System and method for integrating auxiliary energy and waste heat recovery from gas turbine engine

Abstract

To provide a system and a method for integrating an auxiliary power source with power generated from a gas turbine engine.SOLUTION: An integration system (400) for extracting electric power includes a flue gas flow source (110) configured to supply thermal energy from a flue gas flow (302) to a heat exchanger (304, 306) and an auxiliary energy source (AES) (204) configured to selectively supply auxiliary thermal energy to a supplemental heat exchanger (402). The integration system (400) includes a controller (206). The controller (206) is configured to: determine whether the AES (204) is supplying auxiliary thermal energy to the supplemental heat exchanger (402); and if the AES (204) is supplying auxiliary thermal energy to the supplemental heat exchanger (402), cause a turbine (320, 366) to extract electric power from both the flue gas flow and the auxiliary thermal energy.SELECTED DRAWING: Figure 3A

Description

[Technical Field]

[0001] The field of the disclosure relates generally to generating electrical power from auxiliary energy sources, and more particularly to methods and systems for integrating auxiliary energy with waste heat recovery from a gas turbine engine.

[0002] Gas turbines are widely used in a variety of commercial operations, such as power generation operations. Gas turbines generally include a compressor, at least one combustor, and a turbine (e.g., an expansion turbine). The compressor typically compresses a working fluid and discharges the compressed working fluid to a combustor, where fuel is injected into the compressed working fluid flow and the resulting mixture is ignited to generate combustion gases. The combustion gases exit the combustor and are channeled to a turbine, where they are expanded to produce work that is converted to electrical power. At least some known gas turbines utilize thermal energy extracted from the exhaust gases to generate additional electrical power.

[0003] By integrating renewable energy sources with gas turbine engines, power generation systems can generate the steady power required by the power grid while conserving resources and reducing emissions. However, integrating power generation systems for generating power from steady sources and for generating power from intermittent sources (if or when the intermittent sources are available) requires transition and / or reconfiguration downtime. Furthermore, integrating unpredictable intermittent energy sources with little advance notice to prepare for transition between systems can be particularly challenging.

[0004] Therefore, there is a need for a system and method for integrating an auxiliary power source with power generated from a gas turbine engine. Summary of the Invention

[0005] In one aspect, an integrated system for extracting electrical power is provided, the integrated system including a flue gas flow source configured to supply thermal energy of the flue gas flow to a heat exchanger, a supplemental energy source configured to selectively supply supplemental thermal energy to an auxiliary heat exchanger, and a controller coupled to the flue gas flow source and the AES, the controller configured to cause a turbine to extract electrical power from both the thermal energy of the flue gas flow and the supplemental thermal energy when the AES is supplying supplemental thermal energy to the auxiliary heat exchanger.

[0006] In another aspect, an integrated system for extracting electrical power is provided. The integrated system includes a flue gas flow source configured to supply thermal energy of a flue gas flow to a heat exchanger, a supplemental energy source configured to selectively supply supplemental thermal energy to an auxiliary heat exchanger, and a post-combustion carbon capture system that receives the flue gas flow after the flue gas flow passes through the heat exchanger. The system includes a controller coupled to the flue gas flow source. The controller is configured to cause a turbine to extract electrical power from the thermal energy of the flue gas flow extracted by the heat exchanger and the supplemental thermal energy extracted by the auxiliary heat exchanger. In another aspect, a method of operating an integrated system for extracting electrical power from a supplemental energy source is provided. The method includes determining whether the supplemental energy source is supplying supplemental thermal energy to the auxiliary heat exchanger, and, if the AES is supplying supplemental thermal energy to the auxiliary heat exchanger, causing a turbine to generate electrical power from the supplemental thermal energy. [Brief explanation of the drawings]

[0007] These and other features, aspects, and advantages of the present disclosure can be better understood from the following detailed description when read in conjunction with the drawings, in which like characters represent like parts throughout. [Figure 1] 1 is a schematic diagram of an exemplary power generation system including a gas turbine engine and an integrated system. [Figure 2] 2 is a schematic diagram of an exemplary integrated system that may be used, for example, with the power generation system shown in FIG. 1. [Figure 3A] 2 is a schematic diagram of another exemplary integrated system including a flue gas stream energy source and a supplemental energy source that may be used with the power generation system shown in FIG. 1. [Figure 3B] 2 is a schematic diagram of another exemplary integrated system including a flue gas stream energy source and a supplemental energy source that may be used with the power generation system shown in FIG. 1. [Figure 4] FIG. 2 is a schematic diagram of yet another exemplary integrated system that may be used with the power generation system shown in FIG. 1 and includes a flue gas stream energy source, a supplemental energy source, and a post-carbon capture system. [Figure 5A] 2 is a schematic diagram of another exemplary integrated system including a flue gas flow energy source and a supplemental energy source that may be used with the power generation system shown in FIG. 1. [Figure 5B] 2 is a schematic diagram of another exemplary integrated system including a flue gas flow energy source and a supplemental energy source that may be used with the power generation system shown in FIG. 1. [Figure 6] 2 is a schematic diagram of another exemplary integrated system including a flue gas flow energy source and a supplemental energy source that may be used with the power generation system shown in FIG. 1. [Figure 7] FIG. 1 is a process flow diagram of an exemplary method for controlling an integrated system including, for example, a flue gas stream energy source and a supplemental energy source.

[0008] Unless otherwise indicated, the drawings provided herein are intended to illustrate features of embodiments of the present disclosure. These features are believed to be applicable in a wide variety of systems incorporating one or more embodiments of the present disclosure. As such, the drawings are not intended to include all conventional features known by those skilled in the art to be necessary to practice the embodiments disclosed herein. DETAILED DESCRIPTION OF THE INVENTION

[0009] In the following specification and claims, reference will be made to a number of terms, which shall be defined to have the following meanings. The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. "Optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes instances when the event occurs and instances when the event does not occur. Furthermore, references to "one embodiment" are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Furthermore, unless expressly stated to the contrary, embodiments that "comprise" or "have" one or more elements having a particular characteristic may include additional similar elements that do not have that characteristic.

[0010] In exemplary embodiments described herein, an integrated system for generating electrical power is provided for use with a flue gas stream (e.g., a flue gas stream associated with a gas turbine engine). In exemplary embodiments, the integrated system may extract electrical power from either or both a flue gas stream energy source and / or an auxiliary energy source (AES). For example, an integrated system having a heat recovery steam generator (HRSG) may be used to extract flue gas thermal energy from a flue gas stream exhausted from a gas turbine engine and use this thermal energy to generate electrical power. The HRSG may also be referred to herein as a "heat recovery sCO2 generator," where "sCO2" refers to supercritical carbon dioxide. The integrated system also selectively generates electrical power using auxiliary thermal energy from the AES. The AES may include renewable energy sources (such as solar, wind, bioenergy, and / or geothermal energy sources). In some embodiments, the AES may include thermal energy storage, such as, but not limited to, sand storage, ceramic blocks, and / or molten salt. In some embodiments, renewable energy sources may be utilized irregularly and / or unpredictably and may be referred to herein as “intermittent energy sources.” Additionally, in some embodiments described herein, an integrated system may generate power from intermittent energy sources when they are available, while also generating steady energy, for example, to provide a steady supply of power as required by the power grid or mechanical loads, thereby utilizing renewable energy sources when available and improving sustainability.

[0011] In the embodiments described herein, the integrated system can be operated in multiple modes, including a primary mode, a combined mode, and / or an auxiliary mode. In the primary mode, thermal energy extracted from the flue gas stream in the HRSG is used to generate electrical power (e.g., in a steam turbine) in addition to electrical power generated by the gas turbine engine. In the combined mode, in addition to electrical power generated by the gas turbine engine, the integrated system generates electrical power from the auxiliary energy source and the thermal energy of the flue gas stream. In the auxiliary mode, the integrated system extracts energy only from the auxiliary energy source. In exemplary embodiments, the integrated system is modular, allowing the system to be selectively operated in any mode (e.g., primary mode, combined mode, and / or auxiliary mode).

[0012] In some embodiments, the supplemental energy source can be a solar energy source that generates energy intermittently, for example, during periods of sunlight. In some embodiments, the integrated system can operate in a combined mode and / or a supplemental mode during times when the supplemental energy source is available. The integrated system can operate in a primary mode during times when the supplemental energy source is not available. For example, in embodiments in which the supplemental energy source includes a solar energy source, the integrated system can operate in a combined mode during hours of sunlight and in a primary mode at night or when sunlight is insufficient.

[0013] In some embodiments, the integrated system includes a controller and one or more sensors that detect conditions of the integrated system. In some embodiments, the controller automatically selects an operating mode based on at least one detected operating condition (e.g., an operating condition detected by a sensor) and / or at least one target operating condition. For example, the operating conditions may include a determination of when an auxiliary energy source is collecting energy, a temperature of auxiliary heat, and / or a power output required by a power grid or a mechanical load. In some embodiments, the controller may select an operating mode based on a user-selected target operating condition or mode.

[0014] In some embodiments, the controller may adjust an operating parameter to control the amount of power generated by the integrated system. For example, the controller may adjust the mass flow rate of the flue gas flow, the amount of thermal energy extracted from the flue gas flow, or the amount of thermal energy extracted from the supplemental energy source. In some embodiments, the controller may adjust the relative proportions of thermal energy extracted from the flue gas flow and the supplemental energy source. The controller may adjust any suitable operating parameter to control the amount of power generated by the integrated system.

[0015] In some embodiments, the integrated system includes a turbine for generating electrical power from flue gas thermal energy and / or auxiliary thermal energy. The integrated system may include a pair of turbines (i.e., a first turbine and a second turbine). The integrated system may extract thermal energy from the flue gas stream or the auxiliary energy source using one or more heat exchangers. In some embodiments, the flue gas thermal energy may be extracted by a pair of heat exchangers (i.e., a first (high temperature) heat exchanger and a second (low temperature) heat exchanger). The auxiliary thermal energy may be extracted by one or more auxiliary heat exchangers.

[0016] In some embodiments, the integrated system includes a post-combustion capture (PCC) system for capturing CO from a flue gas stream. In some of these embodiments, the carbon capture system can include an absorber that passes a liquid chemical through the flue gas stream to absorb CO carried in the flue gas stream. After the liquid chemical passes through the flue gas stream and binds (captures) the CO, it is sent to a PCC system that uses heat to release the CO in a controlled manner. The released CO by-product is utilized in additional and / or alternative processes and / or sequestered. A post-combustion capture system requires heat (e.g., supplied thermal energy) to release the CO. In some embodiments, the PCC system can include any process that can benefit from low-grade heat (e.g., district heating).

[0017] Some known CO2 power cycles may be thermally limited to turbine inlet temperatures below approximately 600°C due to the operating temperatures of economically viable materials used to manufacture the turbine, connecting piping, and valves located in the high-temperature portion of the sCO2 power cycle. Turbine inlet temperatures above 600°C can be achieved if the increased cost of high-temperature materials (e.g., nickel-based superalloys) is justified. However, the cost associated with using thermally superior materials may be prohibitively expensive. For example, some known sCO2 systems can accommodate fluid flows up to 600°C. As the temperature of the fluid flow increases above 600°C, thermal material limitations may necessitate changing to more thermally superior materials and / or actively cooling the turbine components. For example, sCO2 power generation systems with fluid temperatures above approximately 600°C may use gamma-prime superalloys, but this comes at a significant cost disadvantage. In some cases, gas turbines are also thermally limited by the exhaust gases of HRSGs and / or steam Rankine cycles. For example, steam bottoming cycles are typically limited to 620°C. In the embodiments described herein, the integrated system includes a working fluid of sCO2 and is capable of accepting flue gases having a wide range of flue gas temperatures, including up to 640°C or higher.

[0018] 1 is a schematic diagram of an exemplary power generation or mechanical drive system 100 including a turbine engine 110 (e.g., a gas turbine engine) and an integrated system 200 for integrating a heat recovery steam generator (HRSG) 202 and an auxiliary energy source (AES) 204. The AES 204 may be any suitable renewable energy source (e.g., without limitation, a solar energy source, a wind energy source, a bioenergy source, a thermal energy source, and / or a geothermal energy source). In other embodiments, the AES 204 may include any other energy source (e.g., without limitation, a nuclear energy source, a natural gas source, and / or a fossil fuel source) that enables the system 100 to function as described herein.

[0019] The integrated system 200 may receive heat from the AES 204 intermittently, for example, during periods when the AES 204 is active and / or when the AES 204 is capable of generating energy. For example, in embodiments in which the AES 204 is a solar energy source, the integrated system 200 receives heat from the AES 204 during daylight hours when the solar energy source is capable of converting sunlight into electrical energy. In contrast, the integrated system 200 does not receive heat from the AES 204 during the evening / nighttime when minimal sunlight is available for conversion to electrical energy. In some embodiments, the AES 204 may be a thermal energy source (e.g., a stored thermal energy source), and the AES 204 may provide thermal energy on a generally continuous basis, for example, independent of sunlight.

[0020] Although the exemplary embodiments described herein are illustrated in connection with a gas turbine engine, the present techniques are not limited to that particular engine, and those skilled in the art will appreciate that the present techniques may be used with other turbine engines. The terms "turbine," "turbine assembly," and "turbine engine" are used interchangeably herein. For example, the flue gas stream supplied to integrated system 200 may be exhaust from other known combustion processes.

[0021] In the exemplary embodiment, integrated system 200 may include a controller 206 communicatively coupled to HRSG 202 (or the received flue gas stream) and AES 204. Controller 206 may selectively control the supply of the flue gas stream to integrated system 200 and / or the supply of auxiliary heat to integrated system 200, as described in detail herein.

[0022] In the exemplary embodiment, turbine engine 110 includes an intake section 112, a compressor section 114 downstream from intake section 112, a combustor section 116 downstream from compressor section 114, a turbine section 118 (e.g., an expansion turbine) downstream from combustor section 116, and an exhaust section 120. Turbine section 118 is coupled to compressor section 114 via a rotor shaft 122. Turbine section 118 is coupled to compressor section 114 and to a load 128 (such as, but not limited to, an electrical generator and / or a mechanical drive application). In the exemplary embodiment, each compressor section 114 and turbine section 118 includes at least one rotor disk assembly 130 coupled to rotor shaft 122 to form a rotor assembly 132. Although only one combustor section 116 is shown, turbine engine 110 may include multiple combustor sections. Combustor section 116 is coupled to compressor section 114, which is in fluid communication with combustor section 116. Fuel injectors 124 are coupled to combustor section 116. In the exemplary embodiment, turbine engine 110 includes a manifold 126 that includes a plurality of fuel injectors 124.

[0023] During operation, intake section 112 channels air to compressor section 114, where the air is compressed to a higher pressure and temperature before being discharged toward combustor section 116, where fuel is introduced along with the compressed air into one or more combustors. The fuel-air mixture is ignited in combustor section 116 to generate combustion gases that flow toward turbine section 118. More specifically, when the fuel-air mixture is ignited, hot combustion gases are generated and flow toward turbine section 118. The combustion gases impart rotational energy to turbine section 118 and rotor assembly 132, such that turbine section 118 converts thermal energy from the combustion gas stream into mechanical rotational energy.

[0024] In some embodiments, fuel source 150 may be a variable fuel source that can selectively supply different types of fuels and / or different mixtures of fuels. Fuel source 150 may supply natural gas, liquefied petroleum gas (LPG) blends, methane, hydrogen, hydrogen / natural gas blends, coke oven gas, refinery gas, and / or any other suitable gas fuel or gas fuel mixture that enables engine 110 to function as described herein. The fuel supplied by the fuel source may be adjustable based on operating conditions and / or fuel source availability.

[0025] The turbine engine 110 may include one or more conduits, pipes, ducts, and / or tubes (generally referred to herein as conduits 134) used to flow fuel between components. The fuel may flow from an upstream component to a downstream component through the conduits 134 using gravity. Alternatively and / or additionally, the fuel flow may be pressurized in the conduits 134, for example, using a compressor or pump 136.

[0026] In an exemplary embodiment, the power generation system 100 may be considered a combined cycle in which waste heat from the flue gas stream exiting the turbine section 118 is routed to the HRSG 202 or the integrated system 200, thereby generating electrical power using thermal energy from the flue gas stream in addition to the electrical power generated by the gas turbine engine 110. As described above, the working fluid is the gaseous flue gas stream exhausted from the exhaust section 120, and the HRSG 202 utilizes the hot flue gas stream to provide heat for the sCO2 power cycle. In an exemplary embodiment, the HRSG 202 may have a cascade cycle arrangement. In some embodiments, the flow within the cascade cycle may be split between a high-temperature heater (HTH) and a low-temperature heater (LTH). Exemplary arrangements of integrated systems for generating electrical power using thermal energy extracted from either or both of the flue gas stream and the auxiliary energy source are described in detail in FIGS. 2-5. In some embodiments, the integrated system 200 described herein may be considered a bottoming cycle, and the system 100 may be considered a combined cycle.

[0027] In the exemplary embodiment, integrated system 200 can operate in one of a number of modes, such that integrated system 200 can generate power from the flue gas stream alone, from the flue gas stream and AES 204 (if available), or from AES 204 alone. In the exemplary embodiment, the operating modes include a base mode, a combined mode, and / or an auxiliary mode. In the base mode, integrated system 200 generates power from the hot flue gas stream, for example, from a gas turbine engine. In the combined mode, integrated system 200 generates power using both the hot flue gas stream and auxiliary heat from AES 204. In the auxiliary mode, integrated system 200 generates power using only auxiliary heat from AES 204.

[0028] The controller 206 may be associated with a computer and a processor. As used herein, the terms “processor” and “computer,” as well as related terms (e.g., “processing device,” “computing device,” and “controller”), are not limited to integrated circuits referred to in the art as computers, but instead refer broadly to microcontrollers, microcomputers, programmable logic controllers (PLCs), application-specific integrated (API) circuits, and / or other programmable circuitry, and such terms are used interchangeably herein. In embodiments described herein, memory may include, but is not limited to, computer-readable media (such as random access memory (RAM)) and computer-readable non-volatile media (such as flash memory). Alternatively, floppy disks, compact disc read-only memory (CD-ROM), magneto-optical disks (MODs), and / or digital versatile disks (DVDs) may be used. Also, in embodiments described herein, additional input channels may be, but are not limited to, computer peripherals associated with an operator interface (such as a mouse or keyboard). Alternatively, other computer peripherals (such as, but not limited to, a scanner or touch screen) may be used. Additionally, in the embodiments described herein, additional output channels may include, but are not limited to, an operator interface monitor. Controller 206 may be programmed to control integrated system 200 automatically based on feedback from one or more sensors described herein, and / or manually by allowing an operator to selectively adjust the operating mode of integrated system 200.

[0029] 2 is a schematic diagram of an example integrated system 300 that may be used as the integrated system 200 shown in FIG. 1. In the example embodiment, the integrated system 300 includes a flue gas stream 302, e.g., exhaust gas discharged from the gas turbine engine 110. The flue gas stream 302 enters a high-temperature heat (HTH) exchanger 304 (also referred to herein as the first heat exchanger 304), where thermal energy is transferred from the flue gas stream (combustion gases expanded through the turbine section 118 and exhausted through the exhaust section 120) to a working fluid (e.g., sCO) of the integrated system 300. The flue gas stream 302 then exits the HTH 304 and enters a low-temperature heat (LTH) exchanger 306 (also referred to herein as the second heat exchanger 306), where thermal energy is again transferred from the flue gas stream to the working fluid of the integrated system 300. The flue gas stream 302 is depleted of heat energy by a first heat exchanger 304 and a second heat exchanger 306, then exits the LTH exchanger 306 and flows through an exhaust stack 310 for exiting the integrated system 300. In some embodiments, the LTH exchanger 306 and the HTH exchanger 304 may be referred to herein as a waste heat recovery system. In some embodiments, the LTH exchanger 306 and the HTH exchanger 304 are incorporated into the heat recovery steam generator 202.

[0030] In exemplary embodiments, the working fluid of the integrated system 200, 300 may include supercritical carbon dioxide (sCO), e.g., CO in a supercritical state having a temperature and pressure above its critical point, as the supercritical fluid. In some alternative embodiments, the working fluid may include water vapor and / or steam. In some embodiments, the carbon dioxide (CO) may be in a subcritical state. In some embodiments, the sCO working fluid may be maintained at or above a temperature and / or pressure (e.g., 31°C at 7.4 MPa or 74 bar) such that the working fluid is in a supercritical state at any or all locations within the system (e.g., within or between components). The integrated system may be a closed-loop system, and the working fluid may be introduced at any suitable location on the loop. For example, once the integrated system 200 reaches a steady state, the system 200 may operate as a closed-loop system.

[0031] In some embodiments, the working fluid inventory is controlled and maintained by an inventory management system (not shown). The inventory management system includes a tank for maintaining CO at a pressure between the compressor suction pressure and the compressor discharge pressure. When the overall flow rate in the loop needs to be increased (e.g., because the steady-state inlet pressure of the compressor needs to be increased), an actively managed control valve between the inventory management tank and the compressor inlet opens, allowing working fluid to flow from the relatively high pressure inventory tank to the compressor inlet, introducing working fluid into the closed loop. When the flow rate of working fluid needs to be decreased (e.g., to reduce the compressor inlet pressure), a control valve between the inventory management tank and the compressor discharge opens, removing working fluid at the relatively high pressure compressor discharge from the loop and providing it to the inventory management tank.

[0032] By operating with sCO2 near the fluid's critical point, the compressor consumes less work than if the fluid behaved as an ideal gas in a typical Brayton cycle, thereby improving the thermal efficiency of the systems described herein. Furthermore, because of the favorable thermo-hydraulic properties of the working fluid, the turbomachinery (turbines and compressors) can be much smaller (e.g., have a smaller volume or footprint) compared to conventional power plants, thereby reducing capital costs.

[0033] Integrated system 300 includes a hot stream 312 and a cold stream 314. Hot stream 312 exits HTH exchanger 304 and enters first turbine 320, generating a first integrated system power output 322. In an exemplary embodiment, first integrated system power output 322 may be approximately 12.6 MW. In other embodiments, first integrated system power output 322 may be greater than or less than 12.6 MW. Hot stream 312 then exits first turbine 320 and enters first high-temperature recuperator (HTR) 324. From HTR 324, hot stream 312 enters first mixer 326, where it is combined with other streams, as described in more detail below. In an exemplary embodiment, stream 328 exits first mixer 326 and enters second recuperator 330. In some embodiments, the HTR 324, the first mixer 326, and the recuperator 330 may be referred to as a recuperation system.

[0034] Stream 328 exiting recuperator 330 is separated by first splitter 332 into a first branch 336 and a second branch 338. First branch 336 flows through cooler 340, after which branch 336 enters compressor system 342. Cooler 340 reduces the temperature of first branch 336, for example, by rejecting heat to a low-temperature water source (e.g., lake or river water) before branch 336 enters compressor 342. For example, cooler 340 can also receive stream 341 for heat exchange with branch 336 within cooler 340. First branch 336 exits compressor system 342 at a higher pressure and enters recuperator 330. Within recuperator 330, first branch 336 and stream 328 are in thermal communication. In some embodiments, heat is transferred from stream 328 to first branch 336, increasing the temperature of first branch 336 after passing through recuperator 330 and decreasing the temperature of stream 328. First branch 336 then enters HTR 324, where first branch 336 and stream 312 are in thermal communication, and heat is transferred from stream 312 to first branch 336. Thus, after passing through HTR 324, the temperature of first branch 336 increases while the temperature of stream 312 decreases.

[0035] The second branch stream 338 produced by the flow divider 332 flows into a recompressor 344, which increases the pressure and temperature of the second branch stream 338, before discharging the branch stream 338 to the LTH exchanger 306. The second branch stream 338 exchanges thermal energy with the stream 302, after which the second branch stream 338 exits the LTH exchanger 306 as stream 314.

[0036] First split stream 336 exits HTR 324 and enters second mixer 346. In second mixer 346, split stream 336 is combined with low-temperature heater stream 314 exiting LTH exchanger 306 to form combined stream 352. More specifically, low-temperature heater stream 314 exits LTH exchanger 306 into second mixer 346 where it is combined with split stream 336. Stream 352 exits second mixer 346 into second splitter 354, which separates stream 352 into return stream 360 and second power stream 362. Return stream 360 is sent to HTH exchanger 304, where it is heated by stream 302 and exits HTH exchanger 304 as stream 312. Second power stream 362 exits second flow divider 354 and is routed to second turbine 366, producing integrated power output 368. Second power stream 362 exits second turbine 366 into first mixer 326, where second power stream 362 is combined with stream 312 as described above. In an exemplary embodiment, second integrated system power output 368 may be approximately 13.9 MW. In other embodiments, second integrated system power output 368 is greater than or less than 13.9 MW. In some embodiments, second integrated system power output 368 is less than first integrated system power output 322.

[0037] Integrated system 300 also includes one or more conduits, pipes, ducts, etc. (referred to herein as conduits 370) that channel the working fluid between the components of system 300. In an exemplary embodiment, integrated system 300 further includes one or more flow drivers 372 (e.g., pumps, fans, blowers, etc.) used to drive the working fluid through conduits 370. In some embodiments, differential pressure and / or gravity may be used to move the working fluid between the components. Flow drivers 372 are coupled to controller 206, which may selectively adjust the mass, mass flow rate, and / or flow velocity of the working fluid between the components of system 300. Integrated system 300 may also include one or more additional flow control devices 374 (e.g., valves, control valves, ball valves, gates, etc.) to provide advanced control of the flow of the working fluid. Such additional flow control devices 374 are coupled to controller 206, which controls the opening, closing, and metering of flow control devices 374.

[0038] In the exemplary embodiment, integrated system 300 further includes at least one temperature sensor 376 communicatively coupled to controller 206. Each temperature sensor 376 is disposed between components (e.g., in conduit 370) and can detect the temperature of the working fluid contained within conduit 370. Integrated system 300 may also include at least one pressure sensor 378 coupled to controller 206. Pressure sensor 378 can be coupled between components (e.g., in conduit 370) and can detect the pressure of the working fluid contained within conduit 370. In some embodiments, integrated system 300 also includes at least one flow sensor 380 for detecting the flow rate, flow velocity, or mass flow rate of the working fluid flowing through conduit 370. Flow sensor 380 can be communicatively coupled to controller 206. In some embodiments, temperature sensor 376, pressure sensor 378, and / or flow sensor 380 can be coupled within or near a component of system 300. For example, temperature sensor 376 may be coupled near HTH exchanger 304 to detect the operating temperature within HTH exchanger 304 and / or temperature differences across HTH exchanger 304. Sensors 376, 378, and 380 may be coupled near or to any component of system 300. Sensor data collected by sensors 376, 378, and 380 may be transmitted wirelessly to controller 206.

[0039] 3A is a schematic diagram of an exemplary integrated system 400. System 400 may include one or more components or fluid streams similar to those in system 300. In the exemplary embodiment, system 400 receives stream 312 exiting HTH exchanger 304. Stream 312 enters auxiliary heat exchanger 402, where it is heated, and then exits at a high temperature as stream 412. For example, in some embodiments, the temperature of stream 312 entering auxiliary heat exchanger 402 is approximately 500°C, and the temperature of stream 412 exiting auxiliary heat exchanger 402 is approximately 600°C. Thus, in the exemplary embodiment, auxiliary heat exchanger 402 increases the temperature of stream 312 by approximately 100°C. In other embodiments, auxiliary heat exchanger 402 may increase the temperature of stream 312 by more than 100°C (e.g., by at least 200°C). Heat is supplied to auxiliary heat exchanger 402 through an external heat source. In the exemplary embodiment, heat is supplied to auxiliary heat exchanger 402 by AES 204 .

[0040] Flow 412 enters first turbine 320, which produces first integrated system power output 422. In an exemplary embodiment, first integrated system power output 422 may be approximately 13.1 MW. In other embodiments, first integrated system power output 422 may be lower than first integrated system power output 322.

[0041] In some embodiments, the integrated system 400 can be operated in any of a number of modes (e.g., a primary mode, a combined mode, or a supplemental mode). For example, the integrated system 400 can be operated in a combined mode. For example, the combined mode can include a combined gas turbine and solar mode, in which the integrated system 400 can generate power from the flue gas stream and energy obtained from a solar energy source.

[0042] In some embodiments, the integrated system 400 can operate in a basic mode, in which power is generated using only the flue gas flow, and the auxiliary heat exchanger 402 is turned off and / or the AES 204 is not providing thermal energy to the auxiliary heat exchanger 402.

[0043] 3B is a schematic diagram of an exemplary integrated system 450 that includes one or more components similar to integrated system 400 shown in FIG. 3A. In system 450, stream 352 exiting mixer 346 is directed to heat exchanger 324. Stream 352 exits heat exchanger 324 and is introduced into second flow divider 354. Stream 362 exits second flow divider 354 and is introduced into second turbine 366 to produce second integrated power output 368. Stream 360 exiting flow divider 354 is directed to HTH exchanger 304 and then to auxiliary heat exchanger 402, and stream 412 is introduced into first turbine 320 to produce first integrated power output 422.

[0044] In some embodiments, the integrated system 450 can operate in multiple modes. In some embodiments, the integrated system 450 can operate in an auxiliary mode in which no thermal energy is extracted from the flue gas stream 302. For example, the integrated system can operate in a solar-only mode, in which the auxiliary energy source is solar heat, providing thermal energy to the auxiliary heat exchanger 402. In this solar-only mode, the HTH exchanger 304 and the LTH exchanger 306 can be turned off or in a standby mode. In some embodiments, in the solar-only mode of the integrated system 450, the second turbine 366 can be turned off or in a standby mode. For example, the second power stream 362 can bypass the second turbine 366 and flow from the second flow divider 354 to the first mixer 326.

[0045] 4 is a schematic diagram of an exemplary integrated system 500 including a post-combustion carbon capture (PCC) system 502. System 500 may include any or all of the components or fluid flows similar to those of systems 300, 400, and / or 450. In the exemplary embodiment, system 500 includes a cooling stream 504. In some embodiments, cooling stream 504 is water or low-pressure steam. In other embodiments, cooling stream 504 may be another suitable cooling medium. Cooling stream 504 enters heat exchanger 506 and exits second heat exchanger 508, where it exchanges heat with flue gas stream 302 received from LTH exchanger 306. Specifically, stream 302 is cooled by cooling stream 504, and after cooling, stream 302 flows through stack 310 for exhaust.

[0046] The cooled stream 504 exits the second heat exchanger 508, where the stream 504 enters a post-combustion capture (PCC) unit 510. In some embodiments, the system 500 may be a closed-loop system for cooling the cooled cooled stream 504, which is then recycled to the heat exchanger 506. The cooled cooled stream 504 may be a fluid (e.g., water) that is first heated in the heat exchanger 506 and then further heated in the second heat exchanger 508. Once the cooled stream 504 reaches approximately 120°C, the cooled stream 504 may be used to provide heat to the PCC 510 to recover carbon dioxide from a fluid stream (e.g., the flue gas stream 302).

[0047] In some embodiments, the exhaust temperature of the flue gas stream 302 entering the heat exchanger 508 is high (>180°C), yet can maintain a power output 422, 468 similar to other known sCO power cycles that utilize lower temperature flue gas streams. The heat in the flue gas stream 302 from the gas turbine engine 110, even after passing through the HRH exchanger 304 and LRH exchanger 306, is high enough to generate low temperature steam or hot water from the cooling stream 504, at least enough to meet all of the heating requirements of the PCC unit 510 of the post-combustion capture system 502. Unlike a steam turbine, the integrated system 500 including the system 502 does not require energy extraction from the cycle (i.e., operating a PCC system with a steam Rankine cycle requires the extraction of high temperature steam, which can negatively impact the efficiency of the overall cycle). Thus, there is little or no energy penalty associated with the heating requirements of the PCC unit 510 (although note that there remains a small energy penalty for the PCC unit 510 caused by the electrical auxiliary load). Stream 302 exiting heat exchanger 508 may enter stack 310.

[0048] The first branch stream 336 exiting the first divider 332 is discharged to the first heat exchanger 506 where it is cooled by the cooling stream 504. The cooling stream 504 is therefore heated by the first branch stream 336 in the first heat exchanger 506 and by the flue gas stream 302 in the second heat exchanger 508 before entering the PCC unit 510.

[0049] In some embodiments, the heat duty and temperature rejected from the first heat exchanger 506 and the heat available in the second heat exchanger 508 vary as a function of ambient temperature, the load of the power generation system 100, and / or the turbine inlet temperature. In some embodiments, the controller 206 can maintain both the heat duty and temperature rejected by the heat exchangers 506 and / or 508 to meet the heating demands of the heat exchangers 506 and / or 508 for different ambient temperatures or loads. In some embodiments, the split ratio of the recompressor 344 is actively adjusted and / or controlled by the controller 206.

[0050] The heat rejected by the heat exchangers 506, 508 is significantly reduced during low load conditions (e.g., turndown of the gas turbine engine 110). In some embodiments, the system 100 includes a thermal energy storage system to store excess waste heat during full load demands and provide the stored heat to the heat exchangers 506, 508 when the power generation system 100 is operating under extreme load conditions, thereby reducing inefficiencies caused by adjusting the split ratio of the recompressor 344.

[0051] The integrated system 500 can operate in any of several modes (e.g., fundamental mode, combined mode, and / or auxiliary mode). In some embodiments, the PCC unit 510 can be inoperative while the integrated system 500 is operating in auxiliary mode, and the PCC unit 510 can operate during combined mode or fundamental mode. In embodiments in which the integrated system 500 is operated in auxiliary mode, the integrated system 500 does not receive the flue gas stream 302, and / or the HTH exchanger 304 and the LTH exchanger 306 are turned off or in standby mode. In some embodiments, the integrated system 500 is operated in fundamental mode and does not receive auxiliary energy from the auxiliary energy source 204, but the PCC unit 510 is operational (e.g., capturing carbon dioxide).

[0052] 5A is a schematic diagram of another example integrated system 600. In the example embodiment, the system 600 does not include the HTH exchanger 304, i.e., it includes only the LTH exchanger 306. The integrated system 600 can be run in any of several modes. For example, when the integrated system 600 operates in auxiliary mode, the integrated system 600 does not receive the flue gas stream 302. In auxiliary mode, the integrated system 600 receives thermal energy only from the AES 204, and the LTH 306 can be turned off or in standby mode.

[0053] Return stream 360 exits second flow divider 354 and enters auxiliary heat exchanger 402, where return stream 360 collects heat and has a higher temperature after exiting auxiliary heat exchanger 402. Stream 412 exits auxiliary heat exchanger 402 and flows to first turbine 320 as described above.

[0054] Figure 5B is a schematic diagram of an example integrated system 650 that includes one or more similar components as integrated system 600 shown in Figure 5A. In system 650, stream 336 is introduced into recuperator 330, then directed to heat exchanger 324, and then to second turbine 366, which produces second integrated output 368.

[0055] In some embodiments, the integrated system 650 can operate in any of a number of modes. For example, in some embodiments, the integrated system 650 can operate in an auxiliary mode, in which the integrated system 650 does not receive a flue gas flow and / or the LTH exchanger 306 is turned off or in a standby mode.

[0056] Figure 6 is a schematic diagram of an alternative integrated system 700 that includes one or more components similar to integrated system 300 shown in Figure 2. In system 700, stream 336 enters compressor 342 as stream 702, which is introduced into flow divider 704. From flow divider 704, streams 706 and 708 exit. Stream 706 enters LTH exchanger 306, and stream 708 enters recuperator 330 and exits recuperator 330 as stream 710. Stream 710 exits recuperator 330 and is introduced into heat exchanger 324. Stream 710 exits heat exchanger 324 and is introduced into second mixer 346, where it is combined with stream 314. Integrated system 700 can be operated in any of several modes of operation.

[0057] 7 illustrates a process flow for an exemplary method 800 of operating an integrated system to generate electrical power by extracting heat from one or both of a flue gas stream and a supplemental energy source. Furthermore, the method 800 described in FIG. 7 may be used with, for example, any of the integrated systems 200, 300, 400, 450, 500, 600, 650, and 700 described herein. One or more steps of the method 800 may be performed by, for example, the controller 206. The method 800 may include receiving (802) a flue gas stream, for example, from the exhaust 120 of the gas turbine engine 110. The method 800 may include providing (e.g., routing) the flue gas stream 302 to one or more heat exchangers (e.g., the HTH exchanger 304 and / or the LTH exchanger 306). The method may include extracting (804) thermal energy from the flue gas stream using the heat exchangers 304, 306. The controller 206 may control / adjust the flow (e.g., velocity or mass flow rate) of the flue gas stream 302 delivered to the heat exchangers 304, 306. For example, the flue gas stream 302 may be supplied by the controller 206 sending one or more signals to the flow control device 374 and / or the flow driver 372 to selectively control the flow of the flue gas stream 302 such that the flue gas stream 302 flows through the conduits and delivered to the heat exchangers 304, 306.

[0058] Advantageously, the HTH exchanger 304 can accept hot exhaust gas (e.g., flue gas stream 302) at temperatures exceeding 600°C. The HTH exchanger 304 can drop the temperature by 287°C. In some embodiments, the heat exchangers 304, 306 are sized to maintain a turbine inlet temperature of 600°C (e.g., an approach temperature of 40°C) with a flue gas temperature of 640°C. In some embodiments, the heat exchangers 304, 306 are sized to have an approach temperature of less than 50°C. The approach temperature represents the minimum temperature difference between the fluids flowing through the heat exchanger. For example, for the heat exchanger 304, the inlet temperature of the flue gas stream 302 minus the outlet temperature of the sCO2 is approximately 40°C.

[0059] The method 800 also includes supplying the thermal energy of the flue gas to one or more turbines (e.g., the first turbine 320 and / or the second turbine 366). Supplying the thermal energy of the flue gas to the turbines 320, 366 may include the controller 206 controlling a flow of working fluid from the heat exchangers 304, 306 to the turbines 320, 366. The method 800 includes generating 806, for example, by the first turbine 320 or the second turbine 366, using the thermal energy of the flue gas to generate power.

[0060] Method 800 further includes determining 808 a state of AES 204 (e.g., off / on, whether AES 204 is generating energy, the amount of energy being generated, etc.). Determining 808 may include controller 206 detecting, using sensors 376, 378, and / or 380, whether supplemental thermal energy is being supplied to integrated system 300 and / or whether supplemental thermal energy is being supplied to any of integrated systems 200, 400, 500, and / or 600. In some embodiments, determining 808 may include controller 206 receiving one or more user inputs indicating an operational state of AES 204. In some embodiments, a user may selectively control whether integrated system 200 should receive supplemental thermal energy from AES 204, for example, using a user interface connected to controller 206.

[0061] The method 800 may further include extracting 810 thermal energy from the AES 204, for example, using the auxiliary heat exchanger 402. The method 800 may also include generating 812 electrical power using the extracted auxiliary thermal energy (e.g., the energy provided to the turbines 320, 366). In some embodiments, the method 800 includes providing both the flue gas thermal energy and the auxiliary thermal energy to the turbines 320, 366 to generate 812 electrical power from both the flue gas thermal energy and the auxiliary thermal energy (e.g., simultaneously).

[0062] The method 800 may further include supplying supplemental thermal energy to the turbines 320, 366. Supplying the supplemental thermal energy may include the controller 206 controlling a flow of the supplemental thermal energy to the turbines 320, 366. Supplying may include sending the supplemental thermal energy upstream of the turbines 320, 366. Supplying may include supplying supplemental heat to the supplemental heat exchanger 402 where the supplemental thermal energy is extracted and supplied to the working fluid of the integrated systems 200, 400, 500, and / or 600. In some alternative embodiments, supplying may include supplying the supplemental heat to the heat exchangers 304, 306 to extract the supplemental thermal energy.

[0063] In some embodiments, method 800 includes returning at least a portion of the working fluid exiting the turbine, stream 412, and / or stream 362, to heat exchangers 304, 306 to extract feedback thermal energy. Method 800 may further include supplying the extracted thermal energy (e.g., flue gas thermal energy, supplemental thermal energy, and / or feedback thermal energy) to turbines 320, 366 to extract electrical power.

[0064] In some embodiments, method 800 includes providing stream 412 and / or stream 362 to one or more other components of integrated systems 200, 400, 500, and 600. For example, method 800 may include providing stream 412 and / or stream 362 to a recuperator (e.g., recuperator 330), a mixer (e.g., mixers 326, 346), a recompressor (e.g., recompressor 344), and a cooler (e.g., cooler 340). Method 800 may include providing stream 412 and / or stream 362 to one or more flow dividers (e.g., flow dividers 332, 354).

[0065] In some embodiments, method 800 includes supplying stream 302 and / or stream 336 to one or more components of a post-combustion capture system (e.g., system 502). In some embodiments, method 800 includes supplying stream 302 to PCC unit 510.

[0066] In the embodiments described herein, a power generation system includes an integrated system for generating electrical power by combining an intermittent energy source (such as a renewable energy source) with a heat recovery steam generator. In the embodiments described herein, the integrated system can be operated in one or more of multiple operating modes, continuously generating energy from the flue gas stream exiting the gas turbine engine and generating electrical power from the intermittent energy source when or if the intermittent energy source is available. The embodiments described herein can continuously provide the electrical power required by the power grid or mechanical load, while improving emissions by utilizing renewable energy sources when available. By bridging the technology gap between electrical power generated using flue gas and electrical power generated using auxiliary energy sources, the embodiments described herein provide great flexibility in accepting heat from both types of heat sources in an efficient manner in a simple cycle configuration, thereby achieving high reliability and cost savings in the power generation system.

[0067] In some embodiments described herein, the integrated system generates electricity using a first turbine and a second turbine, which extract power from thermal energy provided by the flue gas stream and / or from an intermittent energy source. In some embodiments described herein, the integrated system includes a post-combustion carbon capture system. Because the temperature of the flue gas stream after the power cycle is relatively high (approximately 180-200°C), the flue gas stream can be used to heat hot water or low-pressure steam to meet the thermal demands of the post-combustion carbon capture system. Therefore, in the embodiments described herein, compared to some known steam cycles with lower exhaust heat temperatures, the thermal energy required by the PCC results in a performance loss for the steam Rankine bottoming cycle. However, in the embodiments described herein, because the exhaust heat temperature of sCO2 is approximately 180°C, the thermal energy for the PCC can be extracted without affecting the performance of the sCO2 bottoming cycle. The electrical load of the PCC can be an equal parasitic loss for both the steam cycle and the sCO2 cycle.

[0068] Other aspects of the present disclosure are provided by the following embodiments. [Embodiment 1] An integrated system for extracting electrical power, the integrated system including: a flue gas flow source configured to supply thermal energy of the flue gas flow to a heat exchanger; an auxiliary energy source (AES) configured to selectively supply auxiliary thermal energy to an auxiliary heat exchanger; and a controller coupled to the flue gas flow source and the AES, the controller configured to determine whether the AES is supplying auxiliary thermal energy to the auxiliary heat exchanger, and, if the AES is supplying auxiliary thermal energy to the auxiliary heat exchanger, cause a turbine to extract electrical power from both the thermal energy of the flue gas flow and the auxiliary thermal energy. [Embodiment 2] 2. The integrated system of embodiment 1, wherein the AES is a renewable energy source comprising at least one of a solar energy source, a wind energy source, a bioenergy source, a thermal energy source, and a geothermal energy source. [Embodiment 3] 3. The integrated system of embodiment 1 or 2, further comprising: a low-temperature heat exchanger configured to extract thermal energy of the flue gas flow from the flue gas flow and supply the extracted thermal energy of the flue gas flow to a first stream; a flow divider configured to divide the first stream into a first turbine stream and a second turbine stream; a first turbine coupled to receive the first turbine stream exiting the flow divider; a second turbine coupled to receive the second turbine stream exiting the flow divider; and another heat exchanger disposed between the flow divider and the first turbine to supply thermal energy to the first stream before the first stream enters the first turbine. [Embodiment 4] The integrated system of any one of embodiments 1 to 3, wherein the integrated system includes a high temperature heat (HTH) exchanger configured to receive a flue gas flow and extract thermal energy provided from the flue gas flow, a high temperature turbine (HTT) coupled to receive a high temperature flow exiting the HTH, and an auxiliary heat exchanger disposed between the HTH exchanger and the HTT, the auxiliary heat exchanger providing auxiliary thermal energy to the high temperature flow before the high temperature flow enters the HTT to generate first turbine power. [Embodiment 5] 5. The integrated system of any one of embodiments 1-4, further comprising: a first heat exchanger coupled to receive a cooling stream and a hot stream exiting the HTH exchanger; a second heat exchanger coupled to receive a flue gas stream and the cooling stream exiting the first heat exchanger, the second heat exchanger exchanging thermal energy between the cooling stream and the flue gas stream; and a post-combustion capture system receiving the cooling stream after it has received thermal energy from the first and second heat exchangers. [Embodiment 6] 6. The integrated system of any one of embodiments 1 to 5, wherein the turbine uses a working fluid comprising supercritical CO2. [Embodiment 7] An integrated system as described in any one of embodiments 1 to 6, wherein the controller is communicatively coupled to at least one of a pressure sensor, a temperature sensor, and a flow sensor. [Embodiment 8] 1. An integrated system for extracting electrical power, the integrated system including: a flue gas flow source configured to supply thermal energy of a flue gas flow to a heat exchanger; an auxiliary energy source (AES) configured to selectively supply supplemental thermal energy to an auxiliary heat exchanger; a post-combustion carbon capture system that receives the flue gas flow after it passes through the heat exchanger; and a controller coupled to the flue gas flow source, the controller configured to cause a turbine to extract electrical power from the thermal energy of the flue gas flow extracted by the heat exchanger and the supplemental thermal energy extracted by the auxiliary heat exchanger. [Embodiment 9] The integrated system of any one of embodiments 1 to 8, wherein the AES is a renewable energy source including at least one of a solar energy source, a wind energy source, a bioenergy source, a thermal energy source, and a geothermal energy source. [Embodiment 10] 10. The integrated system of any one of embodiments 1-9, further comprising: a first heater configured to extract flue gas thermal energy from the flue gas stream and supply the extracted flue gas thermal energy to a first stream; a flow divider configured to divide the first stream into a first turbine stream and a second turbine stream; a first turbine coupled to receive the first turbine stream exiting the flow divider; a second turbine coupled to receive the second turbine stream exiting the flow divider; and another heat exchanger disposed between the flow divider and the first turbine to supply thermal energy to the first stream before the first stream enters the first turbine. [Embodiment 11] The integrated system of any one of embodiments 1 to 10, wherein the integrated system includes a high temperature heat (HTH) exchanger configured to receive a flue gas flow and extract thermal energy provided from the flue gas flow; a high temperature turbine (HTT) coupled to receive a high temperature flow exiting the HTH exchanger; and an auxiliary heat exchanger disposed between the HTH exchanger and the HTT, the auxiliary heat exchanger providing auxiliary thermal energy to the high temperature flow before the high temperature flow enters the HTT to generate first turbine power. [Embodiment 12] 12. The integrated system of any one of embodiments 1-11, wherein the integrated system further includes a first heat exchanger coupled to receive a cooling stream and a high-temperature stream exiting the HTH exchanger, and a second heat exchanger coupled to receive a flue gas stream and the cooling stream exiting the first heat exchanger, wherein the second heat exchanger exchanges thermal energy between the cooling stream and the flue gas stream, and wherein a post-combustion carbon capture system is coupled to receive the cooling stream after it has received thermal energy from the first and second heat exchangers. [Embodiment 13] An integrated system as described in any one of embodiments 1 to 12, wherein the controller is communicatively coupled to at least one of a pressure sensor, a temperature sensor, and a flow sensor. [Embodiment 14] 1. A method of operating an integrated system for extracting electrical power from an auxiliary energy source (AES), the method including: determining whether the auxiliary energy source (AES) is supplying auxiliary thermal energy to an auxiliary heat exchanger; and, if the AES is supplying auxiliary thermal energy to the auxiliary heat exchanger, causing a turbine to generate electrical power from both a flue gas stream and the auxiliary thermal energy. [Embodiment 15] 15. The method of embodiment 14, wherein the AES is a renewable energy source comprising at least one of a solar energy source, a wind energy source, a bioenergy source, a thermal energy source, and a geothermal energy source. [Embodiment 16] 16. The method of claim 14 or 15, wherein the method further comprises extracting thermal energy from the flue gas stream with a high temperature heat (HTH) exchanger to generate a high temperature stream, extracting supplemental thermal energy using the auxiliary heat exchanger, feeding the extracted supplemental thermal energy to the high temperature stream, and generating power from the high temperature stream using the turbine. [Embodiment 17] 17. The method of any one of embodiments 14-16, wherein the method further comprises causing the turbine to extract power from thermal energy of the flue gas stream when the AES is not supplying the auxiliary thermal energy to the auxiliary heat exchanger. [Embodiment 18] 18. The method of any one of embodiments 14-17, wherein determining whether an auxiliary energy source is supplying auxiliary thermal energy to an auxiliary heat exchanger comprises detecting a temperature of the AES. [Embodiment 19] 19. The method of any of embodiments 14-18, wherein the method further comprises extracting thermal energy of the flue gas stream using a first heater, supplying the extracted thermal energy of the flue gas stream to a first stream, splitting the first stream into a first turbine stream and a second turbine stream, extracting auxiliary thermal energy using the auxiliary heat exchanger, supplying auxiliary thermal energy to the first stream, generating power from the first stream using a first turbine, and generating power from the second stream using a second turbine. [Embodiment 20] 20. The method of any of embodiments 14-19, wherein the method further comprises recovering carbon from the flue gas stream using a post-combustion capture system.

[0069] The foregoing description is intended to be illustrative only, and those skilled in the art will recognize that modifications can be made to the described embodiments without departing from the scope of the invention disclosed. Modifications that fall within the scope of the invention will be apparent to those skilled in the art upon review of this disclosure, and such modifications are intended to be included within the scope of the claims.

[0070] Although specific features of various embodiments of the present disclosure may be shown in some drawings and not in others, this is for reasons of convenience and in accordance with the principles of the present disclosure, any feature of a drawing may be referenced and / or claimed in combination with any feature of any other drawing.

[0071] This description uses examples to disclose embodiments of the systems and methods, including the best mode, and also enables one skilled in the art to implement the systems and methods (e.g., to make and use any devices or systems and perform any methods incorporating them). The patentable scope of the systems and methods is defined in the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ in material way from the literal language of the claims. [Explanation of symbols]

[0072] 112 Intake section 114 Compressor section 116 Combustor section 118 Turbine section 120 Exhaust section 122 rotor shaft 124 Fuel Injector 126 Manifold 128 load 130 Rotor disc assembly 132 rotor assembly 134 Conduit 136 Pump 150 fuel source 200 Integrated System 202 Heat Recovery Steam Generator (HRSG) 204 Auxiliary Energy Source (AES) 206 Controller 300 Integrated System 320 First Turbine 324 Heat Exchanger 326 First Mixer 328 Flow 332 First Divider 336 First Branch 338 Second Branch 340 Cooler 341 Flow 346 Second Mixer 352 Flow 354 Second Divider 366 Second Turbine 370 Conduit 372 Flow Driver 374 Flow Control Device 376 Temperature Sensor 378 Pressure Sensor 380 Flow Sensor 400 Integrated System 402 Auxiliary heat exchanger 412 Flow 450 Integrated System 500 Integrated System 502 Post-combustion capture system 504 Cooling flow 506 First Heat Exchanger 508 Second Heat Exchanger 510 PCC unit 600 Integrated System 650 Integrated System 700 Integrated System 704 Flow divider 706 Flow 710 Flow 800 ways

Claims

1. 1. An integrated system (200, 300, 400, 450, 500, 600, 650, 700) for extracting electrical power from an auxiliary energy source (AES) (204), said integrated system (200) comprising: a flue gas flow source (110) configured to supply thermal energy of the flue gas flow to a first heat exchanger (304, 306); an auxiliary energy source (204) configured to selectively supply auxiliary thermal energy to the auxiliary heat exchanger (402); and a controller (206) coupled to the flue gas flow source (110, 202) and the AES (204), the controller (206) comprising: determining whether the AES (204) is providing supplemental heat energy to the supplemental heat exchanger (402); and When the AES (204) is supplying auxiliary thermal energy to the auxiliary heat exchanger (402), the turbine (320, 366) extracts power from both the thermal energy of the flue gas stream and the auxiliary thermal energy. a controller configured to execute An integrated system (200) comprising:

2. The integrated system (200) of claim 1, wherein the AES (204) is a renewable energy source comprising at least one of a solar energy source, a wind energy source, a bioenergy source, a thermal energy source, and a geothermal energy source.

3. 2. The integrated system of claim 1, wherein the first heat exchanger is incorporated into a heat recovery steam generator as part of a waste heat recovery system, the heat recovery steam generator using thermal energy from the flue gas stream to provide heat to a working fluid of the turbine.

4. The working fluid is supercritical CO ２ The integrated system (200) of claim 3, comprising:

5. The first heat exchanger (304, 306) a low-temperature heat exchanger (306) configured to extract flue gas flow thermal energy from the flue gas flow (302) and to supply the extracted flue gas flow thermal energy to the first flow (314) of said working fluid; The integrated system (200) further comprises: a first flow divider (354) configured to divide the first flow (314) into a first turbine flow (360) and a second turbine flow (362); a first turbine (320) coupled to receive the first turbine flow (360) exiting the first flow divider (354); a second turbine (366) coupled to receive the second turbine flow (362) exiting the first flow divider (354); Including, 5. The integrated system of claim 3, wherein the auxiliary heat exchanger is disposed in a flow path between the first flow divider and the first turbine, and supplies thermal energy from an auxiliary energy source to the first turbine flow before the first turbine flow enters the first turbine.

6. The first heat exchanger (304, 306) A high temperature heat (HTH) exchanger (304), comprising: receiving said flue gas stream (302); and Extracting thermal energy from said flue gas stream (302). a high temperature heat (HTH) exchanger (304) configured to perform the turbine (320, 366) is a high temperature turbine (HTT) (320) coupled to receive the high temperature stream (412) exiting the HTH exchanger (304) and configured to produce a first turbine power output (422); The integrated system (200) of claim 5, wherein the HTH heat exchanger (304) is disposed in the flow path between the flow divider (354) and the HTT (320).

7. The method further includes a post-combustion carbon capture (PCC) system (500), the post-combustion carbon capture (PCC) system (500) comprising: a first PCC heat exchanger (506) coupled to receive the cooled stream (504) and the high temperature stream (336) exiting the second flow divider (332) downstream of the HTH exchanger (304); a second PCC heat exchanger (508) coupled to receive the flue gas stream (302) and a cooling stream (504) exiting the first PCC heat exchanger (506), the second PCC heat exchanger (508) exchanging thermal energy between the cooling stream (504) and the flue gas stream (302); and a post-combustion recovery unit (502) that receives the cooled stream (504) after the cooled stream (504) receives thermal energy from the first and second PCC heat exchangers (506, 508), the received cooled stream (504) providing sufficient heat to meet the heating requirements of the C unit (502); The integrated system (200) of claim 6, comprising:

8. The controller (206) maintaining both the heat load and the temperature rejected by the first and second PCC heat exchangers (506, 508) to meet the heating demands of the first and second PCC heat exchangers (506, 508) for different ambient temperatures or turbine loads; and actively adjusting and / or controlling the split ratio of a first branch (336) of the flue gas stream (302) discharged from the second flow divider (332) to the first PCC heat exchanger (506) and a second branch (338) of the flue gas stream (302) discharged from the flow divider (332) to a recompressor (344); The integrated system of claim 7 configured to execute:

9. The integrated system (200) of any preceding claim, wherein the controller (206) is communicatively coupled to at least one of a pressure sensor (378), a temperature sensor (376), and a flow sensor (380).

10. A method (800) of operating an integrated system (200) for extracting power from an auxiliary energy source (AES) (204), the method (800) comprising: determining (808) by the controller (206) whether the auxiliary energy source (204) is providing auxiliary thermal energy to the auxiliary heat exchanger (402); and and causing at least one turbine (320, 366) to generate electrical power from both the flue gas stream (302) and the auxiliary thermal energy when the AES (204) is supplying auxiliary thermal energy to the auxiliary heat exchanger (402). The method (800) includes:

11. 11. The method of claim 10, wherein the AES is a renewable energy source comprising at least one of a solar energy source, a wind energy source, a bioenergy source, a thermal energy source, and a geothermal energy source.

12. The method further comprises: extracting thermal energy from said flue gas stream (302) by a high temperature heat (HTH) exchanger (304) to produce a high temperature stream (312, 412); Extracting supplemental heat energy using said supplemental heat exchanger (402); providing extracted supplemental thermal energy to said hot stream (312, 412); and generating electricity (422) from the hot stream (312, 412) using the at least one turbine (320); 12. The method (800) of claim 10 or 11, comprising:

13. Determining whether the auxiliary energy source (204) is providing auxiliary thermal energy to the auxiliary heat exchanger (402) includes detecting a temperature of the AES (204), and the method further comprises:

13. The method of claim 12, further comprising causing the at least one turbine to extract power from thermal energy of the flue gas stream when the AES is not providing the auxiliary heat exchanger with the auxiliary thermal energy.

14. The method further comprises: extracting thermal energy from the flue gas stream using a first heat exchanger (304, 306); supplying a first stream (312, 314) with thermal energy of the extracted flue gas stream; dividing the first flow (312, 314, 352) into a first turbine flow (360) and a second turbine flow (362) by a flow divider (354); Extracting supplemental heat energy using said supplemental heat exchanger (402); providing supplemental thermal energy to the first turbine flow (360, 312, 412); generating electrical power from the first turbine flow using a first turbine of the at least one turbine; and generating electrical power from the second turbine flow using a second turbine of the at least one turbine; 12. The method (800) of claim 10 or 11, comprising:

15. The method (800) of any one of claims 10 to 14, further comprising capturing carbon from the flue gas stream (302) using a post-combustion capture system (500).

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