EFFECT OF THE 2-ETHYLHEXYL NITRATE DOPED RAPESEED OIL AND AVIATION jP-8 FUEL ON THE COMBUSTION PROCESS AND EMISSIONS OF A DIESEL ENGINE

Gvidonas  LABECKAS; Stasys  SLAVINSKAS; Tomas  MACKEVIČIUS

doi:10.36910/automash.v1i18.756

Gvidonas LABECKAS Doctor of Technical Sciences, Professor of Mechanical, Energy and Biotechnology Engineering department, Vytautas Magnus University
Stasys SLAVINSKAS Doctor of Technical Sciences, Professor of Mechanical, Energy and Biotechnology Engineering department, Vytautas Magnus University
Tomas MACKEVIČIUS Doctor of Technical Sciences, lecturer of Mechanical, Energy and Biotechnology Engineering department, Vytautas Magnus University

DOI: https://doi.org/10.36910/automash.v1i18.756

Abstract

The COP26 Clime Summit brought together Heads of state and ministers from over 200 countries to take urgent actions and protect the planet by limiting global warming to 1.5 degrees Celsius. Low-carbon rapeseed oil (RO) and JP-8 fuel (JF) could be used for diesel engine powering to reduce the climate change. However, at first, too low cetane number related drawbacks of these fuels should be removed to improve the ignition process and achieve efficient and clean combustion. The purpose of the research was to evaluate the cetane improve-made effects on the ignition delay, combustion parameters, thermal efficiency, smoke, and emissions. A naturally aspirated, DI diesel engine operated on the undoped RO and JF to identify the baseline parameters for full (100%) loads corresponding to Indicated Mean Effective Pressures (IMEP) of 0.844 and 0.738 MPa at the most usable speeds of 1400 and 2200 rpm. Then, the engine was fuelled with the cetane improver 2-EHN doped fuels 0.10 (RO-10), 0.30 (RO-30) and 10 (JF-10), 24 vol% (JF-24) to obtain new results important for evaluation of all the benefits and detriments that the use of alternative fuels suggest. It was found that the ignition delay is 10.3% and 44.6% shorter, the Indicated Thermal Efficiency (ITE) is 6.1% higher and 1.2% lower, the NO_x emissions are a little and 10.3% lower with the doped RO-30 and JF-24 fuels at rated speed of 2200 rpm. Also, the fuels RO-30, JF-24 produce smoke opacity and CO emissions 42.1%, 32.1% and 11.6%, 2.7% higher, THC emissions 1.9 times higher, and 28.6% lower for the respective speeds. The enhanced cetane number differently affects the ignition delay, combustion parameters and emissions because the differing fuel properties play a vital role in the injection, evaporation, and combustion processes. Analysis of the combustion attributes, heat release characteristics, ITE and the NO_x-smoke trade-off presents new knowledge that is one of the goals of the study.

Keywords: Diesel engine; Rapeseed oil; JP-8 fuel; Cetane improver; Combustion process; Cyclic variations