Methods and systems are provided for operating an exhaust oxygen sensor coupled to an exhaust passage of an internal combustion engine in response to detecting water at the sensor. In one example, a method may include indicating water at an exhaust oxygen sensor positioned in an engine exhaust passage based on a sensor parameter of the exhaust oxygen sensor while operating the exhaust oxygen sensor in a variable voltage (VVs) mode where a reference voltage is adjusted from a lower, first voltage to a higher, second voltage; and adjusting one or more of sensor operation and engine operation based on the indicating water.

A device and method for correcting emissions can include a first sensor that measures a sample of air not containing an exhaust gas, and a second sensor, wherein the exhaust gas enters a settling chamber and a relative humidity of the exhaust gas is measured by the second sensor. A microcomputer can calculate a mass of water vapor in the sample of air measured by the first sensor and in the exhaust gas measured by the second sensor and can determine a dilution factor of the measured exhaust gas. The dilution factor can be used for correcting emissions based on the measurements of the exhaust gas made by the first sensor and the second sensor. The first and second sensors can comprise one or more of, for example, a relative humidity sensor, a dew point sensor, a trace water vapor sensor and/or other types of sensors.

A sensor device includes a moisture module that includes a sensor element for detecting moisture of a fluid medium flowing in a flow direction and a protective membrane screening the sensor element. The sensor device includes a housing, in a measuring chamber of which the moisture module is at least partially situated, and that includes a protective tube extending into the flowing fluid medium in an axial direction perpendicular to the flow direction, the protective tube is designed for flow of the fluid medium into at least one inlet opening, through an inflow path, into the measuring chamber counter to the axial direction, and out of the measuring chamber via an outflow path in the axial direction and an outlet opening, where, with respect to a direction of gravity, the openings are at a bottom of the protective tube.

There is provided a sensor unit 30 arranged in an exhaust system of an internal combustion engine and including a filter member 31 having a plurality of cells divided by porous partition walls and collecting particulate matter in exhaust gas, and at least one pair of electrode members 32, 33 arranged to face each other with the cell interposed therebetween so as to form a capacitor, and a control unit 40 estimating an amount of the particulate matter in the exhaust gas and detecting water present in the exhaust system of the engine, based on an electrostatic capacitance between the pair of electrode members 32, 33.

The invention relates to a method and to a device, in particular a control and evaluation unit, for recognizing a water passage or a high water level for a vehicle, which has, as a drive, an internal combustion engine having an exhaust train, in which the functionality of an emission control system is monitored or controlled by at least one exhaust sensor and the exhaust sensor is operated at least intermittently at high temperatures and has thermal shock susceptibility by design. According to the invention, a water recognition criterion is determined based on one or a plurality of distance sensors and, at critical values of the water level which are predicted or have already been reached, protective measures are initiated for the emissions control system of the vehicle or for the exhaust sensor or exhaust sensors arranged in the exhaust duct. Damage to exhaust sensors or to components of the emissions control system as a result of the severe cooling upon contact with water can thus be minimized. In addition, misinformation of the exhaust sensors due to a thermal shock and a possible accompanying malfunction can also be recognized by said anticipatory protective measures and correspondingly suppressed.

In order to provide an exhaust gas measuring system capable of more accurately correcting errors in measurement results caused by response delays of exhaust gas measuring devices, and the like, the exhaust gas measuring system is adapted to include: a sampling pipe adapted to, from a lead-out port, lead out exhaust gas introduced from an introduction port; one or more types of exhaust gas measuring devices that are connected to the lead-out port and measure predetermined physical quantities related to the exhaust gas flowing through the sampling pipe; a correction device adapted to correct measurement results by the exhaust gas measuring devices; and a pressure sensor adapted to measure the pressure inside the sampling pipe, in which the correction device corrects errors in the measurement results, which are caused by response delays, with the measured pressure by the pressure sensor as a parameter.

The invention is directed to a method for determining the state of aging of a catalytic converter (2). The disclosed method functions in a non-contacting manner as resonances formed when the catalytic converter (2) located in a housing is excited with high-frequency electromagnetic waves are analyzed.

A gasoline engine having an exhaust system comprises means for trapping particulate matter (PM) from the exhaust gas and a catalyst for catalysing the oxidation of the PM by carbon dioxide and/or water in the exhaust gas, which catalyst comprising a supported alkali metal. The invention further includes a method of combusting PM from a gasoline engine in CO.sub.2 and/or H.sub.2O from the exhaust gas at temperatures in excess of 500 C., which method comprising trapping the PM and contacting it with a catalyst comprising a supported alkali metal.

A method for controlling an emission amount in an exhaust gas stream emitted from a power generation system is presented. The method includes determining a pre-catalyst emission level using a combustion engine model. The method further includes determining a post-catalyst emission level using a three-way catalyst model based on the pre-catalyst emission level. Furthermore, the method includes determining an adjusted post-catalyst emission level based on the post-catalyst emission level. Moreover, the method includes determining a difference between the post-catalyst emission level and the adjusted post-catalyst emission level and comparing the difference with a threshold value. Additionally, the method includes determining whether to adjust an actual value of an engine operating parameter based on the comparison such that the emission amount in the exhaust gas stream is maintained below an emission regulatory limit. An engine controller and a power generation system employing the method are also presented.

A method for reducing emissions from a hydrogen combustion engine includes: a first step in which a controller obtains an H.sub.2O concentration at a front end of an SCR catalyst, an SCR temperature, and a NO.sub.2/NOx ratio derived from a DOC; a second step in which the controller calculates a predicted NOx purification rate based on the H.sub.2O concentration, the SCR temperature, and the NO.sub.2/NOx ratio; and a third step in which the controller calculates a urea dosing amount that aligns with the predicted NOx purification rate and performs control to dose the calculated dosing amount of urea.