combustor by bonding by liquid phase diffusion bonding an outer plate in which an air flow groove is formed and an inner plate without a groove (see paragraph 0010 and
The process of manufacturing a conventional hollow curved plate is as follows.
First, as illustrated in
Lastly, a hollow flat plate 100 (see
In the conventional hollow curved plate 102, as illustrated in
Further, some hollow curved plates 102 are used in an environment where a temperature difference occurs between the plate on an outer circumferential side (the grooved plate 110 in the example of
As described above, when the temperature difference occurs between the plate on the outer circumferential side and the plate on the inner circumferential side, the stress caused by difference in thermal extension between the plates concentrates on the corners 114 of the groove 112, which may result in generation of cracks.
In view of the above issues, it is an object of the present invention to provide a hollow curved plate and a manufacturing method of the same which make it possible to suppress generation of cracks during bending and in a usage environment, and a combustor of a gas turbine.
A hollow curved plate according to the present invention comprises:
a first plate member having a first groove; and
a second plate member having a second groove of approximately the same width as the first groove, the second plate member being bonded to the first plate member by diffusion bonding, and
the first groove faces the second groove, a position of the first groove substantially coincides with a position of the second groove in a width direction, and a hollow part is formed by the first groove and the second groove, and
the hollow curved plate is formed of the first plate member and the second plate member curved by bending in a state where the first plate member and the second plate member are bonded together.
In this specification, “approximately the same” or “substantially coincide with” means that two comparison objects are practically the same or coincide with each other while allowing for manufacturing tolerance.
In this hollow curved plate, the hollow part is formed of the first groove and the second groove by positioning so that the position of the first groove of the first plate member substantially coincides with the position of the second groove of the second plate member in the width direction, the second groove having approximately the same width as the first groove. Therefore, it is possible to avoid formation of the corners 114 (see
In the above hollow curved plate, it is preferable that a relationship 0.9≦T1/T2≦1.1 is satisfied, where T1 is a thickness of the first plate member and T2 is a thickness of the second plate member.
By setting the thickness T1 of the first plate member and the thickness T2 of the second plate member to satisfy the above relationship, the bond interface between the first plate member and the second plate member is disposed near the center of the hollow curved plate in a thickness direction. The part near the center of the hollow curved plate in the thickness direction is a part (a so-called neutral axis) where deformation is less likely to occur compared with an inner circumferential part and an outer circumferential part, and is located at an intermediate position between the inner circumferential part shrinking under compression stress during the bending operation and the outer circumferential part stretching under tensile stress during the bending operation. Therefore, by setting the thickness T1 of the first plate member and the thickness T2 of the second plate member to satisfy the above relationship, it is possible to dispose the bond interface between the first plate member and the second plate member closer to the neutral axis and to effectively suppress generation of cracks during the bending operation.
In contrast, it is necessary in the conventional hollow curved plate 102 to form the groove 112 in the grooved plate 110. In this case, it is inevitable to set a thickness t1 of the grooved plate 110 larger than a thickness t2 of the grooveless plate 120. Therefore, the bond interface between the grooved plate 110 and the grooveless plate 120 is disposed far from the neutral axis, and during the bending operation, the bond interface is likely to be subjected to significant compression stress or tensile stress, which results in generation of cracks in the bond interface.
Further, the thickness T1 of the first plate member and the thickness T2 of the second plate member may be approximately the same.
As a result, the bond interface between the first plate member and the second plate member can be brought even closer to the neutral axis, thereby effectively suppressing generation of cracks during the bending operation.
It is preferable that the first plate member and the second plate member have approximately the same shape.
As a result, the first plate member and the second plate member can be communalized and the production cost can be reduced. Further, as the first plate member and the second plate member are not confused one with the other, it is possible to effectively conduct a manufacturing operation of the hollow curved plate.
In the above hollow curved plate, the first plate member and the second plate member may be bonded together by solid phase diffusion bonding in which an insert metal is not used.
In the case where the plate members are bonded using the insert metal 122 by liquid phase diffusion bonding similarly to the case of the conventional hollow curved plate 102, a melting-point-lowering element contained in the insert metal 122 can embrittle a base material. In view of this, as described above, by boding the first plate member and the second plate member by solid phase diffusion boding without using the insert metal, it is possible to prevent embrittling of the base metal, which is caused by the melting-point-lowering element contained in the insert metal, and also to improve formability during the bending operation.
Further, in the hollow curved plate according to the present invention, grooves (the first groove and the second groove) are formed respectively on the first plate member and the second plate member as described above. Thus, by bonding the plate members together using the insert metal, the melted insert metal flows into the groove located below, which may partially block the hollow part. In this perspective, by bonding the first plate member and the second plate member together by solid phase diffusion bonding without using the insert metal, it is possible to prevent blocking of the hollow part caused by the melted insert metal and also to easily form the hollow part of a desired shape.
Further, as the insert metal which is made of a different material from that of the first plate member or the second plate member is not used, the first plate member and the second plate member become more recyclable. Furthermore, as the insert metal is not used, it is possible to skip a step of arranging the insert metal between the first plate member and the second plate member.
The above hollow curved plate may be used to configure a combustor of a gas turbine which comprises: a combustor basket in which fuel is combusted; and a transition piece for leading combustion gas generated by combustion of the fuel in the combustor basket to a turbine. More specifically, the above hollow curved plate may be used to configure at least one of the combustor basket or the transition piece such that the combustor basket or the transition piece is cooled by a cooling medium introduced to the hollow part of the hollow curved plate.
The above hollow curved plate is capable of suppressing generation of cracks during the bending operation and in the usage environment. Thus, the combustor of the gas turbine can be configured with high reliability by using the above-described hollow curved plate.
A manufacturing method of a hollow curved plate member according to the present invention comprises the steps of:
overlapping a first plate member having a first groove and a second plate member having a second groove of approximately the same width as the first groove so that the first groove faces the second groove and a position of the first groove substantially coincides with a position of the second groove in a width direction;
bonding by diffusion bonding the first plate member and the second plate member having been overlapped; and
curving the bonded first and second plate members by bending, and
the first groove and the second groove form a hollow part.
According to this manufacturing method, the hollow part is formed of the first groove and the second groove overlapped so that the position of the first groove of the first plate member substantially coincides with the position of the second groove of the second plate member in the width direction, the second groove having approximately the same width as the first groove. Therefore, it is possible to avoid formation of the corners 114 (see
In the above manufacturing method of the hollow curved plate member, a positioning hole may be formed in each of the first plate member and the second plate member, and in the step of overlapping, positioning of the first plate member and the second plate member may be performed by inserting a pin in the positioning holes of the first plate member and the second plate member so that the position of the first groove substantially coincides with the position of the second groove in the width direction.
The first plate member and the second plate member are positioned by inserting the pin in the positioning holes in the manner described above, so that the position of the first groove can substantially coincide with the position of the second groove in the width direction with precision. Therefore, it is possible to reliably avoid formation of the corners which could be a cause of stress concentration. This suppresses generation of cracks during the bending operation and in the usage environment.
Alternatively, a projection may be provided in one of the first plate member or the second plate member and a depression may be provided in the other of the first plate member and the second plate member, and in the overlapping step, positioning of the first plate member and the second plate member may be performed by fitting the projection in the depression so that the position of the first groove substantially coincides with the position of the second groove in the width direction.
Thus, by positioning the first plate member and the second plat member by fitting the projection in the depression, the positions of the first groove and the second groove can coincide in the width direction with precision, and generation of cracks can be suppressed effectively during the bending operation and in the usage environment.
According to the present invention, the hollow part is formed of the first groove and the second groove by positioning so that the position of the first groove of the first plate member substantially coincides with the position of the second groove of the second plate member in the width direction, the second groove having approximately the same width as the first groove. Therefore, it is possible to avoid formation of the corners which could cause stress concentration. This suppresses generation of cracks during the bending operation and in the usage environment.
Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It is intended, however, that unless particularly specified in these embodiments, dimensions, materials, and shapes of components, their relative arrangement, and the like shall be interpreted as illustrative only and not limitative of the scope of the present invention.
In a first embodiment, a hollow curved plate as a component of a gas turbine combustor is described.
As illustrated in
The combustor 2 includes a nozzle 10 for ejecting fuel, a combustor basket (combustor liner) 12 where the fuel ejected from the nozzle 10 is combusted, and a transition piece 14 for leading the combustion gas produced in the combustor basket 12 toward the turbine 6. The combustor basket 12 and the transition piece 14 have inside a channel for cooling air and are formed at least in part by the hollow curved plate which is described in details below.
As illustrated in
As materials of the first plate member 241 and the second plate member 341, there are heat-resisting materials such as SUS material, and nickel-based alloys (Hastelloy and Tomilloy, both registered trademark), for instance.
As illustrated in
The hollow flat plate 21 is manufactured, as illustrated in
The shape of the hollow part 401 may be arbitrarily adjusted by adjusting a shape of a tool for cutting the first groove 22 and the second groove 32.
The tangent line L1 of the first groove 22 is, to be specific, a tangent line of the first groove 22 extending from the position 44 toward the first plate member 241. Similarly, the tangent line L2 of the second groove 32 is, to be specific, a tangent line of the second groove 32 extending from the position 44 toward the second plate member 341.
Further, as illustrated in
It is preferable that a relationship 0.9≦T1/T2≦1.1 is satisfied, where T1 is a thickness of the first plate member 241 and T2 is a thickness of the second plate member 341 (see
As a result, the bond interface 42 between the first plate member 241 and the second plate member 341 is arranged closer to a neutral axis of deformation during bending, and thus generation of cracks near the bond interface 42 during the bending is effectively suppressed.
It is preferable that the first plate member 241 and the second plate member 341 have approximately the same shape. More specifically, the thickness T1 of the first plate member 241 is approximately the same as the thickness T2 of the second plate member 341, the first groove 22 and the second groove 32 have approximately the same shape, and the first groove 22 and the second groove 32 are arranged approximately at the same position.
As a result, the first plate member 241 and the second plate member 341 can be communalized and the production cost can be reduced. Further, as the first plate member 241 and the second plate member 341 are not confused one with the other, it is possible to effectively conduct a manufacturing operation of the hollow curved plate 20.
The first plate member 241 and the second plate member 341 are bonded by diffusion bonding. More specifically, the first plate member 241 and the second plate member 341 are bonded using any one of liquid phase diffusion bonding which uses an insert metal, solid phase diffusion bonding which uses an insert metal, and solid phase diffusion bonding which does not use an insert metal.
Particularly, the solid phase diffusion bonding which does not use an insert metal is preferable from the standpoint of improving formability of the hollow curved plate 20 during the bending operation, as it does not cause embrittlement of the base material attributable to the melting-point-lowering element derived from the insert metal. Further, in the solid phase diffusion bonding which does not use the insert metal, there is no blocking of the hollow part by the melted insert metal and thus, it is possible to easily form the hollow part 401 of a desired shape. Further, as the insert metal which is made of a different material from that of the first plate member 241 or the second plate member 341 is not used, the first plate member 241 and the second plate member 341 become more recyclable. Furthermore, as the inserting metal is not used, it is possible to skip a step of arranging the insert metal between the first plate member 241 and the second plate member 341.
In the case where the first plate member 241 and the second plate member 341 are made of a homogeneous metal, as bonding conditions of the solid phase diffusion bonding without using the insert metal, it is possible to set the temperature to 60 to 75% of a melting point (° C.) of the first plate member 241 and the second plate member 341, and to use a mean contact pressure of pressing of 3 to 18 MPa. For instance, in the case where the material of the first plate member 241 and the second plate member 341 is a nickel-base alloy (Hastelloy) having a melting point of 1533 to 1628° C., the first plate member 241 and the second plate member 341 may be bonded by solid phase diffusion bonding which does not use an insert metal while pressing the first plate member 241 and the second plate member 341 at a mean contact pressure of 3 to 18 MPa and maintaining the temperature at 1000 to 1150° C.
Prior to bonding of the first plate member 241 and the second plate member 341, it is necessary to overlap the first plate member 241 and the second plate member 341 so that a position of the first groove 22 substantially coincides with a position of the second groove 32 in the width direction. However, the positions of the first groove 22 and the second groove are not visible from outside in some cases. Therefore, in this embodiment, positioning of the first plate member 241 and the second plate member 341 is performed in the following manner.
In the example illustrated in
In the example illustrated in
Alternatively, the projection may be provided in the first plate member 241, and the depression may be provided in the second plate 341 so that the projection in the first plate member 241 is fitted in the depression in the second plate 341.
In the example illustrated in
As described above, the hollow curved plate 20 of this embodiment includes the first plate member 241 having the first groove 22 and the second plate member 341 having the second groove 32 of the same width as the first groove 22 and bonded to the first plate member 241 by diffusion bonding. Further, the hollow curved plate 20 is formed of the first plate member 241 and the second plate member 341 curved by bending in a state where the first plate member 241 and the second plate member 341 are bonded together. Then, the first groove 22 faces the second groove 32, the position of the first groove 22 substantially coincides with the position of the second groove 32 in the width direction, and the hollow part 401 is formed by the first groove 22 and the second groove 32.
In this manner, the hollow part 401 is formed of the first groove 22 and the second groove 32 so that the position of the first groove 22 of the first plate member 241 substantially coincides with the position of the second groove 32 of the second plate member 341 in the width direction, the second groove 32 having approximately the same width as the first groove 22. Therefore, it is possible to avoid formation of the corners which could cause stress concentration. This suppresses generation of cracks during the bending operation and in the usage environment.
In a second embodiment, the hollow curved plate as a component of a ring segment of the gas turbine is described.
A hollow curved plate 50 of this embodiment has substantially the same configuration and manufacturing procedure as the hollow curved plate 20 of the first embodiment, except that the first plate member, the second plate member and the hollow part are shaped differently. Thus, the same reference numerals are given without adding explanations for those configurations that are the same as the hollow curved plate 20, and mainly the configuration of the hollow curved plate 50 that is different from the hollow curved plate 20 is explained.
As the high temperature combustion gas produced in the combustor flows in the turbine of the gas turbine, a plurality of ring segments 49 having inside a hollow part 402 for cooling and shaped into an arc in cross-section is arranged in the circumferential direction of the rotor to form a wall of a combustion gas channel as illustrated in
As illustrated in
In
As illustrated in
As illustrated in
A nozzle skirt of a rocket engine includes a cooling channel for a cooling medium (liquid hydrogen) to flow therethrough. In a third embodiment, a hollow curved plate as a component of the nozzle skirt of the rocket engine is described.
A hollow curved plate 70 of this embodiment has substantially the same configuration and manufacturing procedure as the hollow curved plate 20 of the first embodiment, except that the first plate member, the second plate member and the hollow part are shaped differently. Thus, the same reference numerals are given without adding explanations for those configurations that are the same as the hollow curved plate 20, and mainly the configuration of the hollow curved plate 70 that is different from the hollow curved plate 20 is explained.
As illustrated in
As illustrated in
While the embodiments of the present invention have been described, the present invention is not limited thereto. It is obvious that various modifications and changes may be made without departing from the scope of the invention.
For instance, in the above embodiments, the hollow curved plates (20, 50, 70) are used as components of the gas turbine combustor, of the ring segment of the gas turbine, and of the nozzle skirt of the rocket engine, respectively. However, applications of the hollow curved plate according to the present invention are not particularly limited, as long as the hollow curved plate is formed of the hollow flat plate with the hollow part curved by bending.
Further, in the above embodiments, the air is used as cooling medium for cooling the combustor or the ring segment of the gas turbine. However, for instance, steam may also be used, and thus the cooling medium is not particularly limited.
Number | Date | Country | Kind |
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2011-115655 | May 2011 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2012/062873 | 5/18/2012 | WO | 00 | 9/30/2013 |