Effect of diesel-biodiesel-ethanol blend on combustion, performance, and emissions characteristics on a direct injection diesel engine

Abstract

The paper presents results of co-combustion of diesel-biodiesel-ethanol fuel blend in direct injection Diesel engine. Test was performed at constant rotational speed at three commonly used loads of this engine: 100%, 85%, and 70% of load. During the test hydrated ethanol was used at a concentration of 89% of alcohol. In this study, the ethanol fuel was added to diesel-biodiesel fuel blend with concentrations up to 50% with the increment of 5%. The biodiesel was used as an additive to pre-vent the stratification of ethanol and diesel blends. Thermodynamic parameters of engine were analyzed, and combustion process and exhaust emission were characterized. It turned out that with the increase in engine load is possible to utilize larger ethanol fraction in blend. With the increase of ethanol fuel in blend the in-crease in ignition delay (38.5% for full load) was observed, but burning duration decreased (49% for full load). The ethanol fuel share in blend generally causes the increase in NOx emission (42% for full load) due to higher oxygen content and higher in-cylinder temperatures. It turned out that, at full load the unrepeatability of indicated mean effective pressure was near the same up to 50% of ethanol fuel in blend (about 2%). In case of partial load at higher ethanol fuel fraction the in-crease in indicated mean effective pressure un-repeatability was observed.