The subject matter disclosed herein relates to systems and methods for an intercooler, and more specifically to an intercooler for a compressor stage of a gas turbine system.
In a gas turbine engine for example, air is pressurized in a compressor and mixed with fuel in a combustor for generating hot combustion gases which flow downstream and expand through turbine stages. A turbine shaft coupled to the turbine stages may drive multiple compressor stages. Turbine engines are utilized generally in the power industry to create energy, which is utilized for industrial use, or in communities' residential and commercial use. Intercoolers may be utilized to cool a fluid (e.g., air) between compression stages by transferring heat from the compressed fluid via a heat exchanger. However, there are various difficulties with known intercooler packages or systems. For example, in power generation industry, the intercoolers utilized are extremely large, expensive, and difficult to transport. Additionally, systems to supply a working fluid to the heat exchanger of the intercooler to cool the fluid are also large, expensive, and difficult to transport.
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.
In a first embodiment, a system includes a gas turbine system, an intercooler heat exchanger, and a liquefaction system. The gas turbine system includes a first compressor stage configured to compress an air flow to a first pressure, a second compressor stage configured to compress the air flow to a second pressure greater than the first pressure, and a turbine disposed along an axis of the gas turbine system. The intercooler heat exchanger is disposed between the first compressor stage and the second compressor stage. The intercooler heat exchanger includes a body having a plurality of channels configured to receive a cooling fluid and a plurality of fins extending from the body. The air flow is configured to flow over the plurality of fins, and the intercooler heat exchanger is configured to transfer heat from the air flow to the cooling fluid. The liquefaction system is indirectly coupled to the intercooler heat exchanger. The liquefaction system includes a liquefaction fluid configured to receive heat from the cooling fluid.
In a second embodiment, a system includes a gas turbine system, an intercooler heat exchanger, and a liquefaction system. The gas turbine system includes a first compressor stage configured to compress an air flow to a first pressure, a second compressor stage configured to compress the air flow to a second pressure greater than the first pressure, and a turbine disposed along an axis of the gas turbine system. The intercooler heat exchanger is disposed between the first compressor stage and the second compressor stage. The intercooler heat exchanger includes a body having a plurality of channels configured to receive a liquefaction fluid and a plurality of fins extending from the body. The air flow is configured to flow over the plurality of fins, and the intercooler heat exchanger is configured to transfer heat from the air flow to the liquefaction fluid. The liquefaction system is directly coupled to the intercooler heat exchanger. The liquefaction fluid of the liquefaction system includes a pre-cooling fluid, a refrigerant, or a liquefied product of the liquefaction system, or any combination thereof.
In a third embodiment, a method includes compressing an air flow to a first pressure, transferring heat from the air flow to a liquefaction fluid via an intercooler heat exchanger, compressing the air flow to a second pressure greater than the first pressure, combusting the air flow and a fuel to generate a combustion product flow, and driving a turbine with the combustion product flow. The turbine is configured to drive machinery of a liquefaction system. The liquefaction fluid includes at least one of a pre-cooling fluid, a refrigerant, and a liquefied product of the liquefaction system.
A volumetric duct conforming fin heat exchanger for an intercooler is provided. The intercooler has a heat exchanger formed of a plurality of segments. The plurality of segments may be arranged to conform to a duct through which a flowpath passes. The intercooler includes a body having a plurality of openings for a fluid to path through. On the outer surface of the body a plurality of fins are skived into the body to engaging the flowpath. According to other embodiments, the heat exchanger may be disposed in alternate devices such as filter houses to control temperature of inlet air as well as control moisture.
According to some embodiments, a plurality of modules may be formed from the segments to ease assembly of the heat exchanger and to provide easier access to remove portions during maintenance or improve access internally of the intercooler. A bifurcation is provided in some embodiments to aerodynamically improve areas of connections between modules. Additionally, the bifurcation will accommodate thermal expansion in various dimensions between modules.
According to other embodiments, a water extraction device is provided. The water extraction device may be disposed within a flowpath, for non-limiting example a flowpath within an intercooler. The water extraction device may have one or more stages to control water content in the air flowpath by containing water droplets which momentum carries linearly through turns in the airflow path.
All of the above outlined features are to be understood as exemplary only and many more features and objectives of the embodiments may be gleaned from the disclosure herein. Therefore, no limiting interpretation of this summary is to be understood without further reading of the entire specification, claims, and drawings included herewith.
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
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 any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development 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.
When introducing elements of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
Gas turbine systems may be used to drive various systems and processes. For example, gas turbine systems may be used to drive industrial systems, such as liquefaction systems. Liquefaction systems cool one or more product gases (e.g., natural gas, methane, propane, nitrogen) for storage and/or transport. As may be appreciated, liquefaction systems may utilize one or more compression stages and one or more expansion stages. In some embodiments, liquefaction systems may utilize one or more liquefaction fluids (e.g., propane, refrigerant, liquid nitrogen, or any combination thereof) to cool or subcool the one or more product gases. The gas turbine system may drive one or more of the compression stages, and the gas turbine system may drive pumps to direct fluids (e.g., product gas, liquefied product, liquefaction fluid) through the liquefaction system.
The liquefaction fluids utilized in or processed by the liquefaction system may be at temperatures cooler than the ambient temperature. For example, liquefied natural gas (LNG) may be cooled to approximately −162° C. (−260° F.) at atmospheric pressure for storage or transport. Additionally, refrigerants or other liquefaction fluids of the liquefaction system may be at still lower temperatures in some embodiments. For example, liquid nitrogen, which boils at approximately −195° C. (−320° F.), may be utilized in some liquefaction systems. Furthermore, working fluids of a liquefaction system that absorb heat from the liquefied product may generally be cooler than the gas compressed by a low pressure compressor stage of the gas turbine system.
As discussed in detail below, one or more liquefaction fluids (e.g., product gas, liquefied product, refrigerant) may be utilized directly or indirectly with an intercooler to cool a compressed gas between compression stages of the gas turbine system. Various embodiments of the intercooler are discussed below in
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The terms fore and aft are used with respect to the engine axis and generally mean toward the front of the turbine engine or the rear of the turbine engine in the direction of the engine axis, respectively. The term radially is used generally to indicate a direction perpendicular to an engine axis.
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The liquefaction system 12 receives a gaseous material 102 and produces a liquefied product 104 from the gaseous material 102. In some embodiments, the liquefaction system 12 is an air separation unit configured to produce a liquefied product output 106 of nitrogen, oxygen, argon, neon, krypton, or xenon, or any combination thereof. In some embodiments, the liquefaction system 12 is a liquefied natural gas (LNG) system configured to produce a liquefied product output 106 of liquefied natural gas from a gaseous material 102 that is substantially (e.g., greater than 90%) gaseous natural gas. As may be appreciated, LNG systems may use one or more of various processes to produce the liquefied product output 106. Some of the processes that may be utilized may include, but are not limited, to AP-C3MR™, Cascade, AP-X®, DMR, SMR, MFC®, PRICO®, and AP-N™, or any combination thereof. In some embodiments, the liquefaction system 12 utilizes a pre-cooling fluid 108 (e.g., water, propane, ethylene glycol solution) to pre-cool the gaseous material 102 prior to compression or other cooling with a refrigerant 110 (e.g., methane, ethane, ethylene, propane, butane, isopentane, nitrogen, argon, krypton, xenon, carbon dioxide, a hydrofluorocarbon (HFC), or any combination thereof). In some embodiments, the pre-cooling fluid 108 and/or the refrigerant 110 may be a mixed refrigerant, which may boil over a range of temperatures based at least in part on the respective boiling points of the component materials of the mixed refrigerant. As utilized herein, the term liquefaction fluid 112 may refer to a pre-cooling fluid 108, a refrigerant 110 (e.g., single refrigerant, mixed refrigerant), a liquefied product 104, or any combination thereof.
The one or more liquefaction fluids 112 of the liquefaction system 12 may be directed through one or more heat exchangers of the liquefaction system 12 by the pumping system 25. In some embodiments, one or more of the liquefaction fluids 112 may be drawn from a reservoir 114 by the pumping system 25. The one or more reservoirs 114 may facilitate thermal expansion and contraction of the respective fluid (e.g., pre-cooling fluid 108, refrigerant 110, liquefied product 104) within the liquefaction system 12, facilitate addition of the respective fluid (e.g., pre-cooling fluid 108, refrigerant 110) from the liquefaction system, facilitate removal of the respective fluid (e.g., liquefied product 104), or any combination thereof. The pre-cooling fluid 108 and the refrigerant 110 may be directed through respective closed loop circuits that include the respective reservoirs 114. The gaseous material 102 that is cooled to form the liquefied product 104 may be directed through an open loop of the liquefaction system 12, and a respective reservoir 114 may store the liquefied product 104 for later transport as the product output 106.
In some embodiments, the working fluid system 14 of the power generation plant 10 is coupled to the intercooler 30 to facilitate heat transfer to an environment 116 of the power generation plant 10 from a compressed gas after one or more first compression stages of the gas turbine system 16. As discussed in detail below, the intercooler 30 is configured to transfer heat from the compressed air to a fluid routed through channels 54 of the intercooler 30. The working fluid system 14 may supply a working fluid (e.g., oil, water, ethylene glycol solution) to the channels 54 of the intercooler 30 via conduits 118. In some embodiments, a heat exchanger 120 of the working fluid system 14 may transfer heat from the working fluid to a liquefaction fluid 112, such that some of the heat from the compressed air is transferred via the working fluid to the liquefaction fluid 112 of the liquefaction system 12. That is, heat is transferred from the compressed air to the environment 116 via the liquefaction system 12. The liquefaction fluid 112 may be coupled to the working fluid system 14 via liquefaction fluid conduits 122. Accordingly, the liquefaction fluid 112 is configured to indirectly cool the compressed air of the gas turbine system 16 that flows through the intercooler 30.
As may be appreciated, the heat exchanger 120 of the working fluid system 14 may include, but is not limited to a shell and tube heat exchanger, a plate heat exchanger, a plate and shell heat exchanger, or any combination thereof. Additionally, or in the alternative, the heat exchanger 120 may be an embodiment of a duct conforming fin heat exchanger, similar to the embodiment illustrated in
In some embodiments, one or more of the liquefaction fluids 112 may be directly coupled to the intercooler 30 as shown by the dashed lines 128. Accordingly, the one or more liquefaction fluids 112 may be directed through the channels 54 of the intercooler 30 to extract heat from the compressed air in place of or in addition to the working fluid of the working fluid system 14. This integration of the liquefaction fluid 112 with the intercooler 30 may enable the working fluid system 14 to be eliminated, thereby reducing the footprint of the power generation plant 10. As may be appreciated, elimination of the working fluid system 14 may reduce the weight and cost of the power generation plant 10. Weight and footprint reductions may be particularly beneficial for sea-based applications of the power generation plant 10.
The use of the liquefaction fluid 112 directly or indirectly with the intercooler 30 may increase a thermal load on the liquefaction system 12 due to the transfer of heat from the compressed air to the liquefaction fluid 112; however, the reduced cost, complexity, and footprint resulting from the reduction or elimination of the working fluid system 14 may be determined to be more beneficial for some power generation plants 10 with liquefaction systems 12. In some embodiments, the liquefaction fluid 112 may be a byproduct of the liquefaction system 12, such that the utilization of the liquefaction fluid does not increase the thermal load on the liquefaction system 12. For example, a portion of the liquefied product 104 (e.g., liquefied natural gas) may be used both for cooling the compressed air via the intercooler, and for fuel with the gas turbine engine 16 after the fuel is warmed.
The liquefaction fluids 112 utilized directly or indirectly with the intercooler 30 via the liquefaction fluid conduits 122 may be drawn from and returned to various points of the liquefaction system 12. As may be appreciated, the temperature of the liquefaction fluid 112 may vary as the liquefaction fluid 112 is directed through a vapor-compression loop within the liquefaction system 12. Accordingly, the pre-cooling fluid 108 or refrigerant 110 may be warmer at an outlet of a heat exchanger of the liquefaction system 12 than at an inlet of the heat exchanger. Moreover, the liquefaction fluid 112 may be warmer prior to an expansion of the respective liquefaction fluid 112 than after expansion. In some embodiments, the intercooler 30 is configured to reduce the temperature of the compressed air from approximately 200° C. to approximately 35° C. The extraction point and temperature of the liquefaction fluid 112 utilized may be selected based at least in part on the effectiveness of the intercooler 30, the flow rate of the liquefaction fluid 112 through the liquefaction fluid conduits 122, material properties of the intercooler 30, among other parameters.
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The segment 50 also includes a plurality of fins 56 extending in the radial direction 53. The fins 56 are formed in a skiving process from a single piece of material which also defines the body 52. By skiving the fins 56, the process of brazing multiple fins to the body 52 is eliminated, and therefore the costs for producing the segments 50 may be reduced. The body structure 52 is generally extruded and in a subsequent process the skiving step carves the fins 56 from the single piece of metal. The fins 56 may be carved in one or more directions, for example as shown in the axial direction 53 and circumferential direction 57. Alternatively, the fins 56 may extend at some angle similar to a helical fin structure as well.
Additionally, the fins 56 are shown extending radially from the body so as to extend outwardly therefrom the body 52. However, according to other embodiments fins 56 may be carved so as to extend either radially inward or both radially inward and outward.
As described earlier, the body 52 includes a plurality of flow paths or channels 54 for a fluid to be cooled or a fluid to cool the airflow. The axially forwardmost flow channel 54 alternatively according to one embodiment may be a blank. That is to say, the forwardmost flow path may not receive any fluid flow therein so as to preclude fluid leakage from foreign objects entering the heat exchanger 40, also referred to as foreign object damage. Additionally, at this forward end of the segment 50, a leading edge 58 of the body 52 is curved to improve aerodynamics of the segment 50. Likewise, the leading edge may have an increased material thickness to decrease damage from foreign object in the air flow path encountering the heat exchanger 40. The trailing edge may alternatively be curved. Various other shapes or arrangements may be utilized for a leading edge to improve overall aerodynamics of the entire assembly of the heat exchanger 40.
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In operation, air flow 59 moves through the intercooler 30 and passes through the heat exchanger 40. After moving through the heat exchanger 40, the air flow 59 turns rapidly and engages the water extraction apparatus 46 located along the rear wall 38 of housing 36. The air flow 59 changes direction rapidly due to change in the profile and shape of the housing 36. However, momentum of the water particles carries along the previously defined path so that the water particles are carried into the water extraction apparatus 46 and collected in the channels 64. The water drains through these channels 64 to a desired extraction point and may be collected or dumped as appropriate from the intercooler 30. The collection or extraction point may be at the bottom of the water extraction apparatus 46 or the intercooler 30 so that gravity moves the collected water out of the system. The water extraction apparatus 46 may have a moisture capture material, such as a mesh fabric, plastic mesh, or sponge material configured to reduce or eliminate re-entrainment of collected water.
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Technical effects of the embodiments described above include a reduced or eliminated footprint of a working fluid system coupled to an intercooler. A liquefaction fluid of a liquefaction system, such as an LNG system, may be utilized directly or indirectly with the intercooler to cool the compressed gas of the gas turbine system. The relatively low temperature of the liquefaction fluid utilized may enable the utilization of a smaller heat exchanger of the working fluid system. Direct use of the liquefaction fluid with the intercooler may eliminate the complexity, cost, and footprint associated with the working fluid system.
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 language of the claims.
This application claims priority from and the benefit of U.S. Provisional Application Ser. No. 62/274,142, entitled “SYSTEM AND METHOD FOR COMPRESSOR INTERCOOLER,” filed Dec. 31, 2015, which is hereby incorporated by reference in its entirety for all purposes.
Number | Date | Country | |
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62274142 | Dec 2015 | US |