http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
DOC 및 요소-SCR 후처리 시스템 부착 LPG 증기보일러의 NO<SUB>x</SUB> 배출물 저감 특성
배명환(Myung-whan Bae),송병호(Byung-Ho Song),강우철(Woo-Cheol Kang),배재옥(Jae-ok Bae) 한국자동차공학회 2012 한국자동차공학회 지부 학술대회 논문집 Vol.2012 No.5-1
The aim of this study is to develop the DOC and urea-SCR aftertreatment system for reducing NOx emissions in LPG steam boilers. The NOx conversion rates are significantly obtained by 100, 96, 90 and 89% at the boiler loads of 40, 60, 80 and 100% because the NO emission is much converted into NO2 by the DOC aftertreatment system. The NOx conversion rate can be raised with increasing the urea injection rate, but the NH3 slip is boosted at the same time. Consequently, to determine the optimal rate of urea injection or the high NOx conversion rate for the respective boiler load, the NOx emissions, NH3 slip and reaction temperature should be simultaneously considered. In this study, the urea is injected by 14,19,20 and 18 mg/min at the boiler loads of 40, 60, 80 and 100%, and the final NH3 slips are measured by 20.05, 18.35, 9.29 and 13.92 ppm at the same conditions.
Merisha Hastarina,Myug-whan Bae(배명환),Jae-ok Bae(배재옥) 한국자동차공학회 2012 한국자동차공학회 지부 학술대회 논문집 Vol.2012 No.11
Due to the increasing stringency of emissions regulation, the development of highly efficient reduction apparatuses including exhaust gas aftertreatment system has been urgently required. At present, the selective catalytic reduction(SCR) is considered as one of the most promising techniques to decrease NOx emissions from the combustion system. The aqueous urea solution in SCR system is used as a reducing agent, since it is easy to handle and successfully applied as post-combustion control to reduce NOx emissions. The catalytic systems of various types have been used to the chemical reaction inside an SCR reactor, including the meta oxide mixtures based on vanadia supported by titania. The efficiency of the vanadium-based catalyst for the SCR of NO with NH3 and its resistance to SO2 poisoning have received much aftention in recent years. The SCR over vanadia-type catalyst has represented the most effective commercial deNOx technique for the last two decades. In this study, the numerical simulation of NOx conversion in a urea-SCR reactor with vanadium-based catalystis conducted. The aim of this study is to investigate the characteristics of exhaust gas temperature and NOx emissions at the backside of SCR reactor, and to understand the complex interactions between the various physical and chemical processes occurred in the system. The results of this modeling are also compared with the ones from the previous study, the experiment and modeling of urea-SCR reactor with zeolite catalyst. From simulation, it is found that the NOx conversion efficiency in vanadium-based catalystis slightly than the one from seolite catayst.
Elvira Fidelia Tanjung,Myung-whan Bae(배명환),Jae-ok Bae(배재옥) 한국자동차공학회 2012 한국자동차공학회 지부 학술대회 논문집 Vol.2012 No.11
The selective catalytic reduction(SCR) is an effective technique to reduce nitrogen oxides (NOx) emitted from engines. A three dimensional numerical modeling of urea spray characteristics and their interaction with the exhaust gas flow is developed to evaluate different configurations during development process of a urea-SCR reactor with zeolite-based catalyst. In this study, the change of urea spray angle and the numbers of urea injector hole have been examined by the numerical simulation. The results show that the urea injector with 90° spray angle has the most amount of ammonia conversion effeciency at the entrance of SCR reactor and also the atomization and evaporation of urea droplets are the best. This is because the droplets spread more uniformly and widely than those of other various spray angles. It is also found that the urea injector with four-hole shows better uniformity than that with two-hole of axial direction injection because the exhaust gases are well mixed with the aqueous urea solution. On the other hand, the atomization efficiency of the urea injector with two-hole is decreased compare to the four-hole injector because the sprayed urea droplets are concentrated on the center region of the exhaust gas inlet and also don"t spread evenly.