The smoke emission of biodiesel fuel was reduced remarkably in comparison with diesel fuel, that is, it was reduced approximately 36% at 2000rpm, full load condition. And, power, torque and brake specific energy consumption showed no significant differences. However, NOx emission of biodiesel fuel was increased compared with commercial diesel fuel. Also, the effects of exhaust gas recirculation(EGR) to reduce the NOx emission has been investigated. It was found that simultaneous reduction of smoke and NOx was achieved with biodiesel fuel(20vol-%) and cooled EGR method(10∼15%).
A demand for bio-diesel oil increases as one of solution for exhaustion of fossil fuel and reduction of CO2 emission, and research on bio-diesel is being carried out. Bio-diesel oil is mainly esterified from vegetable oil with methanol in order to use for fuel on diesel engine and has demerit that costs are increased as compared with directly using like non-esterified one. Bio-diesel oil within 3% mixed with gas oil is used at present, proportion of bio-diesel oil will be increase by 5% in future. We judged that wasted soybean oil non-esterified could be used on diesel engine with an electronic fuel injection according to previous researches with a mechanical fuel injection. A performance test using only gas oil, gas oil with esterified bio-diesel oil 5% and wasted soybean oil non-esterified 5% on diesel engine with the electronic fuel injection were carried out. It is noticed that gas oil with wasted soybean oil non-esterified 5% has more similar characteristics to gas oil than gas oil with esterified bio-diesel oil 5%.
The goal of this study is to propose the effective method of investigating the injurious factors and making improved plans that prevents the workers against musculoskeletal disorders at an diesel engine manufacturing company and the same business field with similar working conditions and process. A questionnaire were adopted to analyze the symptoms of workers' musculoskeletal disorders, and an ergonomic assessment method such as RULA, OWAS were performed to find out harmful factors of workplace and working posture. Based on the result of the evaluation, to enhance the working environment, improvement of worktable, working space, tools, and outfit was suggested, and induction of mechanical system was also suggested. It can be concluded that the method and process described in this paper could be helpful for diagnosing the musculoskeletal disorders and making improvement plans to the diesel engine fuel injection system manufacturing company and the same business field with similar working conditions and process.
Our environment is faced with serious problems related to the air pollution from automobiles in these days. In particular, the exhaust emissions of diesel engines are recognized as main causes of the air pollution. DI diesel engine is widely used for the sake of minimization on exhaust emission. Because biodiesel fuel is a renewable and alternative fuel for diesel engine, its usability is expanded. The smoke emission of esterfied rapeseed oil is reduced remarkably in comparison with commercial gas oil, that is, it was reduced approximately 44.5% at 1500rpm. But, brake specific energy consumption showed very slight differences. It was concluded that esterfied rapeseed oil can utilize effectively as an alternative and renew-able fuel for diesel engine.
This study executed evaluation of drying characteristics based on the polymer injection rate (8%, 10% and 12%) and the drying method[NIF(near-infrared ray). According to this study analyzed VS, VS/TS, and calorific value compared with ‘the auxiliary fuel standard of the thermoelectric power plant and the combined heat & power plant’. The results are as follows. In the case of NIR, the VS was slightly changed at the early stage of the material preheating period and the constant drying rate period with low moisture evaporation. But VS reduction was shown higher as moisture was dried. In the case of non-digested sludge with high VS content, the VS reduction rate by drying was shown lower than that of digested sludge. As the flocculant injection rate increased, the VS loss due th drying was found to be small. Also, the higher the flocculant injection rate was the longer the drying time. Especially, in the case of the NIR drying equipment, as the moisture content of sewage sludge decreased(moisture content 20∼40%), the loss of net VS also showed a tendency to increase sharply. It is shown that the high calorific value according to the drying time of the non-digested sludge was changed from 590 ㎉/㎏ to 3,005 ㎉/㎏ and from 539 ㎉/㎏ to 2,796 ㎉/㎏.