• Journal of the Korean Society of Safety
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• v.20 no.1 s.69
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• pp.24-29
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• 2005

This study aim to derive the operation method of a comprehensive ventilation system which is capable of providing passengers with safe exit paths from platforms in onboard The situations. The airflow distributions in subway platforms under 13 types of tunnel vent system for a double track stop condition was calculated and having analyzed diffusion behaviors of smoke and heat exhaust in such states by performing 13 kinds of different ventilation scenarios by using a 3-D Fire Dynamic Simulation (FDS) simulation model to clarify the safety evaluation for the heat and smoke exhaust on subway fire events.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.66-72
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• 2002

A premixed charge compression ignition engine is experimentally investigated for the reduction of NOx and smoke emissions from diesel engines. In this study, the premixed fuel is injected into the intake manifold to form homogeneous pre-mixture in the combustion chamber and then this pre-mixture is ignited by small amount of diesel fuel directly injected into the cylinder. In the premixed charge compression ignition engine, NOx and smoke concentrations of the exhaust emissions were reduced simultaneously as compared with the conventional diesel engine. But HC emission was increased with the increase of premixed ratio. Also, when EGR system was applied to the PCCI diesel engine, the effect of EGR rate on the combustion characteristics and the exhaust gas emissions was discussed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.7
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• pp.25-32
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• 2021

In the previous study, a study was conducted to improve the exhaust gas intake efficiency by improving the existing soot measurement probe in the shape and angle of the exhaust port. As a result, it can be seen that the smoke measurement performance according to the shape and angle is improved. In previous studies, the performance of the soot probe was not confirmed for the Korean KD 147 mode, which has a low suction flow rate and a long inspection time. So, we would like to confirm the improvement of the smoke probe performance of the Korean KD 147 mode, which is close to the actual driving conditions. The probe used in this study is another type of probe, and has a circular ring shape instead of a rib and variable center position unit, so the probe center hole is located close to the center of the exhaust pipe.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.3
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• pp.64-71
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• 2022

In this study, fire and egress simulation was conducted for the egress safety evaluation of the nursing hospitals. A fire simulation was performed with or without the smoke exhaust system using the FDS, and the available safe egress time (ASET) of the nursing hospitals was calculated. In addition, an egress simulation considering the characteristics of occupants and egress delay time was performed using Pathfinder, and the required safe egress time (RSET) was calculated. By comparing the ASET and RSET, the egress safety of the nursing hospital with or without a smoke exhaust system was evaluated according to the number of egress guides and the egress delay time. The simulation results show that the number of casualties increased as the egress delay time increased, and the required safe egress time decreased as the number of egress guides increased. In addition, it was found that if a smoke exhaust system with the capacity specified in the KFPA is secured, the available safe egress time can be greatly increased and the number of casualties can be greatly reduced.

• Journal of Power System Engineering
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• v.15 no.6
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• pp.11-15
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• 2011

This study investigated the symptoms of the a reduction in output while driving on the road, or increasing of fumer out exhaust gas on inclined road while working air-conditioner in summer. Notice how the experiment in 2010, the Ministry of Environment(Chapter No. 2010-46), and how the vehicle emissions inspection was carried out. 2500cc Diesel cars used in the study were used and compare to output of engine, exhaust gas, inhalation temperature measurement Inhalation of cold air has not been supplied to all agencies when comparing the results when cold air intake temperature of the supply air-conditioning switch range control from 1 to 4, the temperature drops $98^{\circ}C$ to $78^{\circ}C$. At the momentum of switch level 4, output from 63ps to 66ps after the connection has increased 9.6 percent, the highest concentration of exhaust emissions were reduced by 42.8%. This research can contribute in part to the reduction of exhaust directly supply into the cooling air intake line, doing the output of diesel cars in the summer. In addition, construction equipment and machinery that are currently being used excluding the engine's intercooler cooling of the supply line via a separate output in the summer and help reduce exhaust emissions is expected.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.21-26
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• 2015

This study represents the effective fire and smoke control in the case of fire in deep underground tunnels, even if the exhaust system can be calculated, the optimal smoke capacity can be determined by establishing technical standards for the transverse ventilation system focusing on the design as a basis for deriving the parameters for utilization. Numerical analyses were performed using the FDS program as a function of the unsteady flow in a deep underground tunnel fire. The analysis results were calculated within 250 m smoke using an inside wind velocity of 0m/s when the capacity of smoke was exhausted, $80m^3/s$, whereas in case of an internal wind velocity of 3m/s, the capacity of smoke exhaust was $197.1m^3/s$, showing an approximately 2.5 fold increase.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.3
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• pp.180-184
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• 2016

Legislative and regulatory actions regarding the exhaust gas from ships are being strengthened by both international organizations and national governments, to protect human health and the environment. Exhaust gas traps are excluded from exhaust gas regulation applications, but, recently, the United States, Britain, and other developed countries have examined a variety of ways to improve the system, including the introduction of electric propulsion systems to prevent air pollution generated by naval ships. This study investigates a large number of smoke problems of naval diesel engines to verify the effect of improving the nozzle characteristics. An exhaust gas emission measurement method to determine the quality of pollutant exhaust gas generated during low-load operation is proposed through the research methodology of the smoke problem. It was confirmed that the emissions value is improved by decreasing the nozzle hole diameter and increasing the injection pressure. At the same time, the flow rate decrease equation and setting up a test memo based on the nozzle diameter confirmed that the fuel consumption, to which the nozzle diameter in the flow path is related, is reduced.

• Fire Science and Engineering
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• v.30 no.5
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• pp.87-92
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• 2016

Amid the growing number of high-rise complex buildings in Korea, efficient smoke prevention technology in a fire is required and as an alternative of a mechanical smoke control system in high-rise buildings, the use of a smoke control system using sandwich pressurization has been on the rise. In such a system, the appropriate pressure difference and the data for designing the air supply and exhaust flow rate are necessary to prevent the spread of smoke and offer a tenable evacuation environment. As part of such effort, this paper presents a field test process and result after testing a building where such a smoke control system using sandwich pressurization has been installed. A ventilation rate of 6 cycles per hour were applied to simulate the air exhaust flow rate on a fire floor and the air supply flow rate on the floors above and below the fire floor. As a result of the system operation, pressure difference of approximately 260 Pa between the 12th floor of a fire and the 13th floor was generated. The over pressure of the experiment has a serious effect on the evacuation or fire compartment so that it is necessary to examine the improvement.

• Journal of Mechanical Science and Technology
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• v.18 no.9
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• pp.1640-1647
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• 2004

This study was to investigate the effects of water induction through the air intake system on the characteristics of combustion and exhaust emissions in an IDI diesel engine. The fuel injection timing was also controlled to investigate a method for the simultaneous reduction of smoke and NOx when water was injected into the combustion chamber. The formation of NOx was significantly suppressed by decreasing the gas peak temperature during the initial combustion process because the water played a role as a heat sink during evaporating in the combustion chamber, while the smoke was slightly increased with increased water amount. Also, NOx emission was significantly decreased with increase in water amount. A simultaneous reduction in smoke and NOx emissions was obtained when water was injected into the combustion chamber by retarding more 2$^{\circ}C$A of the fuel injection timing than without water injection.

• Journal of Power System Engineering
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• v.14 no.1
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• pp.11-15
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• 2010

Our environment is faced with serious problems related to the air pollution from automobiles in these days. In particular, the exhaust emissions from the diesel engines are recognized as main cause which has a great influence on environment. In this study, the potential of biodiesel fuel and oxygenated fuel(ethylene glycol mono-n-butyl ether; EGBE) was investigated as an effective method of decreasing the smoke emission. The smoke emission of blending fuel(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. On the contrary NOx emissions from biodiesel fuel and EGBE blended fuel were increased compared with diesel fuel. Torque and brake specific energy consumption(BSEC) didn't have large differences.