BACKGROUND OF THE INVENTION
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The present application relates generally to a cooling system on a turbomachine; and more particularly to, a system for regulating a cooling fluid within a wheelspace area of a turbomachine.
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In some turbomachines, such as gas turbines, a portion of the air compressed by the compressor is typically diverted from combustion to cool various stationary and rotating components or to purge cavities within a gas turbine. The diverted airflow (hereinafter "cooling fluid",) consumes a considerable amount of the total airflow compressed by the compressor. The diverted cooling fluid is not combusted, reducing the performance of the gas turbine. Regulating and controlling the cooling fluid can dramatically increase the performance of the turbine.
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Typically, the cooling fluid is extracted from the compressor, bypasses the combustion system, and flows through a cooling circuit. The cooling circuit is typically located near various turbine components including the rotor compressor-turbine joint (hereinafter "marriage joint"), and various wheelspace areas. The cooling circuit is typically integrated with a seal system. Relatively tight clearances may exist between the seal system components and the gas turbine rotor.
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The seal system may include labyrinth seals located between rotating and stationary components. The typical leakages that may occur through the labyrinth seal clearances are commonly used for cooling or purging areas downstream of the seals. For example, a high-pressure packing seal system (HPPS) may include a labyrinth and brush seal arrangement, wherein the leakage flow past the HPPS cools the downstream components including the wheelspace areas. The effectiveness of the cooling circuit is highly dependent on the performance of the HPPS.
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The configuration of the cooling circuit determines whether or not adequate cooling fluid flows to the aforementioned turbine components. The cooling circuit may include a chamber that directs the cooling fluid flow to a specific wheelspace area.
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There may be a few issues with the currently known seal systems. Wear may enlarge the seal system clearances. Seals may wear during a "trip"(an emergency shutdown of the turbomachine). Also, seals gradually wear over time from gas turbine operation. Wear allows excessive cooling fluid to flow downstream of the seals; reducing the overall efficiency of the gas turbine. The unpredictable nature of the seal system wear occurrence does not allow for a deterministic flow of the cooling fluid through the cooling circuit. Furthermore, known seal systems do not compensate for seal system wear. Therefore, the known seal systems do not provide a way to adjust the amount of cooling fluid flowing to the wheelspace areas.
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For the foregoing reasons, there is a desire for a system that allows regulating the cooling fluid passing into the wheelspace areas of the gas turbine. The system should adequately cool while improving the gas turbine efficiency. The system should also provide for a deterministic flow through the cooling circuit.
BRIEF DESCRIPTION OF THE INVENTION
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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.
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The present invention resides in a system for regulating a cooling fluid, the system comprising: a gas turbine comprising: a combustion system that generates a working fluid; a compressor section comprising an inner barrel casing; a compressor discharge casing; and bypass chambers; wherein the cooling fluid flows through the inner barrel casing to the compressor discharge casing; a turbine section comprising rotating blades; diaphragms; nozzles; and wheelspace areas, wherein each wheelspace area comprises a series of rotating blades, a diaphragm, and a nozzle, and each bypass chamber allows the cooling fluid to flow from the compressor discharge casing to the wheelspace areas; and a nozzle cooling circuit substantially located within each stationary component, wherein the nozzle cooling circuit comprises a primary passage and a header; wherein a first end of the primary passage receives the cooling fluid and a second end of the primary passage is connected to header and the cooling fluid flows from the primary passage to the header; wherein the header comprises an upstream port and a downstream port that allows the cooling fluid to discharge from the header and mixing with the working fluid.
BRIEF DESCRIPTION OF THE DRAWING
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Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:
- FIG 1 is a schematic view, in cross-section, of a gas turbine, illustrating the environment in which an embodiment of the present invention operates.
- FIG 2 is an enlarged view of a portion of the gas turbine illustrated in FIG 1.
- FIG 3 illustrates a schematic view of a stationary component of FIG 2 having a known nozzle cooling circuit.
- FIG 4 illustrates a schematic view of a stationary component of FIG 2 having a nozzle cooling circuit, in accordance with an embodiment of the present invention.
- FIG 5 illustrates an exploded schematic view of the stationary. component of FIG 4, in accordance with an embodiment of the present invention.
- FIG 6 illustrates a schematic view of the stationary component of FIG 4 in use, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
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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 an engineering or design project, numerous implementation-specific decisions are made to achieve the specific goals, such as compliance with system-related and/or business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such 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.
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Detailed example embodiments are disclosed herein. However, specific structural and functional details disclosed herein are merely representative for purposes of describing example embodiments. Embodiments of the present invention may, however, be embodied in many alternate forms, and should not be construed as limited to only the embodiments set forth herein.
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Accordingly, while example embodiments are capable of various modifications and alternative forms, embodiments thereof are illustrated by way of example in the figures and will herein be described in detail. It should be understood, however, that there is no intent to limit example embodiments to the particular forms disclosed, but to the contrary, example embodiments are to cover all modifications, equivalents, and alternatives falling within the scope of the present invention.
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The terminology used herein is for describing particular embodiments only and is not intended to be limiting of example embodiments. 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. The terms "comprises", "comprising", "includes" and/or "including", when used herein, 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.
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Although the terms first, second, etc may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term "and/or" includes any, and all, combinations of one or more of the associated listed items.
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Certain terminology may be used herein for the convenience of the reader only and is not to be taken as a limitation on the scope of the invention. For example, words such as "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "horizontal", "vertical", "upstream", "downstream", "fore", "aft", and the like; merely describe the configuration shown in the FIGS. Indeed, the element or elements of an embodiment of the present invention may be oriented in any direction and the terminology, therefore, should be understood as encompassing such variations unless specified otherwise.
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The present invention may be applied to a variety of air-ingesting turbomachines. This may include, but is not limiting to, heavy-duty gas turbines, aero-derivatives, or the like. Although the following discussion relates to the gas turbine illustrated in FIG 1, embodiments of the present invention may be applied to a gas turbine with a different configuration. For example, but not limiting of, the present invention may apply to a gas turbine with different, or additional, components than those illustrated in FIG. 1.
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Referring now to the FIGS, where the various numbers represent like components throughout the several views, FIG 1 is a schematic view, in cross-section, of a portion of a gas turbine, illustrating the environment in which an embodiment of the present invention operates. In FIG 1, a gas turbine 100 includes: a compressor section 105; a combustion section 150; and a turbine section 180.
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Generally, the compressor section 105 includes a plurality of rotating blades 110 and stationary vanes 115 structured to compress a fluid. The compressor section 105 may also include an extraction port 120, an inner barrel 125, a compressor discharge casing 130, a marriage joint 135, and a marriage joint bolt 137.
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The combustion section 150 generally includes a plurality of combustion cans 155, a plurality of fuel nozzles 160, and a plurality of transition sections 165. The plurality of combustion cans 155 may be coupled to a fuel source. Within each combustion can 155, compressed air is received from the compressor section 105 and mixed with fuel received from the fuel source. The air and fuel mixture is ignited and creates a working fluid. The working fluid generally proceeds from the aft end of the plurality of fuel nozzles 160 downstream through the transition section 165 into the turbine section 180.
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The turbine section 180 may include a plurality of rotating components 185; a plurality of stationary components 190, which include nozzles and diaphragms; and a plurality of wheelspace areas 195. The turbine section 180 converts the working fluid to a mechanical torque.
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Typically, during the operation of the gas turbine 100, a plurality of components experience high temperatures and may require cooling or purging. These components may include a portion of the compressor section 105, the marriage joint 135, and the plurality of wheelspace areas 195.
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The extraction port 120 draws cooling fluid from the compressor section 105. The cooling fluid bypasses the combustion section 150, and flows through a cooling circuit 200 (illustrated in FIG 2), for cooling or purging various components, including the marriage joint 135, and a plurality of wheelspace areas 195.
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Referring now to FIG 2, which is a close-up view of the gas turbine illustrated in FIG 1. FIG 2 illustrates a non-limiting example of an embodiment of the cooling circuit 200. The flow path of the cooling circuit 200 may start at the extraction port 120 (illustrated in FIG 1), flow through a portion of the compressor discharge casing 130, the inner barrel casing 125, and then a cavity at the aft end of the compressor section 105. Next, the cooling circuit 200 may reverse direction, flowing past the marriage joint 135, the seal system components 140, and to the wheelspace area 195.
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FIG 3 illustrates a schematic view of the stationary component 190 of FIG 2 having a known nozzle cooling circuit. The stationary component 190 comprises a nozzle cooling circuit 300 that is located internally. The nozzle cooling circuit 300 allows the cooling fluid to cool the stationary component 190 from within. The nozzle cooling circuit 300 receives the cooling fluid, illustrated in the FIGS by the arrows. The currently known circuit 300 includes a path that may direct the cooling fluid to discharge on an upstream side of the stationary component 190. After exiting the stationary component 190, the cooling fluid may flow downstream through the seal system components 140 and then engage a downstream side of the stationary component 190.
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FIG 4 illustrates a schematic view of a stationary component of FIG 2 having a nozzle cooling circuit, in accordance with an embodiment of the present invention. The stationary component 190 comprises a nozzle cooling circuit 400 that is located internally. The nozzle cooling circuit 400 allows the cooling fluid to cool the stationary component 190 in a more controlled and efficient way. The nozzle cooling circuit 400 receives the cooling fluid which is illustrated in the FIGS by the arrows. By comparing FIG 3 and FIG 4, the benefits of embodiments of the present invention are shown. Here, the cooling fluid flows from a primary passage 405 to a header 410; which allows the cooling fluid to discharge from the stationary component 190 in both upstream and downstream directions. This allows for a more efficient cooling of the downstream end of the stationary component 190.
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FIG 5 illustrates an exploded schematic view of the stationary component of FIG 4, in accordance with an embodiment of the present invention. An embodiment of the nozzle cooling circuit 400 may comprise a primary passage 405, a header 410, a port 415, and a tuning plug 420.
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An embodiment of the primary passage 405 may comprise a first end and a second end. The first end may be positioned to receive the cooling fluid. The second end located at an opposite end of the primary passage 405. The second end may be connected to the header 410 in a manner that allows the cooling fluid to enter. In an embodiment of the present invention the nozzle cooling circuit 400 may comprise one primary passage 405. In an alternate embodiment of the present invention, the nozzle cooling circuit 400 may comprise multiple primary passages 405. Here, each primary passage 405 may comprise a dedicated header 410.
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An embodiment of the header 410 may have the form of a through- hole, or the like. Each end of the header 410 may be enclosed via a cap 425, as illustrated, for example, in FIG 5. The cap 425 may be connected to the header 410, via welding, threaded connections, or other connection means.
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Located upstream of the end of the header 410 are an upstream port 415 and a downstream port 415, as illustrated in FIG 6. The ports 415 may be considered an angled passage. The ports 415 are angularly positioned relative to the header 410. This angle 430 may induce a pre-swirl on the cooling fluid exiting each port 415 and entering the wheelspace area 195. In an embodiment of the present invention, the angle 430 may comprise a range of from about 0 degrees to about 100 degrees, depending on the physical constraints associated with the associated components. The pre-swirl allows the cooling fluid to flow in nearly the same direction and orientation as the rotating components 185 and the working fluid. This may improve the mixing of the cooling fluid with the working fluid, increasing the cooling efficiency.
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The upstream ports 415 allows the cooling fluid to discharge the near an upstream end of the stationary component 190. The downstream port 415 allows the cooling fluid to discharge near a downstream end of the stationary component 190. The tuning plug 420 allows a user to control the flow of the cooling fluid exiting a designated port 415. The tuning plug 420 comprises a through hole, or the like, which allows the cooling fluid to flow from the header 410 and discharge via a port 415. The tuning plug 420 may assist the port 415 with directing the cooling fluid toward an outer surface of the stationary component 190. The tuning plug 420 may adjust the mechanical properties of the cooling fluid exiting the nozzle cooling circuit 400. These properties may include, but are not limited to: velocity, flowrate, and pressure.
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An embodiment of the tuning plug 420 may comprise a threaded connection that allows mating with the portion of the port 415. An alternate embodiment of the tuning plug 420 may be press fit into the port 415. Another alternate embodiment of the tuning plug 420 may comprise a variable internal diameter through which the cooling fluid discharges from the header 410, providing more control over the aforementioned properties.
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FIG 6 illustrates a schematic view of the stationary component 190 of FIG 4 in use, in accordance with an embodiment of the present invention. In use, an embodiment of the present invention may function as follows. The nozzle cooling circuit 400 receives the cooling fluid, represented in FIG 4 by the arrows. Next, the cooling fluid may flow through the primary passage 405. Next the cooling fluid may enter the header 410. Here, the flow of the cooling fluid may diverge. A portion may flow towards the upstream port 415, discharging via the connected tuning plug 420. The remaining portion may flow towards the downstream port 415, discharging via the connected tuning plug 420.
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Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art appreciate that any arrangement, which is calculated to achieve the same purpose, may be substituted for the specific embodiments shown and that the invention has other applications in other environments. This application is intended to cover any adaptations or variations of the present invention. The following claims are in no way intended to limit the scope of the invention to the specific embodiments described herein.
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As one of ordinary skill in the art will appreciate, the many varying features and configurations described above in relation to the several embodiments may be further selectively applied to form other possible embodiments of the present invention. Those in the art will further understand that all possible iterations of the present invention are not provided or discussed in detail, even though all combinations and possible embodiments embraced by the several claims below or otherwise are intended to be part of the instant application. In addition, from the above description of several embodiments of the invention, those skilled in the art will perceive improvements, changes, and modifications. Such improvements, changes, and modifications within the skill of the art are also intended to be covered by the appended claims. Further, it should be apparent that the foregoing relates only to the described embodiments of the present application and that numerous changes and modifications may be made herein without departing from the spirit and scope of the application as defmed by the following claims and the equivalents thereof.
