International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

During the decades-long development of internal combustion engines, the main criteria for optimality were the increased power, the low fuel consumption and the adjustment of the working process under non-stationary operating conditions. Even when the air quality in some settlements was significantly worsening, due to the high degree of motorization, special attention has been paid to polluting the atmosphere with exhaust gases from the engines. Problems that are created due to the increased environmental pollution significantly influence the choice of providing minimal environmental conditions, they receive priority, especially in urban areas. As toxic components are considered CO, CnNm, NOx, solid particles, etc. So if we know the conditions in which they are created then they can be the criterion for optimality. The requirements also affect their reduction within certain permitted limits.

By applying a complex, exact and scientific approach, was performed the development, calculation and analysis of a complex pilot installation (bioenergetics system consisting of the following elements: greenhouse for early vegetation crops, digester and internal combustion engine powered by biogas). Using the factorial experiment, i.e. applying the matrix of influence, a complete optimization of the internal combustion engine was performed in function of the other elements of the installation. An analysis is also made from the aspect of the positive current EU regulations in the field of air pollution.

The driving factor is an important technical feature of dynamical loaded working machines. It is especially important to know its value for the working wheel speed reducer of the rotating excavators. In this paper is presented a concept for determining the driving factor of a concrete gearbox speed reducer. To calculate the value of the driving factor according to the specified concept, knowledge of the load regime and the carrying capacity of the gearbox is necessary. The load regime is known from the load function, which is given in the paper, and is determined on the basis of the experimental measurements carried out for this purpose. The carrying capacity of the speed reducer is calculated by theoretical analysis according to the established methodology in this paper, for the characteristic pairs of gears determined in this analysis. As the most important gear pair, from the aspect of determining the driving factor, the most loaded gear pair is taken, in which during the exploitation of the speed reducer the most interventions are made, compared to the other gear pairs of the gearbox.

Safety engineering is consistently promoted and there is an evident need for improvement and development. The maintenance process is dependent on the method of editing and organizing the setup and execution of such kind commitments.
Working with the maintenance system itself determines the manner of maintenance.
Тhe contractor’s responsibility for providing a high level efficiency of system maintenance because the process involves detecting and reducing degradation and restoring the functions of the system in working order.
The purpose of this paper is to overcome the shortage of updating data for occupational safety for maintenance, knowledge and to introduce new methods to protect workers and the working environment, as well as monitoring the current trends and standards.

This paper presents a model for determining the static load on movable spatial console lattice girder and the clamps which bounded the same one. The paper presents guidelines for theoretical determination of the static load using an appropriate software package and conducted modeling for this purpose. Also, the paper displays the methodology for experimental determining the static load by setting a model for the experimental measurement on the specific measuring points of the clams and the characteristic positions of the carrying console. The research is carried out on a concrete real object and the results are shown numerically and graphically, which enables carrying out an analysis of the load and deducing concreting conclusions about the research object.

Environmental pollution should be understood as a permanent process caused mostly by anthropogenic factors, that is man. The products of combustion from internal combustion engines are toxic and harmful effects on humans and the environment. This is one reason for research of biogas as an alternative fuel and its benefits for smaller amounts of harmful products in its combustion. For this purpose is reconstructed diesel engine that runs with a mixed fuel diesel- biogas where diesel fuel used for combustion and biogas propulsion engine combustion. Thus it is given the overall internal construction of this type of engine. There is calculated speed characteristics of the diesel engine and the reconstructed motor biogas. Thus these diagrammatic comparisons will indicate the nature of the changes in both engines.

Geothermal energy, solar energy, industrial thermal effluents, etc. mainly offer low-temperature waters. Heating installation or system, originally developed for one of the alternative energy source. The problem of low-temperature heating of greenhouses is not characteristically only for direct application of geothermal energy but is connected to the problem of all the “alternative” energies use for that purpose. Calculations determine the losses of heat transfer, losses from the application of heat and benefit from the use of hot water. Calculated is necessary and permissible temperature of the floor, the recommended speed of the fluid and plan for layout of pipes in the ground of greenhouse.