• Journal of Energy Engineering
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• v.16 no.3
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• pp.113-119
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• 2007

The auto-ignition characteristics and combustion behaviors of one-dimensional array of water-in-fuel droplets suspended in a high temperature chamber have been investigated experimentally with various droplet spacing and number of droplets. The fuels used were pure n-decane and emulsified n-decane with water contents varied from 10% to 30%. All experiments have been performed at 920 K under the atmospheric pressure. The number of droplets in an array were fixed as 3 or 5 and its spacing was varied from 3 mm to 7 mm by 1mm interval. The imaging technique with a high-speed camera has been adopted to measure the ignition delay and flame life time. The micro-explosion behaviors were also observed. As the droplet array sparing increased, the ignition delay also increased regardless of water contents. However, the life time of droplet array decreased as the droplet spacing increased. The full combustion time in array of 3 droplets was found to be longer than that for 5 droplets case due to the longer ignition delay.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.10
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• pp.1081-1089
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• 2005

In order to examine the application feasibility of Orimulsion fuel in a commercial boiler using heavy fuel oil, a numerical and experimental research efforts have been made especially to figure out the fundamental combustion characteristics of this fuel in a small-scale boiler. One of the notable combustion features of Orimulsion fuel is the delayed appearance of flame location with the flame shape of rather broad distribution, which is found experimentally and confirmed by numerical calculation. This kind of flame characteristics is considered due to the high moisture content included inherently in the process of Orimulsion manufacture together with micro-explosion by the existence of fine water droplets. In order to investigate the effect on the combustion characteristics of Orimulsion, a series of parametric investigation have been made in terms of important design and operational variables such as injected amount of fuel, types of atomization fluid, and phonemenological radiation model employed in the calculation, etc. The delayed feature of peak flame can be alleviated by the adjustment of the flow rate of injected fuel and the generating features of CO, $SO_2$ and NO gases are also evaluated in the boiler. When the steam injection as atomizing fluid is used, the combustion process is stabilized with the reduced region of high flame temperature. In general, the calculation results are physically acceptable and consistent but some refinements of phenomenological models are necessary for the better resolution of pollutant formation. From the results of this small-scale Orimulsion boiler, it is believed that a number of useful information are obtained with the working computer program for the near future application of Orimulsion fuel to a conventional boiler.

• Journal of Korean Institute of Fire Investigation
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• v.9 no.1
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• pp.79-89
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• 2006

본 연구는 2004년 10월 3일 03시 29분경 전북 00시 00동 지리산 흑돼지 정육점에서 발생한 화재현장을 대상으로 화재조사 및 감식을 하여 그 원인을 규명하고자 하였다. 조사 결과 안쪽방과 매장 사이에 있던 냉장고가 심하게 소훼 되었고, 점포와 안방 출입문 부위를 중심으로 가장 심한 탄화상태를 보이는 것으로 발화지점으로 보이며, 점포 내 휴게공간에서 발화하여 점포내부와 화장실을 통해 연소 확대되었음을 확인하였다. 한편, 발화원인으로는 전기적원인, 가스 난방기구 및 담뱃불 등 미소화원 등에 의한 발화 가능성의 특이점이 보이지 않으며, 휴게공간에서의 급격한 연소현상, 폭발 후 화재로 진전된 흔적, 바닥의 가연성액체에 의한 연소흔적 등으로 보아 방화의 가능성이 높다. 화재는 휴식공간입구 우측 큰 교자상과 밑의 작은 교자상 밑, 그 주위에 연소매개체로서 등유를 뿌린 상태에서 휴대용가스렌지를 이용 방화한 것으로 추정된다.