Patent Grant
8016546
1. Technical Field
The disclosure generally relates to gas turbine engines.
2. Description of the Related Art
Since turbine gas flow path temperatures can exceed 2,500 degrees Fahrenheit, cooling schemes typically are employed to cool the platforms that are used to mount turbine vanes and bound the turbine gas flow path. Two conventional methods for cooling vane platforms include impingement cooling and film cooling. Notably, these methods require the formation of cooling holes through the vane platforms.
In operation, there are times during which the pressure of available cooling air is less than that of the static pressure along the turbine gas flow path. Therefore, an insufficient back flow margin can exist that may result in hot gas ingestion into the vane platform cavity via the cooling holes.
Systems and methods for cooling vane platforms are provided. In this regard, an exemplary embodiment of a method for cooling a vane platform comprises: providing a cooling channel on a platform from which a vane airfoil extends, the cooling channel being defined by a cooling surface and a channel cover, the channel cover being spaced from the cooling surface and located such that the cooling surface is positioned between a gas flow path of the vane and the channel cover; and directing a flow of cooling air through the cooling channel such that heat is extracted from the cooling surface of the platform by the flow of cooling air.
An exemplary embodiment of a gas turbine vane assembly comprises: a vane platform having a vane mounting surface and a cooling channel; and a vane airfoil extending outwardly from the platform; the cooling channel being defined by a cooling surface and a channel cover, the channel cover being spaced from the cooling surface and located such that the cooling surface is positioned between a gas flow path of the vane airfoil and the channel cover, the channel having a cooling inlet located in a high pressure region of the platform and a cooling outlet located in a low pressure region of the platform such that during operation, cooling air flows into the cooling inlet, through the cooling channel and out of the cooling outlet.
An exemplary embodiment of a gas turbine engine comprises: a compressor section; a combustion section located downstream of the compressor section; and a turbine section located downstream of the combustion section and having multiple vane assemblies; a first of the vane assemblies having a platform and a vane airfoil, the platform having a vane mounting surface and a cooling channel; the cooling channel being defined by a cooling surface and a channel cover, the channel cover being spaced from the cooling surface, the cooling surface being positioned between a gas flow path of the vane and the channel cover, the channel having a cooling air inlet located in a high pressure region of the platform and a cooling air outlet located in a low pressure region of the platform such that, during operation, cooling air flows into the cooling air inlet, through the cooling channel and out of the cooling air outlet without flowing into the vane airfoil.
Other systems, methods, features and/or advantages of this disclosure will be or may become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features and/or advantages be included within this description and be within the scope of the present disclosure.
Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
As will be described in detail here, systems and methods for cooling turbine vane platforms are provided. In this regard, several embodiments will be described that generally involve the use of cooling channels for directing cooling air. Specifically, the cooling air is directed to flow in a manner that can result in enhanced convective cooling of a portion of a vane platform. In some of these embodiments, surface cooling features are provided on a cooling surface of the vane platform to enhance heat transfer. By way of example, protrusions can be located on the cooling surface to create a desired flow field of air within a cooling channel.
Referring now to the drawings,
As shown in
A representative embodiment of a vane assembly is depicted schematically in
In order to cool the vane airfoil and platforms during use, cooling air is directed toward the vane assembly. Typically, the cooling air is bleed air vented from an upstream compressor. In the embodiment depicted in
Typically the vane outer platform 204 is cooled by directing air from the plenum 210 through small holes in a plate producing jets of cooling air, which impinge upon the non-gas flow path side of the platform, and/or by drilling cooling holes directly through the platform. Typically, the vane inner platform 206 is cooled in a manner similar to the outer platform. Cooling air for the inner platform may be directed from plenum 211.
Additionally or alternatively, cooling of a vane assembly can be provided via a platform cooling channel. An embodiment of a platform cooling channel is depicted schematically in
Channel cover 312 is shaped to conform to at least a portion of the non-gaspath static structure of the platform. In the embodiment of
In this embodiment, the channel cover 312 is wider at the upstream side than at the downstream side. Although the shape along the length of a channel cover can vary, as may be required to accommodate the shape of the base of the platform, for example, this overall tapered shape may enhance airflow by creating a region of accelerated flow. Channel cover 312 is received by mounting land 302 that facilitates positioning of the channel cover on the non-gaspath static structure. Notably, various attachment methods can be used for securing the channel cover, such as brazing or welding.
In operation, cooling air (arrows “IN”) provided to the platform via platform cooling air plenum 320 enters the cooling air inlet 314 and flows through the platform cooling channel 306. The cooling air (arrows “OUT”) exits the cooling channel via holes 316. Although additional cooling need not be provided, in the embodiment of
Note also in
The cooling surface 304 and protrusions 330 of the embodiment of
Each protrusion of this embodiment is cast, or otherwise molded and, as such, exhibits a somewhat tapered profile. Notably, the tapering of the protrusions in this embodiment permits release of the cast cooling surface features from the mold used to form the protrusions.
An alternative embodiment of cooling features is depicted schematically in the plan view of
It should be emphasized that the above-described embodiments are merely possible examples of implementations set forth for a clear understanding of the principles of this disclosure. Many variations and modifications may be made to the above-described embodiments without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the accompanying claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3800864 | Hauser et al. | Apr 1974 | A |
| 4017213 | Przirembel | Apr 1977 | A |
| 4288201 | Wilson | Sep 1981 | A |
| 4820116 | Hovan et al. | Apr 1989 | A |
| 5288207 | Linask | Feb 1994 | A |
| 5344283 | Magowan et al. | Sep 1994 | A |
| 5669759 | Beabout | Sep 1997 | A |
| 6254333 | Merry | Jul 2001 | B1 |
| 6589010 | Itzel et al. | Jul 2003 | B2 |
| 6773230 | Bather et al. | Aug 2004 | B2 |
| 6824352 | Moore et al. | Nov 2004 | B1 |
| 6955523 | McClelland | Oct 2005 | B2 |
| 7004720 | Synnott et al. | Feb 2006 | B2 |
| 7118326 | Liang | Oct 2006 | B2 |
| 20040109765 | Benedetti et al. | Jun 2004 | A1 |
| 20050281663 | Trindade et al. | Dec 2005 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20090028692 A1 | Jan 2009 | US |
