Development of Fast-Response CO₂Analyzer and Analysis of Engine-out Emission during Cold Start of SI Engine

Abstract

A fast-response CO 2 analyzer has been developed for measuring the CO 2 concentration during transient condition of a SI engine. The analyzer consists of the non-dispersive infrared absorption method, electrical chopping system and water cooling system. The analyzer has good repeatability, linearity and permissible drift characteristic. Besides, it showed 18ms of a response to measure the CO 2 concentration. The fastresponse CO 2 analyzer was applied to a 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 confirming the accuracy of the exhaust gas analysis using the fast-response CO 2 analyzer. 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 from the CO 2 concentration of engine-out emissions and engine operating variables.