• Journal of Advanced Marine Engineering and Technology
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• v.16 no.4
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• pp.60-77
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• 1992

The effects of exhaust gas recirculation(EGR) on the characteristics of exhaust emissions and specific fuel consumption have been investigated using an eight-cylinder, four cycle, direct injection diesel engine operating at several loads and speeds. The experiments in this study are conducted on the fixed fuel injection timing of $38^{\circ}$ BTDC regardless of experimental conditions. In conclusion, it is found that $NO_{x}$ emission is markedly reduced with the drop of burnt gas temperature at high speeds and loads especially as the EGR rate increases, while the soot particulate rises with EGR rate and load at a given engine speed, especially high loads. The reduction of exhaust emissions within the Korea heavy duty diesel engine emission standards can be roughly achieved by the optimal EGR rate without degarding the specific fuel consumption, based on the correlations between exhaust emissions.

• Journal of the korean Society of Automotive Engineers
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• v.7 no.3
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• pp.94-101
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• 1985

The flame temperature of LPG-air premixture flame was measured by extrapolation of limiting case corresponding to the infinitely thin diameter of Platinum-resistance-hot-wire. LPG-air premixture flame, initially under atmospheric pressure and room temperature, propagates downward from top of the model combustion chamber maintained at constant pressure through the whole combustion process. Analytical calculation technique was also applied to determine full temperature history or spatial temperature distribution from flame reaction zone to burnt gas region.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.201-204
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• 2012

Combustion characteristics of boiler fuels made of bio-oil and light-oil were experimentally investigated. Bio-oil was obtained by fast pyrolysis of woody biomass. Emulsion fuel made by mixing bio-oil (up to 30wt%) with light-oil and surfactant was completely burnt, resulting in the formation of combusted gas containing CO concentration less than 10ppm. Simple mixtures of bio-oil and light-oil with separate delivery lines also gave nice combustion characteristics.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.11a
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• pp.23-29
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• 1999

Experimental studies are conducted to investigate the flame stability and the thermal/fuel NOx formation characteristics of the low calorific value (LCV) coal derived gas fuel. Synthetic LCV fuel gas is produced by mixing carbon monoxide, hydrogen, nitrogen and ammonia on the basis that the thermal input of the syngas fuel into a burner is identical to that of natural gas. The syngas mixture is fed to and burnt with air on flat flame burner. With the variation of the equivalence ratio for specific syngas fuel, flame behaviors are observed to identify the flame instability due to blow-off or flashback and to define stable combustion range. Measurements of NOx content in combustion gas are made for comparing thermal and fuel NOx from the LCV syngas combustion with those of the natural gas one. In addition, the nitrogen dilution of the LCV syngas is preliminarily attempted as a NOx reduction technique, and its effects on thermal and fuel NOx production are discussed.

• Journal of the Korean Applied Science and Technology
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• v.23 no.2
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• pp.147-152
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• 2006

The accidents occurred by unstable material which is easily exploded or burnt up were caused by heat and collision under the condition of relatively low temperature without oxygen, have been reported frequently. However, the amount of the unstable material is getting higher by development of fine ceramic research area even though its dangerous characteristic is disregarded. This research studied a heat stability and measured boiling point of various carpet material. Carpet has been used in home as well as general indoor usage. Now a day, carpet material which is hardly burnt has been on commercial, but its detailed unstable conditions is not mentioned. This research reports the measurement of the initial temperature of generation heat and heat-radiation change on differential scanning calorimeter (DSC). The DSC data of nylon bulked continuous filament (N-BCF) yam 100%, nylon (NY), poly propylene (PP), and a new material named polytrimethylene terephthalate (PTT) are studied and researched about the effect of them using TGA, furnace, and direct-burning experiment.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.298-304
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• 1996

Thirty-nine samples of roasted sesame seed oils were sensorially evaluated in terms of nutty odor, burnt odor and overall desirability, and their volatile compounds quantitatively analysed using direct sampling capillary GLC. Five volatile compounds were appeared to be significant for the sensory Properties of sesame oils through the multivariate analytical techniques such as stepwise discriminant analysis. canonical discriminant analysis, discriminant analysis and principal component analysis. The most important compounds were 2,5-dimethylpyrazine and 2-methylpyrazine which could be effectively used as chemical indicators related to nutty and burnt odor of sesame oils, respectively. The sesame oils which have represented a good grade of overall desirability have been always kept $35.82{\sim}4.43$ ppm of 2,5-dimethylpyrazine and also $28.90{\sim}6.35$ ppm of 2-methylpyrazine.

• Journal of the Korean Society of Combustion
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• v.10 no.1
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• pp.20-26
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• 2005

In the present study, catalytic combustion of hydrogen-air premixture in a millimeter scale monolith coated with Pt catalyst was investigated. As the combustor size decreases, the heat loss increases in proportion with the inverse of the scale of combustion chamber and combustion efficiency decreases in a conventional type of combustor. Combustion reaction assisted by catalyst can reduce the heat loss by decreasing the reaction temperature at which catalytic conversion takes place. Another advantage of catalytic combustion is that ignition is not required. Platinum was coated by incipient wetness method on a millimeter scale monolith with cell size of $1{\times}1mm$. Using this monolith as the core of the reaction chamber, temperatures were recorded at various locations along the flow direction. Burnt gas was passed to a gas chromatography system to measure the hydrogen content after the reaction. The measurements were made at various volume flow rate of the fuel-air premixture. The gas chromatography results showed the reaction was complete at all the test conditions and the reacting species penetrated the laminar boundary layer at the honeycomb and made contact with the catalyst coated surface. At all the measuring locations, the record showed monotonous increase of temperature during the measurement duration. And the temperature profile showed that the peak temperature is reached at the point nearest to the gas inlet and decreasing temperature along the flow direction.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.3
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• pp.589-597
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• 1992

The effect of pressure on soot formation in premixed propane-air combustion is investigated at high pressures over the pressure range of 1 to 5 MPa by using a specially designed constant volume combustion bomb. The combustiom chamber of disk type with eight spark plugs located on the circumference at an interval of 45deg is 100mm in diameter by 14mm thick. The end gases are compressed to high pressures by the eight converging flames. The soot volume fraction in the chamber center during the final stage of combustion at the highest pressure is measured by the in-situ laser extinction technique, and the burnt gas temperature during the same period is measured by the two-color method. It is found that the soot yield rises with 50 to 100% for the respective equivalence ratio range of 1.9-2.2 at an interval of 0.1 when the combustion pressure is increased from 1 to 5 MPa, and that the turbulent flames decrease in the soot yield as compared with the laminar flames because the burnt gas temperatures increase with the drop of heat loss.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.5
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• pp.66-72
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• 2018

A numerical study was conducted to investigate the performance characteristics of a STED with various pressure ratios (PRs) and cone shapes. Due to momentum loss, the pressure in vacuum chamber increased with cone angle for a PR of 75. Also, the STED is started between PRs of 36 and 37 in the case of a cone angle of $15^{\circ}$ and a blockage ratio (BR) of 15%. The results for various PRs and cone shapes are presented, and the optimal cone shape is found to have a cone angle of between $5{\sim}20^{\circ}$ and a BR of between 15~40%.

• 한국연소학회:학술대회논문집
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• 2004.06a
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• pp.173-179
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• 2004

Combustion of refuse derived fuel(RDF) and refuse plastic fuel (RPF) was carried out in a lab-scale circulating fluidized bed. Experiment was investigated cold flow visualization. RDF was made by C & tech and RPF was made by KRS. The results include distribution of temperature in the combustion chamber, and concentrations of flue gas such as $O_2$, $CO_2$, CO, $NO_x$ and HCs Micro G.C(gas chromatograph) was employed to find out concentration of He Temperature distribution was different when RDF and RPF were burnt respectably. As air ratio became increased, $CO_2$, CO, and total of HCs emissions were decreased. According to the number of carbon atom of HCs, HC were classified as five kinds of HC.