Cooling system for a seal for turbine vane shrouds

A seal for sealing a seal groove in a shroud of a turbine vane. The seal may include a cooling system configured to pass cooling fluids through a cooling fluid supply port in a shroud, through a cooling system in which the cooling fluids contact the shroud and the seal, and exhaust the fluids through a gap between adjacent turbine vanes. The seal may include an elongated cooling channel for channeling cooling fluids from a supply to an exhaust channel at a first end. The cooling system may remove heat from the turbine vane shroud, the seal, and other related components, thereby reducing the likelihood of premature failure.

FIELD OF THE INVENTION

This invention is directed generally to turbine vanes and, more particularly, to turbine vane shroud assemblies.

BACKGROUND

Typically, gas turbine engines operate at high temperatures that may exceed 2,500 degrees Fahrenheit. During operation, turbine engines expose turbine vanes, turbine vane shrouds, and other components to these high temperatures. As a result, turbine vanes and shrouds must be made of materials capable of withstanding such high temperatures. Turbine vanes often contain cooling systems for prolonging the life of the vanes and reducing the likelihood of failure as a result of excessive temperatures. However, these cooling systems often do not include cooling channels for reducing the temperature of seals positioned in seal grooves between adjacent turbine vanes in turbine shrouds. Without adequate cooling, these seals are susceptible to premature failure. Thus, a need exists for a cooling system for seals in seal grooves of turbine vane shrouds to reduce the likelihood of premature failure.

SUMMARY OF THE INVENTION

This invention relates to a seal for sealing gaps between adjacent turbine vane shrouds in a turbine engine. The seal may include a cooling system for removing heat from a turbine vane, a turbine vane shroud, and a seal to prevent premature failure. The seal may, in at least one embodiment, be formed from an elongated body configured to fit within seal grooves on side surfaces of turbine vane shrouds. The seal grooves may be configured such that a seal groove on a first turbine vane shroud is configured to receive about half of a seal, and a recess in a second turbine vane shroud positioned proximate to the first turbine vane shroud is configured to receive the remainder of the seal. In at least one embodiment, the seal may be formed from a first end and a second end generally opposite the first end, a top surface and a bottom surface generally opposite the top surface, and a first side surface and a second side surface generally opposite the first side surface.

The cooling channel may extend generally parallel to a longitudinal axis of the elongated body on an outer surface of the elongated body. In at least one embodiment, the cooling channel may extend generally from a midpoint between the first and second ends to the first end. The cooling channel, in at least one embodiment, may contact a first side surface and a top surface of the elongated body forming a generally rectangular cooling channel. The cooling channel may be formed on two sides by the seal and on two sides by the turbine vane shroud. The cooling channel may extend to the first end of the elongated body where it may contact an exhaust channel. The exhaust channel may, in at least one embodiment, extend the width of the elongated body and provide a flow path for cooling fluids to be exhausted from the cooling system.

During operation of a turbine engine, hot combustion gases pass turbine vanes and turbine vane shrouds, which cause these components to increase in temperature. Cooling fluids may be passed through the cooling system in the seal to remove heat from the turbine vane, the turbine vane shroud, and the seal to prevent premature failure of the components. The cooling fluids may be passed through a cooling fluid supply port in the shroud and into a cooling fluid supply orifice in the seal. The cooling fluids may flow through the cooling channel and remove heat from walls of the cooling channel. The cooling fluids may collect in the exhaust channel and be exhausted from the cooling system through a gap between adjacent turbine vane shrouds.

Also disclosed is a method of removing heat from a turbine vane shroud, comprising passing a cooling fluid through an orifice in the turbine vane shroud; passing the cooling fluid into a cooling channel of a cooling system in a seal in the turbine vane shroud such that the cooling fluid flows from midchord to a leading edge of the turbine vane shroud along a longitudinal axis of the seal, whereby the seal comprises an elongated body having an exterior shape capable of fitting inside a seal groove on the shroud of the turbine vane; a cooling channel on the elongated body extending on an outer surface of the elongated body generally parallel to the longitudinal axis of the elongated body; a cooling fluid supply orifice in communication with the cooling channel; and wherein the cooling channel extends generally from a first side surface about halfway toward a second side surface of the elongated body and extends from a midpoint of the elongated body to a first end of the elongated body; and exhausting the cooling fluid from the cooling channel through a gap between adjacent turbine vane shrouds.

An advantage of this invention is that the cooling fluids remove heat and reduce the temperature of the surrounding components, thereby substantially reducing the risk of premature failure of the components.

Another advantage of this invention is that the cooling system improves cooling of the seal groove and reduces hot spot formation in various components of a turbine vane.

Yet another advantage of this invention is that as cooling fluids are exhausted from the gap between adjacent shrouds, the cooling fluids my reduce the temperature of the external side of the seal from the leading edge to the trailing edge of the seal.

DETAILED DESCRIPTION OF THE INVENTION

As shown inFIGS. 1–4, this invention is directed to a seal10for sealing gaps12between turbine vane shrouds14, which may also be referred to as shroud segments that collectively form a shroud in a turbine engine. The seal10includes a cooling system16for removing heat from the seal10to prevent premature failure of the seal10, the turbine vane shroud14, and the turbine vane. The cooling system16may be configured to receive cooling fluids, which may be, but are not limited to, air, from one or more cooling fluid supply ports18, pass the cooling fluids through the cooling system16, and exhaust the cooling fluids through a gap12between adjacent turbine vane shrouds14.

As shown inFIG. 2, the seal10may be formed from an elongated body22configured to fit into seal grooves24on side surfaces26of the turbine vane shrouds14. The seal10, as shown inFIGS. 2 and 3, may have a first end28and a second end30generally opposite the first end28, a top surface32and a bottom surface34generally opposite the top surface32, and a first side surface36generally orthogonal to the top surface32and a second side surface38generally opposite the first side surface36. Corners of the elongated body22may or may not be filleted or tapered, as shown inFIGS. 3 and 4. A cooling channel20may be formed on a portion of the top surface32and a portion of the first side surface36. In at least one embodiment, the cooling channel20may form a generally rectangular shape formed by portions of the seal10and the turbine vane shroud14. The cooling channel20may extend generally along, or parallel to, a longitudinal axis40of the elongated body22. In at least one embodiment, the cooling channel20extends substantially from a midpoint of the elongated body22to the first end28. The cooling channel20may extend generally midway into the elongated body between the top surface32and the bottom surface34. In addition, the cooling channel20may extend from a first side surface36about half way toward a second side surface38. The cooling channel20is not limited to the this configuration but may include other appropriate configurations capable of channeling cooling fluids through the turbine vane shroud14to reduce the temperature of the shroud14and the seal10. In other embodiments, the cooling channel20may have other lengths, widths, or depths.

The seal10may also include a cooling fluid supply orifice42for supplying cooling fluids to the cooling channel20. The cooling fluid supply orifice42may extend generally orthogonal to the bottom surface34and terminate at the top surface32of the cooling channel20. In other embodiments, the cooling fluid supply orifice42may have other configurations. The cooling fluid supply orifice42may be aligned with the cooling fluid supply port18such that cooling fluids may flow from the cooling fluid supply port18into the cooling fluid supply orifice42and then into the cooling channel20. The cooling fluid supply orifice42may be sized based on the anticipated flow rate of cooling fluids necessary to achieve sufficient heat removal from the shroud14and the seal10. The cooling fluid supply orifice42may be, but is not limited to being, generally circular. The cooling fluid supply orifice42may have other appropriate configurations as well.

The cooling system16may also include an exhaust channel44coupled to the cooling channel20for exhausting cooling fluids from the cooling system16. The exhaust channel44may exhaust gases between a gap12between adjacent turbine vane shrouds14. In at least one embodiment, as shown inFIG. 4, the exhaust channel44may extend the width of the elongated body22forming the seal10. The exhaust channel44may have a depth substantially equal to a depth of the cooling channel20. The exhaust channel44may extend into the elongated body22a distance sufficient to enable the exhaust channel44to collect cooling and exhaust the cooling fluids from the cooling system16. In other embodiments, the exhaust channel44may have other widths, heights, and depths.

During operation of a turbine engine, hot combustion gases flow past turbine vane assemblies and increase the temperature of turbine vanes and turbine vane shrouds14. Cooling fluids, such as, but not limited to, air, may be passed through the cooling system16to remove heat from the turbine vane shroud14, the turbine vane, and the seal10to prevent premature failure. Cooling fluids may be injected into the cooling system16through a cooling fluid supply port18. The cooling fluids may flow from the cooling fluid supply port18and into the cooling fluid supply orifice42. The cooling fluids flow from the cooling fluids supply orifice42into the cooling channel20where the cooling fluids contact surfaces of the seal10and a turbine vane shroud14. In this manner, the cooling fluids flow from midchord of the turbine vane to a leading edge along the seal10. The cooling fluids remove heat from the turbine vane shroud14by convection and flow from the cooling fluid supply orifice42toward the first end28. As the cooling fluids flow toward the first end28, the cooling fluids increase in temperature. The cooling fluids collect in the exhaust channel44at the first end28and are exhausted from the cooling system16through the gap12between adjacent turbine vane shrouds14.