The SCR (selective catalytic reduction) system is highly-effective technique for NOx reduction from exhaust gases. In this study, the effects of the direction and size of nozzle and the ammonia injection concentration on the performance of SCR system are analyzed by using the computational fluid dynamics method. When the nozzle is arranged in zigzaged direction which is normal to exhausted gas flow, it is shown that the uniformity of gas flow and the NH3/NO molar ratio is improved remarkably. With the change of the ammonia injection concentration from 0.2 vol%(wet) to 1.0 vol%(wet), the uniformity of gas flow shows a good results. As the size of nozzle diameter changes from 6 mm to 12 mm, the uniformity of gas flow is maintained well. It is shown that the uniformity of the NH3/NO molar ratio becomes better with decreasing the ammonia injection concentration and the size of nozzle diameter.

Abstract
 1. 서 론
 2. 재료 및 방법
  2.1. 해석 개요
  2.2. 수평형 HRSG SCR 모형의 격자
  2.3. 해석을 위한 가정
  2.4. 지배방정식과 해석모델
  2.5. 경계조건
 3. 결과 및 고찰
  3.1. 암모니아 노즐 방향에 따른 영향
  3.2. 암모니아 유입농도 조절에 따른 영향
  3.3. 암모니아 노즐 직경이 암모니아 농도 균일도에 미치는 영향
 4. 결 론
 참 고 문 헌

• 김경숙(동양미래대학교 생명화공과) | Kyeongsook Kim (Department of Biochemical Engineering, Dongyang Mirae University) Corresponding author
• 이경옥(경기과학기술대학교 청정환경과) | Kyeongok Lee (Department of Cleaner Environment, Gyeonggi College of Science and Technology)