The present disclosure relates to a hydrocarbon dosing system to control dosing of diesel fuel into an exhaust upstream of a vehicle's oxidation catalyst (VOC). The system 100 includes separate inlets (102,104) to allow inflow of a first fluid and the second fluid into the system, and an outlet 116. The first fluid configured to facilitate purging of the second fluid into the VOC through the outlet 116. The system 100 incorporates multiple valves (106, 108, 112) and pressure sensor 114 to control dosing and purging of the fluids. The system 100 provides an intrinsic non-return valve mechanism to restrict the flow of the first fluid into a fluid path of the second fluid, and vice versa. The system 100 provides intrinsic pressure relief mechanism for controlled release of pressure from system 100. The system 100 includes additional optional check valves 208 and filter screens 206 for redundancy purposes.

A method is disclosed for operating an internal combustion engine which comprises a primary air system for providing fresh air and a secondary air system. The secondary air system is configured to branch off secondary air from the primary air system and blow it into an exhaust gas duct. The secondary air system has a compressor for feeding the secondary air and a secondary air valve for shutting off or enabling the blowing in of secondary air. The method includes (i) activating the compressor while the secondary air valve is kept closed, (ii) determining whether compressor surging is occurring or is directly imminent, (iii) sensing at least one sensor signal if compressor surging is occurring or is directly imminent, and (iv) determining whether there is a leak in the secondary air system, on the basis of the sensed sensor signal.

A method is disclosed for operating an internal combustion engine which comprises a primary air system for providing fresh air and a secondary air system. The secondary air system is configured to branch off secondary air from the primary air system and blow it into an exhaust gas duct. The secondary air system has a compressor for feeding the secondary air and a secondary air valve for shutting off or enabling the blowing in of secondary air. The method includes (i) activating the compressor while the secondary air valve is kept closed, (ii) determining whether compressor surging is occurring or is directly imminent, (iii) sensing at least one sensor signal if compressor surging is occurring or is directly imminent, and (iv) determining whether there is a leak in the secondary air system, on the basis of the sensed sensor signal.

An EHC line leakage diagnosis method can operate a heater of an oxygen detector when satisfying one or more conditions of an engine off time, a coolant temperature, and an outside air temperature by a diagnosis controller upon the key-on of the non-operation of an engine, and then, determine the normality or abnormality of a temperature drop using a change in a temperature value of a signal value and the temperature value detected by the oxygen detector after an air pump is driven, and then confirm the leakage of an exhaust line and a line on the rear end portion of an EHC valve of an air line using the number of times of the occurrence of the abnormality of the temperature drop, and can perform the failure diagnosis without generating the exhaust gas by not operating an engine.

This exhaust purification system includes: a pump disposed in an exhaust-side purge passage to supply air or purge gas purged from a canister to a catalyst; a three-way valve disposed upstream of the pump in the exhaust-side purge passage and configured to switch the exhaust-side purge passage between a communicating state allowing the pump to communicate with the canister and an atmosphere open state allowing the pump to communicate with the atmosphere; a flow control valve disposed downstream of the pump and configured to control a flow rate of air to be supplied to the catalyst; and a controller configured to, when a request to regenerate the catalyst occurs, control a purge valve, the pump, the three-way valve, and the flow control valve to supply, to the catalyst, purge gas purged from the canister and air by a necessary amount to burn particulates trapped in the catalyst.

Arrangement (100) for an exhaust gas aftertreatment system (102), comprising a tank (104) for storing a reducing agent (106); a pump unit arrangement (108) arranged in downstream fluid communication with the tank; a nozzle (110) arranged to inject a flow of reducing agent into the exhaust gas aftertreatment system (102), the nozzle being arranged in downstream fluid communication with the tank, via the pump unit arrangement, by means of a reducing agent conduit (112); an air conduit (114) arranged in fluid communication with the nozzle (110) for delivery of compressed air to the nozzle; and a return conduit (116) arranged in fluid communication between the reducing agent conduit and the tank, the return conduit comprising a return conduit valve arrangement (118), wherein the air conduit (114) is arranged in fluid communication with the reducing agent conduit (112) for controllably delivery of reducing agent to the tank via the return conduit valve arrangement (118) by means of providing compressed air from the air conduit to the reducing agent conduit.

A reductant insertion system for inserting reductant into an aftertreatment system via a reductant injector comprises a reductant insertion assembly comprising a pump operatively coupled to the reductant injector via a reductant delivery line. A compressed gas source is operatively coupled to the reductant injector and provides a compressed gas to the reductant injector for gas assisted delivery of the reductant. A controller is operatively coupled to the compressed gas source and the reductant insertion assembly and configured to determine whether there is a reductant demand for the reductant. In response to there being no reductant demand, the controller stops the pump and activates the compressed gas source for a predetermined time so as to provide compressed gas to the reductant injector at a pressure sufficient to force reductant contained in the reductant injector upstream towards the reductant insertion assembly via the reductant delivery line while the pump is stopped.

A catalyst warming apparatus includes an air blower, a fuel feeder, and an air blowing controller. The air blower is disposed between an engine and a purification catalyst in an exhaust pipe communicating with the engine and is configured to blow air toward the purification catalyst. The fuel feeder is configured to cause the purification catalyst to retain fuel. The air blowing controller is configured to start driving the air blower at a predetermined start timing before a start of the engine.

An exhaust purification system includes a filter, an oxygen supply device, and a controller. The filter is configured to trap particulate matters contained in exhaust gas of an engine. The oxygen supply device is configured to supply oxygen contained in intake air of the engine to the filter. The controller is configured to execute filter regeneration processing to oxidize and remove the particulate matters deposited on the filter. The filter regeneration processing includes regeneration processing during an engine stop that is executed during a shut-down of the engine. In the regeneration processing during the engine stop, a future temperature of the filter is calculated. Then, an operation amount of the oxygen supply device is variably set based on a result of comparing the future temperature with an upper limit temperature of the filter.

A dosing module includes a frame assembly, a first manifold, a first dosing tray, and a first rail assembly. The frame assembly includes a plurality of panels. The first manifold is coupled to one of the plurality of panels. The first manifold is configured to separately receive air and reductant. The first manifold includes a first connector extending from the first manifold. The first dosing tray includes a first base panel, a second manifold, and a second connector. The second manifold is coupled to the first base panel. The second manifold is configured to separately receive air and reductant from the first manifold and to provide the air and the reductant back to the first manifold. The second connector extends from the second manifold. The second connector is configured to be selectively coupled to the first connector. The first rail assembly includes a first member and a second member.