• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.204-205
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• 2006

기존의 3${\sim}$4mm 간격을 가진 냉음극 형광램프(CCFL)나 외부전극형광램프(EEFL)는 휘도의 균일성과 응답속도가 열등하기 때문에 42인치보다 큰 크기를 가지는 LCD TV에 적합하지 않다. 그래서 대면적 BLU(backlight unit)에 적합한 평면형광램프(FFL)에 대한 관심이 높아지고 있다. 본 논문에서는 FFL의 발광 효율을 향샹시키기 위하여, 가스 혼합비를 변화시키면서, 2차원 유체코드를 이용한 수치해석을 통하여 방전효율에 영향을 미치는 요소가 Hg임을 확인 하였다.

• Korean Chemical Engineering Research
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• v.46 no.3
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• pp.561-566
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• 2008

Gasification plant using petroleum coke for refinery and power generation process is increased from considering petroleum coke as a valuable fuel. In this study, gasification of petroleum coke was performed to utilize petroleum coke and to develop essential technology using 1T/D coal gasification system. In case of petroleum coke gasification, because of lower reactivity, consumption of oxygen is higher than coal gasification. The calorific value of syngas from petroleum coke mixed with coal at a mass ratio of 1:1 shows about $6.7{\sim}7.2MJ/Nm^3$. Although carbon conversion could reach more than 92% according to oxygen amount, cold gas efficiency shows lower value than the case of coal. Therefore, it was shown that complemental study in burner design to atomize slurry droplet is required to elevate gasification performance of petroleum coke which has lower reactivity than coal.

• Journal of Energy Engineering
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• v.24 no.3
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• pp.82-88
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• 2015

After a reheating furnace installation, the modification of the size and the heat capacity is very difficult. Therefore, the development of design package tool is required for the computation on the correct specifications before the design and the installation. Prior to development of the design tool, a module that calculates the amount of heat loss of each part according to the specifications for determining the thermal efficiency of a continuous heating furnace was developed and applied to the oxy-fuel industrial furnace. Through this, the effects of fuel type, oxygen fraction and recirculation on the efficiency of the furnace of which the output is 110Ton/hour were analyzed. In oxy-fuel combustion condition, the efficiency was 15% higher than air combustion conditions. With the using COG(Coke Oven Gas) instead of LNG, the efficiency was slightly increased. In the air combustion condition, the efficiency was increased about 33% with the preheated air. But, in oxy-fuel condition, the amount of exhaust gas was reduced, so the efficiency was increased about 7%.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.83-86
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• 2006

In this study, the syngas producing facility that consists of pulverized coal feeding/gasification and hot gas clean-up system was tested for Indonesian subbituminous coal. And the DME conversion facilities have been developed and tested for converting syngas to DME by reactions with catalysts. So, the entrained-bed slagging type pi lot scale coal gasifier was operated normally in the temperature range of $1,400{\sim}1,450^{\circ}C,\;7{\sim}8kg/cm^2$ pressure. And Roto middle coal produced syngas that has a composition of $36{\sim}38%$ CO, $14{\sim}16%\;H_2,\;and\;5{\sim}8%\;CO_2$. Particulates in syngas were 99.8% removed by metal filters. $H_2S$ composition in syngas was also desulfurized by the Fe chelate system to yield less than 0.1 ppm level. When the clean syngas $70{\sim}100 Nm^3/h$ was provided to DME conversion rector, normally operated in the temperature range of $230{\sim}250^{\circ}C$ and $60kg/cm^2$ pressure, 4.5% DME was yielded.

• Korean Chemical Engineering Research
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• v.52 no.5
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• pp.657-666
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• 2014

Coal gasification technology is considered as next generation clean coal technology even though it uses coal as fuel which releases huge amount of greenhouse gas because it has many advantages for carbon capture. Coal or pet-coke slurry gasification is very attractive technology at present and in the future because of its low construction cost and flexibility of slurry feeding system in spite of lower efficiency compared to dry feeding technology. In this study, we carried out gasification experiment using bituminous coal slurry sample by integrating coal slurry feeding facility and slurry burner into existing dry feeding compact gasifier. Especially, our experiment was conducted under fairly lower operation temperature than that of existing entrained-bed gasifier, resulting in partial slagging operation mode in which only part of ash was converted to slag and the rest of ash was released as fly ash. Carbon conversion rate was calculated from data analysis of collected slag and ash, and then cold gas efficiency, which is the most important indicator of gasifier performance, was estimated by carbon mass balance method. Fairly high performance considering pilot-scale experiment, 98.5% of carbon conversion and 60.4% of cold gas efficiency, was achieved. In addition, soundness of experimental result was verified from the comparison with chemical equilibrium composition and energy balance calculations.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.11a
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• pp.171-184
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• 2002

Approx. 200,000 bpd vacuum residue oil is produced from oil refineries in Korea. These are supplying to use asphalt, high sulfur fuel oil, and upgrading at the residue hydro-desulfurization unit. Vacuum residue oil has high energy content, however high sulfur content and high concentration of heavy metals represent improper low grade fuel. To meet growing demand for effective utilization of vacuum residue oil from refineries, recently some of the oil refinery industries in Korea, such as SK oil refinery and LG Caltex refinery, have already proceeded feasibility study to construct 435-500 MWe IGCC power plant and hydrogen production facilities. Recently, KIER(Korea Institute of Energy Research) are studing on the Vacuum Residue gasification process using an oxygen-blown entrained-flow gasifier. The experiment runs were evaluated under the reaction temperature : 1,100~1,25$0^{\circ}C$, reaction pressure : 1~6kg/$\textrm{cm}^2$G, oxygen/V.R ratio : 0.8~0.9 and steam/V.R ratio : 0.4-0.5. Experimental results show the syngas composition(CO+H$_2$) : 85~93%, syngas flow rate : 50~110Mm$^3$/hr, heating value : 2,300~3,000 ㎉/Nm$^3$, carbon conversion : 65~92, cold gas efficiency : 60~70%. Also equilibrium modeling was used to predict the vacuum residue gasification process and the predicted values were compared reasonably well with experimental data.

• Journal of Energy Engineering
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• v.12 no.1
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• pp.49-57
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• 2003

Approx. 200.000 bpd vacuum residue oil is produced from oil refineries in Korea, and is supplied to use asphalt, high sulfur fuel oil and for upgrading at the residue hydro-desulfurization unit. Vacuum residue oil has high energy content, however its high sulfur content and high concentration of heavy metals represent improper low grade fuel. To meet growing demand for effective utilization of vacuum residue oil from refineries, recently some of the oil refinery industries in Korea, such as SK oil refinery and LG Caltex refinery, have already proceeded feasibility study to construct 435~500 MWe IGCC power plant and hydrogen production facilities. Recently, KIER (Korea Institute of Energy Research) are studying on the Vacuum Residue gasification process using an oxygen-blown entrained-flow gasifier. The experiment runs were evaluated under the reaction temperature: 1.100~l,25$0^{\circ}C$, reaction pressure: 1~6 kg/$\textrm{cm}^2$G, oxygen/V.R ratio: 0.8~0.9 and steam/V.R ratio: 0.4~0.5. Experimental results show the syngas composition (CO+H$_2$): 85~93%, syngas flow rate: 50~l10 Nm$^3$/hr, heating value: 2,300~3,000 k㎈/Nm$^3$, carbon conversion: 65~92, cold gas efficiency: 60~70%. Also equilibrium modeling was used to predict the vacuum residue gasification process and the predicted values were compared reasonably well with experimental data.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.347-350
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• 2006

The rocket grade hydrogen peroxide has been widely used as a monopropellant in propulsion systems. In the present paper, we described an experimental study of a catalytic reactor that employs two stage catalyst beds to enhance the low temperature performance of the reactor. $K_2MnO_4$ was chosen as the catalyst for the initial stage of the reactor bed for its superior behavior in the low temperature regime. LSC was used for the catalyst of the second stage of the reactor. The gas generator with combined catalyst beds was built and tested to exhibit high decomposition efficiency over 90% and successful cold-start characteristics.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.3
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• pp.87-92
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• 2006

The rocket grade hydrogen peroxide has been widely used as a monopropellant in propulsion systems. In the present paper, we described an experimental study of a catalytic reactor that employs two stage catalyst beds to enhance the low temperature performance of the reactor inlet. $K_2MnO_4$ was chosen as the catalyst for the initial stage of the reactor bed for its superior behavior in the low temperature regime. Alumina sol-gel method was successfully applied for coating $K_2MnO_4$ on a reactor bed of cordierite monolith. LSC was used for the catalyst of the second stage of the reactor. The reactor with combined catalyst beds was built and tested to exhibit superior performance in low temperature regime and high decomposition efficiency.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.4
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• pp.29-38
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• 2009

The GHP(Gas Heat Pump) is an efficient cooling;11eating system in which a compressor is driven by a gas engine and is brodening its application to the facilities such as schools and office buildings. It is difficult to control the GHP system because of slow response, big time constant and time variant system. These nonlinear loads generate harmonic currents and create distortions on the sinusoidal voltage of the power system Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. A cumulative probability approach is the most commonly used method to solve time varying harmonics. This paper provides an in depth analysis on harmonics field measurement of the GHP loads, harmonic assessment by me 61000-3-2, and harmonic simulation and harmonic filter application using EDSA program for the case study system.