Patent Application
20180066539
The subject matter disclosed herein generally relates to gas turbine engines and, more particularly, to impingement cooling with increased cross-flow area for components of gas turbine engines.
Impingement is an effective, widely used type of cooling system that is employed in jet propulsion type systems (e.g., gas turbine engines). Various components of gas turbine engines can benefit from impingement cooling in order to maintain, for example, appropriate operational conditions and/or to maximize component life. For example, impingement cooling may be employed on vanes, blades, combustor panels, and blade outer air seals (“BOAS”). Accordingly, it may be advantageous to provide improved impingement cooling to improve part life or provide other features/benefits.
According to some embodiments, impingement assemblies are provided. The assemblies include an impingement plate having an increased cross-flow structure that forms an increased cross-flow area between the impingement plate and an impingement surface when the impingement plate is installed proximate to the impingement surface. The increased cross-flow structure has a first portion having at least one impingement hole passing through the first portion, the first portion being separated from the impingement surface by an impingement hole height, a second portion separated from the first portion by a separation distance and separated from the impingement surface by a cross-flow structure height, and a third portion extending between the first portion and the second portion. The first portion, the second portion, and the third portion define at least one cross-flow cavity between the impingement plate and the impingement surface, and the cross-flow structure height is greater than the impingement hole height.
In addition to one or more of the features described above, or as an alternative, further embodiments of the impingement assembly may include that the increased cross-flow structure forms a plurality of divots in the impingement plate, wherein at least one of the plurality of divots contains an impingement hole.
In addition to one or more of the features described above, or as an alternative, further embodiments of the impingement assembly may include that the increased cross-flow structure forms at least one channel, the at least one impingement hole located within the at least one channel.
In addition to one or more of the features described above, or as an alternative, further embodiments of the impingement assembly may include that the at least one channel includes a plurality of parallel rails that define the channels.
In addition to one or more of the features described above, or as an alternative, further embodiments of the impingement assembly may include that the at least one channel is a serpentine channel.
In addition to one or more of the features described above, or as an alternative, further embodiments of the impingement assembly may include that the first portion and the second portion define parallel planes.
In addition to one or more of the features described above, or as an alternative, further embodiments of the impingement assembly may include that the third portion intersects at least one of the first portion or the second portion at a ninety degree angle.
In addition to one or more of the features described above, or as an alternative, further embodiments of the impingement assembly may include that the third portion intersects at least one of the first portion or the second portion at a non-ninety degree angle.
According to other embodiments, components of a gas turbine engines are provided. The components include an impingement surface to be cooling by impingement cooling and an impingement plate positioned proximate the impingement surface. The impingement plate includes an increased cross-flow structure that forms an increased cross-flow area between the impingement plate and the impingement surface. The increased cross-flow structure has a first portion having at least one impingement hole passing through the first portion, the first portion being separated from the impingement surface by an impingement hole height, a second portion separated from the first portion by a separation distance and separated from the impingement surface by a cross-flow structure height, and a third portion extending between the first portion and the second portion. The first portion, the second portion, and the third portion define at least one cross-flow cavity between the impingement plate and the impingement surface, and the cross-flow structure height is greater than the impingement hole height.
In addition to one or more of the features described above, or as an alternative, further embodiments of the gas turbine engines may include that the increased cross-flow structure forms a plurality of divots in the impingement plate, wherein each divot contains a respective impingement hole.
In addition to one or more of the features described above, or as an alternative, further embodiments of the gas turbine engines may include that the increased cross-flow structure forms at least one channel, the at least one impingement hole located within the at least one channel.
In addition to one or more of the features described above, or as an alternative, further embodiments of the gas turbine engines may include that the at least one channel includes a plurality of parallel rails that define the channels.
In addition to one or more of the features described above, or as an alternative, further embodiments of the gas turbine engines may include that the at least one channel is a serpentine channel.
In addition to one or more of the features described above, or as an alternative, further embodiments of the gas turbine engines may include that the first portion and the second portion define parallel planes.
In addition to one or more of the features described above, or as an alternative, further embodiments of the gas turbine engines may include that the third portion intersects at least one of the first portion or the second portion at a ninety degree angle.
In addition to one or more of the features described above, or as an alternative, further embodiments of the gas turbine engines may include that the third portion intersects at least one of the first portion or the second portion at a non-ninety degree angle.
In addition to one or more of the features described above, or as an alternative, further embodiments of the gas turbine engines may include that the impingement surface is a surface of an airfoil of the gas turbine engine.
Technical effects of embodiments of the present disclosure include an impingement plate for components of gas turbine engines with improved impingement cooling efficiency. Further technical effects include increased cross-flow structures formed as part of impingement plates that increase a cross-flow area or volume to reduce cross-flow velocity, and thus improve impingement cooling efficiency.
The foregoing features and elements may be executed or utilized in various combinations without exclusivity, unless expressly indicated otherwise. These features and elements as well as the operation thereof will become more apparent in light of the following description and the accompanying drawings. It should be understood, however, that the following description and drawings are intended to be illustrative and explanatory in nature and non-limiting.
The subject matter is particularly pointed out and distinctly claimed at the conclusion of the specification. The foregoing and other features, and advantages of the present disclosure are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
As shown and described herein, various features of the disclosure will be presented. Various embodiments may have the same or similar features and thus the same or similar features may be labeled with the same reference numeral, but preceded by a different first number indicating the Figure Number to which the feature is shown. Thus, for example, element “##” that is shown in FIG. X may be labeled “X##” and a similar feature in FIG. Z may be labeled “Z##.” Although similar reference numbers may be used in a generic sense, various embodiments will be described and various features may include changes, alterations, modifications, etc. as will be appreciated by those of skill in the art, whether explicitly described or otherwise would be appreciated by those of skill in the art.
The gas turbine engine 20 generally includes a low speed spool 30 and a high speed spool 32 mounted for rotation about an engine centerline longitudinal axis A. The low speed spool 30 and the high speed spool 32 may be mounted relative to an engine static structure 33 via several bearing systems 31. It should be understood that other bearing systems 31 may alternatively or additionally be provided.
The low speed spool 30 generally includes an inner shaft 34 that interconnects a fan 36, a low pressure compressor 38 and a low pressure turbine 39. The inner shaft 34 can be connected to the fan 36 through a geared architecture 45 to drive the fan 36 at a lower speed than the low speed spool 30. The high speed spool 32 includes an outer shaft 35 that interconnects a high pressure compressor 37 and a high pressure turbine 40. In this embodiment, the inner shaft 34 and the outer shaft 35 are supported at various axial locations by bearing systems 31 positioned within the engine static structure 33.
A combustor 42 is arranged between the high pressure compressor 37 and the high pressure turbine 40. A mid-turbine frame 44 may be arranged generally between the high pressure turbine 40 and the low pressure turbine 39. The mid-turbine frame 44 can support one or more bearing systems 31 of the turbine section 28. The mid-turbine frame 44 may include one or more airfoils 46 that extend within the core flow path C.
The inner shaft 34 and the outer shaft 35 are concentric and rotate via the bearing systems 31 about the engine centerline longitudinal axis A, which is co-linear with their longitudinal axes. The core airflow is compressed by the low pressure compressor 38 and the high pressure compressor 37, is mixed with fuel and burned in the combustor 42, and is then expanded over the high pressure turbine 40 and the low pressure turbine 39. The high pressure turbine 40 and the low pressure turbine 39 rotationally drive the respective high speed spool 32 and the low speed spool 30 in response to the expansion.
Each of the compressor section 24 and the turbine section 28 may include alternating rows of rotor assemblies and vane assemblies (shown schematically) that carry airfoils that extend into the core flow path C. For example, the rotor assemblies can carry a plurality of rotating blades 25, while each vane assembly can carry a plurality of vanes 27 that extend into the core flow path C. The blades 25 of the rotor assemblies add or extract energy from the core airflow that is communicated through the gas turbine engine 20 along the core flow path C. The vanes 27 of the vane assemblies direct the core airflow to the blades 25 to either add or extract energy.
Various components of a gas turbine engine 20, including but not limited to the airfoils of the blades 25 and the vanes 27 of the compressor section 24 and the turbine section 28, may be subjected to repetitive thermal cycling under widely ranging temperatures and pressures. The hardware of the turbine section 28 is particularly subjected to relatively extreme operating conditions. Therefore, some components may require internal cooling circuits for cooling the parts during engine operation. Example cooling circuits that include features such as airflow bleed ports are discussed below.
Referring to
Although two architectures for gas turbine engines are depicted (e.g., turbofan in
The turbine 200 is housed within a case 212, which may have multiple parts (e.g., turbine case, diffuser case, etc.). In various locations, components, such as seals, may be positioned between airfoils 201, 202 and the case 212. For example, as shown in
Impingement cooling can be used to provide cooling to various components of gas turbine engines, including, but not limited to, blades, vanes, BOAS, combustor panels, etc. Impingement-type cooling can be adjusted or optimized by selecting or defining a specific or desired arrangement of the characteristics or parameters of the impingement holes. For example, impingement hole diameter, impingement hole spacing, and depth-to-diameter ratio of the impingement hole can all be adjusted, selected, or otherwise designed to achieve desired impingement cooling. As known in the art, the impingement hole depth is an important factor for effective cooling and optimal or preferred impingement hole depth may tend toward being small (e.g., a short or shallow impingement hole). However, having a small (e.g., short depth) impingement hole depth can increase cross-flow air velocity that “blows away” impingement jets and therefore reduces impingement effectiveness.
Turning now to
The impingement plate 320 has a first surface 326 and a second surface 328, with the impingement holes 324 extending through the impingement plate 320 from the first surface 326 to the second surface 328. The impingement plate 320 has an impingement plate thickness (i.e., the distance from the first surface 326 to the second surface 328) that defines an impingement hole depth L. Further, each impingement hole 324 has an impingement hole diameter D. A cross-flow area 330 is defined between the impingement surface 322 and the first surface 326 of the impingement plate 320. The cross-flow area 330 has an impingement cavity height X that is defined as the distance between the first surface 326 and the impingement surface 322, as shown.
As noted above, typically it is desirable to provide impingement cooling by optimizing the impingement hole diameter D and positioning the impingement plate 320 at a specific impingement hole height X from the impingement surface 322. However, having a small (e.g., short depth) impingement hole depth can increase cross-flow air velocity that “blows away” impingement jets and therefore reduces impingement effectiveness. That is, air flowing within the cross-flow area 330 can reduce the effectiveness of impingement cooling by having too high of a velocity as the cross-flow air passes through the cross-flow area 330. As shown in
Turning now to
The impingement plate 420 is similar to the impingement plate 320 of
The impingement plate 420 provides improved impingement cooling through an increase in cross-flow area 420 as described herein. The increased cross-flow area enables a lower velocity cross-flow air flow and thus impingement cooling may not be blow away as may happen in configurations such as that shown in
As shown in
As shown, the second portion 440 is separated from the first portion 438 by a separation distance Y. In some embodiments, such as shown in
Further, as shown in
The increased cross-flow structures 436 and the profile or contour of the impingement plate 420 define a cross-flow structure height Z, as shown. The cross-flow structure height Z is height of the first portion 438 plus the separation distance Y of the second portion 440 from the first portion 438. That is, the cross-flow structure height Z is the distance between the impingement surface 422 and the second portion 440 of the increased cross-flow structures 436.
Turning now to
As will be appreciated by those of skill in the art, the first portion 538 is minimized in surface area and the second portion 540 is maximized in surface area. Such configuration can maximize an amount of volume between the impingement plate 520 and the impingement surface 522. Further, the cross-flow structure height Z is greater than the impingement hole height X of the first portion 538.
Turning now to
As will be appreciated by those of skill in the art, an increased cross-flow area will be formed between the impingement plate 620 and the impingement surface 622 such that improved impingement cooling can be achieved. In the embodiment of
Although shown in
Advantageously, embodiments described herein provide improved impingement cooling by increasing cross-flow area and volume. For example, impingement cooling efficiency may be increased through application of embodiments disclosed herein because impingement jets will blow out with less cross-flow force compared to convention impingement plates having flat surfaces or structures.
The use of the terms “a,” “an,” “the,” and similar references in the context of description (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or specifically contradicted by context. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the particular quantity). All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other.
While the present disclosure has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the present disclosure is not limited to such disclosed embodiments. Rather, the present disclosure can be modified to incorporate any number of variations, alterations, substitutions, combinations, sub-combinations, or equivalent arrangements not heretofore described, but which are commensurate with the scope of the present disclosure. Additionally, while various embodiments of the present disclosure have been described, it is to be understood that aspects of the present disclosure may include only some of the described embodiments.
Accordingly, the present disclosure is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
