An exhaust gas control system includes an upstream purification device disposed in an exhaust passage of the internal combustion engine, a downstream purification device disposed in a portion of the exhaust passage downstream from the upstream purification device, a fuel addition valve disposed in a portion of the exhaust passage upstream from the upstream purification device, and a urea addition valve disposed in a portion of the exhaust passage between the upstream purification device and the downstream purification device, and a cooling device. The cooling device is configured such that refrigerant cools the fuel addition valve first and then cools the urea addition valve subsequent to the fuel addition valve.

The present invention shows an exhaust gas aftertreatment system comprising at least a first route and a second route arranged in parallel in an exhaust gas stream, wherein the first route and the second route are provided with exhaust gas aftertreatment subsystems. The exhaust gas aftertreatment subsystems of the first route and the second route use different exhaust gas aftertreatment technologies.

Systems and apparatuses include a selective catalytic reduction system structured to receive exhaust gases from a dual fuel engine system and include a diesel exhaust fluid dosing unit, an ammonia slip catalyst positioned directly downstream of the selective catalytic reduction catalyst, an oxidation catalyst positioned directly downstream of the ammonia slip catalyst, and one or more processing circuits. The circuits receive a system out NOx value, a space velocity, an ammonia to NOx ratio, an exhaust temperature, a substitution rate, and a conversion efficiency target. The circuits determine a conversion efficiency differential, adjust the substitution rate based on the system out NOx value, adjust the ammonia to NOx ratio based on the space velocity, the ammonia to NOx ratio, the exhaust temperature, the substitution rate, the conversion efficiency target, and the conversion efficiency differential, and determine a diesel exhaust fluid dosing rate for the diesel exhaust fluid dosing unit.

The disclosure relates to an exhaust gas aftertreatment system with a turbine arranged in the exhaust gas line and with a main catalytic converter arranged downstream from the turbine, wherein the exhaust gas line has a bypass line and a bypass connector, wherein the bypass line opens downstream from the turbine, wherein a main particle filter and, in the bypass line, a catalytic converter are provided, wherein the bypass valve a1) is formed as a three-way valve is and forms the bypass connector a2) the bypass valve is formed as a three-way valve and is provided at the opening b1) is positioned in the bypass line, wherein an exhaust gas flap is provided upstream from the opening in the exhaust gas line b2) the exhaust gas line is formed without exhaust gas flaps downstream from the bypass connector and upstream from the opening, and the catalytic converter has a three-way coating or the respective main catalytic converter has a DOC coating.

Provided is a flow modification component for use with a muffler, which can be a Helmholtz resonator muffler, a side branch muffler, or a Y-pipe. The flow modification component includes a porous plate adapted for incorporation into a passage to a sound muffling portion connected to a through passage pipe of the muffler or Y-pipe. One or more openings are formed on the porous plate to allow low frequency acoustic waves to pass through into the passage to the sound muffling portion while reducing large-scale turbulent eddies that produce undesirable resonant tones within the aperture tube to small-scale turbulent eddies. The openings having sufficient porosity such that the resulting sound frequency is determined by size, shape, number, and spacing of the openings. The flow modification component can also include a dissipative material component in an internal port passage of the muffler to further reduce resonant tones.

A mixer assembly unit, for an exhaust system exhaust gas treatment unit of an internal combustion engine, mixes exhaust gas discharged by the internal combustion engine with reactant. A mixing section (12), downstream in relation to a reactant release device (14), mixes exhaust gas, flowing in an exhaust gas flow direction, with reactant. The mixing section includes a core flow duct (34), extending in a direction of a mixing section longitudinal axis (L), through which a first exhaust gas partial stream (T1) flows. A second exhaust gas partial stream (T2) flows through a jacket flow duct (36) surrounding the core flow duct and separated from the core flow duct by an inner wall (30). The reactant release device releases reactant into the core flow duct or/and into the first exhaust gas partial stream. A mixer (38) is provided at an upstream end area (22) of the mixing section.

The present disclosure relates to an exhaust pipe apparatus. The exhaust pipe apparatus includes a first exhaust pipe provided to directly discharge exhaust gas discharged from a combustion engine to the outside, a second exhaust pipe connected in parallel with the first exhaust pipe and having a branch pipe connected to one side thereof such that the exhaust gas is directly discharged to the outside or discharged through the branch pipe, and a first damper installed in the second exhaust pipe to control a flow of the exhaust gas to be directly discharged to the outside or discharged through the branch pipe.

An aftertreatment system for a work vehicle includes: a fluid injector configured to inject a treatment fluid; a selective catalytic reducer (SCR) substrate; and a mixer fluidly coupled to the fluid injector and the SCR substrate and including at least one scroll defining a scroll open area and configured to receive a flow of exhaust gas and the treatment fluid. The mixer has a fixed wall and a plate displaceably coupled to the fixed wall, the plate being associated with the at least one scroll such that a change in a flow rate of exhaust gas into the at least one scroll passively causes displacement of the plate to adjust a size of the scroll open area.

In one aspect, a system is provided and includes an engine including an exhaust valve, an exhaust manifold downstream of the exhaust valve and a muffler downstream of the exhaust manifold. The system also includes a catalyst positioned downstream of the exhaust valve.

There is provided an exhaust-gas aftertreatment arrangement for an internal combustion engine comprising a first catalytic converter, a second catalytic converter arranged in parallel with the first catalytic converter, the first and second catalytic converters being arranged to receive exhaust gas from an engine, a connection pipe fluidly connecting an outlet of the second catalytic converter with an inlet of the first catalytic converter, thereby allowing a flow of exhaust gas through the connection pipe, and an outlet valve arranged in the outlet of the second catalytic converter and downstream of the location of the connection pipe, wherein the outlet valve is configured to control a flow of exhaust gas through the second catalytic converter. There is also provided a method for controlling an exhaust-gas aftertreatment arrangement.