The present application relates to combustor liner panels as used, for example, in gas turbine engines. In particular, the present application relates to combustor liner panels made from superalloys or ceramic matrix composite (CMC) materials, and arrangements for attaching such combustor liner panels to a combustor housing.
Combustor liner panels used, e.g., for gas turbine combustors, have an inner surface (hot side) that faces the interior of the combustor, and an outer surface (cold side) that faces the combustor housing. Combustor liner panels currently in service are typically mounted to the combustor housing via studs that are integrally cast into the liner panel. The bases of the studs are positioned at the hot flow path surface (i.e., at the inner surface of the liner panel) and thus are subjected to hot gas environments. For this reason, steps are taken to cool the studs to prevent damage thereto.
The prior art practice is to point an array of effusion cooling apertures around the stud but having no such apertures in the region where the stud is positioned. Further the presence of the stud can result in the clock angle of at least some of these effusion apertures to oppose the mainstream combustion flow direction. When the clock angle of these effusion apertures aligns with the mainstream combustion flow direction, they function to create a cooling layer on the surface of the liner panel that protects it from the hot combustion gases. However, when the clock angle of these effusion apertures are misaligned to the mainstream combustion flow direction, the cooling layer can be disrupted leading to burning around the stud and damage to the fasteners positioned in this area. Over time, this burning can result in partial or complete burn-thru of the area of the panel around the stud and in some cases can result in ultimate liberation of the stud and resultant damage to the engine.
There exists a need for combustor liner panels, and arrangements for attaching combustor liner panels to combustor housings, which ameliorate the issues discussed above.
In one embodiment of the present disclosure, a combustor liner segment is provided in which the liner segment includes a base having an inner surface (hot side), an outer surface (cold side), a front edge, a rear edge, and two side edges, a front wall arranged perpendicular to the base and extending from the front edge, and a rear wall arranged perpendicular to the base and extending from the rear edge.
In this embodiment, the combustor liner segment also includes at least one support member wherein each support member comprises a first portion and a second portion. The first portion has a first end and a second end, wherein the first end is connected to the outer surface of base. The second portion extends laterally from the second end of the first portion and is spaced from the outer surface of the base. The second portion comprises at least one mounting orifice. Additionally, the first portion, the second portion, the outer surface, the front wall, and the rear wall form a partially enclosed space.
In another embodiment of the present disclosure, a combustor is provided where the combustor includes a combustor housing having an inner surface and an outer surface. The combustor also includes at least three combustor liner segments, where each liner segment includes a base having an inner surface (hot side), an outer surface (cold side), a front edge, a rear edge, and two side edges, a front wall arrange perpendicular to the base and extending from the front edge, and a rear wall arrange perpendicular to the base and extending from the rear edge.
In this embodiment, each combustor liner segment also includes at least one support member wherein each support member comprises a first portion and a second portion. The first portion has a first end and a second end, wherein the first end is proximal to the base and is connected to the outer surface of base and the second end is distal with respect to the base. The second portion extends laterally from the second end of the first portion and comprises at least one mounting orifice. Additionally, the first portion, the second portion, the outer surface, front wall, and rear wall form a partially enclosed space.
According to a further embodiment of the present disclosure, a method of assembling a combustor is provided. The method includes providing a combustor housing having an inner surface and an outer surface and attaching at least three combustor liner segments to the outer surface of the combustor housing by fasteners that pass through mounting orifices in each of the combustor liner segments, where each combustor liner segment includes a base having an inner surface (hot side), an outer surface (cold side), a front edge, a rear edge, and two side edges, a front wall arrange perpendicular to the base and extending from the front edge, and a rear wall arrange perpendicular to the base and extending from the rear edge.
In this embodiment, each combustor liner segment also includes at least one support member wherein each support member comprises a first portion and a second portion. The first portion has a first end and a second end and the first end is connected to the outer surface of the base. The second portion extends laterally from the second end of the first portion and is spaced from the curved segment. The second portion comprises at least one mounting orifice. Additionally, the first portion, the second portion, the outer surface, the front wall, and the rear wall form a partially enclosed space.
Implementations of the inventive concepts disclosed herein may be better understood when consideration is given to the following detailed description thereof. Such descriptions make reference to the included drawings, which are not necessarily to scale, and which some features may be exaggerated and some features may be omitted or may be represented schematically in the interest of clarity. Like reference numerals in the drawings may represent and refer to the same or similar element, feature, or function. In the drawings:
Combustor panels provide protection for the combustor housing. Combustor panels are formed by attaching a plurality of liner segments (e.g., three liner segments) to the inner surface of the combustor housing. Each liner segment is mounted onto the inner surface of the combustor housing using fasteners. In embodiments described in more detail below, the liner segment structures are designed to isolate the fasteners from the flow of hot gases at the inner surface of the liner segments.
Each liner segment (1A and 1B) includes a base (40) having an inner surface (41) and outer surface (42). The inner surface (41) faces the interior of the combustor and thus comes into contact with the flow of hot gases passing through the combustor. The outer surface (42) faces the combustor housing (20). In the embodiment shown in
The liner segment also includes at least one support member (50). In the embodiment of
In
Fasteners (30) extend through the combustor housing (20) and connect to the second portions (70) of the support members (50). The fasteners do not extend through the base (40) and, as a result, are not subjected to the hot gas flow within the combustor. The portions of the fasteners (30) that extend through the combustor housing (20) are positioned within a space (100) that is partially enclosed by the base (40), the support member (50), and front and rear walls of the liner segment (1). The arrangement forming this partially enclosed space (100) is shown in more detail in
When, as shown in
As can be seen from
The inclusion of the front wall (90) and the rear wall (95) provide a strength benefit by reducing the max bending stress on the ends of the liner panel by at least 30% as compared to cantilevered ends without a front wall (90) and the rear wall (95).
The fastener (30) and liner segment (1) may be made from the same materials, for example, both may be made of a superalloy. On the other hand, the fastener (30) and liner segment (1) may be made from different materials, for example, one a superalloy and the other a ceramic matrix composite. Particularly when these parts are made of different materials, relative movement of the parts, e.g., in the engine axial direction or circumferential direction, can occur due to thermal expansion (or contraction) resulting from different coefficients of thermal expansion (CTEs). Similarly, the combustor housing (20) and the liner segment (1) made be made of different materials and relative movement can thus occur between the combustor housing (20) and the liner segment (1) due to different coefficients of thermal expansion.
This issue can be addresses by using mounting orifices (71) in the form of slots (73) which can allow for thermal expansion and movement between parts. The slot shape, for example, allows the liner segment (1) to move relative to the fastener (30) and the combustor housing (20). The slots (73) can be arranged at various angles (see, e.g., the angled oval slot (73a) of
As mentioned above, the fasteners (30) pass through the combustor housing (20) and through the mounting orifices (71) of the second portions (70) of the support members (50).
Such a washer stack (33, 34) functions to maintain a clamping load while allowing for radial expansion due to thermal mismatch between, for example, a CMC liner segment and metal components. For example, in the case of expansion of the liner segment (1), the washer stack can compress thereby compensating for the resultant movement and reduce stress imposed by such movement. Alternatively, in the case of contraction of the liner segment (1), the washer stack can exert a force to press the combustor housing (20) and liner segment (1) together and prevent separation. Additionally, the bolt (32) could be subject to expansion and given its length, could expand more than the thinner combustor housing (20). In such a case, the washer stack can exert a force to press the combustor housing (20) and liner segment (1) together and prevent separation. The embodiment of
Other methods are possible for addressing possible movement between components due to differing CTEs. For example, interfaces between a CMC liner segment and metal components can be made thermochemically compatible by the application of suitable coatings. For example, a two-layer coating consisting of a silicon bond coat with a Mullite top coat could be used at the interface between a metal superalloy and CMC components. The CTE of the coating is similar to the CMC substrate but provides a chemical barrier to prevent free silicon in the CMC substrate from reacting with, for example, nickel in the superalloy.
The liner segment embodiment shown in
In
In this embodiment, the first portion (60) and second portion (70) of each support member (50), together with the base (40), the front wall (90) and rear wall (95), partially enclose a space (100) which can house the fasteners and protect them from the hot flow path of the combustor. When the combustor liner segment (1) is attached to combustor housing (20), the fasteners extend through mounting orifices in the second portion (70) of each support member (50) and into the respective partially enclosed space (100). Additionally, when the combustor liner segment (1) is attached to combustor housing (20), the two respective partially enclosed spaces form parts of a larger enclosure. The combustor housing (20) also forms part of this larger enclosure by bridging the gap between the second portion (70) of one support member (50) of liner segment (1) and the second portion (70) of the other support member (50) of the same liner segment (1). The fasteners (30) are positioned within this larger enclosure and are shielded from the flow of hot gases through the combustor.
In
In this embodiment, the first portion (60) and second portion (70) of each support member (50), together with the base (40), the front wall (90) and rear wall (95), partially enclose a space (100) which can house the fasteners and protect them from the hot flow path of the combustor. When the combustor liner segment (1) is attached to combustor housing (20), the fasteners extend through mounting orifices in the second portion (70) of each support member (50) and into the respective partially enclosed space (100). When two combustor liner segments are positioned next to each other (see, e.g.,
In
The support member (50) further includes a third portion (110). The third portion (110) extends laterally from the second end (62) of the first portion (60) in a direction toward the other side edge (80) of the base (40) and is spaced from the outer surface (42). Like the second portion (70), the third portion (110) is provided with one or more mounting orifices for receiving fasteners. In this configuration, the base (40) and the support member (50) form an I shape.
In embodiment of
When the combustor liner segment (1) is attached to combustor housing (20), the fasteners extend through mounting orifices in the second portion (70) of the single support member (50) and into the respective partially enclosed space (100). Additionally, fasteners extend through mounting orifices in the third portion (110) of the single support member (50) and into the respective partially enclosed space (100). When two combustor liner segments are positioned next to each other (see, e.g.,
As shown in
Each reinforcing member (120) is attached to an outer surface of the first portion (60) of a support member (50) and also is attached to one of the side regions of the outer surface (42) of the base (40). The portion of the reinforcement member (120) attached to the side region of the outer surface (42), i.e., the base of the L shape, extends from the outer surface of the first portion (60) in a direction toward a side edge (80) of the base (40). This portion may, optionally, extend beyond the side edge (80) of the liner segments (1) and form a shiplap joint with the reinforcement member (120) of an adjacent liner segment (1). In such an arrangement, the reinforcement member (120) can substitute for, or supplement, a joint member (85) used to join adjacent liner segments (1).
In this embodiment, the first portion (60) and second portion (70) of each support member (50), together with the base (40), the front wall (90) and rear wall (95), partially enclose a space (100) which can house the fasteners and protect them from the hot flow path of the combustor. When the combustor liner segment (1) is attached to combustor housing (20), the fasteners extend through mounting orifices in the second portion (70) of each support member (50) and into the respective partially enclosed space (100). Additionally, when the combustor liner segment (1) is attached to combustor housing (20), the two respective partially enclosed spaces form parts of a larger enclosure. The combustor housing (20) also forms part of this larger enclosure by bridging the gap between the second portion (70) of one support member (50) of liner segment (1) and the second portion (70) of the other support member (50) of the same liner segment (1). The fasteners (30) are positioned within this larger enclosure and shielded from the flow of hot gases through the combustor.
In general, embodiments of concepts disclosed herein are directed to prevention of exposure of the fasteners, used in joining combustor liner segments to the combustor housing, to the hot flow path of a combustor. The liner segments include support members which allow for the attachment of the liner segments to the combustor housing via the fasteners in a manner which form partially enclosed space(s) to protect the fasteners from the flow path of hot gases.
As will be appreciated by one skilled in the art, the embodiments described herein may be embodied as a method, product, or part for use in, for example, a gas turbine engine assembly. Accordingly, embodiments described herein may take the form of a portion of a gas turbine engine assembly.
The corresponding structures, material, acts, and equivalents of all means or steps plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements are specifically claimed. The description of the embodiments described herein has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill without departing from the scope and spirit of the invention. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for embodiments with various modifications as are suited to the particular use contemplated.
Modifications and equivalents may be made to the features of the claims without departing from the spirit or scope of the invention. Thus, it is intended that the embodiments described herein covers the modifications and variations disclosed above provided that these changes come within the scope of the claims and their equivalents.
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