The subject matter disclosed herein relates to steam turbines. Specifically, the subject matter disclosed herein relates to alignment of steam turbines.
Steam turbines include static nozzle assemblies that direct flow of a working fluid into turbine buckets connected to a rotating rotor. The nozzle construction (including a plurality of nozzles, or “airfoils”) is sometimes referred to as a “diaphragm” or “nozzle assembly stage.” Steam turbine diaphragms include two halves, which are assembled around the rotor, creating horizontal joints between these two halves. Each turbine diaphragm stage is vertically supported by support bars, support lugs or support screws on each side of the diaphragm at the respective horizontal joints. The horizontal joints of the diaphragm also correspond to horizontal joints of the turbine casing, which surrounds the steam turbine diaphragm. Diaphragm centering (or, alignment) pins (or keys) are used to position the diaphragms in the transverse direction during installation. These centering pins are also designed to take the torque load generated by the diaphragm.
The centering pin is traditionally installed in an area of the diaphragm assembly with a small interference. The centering pin is traditionally cooled (e.g., frozen) to a point in which it contracts to fit in this area of small clearance. This often requires the use of dry ice or another severe cooling mechanism during installation, e.g., in the field. However, the unavailability and relatively high cost of these severe cooling mechanisms can be undesirable. Additionally, freezing and thawing of the centering pin can cause misalignment of the turbine diaphragm. Other pins are bolted into place, which causes other concerns. Boiling still allows for movement of the pin under loading in one direction. Further, having a small bolt hole in the turbine casing is undesirable due to stress concentration proximate the hole.
Various aspects include an alignment key for a turbomachine, along with a turbomachine including the alignment key and a related storage medium. In some cases, the alignment key includes: a body having primary axis and sized to engage a diaphragm slot in the turbomachine, the body having sidewalls extending along the primary axis; a chamfered tip section continuous with the body, the chamfered tip section sized to engage a casing slot in the turbomachine; and a slot extending through the body and the chamfered tip section, the slot having a first opening proximate an end of the body and a second opening proximate the chamfered tip section, wherein the sidewalls of the body taper from the end of the body toward the chamfered tip section.
A first aspect of the disclosure includes an alignment key having: a body having primary axis and sized to engage a diaphragm slot in the turbomachine, the body having sidewalls extending along the primary axis; a chamfered tip section continuous with the body, the chamfered tip section sized to engage a casing slot in the turbomachine; and a slot extending through the body and the chamfered tip section, the slot having a first opening proximate an end of the body and a second opening proximate the chamfered tip section, wherein the sidewalls of the body taper from the end of the body toward the chamfered tip section.
A second aspect of the disclosure includes a turbomachine having: a turbine diaphragm segment; a turbine casing segment at least partially housing the turbine diaphragm segment; and an alignment key for aligning the turbine diaphragm segment with the turbine casing segment, the alignment key including: a body having primary axis and sized to engage a diaphragm slot in the turbomachine, the body having sidewalls extending along the primary axis; a chamfered tip section continuous with the body, the chamfered tip section sized to engage a casing slot in the turbomachine; and a slot extending through the body and the chamfered tip section, the slot having a first opening proximate an end of the body and a second opening proximate the chamfered tip section, wherein the sidewalls of the body taper from the end of the body toward the chamfered tip section.
A third aspect of the disclosure includes a non-transitory computer readable storage medium storing code representative of an alignment key for a turbomachine, the alignment key physically generated upon execution of the code by a computerized additive manufacturing system, the code having: code representing the alignment key nozzle, the alignment key including: a body having primary axis and sized to engage a diaphragm slot in the turbomachine, the body having sidewalls extending along the primary axis; a chamfered tip section continuous with the body, the chamfered tip section sized to engage a casing slot in the turbomachine; and a slot extending through the body and the chamfered tip section, the slot having a first opening proximate an end of the body and a second opening proximate the chamfered tip section, wherein the sidewalls of the body taper from the end of the body toward the chamfered tip section.
These and other features of this invention will be more readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings that depict various embodiments of the disclosure, in which:
It is noted that the drawings of the invention are not necessarily to scale. The drawings are intended to depict only typical aspects of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numbering represents like elements between the drawings.
The subject matter disclosed herein relates to turbomachines. Specifically, the subject matter disclosed herein relates to alignment of turbomachines, e.g., steam turbines.
In the conventional scenario, the centering pin is installed with a small degree (e.g., 0.0005-0.002 inches, or 0.0127-0.0508 millimeters) interference fit in a casing slot. In order to meet this small level of interference, the centering pin is cooled (e.g., until frozen) to a temperature below zero degrees Fahrenheit (F), e.g., as cold as −140 degrees F. (approximately −95 degrees Celsius), or in the case of liquid nitrogen cooling, up to −320 degrees F. (approximately −195 degrees Celsius) cooling. As noted herein, it may be difficult to cool the centering pin to such a temperature, in particular, while the centering pin is installed on location. Additionally, freezing and thawing of the centering pin can cause misalignment of the turbine diaphragm.
According to various embodiments of the disclosure, in contrast to conventional approaches, a turbomachine alignment key including a tapered body, where the alignment key is sized to engage a diaphragm slot and corresponding casing slot to align the diaphragm of a turbomachine with its casing. In various embodiments, the alignment key includes a chamfered tip section that is continuous with the body, where the outer surfaces of the chamfered tip section are angled at a distinct angle with respect to a reference line than the tapered body. Embodiments of the turbomachine alignment key disclosed are configured to align a diaphragm and casing without requiring the cooling (e.g., freeze-fit) used in conventional approaches. The various features of the alignment keys disclosed allow for more effective and efficient alignment of turbomachines.
As denoted in these Figures, the “A” axis represents axial orientation (along the axis of the turbine rotor, sometimes referred to as the turbine centerline). As used herein, the terms “axial” and/or “axially” refer to the relative position/direction of objects along axis A, which is substantially parallel with the axis of rotation of the turbomachine (in particular, the rotor section). As further used herein, the terms “radial” and/or “radially” refer to the relative position/direction of objects along axis (r), which is substantially perpendicular with axis A and intersects axis A at only one location. Additionally, the terms “circumferential” and/or “circumferentially” refer to the relative position/direction of objects along a circumference (c) which surrounds axis A but does not intersect the axis A at any location. Identically labeled elements in the Figures depict substantially similar (e.g., identical) components.
Turning to
With continuing reference to
In some cases, as shown in
In any case, the alignment keys (and associated alignment apparatuses) shown and described herein allow for the alignment of a turbomachine casing and diaphragm while overcoming the various shortfalls of conventional pins (and apparatuses). The alignment keys (and associated alignment apparatuses) according to various embodiments of the invention have the technical effect of aligning a turbomachine apparatus in a controlled and progressive manner.
Alignment key 26 (
To illustrate an example of an additive manufacturing process,
AM control system 904 is shown implemented on computer 930 as computer program code. To this extent, computer 930 is shown including a memory 932, a processor 934, an input/output (I/O) interface 936, and a bus 938. Further, computer 930 is shown in communication with an external I/O device/resource 940 and a storage system 942. In general, processor 934 executes computer program code, such as AM control system 904, that is stored in memory 932 and/or storage system 942 under instructions from code 920 representative of alignment key 26 (
Additive manufacturing processes begin with a non-transitory computer readable storage medium (e.g., memory 932, storage system 942, etc.) storing code 920 representative of alignment key 26 (
In various embodiments, components described as being “coupled” to one another can be joined along one or more interfaces. In some embodiments, these interfaces can include junctions between distinct components, and in other cases, these interfaces can include a solidly and/or integrally formed interconnection. That is, in some cases, components that are “coupled” to one another can be simultaneously formed to define a single continuous member. However, in other embodiments, these coupled components can be formed as separate members and be subsequently joined through known processes (e.g., soldering, fastening, ultrasonic welding, bonding). In various embodiments, electronic components described as being “coupled” can be linked via conventional hard-wired and/or wireless means such that these electronic components can communicate data with one another.
The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
When an element or layer is referred to as being “on”, “engaged to”, “connected to” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to”, “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Spatially relative terms, such as “inner,” “outer,” “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
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 languages of the claims.
Number | Name | Date | Kind |
---|---|---|---|
3373648 | Pitzer | Mar 1968 | A |
3498727 | Bollinger, Jr. | Mar 1970 | A |
5271714 | Shepherd et al. | Dec 1993 | A |
9028210 | Sankolli et al. | May 2015 | B2 |
20080286097 | Chevrette | Nov 2008 | A1 |
20130078086 | Breugnot et al. | Mar 2013 | A1 |
20140037442 | Tatman et al. | Feb 2014 | A1 |
20170292391 | Burdgick et al. | Oct 2017 | A1 |
Number | Date | Country |
---|---|---|
2 740 902 | Jun 2014 | EP |
2 960 591 | Dec 2011 | FR |
2 309 053 | Jul 1997 | GB |
Entry |
---|
Partial European Search Report and Opinion issued in connection with corresponding EP Application No. 17164376.0 dated Sep. 6, 2017. |
Number | Date | Country | |
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20170292390 A1 | Oct 2017 | US |