1. Field of the Invention
The invention relates to a gas turbine arrangement having a rotor and at least two rows of turbine blades or vanes, a method for operating the gas turbine arrangement, and a turbine blade or vane for use in the gas turbine arrangement.
2. Brief Description of the Related Art
On account of the temperatures of the hot gases which surround them, turbine blades and vanes of gas turbines have to be cooled. Coolable blades or vanes for gas turbines with an internal cooling system have been disclosed, for example, by laid-open specification DE-A1 198 60 788, by EP-A1 0 534 586 or by EP-A1 1 094 200. Cooling air is guided out of a cooling passage located in the rotor into the internal cooling system and is then passed through discharge openings into the flow passage of the respective gas turbine.
One major problem with cooling systems of this type is a leakage stream of cooling air which escapes between turbine blades or vanes and/or rotating and static parts of the gas turbine. Sealing devices which are supposed to minimize the cooling air leakage stream at this location are known from EP-A1 1 094 200, U.S. Pat. No. 6,152,690, U.S. Pat. No. 6,086,329, U.S. Pat. No. 4,820,116, U.S. Pat. No. 4,626,169, U.S. Pat. No. 4,505,640, U.S. Pat. No. 4,439,107, U.S. Pat. No. 4,265,590 and DE-A 1 942 346.
Other documents disclose devices which serve the purpose of minimizing the leakage stream of cooling air and of introducing the remaining stream into the hot gases of the gas turbine with the minimum possible losses and turbulence or utilizing it in some other way. In this context, mention may be made, for example, of U.S. Pat. No. 5,211,533.
Furthermore, U.S. Pat. No. 5,800,124 discloses a seal in which the leakage stream is diverted onto the trailing edge of the turbine blade or vane in order for the platform to be cooled there by impingement cooling.
U.S. Pat. No. 6,077,035 has disclosed a metal diverter sheet which prevents the leakage stream between the rotor blades and introduces the cooling air between the guide vanes and rotor blades with low losses. U.S. Pat. No. 4,348,157 has disclosed a similar device.
The aim of the invention is to avoid the abovementioned drawbacks. The invention is based on the object of providing a gas turbine arrangement in which the leakage cooling air stream is advantageously utilized for further cooling purposes. An additional object of the invention is to provide a method for operating the same gas turbine arrangement and a turbine blade or vane for use in the gas turbine arrangement.
According to the invention, the object is achieved by a gas turbine arrangement in which there are means which guide the leakage stream of cooling air along the surface of the platform to the pressure side of the first row of turbine blades or vanes.
In this way, the leakage stream of cooling air can be put to good use, since additional cooling on the pressure side of the turbine blade or vane, at which experience has shown that a locally increased temperature is established, is achieved without additional outlay for providing the cooling air, i.e. without any significant influence on the efficiency of the gas turbine.
In a first exemplary embodiment, these means may be fins which are arranged on the top side in the front region of the platform of the first row of turbine blades or vanes. To ensure that the leakage cooling air reaches the pressure side of the turbine blade or vane, the fins will advantageously extend as far as the plane in which the airfoil of the first row of turbine blades or vanes begins.
In a second exemplary embodiment, these means may comprise segmented honeycombs which form part of the seal between the two turbine blades or vanes and are arranged on the underside in the rear region of the platform of the second row of turbine blades or vanes. Individual passages, through which the leakage stream of cooling air is guided along the surface of the platform to the pressure side of the first row of turbine blades or vanes, are formed between the individual segments of the honeycombs.
The fins or the passages between the segments of the honeycombs may be straight or curved in order to achieve the object set.
According to the invention, the object is also achieved by a method for operating a gas turbine arrangement in which the leakage cooling air stream which emerges between the first and second rows of turbine blades or vanes is guided to the pressure side of the first turbine blade or vane.
According to the invention, the object is also achieved by a turbine blade or vane for use in a gas turbine arrangement by the turbine blade or vane having fins, which point in the direction of the pressure side of the turbine blade or vane, on the top side in the front region of the platform. As has already been stated, these fins may be straight or curved and may extend axially on the platform as far as the plane in which the airfoil of the turbine blade or vane begins. This advantageously prevents the leakage air from flowing away prematurely to the suction side of the turbine blade or vane.
The turbine blades or vanes in the gas turbine arrangement according to the invention and in the method according to the invention may be guide vanes or rotor blades.
The invention is illustrated on the basis of the appended drawings, in which:
a shows excerpt II from
b shows excerpt II from
Only the elements which are pertinent to the invention are illustrated. Identical elements are provided with identical reference numerals in
Both guide vanes and rotor blades of the gas turbine arrangement are equipped with an internal cooling system, which is not shown in more detail in
Working on the basis of this prior art,
In a second exemplary embodiment of the gas turbine arrangement according to the invention as shown in
As can be seen from
The invention also relates to a method for operating a gas turbine arrangement according to the invention, in which the cooling air leakage stream 7 which emerges between the first and second rows of turbine blades or vanes 1, 2 is guided to the pressure side 10 of the first turbine blade 1. The invention also relates to a turbine blade or vane 1, 2 for use in a gas turbine arrangement, the turbine blade or vane 1, 2 having fins 8, which point in the direction of the pressure side 10 of the turbine blade or vane 1, 2, on the top side in the front region of the platform 4. As has already been stated, these fins 8, 81, 82 may be straight or curved and may extend axially on the platform 4 as far as the plane in which the airfoil 3 of the turbine blade or vane 1, 2 begins.
The turbine blades or vanes 1, 2 in the gas turbine arrangement according to the invention and in the method according to the invention may be guide vanes or rotor blades.
While the invention has been described in detail with reference to preferred embodiments thereof, it will be apparent to one skilled in the art that various changes can be made, and equivalents employed, without departing from the scope of the invention. Each of the aforementioned documents is incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2289/01 | Dec 2001 | CH | national |
This is a Continuation of, and claims priority under 35 U.S.C. 120 to, International application number PCT/CH02/00679, filed 9 Dec. 2002, and claims priority under 35 U.S.C. § 119 to Swiss application number 2001 2289/01, filed 14 Dec. 2001, the entireties of both of which are incorporated by reference herein.
Number | Name | Date | Kind |
---|---|---|---|
3756740 | Deich et al. | Sep 1973 | A |
4265590 | Davies | May 1981 | A |
4348157 | Campbell et al. | Sep 1982 | A |
4439107 | Antonellis | Mar 1984 | A |
4505640 | Hsing et al. | Mar 1985 | A |
4626169 | Hsing et al. | Dec 1986 | A |
4820116 | Hovan et al. | Apr 1989 | A |
5211533 | Walker et al. | May 1993 | A |
5800124 | Zelesky | Sep 1998 | A |
5967745 | Tomita et al. | Oct 1999 | A |
6077034 | Tomita et al. | Jun 2000 | A |
6077035 | Walters et al. | Jun 2000 | A |
6086329 | Tomita et al. | Jul 2000 | A |
6152690 | Tomita et al. | Nov 2000 | A |
Number | Date | Country |
---|---|---|
1 942 346 | Mar 1971 | DE |
3523469 | Jan 1987 | DE |
198 60 788 | Jul 2000 | DE |
0 534 586 | Mar 1993 | EP |
1 094 200 | Apr 2001 | EP |
2 119 027 | Nov 1983 | GB |
2 165 007 | Apr 1986 | GB |
03052240 | Jun 2003 | WO |
Number | Date | Country | |
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20040265118 A1 | Dec 2004 | US |
Number | Date | Country | |
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Parent | PCT/CH02/00679 | Dec 2002 | US |
Child | 10865842 | US |