Effect of input energy on the emission of a motorcycle engine with an electrically heated catalyst in cold-start conditions

Experimental investigation on the cold-start condition of an electrically heated catalyst of a four-stroke motorcycle engine was carried out at idle operation. The effects of input energy from heaters and unburnt gas oxidation on the exhaust temperature and the exhaust emission were investigated. Apart from heating temperature and the CO setting level, the other studied parameters included the heating position and input energy. The heating temperatures included 100, 140 and 180degreesC and the CO levels were set as 1.0%, 1.3%, 1.8% and 2.3%. Six different heating positions were adopted. The experimental results showed that at high CO setting levels, less heating energy was required from the heaters to induce self-initiated reaction of the catalyst. It was also observed that a high total input energy led to a high CO conversion efficiency. Heating at the inlet of the catalyst has also the same effect. When a high heating temperature was coupled with a high CO setting level, self-initiated reaction of the catalyst was easily achieved. (C) 2004 Elsevier Ltd. All rights reserved.