The methodology for determining of the energy costs for the probabilistic nature of the load of a machine-tractor unit

The random nature of the load is the main cause of deterioration of energy parameters and technical and economic indicators of machine-tractor units (MTU). Oscillations of the load lead to an increase in energy costs for technological processes. Direct fuel and energy costs should be determined and predicted with a high degree of reliability, taking into account the specifics of the work of the MTU and the dynamics of its performance of technological processes. The identification and optimization of energy costs of the MTU will ensure an increase in the efficiency of the technological processes and technologies of cultivation in crop production. The subject of the study is the development of mathematical models for determining and optimizing the direct energy costs of MTU equipped with advanced gas turbine engine (GTE) engines. The purpose of the research is to develop a methodology for determining the direct fuel and energy costs of MTU, taking into account the probabilistic nature of the load. The novelty of the research consists in the developed mathematical models and calculation algorithm, as well as optimization of the direct fuel and energy costs of MTU with GTE. The proposed methodology is developed on the basis of a systematic approach, generalization, and analysis of experimental data, mathematical modeling of processes. Experimental studies were carried out in laboratory facilities and in the field using modern measuring instruments and recording experimental data. The proposed methodology allows, with a probability of 0,90-0,95, to predict the optimal values of the direct fuel and energy costs of the MTU with GTE. As an example, the article gives examples of calculation and optimization of direct fuel and energy costs of plowing unit consisting of a Kirovets tractor with a GTD-350T gas turbine engine and a PNI-8/9-40 plow at various levels of turbocharger speed. It is established that at the 100 % level of the turbo compressor speed and the variation of the load variation coefficient from 0 to 0,333, the optimal values of the direct fuel and energy costs of the plowing unit increase from 543,0 to 723,12 MJ/ha. The same trend of increasing the direct fuel and energy costs of MTU is also observed in other levels of implementation of the turbo GTE turbocharger speed. It should be noted that with a decrease in the level of implementation of the turbocharger GTE's speed, direct fuel, and energy costs are increasing. The proposed methodology allows to determine and optimize the values of direct fuel and energy costs of MTU with GTE taking into account the probabilistic nature of the load under the specific conditions of their operation.