• 한국화재소방학회논문지
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• 제25권5호
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• pp.47-53
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• 2011

건축물 적재가연물은 종류 및 양 등의 특성에 따라 화재지속시간과 화재규모 등에 크게 기여한다. 서점은 다른 건축용도보다 가연물이 다량 적재되어 있으므로 화재발생시 화재위험성이 클 가능성이 있다. 그러나 한편으로는 서점 내부의 서적은 연소하면 탄화층이 형성되고 적재가연물량에 비해 노출표면적이 작기 때문에 화재시 열분해가스의 생성이 작을 가능성도 있다. 이러한 가능성을 다양한 실험을 통해 파악하여 서점의 화재안전설계에 합리적으로 반영할 필요가 있다. 따라서 본 연구에서는 서점의 성능위주설계에 활용하기 위하여 적재가연물을 재현한 시험체를 가열로에 넣고 ISO834-1:1999 표준가열곡선에 따라 가열하는 일련의 실험을 실행하였다. 이 실험 결과를 바탕으로 서점의 적재가연물의 연소발열성상을 파악하고 성능위주설계에 필요한 연소속도 및 열방출률 등을 제시하였다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.906-917
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• 1996

This study was conducted to find possible application areas of the by-products generated from the incineration of rice husk. To this end, a pilot-scale rice husk incinerator system was constructed and its performed test was carried. Major findings are summarized as follows. 1. The rice husk incinerator system developed in this study performed satisfactory in terms of thermal efficiencies. At the optimum operating conditions, thermal conversion efficiency and heat exchanger efficiency was 97% ad 60%, respectively, while overall thermal efficiency of the system was 58%. Under all conditions tested, temperatures in the combustion chamber were quite uniform and crystallization of SiO$_2$ in the ash was negligible. 2. NOx and SOx content in the flue gas was well below the legal limit but the CO concentration was around the legal limit. 3. Thermal energy from combustion was successfully recovered by a heat exchanger to provide hot water, ash was found a good supplementary cementing m terial, and the flue gas also was an acceptable $CO_2$ supplier to greenhouses.

• Journal of the Korean Wood Science and Technology
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• 제39권3호
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• pp.244-251
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• 2011

본 연구에서는 소나무(Pinus Densiflora)와 잣나무(Pinus Koraensis)에 대한 연소특성을 비교 평가하였다. 두 수종은 한옥의 부재로 널리 사용되고 있으며, 그 체적밀도는 소나무가 잣나무에 비하여 상대적으로 큰 값을 가지고 있다. 목재의 연소특성은 해당 수종의 체적밀도와 밀접한 관계를 갖고 있는데 본 연구에서 방염성능에 있어서는 뚜렷한 차이를 확인하기는 어려웠지만 콘칼로리미터 시험방법에 있어서는 총 방출열량, 평균 열방출률 비교를 통하여 목재 수종의 체적밀도의 상관성을 확인하였다. CO/$CO_2$의 비로부터 알 수 있는 연소가스의 유해성은 난연처리에 의해 높아진 것으로 나타났다.

• 대한기계학회논문집B
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• 제32권8호
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• pp.574-581
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• 2008

The characteristics of combustion and flow for a lean premixed flame in lab-scale gas turbine combustor was studied through experiment and numerical analysis. From the experiment, flame structure and heat release rate were obtained from OH emission spectroscopy. Qualitative comparisons were made line-integrated OH chemiluminescence image and abel-transformed one. NOx analyzer was implemented to get the characteristic of NOx exhaust from the combustor. From the numerical analysis, the thermal distribution and characteristic of recirculation zone with the change of fuel-air mixing degree, the characteristic of methane distribution with equivalence ratio in the combustor respectively. Total heat release rate is increased with increasing equivalence ratio. Thermal Nox is reduced with increasing fuel-air mixing degree. Increasing equivalence ratio results in the decrease of the size of reaction zone and alteration of the position of the reaction zone into the entrance of the combustor.

• 한국연소학회지
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• 제18권3호
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• pp.24-30
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• 2013

Flame stabilization characteristics of premixed flames in an annular coaxial 5-tubes burner (AC5TB) were investigated experimentally. The AC5TB was made of five quartz tubes, and the flame stabilization conditions in that burner were investigated with the variation of equivalence ratio and the flow velocities. Flame behaviors inside of narrow annular tubes could be observed directly. Overall flame stabilization conditions were similar to that of the previous study, while the flame behaviors and structures were different mainly due to the controlled uniform distribution of the velocities in channels. Flame flashback conditions were thought to be governed by the competition between heat release rate, heat loss and heat recirculation in each channel. Stationary flames at a fixed location were compared in its velocity distribution and burned gas temperature across the channel. This AC5TB can be a basic configuration for the development of flame stabilization model of porous media combustors, and it will help understand about the real behavior of flames in meso-scale combustion spaces.

• 대한기계학회논문집B
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• 제21권10호
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• pp.1363-1370
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• 1997

Single liquid droplet combustion processes including heating, evaporation, droplet burning and flame radiation were theoretically investigated by adopting nongray gas radiation model for the radiative transfer equation (RTE). n-Heptane was chosen as a fuel and the numerical results were compared with the experimental data available in the literature. The discrete ordinate method (DOM) was employed to solve the radiative transfer equation and the weighted sum of gray gases model (WSGGM) was applied to account for nongray effect by CO$_{2}$, and H$_{2}$0. Therefore, detailed effects by nongray gas and its comparison with the gray gas model could be figured out in the results. It is found that the radiative heat flux is higher when the nongray model is used, thereby reducing the maximum gas temperature and the flame thickness, but the total burning time increases due to the deceased conductive heat flux in nongray model. Consequently, a better agreement with experimental data could be obtained by using nongray model.

• 한국연소학회지
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• 제22권2호
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• pp.50-56
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• 2017

This study was conducted an experiment for the thermal flow mechanism of the surrounding butane gas can and pressure change in butane can with oversized cookware. And numerical analysis was performed to analyze the process of heat transfer around butane can. Effect of radiant heat from small size cookware is very small. Thus small size cookware does not have a significant impact on the butane gas range safety. But radiant heat of oversized cookware is larger than small size cookware. Therefore it gives an adverse effect on the butane can. And when internal pressure of butane can is greater than about 406.8~447.2 kPa, a safety device of portable butane gas range were working. The causes of safety device working is because of trivet height. Trivet height is lowered, the radiant heat is increased. This radiant heat is to raise pressure of inside butane can. Experimental and numerical analysis results, the lower thermal conductivity of the cookware is greater the effects of radiant heat.

• 한국연소학회지
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• 제15권4호
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• pp.58-64
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• 2010

Spontaneous ignition tests of five different coals with non-iso-thermal and iso-thermal test method based on the standard test procedure of NF T20-036 were carried. These five coals included the 2 low rank coals and 3 bituminous coals. Test results showed that the ignition temperatures of all coals at the iso-thermal conditions were higher than that of non-isothermal condition, and those of low rank SM and BR coal in both nonisothermal and isothermal conditions were lower than bituminous AN and CN coals. The chemical species of coals such as oxygen and hematite also plays an important role in enhancing the ignition rate that the ignition temperature of SM coal was lowered. The heat accumulation tendency of five coals inside outdoor stack pile was monitored with emphasis on the change in the temperature of the coal depth in stack pile. In case of low rank BR coal, its temperature inside coal stack pile due to the rate of high heat accumulation and oxidation was $59^{\circ}C$ compared to $51^{\circ}C$ for other SW bituminous coal. And the heat accumulation rate inside coal stack piles was increased with increased the Cp value which it was defined as the specific heat of coal at constant pressure, whereas other factors such as thermal diffusivity and conductivity of coal relatively had less effect on heat accumulation.

• 한국연소학회지
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• 제1권1호
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• pp.19-29
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• 1996

This study is to investigate the characteristics of heat transfer of a horizontal tube, with radial fins of various configuration, immersed in a high temperature fluidized bed. The experimental heat transfer variation is compared with that of a smooth tube. The finned tubes and smooth tube, with outside and inside diameter of 48.6mm and 30.6mm, are made of steel tubes. The depth of the fin is 5mm, the rake angles of fin are $25^{\circ},\;35^{\circ},\;45^{\circ}$ and the widthes of fin for each rake angle are 0mm, 1mm, 2mm and 3mm. A bed temperature is fixed at $880\;{\pm}\;10^{\circ}C$. A granular refractory(silica sand) is used as a bed material with mean particle diameters of 1.22mm and 1.54mm. The maximum heat transfer coefficient is achieved with the rake angle of $25^{\circ}$ and the width of 0mm for the mean particle size 1.22mm. The coefficient is 2.14 times larger than that for a smooth tube. The rake angle for the maximum heat transfer coefficient depends on the particle size of bed material. Also the transfer coefficient decreases as the width of fin increases.

• 한국화재소방학회논문지
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• 제12권2호
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• pp.17-28
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• 1998

건물 화재시 예상되는 내장재의 실째 화재성농올 기준으로 한 위험성 명가방법올 제시하였다. 이률 위해 ISO Room Corner Test. (9705)를 기준으로 Qui ntie re의 화재확산 모델을 이용하여 내장재의 열 적 특성과 플래쉬 오버 도달시간과의 상관성을 유도하고 스쩨덴의 실제 시험결과와 비교 분석하였다. 이 결과, 내장재의 상대척인 화재위험성은 화재확산 변수 b륨 기준으로 명가될 수 있었다.