• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1993.11a
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• pp.42-45
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• 1993

내경 0.1 m 의 draft tube 를 갖는 직경 0.3 m, 높이 2.7 m 인 내부순환유동층 가스화반응기에서 호주산 준 역청탄을 공기와 수증기를 사용하여 가스화 하였다. draft tube에 공기를 주입하여 연소반응, annulus 구역에 수증기를 주입하여 가스화하여 연소반응에서 생성된 열을 annulus 에 공급하였다. 반응기온도와 석탄주입량에 따라 H$_2$, CO 및 발열량이 증가하였으나 공기의 유량증가에 따른 H$_2$, CO는 감소하고 $CO_2$ 는 증가하였으며 발열량은 감소하였다.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.316-321
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• 2013

This study was carried out to analyze heat transfer characteristics and heat flow through air-inflated double layer PO film with thermal resistance method. The experiments was conducted in the laboratory controlled air temperature between 258.0 K and 278.0 K. The experimental materials were made up two layers PO film and an inflated-air layer. The thickness of air-inflated layer was fixed at 3 types of 110, 175, 225 mm. The electrical circuit analogy for heat transfer by conduction, radiation and convection was introduced. Experimental data shows that the dominant thermal resistance in heat transfer through the air-inflated double layer film was convection. Calculation errors were 1.1~18.5 W for heat flow. In result, the method of thermal resistance could be introduced for analysis of heat flow characteristics through air-inflated double layer film.

• Fire Science and Engineering
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• v.14 no.1
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• pp.8-12
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• 2000

We had investigated thermal and ignition behaviors of textiles. Decomposition of textiles with temperature was investigated using a DSC and the weight loss according to temperature using a TGA in order to find the thermal hazard of textiles, and the ignition behaviors of textiles according to species and permeation amount of oil. In addition, ignition behaviors of those permeated into oils indicating different iodine value and of those with arid without air in reaction vessel of measuring equipment were studied with constant temperature method among ignition temperature measuring methods. As results, the range of decomposition temperature of synthetic fiber was slightly broad compared with that of natural fiber, pure cotton. Besides, the initiation temperature of heat generation of both samples riced in the case of no air injection in the reaction vessel. On the other hand, in the case of air injection that was lowered according to the increase in permeative amount of oils and fats and decreased quickly as sample was permeated into drying oil.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.97-98
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• 2001

폐기물 소각로는 주입 폐기물의 성상이 균일하지 못하므로 폐기물의 불완전 연소에 의한 유해중간 생성물들이 생성되므로 논란이 되어왔다. 이를 제어하기 위해서는 공기량, 공기 주입방법, 공기 예열온도등에 운전조건들의 선정이 매우 중요하다. 이를 위해 진행되어온 연구는 크게 실험적 방법과 수치 해석적 방법의 두 범주로 나뉘어진다. 이에 본 연구에서는 수치해석적 방법으로 광주 상무신도심에 설치 가동중인 200톤/일 용량의 소각로내의 열유동 현상을 해석하기 위하여 고체 폐기물이 매우 빠르게 탈휘(devolatilization)되는 것으로 가정, 메탄가스로 단순화(Chen et al, 1999)하였다. (중략)

• Tunnel and Underground Space
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• v.21 no.4
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• pp.297-306
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• 2011

In this paper, we performed thermodynamic energy balance analysis of the underground lined rock cavern for compressed air energy storage (CAES) using the results of multi-phase heat flow analysis to simulate complex groundwater-compressed air flow around the cavern as well as heat transfer to concrete linings and surrounding rock mass. Our energy balance analysis demonstrated that the energy loss for a daily compression and decompression cycle predominantly depends on the energy loss by heat conduction to the concrete linings and surrounding rock mass for a sufficiently air-tight system with low permeability of the concrete linings. Overall energy efficiency of the underground lined rock caverns for CAES was sensitive to air injection temperature, and the energy loss by heat conduction can be minimized by keeping the air injection temperature closer to the ambient temperature of the surroundings. In such a case, almost all the heat loss during compression phase was gained back in a subsequent decompression phase. Meanwhile, the influence of heat conductivity of the concrete linings to energy efficiency was negligible.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.270-278
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• 2013

The objective of the present study is to provide data needed to decide covering method to be able to increase the thermal insulation and light transmittance efficiency of commercial greenhouse. The thermal insulation effect, PPF transmittance and quantity of condensation water were estimated in experimental tomato greenhouses covered with three types of coverings of single layer, air inflated and conventional double layers covering. The overall heat flow of air inflated double layers greenhouse was similar to that of conventional double layers greenhouse, but the temperature between covering material and thermal screen in air inflated double layers greenhouse was lower than that in conventional double layers greenhouse at the same outside temperature condition due to air leakage through the gap of roof vent. The overall heat transfer coefficients acquired by experiment that was performed in single layer and conventional double layers greenhouses were close to those obtained from model experiment. Even though the PPF transmittance of air inflated double layers greenhouse was lower than that of single layer greenhouse, which was greater than that of conventional double layers greenhouse. The quantity of condensation water on covering surface of single layer greenhouse was greater than that of air inflated double layers greenhouse due to lower covering surface temperature.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.2
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• pp.45-54
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• 2010

Field study was conducted for 5 months to investigate the effect of leachate recirculation on aerobic landfill stabilization at active landfilling site. The area of field experiment was $24{\times}24m$ and 9 vertical air injection wells with screen ranging 3~9 m were installed. Aerobic landfill operation for 5 months increased average internal landfill temperature to $70^{\circ}C$ and 8 % of landfill height was settled down. $94m^3$ of leachate was recirculated for 1 month to increase moisture content of landfill to favor microbial degradation of organic matter, which resulted in temporary increase of groundwater level and anaerobic environment. But leachate recirculation triggered increase of internal landfill temperature of neighboring monitoring well. Because excessive leachate recirculation decreased internal landfill temperature by cooling effect, internal landfill temperature should be checked to avoid abrupt decrease of temperature during leachate recirculation. Also, to prevent anaerobic environment, intermittent leachate recirculation was recommended.

• 한국연소학회:학술대회논문집
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• 2002.06a
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• pp.237-246
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• 2002

가압유동층연소로(bed dia. 0.17m, freeboard dia. 0.25, total height 5m)에서 국내무연탄을 연소시켜 이에 대한 탈황특성을 고찰하였다. 실험은 압력($2{\sim}6atm$), 요동층온도(($850{\sim}950^{\circ}C$), 과잉공기(10, 20, 30,%)등의 조건과, 탈황을 위한 Ca/S몰비(($0.8{\sim}4.8$)가 탈황특성에 미치는 영향을 고찰하였다. 결과적으로, 본 연구의 실험범위에서 연소효율은 $80{\sim}99%$를 보였고, 연소온도, 압력 그리고 과잉공기가 증가 할수록 증가하였다. 배가스중의 $SO_2$배출농도는 압력, Ca/S몰비가 증가함에 따라 감소하였다. 탈황율은 상압에서 층(bed)온도의 증가에 따라 감소하였다. 운전압력이 증가함에 따라 탈황율의 감소폭이 둔화되었다. 과잉공기가 증가함에 따라 탈황율은 증가하는 경향을 나타냈다. 각각의 운전압력에서 과잉공기의 증가에 따라 약 10%의 증가폭을 보였다. 국내무연탄을 연소하는 경우 운전압력 4atm일 때 Ca/S몰비는 4이상 주입하여야 하고, 6atm일 때 Ca/S 몰비가 2.5이상주입하여야 150ppm이하를 보여 배출규제치를 만족하는 것을 보였다.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.9
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• pp.630-636
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• 2012

The purpose of this study was to determine optimum wavelength, light intensity, aeration rate, and temperature for the cultivation of Dunaliella salina illuminated by various types of light emitting diode. Growth rates of Dunaliella salina were faster at higher temperature than the growth rate at lower temperature. Among the culturing temperatures, $22^{\circ}C$ was the optimum temperature for the growth of Dunaliella salina. White LED was the most efficient light source and lower light intensity (3,000 Lux) resulted in better biomass production (1.30 g/L). The value of aeration varied between 0 and 2.4 vvm at the illumination of 3,000 Lux of white light emitting diode. Highest specific growth rate of $1.12day^{-1}$ was obtained at no-aeration and lower specific growth rates were obtained for other aeration tests, which indicated that aeration could be harmful for the cultivation of Dunaliella salina.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.575-583
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• 2019

The results of the catalytic reaction by pulsed injection of reactants are useful for studying the initial reaction characteristics in the case of many coke invloved reactions. The dehydrogenation characteristics of alumina supported platinum tin catalysts were investigated by pulsed injection of propane. The yield of propylene was maximized when the reduction time of propane injection catalyst was $550^{\circ}C$. Raman analysis showed that the amount of coke was very small when PtSn (4.5) catalyst was used and the short contact time was simulated by propane pulse injection. n order to differentiate the degree of dispersion of platinum, PtSn (4.5) catalyst was sintered at $900^{\circ}C$ with hydrogen, and then the temperature of air - redispersion was varied and propane pulse was injected. As a result, conversione and yield were the highest when air-redispersion temperature is $600^{\circ}C$. The lower the air-redispersion temperature, the higher the selectivity. As the tin content in the platinum catalyst increased, the propane conversion was lowered, but the selectivity to propylene increased and the yield increased. From this, it can be seen that the tin-added platinum catalyst is less active than the platinum catalyst from the beginning of the reaction, which is less affected by coke. The dehydrogenation reaction by the propane pulse injection shows a higher conversion rate than the result of continuous injection due to the formation of COx, and the amount of coke is very small. Decrease in selectivity due to the formation of COx can be reduced by increasing the reduction temperature and time.