| 摘要 |
PCT No. PCT/GB94/00311 Sec. 371 Date Oct. 13, 1995 Sec. 102(e) Date Oct. 13, 1995 PCT Filed Feb. 16, 1994 PCT Pub. No. WO94/24423 PCT Pub. Date Oct. 27, 1994A method is described for operating an engine having an afterburner and a catalytic converter downstream of the afterburner. Sufficient excess fuel is introduced into the engine to produce in the exhaust gases fuel constituents including unburnt hydrocarbons, carbon monoxide and hydrogen. Unburnt hydrocarbons are intercepted upstream of the afterburner so as to allow substantially only carbon monoxide and hydrogen to reach the afterburner. Sufficient additional air is introduced into the exhaust system to bring the composition of only the carbon monoxide, hydrogen and air to stoichiometry or leaner than stoichiometry, the resulting concentration of hydrogen and oxygen in the mixture reaching the afterburner being sufficient for ignition immediately after a cold start. By removing the hydrocarbons temporarily before the exhaust gases reach the afterburner, reliable cold ignition can be achieved with lower levels of fuel enrichment. |
