In a gas turbine a plurality of stationary stator or guide vanes are used which are arranged in rows along the circumference of the turbine portion. As these stator vanes are subjected to the effects of the hot gases flowing out of the combustion chamber and of the high pressures, high stresses can arise in the stator vanes and the platforms. The platform is situated between the hot gas flow and space filled with cooling air. In order to seal this space from the hot gases the platform usually has side walls which are provided with a groove extending in the longitudinal direction of the platform. The grooves of two neighboring platforms (in the circumferential direction) receive a sealing plate extending between the two platforms. In some cases the distance, in the circumferential direction of the gas turbine, between the trailing edge of the stator vane and the groove can be very small. This can lead to considerable stress concentrations, particularly in the trailing edge of the stator vane and in the platform in the area of the trailing edge of the stator vane. Because of these stress concentrations the life time of the stator vane is significantly reduced.
The invention addresses these problems. The present invention aims to provide a stator vane for a gas turbine with a platform having an improved design, which reduces the stress concentrations in the trailing edge of the stator vane and in the vane platform in the region of the trailing edge of the stator vane.
According to the invention a stator vane has a leading edge and a trailing edge and a platform extending at least between the leading and trailing edges. The platform has first and second side walls extending substantially in the axial and radial directions of the gas turbine. The first side wall is provided, at least in the area of the trailing edge, with a groove extending in the longitudinal direction of the platform for receiving a sealing plate, whereby the first side wall of the sealing plate in the area of the trailing edge has a recess extending from the groove.
The recess in the vane platform in the area of the trailing edge of the stator vane reduces the stress concentrations in the trailing edge of the stator vane and in the vane platform in the area of the trailing edge of the stator vane. The low cycle fatigue and the creep rate in these areas are therefore reduced.
In an advantageous embodiment of the invention the depth of the recess in the circumferential direction of the gas turbine is the same as the depth of the groove. As used herein, the same depth means substantially or essentially the same depth. Through this, a considerable reduction in the stress concentrations was observed in the trailing edge of the stator vane and in the vane platform in the area of the trailing edge of the stator vane.
The above and other aspects, features and advantages of the invention will become more apparent from the following description of certain preferred embodiments thereof, when taken in conjunction with the accompanying drawings.
The invention is described referring to an embodiment depicted schematically in the drawings, and will be described with reference to the drawings in more details in the following.
The drawings show schematically in:
The stator vane 1 has a leading edge 12 and a trailing edge 8, whereby the vane platform 2 extends at least between the leading edge 12 and the trailing edge 8. Attachment elements 13 are provided on the radially outer side of the vane platform 2 for positioning the stator vane 1 in the radial and circumferential directions.
The vane platform 2 furthermore has side walls 5, 6 extending substantially in the longitudinal and radial directions of the turbine.
The vane platform 2 is located in the radial direction between a hot gas flow 3 and a space 4 filled with cooling air. In order to seal this space 4 from the hot gas flow the side walls 5, 6 are each provided with a groove 7 extending in the longitudinal direction of the vane platform 2. The grooves 7 of two neighboring vane platforms 2 receive a sealing plate which extends between the two vane platforms. A groove 7 extends in the axial direction of the gas turbine at least in the area of a trailing edge 8 of the stator vane 1, and the distance in the circumferential direction of the gas turbine between the trailing edge 8 of the stator vane 1 and the groove 7 can be very small, as can be seen from
As the stator vane 1 is subjected, in use, to the effects of the hot gases 3 flowing out of the combustion chamber and the high pressures, high stress concentrations can arise in the trailing edge area of the stator vane 1 and in the vane platform 2 in the area of the trailing edge area of the stator vane 1. The life of the stator vane 1 is considerably reduced due to these stress concentrations in the area inside the circle 9 in
The vane platform 2 can be provided with a raised portion 11 on the opposite side to the recess 10 in the radial direction, whereby the recess 10 is provided in the area of the raised portion 11 in the longitudinal direction of the vane platform 2. In particular, the recess 10 can be arranged in the area of a downstream end of the raised portion 11 in the longitudinal direction of the vane platform 2.
Referring to
The depth of the recess 10 in the circumferential direction of the gas turbine is preferably substantially the same as the depth of the groove 7, as can be seen from
In
The preceding description of the embodiments according to the present invention serves only an illustrative purpose and should not be considered to limit the scope of the invention.
Particularly, in view of the preferred embodiments, the man skilled in the art different changes and modifications in the form and details can be made without departing from the scope of the invention. Accordingly the disclosure of the current invention should not be limiting. The disclosure of the current invention should instead serve to clarify the scope of the invention which is set forth in the following claims.
Number | Date | Country | Kind |
---|---|---|---|
1044/07 | Jun 2007 | CH | national |
This application is a continuation of International Patent Application No. PCT/EP2008/057947, filed on Jun. 23, 2008, which claims priority to Swiss Patent Application No. CH 01044/07, filed on Jun. 28, 2007. The entire disclosure of both applications is incorporated by reference herein. The present invention relates to a stator vane for a gas turbine engine, in particular a stator vane with a vane platform.
Number | Name | Date | Kind |
---|---|---|---|
3542483 | Gagliardi | Nov 1970 | A |
3938906 | Michel et al. | Feb 1976 | A |
4524980 | Lillibridge et al. | Jun 1985 | A |
6419447 | Watanabe et al. | Jul 2002 | B1 |
7625174 | Drerup et al. | Dec 2009 | B2 |
7922444 | Propheter-Hinckley | Apr 2011 | B2 |
20070140843 | Drerup et al. | Jun 2007 | A1 |
Number | Date | Country |
---|---|---|
0147354 | Jul 1985 | EP |
1798380 | Jun 2007 | EP |
2195403 | Apr 1988 | GB |
Number | Date | Country | |
---|---|---|---|
20100150710 A1 | Jun 2010 | US |
Number | Date | Country | |
---|---|---|---|
Parent | PCT/EP2008/057947 | Jun 2008 | US |
Child | 12646365 | US |