ROTARY MACHINE HAVING SPACERS FOR CONTROL OF FLUID DYNAMICS
A system includes a rotary machine with a fluid flow path extending along an axis of the rotary machine, a plurality of airfoils disposed about the axis, and a plurality of spacers disposed about the axis. Each spacer of the plurality of spacers is disposed circumferentially between adjacent airfoils of the plurality of airfoils to define a circumferential spacing of the airfoils about the axis.
Latest General Electric Patents:
- SYSTEM FOR READYING SUB-CRITICAL AND SUPER-CRITICAL STEAM GENERATOR, SERVICING METHOD OF SAID SUB-CRITICAL AND SUPER-CRITICAL STEAM GENERATOR AND METHOD OF OPERATION OF SUB-CRITICAL AND SUPER-CRITICAL STEAM GENERATOR
- System and method for repairing a gearbox of a wind turbine uptower
- Modular fuel cell assembly
- Efficient multi-view coding using depth-map estimate for a dependent view
- Airfoil for a turbofan engine
The subject matter disclosed herein relates to rotary machines and, more particularly, turbines and compressors susceptible to resonant behavior in a fluid flow.
Turbines and compressors exchange energy between a fluid and a rotor. For example, a turbine generates energy in response to a fluid flow acting on a plurality of blades, whereas a compressor uses energy to drive a plurality of blades to compress a gas. Unfortunately, the rotation of the blades can create wake and bow waves, which can excite other rotating and stationary structures upstream and downstream from the blades. For example, the wake and bow waves may cause vibration, premature wear, and damage of vanes, blades, nozzles, airfoils, rotors, and other structures in the fluid flow.
BRIEF DESCRIPTION OF THE INVENTIONCertain embodiments commensurate in scope with the originally claimed invention are summarized below. These embodiments are not intended to limit the scope of the claimed invention, but rather these embodiments are intended only to provide a brief summary of possible forms of the invention. Indeed, the invention may encompass a variety of forms that may be similar to or different from the embodiments set forth below.
In a first embodiment, a system includes a rotary machine with a fluid flow path extending along an axis of the rotary machine, a plurality of airfoils disposed about the axis, and a plurality of spacers disposed about the axis. Each spacer of the plurality of spacers may be disposed circumferentially between adjacent airfoils of the plurality of airfoils to define a circumferential spacing of the airfoils about the axis.
In a second embodiment, a system includes a rotary machine with a fluid flow path and a plurality of segments disposed in an annular arrangement along the fluid flow path. The plurality of segments include spacer segments and flow control segments. The flow control segments protrude into the fluid flow path. Each spacer segment is disposed circumferentially between adjacent flow control segments to define a circumferential spacing of the flow control segments.
In a third embodiment, a method includes mounting a plurality of airfoil segments in a rotary machine along a fluid flow path, and spacing the plurality of airfoil segments in a circumferential spacing with a plurality of spacer segments.
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
The disclosed embodiments are directed toward tuning of fluid dynamics in rotary machines, such as a turbine or a compressor, via an adjustment of the spacing between rotating blades or stationary vanes and/or an adjustment of the count of rotating blades or stationary vanes. In particular, the disclosed embodiments adjust the spacing and/or count of blades or vanes to control the frequency of wake and bow waves formed by the rotating blades, stationary vanes, or other structures in the fluid flow. For example, a non-uniform spacing or modified count of rotating blades or stationary vanes may reduce the possibility of resonant behavior, vibration, and undesirable fluid dynamics in the turbine or compressor. In other words, the non-uniform spacing or modified count of rotating blades or stationary vanes may reduce or eliminate the ability of the wake and bow waves to cause resonance in structures along the fluid flow path. Instead, the non-uniform spacing or modified count of rotating blades or stationary vanes may dampen and reduce the response of structures in the fluid flow path by changing the frequency of the wake and bow waves. The non-uniform spacing or modified count may be achieved with spacers, modified mounting structures, mounting adapters, modified stators, modified rotors, or some combination thereof.
For example, the non-uniform spacing of the blades or vanes may be achieved with differently sized spacers between adjacent blades or vanes, differently sized bases of adjacent blades or vanes, or any combination thereof. The non-uniform spacing of the blades or vanes may include both non-uniform spacing of the blades about a circumference of a particular stage (e.g., turbine or compressor stage), non-uniform spacing of the blades from one stage to another, or a combination thereof. The non-uniform spacing effectively reduces and dampens the wake and bow waves generated by the rotating blades, thereby reducing the possibility of vibration, premature wear, and damage caused by such wake and bow waves on stationary and rotating structures.
By further example, the modified count of blades or vanes may be achieved by uniformly spacing a greater or smaller count of blades or vanes via spacers, modified mounting bases, or a combination thereof. In certain embodiments employing spacers, a first set of spacers (e.g., large spacers) may be used to provide a first uniform spacing of blades or vanes, a second set of spacers (e.g., medium spacers) may be used to provide a second uniform spacing of blades or vanes, a third set of spacers (e.g., small spacers) may be used to provide a third uniform spacing of blades or vanes, and so forth. Similarly, in certain embodiments employing modified bases, a first set of blades or vanes with a first mounting base size (e.g., large mounting base) may be used to provide a first uniform spacing of blades or vanes, a second set of blades or vanes with a second mounting base size (e.g., medium mounting base) may be used to provide a second uniform spacing of blades or vanes, a third set of blades or vanes with a third mounting base size (e.g., small mounting base) may be used to provide a third uniform spacing of blades or vanes, and so forth. In each embodiment, the blade or vane count may be increased or decreased to change the frequency of wake and bow waves at specific rotational speeds of the rotary machine. Thus, the modified count is configured to change the frequency of the wake and bow waves to avoid the resonant frequency of the structures in the fluid flow path at specific rotational speeds.
The disclosed embodiments of non-uniform spacing or modified count of rotating blades or stationary vanes may be utilized in any suitable rotary machine, such as turbines, compressors, and rotary pumps. However, for purposes of discussion, the disclosed embodiments are presented in context of a gas turbine engine.
In the illustrated embodiment, the gas turbine engine 150 includes an air intake section 156, the compressor 152, one or more combustors 158, the turbine 154, and an exhaust section 160. The compressor 152 includes a plurality of compressor stages 162 (e.g., 1 to 20 stages), each having a plurality of rotating compressor blades 164 and stationary compressor vanes 166. The compressor 152 is configured to intake air from the air intake section 156 and progressively increase the air pressure in the stages 162. Eventually, the gas turbine engine 150 directs the compressed air from the compressor 152 to the one or more combustors 158. Each combustor 158 is configured to mix the compressed air with fuel, combust the fuel air mixture, and direct hot combustion gases toward the turbine 154. Accordingly, each combustor 158 includes one or more fuel nozzles 168 and a transition piece 170 leading toward the turbine 154. The turbine 154 includes a plurality of turbine stages 172 (e.g., 1 to 20 stages), such as stages 174, 176, and 178, each having a plurality of rotating turbine blades 180 and stationary nozzle assemblies or turbine vanes 182. In turn, the turbine blades 180 are coupled to respective turbine wheels 184, which are coupled to a rotating shaft 186. The turbine 154 is configured to intake the hot combustion gases from the combustors 158, and progressively extract energy from the hot combustion gases to drive the blades 180 in the turbine stages 172. As the hot combustion gases cause rotation of the turbine blades 180, the shaft 186 rotates to drive the compressor 152 and any other suitable load, such as an electrical generator. Eventually, the gas turbine engine 150 diffuses and exhausts the combustion gases through the exhaust section 160.
As discussed in detail below, a variety of embodiments of non-uniform spacing or modified count of rotating blades or stationary vanes may be used in the compressor 152 and the turbine 154 to tune the fluid dynamics in a manner that reduces undesirable behavior, such as resonance and vibration. For example, as discussed with reference to
The illustrated rotor 200 has non-uniformly spaced blades 208, which may be described by dividing the rotor 200 into two equal sections 202 and 204 (e.g., 180 degrees each) via an intermediate line 206. In certain embodiments, each section 202 and 204 may have a different number of blades 208, thereby creating non-uniform blade spacing. For example, the illustrated upper section 202 has three blades 208, while the illustrated lower section 204 has six blades 208. Thus, the upper section 202 has half as many blades 208 as the lower section 204. In other embodiments, the upper and lower sections 202 and 204 may differ in the number of blades 208 by approximately 1 to 1.005, 1 to 1.01, 1 to 1.02, 1 to 1.05, or 1 to 3. For example, the percentage of blades 208 of the upper section 202 relative to the lower section 204 may range between approximately 50 to 99.99 percent, 75 to 99.99 percent, 95 to 99.99, or 97-99.99 percent. However, any difference in the number of blades 208 between the upper and lower sections 202 and 204 may be employed to reduce and dampen wake and bow waves associated with rotation of the blades 208 on stationary airfoils or structures.
In addition, the blades 208 may be evenly or unevenly spaced within each section 202 and 204. For example, in the illustrated embodiment, the blades 208 in the upper section 202 are evenly spaced from one another by a first circumferential spacing 210 (e.g., arc lengths), while the blades 208 in the lower section 204 are evenly spaced from one another by a second circumferential spacing 212 (e.g., arc lengths). Although each section 202 and 204 has equal spacing, the circumferential spacing 210 is different from the circumferential spacing 212. In other embodiments, the circumferential spacing 210 may vary from one blade 208 to another in the upper section 202 and/or the circumferential spacing 212 may vary from one blade 208 to another in the lower section 204. In each of these embodiments, the non-uniform blade spacing is configured to reduce the possibility of resonance on stationary airfoils and structures due to periodic generation of wake and bow waves by rotating airfoils or structures. The non-uniform blade spacing may effectively dampen and reduce the wake and bow waves due to their non-periodic generation by the non-uniform rotating airfoils or structures. In this manner, the non-uniform blade spacing is able to lessen the impact of wake and bow waves on various downstream components, e.g., vanes, nozzles, stators, airfoils, etc.
The illustrated rotor 220 has non-uniformly spaced blades 234, which may be described by dividing the rotor 220 into four equal sections 222, 224, 226, and 228 (e.g., 90 degrees each) via intermediate lines 230 and 232. In certain embodiments, at least one or more of the sections 222, 224, 226, and 228 may have a different number of blades 234 relative to the other sections, thereby creating non-uniform blade spacing. For example, the sections 222, 224, 226, and 228 may have 1, 2, 3, or 4 different numbers of blades 234 in the respective sections. In the illustrated embodiment, each section 222, 224, 226, and 228 has a different number of blades 234. Section 222 has 3 blades equally spaced from one another by a circumferential distance 236, section 224 has 6 blades equally spaced from one another by a circumferential distance 238, section 226 has 2 blades equally spaced from one another by a circumferential distance 240, and section 228 has 5 blades equally spaced from one another by a circumferential distance 242. In this embodiment, sections 224 and 226 have an even yet different number of blades 234, while sections 222 and 228 have an odd yet different number of blades 234. In other embodiments, the sections 222, 224, 226, and 228 may have any configuration of even and odd numbers of blades 234, provided that at least one section has a different number of blades 234 relative to the remaining sections. For example, the sections 222, 224, 226, and 228 may vary in the number of blades 234 with respect to each other by approximately 1 to 1.005, 1 to 1.01, 1 to 1.02, 1 to 1.05, or 1 to 3.
In addition, the blades 234 may be evenly or unevenly spaced within each section 222, 224, 226, and 228. For example, in the illustrated embodiment, the blades 234 in the section 222 are evenly spaced from one another by the first circumferential spacing 236 (e.g., arc lengths), the blades 234 in the section 224 are evenly spaced from one another by the second circumferential spacing 238 (e.g., arc lengths), the blades 234 in the section 226 are evenly spaced from one another by the third circumferential spacing 240 (e.g., arc lengths), and the blades 234 in the section 228 are evenly spaced from one another by the fourth circumferential spacing 242 (e.g., arc lengths). Although each section 222, 224, 226, and 228 has equal spacing, the circumferential spacing 236, 238, 240, and 242 varies from one section to another. In other embodiments, the circumferential spacing may vary within each individual section. In each of these embodiments, the non-uniform blade spacing is configured to reduce the possibility of resonance due to periodic generation of wake and bow waves. Furthermore, the non-uniform blade spacing may effectively dampen and reduce the response of stationary airfoils or structures by the rotating airfoils or structure's wake and bow waves due to their non-periodic generation by the blades 234. In this manner, the non-uniform blade spacing is able to lessen the impact of wake and bow waves on various downstream components, e.g., vanes, nozzles, stators, airfoils, etc.
The illustrated rotor 250 has non-uniformly spaced blades 264, which may be described by dividing the rotor 250 into three equal sections 252, 254, and 256 (e.g., 120 degrees each) via intermediate lines 258, 260, and 262. In certain embodiments, at least one or more of the sections 252, 254, and 256 may have a different number of blades 264 relative to the other sections, thereby creating non-uniform blade spacing. For example, the sections 252, 254, and 256 may have 2 or 3 different numbers of blades 264 in the respective sections. In the illustrated embodiment, each section 252, 254, and 256 has a different number of blades 264. Section 252 has 3 blades equally spaced from one another by a circumferential distance 266, section 254 has 6 blades equally spaced from one another by a circumferential distance 268, and section 256 has 5 blades equally spaced from one another by a circumferential distance 270. In this embodiment, sections 252 and 256 have an odd yet different number of blades 264, while section 254 has an even number of blades 264. In other embodiments, the sections 252, 254, and 256 may have any configuration of even and odd numbers of blades 264, provided that at least one section has a different number of blades 264 relative to the remaining sections. For example, the sections 252, 254, and 256 may vary in the number of blades 264 with respect to each other by approximately 1 to 1.005, 1 to 1.01, 1 to 1.02, 1 to 1.05, or 1 to 3.
In addition, the blades 264 may be evenly or unevenly spaced within each section 252, 254, and 256. For example, in the illustrated embodiment, the blades 264 in the section 252 are evenly spaced from one another by the first circumferential spacing 266 (e.g., arc lengths), the blades 264 in the section 254 are evenly spaced from one another by the second circumferential spacing 268 (e.g., arc lengths), and the blades 264 in the section 256 are evenly spaced from one another by the third circumferential spacing 270 (e.g., arc lengths). Although each section 252, 254, and 256 has equal spacing, the circumferential spacing 266, 268, and 270 varies from one section to another. In other embodiments, the circumferential spacing may vary within each individual section. In each of these embodiments, the non-uniform blade spacing is configured to reduce the possibility of resonance due to periodic generation of wake and bow waves. Furthermore, the non-uniform blade spacing may effectively dampen and reduce the response of stationary airfoils or structures by the rotating airfoils or structure's wake and bow waves due to their non-periodic generation by the blades 264. In this manner, the non-uniform blade spacing is able to lessen the impact of wake and bow waves on various downstream components, e.g., vanes, nozzles, stators, airfoils, etc.
In each of these embodiments, the non-uniform blade spacing is configured to reduce the possibility of resonance due to periodic generation of wake and bow waves. Furthermore, the non-uniform blade spacing may effectively dampen and reduce the response of stationary airfoils or structures by the rotating airfoils or structure's wake and bow waves due to their non-periodic generation by the blades 286. In this manner, the non-uniform blade spacing is able to lessen the impact of wake and bow waves on various downstream components, e.g., vanes, nozzles, stators, airfoils, etc. In the embodiment of
In the illustrated embodiment, the spacers 324 interface with the bases 326 of the blades 328 at an angled interface 330. For example, the angled interface 330 is oriented at an angle 332 relative to a rotational axis of the rotor 322, as indicated by line 334. The angle 332 may range between approximately 0 to 60 degrees, 5 to 45 degrees, or 10 to 30 degrees. The illustrated angled interface 330 is a straight edge or flat surface. However, other embodiments of the interface 330 may have non-straight geometries.
In the illustrated embodiment, the spacers 342 interface with the bases 344 of the blades 346 at a non-straight interface 350. For example, the interface 350 may include a first curved portion 352 and a second curved portion 354, which may be the same or different from one another. However, the interface 350 also may have other non-straight geometries, such as multiple straight segments of different angles, one or more protrusions, one or more recesses, or a combination thereof. As illustrated, the first and second curved portions 352 and 354 curve in opposite directions from one another. However, the curved portions 352 and 354 may define any other curved geometry.
In the illustrated embodiment, the bases 402 interface with one another at an angled interface 406. For example, the angled interface 406 is oriented at an angle 408 relative to a rotational axis of the rotor 400, as indicated by line 409. The angle 408 may range between approximately 0 to 60 degrees, 5 to 45 degrees, or 10 to 30 degrees. The illustrated angled interface 406 is a straight edge or flat surface. However, other embodiments of the interface 406 may have non-straight geometries.
In the illustrated embodiment, the bases 412 interface with one another at a non-straight interface 416. For example, the interface 416 may include a first curved portion 418 and a second curved portion 420, which may be the same or different from one another. However, the interface 416 also may have other non-straight geometries, such as multiple straight segments of different angles, one or more protrusions, one or more recesses, or a combination thereof. As illustrated, the first and second curved portions 418 and 420 curve in opposite directions from one another. However, the curved portions 418 and 420 may define any other curved geometry.
As discussed above, the present embodiments may tune the fluid dynamics in a rotary machine, such as a compressor or turbine, via an adjustment of the spacing between rotating blades or stationary vanes and/or an adjustment of the count of rotating blades or stationary vanes. This tuning may substantially reduce or eliminate the possibility of resonance behavior in the rotary machine, e.g., resonant behavior due to wakes and bow waves. The embodiments of
As illustrated in
In the illustrated embodiment, the second rotational speed 558 is generally the same as the design rotational speed 536 of the rotary machine, and thus the line 542 corresponding to the medium count of blades (e.g.,
Similar to the modification of blade spacing of rotating blades as discussed above with reference to
The embodiments discussed above are directed to changing the frequency of wake and bow waves generated by rotating blades or stationary vanes, such that the frequency does not intersect with a resonant frequency of various structures in the fluid flow. As appreciated, the non-uniform spacing or modified count of rotating blades or stationary vanes may be applied to a single stage of a rotary machine (e.g., a turbine or a compressor), or it may be applied to multiple stages in a similar or different configuration. For example, each stage in a compressor or turbine may change the non-uniform spacing or modified count of blades or vanes to address different fluid dynamics in each particular stage. In other words, each stage may exhibit different resonant behavior, frequencies of wake and bow waves, and other characteristics. Thus, the disclosed embodiments may employ a combination of non-uniform spacing and a modified count of blades and vanes to address the different fluid dynamics from one stage to another.
Technical effects of the disclosed embodiments include the ability to dampen fluid oscillations (e.g., wake or bow waves) and/or reduce resonant behavior caused by the fluid oscillations in a rotary machine. In particular, the disclosed embodiments adjust the spacing and/or count of blades or vanes to control the frequency of wake and bow waves formed by the rotating blades, stationary vanes, or other structures in the fluid flow. For example, a non-uniform spacing of rotating blades or stationary vanes may be achieved with differently sized spacers between adjacent blades or vanes, differently sized bases of the blades or vanes, or a combination thereof. By further example, a modified count of rotating blades or vanes may be achieved with different sets of spacers, each configured to provide a different uniform spacing of the blades or vanes. The non-uniform spacing or modified count of blades or vanes is able to reduce the possibility of resonant behavior in the rotary machine, thereby reducing the possibility of costly wear and damage of vanes, blades, and other structures in the fluid flow path.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
Claims
1. A system, comprising:
- a rotary machine comprising: a fluid flow path extending along an axis of the rotary machine; a plurality of airfoils disposed about the axis; and a plurality of spacers disposed about the axis, wherein each spacer of the plurality of spacers is disposed circumferentially between adjacent airfoils of the plurality of airfoils to define a circumferential spacing of the airfoils about the axis.
2. The system of claim 1, wherein the circumferential spacing of the plurality of airfoils is configured to reduce resonant behavior in the rotary machine.
3. The system of claim 1, wherein the rotary machine comprises a turbine.
4. The system of claim 1, wherein the rotary machine comprises a compressor.
5. The system of claim 1, wherein the rotary machine comprises a stator and a rotor, the plurality of airfoils are coupled to the rotor, and the plurality of spacers are coupled to the rotor.
6. The system of claim 1, wherein the rotary machine comprises a stator and a rotor, the plurality of airfoils are coupled to the stator, and the plurality of spacers are coupled to the stator.
7. The system of claim 1, wherein the plurality of spacers have an equal width in a circumferential direction about the axis.
8. The system of claim 1, comprising a plurality of replacement spacers configured to replace the plurality of spacers, wherein the plurality of replacement spacers have a different width than the plurality of spacers.
9. The system of claim 1, comprising a plurality of second airfoils and a plurality of second spacers disposed about the axis, wherein each second spacer of the plurality of second spacers is disposed circumferentially between adjacent second airfoils of the plurality of second airfoils to define a second circumferential spacing of the second airfoils about the axis.
10. The system of claim 9, wherein the circumferential spacing of the plurality of airfoils is configured to reduce resonant behavior in the rotary machine, and the second circumferential spacing of the plurality of second airfoils is configured to reduce resonant behavior in the rotary machine.
11. A system, comprising:
- a rotary machine comprising: a fluid flow path; and a plurality of segments disposed in an annular arrangement along the fluid flow path, wherein the plurality of segments comprise spacer segments and flow control segments, the flow control segments protrude into the fluid flow path, and each spacer segment is disposed circumferentially between adjacent flow control segments to define a circumferential spacing of the flow control segments.
12. The system of claim 11, wherein the circumferential spacing of the flow control segments is configured to reduce resonant behavior in the rotary machine.
13. The system of claim 11, wherein the rotary machine comprises a turbine, a compressor, or a combination thereof.
14. The system of claim 11, wherein the plurality of segments are stationary, and the flow control segments comprise stationary vanes.
15. The system of claim 11, wherein the plurality of segments are rotatable, and the flow control segments comprise rotatable blades.
16. The system of claim 11, wherein the spacer segments have an equal width in a circumferential direction about the annular arrangement.
17. The system of claim 11, comprising replacement spacer segments configured to replace the spacer segments, wherein the replacement spacer segments have a different width than the spacer segments.
18. A method, comprising:
- mounting a plurality of airfoil segments in a rotary machine along a fluid flow path; and
- spacing the plurality of airfoil segments in a circumferential spacing with a plurality of spacer segments.
19. The method of claim 18, comprising reducing resonant behavior in the rotary machine by adjusting a number of the plurality of airfoil segments and by adjusting a width and number of the plurality of spacer segments.
20. The method of claim 19, wherein mounting comprising removably attaching the plurality of airfoil segments and the plurality of spacer segments in a turbine, a compressor, or a combination thereof.
Type: Application
Filed: Oct 20, 2010
Publication Date: Apr 26, 2012
Applicant: General Electric Company (Schenectady, NY)
Inventors: John McConnell Delvaux (Fountain Inn, SC), Brian Denver Potter (Greer, SC)
Application Number: 12/908,831
International Classification: F04D 29/66 (20060101); B21K 25/00 (20060101); F04D 29/34 (20060101);