• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.7
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• pp.1007-1014
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• 2003

This work deals with a controlled auto-ignition (CAI) single cylinder gasoline engine, focusing on the extension of operating conditions. The fuel is injected indirectly into electrically heated inlet air flow. In order to keep a homogeneous air-fuel mixing, the fuel injector is water-cooled by a specially designed coolant passage. Investigated are the engine performance and emission characteristics under the wide range of operating conditions such as 32 to 63 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, and 150 to 18$0^{\circ}C$ in the inlet air temperature. The compression ignition gasoline engine can be achieved that the ultra lean-burn with self-ignition of gasoline fuel by heating inlet air. For example. the allowable lean limit of air-fuel ratio is extended until 63 at engine speed of 1000 rpm and inlet air temperature of 17$0^{\circ}C$. It can be achieved that the emission concentrations of carbon monoxide, hydrocarbons and nitrogen oxide had been significantly reduced by CAI combustion compared with conventional spark ignition engine.

• Journal of Power System Engineering
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• v.9 no.1
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• pp.14-22
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• 2005

This work deals with a controlled auto-ignition (CAI) single cylinder gasoline engine, focusing on the extension of operating conditions. The fuel is injected indirectly into electrically heated inlet air flow. In order to keep a homogeneous air-fuel mixing, the fuel injector is water-cooled by a specially designed coolant passage. Investigated are the engine performance and emission characteristics under the wide range of operating conditions such as 40 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, $150\;to\;180^{\circ}C$ in the inlet-air temperature, and $80^{\circ}$ BTDC to $20^{\circ}$ ATDC in the injection timing. A controlled auto-ignition gasoline engine can be achieved that the ultra lean-burn with self-ignition of gasoline fuel by heating inlet air. It can be achieved that the emission concentrations of carbon monoxide, hydrocarbons and nitrogen oxide had been significantly reduced by CAI combustion compared with conventional spark ignition engine.

• Journal of Power System Engineering
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• v.10 no.1
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• pp.19-24
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• 2006

This work treats a controlled auto-ignition (CAI) single cylinder gasoline engine, focusing on the extension of operating conditions. The fuel was injected indirectly into electrically heated inlet air flow. In order to keep a homogeneous air-fuel mixing, the fuel injector was water-cooled by a specially designed coolant passage. The engine performance and emission characteristics were investigated under the wide range of operating conditions such as 40 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, 150 to $180^{\circ}C$ in the inlet-air temperature, and $60^{\circ}$ BTDC in the injection timing. The ultra lean-burn with self-ignition of gasoline fuel by heating inlet air was achieved in a controlled auto-ignition gasoline engine. It could be also achieved that the emission concentrations of carbon monoxide, hydrocarbons and nitrogen oxide significantly reduced by CAI combustion compared with conventional spark ignition engines.

• Journal of Power System Engineering
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• v.17 no.2
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• pp.87-94
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• 2013

Applicability of organic Rankine cycle for a passenger car with 3.5 L gasoline engine to convert low grade waste heat to useful shaft power has been numerically studied. Working fluid is R134a, and the Rankine cycle is composed of boiler for recovering engine cooling water heat, super heater for recovering exhaust gas heat, scroll expander for converting waste heat to shaft power, condenser for heat emission, internal heat exchanger, and feed pump. Assuming efficiencies of 90% for the heat exchangers, 75% for the scroll expander, and 80% for the feed pump, the Rankine cycle efficiency of 5.53% was calculated at the vehicle speed of 120 km/hr. Net expander shaft output after subtracting the power required to run the pump was 3.22 kW, which was equivalent to 12.1% improvement in fuel consumption. About the same level of improvement in the fuel consumption was obtained over the vehicle speed range of 60 km/hr~120 km/hr.

• 전자공학회논문지 IE
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• v.48 no.2
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• pp.12-18
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• 2011

In this paper, did numerical simulation to confirm LED module for lighting and protection against heat special quality of heat sink device. Analysis was gone dividing on case that emitting light side turns normalcy department considering that eat of device according to usage and case that turn down looking being street lamp of 200 W or security appointment lighting device analysis case, and also, volume of thermal element divides on big case and small case and analyzed. Confirmed that can do so that may discharge LED's thermal value to outside enough in analysis wave and current heat sink shape, and investigated that difference of protection against heat performance according to position of device and size of thermal element appears.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.950-954
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• 2001

Gasoline engine manufacturers are currently considering designs that will result in low combustion air temperature for improvement of fuel consumption and emission levels. There are a variety of cooling systems that can be used to accomplish this goal. Coolong is therefore normally achieved through a balance of ram and fan action. This paper studies the various systems and compare the cooling performance for several conditions, based on a automotive engine. An experimental analysis was developed to predict the interaction of the fan system and the heat exchangers of the engine cooling system. The local temperature induced by the fan on the cooling system is measured. These experimental result were accomplished using air flow management techniques.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.940-945
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• 2001

Gasoline engine manufacturers are currently considering designs that will result in low combustion air temperature for improvement of fuel consumption and emission levels. There are a variety of cooling systems that can be used to accomplish this goal. Cooling is therefore normally achieved through a balance of ram and fan action. This paper studies the various systems and compare the cooling performance for several conditions, based on a automotive engine. An experimental analysis was developed to predict the interaction of the fan system and the heat exchangers of the engine cooling system. The local temperature induced by the fan on the cooling system is measured. These experimental result were accomplished using airflow management techniques.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.265-266
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• 2012

Recently, preparing countermeasures about energy depletion and CO₂ emission progressing rapidly is considered as an urgent problem not only in domestic country but also in international countries. Among this, the requirement for the comfort development of in door environment is increasing according to housing culture and life environment changing. Thus, it is required urgently to save building energy and develop fusion technology maintaining comfort of indoor environment. Recently, energy-saving ways in saving heating and cooling energy by latent heat and thermal storage is considered significantly. In this study, keeping up with the times, thermal performance analyzed. Also, this study has the aim to draw materials for evaluating usefulness and efficiency.

• Journal of the Korean Wood Science and Technology
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• v.51 no.5
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• pp.410-418
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• 2023

In this study, the combustion characteristics of the Tulip tree, which is the representative broad-leaved afforestation tree in Korea, were analyzed. The flame retardant performance of the Tulip tree was analyzed by analyzing combustion characteristics on a total of three test samples; flame retardant treated, both flame retardant and oil stain-treated, and untreated. Then the flame retardance grade was classified for each of them. According to the result, test samples showed the strongest flame retardance were in order of flame retardant treated (C), both flame retardant and oil stain-treated (B), and untreated (A). As a result of analyzing the total heat emission and maximum heat emission rates, which is the evaluation standard for interior materials of Korean domestic buildings, test samples with flame retardant treat or flame retardant and oil stain treat were qualified for the flame-retardant standard. Both flame retardant and oil stain-treated samples showed higher total heat release (THR) and heat release rate compared to flame retardant-treated samples as the oil causes combustion with oxygen. On the other hand, they didn't qualify the THR in Quasi-non-combustible standards. To determine the correlation between the physical and combustion characteristics of wood, the combustion characteristics of other diffuse porous wood species, with which the Tulip tree is affiliated were analyzed, and noticed that the characteristic correlates with the density and quantity of wood. The results of this study are expected to be used as basic information on the combustion characteristics of the Tulip tree.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.7
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• pp.1123-1130
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• 2004

Numerical simulations have been carried out to investigate the effect of nozzle hole geometry on the combustion characteristics of the large diesel engine. 6S90MC-C. Spray and combustion phenomena were examined numerically using FIRE code. Wane breakup and Zeldovich models were adopted to describe the atomization characteristics and NOx formation processes. Predictions on the cylinder peak pressure and NOx emission were first verified with the experimental data to confirm the reliability of numerical calculations. The comparison results showed good agreements within the range of 0.64% and 4.6% respectively. Finally, the effects of fuel spray angle and diameter on the engine performance were investigated numerically to find the optimum nozzle hole geometry considering fuel consumption, NOx emission and heat flux of the combustion chamber wall. It was concluded that the combustion gas recirculation in cylinder by changing fuel injection direction is an effective method to reduce NOx emission by about 10% with increasing fuel oil consumption, 1.4% in a large diesel engine.