Patent Application
20170314408
The present disclosure relates generally to rotary engines and, more specifically, to turbine seals used with rotary engines.
Generally rotary engine assemblies include a compressor, a combustor, and a turbine coupled in a serial flow relationship. The compressor compresses air from an air intake, and subsequently directs the compressed air to the combustor. Compressed air received from the compressor is mixed with a fuel and is combusted to create combustion gases that are directed into the turbine. In the turbine, the combustion gases flow pass turbine blades of the turbine, thereby driving the turbine blades, and a shaft to which the turbine blades are attached, into rotation. The rotation of the shaft may further drive a load, such as an electrical generator, coupled to the shaft.
At least some known rotary engine assemblies include a plurality of combustors oriented in an annular arrangement around a central axis of the rotary engine. Each combustor directs combustion products through a respective transition piece into the turbine. Seals may be positioned between the plurality of combustors and the turbine to seal the flow path of combustion gases and to reduce leakage thereof. The seals, also known as floating seals, can vibrate during rotary engine operation, causing wear and deterioration to the seal components. Overtime, worn seals can allow leakage of combustion gases through the transition piece or even fail causing a reduction in rotary engine performance. At least some known repair methods require full replacement of the seal components, which increases rotary engine repair and maintenance costs, and which can only be replaced while the rotary engine is off line.
In one aspect, a repair patch for use with a turbine seal is provided. The repair patch includes a shim having a first side and an opposite second side and a cloth seal having a first section and a second section. The cloth seal is coupled to the shim, such that the cloth seal is folded over a radial edge of the shim such that the first section substantially covers the first side and the second section substantially covers the second side. The second section includes an extension section that extends from the second side such that at least a portion of the cloth seal overlaps at least a portion of the turbine seal when coupled thereto.
In a further aspect, a turbine seal for use with a turbine is provided. The turbine seal includes a frame, a backing strip, a first shim, and a first cloth seal. The first cloth seal at least partially surrounds the first shim, and the first shim and the first cloth seal are at least partially coupled between the frame and the backing strip, wherein at least a portion of the frame extends circumferentially beyond the first shim and the first cloth seal. The turbine seal further includes a repair patch coupled adjacent to the portion of the frame. The repair patch includes a second shim having a first side and an opposite second side, and a second cloth seal having a first section and a second section. The second cloth seal is coupled to the second shim, such that the second cloth seal is folded over a radial edge of the second such that the first section substantially covers the first side and the second section substantially covers the second side. The second section includes an extension section that extends from the second side such that at least a portion of the second cloth seal overlaps at least a portion of the first cloth seal.
In another aspect, a method for repairing a turbine seal is provided. The method includes removing a damaged area of the turbine seal. The turbine seal includes a frame, a backing strip, a first shim, and a first cloth seal that at least partially surrounds the first shim, wherein the first shim and the first cloth seal are at least partially coupled between the frame and the backing strip, and wherein the damaged area extends circumferentially adjacent to at least a portion of the frame. The method further includes coupling a repair patch adjacent to the portion of the frame. The repair patch includes a second shim having a first side and an opposite second side, and a second cloth seal having a first section and a second section. The second cloth seal is coupled to the second shim, such that the second cloth seal is folded over a radial edge of the second shim such that the first section substantially covers the first side and the second section substantially covers the second side. The second section includes an extension section that extends from the second side such that at least a portion of the second cloth seal overlaps at least a portion of the first cloth seal.
Unless otherwise indicated, approximating language, such as “generally,” “substantially,” and “about,” as used herein indicates that the term so modified may apply to only an approximate degree, as would be recognized by one of ordinary skill in the art, rather than to an absolute or perfect degree. Approximating language may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about,” “approximately,” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be identified. Such ranges may be combined and/or interchanged, and include all the sub-ranges contained therein unless context or language indicates otherwise.
Additionally, unless otherwise indicated, the terms “first,” “second,” etc. are used herein merely as labels, and are not intended to impose ordinal, positional, or hierarchical requirements on the items to which these terms refer. Moreover, reference to, for example, a “second” item does not require or preclude the existence of, for example, a “first” or lower-numbered item or a “third” or higher-numbered item.
As used herein, the terms “axial” and “axially” refer to directions and orientations extending substantially parallel to a longitudinal axis of a rotary machine. Moreover, the terms “radial” and “radially” refer to directions and orientations extending substantially perpendicularly to the longitudinal axis of the rotary machine. In addition, as used herein, the terms “circumferential” and “circumferentially” refer to directions and orientations extending arcuately about the longitudinal axis of the rotary machine. In addition, although embodiments of the disclosure are described with reference to components of rotary machines, it should be understood that the scope of the disclosure encompasses any suitable component of any suitable structure for which the embodiments are enabled to function as described herein.
The exemplary repair patch for use with a turbine seal and methods to repair the turbine seal described herein overcome at least some of the disadvantages associated with known seal repairs within a rotary engine. The embodiments herein include a repair patch having a shim and a cloth seal that substantially covers the shim. After removing a damaged area from the turbine seal, the repair patch is coupled thereto. A portion of the cloth seal extends from the shim such that when the repair patch is coupled to the turbine seal, fluid leakage is facilitated to be reduced while a stiffness of the turbine seal is maintained. In certain embodiments, the repair patch is coupled to the turbine seal such that wear against the connection joint is facilitated to be reduced, thereby increasing the life-cycle of the repair patch. In some embodiments, the repair patch facilitates a standardized repair of the turbine seal such that the entire turbine seal is not replaced. In such embodiments, the repair patch enables the turbine seal to be repaired, rather than entirely replaced after incurring damage and thus rotary engine repair and maintenance costs are facilitated to be reduced.
In operation, air 122 is channeled through intake 118 and into compressor assembly 102. Compressor assembly 102 compresses air 122 to higher pressures and temperatures and discharges compressed air 124 towards combustor assembly 104. At combustor assembly 104, compressed air 124 is mixed with fuel 126, channeled from fuel nozzles 110, forming a mixture 128 that flows into combustors 112. Mixture 128 is burned within combustors 112 generating combustion gases 130 that are channeled downstream through transition pieces 114 and seal assembly 116 into turbine assembly 106. As combustion gases 130 impinge turbine assembly 106, thermal energy is converted to mechanical rotational energy that is used to drive rotor assembly 108 and, for example, power external mechanical load 120. The flow of combustion gases 130 is discharged from turbine assembly 106 as exhaust gases 132 via an exhaust outlet 134.
In operation, combustion gases 130 (shown in
Within engine system 100, seal assembly 116 is movable or “floats” to accommodate axial and radial movement of the turbine nozzle. Specifically, radially outer seal 136, radially inner seal 138, and side seal 140 are moveable independent of each other. Movement within seal assembly 116 can cause both radial seals 136 and 138 to experience wear due to abrasive contact with transition piece 114 and/or side seal 140. Specifically, a circumferential end 142 of radial seal 136 and/or 138 may experience wear from contact with side seal 140. Additionally, an interior region 144 of radial seal 136 and/or 138 may experience wear from contact with transition piece 114. Depending on an amount of wear, radial seal 136 and/or 138 may need to be replaced and/or repaired within rotor engine system 100.
Seal shim assembly 148 includes a cloth seal 160 and a shim 162. Cloth seal 160 has a first section 164 and a second section 166 that are each folded over shim 162 about a radial edge 168 of shim 162, such that shim 162 is sandwiched between first and second sections 164 and 166. Specifically, shim 162 has a first radially extending side 170 and an opposite second radially extending side 172. First section 164 substantially covers first side 170, and second section 166 substantially covers second side 172. Cloth seal 160 and shim 162 are coupled together via spot welds 174 along circumferential end 142. In the exemplary embodiment, shim 162 includes two metal shims sandwiched between cloth seal 160. Alternatively, any number of shims 162 may be used that enables seal assembly 116 to function as described herein. Moreover, in the exemplary embodiment, cloth seal 160 is formed from a metallic cloth. Alternatively, cloth seal 160 may be formed from any other material that enables seal assembly 116 to function as described herein. Cloth seal 160 and shim 162 facilitate restricting fluid leakage from transition piece 114.
In the exemplary embodiment, frame 146, cloth seal 160, and shim 162 each extend to circumferential end 142 of radial seal 136 and/or 138. Backing strip 150 is offset a distance 176 from circumferential end 142. It should be appreciated that while only one circumferential end 142 is shown in
During operation of engine 100, wear from side seal 140 against radial seal 136 and/or 138 may occur within seal shim assembly 148. Specifically, over time, cloth seal 160 may be abraded and shim 162 may become damaged and/or distorted. When damage at circumferential end 142 occurs, rather than replacing the entire radial seal 136 and/or 138, a removal area 178 may be removed and replaced, as described further below, thereby decreasing repair and maintenance costs.
Removal area 178 is defined as an area on seal shim assembly 148 between a circumferential edge 180 and a line 182 extending generally at an acute angle within a range from approximately 30° to approximately 60° from a corner 184 of backing strip 150. Specifically, acute angle is a 45° angle. In the exemplary embodiment, damage within seal shim assembly 148 generally occurs between edge 180 and an edge 186 of backing strip 150. However, in the exemplary embodiment, removal area 178 extends to line 182. Extending removal area 178 further past the damage to seal shim assembly 148 facilitates increasing the overall size of the repair and a stronger repair of radial seal 136 and/or 138, as will be described further below in reference to
In the exemplary embodiment, when damage occurs and repair is needed, a portion of seal shim assembly 148 is removed from radial seal 136 and/or 138. Specifically, damage area 178 is removed from seal shim assembly 148, for example, using a cut off wheel with a guide block that facilitates a consistent cut at a consistent location. Seal shim assembly 148, including both cloth seal 160 and shim 162, is cut along line 182 to backing strip corner 184 and also along backing strip edge 186. Further, seal shim assembly 148 is cut from frame second end 156 along offset 176, thereby decoupling damaged area 178 from radial seal 136 and/or 138 and forming a new circumferential edge 188 along line 182. Alternatively, damaged area 178 may be removed with any other method and/or cutting tool that enables damaged area 178 to be removed as described herein.
Additionally, during operation of engine 100 wear from transition piece 114 against radial seal 136 and/or 138 may occur within seal shim assembly 148, causing cloth seal 160 to be abraded within interior region 144. In some embodiments, rather than replacing the entire radial seal 136 and/or 138, at least a portion of cloth seal 160 adjacent to damaged interior region 144 is spot welded, such as via a resistance welder, such that additional damage to cloth seal 160 is reduced by restricting further fraying and/or abrading of cloth seal 160. Alternatively, damaged interior region 144 may be repaired using any other suitable procedure that enables radial seal 136 and/or 138 to function as described herein.
In the exemplary embodiment, shim 204 includes two metallic shims sandwiched between cloth seal 202. Alternatively, any number of shims 204 may be used that enables repair patch 200 to function as described herein. Moreover, in the exemplary embodiment, cloth seal 202 is formed from a single piece of metallic cloth, similar to the metallic cloth of cloth seal 160. Alternatively, cloth seal 202 may be formed from any material that enables repair patch 200 to function as described herein.
In the exemplary embodiment, repair patch 200 has a radial edge 220 adjacent to coupling section 216 that facilitates coupling repair patch 200 to frame 146 of radial seal 136 and/or 138. Additionally, repair patch 200 has a first circumferential edge 222 and an opposite second circumferential edge or coupling edge 224 that substantially mirrors circumferential edge 188 of radial seal 136 and/or 138. Specifically, second circumferential edge 224 extends generally at an acute angle relative to first circumferential edge 222 such that second circumferential edge 224 is complementary to the circumferential edge 188 formed by removing the damaged area from seal shim assembly 148, as described above in reference to
Cloth seal 202 is coupled to shim 204 via spot welds 226 spaced along first circumferential edge 222. Spot welds 226 fuse cloth seal 202 to shim 204 by melting the base materials together. Alternatively, cloth seal 202 is coupled to shim 204 via any other coupling method that enables repair patch 200 to function as described herein, for example, a solid continuous weld. In the exemplary embodiment, repair patch 200 is manufactured with a predetermined size such that a plurality of repair patches 200 may be manufactured in advance of the repair of radial seal 136 and/or 138. As described above in reference to
Further in the exemplary embodiment, patch radial edge 220 is welded 230 to radial seal 136 and/or 138. For example, patch radial edge 220 is Tungsten Inert Gas (TIG) welded 230 to frame 146 of radial seal 136 and/or 138 such that the base materials are fused together. Alternatively, radial edge 220 is coupled to frame 146 via any other coupling method that enables radial seal 136 and/or 138 to function as described herein. Additionally, a corner 236 of extension section 218 of repair patch 200 is welded 232 to radial seal 136 and/or 138. Specifically, corner 236 is TIG welded 232 to seal shim assembly 148 such that the base materials are fused together and stiffness and sealing is facilitated to be increased. Alternatively, corner 236 is coupled to seal shim assembly 148 via any other coupling method that enables radial seal 136 and/or 138 to function as described herein.
In some embodiments, after radial seal 136 and/or 138 is repaired with repair patch 200, the useful life of radial seal 136 and/or 138 is increased within seal assembly 116. Overlapping the connection joint between repair patch 200 and seal shim assembly 148 along circumferential edges 188 and 224 respectively, with extension section 218, facilitates increasing repair stiffness and sealing. Furthermore, in some embodiments, the overlap decreases repair time by enabling the use of a spot weld. During operation of rotary engine 100 (shown in
In the exemplary embodiment, when repair patch 200 is coupled to radial seal 136 and/or 138, shim 162 is aligned with repair patch shim 204. It should be appreciated, however, in an alternative embodiment, shim 204 overlaps with shim 162. Alternatively, repair patch 200 may be coupled to radial seal 136 and/or 138 using any other geometry and/or welds that enables repair patch 200 to function as described herein. For example, repair patch 200 includes second section of cloth seal 208 that ends at second circumferential edge 224 such that extension section 218 is not present and repair patch 200 is tack or seam welded to radial seal 136 and/or 136. Additionally, in other embodiments, repair patch 200 is substantially rectangular shape such that second circumferential edge 224 is generally parallel to first circumferential edge 222 which is then welded to radial seal 136 and/or 138. In some embodiments, only cloth seal 160 within removal area 178 (shown in
An exemplary method 300 of repairing a radial seal, such as radial seal 136 and/or 138 in engine 100, is illustrated in the flow diagram of
Further, in some embodiments, method 300 includes removing 306 at least a portion of the first shim and the first cloth seal when the damaged area is removed. In other embodiments, method 300 includes removing 308 the damaged area along a line, such as line 182, that extends angularly from the radial edge.
Moreover, in certain embodiments, method 300 includes welding 310 the extension section to the first shim and the first cloth seal when coupling the repair patch to the remaining radial seal. In other embodiments, method 300 includes welding 312 the repair patch to the frame when coupling the repair patch to the remaining radial seal.
Additionally, in some embodiments, method 300 includes coupling 314 the second cloth seal to the second shim via a weld, such as spot weld 226, extending a distance along a circumferential edge, such as edge 222, of the repair patch. In other embodiments, method 300 includes resistance welding 316 a second damaged area of the first cloth seal, wherein the second damaged area is located on an interior portion, such as region 144, of the first cloth seal.
Exemplary embodiments of a repair patch for use with a turbine seal, and methods to repair the turbine seal, are described above in detail. The embodiments herein provide several advantages in reducing maintenance costs in a rotary machine. Specifically, the apparatus and methods described herein enable portions of the turbine seal to be repaired when damaged rather than replacing the entire seal at a higher material cost. The embodiments described herein provide advantages in that the repair patch maintains existing seal stiffness and fluid sealing functionality. The turbine seal includes a repair patch having a shim and a cloth seal that substantially covers the shim. After removing a damaged area from the turbine seal, the repair patch is coupled thereto. A portion of the cloth seal extends from the shim such that when the repair patch is coupled to the turbine seal, fluid leakage is facilitated to be reduced while a stiffness of the turbine seal is maintained. In certain embodiments, the repair patch is coupled to the turbine seal such that wear against the connection joint is facilitated to be reduced, thereby increasing the life-cycle of the repair patch. In some embodiments, the repair patch facilitates a standardized repair of the turbine seal such that the entire turbine seal is not replaced. In such embodiments, the repair patch enables the radial seal to be repaired, rather than entirely replaced, after incurring damage and thus rotary engine repair and maintenance costs are facilitated to be reduced.
Exemplary embodiments of repair patches for radial seals, and methods of using the repair patches, are described above in detail. The apparatus and methods and systems using such an apparatus, are not limited to the specific embodiments described herein, but rather, components of systems and/or steps of the methods may be utilized independently and separately from other components and/or steps described herein. For example, the exemplary embodiments can be implemented and utilized in connection with many other applications that require a radial seal to be repaired.
While the disclosure has been described in terms of various specific embodiments, those skilled in the art will recognize that the disclosure can be practiced with modification within the spirit and scope of the claims. Although specific features of various embodiments of the disclosure may be shown in some drawings and not in others, this is for convenience only. Moreover, references to “one embodiment” in the above description are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. In accordance with the principles of the disclosure, and feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.
