A turbomachine includes a plurality of transition ducts disposed in a generally annular array. Each transition duct includes an inlet, an outlet, and a passage defining an interior and extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of each transition duct is offset from the inlet along the longitudinal axis and the tangential axis. Each transition duct further includes an upstream portion and a downstream portion. The turbomachine further includes a late injection assembly disposed between the upstream portion and the downstream portion of a transition duct and which provides fluid communication for an injection fluid to flow into the interior downstream of the inlet of the transition duct. The late injection assembly includes a late injection ring.

Methods of determining a desired sensor probe location in a closed loop emissions control (CLEC) system of a gas turbine engine are provided. One method includes determining, at different locations, a plurality of temperature contour profiles for exhaust flowing through an exhaust duct, selecting an emissions component entrained in the exhaust to be measured, and determining a desired sensor probe installation location based on the emissions component to be measured and based on the plurality of temperature contour profiles.

The invention concerns an aircraft propulsion control system in which a gas turbine engine has an actuable flow opening for control of flow to or from a portion of the engine. One or more sensor is arranged to sense a condition indicative of vapor trail formation by the exhaust flow from the engine. A controller is arranged to control actuation of the flow opening so as to reduce the efficiency of the engine upon sensing of said condition by the one or more sensor. In one example, the flow opening is a variable area fan nozzle.

The invention relates to a method for operating a gas turbine power plant, including a gas turbine, a HRSG following the gas turbine, an exhaust gas blower, and a carbon dioxide separation plant which separates the carbon dioxide contained in the exhaust gases and discharges it to a carbon dioxide outlet, the gas turbine, HRSG, exhaust gas blower, and carbon dioxide separation plant being connected by means of exhaust gas lines. According to the method a trip of the gas turbine power plant includes the steps of: stopping the fuel supply, switching off the exhaust gas blower, and controlling the opening angle of a VIGV at a position bigger or equal to a position required to keep a pressure in the exhaust gas lines between the HRSG and the exhaust gas blower above a minimum required pressure. The invention relates, further relates to a gas turbine power plant configured to carry out such a method.

An aircraft including lean-burn gas turbine engines operating in pilot-plus-mains mode with a given initial fuel flow W.sub.0, a method of controlling the optical depth of contrails produced by a first group of engines includes the steps of (i) reducing fuel flow to each engine in the first group to change the operation of each engine from pilot-plus-mains mode to pilot-only mode, and (ii) adjusting fuel flow to one or more engines in a second group of engines such that the total fuel flow to engines of the second group is increased, all engines of the second group remaining in pilot-plus-mains mode, and wherein the set of lean-burn engines consists of the first and second groups. Depending on atmospheric conditions, the average optical depth of contrails produced by the engines may be enhanced or reduced compared to when all engines operate in pilot-plus-mains mode with a fuel flow W.sub.0.

A system has: a combustor; a plenum surrounding the combustor; a transfer tube having an inlet fluidly connected to the plenum and at least two outlets, a first flow passageway defined between the inlet and a first outlet, a second flow passageway defined between the inlet and a second outlet, the second flow passageway connected to a discharge region outside of the plenum; a flow valve disposed within the second flow passageway and operable between an open position and a closed position, in the open position the flow valve fluidly connects the plenum with the discharge region, in the closed position the flow valve blocking fluid communication between the plenum and the discharge region; and a controller communicatively coupled to the flow valve to control operation thereof by: causing the flow valve to open for a time period; and subsequent to the time period, causing the flow valve to close.

An emissions control system for a gas turbine system includes a reducing agent supply, at least one sensor, at least one valve, and a controller. The reducing agent supply has one or more conduits configured to couple to one or more fluid pathways of the gas turbine system, which are fluidly coupled to a flow path of an exhaust gas from a combustor through a turbine of the gas turbine system. The at least one sensor is configured to obtain a feedback of one or more parameters of the gas turbine system, which are indicative of a visibility of emissions of the exhaust gas. The at least one valve is coupled to the reducing agent supply. The controller is communicatively coupled to the at least one sensor and the at least one valve, such that, in response to the feedback, the controller adjusts the at least one valve to adjust a flow of the reducing agent to reduce the visibility of the emissions of the exhaust gas.

Combustion turbine control systems are configured to operate combustion turbine systems in partial or no load while meeting emission targets. The combustion turbine system includes a combustion turbine, an electrical generator, a combustion turbine controller, a catalyst assembly, and/or other relevant equipment. Based on given operating constraints, such as load conditions and emission regulations, the combustion turbine controller may execute corresponding actions to control certain gas concentrations and/or gas mass flows in the exhaust gases in compliance with emission regulations. The corresponding actions may include, but are not limited to: controlling fuel and/or diluent injection(s) to combustor(s) to control combustion (e.g., combustion temperature) to manage combustion gas contents exiting from the combustor, controlling compressor bleed valve(s) to control the combustion temperature, controlling the catalyst assembly to process exhaust gases to be released into the environment, or a combination thereof.

A method of controlling a gas turbine engine capable of operating in at least a high output power range, a medium-high output power range, a medium-low output power range and a low output power range. The method includes during the medium-high output power range bleeding a gas from a downstream part of the compressor to an upstream part of the compressor so that a first predetermined temperature of the combustor is maintained, during the medium-low output power range bleeding a gas from a downstream part of the compressor to an upstream part of the compressor and bleeding a gas from the downstream part of the compressor to the exhaust so that a second predetermined temperature of the combustor is maintained.

An aircraft propulsion system includes a hydrocarbon fuel store, a hydrogen fuel store, an engine system capable of producing thrust by combusting hydrocarbon fuel and/or combusting or oxidising hydrogen fuel, a conveying system to convey hydrocarbon and hydrogen fuel from the fuel stores to the engine system and a control system to control the respective flow rates of the fuel within the conveying system. The control system adapts the fractions of the total fuel energy flow rate to the engine system represented by the hydrocarbon and hydrogen fuel energy flow rates in order to reduce climate warming impact caused by at least one of carbon dioxide, water vapour and condensation trails and/or increase climate cooling impact caused by condensation trails produced by the aircraft propulsion system compared to a dual-fuel propulsion system in which a reserve of hydrocarbon fuel is entirely combusted before any of a reserve of hydrogen fuel.