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

The Korean Society of Mechanical Engineers (대한기계학회)
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Observation of Ignition Characteristics of Coals with Different Moisture Content in Laminar Flow Reactor

층류 반응기를 이용한 수분함량에 따른 석탄 휘발분의 점화 특성에 관한 연구

  • Kim, Jae-Dong (School of Mechanical Engineering, Pusan Nat'l Univ.) ;
  • Jung, Sung-Jae (Koera Southern Power Co., LTD.) ;
  • Kim, Gyu-Bo (Pusan Clean Coal Center(PC3), Pusan Nat'l Univ.) ;
  • Chang, Young-June (School of Mechanical Engineering, RIMT, PC3, Pusan Nat'l Univ.) ;
  • Song, Ju-Hun (School of Mechanical Engineering, RIMT, PC3, Pusan Nat'l Univ.) ;
  • Jeon, Chung-Hwan (School of Mechanical Engineering, RIMT, PC3, Pusan Nat'l Univ.)
  • 김재동 (부산대학교 기계공학부) ;
  • 정성재 (한국남부발전) ;
  • 김규보 (부산대학교 화력발전에너지분석기술센터) ;
  • 장영준 (부산대학교 기계기술연구소) ;
  • 송주헌 (부산대학교 기계기술연구소) ;
  • 전충환 (부산대학교 기계기술연구소)
  • Received : 2010.09.24
  • Accepted : 2011.03.03
  • Published : 2011.05.01
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Abstract

The main objective of this study is to investigate the variation in the ignition characteristics of coals as a function of moisture content in a laminar flow reactor (LFR) equipped with a fuel moisture micro-supplier designed by the Pusan Clean Coal Center. The volatile ignition position and time were observed experimentally when a pulverized coal with moisture was fed into the LFR under burning conditions similar to those at the exit of the pulverizer and real boiler. The reaction-zone temperature along the centerline of the reactor was measured with a $70-{\mu}m$, R-type thermocouple. For different moisture contents, the volatile ignition position was determined based on an average of 15 to 20 images captured by a CCD camera using a proprietary image-processing technique. The reaction zone decreased proportionally as a function of the moisture content. As the moisture content increased, the volatile ignition positions were 2.92, 3.36, 3.96, and 4.65 mm corresponding to ignition times of 1.46, 1.68, 2.00, and 2.33 ms, respectively. These results indicate that the ignition position and time increased exponentially. We also calculated the ignition-delay time derived from the adiabatic thermal explosion. It showed a trend that was similar to that of the experimental data.

본 연구의 주 목적은 연료 수분 미소 정량 공급기를 장착한 층류 반응기(LFR)에서 수분함량 변화에 따른 석탄의 휘발분 점화 특성을 조사하는 것이다. 실제 발전소의 미분기 출구 분위기와 비슷한 수분량이 석탄량의 20, 30, 40%로 LFR에 석탄과 함께 공급했을 때 휘발분의 점화 위치와 시간을 실험적으로 관찰하였다. 석탄이 공급되는 층류 반응기 정 중앙의 수직방향으로 $70{\mu}m$ R-type 열전대를 이용하여 복사 열손실을 고려한 가스온도를 측정하였고, 휘발분 점화 위치는 CCD 카메라를 이용해 촬영한 15~20개의 이미지를 디지털 이미지 프로세싱을 통해 얻은 평균 값으로 결정하였다. 그 결과 수분량이 증가할수록 가스 온도는 감소하였고, 점화 위치는 2.92, 3.36, 3.96, 4.65mm로 지수적으로 증가하였다. 이러한 실험결과는 이론적으로 adiabatic thermal explosion에서의 점화 지연 시간과 같은 경향을 나타내었다.

Keywords

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