摘要:
In a method for reducing the emission of nitrogen dioxide in a motor vehicle having an exhaust gas purification system having an SCR catalytic converter with adsorption centers for nitrogen oxides, an exhaust gas enriched with ammonia is supplied to the SCR catalytic converter above an operating temperature. Below the operating temperature, the exhaust gas supplied to the SCR catalytic converter is enriched with a material such that an adsorption of nitrogen oxides is inhibited at corresponding adsorption centers of the SCR catalytic converter. In order to reduce the overall NOx emissions below a first, predeterminable amount, an exhaust gas enriched with ammonia is supplied to the SCR catalytic converter and the NO2 portion of the total NOx emissions is reduced below a second, predeterminable amount in that NO2 is converted with hydrocarbons stored in the SCR catalytic converter.
摘要:
In a method for reducing the emission of nitrogen dioxide in a motor vehicle having an exhaust gas purification system having an SCR catalytic converter with adsorption centers for nitrogen oxides, an exhaust gas enriched with ammonia is supplied to the SCR catalytic converter above an operating temperature. Below the operating temperature, the exhaust gas supplied to the SCR catalytic converter is enriched with a material such that an adsorption of nitrogen oxides is inhibited at corresponding adsorption centers of the SCR catalytic converter. In order to reduce the overall NOx emissions below a first, predeterminable amount, an exhaust gas enriched with ammonia is supplied to the SCR catalytic converter and the NO2 portion of the total NOx emissions is reduced below a second, predeterminable amount in that NO2 is converted with hydrocarbons stored in the SCR catalytic converter.
摘要:
A multifuel fuel cell system includes a hydrogen production unit; at least one fuel cell; means for heating a first catalytic converter element in the hydrogen production unit to an operating temperature which can be preset; means for metering liquid fuel, air, and optionally water to the catalytic converter element to produce a synthetic gas mixture containing hydrogen or a reformate; and means for passing the synthetic gas or reformate to further components of the hydrogen production unit which are connected between the catalytic converter element and the at least one fuel cell. The fuel cell system also contains means for switching the fuel cell system between a first and a second operating mode. Separation occurs between the hydrogen production unit and the at least one fuel cell during the first operating mode, and a communicating connection occurs between the hydrogen production unit and the at least one fuel cell during the second operating mode, so that reformate can be transferred from the hydrogen production unit to the at least one fuel cell only during the second operating mode.
摘要:
A process for manufacturing a catalyst body for generating hydrogen having at least one thin, large-surface catalyst layer, through which the reaction mixture can be passed includes steps of pressing a copper powder (particularly dendritic copper) to form a thin and highly compressed layer which forms a formed body, sintering, the formed body in a reducing atmosphere so that a net-type carrier structure made of copper is formed, and activating a surface layer of the formed body.
摘要:
A method for operating a motor vehicle diesel engine having an exhaust emission control system is provided. The emission control system includes an oxidation catalytic converter, a particle filter, and an SCR catalytic converter, in which the exhaust gas that is discharged from the diesel engine is passed through the oxidation catalytic converter before passing through the particle filter and the SCR catalytic converter. A regeneration of the particle filter with thermal soot burn-off is occasionally carried out, during which the diesel engine is operated at an air-fuel ratio having a lambda value (λ) of at least approximately 1.0, and air is added to the exhaust gas after it exits the oxidation catalytic converter and before it enters the particle filter air, so that soot deposited on the particle filter is burnt-off.
摘要:
In a device and a method for removing nitrogen oxides from the exhaust of an internal combustion engine which is operated predominantly with an excess of air, the internal combustion engine is assigned an exhaust system having a nitrogen oxide reduction catalytic converter which comprises two catalytic converter parts, whose reducing agent filling levels can be determined. Metering of a reducing-agent-containing additive into the exhaust gas of the internal combustion engine takes place as a function of the reducing agent filling level of the first catalytic converter part and/or of the second catalytic converter part.
摘要:
In a device and a method for removing nitrogen oxides from the exhaust of an internal combustion engine which is operated predominantly with an excess of air, the internal combustion engine is assigned an exhaust system having a nitrogen oxide reduction catalytic converter which comprises two catalytic converter parts, whose reducing agent filling levels can be determined. Metering of a reducing-agent-containing additive into the exhaust gas of the internal combustion engine takes place as a function of the reducing agent filling level of the first catalytic converter part and/or of the second catalytic converter part.
摘要:
in a method for operating a supercharged internal combustion engine and an internal combustion engine including an exhaust gas treatment system which comprises a catalytic converter arranged close to the engine, an exhaust gas turbocharger which is arranged downstream of the catalytic converter, and a post-injection device for introducing additional fuel into the exhaust gas flow upstream of the catalytic converter, wherein the heat energy of the exhaust gas mass flow which acts on the exhaust gas turbocharger is varied by controlling the fuel quantity which is additionally introduced into the exhaust gas flow by means of the post-injection device resulting in an improvement in the response behavior of the internal combustion engine, excess energy which is generated by the exhaust gas turbocharger by means of a motor generator connected to the exhaust gas turbocharger is stored in a storage device and is returned to the motor generator for rapidly accelerating the turbocharger when an increased power output is demanded from the engine.
摘要:
A method for operating a motor vehicle diesel engine having an exhaust emission control system is provided. The emission control system includes an oxidation catalytic converter, a particle filter, and an SCR catalytic converter, in which the exhaust gas that is discharged from the diesel engine is passed through the oxidation catalytic converter before passing through the particle filter and the SCR catalytic converter. A regeneration of the particle filter with thermal soot burn-off is occasionally carried out, during which the diesel engine is operated at an air-fuel ratio having a lambda value (λ) of at least approximately 1.0, and air is added to the exhaust gas after it exits the oxidation catalytic converter and before it enters the particle filter air, so that soot deposited on the particle filter is burnt-off.
摘要:
A device for monitoring an exhaust gas catalytic converter in the exhaust system of an internal combustion engine, includes a measuring apparatus that is arranged in the exhaust system in such a way that, in the greatest part of the operating range of the internal combustion engine, it assumes a temperature that is correlated with a temperature of the exhaust gas catalytic converter. The measuring apparatus has a temperature-sensitive component with a temperature-dependent characteristic component parameter that changes either abruptly at a predetermined transition temperature or temperature range, or continuously in a predetermined way as a function of the temperature. A control and evaluation unit connected to the measuring arrangement detects the characteristic component parameter and/or a change in the latter, and correlates it with an aging state of the exhaust gas catalytic converter.