초록
A fast response $CO_2$ analyzer has been developed for measuring the $CO_2$ concentration during transient condition of SI engine. The analyzer is based on the non-dispersive infrared absorption technique, electrical chopping system and water cooling system. The analyzer has good repeatability, linearity and permissible drift characteristic. Besides, it has 18ms with a response to measure the $CO_2$ concentration. The fast response $CO_2$ analyzer was applied to single cylinder SI engine and the $CO_2$ emission was examined during engine start. Simultaneously, the standard exhaust gas analyzer, which has slow response time, was used for considering the engine-out $CO_2$ characteristic. The developed analyzer showed much faster responsive characteristic than that of a standard analyzer and made cycle by cycle exhaust gas analysis possible. The transient engine operating characteristics will be estimated and the transient behaviors on engine-out emission and performance will be improved.
