Determination mixtures compressibility of diesel fuel with palm oil

Abstract

One of the ways to expand the fuel base for autotractor diesel engines is the use of alternative fuels of vegetable origin. Especially promising is the use of vegetable origin fuels as additives to petroleum diesel fuel. Modeling of the working process and, in particular, the injection process, of diesel engines operating on mixtures of petroleum diesel fuel with fuels of vegetable origin, allows us to evaluate the performance of the engine on such fuel and the need to change the adjustments of the fuel equipment. For modeling these processes, it is required to know the compressibility of mixed fuels. Experiments were carried out to determine the compressibility of petroleum diesel fuel with palm oil. To determine the compressibility, a method based on measuring the speed of sound in the fuel in the injection pipeline was used. The possibility of determining the compressibility not only on the basis of measuring the velocity of propagation of a pressure wave, but also on the basis of measuring the velocity of propagation of a rarefaction wave is investigated. It is shown that with an increase in pressure and the proportion of palm oil in the mixed fuel, the speed of sound increases, and the compressibility decreases. To take into account the indicated differences in the compressibility of fuels based on mixtures of palm oil and diesel fuel when calculating fuel supply processes in diesel engines operating on these mixtures, an approximating equation was proposed to determine the true compressibility coefficient based on polynomials of the second degree.