Existing methods for determining the effective power, based on the calculation of the average indicator operation of the engine during the piston stroke, do not take into account the change in thermodynamic parameters and the polytropic operation of the engine, the value of which depends on the polytropic efficiency of the duty cycle. This is the reason that the calculation of the effective power leads to some error – the margin of the engine features. The identification of this stock allows us to review the entire line of dump trucks in the direction of increasing their pass- port effective capacity, which will lead to a reduction in capital purchase costs due to the choice of a previously un- derestimated and cheaper option, as well as a reduction in current operating costs due to a decrease in the specific fuel consumption rate. Taking into account the stochastic nature of the transport process and assessing the influence of all external and internal factors when calculating the rational mode of operation of a mining truck can further reduce specific fuel consumption by choosing the rational speed of its movement in loaded and empty directions.
The experience of application of self-propelled pneumatic wheeled equipment at sinking with mining excavation by blasting technique is considered and the directions of increase of efficiency of exploitation are determined.
For comparison of environmental performance of rock mass hoists, methods of calculating the volume of harmful emissions into the environment and comparative assessment of their environmental characteristics and economic efficiency are developed. According to the results of calculations recommendations are given and estimated data on the operation of the most promising designs of hoists in deep quarries are given.
The effective operation of transport systems of deep pits requires a comprehensive assessment of their quality on the basis of economic, environmental and mining-technical factors. For this purpose, it is necessary to develop a mathematical model of functioning of transport systems, allowing to estimate in concrete operating conditions various types of open-pit elevators and to define interrelation between operational and ecological characteristics of transport system and conditions of their operation. The final task of the research is to substantiate the rational types of rock mass hoists and the area of their effective application.
The results of calculations of efficiency of application of the main methods of normalization of the atmosphere of the open pit are given. As an example, the conditions of open pit Udachny of AK Alrosa and the basic models of dump trucks with carrying capacity of 100-150 tons of domestic and foreign production are considered. The model and the developed medicine allow to substantiate the choice of optimal transport complex taking into account the dynamics of mining works, the environmental factor and various models of loading and transporting equipment.
Annually at 18 plants of CIS countries 70 million tires are manufactured, for the production of which 15 % of the total gross output of petrochemical and oil refining industry is used. The number of truck tires is 52.5 million - 75 % of all tires (in the USA - 20 %, in Western European countries - up to 12 %). The share of large-size tires (LSTs), which are equipped with dump trucks, construction and agricultural machines, reaches 2 % (in the USA - 1 %). LSTs have high material and energy intensity, which determines their high cost. Mining operations cause great damage to the environment, and a comprehensive environmental assessment of them has not yet been given. Since quarry vehicles are one of the main sources of pollution, the paper attempts to assess the environmental impact of LSTs on the environment during their operation at Russian quarries and utilization.
It is known that the life of machines and their assemblies depends on the strength of parts and loading modes. To determine the time of their failure, statistical processing of observations in specific operating conditions is performed, but it is difficult to obtain analytical dependencies of the resource on various factors in this case. When applying new materials or changing the design of the part, it is not possible to complete operational information about the impact of changes made by designers on the resource and justify the necessary technical solutions to improve reliability. A similar situation occurs when designing tires of dump trucks.
Heavy-duty mining dump trucks have two main damping systems: air-hydraulic suspensions and tires.
In order to improve the efficiency of heavy-duty quarry vehicles, the improvement of the design and increase the service life of oversize tires (UHTS) is of great importance.
