Systems, methods and apparatus are disclosed that include an exhaust system and an air source external to the exhaust system that is configured to force additional air into the exhaust stream downstream of the engine and aftertreatment system to help mix cool air with the exhaust. The amount and timing of the mixing of the forced air with the exhaust can be determined by an electronic controller so that mixing air is provided in response to one or more predetermined operating conditions and/or anticipated operating conditions.

The present application provides a selective catalyst reduction system for use with a combustion gas stream. The selective catalyst reduction system may include a tempering air system with a finger mixer and a number of mixing boxes positioned downstream of the finger mixer and a catalyst positioned downstream of the tempering air system. The tempering air system cools the combustion gas stream and evens out the temperature profile before the combustion gas stream reaches the catalyst.

A gas turbine system includes a gas turbine engine configured to combust a fuel and produce an exhaust gas. An exhaust duct assembly is coupled to the gas turbine engine and is configured to receive the exhaust gas. An absorption chiller is fluidly coupled to the exhaust duct assembly and is configured to receive a take-off stream of the exhaust gas. The absorption chiller is configured to use the take-off stream to drive at least a portion of an absorption cooling process to generate a cooled take-off stream of exhaust gas. The exhaust duct assembly is configured to receive the cooled take-off stream of exhaust gas from the absorption chiller and to mix the cooled take-off stream with exhaust gas present within the exhaust duct assembly to cool the exhaust gas.

The apparatus and systems are for removing contaminants from an exhaust stream. The process may involve passing at least a portion of an exhaust stream through a cooling component, which draws a cooling stream into the cooling component. The cooling stream interacts with the at least a portion of the exhaust stream to form a mixed stream. The resulting mixed stream is a lower temperature than the at least portion of the exhaust stream.

A turboprop engine assembly for an aircraft, including an internal combustion engine having a liquid coolant system, an air duct in fluid communication with an environment of the aircraft, a heat exchanger received within the air duct having coolant passages in fluid communication with the liquid coolant system and air passages air passages in fluid communication with the air duct, and an exhaust duct in fluid communication with an exhaust of the internal combustion engine. The exhaust duct has an outlet positioned within the air duct downstream of the heat exchanger and upstream of an outlet of the air duct, the outlet of the exhaust duct spaced inwardly from a peripheral wall of the air duct. In use, a flow of cooling air surrounds a flow of exhaust gases. A method of discharging air and exhaust gases in an turboprop engine assembly having an internal combustion engine is also discussed.

A connector system includes an adaptor with a magnetic target surface, and a nozzle that is configured to be connected to the magnetic target surface of the adaptor by a magnetic coupling. The nozzle has a housing having an inlet end and an outlet end, and a throughgoing channel having an axial extension therebetween. The housing includes one or more magnets that are arranged at the inlet end and configured to direct or indirect engage the magnetic target surface in a condition when the nozzle is connected to the adaptor. Further, the housing includes one or more air vents that are arranged at the outlet end and which have an axial extension being radially displaced in view of the axial extension of the throughgoing channel.

An engine is configured so that a muffler is affixed to the exhaust opening of the cylinder, and the air-cooled cylinder is cooled by a cooling fan. The engine is provided with a muffler cover for covering the muffler, and exhaust gas is discharged inside the muffler cover along the wall surface of the muffler. A second cooling air is combined with the exhaust gas flow from the upstream side thereof to be parallel thereto, and a first cooling air having been caused to flow under the muffler is caused to perpendicularly impinge against the exhaust gas flow on the downstream side thereof. Thus, the cooling airs are combined inside the muffler cover with the exhaust gas flow, and as a result the temperature of the exhaust gas is sufficiently reduced at the time when the exhaust gas is discharged from the opening of the muffler cover to the outside.

A turboprop engine assembly for an aircraft, including an internal combustion engine having a liquid coolant system, an air duct in fluid communication with an environment of the aircraft, a heat exchanger received within the air duct having coolant passages in fluid communication with the liquid coolant system and air passages air passages in fluid communication with the air duct, and an exhaust duct in fluid communication with an exhaust of the internal combustion engine. The exhaust duct has an outlet positioned within the air duct downstream of the heat exchanger and upstream of an outlet of the air duct, the outlet of the exhaust duct spaced inwardly from a peripheral wall of the air duct. In use, a flow of cooling air surrounds a flow of exhaust gases. A method of discharging air and exhaust gases in an turboprop engine assembly having an internal combustion engine is also discussed.

An airflow control system for a gas turbine system according to an embodiment includes: an airflow generation system for attachment to a rotatable shaft of a gas turbine system for 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 to provide bypass air; an enclosure surrounding the gas turbine system and forming an air passage, the bypass air flowing through the air passage and around the gas turbine system into the mixing area to reduce a temperature of the exhaust gas stream; and an exhaust processing system for processing the reduced temperature exhaust gas stream.

An emission signature modification device for modifying an acoustic signature of an exhaust gas stream, including an exhaust gas guiding device that guides the exhaust gas stream in the flow direction thereof from an inlet area to an outlet area. An active acoustic emission modification device modifies the acoustic emission of the exhaust gas stream in predetermined operating states. If an actuator system of the active acoustic emission modification device is designed such that in a circumferential direction, the actuator system is surrounded by more than 30% of the guided exhaust gas stream, the actuating system can be protected against harmful influences from the environment by way of the exhaust gas guiding device on the one hand, and on the other hand, the required space signifier can be reduced as compared to a lateral, external arrangement of the actuating system.