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2019, Vol. 17, Special Issue 1

Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/5401

Sirvi

Sirvi 2019, Vol. 17, Special Issue 1 Märksõna "biofuels" järgi

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  • Pisipilt
    Kirje
    Combustion characteristics of compression ignition engine operating on rapeseed oil-diesel fuel blends
    (2019) Čedík, J.; Pexa, M.; Mader, D.; Pražan, R.
    The effect of biofuels on the operational parameters of the combustion engines, such as performance parameters or emission production, are monitored often. These changes are, however, based on the effect of biofuels on the course of combustion pressure inside the combustion chamber. The contribution deals with the effect of rapeseed oil-diesel fuel blends on the combustion characteristics of turbocharged compression ignition engine. The course of cylinder pressure was monitored and analysed and heat release rate was calculated. The brake specific fuel consumption, indicated and brake thermal efficiency were calculated and evaluated, in-cylinder temperature and ignition delay were also evaluated. As a test fuels a 5% and 20% concentrations of rapeseed oil in diesel fuel were selected while 100% diesel fuel was used as a reference. Turbocharged CI engine Zetor 1204 located in the tractor Zetor Forterra 8642 was used for measurement. During measurement the rotation speed of the engine was kept constant at approx. 1950 min-1 and the load of the engine was selected at approx. 20, 60, 80 and 100%. The results showed decreased cylinder peak pressure, decreased intensity of heat release rate and earlier end of combustion in all tested loads for both tested fuel blends in comparison with diesel fuel, while the lowest peak cylinder pressure was reached using fuel with 5% rapeseed oil. Fuel with 5% rapeseed oil also showed highest indicated efficiency. Ignition delay was found shorter with both of the blended fuels in comparison with diesel fuel.
  • Pisipilt
    Kirje
    Effect of long-term operation of combustion engine running on n-butanol – rapeseed oil – diesel fuel blend
    (2019) Holúbek, M.; Pexa, M.; Čedík, J.; Mader, D.
    The short time use of biofuels in compression ignition engines is being studied by many authors. However, in many cases the real long–term operation of the engine on biofuels may cause problems. The article deals with the operation parameters of the combustion engine, fuelled by n-butanol – rapeseed oil – diesel fuel blend, during 70 hours operation in total. Two brand new diesel power generators Kipor KDE 6500 with output power of 4.6 kW were used for certain testing. The first generator was operated on 100% diesel fuel and it was used as a reference and the second generator was operated on experimental fuel containing 10% n-butanol – 20% rapeseed oil – 70% diesel fuel blend. The generators were equipped with single cylinder compression ignition engine Kipor KM 186 with the rated power of 5.7 kW. For the first 10 operating hours approx. 40% load was applied. Then, the generators worked for another 60 operating hours with approx. 70% load. The harmful emissions, smoke, fuel consumption and the amount of produced particles were also measured after 10 hours run-in period and then after another 60 hours of operation. Consequently, the results were compared. Measurements were carried out at gradually increasing electric power output, approx. 14%, 28%, 42%, 56%, 68%, 82% and 95% (in results can be found in Watts). Emission analyser and opacimeter BrainBee and Engine Exhaust Particle Sizer TSI were used for the measurements. The results showed increased production of emission of the engine running on fuel blend after 70 hours of operation. On the other hand, engine which operated on standard diesel reached lower fuel consumption. After 70 hours the blended fuel tended to produce more particles in comparison with diesel fuel.