Fuel flush system and method

Abstract

A system includes an enclosure, a gas turbine engine disposed in the enclosure, and a fuel flush system coupled to a side wall of the enclosure above the gas turbine engine. The fuel flush system includes a fluid supply circuit configured to inject a fluid into a fuel circuit of the gas turbine engine. A method of flushing a fuel circuit of a gas turbine engine is also provided.

Description

FUEL FLUSH SYSTEM AND METHODTECHNICAL FIELD

[0001] The present application relates generally to a system and method for flushing fuel (e g., liquid fuel) from a fuel system of a combustion system, such as may be included in a gas turbine system used for electrical power generation.BACKGROUND

[0002] A fuel system may include fuel lines, valves, manifolds, injectors or nozzles, and combustors to support combustion in the combustion system. In a gas turbine system, the fuel system may include multiple fuel lines, valves, manifolds, and injectors or nozzles associated with each combustor. Additionally, the fuel system may be at least partially or substantially exposed to elevated temperatures associated with the combustion process, which can cause coking of liquid fuel in the fuel system. The risk of coking increases when the liquid fuel is not flowing and / or flows at a low flow rate through the fuel system, because the liquid fuel is exposed to the elevated temperatures for a greater duration of time. For example, at certain times, the liquid fuel may not be used in some or all of the fuel injectors or nozzles, and thus the risk of coking is greater during these times. By further example, the gas turbine system may switch between operation using the liquid fuel to operation using a gaseous fuel, and thus the liquid fuel may experience coking in the fuel system during the operation using the gaseous fuel. Thus, a need exists for improved systems and methods for flushing liquid fuel from fuel systems.BRIEF DESCRIPTION

[0003] Certain embodiments commensurate in scope with the originally claimed subject matter are summarized below. These embodiments are not intended to limit the scope of the claimed embodiments, but rather these embodiments are intended only to provide a brief summan of possible forms of the subject matter. Indeed, the presently claimed embodiments may encompass a variety' of forms that may be similar to or different from the embodiments set forth below.

[0004] In an embodiment, a system includes an enclosure, a gas turbine engine disposed in the enclosure, and a fuel flush system coupled to a side wall of the enclosure above the gasturbine engine. The fuel flush system includes a fluid supply circuit configured to inject a fluid into a fuel circuit of the gas turbine engine.

[0005] In another embodiment, a system includes a fuel flush system configured to couple to a side wall of an enclosure above a gas turbine engine disposed in the enclosure. The fuel flush system includes a fluid supply circuit configured to inject a fluid into a fuel circuit of the gas turbine engine.

[0006] In another embodiment, a method includes supplying a fluid to a fuel flush system coupled to a side wall of an enclosure above a gas turbine engine disposed in the enclosure. The method also includes injecting the fluid through a fluid supply circuit of the fuel flush system into a fuel circuit of the gas turbine engine. The fuel circuit includes a liquid fuel circuit, the fluid includes water, and the fuel flush system does not obstruct a top access panel of the enclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] These and other features, aspects, and advantages of the presently disclosed techniques 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:

[0008] FIG. 1 is a block diagram of an embodiment of a gas turbine system having a fuel flush system;

[0009] FIG. 2 is a schematic perspective view of an embodiment of the gas turbine system and the fuel flush system of FIG. 1 ;

[0010] FIG. 3 is a schematic perspective view of an embodiment of the fuel flush system of FIG. 1;

[0011] FIG. 4 is a schematic side view of an embodiment of the fuel flush system of FIG. 1; and

[0012] FIG. 5 is a flowchart of an embodiment of a process of operating the fuel flush system of FIG. 1.DETAILED DESCRIPTION

[0013] One or more specific embodiments of the presently disclosed systems and methods are 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.

[0014] When introducing elements of various embodiments of the presently disclosed embodiments, 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.

[0015] The embodiments disclosed herein are directed towards a fuel flush system for flushing fuel (e.g.. liquid fuel, contaminants, coking, blockages, and the like) from the fuel system of a gas turbine system housed in an enclosure. The fuel flush system includes an injection manifold supported by a skid. The skid is coupled to a top portion of a side wall of the enclosure such that neither the skid nor the injection manifold obstructs access to a top wall of the enclosure. The fuel flush system also includes a plurality’ of injection conduits fluidly coupled to the main conduit via the injection manifold. The fuel flush system also includes a pump configured to pump a fluid through the main conduit, through the plurality of injection conduits, and into the fuel system of the gas turbine system in order to clear (e.g., flush) fuel from the fuel system. In certain embodiments, the fuel flush system may be used to flush and drain the fuel system to mitigate liquid fuel collection in the fuel system prior to and / or after transitioning from liquid fuel operation to gas fuel operation (e.g., natural gas) of the gas turbine system.

[0016] FIG. 1 is a schematic diagram of an embodiment of a gas turbine system 10 having a fuel flush system 12. As discussed in detail below, the fuel flush system 12 receives a fluid 14 from a fluid supply 15 via a pump 16 and directs the fluid 14 through an injection manifold 18 (e.g., injection manifold, flush valve, multi-port flush valve) and to an enclosure19 of the gas turbine system 10. The fluid 14 may include a liquid, such as water, coking prevention and / or cleaning additives, corrosion inhibitor additives, or any combination thereof. The fluid supply 15 may include a fluid tank, a fluid reservoir, a water reservoir (e.g., lake or river), or any combination thereof. Upon reaching the enclosure 19, the fluid 14 may be transported to the gas turbine engine 20 having a fuel circuit 36 within the enclosure 19. As discussed in detail below, the fluid 14 supplied by the fuel flush system 12 is configured to flush residual fuel in all or part of the fuel circuit 36 during operation of the gas turbine system 10, thereby reducing the possibility of fuel coking within the fuel circuit 36 due to heat caused by combustion during operation of the gas turbine system 10. Additionally, the fuel flush system 12 couples to a sidewall of the enclosure 19 rather than a top wall of the enclosure 19. thereby enabling top access to the gas turbine engine 20 through the top wall of the enclosure 19. Accordingly, the addition of the present fuel flush system 12 does not impede or inhibit the regular maintenance of the gas turbine engine 20 as may occur through removal of the top wall of the enclosure 19 in full or in part.

[0017] The gas turbine engine 20 includes a compressor 22, combustor(s) 24, and a turbine 26 (e.g., an expansion turbine). The compressor 22 compresses air from an air intake 21 and supplies compressed air to the combustor(s) 24. The gas turbine engine 20 mayemploy one or more fuel nozzles 28 to route a fuel (e.g., a gas fuel 29 and / or a liquid fuel 30) into the combustor(s) 24 along with the compressed air. For example, the gas turbine engine20 may be configured to selectively operate in a liquid fuel mode using liquid fuel 30 or a gas fuel mode using gas fuel 29 (e.g., natural gas) for combustion in the combustor(s) 24. The liquid fuel 30 is supplied by a liquid fuel supply 32 to a liquid fuel circuit 34, which is coupled to one or more fuel nozzles 28 of each combustor 24. Similarly, the gas fuel 29 is supplied by a gas fuel supply 31 to a gas fuel circuit 33, which is coupled to one or more fuel nozzles 28 of each combustor 24. The gas and liquid fuel supplies 31 and 32 may include fuel tanks, pumps, filters, valves, pressure regulators, or any combination, disposed on respective fuel skids. The gas and liquid fuel circuits 33 and 34 may include fuel conduits, manifolds, valves, sensors, or any combination thereof, extending to one or more of the fuel nozzles 28 and / or combustors 24.

[0018] The combustor 24 ignites and combusts an air-fuel mixture, and then passes hot pressurized combustion gas into the turbine 26. The combustion gas passes through one or more stages of turbine blades of the turbine 26, thereby driving the turbine 26 to rotate abouta shaft. The shaft drives the compressor 22 and / or a load 38. In certain embodiments, the load 38 may include an electrical generator, a pump, a compressor, a propulsion system, machinery, or any combination thereof. Eventually, the gas turbine system 10 discharges an exhaust gas via an exhaust section 40 (e.g., exhaust duct, collector, diffuser, and / or stack).

[0019] In the illustrated embodiment, the fuel flush system 12 is coupled to the fuel circuit 36 at least at the liquid fuel circuit 34. However, the fuel flush system 12 may be coupled to both the gas and liquid fuel circuits 33 and 34. The fuel flush system 12 is coupled to the fuel circuit 36 (e.g., the liquid fuel circuit 34) via one or more fluid supply circuits 11 and one or more fluid drain circuits 13. The fuel flush system 12 supplies the fluid 14 through the one or more fluid supply circuits 11 to the fuel circuit 36 (e.g., the liquid fuel circuit 34) via the fluid supply 15, the pump 16, and the injection manifold 18 as discussed above. Additionally, the fuel flush system 12 may receive a fluid return or drainage flow from the fuel circuit 36 (e.g., the liquid fuel circuit 34) through the one or more fluid drain circuits 13, wherein the drainage flow may flow through a drain manifold 41 and a fluid separator 43. The fluid separator 43 may be configured to separate the fluid 14 from any residual fuel (e.g., liquid fuel 30) in the drainage flow, such that the separated liquid fuel 30 may be recycled back to the liquid fuel supply 32, and the separated fluid 14 may be recycled back to the fluid supply 15. The injection manifold 18 and the drain manifold 41 enable a plurality of fluid connections with the fuel circuit 36 (e.g., liquid fuel circuit 34). such as fluid connections with fuel conduits for each combustor 24, each fuel nozzle 24, or a combination thereof.

[0020] In operation, the pump 16 is configured to pump the fluid 14 from the fluid supply 15 and distribute the fluid 14 to the fuel circuit 36 (e g., liquid fuel circuit 34) via the injection manifold 18. For example, the fluid supply circuits 11 may extend outside of the enclosure 19 to an upper (exterior) sidewall portion of the enclosure 19. wherein the fluid supply circuits 11 may then enter the enclosure 19 and couple with the fuel circuit 36 (e.g., liquid fuel circuit 34). The fluid supply circuit 11 does not interfere with a top access (e.g., top access panel) of the enclosure 19, such that top access through the enclosure 19 to the gas turbine engine 20 is possible. The fluid supply circuit 11 may direct the fluid 14 through the fuel circuit 36 (e.g., liquid fuel circuit 34) while one or more valves (e.g., check valves) block backflow of the fluid 14 to the fuel supply (e.g.. liquid fuel supply 32).

[0021] In some embodiments, the fluid 14 flows through the fuel circuit 36 (e.g., liquid fuel circuit 34), through the fuel nozzles 28. and into the combustors 28, thereby flushing any residual fuel 30 into the combustors 28 during operation of the gas turbine engine 20 on a different fuel (e.g., gas fuel 29). In some embodiments, the fluid 14 flows through the fuel circuit 36 (e.g., liquid fuel circuit 34) and then returns to the fuel flush system 12 via the fluid drain circuits 13. In some embodiments, the fluid 14 flows through the fuel circuit 36 (e.g., liquid fuel circuit 34) and partially flows through the fuel nozzles 28 and the combustors 24 and partially diverts back to the fuel flush system 12 via the fluid drain circuits 13. In some embodiments, the fluid drain circuits 13 are coupled to the fuel circuit 36 (e.g., liquid fuel circuit 34) downstream from the fluid supply circuits 11, and / or the fluid drain circuits 13 are coupled to the fuel nozzles 12. the combustors 24, or any combination thereof. In some embodiments, the fuel circuit 36 (e.g., liquid fuel circuit 34) includes one or more valves downstream from fluid connections with the fluid supply circuits 11 and fluid drain circuits 13, thereby enabling control of any fluid (e.g., fluid 14 and liquid fuel 30) flowing through the fuel nozzles 28 and the combustors 24 during a purge operation by the fuel flush system 12.

[0022] As shown, the gas turbine system 10 also includes a controller 42 having one or more processors 44, memory’ 46, instructions 48 stored on the memory’ 46 and executable by the processor 44, and communication circuitry 50. The communication circuitry 50 couples the controller 42 with various sensors, actuators, valves, and components of the gas turbine system 10 and the fuel flush system 12. For example, the communication circuitry’ 50 couples the controller 42 to the gas fuel supply 31, the liquid fuel supply 32, the fluid supply 15, the pump 16, and valves (e.g., valves in the fuel flush system 12, the fuel circuit 36, the fluid supply circuits 11, and the fluid drain circuits 13). By further example, the communication circuitry’ 50 couples the controller 42 to sensors (e.g., temperature sensors, pressure sensors, flow rate sensors, fuel plug sensors, fuel coking sensors, etc.) of the fuel circuit 36, including the gas fuel circuit 33 and the liquid fuel circuit 34. For example, the sensors may provide sensor feedback to the controller 42 indicating conditions conducive to coking (e.g., temperature above a threshold), conditions indicative of a partial or complete plug (e.g., fuel pressure above a threshold or flow rate below a threshold), or a combination thereof, along the fuel circuit 36. The controller 42 may control the valves to enable flow of the fluid 14 through the fluid supply circuit 11, the fuel circuit 36 (e.g.. liquid fuel circuit 34), and the fluid drain circuit 13.

[0023] In certain embodiments, the controller 42 may operate the fuel flush system 12 to flush the fuel circuits 36 (e.g., liquid fuel circuits 34) during and / or after transitioning operation of the gas turbine engine 20 from a liquid fuel operation using the liquid fuel 30 to a gas fuel operation using the gas fuel 29. In other words, the gas turbine engine 20 changes fuels to combust the gas fuel 29 rather than the liquid fuel 30, while still continuing to generate significant amounts of heat that can otherwise cause coking of the liquid fuel 30 in the liquid fuel circuit 34. Accordingly, the fluid 14 (e.g.. water or aqueous solution) supplied by the fuel flush system 12 fills the liquid fuel circuits 34 and pushes any liquid fuel 30 out of the liquid fuel circuits 34 and into the fuel drain circuits 13 and / or into the combustors 24. Thus, the fluid 14 helps to purge the fuel circuits 36 (e.g.. liquid fuel circuits 34) during an operating mode of the gas turbine engine 20. In certain embodiments, the fuel flush system 12 may be used during and / or after shut down of the gas turbine engine 20, before or during startup of the gas turbine engine 20, or a combination thereof.

[0024] FIG. 2 is a schematic perspective view of an embodiment of the gas turbine system 10 and the fuel flush system 12. The gas turbine system 10 and the fuel flush system 12 may be described with respect to a vertical direction 52 (e.g., vertical axis), an axial direction 54 (e g., axial axis), and a lateral direction 56 (e.g., lateral axis). In the illustrated embodiment, the fuel flush system 12 includes the injection manifold 18, a main conduit 70 fluidly coupled to the injection manifold 18. a plurality of injection conduits 72 fluidly coupled to the main conduit 70 via the injection manifold 18, and a skid 74 (e g., platform) configured to support the injection manifold 18. As shown, the skid 74 is disposed beneath the injection manifold 18 and is coupled to an exterior surface of a side wall 76 of the enclosure 19 housing one or more of the subsystems of the gas turbine engine 20. As shown, the skid 74 is supported by an angled beam 78. A first end 80 of the angled beam 78 is coupled to the side wall 76 and a second end 82 of the angled beam 78 is coupled to a distal end portion 84 of the skid 74. Although the illustrated embodiment shows the skid 74 being supported by one angled beam 78, in certain embodiments the skid 74 may be supported by multiple angled beams 78. For example, the skid 74 may be supported by 2, 3, 4, 5, or 6 angled beams 78. In certain embodiments, the skid 74 may be directly coupled to the side wall 76 of the enclosure 19.

[0025] As shown, the injection manifold 18 and the skid 74 of the fuel flush system 12 are both disposed above a top portion 86 of an exterior 88 of the gas turbine engine 20 havingthe combustor(s) 24. That is, a first height 89 of the injection manifold 18 and the skid 74 in the vertical direction 52 is greater than a second height 91 of the top portion 86 of the exterior 88 of the gas turbine engine 20. As discussed herein, it may be appreciated that by the injection manifold 18 being disposed above the top portion 86 of the gas turbine engine 20, the plurality of injection conduits 72 may be angled downward toward the gas turbine engine 20 from the injection manifold 18, such that gravity’ may be at least partially used to transfer the fluid 14 from the injection manifold 18 to the fuel circuit 36 (e.g.. liquid fuel circuit 34) of the gas turbine engine 20.

[0026] Additionally, as shown, neither the injection manifold 18 nor the skid 74 obstructs a top wall 90 of the enclosure 19. That is, the injection manifold 18 and the skid 74 are disposed laterally past the edge 92 (e.g., joining the top wall 90 and the side wall 76) in the lateral direction 56 such that neither the injection manifold 18 nor the skid 74, nor any portion thereof, is disposed within an outer perimeter 93 of the top wall 90 of the enclosure 19. It may be appreciated that by neither the injection manifold 18 nor the skid 74 being disposed vertically above the top wall 90 of the enclosure 19, an operator may be able to access one or more components (e.g., an access opening, an air conditioning unit) disposed on the top wall 90 without being blocked by either the injection manifold 18 or the skid 74. For example, all or part of the top wall 90 may include a removable access panel(s) to enable top access into an intenor volume of the enclosure 19. such that inspection and maintenance may be performed on the gas turbine engine 20. The gas turbine engine 20 also may be installed and / or removed vertically through an opening in the top wall 90 (e.g., via one or more removable access panels).

[0027] In the illustrated embodiment, the fuel flush system 12 includes the pump 16. As shown, the pump 16 is fluidly coupled to the main conduit 70 of the fuel flush system 12. The pump 16 may be configured to pump (e.g., transport) the fluid 14 from the pump 16, through the main conduit 70, and to the injection manifold 18, which then supplies the fluid 14 to the fuel circuit 36 (e.g., liquid fuel circuit 34) via the fluid supply circuit 11. As shown, the pump 16 is integrated into a modified injection skid 94, which is housed within an injection skid housing 96.

[0028] As shown, the fuel flush system 12 also includes the fluid drain circuits 13 having an auxiliary drain conduit 98 fluidly coupled to a lower end portion 100 of a sloped portion 101 of the main conduit 70. The auxiliary' drain conduit 98 extends in a downward direction102, wherein the downward direction 102 opposes the vertical direction 52. As discussed further herein, it may be appreciated that the auxiliary drain conduit 98 may enable the fluid 14 in the main conduit 70 to drain after a temporary stop of the fluid 14 being transported through the main conduit 70 via the pump 16 due to a temporary stop or shutdown of the fuel flush system 12.

[0029] In the illustrated embodiment, the fuel flush system 12 also includes the drain manifold 41 fluidly coupled to a plurality of drain conduits 104 of the fluid drain circuits 13. In certain embodiments, the plurality7of drain conduits 104 may be fluidly coupled to the fuel circuit 36 (e.g., liquid fuel circuit 34), the fuel nozzles 28, the combustors 24, or a combination thereof, of the gas turbine engine 20. As discussed herein, the controller 42 may control one or more valves to open flow through the fluid drain circuits 13 to the drain manifold 41 to enable drainage of the fluid 14 from the fuel circuit 36 (e.g., liquid fuel circuit 34), the fuel nozzles 28, the compressor 22, the combustors 24, or a combination thereof, through one or more of the drain conduits 104.

[0030] In the illustrated embodiment, the main conduit 70 extends from the pump 16 to the injection manifold 18. As shown, the main conduit 70 includes the sloped portion 101 (e.g., angled portion, diagonal portion), a first vertical portion 106 fluidly coupled to the lower end portion 100 of the sloped portion 101, a horizontal portion 108 fluidly coupled to a high end portion 110 of the first vertical portion 106, and a second vertical portion 112 fluidly coupled to the horizontal portion 108. As shown, the sloped portion 101 is coupled to the side wall 76 of the enclosure 19. The first vertical portion 106 extends in the vertical direction 52 (e.g., upward) relative to the lower end portion 100 of the sloped portion 101. The second vertical portion 112 extends in the downward direction 102 relative to the horizontal portion 108.

[0031] FIG. 3 is a schematic perspective view of an embodiment of the fuel flush system 12 coupled to the fuel circuits 36 (e.g., liquid fuel circuits 34) with the enclosure 19 and the gas turbine engine 20 removed for clarity. As illustrated, the fluid supply circuits 11 extend above and then downwardly in connection with the fuel circuits 36 (e.g., liquid fuel circuits 34), thereby helping to facilitate the distribution of fluid 14 via gravity into and through the fuel circuits 36 (e.g., liquid fuel circuits 34). In the illustrated embodiment, the controller 42 is communicatively coupled to the injection manifold 18, the drain manifold 41, and the pump 16. The injection manifold 18 may include one or more injection valves 130, such thateach injection valve 130 may be fluidly coupled to an injection conduit 72 of the fluid supply circuit 11. That is, each injection valve 130 may correspond to at least one injection conduit of the plurality of injection conduits 72 of the fluid supply circuit 11. In certain embodiments, each injection valve 130 may be selectively and / or independently actuated by the controller 42. For example, the controller 42 may be configured to independently adjust a flow rate of the fluid 14 through each of the injection conduits 72 of the plurality of injection conduits 72. That is, the controller 42 may be configured to set a flow rate of the fluid 14 through a first injection conduit 132 of the plurality of injection conduits 72 at a first flow rate, and additionally to set a flow rate of the fluid 14 through a second injection conduit 134 of the plurality of injection conduits 72 at a second flow rate different from the first flow rate. It may be appreciated that independent control of each of the injection valves 130 of the injection manifold 18 may provide for flushing of different fuel circuits 36 (e.g., liquid fuel circuits 34), fuel nozzles 28, and / or combustor(s) 24 of the gas turbine engine 20 at different times. In certain embodiments, the one or more injection valves 130 may be actuated synchronously and / or simultaneously such that the flow rate of the fluid 14 through each of the injection conduits 72 is the same at each time step.

[0032] In certain embodiments, each injection valve 130 is fluidly coupled to separate injection conduits 72. In some embodiments, at least one injection valve 130 may control the flow rate of more than one injection conduit 72. For example, at least one injection valve 130 may control the flow rate of 2, 3, 4, or more injection conduits 72. In certain embodiments, each injection conduit 72 is fluidly coupled to a separate fuel circuit 36 (e.g., liquid fuel circuit 34), fuel nozzle 28, and / or combustor 24 of the gas turbine engine 20. In some embodiments, at least one injection conduit 72 may be fluidly coupled to more than one fuel circuit 36 (e.g., liquid fuel circuit 34), fuel nozzle 28, and / or combustor 24 of the gas turbine engine 20. For example, at least one injection conduit 72 may be fluidly coupled to 2, 3, 4, or more fuel circuits 36 (e.g., liquid fuel circuits 34). fuel nozzles 28, and / or combustors 24. The ganged 2, 3, 4 or more fuel circuits 36, fuel nozzles 28, and / or combustors 24 do not necessarily have to supply the same combustor 24 or adjacent combustors 24.

[0033] In the illustrated embodiment, the fuel flush system 12 includes the drain manifold 41 coupled to the fluid drain circuits 13. In certain embodiments, the drain manifold 41 includes a plurality of drain valves 136, such that each drain valve 136 may be fluidly coupled to a drain conduit 104 of the fluid drain circuits 13. That is, each drain valve 136may correspond to at least one drain conduit of the plurality of injection conduits 104. In certain embodiments, each drain valve 136 may be selectively and / or independently actuated by the controller 42. For example, the controller 42 may be configured to independently adjust a flow rate of the fluid 14 through each of the drain valves 136 and / or the drain conduits 104 of the fluid drain circuits 13. That is, the controller 42 may be configured to set a flow rate of the fluid 14 (and flushed fuel) through a first drain valve 138 of the plurality of drain valves 136 at a first flow rate, and additionally to set a flow rate of the fluid 14 through a second drain valve 140 of the plurality of drain valves 136 at a second flow rate. It may be appreciated that independent control of each of the drain valves 136 of the drain manifold 41 may provide for flushing of different fuel circuits 36 (e.g., liquid fuel circuits 34), fuel nozzles 28. and / or combustor(s) 24 of the gas turbine engine 20 at different times. In certain embodiments, the one or more drain valves 136 may be actuated synchronously and / or simultaneously such that the flow rate of the fluid 14 through each of the drain valves 136 and / or drain conduits 104 is the same at each time step. In certain embodiments, the controller 42 may be configured to adjust and / or actuate the one or more drain valves 136 based on a flow rate at which the fluid 14 drains from the fuel circuits 36 (e.g.. liquid fuel circuits 34), fuel nozzles 28, and / or combustor(s) 24 of the gas turbine engine 20.

[0034] In certain embodiments, one or more drain conduits 104 may additionally function as conduits for supplying fuel (e.g.. natural gas, liquid fuel) to the fuel nozzles 28 and / or the combustor(s) 24 of the gas turbine engine 20. As shown, the drain conduits 104 may be fluidly coupled with a plurality of fuel conduits 142 of the fuel circuit 36 (e.g., liquid fuel circuit 34) configured to supply liquid fuel 30 to the combustor(s) 24. In certain embodiments, the drain conduits 104 and / or the fuel conduits 142 may include check valves 144. The check valves 144 may be configured to block the drain conduits 104 and / or the fuel conduits 142 such that the fluid 14 does not flow into the fuel conduits 142 that provide liquid fuel to the combustor(s) 24.

[0035] In certain embodiments, the controller 42 may be configured to control the injection manifold 18, the drain manifold 41, and / or the pump 16 separately and / or concurrently as part of a flush cycle. That is, the controller 42 may be configured to control the pump 16 to pump an amount of fluid 14, and concurrently control the injection valves 130 and / or the drain valves 136 to control a flow rate of the fluid 14 through the injectionconduits 72, the fuel circuits 36 (e.g., liquid fuel circuits 34), the fuel nozzles 28. and / or the combustor(s) 24 of the gas turbine engine 20, and / or the drain conduits 104.

[0036] In certain embodiments, the combustor(s) 24 may include one or more sensors 146 configured to determine an amount of buildup or coking of the liquid fuel 30 inside the fuel circuits 36 (e.g.. liquid fuel circuits 34), the fuel nozzles 28. and / or the combustor(s) 24. The controller 42 may be configured to receive a signal indicative of the amount of buildup of coke deposits of the liquid fuel 30 in the fuel circuits 36 (e.g., liquid fuel circuits 34) and determine an estimated buildup of coke deposits in a certain fuel nozzle 28 and / or combustor 24 based on the signal. In response to the estimated buildup exceeding a threshold level of buildup, the controller 42 may be configured to actuate the injection valve 130 and / or the drain valve 136 corresponding to the combustor 24 so as to flush the combustor 24, while not using the fluid 14 to flush the other combustors 24. As shown, the fuel flush system 12 may include an instrumentation air supply 148 configured to supply the one or more sensor(s) 146 and / or other instrumentation with air.

[0037] FIG. 4 is a schematic side view of an embodiment of the fuel flush system 12. In the illustrated embodiment, the skid 74 supports the injection manifold 18. As shown, the skid 74 is coupled to the side wall 76 of the enclosure 19 by the angled beam 78. The skid 74 and the injection manifold 18 are disposed at a top portion 170 of an exterior surface of side wall 76 of the enclosure 19, such that the skid 74 and the injection manifold are disposed above (e.g., in the vertical direction 52) the top portion of the exterior 88 of the gas turbine engine 20. As shown, the skid 74 and the injection manifold 18 are disposed in a front portion 172 of the enclosure 19. In certain embodiments, the skid 74 and the injection manifold 18 may be disposed in a middle portion 174 or a rear portion 176 of the enclosure 19.

[0038] In the illustrated embodiment, the injection conduits 72 are fluidly coupled to the injection manifold 18 and slope diagonally downward (e.g., toward the downward direction 102) from the injection manifold 18 and toward the enclosure 19 (e.g., in the lateral direction 177). It may be appreciated that the diagonally downward orientation of the injection conduits 72 relative to the injection manifold 18 provides for the assistance of gravity’ in transferring the fluid 14 from the injection manifold 18 to the combustor(s) 24 of the gas turbine engine 20 disposed in an interior 178 of the enclosure 19.

[0039] In the illustrated embodiment, the sloped portion 101 of the main conduit 70 is shown as sloping diagonally downward (e.g., toward the direction 102) relative to the injection manifold 18. As shown, the auxiliary drain conduit 98 is fluidly coupled to the lower end portion 100 of the sloped portion 101 of the main conduit 70 and extends in the downward direction 102 to the drain manifold 41. It may be appreciated that the downward slope of the sloped portion 101 may provide for the assistance of gravity in the flow of the fluid 14 from the injection manifold 18 back to the auxiliary drain conduit 98 in the event that the pump 16 ceases to pump the fluid 14 through the main conduit 70. That is, the slope of the sloped portion 101 may draw the fluid 14 back from the injection manifold 18 and lead the fluid 14 to the auxiliary drain conduit 98 through which the fluid 14 may flow- through and exit near a ground surface 180.

[0040] FIG. 5 is a flowchart of an embodiment of a process 200 of operating the fuel flush system 12. The process 200 may be performed by a computing device or controller (e.g., controller 42) disclosed above with reference to FIGS. 1 and 3 or any other suitable computing device(s) or controller(s). Furthermore, the actions of the process 200 may be performed in the order disclosed herein or in any other suitable order. For example, certain actions of the process 200 may be performed concurrently. In addition, in certain embodiments, at least one of the actions of the process 200 may be omitted.

[0041] In block 202 of the process 200, one or more processors instruct a pump to cause a fluid to flow through a main conduit to an injection manifold. The injection manifold is supported by a skid coupled to a side wall of an enclosure housing a gas turbine engine. The injection manifold and skid are disposed vertically above a top side of the gas turbine engine. The main conduit is fluidly coupled to a plurality of injection conduits via the injection manifold. The plurality of injection conduits is fluidly coupled to one or more combustors of the engine.

[0042] In block 204 of the process 200, the one or more processors may instruct the injection manifold to divert the fluid from the main conduit to the plurality of injection conduits. The plurality of injection conduits is fluidly coupled to the one or more combustors of the engine. For example, the controller may receive a signal from one or more sensors indicative of a level of blockage (e.g., coking) of each respective combustor of the one or more combustors. The controller may determine an estimated level of blockage (e.g., 30 percent blocked, 50 percent blocked) of each combustor based on the respective signal. Inresponse to the estimated level of blockage surpassing a threshold blockage, the controller may instruct the injection manifold to divert the fluid form the main conduit to the injection conduit corresponding to the combustor determined by the controller to be blocked beyond a threshold blockage.

[0043] In block 206 of the process 200, the one or more processors may instruct the drain manifold to receive the fluid from one or more drain conduits fluidly coupled to the one or more combustors. In certain embodiments, the one or more drain conduits may merge into a main drain conduit. The drain manifold may include a single valve configured to control a flow rate of the fluid flowing through the main drain conduit. The controller may be configured to adjust the single valve to adjust the flow rate of the fluid flowing through the main drain conduit. In certain embodiments, the one or more drain conduits may include separate valves that control the flow rate of the fluid flowing through each drain conduit separately. The controller may be configured to independently control the separate valves of each of the one or more drain conduits.

[0044] Technical effects of the disclosed embodiments include the ability to flush residual liquid fuel and other debris of a gas turbine engine disposed within an enclosure. The injection manifold in the disclosed embodiments is supported by a skid that is coupled to a top portion of a side wall of the enclosure (e.g., on an exterior surface). The location of the injection manifold near the top of the enclosure provides for the assistance of gravity in transferring the fluid used for flushing the residual fuel from the injection manifold to the one or more combustors of the engine. Additionally, the coupling of the skid and the injection manifold to the side wall of the enclosure, as opposed to the top wall, provides for additional access through the top wall into the enclosure. For example, because the injection manifold is not obstructing the top wall, an operator may be able to install, service, and / or remove the gas turbine engine through the top wall of the enclosure (e.g., via removable access panels).

[0045] The subject matter described in detail above may be defined by one or more clauses, as set forth below.

[0046] A system includes an enclosure, a gas turbine engine disposed in the enclosure, and a fuel flush system coupled to a side wall of the enclosure above the gas turbine engine. The fuel flush system includes a fluid supply circuit configured to inject a fluid into a fuel circuit of the gas turbine engine.

[0047] The system of the preceding clause, wherein the fuel circuit includes a liquid fuel circuit.

[0048] The system of any preceding clause, wherein the fluid comprises water.

[0049] The system of any preceding clause, wherein the fuel flush system does not obstruct a top access panel of the enclosure.

[0050] The system of any preceding clause, wherein fluid supply circuit is coupled to a plurality of fuel conduits of the fuel circuit leading to a plurality of fuel nozzles, a plurality of combustors, or a combination thereof, of the gas turbine engine.

[0051] The system of any preceding clause, wherein the fuel flush system further includes a fluid drain circuit configured to drain at least part of the fluid, a fuel, or a combination thereof, from the fuel circuit of the gas turbine engine.

[0052] The system of any preceding clause, wherein a fluid drain circuit is coupled to the gas turbine engine downstream from the fluid supply circuit.

[0053] The system of any preceding clause, wherein the fuel flush system includes one or more valves configured to control a flow of the fluid through the fluid supply circuit, the fuel circuit, the fluid drain circuit, or a combination thereof.

[0054] The system of any preceding clause, wherein the fuel flush system includes an injection manifold coupled to the side wall of the enclosure above the gas turbine engine.

[0055] The system of any preceding clause, wherein the fluid supply circuit extends from the injection manifold through the enclosure to the fuel circuit.

[0056] The system of any preceding clause, wherein the fluid supply circuit is oriented downwardly to connections with the fuel circuit.

[0057] The system of any preceding clause, wherein the main conduit extends along the side wall of the enclosure to the injection manifold, and the main conduit is oriented downwardly away from the injection manifold.

[0058] The system of any preceding clause, including a pump coupled to the main conduit.

[0059] The system of any preceding clause, wherein the fuel circuit includes a gas fuel circuit and a liquid fuel circuit, the gas turbine engine is configured to operate in a gas fuel mode or a liquid fuel mode, and the fuel flush system is configured to inject the fluid from the fuel supply circuit into the liquid fuel circuit during or after transitioning from the liquid fuel mode to the gas fuel mode.

[0060] The system of any preceding clause, including a controller coupled to the fuel flush system, wherein the controller is configured to operate the fuel flush system in response to a fuel transition between first and second fuels, in response to sensor feedback indicative of conditions conducive to coking, in response to sensor feedback indicative of conditions indicative of a plug, or a combination thereof.

[0061] A system includes a fuel flush system configured to couple to a side wall of an enclosure above a gas turbine engine disposed in the enclosure. The fuel flush system includes a fluid supply circuit configured to inject a fluid into a fuel circuit of the gas turbine engine.

[0062] The system of the preceding clause, wherein the fuel circuit includes a liquid fuel circuit, the fluid comprises water, and the fuel flush system does not obstruct a top access panel of the enclosure.

[0063] The system of any preceding clause, wherein the fuel flush system includes an injection manifold configured to couple to the side wall of the enclosure above the gas turbine engine.

[0064] The system of any preceding clause, wherein the fluid supply circuit is configured to extend from the injection manifold through the enclosure to the fuel circuit, and the fuel supply circuit is oriented downwardly to connections with the fuel circuit.

[0065] The system of any preceding clause, including a controller coupled to the fuel flush system, wherein the controller is configured to operate the fuel flush system in response to a fuel transition between first and second fuels, in response to sensor feedback indicative of conditions conducive to coking, in response to sensor feedback indicative of conditions indicative of a plug, or a combination thereof.

[0066] A method includes supplying a fluid to a fuel flush system coupled to a side wall of an enclosure above a gas turbine engine disposed in the enclosure. The method also includes injecting the fluid through a fluid supply circuit of the fuel flush system into a fuel circuit of the gas turbine engine. The fuel circuit includes a liquid fuel circuit, the fluid includes water, and the fuel flush system does not obstruct a top access panel of the enclosure.

[0067] 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.

Claims

CLAIMS:

1. A system, comprising: an enclosure; a gas turbine engine disposed in the enclosure; and a fuel flush system coupled to a side wall of the enclosure above the gas turbine engine, wherein the fuel flush system comprises a fluid supply circuit configured to inject a fluid into a fuel circuit of the gas turbine engine.

2. The system of claim 1, wherein the fuel circuit comprises a liquid fuel circuit.

3. The system of claim 1, wherein the fluid comprises water.

4. The system of claim 1, wherein the fuel flush system does not obstruct a top access panel of the enclosure.

5. The system of claim 1, wherein fluid supply circuit is coupled to a plurality of fuel conduits of the fuel circuit leading to a plurality of fuel nozzles, a plurality of combustors, or a combination thereof, of the gas turbine engine.

6. The system of claim 1, wherein the fuel flush system further comprises a fluid drain circuit configured to drain at least part of the fluid, a fuel, or a combination thereof, from the fuel circuit of the gas turbine engine.

6. The system of claim 1, wherein a fluid drain circuit is coupled to the gas turbine engine downstream from the fluid supply circuit.

7. The system of claim 6, wherein the fuel flush system comprises one or more valves configured to control a flow of the fluid through the fluid supply circuit, the fuel circuit, the fluid drain circuit, or a combination thereof.

8. The system of claim 1, wherein the fuel flush system comprises an injection manifold coupled to the side wall of the enclosure above the gas turbine engine.

9. The system of claim 8, wherein the fluid supply circuit extends from the injection manifold through the enclosure to the fuel circuit.

10. The system of claim 9, wherein the fluid supply circuit is oriented downwardly to connections with the fuel circuit.

11. The system of claim 10, wherein the main conduit extends along the side wall of the enclosure to the injection manifold, and the main conduit is oriented downwardly away from the injection manifold.

12. The system of claim 11, comprising a pump coupled to the main conduit.

13. The system of claim 1, wherein the fuel circuit comprises a gas fuel circuit and a liquid fuel circuit, the gas turbine engine is configured to operate in a gas fuel mode or a liquid fuel mode, and the fuel flush system is configured to inject the fluid from the fuel supply circuit into the liquid fuel circuit during or after transitioning from the liquid fuel mode to the gas fuel mode.

14. The system of claim 1, comprising a controller coupled to the fuel flush system, wherein the controller is configured to operate the fuel flush system in response to a fuel transition between first and second fuels, in response to sensor feedback indicative of conditions conducive to coking, in response to sensor feedback indicative of conditions indicative of a plug, or a combination thereof.

15. A system, comprising: a fuel flush system configured to couple to a side wall of an enclosure above a gas turbine engine disposed in the enclosure, wherein the fuel flush system comprises a fluid supply circuit configured to inject a fluid into a fuel circuit of the gas turbine engine.

16. The system of claim 15, wherein the fuel circuit comprises a liquid fuel circuit, the fluid comprises water, and the fuel flush system does not obstruct a top access panel of the enclosure.

17. The system of claim 15, wherein the fuel flush system comprises an injection manifold configured to couple to the side wall of the enclosure above the gas turbine engine.

18. The system of claim 17, wherein the fluid supply circuit is configured to extend from the injection manifold through the enclosure to the fuel circuit, and the fuel supply circuit is oriented downwardly to connections with the fuel circuit.

19. The system of claim 15, comprising a controller coupled to the fuel flush system, wherein the controller is configured to operate the fuel flush system in response to a fuel transition between first and second fuels, in response to sensor feedback indicative of conditions conducive to coking, in response to sensor feedback indicative of conditions indicative of a plug, or a combination thereof.

20. A method, comprising: supplying a fluid to a fuel flush system coupled to a side wall of an enclosure above a gas turbine engine disposed in the enclosure; and injecting the fluid through a fluid supply circuit of the fuel flush system into a fuel circuit of the gas turbine engine, wherein the fuel circuit comprises a liquid fuel circuit, the fluid comprises water, and the fuel flush system does not obstruct a top access panel of the enclosure.

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