• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.985-994
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• 2018

Bio-heavy oil for power generation is a product made by mixing animal fat, vegetable oil and fatty acid methyl ester or its residues and is being used as steam heavy fuel(B-C) for power generation in Korea. However, if the fuel supply system of the fuel pump, the flow pump, the injector, etc., which is transferred to the boiler of the generator due to the composition of the raw material of the bio-heavy oi, causes abrasive wear, it can cause serious damage. Therefore, this study evaluates the fuel characteristics and lubricity properties of various raw materials of bio-heavy oil for power generation, and suggests fuel composition of biofuel for power generation to reduce frictional wear of generator. The average value of lubricity (HFRR abrasion) for bio-heavy oil feedstocks for power generation is $137{\mu}m$, and it varies from $60{\mu}m$ to $214{\mu}m$ depending on the raw materials. The order of lubricity is Oleo pitch> BD pitch> CNSL> Animal fat> RBDPO> PAO> Dark oil> Food waste oil. The average lubricity for the five bio-heavy oil samples is $151{\mu}m$ and the distribution is $101{\mu}m$ to $185{\mu}m$. The order of lubricity is Fuel 1> Fuel 3> Fuel 4> Fuel 2> Fuel 5. Bio-heavy oil samples (average $151{\mu}m$) show lower lubricity than heavy oil C ($128{\mu}m$). It is believed that bio-heavy oil for power generation is composed of fatty acid material, which is lower in paraffin and aromatics content than heavy oil(B-C) and has a low viscosity and high acid value, resulting in inhibition of the formation of lubricating film by acidic component. Therefore, in order to reduce friction and abrasion, it is expected to increase the lubrication of fuel when it contains more than 60% Oleo pitch and BD pitch as raw materials of bio-heavy oil for power generation.

• Journal of Institute of Convergence Technology
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• v.3 no.1
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• pp.15-18
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• 2013

The next generation alternative fuel of diesel, DME (Dimethyl Ether) discharges particulate matter hardly due to chemical structural as oxygen-fuel so it has the eco-friendly property. Despite these advantages, the DME has the technical difficulties to apply to the diesel engine because of a low calorific value, viscosity and compressibility effects. From this point of view, we performed experimental studies on improved reliability of DME common-rail vehicle and lubricity enhancement of DME fuel for empirical distribution of eco-friendly DME fuel. Also we analyzed solubility of lubrication enhancer according to a drop in temperature, try to secure reliability about core parts of DME vehicle by applying lubrication enhancer in the DME common-rail vehicle.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1997.10a
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• pp.129-134
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• 1997

현재 외부 가압 공기베어링이 사용되어지는 분야는 PCB 기판, 엔진의 연료분사노즐 등의 고속가공용 스핀들, 전자 기기, 광학 기기 등에 사용되는 초정밀 부품가공용 스핀들, 정밀 측정 기기, 의료 기기, 저온 팽창기등 상대운동을 하는 많은 분야에서 이용되고 있으며, 이들 분야의 고속화 및 고정밀화 추세에 따라 고속에서의 안정성과 높은 운전정밀도가 보장된 외부 가압 공기 베어링이 요구되고 있다. 정밀 스핀들 시스템에 공기베어링이 사용되는 이유는 윤활제인 공기의 압축성에 기인된 평균화효과로 인하여 어느 정도 형상오차가 존재하더라도 축의 회전 시 떨림 진폭이 흡수되어 높은 운전정밀도를 유지하며 운전이 가능하기 때문이다. 그러나, 공기의 압축성에 의한 평균화효과로 어느 정도의 떨림 진폭은 흡수되나 형상오차에 의한 떨림 진폭은 작은 크기라도 여전히 남아있게 된다. 따라서, 초정밀 가공 기기나 정밀 측정 기기 등 높은 운전정밀도가 요구되는 곳에 공기베어링이 사용될 경우에 있어서 형상오차는 운전정밀도에 영향을 미치는 중요한 인자가 된다. 본 연구에서는 각각 두 개의 오비 가압 공기 저널 및 스러스트 베어링으로 구성된 스핀들 시스템에 대한 축과 베어링의 직각도 오차가 운전정밀도에 미치는 영향에 대해 해석하고 결과를 고찰하여 스핀들 시스템에 있어서 형상 공차에 대한 기초 설계자료를 제시하고자 한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.548-551
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• 2010

A 150 lbf-thrust class micro turbojet engine has been developed. The engine could be applied to power plant for small aviation vehicle such as UAV, decoy and anti-radar missile and was designed with concepts that has small size, low-cost and high performance. A prototype was manufactured and performed the ground static test and high altitude test. This paper outlines the features and layout of 150 lbf turbojet engine and also describes the design characteristics and test results of the engine and components.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.8
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• pp.1153-1163
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• 2002

A transient analysis on temperatures of fuel and oil in hydraulic and lubrication systems in an aircraft was studied using the finite difference method. Numerical calculation was performed by an explicit method with modified Dufort-Frankel scheme. Among various missions, air superiority mission was considered as a mission model with 20% hot day ambient condition in subsonic region. The ambience of the aircraft was assumed as turbulent flow. Convective heat transfer coefficient were used in calculating heat transfer between the aircraft surface and the ambience. For an aircraft on the ground, an empirical equation represented as a function of free-stream air velocity was used. And the heat transfer coefficient for flat plate turbulent flow suggested by Eckert was employed for in-flight phases. The governing equations used in this analysis are the mass and energy conservation equations on fuel and oils. Here, analysis of fuel and oil temperature in the engine was not carried out. As a result of this analysis, the ground operation phase has shown the highest temperature and the largest rate of temperature increase among overall mission phases. Also, it is shown that fuel flow rate through fuel/oil heat exchanger plays an important role in temperature change of fuel and oil. This analysis could be an important part of studies to ensure thermal stability of the aircraft and can be applicable to thermal design of the aircraft fuel system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1277-1282
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• 2011

Recently, many car drivers were damaged by gas station which support similar oil product and not quantitative gas. It were expected to increase above-mentioned damages. By using similar oil products, caused damage are working of lubrication in the fuel line, elf-cleaning function, the part of the early deterioration, impure accumulation in the fuel line, toxicity material in exhaust emissions and unidentified chemical reaction. To prevent these damages, proposed system use in-vehicle state data with OBD-II protocol, measure quantitative gas and similar oil. In this paper, there have implemented similar oil identification and quantitative gas system through OBD-II scanner to provide WiFi communcation by using WinCe development Board.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.281-284
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• 2011

Recently, many drivers was the damage caused by similar oil product sales and gas station by not using quantitative gas. so, these damages is expected to rise damages by increasing these problem. By using similar oil products, caused damage in the fuel lines' working of lubrication and self-cleaning function for the occurred trouble in the part of the early obsolescence and the accumulation of impurities in the fuel lines, combustion rate due to the difference between retail gasoline engine, the burden of weight, Toxic substances in exhaust emissions, engine oil and unresolved issue is the chemical reaction can occur. to prevent these damages, using the system use in-vehicle state data with OBD-II protocol and measure quantitative gas and similar oil. In this paper, there implement similar oil identification and quantitative gas system through OBD-II scanner to provide WiFi communcation by using WinCe development Board.

• Journal of the Korean Institute of Gas
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• v.19 no.1
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• pp.12-17
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• 2015

The core of the CNG fueling station is the compressor and most of CNG compressors in Korea require lubrication. Lubrication oil of CNG compressor that can be transferred into the pressure regulators and the engines of fueling system can cause a negative effect on NGV(Nature Gas Vehicle) performance during refueling due to oil Carry-over. In order to avoid the problem, it is necessary to enhance the quality of the compressed natural gas by measuring quantitatively the amount of the transferred oil. In this research, a sampling device and sampling tube were developed, which can be used with a gravimetric method of detection to measure CNG oil Carry-over. In addition, CNG samples were taken at 6 pre-selected CNG fueling stations and analysed for their trace oil Carry-over. The measured total oil Carry-over ranged from 2.569 to 6.509 ppm. This test measurements were compared with those of previous studies to verify the results.