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 internal combustion engine, an exhaust purification catalyst (13), hydrocarbon feed valve (15) and particulate filter (14) are arranged in an exhaust passage. If temperature increasing control should be performed when a first NO.sub.X purification method is performed, injection of hydrocarbons for the first NO.sub.X purification method is performed with a predetermined period and injection of hydrocarbons for temperature increasing control is performed in a time period when injection of hydrocarbons for the first NO.sub.X purification method is not performed, the first NO.sub.X purification method being configured to purify NO.sub.X which is contained in the exhaust gas by injecting hydrocarbons from the hydrocarbon feed valve with the predetermined period, the temperature increasing control being configured to increase a temperature of the particulate filter to remove particulate matters trapped on the particulate filter. An amount of injection of hydrocarbons for temperature increasing control when an actual temperature of the particulate filter is low is set larger than that when the actual temperature of the particulate filter is high.

An exhaust purification system includes: a diesel oxidation catalyst (DOC) provided on an exhaust passage of an engine; a diesel particulate filter (DPF) provided on the exhaust passage at a position downstream of the DOC to collect particulate matter contained in exhaust gas; electrodes that detect a capacitance of the DOC; a particulate matter accumulation estimating unit that estimates an amount of particulate matter accumulated in the DPF on the basis of the detected capacitance; and a forced regeneration control unit that injects fuel into the DOC and performs forced regeneration that burns and removes at least the particulate matter accumulated in the DPF when the estimated accumulated particulate matter amount surpasses a predetermined amount.

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.

A control apparatus for an internal combustion engine includes an electronic control unit. The electronic control unit is configured to: execute increasing a temperature of an exhaust gas control apparatus at a second temperature increase speed as a regeneration control when the temperature of the exhaust gas control apparatus is in a second temperature range; control the temperature of an exhaust gas control apparatus during an idle operation so as to be equal to or smaller than the temperature of the exhaust gas control apparatus when the internal combustion engine enters an idle operation state as a temperature increase suppression control when the temperature of the exhaust gas control apparatus during a regeneration control is in the second temperature range and the internal combustion engine is in the idle operation state.

A particulate filter for trapping the particulate matter which is contained in the exhaust gas is provided inside an engine exhaust passage. Additional fuel is secondarily injected from a fuel injector in an engine expansion stroke or exhaust stroke or hydrocarbons are secondarily added from an addition valve which is provided upstream of the particulate filter in the exhaust pipe. An amount of hydrocarbons which come from the fuel injector or addition valve and then adhere in the form of a liquid to the inflow end of the particulate filter, and an amount of particulate matter which reaches the inflow end of the particulate filter are respectively estimated. A degree of clogging at the inflow end of the particulate filter is estimated based on the amount of hydrocarbons and the amount of particulate matter.

A method of adaptively sampling data to determine the start of injection in a solenoid actuated valve of a fluid injector includes, in an operating cycle or portion thereof of the valve, sampling the signal of current through a solenoid of the valve at sampling points having a pre-defined interval therebetween. At each sampling point, determining the value of the first derivative of current and detecting the sampling point at which the first derivative achieves a maximum as the start of injection. Values of the first derivative of the sampling points immediately preceding and immediately following the start of injection are determined. In a subsequent operating cycle, synchronisation of sampling is altered to shift sampling times depending on the values of the first derivative of the sampling points immediately preceding and immediately following the start of injection.

A burner includes a first tube portion formed with an ejection port; a second tube portion that extends in the first tube portion toward the ejection port and to which gaseous mixture flows in from a side opposite to the ejection port; a third tube portion arranged in the first tube portion and including an open end positioned on the ejection port side; a closing portion that closes the open end; a coupling wall portion that closes a gap between the first tube portion and the second tube portion; a partition wall that is coupled to the first tube portion and the third tube portion, the partition wall being formed with a communication path; and an igniting portion that is arranged on the ejection port side with respect to the partition wall.

A turbocharger-equipped internal combustion engine includes an exhaust turbine, an exhaust filter, a differential pressure detector, an atmospheric pressure sensor, and an electronic control unit. The electronic control unit is configured to control the internal combustion engine such that accumulation amount of a particulate matter in the exhaust filter is regulated. The electronic control unit is configured to control the internal combustion engine such that the accumulation amount of the particulate matter in the exhaust filter is increased, when the pressure difference detected by the differential pressure detector is a lower limit or less. The electronic control unit is configured to set the lower limit such that the lower limit becomes a higher value as the atmospheric pressure detected by the atmospheric pressure sensor becomes lower.

A system and method for diagnosing the oxidation catalyst of a vehicle includes an engine, an exhaust system in fluid communication with an exhaust port of the engine and an oxidation catalyst connected with the engine via the exhaust port to receive an exhaust stream from the engine. A controller is operable to determine the operating state of the engine and vehicle, calculate a heat release value for the oxidation catalyst and determine an ideal heat release value. The controller will determine the oxidation catalyst efficiency by calculating a ratio of the heat release value to the ideal heat release value.