An aircraft engine has a combustor supplied by a hydrogen fuel system and is configured to combust hydrogen and generate water vapor. A water vapor collector receives at least part of the water vapor. A condenser is in fluid communication with the water vapor collector to receive and cool in the condenser the at least part of the water vapor and thereby condense at least part of the at least part of the flow of water vapor. A spray nozzle is in fluid communication with the condenser and operable to spray the condensed part of the at least part of the flow of water vapor onto a component of the aircraft engine.

Control systems and methods suitable for combination with power production systems and methods are provided herein. The control systems and methods may be used with, for example, closed power cycles as well as semi-closed power cycles. The combined control systems and methods and power production systems and methods can provide dynamic control of the power production systems and methods that can be carried out automatically based upon inputs received by controllers and outputs from the controllers to one or more components of the power production systems.

A system for a gas turbine includes a control system comprising a processor. The processor is configured to receive a signal indicating spray intercooling fluid demand of the gas turbine. The processor is configured to determine a rate of change of the spray intercooling fluid demand. The processor is configured to control flow of a nitrogen oxide (NO.sub.X) minimization fluid that reduces NO.sub.X emissions from the gas turbine based at least in part on the rate of change of the spray intercooling fluid demand.

A system for a gas turbine includes a control system comprising a processor. The processor is configured to receive a signal indicating spray intercooling fluid demand of the gas turbine. The processor is configured to determine a rate of change of the spray intercooling fluid demand. The processor is configured to control flow of a nitrogen oxide (NO.sub.X) minimization fluid that reduces NO.sub.X emissions from the gas turbine based at least in part on the rate of change of the spray intercooling fluid demand.

A gas turbine engine including a catalytic reactor and a combustor. The catalytic reactor is configured (i) to receive hydrogen fuel, (ii) to receive air containing oxygen, (iii) to catalytically react at least a portion of the oxygen in the air with at least a portion of the hydrogen in the hydrogen fuel to produce water, and (iv) to output diluent comprising the catalytically produced water. The combustor includes (a) a combustion chamber and (b) at least one nozzle that is fluidly coupled to the catalytic reactor to receive the diluent output by the catalytic reactor and configured to inject the diluent into the combustion chamber.

A gas turbine engine for an aircraft includes a turbine section and an exhaust section configured to receive an exhaust gas stream from the turbine section. The exhaust section includes a monolithic catalyst structure configured to remove nitrogen oxides (NO.sub.x) from the exhaust gas stream.

A gas turbine engine for an aircraft includes a turbine section and an exhaust section configured to receive an exhaust gas stream from the turbine section. The exhaust section includes a monolithic catalyst structure configured to remove nitrogen oxides (NO.sub.x) from the exhaust gas stream.

An exhaust gas purification device (26) for a gas turbine engine (10) comprises a catalyst chamber (64, 96) defined in an exhaust gas passage (22), a reduction agent container (32) containing a solid material that releases a reduction agent gas effective for NOx reduction when heated, a heating device (36, 38) for heating the solid material contained in the reduction agent container, and a reduction agent gas supply passage (48) for supplying the reduction agent gas released from the solid material into the catalyst chamber.

An exhaust gas purification device (26) for a gas turbine engine (10) comprises a catalyst chamber (64, 96) defined in an exhaust gas passage (22), a reduction agent container (32) containing a solid material that releases a reduction agent gas effective for NOx reduction when heated, a heating device (36, 38) for heating the solid material contained in the reduction agent container, and a reduction agent gas supply passage (48) for supplying the reduction agent gas released from the solid material into the catalyst chamber.

A system for reducing a temperature of an exhaust gas stream of a gas turbine system according to an embodiment includes: a compressor component of a gas turbine system; an airflow generation system for attachment to a rotatable shaft of the gas turbine system, the airflow generation system and the compressor component drawing in an excess flow of air through an air intake section; a mixing area for receiving an exhaust gas stream produced by the gas turbine system; an air extraction system for: extracting at least a portion of the excess flow of air generated by the airflow generation system and the compressor component to provide bypass air; and diverting the bypass air into the mixing area to reduce a temperature of the exhaust gas stream; and a fluid injection system for injecting an atomized fluid into the mixing area to reduce a temperature of the exhaust gas stream.