Liquid fuel vapor purging system and method for gas turbine engines

Abstract

To provide an improved purge system for a liquid fuel circuit of a gas turbine engine.SOLUTION: A system is provided with an ejector 18 having an outer wall 208 extending circumferentially about a flow path 203. The outer wall 208 has a throat section 214 along the flow path 203, and a diverging section 216 downstream from the throat section 214 along the flow path 203. The ejector 18 includes a gas inlet 202 configured to supply a gas into the flow path 203, and a water inlet 206 configured to supply water into the flow path 203. The ejector 18 is configured to produce steam in response to mixing of the water and the gas along the flow path 203. The system also includes a controller configured to control flows of the gas and the water to produce the steam for a steam purge of a liquid fuel circuit.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The subject matter disclosed herein relates to gas turbine engines, and more particularly, to fuel circuits of gas turbine engines.

Background Art

[0002] A gas turbine engine can include one or more fuel circuits, such as a liquid fuel circuit and a gas fuel circuit. Unfortunately, the heat generated by the gas turbine engine can cause coking within the liquid fuel circuit. If the liquid fuel circuit is not properly purged, coking can cause fuel lines, valves, and fuel nozzles to become clogged. As a result, coking can lead to undesirable downtime of the gas turbine engine. There is a need for an improved purge system for the liquid fuel circuit of a gas turbine engine.

Summary of the Invention

[0003] Certain embodiments that are within the scope equivalent to the invention claimed at the time of filing are summarized below. These embodiments are not intended to limit the scope of the claimed invention; rather, these embodiments are only intended to provide an overview of possible forms of the invention. In fact, the invention can encompass various forms that may be similar to or different from the embodiments described below.

[0004] In a first embodiment, the system includes an ejector having an outer wall that extends circumferentially around a flow path, the outer wall having a throat section along the flow path and a diverging section downstream of the throat section along the flow path. The ejector has a gas inlet configured to supply gas into the flow path and a water inlet configured to supply water into the flow path. The ejector is configured to generate steam in response to the mixing of water and gas along the flow path. The system also includes a controller configured to control the flow of gas and water to generate steam for the steam purge of the liquid fuel circuit.

[0005] In a second embodiment, the system includes a liquid fuel circuit and a steam purge system configured to purge the liquid fuel circuit with steam, the steam purge system including an ejector. The ejector includes an outer wall extending circumferentially around a flow path, the outer wall having a throat section along the flow path and a diversion section downstream of the throat section along the flow path. The ejector has a gas inlet configured to supply gas into the flow path and a water inlet configured to supply water into the flow path. The ejector is configured to generate steam in response to a mixture of water and gas along the flow path.

[0006] In a third embodiment, the method includes the step of controlling the flow of gas and water to an ejector of a vapor purge system fluid-coupled to a liquid fuel circuit. The ejector includes an outer wall extending circumferentially around a flow path, the outer wall having a throat section along the flow path, and the outer wall having a diversion section downstream of the throat section along the flow path. The ejector has a gas inlet configured to supply gas into the flow path and a water inlet configured to supply water into the flow path. The ejector is configured to generate vapor in response to a mixture of water and gas along the flow path. The method also includes the step of opening the vapor flow from the ejector to the liquid fuel circuit in order to purge the liquid fuel circuit.

[0007] These and other features, aspects, and advantages of this technology will be better understood by reading the following embodiments for carrying out the invention with reference to the accompanying drawings, in which similar letters throughout the drawings represent similar parts. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of one embodiment of a gas turbine system having a steam purge system for purging a liquid fuel circuit, the steam purge system including an ejector that generates steam by combining water and a high-temperature gas (e.g., high-temperature compressed air) to purge the liquid fuel circuit. [Figure 2]Figure 1 is a schematic diagram of one embodiment of a gas turbine system, showing a steam purge system coupled to a liquid fuel circuit extending to multiple combustors having multiple fuel nozzles (e.g., dual fuel nozzles). [Figure 3] Figures 1 and 2 are schematic diagrams of one embodiment of a steam purge system ejector, showing the convergence section, throat, and diversion section of the ejector. [Figure 4] Figures 1 to 3 are schematic diagrams of one embodiment of a steam purging system coupled to a combustor having multiple fuel nozzles (e.g., dual fuel nozzles). [Figure 5] Figures 1-4 are flowcharts illustrating one embodiment of the process of purging liquid fuel from a liquid fuel circuit using the steam purging system. [Modes for carrying out the invention]

[0009] One or more specific embodiments of the present technology are described below. In an effort to provide a concise description of these embodiments, some features of the actual embodiments may not be described herein. In developing any such actual embodiment, it should be understood that, as with any engineering or design project, decisions specific to a number of embodiments must be made to achieve the developer's particular goals, including compliance with system-related and business-related constraints, which may differ from embodiment to embodiment. Furthermore, it should be understood that while such development efforts may be complex and time-consuming, they will still be considered by those skilled in the art to benefit from this disclosure as merely routine design, fabrication, and manufacturing endeavors.

[0010] When describing elements of various embodiments of the present invention, the articles "a," "an," "the," and "said" indicate that one or more elements exist. The terms "equip," "include," and "have" are comprehensive and indicate that additional elements other than those listed may exist.

[0011] Figure 1 is a schematic diagram of one embodiment of a gas turbine system 10 having a gas turbine engine 12, a dual fuel (supply) system 14, and a steam purge system 16. As will be described in more detail below, the steam purge system 16 includes an ejector 18 configured to receive water (e.g., a stream of water) from a feedwater unit 20 and gas (e.g., hot compressed air) from a gas supply unit 22, and to generate a stream of steam, such as saturated steam, for use when purging the liquid fuel circuit 24 of the gas turbine system 10. For example, the ejector 18 of the steam purge system 16 may be configured to generate steam and supply it to the liquid fuel circuit 24 when switching between the liquid fuel supply system 26 and the gas fuel supply system 28, and / or when stopping the operation of the liquid fuel supply system 26. The steam supplied through the liquid fuel circuit 24 is configured to purge any residual liquid fuel from the liquid fuel circuit 24, thereby helping to reduce the possibility of coking in the liquid fuel circuit 24.

[0012] The illustrated gas turbine 10 includes a gas turbine enclosure 30 that houses a gas turbine engine 12. The gas turbine engine 12 includes an intake section 32, a compressor section 34, a combustion section 36, a turbine section 38, and a load 40 (e.g., a generator). The intake section 32 includes an intake duct 42 having a plurality of intake louvers 44, one or more air filters 46, and one or more 48 (e.g., an anti-icing system, a silencer baffle, etc.). The compressor section 34 includes a single-stage or multi-stage compressor 50 having one or more stages of compressor blades 52 coupled to a compressor shaft 54 ​​inside a compressor casing 56. For example, the compressor 50 may include compressor stages of one to 28 stages of compressor blades 52 coupled to the shaft 54. Each stage of the compressor 50 has multiple stages of compressor blades 52 arranged circumferentially around the shaft 54. The compressor section 34 outputs a compressed air flow 94 to the combustion section 36.

[0013] The combustion section 36 includes one or more combustors 58 having one or more fuel nozzles 60. For example, the combustion section 36 may include two to fourteen combustors 58, each combustor 58 including one to six fuel nozzles 60. As can be seen from the following description and details, each fuel nozzle 60 is configured for dual-fuel operation (e.g., dual-fuel nozzle) so that the gas turbine engine 12 can be configured to selectively switch between liquid-fuel operation via a liquid-fuel supply system 26 and gas-fuel operation via a gas-fuel supply system 28. For example, the liquid-fuel supply system 26 may be configured to supply liquid fuel to the fuel nozzles 60 via a plurality of liquid-fuel lines 62, and the gas-fuel supply system 28 may be configured to supply gas-fuel to the fuel nozzles 60 via a plurality of gas-fuel lines 64. In the illustrated embodiment, the liquid-fuel lines 62 extend from the liquid-fuel supply section 26 to a manifold 66 coupled to the fuel nozzles 60 of each combustor 58. Therefore, the fuel manifold 66 distributes liquid fuel to each of the fuel nozzles 60 of each combustor 58. A gas fuel line 64 can be connected to the fuel nozzles 60 in a similar manner. The fuel nozzles 60 facilitate the combustion of the fuel (e.g., liquid or gaseous fuel) in the combustor 58 and then output the high-temperature combustion gas 96 to the turbine section 38.

[0014] The turbine section 38 includes a single-stage or multi-stage turbine 68 having one or more stages of turbine blades 70 coupled to a turbine shaft 72 within a turbine casing 73. For example, the turbine 68 may include one to eight stages of turbine blades 70 coupled to the shaft 72. Each stage of the turbine 68 has multiple stages of compressor blades 70 arranged circumferentially around the shaft 72. The turbine 68 and the compressor 50 are rotatably coupled to each other via an intermediate shaft 74 connected to shafts 54 and 72. Furthermore, the load 40 is rotatably coupled to the turbine 68 via a shaft 76. In certain embodiments, one or more of the shafts 54, 72, 74, and 76 may be integrated as a common shaft. Also, in certain embodiments, the load 40 may be rotatably coupled to the gas turbine engine 12 at the compressor 50 side end of the gas turbine engine 12, rather than at the turbine 68 side end of the gas turbine engine 12. The gas turbine enclosure 30 generally encloses and houses the entire gas turbine engine 12, including the compressor section 34, the combustion section 36, and the turbine section 38. However, the dual fuel system 14, the steam purge system 16, and the load 40 are generally located outside the gas turbine enclosure 30.

[0015] The dual fuel system 14 includes various tanks, pipelines, valves, pumps, manifolds, filters, and other support equipment for supplying both liquid and gaseous fuel to the gas turbine engine 12. In the illustrated embodiment, the liquid fuel supply system 26 may include one or more fuel tanks 78, one or more valves 80, one or more pumps 82, and one or more manifolds and distribution valves 84. One or more pumps 82 are configured to force a flow of liquid fuel from the fuel tanks 78, the valves 80 are configured to open and close the flow from the fuel tanks 78, and the manifolds and valves 84 are configured to distribute the flow of liquid fuel through a plurality of liquid fuel lines 62 to various combustors 58 and fuel nozzles 60.

[0016] Similarly, the gas fuel supply system 28 may include one or more fuel filters 86, one or more valves 88, and one or more manifold and distribution valves 90. The gas fuel supply system 28 may also include one or more fuel storage units, such as a fuel tank and / or pipeline. The gas fuel supplied by the fuel tank and / or pipeline may be pressurized, and as a result, the gas fuel supply system 28 is configured to control the flow of gas fuel by opening and closing the valves 88, allowing the gas flow to pass through the manifold and distribution valves 90 and through a plurality of gas fuel lines 64 to various fuel nozzles 60.

[0017] During operation, the gas turbine engine 12 receives an airflow 92 through the intake section 32, compresses the airflow 92 with one or more stages of compressor blades 52 in the compressor section 34, and directs the compressed airflow 94 to the combustors 58 in the combustion section 36. The engine 12 then mixes the compressed airflow 94 with fuel (e.g., liquid fuel from the liquid fuel supply system 26 and / or gaseous fuel from the gaseous fuel supply system 28) in each of the fuel nozzles 60, ignites the fuel-air mixture, generates hot combustion gases 96 in the combustion chambers 98 of each combustor 58, and outputs the hot combustion gases 96 to the turbine section 38. The engine 12 directs the hot combustion gases 96 through the turbine section 38, thereby driving the rotation of the turbine blades 70 as the hot combustion gases 96 expand through the turbine section 38. When the high-temperature combustion gas 96 drives the rotation of the turbine section 38, the turbine shaft 72 rotates the shaft 74 connected to the compressor shaft 54 ​​and the shaft 76 connected to the load 40. Thus, the turbine section 38 drives the rotation of the compressor 50 to compress the intake air 92 and drives the load 40, such as a generator.

[0018] As described above, the illustrated steam purge system 16 includes a water supply unit 20, a gas supply unit 22, and an ejector 18. The water supply unit 20 may include one or more water tanks 100 and one or more water pumps 102 configured to store and pump the water flow to the ejector 18, respectively. The gas supply unit 22 may include an atomization module 103, such as an air atomization module, configured to facilitate the atomization of liquid fuel in the fuel nozzle 60. Thus, the gas supply unit 22, specifically the atomization module 103, may further include one or more gas supply components 104 and one or more compressors 106. For example, the compressor 106 may include an air compressor for the atomization module 103 (e.g., an atomizing air compressor). The gas supply components 104 may include a filter, a check valve, a tank, a pressure regulator, and other flow control equipment. In some embodiments, the gas supply component 104 may include one or more additional heat sources (e.g., heaters or heat exchangers) configured to raise the temperature of the compressed gas from the compressor 106. However, the compressor 106 may be configured to output compressed gas (e.g., compressed air) at a pressure and temperature sufficient to convert water into steam in the ejector 18 without additional heat sources. While the illustrated embodiment can use high-temperature compressed air as the gas, in some embodiments, the gas supply unit 22 may be configured to supply a high-temperature compressed inert gas such as nitrogen.

[0019] The water supply unit 20 is configured to supply water to the ejector 18 via a water line 108 having one or more flow control devices such as a valve 110, a check valve 112, a water tank 114 (e.g., a buffer tank), and a valve 116. For example, valves 110 and 116 may be rotary valves, gate valves, ball valves, or other suitable actuator-controlled valves that can be selectively opened and closed in response to control signals from the controller 118. The check valve 112 is configured to prevent backflow of gas (e.g., hot compressed air) from the gas supply unit 22 and / or backflow of water from the ejector 18 toward the water supply unit 20. The water tank 114 is configured to provide a water buffer between the check valve 112 and the valve 116. Valves 110 and 116 are configured to open and close the water flow through the water line 108 from the water supply unit 20 toward the ejector 18.

[0020] Similarly, the gas supply unit 22 is configured to supply a gas flow (e.g., a high-temperature compressed air flow) to the ejector 18 along the gas line 120. The gas line 120 may include a valve 122 configured to selectively open and close the gas flow in response to signals from one or more flow control devices, such as a controller 118. Here again, as with valves 110 and 116, valve 122 may be an actuator-controlled valve such as a ball valve, a gate valve, a rotary valve, or another suitable actuator-controlled valve.

[0021] As will be further explained below, water from the water supply unit 20 and gas (e.g., high-temperature compressed air) from the gas supply unit 22 are supplied to the ejector 18, where the gas mixes with the water and converts the water into steam. In particular, the relatively high temperature and pressure of the gas (e.g., high-temperature compressed gas) helps to convert the water into steam within the ejector 18. Furthermore, the Venturi effect of the ejector draws water into the gas flowing through the ejector 18, thereby facilitating the flow of water and mixing within the ejector 18. As the water-gas mixture (e.g., water-air mixture) mixes and expands within the ejector 18, the pressure and heat changes transferred from the gas (e.g., high-temperature compressed air) to the water help to convert the water into steam. In certain embodiments, the steam initially formed within the ejector 18 may not have the desired properties for purging the liquid fuel circuit 24 (e.g., the steam may not immediately become saturated steam). Therefore, the steam purge system 16 can be configured to address the transition of steam to saturated steam before purging the liquid fuel circuit 24.

[0022] The outlet 124 of the ejector 18 is connected to an output line 126 having a valve 128, the manifold 130 is connected to the output line 126, and several distribution lines 132 are connected to the manifold 130 and extend to the liquid fuel line 62 of the liquid fuel circuit 24. In addition, a vent line 134 is connected to the output line 126 between the ejector 18 and the valve 128, and the vent line 134 includes a valve 136 and a vent / drain 138. When the controller 118 initiates a steam purge using the steam purge system 16, the water and gas supplied to the ejector 18 may initially generate steam that is not fully saturated. Therefore, the controller 118 can control the valve 128 to close and the valve 136 to open, thereby preventing steam from flowing through the output line 126 to the manifold 130 and exhausting the steam through the vent line 134 to the vent / drain 138. The controller 118 may be configured to perform this initial exhaust of steam through the vent line 134 based on a predetermined time delay or other criteria. However, if the controller 118 determines that the steam is or should be saturated steam, the controller 118 is configured to open valve 128 and close valve 136, thereby stopping the exhaust of steam through the vent line 134 and allowing the flow of steam (in this case saturated steam) to the manifold 130 through the output line 126.

[0023] Next, the manifold 130 distributes the saturated vapor to the plurality of liquid fuel lines 62 via the distribution lines 132. Each distribution line 132 can include a check valve 140 configured to prevent backflow of the liquid fuel from the liquid fuel line 62 toward the manifold 130 and the ejector 18. Further, each of the liquid fuel lines 62 can include a check valve 141 configured to prevent backflow of the vapor and fuel toward the liquid fuel supply system 26 through the liquid fuel line 62. Thus, when the liquid fuel supply system 26 is not supplying liquid fuel to the fuel nozzle 60 via the liquid fuel circuit 24, the vapor purge system 16 supplies saturated vapor via the liquid fuel line 62 to pass through the entire liquid fuel circuit 24 downstream of the check valves 140 and 141, including the liquid fuel line 62, the manifold 66, the fuel nozzle 60, and any other flow control devices along the liquid fuel line 62. As a result, the saturated vapor helps to remove residual liquid fuel in the liquid circuit 24 and reduce the possibility of coke formation in the liquid fuel circuit 24.

[0024] The vapor purge of the liquid fuel circuit 24 by the vapor purge system 16 may be performed for a predetermined amount of time periodically or during scheduled maintenance. For example, the vapor purge can be performed for 5 - 10 minutes every 1 - 6 months of operation of the gas turbine system 10. Further, the vapor purge system 16 can be configured to perform the vapor purge of the liquid fuel circuit 24 while the gas turbine system 10 is operating, e.g., operating on gas fuel from the gas fuel supply system 28.

[0025] In the illustrated embodiment, the vapor purge system 16 is at least partially disposed within a housing 142 coupled externally to the gas turbine enclosure 30 in the high location region 144, which can be disposed at least partially or entirely vertically above the fuel nozzle 60 and / or the combustor 58. Thus, the liquid fuel line 62 passing through the housing 142 can then enter the gas turbine enclosure 30 at a high location such that the liquid fuel line 62 slopes downwardly toward each of the combustor 58 and the fuel nozzle 60. In this regard, the liquid fuel is driven by gravity downward into and through the fuel nozzle 60 and the combustor 58, thereby serving to facilitate the vapor purge of the liquid fuel within the liquid fuel circuit 24 by gravity.

[0026] As shown, the liquid fuel line 62 passes through the housing 142, the check valve 141 is disposed along the liquid fuel line 62 within the housing 142, the check valve 140 is disposed along the distribution line 132 within the housing 142, and one or more of the other components of the vapor purge system 16 may also be disposed within the housing 142. For example, in certain embodiments, the housing 142 may also house the manifold 130, valves 128 and 136, ejector 18, valves 110, 112, 116, 122, and the water tank 114. Further, in certain embodiments, the housing 142 can house the gas supply 22 and the liquid fuel supply system 26. In some embodiments, a separate housing 143 (shown in dashed lines) can house the manifold 130, valves 128 and 136, ejector 18, valves 110, 112, 116, 122, water tank 114, gas supply 所22, and the liquid fuel supply system 26.

[0027] In some embodiments, as described below with reference to Figure 2, the steam purge system 16 may include a plurality of housings 142, each housing a portion of the liquid fuel line 62 and the corresponding distribution line 132, as well as the associated components of the steam purge system 16. Here again, the liquid fuel line 62, check valve 140, distribution line 132, and check valve 141 are located in a high-altitude region 144, so that the saturated steam supplied to the liquid fuel line 62 benefits from gravity and, during the steam purge, pushes the liquid fuel through the liquid fuel circuit 24 to the combustor 58 via the fuel nozzle 60. After the steam purge via the steam purge system 16 is complete, the gas turbine 10 may open a valve 146 located along an air purge line 148 between the compressor 50 and the liquid fuel line 62 of the liquid fuel circuit 24. The air purge line 148 is configured to extract the flow of compressor air from the compressor 50 to further purge the liquid fuel line 62 after the steam purge is complete. The air purge line 148 also includes a check valve 150 to prevent backflow of liquid fuel and / or vapor entering the compressor 50 through the line 148.

[0028] As described above, the steam purge system 16 includes a gas supply unit 22 which may include one or more compressors 106 separate from the compressor 50 of the gas turbine engine 12. For example, as described above, the gas supply unit 22 may use an air compressor 106 (e.g., an atomizing air compressor) configured to provide each of the fuel nozzles 60 of the combustor 58 with an atomizing flow 152 (e.g., an atomizing air flow) through one or more atomizing air flow lines 154. During operation, the atomizing flow 152 is configured to atomize the liquid fuel in the fuel nozzles 60. Thus, the gas supply unit 22, and in particular the air compressor 106 of the atomizing module 103, can be used for multiple purposes, including atomizing the liquid fuel during liquid fuel operation of the gas turbine engine 12 and generating a high-temperature compressed gas for generating saturated steam in the ejector 18 of the steam purge system 16.

[0029] The gas supply unit 22, such as the air compressor 106, can be configured to provide a temperature and pressure suitable for generating steam (e.g., saturated steam) within the ejector 18. For example, the air compressor 106 can be configured to supply a high-temperature compressed air stream to the ejector 18 at a temperature of at least 170, 180, 190, 200, 225, 250, 275, or 300 degrees Celsius and a pressure of at least 200, 250, 300, 350, or 400 psi. In some embodiments, the gas supply unit 22 can also include an extracted air stream (e.g., a high-temperature compressed air stream) from the compressor 50 of the gas turbine system 10 and / or from a gas supply unit from another tank or compressor within the facility.

[0030] As described above, the gas turbine system 10 includes a controller 118 configured to control the modes of the steam purge system 16. The illustrated controller 118 includes a processor 156 and a memory 158. The memory 158 is configured to store instructions configured to be executed by the processor 156 to operate the steam purge system 16. For example, the controller 118 may be configured to store and execute instructions according to the process shown in Figure 5. During operation, the controller 118 may be configured to open and close various valves, control the operation of the dual fuel system 14, control the generation of saturated steam, control the duration and timing of steam purging, control the transition between liquid fuel operation and gas fuel operation of the gas turbine system 10, and control the modes of operation of the gas turbine engine 12.

[0031] Figure 2 is a schematic diagram showing one embodiment of the gas turbine system 10, showing a plurality of combustors 58 located inside the gas turbine enclosure 30, and the steam purge system 16 includes a plurality of housings 142 in elevated areas 144 on both sides of the gas turbine enclosure 30. In particular, in the illustrated embodiment, the housings 142 are located on both sides of the gas turbine enclosure 30 such that the liquid fuel lines 62 of the liquid fuel supply system 26 and the distribution lines 132 of the steam purge system 16 are evenly divided between the two housings 142. Each housing 142 includes three liquid fuel lines 62 configured to receive steam from the corresponding three distribution lines 132 of the steam purge system 16. As shown, each of the distribution lines 132 includes a check valve 140 configured to prevent backflow of liquid fuel into the steam purge system 16, and each of the liquid fuel lines 62 includes a check valve 141 configured to prevent backflow of steam into the liquid fuel supply system 26. Furthermore, as shown in the figure, the housing 142 is positioned in a high-altitude region 144 such that each of the liquid fuel lines 62 is inclined downward toward each of the fuel nozzles 60 of the combustor 58 in the gas turbine enclosure 30.

[0032] The illustrated embodiment has six combustors 58, each having six fuel nozzles 60. However, any suitable number of combustors 58 and fuel nozzles 60 are within the scope of the disclosed embodiment. The illustrated fuel nozzles 60 are arranged together with one central fuel nozzle 180 and five outer or circumferential fuel nozzles 182. The fuel nozzles 60 are also configured to have a central liquid fuel cartridge 184 surrounded by a gas fuel supply area 186. Details of these fuel nozzles 60 are described further below with reference to Figure 4.

[0033] Figure 3 is a schematic diagram of one embodiment of an ejector 18 of a steam purge system 16. As shown, the ejector 18 receives gas 200 (e.g., hot compressed air) from a gas supply unit 22 (e.g., an air compressor 106) via a gas line 120 having a valve 122. The ejector 18 receives the gas 200 at a gas inlet 202 which is fluidly coupled to a gas flow path 203 via a central gas conduit 204. The ejector 18 is also coupled to a water supply unit 20 via a water line 108 including a valve 110, a check valve 112, a water tank 114, and a valve 116. The water line 108 is coupled to the ejector 18 at a water inlet 206. The ejector 18 shown has an outer wall 208 arranged circumferentially around a central axis 210. For example, the outer wall 208 may be an annular outer wall defining an inner annular chamber 211.

[0034] The outer wall 208 can define a converging section 212, a throat 214 downstream of the converging section 212, and a diversion section 216 downstream of the throat 214. Thus, the ejector 18 provides a Venturi effect that helps draw in water and mix the water and gas 200 within the ejector 18. The converging section 212, the throat 214, and the diversion section 216 can define annular or wall portions of the outer wall 208. For example, the converging section 212 can define a curved annular or conical wall portion of the outer wall 208 where the cross-sectional area or diameter gradually decreases in the downstream flow direction toward the throat 214 (e.g., as indicated by the gas flow path 203). On the other hand, the diversion section 216 can define a curved annular or conical wall portion of the outer wall 208 where the cross-sectional area or diameter increases toward the outlet 124 from the throat 214 of the ejector 18.

[0035] In the illustrated embodiment, the central gas conduit 204 extends at least partially or entirely through the convergence section 212 to the throat 214. However, other embodiments may include a central gas conduit 204 of shorter or longer lengths, and the outlet 218 of the central gas conduit 204 may be located entirely within the convergence section 212, directly within the throat 214, or within the diversion section 216. Some embodiments may also lead the gas 200 directly to the convergence section 212 without using the central gas conduit 204.

[0036] The water inlet 206 is coupled to the outer wall 208 at the throat 214 of the ejector 18. However, in certain embodiments, one or more water inlets 206 may be coupled to the outer wall 208 at an upstream or downstream position of the throat 214. During operation, the flow of gas 200 through the ejector 18, and particularly through the throat 214 into the diversion section 216, creates an attractive force that draws water through the water inlet 206. Thus, the structure of the ejector 18 helps to facilitate the drawing of water through the water inlet 206, and therefore helps to mix the water with the gas 200 in the throat 214 and the diversion section 216. The relatively high pressure and temperature of the gas 200 also help to promote vapor formation when the gas 200 and water mix within the ejector 18.

[0037] For example, after a certain duration, the steam generated in the ejector 18 becomes saturated, thereby generating saturated steam 220 in the ejector 18. Initially, before the steam becomes saturated, valve 136 can be opened to exhaust the steam through the vent line 134, as described above with reference to Figure 1, while valve 128 is closed to block the flow of steam to the liquid fuel line 62 through the output line 126. However, after the steam becomes saturated, valve 136 is closed and valve 128 is opened by the controller 118, thereby sending saturated steam 220 to the liquid fuel line 62 through the output line 126, as described above with reference to Figure 1.

[0038] Figure 4 is a schematic diagram of one embodiment of a gas turbine system 10 having a steam purge system 16 coupled to one of the combustors 58 together with a dual fuel system 14. As shown in the figure, the dual fuel system 14 has both a liquid fuel supply system 26 and a gas fuel supply system 28, which are fluidly coupled to the fuel nozzles 60 of the combustor 58 via a liquid fuel line 62 and a gas fuel line 64. Furthermore, the steam purge system 16 is fluidly coupled to the liquid fuel line 62 via a distribution line 132 having a check valve 140. Here again, the check valve 140 and the distribution line 132, as well as the check valve 141 and the liquid fuel line 62, are configured to prevent backflow through their lines to the steam purge system 16 and the liquid fuel supply system 26, respectively.

[0039] The illustrated combustor 58 has a combustion section 230 and a head end 232. Fuel nozzles 60 are located at the head end 232, separated from the combustion section by a plate 234. The combustion section 230 includes a combustion liner 236 arranged circumferentially around the combustion chamber 98 and a flow sleeve 238 arranged circumferentially around the combustion liner 236, defining an air passage 240. The air passage 240 is fluidly coupled to the discharge from the compressor 50, and as a result, the airflow from the compressor flows between the flow sleeve 238 and the combustion liner 236 in the flow direction toward the head end 232, as indicated by arrow 242. Upon reaching the head end 232, the airflow swirls, as indicated by arrow 244, into each of the fuel nozzles 60.

[0040] Each fuel nozzle 60 includes an outer sleeve 246 arranged circumferentially around a liquid fuel cartridge 184, and a plurality of vanes 248 (e.g., swirling vanes) extending radially between the outer sleeve 246 and the liquid fuel cartridge 184. For example, a fuel nozzle 60 may include 2 to 10 vanes 248 spaced circumferentially around the liquid fuel cartridge 184. Each of these vanes 248 is configured to receive gaseous fuel from a gaseous fuel line 64 of a gaseous fuel supply system 28, thereby directing the gaseous fuel into an air passage 250 (indicated by arrow 250) between the outer sleeve 246 and the liquid fuel cartridge 184. The air passage 250 may be an annular air passage defined between the annularly formed outer sleeve 246 and the annularly formed liquid fuel cartridge 184. The fuel nozzle 60 includes an upstream air inlet 252 and a downstream fuel-air mixture outlet 254. Each fuel nozzle 60 is configured to receive air 244 via an upstream air inlet 252, swirl the airflow through a vane 248, and inject gaseous fuel through an outlet 256 located in the vane 248 (during gaseous fuel operation), mixing the fuel and air within the outer sleeve 246 before exiting through the fuel-air mixture outlet 254 of the fuel nozzle 60. In liquid fuel operation, gaseous fuel is not injected through the outlet 256 of the vane 248. Instead, liquid fuel is injected through a liquid fuel cartridge 184 and exits into the outer sleeve 246 through one or more outlets 258. As described above with reference to Figure 1, the liquid fuel cartridge 184 also receives an atomizing flow 152 from the gas supply unit 22, which helps atomize the liquid fuel exiting the liquid fuel cartridge 184.

[0041] Therefore, in the illustrated embodiment, the gas turbine system 10 is configured to selectively operate in liquid fuel operating mode using a liquid fuel supply system 26, a liquid fuel supply line 62, and a liquid fuel cartridge 184 in a fuel nozzle 60. Furthermore, the gas turbine supply system 10 is configured to selectively operate in gas fuel operating mode using a gas fuel supply system 28, a gas fuel line 64, and vanes 248 located in the fuel nozzle 60. The steam purge system 16 is configured to purge the liquid fuel circuit 24 when stopping the liquid fuel operating mode using the liquid fuel supply system 26 and / or when changing from the liquid fuel operating mode to the gas fuel operating mode using the gas fuel supply system 28. The steam purge system 16 uses an ejector 18 to combine water and gas (e.g., high-temperature compressed air) to generate steam (e.g., saturated steam) and purges liquid fuel from the liquid fuel line 62, manifold 66, liquid fuel cartridge 184, and various valves and other equipment along the liquid fuel circuit 24.

[0042] Figure 5 is a flowchart of one embodiment of a process 270 for purging the liquid fuel circuit 24 of the gas turbine system 10 using a steam purge system 16. As shown, process 270 can be initiated by stopping the flow of liquid fuel to the fuel nozzles 60 (block 272). For example, process 270 may initiate a switch between a liquid fuel operating mode via the liquid fuel supply system 26 and a gas fuel operating mode using the gas fuel supply system 28, or process 270 may initiate an overall shutdown of the gas turbine system 10. Process 270 then proceeds to initiate a gas flow (e.g., a high-temperature compressed air flow) to the ejector 18 of the steam purge system 16 (block 274). For example, process 270 may open a valve 122 along the gas line 120 to enable the operation of a gas supply unit 22, such as a compressor 106 (e.g., an air compressor in the atomization module 103). Next, process 270 can initiate a water flow from the water supply section 20 through the water line 108 to the ejector 18 of the steam purge system 16 (block 276). For example, process 270 can open valves 110 and 116 and start the pump 102 to enable the water flow. Then, process 270 can generate steam in the ejector 18 as the water and gas mix in the ejector 18 (block 278).

[0043] When the ejector 18 begins generating steam in block 278, process 270 can determine whether the steam is saturated in block 280. In certain embodiments, process 270 can determine whether the steam is saturated in block 280 for a predetermined time (e.g., 5, 10, 15, or 20 minutes) based on historical data of the operation of the gas turbine engine 12, a computer model, sensor data regarding the operation of the gas turbine engine 12 and the steam purge system 16, and various other parameters. If the steam is not saturated in block 280, process 270 exhausts the steam to the atmosphere by closing a valve 128 along the output line 126 and opening a valve 136 along the vent line 134 (block 282).

[0044] If process 270 (in block 280) determines that the steam is saturated, process 270 proceeds to open the flow of saturated steam through the liquid fuel circuit 24 of the gas turbine engine 12, as shown by block 284. For example, process 270 may open valve 128 along output line 126 and close valve 136 along vent line 134, thereby allowing saturated steam to flow through manifold 130 into distribution line 132 and into liquid fuel line 62. Furthermore, process 270 may determine an appropriate duration for the steam purge based on user input, historical data, sensor data, time since the last steam purge of liquid fuel circuit 24, or a predetermined duration of steam purging based on one or more conditions.

[0045] In block 286, process 270 can determine whether the steam purging is complete. If the steam purging is not complete, process 270 can continue operating the steam purging as shown in block 288. If process 270 determines in block 286 that the steam purging is complete, process 270 can then proceed to stop the flow of saturated steam through the liquid fuel circuit 24 of the gas turbine engine 12 (block 290).

[0046] The technical advantages of this technology include a steam purge system 16 that generates steam to purge the liquid fuel circuit 24 using an ejector 18, offering various benefits such as the absence of moving parts, low maintenance, and a Venturi effect for drawing in water. The ejector 18 requires little space and utilizes high-temperature compressed gas (e.g., high-temperature compressed air) available from an existing supply source (e.g., an atomization module 103 with an air compressor 106) that is already being used for another purpose within the gas turbine system 10 (e.g., supplying an atomizing flow 152 for atomizing liquid fuel in the fuel nozzle 60). The steam purge system 16 also uses gravity to facilitate the steam purging of the liquid fuel circuit 24 by positioning the liquid fuel line 62 and distribution line 132 from the ejector 18 in a high-altitude region 144 above the combustor 58 and fuel nozzle 60.

[0047] This specification discloses the present invention, including its best mode, and uses examples to enable any person skilled in the art to practice the invention, including the fabrication and use of any device or system and the implementation of any incorporated method. The patentable scope of the present invention is defined by the claims and may include other embodiments that a person skilled in the art may conceive. Such other examples shall be within the claims if they have structural elements that are not different from the language of the claims, or if they include equivalent structural elements that are substantially different from the language of the claims. [Explanation of Symbols]

[0048] 10. Gas turbine systems, gas turbine supply systems 12 Gas turbine engines 14 Dual Fuel System 16. Steam purge system 18 Ejectors 20 Water supply section 22 Gas Supply Department 24 Liquid fuel circuit 26 Liquid fuel supply system, liquid fuel supply unit 28 Gas fuel supply system 30 Gas Turbine Enclosures 32 Intake Section 34 Compressor Section 36 Combustion Section 38 Turbine Section 40 load 42 Intake duct 44 Intake Louvers 46 Air filter 48 Additional air treatment systems 50 Single-stage or multi-stage compressors 52 Compressor Blades 54 Shaft, compressor shaft 56 Compressor casing 58 Combustor 60 Fuel Nozzles 62 Liquid fuel lines, liquid fuel supply lines 64 Gas fuel line 66 Fuel Manifold 68 Single-stage or multi-stage turbines 70 Turbine blades, compressor blades 72 Turbine shaft 73 Turbine Casing 74 Intermediate shaft 76 shaft 78 Fuel Tank 80 valves 82 pumps 84 Manifold and distribution valves 86 Fuel Filter 88 Valves 90 Manifold and Distribution Valve 92 Intake, airflow 94 Compressed air flow 96 High-temperature combustion gases 98 Combustion chamber 100 water tanks 102 pump 103 Atomization Module 104 Gas supply components 106 Air compressor 108 Water Line 110 valve 112 Check valves, valves 114 Water Tank 116 valves 118 Controllers 120 Gas Line 122 valves 124 Exit 126 output lines 128 valves 130 Manifold 132 distribution lines 134 Ventline 136 valves 138 Vent / Drain 140 Check valve 141 Check valve 142 Housing 143 Housing 144 High altitude area 146 Valves 148 Air purge line 150 Check valve 152 Atomization flow 154 Atomizing airflow line 156 processors 158 memory 180 Central fuel nozzle 182 Circumferential fuel nozzle 184 Central Liquid Fuel Cartridge 186 Gas fuel supply area 200 gas 202 Gas Inlet 203 Gas flow path 204 Central Gas Pipeline 206 Water inlet 208 Exterior Wall 210 Center axis 211 Inner annular chamber 212 Convergence Section 214 Throat 216 Diversion Section 218 Exit 220 Saturated steam 230 Combustion Section 232 Head end 234 Plate 236 Combustion Liner 238 Flow Sleeve 240 Airflow channels 242 Arrows 244 Arrow, air 246 Outer sleeve 248 Bane 250 arrows, airflow channels 252 Upstream air inlet 254 Fuel-air mixture outlet 256 Exit 258 Exit 270 processes

Claims

1. A gas turbine system, An outer wall (208) extending circumferentially around a flow channel (203), the outer wall (208) including a throat section (214) along the flow channel (203), and a diversion section (216) downstream of the throat section (214) along the flow channel (203), A gas inlet (202) for supplying gas into the aforementioned flow path (203), and A water inlet (206) configured to supply water into the aforementioned flow path (203) An ejector (18) comprising, The ejector (18) is configured to generate steam in response to drawing the water into the gas along the flow path (203), A controller (118) configured to control the flow of gas and water in order to generate saturated steam for steam purging of the liquid fuel circuit (24) to the combustor of the gas turbine system, and A system that includes these features.

2. The system according to claim 1, further comprising the liquid fuel circuit (24) fluidly coupled to a steam purge system (16) having the ejector (18) and the controller (118).

3. The system according to claim 2, comprising a gas turbine enclosure (30) configured to house a gas turbine engine (12) having a combustor (58) having a fuel nozzle (60) fluidly coupled to a liquid fuel line (62) of the liquid fuel circuit (24), wherein the liquid fuel line (62) extends to a high-altitude region (144) vertically above the combustor (58) and / or the fuel nozzle (60), and the steam purge system (16) is fluidly coupled to the liquid fuel line (62).

4. The system according to claim 3, wherein the steam purging system (16) is fluidly coupled to the liquid fuel line (62) in the elevated region (144).

5. The system according to claim 1, wherein the liquid fuel circuit (24) comprises a fuel nozzle (60) of a gas turbine engine (12), a combustor (58) of the gas turbine engine (12), a gas turbine fuel system (14), or a combination thereof.

6. The system according to claim 1, wherein the gas inlet (202) is connected to a central gas conduit (204) in the outer wall (208) of the ejector (18), and the water inlet (206) is located in the throat section (214) of the ejector (18).

7. The system according to claim 1, wherein the gas inlet (202) is provided with a compressed air inlet, the gas contains compressed air, and the system comprises an air compressor (106) configured to supply the compressed air to the compressed air inlet, the air compressor (106) being configured to supply the compressed air to one or more fuel nozzles (60) for atomizing a liquid fuel.

8. The system according to claim 1, wherein the controller (118) is configured to exhaust the steam to the atmosphere until the steam becomes saturated steam, and to open the flow of the saturated steam through the liquid fuel circuit (24).

9. The outer wall (208) of the ejector (18) is provided with a converging section (212) upstream of the throat section (214) along the flow path (203), The aforementioned gas is high-temperature compressed air. The ejector (18) receives the high-temperature compressed air from the gas supply unit (22) via the gas line (120). The gas supply unit is configured to provide a temperature and pressure suitable for generating the saturated steam within the ejector (18), The convergence section (212) defines a curved annular or conical wall portion of the outer wall (208) in which the cross-sectional area or diameter gradually decreases in the downstream flow direction toward the throat section (214), The flow diversion section (216) has an increasing cross-sectional area or diameter from the throat section (214) toward the outlet (124) of the ejector (18). The curved annular wall portion or the conical wall portion extends at least partially through the converging section (212) to the throat section (214), The water inlet (206) is provided in the throat section (214), The system according to any one of claims 1 to 8, wherein the liquid fuel circuit is fluidly coupled to a steam purge system having the ejector (18) and controller (118).

10. The system according to claim 1, further comprising a manifold (66) downstream of the ejector (18), the manifold (66) comprising a plurality of steam supply lines connected to each of a plurality of liquid fuel lines (62) of the liquid fuel circuit (24), each of the plurality of liquid fuel lines (62) comprising a first check valve (141) configured to prevent backflow of the steam, and each of the plurality of steam supply lines (132) comprising a second check valve (140) configured to prevent backflow of the liquid fuel.

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