The Effect of Swirl on the Blowout Velocities of Partially Premixed Interacting Flames

스월이 부분예혼합 상호작용화염의 화염날림 유속에 미치는 영향

  • 이병준 (영남대학교 기계공학과) ;
  • 최광덕 (한국생산기술연구원 용접접합연구부)
  • Received : 2009.05.22
  • Accepted : 2009.06.23
  • Published : 2009.06.30

Abstract

Adding small amounts of air to the fuel is used in many commercial combustors to avoid sooty flame. But partially premixed jet flame has lower blowout velocity, $u_{b.o}$, than nonpremixed one. Increasing blowout limit would be one of the key factors to develope highly intense compact combustion devices. Swirling flow enhances fuel and air mixing and induces a highly turbulent recirculation zone, which helps flame stabilization. It was known that NOx emission decreases with swirl on the proper range of swirl number. And it was shown that the flame interaction in multiple jets also increases $u_{b.o}$ owing to the internal recirculation and reduces NO emission. If the effects of swirl and flame interaction are combined together in partially premixed flame, both $u_{b.o}$ increasement and NOx emission reduction could be achieved. Blowout limits of partially premixed interacting propane flame in the swirling air coflow are investigated experimentally. The results show that the flame is not extinguished up to the experimental limits, 210 m/s, at the swirl number of 0.32 and $X_{F,o}$ = 0.46.

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