• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.4
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• pp.447-453
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• 2016

The reduction technologies of exhaust gas from both the off-road engine and on-road vehicles are important. It is possible to apply various combustion technologies with engines after the application of a treatment technology to this field. In this study, main injection timing, pilot injection timing, and exhaust gas recirculation (EGR) rate were selected as the experimental parameters whose effects on the emission of exhaust gases and on the fuel consumption characteristics were to be determined. In the experiment, the emission of nitrogen oxide (NOx) and Smoke, and the Torque at the same fuel consumption level, were measured. The experimental data were analyzed using the Taguchi method with an L9 orthogonal array. Additionally, analysis of variation (ANOVA) was used to confirm the influence of each parameter. Consequently, the level of each parameter was selected based on the signal-to-noise ratio data (main injection timing, 3; pilot injection timing, 3; EGR rate, 2), and the results of the Taguchi prediction were verified experimentally (error: NOx, 10.3 %; Smoke, 6.6 %; brake-specific fuel consumption (BSFC), 0.6 %).

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.6
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• pp.963-970
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• 1987

It has been a long time that black smoke emitted from buses and trucks powered with diesel engines, especially city-buses, came to be a serious air pollution problems in large cities as Seoul and Pusan. Therefore, proper means to reduce black smoke from diesel engines have to be considered as soon as possible, because it will take quite a long time to replace major passenger transportation system in cites from city-buses to subway. This paper, as a study on the reduction of diesel black smoke, showes how the black smoke of diesel engines can be reduced at various loads and engine speed by supplying small amount of gaseous fuel as LPG into the intake manifold. Thermal efficiency has been also considered for users, and confirmed through the engine test.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.6
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• pp.833-839
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• 2010

Over the past years, many research works have been carried out to investigate the factors which govern the performance of diesel engine. The air pollutant emission from the diesel engine is still a significant environmental concern in many countries. In the present study, new system of smoke reduction of diesel engine is proposed. This new system is using vacuum equipment for capture smoke. To confirm new system experiments were performed at engine dynamometer. As a result of this experiment, the smoke reduction of this system was identified.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.5
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• pp.679-685
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• 2009

In order to simulate a smoke or poisonous gas emergency in a rectangular tunnel and to investigate a better way to exhaust the smoke, the characteristics of smoke flow have been analyzed using flow field data acquired by Particle Image Velocimetry(PIV). Olive oil has been used as tracer particles with the kinematic viscosity of air, $1.51{\times}10^{-5}\;m^2/s$. The investigation has done in the range of Reynolds number of 1600 to 5333 due to the inlet velocities of 0.3 m/s to 1 m/s respectively. The average velocity vector and instantaneous kinematic energy fields with respect to the three different Reynolds numbers are comparatively discussed by the Flow Manager. In general, the smoke flow becomes more disorderly and turbulent with the increase of Reynolds number. Kinematic energy in the measured region increases with the increase of Reynolds number while decreasing at the leeward direction about the outlet region.

• International Journal of High-Rise Buildings
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• v.2 no.4
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• pp.341-344
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• 2013

During a building fire, smoke can flow through elevator shafts threatening life on floors remote from the fire. Many buildings have pressurized elevators intended to prevent such smoke flow. The computer program, CONTAM, can be used to analyze the performance of pressurization smoke control systems. The design of pressurized elevators can be challenging for the following reasons: (1) often the building envelope is not capable of effectively handling the large airflow resulting from elevator pressurization, (2) open elevator doors on the ground floor tend to increase the flow from the elevator shaft at the ground floor, and (3) open exterior doors on the ground floor can cause excessive pressure differences across the elevator shaft at the ground floor. To meet these challenges, the following systems have been developed: (1) exterior vent (EV) system, (2) floor exhaust (FE) system, and ground floor lobby (GFL) system.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.1
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• pp.201-210
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• 2019

Recently, due to the efforts to mitigate traffic congestion and expansion of space efficiency, the construction of underground roads has been increased in big-scale cities. Since tunnels in the city have a higher chance for a fire leading to a great tragedy during a severe traffic jam than mountain tunnels, it is highly likely that it will be constructed as a tunnel, having a small cross section, for small vehicles. However, if they are constructed as such small-vehicle tunnels, it would be possible to reduce the design fire intensity while the concentration of harmful gases would increase due to a reduction in the small cross sectional area, led by a decrease in the tunnel height. In this study, behaviors of fire smoke by the installation interval and format of large-scale exhaust-gas ports were examined and compared in the analysis of temperatures and CO concentrations of a tunnel and its results were as the following. Although there were no significant differences in the smoke spreading distance between installation intervals, but in this study, 100 m was found to be the most effective installation interval. The smoke exhaustion performance was found to be excellent in the order of $4m{\times}3m$, $6m{\times}2m$, and $3m{\times}2m$ (2 lane) of the smoke spreading distance. Although there was no significant difference in the smoke spreading distance between formats of large-scale exhaust-gas ports, it was found that the smoke spreading distance was larger than other cases when it was $3m{\times}2m$ in the fire growing process. The analysis of smoke spreading distances by the aspect ratio showed that a smoke spreading distance was shorted when its the smoke spreading distance was found to be shorter when its traverse distance was relatively longer than its longitudinal distance.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.3
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• pp.143-148
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• 2010

In this study, the potential possibility of biodiesel fuel(BDF) and oxygenated fuel(ethylene glycolvmono-n-butyl ether; EGBE) was investigated as an effective method of decreasing the smoke emission. The smoke emission of blending fuel (BDF and EGBE 0~20 vol-%) was reduced in comparison with diesel fuel and it was reduced approximately 64% at 2000 rpm, full load in the 20% of blending rate. But torque and brake specific energy consumption( BSEC) didn't have no large differences. Also, the effects of exhaust gas recirculation(EGR) for the reduction of NOx emission has been investigated. Consequently, It was found that simultaneous reduction of smoke and NOx emission was achieved with BDF(90 vol-%) and EGBE(10 vol-%) blended fuel and cooled EGR method(5~10%).

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.4
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• pp.75-80
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• 2008

Biodiesel fuel(BDF) can be effectively used as an alternative fuel in diesel engine. However, BDF may affect the performance and exhaust emissions in diesel engine because it has different physical and chemical properties from diesel fuel such as viscosity, compressibility and so on. To investigate the effect of injection timing on the characteristics of performance and exhaust emissions with BDF in IDI diesel engine, it was applied the BDF derived from soybean oil in this study. The engine was operated at seven different injection timings from TDC to BTDC $12^{\circ}CA$ and six loads at a single engine speed of 1500rpm. When the fuel injection timing was retarded, better results were showed, which may confirm the advantages of BDF. The simultaneous reduction of smoke and NOx was achieved at some fixed fuel injection timings of an IDI diesel engine.

• Fire Science and Engineering
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• v.22 no.1
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• pp.61-67
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• 2008

This study is focused on the numerical predictions of heat and smoke exhaust characteristics in an underground subway station stopping a fire train. Various ventilation operating modes with the fan equipped the platform and tunnels are considered. Distributions of temperature, carbon monoxide and visibility at a height of 1.7 m(breath height) above the platform are analysed for different ventilation fan operation mode. The numerical results show that smoke and heat is rapidly removed through tunnel by operating the tunnels fans. We suggested that during evacuation of passengers is not completed, the ventilation system in the platform is activated. After completion of passenger evacuation tunnel fans are activated but the fans in the platform are stopped.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.134-139
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• 2008

This research investigated variations of the engine performance and the exhaust emission characteristic of a direct injection diesel engine by fueling a commercial diesel fuel, which was blended with the di-ether group (butyl-ether: BE). The smoke emission reduced to 26% from the diesel engine with the blending fuel (diesel fuel 80 vol-% + BE 20 vol-%)at the full engine load of 2500 rpm compared to it with the diesel fuel only. The power, torque and brake specific energy consumption of the diesel engine showed very slight differences. The NOx emission from the diesel engine, however, with the blended fuel was higher than with the commercial diesel fuel only. By applying EGR method, as a counter plan of the NOx reduction, this research obtained reductions of the smoke and NOx emission at the same time from the diesel engine with the BE blended diesel fuel.