Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
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Characteristics of UBC and NOx Emission in Air Staging Combustion

공기 다단 연소 기법 적용에 따른 미연탄소분 및 질소산화물 배출특성

  • Kim, Jeong Woo (Dept. of Mechanical Engineering, Pusan Nat'l Univ.) ;
  • Lim, Ho (Dept. of Mechanical Engineering, Pusan Nat'l Univ.) ;
  • Go, Young Gun (System Engineering Team, Corporate R&D Institute, Doosan Heavy Industries and Construction) ;
  • Jeon, Chung Hwan (Dept. of Mechanical Engineering, Pusan Nat'l Univ.)
  • 김정우 (부산대학교 기계공학부) ;
  • 임호 (부산대학교 기계공학부) ;
  • 고영건 (두산중공업(주) 기술연구원 시스템 엔지니어링팀) ;
  • 전충환 (부산대학교 기계공학부)
  • Received : 2016.02.15
  • Accepted : 2016.07.06
  • Published : 2016.10.01
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Abstract

The purpose of this study is to understand the characteristics of unburned carbon (UBC) and NOx emissions for pulverized coal when air staging combustion is applied. A two-staged drop tube furnace capable of applying air staging combustion was designed and installed. The combustion of sub-bituminous (Tanito) has been investigated. UBC and the NOx concentration were measured under various temperatures and stoichiometric ratios in unstaged and staged combustion. As a result, UBC decreased and the NOx concentration increased with an increase in stoichiometric ratio and temperature. In particular, the NOx reduction mechanism was activated when the temperature in the fuel rich zone increased. Both UBC and the NOx concentration decreased as the temperature increased in the fuel rich zone. A high NOx reduction effect was obtained, compared to the UBC increase, when the air staging technique was applied.

본 연구의 목적은 석탄 입자 연소 시 공기 다단 연소 적용에 따른 UBC(Unburned Carbon) 및 질소 산화물(NOx) 배출 특성을 분석하는 것이다. 이를 위해 공기 다단 연소가 가능한 2단 하향 분류층 반응기(Two Staged Drop Tube Furnace, Two Staged DTF)를 설계 및 제작하였다. 아역청탄(Tanito)의 단일 및 다단 연소 실험을 진행하여 UBC 및 NOx 배출 특성을 분석하였다. 그 결과, 단일 연소 조건에서 온도 및 공기비가 증가함에 따라서 UBC 함량이 감소했지만 NOx의 농도는 증가했다. 특히 과농 연료 연소 영역에서 NOx 저감 반응이 일어났으며, 이때 반응 온도가 증가할수록 NOx 저감 반응이 활성화 될 뿐아니라 UBC는 감소되었다. 공기 다단 연소 실험의 경우 석탄 입자의 UBC 증가량에 비해 높은 NOx 저감 효과를 얻을 수 있었다.

Keywords

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