• 한국가스학회지
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• 제18권3호
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• pp.75-81
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• 2014

이소부틸알코올의 안전한 취급을 위해, 폭발한계는 문헌을 통해 고찰하였으며, 인화점과 발화지연시간에 의한 자연발화온도는 장치를 이용하여 측정하였다. 공정에서는 이소부틸알코올의 폭발하한계는 1.7 Vol.% 그리고 상한계는 10.9 Vol.%가 사용되고 있다. 인화점의 경우 밀폐식 장치인 Setaflash와 Penski-Martens에 의한 하부인화점은 각 각 $25^{\circ}C$와 $30^{\circ}C$로 측정되었으며, 개방식인 Tag와 Cleveland 에서는 각 각 $36^{\circ}C$와 $39^{\circ}C$로 측정되었다. ASTM E659 장치를 사용하여 자연발화온도와 발화지연시간을 측정하였고, 이소부틸알코올의 최소자연발화온도는 $400^{\circ}C$로 측정되었다.

• 한국화재소방학회논문지
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• 제24권6호
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• pp.76-81
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• 2010

노말헵탄의 안전한 취급을 위해서 $25^{\circ}C$에서 폭발한계와 폭발한계 온도의존성 그리고 하부인화점을 고찰하였다. 또한 발화지연시간에 의한 발화온도를 측정하였다. 공정의 안전을 위해서 노말헵탄의 폭발하한계는 1.0Vol%, 상한계는 7.0Vol%를 추천하였고, 하부인화점은 $-4^{\circ}C$를 추천하였다. ASTM E659-78 장치를 사용하여 발화온도와 발화지연시간을 측정하였고, 여기서 측정된 최소자연발화온도는 $225^{\circ}C$였다. 그리고 노말헵탄의 새로운 폭발한계 온도의존식을 제시하였으며, 제시된 식은 문헌값과 일치하였다.

• 에너지공학
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• 제23권4호
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• pp.169-175
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• 2014

에틸벤젠의 안전한 취급을 위해, 폭발한계는 문헌을 통해 고찰하였으며, 인화점과 발화지연시간에 의한 자연발화온도는 시험장치를 이용하여 측정하였다. 인화점의 경우 밀폐식 장치인 Setaflash와 Penski-Martens에 의한 하부인화점은 각 각 $20^{\circ}C$와 $22^{\circ}C$로 측정되었으며, 개방식인 Tag와 Cleveland에서는 각 각 $25^{\circ}C$와 $28^{\circ}C$로 측정되었다. ASTM E659 장치를 사용하여 자연발화온도와 발화지연시간을 측정하였고, 최소자연발화온도는 $430^{\circ}C$로 측정되었다. 에틸벤젠의 측정된 인화점을 이용하여 폭발하한계와 상한계는 0.93 Vol.%와 7.96 Vol.%로 계산되었다.

• 한국가스학회지
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• 제18권4호
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• pp.44-50
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• 2014

아닐린의 안전한 취급을 위해, 폭발한계는 문헌을 통해 고찰하였으며, 인화점과 발화지연시간에 의한 자연발화온도는 시험장치를 이용하여 측정하였다. 인화점의 경우 밀폐식 장치인 Setaflash와 Penski-Martens 에 의한 하부인화점은 각 각 $66^{\circ}C$와 $73^{\circ}C$로 측정되었으며, 개방식인 Tag와 Cleveland 에서는 각 각 $72^{\circ}C$와 $78^{\circ}C$로 측정되었다. ASTM E659 장치를 사용하여 자연발화온도와 발화지연시간을 측정하였고, 최소 자연발화온도는 $590^{\circ}C$로 측정되었다. 아닐린의 측정된 인화점을 이용하여 폭발하한계와 상한계는 1.16 Vol.%와 8.36 Vol.%로 게산되었다.

• International Journal of Aeronautical and Space Sciences
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• 제18권3호
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• pp.512-521
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• 2017

This paper reports development process of a university-based sounding rocket using simplified hybrid rocket propulsion system for low-altitude flight application. A hybrid propulsion system was tried to be designed with as few components as possible for more economical, simpler and safer propulsion system, which is essential for the small scale sounding rocket operation as a CanSat carrier. Using blow-down feeding system and catalytic ignition as combustion starter, 250 N class hybrid rocket system was composed of three components: a composite tank, valves, and a thruster. With a composite tank filled with both hydrogen peroxide($H_2O_2$) as an oxidizer and nitrogen gas($N_2$) as a pressurant, the feeding pressure was operated in blowdown mode during thruster operation. The $MnO_2/Al_2O_3$ catalyst was fabricated for propellant decomposition, and ground test of propulsion system showed the almost theoretical temperature of decomposed $H_2O_2$ at the catalyst reactor, indicating sufficient catalyst efficiency for propellant decomposition. Auto-ignition of the high density polyethylene(HDPE) fuel grain successfully occurred by the decomposed $H_2O_2$ product without additional installation of any ignition devices. Performance test result was well matched with numerical internal ballistics conducted prior to the experimental propulsion system ground test. A sounding rocket using the developed hybrid rocket was designed, fabricated, flight simulated and launch tested. Six degree-of-freedom trajectory estimation code was developed and the comparison result between expected and experimental trajectory validated the accuracy of the developed trajectory estimation code. The fabricated sounding rocket was successfully launched showing the effectiveness of the simplified hybrid rocket propulsion system.

• 자동차안전학회지
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• 제13권2호
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• pp.15-23
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• 2021

Even though the number of CO poisoning casualties caused by unintended idling for the vehicles equipped with keyless ignition systems is more than 70, the problem still remains unsolved and became social issue in the US, and Senates introduced the bill which urges NHSTA to make regulation for this accordingly. To meet market safety needs and the regulations, we decided to provide automatic shut-off system very soon. In this paper, we would like to describe how to validate vehicle shut-off timing including defining required tests and case selections considering vehicle condition, garage/room size and temperatures with several assumptions. We believe that safe implementation of the shut-off function is possible via this methodology and the results. As NHTSA must be interested in shut-off timing, the methodology can be enhanced and conclusions could be reflected highly in the future regulation in case we continue this study with NHTSA or any other 3-rd party institutes.

• Tribology and Lubricants
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• 제26권5호
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• pp.277-282
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• 2010

The purpose of this paper is to study and analysis the failure examples for parasitic current leakage produced in starting system on gasoline engine. It verified the discharge of battery by electric leakage because of internal wiring damage problem for CD auto changer installed in car. Also, it verified the no-stating phenomenon because of deposit forming by chemical reaction of battery fluid between battery post and cable fixing parts. It verified the damage for brush holder and commutator mixing by internal short phenomenon because of brush carbon a particle and engine oil that was flowed into internal of starting motor. It verified the working phenomenon of audio by a point of contact even if the driver turn to "LOCK" position the key.

• International Journal of Automotive Technology
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• 제8권3호
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• pp.275-281
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• 2007

GTL (Gas To Liquid) has the potential to be used in diesel engines as a clean alternative fuel due to advantages in emission reduction, particularly soot reduction. Since the physical properties of GTL fuel differ from those of diesel fuel to some extent, studying how this difference in characteristics of GTL and diesel fuels affects spray and combustion in diesel engines is important. In this study, visual investigation of sprays and flames from GTL and diesel fuels in a vessel simulating diesel combustion was implemented. The effects of various parameters and conditions, such as injection pressure, chamber temperature and pilot injection on liquid-phase fuel length and auto-ignition delay were investigated. It was determined that GTL has a somewhat shorter liquid-phase fuel length, which explains why there is less contact between the fuel liquid-phase and flame for GTL fuel compared to diesel fuel.

• 한국안전학회지
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• 제19권4호
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• pp.60-68
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• 2004

Consequence analysis of flammable materials that affect to a risk of facilities was studied at the risk based inspection using API-581. We found that consequence areas (damage area of equipment and fatality area) by release accident of flammable materials showed high value for the case of liquid phase and auto-ignition likely, and that consequence areas of flammable gases decreased as temperature increased and the pipe diameter and pressure decreased at continuous release.

• 한국연소학회지
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• 제15권4호
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• pp.1-8
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• 2010

Mild combustion is considered as a promising combustion technology for energy saving and low emission of combustion product gases. In this paper, the controllability of reaction region in mild combustion is examined by using co-axial air nozzle. For this purpose, numerical approach is carried out. Propane is considered for fuel and air is considered for oxidizer and the temperature of air is assumed 900K slightly higher than auto ignition temperature of propane. But unlike main air, the atmospheric condition of co-axial air is considered. Various cases are conducted to verify the characteristics of Co-Axial air burner configuration. The use of coaxial air can affect reaction region. These modification help the mixing between fuel and oxidizer. Then, reaction region is reduced compare to normal burner configuration. The enhancement of main air momentum also affects on temperature uniformity and reaction region. The eddy dissipation concept turbulence/chemistry interaction model is used with two step of global chemical reaction model.