摘要:
A device and method for providing a gaseous substance mixture which includes at least one reducing agent and/or at least one reducing agent precursor, includes a reservoir for an aqueous solution which includes at least one reducing agent precursor that can be flow connected to an evaporator chamber, and a device for dosing the aqueous solution in the evaporator chamber. A device can heat the evaporator chamber to a temperature higher than or equal to a critical temperature, in which the aqueous solution is at least partially evaporated. The device and method enable reducing agent to be provided for selective catalytic reduction of nitrogen oxides in the exhaust of an internal combustion engine. Preferably, an evaporator unit is configured as the evaporator chamber and a hydrolysis catalytic converter is disposed outside the exhaust system. As a result, the size of the hydrolysis catalytic converter is reduced, allowing compact construction.
摘要:
A method and a device provide for the controlled feeding of a reducing agent into an exhaust gas treatment unit with a storage capability for an exhaust gas component to be reduced which is generated from a mobile internal combustion engine. The method includes at least the following steps: a) determination of a quantity of the exhaust gas component to be reduced which is generated by the mobile internal combustion engine, b) determination of a storage capability of the exhaust gas treatment unit for the exhaust gas component to be reduced, c) determination of a metering of the reducing agent into the exhaust gas treatment unit as a function of steps a) and b), and d) feeding the reducing agent into the exhaust gas treatment unit.
摘要:
A method for removing particulates from a gas stream includes providing a gas-permeable filter layer having subregions with a parameter of differing magnitudes in the direction of the layer thickness. This parameter relates at least to the porosity, the fiber diameter of fibers or the fiber type content of the filter layer. The gas stream is divided into partial gas streams which are each passed through different subregions of the filter layer. Fiber layers, particulate filters, exhaust systems and vehicles based on this method are also provided.
摘要:
A device and a method for providing a gaseous substance mixture including at least one of a reducing agent and/or a reducing agent precursor, include a reservoir for an aqueous solution including at least one reducing agent precursor, from which the aqueous solution can be delivered into at least one metering line having a dispensing opening by a delivery device, and a device for heating the metering line above a critical temperature greater than the boiling temperature of water. Complete evaporation of an aqueous solution including urea and subsequent hydrolysis to form a substance mixture including ammonia, are carried out. The substance mixture is metered as a reducing agent into an SCR catalytic converter. Carrying out the evaporation outside the exhaust system uses considerably smaller hydrolysis catalytic converters, which is space-saving and cost-saving compared to conventional devices for providing a reducing agent for selective catalytic reduction of nitrogen oxides.
摘要:
A metal foil has a material thickness in a range of from 0.15 mm to 0.02 mm and a structure with elevations and depressions which extend over a length of the metal foil and are disposed adjacent one another. At least some of the elevations or depressions have at least one first indentation and at least one second indentation adjacent the at least one first indentation. The at least one second indentation is at a different distance from the corresponding elevation or depression than the first indentation. An assembly having filter material, a honeycomb body and an exhaust gas treatment device for mobile internal combustion engines, are also provided.
摘要:
A method for regenerating at least one particle agglomerator of an exhaust gas after-treatment system of an internal combustion engine of a motor vehicle, includes operating the internal combustion engine in at least one operating phase in such a way that a sufficient portion of nitrogen dioxides is directly produced in the exhaust gas in order to ensure a conversion of particles containing carbon in the at least one particle agglomerator. A motor vehicle suitable for carrying out the method is also provided.
摘要:
An electrically heatable honeycomb body is formed with at least one wound stack of sheet-metal foils. A first end of the stack is connected to an electrical terminal and a second end is connected to an electrical ground. The stack has a plurality of sheet-metal foils which are in electrical contact with one another and which are at least partially structured and determine, in the direction of the structures, a height of the stack. The stack has at least one curvature with a small radius of curvature and a relatively large radius of curvature. A curvature section including the at least one curvature has at least one zone with increased electrical resistance starting from the small radius of curvature and extending over part of the height of the stack. A motor vehicle having at least one honeycomb body, is also provided.
摘要:
A method and a device for providing ammonia for the selective catalytic reduction of nitrogen oxides in the exhaust system of an internal combustion engine, include the following steps: a) recording at least one actuating variable for influencing the state of the internal combustion engine; b) calculating a possible nitrogen oxide emission of the internal combustion engine on the basis of an evaluation of the at least one measured variable; c) calculating an ammonia quantity which corresponds to the possible nitrogen oxide emission; and d) initiating the provision of the corresponding ammonia quantity by exhaust-gas-external evaporation in an evaporator and exhaust-gas-external hydrolysis of aqueous urea solution, wherein at least one of the following values: i) the heating power of the evaporator or ii) the quantity of aqueous urea solution supplied to the evaporator, is regulated on the basis of the ammonia quantity calculated in step c).
摘要:
A high-temperature-resistant fiber layer for an open particulate trap for purifying exhaust gases from mobile internal combustion engines includes metal fibers. At least a section of the fiber layer has a catalytically active and/or adsorbent coating, in particular such as that of an oxidation catalyst and/or a three-way catalyst and/or an SCR catalyst. A longitudinal section, which is substantially perpendicular to a largest outer surface, has openings formed therein with an average size of 0.01 mm to 0.5 mm, in particular 0.05 mm to 0.25 mm. A particulate trap with the coated fiber layer is also provided.
摘要:
An assembly includes a honeycomb body secured by an inner casing tube in a housing, in particular a housing of an exhaust system of an internal combustion engine. The inner casing tube has an overall length which is bounded axially by two edges and is substantially smaller than the axial length of the honeycomb body. The inner casing tube is also disposed in an approximately axially central position around the honeycomb body and is connected, in particular brazed, thereto in at least one axial connection region. The inner casing tube has a region within the axial connection region in which it is connected to the honeycomb body on the inside or attached directly adjacent the latter on the outside and is connected to the housing. Regions of the inner casing tube which are not connected to the housing but are connected to the honeycomb body toward the inside are constructed as radially elastic spring elements. In this way, a resilient attachment, which adapts to deformations of the honeycomb body, is produced without tearing. That is advantageous in particular in the case of honeycomb bodies made of very thin sheet-metal layers, in particular thinner than 0.03 mm.