System and method for retrofitting a power generation system to incorporate clutchless synchronous condensing

A system includes a clutchless synchronous condensing coupling configured to couple a turbine shaft of a gas turbine system to a generator shaft of a synchronous generator of a power generation system. The clutchless synchronous condensing coupling includes a first coupling portion configured to couple to the turbine shaft, and a second coupling portion configured to couple to the generator shaft. The clutchless synchronous condensing coupling is configured to allow the power generation system to operate in an active power mode and a reactive power mode without a clutch assembly.

BACKGROUND

The present disclosure relates generally to a power generation system having a generator driven by a gas turbine engine, and more specifically to synchronous condensing.

A power generation system often includes a clutch assembly between a generator and a gas turbine system. The clutch assembly enables selective engagement and disengagement between shafts of the generator and the gas turbine system. However, a clutch assembly can increase costs associated with servicing, replacement parts, and downtime of the power generation system. Unfortunately, the clutch assembly may be installed in an existing power generation system having the gas turbine system and the generator already mounted in set positions on a foundation (i.e., a pre-existing footprint), wherein a control system is specifically designed for various modes of operation using the clutch assembly. A need exists for a system and method for retrofitting an existing power generation system to operate without a clutch assembly, while enabling various modes of operation of the power generation system (e.g., an active power mode having a synchronous generator operating to generate power for a power grid, and a reactive power mode having the synchronous generator operating as a synchronous condenser to stabilize the power grid). In particular, a need exists for such a retrofit without requiring substantial changes to the pre-existing footprint, i.e., without requiring any substantial movement of the gas turbine system and the generator from their set positions on the foundation.

SUMMARY

In accordance with an embodiment, a system includes a clutchless synchronous condensing coupling configured to couple a turbine shaft of a gas turbine system to a generator shaft of a synchronous generator of a power generation system. The clutchless synchronous condensing coupling includes a first coupling portion configured to couple to the turbine shaft, and a second coupling portion configured to couple to the generator shaft. The clutchless synchronous condensing coupling is configured to allow the power generation system to operate in an active power mode and a reactive power mode without a clutch assembly.

In accordance with an embodiment, a power generation system includes a gas turbine system, a synchronous generator, a clutchless synchronous condensing coupling, a plurality of bearings, and a sump evacuation system. The gas turbine system includes a compressor, a combustor configured to produce a flow of combustion gas, a first turbine driven by the flow of combustion gas, and a second turbine driven by the flow of combustion gas downstream from the first turbine. A first shaft of the first turbine is not rotationally coupled to a second shaft of the second turbine. The synchronous generator is configured to operate in an active power mode and a reactive power mode. The clutchless synchronous condensing coupling is provided to couple the second shaft to a generator shaft of the synchronous generator. The clutchless synchronous condensing coupling is configured to transfer torque from the second shaft to the generator shaft to drive the synchronous generator in the active power mode to provide an active power to a power grid. The clutchless synchronous condensing coupling is configured to transfer torque from the generator shaft to the second shaft when the synchronous generator is operating as a synchronous condenser in the reactive power mode to generate a reactive power or absorb a reaction power. The plurality of bearings is configured to support the first shaft, the second shaft, the generator shaft, or a combination thereof. The sump evacuation system is configured to operate in a first mode during the active power mode and to operate in a second mode during the reactive power mode, wherein the sump evacuation system is configured to flow a lubricant to the plurality of bearings.

In accordance with an embodiment, a method of retrofitting a power generation system includes removing a clutch assembly between a synchronous generator and a second turbine downstream of a first turbine of a gas turbine system, wherein a first shaft of the first turbine is not rotationally coupled to a second shaft of the second turbine. The method also includes installing a clutchless synchronous condensing coupling that couples the first shaft and a generator shaft of the synchronous generator. The method further includes installing a controller or updating an existing controller to operate the power generation system in an active power mode and a reactive power mode using the clutchless synchronous condensing coupling without the clutch assembly.

DETAILED DESCRIPTION

The disclosed embodiments provide a system and process for retrofitting a power generation system to incorporate a clutchless synchronous condensing system. As set forth in detail below, retrofitting existing power generation systems may include removing a clutch assembly from the power generation system and replacing the clutch assembly with a clutchless synchronous condensing coupling configured to couple a generator shaft of a synchronous generator to a turbine shaft of the gas turbine engine. Further, retrofitting existing power generation systems may include additional modifications and updates to a controller, a sump evacuation system (e.g., incorporation of a pump), as well as other systems.

FIG. 1is a schematic of an embodiment of a power generation system10having a clutchless synchronous condensing module11disposed between a gas turbine system12(or gas turbine engine) and a synchronous generator14(or generator/condenser). As discussed in detail below, the clutchless synchronous condensing module11includes a clutchless synchronous condensing coupling16(e.g., a rotational coupling). The clutchless synchronous condensing module11may be designed as part of a retrofit kit for a previously installed power generation system10and/or as part of the original equipment (e.g., a part of the overall power generation system10). As part of a retrofit kit, the clutchless synchronous condensing module11is configured to add clutchless synchronous condensing capability to a previously installed power generation system10(e.g., equipped with a clutch and/or without synchronous condensing capabilities) by replacing a clutch assembly or module13with the clutchless synchronous condensing module11. In certain embodiments, the clutchless synchronous condensing module11is designed to fit in the same space previously occupied by the clutch assembly13, thereby avoiding changes to the final operating positions of the other major components of the power generation system10.

The gas turbine system12may include a compressor section having one or more compressors or compressor stages18, a combustor section having one or more combustors20, and a turbine section having one or more turbines or turbine stages22. The gas turbine system12and the synchronous generator14may be disposed within a power generation system housing24. The power generation system housing24may be fixed to a foundation26. The power generation system housing24may include housing portions for each component of the gas turbine system12. For example, the power generation system housing24may have a compressor housing portion28configured to house the compressor18, a combustor housing portion30configured to house the combustor20, and a turbine housing portion32configured to house the turbine22. In some embodiments, various housing portions of the power generation system housing24may be configured to house multiple components of the gas turbine system12. The power generation system housing24may also include or house other components, such as an air intake system34, a controller, a turbine ventilation system36(e.g., one or more fans in a ventilation duct) for the gas turbine system12, a generator ventilation system38(e.g., one or more fans in a ventilation duct) for the synchronous generator14, a filter assembly having one or more filters40in the intake system34, an exhaust stack42, an engine lubrication system, a start system, a hydraulic system, electric power and data, or some combination thereof.

In certain embodiments, a previously installed power generation system10may be retrofitted by removing the previously installed connection (e.g., the clutch assembly13) between the turbine22and the synchronous generator14and replacing the clutch assembly13with the clutchless synchronous condensing module11without any significant changes to the installed positions of the housing24, the gas turbine system12, and the synchronous generator14on the foundation26. In other words, the gas turbine system12and the synchronous generator14may remain in their installed positions on the foundation26, while the clutchless synchronous condensing module11fills the space previously occupied by the clutch assembly13. In certain embodiments, the clutchless synchronous condensing module11may be sized specifically to fit in the space occupied by the clutch assembly13or the clutchless synchronous condensing module11may have a base size combined with size adjustment features to enable a proper fit between the turbine22and the synchronous generator14. For example, the clutchless synchronous condensing module11may include adjustable housing panels to increase and/or decrease a height, width, or length of the module11depending on available space. By further example, the clutchless synchronous condensing module11may include adjustable features on the clutchless synchronous condensing coupling16, such an axial adjustment assembly on the coupling16and/or associated shaft. The axial adjustment assembly of the coupling16may enable adjustments to increase or decrease an axial length of the clutchless synchronous condensing coupling16and its associated shaft. For example, the axial adjustment assembly may include resilient connections, expandable/contractible shaft sections, spacers, or any combination thereof. In this manner, the size adjustment features help to enable the clutchless synchronous condensing module11to be efficiently installed in the available space previously occupied by the clutch assembly13. The overall footprint of the power generation system10generally remains the same when the clutchless synchronous condensing module11replaces the clutch assembly13. By fitting the clutchless synchronous condensing module11in the same space as the clutch assembly13, the disclosed embodiments enable a more efficient retrofit with substantially reduced downtime of the power generation system10. In contrast, without the disclosed embodiments, the retrofit procedure may require time consuming and costly movements of the synchronous generator14, the gas turbine system12, and/or the housing24on the foundation26and/or resizing of the foundation26.

Embodiments of the retrofit procedure may include removing and/or opening a portion (e.g., clutch casing or clutch housing portion44) of the power generation system housing24at the location of the clutch assembly13between the gas turbine system12and the synchronous generator14. Upon obtaining access, the clutch assembly13may be removed and replaced with the clutchless synchronous condensing module11(including the clutchless synchronous condensing coupling16). In certain embodiments, the clutch housing portion44is reinstalled after installation of the clutchless synchronous condensing module11. In other embodiments, the clutchless synchronous condensing module11has its own integrated housing and thus is self-contained and ready for operation upon installation in the space previously occupied by the clutch assembly13.

As discussed below, the clutchless synchronous condensing module11may include a variety of supplemental components15,17,19, and21to support clutchless synchronous condensing. For example, the clutchless synchronous condensing module11may include a controller15having a processor, a memory, and instructions stored on the memory and executable by the processor to perform various tasks associated with the clutchless synchronous condensing. In certain embodiments, the controller15may enable updates of a main controller (e.g.,78,FIG. 2) of the power generation system10to provide the computer instructions suitable to perform the clutchless synchronous condensing. Furthermore, in certain embodiments, the controller15may enable local monitoring and/or control of the clutchless synchronous condensing module11(including the clutchless synchronous condensing coupling16) and the other components17,19, and21. The components17may include, for example, all or part of a sump evacuation system72as discussed in further detail below with reference toFIG. 2. The components19may include, for example, one or more sensors dedicated to monitor aspects impacting the clutchless synchronous condensing, including sensors that monitor operational parameters of a power grid (e.g., grid frequency) and one or more operational parameters of the synchronous generator14, the turbine22, and/or the clutchless synchronous condensing coupling16(e.g., a rotational speed, a torque, a vibration level, an acoustic noise, an alignment of rotational axes, or any combination thereof). The controller15and/or78is responsive to feedback from the one or more sensors to control operation of the gas turbine system12to transition the power generation system10between an active power mode and a reactive power mode using the clutchless synchronous condensing coupling16without the clutch assembly13. Additionally, the components21may include, for example, a user interface or control panel configured to allow adjustments to the operation of the clutchless synchronous condensing module11. The components15,17,19, and21may be communicatively coupled together and may be communicatively coupled to the main controller (e.g.,78,FIG. 2) of the power generation system10, thereby helping to complete the retrofit of the system10to incorporate the clutchless synchronous condensing.

FIG. 2is a schematic of an embodiment of the power generation system10retrofitted with a clutchless synchronous condensing module11as illustrated inFIG. 1. The power generation system10includes the gas turbine system12coupled to the synchronous generator14. The gas turbine system12includes the compressor18, the combustor20, and the turbine22. In some embodiments, the gas turbine system12includes a high pressure gas turbine (e.g., core turbine46) and a low pressure gas turbine (e.g., power turbine48) disposed downstream the core turbine46. The core turbine46may be configured to drive a core shaft (e.g., first turbine shaft50), and the power turbine may be configured to drive a power shaft (e.g., second turbine shaft52). The first turbine shaft50may be disposed physically separate from the second turbine shaft52. That is, the first turbine shaft50is not mechanically connected to the second turbine shaft52, and thus the first turbine shaft50does not mechanically drive the second turbine shaft52.

The compressor18may be mechanically coupled to the first turbine shaft50(e.g., via a compressor shaft or compressor shaft portion of the first turbine shaft50) and configured to receive an incoming flow of air54from the air intake system34of the power generation system10. The first turbine shaft50may be supported by one or more bearings56. The compressor18may include a plurality of compressor stages (e.g., 2 to 28 or more compressor stages) each having a plurality of stator vanes positioned about the compressor shaft and a plurality of compressor blades configured to rotate in response to rotation of the first turbine shaft50. The compressor18may be configured to compress the incoming air flow54and to deliver a compressed flow of air58to the combustor20.

The combustor20(including one or more fuel nozzles57) may be configured to mix the compressed flow of air58with a pressurized flow of fuel60received from a fuel source and to ignite the mixture to create a flow of combustion gases62. Although only a single combustor20is shown, the gas turbine system12may include a plurality of combustors. The combustor20may be configured to deliver the flow of combustion gases62to the core turbine46. The core turbine46may include a plurality of turbine stages (e.g., 2 to 10 or more turbine stages) each having a plurality of stator vanes positioned about the first turbine shaft50and a plurality of turbine blades configured to rotate with the first turbine shaft50. The flow of combustion gases62may drive rotation of the core turbine46and the first turbine shaft50; however, the core turbine46itself does not drive rotation of the second turbine shaft52. The core turbine46directs the flow of combustion gases62leaving the core turbine46(e.g., exhaust gases) to the power turbine48.

The power turbine48is mechanically coupled to the second turbine shaft52, but not the first turbine shaft50. The power turbine48is configured to receive the flow of combustion gases62(e.g., exhaust gases) from the core turbine46. The second turbine shaft52may be supported by the one or more bearings56. The power turbine48may include a plurality of stator vanes positioned about the second turbine shaft52and a plurality of turbine blades coupled to and configured to drive rotation of the second turbine shaft52. The flow of combustion gases62from the core turbine46may drive the power turbine48, producing mechanical work. The mechanical work produced by the power turbine48(i.e., due to combustion gases62driving rotation of the power turbine48) may drive the synchronous generator14when the power generating system10is operated in an active power mode (or synchronous generating mode of the generator14). That is, mechanical work produced by the power turbine48may drive the second turbine shaft52. The clutchless synchronous condensing coupling16may be configured to couple the second turbine shaft52to a generator shaft64, such that torque is transferred between the second turbine shaft52and the generator shaft64. The torque from the second turbine shaft52is transferred to the generator shaft64causing the generator shaft64to rotate. The rotation of the generator shaft64drives the synchronous generator14, such that the power turbine48may drive the synchronous generator14(i.e., synchronous generating mode) when the power generating system10is operated in the active power mode.

The synchronous generator14may include a generator rotor66mounted within a generator stator68. The generator shaft64is coupled to the generator rotor66and is configured to rotate therewith. The generator shaft64may be supported by the one or more bearings56. The generator rotor66may be wrapped in field windings, and the generator stator68may be wrapped in armature windings. Thus, rotating the generator shaft64of the synchronous generator14may provide active power to a power grid70in the active power mode of the power generation system10. As set forth above, the synchronous generator14is configured be driven by the generator shaft64to provide active power in the active power mode. In a reactive power mode of the power generation system10, the synchronous generator14operates as a synchronous condenser in a synchronous condensing mode, as needed, to maintain a power factor on the power grid70. The synchronous generator14may be configured to drive the generator shaft64in the reactive power mode to generate reactive power or absorb reaction power in a reactive power mode to maintain the power factor on the power grid70in the reactive power mode. Thus, the synchronous generator14may operate as a synchronous generator14in the active power mode and a synchronous condenser in the reactive power mode. In the reactive power mode, the synchronous generator14(operating as a synchronous condenser in a synchronous condensing mode) is configured to spin freely to adjust conditions on the power grid70while rotating the generator shaft64and the power turbine48; however, the free rotation of the synchronous condenser does not drive rotation of the core turbine46due to the lack of a mechanical connection between the core turbine46and the power turbine48. The synchronous condensing is therefore possible without requiring a clutch for selectively connecting and disconnecting the synchronous generator14and the turbine22.

As set forth above, the one or more bearings56may be configured to support the first turbine shaft50, the second turbine shaft52, the generator shaft64, the clutchless synchronous condensing coupling16, or some combination thereof. A sump evacuation system72may be configured to provide a lubricant (e.g., oil) to the one or more bearings56, as well as to other portions of the power generation system10. The sump evacuation system72may include an oil source74configured to store and/or provide the lubricant for operation of the sump evacuation system72. In some embodiments, the sump evacuation system72is configured to maintain a differential pressure across the one or more bearings56(e.g., lubricant seals of the bearings).

The sump evacuation system72may utilize internal pressure from operation of the gas turbine system12to circulate the lubricant in the active power mode. In the active power mode, the core turbine46of the gas turbine system may be configured to operate above 8,000 RPMs, which provides sufficient internal pressure for the sump evacuation system72to circulate the lubricant. However, during the reactive power mode, the core turbine46may be shut down or operate at a substantially lower RPM (e.g., less than 2500 RPM). To maintain circulation of the lubricant, the power generation system10includes a pump76(or multiple pumps) for the sump evacuation system72installed during the retrofit. In certain embodiments, the pump76and/or the sump evacuation system72may be one of the components (e.g., component17) of the clutchless synchronous condensing module11(e.g., part of the packaged system), or the pump76may be packaged separately and/or with the sump evacuation system72. The pump76may be configured to provide additional pressure for circulating the lubricant. In certain embodiments, the pump76may be configured to operate only in the reactive power mode. In some embodiments, the pump76also may be configured to supplement the internal pressure driving circulation of the lubricant during the active power mode. However, in either case, the pump76may be part of the retrofit associated with the clutchless synchronous condensing module11. Additionally, the retrofit may include controller upgrades to enable operation of the pump76with the clutchless synchronous condensing module11.

The power generation system10may include a controller78configured to control operation of the power generation system10(e.g., cause system to operate in the active power mode or the reactive power mode) via a processor80and a memory82. The controller78may be a main controller and/or a separate controller from the controller15as described above, the controllers15and78may operate together to control various aspects of the power generation system10, the controllers15and78may be integrated together as a single controller, or one or both of the controllers15and78may be configured to operate the power generation system10in the active power mode and the reactive power mode, including aspects specific to the clutchless synchronous condensing module11. Any control features described with respect to either of the controllers15and78is intended to include control features incorporated into one or both of the controllers15and78. Therefore, the following discussion of control features may refer only to the controller78, but is intended to also cover control features of the controller78in certain embodiments.

The processor80of the controller78may include one or more processing devices, and the memory82may include one or more tangible, non-transitory, machine-readable media. By way of example, such machine-readable media can include RAM, ROM, EPROM, EEPROM, or optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by the processor80or by other processor-based devices (e.g., mobile devices). In some embodiments, the memory82is configured to store controller instructions executable by the processor80to output various controller signals84. For example, the processor80may execute the controller instructions to control operation of the gas turbine system10.

The controller78(via the processor80) and/or the controller15(via a processor) may execute controller instructions to control operation of the sump evacuation system72. For example, the controller78and/or15may be configured to deactivate the pump76in the active power mode and activate the pump76in the reactive power mode. In some embodiments, the controller78and/or15may be configured to control operation of the sump evacuation system72based at least in part on user input via a user interface, such as the user interface of the component21of the clutchless synchronous condensing module11as described above. The user interface may include an input/output device (e.g., keyboard, mouse, or touch screen) configured to provide the user input to the controller78and/or15. Further, the user interface may include a display (e.g., computer monitor or personal device screen) configured to display user options for the controller78and/or15.

Moreover, the controller78(or the controller15) may be configured to output the various controller signals84via communications circuitry86. The communications circuitry86may include a wired connection and/or wireless communication circuitry. For example, the communications circuitry86may include antennas, radio transceiver circuits, and signal processing hardware and/or software (e.g., hardware or software filters, A/D converters, multiplexers, amplifiers), or a combination thereof, and that may be configured to communicate over wireless communication paths via infrared (IR) wireless communication, satellite communication, broadcast radio, microwave radio, Bluetooth, Zigbee, Wifi, UHF, NFC, etc.

In some embodiments, the controller78and/or15of the gas turbine system12is configured to maintain a minimum operation speed (e.g., rotations per minute) of the first turbine shaft50and the core turbine46in the reactive power mode. Maintaining a minimum speed of the core turbine46may prevent wind milling of the core turbine46caused by the rotation of the power turbine48disposed adjacent the core turbine46. In some embodiments, the core turbine46of the power generation system10is configured to operate between 1000 rotations per minute (RPM) and 2500 RPM in the reactive power mode. In some embodiments, the core turbine46is configured to operate between 1500 RPM and 3000 RPM in the reactive power mode.

FIG. 3is a side view of an embodiment of the clutchless synchronous condensing module11as illustrated inFIGS. 1 and 2. As discussed above, the module11having the clutchless synchronous condensing coupling16is configured to replace the clutch assembly13as part of the retrofit for the power generation system10. The clutchless synchronous condensing coupling16may be configured to couple the second turbine shaft52to the generation shaft64, such that torque may be transferred between the second turbine shaft52and the generator shaft64. Specifically, the clutchless synchronous condensing coupling16may be configured to transfer torque from the second turbine shaft52to the generator shaft64in the active power mode of the power generation system10, and also transfer torque from the generator shaft64to the second turbine shaft52in the reactive power mode of the power generation system10.

In some embodiments, a first coupling portion or a first end portion88of the clutchless synchronous condensing coupling16is configured to fasten to the second turbine shaft52. Further, a second coupling portion or a second end portion90of the clutchless synchronous condensing coupling16is configured to fasten to the generator shaft64. For example, the first end portion88may include a first flange87(e.g., annular flange) coupled to a first mating flange89(e.g., annular flange) with one or more fasteners92, and the second end portion90may include a second flange91(e.g., annular flange) coupled to a second mating flange93(e.g., annular flange) with one or more fasteners92. The fasteners92may include one or more removable fasteners, such as a plurality of threaded fasteners (e.g., threaded bolts, nuts, etc.), clamps, pins in slots, dovetail joints, or any combination thereof. Alternatively or additionally, the fasteners92may include one or more fixed or permanent joints, such as welded joints. The connections between the flanges87and89and the flanges91and93also may include torque transfer features, such as a plurality of teeth that mate with a corresponding plurality of grooves (e.g., on opposing end faces of the flanges). For example, the torque transfer features may include a hirth coupling, a diaphragm coupling, a grid coupling, a disc coupling, or any combination thereof. In the illustrated embodiment, the torque transfer features include at least a diaphragm coupling95at the connection of the flanges87and89and at the connection of the flanges91and93.

The diaphragm couplings95of the clutchless synchronous condensing coupling16may include a first diaphragm94disposed proximate the first end portion88of the coupling16and a second diaphragm96disposed proximate the second end portion90of the coupling16. The first diaphragm94and the second diaphragm96may be configured to accommodate misalignment between the second turbine shaft52and the generator shaft64. That is, the first diaphragm94and the second diaphragm96are configured to compensate the axial, radial and angular offset of the second turbine shaft52and the generator shaft64. The first diaphragm94and the second diaphragm96each may include one or a plurality of flexible metal diaphragms, discs, or plates disposed within respective portions of the clutchless synchronous condensing coupling16and configured to flex during rotation of the second turbine shaft52and the generator shaft64to accommodate misalignment between the second turbine shaft52and the generator shaft64. The diaphragms94and96of the diaphragm couplings95are configured to transfer torque from an outside diameter to an inside diameter and/or from the inside diameter to the outside diameter of the flexible metal diaphragms, discs, or plates. The diaphragm couplings95may include tapered contoured, multiple straight diaphragms with spokes, and/or multiple convoluted diaphragms. The diaphragm couplings95of the clutchless synchronous condensing coupling16may substantially reduce or eliminate maintenance as compared with the clutch assembly13. For example, the diaphragm couplings95may not require any lubrication and may have a substantially longer life than the clutch assembly13, thereby avoiding potential downtime for repair or replacement. Accordingly, the diaphragm couplings95may be considered lubricant free, self-aligning or self-adjusting for misalignments between shafts, and maintenance free.

In the illustrated embodiment, the clutchless synchronous condensing module11includes a housing or framework97supporting and/or enclosing the clutchless synchronous condensing coupling16having two of the diaphragm couplings95, the components15,17,19, and21, the bearings56disposed about a portion of the second turbine shaft52, the bearings56disposed about a portion of the generator shaft64, and one or more lubricant supply conduits99configured to supply a lubricant (e.g., oil) to the bearings56(e.g. via the system72). Additionally, in some embodiments, the housing or framework97of the clutchless synchronous condensing module11may support the pump76and/or additional components or all of the sump evacuation system72as noted above. Although the illustrated embodiments of the clutchless synchronous condensing module11includes the bearings56, some embodiments of the module11may exclude the bearings56and/or the housing or framework97may be sized based on an axial length of the clutchless synchronous condensing coupling16extending to the flanges87and91and the diaphragm couplings95, as indicated an axial length107. For example, the axial length107of the housing or framework97may be approximately 80 to 120 percent, 90 to 110 percent, or about 100 percent of an axial length of the coupling16. The housing or framework97may include an inner framework101surrounded by one or more outer housing panels103, which may include one or more removable housing panels configured to facilitate installation and inspection. The module11also may include one or more installation/removal tools105(e.g., upper tool and/or lower tool), which may be configured to help lift and/or lower the coupling16, align the coupling16with the shafts52and64, or any combination thereof. For example, the tools105may include motor driven tools, hydraulic tools, pneumatic tools, or a combination thereof. Furthermore, the tools105may include mechanical supports (e.g., support bars, cables, chains, etc.), which may be moved into an appropriate position to support the coupling16during installation and/or removal. These tools105may be packaged with the module11to facilitate an efficient installation of the module11during a retrofit procedure. In certain embodiments, the tools105may be used to remove the clutch assembly13as well. However, in some embodiments, the tools105may be excluded from the module11.

FIG. 4is a flow chart of an embodiment of a process98for retrofitting a power generation system10to incorporate a clutchless synchronous condensing module11as illustrated inFIGS. 1-3. For purposes of discussion of the process98, the power generation system10and the clutchless synchronous condensing module11are substantially the same as described above with reference toFIGS. 1-3. For example, the retrofitting steps of the process98may correspond to the retrofitting shown inFIG. 1, wherein the clutch assembly13is replaced with the clutchless synchronous condensing module11. Accordingly, the power generation system10includes the synchronous generator14configured to generate active power to a power grid in an active power mode and generate reactive power or absorb reaction power in a reactive power mode to maintain the power factor on the power grid. The retrofitting process is configured to enable a clutchless synchronous condensing operation of the power generation system10.

The process98for retrofitting the power generation system10includes the step of opening a clutch casing44of the power generation system (block100). The clutch casing44may be a portion of the power generation system housing24. Opening the clutch casing44may include opening a side portion or top portion of the power generation system housing24disposed proximate the clutch assembly13, such that an operator performing the retrofit has access to the clutch assembly13. In some embodiments, the operator may open a pre-existing opening via an access panel (e.g., hinged panel).

The process98further includes the step of removing lube oil connections to the clutch assembly13for selectively coupling a second turbine shaft52(e.g., of the power turbine48) and a generator shaft64(block102). However, the operator may leave connected lube oil connections to one or more bearings56disposed proximate the clutch assembly13. The retrofitted power generation system10may incorporate the one or more bearings56to support the second turbine shaft52, the generator shaft64, or some combination thereof.

The process98includes the step of removing the clutch assembly13from the clutch casing44(block104). The clutch assembly13may include a plurality of clutch components, such as a flywheel, a pressure plate, pressure springs, releasing levers, a clutch housing, a clutch plate, a clutch actuator and controls, as well as other suitable components. Removing the clutch assembly13from the clutch casing44may include removing the clutch assembly13as an assembled unit or in a sequence of components of the clutch assembly13.

The process98includes the step of installing the clutchless synchronous condensing coupling16(e.g. the clutchless synchronous condensing module11) into the space previously occupied by the clutch assembly13(block106). As set forth above, in some embodiments, the entire clutch assembly13is removed such that the clutchless synchronous condensing coupling16(e.g., module11) may be installed directly between the second turbine shaft52and the generator shaft64. As such, installing the clutchless synchronous condensing coupling16(e.g., module11) may include directly attaching a first end portion88of the clutchless synchronous condensing coupling16to the second turbine shaft52and directly attaching a second end portion90of the clutchless synchronous condensing coupling16to the generator shaft64. However, in other embodiments, one or more components of the clutch assembly13(i.e., not retaining the functionality of the clutch) may remain attached to the second turbine shaft52, the generator shaft64, the housing24, the foundation26, or some combination thereof, particularly if these components are fixed in place and/or will not adversely impact installation of the clutchless synchronous condensing coupling16(e.g., module11). In these embodiments, the first end portion88and/or the second end portion90of the clutchless synchronous condensing coupling16may be configured to couple to one or more remaining components of the clutch assembly13(i.e., not retaining functionality of the clutch) attached to the second turbine shaft52and/or the generator shaft64.

The process98includes the step of providing an update (e.g., updated firmware or software instructions—controller updates) to a controller78for the power generation system10to perform clutchless synchronous condensing (block108). Providing the update to the controller78may include providing updated sump evacuation system instructions to the controller (block110). As set forth in detail below, the updated sump evacuation system instruction may be configured to deactivate the pump76during an active power mode of the power generation system10and activate the pump76during a reactive power mode of the power generation system10.

Moreover, providing an update to the controller78may include providing reactive power mode instructions to the controller78configured to control a gas turbine system12of the power generation system10during the reactive power mode (block112). The reactive power mode instructions may be configured to maintain a minimum operation speed (e.g., rotations per minute) of the turbine shaft in the reactive power mode to prevent wind milling of the core turbine46. The reactive power mode instructions may be configured to cause the power generation system10to operate between 1000 rotations per minute (RPM) and 2500 RPM in the reactive power mode. In some embodiments, the reactive power mode instructions may be configured to cause the power generation system10to operate between 1500 RPM and 3000 RPM in the reactive power mode. The reactive power mode instructions may be configured to cause the power generation system10to operate at a predetermined RPM configured to prevent wind milling of the core turbine46.

FIG. 5is a flow chart of an embodiment of a process114for updating operation of the sump evacuation system72as part of a retrofit of a power generation system10to incorporate a clutchless synchronous condensing module11. For purposes of discussion of the process114, the power generation system10and the clutchless synchronous condensing module11are substantially the same as described above with reference toFIGS. 1-3. For example, the retrofitting steps of the process114may correspond to the retrofitting shown inFIG. 2, wherein the sump evacuation system72is modified to incorporate a pump76. As discussed above, during the reactive power mode of the power generation system10, the gas turbine system12may operate at a lower RPM than during the active power mode. As such, the gas turbine system12may produce less pressure to circulate oil through the sump evacuation system72. In some embodiments, the pressure provided to the sump evacuation system72in the reactive power mode may be too low to fully circulate the oil through the sump evacuation system72, such that excess oil may heat over time and generate residue that may clog the sump evacuation system72. The process114for updating operation of the sump evacuation system72may provide the power generation system10with additional pressure to properly circulate the oil through the sump evacuation system72.

The process114includes the step of installing the pump76in a fluid line between a lubricant source (e.g., oil source) and a plurality of bearings56configured to support the first turbine shaft50, the second turbine shaft52, the generator shaft64, or some combination thereof (block116). The pump76may be a positive displacement pump configured to move the lubricant (e.g., oil) from the oil source toward the plurality of bearings56, as well as other lubricant flow paths through the gas turbine system12and/or the synchronous generator14. The pump76may be configured to provide sufficient pressure within the sump evacuation system72to circulate the lubricant through the sump evacuation system72, the bearings56, and the various lubricant flow paths.

The process114includes the step of sealing the lube oil connections removed from the clutch assembly13(block118). In some embodiments, at least some of the lube oil connections removed from the clutch assembly13may not be connected for the retrofitted power generation system10. Unconnected lube oil connections may leak lubricant and create pressure drops in the sump evacuation system72. Thus, the method includes the step of sealing the lube oil connections removed from the clutch assembly72. The lube oil connections may be sealed via any suitable seal, e.g., a cap, plug, welded joint, crimp, or a combination thereof.

The process114further includes the step of providing updated sump evacuation system instructions (e.g., updated firmware or software instructions—controller updates) to the controller78(block120). The updated sump evacuation system instructions may be configured to deactivate the pump76during an active power mode of the power generation system10and activate the pump76during a reactive power mode of the power generation system10. As set forth above, the pressure provided to the sump evacuation system72in the reactive power mode may be too low to fully circulate the oil through the sump evacuation system72, such that excess oil may heat over time and generate residue that may clog the sump evacuation system72. Providing updated sump evacuation system instructions to cause the sump evacuation system72to activate the pump76in the reactive power mode may provide the power generation system10with sufficient additional pressure to properly circulate the oil through the sump evacuation system72.