• Journal of Korean Society of Environmental Engineers
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• v.22 no.12
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• pp.2255-2261
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• 2000

To eliminate $NO_x$ in diesel emission. selective catalyst reduction (SCR) was used in real diesel engine. Among the SCR methods, metal oxide and perovskite catalysts were introduced in this paper. The removal efficiencies with various major, promoter catalysts on ${\gamma}-Al_2O_3$ at different reaction temperature were investigated, and $LaCuMnO_x$ catalyst which has high removal efficiency at the temperature of real diesel exhaust gas was selected. $NO_x$ reduction was carried out over these catalysts in the flow-through type reactor using by-pass ($SV=3,300h^{-1}$). Under the given condition to this study, perovskite catalysts showed considerably high removal efficiency and $LaCuMnO_x$ was the best one among these catalysts in the temperature range of $150{\sim}450^{\circ}C$.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.3
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• pp.498-506
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• 2002

Improvements of fuel properties have become essential for exhaust emission reduction as well as for optimization of directly-related design factors and exhaust gas aftertreatment. In this study, the potential possibility of oxygenated fuel such as ethylene glycol mono-n-butyl ether(EGBE) was investigated for the sake of smoke reduction from diesel engine. Because EGBE include oxygen content approximately 27%, it is a kind of effective oxygenated fuel that the smoke emission of EGBE is reduced remarkably in comparison with commercial diesel fuel, that is, it can supply oxygen component sufficient at high load and speed in diesel engine. And, it was tried to analyze the quantities of the low and high boiling point hydrocarbon among the exhaust emissions in diesel engine. It have been investigated by the quantitative analysis of the hydrocarbon $C_1$~ $C_{6}$ using the gas chromatography. This study was carried out by comparing the chromatogram with diesel fuel and diesel fuel blended EGBE 20vo1-%. The results of this study show that the hydrocarbon $C_1$~C$_{6}$ among the exhaust emission of the mixed fuels are exhausted lower than those of the diesel fuel at the all load and speed. In particular, high boiling point hydrocarbons such as $C_{5}$ and $C_{6}$ were reduced remarkably at high speed and load.d.

• Journal of Energy Engineering
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• v.23 no.4
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• pp.130-140
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• 2014

Rotary kiln burner has been developed continuously to improve process efficiency and exhaust emission. In this study, the characteristics of the flame and exhaust emission were numerically analyzed according to the diameter of primary air nozzle, equivalent ratio of burner, and equivalent ratio at center and side nozzle for development of multi-nozzle burner in the COG(Coke Oven Gas) rotary kiln for sintering iron ore. The results indicated that the flame length and $NO_x$ emission increase, as the diameter of primary air nozzle and equivalent ratio of burner increase. And according to the change of equivalent ratio at the center and the side of the nozzle, the flame length and average temperature in the kiln show very little change but the $NO_x$ emission shows obvious difference. In conclusion, the best design conditions which have satisfying flame length, average temperature and $NO_x$ emission are as follows: $D_2/D_1$ is 1.33, equivalent ratio of burner is 1.25 and center nozzle conditions are Rich.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.9
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• pp.937-944
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• 2012

The thermodynamic characteristics of a trilateral cycle with water as a working fluid have been theoretically investigated for an electric generation system to recover the waste heat of the exhaust gas from a diesel engine used for the propulsion of a large ship. As a result, when a heat source was given, the efficiencies of energy and exergy were maximized by the specific conditions of the pressure and mass flow rate for the working fluid at the turbine(expander) inlet. In this case, as the condensation temperature increased, the volume expansion ratio of the turbine could be reduced properly; however, the exergy loss of the heat source and exergy destruction of the condenser increased. Therefore, in order to recover the waste exergy from the topping cycle, the combined cycle with a bottoming cycle such as an organic Rankine cycle, which is utilized at relatively low temperatures, was found to be useful.

• Journal of the Korean Institute of Gas
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• v.26 no.5
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• pp.28-34
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• 2022

Since semiconductor factories are located in densely populated areas, safe handling of hazardous materials handled in the manufacturing process is of utmost importance. In particular, the types of hazardous substances discharged after handling in the semiconductor manufacturing process are very diverse, and the treatment methods such as combustion, absorption and adsorption methods for each material are very complicated. Therefore, in recent semiconductor exhaust treatment processes, two or more treatment methods are applied to one treatment facility, and unexpected accidents occur due to the application of such a complex treatment method. In this study, the cause of accidents in treatment facilities that applied both the scrubber method and the electrostatic precipitation method, which are recent accident cases, are identified, and preventive measures are suggested to find out the points to be noted when applying the complex treatment method.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.3
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• pp.148-153
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• 2006

This study dealt with the measurement of exhausted gas concentration, the estimation of a combustion efficiency, and the review of IMO indexing. We concentrated on establishing the basic data to take a counterplan coping with $CO_2$ regulations. The average combustion efficiency was 98% in shop test of new engines and 96.5% in sea trial test of new ships, respectively. It would become lower for the old engine or/and ship. High combustion efficiency results in high $CO_2$ emission and low combustion efficiency results in high emission of incomplete combustion products. The efficient method reducing $CO_2$ emission without an increase in noxious air pollutants would be the development of a substitute fuel and the fuel-efficient and economical engine, and the fair play among shipping agencies in a ship speed. In reviewing of IMO indexing, it is necessary to begin by analyzing the carbon content of a marine fuel for a precise estimates.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.549-557
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• 2017

Numerical studies have been carried out on scrubbers, which are after-treatment devices to satisfy strengthened emission regulations for sulfur dioxide and particulate matter. We investigated the problems with existing scrubbers through numerical analysis and designed and analyzed a new swirl-type scrubber that could solve these problems. As a result, with the swirl-type scrubber, exhaust gas formed a vortex in the lower part of the device, and some of this gas was released along the guide vane through the bottom surface. In this case, the pressure gradient in the vertical direction was not large, but a pressure difference between the inside and outside of the baffle was generated. The shape of the exhaust gas stream was investigated, and when water was not sprayed, the exhaust gas flowed constantly to the outlet along the guide vane, in contrast to when water was sprayed. It was confirmed that the shape of the flow was influenced by the guide vane, nozzle arrangement and water pressure. In the case of the swirl-type scrubber, impact on engine back-pressure was minimal, because differential pressure at the inlet and outlet was less than half of that with a conventional scrubber.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.8
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• pp.683-691
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• 2015

Circulating Fluidized Bed(CFB) combustion has the several advantages which are the fuel flexibility, the economy, the efficiency and the environment. It is necessary to apply a renewable energy to produce electricity due to the Renewable Portfolio Standard(RPS) mandates recently. So, in this study, co-combustion with a coal and a wood pellet was investigated to evaluate the combustibility and the environment as function of blending ratio of them in a Lab-scale CFB reactor. To investigate the characteristics of the co-combustion, the blending ratio which is the weight of wood pellet by the total calorific value of the supplied, was considered. Bed material was a river sand(No. 7). As increasing the blending ratio, the exhausted gas emissions such as CO, NOx, HC and SOx were decreased. But in case of wood pellet over 30%, CO, HC and SOx emission were increased. And the gas temperatures at the downstream were decreased.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.2
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• pp.131-136
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• 2012

This paper investigated the combustion and exhaust gas characteristics of gasoline direct injection engines for various cooling water temperature. The engine-out nanoparticle emission number and size distribution were measured by a DMS-500 equipped upstream of the catalyst. A CLD-400 and an HFR-400 were equipped at the exhaust port to analyze the cyclic NOx and total hydrocarbon emission characteristics. The results showed that the nanoparticle emission number greatly increased at low coolant temperatures and that the exhaust mainly contained particulate matter of 5.10 nm. THC also increased under low temperature conditions because of fuel film on the combustion chamber. NOx emissions decreased under high temperature conditions because of the increase in internal exhaust gas recirculation. In conclusion, an engine management system control strategy for driving coolant temperature up rapidly is needed to reduce not only THC and NOx but also nanoparticle emissions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.231-235
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• 2009

The mainly objectives of this study was a combustion dynamics and instability characteristics in a model dump type combustor which is scale down of GE 7FA+e DLN 2.6 gas turbine combustor with running at Seo-Inchon combined cycle power plant. Model gas turbine injector has 2-stage swirl vane and it's reduced 1/3 size of the original one. The shape of plenum and combustor were designed for similar acoustic characteristics. As the result, this research have been shows the peak frequency of model combustor was changed quarter-wave mode to Helmholtz resonator mode in plenum and longitudinal mode in dump combustor at unstable flame conditions caused by the different of combustor temperature and fuel-air mixture distributions.