• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.651-655
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• 2000

The objective of present work is to investigate experimentally the characteristics of heat transfer. A fluidized bed combustion has advantages of pollution control, fuel flexibility and excellent heat transfer. The present study investigates fundamental phenomena of bed-to-surface heat transfer in high temperature fluidized beds to improve design of immersed tube surface. The tested operating variables are bed temperature, supeficial velocity, mean size of bed material, and the rake angle of fin. Generally, heat transfer rates between the fluidized bed and immersed finned-tube are much higher than those of a smooth tube. A life time of finned-tube is generally longer than that of smooth tube.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.111.1-111.1
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• 2010

This paper focuses on a systematic configuration of steam reforming fuel processor, particularly designed for small and medium sized hydrogen production application. In a typical integration of the fuel processor, there exist significant temperature gradients over the entire system which has negative effect on both catalyst life-time and system performance. Also, the volumetric inefficiency should be avoided to obtain the possible compactness for the commercial purpose. In the present work, the computational analysis will be performed to gain the fundamental insight on the transport phenomena and chemical reactions in the reformer consisting of preheating, steam reforming (SR), and water gas shift (WGS) reaction beds in the flow direction. Also, the fuel processing system includes a top-fired burner providing necessary thermal energy for endothermic catalytic reactor. A fully two-dimensional numerical modeling for a integrated fuel processing system is introduced for in-depth analysis of the heat and mass transport phenomena based on surface kinetics and catalytic process. In the model, water gas shift reaction and decomposition reaction were assumed to be at equilibrium. A kinetic model was developed and then computational results were compared with the experimental data available in the literature. Finally, the case study was done by considering the key parameters, i.e. steam to carbon (S/C) ratio and temperature. The computer-aided models developed in this study can be greatly utilized for the design of advanced fast-paced compact fuel processors research.

• 한국화재소방학회논문지
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• 제23권5호
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• pp.24-31
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• 2009

본 연구에서는 우리나라 주요 침엽수종인 소나무(Pinus densiflora)와 활엽수종인 굴참나무(Quercus variabilis)의 낙엽에 대해 FTIR(Fourier Transform Infrared) 분광계를 이용하여 배출 연소가스 종류 및 농도를 측정하였다. 실험결과 소나무와 굴참나무 낙엽에서 Carbon monoxide, Carbon dioxide, Acetic acid, Butyl acetate, Ethylene, Methane, Methanol, Nitrogen dioxide, Ammonia, Hydrogen Fluoride, Sulfur dioxide, Hydrogen bromide 등 13개 연소가스가 검출되었고 굴참나무 낙엽에서는 Nitrogen monoxide가 추가로 검출되었다. 방출된 연소가스의 전체 농도는 소나무 낙엽이 굴참나무 낙엽에 비해 4.5배 많이 검출되었다. 특히, 시간가중평균가스농도(Time-Weighted Average, TWA, ppm) 기준을 초과하는 연소가스는 Carbon monoxide, Carbon dioxide, Butyl acetate가 검출되었고 단시간노출기준(Short Term Exposure Limit, STEL, ppm) 기준을 초과하는 연소가스는 Carbon monoxide, Carbon dioxide로 소나무 및 굴참나무 모두에서 나타났다. 이에 산불에서의 낙엽의 지표화 연소시 전체 가스 방출량의 99% 이상을 차지하고 있는 Carbon monoxide, Carbon dioxide의 건강 위험성이 높은 것으로 나타났다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.156.1-156.1
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• 2011

It is of great importance to predict operating parameter characteristics of an integrated fuel processor by the increased life-time and system performance. In this study, computational analysis is performed to gain fundamental insights on transport phenomena and chemical reactions in reformer which consists of preheating, steam reforming, and water gas shift reaction beds. Also, a top-fired burner locates inside of the reforming system. The combustor is providing thermal energy necessary for the steam reforming bed which is a endothermic catalytic reactor. Two-dimensional numerical model of the integrated fuel processing system is introduced for the analysis of heat and mass transport phenomena as well as surface kinetics and catalytic process. A kinetic model was developed and then computational results were compared with the experimental data available in the literature. Subsequently, parameter study using the validated steam methane reforming model was conducted by considering operating parameters, i.e. steam to carbon ratio and temperature.

• 한국산림과학회지
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• 제113권3호
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• pp.308-318
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• 2024

최근 동시다발화·대형화되고 있는 산불에 대비하기 위해 산불연료관리의 중요성이 부각되고 있다. 본 연구에서는 실내실험 및 Wildland-Urban Interface Fire Dynamics Simulator(WFDS)를 활용한 지표화 확산모의를 통해 연료관리가 산불위험성 저감에 미치는 영향을 평가하였다. 소나무 낙엽을 대상으로 강원 고성군에 위치한 국립산림과학원 '대형산불방지 소나무 숲 연료관리' 시험지의 현장조사를 통해 대조구, 간벌강도 20%, 간벌강도 40% 구역의 지표연료량을 적용하였다. 본 연구결과에서 화염높이, 수직온도분포 및 최대열방출량은 간벌강도가 높아질수록 감소하는 경향을 나타내면서 산불위험성이 낮아지는 것으로 나타났다. 전반적으로 WFDS가 실내실험에 비해 수치가 높게 모의되는 현상이 있었으나, 경향성은 유사하게 나타났기 때문에 국내 소나무 지표화에 대한 WFDS의 적용가능성을 확인할 수 있었다. 본 연구결과는 숲가꾸기 강도에 따른 산불위험성을 평가하여 산불예방을 위한 연구 기반을 구축하는 데 있어 기초자료로 활용할 수 있을 것이다.