Designing a fast-igniting catalytic converter system

Through analysis and numerical simulation, the late lightoff (similar to3 m in) of the current automobile catalytic converter is attributed to a downst ream ignition phenomenon that is unstable to flow-rare fluctuations. A desi gn is proposed which incorporates a stable and thermally efficient leading- edge ignition. The key feature involves diverting a small portion of exhaus t gas through a bypass stream which contains an electric preheater and a pr eigniter, during startup. This allows the preheater to utilize a low power input using the existing battery and yet raise the gas temperature beyond a precise minimum that rapidly lights off the entire preigniter. The hot pre igniter is then used to light off the main catalytic converter Removal of t he bypass after complete ignition presumes the preigniter catalyst, a major advantage. The optimal design is shown to lightoff within 10 s and reduce pollution by almost 90% over current designs and thus meet ultra low emissi on vehicle (ULEV) standards.