COMPONENT AND A METHOD OF COOLING A COMPONENT

Abstract

A component and method of cooling a component are provided. The component includes a leading edge, a trailing edge, at least one cavity between the leading edge and the trailing edge, at least one diffusion member adjacent to the cavity. The diffusion member includes an inlet adjacent to the cavity, a metering zone adjacent to the inlet, a diffusion zone adjacent to the metering zone, and an outlet adjacent the diffusion zone and adjacent the trailing edge. The diffusion member provides up to about 70% reduction in flow and uniform cooling of the trailing edge of the component.

Description

FIELD OF THE INVENTION

The present invention relates generally to turbines. More specifically, to a component and a method of cooling a component in turbine.

BACKGROUND OF THE INVENTION

The objective of designing and building more efficient turbine engines is a significant one, particularly considering the growing scarcity and increasing cost of fossil fuels. While several strategies for increasing the efficiency of turbine engines are known, it remains a challenging goal because the known alternatives, which, for example, include increasing the size of the engine, increasing the temperatures through the hot-gas path, and increasing the rotational velocities of the rotor blades, generally place additional strain on parts, including additional strain on turbine airfoils, which are already highly stressed. As a result, improved apparatus, methods and/or systems that reduce operational stresses placed on turbine airfoils or allow the turbine airfoils to better withstand these stresses are in great demand.

One strategy for alleviating thermal stresses is through cooling the airfoils such that the temperatures experienced by the airfoils are lower than that of the hot-gas path. Effective cooling may, for example, allow the airfoils to withstand higher firing temperatures, withstand greater mechanical stresses at high operating temperatures, and/or extend the part-life of the airfoil, all of which may allow the turbine engine to be more cost-effective and efficient. One way to cool airfoils during operation is through the use of internal cooling passageways or circuits. Generally, this involves passing a relatively cool supply of compressed air, which may be supplied by the compressor of the turbine engine, through internal cooling circuits within the airfoils. As the compressed air passes through the airfoil, it convectively cools the airfoil, which may allow the part to withstand firing temperatures that it otherwise could not.

In some instances, the supply of compressed air is released through small holes on the surface of the airfoils. Released in this manner, the supply of air forms a thin layer or film of relatively cool air at the surface of the airfoil, which both cools and insulates the part from the higher temperatures that surround it. This type of cooling, which is commonly referred to as “film cooling,” however, comes at an expense. The release of the compressed air in this manner over the surface of the airfoil, lowers the aero-efficiency of the engine. As a result, there is an ongoing need for improved cooling strategies for turbine airfoils.

Therefore, a component and a method of cooling a component in turbine that do not suffer from the above drawbacks is desirable in the art.

SUMMARY OF THE INVENTION

According to an exemplary embodiment of the present disclosure, a component is provided. The component may include a leading edge, a trailing edge, at least one cavity between the leading edge and the trailing edge and at least one diffusion member adjacent to the cavity. The diffusion member may include an inlet adjacent to the cavity, a metering zone adjacent to the inlet, a diffusion zone adjacent to the metering zone, and an outlet adjacent the diffusion zone and adjacent the trailing edge. The diffusion member may provide up to about 70% reduction in flow and uniform cooling of the trailing edge of the component.

According to another exemplary embodiment of the present disclosure, a method of cooling a component is provided. The method may include providing the component. The component may include a leading edge, a trailing edge, at least one cavity between the leading edge and the trailing edge and at least one diffusion member adjacent to the cavity. The diffusion member may include an inlet adjacent to the cavity, a metering zone adjacent to the inlet, a diffusion zone adjacent to the metering zone, and an outlet adjacent the diffusion zone and adjacent the trailing edge. The diffusion member may provide up to about 70% reduction in flow and uniform cooling of the trailing edge of the component. The method may include circulating cooling air in the at least one cavity through the diffusion member. The heat from the component may be removed through the diffusion zone.

Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective schematic of a component of the present disclosure.

FIG. 2 is a blown-up view of FIG. 1 of the diffusion zone of the present disclosure.

FIG. 3 section view of FIG. 1 taken along line 3-3 of the present disclosure.

FIG. 4 is a blown-up view of the diffusion zone of FIG. 3 of the present disclosure.

FIG. 5 is an alternative embodiment of the diffusion zone of FIG. 3 of the present disclosure.

FIG. 6 is an alternative embodiment of the diffusion zone of the present disclosure.

Wherever possible, the same reference numbers will be used throughout the drawings to represent the same parts.

DETAILED DESCRIPTION OF THE INVENTION

Provided is a component and a method of cooling a component.

One advantage of an embodiment of the present disclosure includes reducing parasitic flows from a turbine. Another advantage of an embodiment of the present disclosure includes reducing the discharge velocity of the nozzle trailing edge cooling slots. Yet another advantage of the present disclosure is increased engine efficiency.

According to one embodiment, a component including a leading edge, a trailing edge, at least one cavity between the leading edge and the trailing edge, and at least one diffusion member adjacent to the cavity is provided. Component may generally be a hot gas flow path component and may include turbine components, such as, but not limited to, nozzles, blades and shrouds. According to one embodiment the diffusion member may provide up to about 70% reduction in flow and uniform cooling of the trailing edge of the component. In one embodiment, the component may be a ceramic matrix composite. In another embodiment, the component may be a superalloy metal, such as but not limited to nickel-based superalloy, cobalt-based superalloy, or a combination thereof.

For example, FIG. 1 is a perspective schematic of a component 100. For example, as depicted, component 100 may be a nozzle. Component 100 may include an airfoil 102. Airfoil 102 may be a member between the inner and outer turbine flow path with purpose to change the flow gas path direction. Airfoil may include a leading edge 110, a trailing edge 112, and a body 104 between leading edge 110 and trailing edge 112. As shown in FIG. 2, for example, component 100 may include at least one cavity 200, 310, 320 between leading edge 110 and trailing edge 112. Component 100 may include at least one diffusion member 130 adjacent to the at least one cavity.

According to one embodiment, diffusion member may include an inlet adjacent to the cavity, a metering zone adjacent to the inlet, a diffusion zone adjacent to the metering zone, and an outlet adjacent the diffusion zone and adjacent the trailing edge. For example, as shown in FIG. 2, diffusion member 130 may include an inlet 210 adjacent to cavity 200. Diffusion member 130 may include a metering zone 220 adjacent to inlet 210. Diffusion member 130 may include a diffusion zone 230 adjacent to metering zone 220. Diffusion member 130 may include an outlet 240 adjacent diffusion zone 220 and adjacent trailing edge 112. Diffusion member 130 may provide up to about 70% reduction in flow and uniform cooling of trailing edge 112 of component 100. Velocity of flow at outlet 240 may be significantly reduced. Diffusion member 130 may expand the cross section area from inlet 210 to outlet 240. As used herein “flow expansion” may be a process in which the mass flux is reduced with increasing through-flow area, or a device that enables said process, such as the diffusion member 120. As used herein “flow metering” may be a process or device that controls the quantity of flow traversing the member containing the metering process or device.

As shown in FIG. 2, inlet 210 may be the location that flow enters trailing edge 112 cooling scheme from aft cavity 200 (see FIG. 3). Inlet 210 may be typically short in length with the ratio of the length to hydraulic diameter being less than about 5. Inlet 210 may have unique geometric characteristics intended to reduce its metering characteristics. Metering zone 220 may be primarily a controlled geometry feature the size of which has the most significant impact on the flow rate passing through trailing edge 112 cooling scheme. Metering zone 220 may have a secondary geometry feature that causes or is intended to cause a reduction in the flow rate. Secondary metering may have a non-negligible impact on flow rate but may not be the flow controlling feature.

Diffusion zone 230 or expansion region may be a region with through-flow area increase of about 150% to about 500%, between the metering zone 220 and outlet 240. Diffusion zone 230 may include a diffusion angle 232. Diffusion angle 232 may be any angle that provides the desired expansion of flow. Outlet 240 may be the location where flow exits internal portion of trailing edge 112 cooling scheme. Outlet 240 may be characterized by film coverage and in the event outlet 240 bisects the trailing edge 112 with no film coverage zone, then outlet 240 may have an open-to-solid ratio in the range of about 25% to about 100%. As used herein, “film coverage,” may be measured in the direction orthogonal to the flow, and is the fraction of the distance that is exposed to outlet 240.

FIG. 3 is a sectional view along line 3-3 of FIG. 1 and shows forward cavity 320 adjacent leading edge 110. Second cavity 310 may be adjacent forward cavity 320. Aft cavity 200 may be adjacent diffusion member 130. Diffusion member 130 may be adjacent external portion 350. External portion 350 may be the distance between outlet 240 of diffusion member 130 and airfoil closeout, having a ratio of length (L) to hydraulic diameter (D) in the range of about zero to about twelve. In one embodiment, when the L/D ratio may be finite, the film coverage may be in the range of about 33% to 100%. In another embodiment when the L/D ratio may be zero, the outlet 240 may have “open” coverage in the range of about 33% to 100%.

According to one embodiment, a diffusion member is provided. For example, FIG. 4 illustrates a schematic blow-up of FIG. 3 highlighting the diffusion member 130. Inlet 210 may be adjacent to aft cavity 200. Metering zone 220 may be adjacent inlet 210. Diffusion zone 230 may be adjacent metering zone 220. Outlet 240 may be adjacent diffusion zone and external portion 350 of airfoil 102 trailing edge 112. In an alternative embodiment, as shown in FIG. 5, outlet 240 may exit at base of trailing edge 112, having no breakout length.

According to one embodiment, a diffusion member may include two or more diffusion zones. For example, as illustrated in FIG. 6 diffusion member 130 may include inlet 210 adjacent to aft cavity 220 of component 100. Inlet 210 may be adjacent to metering zone 220. There may be two or more diffusion zones 230 adjacent to metering zone 220. Each diffusion zone 230 may provide the desired expansion and decrease in flow. Each diffusion zone 230 may include an outlet 240 adjacent to trailing edge 112.

Diffusion member 130 may be formed in component 100 using any suitable technologies, such as, but not limited to, lasers, or electrical discharge machining (EDM).

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A component comprising: a leading edge;a trailing edge;at least one cavity between the leading edge and the trailing edge;at least one diffusion member adjacent to the cavity, the diffusion member including: an inlet adjacent to the cavity;a metering zone adjacent to the inlet;a diffusion zone adjacent to the metering zone; andan outlet adjacent the diffusion zone and adjacent the trailing edge;wherein the diffusion member provides up to about 70% reduction in flow and uniform cooling of the trailing edge of the component.

2. The component of claim 1, wherein the component is a ceramic matrix composite.

3. The component of claim 1, wherein the component is a superalloy metal.

4. The component of claim 1, wherein the component is a blade, a nozzle, or a shroud.

5. The component of claim 1, wherein the diffusion member expands the cross section area from the inlet to the outlet.

6. The component of claim 1, wherein the diffusion zone increases through-flow area from about 150% to about 500% between the metering zone and the outlet.

7. The component of claim 1, wherein the outlet has an open-to-solid ratio of about 25% to about 100%.

8. A method of cooling a component comprising: providing the component having: a leading edge;a trailing edge;at least one cavity between the leading edge and the trailing edge;at least one diffusion member adjacent to the at least one cavity, the diffusion member including: an inlet adjacent to the cavity;a metering zone adjacent to the inlet;a diffusion zone adjacent to the metering zone; andan outlet adjacent the diffusion zone and adjacent the trailing edge;wherein the diffusion member provides up to about 70% reduction in flow and uniform cooling of the trailing edge of the component; andcirculating cooling air in the at least one cavity through the diffusion member, wherein heat from the component is removed through the diffusion zone.

9. The method of claim 8, wherein the component is a ceramic matrix composite.

10. The method of claim 8, wherein the component is a superalloy metal.

11. The method of claim 8, wherein the component is a blade, a nozzle, or a shroud.

12. The method of claim 8, wherein the diffusion member expands the cross section area from the inlet to the outlet.

13. The method of claim 8, wherein the diffusion zone increases through-flow area from about 150% to about 500% between the metering zone and the outlet.

14. The method of claim 8, wherein the outlet has an open-to-solid ratio of about 25% to about 100%.