System and method for air cooling fuel purge flow

A system includes an air cooling system having a heat exchanger, a fan, and a mount. The heat exchanger includes an inlet, an outlet, and a heat exchange conduit between the inlet and the outlet. The inlet is configured to couple to a bleed system of a gas turbine system to extract a bleed flow. The heat exchanger is configured to cool the bleed flow along the heat exchange conduit in a surrounding air to produce a cooled bleed flow. The outlet is configured to couple to a fuel purge system of the gas turbine system to supply the cooled bleed flow as a fuel purge flow. The fan is configured to force an airflow from the surrounding air through the heat exchanger. The mount is configured to mount the air cooling system outside of an enclosure surrounding the gas turbine system.

BACKGROUND

The subject matter disclosed herein relates to a gas turbine system and, more particularly, a system and method for cooling a fuel purge flow.

A gas turbine system includes a compressor, a combustor, and a turbine. The compressor compresses an intake air in one or more stages to produce a compressed air. The combustor mixes the compressed air with fuel and combusts the fuel with the compressed air to generate hot combustion gases. The turbine directs the hot combustion gases through one or more turbine stages to drive rotation of a shaft, which may be coupled to the compressor and a load. In certain situations, a fuel system may be purged by a fuel purge flow. However, if a temperature of the fuel purge flow is too high, then the fuel purge flow can create problems such as coking. In a mobile gas turbine system, such as a trailer mounted gas turbine system having a generator driven by a turbine, it may be difficult to provide suitable cooling for the fuel purge flow. For example, the mobile gas turbine system may not be able to use water for cooling the fuel purge flow due limitations at a particular site. Accordingly, a need exists for cooling a fuel purge flow using resources available at various sites, such that the mobile gas turbine system can operate in a more flexible manner.

BRIEF DESCRIPTION

In certain embodiments, a system includes an air cooling system having a heat exchanger, a fan, and a mount. The heat exchanger includes an inlet, an outlet, and a heat exchange conduit between the inlet and the outlet. The inlet is configured to couple to a bleed system of a gas turbine system to extract a bleed flow. The heat exchanger is configured to cool the bleed flow along the heat exchange conduit in a surrounding air to produce a cooled bleed flow. The outlet is configured to couple to a fuel purge system of the gas turbine system to supply the cooled bleed flow as a fuel purge flow. The fan is configured to force an airflow from the surrounding air through the heat exchanger. The mount is configured to mount the air cooling system outside of an enclosure surrounding the gas turbine system.

In certain embodiments, a method includes intaking, into an inlet of a heat exchanger of an air cooling system, a bleed flow extracted from a bleed system of a gas turbine system. The method further includes cooling, along a heat exchange conduit of the heat exchanger in a surrounding air, the bleed flow to produce a cooled bleed flow. The method further includes supplying, out of an outlet of the heat exchanger, the cooled bleed flow as a fuel purge flow into a fuel purge system of the gas turbine system. The method further includes forcing, via a fan of the air cooling system, an air flow from the surrounding air through the heat exchanger, wherein the air cooling system includes a mount configured to mount the air cooling system outside of an enclosure surrounding the gas turbine system.

In certain embodiments, a method includes mounting, via a mount, an air cooling system outside of an enclosure surrounding a gas turbine system. The air cooling system includes a heat exchanger having an inlet, an outlet, and a heat exchange conduit between the inlet and the outlet. The inlet is configured to couple to a bleed system of the gas turbine system to extract a bleed flow. The heat exchanger is configured to cool the bleed flow along the heat exchange conduit in a surrounding air to produce a cooled bleed flow. The outlet is configured to couple to a fuel purge system of the gas turbine system to supply the cooled bleed flow as a fuel purge flow. The air cooling system also includes a fan configured to force an airflow from the surrounding air through the heat exchanger.

DETAILED DESCRIPTION

As discussed in further detail below, a fuel purge system may be used to purge a fuel, such as a gas fuel or liquid fuel, from a fuel supply system of a gas turbine system. The fuel purge system may route a fuel purge flow through various fuel conduits, manifolds, valves, and equipment within an enclosure surrounding the gas turbine system. In certain embodiments, the fuel purge flow may be extracted from a compressor via a bleed system (e.g., a bleed flow comprising compressed air), and subsequently cooled by an air cooling system rather than relying on water cooling. The air cooling system may be mounted outside of the enclosure in close proximity to the fuel supply system, the fuel purge system, and/or the bleed system. The position of the air cooling system outside of the enclosure helps to transfer heat away from the gas turbine system, taking advantage of the ambient air surrounding the enclosure. The position of the air cooling system in close proximity to the fuel supply system, the fuel purge system, and/or the bleed system helps to reduce the length of the conduits leading to and from the air cooling system, thereby helping to substantially reduce or minimize the pressure drop associated with the air cooling system. As a result, the air cooling system is configured to cool the fuel purge flow using ambient air, while reducing a pressure drop associated with passage of the fuel purge flow through the air cooling system. Details of the bleed system, the fuel purge system, and the air cooling system are discussed in further detail below with reference toFIGS.1-6.

FIG.1is a block diagram of an embodiment of a gas turbine system10having a gas turbine engine12, a bleed system14, a fuel purge system16, and an air cooling system18. As discussed in further detail below, the bleed system14is configured to extract a bleed flow (e.g., a compressed air flow), the fuel purge system16is configured to purge one or more fuel lines with the bleed flow, and the air cooling system18is configured to cool the bleed flow being used by the fuel purge system16. The bleed system14is configured to route the bleed flow along a central axis20of the gas turbine system10between a high pressure region13and a low pressure region15of the gas turbine system10. The air cooling system18is configured to cool the bleed flow by transferring heat from the bleed flow to a surrounding environment, e.g., air to air cooling. The fuel purge system16may be configured to route the bleed flow, after cooling by the air cooling system18, through gas fuel lines during operation of the gas turbine system12with liquid fuel, or through one set of fuel lines during operation of the gas turbine system12using another set of fuel lines. Embodiments of the fuel purge system16and the air cooling system18are described in further detail below.

The gas turbine engine12includes an exhaust section22, an air intake section24, a compressor section26, a combustion section28, a turbine section30, and a load32, such as an electrical generator. The gas turbine engine12also may include one or more controllers34having one or more processors36, memory38, and instructions40stored on the memory38and executable by processors36to perform various control functions of the gas turbine system10and the bleed system14. For example, the controller34may be configured to control one or more valves of the bleed system14to control a bleed flow between the high and low pressure regions13and15, one or more valves of the fuel purge system16to control a fuel purge flow (e.g., a portion of the bleed flow extracted from the bleed system14), and one or more components (e.g., fans, valves, etc.) of the air cooling system18to control a temperature and flowrate of the fuel purge flow. The air intake section24may include one or more air filters, fluid injection systems (e.g., heated fluids and/or cooled fluids), anti-icing systems, silencer baffles, or any combination thereof. The air intake section24routes an air flow42into one or more compressor stages44of a compressor section26.

The compressor section26includes a compressor casing46, one or more vanes48extending inwardly from the compressor casing46in each of the compressor stages44, one or more blades50extending outwardly from a shaft52in each of the compressor stages44, and connections54with the bleed system14. The shaft52is configured to rotate a plurality of circumferentially spaced blades50in each of the compressor stages44, while a plurality of circumferentially spaced vanes48remain stationary in each of the compressor stages44. The connections54may include fluid conduit connections with the bleed system14, such as connections54at one or more of the compressor stages44. The connections54may be disposed on opposite sides (e.g., diametrically opposite sides) of the compressor casing46, or in any suitable location on the compressor casing46. The compressor section26outputs a compressed air flow56into one or more combustors58of the combustion section28.

Each combustor58includes one or more fuel nozzles60, which are configured to route the compressed air56and fuel62from a fuel supply system64into a combustion chamber66of the combustor58. The fuel62and the compressed air56mix and combust within the combustion chamber66, thereby producing hot combustion gases68that are routed into the turbine section30. In certain embodiments, the combustion section28has a single annular combustor58disposed circumferentially about a central axis of the gas turbine system10. However, in some embodiments, the combustion section28includes a plurality of combustors58(e.g., combustor cans) spaced circumferentially about the central axis of the gas turbine system10. The fuel nozzles60may include 1, 2, 3, 4, 5, 6, or more fuel nozzles, which may be configured to operate on a plurality of fuel circuits. As discussed below, the fuel circuits may be designed to deliver the same fuel or different fuels, such as liquid and gas fuels. The gas turbine system10may be configured to switch between the different fuels using the different fuel circuits. When switching between fuels and fuel circuits, the fuel purge system16may be configured to circulate the fuel purge flow through the unused fuel circuits to block any backflow, reduce the possibility of coking, and generally protect the unused fuel circuits. The air cooling system18is configured to cool the fuel purge flow using the environmental air, rather than using a supply of water for cooling. Regardless, once the fuel combusts, the hot combustion gases68are used to drive the turbine section30.

The turbine section30includes a plurality of turbine stages70configured to gradually expand the hot combustion gases68and drive components of the gas turbine system10. The turbine section30includes a turbine casing72, one or more turbine vanes74extending inwardly from the turbine casing72in each of the turbine stages70, and one or more turbine blades76extending outwardly from a turbine shaft78in each of the one or more turbine stages70. The turbine shaft78is driven to rotate by the hot combustion gases68flowing against a plurality of circumferentially spaced turbine blades76in each of the turbine stages70, while a plurality of circumferentially spaced turbine vanes74remain stationary in each of the turbine stages70. The hot combustion gases68expand through the turbine section30while driving rotation of the turbine blades76and turbine shaft78and then discharge through the exhaust section22.

The exhaust section22includes an exhaust plenum80disposed downstream from the turbine section30, and the exhaust plenum80includes an exhaust outlet82. The exhaust outlet82may be positioned in a variety of exhaust outlet orientations depending on the particular configuration of the gas turbine system10. In the illustrated embodiment, the exhaust outlet82is arranged in a right-hand orientation or configuration84on a right-hand side of the exhaust plenum80(when viewed from an aft end of the gas turbine system10), thereby directing an exhaust flow in a right hand direction as indicated by arrows86. However, the exhaust outlet82may be arranged in other configurations (shown in phantom lines inFIG.1), such as a top orientation or configuration88to direct a vertical flow of the exhaust gas, or a left-hand orientation or configuration90configured to direct the exhaust flow in a left-hand direction as indicated by arrows92.

In operation, the gas turbine engine12receives air through the air intake section24, compresses the air in one or more compressor stages44via rotation of a plurality of compressor blades50in each of the compressor stages44, and then routes the compressed air56into one or more combustors58of the combustion section28. The combustors58combust the fuel62with the compressed air56via injection through the fuel nozzles60and combustion within the combustion chamber66, and then route the hot combustion gases68into one or more turbine stages70. The turbine stages70use the energy of the hot combustion gases68to drive a plurality of turbine blades76in each of the turbine stages70, thereby driving rotation of the turbine shaft78. In turn, the turbine shaft78drives rotation of a common shaft94between the turbine section30and the compression section26, thereby driving the shaft52of the compressor section26. The rotation of the turbine shaft78also drives rotation of a shaft96coupled to the load32, which may be an electrical generator to generate electricity for a local facility or the power grid. In operation, the controller34is configured to control a fuel flow from the fuel supply system64, a bleed flow through the bleed system14, a fuel purge flow from the bleed system14through the air cooling system18, the fuel purge flow from the air cooling system18through the fuel purge system16, and other aspects of the gas turbine system10.

The bleed system14is configured to route a compressed air stream from the high pressure region13, which may include the compressor section26, to the low pressure region15, which may include the exhaust plenum80of the exhaust section22. However, the bleed system14may be used between other high and low pressure regions of the gas turbine system10. In the illustrated embodiment, the bleed system14includes a first bleed conduit section100fluidly coupled to the compressor section26via the connections54, and a second bleed conduit section102movably (e.g., rotatably) coupled to the first bleed conduit section100and movably coupled to the exhaust section22. The first and second bleed conduit sections100and102may include a plurality of flexible and/or movable structures, which are configured to provide freedom of movement in one or more directions (e.g., rotational direction, horizontal direction, and/or vertical direction). The flexible and/or movable structures may include, for example, one or more gimbals104, one or more spring hangers106, one or more flexible conduits or hoses, and one or more rotatable joints108. The flexible and/or movable structures (e.g.,104,106, and108) may be configured to enable freedom of movement to accommodate thermal expansion and contraction in the bleed system14and between components of the gas turbine system10. Additionally, the first and second bleed conduit sections100and102may include one or more mounting brackets110, a staged expansion conduit112, an outlet section114, one or more straight conduits116between the various components, and one or more bending conduits or elbows118between the various components.

As discussed in further detail below, the first bleed conduit section100may have a U-shaped conduit configuration120configured to partially extend around opposite sides of the compressor section26before fluidly connecting with the internal fluid flow through the compressor section26via the connections54. The U-shaped conduit configuration120of the first bleed conduit section100includes a central straight section or straight conduit124generally centered and oriented crosswise relative to the central axis20, gimbals126and128coupled to opposite ends of the straight conduit124, bending conduits or elbows130and132coupled to the respective gimbals126and128, gimbals134and136coupled to the respective bending conduits or elbows130and132, and the connections54between the gimbals134and136and the compressor casing46of the compressor section26. In the illustrated embodiment, the U-shaped conduit configuration120may remain in a fixed orientation once mounted to the compressor casing46, while a J-shaped conduit configuration122of the second bleed conduit section102may be reoriented or rotated about the central axis20to accommodate the different configurations84,88, and90of the exhaust outlet82.

The J-shaped conduit configuration122of the second bleed conduit section102extends from the first bleed conduit section100and turns toward and connects with the exhaust plenum80of the exhaust section22at the staged expansion conduit112and the outlet section114. The J-shaped conduit configuration122of the second bleed conduit section102includes a straight conduit138coupled to the central straight conduit124in a generally crosswise orientation along the central axis20and a rotational joint140coupled to the straight conduit138. The J-shaped conduit configuration122also includes a bending conduit or elbow142coupled to the rotational joint140, a gimbal144coupled to the bending conduit or elbow142via an intermediate straight conduit146, and a straight conduit148coupled to the gimbal144opposite the intermediate straight conduit146. The J-shaped conduit configuration122also includes a bending conduit or elbow150coupled to the straight conduit148, one or more spring hangers152coupled to one or both of the conduits148and150, and a gimbal154coupled to the bending conduit or elbow150. The J-shaped conduit configuration122also includes a straight conduit156coupled to (and extending between) the gimbal154and a gimbal158and a plurality of spring hangers160coupled to the straight conduit156via an intermediate bracket162. The J-shaped conduit configuration122also includes a rotatable joint164removably coupled between a straight conduit166coupled to the gimbal158and a straight conduit168coupled to a valve assembly170. The J-shaped conduit configuration122also includes a rotatable joint172removably coupled between a straight conduit174coupled to the valve assembly170and a straight conduit176coupled to a gimbal178. The J-shaped conduit configuration122also includes a straight conduit180coupled to the gimbal178opposite the straight conduit176, and the staged expansion conduit112is coupled to the straight conduit180and extends to the outlet section114in the exhaust section22.

The valve assembly170may include one or more valves182driven by an actuator184, which is communicatively coupled to and controlled by the controller34. For example, the valve182may include a gate valve, a ball valve, a flapper valve, or any combination thereof. The actuator184may include an electric drive or motor, a solenoid, a pneumatic drive, a hydraulic drive, or any combination thereof. Accordingly, the controller34may control the actuator184to open and close the valve182, thereby controlling a bleed flow through the bleed system14, including the bleed flow through both the first and second conduit sections100and102between the high pressure region13in the compressor section26and the low pressure region15in the exhaust section22. The valve assembly170also may include a protective shield, a tray to collect fluid spills or leaks, and/or a wall structure186at least partially or entirely extending around the valve182and/or the actuator184.

The shield186of the valve assembly170also may be coupled to an enclosure188of the gas turbine engine12via a mounting bracket190. In certain embodiments, the mounting bracket190may extend between and couple with the enclosure188and the valve assembly170, the straight conduit168, the straight conduit174, and/or some other portion of the second bleed conduit section102. The enclosure188may substantially or completely surround the compressor section26, the combustion section28, and the turbine section30of the gas turbine engine12, and the mounting bracket190may rigidly support the valve assembly170and the second bleed conduit section102relative to a sidewall192of the enclosure188. The mounting bracket190may include a plurality of bracket sections194coupled together with intermediate flanges196. For example, the flanges196may be bolted together with a plurality of threaded fasteners, such as threaded bolts and nuts.

As further illustrated inFIG.1, the staged expansion conduit112includes a plurality of alternating constant-diameter conduits202and expanding-diameter conduits204, thereby defining a plurality of stages of expansion and depressurization. In particular, the illustrated staged expansion conduit112includes, in series, an expanding conduit206, a constant conduit208, an expanding conduit210, a constant conduit212, and an expanding conduit214. The conduits206,208,210,212, and214progressively increase in diameter and cross-sectional area, wherein each constant conduit208and212has a constant diameter and cross-sectional area, and each expanding conduit206,210, and214has a gradually increasing diameter and cross-sectional area in a direction of bleed flow. The expanding conduit214is coupled to an end wall216of the exhaust section122between the enclosure188and the exhaust plenum80. The expanding conduit214also leads into the outlet section114, which is disposed inside of the exhaust plenum80. At a connection between the staged expansion conduit112and the end wall216, the bleed system14may enable freedom of movement in one or more directions, such axial, radial, and/or rotational directions of movement relative to the end wall216. The outlet section114includes a plurality of outlets218disposed in an annular housing220, wherein the outlets218are configured to distribute or diffuse the bleed flow from the bleed system14into the exhaust plenum80. For example, the outlets218may be disposed along a sidewall222(e.g., annular sidewall) and an end wall224(e.g., axially facing end wall) of the annular housing220. In certain embodiments, the connection between the end wall216and the staged expansion conduit112and/or the outlet section114may include a moveable joint configured to enable axial movement and/or rotation therebetween.

The staged expansion conduit112is configured to gradually depressurize the bleed flow to reduce the vibration and/or noise of the bleed system14, such as vibration of a bleed valve. The staged expansion conduit112may have at least two stages configured to gradually (e.g., incrementally) depressurize the bleed flow. Each stage of the staged expansion conduit112may have an expansion section and/or a diffuser plate. The number of stages may be determined at least in part on the difference in pressure between the high pressure region13and the low pressure region15. More stages may be used for large pressure differences than for small pressure differences. The expansion sections increase the dimension of the staged expansion conduit112to at least reduce the static pressure of the bleed flow. The diffuser plates partially obstruct the bleed flow and permit passage of the bleed flow through orifices. The diffuser plates are configured to at least reduce the kinetic energy or dynamic pressure of the bleed flow. The characteristics of the expansion sections (e.g., expansion percentage, size, cross-sectional shape, length) and diffuser plates (e.g., orifice size, orifice quantity, orifice shape, orifice configuration, diffuser plate size) affect the vibration of the bleed system14.

Vibration and thermal expansion/contraction of the bleed system14may cause the bleed system14to move. Certain mounting and coupling features may be utilized to accommodate the movements of the bleed system14. For example, the various components of the bleed system14may be configured to allow for movement in one or more directions, such as an axial direction along an axis of the conduit, rotationally about the axis of the conduit, in a horizontal direction, a vertical direction, or any combination thereof. Each gimbal104may be configured to allow for axial movement, rotational movement, or any combination thereof, relative to an axis of the adjacent conduits. The rotatable joints108are configured to enable rotation about an axis of the adjacent conduits. The rotatable joints108also may be configured to enable separation and reattachment of the adjacent conduits. The spring hangers106are configured to enable movement along an axis of the spring portion of the spring hangers, which may be oriented in a vertical direction, a horizontal direction, or any other suitable angular direction between horizontal and vertical within the enclosure188of the gas turbine engine12. For example, each of the spring hangers106may be hung from a top wall or ceiling of the enclosure188, thereby allowing some vertical movement of the various conduits and sections of the bleed system14.

The fuel purge system16includes a fuel purge circuit230fluidly coupling the bleed system14, the air cooling system18, and the fuel supply system64. The air cooling system18includes one or more heat exchangers232, one or more fans234, and a support structure or mount236(e.g., a mounting framework). The one or more heat exchangers232include one or more heat exchange conduits238and a plurality of fins240coupled to the heat exchange conduits238. The one or more fans234include a plurality of fan blades242coupled to an electric motor244, which is communicatively coupled to and controlled by the controller34. The mount236may include a plurality of frame members or legs246disposed about and coupled to the heat exchanger232and the fan234, wherein the mount236is configured to mount the heat exchanger232and the fan234outside of the enclosure188in the surrounding environment (e.g., ambient air). For example, the mount236may be configured to mount the heat exchanger232and the fan234to the sidewall192and/or a top wall248of the enclosure188. In certain embodiments, the mount236may be configured to mount the heat exchanger232and the fan234adjacent the enclosure188on a common trailer or mobile unit carrying the gas turbine system10, such as on a trailer bed of the common trailer or an adjacent component mounted on the common trailer. However, regardless of the specific external mounting location, the mount236is configured to mount the heat exchanger232and the fan234in close proximity to the bleed system14, the fuel purge system16, and the fuel supply system64, thereby helping to reduce the amount of pressure drop through the fuel purge system16and reduce the heat transfer from within the enclosure188(e.g., due to heat generated by the gas turbine system10) into the bleed flow in the bleed system14and the fuel purge flow in the fuel purge system16.

The fuel purge circuit230may be coupled to the fuel supply system64at one or more locations. The fuel supply system64may include a fuel supply250, one or more fuel circuits252coupled to the fuel supply250, and one or more fuel manifolds254coupled to the fuel circuits252and the fuel nozzles60in the combustors58. The fuel supply250may include one or more liquid fuel supplies256and one or more gas fuel supplies258. The fuel supplies256and258may include fuel tanks, fuel pumps, fuel lines or conduits, fuel pipelines, fuel compressors, pressure regulators, fuel treatment units (e.g., filters, water removal units, etc.), or any combination thereof. The fuel circuits252may include one or more liquid fuel circuits260extending between the liquid fuel supplies256and the fuel manifolds254, and one or more gas fuel circuits262extending between the gas fuel supplies258and the fuel manifolds254. The fuel circuits252(e.g.,260and262) may include fuel conduits, fuel valves, and other fuel distribution and flow control components. The fuel manifolds254may include separate liquid and gas fuel manifolds coupled to the respective liquid and gas fuel circuits260and262, or the fuel manifolds254may include one or more common fuel manifolds coupled to both the liquid and gas fuel circuits260and262. In certain embodiments, the fuel circuit252(e.g.,260and262) may include the fuel flow paths in the fuel supply250, the fuel manifolds254, and the fuel nozzles60, thereby encompassing the fuel flow paths up until fuel injection into the combustion chamber66of the combustor58.

The fuel purge circuit230is shown coupled to the fuel manifolds254. However, the fuel purge circuit230may be coupled to the fuel supply system64at any one or more locations along the fuel circuit252(e.g.,260and262), such as at the fuel nozzles60, the fuel manifolds254, the fuel supply250, or any location between these components60,254, and250. The fuel purge circuit230may include a plurality of circuit portions (e.g., fuel purge conduits), such and circuit portions264and266disposed upstream and downstream of the air cooling system18. For example, the circuit portion264extends between and couples to the bleed system14and the heat exchange conduit238of the heat exchanger232, and the circuit portion266extends between and couples to the heat exchange conduit238of the heat exchanger232and the fuel supply system64. In the illustrated embodiment, the circuit portion264couples to the straight conduit168of the bleed system14; however, the circuit portion264may couple to the bleed system14at or between any of the numbered components of the bleed system14. Additionally, in the illustrated embodiment, the circuit portion266couples to the fuel manifold254of the fuel supply system64; however, the circuit portion266may couple to any one or more components of the fuel supply system64(e.g., the fuel nozzles60, the fuel manifolds254, the fuel circuit252, or the fuel supplies250). For example, the circuit portion266may couple to the fuel supply system64along a liquid fuel passage from the liquid fuel supply256to the fuel nozzles60, a gas fuel passage from the gas fuel supply258to the fuel nozzles60, or a combination thereof.

In certain embodiments, the circuit portion266may selectively provide a fuel purge flow to: only the liquid fuel passage, only the gas fuel passage, or both the liquid and gas fuel passages. When operating the gas turbine system10with liquid fuel, the circuit portion266may provide the fuel purge flow to the gas fuel passage. When operating the gas turbine system10with gas fuel, the circuit portion266may provide the fuel purge flow to the liquid fuel passage. Accordingly, embodiments of the fuel purge system16include various valves (e.g.,270,271, and/or272) and controls to change the flow path of the fuel purge flow depending on various operational conditions.

The controller34may be programmed to control operation of the bleed system14, the fuel purge system16, and the air cooling system18in response to sensor feedback from a plurality of sensors268, designed by S. For example, the controller34may be communicatively coupled to the sensors268at one or more components along the bleed system14, one or more components along the fuel purge system16(e.g., circuit portions264and266), one or more components along the air cooling system18(e.g., heat exchange conduit238and/or fan234), and one or more components along the fuel supply system64(e.g., fuel supply250, fuel circuit252, and fuel manifold254). The sensors268may be configured to monitor one or more parameters, such as temperature, pressure, flow rate, or any combination thereof. In the illustrated embodiment, the plurality of sensors268include sensors disposed along the circuit portion264between the bleed system14and the heat exchange conduit238, and sensors along the circuit portion266between the heat exchange conduit238and the fuel supply system64. The sensors268may be configured to monitor temperature, flow rate, pressure, or any combination thereof, of the fuel purge flow.

The controller34also may be configured to monitor other sensor feedback and operational parameters of the gas turbine system10when controlling the bleed system14, the fuel purge system16, and the air cooling system18. For example, the sensors268may be configured to monitor the surrounding environment outside of the enclosure188(e.g., temperature of exterior ambient air), the space surrounding the gas turbine system10inside of the enclosure188(e.g., temperature of interior air), the temperature of the fuel supply system64(e.g., temperature of the fuel circuit252), or any combination thereof. The controller34also may monitor sensors268coupled to the fuel nozzles60, the combustors58, the turbine section30, the exhaust section22, or any combination thereof. The controller34also may monitor operational modes of the gas turbine system10, such as a startup mode, a steady state mode, a shutdown mode, a part load mode, a full load mode, or any combination thereof. The controller34may be configured to adjust and/or change the fuel purge flow in response to any of the foregoing sensor feedback and monitored parameters.

The controller34is configured to process the sensor feedback from the sensors268and control one or more valves (e.g., valve182) of the bleed system14, one or more valves of the fuel purge circuit230(e.g., valve270along circuit portion264and valves271and/or272along circuit portion266), and one or more valves along the fuel supply system64(e.g., valves along the fuel circuit252). For example, the controller34may be configured to adjust the valves270,271, and/or272to control the flow rate of the fuel purge flow extracted from the bleed system14and routed through the heat exchanger232of the air cooling system18, and the controller34may be configured to control the fan speed of the fan234. As appreciated, a lower flow rate of the fuel purge flow and a higher fan speed of the fan234may increase the cooling performance of the air cooling system18to reduce the temperature of the fuel purge flow, while a higher flow rate of the fuel purge flow and a lower fan speed of the fan234may decrease the cooling performance of the air cooling system18to increase the temperature of the fuel purge flow. Additionally, the controller34is configured to control one or more valves along the fuel purge circuit230to enable or disable the fuel purge flow through a gas fuel passage, a liquid fuel passage, or both, of the fuel supply system64. The controller34also may be configured to adjust the fuel purge flow when switching between fuels, when switching between modes of operation of the gas turbine system10(e.g., startup mode, steady state mode, shutdown mode, part load mode, and full load mode), or any combination thereof. Embodiments of the fuel purge system16and the air cooling system18are discussed in further detail below with reference toFIGS.2-6.

FIG.2is a schematic side view of an embodiment of the gas turbine system10ofFIG.1, further illustrating details of the bleed system14, the fuel purge system16, and the air cooling system18. The components of the bleed system14, the fuel purge system16, and the air cooling system18are substantially the same as discussed in detail above with reference toFIG.1. However, additional details and components are further illustrated inFIG.2. As illustrated, the bleed system14is disposed entirely inside the enclosure188, the air cooling system18is disposed outside of the enclosure188, and the fuel purge system16is disposed partially inside and partially outside of the enclosure188. In particular, the bleed system14is disposed inside of the enclosure188above and/or laterally to the side of the gas turbine engine12, such as partially above and to the side of the compressor section26, the combustion section28, and the turbine section30. The air cooling system18is disposed generally above the bleed system14, such that connections between the bleed system14and the air cooling system18are relatively short to minimize any pressure drop and heat transfer to the extracted bleed flow being used as the fuel purge flow. Similarly, the fuel purge system16is relatively close to both the air cooling system18and the manifold254of fuel supply system64, thereby helping to minimize a pressure drop and heat transfer from the interior of the enclosure188into the fuel purge flow and the fuel purge system16.

The gas turbine system10may be disposed on one or more mobile units or trailers300, which may include a platform302having a plurality of wheels304. One or more of the mobile units or trailers300may be configured to transport the gas turbine system10and the air cooling system18across the country on highways or other roads. Accordingly, the gas turbine system10may be a mobile power plant having the gas turbine system10and the air cooling system18disposed on one or more mobile units or trailers300. In certain embodiments, the air cooling system18may be disposed on a different mobile unit or trailer300than the gas turbine system10during transportation, wherein the air cooling system18is subsequently mounted on the top wall248of the enclosure188at a desired site while setting up the gas turbine system10for operation (e.g., power generation). The platform302may include a base panel306, a walking panel or floor308above the base panel306, and a floor cavity310disposed between the base panel306and the floor308. The floor308enables a technician or operator to walk inside the enclosure188to inspect, control, service, or perform other functions on the gas turbine system10.

The air cooling system18is disposed outside of the enclosure188, such that the heat exchanger232and the fan234are configured to provide cooling by exchanging heat with a surrounding environment. In the illustrated embodiment, the air cooling system18has the heat exchanger232and the fan234supported by the mount236, which is coupled to the top wall248of the enclosure188directly above a portion of the bleed system14. However, in certain embodiments, the mount236may support the fan234and the heat exchanger232on one of the sidewalls192, on the floor308of the trailer300, or on another component disposed on the floor308of the trailer300.

The mount236may include a skid312having a framework314coupled to a base316. The base316of the skid312is configured to mount on the top wall248, while the framework314extends upwardly from the base316to support the heat exchanger232, the fan234, and various piping and other equipment. The base316of the skid312may be coupled to the top wall248of the enclosure188via one or more fixed connections and/or removable connections, such as a plurality of threaded fasteners, clamps, ties, or any combination thereof.

The air cooling system18may include portions of the fuel purge circuit230, such as conduit portions of the circuit portions264and266. For example, the circuit portion264may include a branch conduit318disposed inside of the enclosure188and an inlet conduit320disposed outside of the enclosure188. The branch conduit318couples to and branches off from the bleed system14, such as at a location along the straight conduit168between the gimbal158and the valve assembly170of the bleed system14. The branch conduit318extends directly from the bleed system14to the top wall248, where the inlet conduit320couples with the branch conduit318at a flange coupling322. The branch conduit318may be a straight conduit to help minimize a pressure drop between the bleed system14and the air cooling system18. The branch conduit318and the inlet conduit320may be coupled together at the flange coupling322via a plurality of joints or fasteners, such as threaded fasteners or bolts, welded joints, clamps, ties, or any combination thereof. The inlet conduit320extends upwardly away from the top wall248and turns into the heat exchanger232to connect with the heat exchange conduits238as discussed above with reference toFIG.1. In certain embodiments, the air cooling system18may include the inlet conduit320and the flange coupling322at least partially supported by the mount236, e.g., coupled to and supported by the framework314on the skid312.

The circuit portion266has an outlet conduit324disposed outside of the enclosure188and a purge conduit326disposed inside of the enclosure188. Similar to the conduits318and320, the outlet conduit324and the purge conduit326may be coupled together at a flange coupling328, which may be disposed along the top wall248. In certain embodiments, the outlet conduit324and/or the purge conduit326may include or exclude insulation (e.g., one or more layers of exterior insulation). For example, while the insulation may help to reduce heat transfer into the conduits324and326, the conduits324and326may be sized sufficiently short as to minimize (or avoid any significant) heat transfer into the conduits324and326. The outlet conduit324may extend from the heat exchange conduit238of the heat exchanger232downwardly to the flange coupling328at the top wall248of the enclosure188. The flange coupling328may include flanges coupled together with a plurality of joints or fasteners, such as threaded fasteners or bolts, ties, clamps, welded joints, or a combination thereof. In certain embodiments, the air cooling system18may include the outlet conduit324and the flange coupling328at least partially supported by the mount236, e.g., coupled to and supported by the framework314on the skid312.

The flange couplings322and328may be disposed along the top wall248to provide easy access for connecting and installing the air cooling system18. For example, the flange couplings322and328may be disposed along a common plane with the base316of the skid312, or the flange couplings322and328may be slightly offset relative to the base316of the skid312(e.g., between 0 to 25, 1 to 15, or 2 to 10 centimeters vertical offset relative to the base316). In certain embodiments, the flange couplings322and328may be disposed at least partially or entirely inside of the enclosure188. However, the illustrated embodiment positions the flange couplings322and328partially or completely outside of the enclosure188to provide easy access for connecting and installing the air cooling system18. The purge conduit326of the fuel purge circuit230extends from the flange coupling328at the top wall248to the fuel manifold254at the combustion section28. The purge conduit326is routed through the interior of the enclosure188in a manner to reduce a length of the fuel purge circuit230, such that the fuel purge circuit230has a relatively low pressure drop and heat transfer from within the enclosure188into the fuel purge flow that flows through the fuel purge conduit326.

As illustrated, the purge conduit326includes an elbow330coupled to the flange coupling328at the top wall248, a straight conduit332coupled to the elbow330and extending lengthwise along the top wall248, an elbow333coupled to the straight conduit332, a straight conduit334coupled to the elbow333and extending downwardly away from the top wall248toward the floor208. For example, the straight conduit332may be generally parallel with the top wall248, while the straight conduit334may be generally crosswise or perpendicular to the top wall248. The purge conduit326also includes an elbow336coupled to the straight conduit334, and one or more conduits within a valve assembly338coupled to the elbow336. The valve assembly338may include one or more valves, such as custom or off-the-shelf valves, suitable for the pressures and temperatures associated with the gas turbine system10. Details of the valve assembly338will be discussed in further detail below with reference toFIGS.5and6.

Downstream of the valve assembly338, the purge conduit326also includes an elbow340coupled to the valve assembly338, a straight conduit342coupled to the elbow340and extending downwardly from the valve assembly338toward the floor308, an elbow344coupled to the straight conduit342, a straight conduit346coupled to the elbow344, an elbow348coupled to the straight conduit346, a flow distribution assembly350coupled to the elbow348, and one or more supply conduits352extending between the flow distribution assembly350and the fuel manifold254. The elbow340may turn and direct the straight conduit342in a crosswise or perpendicular direction relative to the top wall248, while the elbow344may turn and direct the straight portion346substantially parallel to the top wall248and the floor308. The illustrated embodiment of the purge conduit326also positions the elbow344, the straight conduit346, and the elbow348in the floor cavity310between the floor308and the base panel306. The elbow348turns the purge conduit326upwardly from the floor308to the flow distribution assembly350, which may include one or more manifolds, valves, elbows, straight conduit portions, or any combination of flow control equipment, to distribute a fuel purge flow from the purge conduit326into the fuel supply system64, such as into the fuel manifold254.

In some embodiments, the flow distribution assembly350may include fuel flow distribution, fuel purge flow distribution, diluent flow distribution, or any combination thereof. For example, the flow distribution assembly350may be configured to supply one or more fuels, such as the liquid fuel, a gas fuel, or any combination thereof, into the supply conduits352leading into the fuel manifold254. The fuel distribution assembly350also may be configured to supply one or more diluents, such as steam, nitrogen, a recirculated exhaust gas, or any combination thereof, through one or more of the supply conduits352into the fuel manifold254. Additionally, the flow distribution assembly350may be configured to distribute the fuel purge flow from the purge conduit326through the supply conduits352into the fuel manifold254. Accordingly, the fuel purge flow from the purge conduit326may be configured to purge the fuel supply system64starting at the flow distribution assembly350, the supply conduits352, the fuel manifold254, the fuel nozzles60, or any combination thereof.

The purge conduit326may include one or mounting components. For example, the valve assembly338along the purge conduit326may include a wall mount354, which is configured to mount the valve assembly338on one of the sidewalls192. The purge conduit326also may include one or more gimbals, spring hangers, or other mounts disposed along the elbows and straight conduits of the fuel purge circuit230. In the illustrated embodiment, the purge conduit326of the fuel purge circuit230has a relatively short length from the air cooling system18to the fuel supply system64, such that the purge conduit326does not create a substantial pressure drop and the purge conduit326does not become substantially heated by the heat generated by the gas turbine engine12.

FIG.3is a partial perspective view of an embodiment of the gas turbine system10ofFIGS.1and2, further illustrating details of the air cooling system18mounted to the top wall248of the enclosure188of the gas turbine system10. As illustrated, the base316of the skid312includes mounting brackets370and372disposed along the top wall248adjacent to the opposite walls192of the enclosure188. Each of the mounting brackets370and372may include a beam, a plate, an elongated C-shaped channel, or any suitable structure extending along the top wall248. The mounting brackets370and372are removably coupled to the top wall248via a plurality of fasteners374, such as threaded fasteners or bolts. However, the mounted brackets370and372may be removably coupled to the top wall248via clamps, ties, dovetail joints, male and female railing structures, or any combination thereof. In some embodiments, the mounting brackets370and372may be fixedly coupled to the top wall248via welded joints, brazed joints, or another fixed connection.

The framework314is disposed on top of the mounting brackets370and372, wherein the framework314includes horizontal supports or beams376and378extending crosswise relative to the opposite sidewalls192and the mounting brackets370and372. For example, the horizontal supports or beams376and378may be perpendicular to the mounted brackets370and372, and may extend across the top wall248and connect with each of the mounted brackets370and372. The horizontal supports or beams376and378may be fixedly or removably coupled to the mounting brackets370and372. For example, the horizontal supports or beams376and378may be welded or brazed onto the mounting brackets370and372, or a plurality of fasteners such as threaded bolts may be used to connect the components together.

The framework314further includes the legs246disposed about the heat exchanger232and the fan234, such as four legs246extending vertically upward from the horizontal supports or beams376and378on opposite sides of the heat exchanger232and the fan234. The legs246also may be supported via one or more angle supports or braces380on opposite sides of the heat exchanger232and the fan234. The braces380may be coupled to the legs246via fixed joints such as welds, removable joints such as threaded fasteners, or any combination thereof. Similarly, the legs246may be coupled to the horizontal supports or beams376and378via fixed joints such as welds, removable joints such as threaded fasteners, or any combination thereof.

The framework314also may include vertical supports or legs382,384, and386extending vertically upward from the horizontal supports or beams376and378. The legs382,384, and386may be coupled to the horizontal supports or beams376and378via fixed joints such as welds, removable joints such as threaded fasteners, or a combination thereof. The framework314also includes angle supports or braces388and390, which extend between and couple to the legs382and384and the horizontal supports or beams376and378at the mounting bracket370via fixed joints such as welds, removable joints such as threaded fasteners, or a combination thereof. The angle supports or braces388and390may be disposed at angles that are fixed or adjustable, such as by including adjustment mechanisms (e.g., a plurality of vertical mounting positions) along the legs382and384.

The leg386also couples with conduit supports392and394, which may be horizontal beams supported by angle supports or braces396. The conduit supports392and394may be coupled to the leg386via a fixed joint such as a weld, a removable joint such as threaded fasteners, or a combination thereof. Similarly, the braces396may be coupled to the respective conduit supports392and394via fixed joints such as welds, removable joints such as threaded fasteners, or a combination thereof. The leg386also couples with a horizontal cross-support398extending between the horizontal supports or beams376and378. The horizontal support398may be coupled to the horizontal supports or beams376and378via fixed joints such as welds, removable joints such as threaded fasteners, or a combination thereof. The conduit supports392and394provide support for the inlet conduit320between the flange coupling322and the connection with the heat exchanger232.

As illustrated, the inlet conduit320includes the flange coupling322, a straight conduit400coupled to the flange coupling322, a gimbal402coupled to the straight conduit400, an elbow404coupled to the gimbal402, a straight conduit406coupled to the elbow404, a gimbal408coupled to the straight conduit406, an elbow410coupled to the gimbal408, a straight conduit412coupled to the elbow410, a gimbal414coupled to the straight conduit412, and straight conduits416and418coupled together at a flange connection420. The straight conduit416is coupled to the gimbal414, the straight conduit418is coupled to the heat exchanger232via the heat exchange conduit238as discussed above with reference toFIG.1, and the flange coupling420includes mating flanges422and424coupled together via a plurality of fasteners426. The fasteners426may include threaded fasteners such as bolts, nuts, or any combination thereof. As illustrated, the straight conduit400is vertical or substantially perpendicular relative to the top wall248, while the straight conduit406,412,416, and418are generally horizontal or parallel relative to the top wall248. Additionally, the straight conduits400and406are generally crosswise relative to one another, such as perpendicular via the turn at the elbow404. Similarly, the straight conduits406and412are generally crosswise relative to one another, such as perpendicular to one another via the turn at the elbow410.

The outlet conduit324extends between the flange coupling328and the heat exchanger232, wherein the outlet conduit324may be coupled to the heat exchanger232via the heat exchange conduit238as discussed in detail above with reference toFIG.1. As illustrated, the outlet conduit324may include an elbow428coupled to the flange coupling328, a straight conduit430coupled to the elbow428, an elbow432coupled to the straight conduit430, a flange coupling434coupled to the elbow432and an elbow436, and a straight conduit438coupled to the elbow436. The flange coupling434includes opposite flanges440and442coupled together via a plurality of fasteners444, such as threaded bolts, threaded nuts, or a combination thereof. The straight conduit438may be coupled to the heat exchanger232via the heat exchange conduit238and/or one or more additional fluid couplings. The straight conduits418and438also may be supported via one or more additional conduit supports coupled to the framework314.

In certain embodiments, the inlet conduit320and the outlet conduit324may be coupled to the framework314, such that the inlet and outlet conduits320and324are part of a self-contained package with the framework314, the heat exchanger232, the fan234, and various other components of the air cooling system18. Accordingly, the air cooling system18may be installed on the top wall248of the enclosure188by lowering the skid312onto the top wall248, fastening the mounting brackets370and372onto the top wall248via the fasteners374, and connecting the flange couplings322and328with the branch conduit318and the purged conduit326within the enclosure188as discussed above with reference toFIG.2.

As illustrated, the skid312may further include a plurality of lift couplings446coupled to one or more of the legs246,382, and384. The lift couplings446may include hooks, loops, or other connectors configured to connect with cables of a lift, such as a crane configured to lift and lower the air cooling system18onto the top wall248of the enclosure188. Again, as discussed above, the air cooling system18is disposed in an environment surrounding the enclosure188, such that the heat exchanger232and the fan234use ambient air to transfer heat away from the fuel purge flow in the inlet and outlet conduits320and324. Accordingly, the air cooling system18may be used at any location without the need for a water supply or other coolant supply, which may not be available for use with the gas turbine system10.

FIG.4is a top view of an embodiment of the gas turbine system10ofFIGS.1-3, further illustrating details of the air cooling system18mounted on the top wall248as illustrated inFIG.3. As illustrated inFIG.4, the framework314has the mounting brackets370and372generally parallel with the opposite sidewalls192, while the horizontal supports or beams376and378are generally perpendicular to the opposite sidewalls192and the mounting brackets370and372. Additionally, the mounting brackets370and372are generally parallel to one another, and the horizontal supports or beams376and378are generally parallel with one another. The legs246are coupled to the horizontal support or beams376and378at a first end portion460of the skid312, while the conduit supports392and394and the inlet conduit320are generally disposed at a second end portion462of the skid312. As further illustrated inFIG.4, the flange connections322and328are generally disposed on opposite sides of the skid312at the opposite first and second end portions460and462. Accordingly, the skid312of the air cooling system18is generally disposed between the flange couplings322and328to help reduce the length of the inlet and outlet conduits320and324, while also maintaining close proximity with the bleed system14and the fuel purge system16within the enclosure188as discussed above with reference toFIG.2.

FIG.5is a partial perspective view of the fuel purge system16ofFIG.2, further illustrating details of the purge conduit326, the valve assembly338, and the wall mount354. As illustrated, the valve assembly338includes a double block and bleed valve assembly470having a block and bleed valve472and a block and bleed valve474disposed along the purge conduit326. The illustrated valve assembly338, including the double block and bleed valve assembly470, is one non-limiting example of a valve assembly that may be used with the fuel purge system16. The valve assembly338may be an off-the-shelf valve assembly or a custom valve assembly suitable for the temperatures and pressures associates with the gas turbine system10. The block and bleed valve472is coupled to the purge conduit326at an inlet conduit476coupled to the elbow336, while the block and bleed valve474is coupled to the purge conduit326at an inlet conduit478coupled to a J-shaped conduit480coupled to the elbow340. Additionally, the J-shaped conduit480is coupled to a J-shaped conduit482, which in turn is coupled to the inlet conduit476. The double block and bleed valve assembly470is also coupled to a vent conduit484, which is configured to vent or bleed a flow from the block and bleed valves472and474.

The block and bleed valves472and474are also coupled to the wall mount354, which includes wall mounts486and488. Each of the wall mounts486and488includes a horizontal support or rail490extending between opposite mounting brackets492and494. The mounting brackets492and494may be coupled to the horizontal support or rail490via a plurality of fasteners496, such as threaded fasteners or bolts. Additionally, the mounting brackets492and494may be coupled to the sidewall192of the enclosure188via a plurality of fasteners498, such as threaded fasteners or bolts. The horizontal supports or rails490may be generally parallel with one another in the wall mounts486and488. Additionally, although the horizontal support or rails490are shown removably coupled with the mounting brackets492and494, the horizontal support or rails490may be fixedly coupled to the mounting brackets492and494via a welded joint, a brazed joint, or a one piece construction of the components.

The wall mounts486and488further include a mating rail mount500configured to slide lengthwise along the horizontal support or rail490. For example, the rail mount500may be coupled to the horizontal support or rail490via a hollow-rectangular coupling or a C-shaped coupling disposed about the horizontal support or rail490, such that the rail mount500can move lengthwise along the horizontal support or rail490while blocking lateral separation away from the horizontal support or rail490. In operation, the connection between the rail mount500and the horizontal support or rail490allows horizontal movement of the purge conduit326and the valve assembly338lengthwise along the horizontal support or rail490in each of the wall mounts486and488. The horizontal movement enabled by the wall mounts486and488allows for thermal expansion and contraction of components, including the purge conduit326and sections of the gas turbine system10, during operation of the gas turbine system10.

FIG.6is a partial perspective view of an embodiment of the valve assembly338as illustrated inFIG.5, further illustrating details of the wall mount354. In particular,FIG.6illustrates a connection between the horizontal support or rail490and the rail mount500of the wall mount486. The wall mount488has substantially the same construction as the wall mount486. As illustrated inFIG.6, the horizontal support or rail490is a flat rectangular plate extending from the mounting bracket492in a horizontal direction toward the mounting bracket494. The rail mount500substantially surrounds the horizontal support or rail490. For example, in the illustrated embodiment, the rail mount500includes a rectangular enclosure502defining a rectangular slot504, which receives the horizontal support or rail490. The rectangular enclosure502includes plates506,508,510, and512arranged in a rectangular shape to define the rectangular enclosure502and the rectangular slot504. For example, the plates506and508are substantially flat and parallel with one another, while the plates510and512are substantially flat and parallel with one another. Although the rail mount500ofFIG.6has a rectangular enclosure502, the rail mount500may include other types of attachment couplings (e.g., C-shaped couplings) configured to block separation between the rail mount500and the horizontal support or rail490, while allowing movement of the rail mount500lengthwise along the horizontal support or rail490as indicated by arrow514. Again, the wall mount354having the horizontal support or rail490and the rail mount500is configured to allow movement of the valve assembly338and the purge conduit326within the enclosure188to accommodate vibration, movement of parts, or other fitment issues within the enclosure188. For example, the connection between the horizontal support or rail490and the rail mount500may accommodate thermal expansion and contraction of components within the gas turbine system10.

Technical effects of the disclosed embodiments include air cooling, rather than water cooling, of a fuel purge system, which is configured to purge fuel (e.g., gas fuel and/or liquid fuel) from various fuel passages of a fuel supply system of a gas turbine system. The air cooling is achieved with an air cooling system mounted outside of an enclosure surrounding the gas turbine system, wherein the air cooling system includes one or more heat exchangers and fans. The air cooling system may be a self-contained system disposed on a skid, such that the skid can be mounted on a top wall of the enclosure and quickly connected to the fuel purge system. The air cooling system eliminates the need for a local water supply, which may not be available or feasible at certain sites.

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

A system includes an air cooling system having a heat exchanger, a fan, and a mount. The heat exchanger includes an inlet, an outlet, and a heat exchange conduit between the inlet and the outlet. The inlet is configured to couple to a bleed system of a gas turbine system to extract a bleed flow. The heat exchanger is configured to cool the bleed flow along the heat exchange conduit in a surrounding air to produce a cooled bleed flow. The outlet is configured to couple to a fuel purge system of the gas turbine system to supply the cooled bleed flow as a fuel purge flow. The fan is configured to force an airflow from the surrounding air through the heat exchanger. The mount is configured to mount the air cooling system outside of an enclosure surrounding the gas turbine system.

The system of the preceding clause, including the gas turbine system disposed inside of the enclosure.

The system of any preceding clause, including a mobile power plant having the gas turbine system and the air cooling system mounted on one or more trailers.

The system of any preceding clause, including the enclosure, wherein the mount is coupled to a top wall of the enclosure.

The system of any preceding clause, including the enclosure, wherein the bleed system is disposed inside of the enclosure, and the bleed system is coupled to a compressor of the gas turbine system.

The system of any preceding clause, wherein a branch conduit is coupled to the bleed system, the branch conduit extends to a wall of the enclosure, and the inlet of the heat exchanger is coupled to the branch conduit via an inlet conduit.

The system of any preceding clause, wherein the branch conduit extends directly from the bleed system to the wall.

The system of any preceding clause, wherein the fuel purge system includes a purge conduit disposed inside of the enclosure, the purge conduit extends to the wall of the enclosure, and the outlet of the heat exchanger is coupled to the purge conduit via an outlet conduit.

The system of any preceding clause, wherein the fuel purge system includes a valve assembly disposed along the purge conduit, and the valve assembly includes a wall mount having a rail mount coupled to and movable along a rail.

The system of any preceding clause, wherein the mount includes a skid having a framework disposed on a base.

The system of any preceding clause, wherein the air cooling system includes an inlet conduit coupled to the inlet and extending to a first flange coupling configured to couple with a branch conduit of the bleed system inside of the enclosure, and an outlet conduit coupled to the outlet and extending to a second flange coupling configured to couple with a purge conduit of the fuel purge system inside of the enclosure.

The system of any preceding clause, wherein the first and second flange couplings are disposed on opposite sides of the skid.

The system of any preceding clause, wherein the first and second flange couplings are configured to couple with the branch conduit and the purge conduit, respectively, along a top wall of the enclosure, wherein the skid is configured to mount on the top wall of the enclosure.

The system of any preceding clause, wherein at least one of the inlet conduit and the outlet conduit is supported by the framework.

A method includes intaking, into an inlet of a heat exchanger of an air cooling system, a bleed flow extracted from a bleed system of a gas turbine system. The method further includes cooling, along a heat exchange conduit of the heat exchanger in a surrounding air, the bleed flow to produce a cooled bleed flow. The method further includes supplying, out of an outlet of the heat exchanger, the cooled bleed flow as a fuel purge flow into a fuel purge system of the gas turbine system. The method further includes forcing, via a fan of the air cooling system, an air flow from the surrounding air through the heat exchanger, wherein the air cooling system includes a mount configured to mount the air cooling system outside of an enclosure surrounding the gas turbine system.

The method of the preceding clause, including purging a fuel from a fuel supply system of the gas turbine engine via the fuel purge flow supplied to the fuel purge system.

The method of any preceding clause, including controlling a temperature of the fuel purge flow at least partially by controlling the air cooling system.

The method of any preceding clause, including mounting the air cooling system to a top wall of the enclosure via the mount.

A method includes mounting, via a mount, an air cooling system outside of an enclosure surrounding a gas turbine system. The air cooling system includes a heat exchanger having an inlet, an outlet, and a heat exchange conduit between the inlet and the outlet. The inlet is configured to couple to a bleed system of the gas turbine system to extract a bleed flow. The heat exchanger is configured to cool the bleed flow along the heat exchange conduit in a surrounding air to produce a cooled bleed flow. The outlet is configured to couple to a fuel purge system of the gas turbine system to supply the cooled bleed flow as a fuel purge flow. The air cooling system also includes a fan configured to force an airflow from the surrounding air through the heat exchanger.

The method of the preceding clause, wherein mounting the air cooling system includes coupling the mount to a wall of the enclosure and positioning the heat exchanger and the fan above the enclosure.