Energy generation, along with other sectors of Russia’s economy, is on the cusp of the era of digital transformation. Modern IT solutions ensure the transition of industrial enterprises from automation and computerization, which used to be the targets of the second half of the last century, to digital enterprise concept 4.0. The international record of technological and structural solutions in digitization may be used in Russia’s energy sector to the full extent. Specifics of implementation of such systems in different countries are only determined by the level of economic development of each particular state and the attitude of public authorities as related to the necessity of creating conditions for implementation of the same. It is shown that a strong legislative framework is created in Russia for transition to the digital economy, with research and applied developments available that are up to the international level. The following digital economy elements may be used today at enterprises for production of electrical and thermal energy: — dealing with large amounts of data (including operations exercised via cloud services and distributed data bases); — development of small scale distributed generation and its dispatching; — implementation of smart elements in both electric power and heat supply networks; — development of production process automation systems, remote monitoring and predictive analytics; 3D-modeling of parts and elements; real time mathematic simulation with feedback in the form of control actions; — creating centres for analytical processing of statistic data and accounting in financial and economic activities with business analytics functions, with expansion of communication networks and computing capacities. Examples are presented for implementation of smart systems in energy production and distribution. It is stated in the paper that state-of art information technologies are currently being implemented in Russia, new unique digital transformation projects are being launched in major energy companies. Yet, what is required is large-scale and thorough digitization and controllable energy production system as a multi-factor business process will provide the optimum combination of efficient economic activities, reliability and safety of power supply.

Transition to a new industrial revolution (“Industry 4.0”) in power engineering has stimulated introduction of advanced efficient equipment through modernization of existing or construction of new power units. At this stage, production processes are now characterized by deep integration of information technologies. This does not only apply to the processes of financial and economic acivities, but also the processes of providing up-to-date information on the current state of equipment, various supporting systems (security, fi re safety, movement control, work progress control, etc.) for making decisions in real time, as well as predictive analytics.

Raising the efficiency of management of equipment maintenance and repair is a top priority issue. The proper setup of this process does not only determine the quality and operability of equipment, but also the accuracy of evaluation of expenditure, which eventually affects the company’s financial standing. Therefore, the author is set to analyze the causes preventing efficient implementation of the process of equipment maintenance and repair at fuel and energy complex companies and suggests measures for their possible adjustment.

Key aspects are formed, which enable the organizations involved to get closer to more accurate formation of repair and maintenance operations.

Measures are presented that enable to create and develop a proper working system for the management of maintenance and repair measures. In particular, logical blocks are specified for implementation of a data management system in maintenance and repair.

The article outlines scientifi c approaches to the formation of digital technologies for managing the main factors of energy production. The assessment of the state of the production system is based on the index of the state of the production system of the power facility. Its target function is formulated, including dimensionless indices of fuel supply, the state of material and human capital assets. The author has formulated and solved the problem of finding the optimal values of a function using the mathematical apparatus of fuzzy sets. The indices characterizing the factors of production are defined as the solution of the optimization problem using ranking by values and weight coefficients determined by Saaty’s method. The determination of the fuel supply index and the technical condition of assets is carried out on the basis of the methods adopted in the energy sector, taking into account their actual state, provided that the reliability of the functioning of the UES is ensured. The article discusses in detail the technologies for assessing the company's human capital, shows the investment benefits of its development, presents the rational ranges of these investments, and provides statistical data that support the theoretical conclusions.

The possibilities of increasing the efficiency of cogeneration turbines of CHP plants through the use of low-potential heat carriers for water heating in district heat supply systems and increasing the generation of CHP electricity are considered. The existing technologies of heating the makeup water of the district heating system upstream water treatment apparatuses do not always provide the required heating temperature and do not have the sufficient energy efficiency. The technologies of using the main condensate of the exhaust steam in the turbine to heat the feed water in additional heaters included in the system of regeneration of cogeneration turbines are developed. The use of these technologies contributes to increasing the flow rate and reducing the enthalpy of the steam of regenerative outlets of the turbine used to heat this condensate, and, therefore, increases the combined heat and power generation. In order to determine the industrial applicability of the proposed solutions, experimental studies of the regeneration systems of turbo-units under the conditions of Ulyanovsk СHPPs-1 have been carried out. Multiparameter data arrays on operation of turbine condensate-feed path have been collected, and regression equations have been obtained to calculate the main condensate flow temperatures depending on various factors. On the basis of experimental data there have been calculated the minimum and maximum flow rates of feed water that can be heated to the desired temperature in the surface heaters included in the regeneration system of the turbines, the flow graphs of the heated feed water are constructed depending on the temperature of the main condensate after the turbines. The fields of application of the proposed technological solutions in operating heat supply systems are defined. The evaluation of energy efficiency is carried out using the method of specific generation of CHP electricity and conventional fuel economy at the implementation of the proposed solutions is calculated.

Ensuring environmental safety for energy companies in accordance with the requirements of Federal Law No. 219 of 21.07.2014 is a top priority task today. Experimental studies and industrial experience show that one of the main factors for the formation of virtually all toxic fuel combustion products in boiler plants is the ignition conditions in each burner of the furnace: the fuel-air ratio in the ignition zone, the proportion of primary air, the ratio between the secondary and primary air velocities, etc. However, according to the current regulations, the calculation of emissions of fuel oxides of nitrogen, as well as benz(a)pyrene, is based on averaged values for all burners of the furnace, and the influence of the most important factor — the uniformity of the distribution of fuel and air over the burners — on their formation is not taken into account.

In the work presented, a calculation analysis is performed of the effect of uneven distribution of solid fuel on the burners of boiler plants on emissions of nitrogen oxides, as well as benz(a)pyrene, in combustion products. A calculation procedure has been developed and the dependences of the change in NO_x emissions on the nonuniformity of the Δg distribution, the average air excess factor in the αG burners, the number of burners and the dust distribution models have been obtained. It is shown that with the value of the parameter Δg <10%, the uneven distribution of fuel has practically no effect on emissions of nitrogen oxides and benz(a)pyrene, and Δg5 (at which the increase in NO_x emissions due to uneven distribution of dust does not exceed 5%) should make: for two burners — 22% ... 27%, four — 12% ... 22%, six — 11% ... 13%. At higher values of Δg and with increasing α, there is a significant increase in emissions of nitrogen oxides and benz(a)pyrene. It is obtained that simultaneously there is a simultaneous increase in NO_x and BP. Recommendations are given on the use of dust distribution circuits and designs of dust dividers that meet the requirements to ensure that the uneven distribution of fuel over the burners would not affect emissions of nitrogen oxides.

The methodology is presented for assessment of the technical condition of an object, which is a separate unit of power equipment from a group of the same type of equipment of power plants. It is demonstrated that technical condition is a characteristic of quality of an object under investigation, which, for practical purposes, should be calculated as a deviation from an established value. The assessment of technical condition is fulfilled with uniform criteria based on a limited amount of initial data on each of the basic properties of the object. The assessment can be fulfilled at the level of the object performance indicator, at the level of the object individual property and at the level of a set of the object properties. The top level assessment is a function of the loss of quality by the object, which is calculated through convolution of low level values. The assessment of technical condition of an object is accompanied by calculation of uncertainty of quality loss functions by means of transformation of uncertainties of initial data into uncertainties of output values. The evaluation of the technical condition can be expressed either in relative units - the percentage of quality loss relative to the maximum possible quality of the object, or in absolute units - the monetary equivalent of a loss of quality by the object. Evaluation in relative units enables to determine the residual gamma resource of the object, but this requires the participation of an expert to assign the weight of performance indicators. Evaluation in absolute units makes it possible to identify objects whose improvement in technical condition is appropriate from the economic point of view. To track the reasons for deviations in the technical condition from the set values, a structured list of performance indicators and factors affecting them is used. It is shown that the possibilities of evaluating the technical condition in relative units are limited: an attempt to perform assessment and analysis of the technical condition by convolving values of indicators and characteristics of properties into a single numerical index gives incorrect results. Neglect of these restrictions leads to emergence of inadequate, unsubstantiated scientifically methodological requirements for assessment of the technical condition of power equipment.

Quality taking and analysis of gas and oil samples upon actuation of gas protection is an essential component of transformer operation, in making a prompt decision on its admissibility to operation after an emergency shutdown. Existing conventional systems for taking, storage and transportation of gas samples from gas relays have a number of significant drawbacks. At the same time, the devices in use at present often fail to ensure the representative nature of samples; besides, when used in line with established rules, they are inconvenient in sampling and “combustibility” checks.

To solve the aforesaid problem, a study has been performed at the facilities of the physical-chemical and chromatographic analysis laboratory of the diagnostics directorate of the branch of PJSC “IDGC of North-West” on a number of advanced technologies that could be used for taking, transportation and storage of gas samples. In the experimental study, 0.5 l gastight bags made by SKC (США) (models No.237-02 and No.232-02, differing in the design of the sampling system) and 0.5 l bags made by Elchrom (model EL-PACK G-300) were used. Experimental work on examination of gas-tight bags was carried out in two stages. At the first stage, gas-tightness was assessed at room temperature, and at the second stage, the effect of negative temperatures on gas-tightness was investigated.

In the course of the experimental studies, the feasibilility was confirmed of using advanced Russian and foreign technologies for taking, storage and transportation of gas samples from transformer gas relays. The models of gas-tight bags under investigation are found to be appropriate for taking, storage and transportation of gas samples, both at positive temperatures of the ambient air, and at temperatures as low as minus 15–18°С (the effects of still lower temperatures was beyond the scope of the study). To establish the feasibility of repeated use of gas-tight bags, it is proposed to continue experimental studies.

An elementary arrangement of a heat supply of residential buildings with direct connection to external heating systems is considered, providing reliability of heat supply and comfort required in indoor premises in case of cold snaps after the official closure of the heating season, or before the beginning of the same, by supplying water from the return main of the heating system after the hot water heat exchangers. The basic equations are analyzed relating the heat transfer to the heating system with water temperature in the manifold, the inside air temperature and the characteristics of the heaters, with a review of possible methods of regulating the heat supply near the beginning and the end of the heating period provided taking into account requirements of normative documents of the Russian Federation. Calculations are performed to determine the amount of the main components of the heat balance of a residential building on the example of one of the standard projects used currently in the climatic conditions of Moscow taking into account the constructive structural characteristics of the building and its occupancy level. Analysis of the obtained results and conclusions regarding the appropriateness of the application of this arrangement are provided. It is established that the actual heat output of the heating system when using a chilled water network down-stream the hot water supply heat exchangers as a heat source enables to maintain the safe indoor temperature in the building, with the average daily temperature of outdoor air above +2° C in conditions of moderate amount of heat received with solar radiation. It is shown that the use of this arrangement is virtually not accompanied by additional costs, provides hydraulic resistance of the heating system and gives a system-wide effect in the form of higher electricity generation at thermal consumption when using cogeneration.

The article studies the matters of physics of interaction of parallel overhead power transmission lines. Cases are presented, where the maximum induced voltage values are expected on individual sections of closely approaching de-energized and energized power transmission lines. Possible scenarios are presented of direct contact with an unearthed conductor (wire) of OPL in the normal operation mode. Substantiation is presented of review of the list of the lines, which, when de-energized or earthed at terminal sections (in the switchgear of substations and power plants) have the values of induced voltage on the earthed conductors, as reduced to the maximum permissible continuous current of the affecting OPL, exceeding 25 V . Criteria are identified to classify OPL as being affected by induced voltage. The article considers organizational and technical procedures applied to provide safe maintenance works under induced voltage on de-energized overhead power lines (OPL) located within an area affected by energized OPL.  Attention is given to the detailed description of types of earthing of OPL, line equipment, working section and workplaces used by State Production Association Belenergo. The mathematical apparatus used in the analytical calculations of the induced voltage values has been analyzed. The technical implementation of acceptable schemes of performing the repair and maintenance works on the earthing of de-energized OPL is considered. Performing geophysical ground survey by the method of vertical electrical sounding at places of mounting special low-resistance earthing electrodes is proposed and implemented. The methodology is developed and tested for measuring induced voltage values, which sets the order of induced voltage measurements on de-energized OPL running close to energized OPL with the voltage 110 kV, and higher. Comparative analysis is presented of results of analytical calculations and experimental research. Conclusions are made supporting the approach adopted and confirming the expediency of the system of ensuring electrical safety of maintenance works performed on 35–750 kV power transmission lines being under induced voltage implemented in the Republic of Belarus.

The so-called expander-generator sets (EGS) have found some application in Western Europe. Their operation is based on a drop in the pressure of natural gas (NG), which comes to a power-generating or industrial facility, and which used to be lost in choking devices of the gas distribution station (GDS) of these facilities. The capacity of such sets, e.g., in Germany, is limited to just tens to hundreds of kilowatts. The benefit for their owners lies in obtaining, according to the German law, markups to the cost of energy released to electricity consumers. However, the economic environment in place in Russia is somewhat different.

According to the author, the limited number of  EGS in Russia’s power industry, as well as cases of their decommissioning, are due to the lack of evidence of their thermodynamic or technical-economic efficiency, or even worsening economic conditions at facilities, where those were implemented. Besides, the facilities in question have to be provided with considerable specific conditions. These include a relatively high value of initial NG pressure at the input of EGS, its considerable flow rate and the possibility of NG heating at the input of EGS. This necessity to heat NG upstream the EGS is determined, on the one hand, by the intention to enhance the EGS capacity, and on the other hand, by having to comply with requirements imposed by the EGS manufacturer regarding the temperature values upstream and downstream the EGS. Without a required source of heat of relevant parameters at the facility, application of EGS turns out to be impossible, altogether. An interest in EGS in Russia arose due to construction and commissioning (first, at CHPP-21, and later at CHPP-23 of Mosenergo) of two power-generating centers, each equipped with two 5 MW EGS. Since then, a large number of articles have been published, and numerous theses have been defended based on the studies undertaken, mostly of analytical nature. Yet, those publications have not considered, for a real expander, matters of effects produced by the relation between the absolute electrical efficiency (η_e) of CPP and/or CHPP and the efficiency ratio of expander (η_er ), the NG expansion ratio (δ). Conditions, at which heating NG upstream the EGS is expedient, have not been established, either, whereas these are the factors crucial for economic feasibility of a TPP to be equipped with EGS.