The tasks of ensuring reliable and uninterrupted supply of electricity to consumers, industrial and environmental safety, the ability to monitor the state of energy equipment, to forecast and prevent emergencies, with the current situation in the energy sector taken into account, are becoming top priority areas for development of the industry’s production complex. Developments in the foreign policy and the global economic situation have signifi cantly changed the market conditions for manufacturers of power equipment, generating new challenges to Russia’s power engineering. Solving the problem of innovative development of the Russian power engineering industry has its specifi cs. First, the equipment used at the power industry facilities of the Russian Federation is mostly foreign-made, previously purchased and not requiring replacement in connection with expiration of its service life. Second, foreign-made equipment has improved technical and operational characteristics, is easy to use, can be maintained with a guaranteed supply of spare parts, and is provided with easily integrated complementary goods, such as software for industrial plant management, additional industrial safety systems, etc. Third, the manufacture and assembly of foreign equipment are localized mainly at places of the greatest demand, which gives an additional advantage to foreign producers for its delivery and subsequent maintenance. Fourth, the sale and support of foreign-made equipment are carried out by a well-organized dealer network. Fifth, one should note the high level of organization of technological processes for development, introduction and production of foreign equipment. It is based on these specifi c features that the structure of energy needs in high capacity gas turbines is formed, and the prospects for development of power engineering in this area are substantiated, the needs are shown, and the power rating values are substantiated for gas turbines for machine-building plants to place orders. The retrospective analysis of turbine construction in Russia enables to determine the prospects for its development. Successful development of turbine construction in Russia requires creating industrial and organizational infrastructure. Conclusions drawn as a result of analysis of the problem are of practical signifi cance and form an innovative way of development of heavy energy machine building.

The possibility is considered of applying a mathematically correct criterion of zero transition of the Jacobian of sets of equations in post-emergency conditions in problems of reliability of estimation of static stability of energy systems in case of emergency shutdowns of main power transmission lines. With a common classical method of successive loading in a certain direction used, the problem of generation of estimated cross-sections for estimating the static stability has no unambiguous solution, and accordingly has no unambiguous result. In this case, it may turn out that for diff erent cross-sectional setups, the same disturbances (disconnections of power transmission lines, or blackouts of the circuit nodes) may or may not cause a disruption of static stability of the energy system. In this case, the chosen loading path will have a signifi cant impact on the zone of uncertainty of results. Therefore, to increase the stability of the results of calculations of static stability of an energy system, other principles are suggested for determining its static stability, which are characterized by unambiguity of solutions obtained. The analysis performed has enabled to draw two important conclusions that change the current principles of managing static stability: - with an increase in the power fl ow over a certain heterogeneous cross-section, the limit of static stability of the power system occurs when the power transmission angle reaches 90° in the line with the highest relative reactance (the «weakest link» model); - when the limit of static stability of the system is reached by the criterion of changing the sign of the Jacobian, at least one transmission line with a maximum transmission angle is necessarily found in the network, which must be included in the most dangerous section, regardless of its structure. Therefore, instead of identifying and monitoring the «dangerous cross-sections», it is proposed to calculate and control the power flow through the transmission lines with the largest transmission angle.

 

After the collapse of the Soviet Union, independent states switched to market relations and faced a number of problems, which predetermined creation of integration unions that enable them to develop as a single organism. First, the former USSR republics merged into the Commonwealth of Independent States, and then the Republic of Belarus, the Republic of Kazakhstan and the Russian Federation merged into the Customs Union, which later became the Eurasian Economic Union, eventually joined by the Republic of Armenia and the Republic of Kyrgyzstan. On today's agenda of the Eurasian Economic Union is launching of the Common Electricity Market of the Eurasian Economic Union by July 1, 2019. Creation of the Common Electricity Market of the Eurasian Economic Union will certainly let the countries carry out cross-border electricity fl ows and ensure the balance of electricity production and consumption, improve the reliability of electricity supply, and maintain the stability and safety of energy facilities. The paper analyzes the electric power industry of the Republic of Belarus, presents the parameters of production and consumption of electric power, specifi c consumption of fuel equivalent, emissions of pollutants into the atmosphere, energy equipment failures, renewal factors, introduction and withdrawal of fi xed assets and innovative activity. The conclusion is made about the expediency of the republic's participation in the Common Electricity Market of the Eurasian Economic Union, with the positive and negative aspects of such integration for the Republic of Belarus revealed.

 

The research is performed of statistical data on power line failures (110 kV overhead lines) in the Lower Volga region for the period of operation from 2010 to 2016, inclusive, after commissioning in 1965. The identifi ed failures led to a loss of power and, consequently, to the need in repair of the power transmission line. The mathematical relationships of the estimation of reliability indicators are presented in the form of failure rates and the time between failures, both by the length of the transmission lines and by the time of operation. The novelty of this paper is that for the fi rst time in the Lower Volga region, studies have been carried out on reliability of high-voltage transmission lines with a voltage of 110 kV. Based on the results of the research, specifi c numerical values of failure rates and estimates of time between failures were obtained by the length of the transmission lines and by the time of operation. To establish the law of distribution of failures, an agreement criterion (chi-square) is given. It is found that the distribution of failures of power transmission lines (110 kV) obeys the exponential distribution with length parameters λп = 0.0011 (1/km), Tп = 1265 km, λв = 0.0049 (1/hr), Tв = 257 hrs. The resulting estimations of reliability parameters are recommended to use for creating state-of-art modern highvoltage transmission lines.

 

 

The main types of accidents in 6–10 kV power supply systems of mining enterprises are considered, such as short circuits, single-phase earth faults, phase failures, with their percentage relationships established. Mining enterprises are divided into three groups: open-cut mining enterprises (quarries and open coal pits); enterprises for extraction of minerals by underground method (underground coal and ore mines); mining & processing enterprises (concentrating factories, alumina plants, fertilizer production enterprises). The analysis of the accident rate of power supply systems of mining enterprises carried out for the period from 1995 to 2015 makes it possible to trace the dynamics of the above types of accidents and determine their most common form — single-phase earth fault. Over the above period, in the 6 – 10 kV power supply systems of quarries and open coal pits, underground coal and ore mines, and mining & processing enterprises, the share of single-phase earth faults was found to be within the following ranges: 65 – 76%; 60 – 69%; 58 – 67%, respectively. The greatest increase in accidents during the period under review was observed in 6 –10 kV power supply systems of quarries and open coal pits; with the total accident rate having risen with a factor of 3.21 from 1995 to 2015. The accident rate growth factor for underground coal and ore mines, and mining & processing enterprises amounted to 2.06 and 2.72, respectively. The changes are shown in specifi c types of accidents and general accident rate in the systems of electricity supply to quarries and open pits, underground coal and ore mines, and mining & processing enterprises. It is established that in the 6 – 10 kV power supply systems of the above-mentioned mining enterprises, the changes in single-phase earth faults and general accident rate are described by linear equations. On the basis of established patterns, a forecast is made of the change in the accident rates in power supply systems of the mining enterprises under consideration up to the years 2020 ÷ 2025.

 

The problem of massive damageability of low pressure rotors of cogeneration turbines of types T-175 and PT-135 is considered. The hypotheses of crack formation in low-temperature rotors of steam turbines under the action of bending and torsional oscillations are compared. Based on the analysis of a variety of factors, including those of structural and operational nature, it is shown that there are a number of prerequisites that make the second of the hypotheses considered somewhat more preferable. However, the eff ects of torsional oscillations can only be estimated on the basis of the results of experimental studies of dynamic stresses in rotors on real turbine generating units under operating conditions. This required the development and creation of a multichannel control and monitoring system for torsional oscillations of the shaft train of turbine units, its pilot-industrial version implemented on the T-175/210-130 turbine generator unit. Based on the calculations performed out and the analysis of the causes of both the intrinsic and forced torsional oscillations of the shaft train, the requirements were formulated that must be imposed to recording the parameters of torsional oscillations and, what is especially important, for algorithms and software for processing data and presenting the results. It is shown that in most of the published studies only intrinsic torsional oscillations of the shaft trains are given. Typical mistakes are analyzed, and it is shown that the forced oscillations which are multiples of the rotation frequency could not be obtained with the data processing algorithms used, and that conclusions based on such studies are untenable. Moreover, in most cases, using source data not subjected to necessary pre-adjustment prior to using the same in the Fourier transform may cause signifi cant distortion of the analysis results. The methods of measurement, preparation and processing of data suggested in the paper enable to record both intrinsic and forced torsional oscillations of shaft train. The results of studies are presented that have shown that forced torsional oscillations multiple to rotation speed are mostly implemented in the shaft train. Further ways of improving the created system are provided.

 

Fluorocarbon substances are most widely used as dielectric fl uids in technologies of microelectronics, fi re extinguishing agents, heat transfer fl uids and working substances of refrigeration and heat pumping equipment. The paper examines the prerequisites for using fl uorocarbon working fl uids (FWF) as a working fl uid (instead of water) in turbine cycles of converting thermal energy into electrical energy for newly developed advanced nuclear power plants (NPP). The results and methods of research of chemical and physical properties of FWF in the range of operating parameters of power plants (at temperatures up to 550ºS), as well as their radiation stability are analyzed. It is shown that using domestically manufactured mass spectrometers with adjustable ionization energy is a simple and effi cient method for analyzing the state of FWF. Information is provided on results published in available literature, as well as on results of the authors’ own research on thermal stability, thermal properties, processes and confi guration of the thermodynamic cycles for fl uoroorganic composition substances. It is established that, with such known advantages and benefi ts of FWF as non-toxicity, non-fl ammability, heat resistance, favorable thermodynamic properties, etc., some chemical elements (silicon and titanium) making part of structural materials at high temperatures can be "catalysts" of thermal decomposition. It is concluded that, based on the accumulated information, a database can be generated containing data required for designing FWF-based plants, and a number of technological and environmental advantages are achieved with their introduction in the thermal and power facilities of reactor plants with a liquid heat transfer metal.

 

The purpose of the paper is experimental evaluation of thermal characteristics in a heat insulating structure with a thin fi lm coating applied onto the same, such as conductive heat transmission capacity, radiation and convection, assessment of the extent of infl uence of each component on reducing heat fl ux density. Experimental studies have been held on determination of thermal conductivity factor, integral factor of emissivity and air permeability of the heat insulating structure. Investigation of thermal conductivity of the heat insulating structure with a thin fi lm coating has been carried out using the method of continuous heat fl ux passing through a sample of heat insulating structure under study. Investigation of thermal radiation of the heat insulating structure with a thin film coating consisted in determining the integral emissivity factor by the radiation method. The air permeability of the heat insulating structure with a thin fi lm coating has been determined by a method based on establishing the time of passage of a certain amount of air through the sample at a known air pressure. The results are presented of the infl uence produced by the thin fi lm coating in the design of thermal insulation of pipelines of heat networks on reducing heat losses through reducing heat fl ow density. It is found that the greatest eff ect on reducing heat fl ow density is produced by air permeability of the thermal insulation material after application of the thin fi lm coating to its surface, which generally enhances the effi ciency and reliability of thermal insulation structures of pipelines in heat supply systems.

 

An elementary arrangement is considered for heat supply of residential buildings with dependent connection to external heating systems, providing reliable heat delivery and required comfort indoors due to admixing of water from the heating system return line at an outdoor temperature exceeding the breakpoint temperature. Basic equations are analyzed describing dependence of the temperature of water in the trunk lines on the outside air temperature, and an overview is presented of possible ways to regulate heat delivery and prevent oversupply of heat near the beginning and the end of the heating season with consideration of requirements of the current Russian Federation regulations. Calculations are performed, which enable to determine the desired admixing ratio in conditions of application of an arrangement with buildings connected to a heating system involving use of mixing pump based on linearization of the equation of the temperature curve in the heating system in a close proximity to the breakpoint temperature. Analysis is given of results obtained, and conclusions are drawn regarding the feasibility of the arrangement under consideration. It is found that the value of the current dimensionless diff erence of temperatures of indoor and outdoor air at the breakpoint does not depend on climatic parameters of the construction area, and the required admixing ratio is almost directly proportional to the excess of outdoor temperature compared to the breakpoint temperature. It is shown that the higher the estimated water temperature in the return line of the heat network at the breakpoint is, the higher the value of the admixing ratio. Recommendations are given on sharing the elevator and the mixing pump in order to minimize variations at reconstruction of the heat entry to eliminate oversupply of heat.

 

The statements of developers and manufacturers of catalytic heat generators are analyzed regarding signifi cant advantages of these devices over boilers based on traditional fuel combustion methods: a signifi cant increase in the effi ciency of catalytic boilers, an increased ecological safety of these boilers due to a decrease in the temperature of combustion processes and reduced formation of thermal nitrogen oxides in combustion products, the possibility of signifi cant reduction in the dimensions of catalytic boilers owing to an increase in heat density of heating surfaces in the furnace, as well as increased reliability of catalytic heat generators. The aforesaid statements are demonstrated to be unsubstantiated and inconsistent with the fundamental laws of thermodynamics, physics and chemistry. The results of the experimental studies carried out by the authors of the catalytic boilers are presented. The claims of the creators of catalytic boilers to increase the effi ciency of heat generators due to an increase in the fuel calorifi c value at multi-stage catalytic combustion of fuel are considered. It is theoretically proved that it is impossible to increase the fuel calorifi c value at catalytic combustion, as this assumption of the developers of catalytic boilers contradicts Hess's law, the law of constancy of the sums of the calorifi c values, as well as the laws of Lavoisier and Laplace. The claim of V.N. Parmon on the possibility of increasing the effi ciency of a catalytic heat generator with a factor of 3 – 4, compared to conventional boilers, is shown to be untenable. It is noted that, based on the thermal balance of the boiler, the latter’s thermal effi ciency is not determined by the heat generation method, but, fi rst and foremost, by the extent of cooldown of fuel combustion products. An insuperable theoretical contradiction is shown of the claims of the creators of catalytic boilers on the possibility of low-temperature catalytic combustion of fuel concurrently with an increase in the heat density of the furnace and reduction in the dimensions of the boiler. It is noted that, according to the Stefan-Boltzmann law, the intensity of radiant heat exchange in the furnace is proportional to the absolute temperature of the combustion products to the fourth power. Therefore, in order to provide the necessary intensity of heat exchange in catalytic heat generators, the temperature of the combustion products must be at least as high as that in traditional boilers, and in boilers with an increased heat density of the furnace, even higher. Hence, it follows that the possibility of increasing the ecological safety of these boilers by reducing generation of thermal nitrogen oxides, as declared by the authors and manufacturers of catalytic boilers, is neither theoretically substantiated, nor practically supported. The causes of low reliability of catalytic heat generators are considered. An example is cited of operation of catalytic heat generators in the city of Ulyanovsk, which showed their extremely low reliability. The conclusion is made that it is inexpedient to apply the existing designs of catalytic boilers in domestic heat power engineering.

 

In European countries, the expander technology has found application at some facilities. It consists in producing electricity and/or cold using the so-called expander-generator units (EGU). These units are designed to use natural gas (NG) overpressure fed to the facility. For example, in Germany, a number of such smaller plants are in operation, each having the capacity of an order of hundreds of kilowatts. What makes such plants advantageous for their owners is that, these can obtain allowances established by the German law in addition to the cost of electricity produced in the EGU released to consumers. In Russia, an interest in such units arose after Mosenergo built a power-generating complex made up of two 5 MW EGUs at CHPP-21 in 1994. In the years following its commissioning, diff erent authors held studies (mostly, of theoretical nature) of the eff ects of EGU on the technical and economic parameters of facilities, where they can be installed, including thermal power plants and CHP plants, boiler rooms, gas supply systems, as standalone facilities and in combination with heat pumps, air compressors, turbines, etc. The results were published in a large number of articles and defended in theses. Still, of the greatest interest for the power industry is the generalization of the results of research and the record of operation of EGU at CHPP-21 of Mosenergo, where the prototypes of this equipment were installed. To this eff ect, the authors of this paper undertake to present an overview of publications prepared by diff erent researchers over the years and published in a variety of power engineering journals. The generalization of the test results and operating record indicates the absence of an eff ect of introduction of EGU in the heat circuit of the CHPP on the latter’s thermal effi ciency and proves the futility of using EGU in the Russian energy sector, as evidenced by the fact that Mosenergo eventually rejected further use of EGU in its system.