Substantiation of methods for determination of the effectiveness of the use of alternative fuels in automotive diesel engines

Abstract

The subject of the research is to determine the parameters of the operating cycle of a tractor diesel engine when it is running on a mixed fuel, consisting of diesel fuel and rapeseed oil. The main goal of this work is to determine the efficiency of using alternative fuels in automotive diesel engines. In order to determine the dependences of the parameters of the operating cycle, the theoretical and experimental studies of a tractor diesel engine were carried out on the following compositions of mixed fuel: with a rapeseed oil content of 20%, 55% and 80%, as well as pure diesel fuel. As a result of the research, the following was obtained: a nomogram for determining the value of the decrease in the ratio of the indicator efficiency to the excess air ratio, the dependence of the ratio of the indicator efficiency to the excess air ratio on the excess air ratio for different compositions of mixed fuel, diesel engine crankshaft rotational speed, load at 1800 min-1 and 1400 min-1. It was experimentally established that an increase in the proportion of rapeseed oil in mixed fuel from 0 to 80%, the speed from 1400 to 2000 min-1 and the excess air ratio from 1.18 ... 1.22 to 4.32 ... 5.61 led to a decrease in the indicator efficiency from 0.46 to 0.35, and the ratio decreased from 0.30 to 0.08, an increase in the load from 0.2 to 1.2 MPa, at 1800 min-1, and 1400 min-1, and the excess air ratio from 1.17 ... 1.68 to 3.53 ... 3.60 led to a decrease in the indicator efficiency from 0.44 ... 0.40 to 0.28 ... 0.22, and the ratio from 0.34 ... 0.25 to 0 , 10 0.09, respectively. A 4.5% reduction in the ratio is theoretically calculated when the diesel engine runs on a mixed fuel containing 80% rapeseed oil as compared to pure diesel fuel, and this reduction by 4.1% has been experimentally confirmed. The convergence of the calculated value of the decrease in the ratio with the experimental data was 91.11%. In this regard, the well-known statement about the equality of the input of heat with fuel requires clarification.