An exhaust gas system is provided for a transport refrigeration unit (TRU) engine. The exhaust gas system includes an exhaust system. The exhaust system includes a catalyst operable in a temperature range to catalyze exhaust gas produced in the TRU engine and flown through the exhaust system. The exhaust gas system further includes temperature sensors respectively disposed to sense exhaust gas temperatures upstream of and downstream from the catalyst, at least one of first, second and third valves which are proportionally controllable to moderate amounts of air provided to the TRU engine, fuel provided to the TRU engine and air provided to the catalyst, respectively, and a controller. The controller is configured to compare sensed exhaust gas temperatures with the temperature range and issue a proportional signal to the at least one of the first, second and third valves in accordance with results of the comparison.

The invention concerns a method for unblocking pores in a metal zeolite based selective catalytic reduction (SCR) catalyst. The method includes filling, at least partially, the SCR catalyst with a liquid, the liquid being preferably distilled water. The method includes letting said liquid inside the SCR catalyst enough time to allow said liquid to dissolve, at least partially, the obstructions and to penetrate into the pores. The method includes heating the SCR catalyst at a temperature above the ebullition temperature of the liquid so as to vaporize the part of the liquid remained into the pores, and generate steam flows through the obstructions, the steam flows removing the obstructions and unblocking the pores, wherein no hydrocarbons are injected during the step of heating.

The invention concerns a method for unblocking pores in a metal zeolite based selective catalytic reduction (SCR) catalyst. The method includes filling, at least partially, the SCR catalyst with a liquid, the liquid being preferably distilled water. The method includes letting said liquid inside the SCR catalyst enough time to allow said liquid to dissolve, at least partially, the obstructions and to penetrate into the pores. The method includes heating the SCR catalyst at a temperature above the ebullition temperature of the liquid so as to vaporize the part of the liquid remained into the pores, and generate steam flows through the obstructions, the steam flows removing the obstructions and unblocking the pores, wherein no hydrocarbons are injected during the step of heating.

Engine systems use a three-way catalyst followed by air injection and mixing to convert all hydrocarbons and carbon monoxide under various load conditions when exhaust gas temperature is above 500 degrees Celsius. A three-way catalytic converter is disposed in the exhaust system. A nozzle is configured to inject air into the exhaust system downstream from the three-way catalytic converter. A mixing plate with or without catalyst coatings is disposed in the exhaust system downstream from the nozzle. The mixing plate is bow shaped with a concave shaped side facing the nozzle to enhance carbon monoxide conversion. Optional two way catalytic converters are added downstream from the mixing plate to further reduce tailpipe hydrocarbon and carbon monoxide emissions.

An engine system includes an internal combustion engine having an engine block with one or more piston-cylinder arrangements communicating with an intake manifold and an exhaust manifold, a charge air passageway to the intake manifold, and an exhaust gas passageway that receives exhaust gas from the exhaust manifold. The engine system also includes one or more turbochargers each including a compressor to compress charge air and output the compressed charge air to the charge air passageway and a turbine that receives exhaust gas from the exhaust gas passageway and drives the compressor in response to the exhaust gas passing through the turbine. An air pump is positioned downstream of the compressor that supplies a portion of the compressed charge air into the exhaust gas passageway upstream of the turbine, such that the turbine receives both exhaust gas and compressed charge air.

An apparatus of purifying exhaust gas of a hybrid vehicle includes an electric supercharger disposed on an air intake line, a post-treatment unit disposed on an exhaust gas line and including an electrically-heated catalyst, an exhaust gas recirculation unit including an exhaust gas recirculation cooler disposed on a recirculation line connecting the post-treatment unit and the intake line and an exhaust gas recirculation valve disposed on the recirculation line, a three-way valve disposed at a position at which the recirculation line diverges into a front end portion and a rear end portion of the intake line, and a controller electrically connected to the three-way valve and configured for controlling the three-way valve connecting the intake line and the recirculation line at the front end portion of the electric supercharger to be selectively opened or closed.

An apparatus of purifying exhaust gas of a hybrid vehicle includes an electric supercharger disposed on an air intake line, a post-treatment unit disposed on an exhaust gas line and including an electrically-heated catalyst, an exhaust gas recirculation unit including an exhaust gas recirculation cooler disposed on a recirculation line connecting the post-treatment unit and the intake line and an exhaust gas recirculation valve disposed on the recirculation line, a three-way valve disposed at a position at which the recirculation line diverges into a front end portion and a rear end portion of the intake line, and a controller electrically connected to the three-way valve and configured for controlling the three-way valve connecting the intake line and the recirculation line at the front end portion of the electric supercharger to be selectively opened or closed.

An injector for a diesel exhaust fluid (DEF) delivery system includes a first conduit extending along a longitudinal direction; a second conduit extending along the longitudinal direction and disposed within the first conduit; a nozzle tip having a side wall and an end wall; and a shell surrounding the first conduit and being spaced apart from the first conduit along a radial direction. The side wall has a thickness extending along the radial direction from an external surface of the nozzle tip to an inner surface of the second conduit. The end wall defines an outlet flow passage therethrough, and the outlet flow passage is in fluid communication with the first conduit and the second conduit via a chamber defined by an internal surface of the nozzle tip.

An injector for a diesel exhaust fluid (DEF) delivery system includes a first conduit extending along a longitudinal direction; a second conduit extending along the longitudinal direction and disposed within the first conduit; a nozzle tip having a side wall and an end wall; and a shell surrounding the first conduit and being spaced apart from the first conduit along a radial direction. The side wall has a thickness extending along the radial direction from an external surface of the nozzle tip to an inner surface of the second conduit. The end wall defines an outlet flow passage therethrough, and the outlet flow passage is in fluid communication with the first conduit and the second conduit via a chamber defined by an internal surface of the nozzle tip.

In a turbocharged internal combustion engine (ICE) system, a catalytic treatment device receives exhaust gases from the ICE after they have passed through the turbocharger turbine. The system includes a secondary air pump (SAP) for injecting pressurized air into the exhaust gases ahead of the catalytic treatment device. The SAP is a single-stage centrifugal compressor that includes an air recirculation passage for causing a first portion of the air pressurized by the SAP to be continuously recirculated back to the inlet of the SAP, which is effective for heating the air in the volute of the SAP. A second portion of the pressurized air, having thereby been heated, is injected into the exhaust gases proceeding toward the catalytic treatment device.