Abstract
Most of the recent clean diesel engines are generally equipped with an exhaust recirculation (EGR) technology in order to meet the strict criteria of NOx emission regulations. In the field of emission control, accurate and fast transient EGR ratio operation is becoming very critical. In this study, a transient EGR analyzer has been developed and evaluated with a conventional exhaust gas analyzer system to confirm the advantage of the transient EGR analyzer. As a consequence, the faster response has been observed from the transient EGR analyzer without significant transient error under transient test cycles. The EGR ratio measured by the transient EGR analyzer followed up the EGR valve operation well. These results show the advantages of the transient EGR analyzer for measuring EGR ratio under the transient cycle. Additionally, a simulation of the optimum response time was conducted. The gas transition time of the engine EGR system was simulated by z-transformation using the response time of measured actual exhaust gas. As a result, the optimum response time required to the EGR measurement system was estimated for the test engine.
