摘要 |
1516184 Reducing emissions from IC engines: FUJI HEAVY INDUSTRIES Ltd 18 Aug 1975 [12 Sept 1974] 34289/75 Heading F1B [Also in Division F4] To reduce the emission of NO x from an I.C. engine the ignition is retarded to give a peak combustion temperature in the cylinder 15 of below 2000‹C and to effect afterburning without loss of exhaust gas pulsations, there is provided a heatinsulated portion in the exhaust system of a length "1" maintaining the exhaust gases above 750‹C, the length extending from the exhaust valve seat(s) 5 along pipes 6 and 7 and defining a volume at least equal to the displacement volume of the cylinder or cylinders to which the pipes 6, 7 are connected. The engine may be run on a lean (15:1 to 20:1) air/fuel mixture at light loads; at heavier loads a richer mixture is employed and afterburning air is induced into the exhaust system via a check valve by the exhaust gas pulsations. |