Prediction of ignition time delay in a diesel engine when using composite fuel

Abstract

BACKGROUND: Analytical determination of ignition time delay (ITD) which would give a prediction of ignition in diesel engines of various types using composite fuel (CF) of various kinds and compositions depending on loading and speed operation modes is a relevant issue.
 AIMS: Determination of the ITD values for a diesel engine at all loading and speed operation modes with using various kinds and compositions of CF.
 METHODS: In order to determine ITD, theoretical and experimental studies of the D-245.582 tractor diesel engine of 4ChN 11.0/12.5 size with using compositions of CF including diesel oil (DO) and rapeseed oil (RO) or ethanol (E) were carried out. As a result of the studies, the diesel engine ITD predictive indicators determination method considering dependence on loading and speed operation modes and CF kind and composition has been developed.
 RESULTS: Calculated values of the ITD numerical relationships revealed that the load (pe) increase from 0.2 to 1.0 MPa, the engine speed (n) decrease from 1800 to 1400 min-1 and decrease of mass fraction of rapeseed oil (RO) and ethanol (E) in CF from 40 to 20% lead to diesel engine ITD decrease from 7.69 to 4.82 degrees of crankshaft rotation and from 11.70 to 7.92 degrees of crankshaft rotation respectively. It was experimentally found that the load (pe) increase from 0.2 to 1.0 MPa, the engine speed (n) decrease from 1800 to 1400 min-1 and decrease of mass fraction of rapeseed oil (RO) and ethanol (E) in CF from 40 to 20% lead to diesel engine ITD decrease from 7.59 to 4.22 degrees of crankshaft rotation and from 11.20 to 7.72 degrees of crankshaft rotation respectively. The degree of convergence of the experimental data with the calculated values, assessed with a statistical processing method and experimental error calculation, is 94.04%.
 CONCLUSIONS: Practical value of the study lies in prediction of diesel engine ITD with using composite fuels of various kinds and compositions at all loading and speed operation modes.