The article is a continuation of a series of publications focusing on the analytical assessment of specifics of power transmission in various structural divisions of PJSC Rosseti and is dedicated to the consideration of specific features of electric energy transport in the PJSC Rosseti Volga – Penzaenergo branch electric networks over the period of 2018 – 2023. The characteristic of the structural and balance state of the company's electrical networks for the period under study is presented. Based on the data published in the open press, the analysis of the number of emergency shutdowns and their consequences in electric networks of all levels of rated voltage was carried out. In accordance with the accepted classification, the intensity of these outages was analyzed depending on the amount of electrical energy undersupplied to consumers. The percentage ratio of the value of electrical energy not delivered as a result of emergency shutdowns is analyzed according to the accepted criteria of the intensity level of these failures. It was found that the smallest number of failures of extreme intensity accounts for more than 25% of undelivered electrical energy. The percentage ratio of the amount of electricity not delivered as a result of emergency outages is compared with losses of electricity as a result of unauthorized connections. Specific groups of causes of emergency shutdowns have been identified and the percentage ratio of the number of failures due to these causes to the total number of failures during the period under study has been determined. General scientific methods and methods of numerical analysis were used in the study. The technologies of Excel, Paint 3D software shells, MATLAB graphics editor, as well as author's software solutions were used as a tool base. The results obtained may be of interest to the management of the power grid structures of the Russian Federation, as well as to engineers and researchers engaged in research in the field of improving the reliability of power supply to consumers.

The article considers the direction of increasing the energy and environmental efficiency of the city's energy infrastructure through the modernization of existing thermal power plants (TPP) and combined heat and power (CHP) plants using combined-cycle gas turbine (CCGT) plants.  Fuel and energy balances of electric power plants have been constructed, and the energy and environmental effects of the use of CCGT have been assessed. The modeling of energy and environmental indicators for the thermal circuits of the CCGT was conducted using the Thermoflex, GT PRO software (Thermoflow) and the ISC Manager program developed at the National Research University "Moscow Power Engineering Institute (MPEI)". The analysis of CCGT efficiency in urban energy applications is based on modeling and optimizing the city’s fuel and energy balance (FEB). For this purpose, the OptiTEB program developed at the Department of PTS at the National Research University "MРEI" is used. Constructing fuel and energy systems in cities and regions is a pressing task that enables the planning of a strategy for the development of the urban fuel and energy complex (FEC), with an assessment of the magnitude of harmful emissions, including greenhouse gases. The article presents the results of work on establishing scientific foundations for modern heat supply systems, exemplified by a mathematical model of the Moscow thermal power plant and its optimization, taking into account the projected development of electric transport infrastructure over the coming decades, improving the thermal protection characteristics of newly constructed buildings, and the potential increase in the use of renewable energy sources (RES). The growth in the share of electric transport should be linked to an increase in the share of renewable energy sources (RES). Simply increasing the number of electric vehicles without a significant rise in renewable energy usage in the city's energy balance will not result in a reduction of carbon dioxide and harmful substance emissions. Expanding electricity generation through CCGT, alongside the growth of renewable energy use in the city, can lead to a significant decrease in carbon dioxide emissions.

The article considers the challenges of using cyclone devices for cleaning gas emissions from solid fuel combustion in power engineering and industry. With the increasing energy consumption and generation, including the use of coal, the requirements for the efficiency of cleaning emissions from small solid particles of classes PM10 and PM2.5 are also rising. One of the key tasks is to maintain high cleaning efficiency while minimizing energy costs, which is also important for reducing the environmental impact of generation and industrial production. The article considers the design features of currently used cyclones, as well as existing approaches to their classification. The main focus is on modern areas of research related to numerical modeling based on CFD (Computational fluid dynamics) aimed at optimizing the design of separators. It is shown that most studies are carried out for cyclone operating conditions in production cycles, rather than in emission cleaning systems that operate at low suspended matter loads. Using the example of creating numerical models of cyclones with inclined and horizontal inlet pipes (CN-11, SK-CN-34), the article discusses certain features of geometry creation in the SpaceClaim Direct Modeler (SCDM) environment, which ensure the correctness of grid generation and calculations in the future. The results of numerical modeling carried out using the ANSYS Fluent software are presented. The turbulence model (RANS, Reynolds Averaged Navier – Stokes), methods for closing the Navier – Stokes equations (k-ε model with near-wall functions), and methods for calculating the dispersed part of the flow (Euler – Lagrange, DPM) are selected based on the conditions relevant to the systems for cleaning emissions from coal generation. The results indicate that, with the same pressure drop, the efficiency of settling suspended matter with a concentration of 100 mg/m³ or less in an apparatus with an inlet angle of 11° to the horizontal can be higher than that of a cyclone with a horizontal inlet.

This article discusses the application of digital twin technology in thermal power engineering. Special attention is paid to the influence of digital models of the existing equipment of the powerplant on the educational process in higher educational institutions and professional development of service personnel. The article summarizes the results of the introduction of power plant simulators into the curriculum, the methodology of laboratory work and the organization of training sessions. It is also shown that the introduction of physical and mathematical modeling in education and practice contributes to improving the safety and efficiency of work in the energy sector. The results of the introduction of plant simulators into the curriculum are summarized. The software of computer equipment provided for classes at a higher educational institution is considered as a tool for practicing operation skills and creating digital models. When working in a software package, the user is given the opportunity to control units of equipment individually, collectively as a whole unit, or create computational models consisting of simple blocks of equipment. The proposed mutual cooperation between software developers and universities can lead to the creation of digital models to enable retraining of specialists in the workplace, as well as increasing the level of knowledge of graduates. The result of the introduction of a virtual testing ground in a higher educational institution in order to verify the knowledge of students is considered. Thus, the introduction of digital twins into the educational process and practice of work in the thermal power industry is a promising direction for the development of the industry. It contributes to improving the level of training of specialists, ensuring the safety and efficiency of equipment operation, as well as reducing the risks of emergency situations

In the long-term planning of repairs at power grid facilities in conditions of limited operational and investment resources, it is important to determine the "points of maximum return", that is, the objects whose repair will cause the greatest effect in terms of the company's target priorities. This requires an operational assessment and ranking of electric grid facilities, taking into account the technological and resource characteristics of the energy company. The article presents a decision-making methodology that, based on operational calculations and priority assessment, enables to identify power grid facilities with the highest repair efficiency in the sense of criteria characterizing the strategic goals of asset management of an energy company. The methodology combines methods of modeling and calculating the probabilities of failure in consumer power supply systems (PSS) with the determination of indices of the technical condition of equipment, methods for calculating labor costs for maintaining and restoring reliability and assessing damage from its disruptions.

The developed methodology allows the energy company — the owner of assets, when choosing the most effective repair management system according to enlarged indicators and simplified models, to form prioritization lists of objects for which the critical repair rank corresponds to its strategic priorities. The possibility of cost estimation of the total labor costs for the maintenance of facilities for each of the received prioritization lists in comparison with the repair fund stated by the energy company expands the scope of the methodology and increases the validity of the decisions made. The methodology has been verified and confirmed by consideration on the example of a real PSS of oil fields using up-to-date operational information.

Due to the growing number of accidents associated with damage to turbine unit shafts, there is a pressing need to diagnose the occurrence and growth of ring cracks not only during planned repair work on the turbine unit, but also directly during its operation to prevent emergency failures and costly repairs of the machine. Ring cracks that develop in the shafting do not lead to an increase in the level of vibration of the rotor or its support bearings and, therefore, cannot be detected by standard operational vibrodiagnostic systems. In this paper we propose a method that allows for the diagnosis of the occurrence and growth of ring cracks on the turbine unit shafting. The method is based on the influence of the depth of an annular crack in the shaft on the angle of its twist during machine operation. The presence of this relationship is determined through calculations based on the parameters of the experimental low-pressure turbine 2, used by the Central Boiler and Turbine Institute named after I. I. Polzunov. The practical implementation of this method is proposed to be carried out using the twist angle determination technique developed based on the discrete-phase method by means of measuring and analyzing changes in the shaft twist angle during turbine unit operation. Technically, this is achieved by employing a system consisting of inductors and sensors fixed to the stator and rotor parts of the machine. The proposed method can be used as a supplement to existing methods of operational control of the actual condition of the shafting, as well as, in the future, to assess the actual efficiency of the turbomachinery cylinders.

The article presents an exergy analysis of a district heating system (DHS) that incorporates a predictive model based on neural network algorithms. The study focuses on evaluating the thermodynamic efficiency of the DHS when these methods are applied, enabling the prediction of temperature changes and rapid adjustment of system parameters to enhance efficiency. The impact of increasing the number of connected consumers on the exergy efficiency of the DHS with the predictive model (DHPM) is examined. The use of neural network algorithms, such as LSTM, significantly enhances the system's ability to predict external temperature changes and respond promptly, resulting in optimized energy consumption and improved exergy efficiency, particularly at the beginning and end of the heating season. A comparative analysis of the exergy efficiency of traditional DHS and the system with the predictive model is included. The exergy analysis is based on modeling the system’s performance with varying numbers of consumers. The results indicate that an increase in the number of consumers leads to a rise in exergy efficiency due to better energy distribution management. The potential for significant thermal energy savings and reduced operational costs through the use of predictive methods is discussed. The study confirms that applying neural network algorithms in predictive models of DHS can substantially improve efficiency and reliability, leading to a more rational use of energy resources, cost reduction, and minimized environmental impact. The findings support the adoption of these methods in large-scale district heating systems for optimization and enhanced energy efficiency.

The analysis of turbine oils currently in use is given. The classifications for petroleum base oils according to the systems developed at JSC VNIINP and the American Petroleum Institute are presented. The transition from the operation of turbine oils of the first group to more advanced oils obtained on the basis of base oils of the second group and above is justified. The problems that may arise when replacing oils of the first group with modern oils in connection with the processes of mixing energy oils of various formulations are outlined. The mixing process is complicated by the compatibility factors of both the commercial products themselves and the additive compositions used, as well as possible contamination with oil sludge of lubricants in operation and possible contamination with water and mechanical impurities of the new energy oil at the delivery stage. The necessity of analyzing the possibility of mixing is explained both by the compatibility of the energy oils being tested and by the compatibility of the additive package used in them. A list of indicators is presented by which it is possible to judge the possible compatibility of the energy oils under consideration. The results of the compatibility analysis are presented. In modern foreign policy conditions, for the Russian Federation, there is a need to activate Russian developments and provide modern lubricants for a new generation of energy facilities. A possible solution to this issue, developed by the specialists of the NRU MPEI, is presented. A system for the production of oil distillate with subsequent production of base (group III) and commercial oil for high-ash initial coals of the brown coal and early black coal stages of coalification of coal basins closed for development is presented.

In various spheres of modern industry, including power engineering, the issue of low efficiency of operation of heatexchange equipment, where condensation of vapour-gas media occurs, is a significant concern. It is known that one of the effective ways of solving this problem is intensification of heat exchange processes by transitioning from the traditional film condensation mode to the droplet condensation mode. A promising and technically straightforward way to achieve the droplet mode of condensation is a method based on the treatment of heat-exchange surfaces using a surfactant – octadecylamine (ODA). The analysis of studies, in which results of experimental research and industrial implementation are given, has shown that application of the specified method in conditions of condensation of water steam promotes formation of a stable droplet mode of condensation; as a result, the heat transfer coefficient on the steam side can more than double.

Equally important and interesting is the question of how the efficiency of heat exchangers impacts the overall efficiency of complex systems, in which they operate. In this study, we examined the effect of the operational efficiency of network and regenerative heaters on the energy efficiency and economic performance of a power unit based on steam turbine unit T-110-12,8-3 operating in the heat recovery mode. To this end, we calculated the thermal scheme under various operating conditions of these heat exchangers and determined several key efficiency indicators, including the fuel heat utilisation factor (HUF) and electrical efficiency (EE). It is revealed that intensification of heat-exchange processes by a factor of 2 in horizontal delivery water heaters (HDWH) or in low-pressure heaters (LPH) significantly enhances the efficiency indicators of the power unit as a whole. At the same time, as the analysis of calculation results showed, the greatest benefits are realized when this measure is implemented in HDWH.

Various variations of reducing the aerodynamic resistance of devices with a complex flow-through configuration are considered. About 50% of power plants in the Russian Federation operate on coal, with two-stage cleaning used in the ash collection process. Modern coarse ash collectors allow achieving an efficiency of 55 – 80% depending on their service life. It is advisable to reduce the number of cleaning stages by upgrading them with modern cleaning devices that allow achieving high efficiency of cleaning the dusty flow and subjecting this cleaning complex to less repair work. IVACis an inertial-vacuum ash collector, which can achieve the capture of a wide range of studied particles (1 – 100 μm) with an efficiency of up to 99%. This device was tested at the Omsk CHP Plant, but it was found to feature an increased aerodynamic resistance, as well as high efficiency. The objective of this work is to keep an aerodynamic resistance to 660 Pa (the resistance of the cyclone apparatus so that the apparatus can be used as the first and, consequently, as two stages of purification) while maintaining the efficiency of the apparatus. The results of changing the configuration of the flow part of the IVAC are analyzed, the model submitted for patenting after numerous is considered. The research methodology is the analysis of a numerical experiment in ANSYS CFX using the k-ε mathematical model (ash mass content of 70 g / kg; One-Way Coupling). In conclusion, recommendations are proposed for further prospects of IVAC research.