EE2-3 Transient EGR Ratio Measurement by Heated NDIR Method and Analysis of Engine EGR Response Time(EE: Exhaust Emissions and Measurement,General Session Papers)

Abstract

Most ofthe 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 studM a transient EGR analyzer has been developed and evaluated with a conventional exhaust gas analyzer system to confirm the advantage ofthe transient EGR analyzer. As a consequence, the faster response has been observed from the transient E6R analyzer without significant transient error under transient test cycles.The EGR ratio measured by the transient EGR analyzer fo11owed up the EGR valve operation well. These results show the adyantages ofthe transient EGR analyzer for measuring EGR ratio under the transient cycle.Additionally, a simulation ofthe 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 fbr the test engine.