A catalytic aftertreatment system for a diesel engine exhaust gas is described. The system comprises a diesel oxidation catalyst (DOC) and an aftertreatment device located downstream of the diesel oxidation catalyst (DOC), which aftertreatment device requires periodic heat treatment, and means to generate a temperature increase within the aftertreatment device, said diesel oxidation catalyst (DOC) comprising an upstream zone of length from 0.5 to 2 inches (12.7-50.81 mm) of higher oxidation activity for hydrocarbons (HC) than the remainder of the diesel oxidation catalyst (DOC).

The present disclosure relates to an exhaust purification apparatus and a method of controlling the apparatus. The exhaust purification apparatus includes: an injector for injecting urea solution into an exhaust pipe; a driving unit to provide driving force for adjusting an injection angle of the injector; and a control unit to determine the injection angle of the injector based on values of a spatial velocity, flow rate, pressure and temperature of exhaust gas and to drive the driving unit so as to control the injection angle of the injector. In particular, the injection angle of the injector is adjusted by pivotal movement of the injector.

During execution of a first purification process of fluctuating a hydrocarbon concentration in exhaust gas flowing into a first catalyst with an amplitude within a prescribed range at a time interval within a prescribed range, when a switch request to a second purification process of purifying NOx in a second catalyst by adding urea water into the exhaust gas is generated, the switch to the second purification process is prohibited on the condition that a current NOx purification rate (a first purification rate R1) is higher than a purification rate (a second purification rate R2) on the assumption that the second purification process is executed, and an HC poisoning recovery stand-by process of reducing an additive amount of hydrocarbon per once in the first purification process is executed so as to reduce a slip amount of hydrocarbon into the downstream of the first catalyst.

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.

Provided is a diesel engine capable of regenerating a DPF even during no-load and/or light-load operation. In a DPF regeneration process, opening-degree reduction control S2 for an exhaust-air throttle valve is performed after a start condition S1 of the regeneration process of the DPF in which PM is deposited is satisfied. When exhaust air reaches a temperature equal to or higher than a predetermined after-injection permissible temperature TA, after-injection control is subsequently started S5. Post-injection control is started S7 after the exhaust air reaches a temperature equal to or higher than a predetermined post-injection permissible temperature TP by combustion of after-injection fuel. The PM deposited in the DPF is incinerated by the exhaust air increased in temperature by catalytic combustion of post-injection fuel in a valve downstream-side DOC.

Systems and methods for an aftertreatment system configured for use with a dual-fuel engine system are described. The method comprises determining an operating mode of the dual-fuel engine. Upon determining that the dual-fuel engine is operating in a dual-fuel mode or a natural gas mode, the dual-fuel engine operates in a stoichiometric operating condition, and the exhaust is received into a three-way catalyst communicatively connected to a selective catalytic reduction catalyst. Upon determining that the dual-fuel engine is not operating in the dual-fuel mode or the natural gas mode, the engine operates in a lean operating condition.

An exhaust gas control device for an internal combustion engine includes an estimation unit configured to estimate a temperature of a catalyst on the basis of an acquired operation state of the internal combustion engine and a difference between a lean air-fuel ratio and a rich air-fuel ratio which are set as target air-fuel ratios during execution of catalyst regeneration control, a determination unit configured to determine whether the estimated temperature of the catalyst is higher than a threshold value during execution of the catalyst regeneration control, and a prohibition unit configured to prohibit the catalyst regeneration control when it is determined that the estimated temperature of the catalyst is higher than the threshold value during execution of the catalyst regeneration control.

Apparatus and methods are provided whereby a component can be cleaned while the furnace is operational. Additionally, particulates that have accumulated on the component can be collected and retained. The apparatus may include a portable frame, a tubular lance supported by the frame and having a nozzle at a distal end thereof, and a suction generator operatively connected to a proximal end of the lance to generate a suction at the nozzle. Manipulation of the lance to move the nozzle across a component allows accumulated particulates to be removed therefrom through the lance.

A method for controlling a vehicle propulsion system. More particularly, the method estimates a future, upcoming driving condition and controls the vehicle propulsion system to operate the prime mover in a specific operation mode based on a determined regeneration level of a particle filter for the estimated future, upcoming driving condition.

According to various embodiments, an exhaust treatment system includes a catalyst that is in direct contact with an exhaust stream, at least one sensor that senses a system parameter and produces one or more signals corresponding to the system parameter, and a controller that is configured to receive the one or more signals and control catalyst performance based on the one or more signals by regenerating the catalyst. Regenerating the catalyst includes increasing a temperature of the exhaust stream flowing to the catalyst and directing a reductant injector to adjust a flow rate of reductant being injected into the exhaust stream flowing to the catalyst.