The invention relates to a base material with a cooling air hole. The base material is, in particular, a gas turbine part in which cooling air holes are present.
The documents U.S. Pat. No. 5,192,192, U.S. Pat. No. 4,075,455, U.S. Pat. No. 5,779,437, U.S. Pat. No. 4,606,701 or U.S. Pat. No. 5,183,385 generally show air-cooled turbine blades, in which cooling air flows through cooling air holes arranged at various locations. The shape of the cooling air holes is designed to correspond to their position and their function. In these examples, film cooling holes are involved which form a film on a surface of a component and, by this means, cool the basic component.
In addition, various blading arrangements with cooling devices have become known from the publications DE-OS-2 042 947, EP-A1-0 534 207, WO99/36675, U.S. Pat. No. 6,120,249 or U.S. Pat. No. 4,040,767. In contrast to the publications mentioned above, however, impingement cooling is involved in this case. Cooling air flows through cooling air holes of an impingement panel onto a turbine blading platform located at a distance under them.
One problem in the cooling system of such turbine blading consists in the fact that the cooling air contains dirt or dust particles. Whereas smaller particles can flow unhindered without further problems through the cooling air holes, which can, for example, have a diameter of between 0.5 and 1 mm, larger particles close the cooling air holes so that the cooling performance is reduced overall and there is the threat of overheating of the component.
The publication EP-A1-1 072 757 therefore proposes a dust-resistant, internal cooling system for turbine blading.
The publications U.S. Pat. No. 3,066,912, U.S. Pat. No. 5,983,623, GB-A-2,342,142, DE-A1-44 22 965, DE-A1-35 32 168, DE-AS-25 14 704 or U.S. Pat. No. 4,173,458 solve the problem mentioned above by means of cyclones. The polluted air is fed through the cyclone, the ash is separated, and the cleaned air is subsequently further used at a suitable location.
The measures proposed for separating cooling air and dust are, however, extremely complex.
The invention achieves the object of creating a base material with cooling air holes which are no longer completely closed by particles which are present in the cooling air. In particular, the base material is an impingement panel of a turbine blading platform.
According to the invention, this is achieved in the case of a base material with a cooling air hole according to the preamble to claim 1 by means which prevent the particles closing the cooling air hole being present at the cooling air hole.
Although the particles which pollute the cooling air are located above the cooling air hole, the particles no longer close the latter, so that a certain cooling performance is advantageously always maintained by cooling air which flows past the particles and through the cooling air hole. In addition, there is a greater probability of the particles being removed from this position again by vibrations or flow fluctuations in the cooling air.
In what follows, the means can consist of the edge of the cooling air hole being uneven or having a ridge. This ridge can appear due to punching or stamping of the cooling air hole or can have already appeared during a casting process of the base material.
The possibility also exists of arranging a protuberance, a wire mesh or another type of filter over the cooling air hole. It is also conceivable for the means to consist of a star-shaped, ellipsoidal or linear cooling air hole or of a circular cooling hole with lateral slots, it being possible to manufacture the cooling air holes by means of a laser, water jet or electrode jet.
In an exemplary embodiment, the base material can be a part of a gas turbine, for example a sheet-metal part, for example therefore an impingement plate of a rotor blade platform or, generally, a cast part to be cooled.
The invention is explained in more detail below using the enclosed figures, in which
Only the features essential to the invention are represented. Similar elements have the same designations in different figures. Flow directions are designated by arrows.
In
In
According to the invention, all means, which generate a ridge 3 or an uneven edge at the cooling air hole 1, are appropriate for the exemplary embodiments of FIGS. 1 to 4, so that cooling air 4 continues to flow past the particles 5, which are located on the cooling air hole 1, and through the cooling air hole 1 and a certain cooling performance is maintained. The probability that the particles 5 will again leave their position is, furthermore, greater.
FIGS. 5 to 8 show further exemplary embodiments, according to the invention, of a base material 2 with cooling air holes 1.
Corresponding to
The possibility also exists of arranging, over the cooling air hole 1, a stirrup 6 (
In an exemplary embodiment, the base material can be a part of a gas turbine, for example a sheet-metal part, therefore for example an impingement plate of a platform of a rotor blade, or a cast part to be cooled.
Number | Date | Country | Kind |
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2001 1291/01 | Jul 2001 | CH | national |
Number | Date | Country | |
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Parent | 10183853 | Jun 2002 | US |
Child | 10899031 | Jul 2004 | US |