No abstract available

No abstract available

[en] A four cycle diesel engine performance test was performed with four kinds of oils such as rape seed oil, effective micro-organism rape seed oil, activated clay rape seed oil and light oil. The experiment was conducted at full load condition with constant injection time of the engine and the test oil temperature was maintained at 70±2 .deg. C. 1. The torque and the horsepower with rape seed fuel is increased about 10% compare with light seed oil at full load condition of the engine. High viscosity of the rape makes oil films in the combustor which leads to higher compression ratio and explosion. The results of the high viscosity make higher torque of the engine. The brake specific fuel consumption of the rape seed fuel increased 8%∼10% than that of the light oil. This effect could be the difference of heating value between the two kinds of oil. 2. The emission of the smoke gas was decreased 29%, 38% and 52% compare with light oil in rape seed oil, effective micro-organism rape seed oil and activated clay rape respectively due to the low volatility and high viscosity of the soot. The NOx emission with rape seed oil is twice larger than that of the light oil at full load condition. The reason is that the fuel temperature increment effects on the combustor temperature and it makes thermal NOx of the engine. 3. The test engine could be started over 40 .deg. C of the rape seed oil. Engine inspection results shows that the soot adherence amount of the cylinder head piston head is higher in following order; activated clay rape seed oil > effective micro-organism rape seed oil > rape seed oil > light oil

No abstract available

[en] In this study, evaporative characteristics of emulsified fuel consisting of diesel and H2O2 were studied. The surfactant for mixing emulsified fuel comprised of span 80 and tween 80 mixed as 9:1, and it was set at 3 of the total volume of emulsified fuel. Considering the mixing ratio of the surfactant, the mixing ratio of H2O2 in emulsified fuel was set as emulsified fuel (EF)0, EF2, EF12, EF22, EF32 and EF42. Evaporative characteristics were analyzed through experiments on droplets of emulsified fuel by using scattered light and the Schlieren system. Experimental free spray based on droplet experiment was conducted about EF0~EF22 by using a constant volume chamber maintained at 150℃, satisfying condition of evaporation. The results showed that a higher increase in the mixing ratio of H2O2 corresponded to a higher promotion of the evaporation of droplet and spray. From these results, when applying emulsified fuel to diesel engine, a faster mixture formation can be expected compared to that using diesel.

[en] In order to meet the growing energy needs, alternative energy sources particularly bio fuels are receiving increasing attention during the last few years. Biodiesel, consisting of alkyl monoesters of fatty acids from vegetable oils or animal fats, has already been commercialized in the transport sector. In the present work, a turbo charged, inter cooled, DI (Direct Injection) diesel engine was fuelled with biodiesel from waste cooking oil and its 20% blend with commercial diesel to study the regulated exhaust pollutants in the light of combustion parameters in the cylinder. The experimental results show that BTE (Brake Thermal Efficiently), MCP (Maximum Combustion Pressure) and SOI (Start of injection) angle were increased, ID (Ignition Delay) was decreased; however, RHR (Rate of Heat Release) remained almost unaffected in case of biodiesel. The BTE and RHR were not much affected with B20; however Sol angle and MCP were improved, and ID was decreased with B20. Smoke opacity, CO (Carbon Monoxide), and HC (HydroCarbons) emissions were decreased, but NO. (Oxides of Nitrogen) pollutants were increased in case of both B100 and B20 compared to fossil diesel. However, the increase in NO emissions was lower with B20. (author)

[en] An Emergency Diesel Generator (EDG) manufactured by a French company Wartsila SACM, is a tandem type engine, consisted of two 10 cylindered diesel engines on each side. Manual provided by the manufacturer states that engine bearing requires inspection every 15 years. However, it is difficult for an inspector to access through a manhole located in the lower compartment of engine. Furthermore, during a routine or scheduled maintenance, it is not possible to disassemble main engine bearing and crank shaft, and perform inspection. Two methodologies are suggested here to resolve the problem. One method is to lift the engine and partially perform the maintenance service, and the other method is to disassemble the engine completely and to perform maintenance service by the manufacturer. Pros and cons of two methodologies were thoroughly compared

[en] An experimental study was conducted to examine the effect of injection pressure and fuel type on the spray tip penetration length and the angle of spray injected into atmospheric chamber. The objective of the present study is to formulate empirical correlations of the spray tip penetration and the spray angle for non evaporative condition. The experiment was performed by a common rail type high pressure injector for the diesel engine at the injection pressure 40∼100 MPa and four different fuels (D100, BD25, BD45, and BD65). The results showed that the biodiesel content increased the spray tip penetration and decreased the spray angle. The correlation of spray tip penetration is expressed for each region before and after spray break up time in terms of injection pressure, fuel viscosity and time after start of injection. The correlation is also obtained for spray angle equation terms of injection pressure and fuel viscosity

[en] The instantaneous wear rates for both the top compression piston-ring and the cylinder-bore, in a ZS1105 diesel engine, were measured in situ using the method of thin layer activation (TLA). The experimental arrangement and methods for calibrating the test specimens are described. During a 300 s counting interval, the minimum detectable wear depths for the cylinder-bore and piston-ring were 9 and 75 nm, respectively. These values reflect average recession depths and may not reflect localized differences in wear damage. Nevertheless, such in situ techniques can be usefully employed in engine development

[en] Selection of diagnosis data, troubleshooting table(symptom/diagnosis/remedy) - visiting Uljin 2 times, Yeonggwang once, examination of monitoring system, data collection of piping system, analysis of operation parameter for Pielstic DMDS, analysis of DMDS trial data for Uljin 5/6 EDG, embodiment of diagnosis knowledge for diesel engine(class/method/member), framing roubleshooting for Pielstic PC2-5V. Development of display module for monitoring and diagnosis - system classification of EDGS, design of system GUI based on in-touch, development of interface to diagnosis module. Development of diagnosis module - expression of EDG object using Java language, development of inference engine based on ILOG Jrules, development of interface to in-touch