• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.464-466
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• 2011

This technical paper presents a new solid propellants family. The views are based on open literature and patents recently. Electrically controlled extinguishable solid propellants (ESCSP) are capable of multiple ignitions, extinguishments and throttle control by the application of electrical power. Both core and end burning no moving parts ECESP grains/motors to three inches in diameter have now been tested. Ongoing research has led to a newer family of even higher performance ECESP providing up to 10% higher Isp, manufacturing ease, and significantly higher electrical conduction.

• Journal of the Korean Institute of Gas
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• v.1 no.1
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• pp.1-6
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• 1997

In case of using the electrical apparatus in the hazardous atmosphere which exist flammable gas mixtures, There is a dangerosity of gas explosion accident by the electrical spark. The most general method to prevent the explosion by the spark is to use the flame-proof type electrical apparatus to isolate the ignition source. from the flammable atmosphere. But actualy it is impossible to isolate the ignition sources from the atmosphere. So it was needed to find the safe gap which prevent ignition of flammable atmosphere by transmission of flame or heat when a flammable gas mixture exploded inside the apparatus. In this study we tried to find the maximum experimental safe gap(MESG) of $H_2$-air, and $CH_4$-air mixtures by using the 8 litre spherical vessel with 25mm flange. The experiment parameter were ignition position, concentration and initial pressure before explosion. From the experiment the ignition position was affected to the MESG. MESG value was minimum near the stoichiometric concentration of gas mixtures, and according to the increase of initial pressure MESG was decreased.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.4
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• pp.26-32
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• 2014

The combustion characteristics of Boron-beads to improve the energy density of gas generator has been investigated in accordance with diameter of beads and their composition. In this paper, electrically heated tungsten sheet and visualized furnace are applied to measure ignition temperature and burning time of bead respectively. The results proposes ignition temperature between 720~800 K and burning time proportional to bead diameter. Also a ignition delay of boron particle is detected through the temperature and radiation intensity measurements.

• Journal of the Korean Institute of Gas
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• v.21 no.5
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• pp.70-76
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• 2017

The standards related to the "Urban Gas Business Act" and the "Safety Control and Business Regulation of Liquefied Petroleum Gas Act" prescribe the separation distance between gas piping joint excluding welded joints and electric equipments(electric switch, watt meter, breaker, connector, etc). The "Korea Electro technical Regulation" also prescribes the distance between gas piping joints and electric equipments in accordance with the gas related standards. In case of the standards related to the "Urban Gas Business Act", the distance criteria stipulated in the standard of supplying facilities are different from those stipulated in the standard of using facilities. In this study, we have conducted pilot test on the possible ignition distance from the piping joint when LP gas is leaked from the point. We have also examined the adequacy of current standards on the separation distance between gas piping joint and electric equipments. As a result of the tests, we have found that ignition is able to occur at a distance of 30 cm as stipulated in the current standards or more when LP gas is leaked from the joint of the pipe. Therefore, we have made a decision that the criteria for separation distance between gas piping joint and electric equipment specified in the current standards related to the "Urban Gas Business Act" and the "Safety Control and Business Regulation of Liquefied Petroleum Gas Act" is appropriate.

• 전기의세계
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• v.37 no.5
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• pp.3-8
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• 1988

우리나라의 전력 사업은 1887년 경복궁내 건청궁에서 하나의 전등이 최초로 점화된 이후 100년이 경과하여 1988년 금년은 한국 전기의 2세기를 맞이하는 첫해가 되고 있다. 현재 한국이 보유하고 있는 전력생산 설비는 민간기업이 소유한 자가용 발전시설을 제외하고 총 1900만 kW에 달하고 있으며, 1987년도의 총 발전량은 785kWh에 이르러 전력수요성장은 전년도 대비 14%의 증가를 나타내고 있다. 특히, 이러한 전력 수요에 부응하기 위한 총 발전량의 53.1%의 393억kWh는 원자력 발전소에서 공급되었다는 사실은 경제성장과 사회문화의 발전에 따라 에너지 특히, 전력에너지의 역할이 더욱 중요해지고 있다는 점을 감안한다면 이미 원자력발전은 우리 경제 사회활동과 생활여건에 크게 영향을 미치고 있다는 현실로 인식할 필요가 있다.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.3
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• pp.122-129
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• 1996

The spark timing is one of major parameters to the engine performance and emissions. The ECU controls the spark timing based on preset values, which are functions of load and speed, in most of today's automotive SI engine. In this system, the preset spark timing can be different from optimum value due to the deviations from mass production, aging effects and so on. In the present study, a control logic is investigated for real time adaptation of spark timing to optimal value. It has been found that crank angle of miximum cylinder pressure is one of the appropriate parameters to estimate the optimum spark timing throught experiment. It has also been observed for spark timing convergence by variation of engineering model factors. The simulation program including engineering model for cycle by cycle variation of combustion is developed for surveying spark timing control logic. It is also shown that simulation results reflect experiment outputs and reasonableness of spark timing control logic for crank angle of maximum cylinder pressure.

• Journal of the Korean Institute of Gas
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• v.20 no.3
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• pp.30-37
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• 2016

Electrical apparatuses for use in the presence of flammable gas atmospheres have to be specially designed to prevent them from igniting the explosive gas. Flameproof design implies that electrical components producing electrical sparks are contained in enclosures and withstand the maximum pressure of internal gas or vapours. In addition, any gaps in the enclosure wall have to designed in such a way that they will not transmit a gas explosion inside the enclosure to an explosive gas or vapours atmosphere outside it. In this study, we explained some of the most important physical mechanism of MESG(Maximum Experimental Safe Gap) that the jet of combustion products ejected through the flame gap to the external surroundings do not have an energy and temperature large enough to initiate an ignition of external gas or vapours. We measured the MESG and maximum explosion pressure of ternary gas mixtures(propane-acetylene-air) by the test method and procedure of IEC 60079-20-1:2010. As a result, the composition of propane gas that has lower explosive power than acetylene gas in the ternary gas mixtures makes greater effects on MESG and explosion pressure.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.6
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• pp.8-17
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• 2010

This paper proposes a novel LCD CCFL-backlight electronic ballast using the phase-shift full-bridge inverter. The proposed electronic ballast reduces the ignition voltage and eliminates current spikes using the new digital dimming control applied with soft-starting. Thus the electronic ballast improves ignition behavior of the CCFL and hence increases the CCFL's life span. For this, this paper analyzes the full-bridge inverter topology of the proposed electronic ballast and explains the new digital dimming control algorithm applied to the ballast, briefly. And this paper shows a design example of the prototype circuit and explains an implementation method of the digital dimming control which is implemented on a single-chip microcontroller with software. This was implemented as actual prototype electronic ballast, and its experimental results showed that the proposed electronic ballast operates correctly. The ignition voltage of the prototype in the digital dimming operation was reduced about 30[%] compared with the conventional electronic ballast and there were not any current spikes.

• Journal of IKEEE
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• v.18 no.2
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• pp.179-184
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• 2014

In this paper, we have developed a data monitoring system for activation analysis based on fuel heater of diesel cars. The light oil of diesel engine below a constant temperature be changed to the waxing materials of a semisolid status like a paraffin, and then it may not start. In order to evaluate an engine activation performance, we suggest an engine start time with an change between an extremely low temperature and high temperature, a delay time goes with heater resistor and current and pressure. So, we have developed sensor module system that can obtain the operational status data between fuel line and fuel heater, and evaluate the performance of fuel heater through monitoring of a temperature and pressure. Finally, we can gather the temperature and pressure data of this system with mobile terminal, remotely and propose an utility of this system that can find problems of fuel heater through measured data.

• Journal of the korean Society of Automotive Engineers
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• v.6 no.3
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• pp.36-44
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• 1984

The prediction of the emission concentrations in 4-cycle 4-cylinder spark ignition engine is made by considering the model with the extended Zedovich mechanism. The predicted values for nitric oxide, carbon dioxide and carbon monoxide agree with the experimentally measured ones.