A transportation refrigeration unit includes an evaporator circulating a flow of refrigerant therethrough to cool a flow of supply air flowing over the evaporator, a compressor in fluid communication with the evaporator to compress the flow of refrigerant, and an engine operably connected to the compressor to drive operation of the compressor. The engine includes an exhaust pathway to direct an exhaust gas flow from the transportation refrigeration unit, and a nozzle extending circumferentially around the exhaust pathway defining a nozzle flowpath between the exhaust pathway and the nozzle, the nozzle configured to flow a cooling airflow along the nozzle flowpath to reduce a temperature of the exhaust gas flow.

An airflow control system for a gas turbine system according to an embodiment includes: an airflow generation system for attachment to a rotatable expander shaft of a gas turbine system, downstream of the gas turbine system, for drawing in a flow of ambient air through an air intake section into a mixing area; and an eductor nozzle for attachment to a downstream end of the turbine component for receiving an exhaust gas stream produced by the gas turbine system and for drawing in a flow of ambient air through the air intake section into the mixing area, the exhaust gas stream passing through the eductor nozzle into the mixing area; wherein, in the mixing area, the exhaust gas stream mixes with the flow of ambient air drawn in by the airflow generation system and the flow of ambient air drawn in by the eductor nozzle to reduce a temperature of the exhaust gas stream.

An external air introduction apparatus includes: an external air introduction opening that guides external air into an exhaust channel, and opened and closed by a pressure difference between an external air pressure and a pressure inside the exhaust channel; a valve plate having a valve body that elastically deforms due to the pressure difference; a base plate stacked on the valve plate and having an opening that faces the valve body and smaller than the valve body and a seat surface formed around the opening; and a restriction plate that restricts elastic deformation of the valve body. The opening is closed and opened by the contact and separation of the valve body and the seat surface. The plates are fixed to a wall that forms the exhaust channel with a fastening member.

A diffuser is configured for use on a vehicle having an engine and an exhaust pipe. The diffuser includes a conduit with a first end configured to receive exhaust gases from the engine. A diffusion fitting is coupled to a second end of the conduit to receive exhaust gases discharged from the conduit. The diffusion fitting has an outer wall that includes a curved surface. The curved surface is configured to guide the exhaust gases discharged from the conduit about an axis so that exhaust gases exit a first side of the diffusion fitting rotating about the axis.

A method for flushing an exhaust-gas cleaning system of an internal combustion engine having a catalytic converter with at least one catalyst bed, whereby an exhaust gas from the internal combustion engine is supplied to the exhaust-gas cleaning system in an active operating phase of the exhaust-gas cleaning system, and no exhaust gas is supplied to the exhaust-gas cleaning system in a passive operating phase of the exhaust-gas cleaning system, whereby a temperature of the at least one catalyst bed is determined and the flushing is performed depending on the determined temperature, whereby the exhaust-gas cleaning system is flushed in the passive operating phase of the exhaust-gas cleaning system by a flushing device, which is connected directly to an exhaust-gas line.

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.

The present application provides a selective catalyst reduction system for use with a combustion gas stream of a gas turbine. The selective catalyst reduction system may include an inlet positioned about the gas turbine, a combined ammonia-tempering air injection grid positioned about the inlet, and a catalyst positioned downstream of the combined ammonia-tempering air injection grid. The combined ammonia-tempering air injection grid injects air and ammonia into the combustion gas stream upstream of the catalyst.

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 provision of assemblies and methods for treating an exhaust gas from an internal combustion engine. The treatment method comprises at least two catalyst stages. The exhaust gas is directed to a first stage catalyst. After the first stage catalyst, the exhaust is passed to an inter-catalyst stage comprising an exhaust cooling process and an oxygen enrichment process. Next, the exhaust is passed to a second stage catalyst for reducing carbon monoxide, ammonia and hydrocarbon concentration in the exhaust gas, before exiting via an outlet.

A system includes a system includes an exhaust section which receives an exhaust flow of a gas turbine, where the exhaust section includes a catalyst assembly. The system includes an exhaust duct coupled to the diffuser section upstream of the catalyst assembly, where the exhaust duct extracts a return portion of the exhaust flow. The system includes a filter house coupled to the exhaust duct, where the filter house is receives a combined flow of an ambient air flow and the return portion. The system includes a return conduit coupled to the filter house and the exhaust section, where the return conduit is coupled to the exhaust section upstream of the exhaust duct. The return conduit directs the combined flow to the exhaust section, and the catalyst assembly receives a mixed flow including the exhaust flow and the combined flow.