Time-Resolved, Speciated Emissions from an SI Engine During Starting and Warm-Up 961955
A sampling system was developed to measure the evolution of the speciated hydrocarbon emissions from a single-cylinder SI engine in a simulated starting and warm-up procedure. A sequence of exhaust samples was drawn and stored for gas chromatograph analysis. The individual sampling aperture was set at 0.13 s which corresponds to ∼ 1 cycle at 900 rpm. The positions of the apertures (in time) were controlled by a computer and were spaced appropriately to capture the warm-up process. The time resolution was of the order of 1 to 2 cycles (at 900 rpm). Results for four different fuels are reported: n-pentane/iso-octane mixture at volume ratio of 20/80 to study the effect of a light fuel component in the mixture; n-decane/iso-octane mixture at 10/90 to study the effect of a heavy fuel component in the mixture; m-xylene and iso-octane at 25/75 to study the effect of an aromatics in the mixture; and a calibration gasoline. The fuel species in the HC emissions followed the volatility of the fuel components: in the early cycles, the light fuel components were the major emitted HC species. At steady state, the exhaust fuel species HC composition was different from the fuel composition. When the major decomposition products were accounted for, however, the exhaust HC emissions matched the fuel composition well.
Kuo Chiang Chen, Wai K. Cheng, Jane M. Van Doren, James P. Murphy, Matthew D. Hargus, Sarah A. McSweeney
Massachusetts Institute of Technology, College of the Holy Cross
1996 SAE International Fall Fuels and Lubricants Meeting and Exhibition
Outcome of the European Programme on Emissions, Fuels and Engine Technologies (Epefe)-SP-1204, Emissions Formation and In-Cylinder Control of Emissions in SI Engines-SP-1268, SAE 1996 Transactions - Journal of Fuels and Lubricants-V105-4