• 한국재료학회:학술대회논문집
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• 한국재료학회 1994년도 추계 학술발표 강연 및 논문 개요집
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• pp.53-54
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• 1994

• 대한기계학회논문집B
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• 제37권2호
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• pp.187-196
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• 2013

화력발전용 관류보일러 화로벽관에서의 밀도파 불안정 예측을 목적으로 수치모델을 개발하였다. 시간 도메인에서 1 차원 유한체적법을 적용하여 관내 비정상상태의 유동장을 계산하였으며, 화로벽관의 평행관 연결을 모사하기 위해 헤더의 모델도 포함하였다. 평행관들 가운데 하나의 관에 열 섭동을 부가 후 관 입출구 유량의 변동을 관찰함으로써 밀도파 불안정을 찾았다. 개발된 모델은 문헌의 실험결과와 검증을 거쳐 700MW 보일러 화로벽관에 적용하였다. 그 결과 Takitani 의 실험결과에서는 평행으로 연결된 우회 유량이 줄어들수록 불안정 경계 열량이 상승하는 경향이 있었던 반면, 보일러 화로벽관의 경우에는 평행관 모델링에 크게 영향을 받지 않음을 확인하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1207-1212
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• 2004

For the design of Aluminium pool furnace, position of burner and pool depth effects on flow and temperature field in Aluminium pool furnace are examined by the commercial computational code, CFD-ACE+. From the results, position of burner which is on the same face in side wall is better to distribute the flow field in Al furnace. That yields temperature to distribute more uniformly. And the burner position is on upper wall, fire frame reach pool surface. Customer must consider that, because it make Aluminium to oxidize.

• 보존과학회지
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• 제36권5호
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• pp.421-429
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• 2020

본 연구는 진천 송두리 유적에서 출토된 노벽을 대상으로 총 11개의 층위별로 물리화학적인 분석을 실시하여 노벽의 층위 간 재료학적 차이 및 제작방법을 추론하였다. 미세조직 관찰 결과, 출토 노벽의 층위는 크게 3개의 그룹으로 나누어지며, 1층은 과소성층, 2~9층은 일부 피열이 관찰되는 소성층, 10~11층은 비소성 토양층으로 구분되었다. 입도분석 결과, 소성층은 굵은 모래의 함량이 비소성층에 비해 상대적으로 높았고, 곡률계수 분석결과에서도 차이를 확인하였다. 구성광물 분석결과, 전체적인 XRD 회절 패턴은 유사하나 저온성 광물과 고온성 광물의 강도가 층위 간 차이가 발생하여 피열의 정도가 달랐으며, 열분석 결과에서 1층과 2층에서만 뮬라이트 발열피크가 발견되지 않아 최종적으로 사용된 층위로 추정하였다. 결과적으로 노벽의 층위 간 재료학적 차이가 크지 않아 노벽 제작 시 기존 주변의 토양과 성분이 유사한 점토를 사용하여 축로하였을 것으로 판단되나, 층위 간 구성입자의 형상과 특징이 일부 다른 것으로 보아 수비를 하거나 석립을 일부 첨가했을 가능성이 있다.

• 한국연소학회지
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• 제10권2호
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• pp.18-25
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• 2005

An experimental study has been conducted to evaluate the effects of reburning on $NO_x$ reduction and also to examine heat transfer characteristics from LPG flame. Experiments were performed in flames stabilized by a co-flow swirl burner, which was mounted at the bottom of the furnace. Tests were conducted using LPG gas as main fuel and also as reburn fuel. The effects of reburn fuel fraction and injecting location of reburn fuel are studied. The paper reports data on flue gas emissions, temperature distribution in furnace and various heat fluxes at the wall for a wide range of experimental conditions. In a steady state, the total as well as radiative heat flux from the flame to the wall of furnace has been measured using a heat flux meter. Temperature distribution and emission formation in furnace have been also measured and compared.

• 보존과학회지
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• 제35권4호
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• pp.373-383
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• 2019

We characterized the smelting process and smelting furnace through scanning electron microscopy-energy dispersive spectroscopy, wavelength dispersive X-ray fluorescence, X-ray diffraction, and raman micro-spectroscopy with 13 relics including slags and furnace walls excavated from square-shaped building sites and pits of the Three Kingdoms site at the Ungyo site section I. Our results revealed that the principal components were FeO and SiO₂; and CuO, PbO, and ZnO were contained in small quantities. Furthermore, fayalite, magnetite, augite, copper, and cuprite were found. High contents of FeO or SiO₂ components seem to have been added to form fayalite to remove gangue in the smelting process. The relatively low content of S detected in the copper prills suggests that roasting was performed well. Cristobalite and mullite, which are minerals that indicate high-temperature found in the furnace wall, show that the smelting temperature was higher than 1,250℃. The findings of this study show a high possibility that the Wanju Ungyo site is smelting remains of copper ores, which are nonferrous metals, rather than iron. Various smelting byproducts excavated in this area in the future will help us better understand the copper smelting process that may have been performed since ancient times.

• 대한기계학회논문집B
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• 제30권9호
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• pp.842-849
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• 2006

An experimental study has been conducted to investigate the effects of a multi air-staged burner on NOx formation and heat transfer in a 15kW large-scale laboratory furnace adopted the reburning process. The reburn fuel as well as burnout air was injected from each nozzle attached at the wall of the cylindrical furnace. Fuel in both main burner and reburn nozzle was LPG (Liquefied Petroleum Gas). The paper reports the influences on NOx reduction of reburn fuel fraction in reburning zone. Temperature distribution inside the overall region as well as total heat flux at the wall of the furnace has been measured to examine the heat transfer characteristics due to the reburning process. For comparison, the reburning effects were examined for a combustor with two types of burner; a regular single staged burner and a multi-air staged burner. A gas analysis was also performed to evaluate an appropriate condition for NOx emission in a primary zone for the excess air ratio of 1.1. As a result, combustion efficiency expected to become more efficient due to the reduction of heat loss in burnout zone decrease when multi air-staged burner in furnace adopted reburning technology was used.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.109-112
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• 2008

In this work, a mathematical heat transfer model of a walking-beam type reheating furnace that can predict the formation and growth of the scale layer, which is produced due to oxidative reaction between the furnace oxidizing atmosphere and the steel surface in the reheating furnace, has been developed. The model can also predict the heat flux distribution within the furnace and the temperature distribution in the slab and scale throughout the reheating furnace process by considering the heat exchange between the slab and its surroundings in the furnace, including radiant heat transfer among the slabs, the skids, the hot gases and the furnace wall as well as the gas convection heat transfer in the furnace. Using the model developed in this work, the effects of the scale layer on the heat transfer characteristics and temperature behavior of the slab is investigated. A comparison is also made between the predictions of the present model and the data from an in situ measurement in the furnace, and a reasonable agreement is founded.

• 한국연소학회지
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• 제12권4호
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• pp.14-21
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• 2007

In order to enhance combustion efficiency, oxygen-enriched combustion is used by increasing the oxygen ratio in the oxidizer. However, since the flame temperature increases, NOx formation in the furnace seriously increases for low oxygen enrichment ratio. In this case, reburning is a useful technology for reducing nitric oxide. In this research, experimental studies have been conducted to evaluate the hybrid effects of reburning/selective non-catalytic reaction (SNCR) and reburning/air staging on NOx formation and also to examine heat transfer characteristics in various oxygen-enriched LPG flames. Experiments were performed in flames stabilized by a co-flow swirl burner, which were mounted at the bottom of the furnace. Tests were conducted using LPG gas as main fuel and also as reburn fuel. The paper reported data on flue gas emissions, temperature distribution in furnace and various heat fluxes at the wall for a wide range of experimental conditions. Overall temperature in the furnace, heat fluxes to the wall and NOx generation were observed to increase by low level oxygen-enriched combustion, but due to its hybrid effects of reburning, SNCR and Air staging, NOx concentration in the exhaust have decreased considerably.

• 한국수소및신에너지학회논문집
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• 제30권3호
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• pp.260-268
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• 2019

The pyrolysis characteristics of pulverized coal particle was numerically analyzed with the drop tube furnace. Based on the simulated gas flow field in the drop tube furnace, the particle velocity, temperature and volatile evolution were calculated with the fourth order Runge-Kutta method. The effects of changes in reactor wall temperature and particle diameter on the pyrolysis behavior of coal particle were investigated. The particle heating rate was very sensitive to the reactor wall temperature and particle size, that is, the higher wall temperature and the smaller particle size resulted in the higher heating rate and the consequent quicker volatile evolution.