The thesis is devoted to solving the urgent scientific task of increasing the efficiency and environmental friendliness of mining transport services by implementing trolley-assistant (TA) open-pit dump trucks with electromechanical transmission.
The introduction provides the problem statement, as well as outlining the aims and objectives of the research.
The first chapter of the study examines contemporary strategies for enhancing efficiency and reducing carbon footprint in mining road haulage. It assesses the advantages and disadvantages of conventional open-pit dump trucks with electromechanical transmission and TA open-pit dump trucks. Conventional open pit dump trucks outperform other technological transport alternatives in terms of flexibility, capital costs, refueling convenience, reliability, scalability, and operational capabilities, however, they exhibit drawbacks such as low energy efficiency and complex environmental impacts including noise, dust, emissions of pollutants, and reliance on fossil fuels. Due to the appropriate limitations, TA open-pit dump trucks demonstrate moderate performance across all parameters but offer the advantage of utilizing electricity from renewable sources and significantly reducing exhaust gas emissions. The contemporary truck trolley system is well-suited for deep open pits where one or more primary transportation lines are situated on non-working sides of the open pit, outside the blasting zones, and do not require removing and restoring trolley lines after blasting.
In the second chapter, the modeling and determination of reliability parameters for TA open-pit dump trucks were conducted. A graphical representation detailing the subsystems of technological states for a TA open pit dump truck has been created. This graph is the foundation for a mathematical model formulated under the "Markov process with discrete states and continuous time." In this model, the technological states of TA open-pit dump trucks evolve in a stochastic, unpredictable manner based on the assumption that the future technological state of a TA open-pit dump truck depends solely on its current state, independent of the history of how and when that state was reached at any specific moment in time. The mathematical framework known as the "Markov process with discrete states and continuous time" describes these technological states. The mathematical model describing the operation of TA open-pit dump trucks was refined by incorporating additional types of maintenance and repair, as well as their interdependencies, enabling the determination of the probability of TA open-pit dump trucks being in operational or alternative states.
In the third chapter, the operational parameters of TA open pit trucks about conventional open pit dump trucks are analyzed and established. Variations in transportation productivity and diesel fuel consumption (emissions) from the length of the trip with a load are examined in relative terms under different degrees of trolley integration for machines with varying carrying capacities. The baseline values consist of the performance indicators of open pit dump trucks with carrying capacities of 90, 130, and 220 tons that are not equipped with a trolley system, which can be used in these operating conditions. The study established, for the first time, two-parameter patterns of changes in specific productivity and specific fuel consumption of TA open-pit dump trucks depending on the length of the road and specific part of the trolley section in the total length of the road. The study also identified the patterns of changes in exhaust gas emissions based on the operational conditions and technical status of TA open-pit dump trucks with a carrying capacity of 130 tons.
In the fourth chapter, economic and mathematical modeling of the operation of TA open-pit dump trucks is conducted to establish the limits of their effective operation based on which the methodology for economic and mathematical determination of the conditions for the effective operation of TA open-pit dump trucks in mineral deposit development is improved. This methodology enables the assessment of operational efficiency in iron ore open pits, incorporating the generation of electricity during the operation of TA open-pit dump trucks. Thirty scenarios were calculated (5 for conventional open pit dump trucks and 25 for TA open pit trucks) to determine the current costs for haul roads ranging from 1 to 5 km in length, with trolley sections ranging from 0 km to 3.5 km in length.
The thesis is supplemented with a document detailing the utilization of research results in the educational process of Kryvyi Rih National University.
