• 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 Society of Agricultural Engineers
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• v.57 no.5
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• pp.81-88
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• 2015

바이오매스는 유망한 신재생 에너지이다. 바이오매스는 액체 및 기체 연료로 전 환 할 수 있고, 다양한 공정을 통해 열 및 전력을 생산시키는데 사용된다. 바이오매스 가스화 공정은 바이오매스를 일산화탄소, 이산화탄소, 수소 및 메탄으로 이루어진 합성 가스로 전환시키는 기술이다. 바이오매스를 이용한 합성 가스 생산 및 활용은 세계적으로 늘어나는 에너지 필요성을 충족시킬 수 있는 대체에너지이다. 현재, 바이오매스 가스화의 주요 원료는 목질계 우드 칩을 주로 사용하고 있지만, 일반적으로 우드칩의 경우 수분을 다량 함유하고 있기 때문에 가스화 공정을 위해서는 별도의 건조처리를 필요로 한다. 우드칩의 건조에는 많은 에너지가 소요되고, 다량의 우드칩 건조에는 시간과 기상 및 공간적인 환경에 영향을 받는다. 본 연구에서는 미건조 우드칩의 가스화 공정을 위하여 미건조 우드칩에 숯을 각각 10, 30, 50 % 비율로 혼합하여 실험을 수행하였고, 실험결과 생산된 합성가스의 CO 농도 는 숯의 비율에 따라 14.9 ~ 25.6 % 증가되는 경향을 나타내었지만, 반대로 $CO_2$ 및 $CH_4$ 농도는 감소하였다. 이에 따라 합성가스 생산을 위한 미건조 우드칩과 숯의 최적혼합비율은 약 30 %로 판단되며, 발열량은 $1285.7kcal/Nm^3$, Gas yield는 $2.3Nm^3/kg$ 로 나타났다. 이에 적절한 숯의 혼합사용은 미건조 우드칩의 직접적인 가스화에 도움이 될 것으로 사료되며, 바이오매스 건조 공정에 필요한 에너지를 절약할 수 있을 것으로 판단된다.

• Fire Science and Engineering
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• v.21 no.3
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• pp.78-83
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• 2007

Diesel, a kind of petroleum, which is used in vehicles, vessels, boilers etc causes great damage when a fire happens, because it has higher caloric value than gasoline or kerosene has at burning. Therefore, pool fire experiment was carried using diesel which is sold on the gas station and radiation heat flux that occurs from flame and inner temperature of flame at burning was estimated. The maximum instantaneous flame temperature of diesel was more than $900^{\circ}C$, and the average of maximum flame temperature was $800^{\circ}C$ which occurred at 0.5 H/D distance from the surface of inflammable liquid, the distance has more long that has the lower the temperature of flame. In case of radiation heat flux, it grew to vary according to the size and amount of sample. When the size of a container for experiment was 0.5 m and sample layer was 13 mm and 20 mm, the radiant heat was 92.29 kW and 117.43 kW each. When the container was 1.0 m, it was 364.35 kW and 405.88 kW each.

• Applied Chemistry for Engineering
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• v.23 no.1
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• pp.23-27
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• 2012

To make synthetic liquid fuel from biomass such as wood pellet, energy crop and so on, a biomass to liquid (BTL) process by using a biomass gasifier with Fisher-Tropsch (FT) reaction was developed. However $H_2S$, COS and $CO_2$ in syngas from biomass gasifiers resulted in a decrease of the conversion efficiency and the deactivation of the catalyst. To remove acid gases in syngas, a lab-scale methanol absorption tower was developed and the removal characteristics of acid gases were investigated. The methanol absorption tower efficiently removed $H_2S$ and COS with a removal of $CO_2$, so it could be useful process for the BTL process.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.3
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• pp.258-263
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• 2012

In this paper the Chemical Propulsion Subsystem of COMS is briefly explained and some telemetries acquired by a series operations of CPS during the Launch and Early Operation Phase of COMS are presented. The pressure and temperature of pressurant tank telemetries are compared with the results of the developed computer program. The changes in pressure are due to the two major phases. The first one is the initialization phases of CPS composed of the venting phase to vent the helium gas in the pipe network from the downstream of the propellant tanks to the thrusters for safety, the priming phase to fill the vented pipe network with oxidizer and fuel respectively and then the pressurization phase to pressurize the ullage of propellant tank to regulated pressure. And the other is the apogee engine firings in which COMS CPS is in the orbit raising phase to use helium as a pressurant to keep the pressure of propellant tank as the liquid apogee engine get fired until COMS reached to the target orbit. This program can be applicable to prepare basis design data of the next Geostationary Satellite CPS.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.1
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• pp.35-45
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• 2005

Numerical study is carried out to investigate the effects of chemistry and thermal radiation on the rocket plume flow field at various altitudes. Navier-Stokes equations for compressible flows were solved by a fully-implicit TVD code based on the finite volume method. An infinitely fast chemistry module for hydrocarbon mixture with detailed thermo-chemical properties and a thermal radiation module for optically thick media were incorporated with the fluid dynamics code. The plume flow fields of a kerosene-fueled rocket flying at Mach number zero at sea-level, 1.16 at altitude of 5.06 km and 2.90 at 17.34 km were numerically analyzed. Results showed the plume structures at different altitude conditions with the effects of chemistry and radiation. It is understood that the excess temperature by the chemical reactions in the exhaust gas may not be ignored in the view point of propulsion performance and thermal protection of the rocket base, especially at higher altitude conditions.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.1
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• pp.53-60
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• 2005

The use of pipe-bends brings about non-uniform flows at the exit of them due to the velocity difference between inner and outer flows inside the bend. These phenomena may cause turbopump of satellite launch vehicle to run off-design and reduce its efficiency, and also introduce unstable influx of propellants to engine manifold after passing through a turbopump. In order to improve the uniformity of flow at the bend exit, certain turning vanes are set up in the bend pipe normally. Correspondingly the design is an $90^{\circ}\;and\;45^{\circ}$ bend pipes that incorporate with the maximum three turning vanes. All designs were analyzed with numerical analysis by solving the Navier-Stokes equations in three dimensions in case of each respective fuel and oxidizer. Evaluations of the vaned pipe bends designs were accomplished by the velocity magnitude distributions and the predicted pressure drops. We could find that the more vaned bend pipe and larger angle pipe under consideration effectively, the more uniform velocity magnitude of the bend and pressure losses.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.05a
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• pp.258-261
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• 2003

The optimal design and combustion analysis of the gas generator for Liquid Rocket Engine (LRE) were performed. A fuel-rich gas generator in open cycle turbopump system was designed for 101on1 in thrust with RP-1/LOx combination. The optimal design was done for maximizing specific impulse of main combustion chamber with constraints of combustion temperature and power matching in turbopump system. Results of optimal design show the dimension of length, diameter, and contraction ratio of gas generator. The configuration of the gas generator and the condition for performance which can maximize the objective function were determined and found to meet the design constraints. Also, the combustion analysis was conducted to evaluate the performance of designed chamber and injector of gas generator. And the effect of the turbulence ring was investigated on the mixing enhancement in the chamber.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.795-796
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• 2010

Interest has been increasing worldwide in Fischer-Tropsch synthesis (F-T) as a method of producing synthetic liquid fuels from biomass. Hydroisomerization of $C_7-C_{15}$ paraffins applies to production of diesel fuel with high cetane number and improved cold flow properties, such as viscosity, pour point and freezing point. The commercial products such as fuel jet produced from F-T synthesis should have low freezing and pour points. In this study, our major aim is to develop a catalyst for hydroisomerization of synthesis-oil for bio-jet fuel. Effects of zeolites and platinum loading on hydroisomerization of dodecane were investigated as a model reaction in a batch reactor.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.2
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• pp.122-134
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• 2020

To improve traffic congestion, reduce fuel consumption, and improve the stability of truck operations, truck platooning, in which several trucks are organized in a single platoon, is being actively researched globally. Compared to the operation of a single truck, the operation of a truck platoon requires more caution before the actual operation because an accident of one vehicle in the platoon can lead to an accident with all the vehicles in the platoon. Therefore, this study examined the types of trucks and cargo suitable for truck platooning to prevent safety accidents. The review showed that a closed-van-type truck is appropriate for truck platooning to prevent falling objects during driving. In the case of cargo types, it is necessary to exclude liquids and dangerous goods defined in related laws from truck platooning.