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전기히터방식 매연여과장치의 재생특성에 관한 실험적 연구
함윤영(Yunyoung Ham),김대하(Daeha Kim),김경운(Kyungwoon Kim) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.5_1
Regeneration of Diesel Particulate Filter(DPF) system is performed through combustion of the accumulated soot. Electrical heating is one of attractive methods for active regeneration but it should be optimized for high regeneration efficiency and low electric energy. In this study, regeneration characteristics was studied for various air flow rate, trapped PM mass and target temperature for heater control. This study showed that the operating condition of high PM loading 30g, heater control to reach front target temperature 700℃ and optimized air flow rate 50lpm was effective to get high regeneration efficiency and low electric energy.
Urea-SCR 시스템의 분사노즐 형상에 따른 NOx 저감 및 NH₃ slip 특성에 관한 실험적 연구
함윤영(Yunyoung Ham),이성호(Seongho Lee),김용우(Yongwoo Kim),김경남(Kyungnam Kim),정홍석(Hongseok Jung),신동현(Donghyun Shin) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
To meet the NOx limit without a penalty of fuel consumption, urea SCR system is currently regarded as promising NOx reduction technology for diesel engines. SCR system has to achieve maximal NOx conversion in combination with minimal NH₃ slip. In this study, to develop an optimized urea injection system, the characteristics of NOx reduction and NH₃ slip for various shapes of injection nozzle were investigated using 2L DI diesel engine. Test results show that the shape of nozzle and the presence of air assist give a great impact on NOx reduction. Using 4 hole swirl nozzle with air assist was effective to get a good results for NOx reduction. However, when using 1 hole airless type and 4 hole non-swirl type nozzle, it could be found that there were mal-distribution of urea injection and it caused NOx concentration of SCR downstream fluctuate accompanying low NOx conversion efficiency. From the test results with swirl type nozzle. urea injection need to be controlled under NSR 1 condition to prevent NH₃ slip.
스파크플러그 이온신호의 특성 및 연소압력신호와의 상관관계에 관한 실험적 연구
함윤영(Yunyoung Ham),전광민(Kwangmin Chun) 한국자동차공학회 2002 한국자동차공학회 Symposium Vol.2002 No.11
Recently attention has focused upon the development of inexpensive sensing devices which can closely monitor<br/> the combustion process in order to reduce pollutant emissions and improve fuel economy of the engine. The ion<br/> signal is one of the best ways to extract all of the performance which the engine itself has. In this paper, the ion signal<br/> is obtained by using the spark plug as a sensor while acquiring the cylinder pressure simultaneously. The test results<br/> show that when spark timing is advanced, both of chemical and thermal ion signals are increased and for the low<br/> engine load, the thermal ion signal is too low to distinguish from chemical ion. At the misfire condition, the ion<br/> signal does not occur completely. And it is confirmed that the thermal ion peak location correlates quite well with the<br/> cylinder pressure maximum location under high load condition.