비정렬 다면체 격자구조를 사용한 Urea-SCR 전산모델의 암모니아 농도균일도지수 산출 방법

It is well known that diesel vehicle should be equipped with emission after-treatment devices as NOx reduction catalyst in order to meet more stringer diesel emission standard. One of the promising technologies for the reduction of NOx emitted from diesel engines is Urea-SCR, and recent studies have begun to mount the Urea-SCR device for diesel passenger cars and light duty vehicles. Therefore, diesel passenger car needs to improve conversion efficiency of ammonia in front of Urea-SCR system for de-NOx performance improvement. In this study, we suggests the NH₃ uniformity index from the assumed 100% yield rate of NH₃. Accordingly, the uniformity index of NH₃ which is defined in new equation is used as the performance criterion of this system. As the value of uniformity index is closed to unit, the urea-solution is uniformity transfer to NH₃ so that the de-NOx efficiency is improved and the slip phenomenon of NH₃ can be dramatically decreased.