An investigation of engine and fuel injection system performance in an agricultural tractor operating with b20 biofuel

Abstract

In this study, two different 55-kW powered agricultural tractors of the same make and model were operated for 1000 h under similar field conditions, one using diesel fuel (DF) and the other a fuel blend of 20% biodiesel-80% diesel (B20). By the end of 1000 h of operation, the performance values of the B20 fuel were determined to be 3% lower than for the DF. Although the values of CO (40%), HC (40%), and PM (46%) were lower than those of DF, the NOx (7%) was determined to be higher, as expected. Each injector needle and nozzle tip was examined in terms of a functional evaluation via visual inspection, scanning electron microscopy (SEM), and energy dispersive X-ray (EDX). According to the analyses, the B20 fuel blend C content was determined to be 73.47% and its O content 23.34%, with the quantity of the other elements lower than 1%. Similarly, for DF, the C content was determined to be 50.49% and that of O 19.95%, with the other elements in trace amounts. Furthermore, Fourier-transform infrared spectroscopy (FTIR) spectral analysis was used to examine the deposits on the injector nozzle tips and needles. Polyisobutylene succinimide (PIBSI) and inorganic components were observed on the injector needles, whereas aging products and inorganic components were seen on the injector nozzle tips. No significant difference was found between the results of the DF and B20 fuels in terms of injector nozzle function.