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The concept of multi-energy systems (MES) is widely applied in various areas of energy supply. This approach makes it possible to analyze the distribution of energy flows and their mutual influence both for local facilities and for power supply systems. At the same time, currently, promising systems for analysis, forecast, and control of the behavior of energy facilities are those that employ innovative methods, for example, different technologies of mathematical modeling. Their successful application requires a methodological approach to build mathematical models of integrated energy systems relying on simulation modeling. The approach proposed in this paper is based on the concept of an energy hub. It has been tested on a simulation model for two energy supply channels for a fragment of a real-world energy facility. The presented methodological approach to create mathematical models of integrated energy systems is based on simulation. This approach offers broad prospects for expanding the capabilities in the design and operation of integrated multi-energy systems.

Energy performance contracts are a very promising area for attracting private investment in the renewable energy sector. The concept of energy performance contracting is a well-established mechanism aimed at increasing the energy efficiency of a facility and reducing annual maintenance costs. This paper presents a hierarchical model of a decentralized energy system with renewable energy sources and a battery energy storage system under an energy service agreement. This model reflects the interaction between the client and the performance company. The model includes the main parameters characterizing the energy service contract, such as net present value, contract duration and levelized cost of energy. As an example, a real decentralized power system is considered, which currently only uses diesel generation. In the case of building a photovoltaic system, the optimal equipment composition consists of a 100 kW solar station and storage batteries with a capacity of 240 kW·h. The optimal contract term is 5 years, and diesel fuel savings are 69%.

Asynchronous loads (AL), because of their low negative-sequence resistance, produce the effect of reduced unbalance at their connection points. Therefore, proper modeling of unbalanced load flows in power supply systems requires properly accounting for AL. Adequate models of the induction motor can be realized in the phase frame of reference. The effective use of such models is possible only if accurate data on the parameters of induction motor equivalent circuits for positive and negative sequences are available. Our analysis shows that the techniques used to determine these parameters on the basis of reference data can yield markedly disparate results. It is possible to overcome this difficulty by applying parameter identification methods that use the phase frame of reference. The paper proposes a technique for parameter identification of models of individual induction motors and asynchronous load nodes. The results of computer-aided simulation allow us to conclude that by using parameter identification, we can obtain an equivalent model of an asynchronous load node, and such a model provides high accuracy for both balanced and unbalanced load flow analysis. By varying load flow parameters, we demonstrate that the model proves valid over a wide range of their values. We have proposed a technique for the identification of asynchronous load nodes with such asynchronous loads, including electrical drives equipped with static frequency converters. With the aid of the AL identification models proposed in this paper, it is possible to solve the following practical tasks of management of electric power systems: increasing the accuracy of modeling their operating conditions; making informed decisions when taking measures to reduce unbalance in power grids while accounting for the balancing adjustment effect of AL.

Fault location on overhead power lines achieved with the highest possible accuracy can reduce the time to locate faults. This contributes to ensuring the stability of power systems, as well as the reliability of power supply to consumers. There are a number of known mathematical techniques based on different physical principles that are used in fault location on overhead power lines and whose errors vary. Fault location on overhead power lines uses techniques based on the estimation of emergency state parameters, which are referred to as distance-to-fault techniques and are widely used. They are employed in digital protection relay terminals and power-line fault locators. Factors that have a significant impact on the error of fault location on overhead power lines by emergency state parameters are design, manufacturing, and operation. The aim of this article is to analyze the existing techniques and to present a new analytical technique for estimating errors of fault location on overhead power lines by using emergency state parameters. The technique developed by the authors makes it possible to properly take into account a set of random factors, including various measurement errors of currents and voltages in the emergency state, which have a significant impact on the fault location on overhead power lines error. The technique allows one to determine more accurately the fault location and the size of the inspection area, which is necessary to reduce the time it takes to carry out emergency recovery operations. The proposed technique can be applied in fault locators and digital protection relay terminals that use both single-end, double- and multi-end sensing of currents and voltages in the emergency state.

The problem of the quality of electric energy in the utilization of petroleum gas is considered. The article presents the results of the development of a mathematical description of power supply systems with gas turbine power stations based on two-shaft gas turbine units. The typical power distribution scheme of a gas turbine power station is given. The joint analysis of the generation modes of the gas turbine power station and the detected deviations of the power quality indicators values was carried out. The influence of the used mode on the power quality indicators is determined. As a result, the factors of operation of a gas turbine power station that affects power quality are identified, and recommendations for their elimination are given.

The trend towards the decentralization and decarbonization of the energy sector stimulates the adoption of generation facilities based on renewable energy sources (RES) and distributed generation (DG) facilities that utilize secondary energy resources. Operation features of DG facilities, such as a high speed of electromechanical transient processes and significant deviations of power quality indicators from standard values, require improvement and an increase in the speed of automation devices. Modern electroautomatic devices must determine the operating regions (normal and emergency) and adapt the operation algorithms to the conditions of the current mode. The study presented proposes methods developed to use the Wald Sequential Probability Ratio Test (WSPRT) to improve the reliability and efficiency of the power system automation devices. The paper provides examples of using WSPRT in the devices of automatic frequency load shedding, automatic transformer disconnection, and power quality control. The results of mathematical modeling confirm the high performance of WSPRT in power system automation devices owing to an increase in the reliability of operating regions identification and speed of response. For example, in the automatic frequency load shedding (AFLS) algorithm for a network with DG facilities at a sampling rate that meets the requirements of the IEC 61850 (80 samples per period), the acceptance time does not exceed 1 ms. The study substantiates the need to use WSPRT in the logic blocks of automation devices employed in active distribution networks.

The Francis hydro-turbine is a typical nonlinear system with coupled hydraulic, mechanical, and electrical subsystems. It is difficult to understand the reasons for its operational failures, since the main cause of failures is due to the complex interaction of the three subsystems. This paper presents an improved dynamic model of the Francis hydro-turbine. This study involves the development of a nonlinear dynamic model of a hydraulic unit, given start-up and emergency processes, and the consideration of the effect of water hammer during transients. To accomplish the objectives set, existing models used to model hydroelectric units are analyzed and a mathematical model is proposed, which takes into account the dynamics during abrupt changes in the conditions. Based on these mathematical models, a computer model was developed, and numerical simulation was carried out with an assessment of the results obtained. The mathematical model built was verified on an experimental model. As a result, a model of a hydraulic unit was produced, which factors in the main hydraulic processes in the hydro-turbine.

Gas-fired reciprocating engine plants (GREPs) are widely used in power supply systems of industrial facilities, which allows for ensuring the operation of electrical loads in case of accidents in the power system. Operating experience attests to the fact that during islanded operations, GREPs are shut down by process protections or protective relays in the event of severe disturbances. This leads to complete load shedding, which is accompanied by losses and damage to industrial facilities. Severe disturbances include the following ones: large load surges on GREPs due to one of them being switched off, the group starting of electric motors, and load shedding (more than 50%) during short circuits or disconnection of process lines. Energy storage systems (ESS) have the ability to compensate for instantaneous power imbalances to prevent GREPs from switching off. The authors of this study have developed methods for intelligent control of the ESS that allow one to solve two problems: prevention of GREPs shutdowns under short-term frequency and voltage deviations as well as preservation of the calendar and cycling lifetime of battery storage (BS) of the GREP. The first method does not require performing the calculation of adjustments of control actions for active and reactive power on the ESS online but rather determines them by the value of frequency deviations and the voltage sag configuration, which greatly simplifies the system of automatic control of the ESS. The second method, which consists in dividing the steady-state power/frequency characteristic into sections with different droops that are chosen depending on the current load of the ESS and the battery state of charge, and offsetting it according to a specified pattern, allows for preventing the premature loss of power capacity of the ESS BS.

The creation of a decentralized low-carbon energy infrastructure is the main trend in the development of the electric power industry in many countries. Distributed generation facilities (DGs) based on gas reciprocating units (GRUs) are often built by industrial entities for the efficient utilization of secondary energy resources in order to minimize the environmental impact. Modern GRUs have some advantages, but they have design features that should be factored in when connecting them to the internal power systems of industrial entities. Incorrect consideration of possible operating conditions of GRU in their design can lead to their damage, excessive shutdowns, and disruptions in power supply to essential power consumers with significant damage and losses from undersupply of their products. Excessive shutdowns of GRUs are often caused by a non-selective choice of settings for relay protection devices or by load surges that exceed the allowable ones. With high availability factors, GRUs are disconnected five to eight times more often compared to large gas turbine and steam turbine power units. The large total power consumed by electric motors, as part of the load of an industrial entity, determines the nature and parameters of electromechanical transient processes during emergency disturbances. The presented analysis of issues facing real DG facilities relies on the acts of investigation into the causes of accidents. Calculations have shown that the action of the “Load Agreement Module” in the GRU excitation controller can provoke the occurrence of a voltage avalanche in the internal power system with a complete shutdown of the load. The paper presents recommendations on the choice of control algorithms and voltage settings for the GRU excitation controller. Technical solutions are given to prevent damage and excessive shutdowns of GRU in various operating conditions of the system, and to help ensure a reliable power supply to power consumers. The change in approaches to the design of DG facilities is substantiated in the light of their significant differences from other electric power facilities.

The current stage of development of autonomous energy systems is characterized by a rapid increase in renewable energy sources’ installed capacity. Such growth is observed both in centralized and isolated energy systems. Renewable energy sources show high efficiency in the electrification of rural remote settlements around the world. The power of such power complexes varies from several kilowatts to tens of megawatts. When solving the problems of rural remote settlements electrification, the main issues of optimizing the composition of equipment and the structure of the energy systems play an extremely important role. Moreover, depending on the specifications of the problem being solved, criteria for evaluating efficiency are used, which are different. For example, the following are used as objective functions: minimization of the levelized cost of energy and fossil fuel consumption; maximizing the standard of people living and reliability indicators; the payback period of the project and other indicators. Various combinations of objective functions and the solution to the multi-criteria optimization problem are possible. Moreover, an important stage in the development of renewable energy in remote rural areas is the availability of new mechanisms to support an environmentally friendly generation. These mechanisms can be used in solving problems of optimizing the structure and composition of energy equipment in remote power systems. The main purpose of this article is to demonstrate the world practices of optimal design of isolated energy systems. The review includes both the main questions that arise when solving such problems, and specific problems that require a more detailed analysis of the object of study.

The 25 kV traction network creates highly intensive electromagnetic fields. These fields affect the long conductive structures located near railway lines and can induce voltage, posing a danger for maintenance personnel. Typical examples of such structures are pipelines, which are used to transport liquid and gaseous products. In addition to compromising electrical safety, the induced voltage can result in dangerous densities of corrosion currents in pipe insulation defects. Therefore, the determination of the induced voltage and current in the pipes is undoubtedly relevant. An analysis of existing literature on the electromagnetic compatibility of traction networks and pipelines indicates that important aspects regarding the effects of traction networks and high-voltage power lines on extended conductive structures have been addressed. However, these works do not present a unified method to determine the induced voltage on parts of the structures and the current flowing through the pipeline. Such a method could be based on a technology that models the operation of electric power systems in phase coordinates. This paper presents the development of a method and the results of the studies aimed at modeling the voltage induced by complex traction networks. The developed digital models make it possible to adequately determine the induced voltage created by multi-wire traction networks and the current flowing through the pipes. Using these models, one can make an informed decision regarding the appropriate measure to ensure the safety of personnel working on these structures, as well as the development of corrosion prevention methods and measures.

Current microprocessor-based relay protection and automation (RPA) devices supported by IEC 61850 provide access to a large amount of information on the protected or controlled electric power facility in real time. The issue of using such information (Big Data) in order to improve the parameters of technical modification of intelligent electronic devices at digital substations remains unaddressed. Prerequisites arise for designing modern power systems with relay protection devices of a new generation based on new information algorithms. In particular, it is expedient to develop multi-parameter protections using more than one information parameter: modules of current, voltage, derivatives thereof, phase angles, active and reactive resistances, etc. An information approach based on multiple modeling and statistical processing of modeling results is also promising. This article explores the issues of enhanced sensitivity of multi-parameter relay protection using long-range redundancy protection as an example. Transition to “generalized features” is proposed in order to simplify multi-parameter protection and reduction in the computational load on the RPA device. Out of a large number of analyzed indicators (currents, voltages, their derivatives, resistances, increments of currents, angles between current and voltage, etc.), we specify the most informative by using the method of “data compression”. The transition to generalized features simplifies the parameterization of settings, and the process of making a decision by the relay protection device is reduced to obtaining a generalized feature and comparing it with a dimensionless setting in relative terms. For the formation of generalized information features, two mathematical methods are studied: the method of principal components and Fisher’s linear discriminant.

The development of AC distribution systems provides for the seamless integration of low-voltage microgrids with distributed energy resources (DERs). This poses new challenges for the control of normal, emergency, and post-emergency states of microgrids, calling for the creation and development of information and communications technology infrastructure. Power converters/inverters that are used to integrate renewable DERs lack inertia. Along with them, fossil fuel-fired generation units are also being integrated into microgrids. These include gas generator sets, diesel generator sets, and microturbines, having small (up to 1–2 s) values of mechanical inertia constants—Tj. This leads to an increase in the rate of transients by a factor of 5–10. Under these conditions, the technical requirements for the speed of automatic power flow control systems, as well as the methods they rely on, have to be reconsidered. Microgrids include DC microgrids, AC microgrids, and hybrid (AC-DC) microgrids. In the case of hybrid microgrids, DERs are connected to the DC grid and are integrated into the AC grid through a common inverter. The complexity of the task of microgrid control is due to the need to choose properly the type and extent of control actions so as to prevent the emergence and development of accidents. The employed control methods must ensure the reliable power supply to consumers and the quality of power in microgrids, as well as the reliable operation of the external distribution systems into which they are integrated. The article gives an overview of control methods for low-voltage AC and AC-DC microgrids, which allow one to tackle effectively solve the tasks.

The identification of fault locations (FL) on overhead power lines (OHPLs) in the shortest possible time allows for a reduction in the time to shut down OHPLs in case of damage. This helps to improve the reliability of power systems. FL devices on OHPLs according to the emergency mode parameters (EMPs) are widely used, as they have a lower cost. However, they have a larger error than FL devices that record traveling wave processes. Most well-known algorithms for FL on OHPL by EMP assume a uniform distribution of resistivity along the OHPL. In real conditions, this is not the case. The application of these algorithms in FL devices on OHPLs with inhomogeneities leads to significant errors in calculating the distance to the fault location. The use of search algorithms for unconditional one-dimensional optimization is proposed to increase the speed of the implementation of iterative procedures in FL devices on OHPLs by EMPs. Recommendations have been developed for choosing optimization criteria, as well as options for implementing computational procedures. Using the example of a two-sided FL on OHPL, it is shown that the use of search algorithms can significantly (from tens to hundreds of times) reduce the number of steps of the computational iterative procedure. The implementation of search algorithms is possible in the software of typical relay protection and automation terminals, without upgrading their hardware.

One of the main tasks of the circular economy is the decoupling between economic growth and natural resource consumption at the input and the volume of generated waste at the output. The effectiveness of this process can be assessed by the dynamics of the eco-intensity indicators at the macro-, meso- and micro-levels. The article presents the assessment results of the decoupling and growth color of the mining sector in Russia, which show the dynamics of eco-intensity indicators and may reflect the trend towards a circular economy. For the period 2010–2021, it was revealed that negative expansion decoupling and “Black” growth have been observed in terms of generated waste and atmospheric pollution, strong decoupling and “Green” growth in terms of hydrosphere pollution, weak decoupling and “Brown” growth in terms of electricity consumption, and according to water intake from natural water bodies, expansion coupling and “Black” growth. During the study period, the gross value added (GVA) of the mining industry in Russia in comparable prices increased by 77%, while the industry’s negative impact on the atmosphere increased by 34%; the volume of production and consumption waste generation increased by 131%, and the negative impact on the hydrosphere decreased by 51%. The growth of the environmental and economic efficiency of any system can be achieved by influencing the drivers and barriers to moving towards a circular economy, so it is important to identify the most significant factors of influence for a particular industry, region or country in the current conditions. Using the ordinary least squares (OLS) method, it was revealed that factors reflecting innovative activities of the mining industry have a significant impact on reducing eco-intensity in the field of electricity consumption and water intake from natural water bodies. The significance of these factors’ influence has been confirmed not only at the macro-level, but also at the micro-level.

Wax deposition is one of the most common complications in oil production. The most promising method of preventing wax depositing is dosing of wax inhibitors. Based on the results of studies at the Cold Finger installation, it was found that dosing an inhibitor at a temperature below wax appearance temperature reduces the efficiency of the inhibitors. Based on large scale, numerical simulation was found that dosing by “drop” injection through the impulse tube leads to the accumulation of the inhibitor in the near-wall zone and low distribution over the cross section of the tubing. When dosing with a nozzle, the degree of distribution of the inhibitor increases and reaches the highest value at a nozzle diameter of 0.5 mm and a length 1.5 cm. The influence of flow rate on the degree of inhibitor distribution was also evaluated. It was found that with an increase in the flow rate to 45 m3/day, the distribution of inhibitor improves and reaches the highest value, after which it does not change. The results of the work performed will make it possible to scientifically substantiate the choice of the inhibitor dosing site in order to achieve the greatest efficiency and reduce the cost of servicing oil wells.

A great number of factors determining the development of photovoltaics are associated with the assessment of possible volumes of solar energy use in correlation with the technical and economic characteristics of photovoltaic equipment. An appropriate assessment of solar energy potential that applies universally to any subsequent use option still remains a crucial task. This work is devoted to the assessment and analysis of the gross, technical and economic potentials of solar energy for photovoltaics. The smart analysis includes the basic program working in the context of connection to databases and to the programs used for determining required initial data or, as a limited option, in the context of full or partial initial data input by the user. Therefore, optimally, a smart network is formed, which for the purposes of obtaining the values of potentials, uses the most up-to-date values of initial data and other required information. This work sets out the tried and tested assessment program for the potentials of solar energy available in large and medium areas. The proposed approach to the analysis of solar energy potential in a region makes it possible to secure a high degree of assessment reliability which can be used for more detailed calculations, including the potentials analysis for a specific point on the ground or a specific type of PV system.

Most of the operating oil fields are in the late stages of development, in which special attention is paid to the oil production energy efficiency. In accordance with the trend toward the digitalization of technical processes, intelligent control stations for production wells are currently being developed, one of the main tasks of which is to maintain the equipment operation in an optimal mode. This work aims to develop a methodology for selecting an energy-efficient well operation mode by choosing the methods for controlling an electrical submersible pump. To solve this problem, a mathematical apparatus for calculating power consumption is presented, which considers the well pressure curve, while taking into account its degradation when pumping reservoir fluids, the fluids’ properties, the supply of demulsifier, and the equipment’s operating parameters. Based on the simulation results, it is revealed that the optimal method for controlling electrical submersible pump installations is a combination of frequency control and choke control. The reduction in specific power consumption with the combined control relative to the use of separate control types is up to 7.30%, and in the case of additional use of a demulsifier, it is up to 12.01%. The developed algorithms can be implemented based on programmable logic controllers of intelligent control stations.

This paper analyzes the key defining features of modern electric power distribution networks of industrial enterprises. It is shown that the requirements set by industrial enterprises with respect to power quality parameters (PQPs) at the points of their connection to external distribution networks of utilities have been becoming increasingly strict in recent years. This is justified by the high sensitivity of critical electrical loads and distributed generation facilities to distortions of currents and voltages from a pure sine wave. Significant deviations of PQPs lead to significant damage at the consumer end due to the shutdown of electrical equipment by electrical and process protections as a result of overheating and increased wear and tear of individual elements of process lines. This necessitates the implementation of continuous monitoring systems at industrial enterprises, or sampling-based monitoring of PQPs at the boundary bus with an external distribution network. When arranging sampling-based monitoring of PQPs at certain time intervals, only those parameters that are critical for specific electrical loads should be calculated. We provide a rationale for the transition from the monitoring of a set of individual PQPs to a generalized PQP with the arrangement of simultaneous monitoring of several parameters. The joint use of the results of simulation and data from PQP monitoring systems for PQP analysis using the sampling-based procedure produces the desired effect. We present an example of a sequential decision-making process in the analysis of a generalized PQP based on Wald’s sequential analysis procedure. This technique makes it possible to adapt the PQP monitoring procedure to the features of a specific power distribution network of an industrial enterprise. We present the structural diagram of the device developed by the authors, which implements the sampling-based monitoring procedure of the generalized PQP. We put forward an approach for determining the average number of sampling data points required to make a decision about the power quality in the implementation of the sequential analysis procedure.

A model of multi-stage formation of Visean oil deposits in Solikamsk depression in condition of stabilization of ancient oil-water contacts is provided. When reservoir rocks stay in condition of oil-water zones for extended periods of time, oxidizing processes actively develop, as result of which oil saturated reservoirs undergo non-reversible changes in rock wettability. After inflow of new portions of hydrocarbons and formation of modern oil-water contact residual products of oil oxidation are formed as solid bitumen. Cases of absence of reservoir bitumenosity in ranges of ancient oil-water contacts are explained by active fluid exchange in reservoirs. It is established that high specific resistance values in terrigenous reservoirs of Visean deposits in Solikamsk depression, exceeding 600 Ohm*m, are related to their hydrophobization in conditions of ancient oil-water contacts. Electrical laterlog results are compared with evaluation of rock wettability based on X-ray core tomography and microscopic analysis of thin sections. For Visean high-ohmic reservoirs of Shershnevskoe deposit statistically significant excess of rock porosity comparing to standard geophysical section is established. For ranges with resistivity < 120 Ohm*m porosity distribution maximum is observed within 12–16 %. In high-ohmic section for resistivity from 200 to 600 Ohm*m maximal porosity frequency is observed within 16–18 %; for resistivity > 600 Ohm*m – at porosity over 18 %. In average, excess porosity in high-ohmic section is over 3 %, which is probably due to predominance of reservoir deconsolidation (dissolution) processes over their cementation at levels of ancient oil-water contacts. For Visean operational objects of Shershnevskoe deposit geological model is built on basis of resistivity data, separating zones (volumes) of different wettability type reservoir development. In general, the established zones of development of hydrophilic and hydrophobic reservoirs are of regular spatial arrangement. Geological models built with regard to rock wettability may be used to optimize reservoir management technologies at oil operational objects.

The modeling of battery energy storage systems (BESS) remains poorly researched, especially in the case of taking into account the power loss due to degradation that occurs during operation in the power system with a large penetration of generation from renewables and stochastic load from electric vehicles (EV). Meanwhile, the lifetime varies considerably from the manufacturer’s claim due to different operating conditions, and also depends on the level of renewable energy sources (RES) penetration, cyclic operation, temperature, discharge/charge rate, and depth of discharge. Choosing a simplistic approach to the degradation model can lead to unreliable conclusions in choosing the best management strategy and significant investment and operating costs. Most existing BESS models in stationary applications either assume zero degradation costs for storage or simplify battery life to a linear function of depth of discharge (DOD), which can lead to additional error in estimating the cost of BESS degradation. The complexity of constructing a lifetime model of BESS is due to the presence of nonlinear degradation of BESS at the beginning and at the end of the lifetime, as well as the difficulty in obtaining a large amount of experimental data that are close to the real-world operating conditions for the construction of most models. This article analyzes the features of BESS that are specific to their operation in microgrids in terms of the influence of the main stress factors on the degree of BESS degradation. This study also provides a review of existing models for assessing battery degradation.

An algorithm for constructing a dynamic analysis during the formation of a wave field of stand for testing turbines and the effect of the frequency interaction of the stand’s elements on the measurement of its magnitude is described. The research algorithm involves the use of theoretical solutions of nonlinear wave processes using linear oscillations, refined by experiments. The diagnostic model can determine the technical condition of the stand’s elements and also determine the causes of the discrepancies between the calculated and measured turbine power values. To clarify the stiffness coefficients between the stand’s elements, a modal analysis was used to obtain the range of their changes depending on the external dynamic load, which made it possible to assess the impact of changes in the frequency interaction conditions on the turbine power measurement at different test modes. The conditions for amplifying the amplitude of oscillations at their eigenfrequencies are obtained, and the value of the possible deviation of the expected power value at its measurement for specific modes of the turbine is calculated. The algorithm allows to estimate the dynamic state of the stand-in different research modes of turbines and give recommendations for reducing the level of frequency interaction.

Mechanisms of formation of deposition of asphaltenes, resins and paraffins (DARP) are considered. Molecular diffusion based on the influence of the temperature gradient is the main mechanism for DARP formation. The analysis of existing methods against DARP is given. Modern methods of DARP prevention that affect the temperature gradient are aimed at maintaining the oil temperature above the crystallization temperature of paraffin. The cold flow method is an alternative control method which involves cooling the oil to a surrounding temperature. The purpose of the work is to assess the effectiveness of the cold flow method against DARP; its advantages and disadvantages are revealed. In order to assess the effectiveness of the proposed method. The sample of oil and produced water was taken at the pumping station. Using gas chromatography, the fractional composition of an oil sample was determined using the SimDis method. Using a calibration table, a component composition of oil up to C52 was calculated using values of boiling point and equations of fluid state were formed in PVTsim software. Rheological studies of the transported oil are carried out. Based on results of laboratory studies in OLGA software package, a hydraulic calculation of the pipeline was performed for various values of the flow temperature using the “Wax deposition” paraffin deposition module on the Matzain model. Thus, having the flow with temperature equal to the ambient temperature, in 10 days 5.6 kg of paraffin is formed on pipeline walls, whereas in the current conditions it is 100 kg. As a result, it is established that the effectiveness of the application of the cold flow method against DARP is 94 %. Proposed method can significantly reduce production costs associated with paraffin oil transportation.

In recent years, pharmaceutical production has been stimulating the gradual miniaturization of continuous-flow chemical reactors. This process eventually resulted in the emergence of a new generation of microreactors. The advantages of these new reactor types are the flexible production that allows us to quickly reconfigure the scheme, small reactant quantities used for the synthesis, the control of the main reaction parameters with high accuracy. Nevertheless, a decrease in the thickness of the channels where the species contact and react forces us to search for new non-mechanical mechanisms for mixing. This problem is relevant for the slow reaction occurring in a slot where diffusion alone cannot provide mixing at reasonable distances from the entrance. It is also true for the fast reaction that takes place in a frontal manner. In this work, we consider the efficiency of mixing the reactants induced by electro-osmotic flow in a Hele-Shaw configuration with non-uniform zeta potential distribution. As a test reaction, we take the neutralization reaction with simple albeit non-linear kinetics. The reaction occurs between two miscible solutions, which are initially separated in space and come into contact in a continuous-flow microreactor. The reaction proceeds frontally, which prevents the efficient mixing of the reactants due to diffusion. Using direct numerical simulations of 2D and 3D flows, we demonstrate that the zeta potential applied to boundaries can effectively control the mixing rate of fluids by lengthening the front of the reaction. This approach makes it possible to increase the yield of the reaction product.

The paper presents the results of integrating distributed generation (DG) facilities in the distribution grids and internal grids of industrial enterprises. It proves such locations require many more additional relay protection and automation devices, including emergency controls; the cost of such systems is on par with that of a DG facility. The paper presents the prerequisites for equipping DG-enabled power districts with routine and emergency controls (REC). It substantiates the use of phasor measurement units as REC sensors in low- and medium-voltage grids. Presented herein are the fundamental principles behind, and functionality of, REC. The paper proves feasible using offline-computed parameters to implement a REC system for further transition to online software-based computing of steady states and transients.