The article considers the method of using mixtures to optimize the electrophysical  parameters of grounding devices in conjunction with vertical composite grounding conductors.  It has been found that fluctuations in soil resistivity caused by changes in weather and climatic conditions can lead to instability of the ground loop resistance. The study shown that without appropriate measures, the resistance of the loop as a result of seasonal changes in soil properties may exceed acceptable values. This is fraught with deviations in the resistance to current spreading of grounding devices beyond the limits of acceptable parameters. To compensate for these fluctuations, a method is proposed to reduce the seasonality factor. Reducing seasonality plays an important role in ensuring the safety of service personnel and farm animals by maintaining the  resistance of the grounding device within the limits of regulatory values. The authors discuss methods for artificially reducing the resistance of the ground loop, including increasing its size and using deep ground electrodes. The results of vertical electrode probing of the soil at the sites of grounding conductors are presented, the effect of humidity on the resistivity of the soil is shown, the influence of soil layering and the presence of moisture-saturated soil layers is considered.  A method is proposed that allows the mixture to be introduced together with a vertical composite grounding device, the design of the coupling, tip and auxiliary device, experimental studies of the proposed designs are carried out and the results of measuring the current spreading resistance  of such a grounding device with both standard and proposed couplings are presented. A comparison was made with a grounding device without the use of mixtures. The measurement results demonstrate that with an increase in the length of the grounding device, its diameter and the volume of the injected mixture, the resistance decreases. It is shown that the proposed solution makes it possible to reduce seasonality by 1.64–2.1 times, depending on the couplings used, and to obtain a grounding conductor with an equivalent diameter dozens of times larger than the diameter of  a composite grounding conductor. The authors propose the use of soil-replacing mixtures to reduce soil resistivity and ensure the stability of the grounding loop throughout the entire service life.  The proposed method of applying mixtures without pre-drilling makes it possible to reduce the cost of constructing grounding devices.

The article considers the issue of choosing the optimal construction arrangement  of cable lines with a voltage of 10 (20, 35) kV with cross-linked polyethylene insulation. The options for using three or single-core cables laid in a triangle or in a plane are analyzed. The methodological basis of the work is the principle of minimizing the expected costs, taking into  account both capital investments and annual costs, including losses of electrical energy in cables. Within the framework of the study, a nomogram of economic intervals was scheduled, which makes it possible to determine the optimal cable core sections and boundary conditions for the use of threeand single-core cables, depending on the calculated current load. It is shown that with the existing nomenclature of three-core cables with a maximum core cross-section up to 630 mm², single-core cables can be economically feasible only with a core cross-section of 800 mm²  and above. It has been discovered that the expected costs for laying single-core cables in the plane with two-way grounding of screens always turn out to be higher than when laying a triangle.  This effect is due to an increase in both capital costs and power losses in cable screens. To increase the efficiency of cable lines, it is proposed to expand the range of three-core cables by including cables with the maximum possible core cross-section. This will make possible to increase  the range of current loads in which the use of three-core cables will be economically justifiable. The results presented in the article can be used in the design of new cable lines, the analysis of  the effectiveness of existing ones, as well as in the modernization and reconstruction of urban medium-voltage cable networks.

The article considers promising areas for solving problems of energy and resource conservation, as well as issues of rational use of natural and secondary resources generated in industrial and communal activities. The aspects of research and development of technological options for the use of various wastes based on multicomponent compositions of solid fuels as alternative energy sources are presented. Also presented are the main stages of the developed and applied technologies for briquetting and incineration of multicomponent mixtures based on various combustible waste. The developed algorithm for solving the problem under consideration which makes it possible to rationally use substandard combustible industrial municipal waste to obtain multicomponent solid fuel that meets the quality criteria for energy and environmental indicators is reviewed. The results of the applied research directly related to the qualitative assessment of multicomponent briquetted fuels and facilitating achievement of the best production and consumer indicators values of energy quality and environmental friendliness are presented.

. The basic laws of the kinetics of drying thin flat materials during the period of drop in the drying speed are outlined. A method for calculating the average integral temperature of wet material on the basis of the relative temperature coefficient of drying is presented. Experimental data are processed based on the relative drying rate in the drying processes of ceramics, asbestos, and woolen fabric. A formula for calculating the average temperature is proposed. The solution of the differential equation of thermal conductivity for a wet plate during the drying process (namely during the period of drop in the drying speed) under boundary conditions taking into account the conditions of drying is given. The calculation of the heat transfer coefficient is given, too. Based on the study of various sources and processing of experimental results, formulas for calculating the thermal conductivity coefficient of wet materials have been presented. The analytical solution of the problem confirmed that during convective drying in low-intensity processes of the second drying period, the temperature change with a decrease in moisture content turns from an exponential dependence smoothly into a linear one, which is completely consistent with the experiment.  A comparison of the temperature calculation by the experimental formula with the results of analytical solutions has been presented. A sufficiently reliable coincidence of experimental and calculated analytical values of temperature for the period of drop in speed drying of ceramics, asbestos, and fabric is obtained.

The development of biogas technologies in the Republic of Belarus takes place within the framework of power construction and the formation of a raw material base, which is determined by the peculiarities of economic development. Currently, biogas is produced using two main waste fermentation technologies: wet technology for processing organic livestock waste and dry technology for converting solid household waste. The first category includes 16 biogas plants with a total capacity of 21.219 MW, the main raw materials for which are organic waste from  animal husbandry, characterized by high humidity. The main equipment used in these plants are bioreactors. The second category of biogas complexes includes 21 biogas plants with gas piston units with a total installed capacity of 32.463 MW. Their main raw material for them is household solid waste, from which landfill gas is produced. Additional equipment, viz. cogeneration plants in both technologies makes it possible to increase the power efficiency of biogas production. According to the results of the assessment of the theoretical and technically possible potential of biogas from livestock waste while maintaining the number of livestock in agricultural organizations at the level of the beginning of 2023, there is a possibility of annual replacement of 1,325 million m³  and 982 million m³ of natural gas in the fuel balance of our country, respectively. In the last few years, there has been an urgent need to reorient the production activities of biogas complexes due to the commissioning of the Belarusian nuclear power plant. The change in the country’s energy structure has made significant adjustments to the functioning of alternative power engineering, including the production of biogas, primarily according to its target indicators. The issues of alternative energy production in the new conditions remain significant, since electric and thermal energy produced from biogas can and should be used for the operation of equipment, water heating, dehydration of the resulting vermicompost, and other local purposes. The environmental advantages  of biogas technologies remain highly relevant, i.e., effective management of organic waste from large livestock farms, which can significantly reduce pollution of soils, surface and groundwater, atmospheric air with organic pollutants, near livestock complexes. In the Republic of Belarus, there is now a need  to change the production activities of biogas complexes, primarily due to the appearance of nuclear power produced at the Belarusian nuclear power plant in the country’s energy balance.

The article discusses issues related to the actual condition of pre-insulated (PI) pipelines of district heating systems (DHS). Some of the pipelines in operation are approaching their estimated service life, so the issue of their further use is relevant. The aging of the heating supply pipelines occurs due to various processes associated with both operating temperature regimes and oxidation. The durability of polymer materials used in pre-insulated pipes can be assessed through empirical or predictive methods. For six batches of PI pipes that were in operation at different times in the Minsk DHS, tests were carried out according to standardized parameters in order to determine their actual values. For most of the samples presented, the values of the average cell size, thermal insulation density, compression strain stress and the number of closed pores significantly meet the requirements of STB 2252–2012 for new pipes. The value of the thermal conductivity coefficient is in the range of 0.030 to 0.037 W/(m·K), which is 10 % higher than the required value for new pipes. Values of the shear strength limit of the pre-insulated pipe construction  in many tests was less than 0.12 MPa, indicating a potential risk of failure in the thermal insulation structure of the pipe. Besides, there is no specific correlation with either the service life of the pipes or the temperature regime.