With increasing concern over global warming and energy consumption, diesel engines have received ... more With increasing concern over global warming and energy consumption, diesel engines have received considerable attention due to their high thermal efficiency. However, diesel engines still suffer from high NOx and PM emissions. Therefore, this study focuses on the use of diesel–water emulsified (DE) fuel to reduce NOx and PM emissions and evaluates its application to conventional diesel engines based on the fundamental characteristics of DE fuel. DE fuels were applied to actual diesel engines, and their combustion, emission, and fuel consumption characteristics were compared with those of diesel fuel. The injection time was the same in all experiments. The coefficient of variation (COV) of all DE fuels was stable at a value as low as 2.0%, and the combustion duration was shorter than that of diesel fuel. The NOx and PM generation rates of DE fuels were considerably lower than those of diesel fuel because of the beneficial effects of the microexplosion and evaporative latent heat.
In this study, it was applied to the diesel–water emulsified (DE) fuel that carried out the exper... more In this study, it was applied to the diesel–water emulsified (DE) fuel that carried out the experiment for the characteristic of sprat using diesel water emulsified fuel in a diesel engine, and the possibility of its application to conventional diesel engines was evaluated from the fundamental characteristics of diesel–water emulsified fuel. According to the results of the spray characteristics such as spray penetration and spray distribution were measured in the experiment, and then analyzed through digital image processing. The DEs were applied to actual diesel engines and their combustion, emission, and fuel consumption characteristics were compared with those of diesel. The results showed that the experiments were confirmed as the spray atomization characteristics at the various emulsified fuels.
: Recently, the internal combustion engines have focused on reducing the CO 2 gas in order to cop... more : Recently, the internal combustion engines have focused on reducing the CO 2 gas in order to cope with severe regulations for fuel economy. Therefore, various new technologies have been developed. Among them, cooling system is spotlighted because it has great effect on fuel economy. In this study, we measured the friction losses of engine parts according to engine speed and oil temperature. We also obtained optimized oil temperature which has the minimum friction losses. Then, we selected optimized oil temperature range and gave informations of friction losses for each engine parts. In addition, we analyzed relationship between coolant temperature and oil temperature by using engine performance test system. From this experiment, we obtained the database for relationship between coolant temperature and oil temperature. Then, we found the optimal temperature about engine oil. We analyzed BSFC and exhaust emissions by controlling the high coolant temperture. If we controlled coolant t...
International Journal of Automotive Technology, 2014
Diesel engines are most frequently used in vehicles because of their high efficiency and durabili... more Diesel engines are most frequently used in vehicles because of their high efficiency and durability. However, nitrogen oxide (NOx) and particulate matter (PM) from diesel engines are became problem. Recently, the premixed charged compression ignition (PCCI) technique has been studied specifically to reduce NOx and PM emissions simultaneously. While the PCCI engine has the advantage of reducing NOx and PM emissions, control of the combustion phase is difficult. Therefore, it is very important to understand the flame developing process and heat release pattern in a real PCCI engine. However, most research into the characteristics of PCCI combustion has used an optical access engine. This paper describes the combustion characteristics obtained using a micro-Cassegrain sensor and discusses how the sensor can be used to directly detect the flame characteristics for future control of PCCI combustion. From this research, the differences of flame characteristics between PCCI engine and conventional diesel engine were clarified.
In this study, it was applied to the diesel–water emulsified (DE) fuel that carried out the exper... more In this study, it was applied to the diesel–water emulsified (DE) fuel that carried out the experiment for the characteristic of sprat using diesel water emulsified fuel in a diesel engine, and the possibility of its application to conventional diesel engines was evaluated from the fundamental characteristics of diesel–water emulsified fuel. According to the results of the spray characteristics such as spray penetration and spray distribution were measured in the experiment, and then analyzed through digital image processing. The DEs were applied to actual diesel engines and their combustion, emission, and fuel consumption characteristics were compared with those of diesel. The results showed that the experiments were confirmed as the spray atomization characteristics at the various emulsified fuels.
In this study, we produced pure biodiesel and analyzed its properties. Also, pure biodiesel was b... more In this study, we produced pure biodiesel and analyzed its properties. Also, pure biodiesel was blended with conventional diesel fuel in volumetric mixing rates of 5%, 20%, and 35%. Therefore, a total seven kinds of fuels were tested for this study. Injection quantity was measured according to the blending rate. Spray penetration, distribution, and evaporation characteristics were also clarified through a spray visualization system. Furthermore, the combustion flame was investigated using a single cylinder optical engine and a high-speed camera to understand how evaporation characteristics affect the combustion flame. Moreover, exhaust emissions were measured with an exhaust emission analyzer and a smoke meter. According to the results of the injection test, there were few differences between the characteristics of diesel and biodiesel-blended fuel regarding the injection quantity and penetration length when the fuel temperature was maintained at 60 °C. Hence, there were not any problems such as additiona...
With increasing concern over global warming and energy consumption, diesel engines have received ... more With increasing concern over global warming and energy consumption, diesel engines have received considerable attention due to their high thermal efficiency. However, diesel engines still suffer from high NOx and PM emissions. Therefore, this study focuses on the use of diesel–water emulsified (DE) fuel to reduce NOx and PM emissions and evaluates its application to conventional diesel engines based on the fundamental characteristics of DE fuel. DE fuels were applied to actual diesel engines, and their combustion, emission, and fuel consumption characteristics were compared with those of diesel fuel. The injection time was the same in all experiments. The coefficient of variation (COV) of all DE fuels was stable at a value as low as 2.0%, and the combustion duration was shorter than that of diesel fuel. The NOx and PM generation rates of DE fuels were considerably lower than those of diesel fuel because of the beneficial effects of the microexplosion and evaporative latent heat.
In this study, it was applied to the diesel–water emulsified (DE) fuel that carried out the exper... more In this study, it was applied to the diesel–water emulsified (DE) fuel that carried out the experiment for the characteristic of sprat using diesel water emulsified fuel in a diesel engine, and the possibility of its application to conventional diesel engines was evaluated from the fundamental characteristics of diesel–water emulsified fuel. According to the results of the spray characteristics such as spray penetration and spray distribution were measured in the experiment, and then analyzed through digital image processing. The DEs were applied to actual diesel engines and their combustion, emission, and fuel consumption characteristics were compared with those of diesel. The results showed that the experiments were confirmed as the spray atomization characteristics at the various emulsified fuels.
: Recently, the internal combustion engines have focused on reducing the CO 2 gas in order to cop... more : Recently, the internal combustion engines have focused on reducing the CO 2 gas in order to cope with severe regulations for fuel economy. Therefore, various new technologies have been developed. Among them, cooling system is spotlighted because it has great effect on fuel economy. In this study, we measured the friction losses of engine parts according to engine speed and oil temperature. We also obtained optimized oil temperature which has the minimum friction losses. Then, we selected optimized oil temperature range and gave informations of friction losses for each engine parts. In addition, we analyzed relationship between coolant temperature and oil temperature by using engine performance test system. From this experiment, we obtained the database for relationship between coolant temperature and oil temperature. Then, we found the optimal temperature about engine oil. We analyzed BSFC and exhaust emissions by controlling the high coolant temperture. If we controlled coolant t...
International Journal of Automotive Technology, 2014
Diesel engines are most frequently used in vehicles because of their high efficiency and durabili... more Diesel engines are most frequently used in vehicles because of their high efficiency and durability. However, nitrogen oxide (NOx) and particulate matter (PM) from diesel engines are became problem. Recently, the premixed charged compression ignition (PCCI) technique has been studied specifically to reduce NOx and PM emissions simultaneously. While the PCCI engine has the advantage of reducing NOx and PM emissions, control of the combustion phase is difficult. Therefore, it is very important to understand the flame developing process and heat release pattern in a real PCCI engine. However, most research into the characteristics of PCCI combustion has used an optical access engine. This paper describes the combustion characteristics obtained using a micro-Cassegrain sensor and discusses how the sensor can be used to directly detect the flame characteristics for future control of PCCI combustion. From this research, the differences of flame characteristics between PCCI engine and conventional diesel engine were clarified.
In this study, it was applied to the diesel–water emulsified (DE) fuel that carried out the exper... more In this study, it was applied to the diesel–water emulsified (DE) fuel that carried out the experiment for the characteristic of sprat using diesel water emulsified fuel in a diesel engine, and the possibility of its application to conventional diesel engines was evaluated from the fundamental characteristics of diesel–water emulsified fuel. According to the results of the spray characteristics such as spray penetration and spray distribution were measured in the experiment, and then analyzed through digital image processing. The DEs were applied to actual diesel engines and their combustion, emission, and fuel consumption characteristics were compared with those of diesel. The results showed that the experiments were confirmed as the spray atomization characteristics at the various emulsified fuels.
In this study, we produced pure biodiesel and analyzed its properties. Also, pure biodiesel was b... more In this study, we produced pure biodiesel and analyzed its properties. Also, pure biodiesel was blended with conventional diesel fuel in volumetric mixing rates of 5%, 20%, and 35%. Therefore, a total seven kinds of fuels were tested for this study. Injection quantity was measured according to the blending rate. Spray penetration, distribution, and evaporation characteristics were also clarified through a spray visualization system. Furthermore, the combustion flame was investigated using a single cylinder optical engine and a high-speed camera to understand how evaporation characteristics affect the combustion flame. Moreover, exhaust emissions were measured with an exhaust emission analyzer and a smoke meter. According to the results of the injection test, there were few differences between the characteristics of diesel and biodiesel-blended fuel regarding the injection quantity and penetration length when the fuel temperature was maintained at 60 °C. Hence, there were not any problems such as additiona...
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Papers by Hyungik Kim