Turbomachine nozzle segment having an integrated diaphragm   

Abstract: A turbomachine nozzle segment includes a vane having a first end extending to a second end through an airfoil portion. An outer member is positioned at the first end of the vane. The outer member includes a mounting element configured and disposed to secure the turbomachine nozzle segment to a turbomachine. An inner member is positioned at the second end of the vane. The inner member includes an upstream section and a downstream section. An upstream diaphragm member extends substantially radially outwardly from the inner member at the upstream section, and a downstream diaphragm member extends substantially radially outwardly from the inner member at the downstream section. Each of the upstream diaphragm member and down stream member includes an outer surface and an inner surface. One of the outer surface and inner surface of each of the upstream diaphragm member and downstream diaphragm member includes a cartridge mounting member.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to the art of turbomachines and, more particularly, to a turbomachine nozzle segment having an integrated diaphragm.

In general, gas turbomachines combust a fuel/air mixture that releases heat energy to form a high temperature gas stream. The high temperature gas stream is channeled to a turbine section via a hot gas path. In the turbine, the high temperature gas stream passes through a plurality of stages. Each stage includes a plurality of nozzles arranged upstream from a plurality of turbine blades. The high temperature gas stream passes over the nozzles, then acts upon or rotates the turbine blades. The plurality of nozzles are mounted to a housing of the turbine section and a diaphragm is mounted to each of the plurality of nozzles. A discourager seal is provided at an interface between each of the plurality of nozzles and the associated diaphragm. The discourager seals on each of the plurality of nozzles interact one with the other to reduce loss of the high temperature gases or working fluid from the corresponding one of the plurality of stages of the turbine section. The turbine blades convert thermal energy from the high temperature gas stream to mechanical energy that rotates a turbine shaft. The turbine may be used in a variety of applications such as providing power to a pump or an electrical generator.

According to one aspect of the invention, a turbomachine nozzle segment includes a vane having a first end extending to a second end through an airfoil portion. An outer member is positioned at the first end of the vane. The outer member includes a mounting element configured and disposed to secure the turbomachine nozzle segment to a turbomachine. An inner member is positioned at the second end of the vane. The inner member includes an upstream section and a downstream section. An upstream diaphragm member extends substantially radially outwardly from the inner member at the upstream section, and a downstream diaphragm member extends substantially radially outwardly from the inner member at the downstream section. Each of the upstream diaphragm member and down stream member includes an outer surface and an inner surface. One of the outer surface and inner surface of each of the upstream diaphragm member and downstream diaphragm member includes a cartridge mounting member.

According to another aspect of the invention, a turbomachine nozzle cartridge includes a main body having an outer surface and an inner surface that extend between an upstream end and a downstream end. The nozzle cartridge is configured and disposed to be mounted between an upstream diaphragm member and a downstream diaphragm member of a turbomachine nozzle.

According to yet another aspect of the invention, a turbomachine includes a compressor section, a turbine section operatively connected to the compressor section, and a turbine nozzle positioned within the turbine section. The turbine nozzle includes a vane having a first end extending to a second end through an airfoil portion. An outer member is positioned at the first end of the vane. The outer member includes a mounting element configured and disposed to secure the turbomachine nozzle to a turbomachine. An inner member is positioned at the second end of the vane. The inner member includes an upstream section and a downstream section. An upstream diaphragm member extends substantially radially outwardly from the inner member at the upstream section, and a downstream diaphragm member extends substantially radially outwardly from the inner member at the downstream section. Each of the upstream diaphragm member and down stream member includes an outer surface and an inner surface. One of the outer surface and inner surface of each of the upstream diaphragm member and downstream diaphragm member includes a cartridge mounting member. A cooling passage extends from the outer member through the airfoil portion to the inner member. A nozzle cartridge includes a main body having an outer surface and an inner surface that extend between an upstream end and a downstream end. The nozzle cartridge is mounted between the upstream diaphragm member and the downstream diaphragm member of a turbomachine nozzle.

These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.

The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a partial cross-sectional side view of a turbine section of a turbomachine including a plurality of turbine nozzles having an integrated diaphragm members in accordance with an exemplary embodiment;

FIG. 2 is a perspective view of a nozzle segment including integrated upstream and downstream diaphragm members of the turbine section of FIG. 1;

FIG. 3 is a perspective view of an inner member of the nozzle segment of FIG. 2;

FIG. 4 is a perspective view of the nozzle segment of FIG. 2 including a nozzle cartridge in accordance with an exemplary embodiment; and

FIG. 5 is a perspective view of an inner member of a nozzle segment joined to a nozzle cartridge in accordance with another exemplary embodiment.

The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.

DETAILED DESCRIPTION

Referring to FIG. 1, a turbomachine, in accordance with an exemplary embodiment, is indicated generally at 2. Turbomachine 2 includes a turbine section 3 having a housing 4 that defines, at least in part, a hot gas path 10. Turbine section 3 includes a first stage 12, having a plurality of first stage vanes or nozzles 14, and blades 16; a second stage 17 having a plurality of second stage vanes or nozzles 18 and blades 20; and a third stage 21 having a plurality of third stage vanes or nozzles 22 and blades 24. Of course it should be understood that turbine section 3 could also include additional stages (not shown). Hot combustion gases flow axially along hot gas path 10 through nozzles 14, 18, and 22, impact and rotate blades 16, 20, and 24. In addition, a cooling airflow is guided into turbine section 3 in order to mitigate thermal fluxes that develop between portions of nozzles 14, 18, and 22.

Reference will now be made to FIGS. 2-4 in describing a nozzle segment 30 of second stage 17 in accordance with an exemplary embodiment. Nozzle segment 30 includes a plurality of second stage nozzles or airfoils 18, 18a, and 18b. As each airfoil 18, 18a, and 18b is similarly formed, a detailed description will follow referencing airfoil 18 with an understanding that airfoil 18a and 18b include similar structure. Airfoil 18 includes a first end 34 that extends to a second end 35 through an intermediate or airfoil portion 36. Nozzle segment 30 includes an outer member 40 integrally formed with airfoils 18, 18a, and 18b at first end 34. Outer member 40 supports nozzle segment 30 from a casing portion (not separately labeled) of turbomachine 2 and includes a main body 42 having a first circumferential edge 46 and an opposing second circumferential edge 47. First and second circumferential edges 46 and 47 establish a circumferential profile 50 for outer member 40. In the exemplary embodiment shown, circumferential profile 50 is about 22.5° of an overall circumference of second stage 17. Each circumferential edge 46 and 47 includes a corresponding angled or dogleg section 48 and 49.

Nozzle segment 30 also includes an inner member 60 integrally formed at second end 35 of airfoils 18, 18a, and 18b. Inner member 60 includes a main body 64 having an upstream section 67 and a downstream section 69. Main body 64 also includes a first circumferential edge 72 and a second, opposing, circumferential edge 73 that establish a circumferential profile 75 for inner member 60. In a manner similar to that described above, in the exemplary embodiment shown, circumferential profile 75 is about 22.5° of an overall circumference of second stage 17. Each circumferential edge 72 and 73 includes a corresponding angled or dogleg section 79 and 80. Each circumferential edge 72 and 73 is also provided with a seal slot or groove 81 and 82 respectively. At this point it should be understood that the term “inner” refers to a portion of nozzle segment 30 that is positioned near a centerline of turbomachine 2. The term “outer” refers to a portion of nozzle segment 30 that is positioned away from the centerline in a direction of a casing of turbomachines 2.

In accordance with the exemplary embodiment, inner member 60 includes an upstream diaphragm member 84 and a downstream diaphragm member 86. Upstream diaphragm member 84 is integrally formed with inner member 60 and extends generally radially outwardly from upstream section 67 between first and second circumferential edges 72 and 73. Similarly, downstream diaphragm member 86 is integrally formed with inner member 60 and extends generally radially outwardly from downstream section 69 between first and second circumferential edges 72 and 73. Upstream diaphragm member 84 includes a first end 90 that extends from upstream section 67 to a second end 91. Second end 91 includes a generally curvilinear circumferential profile (not separately labeled). Upstream diaphragm member 84 also includes an outer surface 93 and an inner surface 94 (FIG. 3) that extend between first and second ends 90 and 91. A first seal groove element 95 is formed in upstream diaphragm member 84 at circumferential edge 73. First seal groove element joins with seal groove 82. A second seal groove element 96 is formed in upstream diaphragm member 84 at circumferential edge 72. Second seal groove element 96 is linked with seal groove 81. Similarly, downstream diaphragm member 86 includes a first end 97 that extends from downstream section 69 to a second end 98. Second end 98 includes a generally curvilinear circumferential profile (not separately labeled). Downstream diaphragm member 86 also includes an outer surface 100 and an inner surface 101 that extend between first and second ends 97 and 98. A first seal groove member 102 is formed in downstream diaphragm member 86 at circumferential edge 73. First seal groove member 102 joins with seal groove 82. A second seal groove member 103 is formed in downstream diaphragm member 86 at circumferential edge 72. Second seal groove member 103 is linked with seal groove 81.

Upstream diaphragm member 84 and downstream diaphragm member 86 are also shown to include discourager seals 104 and 105 provided on outer surfaces 93 and 100 respectively. Discourager seals 104 and 105 can either be integrally formed on corresponding ones of outer surfaces 93 and 100 or may be mounted in grooves or other structure (not shown) provided on corresponding ones of outer surfaces 93 and 100. In addition, upstream diaphragm member 84 and downstream diaphragm member 86 are also shown to include cartridge mounting members 110 and 112 provided on corresponding ones of inner surfaces 94 and 101. As will be discussed more fully below, cartridge mounting members 110 and 112 provide an interface for additional sealing structure for nozzle segment 30. Nozzle segment 30 is also shown to include a plurality of passages 118-120 that deliver cooling fluid flow, in the form of compressor discharge air, through airfoils 18, 18a, and 18b respectively. Passages 118-120 lead though airfoils 18, 18a, and 18b into a region 121 that extends between upstream diaphragm member 84 and downstream diaphragm member 86. Region 121 receives extraction air through a plurality of cooling passages 118-120 that extend through airfoils 18, 18a, and 18b, and is pushed out through openings 122-124 that are formed in upstream diaphragm member 84. At this point it should be understood that various other cooling scheme, including the use of cooling tubes or conduits that extend from upstream diaphragm member 84, through airfoils 18, 18a, and 18b, and to a casing of turbomachine 2 could also be employed

In further accordance with the exemplary embodiment, nozzle segment 30 includes a nozzle cartridge 136 (FIG. 4) that is detachably mounted to inner member 60. Nozzle cartridge 136 provides a seal that limits leakage flow from passing between nozzle segment 30 and a wheel space (not separately labeled) of turbine section 3. Nozzle cartridge 136 includes a main body 139 having a substantially linear cross-section and a substantially curvilinear circumferential profile. In a manner similar to that described above, in the exemplary embodiment shown, the circumferential profile is about 22.5° of an overall circumference of second stage 17. Nozzle cartridge 136 is shown to include a main body 139 having an upstream end 141 and a downstream end 142. Main body 139 also includes an outer surface 144, an inner surface 145, a first side portion 146 and a second side portion (not shown). Side portion 146 includes an angled or dogleg portion 147 on side portion corresponds to dogleg sections 80 on inner member 60. The second side portion (not shown) includes a similar angled or dogleg portion (also not shown). Side portion 146 is also shown to include a seal groove portion 148 that links with first seal groove element 95 and first seal groove member 102 to form a seal zone (not separately labeled) that prevents leakage flow from passing between adjacent nozzle cartridges.

As best shown in FIG. 4, nozzle cartridge 136 defines a region 148 in inner member 60. In a manner similar to that described above, region 148 is an encapsulated region defined/bounded by upstream diaphragm member 84, downstream diaphragm member 86 and nozzle cartridge 136. Region 148 channels extraction air passing through airfoils 18, 18a, and 18b to provide cooling to the wheel space. Nozzle cartridge 136 includes a plurality of projections, one of which is indicated at 150 that define a labyrinth seal which limits leakage flow across stages 17, and 21. Nozzle cartridge 136 is further shown to include first cartridge mounting element 152 provided on upstream end 141 and a second cartridge mounting element 154 provided on downstream end 142. First and second cartridge mounting elements 152 and 154 engage with first and second cartridge mounting members 110 and 112 on inner member 60 to secure nozzle cartridge 136 to nozzle segment 30

Reference will now be made to FIG. 5 in describing a nozzle segment 180 in accordance with another aspect of the exemplary embodiment. Nozzle segment 180 includes a plurality of airfoils, one of which is indicated at 183 that extend between an outer member (not shown) and an inner member 190. Inner member 190 includes a main body 193 having an upstream section 195 and a downstream section 196. Main body 193 also includes a first circumferential edge (not shown) that extends to a second circumferential edge 198 to define a circumferential profile 200. In a manner similar to that described above, in the exemplary embodiment shown, circumferential profile 200 is about 22.5° of an overall circumference of second stage 12. In a manner also similar to that described above circumferential edge 198 includes an angled or dogleg section 202.

An upstream diaphragm member 205 is integrally formed with inner member 190 and extends generally radially outwardly from upstream section 195. Similarly, a downstream diaphragm member 207 is also integrally formed with inner member 190 and extends generally radially outwardly from downstream section. Upstream diaphragm member 205 includes a first end 211 that extends from upstream section 195 to a second end 212. Second end 212 includes a generally curvilinear circumferential profile (not shown). Upstream diaphragm member 205 also includes an outer surface 214 and an inner surface 215 that extend between first and second ends 211 and 212. Similarly, downstream diaphragm member 207 includes a first end 219 that extends from downstream section 196 to a second end 220. Second end 220 includes a generally curvilinear circumferential profile (not shown). Downstream diaphragm member 207 also includes an outer surface 222 and an inner surface 223 that extend between first and second ends 219 and 220. A first discourager seal 225 is provided on outer surface 214 of upstream diaphragm member 205 and a second discourager seal 226 is provided on outer surface 222 of downstream diaphragm member 207. Inner member 190 is also shown to include a first cartridge mounting member 228 that is provided on outer surface 214 of upstream diaphragm member 205 and a second cartridge mounting member 230 provided on outer surface 222 of downstream diaphragm member 207.

In further accordance with the exemplary aspect depicted in FIG. 5, a nozzle cartridge 240 is mounted to inner member 190. Nozzle cartridge 240 includes a main body 243 having an upstream end 245 and a downstream end 246 that are separated by an outer surface 248 and an inner surface 249. Cartridge 240 also includes a first side portion 250 and a second side portion (not shown). Each of the first and second side portions includes an angled or dogleg section, one of which is shown at 251 on side portion 250 that corresponds to dogleg section 202 on inner member 190. A first mounting flange 252 extends from upstream end 245 and a second mounting flange 253 extends from downstream end 246. Each mounting flange 252, 253 includes a corresponding cartridge mounting element 255 and 257. Cartridge mounting elements 255 and 257 cooperate with cartridge mounting members 228 and 230 on inner member 190. With this arrangement, mounting flanges 252 and 253 wrap around outer surfaces 214 and 222 of upstream diaphragm member 205 and downstream diaphragm member 207 respectively. Once in place, nozzle cartridge 240 forms a cavity 260 in inner member 190.

At this point it should be appreciated that the exemplary embodiments provide a nozzle segment having an integrated diaphragm that reduces leakage points and simplifies construction by reducing or even eliminating numerous welded joints. In addition the particular construction of the nozzle segment eliminates load sharing with adjacent nozzle segments. The integrated diaphragm eliminates numerous diaphragm machining operations saving time/labor/costs associated with forming and installing nozzles in a turbomachine. The exemplary embodiments are further shown to reduce both known and unknown leakages thereby enhancing turbomachine efficiency. Finally, it should be understood that the particular nozzle segment shown is exemplary, the number of vanes as well as the materials used may vary.

While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.