An aftertreatment system includes an exhaust reductant tank configured to store an exhaust reductant. A filter is fluidically coupled to the exhaust reductant tank. The aftertreatment system includes a hydrocarbon detection device configured to indicate the presence of a hydrocarbon in the exhaust reductant. A catalyst is included in the system and configured to treat the exhaust reductant flowing through the system. The hydrocarbon detection device can include a hydrophobic paper, and can be disposed in the filter.

The present invention pertains an onboard device for checking the quality of DEF in a work machine, comprising a flow channel configured to fluidly connect a DEF inlet with a DEF tank. The flow channel comprises a DQS configured to be brought into contact with DEF passing through the flow channel. The present invention also pertains to a method of checking the quality of DEF comprising the steps of tilling DEF into a flow channel configured to fluidly connect a DEF inlet with a DEF tank; and checking, by means of a DQS, the quality of the DEF in the flow channel,

An abnormality determination apparatus for an ammonia sensor is usable in an exhaust purification system including a catalyst, a supply apparatus, an ammonia sensor, an NO.sub.X sensor, and an oxygen sensor. During a continuation period within which ammonia supply to the catalyst continues after the supply apparatus stops supply of reductant, the abnormality determination apparatus calculates the ammonia concentration on a downstream side of the catalyst as a first concentration value, based on an output of the ammonia sensor and an output of the oxygen sensor. During the continuation period, the abnormality determination apparatus calculates the ammonia concentration on the downstream side of the catalyst as a second concentration value, based on an output of the NO.sub.X sensor and the output of the oxygen sensor. The abnormality determination apparatus determines presence or absence of abnormality in the ammonia sensor based on the first concentration value and the second concentration value.

The present disclosure describes methods for evaluating quality of DEF dosed to an EAS including a close coupled SCR unit a downstream SCR unit. A NOx conversion efficiency of the close coupled SCR unit and a NOx conversion efficiency of the downstream SCR unit are used to evaluate quality of DEF. In some embodiments, the NOx conversion efficiency of close coupled SCR unit is used to evaluate quality of DEF. Operation of an EAS using the results of the evaluation of quality of DEF are described.

A method (200) for operating an exhaust gas burner (120) in an exhaust section (102) of an internal combustion engine (110), comprising introducing a purging fluid comprising at least air (20) into the exhaust gas burner (120) during a purging operating phase (205), which lies outside the time of a normal operating phase (201) of the exhaust gas burner (120), and discharging a discharge mixture formed using the purging fluid from the exhaust gas burner (120), wherein the exhaust gas burner (120) is operated for the purpose of heating a component (130, 150) of the exhaust section (102) to its operating temperature during the normal operating phase (201). A processor unit (140) and a computer program for carrying out such a method (200) are furthermore proposed.

A method for an exhaust system is provided, comprising adjusting reductant injection responsive to a reductant concentration, the reductant concentration based on concentration sensor readings and vehicle motion. If the reductant freezes, the reductant may stratify, leading to inaccurate concentration sensor readings. Vehicle motion may mix the reductant, thereby ensuring an accurate concentration measurement which may then be used to adjust reductant injection.

An aftertreatment system includes an exhaust reductant tank configured to store an exhaust reductant. A filter is fluidically coupled to the exhaust reductant tank. The aftertreatment system includes a hydrocarbon detection device configured to indicate the presence of a hydrocarbon in the exhaust reductant. A catalyst is included in the system and configured to treat the exhaust reductant flowing through the system. The hydrocarbon detection device can include a hydrophobic paper, and can be disposed in the filter.

Systems and apparatuses include a diesel exhaust fluid tank, a first temperature sensor positioned within the diesel exhaust fluid tank and structured to provide first temperature information indicative of a first temperature, and a second temperature sensor positioned within the diesel exhaust fluid tank and structured to provide second temperature information indicative of a second temperature. The systems and apparatuses further include one or more processing circuits including one or more memory devices coupled to one or more processors, the one or more memory devices configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to provide energy to a heating system based on the first temperature information and the second temperature information.

The present disclosure describes methods for evaluating quality of DEF dosed to an EAS including a close coupled SCR unit a downstream SCR unit. A NOx conversion efficiency of the close coupled SCR unit and a NOx conversion efficiency of the downstream SCR unit are used to evaluate quality of DEF. In some embodiments, the NOx conversion efficiency of close coupled SCR unit is used to evaluate quality of DEF. Operation of an EAS using the results of the evaluation of quality of DEF are described.

A reduction-causing agent supply device includes a tank to store a reduction-causing agent, a pumping unit to pump the reduction-causing agent, a reduction-causing agent supply passage to supply the reduction-causing agent, an injection nozzle to inject the reduction-causing agent into an exhaust pipe, a drawing-back unit to draw the reduction-causing agent toward the tank, and a controller. After stop of an engine, the controller performs: reduction-causing agent drawing-back process of drawing the reduction-causing agent toward the tank and introducing exhaust gas from the injection nozzle into the reduction-causing agent supply passage; and gas discharge process of supplying the reduction-causing agent to compress the exhaust gas inside the reduction-causing agent supply passage, discharging the compressed exhaust gas from the injection nozzle, and closing a valve of the injection nozzle before the reduction-causing agent reaches the injection nozzle.