Abstract: A combined cycle power unit (10) including a gas turbine (16), a heat recovery steam generator (HRSG) (34) to generate steam from an exhaust flow (24) of the gas turbine (16), and a steam turbine (64) driven by the steam generated from the HRSG (34). Steam generated in an evaporator (50) in the HRSG (34) is conveyed through an upstream superheater stage (46a) and a downstream superheater stage (46b) in the HRSG (34). The steam is then conveyed from the downstream superheater stage (46b) to the steam turbine (64). Between the upstream and downstream superheater stages (46a, 46b), the steam flow from the upstream superheater stage (46a) is throttled to a lower pressure to form a reduced pressure steam flow prior to entering the downstream superheater stage (46b) where the steam is reheated to an elevated temperature at the reduced pressure.

Abstract: A combine cycle power plant is presented. The combine cycle power plant includes a gas turbine, a heat recovery steam generator, a main steam turbine and a supercritical steam turbine. The supercritical steam turbine may be operated as a separate steam turbine that may be not a single steam turboset with the main steam turbine. The supercritical steam turbine receives supercritical steam generated in the heat recovery steam generator to produce power output. Exiting steam from the supercritical steam turbine may be routed to the main steam turbine. The supercritical steam turbine may be operated at a rotational speed that is higher than a grid frequency. The rotational speed of the supercritical steam turbine may be reduced to the grid frequency via a gearbox.

Abstract: A method for operating a combined cycle power plant (CCPP) and improving a part load operation of the CCPP is provided. The CCPP may include at least a gas turbine, a heat recovery steam generator (HRSG) located downstream of the gas turbine, a main steam turbine, and a supercritical steam turbine. The HRSG may include a low pressure steam system, an intermediate pressure steam system, and a high pressure steam system. To improve the part load efficiency of the CCPP, a base load operation of the CCPP may be initiated with supercritical pressure, via the supercritical steam turbine, such that the efficiency impact resulting from the part load operation is reduced.

Abstract: A combine cycle power plant is presented. The combine cycle power plant includes a gas turbine, a heat recovery steam generator, a main steam turbine and a supercritical steam turbine. The supercritical steam turbine may be operated as a separate steam turbine that may be not a single steam turboset with the main steam turbine. The supercritical steam turbine receives supercritical steam generated in the heat recovery steam generator to produce power output. Exiting steam from the supercritical steam turbine may be routed to the main steam turbine. The supercritical steam turbine may be operated at a rotational speed that is higher than a grid frequency. The rotational speed of the supercritical steam turbine may be reduced to the grid frequency via a gearbox.

Abstract: A method for operating a combined cycle power plant (CCPP) and improving a part load operation of the CCPP is provided. The CCPP may include at least a gas turbine, a heat recovery steam generator (HRSG) located downstream of the gas turbine, a main steam turbine, and a supercritical steam turbine. The HRSG may include a low pressure steam system, an intermediate pressure steam system, and a high pressure steam system. To improve the part load efficiency of the CCPP, a base load operation of the CCPP may be initiated with supercritical pressure, via the supercritical steam turbine, such that the efficiency impact resulting from the part load operation is reduced.

Abstract: A combined cycle power unit (10) including a gas turbine (16), a heat recovery steam generator (HRSG) (34) to generate steam from an exhaust flow (24) of the gas turbine (16), and a steam turbine (64) driven by the steam generated from the HRSG (34). Steam generated in an evaporator (50) in the HRSG (34) is conveyed through an upstream superheater stage (46a) and a downstream superheater stage (46b) in the HRSG (34). The steam is then conveyed from the downstream superheater stage (46b) to the steam turbine (64). Between the upstream and downstream superheater stages (46a, 46b), the steam flow from the upstream superheater stage (46a) is throttled to a lower pressure to form a reduced pressure steam flow prior to entering the downstream superheater stage (46b) where the steam is reheated to an elevated temperature at the reduced pressure.

Abstract: An electrical power system includes a power grid and a plurality of power plants connected to the power grid. A central repository including one or more electrical energy storage devices is connected directly to the power grid. The one or more energy storage devices are configured to be connected to the power plants via the power grid. The central repository is operable to draw a portion of a power output produced by one or more of the power plants via the power grid during a first period, for storage therein. The central repository is operable to discharge power to the power grid during a second period shifted in time from the first period. The discharged power is a function of a grid requirement or a function of a power demand notified by an individual power plant of the electrical system.

Abstract: A system and method for increasing the efficiency and/or power produced by an integrated gasification combined cycle system by increasing the integration between the air separation unit island, the heat recovery steam generator and the remainder of the system. By integrating heat produced by the heat recovery steam generator in the remainder of the integrated gasification combined cycle system, heat may be utilized that may have otherwise been lost or used further downstream in the system. The integration helps to increase the efficiency of the combustion reaction and/or the gasification reaction used to produce the syngas utilized in the integrated gasification combined cycle system.

Abstract: A system (10) and a method for converting carbonaceous fuel (102) into a gaseous product (42). According to one embodiment a fuel slurry (118) is introduced into a chamber (120) and heated under sufficient pressure to prevent the carrier component (100) from boiling so that the carbonaceous component (102) does not separate from the carrier component (100). The step of heating the carrier component (100) may include increasing pressure and temperature to place the carrier component (100) in a supercritical state while sustaining the carbonaceous component (102) and carrier component (100) in a mixed state. In this embodiment a pump (136) imposes sufficient chamber pressure to prevent boiling of the carrier component (100) as the mixture is heated to at least 345° C., and a gasifier chamber (120) is positioned to receive the gaseous mixture (118) at a lower pressure than the supercritical pressure for creation of syngas (42).

Abstract: A method and system for augmenting the output of a combined cycle power plant having a gas turbine driving a generator, a heat recovery steam generator that recovers exhaust heat from the gas turbine to drive a steam turbine also driving a generator, and a refrigeration element that is powered by available energy in steam exhausted from the steam turbine to cool water. The refrigeration element employs a substantially closed cycle refrigeration system that is either an absorption chilling system or a thermal compression chilling system. The refrigeration element provides cool water to an inlet chiller arranged to chill inlet to the gas turbine to augment the power output of the gas turbine and the water is recirculated to be chilled and used again. Since the refrigeration cycle is substantially closed, little or no additional plant water consumption is imposed on the power plant.

Abstract: A system and method for producing multiple syngas products. In one embodiment (FIG. 5) a syngas producing system (200) includes a gasifier (210) and a hydrocarbon steam reformer (226). The gasifier (210) is configured to react a solid or liquid carbonaceous material (212) and provide a first syngas product (222). The reformer (226) is coupled to receive sensible heat from the first syngas product (222) and drive an endothermic reaction in which a second syngas product (238) is produced from a liquid or gaseous hydrocarbon supply (150). In a method of processing fuel, a solid or liquid carbonaceous material (212) is provided to a gasifier (210) in the form of a slurry, which is converted into a first syngas product (222) in an exothermic reaction. A liquid or gaseous hydrocarbon supply (150) receives sufficient sensible heat generated during the exothermic reaction to convert the liquid or gaseous hydrocarbon supply (150) into a second syngas product (238).

Abstract: A system and method for increasing the efficiency and/or power produced by an integrated gasification combined cycle system by increasing the integration between the air separation unit island, the heat recovery steam generator and the remainder of the system. By integrating heat produced by the heat recovery steam generator in the remainder of the integrated gasification combined cycle system, heat may be utilized that may have otherwise been lost or used further downstream in the system. The integration helps to increase the efficiency of the combustion reaction and/or the gasification reaction used to produce the syngas utilized in the integrated gasification combined cycle system.

Abstract: A system and method for increasing the efficiency and/or power produced by an integrated gasification combined cycle system by increasing the integration between the air separation unit island, the heat recovery steam generator and the remainder of the system. By integrating heat produced by the heat recovery steam generator in the remainder of the integrated gasification combined cycle system, heat may be utilized that may have otherwise been lost or used further downstream in the system. The integration helps to increase the efficiency of the combustion reaction and/or the gasification reaction used to produce the syngas utilized in the integrated gasification combined cycle system.

Abstract: A system (10) and method of modifying a combined cycle power generation system (12, 14, 16, 18). In one embodiment of the invention an existing system includes one or more first gas turbines, one or more first steam turbines, and one or more heat recovery steam generators (HRSGs). An exemplary method includes providing at least one second gas turbine of greater operating efficiency than each of the one or more first gas turbines and connecting at least one existing HRSG to receive exhaust output from the second gas turbine to generate steam. Also according to the invention a path is provided for mixing steam exiting a high pressure steam turbine with steam generated in a low pressure HRSG to route such mixed steam through a reheat section of a high temperature, high pressure HRSG so that reheated mixed steam exiting the reheat section can be routed into a low pressure steam turbine.

Abstract: A power plant may include a combustion apparatus (11) producing an exhaust gas (12), an absorber (20) receiving the exhaust gas (12), the absorber (20) including a desiccant and producing a first stream of desiccant solution containing water and a first concentration of desiccant, and an apparatus (29, 70, 94) for dehydrating the first stream of desiccant solution while maintaining the water in a liquid phase. The apparatus (29, 70, 94) may include a heat exchanger (71, 110), a crystallizing heat exchanger (74, 96), a separator (78, 98) and a flash tank (112) for dehydrating the desiccant solution while maintaining water in a liquid phase and subsequently recovering water from the solution.

Abstract: A method and system for augmenting the output of a combined cycle power plant having a gas turbine driving a generator, a heat recovery steam generator that recovers exhaust heat from the gas turbine to drive a steam turbine also driving a generator, and a refrigeration element that is powered by available energy in steam exhausted from the steam turbine to cool water. The refrigeration element employs a substantially closed cycle refrigeration system that, in a preferred embodiment, is either an absorption chilling system or a thermal compression chilling system. The refrigeration element provides cool water to an inlet chiller arranged to chill inlet to the gas turbine to augment the power output of the gas turbine and the water is recirculated to be chilled and used again. Since the refrigeration cycle is substantially closed, little or no additional plant water consumption is imposed on the power plant.

Abstract: A power plant may include a combustion apparatus (11) producing an exhaust gas (12), an absorber (20) receiving the exhaust gas (12), the absorber (20) including a desiccant and producing a first stream of desiccant solution containing water and a first concentration of desiccant, and an apparatus (29, 70, 94) for dehydrating the first stream of desiccant solution while maintaining the water in a liquid phase. The apparatus (29, 70, 94) may include a heat exchanger (71, 110), a crystallizing heat exchanger (74, 96), a separator (78, 98) and a flash tank (112) for dehydrating the desiccant solution while maintaining water in a liquid phase and subsequently recovering water from the solution.

Abstract: A combined cycle power plant (20) including a main air-cooled condenser (22) condensing steam at a first pressure and an auxiliary air-cooled condenser (24) condensing steam at a second pressure higher than the first pressure. Designing an air-cooled combined cycle power plant for startup on a hot day can significantly increase the size and cost of the required air-cooled condenser. Adding an auxiliary air-cooled condenser having appropriate thermal characteristics relative to a main air cooled compressor to the steam bypass circuit of an air-cooled combined cycle power plant enables the plant to meet plant startup requirements during periods of peak thermal load in a more cost effective manner than would be achievable with the main air cooled condenser alone.

Abstract: A steam power plant (100) implementing an improved Rankine cycle (55) wherein steam is injected (82, 96) directly into the energy addition portion of the plant, and the resulting two-phase flow is pressurized by multiphase pumps (88, 98). By relying more heavily on pump pressurization than on a temperature difference for energy injection, plant efficiency is improved over prior art designs since energy injection by pump pressurization results in less irreversibility than energy injection by temperature difference. Direct steam injection and multiphase pumping may be used to bypass the condenser (20), to replace any one or all of the feedwater heaters (24, 32, 34), and/or to provide additional high-pressure energy addition.

Abstract: A system (10) and method of modifying a combined cycle power generation system (12, 14, 16, 18). In one embodiment of the invention an existing system includes one or more first gas turbines, one or more first steam turbines, and one or more heat recovery steam generators (HRSGs). An exemplary method includes providing at least one second gas turbine of greater operating efficiency than each of the one or more first gas turbines and connecting at least one existing HRSG to receive exhaust output from the second gas turbine to generate steam. Also according to the invention a path is provided for mixing steam exiting a high pressure steam turbine with steam generated in a low pressure HRSG to route such mixed steam through a reheat section of a high temperature, high pressure HRSG so that reheated mixed steam exiting the reheat section can be routed into a low pressure steam turbine.