• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.5
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• pp.61-66
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• 2009

An experimental investigation was conducted to analyze the effects of biodiesel-ethanol and biodiesel-diesel blended fuels on the characteristics of combustion and exhaust emissions, and size distributions of particulate matter in a single cylinder diesel engine. The three types of test fuel were biodiesel and two blended fuels which were added ethanol and diesel by 20 % volume based fraction into biodiesel, respectively. In this study, the injection rate, combustion pressure, exhaust emissions and size distributions of particulate matter were measured under various injection timings and injection pressures. The experimental results show that biodiesel-ethanol blended fuel has lengthened ignition delay and low combustion pressure in comparison with those of biodiesel and biodiesel-diesel blended fuel even if all fuels indicated similar trends of injection rate under equal injection pressures. In addition, the ethanol blended fuel significantly reduced nitrogen oxidies (NOx) and soot emissions. And then the size distribution of particulate matters shows that blended fuels restrain the formation of particles which were beyond the range of 150nm comparison with biodiesel fuel.

• Journal of ILASS-Korea
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• v.13 no.4
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• pp.180-186
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• 2008

The aim of this work is to investigate the effect of ambient conditions on the spray behavior of biodiesel-ethanol blended fuels. In order to analyze the spray behavior, spray tip penetration and spray cone angle were obtained from the visualization system and the effects of ethanol blending are compared macroscopic characteristics with the numerical results. It was reveled that the ethanol contents in biodiesel-ethanol blended fuels affect the spray tip penetration a little and increased the spray cone angle. Increased ambient pressure induced the decrease of the spray tip penetration, and the increased ambient temperature lead to the increase of the spray tip penetration. In addition, the increased ambient temperature promoted the vaporization and atomization of spray with the effect of increasing ethanol fuel.

• Journal of Power System Engineering
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• v.9 no.2
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• pp.14-18
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• 2005

In this study, the spray characteristics of blended fuels with biodiesel were investigated. The experiments were performed for the effect of mixing ratio and injection pressures on the spray behavior. Conventional diesel fuel and biodiesel fuel and blended fuels were used as test fuels. Through the spray visualization system, composed of a Halogen lamp and High speed camera. The process of spray injection was visualized. Fuel containing biodiesel has different spray pattern on account of the high viscosity and large surface tension. Through this experimental result, we found that, after solenoid driving pulse generates, the increase of injection pressure enables delay time to get shorter, but the increase of mixing ratio makes delay time lengthen.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.4
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• pp.135-143
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• 2013

In this study, we suggested effective countermeasure of biodiesel oxidation problems by investigating the oxidation degradation of biodiesels derived from variable resources and the level of oxidation stability of current distributing biodiesel blended fuels (2%) in Korea, and oxidation stability change according to storage time (for 3 month) and biodiesel blending ratio (2, 5, 7, 10%). By the composition analysis results of biodiesel from various resources which are possible to distribute in Korea, the biodiesel from animal fat has poor oxidation stability and cold performance, while the biodiesel from coconut and palm kernel which are considered as future potential raw material showed good oxidation stability and cold performance. The oxidation stability level of current distributing biodiesel blended fuels in Korea was excellent with showing over 30 hours (average 68 hours) stability, but the oxidation stability of the blended fuel with animal fat biodiesel having poor oxidation property (1.22 hours) was rapidly decreased to below 32 hours by mixing only 2%. Therefore, we have to pay attention to quality control of oxidation property, because the oxidation stability problem can be caused by increasing biodiesel blending ratio and diversifying raw materials those have worse property.

• Journal of ILASS-Korea
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• v.18 no.4
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• pp.169-175
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• 2013

Hydrotreated biodiesel (HBD) would be one of the promising alternative fuels instead of current biodiesel. In this study, spray characteristics in terms of spray penetration and spray angle were conducted experimentally including calculated SMDs as well. The ambient pressures of 1, 3, and 5 MPa and injection pressures of 30, 80, and 130 MPa were introduced and the fuels employed were petro-diesel, and 2, 10, 20, 30, and 50% for hydrotreated biodiesel, respectively. The result of this study found that the more HBD blended diesels have the slightly shorter spray tip penetration lengths especially on the lowest injection pressure and at the highest ambient pressure, but have the larger spray angles and SMDs than petro-diesel. Consequently, this study found that HBD has a little bit merits and demerits of macro- and micro- spray patterns compared to petro-diesel.

• Journal of ILASS-Korea
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• v.9 no.3
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• pp.1-7
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• 2004

This experiment was undertaken to investigate the atomization characteristics of the low viscosity biodiesel blended fuel and ultrasonic energy added one. Test fuels were conventional diesel fuel and biodiesel fuel. We compared to the characteristics of viscosity and surface tension, SMD between low viscosity biodiesel blended fuel and ultrasonic energy added one. Sauter mean diameter was measured under the variation of the spray distance. Viscosity and surface tension was measured under the variation of the time trace. To measure the droplet size, we used the Malvern system 2600C. Droplet size distribution was analyzed from the result data of Malvern system. Through this experiment, we found that the condition of the ultrasonic energy added situation had smaller Sauter mean diameter of droplet, viscosity and surface tension than that of the conventional situation.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.1
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• pp.67-73
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• 2011

The purpose of this study is to investigate experimentally the spray-atomization and combustion-emission characteristics of biodiesel-DME blended fuel. In this study, two types of test fuels pure biodiesel (BD100) and blended fuel (B-DME20) were used, and the spray and combustion characteristics of different fuel compositions were analyzed. DME constitutes 20% and biodiesel constitutes 80% (by mass fraction) of the blended fuel. The overall spray characteristics, spray tip penetration, and cone angle were evaluated using frozen spray images. In addition, the combustion and emission characteristics were analyzed on the basis of the evaluated data for a single-cylinder CI engine with common-rail injection system. It was revealed that the injection profiles of both the test fuels for a given injection pressure showed similar trends. However, the injection profiles of the blended fuel (B-DME20) indicated shorter ignition delay than those of biodiesel.

• Journal of the Korean Applied Science and Technology
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• v.30 no.4
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• pp.701-714
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• 2013

Recently, due to the activation policy of biodiesel, the blending biodiesel to petroleum product is increasing. Low-temperature fluidity and oxidation stability are the most significant issues to the marketers and end users of biodiesel. Thus, the way to control the quality of biodiesel blended fuels was investigated by duplicating the real storage situation of biodiesel blended fuels and evaluating the effect of oxidation trend and quality degradation. From the results of oxidation degradation test of biodiesel blended fuels, no special quality degradation has been observed through the evaporation for 18 weeks in a summer season under a storage circumstance without exposure to the sun light. However, the severe quality degradation was observed in PE vessel in only 2 weeks of storage. This oxidation degradation was also verified with FT-IR spectrum change. However, the special symptom cannot be distinguished by the quality test because the quality specifications were satisfied despite of the drastic oxidation degradation. Namely, the problem in a vehicle could be occurred by oxidation materials(polymer, organic acid. etc.) under oxidation even though it satisfied the quality specification.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3383-3388
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• 2014

An experimental study was performed to compare the characteristics of the combustion pressure and exhaust emissions in the case of using pure diesel when the EGR rate was changed in a CRDI 4-cylinder diesel engine with those using biodiesel blended and pure diesel fuel. In this study, the EGR rate variation were conducted at an engine speed of 2000rpm with fuel with a biodiesel blended rate of 20%. The combustion pressure of the biodiesel blended rate 20% and pure diesel fuels decreased with increasing EGR rate. The IMEP of biodiesel was higher than that of ULSD (Ultra low sulfur diesel). The emission results showed that the NOx emission of biodiesel blended fuel with increasing EGR rate was higher than that of ULSD. In addition, the NOx emission of biodiesel blended and diesel fuel decreased with increasing EGR rate. The CO and soot, $CO_2$ emissions increased with increasing EGR rate, and the CO and soot emissions from the biodiesel blended fuel were lower than that of ULSD but the $CO_2$ emissions were higher.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.2
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• pp.82-89
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• 2009

In order to investigate the spray characteristics according to diesel and bioethanol blending with biodiesel fuel, macroscopic spray characteristics were analyzed from the comparison of the effect of the injection pressure, ambient pressure and density on the spray tip penetration and spray cone angle. In addition, spray atomization characteristics were studied with local and overall Sauter mean diameter (SMD) and the contour map of SMD distribution at various injection conditions. It was revealed that the spray tip penetration of biodiesel fuels blended with diesel and ethanol was shorter than that of an undiluted biodiesel fuel at low injection pressure. However, the difference of spray tip penetration among three test fuels reduces at a high injection pressure. Increase of the ambient gas density leads to the decrease of the spray tip penetration of three test fuels. When diesel and ethanol fuels add to an undiluted biodiesel fuel, spray cone angle increases due to the decrease of the fuel density at the same ambient pressure condition. On the other hand, the droplet mean diameter decreases due to the reduction of the kinematic viscosity and surface tension.