• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
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• pp.502-506
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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.

• 한국추진공학회지
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• 제16권4호
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• pp.87-92
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• 2012

우주발사체 추진기관은 일반적으로 산화제와 연료를 연소실로 공급하여 추진력을 얻게 된다. 개발중에 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 연료공급시스템에 대한 모델링을 수행하여 연료 공급특성을 해석하였다.

• 한국자동차공학회논문집
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• 제22권3호
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• pp.81-89
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• 2014

This study researched on the effect of HP/LP-EGR system to improve fuel consumption of Low Temperature Combustion Engine. Firstly, low temperature combustion engine with HP/LP-EGR system was established using 6.0L wastegate turbocharger HDDI engine. And suppliable EGR rate of the engine was proven to be enough to realize stable low temperature combustion. Then, optimum operating strategy was founded to develop fuel consumption of the engine. Control parameters were HP/LP-EGR valve and IPCV(Intake Pressure Control Valve) duty. Experiments method was that characteristics of the engine were measured and analyzed according to HP/LP-EGR strategies while EGR rate was fixed. Operating range for the strategy were divided into three parts, low load for low temperature combustion, high load for conventional diesel combustion, and transient condition. Finally, with the above strategy of this study, BSFC of the engine was improved about 2% compared to the base engine, and emission level, NOx and PM, met Tier4Final emission regulation.

• 한국해양공학회지
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• 제13권3B호
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• pp.38-46
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• 1999

Increasing stringent emissions legislation and requirement of more effective energy used for diesel engine demand the fine control of the fuel injection system. Recently, the electromagnetic fuel injection control system for diesel engine is tried to realize the optimum diesel combustion by the feel back sensing as optical signal of combustion flame. The photo detectors were made for the feed back signal of electromagnetic fuel injection control for small DI diesel engine. Their abilities to detect defining combustion events were examined. By evaluating test results, it was shown that the wider acceptable optical range design of optical probe window face, and selection of installation position and installation method of detector were important point for improving sensing ability. The detector was shown to detect start and end of diffused combustion and maximum point of flame intensity impossible for pressure sensor, and also shown that the maximum point of flame intensity was 75% of accumulated heat release point within the experimental conditions.

• 오토저널
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• 제9권1호
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• pp.69-76
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• 1987

This paper deals with the theoretical prediction and cyclic variation of combustion characteristics in a four stroke, single0cylinder, diesel engine. Theoretical calculations employed a simple empirical model of analysis of energy equation for the thermodynamic system of engine cylinder. The cyclic variation of combustion characteristics is investigated, in term of frequency distribution and standard deviation of peak characteristics, as obtained by combustion analyzer system. The results of theoretical prediction are shown to be in close agreement with the experimental data. The effect of fuel injection timing, engine speed, cooling water temperature, and the compression ratio on the cyclic variations of combustion characteristics were discussed.

• 한국연소학회지
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• 제21권4호
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• pp.39-47
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• 2016

The aims of this research were to investigate combustion characteristics of lab-scale pressurized oxy-fuel combustion(POFC) system. In this study, the reactor, 800 mm long, was equipped with co-axial burner. Low calorific value syngas that is composed of mainly CO and $H_2$ was used as fuel whereas pure oxygen was used as an oxidant. Thermal heat input to the reactor varied from 2.6 kW to 6.1 kW. The reactor pressure also increases from atmospheric up to 15 bar. The results show that as the pressure increase, the temperature of reactor decreases on the whole in all cases. A significant temperature drop was observed especially at the bottom section of the reactor that exist flame. In addition, the flame instability increases as the pressure increases. Furthermore $NO_x$ emissions increases from atmospheric up to 2 bar. However beyond 2 bar, $NO_x$ emission reduces as pressure increases. Lastly $NO_2$ ratio in $NO_x$ also increases as pressure increases.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.493-495
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• 2005

This paper proposes a swarm-based fuzzy system modeling technique for coke oven combustion control diagnosis. The coke plant produces coke for the blast furnace plant in steel making process by charging coal into oven and supplying gas to carbonize it. A conventional mathematical model for coke oven combustion control has been used to control the amount of gas input, but it does not work well because of highly nonlinear feature of coke plant. To solve this problem, swarm-based fuzzy system modeling technique is suggested to construct a diagnosis model of coke oven combustion control. Based on the measured input-output data pairs, the fuzzy rules are generated and the parameters are tuned by the PSO(Particle Swarm Optimizer) to increase the accuracy of the fuzzy system is operated. This system computes the proper amount of gas input taking the operation conditions of coke oven into account, and compares the computed result with the supplied gas input.

• 동력기계공학회지
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• 제19권2호
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• pp.64-69
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• 2015

Marine diesel engines with high thermal efficiency and fuel diversity used for propulsive power have been taking charge of important position on marine transport. However, marine environment has recently focused on emissions such as nitrogen oxide and sulfur oxide which is generated from combustion of low grade fuels. EGR(Exhaust gas recirculation) system is one of effective methods to reduce the nitrogen oxide emission from marine diesel engines. In general, it is considered that recirculating gas influences fuel combustion and emissions in diesel engines. However, along with positive effects of EGR, the EGR system using fuels of including high sulfur concentration should be considered about re-combustion and activation of sulfur dioxide in recirculating gas. Therefore, in experimental study, an author investigates effects of sulfur dioxide mixture concentration in intake air on combustion and exhaust emission characteristics in a direct injection diesel engine. In results, change of sulfur dioxide concentrations in intake air had negligible impact on combustion chamber pressure, rate of heat release and emissions compared with effects of oxygen decreasing and carbon dioxide increasing of EGR.

• 한국자동차공학회논문집
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• 제20권4호
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• pp.39-45
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• 2012

Today gasoline engines for vehicular application are not only faced with stringent emission regulation but also with increasing requirements to better fuel economy, while guaranteeing power density. The spray-guided type gasoline direct injection (GDI) engine has an advantage of improved thermal efficiency and lower harmful emissions. Centrally mounted high pressure injector and adjacent spark plug allow stable lean combustion due to the flexible mixture stratification. In the present study, the performance and emissions characteristics of developed spray-guided type GDI combustion system were evaluated at various excess air ratio conditions. The specific fuel consumption and nitrogen oxides ($NO_x$) emissions were reduced due to the achievement of stable lean combustion under flammability limit. Multiple injection strategy was not helpful to improve fuel consumption while further reduction of $NO_x$ emissions was possible.

• 한국연소학회지
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• 제20권2호
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• pp.36-39
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• 2015

The combustion characteristics of metal fiber burner fueled natural gas with tail gas produced from reforming process were analyzed on the point of flame stability and excess air conditions. Also, it was analyzed the effect of energy efficiency improvement due to decrease the fuel input in reforming system by using residue gases. As a results, it was confirmed that tail gas including hydrogen, CO and $CO_2$ could be directly injected without any change of air control system in natural gas burner and also energy efficiency was increased up to 30% maintained stable combustion.