Methods and systems for heating an emission control device are provided. In one example, a method for a vehicle comprises during an engine cold start, heating an emission control device of the engine using a dual heat exchanger to heat secondary air and cool exhaust gas, and further heat secondary air with an electric heater. The method further comprises directing the heated secondary air to each exhaust runner of the engine via individual air injectors to mix with exhaust gas. In this way, an improved mixture of air and exhaust reduces catalyst light-off time and increases conversion efficiency, thereby reducing hydrocarbon emissions during engine cold start.

Methods and systems for heating an emission control device are provided. In one example, a method for a vehicle comprises during an engine cold start, heating an emission control device of the engine using a dual heat exchanger to heat secondary air and cool exhaust gas, and further heat secondary air with an electric heater. The method further comprises directing the heated secondary air to each exhaust runner of the engine via individual air injectors to mix with exhaust gas. In this way, an improved mixture of air and exhaust reduces catalyst light-off time and increases conversion efficiency, thereby reducing hydrocarbon emissions during engine cold start.

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.

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.

Methods and systems are provided for controlling the temperature and ratio of gases within a gas mixing tank reservoir and selectively charging/discharging gases from the reservoir to one or both of an intake system or an exhaust system. In one example, a method (or system) may include storing exhaust gas and/or compressed intake air into a gas mixing reservoir, and increasing or decreasing flow of coolant to the reservoir based on engine operating conditions. The stored gases may be discharged to an intake system and/or an exhaust system based on requests from a controller, and coolant flow to the reservoir may be adjusted based on the composition of the gases stored within the reservoir.

Engine exhaust system for an internal combustion engine, the engine exhaust system comprising an exhaust conduit (14) connected to an engine (30), an exhaust gas return conduit (32,33) such that at least a part of the exhaust gas can be returned to the engine. The exhaust gas return conduit, at least along a part of its length, is formed with at least two flow paths (48,49). The engine exhaust system further comprises a particle filter arranged in each of the at least two flow paths and at least one cold flame vaporizer (11) in which fuel is partially oxidized in preheated air to form a cold flame gas. The at least one cold flame vaporizer is arranged in fluid communication with all the flow paths such that the cold flame gas can flow through the particle filters, whereby the cold flame gas can be used to regenerate the particle filter in at least one of the exhaust flow paths while, simultaneously, exhaust gas can flow through the other exhaust flow path or exhaust flow paths. A method for the cleaning of a particle filter is also provided.

In an exhaust gas purification system provided with a denitration catalyst layer, a reducing agent oxidation catalyst layer is installed together; a reducing agent and air are supplied into the reducing agent oxidation catalyst layer at the time of catalyst regeneration of the denitration catalyst layer; a high-temperature oxidation reaction gas is produced by a reaction heat generated by an oxidation reaction of the reducing agent and the air in this reducing agent oxidation catalyst layer; and this high-temperature oxidation reaction gas is introduced into the denitration catalyst layer to heat the denitration catalyst, thereby recovering a denitration performance of the catalyst.

The present invention relates to a method for controlling an internal combustion engine arrangement (100) connected to an exhaust gas aftertreatment system (200), wherein the method is arranged to control a gas heating device ( 122), as well as a gas feeding arrangement to direct a flow of intake air through the exhaust gas recirculation conduit (112) from the intake system to the exhaust system, the flow of intake air being directed through the gas heating device before the intake air enters the exhaust gas aftertreatment system, in response to determining a requested start of the internal combustion engine to heat the aftertreatment system before starting the engine.

Method and system for thermal regeneration of a catalyst by inlet turbine exhaust gas from a diesel engine, where a gas split stream (08) is led from the engine exhaust (02) through an eductor (04) and further to regeneration of a catalyst, wherein a cold air stream (09) is used to keep the regeneration gas stream at a desired constant temperature range.

Methods and systems are provided for reducing emissions during an engine cold start. In one example, a method may include, during emission control device heating, injecting heated air into an exhaust runner of each cylinder of the engine during an exhaust stroke of the corresponding cylinder, after a blowdown exhaust pulse. In this way, an amount of hydrocarbons in feedgas provided to the emission control device prior to the emission control device reaching its light-off temperature may be reduced.