Investigation on combustion process and emissions characteristic in direct injection diesel engine powered by wet ethanol using blend mode

This paper presents results of investigation of the engine powered by diesel-ethanol fuel blends with wide range of ethanol fraction. Two supply systems of fuel pump are investigated. It is used two supply systems of fuel pump: low pressure 0.1 bar and high pressure 1 bar. Researches are conducted on 1-cylinder direct injection compression ignition engine with constant rotational speed 1500 rpm. Thermodynamic parameters and exhaust emission of engine powered by fuels blend are taken into account. Heat release rate and pressure rise have been analyzed as well. Test results confirmed that the combustion process occurring in the diesel engine powered by blend takes place in a shorter time than in the typical diesel engine. High pressure supply system (HPSS) allows to combustion blends with higher ethanol fraction, up to 45%. With high pressure supply system the value of indicated mean effective pressure (IMEP) up to 40% of ethanol fuel fraction kept almost constant with value near to 6 bar. For 15% ethanol fuel fraction in HPSS case the COVImEp was 2.5-times lower then in low pressure supply system (LPSS) case. In both supply systems emission of THC increased or was on near a constant level. With the increase of ethanol fraction in blend the NO. increased as far as combustion process started to deteriorate. (C) 2016 Elsevier B.V. All rights reserved.