Abstract: The present application provides a doubly-fed induction generator system for a multi-shaft gas turbine engine. The doubly-fed induction generator system may include a first doubly-fed induction generator in communication with a first shaft of the multi-shaft gas turbine engine, a first rotor of the first doubly-fed induction generator in communication with a converter via a first rotor bus, and a first breaker on the first rotor bus. The first doubly-fed induction generator acts as a generator or a motor depending in part upon the position of the first breaker.

Abstract: The present application provides a doubly-fed induction generator system for a multi-shaft gas turbine engine. The doubly-fed induction generator system may include a first doubly-fed induction generator in communication with a first shaft of the multi-shaft gas turbine engine, a first rotor of the first doubly-fed induction generator in communication with a converter via a first rotor bus, and a first breaker on the first rotor bus. The first doubly-fed induction generator acts as a generator or a motor depending in part upon the position of the first breaker.

Abstract: Embodiments of the present disclosure relate to cooling a gas turbine which operates at varying loads. An apparatus according to embodiments of the present disclosure may include: an outlet heat exchanger positioned within a transition duct of a turbine outlet of a gas turbine, wherein the transition duct is positioned upstream from a heat recovery steam generator (HRSG); an extraction line fluidly connecting the outlet heat exchanger to the HRSG, such that a heat exchange fluid flows from the HRSG to the outlet heat exchanger through the extraction line; and a return line fluidly connecting the outlet heat exchanger to the HRSG, such that the heat exchange fluid returns to the HRSG through the return line after passing through the outlet heat exchanger.

Abstract: A fuel purge system for a gas turbine engine includes a fuel manifold configured to receive a liquid fuel from a fuel supply and distribute the liquid fuel to a combustor assembly. Also included is a liquid pump configured to receive a liquid from a liquid supply and distribute the liquid to the fuel manifold for pressurization of the fuel manifold during a purge operation of the combustor assembly.

Abstract: In one or more of the inventive aspects, a boiler feedwater pump may provide feedwater to a heat recovery steam generator, and the heated feedwater may be used for liquid fuel heating in a liquid fuel heater. The feedwater from the boiler feedwater pump may also be used for water injection in a combustor.

Abstract: A gas turbine engine system. The system includes a compressor with a first compressor stage and a second compressor stage, a turbine with a first turbine stage and a second turbine stage, a first flow path connecting the first compressor stage and the first turbine stage, a second flow path connecting the second compressor stage and the second turbine stage, a crossover flow path connecting the first flow path and the second flow path, and an ejector positioned about the crossover flow path and the first flow path. The ejector may be a variable motive nozzle ejector.

Abstract: An active clearance control system is provided that uses compressor extraction air to manipulate blade tip clearance in an industrial gas turbine and compressor. A stream of air is taken from a cooling and sealing air circuit and redirected to be used for active clearance control. The spent clearance control air is re-introduced into the hot gas path of the gas turbine for cooling and sealing purposes.

Abstract: A system and related method for cleaning structures including structures with interior surfaces. The system includes a mixing chamber for selectively combining a cleaning gas and liquid droplets together so that the droplets are entrained in the gas. The combination is directed to the structure to be cleaned. The velocity of the gas combined with the density of the liquid droplets provides a washing momentum to effect removal of particulate matter from the structure. The system also includes a condenser and a separator for separating the liquid from the gas after cleaning. A filter is employed to isolate and measure the quantity of particulate removed from the cooling circuit. A rotameter forms part of the system and is used to measure the accumulated quantity of liquid suitable for effecting a satisfactory cleaning. The system and related cleaning method may be used to clean the cooling system of a rotor bucket.