• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.227-227
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• 2017

• 열병합발전
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• s.71
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• pp.19-23
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• 2009

• 열병합발전
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• s.60
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• pp.21-25
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• 2007

• Journal of ILASS-Korea
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• v.15 no.4
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• pp.195-201
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• 2010

Due to its carbon-neutral nature, biogas generated from anaerobic digestion or fermentation of biodegradable wastes is one of the important renewable energy sources to reduce global warming. It is mainly composed of methane and various inert gases such as $CO_2$ and $N_2$, and the actual composition of biogas significantly varies depending on the origin of anaerobic digestion process. Therefore, in order to effectively utilize this fuel as an energy source for electricity, it is important to develop power generation engines which can successfully apply biogas with significant composition variations. In this study, efforts have been made to develop a diesel-biogas duel fuel engine as a way to achieve such a stable power generation. The effects of diesel fuel injection quantity and pressure on stable combustion and engine performance were investigated, and an impact of diesel fuel atomization was discussed. The engine test results show that there exists a 2 stage combustion which consists of diesel pilot fuel burning and premixed biogas/air mixture burning in dual fuel engine operation and optimum diesel injection parameters were suggested for biogases with various compositions and heating values.

• Journal of the Korean Institute of Gas
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• v.15 no.1
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• pp.9-14
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• 2011

Heavy duty diesel engine has relatively small portion of whole vehicles due to long drive distance and large engine displacement, but largely influences atmosphere environment. City buses changed to CNG (Compressed Natural Gas) bus with Korea-Japan Worldcup. Heavy duty truck and intercity bus, however, were impossible to use CNG because those kinds of vehicles had long drive distance and CNG station was installed mainly at the around of the bus garage of city. Insulation container storing the natural gas as a liquid makes heavy duty truck and intercity bus possible to use the natural gas. Drive using diesel is possible where is hard to recharge the gas. With LNG (Liquefied Natural Gas), the dependence on oil is largely decreased, PM (Particulate Matter) and NOx which is chronic disadvantage of diesel is remarkably reduced and finally $CO_2$, the representative green house gas, is reduced over 10%.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.34-39
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• 2015

Recently, most of the energy consumed in vehicle is derived from fossil fuels. For this reason, the demand for clean, renewable and affordable alternative energy is forcing the automotive industry to look beyond the conventional fossil fuels. Natural gas represents today a promising alternative to conventional fuels for vehicles propulsion, because it is characterized by a relatively low cost, better geopolitical distribution than oil, lower environmental impact, higher octane number and a higher self ignition temperature. Above all, CNG is an environmentally clean alternative to the existing spark ignition engines with the advantages of minimum change. In this study was installed bi-fuel system that a conventional 2 liters gasoline engine was modified to run on natural gas by a gas injection system. Experiments were mainly carried on the optimization of an ECU control strategy affecting the emission characteristics of CNG/Gasoline bi-fule vehicle. The test results shown that CO2 emission in bi-fuel mode was reduced 16% compared to gasoline fuel in the NEDC mode. Also the amount of CO and HC emissions in bi-fuel and gasoline modes were found to equality. But Compared to gasoline, the bi-fuel mode resulted in higher NOx emissions.

• Journal of the Korean Institute of Gas
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• v.14 no.1
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• pp.15-20
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• 2010

The interest on the utilization of landfill gases and biogases for energy production has been increasing due to environment concerns and global warming caused by burning fossil fuels, renewable nature of these gases. Using those synthesis gases to generate energy with engine encourages more efficient collection reducing emissions into the atmosphere and generates revenues for the operators. However the lower calorific value of synthesis gases than that of LPG or CNG affects the combustion stability and power output. Thus it becomes necessary to address disadvantages involved by studying synthesis gases in technological perspective. This paper discussed synthesis gas as a fuel for 60kW dual-fuel engine to produce power in an effective way. The methane diluted with $N_2$ was used as a fuel and developed ECU and injector driver facilitated the investigations with diesel fuel.

• Journal of ILASS-Korea
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• v.17 no.2
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• pp.94-99
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• 2012

The characteristics of spray behavior and injected amount were studied with two types of nozzles for using in a compression ignition engine with dual fuel technology for construction machines. A penetration length of spray tends to shorten due to a decrease of injected amount of a diesel fuel with dual fuel engine application. In order to ignite the gaseous fuel premixed with air during intake process, a diesel fuel, which was compression ignited, needs to penetrate somehow similar depth compared with the case of a diesel fuel-only-injection. In this work, a nozzle with reduced hole diameter and increased number of holes was tested and demonstrated that, compared to diesel 100% case, its penetration lengths are comparable to 74% and 79%, respectively, of those of 100% and 50% supply of a diesel fuel with the baseline nozzle that has four holes and 30.4% increased diameter. This will presumably enhancement the combustion in a dual fuel engine. A design suggestion was also made in this work to achieve similar penetration length of spray with diesel 100% case to prevent combustion from being deteriorated in a dual fuel engine.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.4
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• pp.369-376
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• 2015

Recently KEPCO, KOGAS and other institutions are jointly conducting an R&D for the development and demonstration of the power generation system based on a natural gas/diesel engine on an island. As a preliminary study, co-combustion in the dual fuel engine, which is expected to produce a few mega-watts of electricity, was modeled and calculated using computational fluid dynamics (CFD). The applied key assumptions are 2-dimensional axisymmetric, transient and static volume chemical reaction. Based on the selected blending ratio, which is the key operating condition, natural gas is substituted instead of diesel fuel (basis of high heating value). Results showed that as the blending ratio increases, the reaction rate of the combustion increases and thus maximum temperature is reached more rapidly. For the optimal performance, various geometric or operational studies will further be conducted.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.9
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• pp.869-874
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• 2011

In a CNG/diesel dual-fuel engine, CNG is used as the main fuel and a small amount of diesel is injected into the cylinder to provide ignition priming. In this study, a remodeling of the existing diesel engine into a CNG/diesel dual-fuel engine is proposed. In this engine, diesel is injected at a high pressure by common rail direct injection (CRDI) and CNG is injected at the intake port for premixing. The CNG/diesel dual-fuel engine had an equally satisfactory coordinate torque and power as the conventional diesel engine. Moreover, the CNG alternation rate is over 89% throughout the operating range of the CNG/diesel dual-fuel engine. PM emission by the dual-fuel engine is 94% lower than that by the diesel engine; however, NOx emission by the dual-fuel engine is higher than that by the diesel engine.