Gas turbine inlet heating system

BACKGROUND OF THE INVENTION

p-0002The subject matter disclosed herein relates to a gas turbine inlet heating system. Specifically, the subject matter disclosed herein relates to a system for extracting air from a compressor discharge section to heat a portion of a gas turbine inlet.

p-0003Conventional gas turbine power systems employ a myriad of pipes and conduits to heat high pressure inlet bleed air. More particularly, conventional gas turbine systems divert heated compressed air from a compressor extraction discharge manifold, via a line, to an inlet duct of the compressor. The flow of the diverted heated compressed air from the compressor is controlled by an isolation valve and a control valve. After passing the control valve, the diverted air then flows through an array of heater tubes and eventually to the inlet guide vanes (IGVs) of the compressor for recycling through the compressor and potential use in an adjoining gas turbine. The distance that the diverted compressed air is required to travel before reaching the IGVs of the compressor can result in performance losses, and the hardware (e.g., piping, conduits, etc.) required to transport this diverted air can be costly.

p-0004Other conventional gas turbine systems (e.g., an aircraft engine) can include less piping than in the conventional power system (described above), however these systems provide little control over the flow of diverted air. That is, these systems traditionally have merely a simple “on/off” switch, that either provides diverted compressor air, or does not, according to the position of the switch. In this case, the engine controller simply flips a switch allowing for a large portion of heated compressor air to be diverted away from the turbine and to the compressor inlet. This can cause a significant decrease in the output of the turbine, and cause system inefficiencies. Additionally, the amount of air delivered to the compressor inlet is fixed and subject to the size of the on/off valve.

BRIEF DESCRIPTION OF THE INVENTION

p-0005A gas turbine inlet heating system is disclosed. In one embodiment, the system includes: a compressor having: an inlet bellmouth adjacent to a set of inlet guide vanes (IGVs); and an outlet fluidly connected to the inlet bellmouth; and a conduit coupled to an outlet of the compressor, the conduit including a control valve, the conduit for diverting a first portion of compressed air from the outlet of the compressor to the inlet bellmouth.

p-0006A first aspect of the invention includes a system having: a compressor including: an inlet bellmouth adjacent to a set of inlet guide vanes (IGVs); and an outlet fluidly connected to the inlet bellmouth; and a conduit coupled to an outlet of the compressor, the conduit including a control valve, the conduit for diverting a first portion of compressed air from the outlet of the compressor to the inlet bellmouth.

p-0007A second aspect of the invention includes a gas turbine system having: a turbine; a compressor coupled to the turbine at an outlet of the compressor, the compressor including: an inlet bellmouth adjacent to a set of inlet guide vanes (IGVs); and an outlet fluidly connected to the inlet bellmouth; and a conduit coupled to the outlet of the compressor, the conduit including a control valve, the conduit for diverting a first portion of compressed air from the outlet of the compressor to the inlet bellmouth.

p-0008A third aspect of the invention includes a gas turbine system having: a turbine; a compressor coupled to the turbine at an outlet of the compressor, the compressor including: an inlet bellmouth adjacent to a set of inlet guide vanes (IGVs); and an outlet fluidly connected to the inlet bellmouth; a conduit coupled to the outlet of the compressor and the inlet bellmouth, the conduit including a control valve; and a control system configured to instruct the control valve to provide a first portion of compressed air from the outlet of the compressor to the inlet bellmouth.

BRIEF DESCRIPTION OF THE DRAWINGS

p-0009These 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:

p-0010<figref idrefs="DRAWINGS">FIG. 1</figref> shows a schematic view of a system according to embodiments of the invention.

p-0011It 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.

DETAILED DESCRIPTION OF THE INVENTION

p-0012As indicated above, aspects of the invention provide for a gas turbine inlet heating system. Specifically, the subject matter disclosed herein relates to system for extracting air from a compressor discharge section to heat a portion of a gas turbine inlet.

p-0013As noted herein, two conventional systems have been employed for diverting heated compressed air from a compressor for the purposes of heating that compressor's inlet air. The first conventional system is the gas turbine power system. This system employs a myriad of pipes and conduits to heat high pressure inlet bleed air. More particularly, conventional gas turbine systems divert heated compressed air from a compressor extraction discharge manifold, via a line, to an inlet duct of the compressor. The flow of the diverted heated compressed air from the compressor is controlled by an isolation valve and a control valve. After passing the control valve, the diverted air then flows through heater tubes and eventually to the inlet guide vanes (IGVs) of the compressor for recycling through the compressor and potential use in an adjoining gas turbine. The distance that the diverted compressed air is required to travel before reaching the IGVs of the compressor can result in performance losses, and the hardware (e.g., piping, conduits, etc.) required to transport this diverted air can be costly.

p-0014The second conventional system is the engine (e.g., an aircraft engine). The aircraft engine includes less piping than in the conventional power system (described above), and utilizes the diverted heated compressor air for the purposes of anti-icing (e.g., on a cold day). While this conventional system does feed diverted compressor air back to the compressor inlet with less hardware (e.g., piping), it provides little control over the flow of diverted air. That is, the aircraft engine is designed with a simple “on/off” switch, that either provides diverted heated compressor air, or does not, according to the position of the switch. In this case, the engine controller (e.g., an aircraft pilot) simply flips a switch allowing for a large portion of heated compressor air to be diverted away from the turbine and to the compressor inlet. This can cause a significant decrease in the output of the turbine, and cause system inefficiencies. Additionally, the amount of air delivered to the compressor inlet is fixed and subject to the size of the on/off vale size.

p-0015In contrast to the conventional systems described herein, aspects of the invention provide for a gas turbine inlet heating system having: a compressor including: an inlet bellmouth adjacent to a set of inlet guide vanes (IGVs) and an outlet fluidly connected to the inlet bellmouth; and a conduit including a control valve, the conduit for diverting a portion of compressed air from the outlet of the compressor to the inlet bellmouth.

p-0016Turning to <figref idrefs="DRAWINGS">FIG. 1</figref>, a schematic view of a system (e.g., a gas turbine inlet heating system) <b>2</b> is disclosed including a compressor <b>4</b> having an inlet bellmouth <b>6</b> adjacent to a set of inlet guide vanes (IGVs) <b>8</b> (shown in phantom as an internal component within compressor <b>4</b>). The compressor <b>4</b> may further include an outlet <b>10</b> (e.g., an outlet manifold) fluidly connected to the inlet bellmouth <b>6</b> via a conduit <b>14</b>, as described further herein. As shown, the conduit <b>14</b> can be coupled to the outlet <b>10</b> of the compressor <b>4</b>. The conduit <b>14</b> can include a control valve <b>16</b>, which is described further herein with respect to a control system <b>18</b> and control processes according to embodiments of the invention. In embodiments of the invention, the conduit <b>14</b> is for diverting a first portion of compressed air from the outlet <b>10</b> of the compressor <b>4</b> to the inlet bellmouth <b>6</b>. That is, in contrast to conventional systems, the system <b>2</b> is capable of diverting exhaust compressed air from the outlet <b>10</b> of the compressor <b>4</b> directly to the IGVs <b>8</b>, via the inlet bellmouth <b>6</b> (or, manifold). These conventional systems do not have the inlet bellmouth <b>6</b> as shown and described with reference to <figref idrefs="DRAWINGS">FIG. 1</figref>.

p-0017The system <b>2</b> can further include a control system <b>18</b> operably connected to the control valve <b>16</b>. The control system <b>18</b> and control valve <b>16</b> can take any conventional forms capable of controlling the flow of fluid (e.g., air) through the conduit <b>14</b> (which may be a conventional conduit for carrying fluid). For example, where control valve <b>16</b> is a mechanically controlled valve, the control system <b>18</b> may include mechanical components for opening and closing the control valve <b>16</b>. Where the control valve <b>16</b> is configured to be controlled electronically (e.g., via electrical switches), the control system <b>18</b> can be an at least partially electrical system. In some cases, the control system <b>18</b> and/or control valve <b>16</b> can be electro-mechanical devices. In some embodiments, the control system <b>18</b> and/or control valve <b>16</b> can be at least partially software controlled. In any case, the control system <b>18</b> can be configured to provide instructions to the control valve <b>16</b> for providing a portion of the compressed air from the outlet <b>10</b> to the inlet bellmouth <b>6</b>.

p-0018The control system <b>18</b> can be further configured to monitor parameters of the turbine <b>20</b> and/or compressor <b>4</b> to determine an amount of air to be diverted via the conduit <b>14</b> (and/or bypass conduit <b>22</b>). That is, the control system <b>18</b> may monitor temperature, flow rates, volumes, output, shaft speeds, etc. of one or more of the turbine <b>20</b> and/or compressor <b>4</b> to determine an amount of air to be diverted through conduit <b>14</b> and provided to inlet bellmouth <b>6</b>. Further, the control system <b>18</b> may include or be operably connected with, a temperature sensor for determining an ambient temperature proximate to the compressor <b>4</b> and/or the turbine <b>20</b>. This may allow the control system <b>18</b> to determine, e.g., whether anti-icing conditions are in effect.

p-0019The inlet bellmouth <b>6</b> may be designed to receive compressed air exhaust from the outlet <b>10</b> directly from the conduit <b>14</b>. In some embodiments, the inlet bellmouth <b>6</b> may have an inner diameter of approximately 38 inches to approximately 66 inches. In other embodiments, the inlet bellmouth <b>6</b> may have an inner diameter of approximately 70 inches to approximately 95 inches.

p-0020As shown, the compressor <b>4</b> can be coupled to a gas turbine <b>20</b>, which may be a conventional gas turbine used for converting the motion of a gas across turbine blades within the turbine <b>20</b> into rotational motion in the turbine's shaft. In some embodiments, the gas turbine <b>20</b> is configured to receive a second portion of compressed air from the outlet <b>10</b> of the compressor <b>4</b> via a second, or bypass conduit <b>22</b>. As shown, the bypass conduit <b>22</b> can be connected with the first conduit <b>14</b> upstream of the control valve <b>16</b>. That is, the bypass conduit <b>22</b> is connected to the first conduit <b>14</b> at a location closer to the outlet <b>10</b> of the compressor <b>4</b> than the location of the control valve <b>16</b> within the first conduit <b>14</b>. The bypass conduit <b>22</b> is configured to receive a distinct portion of exhaust from the compressor <b>4</b> than the portion provided to the compressor's inlet bellmouth <b>6</b>. In some cases, the bypass conduit <b>22</b> is configured to supply bypass compressed air from the outlet <b>10</b> of the compressor <b>4</b> to a stage of the gas turbine <b>20</b>, between the turbine's inlet <b>23</b> and its outlet <b>24</b>. That is, the bypass conduit <b>22</b> is configured to supply bypass compressed air to a portion of the gas turbine downstream of the turbine inlet <b>23</b>, in a lower-pressure section of the gas turbine <b>20</b>. The flow of compressed air through the bypass conduit <b>22</b> can be controlled by a shut-off valve <b>26</b> (e.g., via the control system <b>18</b>, or optionally, independently). As will be understood by those having skill in the art, the amount of compressed air extracted from the outlet <b>10</b> of the compressor <b>4</b> and provided to the inlet bellmouth <b>6</b> may be a function of the position of the control valve <b>16</b>, compressor IGV's (<b>8</b>) angle position, and the compressor measured pressure ratio. The shut-off valve <b>24</b>, together with control valve (<b>16</b>) can be controlled by the control system <b>18</b>.

p-0021In contrast to conventional systems, aspects of the invention provide a control system <b>18</b> for actively controlling the control valve <b>16</b> (and/or the shut-off valve <b>26</b>) to provide a predetermined portion of compressed air from the compressor outlet <b>10</b> to the IGVs <b>8</b>, thereby allowing for heating of the compressor inlet bellmouth <b>6</b>. This may allow for, among other things, anti-icing of the area around the compressor inlet bellmouth <b>6</b>. As the configuration disclosed in the system herein delivers compressed air directly to the IGVs, the compressor inlet bellmouth <b>6</b> is designed to receive higher-pressure, higher temperature compressed air than in conventional systems. In some cases, this can require the compressor inlet bellmouth <b>6</b> to include a built-up, or reinforced portion configured to receive higher-pressure, higher-temperature compressed air. By definition, the inlet bellmouth <b>6</b> can include a flared-out or bell-shaped section having a greater inlet diameter than a portion of the compressor <b>4</b> surrounding the IGVs <b>8</b>. That is, the inlet bellmouth <b>6</b> may have an inner diameter of such dimension that it can receive the higher-pressure compressed air from the conduit <b>14</b>. In some cases, the inlet bellmouth <b>6</b> may take a conventional manifold shape, which includes sections or steps that progressively narrow upon axial approach to the IGVs <b>8</b> from the inlet. In contrast to conventional compressor inlets, the inlet bellmouth <b>6</b> can include several steps or sections along its inner surface for receiving air from the conduit <b>14</b>.

p-0022The system <b>2</b> shown and described herein can provide for performance gains in at least the following scenarios: a) Turndown operation, where the output of the turbine is being intentionally reduced; b) Anti-icing, where the ambient temperature conditions are cold enough to warrant heating of the compressor inlet (or, compressor skin); and c) Surge control, where unwanted variations in turbine output are being regulated. As compared to conventional power generation systems, the system <b>2</b> shown and described herein can provide for a reduction in hardware components (e.g., additional piping, valves, etc.) while maintaining performance goals of the system. Further, as compared to conventional engine systems (e.g., aircraft engines) aspects of the invention allow for control of an amount of extracted compressed air (via control system <b>18</b>) from the compressor outlet <b>10</b>, which may allow for improved performance as compared to those conventional engine systems.

p-0023The 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.

p-0024This 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.