• 한국연소학회:학술대회논문집
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• 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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• pp.50-57
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• 2005

The aim of this study is to numerically investigate a compact reformer system currently under development and to design a better reforming system with more efficient heat transfer and reforming reactions. Numerical models were established separately for both the combustion part and the reforming reaction part. A comparison between the calculation results and experimental data showed that the concentration of the reformate at the exit of the reforming system was in good agreement with the measured data, but for the temperature at the exit little difference between them was found. After checking the validity of the numerical models, the heat transfer between the combustion gas and reforming catalysts was estimated and the behavior of the catalyst bed was investigated as a function of the operation parameters.

• 로봇학회논문지
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• 제17권1호
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• pp.93-101
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• 2022

Bioheavy oil, which is expanding its range of use as an alternative fuel to reduce environmental pollutant emissions, has a lot of difficulty in combustion due to its low emission of pollutants such as nitrogen oxide (NOx) and sulfur oxide (SOx), while its low dissipation and high oxygen content in fuel. many studies have been conducted on change in characteristics by mixing rate combustion characteristics and combustion reactions, but there have been no specific and effective studies on the composition of control system, optimization of control, development of logic for mixing and burning, minimizing environmental pollutantants discharge. In this study, we intend to consider systemmatic and empirical considerations on the composition, logic development, solve the problem of manual switching of bioler master due to excessive oxygen content and tuning of the control system for optimal combustion of bioheavy oil.

• 한국분무공학회지
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• 제14권4호
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• pp.171-177
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• 2009

This study proposes a new stratified charge system for low emission and ultra lean burn. In order to examine combustion characteristics of the new system, sparkplug with a hole at positive pole and a common CNG injector for injecting fuel were used in this study as injector-type spark plug. The new stratified charge system injects fuel of extremely small quantities and ignites mixture around sparkplug gap. Also, the system was fitted in a visualized constant volume chamber. Then, for analysis of the combustion characteristics, we examined combustion pressure, lean inflammable limit, and visualized combustion flame according to equivalence ratio by comparison with homogeneous charge (HC) method and the new stratified charge (SC) method. As results of this study, in the case of using this system, the propagation speed of initial flame was increased and total combustion period was reduced in the ultra lean burn in the same equivalence ratio. These phenomena occurred clearly under the conditions of lean equivalence ratio. Furthermore, the lean inflammable limit of mixture was extended by using the injector-type spark plug.

• 동력기계공학회지
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• 제18권6호
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• pp.113-119
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• 2014

Due to the development of the petroleum refining technology and continuously increased demand from markets, a quantity of gasoline and diesel oil produced from a restricted quantity of crude oil has been increasing, and residual fuel to be used at marine diesel engines has been gradually becoming low quality. As a result, it was recently reported that trouble oils which cause abnormal combustion such as knocking with extreme noise and misfire from internal combustion engines were increasing throughout the world. In this study, an author investigated ignitability and combustion quality by using combustion analyzer with constant volume(FCA, Fuel Combustion Analyzer) and middle speed diesel engine about MDO(Marine Diesel Oil), HFO(Heavy Fuel Oil), LCO(Light Cycle Oil) and Blend-HFO which was blended LCO of 1000 liters with HFO of 600 liters. Moreover, for betterment of ignitability and combustion quality of injected fuels, multi-injection experiment was carried out in the diesel engine using Blend-HFO. According to the results of FCA analysis, ignitability and combustion quality was bad in the order of MDO

• 한국연소학회지
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• 제22권2호
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• pp.42-49
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• 2017

A premixed combustion has many advantages including low NOx and CO emission, high thermal efficiency and a small volume of combustor. This study focused on combustion characteristics in a premixed combustion burner using the nickel based metal foam. The results show that the blue flame is found to be very stable at heating load 6,300-25,200 kcal/h by implementing the proper nickel based metal foam and baffle plate. The premixed flame mode is changed into green flame, red flame, blue flame and lift off flame with decreasing equivalence ratio. NOx emission was measured 80 ppm(0% oxygen base) from 0.710 to 0.810 of equivalence ratio and CO emission is 90 ppm(0% oxygen base) under the same equivalence ratio. It is also found that the stable blue flame region in flame stability curve becomes wider with increasing the heat load.

• 한국연소학회:학술대회논문집
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• 한국연소학회 1999년도 제19회 KOSCO SYMPOSIUM 논문집
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• pp.189-200
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• 1999

Combustion characteristics of a regenerative combustor for high temperature air combustion have experimentally studied. Temperature measurement on regenerative ceramic material and combustor has been carried out with changing equivalence ratio at constant turn-over period. Stable and unstable combustion region have been found and also detailed averaged temperature profile with respect to various air flow conditions have been obtained.

• International Journal of Automotive Technology
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• 제2권3호
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• pp.85-91
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• 2001

Characteristics of methane direct-injection spark-ignition stratified combustion in lean hydrogen mixture were analyzed both in a single cylinder engine and in a constant volume combustion chamber. Combustion pressure and Instantaneous combustion chamber wall temperature during the combustion process were measured with a thin-film thermocouple and used in analyses of combustion and cooling loss. Results in this research show that the premixed hydrogen increases cooling loss to combustion chamber wall while achieving combustion promotion, and the combustion system is effective especially in lean mixture conditions. Analysis of flame propagation was also done with Schlieren photography in the constant volume combustion chamber.

• 신재생에너지
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• 제2권4호
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• pp.33-38
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• 2006

The Dish/Stirling system with the Stirling engine is currently used to convert solar energy directly to electrical energy. Successful operation of dish/Stirling system is supported by hybrid system, which will allow continuous operation driven by solar and combustion heating. The hybrid Receiver has to be provided with an additional combustion system. The heat pipe receiver and conbustion system were manufactured and tested for thermal characteristics of receiver. Maximum temperature difference along the heat pipe surface is $200^{\circ}C$. Emission measurements showed low NOx values of 28 to 46 ppm and very high CO values of 18 to 201 ppm.

• 한국추진공학회지
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• 제4권2호
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• pp.6-11
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• 2000

고압의 불활성 기체를 이용하여 엔진에 추진제를 공급하는 액체로켓의 경우, 추진제 탱크의 압력은 정상연소상태의 연소압을 기준으로 하여 설계한다. 그러나 연소초기의 연소실 압력은 대기압 상태이므로 과도한 유량이 공급되어 이로 인해 hard-start가 발생하며, 최악의 경우 엔진의 파손을 가져온다. 본 연구에서는 이러한 문제를 해결하고 안정된 연소를 위하여 개선된 추진제 공급시스템을 제안하며, 이는 실제 연소실험을 통해 그 성능을 규명하였다. 이 공급시스템은 연소초기의 급격한 연소실압의 상승을 막기 위하여 추진제를 예연소단계와 주연소단계의 2단계로 공급하며, 연소초기 및 연소 중의 일정한 유량공급을 위해 Cavitating Venturi를 사용하는 시스템이다. 설계 유량보다 적은 양의 추진제를 먼저 공급하여 연소압이 일정수준에 달하도록 예연소압을 형성하게 하는 방법이다. 또한, Cavitating Venturi는 오직 공급압에 의해서만 유량이 결정되며, 출구 압에 영향을 받지 않으므로 연소초기는 물론이고, 연소 중 이상연소에 의해 연소압이 떨어져도 설계치 이상의 유량이 공급되지 않는다.

• 한국추진공학회지
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• 제16권6호
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• pp.92-97
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• 2012

발사체의 추진기관은 일반적으로 산화제와 연료를 연소실로 공급하여 추진력을 얻게 된다. 개발 중에 있는 한국형 발사체(KSLV-II) 2단 엔진의 경우 산화제로는 액체산소(Liquid Oxygen)를 사용하고 연료로는 JET-A1이 사용될 예정이다. 터보펌프 공급방식인 2단 엔진의 주요 구성은 연소기와 터보펌프, 엔진공급시스템 등으로 구성되어 있다. 액체 추진 엔진 개발을 위해서는 서브시스템인 연소기 개발이 선행되어야 하고 설계 및 제작된 연소기의 성능 검증은 연소기 연소시험설비(CCTF)에서 수행된다. 우주센터에 구축 예정인 연소기 연소시험설비에 대한 상세설계가 수행되었으며, 본 설계 결과를 기준으로 AMESim을 사용하여 산화제공급시스템에 대한 모델링을 수행하여 산화제 공급특성을 해석하였다.