• Journal of the Korean Institute of Gas
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• v.18 no.6
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• pp.21-26
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• 2014

Renewable gas fuels such as biogas and landfill gas have carbon-neutral nature which can reduce carbon dioxide. However, it is necessary to make stable combustion when this fuel is used in power generating SI(spark ignition) gas engines due to its low heating value and non-uniformity. In this study, it was shown that addition of hydrogen can increase combustion stability of gas engine which is running with high inert gas composition. Thermal efficiency and emission characteristics of this engine was also investigated. In addition, a new spark plug with a long electrode was tested and compared with a base spark plug as a way to improve engine efficiency and reduce exhaust emissions.

• Journal of the Korean Society of Industry Convergence
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• v.16 no.1
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• pp.21-26
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• 2013

Burned gas of methane-air mixtures with water vapor have been analysed to study the exhaust emission using gas-chromatography and computation. The computations were carried out for the gas analysis using premix code of Chemkin program to compare the experimental results. The quantity of water vapor contained were changed 5% and 10% of total mixtures, and equivalence ratio of mixtures between 0.6 and 1.2 were tested under the ambient temperature 323K and 373K. The results showed CO, $CO_2$ decreased and $H_2$ increased by increasing the water contents. The CO increased and $CO_2$ decreased by increasing the ambient temperature. The $CO_2$ shows the maximum product at equivalence ratio 1.0, in otherwise the $CH_4$ produced the minimum values in the same range. The results showed little difference between these two methods.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.2
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• pp.147-153
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• 2015

The International Maritime Organization has conducted SEEMP for reducing $CO_2$ emission from ships. The study was carried out by comparing the real application of three shipping companies with IMO guideline about SEEMP on the same category. This paper suggests a method to improve implementation of SEEMP more efficiently through a grasp of the problem from its real application. Improvements are error correction of Company EEOI, unification of EEOI data acquisition period, compliance of measurements for fuel-efficient operation, suggestion of $CO_2$ mass conversion factors for various fuel and EEOI goal setting through formal standards of the International Maritime Organization.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.1
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• pp.72-78
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• 2003

Recently, lots of researchers have been attracted to develope various alternative fuels and to use renewable fuels as a solution of environmental problems from automobile. The use of biodiesel fuel is an effective way of substituting diesel fuel in the long nun. It is a domestically produced, renewable fuel that can be manufactured from vegetable oils, used vegetable oils, or animal fats. In this study, the usability of biodiesel fuel derived from rice ban oil, one of the oxygenated fuels as an alternative fuel for diesel engines was investigated in IDI diesel engine. Emissions were characterized with neat biodiesel fuel and with a blend of biodiesel fuel and conventional diesel fuel. Since the biodiesel fuel includes oxygen of about 11%, it could influence the combustion process strongly. So, the use of biodiesel fuel resulted in lower emissions of carbon monoxide and smoke emissions with some increase in emissions of oxides of nitrogen. It is concluded that biodiesel fuel can be utilized effectively as a renewable fuel for IDI diesel engine.

• Journal of Institute of Convergence Technology
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• v.7 no.1
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• pp.15-18
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• 2017

As emission gas regulation of deisel vehicles is strengthened to Euro-6, It becomes difficult to deal with NOx regulated value mainly by EGR without additional after-treatment system. In addition, RDE(Real Driving Emissions) test will be introduced after september 2017. Therefore, It is essential to develop the after-treatment of diesel vehicles which reduce NOx emissions. It is possible to use DOC, DPF, LNT or DOC, DPF and SCR as a after-treatment system for reducing NOx. However, It is expected that the SCR will be applied widely because LNT alone does not have sufficient NOx purification efficiency. In this study, It tried to analyze the efficiency of reducing NOx emissions during the mode test by attaching a NOx sensor to test vehicle. As a result, It was confirmed that NOx emissions was significantly reduce through the after-treatment system from engine. And the NOx reduction efficiency of SCR was about 4.5 times better than DOC, DPF.

• Journal of the Korean Society of Combustion
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• v.20 no.3
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• pp.21-26
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• 2015

This study was performed to provide the information of the combustion characteristics of n-butanol fuel in accordance with the n-heptane fuel mixing ratio. The closed homogeneous reactor model was used for the analysis. The analysis conditions were set to 800 K of the initial temperature, 20 atm of initial pressure and 1.0 of equivalence ratio. The results of analysis were compared in terms of combustion temperature, combustion pressure, CO, Soot and $NO_X$ emissions. The results of combustion and exhaust emission characteristics showed that ignition delay was decreased and the combustion temperature was increased as the n-heptane mixing ratio was increased. Also, the carbon monoxide(CO) was slightly decreased however, the soot and nitrogen oxides($NO_X$) increased a little in accordance with the n-heptane fuel mixing ratio. In addition, the pressure difference was almost the same in any conditions.

• Ocean and Polar Research
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• v.37 no.3
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• pp.235-247
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• 2015

The main purpose of procuring the oceanographic research vessel with state-of-the-art technology is to provide a floating laboratory to conduct field work on the global oceans. The vessel should be properly utilized to locate and evaluate unexplored natural resources as well as to contribute international efforts to better understand and manage global environmental issues. Top priorities in the vessel design are high safety standards, noise and vibration control efficiency, and effective application of research equipment. For the accomplishment of all activities, the vessel length over all should be extended ~100 m with a gross tonnage of ~5,900 ton. In particular, the dynamic positioning system II will essentially operate at sea state 6. The high efficiency emissions reduction system will also be adopted in preparation for entry into force of 3rd exhaust emission control (Tier III). About 130 navigational and scientific instruments will be installed. The final design and model test of the new research vessel were reviewed and completed, respectively, in 2014. Currently, the ship is being built on schedule and expected to be delivered in December 2015. Within the near future, the new vessel will assume the role of carrying out multidisciplinary oceanographic researches of the highest standards in a technologically advanced and environment friendly manner.

• Journal of the Korean Society of Combustion
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• v.8 no.4
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• pp.9-14
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• 2003

High temperature air combustion technology has been utilized by using preheated air over 1100 K and excessive exhaust gas recirculation. Numerical analysis was performed to investigate the combustion characteristics with high temperature deficient oxygen air combustion by adopting a counterflow as a model problem accounting for detailed chemical kinetics. Methane($CH_4$) was used as a test fuel and calculated oxidizer conditions were low temperature high oxygen (300K, $X_{O2}=0.21$) and high temperature low oxygen (1300K, $X_{O2}=0.04$) conditions. The latter case showed that the flame temperature is lower than the former case and its profile showed monotonic decrease from oxidizer to fuel side, without having local maximum flame temperature at high stretch rate. Also, heat release rate was one order lower and it has one peak profile because of low oxygen concentration and heat release rate integral is almost same for stretch rate. High temperature low oxygen air combustion shows low NO emission characteristics.

• Journal of the Korean Society of Combustion
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• v.15 no.3
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• pp.48-56
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• 2010

Performances of power generation engine were investigated with syngas from RPF. A stoker type, multi-staged pyrolysis-gasification system, was employed for syngas generation and the syngas was refined with the sequential cleaning processes composed of a gas cooler, a bag filter and a wet scrubber. 20 kWe commercial syngas power generation engine was adopted to burn the cleaned syngas which is mainly composed of hydrogen, carbon monoxide, carbon dioxide and methane. The performance of the engine was tested with various syngas compositions and the results were compared to LNG case. Electric power output, exhaust gas temperature, and emission characteristics were measured, and the efficiency of engine generation was investigated as a function of load of power generation.

• Journal of the Korean Solar Energy Society
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• v.32 no.2
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• pp.11-18
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• 2012

Diesel fuel is expensive because transportation to remote areas adds extra cost, and it causes air pollution by engine exhaust. Providing a feasible economical and environmental solution to diesel generators is important. A hybrid system of renewable plants and diesel generators can benefit islands or other isolated communities and increase fuel savings. Renewable energy is, however, a natural source that produces a fluctuating power output. In this paper, hybrid power system of the marado lighthouse is proposed to supply stable power in the stand-alone hybrid power system. The proposed hybrid power system consists of the diesel generator, wind turbine, photovoltaic, fuel cell, and battery bank. To decrease the carbon emissions and find the optimization, the cost analysis of hybrid system is simulated using HOMER program and the optimized hybrid power system is designed.