• Fire Science and Engineering
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• v.34 no.3
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• pp.49-57
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• 2020

Apartment buildings are becoming taller and more densely populated with the advancements in science and the development of cities, Consequently, various amenities and safety facilities are being developed to improve the quality of life for residents. However, according to statistics, the number of casualties in apartments accounts for a high proportion of accidents, and the leading cause of the casualties is smoke emitted from fires while sleeping at night. Although it is best to install separate indoor facilities in apartments to minimize smoke damages to occupants, it is useful to minimize the smoke damages by utilizing the installed facilities while reducing the financial burden of occupants. Based on the review, the heat exchanger ventilation system and the kitchen collective exhaust system were selected, and the feasibility of these systems was verified through fire simulation. From the verification results, the available safe egress time improved by 27, 30, and 35 s on the 25th, 35th, 50th floors, respectively.

• 한국연소학회:학술대회논문집
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• 2003.05a
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• pp.7-12
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• 2003

The purpose of this work is to investigate the effect of premixing condition on the combustion and exhaust emission characteristics in a HCCI diesel engine. To form homogeneous charge before intake manifold, the premixed fuel is injected into premixed tank by GDI injection system and the premixed fuel is ignited by direct injected diesel fuel. But in the case of high intake air temperature, premixed fuel is auto-ignited before diesel combustion and soot emission is increased. In the case of light load condition, the BSFC is improved by intake air heating because increased air temperature promoted the combustion of premixed mixture. NOx and smoke concentration of exhaust emissions are reduced compared to conventional diesel engine. The combustion characteristics of the HCCI diesel engine such as combustion pressure, rate of heat release, and exhaust emission characteristics are discussed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.12
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• pp.1756-1762
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• 2002

To effectively meet current regulations on the exhaust emissions of diesel engine required to control the deterioration of air pollution in the whole world, this study is to investigate the effects of water induction through the air intake system on the characteristics of combustion and exhaust emissions in IDI diesel engine. A method fur supplying water through the air intake system to reduce the exhaust emissions has been considered with other methods such as water introduction in the form of water-in-fuel emulsion or water injection directly into the combustion chamber, but it has not been studied about the effects of water on the combustion concepts and the characteristics of exhaust emissions in detail until now. In this study, the formation of NOx was significantly suppressed by decreasing the gas peak temperature during the initial combustion process because the water play a role as a heat sink during evaporating in the combustion chamber, but the smoke was slightly increased by increasing water amount.

• Fire Science and Engineering
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• v.20 no.4 s.64
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• pp.135-142
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• 2006

The experiment applied Positive Pressure Ventilation to rapidly exhaust heat and smoke inside the construction in the fire was done. Changes of heat discharge and smoke density were measured, with the various blowing condition like a fan tilting angle to find the effect of the parameter. Experimental apparatus were with PPV and water mist system for better efficiency, and investigate the effect of heat discharge and smoke removal. In the experiment, flame temperature has decreased when PPV was applied. Smoke density, generated from fire also decreased dramatically and the efficiency showed the highest rate at $0^{\circ}$ tilting angle. In addition, combination of PPV and water mist system highly improved the efficiency of evacuation on heat and smoke density, clearly was influenced by the tilting angle.

• Proceedings of the SAREK Conference
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• 2006.11a
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• pp.47-47
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• 2006

• Journal of Korean Society of Environmental Engineers
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• v.36 no.7
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• pp.476-482
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• 2014

In this study, the characteristics of emulsified fuel and engine emissions were studied with engine dynamometer. Microexplosion took place in the combustion chamber. While combustion, emulsion fuel scattered to micro particles and it caused to smoke reduction. The heat produced from water vapour reduce the temperature of internal combustion chamber and it caused to inhibition of NOx production. It can be verified by the lower exhaust temperature of each ND-13 mode using emulsion fuel than that of MDO fuel. The NOx and smoke concentration were reduced by increasing water content in emulsion fuel. The power also decreased according to the increment of water content of emulsion fuel because emulsion fuel has low calorific value due to high water content than MDO. As a result of ND-13 mode test with 17% moisture content, it was achieved 24% reduction in NOx production, 76% reduction in smoke density, 11% reduction of $SO_2$ and 13% reduction in power loss.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.3
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• pp.37-42
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• 2008

This study is focused on the numerical predictions for different smoke-control ventilation modes for the subway fire. Smoke-control ventilation mode in the domestic platform is that exhausting for the smoke detected zones while supplying air or stopping any ventilation for other zones in the platform. Three cases of smoke control ventilation modes are considered. First and second case are present running smoke control mode in Korea. The third is that smoke-control ventilation fans equipped in the platform are operated in first 4 minute(platform evacuation time, NFPA130) since then the fans equipped in the platform are stopped and the fans equipped in the tunnels are operated. Distributions of heat, carbon monoxide and visible range are compared at a height of 1.7m(passenger breath/sight height) above the platform. The numerical results show that air supply fan operation in the platform causes the smoke disturbance and a rapid spread of the smoke. The switch-operation with fans in both the platform and tunnel are better than operation with only platform fans in smoke rejection efficiency.

• Journal of the Korean Society of Combustion
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• v.16 no.1
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• pp.52-57
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• 2011

The present study describes the characteristics of combustion and exhaust emissions in compression ignition engines using diesel-gasoline dual fuel. For investigating combustion characteristics, diesel fuel was injected directly in a single-cylinder compression ignition engine with a common-rail injection system and gasoline fuel was injected into a premixed chamber installed in an intake port. In order to investigate exhaust emission characteristics, exhaust gas was measured by emission analyzer and smoke meter. The experimental results showed that cases of diesel-gasoline dual fuel combustion exhibited extended ignition delay and reduced peak combustion pressure compared to those of directly injected diesel fuel cases. Furthermore, premixed gasoline-air mixture reduced NOx emissions due to low peak of rate of heat release(ROHR).

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.3
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• pp.85-93
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• 1994

The engine performance and combustion characteristics of diesel oil and fish oil blended with diesel oils were investigated at various blending rate of fish oil in a diesel engine. The maximum pressure showed no significant difference among test fuels at low load, but it was higher as the blending rate of fish oil increases at high load. Increasing the blending rate of fish oil, the rate of heat release and burned fraction were higher than those of diesel oil. The ignition delay became longer than that of diesel oil as the blending rate of fish oil increases, and its differences were larger at different loads. The combustion duration and density of smoke were shorter and lower as the blending rate of fish oil increases. The rate of fuel consumption showed no significant difference between diesel oil and fish blended with diesel oils.

• Transactions of the Korean Society of Mechanical Engineers
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• v.3 no.1
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• pp.1-9
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• 1979

Methanol was examined as supplemental fuel for open chamber type and pre-combustion chamber type diesel engine. Pre-determined quantities of diesel oil were injected as ordinary diesel engines and methanol was added at inlet pipe using venturi, nozzel and and float chamber for the rest of the charge. In this mode of operation, addition of methanol reduced inlet and exhaust temperature. Inlet air quantities were essentially unchanged in spite of lower inlet temperature. Exhaust smoke was significantly reduced At light load when both diesel oil and methanol were introduced with small quantities, specific heat consumption was considerably increased. However, with the increase of the quantity of methanol or diesel oil, specific heat consumption was improved. With sufficient quantities of diesel oil enough to produce the power above 3/4 load, addition of methanol showed better thermal economy.