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Research Article
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Comparison of NO Emission with Flue Gas Recirculation Methods in Preheated Air Condition
예열공기 조건의 대향류 확산화염에서 배기가스 재순환 방식에 따른 NO 배출 비교
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Seo Hee Cho, Kee Man Lee
조서희, 이기만
- External flue gas recirculation has been applied to achieve ultra-low NOX combustion in industrial boilers. In this paper, three recirculation methods …
- External flue gas recirculation has been applied to achieve ultra-low NOX combustion in industrial boilers. In this paper, three recirculation methods were studied numerically in methane-air counterflow diffusion flames, which flue gas was diluted in fuel (FIR), air (FGR) and both (FIR+FGR) sides. Burned gas was used as a diluent, and NOX emission was calculated in ambient and preheated air to simulate the practical boiler conditions. As a result, the maximum flame temperature of FIR was the lowest, and the flame extinction limit of FGR was the widest. Before the flame zone, NOX consumption reaction steps occurred near the nozzles, especially the fuel side. To eliminate this effect, emission index of NO (EINO) was calculated at the flame zone and it is compared with original EINO. EINO of FIR was the lowest, and the tendencies of FIR and FIR+FGR were similar. It can be seen that the recirculation of fuel-side is greatly influenced on the flame zone and effective in reducing NO. Finally NO emission was evaluated through NO formation mechanism. - COLLAPSE
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Comparison of NO Emission with Flue Gas Recirculation Methods in Preheated Air Condition
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Research Article
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A Study on the Hydrogen Combustor with Swirl Nozzles
Swirl 타입 노즐 적용 수소 전소 연소기 연구
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Jeongjae Hwang, Min Kuk Kim, Won June Lee, Shershnyov Borys , Youngjun Shin, Eun-Seong Cho
황정재, 김민국, 이원준, BorysShershnyov, 신영준, 조은성
- A hydrogen combustor for applying to 5MWe-class small gas turbines was designed and experimentally investigated in this study. A swirl type, not …
- A hydrogen combustor for applying to 5MWe-class small gas turbines was designed and experimentally investigated in this study. A swirl type, not a multi-tube type, which is widely used in the recently developed hydrogen combustor, was applied to this hydrogen combustor. The test was conducted at the inlet temperature of 410°C which is derived from cycle analysis and at atmospheric pressure (1.35 barA). First, the ignition test was performed while switching from NG flame to hydrogen flame. Flame structures (from direct photo and OH* chemiluminescence), NOX emission and dynamic pressure were observed with varying adiabatic flame temperatures and fuel splits of FC1 and FC2. Lean blowout and flashback characteristics were investigated with varying equivalence ratio and flow velocity. Flame was converted from V-shaped flame to M-shaped flame as equivalence ratio increases and M-shaped one has higher NOX emissions. NOX emission is under 3 ppm (@15% O2) at 1860 K of flame temperature which is equivalent or even lower level of NG combustors. It was found that the operating range from lean blowout to flashback is very wide. - COLLAPSE
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A Study on the Hydrogen Combustor with Swirl Nozzles
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Research Article
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Predicting Fundamental Combustion Properties and Products from Synthetic Oxymethylene Ethers as an E-diesel Blendstock
경유 대체 합성연료로서 OME 혼합 사용시 예상되는 기본 연소 특성 변화 및 생성물 예측
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Hwasup Song, Jaeho Wi
송화섭, 위재호
- Ignition delay times and counterflow diffusion flame products are predicted by blending oxymethylene ether-2 (OME-2) into a surrogate diesel. OME-2 is one …
- Ignition delay times and counterflow diffusion flame products are predicted by blending oxymethylene ether-2 (OME-2) into a surrogate diesel. OME-2 is one of a promising e-diesel blendstock which is synthesized from carbon dioxide and hydrogen, thereby reducing net carbon emission from a carbon life-cycle perspective. Results show that OME-2 is more reactive in engine-relevant conditions and the formation of particulate matter from a diffusion flame could be suppressed, thanks to its higher oxygen content. However, potentially harmful intermediates, e.g., formaldehyde and methyl formate, could be formed in large quantity with the use of OME-2, therefore novel combustion strategy and proper exhaust after-treatment system shall be essential for its practical use. - COLLAPSE
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Predicting Fundamental Combustion Properties and Products from Synthetic Oxymethylene Ethers as an E-diesel Blendstock
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Research Article
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Improvement of Low-temperature Oxidation Reaction of Biodiesel Reduction Mechanism and Analysis of 3-D Engine
바이오디젤 축소 메커니즘의 저온산화반응 개선 및 3-D 엔진 해석
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Yun Seok Song, Young Chan Lim, In Gang Park, Hyun Kyu Suh
송윤석, 임영찬, 박인강, 서현규
- This study was conducted to improve errors such as low-temperature heat release, ignition delays, and exhaust emissions that occurred during the mechanism …
- This study was conducted to improve errors such as low-temperature heat release, ignition delays, and exhaust emissions that occurred during the mechanism reduction process. To achieve this, the error of the reduced mechanism was improved by modifying the A-factor of the important reaction in the selected combustion process through the analysis of the reaction path of 0D CVC. As a result of the 3D CFD analysis, the NOx error rate of the improved mechanism decreased from 92% to 14%, the ignition delay error decreased by 2% on average, and the low temperature and NTC regions, which were the key targets, decreased by 6%. - COLLAPSE
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Improvement of Low-temperature Oxidation Reaction of Biodiesel Reduction Mechanism and Analysis of 3-D Engine
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Research Article
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Comparisons of Flashback Characteristics of Hydrogen Flames by Combustion Models in an Industrial Gas Turbine Combustor
산업용 가스터빈 연소기에서 연소 모델에 따른 수소 화염의 역화 특성 비교연구
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Minjun Choi, Inyeong Gu, Youngjun Shin, Eun-Seong Cho, Dong-hyuk Shin
최민준, 구인영, 신영준, 조은성, 신동혁
- Four different combustion models were investigated to test hydrogen flame flashback prediction capability in an industrial gas turbine combustor. The applied combustion …
- Four different combustion models were investigated to test hydrogen flame flashback prediction capability in an industrial gas turbine combustor. The applied combustion models are (i) flamelet generated manifold - finite rate (FGM-FR) model, (ii) flamelet generated manifold - turbulent flame speed (FGM-ST) model, (iii) steady diffusion flamelet (SDF) model, and (iv) eddy dissipation concept (EDC) model. Two conditions were simulated which showed experimentally non-flashback and flashback respectively. For the experimentally non-flashback condition, FGM-ST, SDF, and EDC model simulations show flashback, while FGM-FR did not show flashback. For the experimentally flashback condition, FGM-ST, SDF, and EDC model simulations show flashback, while FGM-FR did not show flashback. To be able to predict hydrogen-flame flashback, further investigation on combustion model are needed. - COLLAPSE
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Comparisons of Flashback Characteristics of Hydrogen Flames by Combustion Models in an Industrial Gas Turbine Combustor
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Research Article
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Physical and Chemical Properties of ULSD Particulate Matter with Hygroscopicity
습식 성장한 ULSD 입자상 물질의 물리적 및 화학적 특성 분석에 관한 연구
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Byeol Kang, Seul-Hyun Park
강별, 박설현
- Condensation of water can affect the morphology of particulate matter (PM) produced from burning hydrocarbon fuel and thus their refractive index, eventually …
- Condensation of water can affect the morphology of particulate matter (PM) produced from burning hydrocarbon fuel and thus their refractive index, eventually altering the light scattering properties of particles. Optical characteristics of PMs released in the air is an essential research to reduce uncertainty in terms of environmental and climate models. However, research results on the effect of hygroscopicity of particulate matter on optical properties are relatively insufficient. Therefore, in this study, optical characteristics were studied through physical and chemical analysis of Ultra Low Sulfur Diesel (ULSD) PM produced under different relative humidity conditions. While Transmission Electron Microscope(TEM) analysis was performed to confirm the physical shape, Raman spectra & total carbon analysis were performed to elucidate the degree of graphitization of carbon of PM. Results obtained from series of analyses clearly indicate that ULSD PM reacted with water to collapse the agglomerate structure into a compact form, thus resulting in an increase in the light scattering effect. - COLLAPSE
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Physical and Chemical Properties of ULSD Particulate Matter with Hygroscopicity
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Research Article
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The Economic Feasibility and the Impact of GHG Emission for Greenhouse Heating and CO2 Enrichment System by Using Gas Engine Driven Heat Pump
가스히트펌프를 이용한 온실 난방 및 배가스 탄산시비 시스템의 경제성 및 온실가스 배출 영향 평가
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Jeong Hwa Cho, Sang Seok Yu, Sang Min Lee
조정화, 유상석, 이상민
- The area of domestic horticulture continuously enlarged and the heating costs also increased to about 30 ~ 40% of the total operating …
- The area of domestic horticulture continuously enlarged and the heating costs also increased to about 30 ~ 40% of the total operating expenses. To enhance the profitability of production, it is increasingly important to estimate the energy costs of greenhouses properly. This study aimed to compare the economic feasibility and the greenhouse gas emission of greenhouse energy systems according to heating methods with different fuel types. The annual power consumption was calculated by using TRNSYS, a commercial Building Energy Simulation(BES) tool. First, the model validation was performed using the experimental data obtained from the greenhouse that uses a gas engine drive heat pump. The results were compared with the reference kerosene heating case (CASE 1), which is widely used in domestic greenhouses. The analysis showed that gas heating case (CASE 2) has reduced total energy costs by 20% and greenhouse gas emissions by 10%. Whereas, the exhaust gas from gas engine driven heat pump can be used as a CO2 source for enhancing photosynthesis. Lastly. the results from the GHP heating case (CASE 3) showed a 46% reduction in total cost and a 63% reduction in greenhouse gas emissions. - COLLAPSE
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The Economic Feasibility and the Impact of GHG Emission for Greenhouse Heating and CO2 Enrichment System by Using Gas Engine Driven Heat Pump