Method of and apparatus for reducing harmful emissions from internal combustion engines

摘要

Combustion air for an internal combustion engine is compressed in a dynamic pressure-wave machine by utilization of heat remaining in the engine exhaust gases. A reduction in harmful emissions from the engine is effected within the rotor of the pressure-wave machine due to a primary recirculation of the exhaust gas into the air at the interface between the exhaust gas and the air, the amount of the recirculation being at its lowest value at full load on the engine and being increased sharply with decreasing load. The change in the amount of exhaust gas being recirculated is made more uniform over the whole load range by means of a secondary recirculation, increasing at full load, and which is brought about by introducing exhaust gas directly into the machine in at least one place at which the cells of the rotor are filled with air by means of a crossover pipe.