Patent Application
20140154066
The subject matter disclosed herein relates to power systems. More particularly, the subject matter relates to turbomachine systems.
Conventional turbomachines (also referred to as turbines), such as steam turbines (or, steam turbomachines), generally include static nozzle assemblies that direct the flow of working fluid (e.g., steam) into rotating buckets that are connected to a rotor. In steam turbines the nozzle (or, airfoil) construction is typically called a “diaphragm” or “nozzle assembly” stage. Nozzle assemblies are assembled in two halves around the rotor, creating a horizontal joint.
Conventionally, steam turbines also include packings (or, seals) at the root of the nozzle and the tip of the rotating bucket. These packings are used to reduce axial leakage across the interface between the nozzle and rotor body, and bucket and stator diaphragm, respectively. The leakage in these areas can disturb the flow of working fluid (e.g., steam) prior to introduction of that fluid to the buckets, causing performance losses.
Various embodiments include a steam turbine nozzle and turbomachinery including such a nozzle. In various particular embodiments, a steam turbine nozzle includes: a body having: a first sidewall and a second sidewall opposite the first sidewall; a pressure side and a suction side each extending between the first sidewall and the second sidewall; and a leading edge section at a first junction of the pressure side and the suction side, and a trailing edge section at a second junction of the pressure side and the suction side; and a bypass fluid conduit including: a channel having an opening to at least one of the first sidewall or the second sidewall; and an outlet passageway fluidly connected with the channel between the first sidewall and the second sidewall, the outlet passageway including a first opening on at least one of the pressure side of the body, the suction side of the body or the trailing edge section.
A first aspect of the invention includes a steam turbine nozzle having: a body including: a first sidewall and a second sidewall opposite the first sidewall; a pressure side and a suction side each extending between the first sidewall and the second sidewall; and a leading edge section at a first junction of the pressure side and the suction side, and a trailing edge section at a second junction of the pressure side and the suction side; and a bypass fluid conduit including: a channel having an opening to at least one of the first sidewall or the second sidewall; and an outlet passageway fluidly connected with the channel between the first sidewall and the second sidewall, the outlet passageway including a first opening on at least one of the pressure side of the body, the suction side of the body or the trailing edge section.
A second aspect of the invention includes a turbomachine diaphragm including: an inner diaphragm ring; an outer diaphragm ring radially outward of the inner diaphragm ring; and a set of static nozzles spanning between the inner diaphragm ring and the outer diaphragm ring, wherein at least one static nozzle in the set of static nozzles includes: a body having: a first sidewall and a second sidewall opposite the first sidewall; a pressure side and a suction side each extending between the first sidewall and the second sidewall; and a leading edge section at a first junction of the pressure side and the suction side, and a trailing edge section at a second junction of the pressure side and the suction side; and a bypass fluid conduit including: a channel having an opening to at least one of the first sidewall or the second sidewall; and an outlet passageway fluidly connected with the channel between the first sidewall and the second sidewall, the outlet passageway including a first opening on at least one of the pressure side of the body, the suction side of the body or the trailing edge section.
A third aspect of the invention includes a turbomachine having: a rotor section; and a stator section substantially housing the rotor section, the stator section including: a packing section; and a set of static nozzles spanning between an inner diaphragm ring and an outer diaphragm ring, wherein at least one static nozzle in the set of static nozzles includes: a body having: a first sidewall and a second sidewall opposite the first sidewall; and a pressure side and a suction side each extending between the first sidewall and the second sidewall; and a bypass fluid conduit including: a channel having an opening to at least one of the first sidewall or the second sidewall proximate the packing section; and an outlet passageway fluidly connected with the channel between the first sidewall and the second sidewall, the outlet passageway including a first opening on the pressure side of the body, wherein the bypass fluid conduit is configured to divert a fluid from the packing section to the first opening on the pressure side of the body during operation of the turbomachine.
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 invention, 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.
As noted, the subject matter disclosed herein relates to power systems. More particularly, the subject matter relates to turbomachine systems.
As described herein, conventional steam turbines include packings (or, seals) at the root of the nozzle and the tip of the rotating bucket. These packings are used to reduce axial leakage across the interface between the nozzle and rotor body, and bucket and stator diaphragm, respectively. The leakage in these areas can disturb the flow of working fluid (e.g., steam), especially where that leakage flow re-enters the main steam flow downstream of the nozzle prior to reaching the bucket. This disturbance can cause performance losses.
In contrast to conventional turbomachines (e.g., steam turbines), various embodiments of the invention include at least one static nozzle having a bypass fluid conduit extending there-through, which diverts flow of fluid, e.g., leakage fluid, from the packing (seal) proximate the static nozzle and to the pressure side of the static nozzle. Once the diverted fluid reaches the pressure side of the static nozzle, it is introduced into the main (or, primary) steam flow path and can perform mechanical work in the turbomachine.
Various particular embodiments of the invention include a steam turbine nozzle. The nozzle can include: a body including: a first sidewall and a second sidewall opposite the first sidewall; a pressure side and a suction side each extending between the first sidewall and the second sidewall, the pressure side and the suction side; and a leading edge section at a first junction of the pressure side and the suction side, and a trailing edge section at a second junction of the pressure side and the suction side; and a bypass fluid conduit having: a channel having an opening to at least one of the first sidewall or the second sidewall; and an outlet passageway fluidly connected with the channel between the first sidewall and the second sidewall, the outlet passageway including a first opening on at least one of the pressure side of the body, the suction side of the body or the trailing edge section.
Various other particular embodiments of the invention include a turbomachine diaphragm (e.g., a steam turbine). The diaphragm can include: an inner diaphragm ring; an outer diaphragm ring radially outward of the inner diaphragm ring; and a set of static nozzles spanning between the inner diaphragm ring and the outer diaphragm ring, wherein at least one static nozzle in the set of static nozzles includes: a body having: a first sidewall and a second sidewall opposite the first sidewall; a pressure side and a suction side each extending between the first sidewall and the second sidewall, the pressure side and the suction side; and a leading edge section at a first junction of the pressure side and the suction side, and a trailing edge section at a second junction of the pressure side and the suction side; and a bypass fluid conduit having: a channel having an opening to at least one of the first sidewall or the second sidewall; and an outlet passageway fluidly connected with the channel between the first sidewall and the second sidewall, the outlet passageway including a first opening on at least one of the pressure side of the body, the suction side of the body or the trailing edge section.
Various additional particular embodiments of the invention include a turbomachine (e.g., a steam turbine). The turbomachine can include: a rotor section; and a stator section substantially housing the rotor section, the stator section including: a packing section; and a set of static nozzles spanning between an inner diaphragm ring and an outer diaphragm ring, wherein at least one static nozzle in the set of static nozzles includes: a body having: a first sidewall and a second sidewall opposite the first sidewall; and a pressure side and a suction side each extending between the first sidewall and the second sidewall, the pressure side and the suction side; and a bypass fluid conduit having: a channel having an opening to at least one of the first sidewall or the second sidewall proximate the packing section; and an outlet passageway fluidly connected with the channel between the first sidewall and the second sidewall, the outlet passageway including a first opening on the pressure side of the body, wherein the bypass fluid conduit is configured to divert a fluid from the packing section to the first opening on the pressure side of the body during operation of the turbomachine.
As used herein, the terms “axial” and/or “axially” refer to the relative position/direction of objects along axis A, which is substantially perpendicular to 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.
Turning to
In contrast to conventional nozzles, the body 4 further includes a bypass fluid conduit 22. The bypass fluid conduit 22 can include a channel 24 which has an opening 26 to at least one of the first sidewall 6 or the second sidewall 8. The channel 24 is visible through a partially transparent depiction of the body 4 in
Also shown, the bypass fluid conduit 22 can include an outlet passageway 28 that is fluidly connected with the channel 24, between the first sidewall 6 and the second sidewall 8. That is, the outlet passageway 28 can form a continuous flow path with the channel 24, such that a fluid can flow between the channel 24 and the outlet passageway 28. In some cases, the outlet passageway 28 extends substantially perpendicularly from the channel 24, although it is understood that the outlet passageway 28 and the channel 24 could be oriented in a variety of ways to facilitate flow there between. In some cases, the outlet passageway 28 has a lesser length than the channel 24, however, in other cases, the outlet passageway 28 can have a substantially equal or greater length than the channel 24. In any case, the outlet passageway 28 can include a first opening 30 on the pressure side 10 of the body 4. That is, the outlet passageway 28 can terminate at the pressure side 10 of the body 4 allowing a fluid (e.g., leakage fluid) to pass from the opening 26 of the channel 24, through the channel 24 and the outlet passageway 28 to the first opening 30 on the pressure side 10 of the body 4 (e.g., to join with a primary flow path across the pressure side 10 of the body 4).
In some cases, the first opening 30 has a substantially oval shape (shown most clearly in
In various embodiments of the invention, the channel 24 has a larger inner diameter (IDc) than an inner diameter (IDop1) of the first outlet passageway 28. Similarly, the inner diameter IDc of the channel 24 can be larger than an inner diameter (IDop2) of the second outlet passageway 32.
In various embodiments of the invention, the bypass fluid conduit 22 is configured to divert a fluid (e.g., a leakage fluid such as steam or condensate) from the packing section 120 to the first opening 30 on the pressure side 10 of the body 4 during operation of the turbomachine 102. In some cases, where the bypass fluid conduit 22 includes more than one outlet passageway 28, 32, and the fluid flow is sufficient, the bypass fluid conduit 22 is configured to divert the fluid to each of the first opening 32 and the second opening 34 on the pressure side 10 of the body 4. It is understood that in alternate embodiments, the bypass fluid conduit 22 can include one or more outlet passageways 28, 32, which open to the suction side 12 of the blade (e.g., blade 52) and/or the trailing edge section 18. In any case, the bypass fluid conduit 22 is configured to divert the fluid (e.g., leakage fluid such as steam or condensate) from the packing section 120 to at least one of the openings 30 on the pressure side 10, suction side 12 and/or trailing edge section 18.
As described herein, various embodiments of the invention include a turbine nozzle design which allows for introduction of leakage fluid flow into the primary flow path of the turbine. The nozzle includes a conduit which is fluidly connected with a leakage fluid source such as a packing or seal that traditionally traps and routes leakage fluid. In the designs shown and described herein, this leakage fluid is joined with the primary working fluid to increase the efficiency of the overall turbine, thereby alleviating leakage flow related performance losses associated with conventional systems that do not utilize the nozzles disclosed according to various embodiments of the invention.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It is further understood that the terms “front” and “back” are not intended to be limiting and are intended to be interchangeable where appropriate.
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.
