• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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• pp.235-241
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• 2004

Computations were performed to investigate the effects of air staging on combustion in three stage heavy-oil fired combustion burner. The burner was designed for 3 MW. Different amounts of air are introduced into each 3 three stages by means of each dampers. The goal of the study is to understand combustion phenomena according to each air stage mass ratios through CFD. Air flow rates at three inlets are adjusted by dampers inside a burner. Here, injection conditions of liquid fuel are kept constant throughout all simulations. This assumption is made in order to limit the complexity of oil combustion though it may cause some disagreement. In case of cold flows, only longitudinal velocities arc considered, On the other hand, flow, temperature and NOx generations are taken into account for reactive flows. Simple parametric study was conducted by setting 1'st air stage mass ratio as a parameter. And an optimal operation condition was found. The computational study is based on k-e model, P-1 radiation model(WSGGM) and PDF, and is implemented on a commercial code, FLUENT.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.338-343
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• 2003

Computations were performed to investigate the spray characteristics of the twin fluid nozzle in three stage heavy-oil combustion burner. The burner geometry and flow conditions were provided by a burner company. The goal of the study is to estimate mean droplet size, initial velocity and spread factor of the nozzle through comparison between experiments and numerical analyses. Air stage ratio is 2:4:4 by mass, and O2 in exhaust gas is about 4 % by volume. Here, the agreement between the experiment and numerical analyses is evaluated by NOx generation. Spray characteristics will be linearly interpolated between fuel consumption rate l20L/h and 240 L/h.

• 한국연소학회지
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• 제13권3호
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• pp.33-40
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• 2008

Two- and Three- dimensional numerical simulations are carried out to understand the combustion characteristics of LNG-fueled gas turbine combustor for power generation using imported and domestic natural gases. Reacting flow characteristics of the swirl stabilized natural gas combustor were understood from the numerical results with the flow conditions selected from the gas turbine operation data. The thermal influences of different natural gases were very small and the fuel composition and flow rate were considered to be tuned well. The flow structures of the recirculation and combustion region was understood from the comparison of the two- and three-dimensional results. The complexity of the three-dimensional swirl flows inside the gas turbine combustor with multiple swirlers was understood those resulting from the interactions of the stage and pilot burners.

• Transactions on Electrical and Electronic Materials
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• 제2권3호
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• pp.7-11
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• 2001

Utility boiler operators seeking to gain the greatest economic advantage from their units are faced with three challenges, namely the obligatory light-up fuel costs, the additional expense of supplementary fuel firing should they wish to use a cheaper fuel that may be beyond the original burner manufacturer’s stability and combustion performance assurances and the immediate environmental impact of both. The novel use of plasma arc technology can provide a solution to these challenges. This paper introduces the work being undertaken through a joint collaboration between the EU, Kazahkstan and Russia in order to develop a tried and tested engineering methodology and a mathematical based application and sensitivity analysis approach for the design and optimisation stage of these plasma devices that, as a consequence, their assist in their universal introduction.

• 정보관리연구
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• 제39권3호
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• pp.95-113
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• 2008

급속도로 변화하는 과학기술 환경 속에서 기업들은 현존하는 기술의 발전을 모니터링함과 동시에 새롭게 부상하는 유망기술을 찾아야만 경쟁력을 가질 수 있다. 각 국가에서는 경쟁적으로 유망연구 영역을 찾고 있는데, 대부분의 국가에서는 전문가 평가를 기반으로 한 델파이 방법으로 유망기술을 탐색하고 있다. 그러나 델파이와 같은 전문가방식은 기본적으로 전문가의 주관적 판단에 의지하기 때문에 편향성과 이에 따른 문제가 발생한다. 본 연구에서는 델파이 방법의 기술예측방법이 가지는 문제점을 개선하기 위해 과학계량학적 방법으로 유망연구영역을 탐색하였다. 탐색과정에서는 다음 3가지의 특별한 노력을 통해 과학계량학적 방법의 성능을 제고하고자 하였다. 첫째, 데이터베이스 선정에 있어서 공학 등 저널수가 적은 기술분야에서도 유망연구영역의 도출이 가능한가를 고려하였다. 둘째, 과학기술 전분야를 대상으로 하는 분석에서 과학기술분야별로 가지고 있는 인용수의 차이로 인해 발생하는 문제점을 해결하고자 부분인용계상(fractional citation counting)과 이동평균을 이용한 선형회귀분석을 도입하였다. 셋째, 과학계량학적 분석으로 나온 결과를 정성적으로 검증하여 과학계량학적 방법에 의한 오류를 최소화 하였다. 최종 290개의 유망연구영역을 선정하였으며, 각 영역은 기술의 네트워크상에서 가시화하였다. 본 연구에서는 Scopus 데이터베이스가 사용되었으며, 데이터마이닝과 가시화에는 한국과학기술정보연구원에서 개발한 KnowledgeMatrix가 사용되었다.