Avl List Gmbh

Avl Gesellschaft Fur Verbrennungskraftmaschinen Und Messtechnik M.b.h.

Kurt Engeljehringer

Wolfgang Schindler

Hans Erlach

Johann Simperl

Harald Koch

In a method of measuring exhaust gas of internal combustion engines, preferably in test benches, through the use of CVS (constant value sampling) full-flow systems, the exhaust gas of the internal combustion engine is mixed with combustion gas, preferably air, and the volume flow or mass flow of the combustion air is determined by the CVS full-flow system. This mass flow exceeds thereby the maximum quantity of combustion air needed by the internal combustion engine. An essentially constant and fully conditioned quantity of humidity-conditioned and/or temperature-conditioned combustion gas is fed into the internal combustion engine at any time, whereby this quantity is at least equal to the maximum quantity needed by the internal combustion engine, and whereby combustion gas not needed is fed into the CVS full-flow system, and a pre-determinable set pressure value is adjusted for the combustion gas upstream from the CVS full-flow system and also upstream from the point of conditioning of the combustion gas to be able to use the CVS full-flow systems increasing control dynamics without considerable effects on the entire control system and to avoid thereby dilution of the engine exhaust gases upstream from the CVS full-flow system. An essentially constant and fully conditioned quantity of humidity-conditioned and/or temperature-conditioned combustion gas can possibly be fed at any time into the CVS full-flow system, whereby fully conditioned combustion gas is drawn from the CVS full-flow system upstream from the mixing area to be used by the internal combustion engine.

Method of measuring exhaust gas on internal combustion engines

For the indirect identification of the mass flow of a specimen fluid stre the specimen fluid stream is mixed with a dilution fluid stream to form an total fluid stream that is to be investigated in view of specific constituents of the specimen fluid stream. The mass flow of a specimen fluid stream is identified from the difference between the measured mass flows of the dilution fluid stream and the total fluid stream. In order to reduce the possibilities of error in the setting of a defined dilution ration, the mass flows of the dilution fluid stream and the total fluid stream are calibrated relative to one another, to which end one of the calibration measurements is not undertaken at the respective fluid stream but is separately undertaken at the specimen fluid stream.

Growing community of inventors

Graz, Austria

Kurt Engeljehringer