阅读说明：本技术 用于阻尼涡轮叶片振动的加压阻尼流体注入 (Pressurized damping fluid injection for damping turbine blade vibrations ) 是由 约翰·麦康内尔·德尔沃 克莱尔·弗里德乔夫·兰格 S·查克拉巴蒂 于 2021-03-17 设计创作，主要内容包括：本发明题为“用于阻尼涡轮叶片振动的加压阻尼流体注入”。本发明提供了一种叶片减振系统(118),该叶片减振系统与涡轮(108)的多个叶片(114)的振动移动相反地将加压阻尼流体(176)冲击在涡轮的多个叶片中的至少一个叶片的表面上,以在涡轮(108)的操作期间引起叶片(114)的振动的阻尼。该系统包括位于与多个叶片(114)相邻的静止部件中的流体注入喷嘴(174)。阀(182)选择性地允许加压阻尼流体(176)从加压阻尼流体源(184)进入流体注入喷嘴(174),并且控制系统(190)响应于操作参数在涡轮(108)的操作期间超过阈值来控制阀(182)以操作流体注入喷嘴(174)。本发明还提供了相关的涡轮壳体(126)和方法。(The invention provides pressurized damping fluid injection for damping turbine blade vibrations. A blade dampening system (118) impinges pressurized damping fluid (176) on a surface of at least one of a plurality of blades of a turbine (108) in opposition to vibratory movement of the blades (114) to cause dampening of vibrations of the blades (114) during operation of the turbine (108). The system includes a fluid injection nozzle (174) located in a stationary component adjacent to the plurality of blades (114). A valve (182) selectively allows pressurized damping fluid (176) from a pressurized damping fluid source (184) into the fluid injection nozzle (174), and a control system (190) controls the valve (182) to operate the fluid injection nozzle (174) in response to an operating parameter exceeding a threshold during operation of the turbine (108). The invention also provides a related turbine housing (126) and method.)

1. A housing (126) for a turbine (108), comprising:

a stationary component (160) defining at least a portion of a working fluid path to direct a working fluid through a blade (114) stage comprising a plurality of blades (114) operatively coupled to a rotor (110); and

a fluid injection nozzle (174) in the stationary component (160) configured to impinge a pressurized damping fluid (176) on a surface (178) of at least one of the plurality of blades (114) of the blade stage in opposition to vibratory movement of the plurality of blades (114) of the blade (114) stage to cause damping of vibrations of the at least one of the plurality of blades (114) during operation of the turbine (108).

2. The housing (126) according to claim 1, further comprising:

a valve (182) for selectively allowing the pressurized damping fluid (176) from a pressurized damping fluid source (184) into the fluid injection nozzle (174); and

a control system (190) for controlling the valve (182),

wherein the control system (190) opens the valve (182) to operate the fluid injection nozzle (174) in response to an operating parameter of the turbine (108).

3. The housing (126) of claim 2, wherein the pressurized damping fluid (176) is injected at a substantially constant flow rate.

4. The housing (126) of claim 2, wherein the fluid injection nozzle (174) includes a plurality of fluid injection nozzles (174) circumferentially spaced apart in the stationary component (160), each fluid injection nozzle (174) including a respective valve (182) for selectively allowing the pressurized damping fluid (176) to enter the fluid injection nozzle (174) from the pressurized damping fluid source (184) under control of the control system (190), and further comprising:

a sensor system (170) operatively associated with the plurality of blades (114) for determining an amplitude of the at least one of the plurality of blades (114), and

wherein the control system (190) opens at least one valve (182) to operate at least one respective fluid injection nozzle (174) in response to the amplitude of the at least one of the plurality of vanes (114) exceeding a threshold during operation of the turbine (108).

5. The housing (126) of claim 1, wherein the stationary component (160) includes a tip shroud extending circumferentially around the plurality of blades (114).

6. The housing (126) of claim 1, wherein the stationary component (160) comprises a portion of a nozzle (174) portion extending circumferentially around the plurality of vanes (114).

7. The housing (126) of claim 1, wherein the fluid injection nozzle (174) is aligned with a surface (178) of an outer tip (148) of the at least one of the plurality of blades (114).

8. The housing (126) of claim 1, wherein the pressurized damping fluid (176) comprises at least one of pressurized air, water, steam, or a combination thereof.

9. The housing (126) of claim 1, wherein the rotor (110) includes a plurality of stages of blades (114), and wherein the at least one blade of the plurality of blades (114) is part of a last stage of the plurality of stages of blades (114).

10. The housing (126) of claim 1, wherein the surface (178) of the at least one of the plurality of vanes (114) is a surface of an airfoil (124,138) thereof, and the fluid injection nozzle (174) is positioned to inject the pressurized damping fluid (176) in a direction perpendicular to the surface (178).

11. The housing (126) of claim 1, wherein the fluid injection nozzle (174) comprises a nozzle (174) insert in an opening (188) in the stationary component (160).

12. The housing (126) of claim 1, wherein the fluid injection nozzle (174) is integrally formed in the stationary component (160).

13. The housing (126) of claim 1, wherein the pressurized damping fluid (176) is derived from at least one of: a cooling fluid supply (185) to a portion of the nozzle (174) upstream of the vane (114) stage, and a compressor (102) discharge.

14. A blade (114) damping system (118) for a turbine (108), the system (118) comprising:

a fluid injection nozzle (174) located in a stationary component (160) adjacent to a plurality of blades (114) in the turbine (108), the fluid injection nozzle (174) configured to impinge a pressurized damping fluid (176) on a surface (178) of the at least one of the plurality of blades (114) in opposition to vibratory movement of the plurality of blades (114) to cause damping of vibrations of the at least one of the plurality of blades (114) during operation of the turbine (108);

a valve (182) for selectively allowing the pressurized damping fluid (176) from a pressurized damping fluid source (184) into the fluid injection nozzle (174); and

a control system (118) (190) for controlling the valve (182) to operate the fluid injection nozzle (174) in response to an operating parameter exceeding a threshold value during operation of the turbine (108).

15. The system (118) of claim 14, wherein the pressurized damping fluid (176) is injected at a substantially constant flow rate.

Background

The present disclosure relates generally to turbines and, more particularly, to damping vibration of turbine blades using pressurized damping fluid injection.

One problem in turbine operation is the tendency of the blades to experience vibratory stresses during operation. In many installations, turbines operate under conditions of frequent acceleration and deceleration. During acceleration or deceleration of the turbine, the blades are temporarily subjected to vibratory stresses at least at certain frequencies, and in many cases, at second or third frequencies. When the blade is subjected to vibratory stresses, its vibration amplitude can easily be increased to such an extent that the operation can be changed.

The turbine and compressor sections within an axial flow turbine typically include a rotor assembly including a rotating disk and a plurality of rotor blades disposed circumferentially about the disk. Each blade includes a root, an airfoil, and a platform positioned in a transition region between the root and the airfoil. The root of the blade is received in a complementary shaped recess in the disk. The platforms of the blades extend laterally outward and collectively form a working fluid flow path for fluid flow through the rotor stages. The leading edge of each blade is generally referred to as the leading edge and the trailing edge as the trailing edge. Forward is defined as being upstream aft in the flow of working fluid through the turbine.

During operation, the blade may be excited to vibrate by a number of different forcing functions. For example, changes in working fluid temperature, pressure, and/or density may excite vibrations throughout the rotor assembly, particularly vibrations within the blade airfoil and/or tip. Gases exiting the turbine section and/or upstream of the compressor section in a periodic or "pulsed" manner may also excite undesirable vibrations.

To test for vibration in the blade, one current test system uses a piezo-actuated shuttle valve to generate a high velocity jet of air pulses to excite/vibrate the blade to determine the resonant frequency of the blade. Another test system for steam turbines (see U.S. Pat. No. 4,776,216) provides controllable fluid jets disposed about the row of blades for exciting the rotating blades to determine the resonant frequency of the blades from the amplitude of the vibrations. The test system introduces steam pulses upstream of the bucket stage (see, e.g., the position of nozzle 18 relative to buckets 22 in FIG. 2) and is used when the steam turbine is operating at a constant shaft rotational speed. However, none of the aforementioned test systems are capable of correcting for vibrations during actual operation of the turbine.

One approach to addressing vibration during turbine operation includes altering the physical structure of the blades to strengthen the blades against vibration. For example, mid-span shrouds may be used that couple adjacent blades. Changing or adding structure presents additional challenges by changing the aerodynamic properties of the blade and increasing weight and/or length. In other approaches, mechanisms are employed that passively absorb the pressure that generates the vibrations during use. In one example, a cavity may be provided adjacent the tip of the blade or in another example a baffle to absorb pressure changes during operation. In another case, the high pressure gas stream may be directed into the leading edge of the blade stage from an upstream location. The effectiveness of the latter approach is limited because the airflow is directed only toward the leading edge of the blade.

Disclosure of Invention

One aspect of the present disclosure provides a housing for a turbine, the housing comprising: a stationary component defining at least a portion of a working fluid path to direct a working fluid through a blade stage comprising a plurality of blades operatively coupled to a rotor; and a fluid injection nozzle in the stationary component configured to impinge a pressurized damping fluid on a surface of at least one of the plurality of blades of the blade stage in opposition to the vibratory movement of the plurality of blades of the blade stage to cause damping of the vibration of the at least one of the plurality of blades during operation of the turbine.

Another aspect of the present disclosure provides a blade damping system for a turbine, the system comprising: a fluid injection nozzle located in a stationary component adjacent to the plurality of blades in the turbine, the fluid injection nozzle configured to impinge a pressurized damping fluid on a surface of at least one of the plurality of blades in opposition to vibratory movement in the plurality of blades to cause damping of vibrations of the at least one of the plurality of blades during operation of the turbine; a valve for selectively admitting pressurized damping fluid from a pressurized damping fluid source into the fluid injection nozzle; and a control system for controlling the valve to operate the fluid injection nozzle in response to the operating parameter exceeding a threshold value during operation of the turbine.

Another aspect of the present disclosure provides a method, comprising: operating the turbine by passing a working fluid through a working fluid path defined between a stationary component of the housing and the rotor and through a plurality of blades operatively coupled to the rotor; and damping, during operation of the turbine, vibration of at least one of the plurality of blades by impinging a pressurized damping fluid on a surface of the at least one of the plurality of blades in opposition to the vibratory movement of the plurality of blades.

Exemplary aspects of the present disclosure are designed to solve the problems herein described and/or other problems not discussed.

Drawings

These and other features of the present disclosure will be more readily understood from the following detailed description of the various aspects of the present disclosure taken in conjunction with the accompanying drawings that depict various embodiments of the disclosure, in which:

FIG. 1 illustrates a schematic view of an exemplary turbomachine in the form of a gas turbine system;

FIG. 2 illustrates a cross-sectional partial schematic view of an exemplary turbine including a blade damping system according to an embodiment of the present disclosure;

FIG. 3 illustrates a perspective view of a turbine rotor blade of the type that may employ embodiments of the present disclosure;

FIG. 4 illustrates a partial schematic cross-sectional view of a blade damping system in a casing taken along line 4-4 in FIG. 2 according to an embodiment of the present disclosure;

FIG. 5 illustrates a perspective view of a blade dampening system in a housing according to other embodiments of the present disclosure; and is

Fig. 6 illustrates a cross-sectional view of a fluid injection nozzle according to an alternative embodiment of the present disclosure.

It should be noted that the drawings of the present disclosure are not necessarily drawn to scale. The drawings are intended to depict only typical aspects of the disclosure, and therefore should not be considered as limiting the scope of the disclosure. In the drawings, like numbering represents like elements between the drawings.

Detailed Description

As an initial matter, in order to clearly describe the present technique, it will be necessary to select certain terms when referring to and describing the relevant machine components within the turbine. To the extent possible, the general industry terminology will be used and employed in a manner consistent with the accepted meaning of that term. Unless otherwise indicated, such terms should be given a broad interpretation consistent with the context of the application and the scope of the appended claims. One of ordinary skill in the art will appreciate that often several different or overlapping terms may be used to refer to a particular component. An object that may be described herein as a single part may comprise multiple components and in another context be referred to as being made up of multiple components. Alternatively, an object that may be described herein as comprising a plurality of components may be referred to elsewhere as a single part.

Furthermore, several descriptive terms may be used regularly herein, and it should prove helpful to define these terms at the beginning of this section. Unless otherwise indicated, these terms and their definitions are as follows. As used herein, "downstream" and "upstream" are terms that indicate a direction relative to a fluid flow, such as a working fluid through a turbine engine, or, for example, an air flow through a combustor or a coolant through one of the component systems of the turbine. The term "downstream" corresponds to the direction of fluid flow, and the term "upstream" refers to the direction opposite to flow. Without any additional specificity, the terms "forward" and "aft" refer to directions, where "forward" refers to the forward or compressor end of the engine and "aft" refers to the aft or turbine end of the engine.

It is often desirable to describe components that are disposed at different radial positions relative to a central axis. The term "radial" refers to movement or position perpendicular to an axis. For example, if a first component is closer to an axis than a second component, the first component will be described herein as being "radially inward" or "inboard" of the second component. On the other hand, if the first component resides farther from the axis than the second component, it may be described herein that the first component is "radially outward" or "outboard" of the second component. The term "axial" refers to movement or position parallel to an axis. Finally, the term "circumference" refers to movement or position about an axis. It should be understood that such terms may apply with respect to a central axis of the turbine.

Furthermore, several descriptive terms may be used regularly herein, as described below. The terms "first," "second," and "third" may be used interchangeably to distinguish one component from another component and are not intended to denote the position or importance of the individual components.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. "optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

Where an element or layer is referred to as being "on," "engaged to," "connected to" or "coupled to" another element or layer, it can be directly on, engaged, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to" or "directly coupled to" another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between …" and "directly between …", "adjacent" and "directly adjacent", etc.). As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Embodiments of the present disclosure include, among other things, blade damping systems, housings for turbines including the damping systems, and related methods. The blade dampening system impinges a pressurized damping fluid on a surface of at least one of the plurality of blades of the turbine in opposition to vibratory movement of the plurality of blades of the turbine to cause damping of the vibrations of the blades during operation of the turbine. The system includes a fluid injection nozzle located in a stationary component adjacent to the plurality of vanes. A valve selectively allows pressurized damping fluid from the pressurized damping fluid source to enter the fluid injection nozzle, and a control system controls the valve to operate the fluid injection nozzle in response to the operating parameter exceeding a threshold value during operation of the turbine. The operating parameters may include, for example, amplitude and phase of vibration. The pressurized damping fluid may be injected in a pulsed flow, for example pulsed 180 ° out of phase with the blade vibrations, to counteract and damp the vibrations. The fluid injection nozzle may be positioned in a stationary component defining at least a portion of a working fluid path to direct a working fluid through a blade stage comprising a plurality of blades operatively coupled to a rotor. The teachings of the present disclosure are in contrast to current test systems that employ fluid injection to determine resonant frequency vibrations, but do not serve to dampen the vibrations during actual operation of the turbine.

Referring to the drawings, FIG. 1 is a schematic illustration of an exemplary machine including a turbine to which the teachings of the present disclosure may be applied. In fig. 1, a turbomachine 90 in the form of a combustion turbine or Gas Turbine (GT) system 100 (hereinafter "GT system 100") is shown. The GT system 100 includes a compressor 102 and a combustor 104. The combustor 104 includes a combustion region 105 and a fuel nozzle portion 106. The GT system 100 also includes a turbine 108 and a common compressor/turbine shaft 110 (hereinafter "rotor 110").

In one embodiment, the GT system 100 is a 7ha.03 engine, commercially available from General Electric Company (Greenville, s.c.). The present disclosure is not limited to any one particular GT system and may be implemented with other engines, including, for example, the HA, F, B, LM, GT, TM, and E class engines of General Electric Company, and engines of other companies. More importantly, the teachings of the present disclosure are not necessarily applicable only to turbines in GT systems, and are applicable to virtually any type of turbine, such as steam turbines, jet engines, compressors (as shown in fig. 1), turbo fans, turbochargers, and the like. Accordingly, reference to the turbine 108 of the GT system 100 is for descriptive purposes only and not limiting.

FIG. 2 shows a cross-sectional partial schematic view of an illustrative portion of the turbine 108 including a blade damping system 118 and a casing 126 including a portion of the system, according to an embodiment of the present disclosure. In the illustrated example, the turbine 108 includes four stages L0-L3 that may be used with the GT system 100 in fig. 1. The four stages are referred to as L0, L1, L2, and L3. The stage L0 is the first stage and is the smallest stage (in the radial direction) of the four stages. Stage L1 is the second stage and is the next stage in the axial direction. Stage L2 is the third stage and is the next stage in the axial direction. Stage L3 is the fourth stage (last stage) and is largest (in the radial direction). It should be understood that four stages are shown as an example only, and that each turbine may have more or less than four stages.

A plurality of stationary vanes or nozzles 112 may cooperate with a plurality of turbine blades 114 (hereinafter "vanes 114") to form each stage L0-L3 of the turbine 108 and to define a portion of a Working Fluid Path (WFP) through the turbine 108. The blades 114 in each stage are coupled to the rotor 110, such as by a respective rotor wheel 116 that couples them circumferentially to the rotor 110. That is, blades 114 are mechanically coupled to rotor 110 in a circumferentially spaced manner, such as by rotor wheel 116. Where provided, the stationary nozzle portion 115 includes a plurality of stationary nozzles 112 spaced circumferentially about the rotor 110. Each nozzle 112 may include at least one endwall (or platform) 120, 122 connected to an airfoil 124. In the example shown, the nozzle 112 includes a radially outer end wall 120 and a radially inner end wall 122. Radially outer endwall 120 couples nozzle 112 to a casing 126 of turbine 108. In some forms of the turbine, the nozzle 112 may be omitted.

FIG. 3 illustrates a perspective view of a blade 114 of the type that can employ embodiments of the present disclosure. Each of the plurality of blades 114 includes a root 130 by which the blade 114 is attached to the rotor 110 (FIG. 1). The root 130 may include a dovetail 132 configured to fit in a corresponding dovetail slot in the perimeter of the rotor wheel 116 (FIG. 2) of the rotor 110 (FIG. 1). The root 130 may also include a shank 134 extending between the dovetail 132 and a platform 136 disposed at the junction of the airfoil 138 and the root 130 and defining a portion of an inboard boundary of a Working Fluid Path (WFP) (FIG. 2) through the turbine 108. It should be appreciated that airfoils 138 are moving parts of blades 114 that intercept the flow of working fluid and cause rotor 110 to rotate. As can be seen, airfoil 138 of blade 114 includes a concave Pressure Side (PS) outer wall 140 and a circumferentially or laterally opposite convex Suction Side (SS) outer wall 142 that extend axially between opposite leading and trailing edges 144 and 146, respectively. Sidewalls 140 and 142 also extend in a radial direction from platform 136 to outer tip 148. While an exemplary blade 114 has been described, it should be understood that the blade may vary in structure across different types of turbines.

Returning to FIG. 2, the casing 126 may include a stationary member 160 defining at least a portion of a Working Fluid Path (WFP) to direct a Working Fluid (WF) through a blade stage (e.g., L0-L3) including a plurality of blades 114 operatively coupled to the rotor 110. As noted, for the GT system 100 (fig. 1), the working fluid WF is the combusted fuel. Other turbines may use other working fluids such as, but not limited to, steam, water, air, fuel, or a fuel/air mixture. The stationary component 160 may include any now known or later developed portion of a casing for a turbine that forms a Working Fluid Path (WFP). In one non-limiting example, the stationary member 160 may include a tip shroud that surrounds the outer tips 148 (FIG. 3) of the blades 114. In other embodiments, the stationary component 160 can include a portion of the nozzle portion 115 extending circumferentially around the plurality of vanes 114, such as the outer end wall 120 of the upstream or downstream nozzle portion 115.

Referring to fig. 1 and 2, in operation, air flows through the compressor 102 and pressurized air is supplied to the combustor 104. Specifically, pressurized air is supplied to a fuel nozzle portion 106, which is integral with combustor 104. The fuel nozzle portion 106 is in fluid communication with the combustion region 105. Fuel nozzle portion 106 is also in fluid communication with a fuel source (not shown in fig. 1) and channels fuel and air to combustion region 105. The burner 104 is ignited and the fuel is burned. The combustor 104 is in flow communication with a turbine 108 within which the gas stream thermal energy is converted to mechanical rotational energy by directing combusted fuel (e.g., working fluid) into a Working Fluid Path (WFP) to turn blades 114. Turbine 108 is rotatably coupled to and drives rotor 110. Compressor 102 is rotatably coupled to rotor 110. At least one end of rotor 110 may extend axially away from turbine 108 and may be attached to a load or machinery (not shown), such as, but not limited to, an electrical generator, a load compressor, and/or another turbine.

As noted, during operation of the turbine, the blades 114 may be excited into vibration by a number of different forcing functions. For example, changes in working fluid temperature, pressure, and/or density may excite vibrations throughout the rotor assembly, particularly vibrations within the blade airfoil and/or tip. Gas exiting the turbine and/or compressor sections upstream in a periodic or "pulsed" manner may also excite undesirable vibrations. Other common causes of turbine blade vibration may include, but are not limited to, excitation from upstream nozzles, low per-revolution circumferential flow distortion from combustor cans, structural excitation from generators, and turbine blade flutter.

Fig. 2 and 4 illustrate a blade damping system 118 (hereinafter "system 118") for the turbine 108 according to an embodiment of the present disclosure. FIG. 4 illustrates a partial schematic cross-sectional view (taken along line 4-4 in FIG. 2) of the system 118 and the housing 126 of the turbine 108. The system 118 may also optionally include a sensor system 170 operatively associated with the plurality of blades 114 in the turbine 108. The sensor system 170 may be configured to determine, for example, the amplitude and phase of the vibrations, or another operating parameter of at least one of the plurality of blades 114. The sensor system 170 may include one or more sensors 172 coupled to the stationary housing 126 at any location adjacent the outer tip 148 of the blade 114 for accurate vibration measurements. Any number of circumferentially spaced sensors 172 may be employed. The connection from the sensor 172 to the control system 190 described elsewhere herein is well known and not shown. The sensor 172 may be any of a variety of suitable sensors, such as an electromagnetic probe.

The system 118 may also include a fluid injection nozzle 174 located in the stationary member 160 adjacent the plurality of blades 114. The fluid injection nozzle 174 is configured to impinge a pressurized damping fluid 176 on a surface 178 of at least one of the plurality of blades 114 in opposition to the vibratory movement of the plurality of blades 114 to cause damping of the vibrations of the at least one of the plurality of blades 114 during operation of the turbine. As used herein, "damping" refers to reducing the amplitude of oscillation or vibration (e.g., the resonant frequency of the blade) by expelling energy from an object, such as a blade.

In many, but perhaps not all, cases, the optimal positioning of the fluid injection nozzle 174 for damping vibrations causes the pressurized damping fluid 176 to be injected in a direction perpendicular to the surface 178. To this end, fluid injection nozzles 174 may be angled in any manner within stationary member 160 to ensure that pressurized damping fluid 176 strikes a desired surface at a desired angle with respect to associated blade 114. In one example shown in fig. 4, the fluid injection nozzle 174 may be angled at an angle α relative to the radial axis R to direct the pressurized damping fluid 176 perpendicular to a surface 178 of the blade 114. Here, the fluid injection nozzles 174 are in or parallel to a radial plane 192, i.e., the plane of the page perpendicular to the axis of the rotor 110 (fig. 1).

In another example shown in the perspective view of fig. 5, the fluid injection nozzles 174 are at an angle a relative to the radial axis R and an angle β relative to a radial plane 192 (i.e., a plane perpendicular to the axis of the rotor 110 (fig. 1)) to direct the pressurized damping fluid 176 perpendicular to the surface 178 of the blades 114.

In one example, fluid injection nozzle 174 is aligned with a surface 178 of outer tip 148 of at least one of plurality of blades 114. In this setting, the pressurized damping fluid 176 may also be used to at least partially reduce over-tip leakage of the working fluid. In another example, the surface 178 of the blade 114 may be the surface of its airfoil 138, i.e., the surface distal from the outer tip 148. However, the surface 178 may be any surface of the blade 114, such as, for example, the pressure side outer wall 140 or the suction side outer wall 142 of the airfoil 138, as shown in FIG. 2.

In the example shown in FIG. 4, the blades 114 rotate clockwise. In this case, the pressurized damping fluid 176 is directed at the suction side outer wall 142 of the airfoil 138, opposite the rotation. However, it should be emphasized that the pressurized damping fluid 176 may be directed in any direction, including the direction of rotation, and impact any blade surface to dampen vibrations. The pressurized damping fluid 176 may include, for example, pressurized air, water, steam, or a combination thereof. While the angle of impact has been described herein as perpendicular, other angles of impact may be employed.

The fluid injection nozzles 174 may have any size commensurate with the size of the turbine 108 and the desired damping effect. As shown in fig. 4 and 5, the fluid injection nozzle 176 may include, for example, a nozzle insert 186 (fixed) in an opening 188 in the stationary member 160. Alternatively, as shown in the enlarged partial cross-sectional view in fig. 6, the fluid injection nozzle 174 may be integrally formed in the stationary member 160, such as by casting, additive manufacturing, or machining therein. In any case, the nozzle 174 may be configured to provide any shape and/or form to the pressurized damping fluid 176 as it exits the stationary member 160. Further, the system 118 may be implemented on a new turbine 108 and, advantageously, may be retrofitted onto an older turbine 108, for example, by drilling an opening 188 in its stationary component 160 and using a nozzle insert 186.

The fluid injection nozzle 174 and the sensor 172 (if provided) may be axially aligned in the radial plane 192 (fig. 4 and 6) (see stages L0, L2, and L3 in fig. 2), or they may be axially offset (see stage L1 in fig. 2).

The system 118 may also include a valve 182 for selectively allowing the pressurized damping fluid 176 from a pressurized damping fluid source 184 (hereinafter "source 184") into the fluid injection nozzle 174. The source 184 may be any now known or later developed supply suitable for pressurizing the damping fluid 176. In a non-limiting example, the source 184 may be at least one of: pressurized storage tanks (e.g., water or air), compressor 102 (FIG. 1) exhaust (air), a cooling fluid supply 185 (e.g., air) to nozzle portion 115 upstream of the associated blade stage, a Heat Recovery Steam Generator (HRSG) for steam, and the like. The valve 182 may be any suitable valve for the pressurized damping fluid 176 used, such as an electronically controllable ball valve for air.

System 118 may also include a control system 190 for controlling valve 182 to operate fluid injection nozzles 174 in response to an operating parameter of turbine 108 exceeding a threshold value during operation of turbine 108. The operating parameter may be a now known or later developed parameter that may indicate a need to address blade vibration. In one non-limiting example, where a sensor system 170 is provided, the operating parameter may be the amplitude and phase of the vibration of at least one of the plurality of blades 114 as measured by the sensor 172. Here, the control system 190 may operate the valve 182 in response to at least one of an amplitude and a phase of vibration of at least one of the plurality of blades exceeding a threshold during operation of the turbine. Specifically, the phase of the vibration may be used to cause the valve 182 to open accurately in time to provide reverse flow to dampen the vibration, such as pulsing at 180 ° from the blade vibration to cancel and dampen the vibration. In other non-limiting examples, the operating parameter may be any other parameter measured in the turbine 108, such as, but not limited to: working fluid temperature, pressure, and/or density; and/or determine that gas exits the turbine 108 section and/or upstream of the compressor 102 section in a pulsed manner. The operating parameter may also be a combination of measurable parameters, such as working fluid temperature and density exceeding respective thresholds, working fluid pressure, and amplitude of one or more blades 114 as measured by sensor system 170.

In one embodiment, the fluid injection nozzles 174 may be configured to continuously impinge the pressurized damping fluid 176 on the surface 178 of the blades 114 of the blade stage to alter the flow field (e.g., volume, flow rate, direction, etc.) around the blade stage to reduce the overall dynamic excitation of the blades 114 during operation of the turbine 108. In this case, the valve 182 will be in a continuously open position. However, in other embodiments, the control system 190 may operate the valve 182 to provide the pressurized damping fluid 176 in any desired selective manner. For example, in one embodiment, the pressurized damping fluid 176 may be injected at a substantially constant flow rate, such as, for example, with some small shut-down period during startup of the turbine 108. Constant flow rate means constant as compared to conventional test systems that pulse the flow to produce the required vibration for test and design purposes. In other embodiments, the pressurized damping fluid 176 may be injected intermittently or in pulses to counteract the phase of the vibratory movement of at least one of the plurality of blades of the blade stage. For example, it may be pulsed 180 ° out of phase with the blade vibration. The duration of any type of stream may also be controlled. Control system 190 may be any now known or later developed digital controller, and may be a stand-alone controller or incorporated into a larger control system, such as for overall control of turbine 108 or turbomachine 90 (FIG. 1).

As shown in fig. 4, embodiments of the present disclosure may optionally include a plurality of fluid injection nozzles 174 circumferentially spaced in the stationary component 160. In such a case, each fluid injection nozzle 174 may include a respective valve 182 for selectively allowing pressurized damping fluid 176 from a pressurized damping fluid source 184 into the nozzle under the control of a control system 190. However, it is possible that one valve 182 may control flow to more than one nozzle 174. In any case, the control system 190 opens the at least one valve 182 to operate the at least one respective fluid injection nozzle 174 in response to an operating parameter (e.g., an amplitude of at least one of the plurality of vanes) exceeding a threshold value during operation of the turbine as described herein. Any number of fluid injection nozzles 174 may be employed as part of the system 118.

As shown in FIG. 2, rotor 110 may include a plurality of blade stages L0-L3. Although each blade stage is shown as including system 118, this arrangement may not always be necessary. For example, only selected blade stages may include the system 118. In one example, as shown in fig. 4 and 5, the blades 114 are adjacent a casing end wall 196 of the casing 126, and thus may be part of only the last (largest) of the blade stages L0-L3.

Embodiments of the present disclosure may also include a housing 126 for the turbine 108 that includes a fluid injection nozzle 174 in the stationary component 160 thereof. Further, the housing 126 may include a valve 182 (coupled to or external to it) for selectively allowing the pressurized damping fluid 176 from a pressurized damping fluid source 184 to enter the fluid injection nozzle 174. The housing 126 may also include a control system 190 (coupled to or external to it) that opens the valve 182 to operate the fluid injection nozzle 174 in response to an operating parameter of the turbine exceeding a threshold as described herein.

In operation, a method according to an embodiment of the present disclosure includes operating a turbine 108. In contrast to the test system, embodiments of the present disclosure are applied to turbine 108 during actual active operation of turbine 108 to generate its design output (e.g., rotational power, compressed air/fuel mixture, etc.). Turbine 108 may operate at any load and/or speed where blade vibration may be a problem. The turbine 108 may operate by passing a working fluid through a Working Fluid Path (WFP) (FIG. 2) defined between a stationary component 160 of the casing 126 and the rotor 110 and through a plurality of blades 114 operatively coupled to the rotor 110. As described herein, the method further includes damping vibrations of at least one of the blades 114 during operation of the turbine 108 by impinging pressurized damping fluid 176 on a surface 178 of at least one of the blades 114 in opposition to the vibratory movement of the blades. As described herein, the damping may include, during operation of the turbine 108, selectively operating a valve 182 configured to selectively allow the pressurized damping fluid 176 from a source 184 into a fluid injection nozzle 174 configured to impinge the pressurized damping fluid 176 on a surface 178 of at least one of the blades 114. During operation of the turbine 108, any number of blades 114 may simultaneously dampen the vibrations thereof by impinging pressurized damping fluid 176 on a surface 178 of each of the plurality of blades.

Embodiments of the present disclosure provide systems and methods for selectively damping vibrations in one or more turbine blades during operation of a turbine. These teachings apply to any of a variety of turbines: jet engines, steam or gas turbines, compressors, turbochargers, and the like. Damping the turbine stages and/or blades in this manner facilitates extending a life of the blades, allowing larger blades to be used, generating more power, and improving efficiency. Further, damping the turbine stages and/or blades may allow for elimination of the tip span and intermediate span shrouds that would otherwise be used to reduce vibrations. Embodiments of the present disclosure also do not add any mass to the blade, unlike other blade dampers that add fixed loads to the blade and have durability issues due to exposure to high temperatures, centrifugal loads, and blade vibration.

Approximating language, as used herein throughout the specification and claims, 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", "about" and "substantially") is not to be limited to the precise value specified. In at least some cases, 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 combined and/or interchanged. Unless context or language indicates otherwise, such ranges are identified and include all sub-ranges subsumed therein. "about" as applied to a particular value of a range applies to both end values, which may indicate +/-10% of the value unless otherwise dependent on the accuracy of the instrument measuring the value.

The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiments were chosen and described in order to best explain the principles of the disclosure and the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated.