Systems and methods for retrofitting a power generation system to incorporate clutchless synchronous condensation

Abstract

The present invention discloses a system that includes a clutchless synchronous condensation coupling (16) configured to couple a turbine shaft (52) of a gas turbine system (12) to a generator shaft (64) of a synchronous generator (14) of a power generation system (10). The clutchless synchronous condensation coupling (16) includes: a first coupling portion (87) configured to be coupled to the turbine shaft (52); and a second coupling portion (91) configured to be coupled to the generator shaft (64). The clutchless synchronous condensation coupling (16) is configured to allow the power generation system (10) to operate in an active power mode and a reactive power mode without a clutch assembly (13).

Description

BACKGROUND OF THE INVENTION

[0001] The present disclosure relates generally to power generation systems having a generator driven by a gas turbine engine and, more particularly, to synchronous condensation.

[0002] Power generation systems typically include a clutch assembly between the generator and the gas turbine system. The clutch assembly enables selective engagement and disengagement between the shaft of the generator and the gas turbine system. However, the clutch assembly can increase the costs associated with maintenance, replacement parts, and downtime of the power generation system. Unfortunately, the clutch assembly can be installed in an existing power generation system that has a gas turbine system and a generator in set positions on a foundation (i.e., a pre-existing footprint), where a control system is designed specifically for various operating modes using the clutch assembly. There is a need for a system and method for retrofitting an existing power generation system to operate without a clutch assembly while achieving the various operating modes of the power generation system (e.g., an active power mode and a reactive power mode, where the active power mode operates the synchronous generator to generate power for the power grid and the reactive power mode operates the generator as a synchronous condenser to stabilize the power grid). Specifically, such a retrofit is needed without substantial alteration of the pre-existing footprint, i.e., without any substantial movement of the gas turbine system and the generator from their set positions on the foundation. SUMMARY OF THE INVENTION

[0003] Certain embodiments are outlined below that are commensurate in scope with the originally claimed subject matter. These embodiments are not intended to limit the scope of the disclosure, but rather these embodiments are only intended to provide a brief overview of certain disclosed embodiments. Indeed, the disclosure may include various forms that may be similar or different from the embodiments set forth below.

[0004] According to one embodiment, a system includes a clutchless synchronous condensation 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 condensation 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 condensation 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.

[0005] According to one embodiment, a power generation system includes a gas turbine system, a synchronous generator, a clutchless synchronous condenser coupling, a plurality of bearings, and a sump drain system. The gas turbine system includes a compressor, a combustor configured to generate a combustion gas flow, a first turbine driven by the combustion gas flow, and a second turbine downstream of the first turbine and driven by the combustion gas flow. A first shaft of the first turbine is non-rotatably 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. A clutchless synchronous condenser coupling is provided to couple the second shaft to a generator shaft of the synchronous generator. The clutchless synchronous condenser coupling is configured to transfer torque from the second shaft to the generator shaft in the active power mode to drive the synchronous generator, thereby providing active power to the power grid. The clutchless synchronous condenser coupling is configured to transfer torque from the generator shaft to the second shaft when the synchronous generator operates as a synchronous condenser in the reactive power mode to generate reactive power or absorb reactive power. The plurality of bearings are configured to support the first shaft, the second shaft, the generator shaft, or a combination thereof. The sump drain system is configured to operate in a first mode during the active power mode and in a second mode during the reactive power mode, wherein the sump drain system is configured to flow lubricant to the plurality of bearings.

[0006] According to one 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 non-rotatably coupled to a second shaft of the second turbine. The method further includes installing a clutchless synchronous condenser 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 condenser coupling without the clutch assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] These and other features, aspects, and advantages of the present disclosure will be better understood when the following detailed description is read with reference to the accompanying drawings, in which like characters represent like parts throughout the drawings, wherein:

[0008] Figure 1 is a schematic diagram of an embodiment of a power generation system having a clutchless synchronous condenser module with a replacement clutch assembly according to an embodiment of the present disclosure;

[0009] Figure 2 is a schematic diagram of an embodiment of a power generation system retrofitted with a clutchless synchronous condenser module as shown in Figure 1 ;

[0010] Figure 3 is as shown in Figure 1 and Figure 2Side view of an embodiment of the clutchless synchronous condensation module 11 shown;

[0011] Figure 4 is a flowchart of an embodiment of a process for retrofitting a power generation system to incorporate a clutchless synchronous condensation module as shown; and Figures 1 to 3 is a flowchart of an embodiment of a process for updating the operation of a storage tank evacuation system as part of retrofitting a power generation system to incorporate a clutchless synchronous condensation module.

[0012] Figure 5 DETAILED DESCRIPTION One or more specific embodiments of the present disclosure will now be described. To provide a concise description of these embodiments, not all features of an actual implementation may be described in the specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Additionally, it should be understood that such development efforts may be complex and time-consuming, but would still be a routine task of design, fabrication, and manufacture for those of ordinary skill in the art who would benefit from the present disclosure.

[0013] When introducing elements of various embodiments of the present disclosure, the articles "a," "an," and "the" are intended to mean that there is one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements. Further, it should be understood that references to "one embodiment" or "an embodiment" of the present disclosure are not intended to be construed as excluding the existence of other embodiments that also incorporate the recited features.

[0014] The disclosed embodiments provide systems and processes for retrofitting a power generation system to incorporate a clutchless synchronous condensation system. As detailed below, retrofitting an existing power generation system may include removing a clutch assembly from the power generation system and replacing the clutch assembly with a clutchless synchronous condensation coupling configured to couple a generator shaft of a synchronous generator to a turbine shaft of a gas turbine engine. Additionally, retrofitting an existing power generation system may include additional modifications and updates to a controller, a storage tank evacuation system (e.g., incorporating a pump), and other systems.

[0015]

[0016] Figure 1 ​Schematic diagram of an embodiment of a power generation system 10 having a clutchless synchronous condensation module 11 disposed between a gas turbine system 12 (or gas turbine engine) and a synchronous generator 14 (or generator / condenser). As discussed in detail below, the clutchless synchronous condensation module 11 includes a clutchless synchronous condensation coupling 16 (e.g., a rotary coupling). The clutchless synchronous condensation module 11 can be designed as part of a retrofit kit for a previously installed power generation system 10 and / or designed as part of the original equipment (e.g., part of the entire power generation system 10). As part of a retrofit kit, the clutchless synchronous condensation module 11 is configured to add clutchless synchronous condensation capability to a previously installed power generation system 10 (e.g., equipped with a clutch and / or not equipped with synchronous condensation capability) by replacing a clutch assembly or module 13 with the clutchless synchronous condensation module 11. In certain embodiments, the clutchless synchronous condensation module 11 is designed to fit in the same space previously occupied by the clutch assembly 13, thereby avoiding changing the final operating positions of other major components of the power generation system 10.

[0017] The gas turbine system 12 can include a compressor section having one or more compressors or compressor stages 18, a combustor section having one or more burners 20, and a turbine section having one or more turbines or turbine stages 22. The gas turbine system 12 and the synchronous generator 14 can be disposed within a power generation system enclosure 24. The power generation system enclosure 24 can be fixed to a foundation 26. The power generation system enclosure 24 can include enclosure portions for each component of the gas turbine system 12. For example, the power generation system enclosure 24 can have a compressor enclosure portion 28 configured to house the compressor 18, a combustor enclosure portion 30 configured to house the burner 20, and a turbine enclosure portion 32 configured to house the turbine 22. In some embodiments, the various enclosure portions of the power generation system enclosure 24 can be configured to house multiple components of the gas turbine system 12. The power generation system enclosure 24 can also include or house other components, such as an intake system 34, a controller, a turbine ventilation system 36 for the gas turbine system 12 (e.g., one or more fans in a ventilation duct), a generator ventilation system 38 for the synchronous generator 14 (e.g., one or more fans in a ventilation duct), a filter assembly having one or more filters 40 in the intake system 34, an exhaust stack 42, an engine lubrication system, a starting system, a hydraulic system, power and data, or some combination thereof.

[0018] In some embodiments, a previously installed power generation system 10 can be retrofitted by removing a previously installed connection (e.g., clutch assembly 13) between turbine 22 and synchronous generator 14 and replacing clutch assembly 13 with a clutchless synchronous condensing module 11 without any significant change to the mounting locations of housing 24, gas turbine system 12, and synchronous generator 14 on foundation 26. In other words, gas turbine system 12 and synchronous generator 14 can remain in their mounting positions on foundation 26 while clutchless synchronous condensing module 11 fills the space previously occupied by clutch assembly 13. In some embodiments, the size of clutchless synchronous condensing module 11 can be specifically configured to fit within the space occupied by clutch assembly 13, or clutchless synchronous condensing module 11 can have a base size combined with sizing features to achieve a proper fit between turbine 22 and synchronous generator 14. For example, clutchless synchronous condensing module 11 can include adjustable housing panels to increase and / or decrease the height, width, or length of module 11 depending on the available space. By another example, clutchless synchronous condensing module 11 can include adjustable features on clutchless synchronous condensing coupling 16, such as an axial adjustment assembly and / or associated couplings on coupling 16. The axial adjustment assembly of coupling 16 can effect adjustments to increase or decrease the axial length of clutchless synchronous condensing coupling 16 and its associated shaft. For example, the axial adjustment assembly can include resilient connectors, expandable / contractible shaft segments, spacers, or any combination thereof. Thus, the sizing features help enable clutchless synchronous condensing module 11 to be effectively installed within the available space previously occupied by clutch assembly 13. When clutchless synchronous condensing module 11 replaces clutch assembly 13, the overall footprint of power generation system 10 generally remains the same. By fitting clutchless synchronous condensing module 11 within the same space as clutch assembly 13, the disclosed embodiments achieve a more efficient retrofit with significantly reduced downtime of power generation system 10. In contrast, without the disclosed embodiments, a retrofit procedure may require time-consuming and costly movement of synchronous generator 14, gas turbine system 12, and / or housing 24 on foundation 26 and / or sizing of foundation 26.

[0019] The implementation of the retrofit procedure may include removing and / or opening a portion of the power generation system housing 24 (e.g., the clutch housing or clutch housing portion 44) at the location of the clutch assembly 13 between the gas turbine system 12 and the synchronous generator 14. Upon gaining access, the clutch assembly 13 may be removed and replaced with a clutchless synchronous condenser module 11 (including a clutchless synchronous condenser coupling 16). In some embodiments, the clutch housing portion 44 is reinstalled after installing the clutchless synchronous condenser module 11. In other embodiments, the clutchless synchronous condenser module 11 has its own integrated housing and is thus self - contained and ready to operate when installed in the space previously occupied by the clutch assembly 13.

[0020] As discussed below, the clutchless synchronous condenser module 11 may include a plurality of supplementary components 15, 17, 19, and 21 to support clutchless synchronous condensation. For example, the clutchless synchronous condenser module 11 may include a controller 15 having a processor, a memory, and instructions stored on the memory and executable by the processor to perform various tasks associated with clutchless synchronous condensation. In some embodiments, the controller 15 may enable updating of the main controller of the power generation system 10 (e.g., 78, Figure 2 ) to provide computer instructions suitable for performing clutchless synchronous condensation. Additionally, in some embodiments, the controller 15 may enable local monitoring and / or control of the clutchless synchronous condenser module 11 (including the clutchless synchronous condenser coupling 16) and other components 17, 19, and 21. Component 17 may include, for example, all or part of a storage tank drain system 72, as further discussed in detail below with reference to Figure 2 . Component 19 may include, for example, one or more sensors dedicated to monitoring aspects affecting clutchless synchronous condensation, including sensors that monitor operating parameters of the power grid (e.g., grid frequency) and one or more operating parameters of the synchronous generator 14, turbine 22, and / or the clutchless synchronous condenser coupling 16 (e.g., rotational speed, torque, vibration level, acoustic noise, alignment of the rotational axis, or any combination thereof). The controller 15 and / or 78 respond to feedback from one or more sensors to control the operation of the gas turbine system 12, thereby using the clutchless synchronous condenser coupling 16 of the clutchless assembly 13 to transition the power generation system 10 between the active power mode and the reactive power mode. Additionally, component 21 may include, for example, a user interface or control panel configured to allow adjustment of the operation of the clutchless synchronous condenser module 11. Components 15, 17, 19, and 21 may be communicatively coupled together and communicatively coupled to the main controller of the power generation system 10 (e.g., Figure 2 's 78), thereby facilitating the retrofit of the system 10 to incorporate clutchless synchronous condensation.

[0021] Figure 2 It was modified like Figure 1 Schematic diagram of an embodiment of a power generation system 10 of a clutchless synchronous condensing module 11 is shown. The power generation system 10 includes a gas turbine system 12 coupled to a synchronous generator 14. The gas turbine system 12 includes a compressor 18, a combustor 20, and a turbine 22. In some embodiments, the gas turbine system 12 includes a high-pressure gas turbine (e.g., a core turbine 46) and a low-pressure gas turbine (e.g., a power turbine 48) disposed downstream of the core turbine 46. The core turbine 46 may be configured to drive a core shaft (e.g., a first turbine shaft 50), and the power turbine may be configured to drive a power shaft (e.g., a second turbine shaft 52). The first turbine shaft 50 may be physically separated from the second turbine shaft 52. That is, the first turbine shaft 50 is not mechanically connected to the second turbine shaft 52, and therefore the first turbine shaft 50 does not mechanically drive the second turbine shaft 52.

[0022] The compressor 18 may be mechanically coupled to the first turbine shaft 50 (e.g., via a compressor shaft or compressor shaft portion of the first turbine shaft 50), and is configured to receive an incoming air flow 54 from the intake system 34 of the power generation system 10. The first turbine shaft 50 may be supported by one or more bearings 56. The compressor 18 may include a plurality of compressor stages (e.g., 2 to 28 or more compressor stages), each compressor stage having a plurality of stator blades positioned about the compressor shaft and a plurality of compressor blades configured to rotate in response to rotation of the first turbine shaft 50. The compressor 18 may be configured to compress the incoming air flow 54 and deliver the compressed air flow 58 to the combustor 20.

[0023] The combustor 20 (including one or more fuel nozzles 57) may be configured to mix a compressed air flow 58 with a pressurized fuel flow 60 received from a fuel source, and ignite the mixture to produce a combustion gas flow 62. Although only a single combustor 20 is shown, the gas turbine system 12 may include multiple combustors. The combustor 20 may be configured to deliver the combustion gas flow 62 to the core turbine 46. The core turbine 46 may include multiple turbine stages (e.g., 2 to 10 or more turbine stages), each turbine stage having a plurality of stator blades positioned around a first turbine shaft 50 and a plurality of turbine blades configured to rotate with the first turbine shaft 50. The combustion gas flow 62 may drive the rotation of the core turbine 46 and the first turbine shaft 50; however, the core turbine 46 itself does not drive the rotation of the second turbine shaft 52. The core turbine 46 directs the combustion gas flow 62 (e.g., exhaust gas) leaving the core turbine 46 to the power turbine 48.

[0024] The power turbine 48 is mechanically coupled to the second turbine shaft 52, but not mechanically coupled to the first turbine shaft 50. The power turbine 48 is configured to receive a combustion gas flow 62 (e.g., exhaust gas) from the core turbine 46. The second turbine shaft 52 may be supported by one or more bearings 56. The power turbine 48 may include a plurality of stator blades positioned around the second turbine shaft 52 and a plurality of turbine blades coupled to the second turbine shaft 52 and configured to drive the rotation of the second turbine shaft. The combustion gas flow 62 from the core turbine 46 may drive the power turbine 48, thereby generating mechanical work. When the power generation system 10 operates in an active power mode (or synchronous power generation mode of the generator 14), the mechanical work generated by the power turbine 48 (i.e., due to the rotation of the power turbine 48 driven by the combustion gas 62) may drive the synchronous generator 14. That is, the mechanical work generated by the power turbine 48 may drive the second turbine shaft 52. The clutchless synchronous condensation coupling 16 may be configured to couple the second turbine shaft 52 to the generator shaft 64 such that torque is transmitted between the second turbine shaft 52 and the generator shaft 64. The torque from the second turbine shaft 52 is transmitted to the generator shaft 64, causing the generator shaft 64 to rotate. The rotation of the generator shaft 64 drives the synchronous generator 14 such that when the power generation system 10 operates in an active power mode, the power turbine 48 may drive the synchronous generator 14 (i.e., synchronous power generation mode).

[0025] The synchronous generator 14 may include a generator rotor 66 mounted within a generator stator 68. A generator shaft 64 is coupled to the generator rotor 66 and configured to rotate therewith. The generator shaft 64 may be supported by one or more bearings 56. The generator rotor 66 may be wrapped in field windings, and the generator stator 68 may be wrapped in armature windings. Thus, rotation of the generator shaft 64 of the synchronous generator 14 may provide active power to the power grid 70 in the active power mode of the power generation system 10. As described above, the synchronous generator 14 is configured to be driven by the generator shaft 64 to provide active power in the active power mode. In the reactive power mode of the power generation system 10, the synchronous generator 14 operates as a synchronous condenser in the synchronous condensation mode as needed to maintain the power factor on the power grid 70. The synchronous generator 14 may be configured to drive the generator shaft 64 to generate reactive power in the reactive power mode, or absorb reactive power in the reactive power mode to maintain the power factor on the power grid 70. Thus, the synchronous generator 14 may operate as a synchronous generator 14 in the active power mode and as a synchronous condenser in the reactive power mode. In the reactive power mode, the synchronous generator 14 (operating as a synchronous condenser in the synchronous condensation mode) is configured to rotate freely to adjust conditions on the power grid 70 while rotating the generator shaft 64 and the power turbine 48; however, due to the lack of a mechanical connection between the core turbine 46 and the power turbine 48, the free rotation of the synchronous condenser does not drive the rotation of the core turbine 46. Thus, synchronous condensation is possible without a clutch for selectively connecting and disconnecting the synchronous generator 14 and the turbine 22.

[0026] As described above, one or more bearings 56 may be configured to support the first turbine shaft 50, the second turbine shaft 52, the generator shaft 64, the clutchless synchronous condensation coupling 16, or some combination thereof. A sump drain system 72 may be configured to provide lubricant (e.g., oil) to one or more bearings 56 and other parts of the power generation system 10. The sump drain system 72 may include an oil source 74 configured to store lubricant and / or provide lubricant for the operation of the sump drain system 72. In some embodiments, the sump drain system 72 is configured to maintain a pressure differential across one or more bearings 56 (e.g., lubricant seals of the bearings).

[0027] The storage tank evacuation system 72 can utilize the internal pressure from the operation of the gas turbine system 12 to circulate lubricant in the active power mode. In the active power mode, the core turbine 46 of the gas turbine system can be configured to operate at a speed higher than 8,000 RPM, which provides sufficient internal pressure for the storage tank evacuation system 72 to circulate the lubricant. However, during the reactive power mode, the core turbine 46 can be shut down or operate at a substantially lower RPM (e.g., less than 2,500 RPM). To maintain the circulation of the lubricant, the power generation system 10 includes a pump 76 (or pumps) of the storage tank evacuation system 72 installed during the retrofit. In some embodiments, the pump 76 and / or the storage tank evacuation system 72 can be one of the components (e.g., component 17) of the clutchless synchronous condenser module 11 (e.g., part of a packaged system), or the pump 76 can be separately packaged and / or packaged together with the storage tank evacuation system 72. The pump 76 can be configured to provide additional pressure for circulating the lubricant. In some embodiments, the pump 76 can be configured to operate only in the reactive power mode. In some embodiments, the pump 76 can also be configured to supplement the internal pressure driving the lubricant circulation during the active power mode. However, in either case, the pump 76 can be part of the retrofit associated with the clutchless synchronous condenser module 11. Additionally, the retrofit can include a controller upgrade to enable the pump 76 to operate with the clutchless synchronous condenser module 11.

[0028] The power generation system 10 can include a controller 78 configured to control the operation of the power generation system 10 (e.g., cause the system to operate in the active power mode or the reactive power mode) via a processor 80 and a memory 82. As described above, the controller 78 can be a main controller and / or a controller separate from the controller 15, the controllers 15 and 78 can operate together to control various aspects of the power generation system 10, the controllers 15 and 78 can be integrated together as a single controller, or one or both of the controllers 15 and 78 can be configured to operate the power generation system 10 in the active power mode and the reactive power mode, including aspects specific to the clutchless synchronous condenser module 11. Any control features described with respect to either of the controllers 15 and 78 are intended to include control features incorporated into one or both of the controllers 15 and 78. Thus, the following discussion of the control features can relate only to the controller 78, but in some embodiments is intended to cover the control features of the controller 78.

[0029] The processor 80 of the controller 78 may include one or more processing devices, and the memory 82 may include one or more tangible non-transitory machine-readable media. By way of example, such machine-readable media may include RAM, ROM, EPROM, EEPROM, or optical disk storage, magnetic disk storage, or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of machine-executable instructions or data structures and that can be accessed by the processor 80 or other processor-based devices (e.g., a mobile device). In some embodiments, the memory 82 is configured to store controller instructions executable by the processor 80 to output various controller signals 84. For example, the processor 80 may execute the controller instructions to control the operation of the gas turbine system 10.

[0030] The controller 78 (via the processor 80) and / or the controller 15 (via the processor) may execute controller instructions to control the operation of the storage tank emptying system 72. For example, the controller 78 and / or 15 may be configured to deactivate the pump 76 in the active power mode and activate the pump 76 in the reactive power mode. In some embodiments, the controller 78 and / or 15 may be configured to control the operation of the storage tank emptying system 72 at least in part based on user input via a user interface (such as the user interface of the component 21 of the clutchless synchronous condenser module 11 described above). The user interface may include an input / output device (e.g., a keyboard, a mouse, or a touch screen) configured to provide user input to the controller 78 and / or 15. Additionally, the user interface may include a display (e.g., a computer monitor or a personal device screen) configured to display user options for the controller 78 and / or 15.

[0031] In addition, the controller 78 (or the controller 15) may be configured to output various controller signals 84 via the communication circuit 86. The communication circuit 86 may include a wired connection and / or a wireless communication circuit. For example, the communication circuit 86 may include an antenna, a radio transceiver circuit, and signal processing hardware and / or software (e.g., hardware or software filters, A / D converters, multiplexers, amplifiers) or a combination thereof, and may be configured to communicate via a wireless communication path via infrared (IR) wireless communication, satellite communication, broadcast radio, microwave radio, Bluetooth, Zigbee, Wifi, UHF, NFC, etc.

[0032] In some embodiments, the controller 78 and / or 15 of the gas turbine system 12 is configured to maintain a minimum operating speed (e.g., revolutions per minute) of the first turbine shaft 50 and the core turbine 46 in a reactive power mode. Maintaining the minimum speed of the core turbine 46 can prevent self-rotation of the core turbine 46 caused by the rotation of the power turbine 48 disposed adjacent to the core turbine 46. In some embodiments, the core turbine 46 of the power generation system 10 is configured to operate between 1000 revolutions per minute (RPM) and 2500 RPM in a reactive power mode. In some embodiments, the core turbine 46 is configured to operate between 1500 RPM and 3000 RPM in a reactive power mode.

[0033] Figure 3 is as Figure 1 and Figure 2 A side view of an embodiment of the clutchless synchronous condenser module 11 as shown. As discussed above, the module 11 with the clutchless synchronous condenser coupling 16 is configured to replace the clutch assembly 13 as part of a retrofit of the power generation system 10. The clutchless synchronous condenser coupling 16 can be configured to couple the second turbine shaft 52 to the power generation shaft 64 such that torque can be transferred between the second turbine shaft 52 and the generator shaft 64. Specifically, the clutchless synchronous condenser coupling 16 can be configured to transfer torque from the second turbine shaft 52 to the generator shaft 64 in the active power mode of the power generation system 10 and also transfer torque from the generator shaft 64 to the second turbine shaft 52 in the reactive power mode of the power generation system 10.

[0034] In some embodiments, the first coupling portion or first end portion 88 of the clutchless synchronous condensation coupling 16 is configured to be fastened to the second turbine shaft 52. Additionally, the second coupling portion or second end portion 90 of the clutchless synchronous condensation coupling 16 is configured to be fastened to the generator shaft 64. For example, the first end portion 88 may include a first flange 87 (e.g., an annular flange) coupled to a first mating flange 89 (e.g., an annular flange) by one or more fasteners 92, and the second end portion 90 may include a second flange 91 (e.g., an annular flange) coupled to a second mating flange 93 (e.g., an annular flange) by one or more fasteners 92. The fasteners 92 may 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 in addition, the fasteners 92 may include one or more fixed or permanent joints such as welded joints. The connection between the flanges 87 and 89 and the flanges 91 and 93 may also include torque transfer features such as a plurality of teeth that mate with corresponding grooves (e.g., on opposite end faces of the flanges). For example, the torque transfer features may include face gear couplings, diaphragm couplings, grid couplings, disc couplings, or any combination thereof. In the illustrated embodiment, the torque transfer features include at least diaphragm couplings 95 at the junctions of the flanges 87 and 89 and at the junctions of the flanges 91 and 93.

[0035] The diaphragm coupling 95 without a clutch synchronous condensate coupling 16 may include a first diaphragm 94 disposed near a first end portion 88 of the coupling 16 and a second diaphragm 96 disposed near a second end portion 90 of the coupling 16. The first diaphragm 94 and the second diaphragm 96 may be configured to accommodate misalignment between the second turbine shaft 52 and the generator shaft 64. That is, the first diaphragm 94 and the second diaphragm 96 are configured to compensate for axial, radial, and angular offsets between the second turbine shaft 52 and the generator shaft 64. Each of the first diaphragm 94 and the second diaphragm 96 may include one or more flexible metal diaphragms, disks, or plates that are disposed within corresponding portions of the clutchless synchronous condensate coupling 16 and are configured to flex during rotation of the second turbine shaft 52 and the generator shaft 64 to accommodate misalignment between the second turbine shaft 52 and the generator shaft 64. The diaphragms 94 and 96 of the diaphragm coupling 95 are configured to transfer torque from the outer diameter of the flexible metal diaphragm, disk, or plate to the inner diameter and / or from the inner diameter to the outer diameter. The diaphragm coupling 95 may include a plurality of straight diaphragms with a tapered profile, spokes, and / or a plurality of corrugated diaphragms. Compared with the clutch assembly 13, the diaphragm coupling 95 of the clutchless synchronous condensate coupling 16 may significantly reduce or eliminate maintenance. For example, the diaphragm coupling 95 may not require any lubrication and may have a significantly longer life than the clutch assembly 13, thereby avoiding possible downtime for repair or replacement. Thus, the diaphragm coupling 95 may be considered lubricant-free, self-aligning or self-adjusting for misalignment between shafts and maintenance-free.

[0036] In the illustrated embodiment, the clutchless synchronous condensation module 11 includes a housing or frame 97 that supports and / or encloses a clutchless synchronous condensation coupling 16 having two diaphragm couplings 95, components 15, 17, 19, and 21, bearings 56 disposed about a portion of the second turbine shaft 52, bearings 56 aligned about a portion of the generator shaft 64, and one or more lubricant supply conduits 99 configured to supply a lubricant (e.g., oil) to the bearings 56 (e.g., via system 72). Additionally, in some embodiments, the housing or frame 97 of the clutchless synchronous condensation module 11 may support additional components or all of the pump 76 and / or the sump drain system 72, as described above. Although the illustrated embodiment of the clutchless synchronous condensation module 11 includes bearings 56, some embodiments of the module 11 may not include bearings 56, and / or the size of the housing or frame 97 may be set based on the axial length of the clutchless synchronous condensation coupling 16 extending to the flanges 87 and 91 and the diaphragm couplings 95, as indicated by the axial length 99. For example, the axial length 99 of the housing or frame 97 may be about 80% to 120%, 90% to 110%, or about 100% of the axial length of the coupling 16. The housing or frame 97 may include an internal frame 101 surrounded by one or more outer housing panels 103, which may include one or more removable housing panels configured to facilitate installation and inspection. The module 11 may also include one or more installation / removal tools 105 (e.g., an upper tool and / or a lower tool), which may be configured to assist in lifting and / or lowering the coupling 16, aligning the coupling 16 with the shafts 52 and 64, or any combination thereof. For example, the tool 105 may include a motor-driven tool, a hydraulic tool, a pneumatic tool, or a combination thereof. Additionally, the tool 105 may include mechanical supports (e.g., support bars, cables, chains, etc.) that may be moved into position to support the coupling 16 during installation and / or removal. These tools 105 may be packaged with the module 11 to facilitate efficient installation of the module 11 during a retrofit procedure. In certain embodiments, the tool 105 may also be used to remove the clutch assembly 13. However, in some embodiments, the tool 105 may not be included in the module 11.

[0037] Figure 4 is an embodiment of a process 98 for retrofitting a power generation system 10 to incorporate a clutchless synchronous condensation module 11 as shown Figures 1 to 3 in the flowchart. For purposes of discussing the process 98, the power generation system 10 and the clutchless synchronous condensation module 11 are substantially the same as described above with reference to Figures 1 to 3 For example, the retrofit steps of the process 98 may correspond to Figure 1The modification shown, in which the clutch assembly 13 is replaced by a clutchless synchronous condensation module 11. Thus, the power generation system 10 includes a synchronous generator 14 configured to generate active power for the power grid in the active power mode and to generate reactive power or absorb reactive power in the reactive power mode to maintain the power factor on the power grid. The modification process is configured to implement clutchless synchronous condensation operation of the power generation system 10.

[0038] The process 98 for modifying the power generation system 10 includes the step of opening the clutch housing 44 of the power generation system (block 100). The clutch housing 44 can be part of the power generation system housing 24. Opening the clutch housing 44 can include opening a side portion or a top portion of the power generation system housing 24 disposed adjacent to the clutch assembly 13 such that an operator performing the modification can access the clutch assembly 13. In some embodiments, the operator can open a pre-existing opening via an access panel, such as a hinged panel.

[0039] The process 98 also includes the step of removing the lubricating oil connection member of the clutch assembly 13 for selectively coupling (e.g., the second turbine shaft 52 of the power turbine 48) and the generator shaft 64 (block 102). However, the operator can leave the connected lubricating oil connection members of one or more bearings 56 disposed adjacent to the clutch assembly 13. The modified power generation system 10 can incorporate one or more bearings 56 to support the second turbine shaft 52, the generator shaft 64, or some combination thereof.

[0040] The process 98 includes the step of removing the clutch assembly 13 from the clutch housing 44 (block 104). The clutch assembly 13 can include a plurality of clutch components, such as a flywheel, a pressure plate, a pressure spring, a release lever, a clutch housing, a clutch plate, a clutch actuator, and a controller, as well as other suitable components. Removing the clutch assembly 13 from the clutch housing 44 can include removing the clutch assembly 13 as an assembled unit or in a sequence of components of the clutch assembly 13.

[0041] Procedure 98 includes the step of installing a clutchless synchronous condensation coupling 16 (e.g., clutchless synchronous condensation module 11) into the space previously occupied by the clutch assembly 13 (block 106). As described above, in some embodiments, the entire clutch assembly 13 is removed such that the clutchless synchronous condensation coupling 16 (e.g., module 11) can be directly installed between the second turbine shaft 52 and the generator shaft 64. Thus, installing the clutchless synchronous condensation coupling 16 (e.g., module 11) can include directly attaching a first end portion 88 of the clutchless synchronous condensation coupling 16 to the second turbine shaft 52 and directly attaching a second end portion 90 of the clutchless synchronous condensation coupling 16 to the generator shaft 64. However, in other embodiments, one or more components of the clutch assembly 13 (i.e., those that do not retain the function of the clutch) can remain attached to the second turbine shaft 52, the generator shaft 64, the housing 24, the foundation 26, or some combination thereof, particularly if these components are fixed in place and / or will not adversely affect the installation of the clutchless synchronous condensation coupling 16 (e.g., module 11). In these embodiments, the first end portion 88 and / or the second end portion 90 of the clutchless synchronous condensation coupling 16 can be configured to couple to one or more remaining components of the clutch assembly 13 (i.e., those that do not retain the function of the clutch) attached to the second turbine shaft 52 and / or the generator shaft 64.

[0042] Procedure 98 includes the step of providing an update (e.g., updated firmware or software instructions—a controller update) to the controller 78 for the power generation system 10 to perform clutchless synchronous condensation (block 108). Providing the update to the controller 78 can include providing updated sump drain system instructions to the controller (block 110). As detailed below, the updated sump drain system instructions can be configured to deactivate the pump 76 during the active power mode of the power generation system 10 and activate the pump 76 during the reactive power mode of the power generation system 10.

[0043] In addition, providing the update to the controller 78 can include providing reactive power mode instructions to the controller 78 of the gas turbine system 12 configured to control the power generation system 10 during the reactive power mode (block 112). The reactive power mode instructions can be configured to maintain a minimum operating speed (e.g., revolutions per minute) of the turbine shaft during the reactive power mode to prevent autorotation of the core turbine 46. The reactive power mode instructions can be configured to cause the power generation system 10 to operate between 1000 revolutions per minute (RPM) and 2500 RPM during the reactive power mode. In some embodiments, the reactive power mode instructions can be configured to cause the power generation system 10 to operate between 1500 RPM and 3000 RPM during the reactive power mode. The reactive power mode instructions can be configured to cause the power generation system 10 to operate at a predetermined RPM configured to prevent autorotation of the core turbine 46.

[0044] Figure 5 is a flowchart of an embodiment of process 114 for updating the operation of the storage tank drain system 72, which is part of retrofitting the power generation system 10 to incorporate the clutchless synchronous condensation module 11. For purposes of discussing process 114, the power generation system 10 and the clutchless synchronous condensation module 11 are substantially the same as those described above with reference to Figures 1 to 3 the same. For example, the retrofit steps of process 114 may correspond to Figure 2 the retrofit shown, where the storage tank drain system 72 is modified to incorporate the pump 76. As described above, during the reactive power mode of the power generation system 10, the gas turbine system 12 may operate at a lower RPM than during the active power mode. Thus, the gas turbine system 12 may generate less pressure to circulate oil through the storage tank drain system 72. In some embodiments, the pressure provided to the storage tank drain system 72 during the reactive power mode may be too low to fully circulate the oil through the storage tank drain system 72, such that excess oil may heat over time and generate residues that can clog the storage tank drain system 72. Process 114 for updating the operation of the storage tank drain system 72 may provide additional pressure to the power generation system 10 to properly circulate the oil through the storage tank drain system 72.

[0045] Process 114 includes the step of installing the pump 76 in a fluid line between a lubricant source (e.g., an oil source) and a plurality of bearings 56 configured to support the first turbine shaft 50, the second turbine shaft 52, the generator shaft 64, or some combination thereof (block 116). The pump 76 may be a positive displacement pump configured to move lubricant (e.g., oil) from the oil source towards the plurality of bearings 56 and through other lubricant flow paths of the gas turbine system 12 and / or the synchronous generator 14. The pump 76 may be configured to provide sufficient pressure within the storage tank drain system 72 to circulate the lubricant through the storage tank drain system 72, the bearings 56, and the various lubricant flow paths.

[0046] Process 114 includes the step of sealing the lubricating oil connections removed from the clutch assembly 13 (block 118). In some embodiments, at least some of the lubricating oil connections removed from the clutch assembly 13 may not be connected for the retrofitted power generation system 10. The unconnected lubricating oil connections may leak lubricant and create a pressure drop in the storage tank drain system 72. Thus, the method includes the step of sealing the lubricating oil connections removed from the clutch assembly 72. The lubricating oil connections may be sealed via any suitable seal, such as a cap, plug, welded joint, crimp, or a combination thereof.

[0047] Process 114 also includes the step (block 120) of providing updated storage tank evacuation system instructions (e.g., updated firmware or software instructions—a controller update) to controller 78. The updated storage tank evacuation system instructions can be configured to deactivate pump 76 during the active power mode of power generation system 10 and to activate pump 76 during the reactive power mode of power generation system 10. As described above, the pressure provided to storage tank evacuation system 72 during the reactive power mode may be too low to allow the oil to fully circulate through storage tank evacuation system 72, such that excess oil may heat over time and generate residues that can clog storage tank evacuation system 72. Providing updated storage tank evacuation system instructions to cause storage tank evacuation system 72 to activate pump 76 during the reactive power mode can provide power generation system 10 with sufficient additional pressure to allow the oil to properly circulate through storage tank evacuation system 72.

[0048] Although only certain features of the present disclosure have been illustrated and described herein, many modifications and variations will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and variations that fall within the true spirit of the present disclosure.

[0049] The technology presented and claimed herein is referenced and applied to physical objects and specific examples of a practical nature, which physical objects and specific examples significantly improve the present technical field and are thus not abstract, intangible, or purely theoretical. Additionally, if any claim appended to the end of this specification contains one or more elements designated as "[perform][a function]..." or "steps of [perform][a function]", then those elements shall be construed in accordance with 35 U.S.C. 112(f). However, for any claim that contains elements designated in any other manner, such elements shall not be construed in accordance with 35 U.S.C. 112(f).

Claims

1. A system, comprising: a clutchless synchronous condensation coupling (16) configured to couple a turbine shaft (52) of a gas turbine system (12) to a generator shaft (64) of a synchronous generator (14) of a power generation system (10) in a space previously occupied by a clutch assembly (13), wherein the clutchless synchronous condensation coupling (16) comprises: a first coupling portion (87) configured to be coupled to the turbine shaft (52); and a second coupling portion (91) configured to be coupled to the generator shaft (64), wherein the clutchless synchronous condensation coupling extends an axial length between the first coupling portion and the second coupling portion; wherein the clutchless synchronous condensation coupling (16) is configured to allow the power generation system (10) to operate in an active power mode and a reactive power mode without the clutch assembly (13), and wherein the clutchless synchronous condensation coupling comprises an axial adjustment assembly configured to effect an adjustment to increase or decrease the axial length of the clutchless synchronous condensation coupling.

2. The system according to claim 1, comprising one or more components (76, 78) configured to retrofit the power generation system (10) previously equipped with the clutch assembly (13) to operate in the active power mode and the reactive power mode without the clutch assembly (13).

3. The system according to claim 2, wherein the one or more components comprise a pump (76) configured to circulate a lubricant when the power generation system (10) operates in the reactive power mode.

4. The system according to claim 3, wherein the one or more components comprise a controller (78) or instructions for upgrading an existing controller (78) of the power generation system (10) to operate the pump (76) during the reactive power mode when pressure in the gas turbine system (12) is insufficient to circulate the lubricant, wherein the pressure in the gas turbine system (12) is sufficient to circulate the lubricant in the active power mode.

5. The system according to claim 4, comprising a clutchless synchronous condensation module (11) having the clutchless synchronous condensation coupling (16) and the one or more components.

6. The system according to claim 1, wherein the clutchless synchronous condensation coupling (16) is configured to fit into the space previously occupied by the clutch assembly (13) mounted between the gas turbine system (12) and the synchronous generator (14) such that the gas turbine system (12) and the synchronous generator (14) remain in their respective mounting positions on a foundation (26) of the power generation system (10).

7. The system according to claim 1, wherein the clutchless synchronous condensation coupling (16) comprises at least one diaphragm coupling (95).

8. The system according to claim 7, wherein the first coupling portion (87) comprises a first diaphragm coupling (95) of the at least one diaphragm coupling (95), the second coupling portion (91) comprises a second diaphragm coupling (95) of the at least one diaphragm coupling (95), and the first diaphragm coupling and the second diaphragm coupling (95) are configured to accommodate misalignment between the turbine shaft (52) and the generator shaft (64).

9. The system according to claim 1, comprising the gas turbine system (12), the gas turbine system having a burner (20) configured to generate a combustion gas flow, a first turbine (46) driven by the combustion gas flow, and a second turbine (48) driven by the combustion gas flow and located downstream of the first turbine (46), wherein the first turbine and the second turbine (48) are non-rotationally coupled together, and wherein the first coupling portion (87) of the clutchless synchronous condensation coupling (16) is coupled to the turbine shaft (52) of the second turbine (48).

10. The system according to claim 9, comprising a controller (78) configured to control the gas turbine system (12) in the reactive power mode to stop combustion in the burner (20), thereby stopping the generation of the combustion gas flow that drives the first turbine and the second turbine (48).

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