Introduction (problem statement and relevance). Today, vegetable oils, in particular, rapeseed oil (RO) are widely used types of fuels for diesel engines. The main physicochemical properties of RO are somewhat similar to diesel fuel (DF). However, one can highlight a large fraction of the oxygen content in it, which affects the fuel combustion intensity in diesel cylinders. In this regard, the addition of rapeseed oil is very important to optimize the composition of mixed fuel (MF) for its use in diesel engines. The purpose of the study was optimizing the MF composition and obtaining experimental data of diesel engine effective performance by means of regression analysis.Methodology and research methods. To optimize the MF composition studies were carried out to determine the relative fractions of carbon, hydrogen, oxygen in RO and MF, as well as bench tests of diesel fuel and MF with various RO additives operation, followed by the regression analysis of effective indicators.Scientifi c novelty and results. The effective performance dependences of the diesel engine on the RO content in the MF have been determined. Basing on the obtained load characteristics of the diesel engine, it was concluded that an increase in the average effective pressure from 0.2 to 1.2 MPa, as well as in the share of RO in MF from 0 to 80%, would lead to an increase in the effective specifi c fuel consumption to 383–506 g/kW·h and the decrease in effective effi ciency by 14–28%. On the basis of the regression analysis the maximum values of the optimality criterion indicators D-optimum = 0.98–1.0 with the addition of RO to MF from 45 to 50% were determined.Practical signifi cance. The value of the maximum permissible composition of MF, consisting of 50–55% of diesel fuel and 45–50% of RO and ensuring maximum compliance with the specifi ed conditions of optimality on the diesel engine under consideration has been obtained.
Study of the effective performance of the diesel engine when working on methanol and methyl ether rapeseed oil