The subject matter disclosed herein relates to seals, and more specifically, to seals disposed between segments of a turbomachine.
A variety of turbomachines, such as turbines and compressors, may include seals disposed between segments. For example, a gas turbine may include stationary segments arranged circumferentially about a rotor, which includes turbine blades. Unfortunately, the segments may experience thermal expansion and contraction, vibration, bending, and other forces, which can reduce the effectiveness of intermediate seals. Furthermore, the seals may experience substantial pressure differences between different fluid flows, such as a hot gas flow driving the turbine blades and an air flow cooling the segments. As a result, the seals may experience uncontrolled amounts of leakage, which can reduce performance and reliability of the turbomachine (e.g., gas turbine). Accordingly, a seal is needed to address one or more of these deficiencies of existing seals.
Certain 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 seal having a first sealing end portion, a second sealing end portion, and an intermediate portion between the first and second sealing end portions, wherein the seal has at least one metering hole configured to control a leakage flow across the seal.
In a second embodiment, a system includes a turbomachine seal having a first sealing end portion having a first and second curved sealing interface disposed opposite from one another about a first space, and the first and second curved sealing interfaces are configured to resiliently deflect toward and away from one another. The turbomachine seal also includes a second sealing end portion having a third and fourth curved sealing interface disposed opposite from one another about a second space, and the third and fourth curved sealing interfaces are configured to resiliently deflect toward and away from one another. The turbomachine seal also includes an intermediate portion extending between the first and second sealing end portions.
In a third embodiment, a system includes a turbomachine seal having a first plate having a first curved sealing interface, a second curved sealing interface, and a first intermediate portion extending between the first and second curved sealing interfaces. The turbomachine seal also includes a second plate having a third curved sealing interface, a fourth curved sealing interface, and a second intermediate portion extending between the third and fourth curved sealing interfaces. The first and second intermediate portions of the turbomachine seal are coupled together. Furthermore, the first and third curved sealing interfaces are configured to resiliently deflect toward and away from one another about a first space, and the second and fourth curved sealing interfaces are configured to resiliently deflect toward and away from one another about a second space. Also, the first and second plates of the turbomachine seal have different coefficients of thermal expansion to cause thermal bending of the turbomachine seal in response to different degrees of thermal expansion of the first and second plates.
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.
As discussed in detail below, the disclosed embodiments include a variety of seals that may be used in turbomachines, such as compressors and turbines, and other applications. In certain embodiments, the seals may include holes specifically designed to control leakage and/or cool various seal surfaces. In the following discussion, these holes may be referred to as metering holes or impingement cooling holes, although the holes may provide any combination of metering or cooling functionality. For example, the holes may be specifically sized and/or shaped to control or meter the amount of leakage (e.g., leakage flow rate) from one side of the seal to an opposite side of the seal. In this manner, the metered leakage flow may ensure that uncontrolled amounts of leakage do not occur between the seal and the seal surfaces along the turbomachine. Furthermore, the holes may be specifically sized, shaped, or angled to provide cooling flows to hot regions on or adjacent the seal. In some embodiments, the holes may be configured to provide film cooling or impingement cooling. In addition to the disclosed holes, the seals may have curved end portions to enable pivoting or rotation along the seal surfaces of the turbomachine. For example, the curved end portions may ensure that contact is maintained between the seal and the seal surfaces despite any movement due to thermal expansion and contraction, vibration, and so forth. The curved end portions also may act as springs, such that a biasing force is maintained along the seal surfaces. The disclosed seals may include one-piece seals and multi-piece seals, such as a two-piece seal made with two different materials. In certain embodiments, the two-piece seal may be made of two different materials (e.g., bimetallic), which have different coefficients of thermal expansion. Thus, the different materials of the seal may respond differently to thermal changes, thereby causing thermal bending to assist with sealing against the seal surfaces. In the following discussion, reference is made to a turbine system 10, although the disclosed seals may be used in any type of turbomachine, combustion systems, thermal fluid systems, and so forth.
Although the seal 50 may be a one-piece structure, the illustrated embodiment of the seal 50 is made with first and second pieces 52 and 54 coupled together at the intermediate portion 58. The first piece 52 includes a first plate 86 having a first intermediate plate portion 88 disposed between opposite curved end plate portions 90 and 92, wherein the curved end plate portion 90 includes the curved sealing interface 68, and the curved end plate portion 92 includes the curved sealing interface 74. The second piece 54 includes a second plate 94 having a first intermediate plate portion 96 disposed between opposite curved end plate portions 98 and 100, wherein the curved end plate portion 98 includes the curved sealing interface 70, and the curved end plate portion 100 includes the curved sealing interface 76. As illustrated, the curved end plate portions 90 and 98 of the first and second plate 86 and 94 have the curved sealing interfaces 68 and 70 curving away from one another and then curving toward one another in the direction 80 away from the first and second intermediate plate portions 88 and 96. Similarly, the curved end plate portions 92 and 100 of the first and second plate 86 and 94 have the curved sealing interfaces 74 and 76 curving away from one another and then curving toward one another in the direction 82 away from the first and second intermediate plate portions 88 and 96. The first and second intermediate plate portions 88 and 96 are coupled together at an interface 102 along the longitudinal axis 84 at one or more locations, such as joints 104 and 106. For example, the interface 102 may be a planar interface between the plate portions 88 and 96, while the joints 104 and 106 may be linear joints, planar joints, or spot joints between the plate portions 88 and 96. For example, the linear joints 104 and 106 are depicted as linear joints, as represented by dashed lines 104 and 106. The joints 104 and 106 may include welded joints, brazed joints, diffusion bonded joints, adhesive joints, or any other type of fastening mechanism.
In certain embodiments, the first and second pieces 52 and 54 may be constructed of the same material or a different material. For example, the pieces 52 and 54 may be made of the same or different metals, such as different spring steels or nickel based alloys. By further example, the pieces 52 and 54 may be made with materials having the same or different coefficient of thermal expansion, modulus of elasticity, materials, or a combination thereof. The first and second pieces 52 and 54 also may be constructed with different thicknesses or other dimensions to vary the bending stiffness of the curved end plate portions 90, 92, 98, and 100. As discussed below, the different construction of the two pieces 52 and 54 may improve the performance of the seal 50 subjected to high temperatures. For example, the two-piece seal 50 constructed with the first and second pieces 52 and 54 made of two different materials with different coefficients of thermal expansion may cause the seal 50 to bend or bow along its longitudinal axis 84, thereby improving the sealing effectiveness between sealing surfaces. This thermal bending behavior of the seal 50 is discussed in further detail below with reference to
The shape or geometry of the seal 50 also may improve the sealing effectiveness of the seal 50, particularly in environments subject to high temperatures, vibration, motion, and thermal expansion and contraction. In the illustrated embodiment, the intermediate plate portions 88 and 96 of the plates 86 and 94 are substantially flat or planar, although other embodiments of the plate portions 88 and 96 may have a wavy shape as discussed in further detail below. Furthermore, the intermediate plate portions 88 and 96 (e.g., joints 104 and 106) may function as pivot points, axes of rotation, or axes of bending for the curved end plate portions 90, 92, 98, and 100 of the plates 86 and 94. The curved sealing interfaces 68 and 70 along the curved end plate portions 90 and 98 are configured to resiliently deflect toward and away from one another relative to the intermediate portion 58 (e.g., portions 88 and 96), and the curved sealing interfaces 74 and 76 along the curved end plate portions 92 and 100 are configured to resiliently deflect toward and away from one another relative to the intermediate portion 58 (e.g., portions 88 and 96). For example, the resilient deflection of the curved end plate portions 90, 92, 98, and 100 may occur relative to the joints 104 and 106. Thus, the U-shaped end 64 defined by the opposite curved end plate portions 90 and 98 (e.g., curved sealing interfaces 68 and 70) may serve as a first U-shaped spring element, while the U-shaped end 66 defined by the opposite curved end plate portions 92 and 100 (e.g., curved sealing interfaces 74 and 76) may serve as a second U-shaped spring element. Together, the U-shaped ends 64 and 66 and the intermediate portion 58 may be described as forming an X-shaped seal 50, such as a spring-loaded X-shaped seal 50. The U-shaped ends 64 and 66 also may serve as rotational joints, pivot joints, or cam members, thereby enabling rotational motion along sealing surfaces. For example, the curved sealing interfaces 68 and 70 are configured to enable rotation of the sealing end portion 60 along a first sealing region, while the curved sealing interfaces 74 and 76 are configured to enable rotation of the second sealing end portion 62 along a second sealing region.
The illustrated metering holes 56 include a first plurality of metering holes 108 and a second plurality of metering holes 110. The metering holes 56 are configured to control or meter the leakage flow through the seal 50. For example, the metering holes 56 may be designed to provide a certain flow rate or percentage of leakage flow depending on the particular application. In this manner, the metering holes 56 may permit a controlled amount of leakage flow to improve the sealing effectiveness of the seal 50 along the curved sealing interfaces 68, 70, 74, and 76, thereby reducing the possibility of leakage along the curved sealing interfaces 68, 70, 74, and 76. The metering holes 56 also may be used for cooling various hot regions along the seal 50, in the seal regions, or in the parts adjacent the seal regions. For example, the metering holes 56 may be configured to provide film cooling (e.g., a thin film of coolant flow) along a surface of the seal 50 or adjacent structures, or the metering holes 56 may be configured to provide impingement cooling (e.g., jets of coolant flow) against a surface of the seal 50 or adjacent structures. The film cooling may be described as flowing parallel to the surface being cooled, whereas the impingement cooling may be described as flow crosswise (e.g., perpendicular) to the surface being cooled. However, the metering holes 56 may be oriented at any angle relative to hot regions to cool the hot regions. For example, the first plurality of metering holes 108 may be directed toward the first sealing end portion 60 (e.g., curved sealing interface 68 or 70) or associated sealing region at a first angle 112, while the second plurality of metering holes 110 may be directed toward the second sealing end portion 62 (e.g., curved sealing interface 74 or 76) or associated sealing region at a second angle 114. The angles 112 and 114 may range between approximately 0 to 90, 5 to 60, 10 to 45, or 15 to 30 degrees. Various angles, shapes, and configurations of the metering holes 56 are discussed in further detail below with reference to
In the illustrated embodiment, the first and second sealing end portions 60 and 62 are configured to seal with the respective seal regions 130 and 132 via spring forces and frictional forces. For example, the first sealing end portion 60 includes the U-shaped end 64 with the opposite curved sealing interfaces 68 and 70, which are configured to deflect toward and away from one another as indicated by arrow 154, thereby providing biasing forces or spring forces 156 and 158 against the side walls 138 and 140. For example, the curved sealing interfaces 68 and 70 may be compressed together between the side walls 138 and 140, such that the curved sealing interfaces 68 and 70 maintain contact despite vibration or motion. The curved sealing interfaces 68 and 70 are also frictionally seated along the side walls 138 and 140 via respective frictional forces 160 and 162. Furthermore, the curved sealing interfaces 68 and 70 are also configured to pivot or rotate relative to the side walls 138 and 140 as indicated by rotational arrows 164 and 166. As discussed in further detail below with reference to
In operation, the seal 50 is configured to seal the gap 126 between the adjacent segments 120 and 122 between a first fluid region or flow 182 and a second fluid region or flow 184. For example, in certain embodiments, the first flow 182 may be substantially cooler than the second flow 184. In context of a turbomachine, such as a compressor or turbine, the first flow 182 may be a cooling flow (e.g., air flow), while the second flow 184 may be a heated fluid such as compressed air, hot gases of combustion, or the like. Accordingly, the seal 50 may be subjected to significant temperatures, thermal gradients, vibration, motion, and thermal expansion and contraction between the segments 120 and 122. For example, the width 128 of the gap 126 may decrease in response to thermal expansion of the segments 120 and 122, while the width 128 may increase in response to thermal contraction of the segments 120 and 122. Accordingly, the biasing forces 156, 158, 170, and 172, the frictional forces 160, 162, 174, and 176, the deflection motion 154 and 168, and the rotational motion 164, 166, 178, and 180 may be configured to maintain a positive and consistent sealing interface between the seal 50 and the side walls 138, 140, 146, and 148 of the seal regions 130 and 132 despite the conditions of the system.
The metering holes 56 further improve the seal 50 by controlling any leakage flow between the first and second flows 182 and 184. In the illustrated embodiments, the leakage flow includes a first fluid flow 186 (e.g., air flow) through the first plurality of metering holes 108, and a second fluid flow 188 (e.g., air flow) through the second plurality of metering holes 110. These fluid flows 186 and 188 are configured to control the amount of leakage flow from region 182 to region 184, thereby helping to reduce the possibility of leakage along the curved seal interfaces 68, 70, 74, and 76. The fluid flows 186 and 188 also provide cooling in the vicinity of the seal 50, e.g., areas 190 and 192. As illustrated, the metering holes 56 (e.g., metering holes 108 and 110) are angled away from one another toward the opposite segments 120 and 122 and/or associated seal regions 130 and 132. For example, the fluid flows 186 and 188 may be angled to flow into the seal regions 130 and 132 to help cool the side walls 138, 140, 146, and 148 and the curved sealing interfaces 70 and 76 of the seal 50. In this manner, the cooling fluid flows 186 and 188 may protect the seal 50 and/or walls 138, 140, 146, and 148 from any thermal damage, wear, or the like. The cooling flows 186 and 188 also may serve as shielding fluid flows to reduce chemical attack, corrosion, or other damage to the seal 50 caused by the second fluid flow 184.
As further illustrated in
The seal 50 also includes various angles and offsets relative to the longitudinal axis 84 through the seal 50. For example, the curved end plate portions 90, 92, 98, and 100 may be disposed at respective angles 250, 252, 254, 256, 258, 260, 262, and 264 relative to the longitudinal axis 84, wherein the angles may be approximately 0 to 90, 5 to 75, 10 to 60, 15 to 45, or 20 to 30 degrees. In particular, the angles are selected to provide convergence toward the longitudinal axis 84 at opposite ends of each curved end plate portion 90, 92, 98, and 100, thereby enabling the curved sealing interfaces 68, 70, 74, and 76 to maintain contact while pivoting along the side walls 138, 140, 146, and 148. For example, the curved end plate portions 90 and 98 have the converging curved portions 218 at the angles 250 and 252 adjacent the intermediate portion 58, and the converging curved portions 220 at the angles 254 and 256 furthest away from the intermediate portion 58. Similarly, the curved end plate portions 92 and 100 have the converging curved portions 228 at the angles 258 and 260 adjacent the intermediate portion 58, and the converging curved portions 230 at the angles 262 and 264 furthest away from the intermediate portion 58. These angles may be increased to enable a greater range of pivoting movement of the curved sealing interfaces 68, 70, 74, and 76 along the side walls 138, 140, 146, and 148. Furthermore, the radii of each curved portion 216, 218, 220, 226, 228, and 230 may be adjusted to control the slope of pivoting movement.
As further illustrated in
The metering holes 56 also may have a variety of angles, shapes, and configurations configured to control the leakage flow and cooling. As illustrated in
The seal 50 depicted in
Referring first to
Although the seal 550 may be a one-piece structure, the illustrated embodiment of the seal 550 is made with first and second pieces 552 and 554 coupled together at the intermediate portion 558. The first piece 552 includes a first plate 596 having a first intermediate plate portion 598 disposed between opposite curved end plate portions 600 and 602, wherein the curved end plate portion 600 includes the curved sealing interface 568, and the curved end plate portion 602 includes the curved sealing interface 582. The second piece 554 includes a second plate 604 having a first intermediate plate portion 606 disposed between opposite curved end plate portions 608 and 610, wherein the curved end plate portion 608 includes the curved sealing interface 570, and the curved end plate portion 610 includes the curved sealing interface 584. As illustrated, the curved end plate portions 600 and 608 of the first and second plate 596 and 604 have the curved sealing interfaces 568 and 570 that first curve away from one another in the first direction 578 (i.e., away from the first and second intermediate plate portions 598 and 606), and then curve away and then towards one another in the second direction 580 (i.e., towards the first and second intermediate plate portions 598 and 606). Similarly, the curved end plate portions 602 and 610 of the first and second plate 596 and 604 have the curved sealing interfaces 582 and 584 that first curve away from one another in the first direction 592 (i.e., away from the first and second intermediate plate portions 598 and 606), and then curve away and then towards one another in the second direction 594 (i.e., towards the first and second intermediate plate portions 598 and 606). The first and second intermediate plate portions 598 and 606 are coupled together at an interface 612 along the longitudinal axis 618 at one or more locations, such as joints 614 and 616. For example, the interface 612 may be a planar interface between the plate portions 598 and 606, while the joints 614 and 616 may be linear joints, planar joints, or spot joints between the plate portions 598 and 606. For example, the linear joints 614 and 616 are depicted as linear joints, as represented by dashed lines 614 and 616. The joints 614 and 616 may include welded joints, brazed joints, diffusion bonded joints, adhesive joints, or any other type of fastening mechanism.
In certain embodiments, the first and second pieces 552 and 554 may be constructed of the same material or a different material. For example, the pieces 552 and 554 may be made of the same or different metals, such as different spring steels or nickel based alloys. By further example, the pieces 552 and 554 may be made with materials having the same or different coefficient of thermal expansion, modulus of elasticity, materials, or a combination thereof. The first and second pieces 552 and 554 also may be constructed with different thicknesses or other dimensions to vary the bending stiffness of the curved end plate portions 600, 602, 608, and 610. As discussed below, the different construction of the two pieces 552 and 554 may improve the performance of the seal 550 subjected to high temperatures. For example, the two-piece seal 550 (e.g., the first and second pieces 552 and 554) may be made of two different materials with different coefficients of thermal expansion to cause the seal 550 to bend or bow along its longitudinal axis 618, thereby improving the sealing effectiveness between sealing surfaces, as discussed above with reference to the embodiment of
The shape or geometry of the seal 550 also may improve the sealing effectiveness of the seal 550, particularly in environments subject to high temperatures, vibration, motion, and thermal expansion and contraction. In the illustrated embodiment, the intermediate plate portions 598 and 606 of the plates 596 and 604 are substantially flat or planar, although other embodiments of the plate portions 598 and 606 may have a wavy shape as discussed in further detail below. Furthermore, the intermediate plate portions 598 and 606 (e.g., joints 614 and 616) may function as pivot points, axes of rotation, or axes of bending for the curved end plate portions 600, 602, 608, and 610 of the plates 596 and 604. The curved sealing interfaces 568 and 570 along the curved end plate portions 600 and 608 are configured to resiliently deflect toward and away from one another relative to the intermediate portion 558 (e.g., portions 598 and 606), and the curved sealing interfaces 582 and 584 along the curved end plate portions 602 and 610 are configured to resiliently deflect toward and away from one another relative to the intermediate portion 558 (e.g., portions 598 and 606). For example, the resilient deflection of the curved end plate portions 600, 602, 608, and 610 may occur relative to the joints 614 and 616. Thus, the m-shaped end 564 defined by the opposite curved end plate portions 600 and 608 (e.g., curved sealing interfaces 568 and 570) may serve as a first m-shaped spring element, while the m-shaped end 566 defined by the opposite curved end plate portions 602 and 610 (e.g., curved sealing interfaces 582 and 584) may serve as a second m-shaped spring element. Together, the m-shaped ends 564 and 566 and the intermediate portion 558 may be described as forming a spring-loaded seal 550. The m-shaped ends 564 and 566 also may serve as rotational joints, pivot joints, or cam members, thereby enabling rotational motion along sealing surfaces. For example, the curved sealing interfaces 568 and 570 are configured to enable rotation of the sealing end portion 560 along a first sealing region, while the curved sealing interfaces 582 and 584 are configured to enable rotation of the second sealing end portion 562 along a second sealing region.
The illustrated metering holes 556 include a first plurality of metering holes 620 and a second plurality of metering holes 622. The metering holes 556 are configured to control or meter the leakage flow through the seal 550. For example, the metering holes 556 may be designed to provide a certain flow rate or percentage of leakage flow depending on the particular application. In this manner, the metering holes 556 may permit a controlled amount of leakage flow to improve the sealing effectiveness of the seal 550 along the curved sealing interfaces 568, 570, 582, and 584, thereby reducing the possibility of leakage along the curved sealing interfaces 568, 570, 582, and 584. The metering holes 556 also may be used for cooling various hot regions along the seal 550, in the seal regions, or in the parts adjacent the seal regions. For example, the metering holes 556 may be configured to provide film cooling (e.g., a thin film of coolant flow) along a surface of the seal 550 or adjacent structures, or the metering holes 556 may be configured to provide impingement cooling (e.g., jets of coolant flow) against a surface of the seal 550 or adjacent structures. The film cooling may be described as flowing parallel to the surface being cooled, whereas the impingement cooling may be described as flow crosswise (e.g., perpendicular) to the surface being cooled. However, the metering holes 556 may be oriented at any angle relative to hot regions to cool the hot regions. For example, the first plurality of metering holes 620 may be directed toward the first sealing end portion 560 (e.g., curved sealing interface 568 or 570) or associated sealing region at a first angle 624, while the second plurality of metering holes 622 may be directed toward the second sealing end portion 562 (e.g., curved sealing interface 582 or 584) or associated sealing region at a second angle 626. The angles 624 and 626 may range between approximately 0 to 90, 5 to 60, 10 to 45, or 15 to 30 degrees. Various angles, shapes, and configurations of the metering holes are discussed in detail above with reference to
In the illustrated embodiment, the first and second sealing end portions 560 and 562 are configured to seal with the respective seal regions 130 and 132 via spring forces and frictional forces. For example, the first sealing end portion 560 includes the m-shaped end 564 with the opposite curved sealing interfaces 568 and 570, which are configured to deflect toward and away from one another as indicated by arrow 640, thereby providing biasing forces or spring forces 642 and 644 against the side walls 138 and 140. For example, the curved sealing interfaces 568 and 570 may be compressed together between the side walls 138 and 140, such that the curved sealing interfaces 568 and 570 maintain contact despite vibration or motion. The curved sealing interfaces 568 and 570 are also frictionally seated along the side walls 138 and 140 via respective frictional forces 646 and 648. Furthermore, the curved sealing interfaces 568 and 570 are also configured to pivot or rotate relative to the side walls 138 and 140 as indicated by rotational arrows 650 and 652. As discussed in detail above with reference to
In operation, the seal 550 is configured to seal the gap 126 between the adjacent segments 120 and 122 between a first fluid region or flow 182 and a second fluid region or flow 184. For example, in certain embodiments, the first flow 182 may be substantially cooler than the second flow 184. In context of a turbomachine, such as a compressor or turbine, the first flow 182 may be a cooling flow (e.g., air flow), while the second flow 184 may be a heated fluid such as compressed air, hot gases of combustion, or the like. Accordingly, the seal 550 may be subjected to significant temperatures, thermal gradients, vibration, motion, and thermal expansion and contraction between the segments 120 and 122. For example, the width 128 of the gap 126 may decrease in response to thermal expansion of the segments 120 and 122, while the width 128 may increase in response to thermal contraction of the segments 120 and 122. Accordingly, the biasing forces 642, 644, 656, and 658, the frictional forces 646, 648, 660, and 662, the deflection motion 640 and 654, and the rotational motion 650, 652, 664, and 666 may be configured to maintain a positive and consistent sealing interface between the seal 550 and the side walls 138, 140, 146, and 148 of the seal regions 130 and 132 despite the conditions of the system.
The metering holes 556 further improve the seal 550 by controlling any leakage flow between the first and second flows 182 and 184. In the illustrated embodiments, the leakage flow includes a first fluid flow 668 (e.g., air flow) through the first plurality of metering holes 620, and a second fluid flow 670 (e.g., air flow) through the second plurality of metering holes 622. These fluid flows 668 and 670 are configured to control the amount of leakage flow from region 182 to region 184, thereby helping to reduce the possibility of leakage along the curved seal interfaces 568, 570, 582, and 584. The fluid flows 668 and 670 also provide cooling in the vicinity of the seal 550, e.g., areas 190 and 192. As illustrated, the metering holes 556 (e.g., metering holes 620 and 622) are angled away from one another toward the opposite segments 120 and 122 and/or associated seal regions 130 and 132. For example, the fluid flows 668 and 670 may be angled to flow into the seal regions 130 and 132 to help cool the side walls 138, 140, 146, and 148 and the curved sealing interfaces 570 and 584 of the seal 550. In this manner, the cooling fluid flows 668 and 670 may protect the seal 550 and/or walls 138, 140, 146, and 148 from any thermal damage, wear, or the like. The cooling flows 668 and 670 also may serve as shielding fluid flows to reduce chemical attack, corrosion, or other damage to the seal 550 caused by the second fluid flow 184.
The seal 550 also includes various angles and offsets relative to the longitudinal axis 618 through the seal 550. For example, the curved end plate portions 600, 602, 608, and 610 may be disposed at respective angles 690, 692, 694, and 696 relative to the longitudinal axis 618, wherein the angles may be approximately 0 to 90, 5 to 75, 10 to 60, 15 to 45, or 20 to 30 degrees. In particular, the angles are selected to provide divergence away from points 698 and 700 along the longitudinal axis 618 at opposite ends of each curved end plate portion 600, 602, 608, and 610. At a distance 702 from the point 698, the curved end plate portion 600 converges toward the axis 618 in opposite directions 578 and 580. Similarly, at a distance 704 from the point 698, the curved end plate portions 608 converges toward the axis 618 in opposite directions 578 and 580. In other words, the curved end plate portions 600 and 608 curve inwardly towards the axis 618 and one another about the point 698. Similarly, at a distance 706 from the point 700, the curved end plate portion 602 converges toward the axis 618 in opposite directions 592 and 594. Similarly, at a distance 708 from the point 700, the curved end plate portions 610 converges toward the axis 618 in opposite directions 592 and 594. In other words, the curved end plate portions 602 and 610 curve inwardly towards the axis 618 and one another about the point 700. This curvature of the sealing end portions 560 and 562 provide the m-shaped ends 564 and 566, which enable the curved sealing interfaces 568, 570, 582, and 584 to maintain contact while pivoting along the side walls 138, 140, 146, and 148. The angles 690, 692, 694, and 696 may be increased to enable a greater range of pivoting movement of the curved sealing interfaces 568, 570, 582, and 584 along the side walls 138, 140, 146, and 148. Furthermore, the radii of each curved portion 600, 608, 602, and 610 may be adjusted to control the slope of pivoting movement.
As further illustrated in
The metering holes 556 also may have a variety of angles, shapes, and configurations configured to control the leakage flow and cooling. As illustrated in
The seal 550 depicted in
Although the seal 750 may be a two-piece structure, the illustrated embodiment of the seal 750 is made with a single piece 752. The piece 752 includes plate 786 having an intermediate plate portion 788 disposed between opposite curved end plate portions 790 and 792, wherein the curved end plate portion 790 includes the curved sealing interfaces 768 and 770, and the curved end plate portion 792 includes the curved sealing interface 774 and 776. As illustrated, the curved end plate portion 790 has the curved sealing interface 768 extending from the intermediate plate portion 788, while the curved sealing interface 770 extends to a free end 771. Similarly, the curved end plate portions 792 has the curved sealing interface 776 extending from the intermediate plate portion 788, while the curved sealing end interface 774 extends to the free end 775. As illustrated, the curved sealing interfaces 774 and 770 are disposed on opposite sides of the intermediate portion 788 of the plate 786.
The shape or geometry of the seal 750 also may improve the sealing effectiveness of the seal 750, particularly in environments subject to high temperatures, vibration, motion, and thermal expansion and contraction. In the illustrated embodiment, the intermediate plate portion 788 of the plate 786 is substantially flat and tilted with respect to a longitudinal axis 784, although other embodiments of the intermediate plate portion 788 may have a wavy shape as discussed in further detail below. Furthermore, the intermediate plate portion 788 may function as a pivot point, axis of rotation, or axis of bending for the curved end plate portions 790 and 792 of the plate 786. The curved sealing interfaces 768 and 770 along the curved end plate portion 790 are configured to resiliently deflect toward and away from one another relative to the longitudinal axis 784, and the curved sealing interfaces 774 and 776 along the curved end plate portion 792 are configured to resiliently deflect toward and away from one another relative to the longitudinal axis 784. Thus, the c-shaped end 764 defined by the curved end plate portion 790 (e.g., curved sealing interfaces 768 and 770) may serve as a first c-shaped spring element, while the c-shaped end 766 defined by the curved end plate portion 792 (e.g., curved sealing interfaces 774 and 776) may serve as a second c-shaped spring element. Together, the c-shaped ends 764 and 766 and the intermediate portion 758 may be described as forming an s-shaped seal 750, such as a spring-loaded s-shaped seal 750. The c-shaped ends 764 and 766 also may serve as rotational joints, pivot joints, or cam members, thereby enabling rotational motion along sealing surfaces. For example, the curved sealing interfaces 768 and 770 are configured to enable rotation of the sealing end portion 760 along a first sealing region, while the curved sealing interfaces 774 and 776 are configured to enable rotation of the second sealing end portion 762 along a second sealing region.
The illustrated metering holes 756 include a first plurality of metering holes 808 and a second plurality of metering holes 810. The metering holes 756 are configured to control or meter the leakage flow through the seal 750. For example, the metering holes 756 may be designed to provide a certain flow rate or percentage of leakage flow depending on the particular application. In this manner, the metering holes 756 may permit a controlled amount of leakage flow to improve the sealing effectiveness of the seal 750 along the curved sealing interfaces 768, 770, 774, and 776, thereby reducing the possibility of leakage along the curved sealing interfaces 768, 770, 774, and 776. The metering holes 756 also may be used for cooling various hot regions along the seal 750, in the seal regions, or in the parts adjacent the seal regions. For example, the metering holes 756 may be configured to provide film cooling (e.g., a thin film of coolant flow) along a surface of the seal 750 or adjacent structures, or the metering holes 756 may be configured to provide impingement cooling (e.g., jets of coolant flow) against a surface of the seal 750 or adjacent structures. The metering holes 756 may be oriented at any angle relative to hot regions to cool the hot regions. For example, the first plurality of metering holes 808 may be directed toward the first sealing end portion 760 (e.g., curved sealing interface 768 or 770) or associated sealing region at a first angle 812, while the second plurality of metering holes 810 may be directed toward the second sealing end portion 762 (e.g., curved sealing interface 774 or 776) or associated sealing region at a second angle 814. The angles 812 and 814 may range between approximately 0 to 90, 5 to 60, 10 to 45, or 15 to 30 degrees. Various angles, shapes, and configurations of the metering holes 756 are discussed in detail above with reference to
In the illustrated embodiment, the first and second sealing end portions 760 and 762 are configured to seal with the respective seal regions 130 and 132 via spring forces and frictional forces. For example, the first sealing end portion 760 includes the c-shaped end 764 with the opposite curved sealing interfaces 768 and 770, which are configured to deflect toward and away from one another as indicated by arrow 854, thereby providing biasing forces or spring forces 856 and 858 against the side walls 138 and 140. For example, the curved sealing interfaces 768 and 770 may be compressed together between the side walls 138 and 140, such that the curved sealing interfaces 768 and 770 maintain contact despite vibration or motion. The curved sealing interfaces 768 and 770 are also frictionally seated along the side walls 138 and 140 via respective frictional forces 860 and 862. Furthermore, the curved sealing interfaces 768 and 770 are also configured to pivot or rotate relative to the side walls 138 and 140 as indicated by rotational arrows 864 and 866. As discussed in detail above with reference to
In operation, the seal 750 is configured to seal the gap 126 between the adjacent segments 120 and 122 between a first fluid region or flow 182 and a second fluid region or flow 184. For example, in certain embodiments, the first flow 182 may be substantially cooler than the second flow 184. In context of a turbomachine, such as a compressor or turbine, the first flow 182 may be a cooling flow (e.g., air flow), while the second flow 184 may be a heated fluid such as compressed air, hot gases of combustion, or the like. Accordingly, the seal 750 may be subjected to significant temperatures, thermal gradients, vibration, motion, and thermal expansion and contraction between the segments 120 and 122. For example, the width 128 of the gap 126 may decrease in response to thermal expansion of the segments 120 and 122, while the width 128 may increase in response to thermal contraction of the segments 120 and 122. Accordingly, the biasing forces 856, 858, 870, and 872, the frictional forces 860, 862, 874, and 876, the deflection motion 854 and 868, and the rotational motion 864, 866, 878, and 880 may be configured to maintain a positive and consistent sealing interface between the seal 750 and the side walls 138, 140, 146, and 148 of the seal regions 130 and 132 despite the conditions of the system.
The metering holes 756 further improve the seal 750 by controlling any leakage flow between the first and second flows 182 and 184. In the illustrated embodiments, the leakage flow includes a first fluid flow 886 (e.g., air flow) through the first plurality of metering holes 808, and a second fluid flow 888 (e.g., air flow) through the second plurality of metering holes 810. These fluid flows 886 and 888 are configured to control the amount of leakage flow from region 182 to region 184, thereby helping to reduce the possibility of leakage along the curved seal interfaces 768, 770, 774, and 776. The fluid flows 886 and 888 also provide cooling in the vicinity of the seal 750, e.g., areas 190 and 192. As illustrated, the metering holes 756 (e.g., metering holes 808 and 810) are angled away from one another toward the opposite segments 120 and 122 and/or associated seal regions 130 and 132. For example, the fluid flows 886 and 888 may be angled to flow into the seal regions 130 and 132 to help cool the side walls 138, 140, 146, and 148 and the curved sealing interfaces 770 and 776 of the seal 750. In this manner, the cooling fluid flows 886 and 888 may protect the seal 750 and/or walls 138, 140, 146, and 148 from any thermal damage, wear, or the like. The cooling flows 886 and 888 also may serve as shielding fluid flows to reduce chemical attack, corrosion, or other damage to the seal 750 caused by the second fluid flow 184.
The seal 750 also includes various angles and offsets throughout the seal 750. For example, an axis 950 of the intermediate portion 758 may be disposed at an angle 952 relative to the longitudinal axis 784. In certain embodiments, the angle 952 may be approximately 0 to 90, 5 to 75, 10 to 60, 15 to 45, or 20 to 30 degrees. The curved end plate portions 790 and 792 extend from and curve relative to the intermediate portion 758 (i.e., from lines 947 and 949) to the free ends 771 and 775. For example, the curved end plate portions 790 and 792 may extend through arcs 958 and 960 from the lines 947 and 949 to the free ends 771 and 775, respectively, wherein the angles of the arcs may be approximately 180 to 270, 190 to 260, 200 to 250, 205 to 245, or 210 to 240 degrees. In particular, the angles of the arcs 958 and 960 are selected to provide convergence of the curved end plate portions 790 and 792 toward the intermediate portion 758 of the seal 750. The curvature of the sealing ends 760 and 762 enables the curved sealing interfaces 768, 770, 774, and 776 to maintain contact while pivoting along the side walls 138, 140, 146, and 148. The angle and arcs 958 and 960 may be increased to enable a greater range of pivoting movement of the curved sealing interfaces 768, 770, 774, and 776 along the side walls 138, 140, 146, and 148. Furthermore, the radii of the sealing ends 760 and 762 may be adjusted to control the slope of pivoting movement.
As further illustrated in
The metering holes 756 also may have a variety of angles, shapes, and configurations configured to control the leakage flow and cooling. As illustrated in
Although the seal 1050 may be a two-piece structure, the illustrated embodiment of the seal 1050 is made with a single piece 1052. The piece 1052 includes a plate 1086 having a wavy intermediate plate portion 1088 disposed between opposite curved end plate portions 1090 and 1092, wherein the curved end plate portion 1090 includes the curved sealing interfaces 1068 and 1070, and the curved end plate portion 1092 includes the curved sealing interface 1074 and 1076. As illustrated, the curved end plate portion 1090 has the curved sealing interface 1070 extending from the intermediate plate portion 1088, while the curved sealing interface 1068 extends to a free end 1069. Similarly, the curved end plate portion 1092 has the curved sealing interface 1076 extending from the wavy intermediate portion 1088, while the curved sealing interface 1074 extends to a free end 1075. As illustrated, the curved sealing interfaces 1068 and 1074 are disposed on the same side of the wavy intermediate portion 1088 of the plate 1086.
The shape or geometry of the seal 1050 also may improve the sealing effectiveness of the seal 1050, particularly in environments subject to high temperatures, vibration, motion, and thermal expansion and contraction. In the illustrated embodiment, the intermediate plate portion 1088 of the plate 1086 is substantially wavy to enable compression and expansion of the intermediate portion 1088 of the plate 1086 along a longitudinal axis 1084. Furthermore, the wavy intermediate plate portion 1088 may function as a pivot point, axis of rotation, or axis of bending for the curved end plate portions 1090 and 1092 of the plate 1086. The curved sealing interfaces 1068 and 1070 along the curved end plate portion 1090 are configured to resiliently deflect toward and away from one another relative to the longitudinal axis 1084, and the curved sealing interfaces 1074 and 1076 along the curved end plate portion 1092 are configured to resiliently deflect toward and away from one another relative to the longitudinal axis 1084. Thus, the c-shaped end 1064 defined by the curved end plate portion 1090 (e.g., curved sealing interfaces 1068 and 1070) may serve as a first c-shaped spring element, while the c-shaped end 1066 defined by the curved end plate portion 1092 (e.g., curved sealing interfaces 1074 and 1076) may serve as a second c-shaped spring element. Together, the c-shaped ends 1064 and 1066 and the intermediate portion 1058 may be described as forming an ox horn shaped seal 1050, such as a spring-loaded ox horn shaped seal 1050. The c-shaped ends 1064 and 1066 also may serve as rotational joints, pivot joints, or cam members, thereby enabling rotational motion along sealing surfaces. For example, the curved sealing interfaces 1068 and 1070 are configured to enable rotation of the sealing end portion 1060 along a first sealing region, while the curved sealing interfaces 1074 and 1076 are configured to enable rotation of the second sealing end portion 1062 along a second sealing region.
The illustrated metering holes 1056 include a first plurality of metering holes 1108 and a second plurality of metering holes 1110. The metering holes 1056 are configured to control or meter the leakage flow through the seal 1050. For example, the metering holes 1056 may be designed to provide a certain flow rate or percentage of leakage flow depending on the particular application. In this manner, the metering holes 1056 may permit a controlled amount of leakage flow to improve the sealing effectiveness of the seal 1050 along the curved sealing interfaces 1068, 1070, 1074, and 1076, thereby reducing the possibility of leakage along the curved sealing interfaces 1068, 1070, 1074, and 1076. The metering holes 1056 also may be used for cooling various hot regions along the seal 1050, in the seal regions, or in the parts adjacent the seal regions. For example, the metering holes 1056 may be configured to provide film cooling (e.g., a thin film of coolant flow) along a surface of the seal 1050 or adjacent structures, or the metering holes 1056 may be configured to provide impingement cooling (e.g., jets of coolant flow) against a surface of the seal 1050 or adjacent structures. The metering holes 1056 may be oriented at any angle relative to hot regions to cool the hot regions. For example, the first plurality of metering holes 1108 may be directed toward the first sealing end portion 1060 (e.g., curved sealing interface 1068 or 1070) or associated sealing region at a first angle 1112, while the second plurality of metering holes 1110 may be directed toward the second sealing end portion 1062 (e.g., curved sealing interface 1074 or 1076) or associated sealing region at a second angle 1114. The angles 1112 and 1114 may range between approximately 0 to 90, 5 to 60, 10 to 45, or 15 to 30 degrees. Various angles, shapes, and configurations of the metering holes 1056 are discussed in detail above with reference to
In the illustrated embodiment, the first and second sealing end portions 1060 and 1062 are configured to seal with the respective seal regions 130 and 132 via spring forces and frictional forces. For example, the first sealing end portion 1060 includes the c-shaped end 1064 with the opposite curved sealing interfaces 1068 and 1070, which are configured to deflect toward and away from one another as indicated by arrow 1154, thereby providing biasing forces or spring forces 1156 and 1158 against the side walls 138 and 140. For example, the curved sealing interfaces 1068 and 1070 may be compressed together between the side walls 138 and 140, such that the curved sealing interfaces 1068 and 1070 maintain contact despite vibration or motion. The curved sealing interfaces 1068 and 1070 are also frictionally seated along the side walls 138 and 140 via respective frictional forces 1160 and 1162. Furthermore, the curved sealing interfaces 1068 and 1070 are also configured to pivot or rotate relative to the side walls 138 and 140 as indicated by rotational arrows 1164 and 1166. As discussed in detail above with reference to
In operation, the seal 1050 is configured to seal the gap 126 between the adjacent segments 120 and 122 between a first fluid region or flow 182 and a second fluid region or flow 184. For example, in certain embodiments, the first flow 182 may be substantially cooler than the second flow 184. In context of a turbomachine, such as a compressor or turbine, the first flow 182 may be a cooling flow (e.g., air flow), while the second flow 184 may be a heated fluid such as compressed air, hot gases of combustion, or the like. Accordingly, the seal 1050 may be subjected to significant temperatures, thermal gradients, vibration, motion, and thermal expansion and contraction between the segments 120 and 122. For example, the width 128 of the gap 126 may decrease in response to thermal expansion of the segments 120 and 122, while the width 128 may increase in response to thermal contraction of the segments 120 and 122. Accordingly, the biasing forces 1156, 1158, 1170, and 1172, the frictional forces 1160, 1162, 1174, and 1176, the deflection motion 1154 and 1168, and the rotational motion 1164, 1166, 1178, and 1180 may be configured to maintain a positive and consistent sealing interface between the seal 1050 and the side walls 138, 140, 146, and 148 of the seal regions 130 and 132 despite the conditions of the system.
The metering holes 1056 further improve the seal 1050 by controlling any leakage flow between the first and second flows 182 and 184. In the illustrated embodiments, the leakage flow includes a first fluid flow 1186 (e.g., air flow) through the first plurality of metering holes 1108, and a second fluid flow 1188 (e.g., air flow) through the second plurality of metering holes 1110. These fluid flows 1186 and 1188 are configured to control the amount of leakage flow from region 182 to region 184, thereby helping to reduce the possibility of leakage along the curved seal interfaces 1068, 1070, 1074, and 1076. The fluid flows 1186 and 1188 also provide cooling in the vicinity of the seal 1050, e.g., areas 190 and 192. As illustrated, the metering holes 1056 (e.g., metering holes 1108 and 1110) are angled away from one another toward the opposite segments 120 and 122 and/or associated seal regions 130 and 132. For example, the fluid flows 1186 and 1188 may be angled to flow into the seal regions 130 and 132 to help cool the side walls 138, 140, 146, and 148 and the curved sealing interfaces 1070 and 1076 of the seal 1050. In this manner, the cooling fluid flows 1186 and 1188 may protect the seal 1050 and/or walls 138, 140, 146, and 148 from any thermal damage, wear, or the like. The cooling flows 1186 and 1188 also may serve as shielding fluid flows to reduce chemical attack, corrosion, or other damage to the seal 1050 caused by the second fluid flow 184.
The seal 1050 also includes various angles and offsets throughout the seal 1050. For example, an axis 1250 of the wavy intermediate portion 1058 may be offset from the longitudinal axis 1084 by a variable offset distance 1252, which may alternatingly increase and decrease between lines 1247 and 1249. In the illustrated embodiment, the distance 1252 is greater at a midpoint 1249 between points 1246 and 1248, while it is lesser at points 1251 and 1253. In other words, the points 1249,1251, and 1253 may be described as extrema or points where the axis 1250 of the wavy intermediate portion 1058 is nearest to and farthest from the longitudinal axis 1084. In certain embodiments, the wavy intermediate portion 1058 may have 1 to 10 or more extrema or inflection points. The curved end plate portions 1090 and 1092 are curved from the edges of the intermediate portion 1258 (i.e., from lines 1247 and 1249) to the free ends 1069 and 1075 according to a particular arc. For example, the curved end plate portions 1090 and 1092 may extend through arcs 1258 and 1260 relative to lines 1247 and 1249, respectively, wherein the angles of the arcs may be approximately 180 to 270, 190 to 260, 200 to 250, 205 to 245, or 210 to 240 degrees. In particular, the angles of the arcs 1258 and 1260 are selected to provide convergence of the curved end plate portions 1090 and 1092 toward the intermediate portion 1058 of the seal 1050. The curvature of the sealing end portions 1060 and 1062 enables the curved sealing interfaces 1068, 1070, 1074, and 1076 to maintain contact while pivoting along the side walls 138, 140, 146, and 148. The described angles 1258 and 1260 may be increased to enable a greater range of pivoting movement of the curved sealing interfaces 1068, 1070, 1074, and 1076 along the side walls 138, 140, 146, and 148. Furthermore, the radii of the sealing ends 1060 and 1062 may be adjusted to control the slope of pivoting movement.
As further illustrated in
The metering holes 1056 also may have a variety of angles, shapes, and configurations configured to control the leakage flow and cooling. As illustrated in
Although the seal 1350 may be a two-piece structure, the illustrated embodiment of the seal 1350 is made with a single plate 1374. The plate 1374 includes a wavy intermediate plate portion 1376 disposed between opposite curved end plate portions 1378 and 1380, wherein the curved end plate portion 1378 includes the curved sealing interfaces 1362 and 1364, and the curved end plate portion 1380 includes the curved sealing interface 1368 and 1370. As illustrated, the curved sealing interfaces 1362 and 1364 are disposed on the same side of the wavy intermediate portion 1376 of the plate 1374.
The shape or geometry of the seal 1350 also may improve the sealing effectiveness of the seal 1350, particularly in environments subject to high temperatures, vibration, motion, and thermal expansion and contraction. In the illustrated embodiment, the intermediate plate portion 1376 of the plate 1374 is substantially wavy to enable compression and expansion of the intermediate portion 1376 of the plate 1374 along a longitudinal axis 1382. Furthermore, the wavy intermediate plate portion 1376 may function as a pivot point, axis of rotation, or axis of bending for the curved end plate portions 1378 and 1380 of the plate 1374. The curved sealing interfaces 1362 and 1364 along the curved end plate portion 1378 are configured to resiliently deflect toward and away from one another relative to the longitudinal axis 1382, and the curved sealing interfaces 1368 and 1370 along the curved end plate portion 1380 are configured to resiliently deflect toward and away from one another relative to the longitudinal axis 1382. Thus, the c-shaped end 1358 defined by the curved end plate portion 1378 (e.g., curved sealing interfaces 1362 and 1364) may serve as a first c-shaped spring element, while the c-shaped end 1360 defined by the curved end plate portion 1380 (e.g., curved sealing interfaces 1368 and 1370) may serve as a second c-shaped spring element. The c-shaped ends 1358 and 1360 also may serve as rotational joints, pivot joints, or cam members, thereby enabling rotational motion along sealing surfaces. For example, the curved sealing interfaces 1362 and 1364 are configured to enable rotation of the sealing end portion 1354 along a first sealing region, while the curved sealing interfaces 1368 and 1370 are configured to enable rotation of the second sealing end portion 1356 along a second sealing region.
In certain embodiments, the plate 1374 may have a thickness 1384 to provide the desired characteristics (e.g., bending stiffness) of the spring 1350, e.g., in the c-shaped ends 1358 and 1356 or the wavy intermediate portion 1376. For example, the plate 1374 may have a uniform or variable thickness 1384 lengthwise along the longitudinal axis 1382. For example, the thickness 1384 may increase or decrease with distance from the intermediate portion 1352. The seal 1350 also includes a central length 1386 of the intermediate portion 1352, which extends between point 1388 (i.e. line 1390) and point 1392 (i.e., line 1394) located at the centers of the first and second spaces 1366 and 1372. The remainder of the length of the seal 1350 divided between the first sealing end portion 1354 and the second sealing end portion 1356. The central length 1386 and the lengths of the sealing end portions 1354 and 1356 may be varied to control the range of deflection of the entire seal 1350 as well as the c-shaped ends 1358 and 1360. Furthermore, the central length 1386 as well as the lengths of the sealing end portions 1060 and 1062 may be selected based on the width of the gap between adjacent segments, as discussed in further detail below with reference to
The seal 1350 also includes various angles and offsets throughout the seal 1350. For example, an axis 1396 of the plate 1374 may alternatingly curve back and forth between extrema 1398, where the axis 1396 is nearest to and farthest from the longitudinal axis 1382. That is, at the extrema 1398 an offset distance between the axes 1382 and 1396 varies between local minimum and maximum values. In certain embodiments, the plate 1374 may include 1 to 10 or more extrema 1398 or inflection points. As illustrated, the distance 1400 is a local maximum at extrema 1398 at lines 1390 and 1394 as well as at a midpoint 1402 between lines 1390 and 1394. The distance 1400 is a local minimum at extrema 1398 between the midpoint 1402 and the lines 1390 and 1394. Again, the plate 1374 may have any number of extrema 1398 (e.g., local minima or maxima) or inflection points. The curved end plate portions 1378 and 1380 extend from the intermediate portion 1352 (i.e., from lines 1390 and 1394) to lines 1406 and 1408, respectively, according to a particular arc. For example, the curved end plate portions 1378 and 1380 may extend through arcs 1410 and 1412 relative to lines 1390 and 1394 and lines 1406 and 1408, respectively, wherein the arcs 1410 and 1412 may be approximately 180 to 270, 190 to 260, 200 to 250, 205 to 245, or 210 to 240 degrees. Beyond the lines 1406 and 1408, the curved end plate portions 1378 and 1380 have inwardly curved portions 1414 and 1416 that converge toward the longitudinal axis 1382, respectively. In particular, the inwardly curved portions 1414 and 1416 are selected to provide convergence of free ends 1418 and 1420 of curved end plate portions 1378 and 1380 toward the wavy intermediate portion 1376 of the seal 1350. The curvature of the sealing end portions 1354 and 1356 enables the curved sealing interfaces 1362, 1364, 1368, and 1370 to maintain contact while pivoting along the side walls between to turbine segments. The described arcs 1410 and 1412 may be increased to enable a greater range of pivoting movement of the curved sealing interfaces 1362, 1364, 1368, and 1370 between turbine segments.
In the illustrated embodiment, the first and second sealing end portions 1354 and 1356 are configured to seal with the respective seal regions 1460 and 1462 via spring forces (e.g., spring loaded). For example, the first sealing end portion 1354 includes the c-shaped end 1358 with the curved sealing interfaces 1362, 1364, and 1472, which are configured to deflect as indicated by arrow 1480, thereby providing biasing forces or spring forces 1482, 1484, and 1486 against the side walls 1468, 1470, and 1474. For example, the curved sealing interfaces 1362 and 1364 may be compressed together between the side walls 1468 and 1470, such that the curved sealing interfaces 1362 and 1364 maintain contact despite vibration or motion. Furthermore, the curved sealing interfaces 1362 and 1364 are also configured to pivot or rotate relative to the side walls 1468 and 1470 as indicated by rotational arrows 1488 and 1490. As discussed in detail above with reference to
In operation, the seal 1350 is configured to seal the gap 1456 between the adjacent segments 1450 and 1452 between a first fluid region or flow 1504 and a second fluid region or flow 1506. For example, in certain embodiments, the first flow 1504 may be substantially cooler than the second flow 1506. In context of a turbomachine, such as a compressor or turbine, the first flow 1504 may be a cooling flow (e.g., air flow), while the second flow 1506 may be a heated fluid such as compressed air, hot gases of combustion, or the like. Accordingly, the seal 1350 may be subjected to significant temperatures, thermal gradients, vibration, motion, and thermal expansion and contraction between the segments 1450 and 1452. For example, the width 1458 of the gap 1456 may decrease in response to thermal expansion of the segments 1450 and 1452, while the width 1458 may increase in response to thermal contraction of the segments 1450 and 1452. Additionally, the arcs 1410 and 1412 of the sealing ends 1354 and 1356 may be increased or decreased to control the spring stiffness (e.g., biasing forces), the range of deflection, and other characteristics of the c-shaped ends 1358 and 1360. For example, the curved end plate portions 1378 and 1380 may have be compressed by approximately 5 to 100, 10 to 75, or 25 to 50 percent from a normal state to a compressed state, which fits within the sealing regions 1460 and 1462. Accordingly, the biasing forces 1482, 1484, 1486, 1494, 1496, and 1498, the deflection motion 1492 and 1480, and the rotational motion 1488, 1490, 1500, and 1502 may be configured to maintain a positive and consistent sealing interface between the seal 1350 and the side walls 1468, 1470, 1474, and 1478 of the seal regions 1460 and 1462 despite the conditions of the system.
In contrast to embodiments previously presented, the embodiment of the seal 1350 of
The seal 1350 depicted in
Technical effects of the invention an improvement of seal effectiveness using spring loaded seals between turbomachine segments. This disclosure further improves seal effectiveness through the controlled thermal expansion and bending of seals, wherein the thermal expansion and bending of the seal helps to maintain seal seating during turbomachine operation. Also, this disclosure adds additional functionality to turbomachine seals through the introduction of metering holes, which provide a controlled leakage flow path that may be employed for impingement cooling of hot segment surfaces.
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.