Patent Application
20140064945
The present application and resultant patent generally to gas turbine engines and more particularly relate to a stator vane assembly having stator ring segments with a stepped configuration to reduce aerodynamic moment transmitted from adjacent segments.
Generally described, many compressors include stator vane assemblies with a number of stator vanes. Each of the stator vanes includes an airfoil that may extend from a dovetail slot. The stator vanes assemblies may be arranged between adjacent rows of rotor blades. The stator vane assemblies may include a number of stator rings coupled to circumferential slots in the compressor casing. A typical stator ring may be cut into a number of segments and then reassembled to create a 360 degree ring. The ends of these segments generally may have a straight cut while a stator vane dovetail slot may be angled to align with the vane skew angle.
For high solidity stator stages (i.e., high vane count stages), angled end cuts that match the skew angle of the stator vane dovetail slots may be used. Such an angled cut, however, may not effectively transmit tangential aerodynamic loads between adjacent ring segments. Rather, a moment may be created in the ring segment due to the aerodynamic loading of the stator vane. The angled cuts may force the ring segment to rotate within the casing slot so as to produce point loads between the ring segments and the casing and between the ring segments themselves. Such point loads may result in-excessive wear between the components.
There is thus a desire for an improved stator vane assembly. Such an improved assembly may minimize segment to casing wear as well as segment to segment wear due to ring rotation and the like. Reducing such wear may lead to lower overall maintenance and replacement costs for the stator vane assembly and other compressor components.
The present application and the resultant patent thus provide a stator vane assembly for a turbine engine. The stator vane assembly may include a casing slot and a number of ring segments positioned within the casing slot. Each of the ring segments may include a first end and a second end. The first end and the second end may have a stepped configuration.
The present application and the resultant patent further provide a stator vane assembly for a turbine engine. The stator vane assembly may include a casing slot and a number of ring segments positioned within the casing slot. Each of the ring segments may include a first portion and a second portion. The first portion may have a straight cut and the second portion may have an angled cut.
The present application and the resultant patent further provide a ring segment for use with a stator vane assembly. The ring assembly may include a first end, a second end, and a number of dovetail slots therebetween. The first end and the second end may include a stepped configuration.
These and other features and improvements of the present application and the resultant patent will become apparent to one of ordinary skill in the art upon review of the following detailed description when taken in conjunction with the several drawings and the appended claims.
Referring now to the drawings, in which like numerals refer to like elements throughout the several views,
The gas turbine engine 10 may use natural gas, various types of syngas, and/or other types of fuels. The gas turbine engine 10 may be any one of a number of different gas turbine engines offered by General Electric Company of Schenectady, N.Y., including, but not limited to, those such as a 7 or a 9 series heavy duty gas turbine engine and the like. The gas turbine engine 10 may have different configurations and may use other types of components. Other types of gas turbine engines also may be used herein. Multiple gas turbine engines, other types of turbines, and other types of power generation equipment also may be used herein together.
Each of the ring segments 80 also may have a pair of ends 95 in communication with the ends 95 of adjacent ring segments 80. In the case of high vane count or high solidarity stator stages, the ends 95 may include an angled cut 97. As described above, however, the angled cuts 97 may force the ring segments 80 to rotate within the casing slot 85 so as to result in point loads and wear between the segments 80 and the casing 85 as well as between the segments 80 themselves. Specifically, the angled cuts 95 may produce point loads LP of axial, tangential, and key reaction as well as transferred momentum. The transferred momentum may cause the segments 80 to twist so as to result in the point loads LP.
Each ring segment 110 also includes a first end 140 and a second end 150. Both ends 140, 150 may have a stepped configuration 160. The stepped configuration 160 may include a bottom or a first portion 170 and a top or a second portion 180. The bottom or first portion 170 may have a straight cut thereon. The straight cut 190 may be largely perpendicular to the direction of the ring segments 110 and the casing slot 120. The straight cut 190 creates a flat surface 200 so as to provide for uniform loading conditions with adjacent ring segments 110 and the casing slot 120. Specifically, the flat surface 200 may transmit aerodynamic loads between adjacent ring segments 110. The top or second portion 180 may include an angled cut 210. The angled cut 210 may have an end angle 220. The end angle 220 may be aligned substantially with the dovetail angle 135 of the dovetail slots 130 although the degree of the end angle 220 of the angled cut 210 may vary. The angled cut 210 thus may accommodate high solidity or high vane count stages and the like. Other components and other configurations may be used herein.
Use of the stepped configuration 160 with both the straight cut 190 and the angled cut 210 thus accommodates vane stagger and the transfer of tangential force. As a result, little or no moment or twists may be imposed on the ring segments 110. Moreover, axial reaction or point load may be reduced or eliminated. Such uniform loading should reduce ring wear and improve durability. The stepped configuration 160 may have other combinations and other configurations of the first portion 170 and the second portion 180 and the angles inbetween.
It should be apparent that the foregoing relates only to certain embodiments of the present application and the resultant patent. Numerous changes and modifications may be made herein by one of ordinary skill in the art without departing from the general spirit and scope of the invention as defined by the following claims and the equivalents thereof.
