• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2375-2380
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• 2013

In this paper, we have implemented the unified fuel heater and performance evaluation system for diesel cars. In order to strengthen an engine starting of diesel car, we need to assembly the fuel filter and heater. Especially, this assembly fuel heater is very important in winter, it is necessary for heating to operate the diesel engine. The heater for unifying the sensor and heater body can advance the performance of car and reduce the production cost. Finally, the performance test chamber is needed to evaluate the performance of heater.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.9
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• pp.2353-2364
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• 1995

The ignition phenomena of a solid fuel plate of polymethyl-methacrylate(PMMA), which is vertically positioned and exposed to a thermal radiation source, is numerically studied here. A two-dimensional transient model includes such various aspects as thermal decomposition of PMMA, gas phase radiation absorption, gas phase chemical reaction and air entrainment by natural convection. Whereas the previous studies considers the problem approximately in a one-dimensional form by neglecting the natural convection, the present model takes account of the two-dimensional effect of radiation and air entrainment. The inert heating of the solid fuel is also taken into consideration. Radiative heat transfer is incorporated by th Discrete Ordinates Method(DOM) with the absorption coefficient evaluated using gas species concentration. The thermal history of the solid fuel plate shows a good agreement compared with experimental results. Despite of induced natural convective flow that induces heat loss from the fuel surface, the locally absorbed radiant energy, which is converted to the internal energy, is found to play an important role in the onset of gas phase ignition. The ignition is considered to occur when the rate of variation of gas phase reaction rate reaches its maximum value. Once the ignition takes place, the flame propagates downward.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.817-820
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• 2009

Research on usage of syngas produced by waste gasification is on going all around the world. Syngas which consists of $H_2$, CO, $CO_2$, $N_2$, has different combustion characteristics from current city gas; due to distinct flame propagation speed of the fuel, syngas has different spark timing and air fuel ratio at maximum generating efficiency. This is why finding both the optimum point of spark timing and air fuel ratio is so important in order to improve thermo efficiency and secure stable running of gas generated by relatively low heating value syngas. Moreover, since emission of $NO_x$ is strictly regulated, it is important to operate lean burn condition that reduces NOx emission.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.3
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• pp.63-71
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• 2006

A downdraft gasifier was made of stainless steel for biomass gasification. Internal reactor had a 300 mm diameter and 8 air intakes. Three thermocouples were installed to measure the temperature inside the reactor. Three different biomass fuels were provided in the experiments to find out the effects of fuel conditions on gasification processes; charcoals, woodchips, and mixture of woodchip and charcoals. Two different experiments were conducted fer charcoal experiments, small and larger sizes of charcoal fuels. It took about 10 minutes after ignition to generate combustible producer gas when charcoal was f9d, but 20 or more minutes for woodchips. When the gasification was stabilized, the highest temperature was observed just below the combustion zone. The air flow rate for woodchip experiment was provided at 25% of a stoichiometric requirement of combustion, which was within the range of typical air flow rate fer woody biomass gasification. Carbon monoxide concentrations were also within the values reported in the previous studies, ranging 20 to 30% depending on fuel types. It could be seen that fuel size and heating value were very important parameters in biomass gasification. These parameters should be taken into account in operating and designing biomass gasifiers.

• 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.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.4
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• pp.12-23
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• 2004

The effects of improved rice bran oil on the characteristics of exhaust emissions have been experimentally examined by a single cylinder, four cycle, direct injection, water-cooled agricul-tural diesel engine operating at several loads and speeds. The experiments are conducted with light oil, rice bran oil, and improved rice bran oil as a fuel. The fuel injection timing is fixed to 22$^{\circ}$ BTDC regardless of fuel types, engine loads and speeds. To reduce the viscosity of rice bran oil, it is used with the methods of heating, methyl ester and ultrasonic system in a highly viscous rice bran oil. In this study, it is found that the brake specific fuel consumption rate of light oil is the lowest and that of improved rice bran oils is lower than that of pure rice bran oil, and NO$_{x}$ emissions of light oil are the lowest and those of pure rice bran oil are the high- est, while soot emissions of light oil are the highest and those of pure and improved rice bran oils are lower than that of light oil. However these results are not amply satisfied with the emissions regulation limit using the pure and improved rice bran oil as fuels in diesel engines.s.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.2
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• pp.91-101
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• 2012

A 200 W portable polymer electrolyte membrane fuel cell (PEMFC) system is developed. The PEMFC system consists of an air-cooled fuel cell stack module, a fuel supply subsystem, a power management subsystem, and a control electronics subsystem. The control logic is designed for the stable system operation. The system-level performance evaluation discloses that the present PEMFC system provides a rated power output of 200.5 W at 13.4 V with the maximum balance-of-plant (BOP) efficiency of 72%, and maximum system efficiency based on lower heating value (LHV) is 37% at 120.7 W system power output.

• 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.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.1
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• pp.38-46
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• 2023

Carbon neutrality policies have been strengthened to reduce emissions, and the importance of technology road maps has been emphasized. In the global industrial boiler market, carbon neutrality is implemented through fuel diversification of methane-hydrogen mixture gas. However, various problems such as flashback and flame unstability arise. There is a limit to implementing the actual system as it remains in the early stage. Therefore, it is necessary to secure the source technology of methane-hydrogen hybrid combustion system applicable to industrial fields. In this study, control program for methane-hydrogen fuel conversion was developed to expect various parameters. After determining the hydrogen mixing ratio and the input air flow, the fuel conversion control algorithm was constructed to get the parameters that achieve the target oxygen concentration in the exhaust gas. LabVIEW program was used to derive correlations among hydrogen mixing rate, oxygen concentration in exhaust gas, input amount of air and heating value.

• Journal of Energy Engineering
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• v.23 no.1
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• pp.81-89
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• 2014

The purpose of this study is to obtain low-emission and high-efficiency in LPG engine with hydrogen enrichment. The objective of this paper is to clarify the effects of hydrogen enrichment in LPG fuelled engine on exhaust emission, thermal efficiency and performance. The compression ratio of 8 was selected to avoid abnormal combustion. To maintain equal heating value of fuel blend, the amount of LPG was decreased as hydrogen was gradually added. The relative air-fuel ratio was increased from 0.76 to 1.5, and the ignition timing was controlled to be at minimum spark advance for best torque (MBT).