• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.4
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• pp.152-159
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• 2014

Urea solution as a reductant of SCR has been widely used to reduce NOx emissions from diesel engine. But it has lots of problems which are freezing at low temperature due to liquid state, deposition of solid formation in the exhaust, dosing device, and complex package such as mixers for uniform concentration of ammonia. In order to overcome these obstacle, ammonium carbonate which is one of solid ammonium materials to produce ammonia gas directly by sublimation process is considered. Simple reactor with visible widow was designed to predict equilibrium temperature and pressure of ammonium carbonate. To simulate real operation conditions under automobile environment, several cycles of heating and cooling condition were settled, two different re-solidification materials were extracted from the reactor and visible window. Analytical study is performed to characterize these unknown materials by XRD(X-Ray Diffraction), FT-IR(Fourier Transform Infrared Spectroscopy), and EA(Elemental Analyzer). From analytical results, re-solidification materials from heating and cooling cycles are very similar to original material of ammonium carbonate.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.9
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• pp.1736-1743
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• 1992

The combustion in the cylinder of spark ignition engine is completed after the delayed time that the liquid film fuel is vapourized as flowing into the combustion chamber. It is necessary to enhance the homogeneity of mixture and the combustion phenomenon in order to improve the heat efficiency and the emission characteristics of spark ignition engine. The main purpose of this paper is to manufacture a combustion analyzing system and examine closely the influence of non-uniformity due to the liquid film fuel flowing in the intake manifold on the combustion characteristics by using a 4 stroke multi- cylinder spark ignition engine. Moreover, with each cylinder, the interpretation of combustion characteristics by indicator diagram and the concentration of exhaust gas were investigated.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.899-905
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• 2000

The characteristics of air flow and engine performance with swirl ratio variance of intake port In a turbocharged DI diesel engine was studied in this paper. The intake port flow is important factor which have influence on the engine performance and exhaust emission because the properties in the injected fuel depend on the combustion characteristics. The swirl ratio for ports was modified by hand-working and measured by impulse swirl meter. For the effects on performance and emission, the brake torque and brake specific fuel consumption were measured by engine dynamometer and NOx, smoke were measured by gas analyzer and smoke meter. As a result of steady flow test, when the valve eccentricity ratio are closed to cylinder wall, the flow coefficient and swirl intensity are increased. And as the swirl ratio is increased, the mean flow coefficient is decreasing, whereas the gulf factor is increasing. Also, through engine test its can be expected to meet performance and emission by optimizing the main parameters; the swirl ratio of intake port, injection timing and compression ratio.

• Journal of ILASS-Korea
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• v.17 no.3
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• pp.152-157
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• 2012

This investigation decribes the effect of the combustion and emission characteristics of HCNG engine according to the high purity hydrogen contents. The HCNG fuel was made by the mixture with a high purity hydrogen ($H_2$) and a natural gas. The test vehicle was applied to the bi-fuel (Gasoline and CNG) system and this system was modified from the fuel supply and fuel tank. In addition, the three premixed HCNG fuels with mixed rate of 10, 20 and 30% of hydrogen were used to maintain the safety. In order to analyze the combustion characteristics of HCNG and CNG, the fuel was injected in the combustor with constant volume. The exhaust emission from light duty vehicle with bi-fuel system was analyzed by a chassis dynamometer and emission analyzer. From these results, the reduction rate of NOx emission increased in the HCNG fuel and emission amount of THC and CO shows a similar level with CNG fuel. This study can be utilized the basic data for the development of a new business plans related with HCNG engines.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.6
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• pp.125-131
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• 2013

This study was carried out to develop a diesel engine for marine propulsion. This marine diesel engine was developed based on a 500Ps vehicle diesel engine. Many main parts, such as the intercooler, radiator, and engine controller were designed for the marine diesel engine. The intercooler was designed to be of sea water cooling type; inlet air is cooled by sea water. Engine coolant is cooled by sea water in the radiator too. The water cooling heat exchanger has high cooling performance. In the cooling system, consists of the intercooler and the radiator, the sea water passes through the intercooler and then the radiator, in sequence. This process is very effective compared to the reverse method in which sea water passes through the radiator and then the intercooler, in sequence. The control performance of the engine controller and the fuel injection rate were improved using an engine speed controller. This system was tested on an engine dynamometer and an exhaust gas analyzer using the marine diesel engine test method. Test results show that the 500Ps marine diesel engine satisfied the IMO NOx regulations; Tier II.

• Advances in Computational Design
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• v.4 no.4
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• pp.367-379
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• 2019

Multiple Inputs and Multiple Outputs (MIMO) Fuzzy logic model is developed to predict the engine performance and emission characteristics of pongamia pinnata biodiesel with hydrogen injection. Engine performance and emission characteristics such as brake thermal efficiency (BTE), brake specific energy consumption (BSEC), hydrocarbon (HC), carbon monoxide (CO), carbon dioxide ($CO_2$) and nitrous oxides ($NO_X$) were considered. Experimental investigations were carried out by using four stroke single cylinder constant speed compression ignition engine with the rated power of 5.2 kW at variable load conditions. The performance and emission characteristics are measured using an Exhaust gas analyzer, smoke meter, piezoelectric pressure transducer and crank angle encoder for different fuel blends (Diesel, B10, B20 and B30) and engine load conditions. Fuzzy logic model uses triangular and trapezoidal membership function because of its higher predictive accuracy to predict the engine performance and emission characteristics. Computational results clearly demonstrate that, the proposed fuzzy model has produced fewer deviations and has exhibited higher predictive accuracy with acceptable determination correlation coefficients of 0.99136 to 1 with experimental values. The developed fuzzy logic model has produced good correlation between the fuzzy predicted and experimental values. So it is found to be useful for predicting the engine performance and emission characteristics with limited number of available data.

• 연구논문집
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• s.27
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• pp.101-108
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• 1997

The characteristics of combustion and emissions in multi-staged oil burner have been experimentally studied for the various range of equivalence ratios, drop sizes and fuel formulations. Malvern system was used to measure droplet size of fuel. Light fuel oil and light fuel oil doped with pyridine($C_5H _5N$) were used to investigate the effects on fuel NOx emission. The emissions of NO and CO in exhaust gas and the flame temperatures were measured by the gas analyzer and thennocouples. NOx emissions were increased by increasing the excess air ratio (range:$lambda=1.1-1.4$) or decreasing the SMD of droplet in single-staged burner. In comparison with the single-staged burner, the emission of NOx in multi-staged burner was reduced by 50% but CO emission was slightly increased. It is found that multi-staged burner has a good capability in reducing thermal NOx resulting from the distributed heat release rate and lower flame temperature in fuel-rich and fuel-lean combustion zone. Moreover, the fuel NOx emission of the multi-staged burner is lower than that of single-staged burner, because multi-staged burner has fuel rich zone where fuel N is converted to $N_2$ more than NO. In 3-staged burner, the percentage of each stage combustion air have strong influence on emission characteristics. It is also found that NOx emission can be reduced by decreasing inner and outer air percentage or increasing middle air flow rate and CO emission is vice versa.

• Journal of Energy Engineering
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• v.17 no.3
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• pp.153-160
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• 2008

The combustion behaviors of the blends of Korean anthracite, bituminous coal and their blends were studied with a thermogravimetric analyzer. Concerning the burning profiles of the anthracite-bituminous coal blends in TGA, it has been observed the independent burning of two coals without any interaction between two coals. With the blends of 50% anthracite with 50% bituminous coal in weight basis, the combustion tests in a utility boiler have been carried out for the analysis of the combustion and operational characteristics by increasing the power output from 134 MW to 197 MW. The stable combustion has been observed in a boiler. With the increase of power output, the exhaust gas temperature was exceeded the design value of $430^{\circ}C$, so the combustion air was taken from atmosphere instead of the boiler penthouse.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.9
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• pp.1185-1194
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• 2000

The characteristics of intake port flow and engine performance with swirl ratio variance in a turbocharged D.I. diesel engine were studied in this paper. The intake port flow is important factor which have influence on the engine performance and exhaust emission because the properties in the injected fuel depend on the combustion characteristics. Through these experiments it can be expected to satisfy performance and emission by optimizing the main parameters; the swirl ratio of intake port, injection timing and compression ratio. The swirl ratio for ports was modified by hand-working and measured by impulse swirl meter. For the effects on performance and emission, the brake torque and brake specific fuel consumption were measured by engine dynamometer, NOx and smoke were measured by gas analyzer and smoke meter. The results of steady flow test are as follows; as the valve eccentricity ratio are closed to cylinder wall, the flow coefficient and swirl intensity are increased. Also we realized that there is a trade-off that the increase of swirl ratio decreases mean flow coefficient and increases the Gulf factor. And the optimum parameters to meet performance and emission through engine test are as follows; the swirl ratio 2.43, injection timing BTDC 13oCA and compression ratio 15.5.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.5 no.2
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• pp.172-183
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• 1995

The airborne concentrations of the welding fumes produced during $CO_2$ arcwelding process at shipbuilding, shiprepairing, container manufacturing and car accessary manufacturing industry were investigated. The effects how much reduced the welding fume were checked when the portable fan was used. The results were as follows; 1.The geometric mean of welding fume concentration in shipbuilding factory was $10.05mg/m^3$. This exposure concentration was higher than other 3 manufacturing industries at 95% confidence level. 2. The sampling filters for welding fume could be digested with acid within 1 hour by microwave oven. The recoveries for investigated metal elements were all over 95%. 3. The optimal wavelength could be selected for the simultaneous analysis of 8 metal elements by ICP(Inductively Coupled Plasma). 4. Noxious gases($O_1,NO_2$) produced during $CO_1$ gas arc welding process were detected that the concentration of ozone($O_1$) was less than 0.01 ppm and that of nitrogen dioxide($NO_2$) was 0.01-0.03 ppm. 5. The geometric mean of welding fume particle diameter was $1.26{\mu}m$ and geometric standard deviation was 1.51 for the counts when particle an analyzer(ELZONE) had been used. 6. When the portable fan had been used,the reduced percent of total welding fume for workers was about 47.8% when portable fan was applied to blow and 71.7% when to exhaust.