• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.92-95
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• 2011

A multi-step quasi-global mechanism is developed for the kerosene/oxygen combustion analysis including dissociation products. Reaction constants of the global reaction are determined to have agreement with experimental data. The mechanism is used for the numerical analysis of the combustion flow field of the kerosene/oxygen shear coaxial injector. The results from high-resolution numerical analysis confirmed qualitatively that the recess enhance the fuel/air mixing and combustion efficiency by the increased flow instabilities.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.139-141
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• 2015

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.84-90
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• 2023

Oxygen, which is always present in the atmosphere among the three elements of combustion, can cause fires and explosions with only a very small amount of combustibles under high-pressure oxygen conditions. The burning rate is also significant, and can rise to temperatures that can have a direct impact, such as melting process equipment and piping in an instant. Therefore, accidents that occur under high pressure oxygen often cause more damage than other accidents. Recently, while operating a valve installed in an oxygen supply pipe, rapid combustion and rupture occurred inside, resulting in human casualties due to an explosion. In the case of an old carbon steel pipe, particles generated during operation become combustible and can cause accidents. . In particular, since oxygen facilities are facilities licensed under the High Pressure Gas Safety Management Actand there are no restrictions under the Occupational Safety and Health Act, accumulating these standards is of utmost importance. Therefore, in this study, based on accident cases and overseas standards, methods for improving safety when handling hyperbaric oxygen are reviewed.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.6
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• pp.45-52
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• 2021

A hot-firing test was conducted using gaseous-methane and gaseous-oxygen under highly fuel-rich condition as a prior study for the development of a liquid propellant small rocket engine. To compare combustion characteristics for various equivalence ratios, the oxygen flow rate was set to 12 g/s and the methane flow rate was changed according to the equivalence ratio. As a result, it was observed that the steady-state characteristic velocity obtained during the hot-firing test steeply rose in the latter part of each test: the difference between the former and the latter steady value was enhanced overall in proportion to the equivalence ratio. Based on this, the equivalence ratio range depending on the variational characteristics of the characteristic velocity could be divided into three combustion regimes.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.11
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• pp.1065-1072
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• 2012

Due to its oxygen (O) content, biodiesel (BD) is advantageous in that it lowers PM emissions in CI engines. Therefore, BD is considered one of the best candidates for low temperature combustion (LTC) operation because its use can extend the regime for simultaneous reduction of PM and $NO_x$. Thus, in this study, LTC operation was realized using BD and diesel with a 5~7% $O_2$ fraction. Engine test results show that the use of BD increased the efficiency and reduced emissions such as PM, THC, and CO; furthermore, IMEP reduced by 10~12% owing to the lower LHV of the fuel. In particular, smoke was suppressed by up to 90% because O atoms in the BD enhanced the soot oxidation reaction. To compensate the IMEP loss, turbocharging (TC) was then tested, and the results showed that the power output increased and PM was reduced further. Moreover, TC in BD engine operation allowed a similar level of reduction in both $NO_x$ and PM at 11~12% $O_2$ fraction, suggesting that there is a potential to widen the operating range by the combination of TC and BD.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.05a
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• pp.38-40
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• 2003

본 연구에서 적용한 저 NOx 연소법의 NOx 저감 효과를 비교해 보면 다단 연소법이 지연연소 효과와 국부적인 최고 화염온도 감소, 고온부에서의 산소농도 감소효과 등이 동시에 나타나 저 과잉공기 연소법, 배기가스 재순환법, 이단 연소법 보다 더 큰 NOx 저감효과를 얻을 수 있음을 알 수 있었다. 다만, 총 공급공기 량에 대한 분할 공급공기량의 비가 일정수준 이상으로 커지면 CO 발생량 증가로 효율저하 등의 문제점이 우려되므로 연소상태를 저하시키지 않는 공급비를 산정하는 것이 중요할 것으로 생각된다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.608-611
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• 2011

Laser-induced combustions and explosions generated by high laser irradiances were explored by Laser-Induced Breakdown Spectroscopy (LIBS) in rich, and stoichiometric conditions. The laser used for target ablation is a Q-switched Nd:YAG laser with 7 ns pulse duration at wavelength of 1064 nm laser energies from 40 mJ to 2500 mJ ($6.88{\times}10^{10}-6.53{\times}10^{11}\;W/cm^2$). The plasma light source from aluminum detected by the echelle grating spectrometer and coupled to the gated ICCD(a resolution (${\lambda}/{\Delta}{\lambda}$) of 5000). This spectroscopic study has been investigated for obtaining both the atomic signals of aluminum (fuel) - oxygen (oxidizer) and the calculated ambient condition (plasma temperature and electron density). The essence of the paper is observing specific electron density ratio which can support the processes of combustion and explosion between ablated aluminum plume and oxygen from air by inducing high power laser.

• Journal of Korean Society of Forest Science
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• v.79 no.3
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• pp.255-259
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• 1990

To investigate relative flammability in flaming combustion among 10 softwoods and 10 hardwoods, oxygen indices were determined for flat-grained sapwoods through Up and Down method following oxygen index test of ASTM D 2863-77. Oxygen index ranged from 21.0 for Pinus strobus to 28.2 for Larix gmelinii var. principis-ruprechtii in softwoods and from 20.7 for Populus davidiana to 27.6 for Quercus acntissima in hardwoods, which indicates Larix gmelinii var. principis-ruprechtii and Quercus acutissima being ranked first in inflammability and Pinus strobus and Populus davidiana being the least in fire resistance by softwood and hardwood because highly flammable materials are likely to have a low oxygen index.

• Clean Technology
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• v.22 no.3
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• pp.161-167
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• 2016

Catalytic combustion of benzene over various metal cation-exchanged zeolites has been investigated. Y(4.8)-type zeolite showed the highest activity among the used zeolites and Cu/Y(4.8) catalyst also showed the highest activity among metal cation/ Y(4.8) zeolites. The catalytic activity increased according to the amount of adsorbed oxygen acquired from O₂ TPD results. The catalytic activity also increased with an increase of Cu cation concentration on Cu/Y(4.8) catalysts. The conversion of benzene on the combustion reaction depended on not benzene concentration but the oxygen concentration. In addition, the introduction of water into reactants decreased the catalytic activity.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.1
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• pp.66-72
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• 2010

This study was done to analyze the condition of combustion exhaust gas that is produced according to incinerator operating condition in A area Kyonggido. The boiler exhaust gas temperature, the oxygen concentration of boiler, the outgassing temperature of Semi Drying Sorber(SDS), the temperature of catalytic reactor, the concentration of NOx, SOx, CO, Hcl and Dust were investigated by change the temperature of incinerator. The concentration of SOx, CO, HCL and DUST were below 5 ppm as increase the temperature of incinerator however the concentration of NOx was increased from 40 ppm to 70 ppm as increase the temperature of incinerator. The boiler exhaust gas temperature and the temperature of catalytic reactor were not changed however the oxygen concentration of boiler was decreased gradually as increase the temperature of incinerator.