Abstract:
A system including an air intake subsystem having a housing is provided. A coalescer having a frame is disposed inside the housing. The system includes a mounting bracket, and a release mechanism coupled to the frame and the mounting bracket. The release mechanism is adapted to selectively release the frame.

Description:
TECHNICAL FIELD 
       [0001]    The subject matter disclosed herein generally relates to inlet air treatment systems, and more specifically to systems and methods for bypassing panel or pocket coalescers for gas turbine systems. 
       BACKGROUND 
       [0002]    Gas turbine systems typically include a compressor for compressing incoming air, a combustor for mixing fuel with the compressed air and igniting a fuel and air mixture to form a high temperature gas stream, and a turbine section driven by the high temperature gas stream. 
         [0003]    The gas turbine system may be a component in a gas turbine plant such as a power plant for the production of electricity. In some cases the gas turbine system may be used in a combined cycle power plant. In a combined cycle power plant, the gas turbine system generates power and electricity from the combustion of the mixture of fuel and air. The heat energy from this combustion is transmitted to a heat recovery steam generator, which converts the heat into steam. The steam is then communicated to a steam turbine engine where additional power and electricity are produced. The gas turbine plant may include a distributed plant control system. 
         [0004]    Some gas turbine systems include inlet air treatment systems that remove moisture and/or particulates and dissolved solids from air channeled to the compressor. Air filtration systems may include pocket or panel coalescers that remove moisture in the air stream, which protects the downstream filters and the turbine. This is essential in environments with high levels of ambient moisture, including humidity, rain, fog and mist. Coalescers also can help to remove liquid phase corrosives, reducing the likelihood of such corrosives reaching the turbine and causing damage. Coalescers remove moisture by agglomerating water droplets, making them larger and heavier, so that they can drain away rather than continue in the airstream. 
         [0005]    During normal operating conditions, it is desired to have the inlet air treatment system channel filtered air to the compressor with minimal air disruption and pressure drop through the inlet air treatment system. 
         [0006]    Over time, the pressure drop across the coalescers may increase resulting in a decrease in the amount of air flow provided to the compressor. This decrease reduces the operating efficiency of the gas turbine. In some instances, the reduced air flow may cause a compressor surge that may damage the compressor. To prevent compressor surges, in at least some known inlet air treatment systems, coalescers have to be removed manually to be cleaned. This removal process may require shutdown of the gas turbine. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0007]    The disclosure provides a solution to the problem of high pressure loss due to clogging of a coalescer in a gas turbine system. 
         [0008]    In accordance with one exemplary non-limiting embodiment, the invention relates to a system including an air intake subsystem having a housing and a coalescer that is disposed inside the housing. The system includes a mounting bracket and a release mechanism coupled to the coalescer and the mounting bracket. The release mechanism is adapted to selectively release the frame. 
         [0009]    In another embodiment, the invention relates to a gas turbine system comprising a turbine inlet; a compressor coupled to the turbine inlet; a combustor; a turbine; and an air intake subsystem having a housing. The gas turbine system includes a coalescer that is disposed inside the housing and a mounting bracket attached to the housing. A means for coupling the frame to the mounting bracket is provided. The means for coupling is adapted to selectively release the coalescer. 
         [0010]    In another embodiment, the invention relates to a gas turbine plant having a turbine inlet; a compressor coupled to the turbine inlet; a combustor; a turbine; a mechanical load; a distributed plant control system that operates at least a portion of the gas turbine plant; and an air intake subsystem having a housing. The gas turbine plant includes a coalescer that is disposed inside the housing and a mounting bracket attached to the housing. The gas turbine plant also includes a release mechanism coupled to the frame and the mounting bracket. The release mechanism is adapted to selectively release the coalescer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of certain aspects of the invention. 
           [0012]      FIG. 1  is a schematic of a gas turbine system. 
           [0013]      FIG. 2  is a schematic of an inlet system for a gas turbine. 
           [0014]      FIG. 3  is a cross-sectional view of an embodiment of a coalescer bypass system. 
           [0015]      FIG. 4  is a cross-sectional view of an embodiment of a release mechanism. 
           [0016]      FIG. 5  is a cross-sectional view of an embodiment of a magnet release mechanism. 
           [0017]      FIG. 6  is a cross-sectional view of an embodiment of an electromagnet release mechanism. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    Referring now to the drawings,  FIG. 1  illustrates a simplified, schematic depiction of one embodiment of a gas turbine system  100 . In general, the gas turbine system  100  may include a compressor  105 , one or more combustor(s)  110  and a turbine  115  drivingly coupled to the compressor  105 . During operation of the gas turbine system  100 , the compressor  105  supplies compressed air to the combustor(s)  110 . The compressed air is mixed with fuel and then burned within the combustor(s)  110 . Hot gases of combustion flow from the combustor(s)  110  to the turbine  115  in order to turn the turbine  115  and generate work, for example, by driving a generator  120 . 
         [0019]    Additionally, the gas turbine system  100  may include an inlet duct  125  configured to feed ambient air and possibly injected water to the compressor  105 . The inlet duct  125  may have ducts, filters, coalescers, screens and/or sound absorbing devices that contribute to a pressure loss of ambient air flowing through the inlet duct  125  and into one or more inlet guide vanes  130  of the compressor  105 . The gas turbine system  100  may include a heat recovery steam generator system (HRSG)  131 . The HRSG  131  is an energy recovery heat exchanger that recovers heat from a hot gas stream. It produces steam that can be used in an external process integrated with the gas turbine system  100  (cogeneration) or used to drive a steam turbine. Moreover, the gas turbine system  100  may include an exhaust duct  135  configured to direct combustion gases from the outlet of the turbine  115 . The exhaust duct  135  may include sound absorbing materials and emission control devices that apply a backpressure to the turbine  115 . The amount of inlet pressure loss and back pressure may vary over time due to the addition of components to the inlet duct  125 , and exhaust duct  135  and/or due to particulates and dissolved solids and/or dirt clogging the inlet duct  125 , and exhaust duct  135 . 
         [0020]    Moreover, the gas turbine system  100  may also include a controller  140 . In general, the controller  140  may comprise any suitable processing unit (e.g., a computer or other computing device) capable of functioning as described herein. For example, in several embodiments, the controller  140  may comprise a General Electric SPEEDTRONIC™ Gas Turbine Control System, such as is described in Rowen, W. I., “SPEEDTRONIC™ Mark V™ Gas Turbine Control System,” GE-3658D, published by GE Industrial &amp; Power Systems of Schenectady, N.Y. The controller  140  may generally include one or more processors that execute programs, such as computer readable instructions stored in the controller&#39;s memory, to control the operation of the gas turbine system  100  using sensor inputs and instructions from human operators. For example, the programs executed by the controller  140  may include scheduling algorithms for regulating fuel flow to the combustor(s)  110 . As another example, the commands generated by the controller  140  may cause actuators on the gas turbine system  100  to, for example, adjust valves between the fuel supply and the combustor(s)  110  that regulate the flow, fuel splits and type of fuel flowing to the combustor(s)  110 , adjust the angle of the inlet guide vanes  130  of the compressor  105  and/or to activate other control settings for the gas turbine system  100 . 
         [0021]    The scheduling algorithms may enable the controller  140  to maintain, for example, the NOx and CO emissions in the turbine exhaust to within certain predefined emission limits, and to maintain the combustor firing temperature to within predefined temperature limits. Thus, it should be appreciated that the scheduling algorithms may utilize various operating parameters as inputs. These parameters may be derived from measurements made by a plurality of sensors  150 . The controller  140  may then apply the algorithms to schedule the gas turbine system  100  (e.g., to set desired turbine exhaust temperatures and combustor fuel splits) so as to satisfy performance objectives while complying with operability boundaries of the gas turbine system  100 . 
         [0022]    Referring still to  FIG. 1 , a fuel control system  145  may be configured to regulate the fuel flowing from a fuel supply to the combustor(s)  110 , the split between the fuel flowing into primary and secondary fuel nozzles and/or the amount of fuel mixed with secondary air flowing into the combustion chamber of the combustor(s)  110 . The fuel control system  145  may also be adapted to select the type of fuel for the combustor(s)  110 . It should be appreciated that the fuel control system  145  may be configured as a separate unit or may comprise a component of the controller  140 . 
         [0023]      FIG. 2  shows an example of a turbine inlet air system  200 . The turbine inlet air system  200  may be used with a gas turbine system  100 . The turbine inlet air system  200  may include a weather hood  205 . The weather hood  205  may be in communication with the gas turbine system  100  via an inlet duct  210 . A filter house  215  may be positioned about the inlet duct  210 . The filter house  215  may have a number of filters  220  therein. The weather hood  205  also may include a plurality of coalescer assemblies  225 . The incoming flow of air  235  passes through the weather hood and the coalescer assemblies  225  and is conveyed by the inlet duct  210  to the compressor  105 . 
         [0024]      FIG. 3  illustrates one of the plurality of coalescer assemblies  225 . Each of the plurality of coalescer assemblies  225  may include a moisture separator  255  and a coalescer  260 . The moisture separator separates moisture from the stream of air flowing through the coalescer assemblies  225 . Additional components such as a filter (not shown) disposed adjacent to the coalescer  260  may be added to the coalescer assemblies  225 . The coalescer  260  may be a panel or pocket coalescer having a frame  265 . Other types of coalescing materials/forms (tubes, cartridges, sponges, screens, depth media, etc.) may also be used. The weather hood  205  includes a back plate  270 . Each of the plurality of coalescer assemblies  225  may include a gasket  275 . Each of the plurality of coalescer assemblies  225  also includes a release mechanism  280  coupled to a support bracket  285  that is attached to the back plate  270 . The release mechanism  280  is adapted to release the frame  265  when a pressure differential across the coalescer  260  exceeds a predetermined pressure differential. It should be noted that although the coalescer assemblies  225  have been described in association with a hood, other types of housings may be used to support the coalescer assemblies  225 . 
         [0025]    In operation, when the pressure differential across the coalescer  260  exceeds a predetermined pressure differential, release mechanism  280  releases the frame  265  from the support bracket  285 . Upon release of the frame  265  the pressure differential will cause the coalescer  260  to pivot thereby allowing the airflow  290  to bypass the coalescer  260  in a direction denoted by arrow  295 . 
         [0026]    Illustrated in  FIG. 4  is an embodiment of a release mechanism  280  which comprises a detachable spacer  300 . The detachable spacer  300  includes a body section  305  a first flange section  310  and a second flange section  315 . The detachable spacer  300  also includes the first notch  320  and a top portion  325 . The detachable spacer  300  also includes a second notch  330  and a bulbous bottom portion  335 . 
         [0027]    During assembly, the top portion  325  is inserted through a hole in the frame  265  of the coalescer  260  until the frame  265  is positioned around the first notch  320 . During insertion, top portion  325  deforms to allow the top portion  325  to be inserted through the hole in the frame  265 . The bottom portion  335  is inserted through a hole in the support bracket  285  until the support bracket  285  is positioned around the second notch  330  of the detachable spacer  300 . During insertion, the bottom portion  335  deforms to allow the bottom portion  335  to be inserted through the hole in the support bracket  285 . 
         [0028]    In operation, the detachable spacer  300  secures the frame  265  of the coalescer  260  to the support bracket  285 . When the pressure differential across the coalescer  260  exceeds a predetermined level, the bottom portion  335  deforms to allow the bottom portion  335  to be detached from the support bracket  285  thereby allowing the coalescer  260  to pivot and the airflow to bypass the coalescer  260 . 
         [0029]    Illustrated in  FIG. 5  is an embodiment of a release mechanism  280  which comprises a magnet assembly  400 . The magnet assembly  400  may include a first magnet  405  secured to the frame  265  and optionally a second magnet  410  secured to the support bracket  285 . Although the first magnet  405  and a second magnet  410  are illustrated in  FIG. 5 , it would be apparent to one of ordinary skill in the art that a single magnet (e.g. first magnet  405 ) may be employed, and the single magnet may be attached to either the frame  265  or the support bracket  285 . 
         [0030]    In operation, when the pressure differential across the coalescer  260  exceeds a predetermined level sufficient to overcome the attraction forces of the first magnet  405 , the first magnet  405  will release. The coalescer  260  will then pivot, thereby allowing the airflow to bypass the coalescer  260 . 
         [0031]    Illustrated in  FIG. 6  is an embodiment of an electromagnet release mechanism  500  including an electromagnet  501 . The electromagnet release mechanism  500  includes a ferromagnetic rod  505  with a coil  510 . The coil is coupled to a power source  515  such as a battery. A controller  520  may be provided to control a switch  525  enabling the operator to release the frame  265 . The controller  520  provides an operator with additional flexibility to control when the electromagnet release mechanism  500  releases. The controller  520  may cut the power and release the electromagnet  501  at any desired time. The controller  520  may also re-engage the electromagnet circuit thereby providing a positive force which causes the electromagnet  501  to re-engage the frame  265  and close the coalescing panel. 
         [0032]    Although three embodiments of the release mechanism  280  have been presented in detail, other release mechanisms  280  are contemplated by the present invention. For example, a fabric hook-and-loop fastener, a detachable or frangible cable or other detachable fasteners may be used. 
         [0033]    Where the definition of terms departs from the commonly used meaning of the term, applicant intends to utilize the definitions provided below, unless specifically indicated. 
         [0034]    The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Where the definition of terms departs from the commonly used meaning of the term, applicant intends to utilize the definitions provided herein, unless specifically indicated. 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 understood that, although the terms first, second, etc. may be used to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. The term “and/or” includes any, and all, combinations of one or more of the associated listed items. The phrases “coupled to” and “coupled with” contemplates direct or indirect coupling. 
         [0035]    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.