• International Journal of Automotive Technology
• /
• 제8권1호
• /
• pp.9-18
• /
• 2007

Phase separation and low cetane number are the main barriers to the large-scale use of ethanol-diesel blend fuel on small diesel engines. In this paper, an additive package is designed on the basis of the blended fuel properties to overcome these limitations. The experiments show that the solubility of ethanol in diesel is evidently increased by adding $1{\sim}2%$ (in volume) of the additive package and the flammability of ethanol-diesel blend fuel with the additive has reached the neat diesel level under the cold start conditions. Effects of the ethanol content in diesel on fuel economy, combustion characteristics, and emission characteristics are also investigated with the ethanol blend ratios of 10%, 20% and 30%. The increase in ethanol content shows that the specific fuel consumption and the brake thermal efficiency are both gradually increased compared to neat diesel. The soot concentrations of the three blended fuels are all greatly lower than that of neat diesel. $NO_x$ emission is increased with an increase in the engine load and is reduced with the increase in the ethanol blend ratio under a high load.

• International Journal of Automotive Technology
• /
• 제7권6호
• /
• pp.653-658
• /
• 2006

The enormous increase in the use of fossil energy sources throughout the world has caused severe air pollution and a depletion of energy. Besides, it seems very difficult to comply with the upcoming stringent emission standards in vehicles. In order to develop low emission engines, research on better qualified fuels as alternative fuels to secure high engine performance becomes a more important issue than ever. Since sulfur contained in diesel fuel is transformed in sulfate-laden particulate matters when a catalyst is applied, it is necessary to provide low sulfur fuels before any Pt-based oxidation catalysts are applied. But the excessive reduction of sulfur levels may cause the lubricity of fuel and engine performance to degrade. In this aspect, biodiesel fuel derived from rice bran is applied to compensate viscosity lost in the desulfurization treatment. This research is focused on the performance of an 11,000cc diesel engine and the emission characteristics by the introduction of ULSD(Ultra Low Sulfur Diesel), BD20(Diesel 80%+Biodiesel 20%) and a diesel oxidation catalyst, where BD20 is used to improve the lubricity of fuel in fuel injection systems as fuel additives or alternative fuels.

• 동력기계공학회지
• /
• 제12권1호
• /
• pp.5-12
• /
• 2008

We measured emission characteristics of CRDI diesel engine equipped with a commercial CPF. Experimental parameters adopted a neat diesel fuel, a blend of diesel fuel with 20% biodiesel, a blend of diesel fuel with 15% biodiesel and 5% ethanol. The experiments were carried out to measure the emission and engine performance according to ESC 13-mode cycles. The maximum torque with biodiesel blend fuel is slightly lower than that of neat diesel fuel in the entire the 13-mode cycles, and 5% ethanol and 15% biodiesel blend fuel is slightly higher than that of neat diesel fuel. THC and CO emissions of the biofuel blended diesel fuel were slightly increased and decreased, and mean conversion efficiencies of THC and CO on the commercial CPF were achieved about 70$\sim$87% in the ESC 13-mode. From the measurement by the Scanning Mobility Particle Sizer(SMPS), the total number and mass of nano-sized particles by a commercial CPF were decreased about 97.8% and 96.8 % in the range of the nano-size from 10.6 to 385nm, respectively.

• Environmental Engineering Research
• /
• 제23권3호
• /
• pp.242-249
• /
• 2018

The use of palm oil and diesel blended with ethanol, known as a microemulsion biofuel, is gaining attention as an attractive renewable fuel for engines that may serve as a replacement for fossil-based fuels. The microemulsion biofuels can be formulated from the mixture of palm oil and diesel as the oil phase; ethanol as the polar phase; methyl oleate as the surfactant; alkanols as the cosurfactants. This study investigates the influence of the three cosurfactants on fuel consumption and exhaust gas emissions in a direct-injection (DI) diesel engine. The microemulsion biofuels along with neat diesel fuel, palm oil-diesel blends, and biodiesel-diesel blends were tested in a DI diesel engine at two engine loads without engine modification. The formulated microemulsion biofuels increased fuel consumption and gradually reduced the nitrogen oxides ($NO_x$) emissions and exhaust gas temperature; however, there was no significant difference in their carbon monoxide (CO) emissions when compared to those of diesel. Varying the carbon chain length of the cosurfactant demonstrated that the octanol-microemulsion fuel emitted lower CO and $NO_x$ emissions than the butanol- and decanol-microemulsion fuels. Thus, the microemulsion biofuels demonstrated competitive advantages as potential fuels for diesel engines because they reduced exhaust emissions.

• 한국산업보건학회지
• /
• 제17권2호
• /
• pp.144-152
• /
• 2007

Diesel vehicles are a significant source of fine carbon particle emissions including polynuclear aromatic hydrocarbons (PAHs). Urinary 1-hydroxypyrene (1-OHP) is firmly established as a useful biomarker of PAHs uptake in human. To investigate the exposure effect of PAHs in miners according to using diesel truck which was for transportation of ore, we measured urinary 1-OHP as the PAHs exposure biomarker, and analyzed the relationship between urinary 1-OHP concentration and using diesel truck. The study was performed on 118 workers (56 miners in factories using diesel truck, 62 miners in factories non-using diesel truck) and 21 controls. Urine samples were obtained at the end of shift on the survey day. There was no significance in comparison with the mean concentrations on urinary 1-OHP by age, BMI, work duration, smoking, drinking and ventilation type. But significant difference were found among urinary 1-OHP concentrations on factories according to using diesel truck (p=0.000). The urinary 1-OHP mean concentration on underground miners using diesel truck ($0.54{\mu}mol/mol$ creatinine) was higher than those of surface miners using diesel truck ($0.33{\mu}mol/mol$ creatinine, p=0.028), underground miners non-using diesel truck ($0.32{\mu}mol/mol$ creatinine, p=0.001) and controls ($0.22{\mu}mol/mol$ creatinine, p=0.000). In comparison with using status diesel truck, the urinary 1-OHP mean concentration of underground miners using diesel trucks was higher than those of other mine status. The study results would be beneficial to future environmental and biological studies of PAHs exposure to diesel exhaust in mines.

• 동력기계공학회지
• /
• 제18권2호
• /
• pp.5-11
• /
• 2014

The purpose of this study is to investigate the specific characteristics of combustion and exhaust emissions on a 4-cylinder common rail diesel engine as EGR rate and the rate of blended bio-diesel was altered. Bio-diesel fuel which is a sort of alternative fuels can be adapted to diesel engine directly without modifying. This study was performed to 2000rpm of engine speed with torque 30Nm while EGR rate and the rate of blended bio-diesel was changed. Decreasing combustion pressure and increasing the rate of heat were occurred when we had changed the EGR rate on the 20% of bio-diesel blended diesel fuel. The maximum pressure of combustion and the IMEP became higher as the EGR rate and the rate of blended bio-diesel were changed. Exhaust gas temperature was increased the higher rate of the blended bio-diesel under the fixed EGR rate. However, it went down as the EGR rate increased. The amounts of CO and Soot were reduced with increasing the rate of the blended bio-diesel without changing EGR rate and raised with increasing of the EGR rate. On the fixed EGR rate, NOx was increased along with growing the rate of the bio-diesel. On the other hand, it was decreased while EGR rate were going up.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2003년도 봄 학술발표회 논문집
• /
• pp.577-584
• /
• 2003

This study investigated the modeling of dissolution Diesel to estimate the behavior of contaminants in the ground. The modeling based on the initial concentration change considering dissolution potential of pure Diesel and Xylene was performed using VISUAL MODFLOW, and was compared with general modeling ignored the initial concentration change condition.

• 한국자동차공학회논문집
• /
• 제22권5호
• /
• pp.116-125
• /
• 2014

Pyrolysis oil (PO), derived from biomass through fast pyrolysis process have the potential to displace significant amounts of petroleum fuels. The PO derived from wood has been regarded as an alternative fuel to be used in diesel engines. However, the use of PO in a diesel engine is very limited due to its poor properties like low energy density, low cetane number, high acidity and high viscosity of PO. Therefore, one of the easiest way to adopt PO to diesel engine without modifications is blended with other fuels that have high centane number. However, PO that has high amount of polar chemicals is immiscible with non polar hydrocarbons of diesel or biodiesel. Thus, to stabilize a homogeneous phase of diesel/biodiesel-PO blends, a proper surfactant should be used. Nevertheless, PO which was produced from different biomass type have varied characteristics and this complicates the selection of a suitable additive for a specific PO-diesel emulsion. In this regard, a more simple approach such as the use of a co-solvent like ethanol or butanol to induce a more stable phase of the PO-diesel mixture could be a promising alternative. In this study, a diesel engine operated with diesel/biodiesel-PO-butanol blends was experimentally investigated. Performance and gaseous & particle emission characteristics of a diesel engine were examined under the engine loads of IMEP 0.2 ~ 0.8MPa.

• Journal of Advanced Marine Engineering and Technology
• /
• 제22권3호
• /
• pp.320-327
• /
• 1998

The purpose of this study is to design the intelligent speed control system for marine diesel engine by combining the Model Matching Method and the Nominal Model Tracking Method. Recently for the speed control of a diesel engine some methods using the advanced control techniques such as LQ control Fuzzy control or H$\infty$ control etc. have been reported. However most of speed controllers of a marine diesel engine developed are still using the PID control algorithm But the performance of a marine diesel engine depends highly on the parameter setting of the PID controllers. The authors proposed already a new method to tune efficiently the PID parameters by the Model Mathcing Method typically taking a marine diesel engine as a non-oscillatory second-order system. It was confirmed that the previously proposed method is superior to Ziegler & Nichols's method through simulations under the assumption that the parameters of a diesel engine are exactly known. But actually it is very difficult to find out the exact model of the diesel engine. Therefore when the model and the actual diesel engine are unmatched as an alternative to enhance the speed control characteristics this paper proposes a Model Refernce Adaptive Speed Control system of a diesel engine in which PID control system for the model of a diesel engine is adopted as the nominal model and a Fuzzy controller is adopted as the adaptive controller, And in the nominal model parameters of a diesel engine are adjusted using the Model Matching Method. it is confirmed that the proposed method gives better performance than the case of using only Model Matching Method through the analysis of the characteristics of indicial responses.

• Journal of Advanced Marine Engineering and Technology
• /
• 제37권7호
• /
• pp.685-693
• /
• 2013

The biodiesel used as an alternative fuel for diesel engines is well- known, however the price of the bio-diesel is still higher than conventional diesel oil (DO) by 10% to 15% depending on a kind of bio-oil and a country producing the bio-diesel. One of idea to reduce the price of bio-diesel is to use the pure bio-oil as fuel for marine diesel engines, because to use the pure bio-oil as fuel without the esteritification process can reduce the price of bio-fuel. At present time, some experts in some countries who have been carrying out experiments on the use of pure bio-oil produced from rape seeds, sunflower seeds... as fuel for marine diesel engines have achieved important results. In recent years, at Vietnam Maritime University we also have been using the pure palm oil and its blended fuel (Palm oil and DO) as fuel for marine diesel engines in laboratory and on board of ships. The blended fuel is a mixing fuel of the pure palm oil and diesel oil with content of pure palm oil by 5%, 10%, 15%, 20% and 35%. In this paper, we would like to present some results from our experiments to investigate the impacts of using the palm oil and its blended fuel on the important technical features of the fuel supply system of marine diesel engines such as the fuel supply amount for one cycle, fuel supplying pressure, ignition delay time and so on. The results from the research will be good fundamental parameters to support proper operation of marine diesel engines using bio-oil and blended fuels as alternative fuel in near future.