FR2877035A1 - GROUP REACTION NOZZLE BANDAGES WITH INTEGRATED SEAL SEALS. - Google Patents

Abstract

Reaction turbine stator vane segment (10) comprising an integral multiple vane array (12), an arcuate tip tire (14) connected between the radially inner tips of the vanes and an arcuate mounting portion (15 ) extending through the radially outer tips of the vanes, the arched tip tire formed of multiple seal components extending radially inward from the tip tire.

Description

GROUP REACTION NOZZLE BANDAGES WITH SEAL JOINTS

INTEGRATED

  The present invention relates to steam turbines having seals between the rotating and non-rotating components and more particularly seal configurations incorporated in the integrated tip tires of the stator vanes grouped in a reaction turbine.

  Each stage of a jet steam turbine includes a plurality of circumferentially spaced fins mounted on a drum rotor surrounded by a plurality of fixed reaction stator vanes. The fins and nozzles form a turbine stage and define the main steam flow path. In contrast, in an impeller, the fins are mounted on the periphery of the rotor wheels and the nozzle walls are supported in the surrounding membranes. It is highly desirable in all cases to minimize or eliminate as many steam leakage paths as possible that result from the main steam flow path.

  A source of leakage in a reaction turbine is a radial gap between the group of reaction stator vane assemblies provided with endcaps and radially opposed to the outer portions of the rotor. One known technique for sealing this radial gap involves the use of insertable band gaskets on the rotor which is opposed to the seal surfaces on the reaction stator tip tires which have been sprayed with a usable coating. by friction. Another prior art involves incorporating radially projecting labyrinth teeth at the inner free ends of the nozzle or stator vanes which form labyrinth seals with radially opposed turbine rotor component parts. See, for example, commonly owned U.S. Patent No. 6,786,699. The combination of labyrinth seal teeth and brush seals was also used at the interface between the inner diaphragm flanges at the radially inner ends of the nozzle bulkheads and the rotor ranges in the action turbines. See, for example, commonly owned U.S. Patent No. 6,669,443 and commonly owned U.S. Patent No. 6,290,232.

  There remains, however, a need for effective seal configurations for use with grouped reaction turbine stator vanes having integral tip bandages that effectively reduce the radial gap between the tip bandages and the rotor edges. opposed.

  The present invention relates to novel seal configurations for reaction stator vane segments bundled with integrated tip bandages. Exemplary embodiments relate to integral one-piece stator vane segments incorporating multiple vanes and seal configurations that may include band seals, brush seals, or integral seal teeth that are opposed to rotor seal bearings in the Steam turbine mounted.

  For the purposes of the present invention, the term grouped reaction stator vanes with integrated end mills refers to a plurality (2 or more and up to about 50) of reaction turbine stator vanes with tire bandages. integrated covers which have been grouped together by machining in the form of a unitary or unitary group, where two or more groups make a ring of 360, or by welding or brazing individual blades to form a group where two or more groups also make a 360 ring.

  In a first configuration, a machined monoblock stator vane segment includes a plurality of vanes, a one-piece end band and an integral dovetail (or other mounting configuration). The stator tip bandage extends over the plurality of blades, thereby connecting the tips thereof, and is provided with a generally centered packing. The gasket includes a brush seal and the gasket is flanked by traditional caulking tape seals upstream and downstream of the gasket. In a second exemplary configuration, the integral stator bit band is provided with a generally axially centered packing (i.e., in the direction of flow) having a brush joint with machined labyrinth seal teeth. located upstream and downstream of the liner. In a third configuration, the stator bit band is machined to include a dovetail slot into which a set of seal strips may be inserted. The insert seal strip assembly is provided with an axially centered brush seal with the integral labyrinth seal teeth upstream and downstream of the brush seal.

  For all configurations, the opposing rotor surface can be machined to include a high-low-high range configuration or, a low-high-low range configuration to accommodate a similar seal assembly in the tip wraps. In addition, the specific number of seals, opposite seals and the choice of specific seals and / or combination of seals may vary depending on the specific application.

  Also, the present invention in its broader aspects relates to a jet turbine stator vane segment comprising a group of a multiple vane block, an arcuate tip bandage connected between the radially inner tips of the blades and a an arcuate mounting portion extending through the radially outer tips of the blades, the arcuate tip reinforcement formed with the multiple seal components extending radially inwardly from the tip bandage.

  The jet turbine stator vane segment may include multiple seal components that include a combination of band seals and brush seals.

  The jet turbine stator vane segment may include multiple seal components that include a combination of labyrinth seal teeth and brush seals.

  The jet turbine stator vane segment may include multiple seal components that include a pair of band seals one on each side of a brush seal.

  The jet turbine stator vane segment may include multiple seal components that include a pair of labyrinth seal teeth, one on each side of a brush seal.

  The jet turbine stator vane segment may include multiple seal components that are mounted in an arcuate liner and said arcuate liner is received in a groove in said tip wrap.

  The jet turbine stator vane segment may include multiple seal components that include a brush seal flanked by a pair of labyrinth seal teeth.

  The jet turbine stator vane segment may include integral clustering that is machined from a single solid block.

  The jet turbine stator vane segment may comprise multiple seal components that include a brush seal liner received in a groove in said tip wrap, with additional seal components on opposite sides of said seal liner. brush seal.

  The jet turbine stator vane segment may include additional seal components that include band seals.

  In another aspect, the present invention relates to a jet turbine stator vane segment comprising a machined unit group of multiple vanes, an arcuate tip band connected between the radially inner blade tips and a mounting portion. arcuate extending through the radially outer tips of the blades, the arcuate tip band formed with the multiple seal components extending radially inwardly from the tip band, wherein the multiple seal components comprise Brush seal gasket received in a groove in the nozzle tread with additional gasket components on opposite sides of the gasket.

  The present invention will now be described in detail in connection with the drawings identified below.

  1 represents a perspective view of a group reaction stator vane segment; FIG. 2 shows a partial end view of a group reaction stator vane segment incorporating a seal configuration in accordance with FIG. FIG. 3 is a partial end view of a group reaction stator vane segment incorporating a seal configuration in accordance with a second exemplary embodiment of the present invention, FIG. is a partial end view of a group reaction stator vane segment incorporating a seal configuration in accordance with a third exemplary embodiment of the present invention.

  Referring to Figure 1, a group reaction stator vane segment 10 comprises a plurality of reaction vanes 12, a one-piece arcuate tip band 14 at the ends of the radially inner blades, and a dovetail or other mounting configuration 14 at the ends of the radially outer blades. Although the figure represents a group of four blades 12, it should be understood that the segment may include other numbers of blades, for example 6, 8, 12 up to 50 or more blades, the latter forming a segment of 180. Two or more segments together form a closed ring of 360 reaction vanes.

  In the preferred embodiment, the segment 14 is machined from a single block of a metallic material, preferably a stainless steel alloy, but individual blades may also be grouped by welding, soldering or any other suitable means for to form a segment.

  Referring now to Figure 2, the segment 10 and, in particular, the tip band 14 is provided with a band seal and brush seal device. In particular, a brush seal liner 16 is slidably received in a groove 18 formed in a radially inner face 19 of the bead band 14. The liner incorporates brush seal members 20 which extend radially inwardly. to a location closely adjacent to a bearing surface 22 on the turbine rotor 24. A pair of belt seals 26, 28 is located in the respective grooves 30, 32 in the face 19 of the end mill on opposite sides of the seal gasket, and fixed for example by hammering. These belt seals extend inwardly with the closely adjacent ends of the respective bearing surfaces 34, 36 of the rotor 24. It should be noted that the belt seals 26, 28 lie, respectively, upstream and downstream of the brush seal generally axially centered 16 (with respect to the direction of flow of the steam), in a high-low-up device vis-à-vis the turbine doors. It should be understood that the configuration of the turbine reach can be reversed with proper repositioning of the seal ends in a low-high-low configuration.

  Figure 3 shows a replacement device in connection with a reaction stator vane segment 38. In this embodiment, the tip band 40 is mounted with a generally axially centered brush seal gasket 42, located in a groove 43. formed in the radially inner face 44 of the bit band, with brush seal members 45 similar to the pad 16 in Figure 2. The labyrinth seal teeth 46, 48 are integrally formed with the bit bandage 40 and resting upstream and downstream of the brush seal gasket 42, interacting with the bearings 50 and 52 on the rotor 54. The brush seal members 44 extend inwardly toward a turbine bearing surface 56. Here again, a high-low-high range configuration is shown, but, as in the case of Figure 2, this configuration can be reversed for a low-high-low device.

  Figure 4 shows yet another embodiment of the present invention wherein the reaction blade segment 58 comprises an integrated tip band 60, whose radially inner face 61 is formed with a dovetail groove 62 which receives a seal seal 64. The seal 64 is provided with a generally axially centered brush seal 66 having brush seal members 68 which extend inwardly to a location closely adjacent the turbine bearing surface 70. The seal 64 is also formed with integrated upstream and downstream labyrinth seal teeth 72, 74 which extend radially inwardly to a closely adjacent location of the respective bearing surfaces 72, 74 which extend radially inwardly to a location closely adjacent the respective bearing surfaces 76, 78 of the rotor 80. As in the previous embodiments, the high-low-high range configuration can be inverted for low-low configuration, with appropriate modification of the sealing elements. It will be understood that the labyrinth seal teeth 72, 74 could be replaced by belt seals similar to those of FIG. 2.

  The seal configurations described above reduce the radial gap between the rotor and the reaction stator vane nozzle casings and at the same time reduce the mounting time for the rotor and eliminate the need for a usable coating. by friction on the one-piece nozzle bandage of the reaction stator. It will be understood that the tip bandages may incorporate seals and / or seals with any combination of band seals, brush seals or labyrinth seal teeth.

  Although the present invention has been described in connection with what is currently considered to be the most practical and preferred embodiment, it should be understood that the present invention should not be limited to the disclosed embodiment, but rather, is intended to cover different modifications and equivalent arrangements.

  Group reaction stator blade segment 10 Plurality of reaction vanes 12 Trunnion bushing 14 Mounting part 15 Brush seal packing 19 Brush seal elements 20 Scope 22 Turbine rotor 24 Belt seals 26, 28 Grooves, 30, 32 Reaches 34, 36 Reactor stator blade segment 38 Ferrule 40 Seal Brush Seal 42 Groove 43 Radial Inner Face 44 Brush Seal Elements 45 Labyrinth Seal Teeth 46, 48 Ranges 50, 52 Rotor 54 Turbine Reach 56 Reaction Vane Segment 58 Integrated End Band 60 Inner Radius 61 Dovetail Groove 62 Arc Joint Seal Mounting Kit 64 Axially Centered Brush Seal 66 Brush Seal Elements 68 Turbine Reach 70 Labyrinth seal teeth 72, 74 Scopes 76, 78 Rotor 80

Claims (10)

  A jet turbine stator vane segment (10) comprising a cluster of multiple blades (12), an arcuate tip bandage (14) connected between the radially inner tips of the vanes and an arcuate mounting portion (15) extending through the radially outer tips of the blades, said arcuate tip reinforcement (14) formed of multiple seal components (20, 26, 28) extending radially to the interior from said tip bandage (14).   The jet turbine stator vane segment of claim 1, wherein said multiple seal components comprise a combination of belt seals (26,28) and brush seals (20).   The jet turbine stator vane segment of claim 1, wherein said multiple seal components comprise a combination of labyrinth seal teeth (46, 48) and brush seals (45).   The jet turbine stator vane segment of claim 1, wherein said multiple seal components comprise a pair of band seals (26, 28), one on each side of a brush seal (20).   A jet turbine stator vane segment according to claim 1, wherein said multiple seal components comprise a pair of labyrinth seal teeth (46, 48), one on each side of a brush seal (45). .   A jet turbine stator vane segment according to claim 1, wherein said multiple seal components are mounted in an arcuate liner (64) and said arcuate liner is received in a groove (62) in said tire liner. tip.   The jet turbine stator vane segment of claim 6, wherein said multiple seal components comprise a brush seal (68) flanked by a pair of labyrinth seal teeth (72, 74).   The jet turbine stator vane segment of claim 1, wherein the integral cluster (12) is machined from a single solid block.   The jet turbine stator vane segment of claim 1, wherein said multiple seal components comprise a brush seal liner (16) received in a groove (18) in said tip wrap, with components additional gasket (26, 28) on opposite sides of said brush seal gasket.   The jet turbine stator vane segment of claim 9, wherein said additional seal components comprise band seals (26, 28).