Mercedes-benz Aktiengesellschaft

Daimler Chrysler Ag

Dirk Naber

Franz Bender

Gernot Hertweck

Guido Vent

Detlef Panten

Eckhard Sausen

A method for operating an internal combustion engine used as a fuel which, special fuel characteristics, during combustion by compression ignition may achieve a favorable efficiency, and may provide consumption advantages over conventional combustion methods using conventional fuels. The fuel used may be straight-run naphtha, which is also known as raw gasoline. The fuel characteristics of this fuel are less expensive than conventional fuels, since expensive further treatment of the fuel may be dispensed with during production.

Internal combustion engine with compression ignition

In an internal-combustion engine, in particular a diesel engine, with an exhaust-gas filter and an exhaust gas recirculation, the exhaust counter-pressure prevailing upstream of the exhaust-gas filter is used as one of a number of controlled variables for automatically controlling the exhaust gas recirculation. Since the exhaust-gas filter experiences flow resistance variations, particularly if it is a soot burn-off filter, which variations are independent of engine operation and consequently falsify the automatic control of the exhaust gas recirculation, the respective instantaneous exhaust-gas filter flow resistance must be measured as a correcting quantity and taken into account. A measuring device is fitted into a bypass line bridging the exhaust-gas filter and operates with a negligible bypass flow such that, above a predeterminable upper exhaust-gas filter differential pressure, it can lead past the exhaust-gas filter an increased bypass flow, which can, if appropriate, correspond to the entire exhaust flow.

Diesel engine with an exhaust-gas filter

In an exhaust-gas recycling device for internal-combustion engines, especially diesel engines, in which the exhaust-gas recycling quantity is controlled as a function of the engine running via an exhaust-gas recycling valve mounted in the exhaust-gas recycling line, it is to be possible to regulate the exhaust-gas recycling flow quantity independently of flow resistances changing in the fresh-gas intake and exhaust-gas lines. For this purpose, changes of flow resistance in the fresh-gas intake and exhaust-gas lines are fed as additional pressure control signals to the exhaust-recycling valve. A change of flow resistance in the exhaust-gas line can occur particularly as a result of a soot burn-off filter which is installed there an on which the soot is burnt off at irregular time intervals.

Growing community of inventors

Stuttgart, Germany

Dirk Naber