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Abstract: This article presents the design of a TVF-165V-2UZ turbine generator with a forced hydrogen cooling system (i.e., indirect cooling of the stator winding and direct cooling of the rotor winding using hydrogen) and a rated power of 165 MW. The primary features of the design, technical parameters, overall and mounting dimensions, power diagram, and the thermal test results of the turbine generator are presented. TVF-165V-2UZ is designed for broad applications in the implementation of projects for the modernization and replacement of overaged generators, such as TV2-150-2, TVV-160-2, and TVV-165-2, and in the construction of new power units of thermal power plants. PubDate: 2023-11-25
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Abstract: The article outlines main stages in the development of a low emission combustor (LEC) for a GTE-110M gas turbine and the results obtained in the single-burner compartment on a test bench of full parameters. A list of necessary works for preparing tests of flame tubes on a test bench as part of a gas turbine is presented. Potential risks include the following: overheating in individual sections of the metal walls of the flame tubes, excess pressure losses on the fuel lines, deviation from the given diagram of the temperature field at the turbine inlet, lack of ignition of individual flame tubes, occurrence of pressure fluctuations with high amplitudes, etc. The ways to eliminate the risks are suggested. Crucial imported components that require replacement with domestic counterparts are considered. PubDate: 2023-11-25
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Abstract: In this study, the reverse plumb lines of the Chirkey hydropower plant dam were analyzed in association with seasonal changes in atmospheric temperature and water level in the reservoir during 2010 – 2014. The WinABD software package was used, which is designed to study time series obtained as a result of continuous long-term observations and provides a full cycle of statistical analysis of series that comprise failures, errors, and omissions. A significant relationship was established with seasonal changes in atmospheric temperature and water level in the reservoir. PubDate: 2023-11-25
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Abstract: A specific example demonstrates the aspects of transient processes in hydropower plants with double-regulated turbines. To prevent malfunctioning of the unit blocks of hydropower plants, such as unit throwing up, recommendations are provided on the choice of modes of movement of the regulating unit to reduce the negative axial forces acting on the turbine impeller. PubDate: 2023-11-25
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Abstract: This paper presents the findings of a survey of the temperature regimes of enclosing structures at a high-voltage wastewater pumping station in Moscow. The study reviewed the factors that influence the temperature and humidity modes of the building envelope walls in the underground part. Contemporary research on the modeling of various physical characteristics of hydraulic structures is also presented. The present research will benefit designers, maintenance organization engineers, graduate students, and students studying hydraulic engineering, water supply, and wastewater disposal. PubDate: 2023-11-25
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Abstract: This study describes the current state of research in the field of protection of concrete and reinforced concrete structures from biological damage in an aggressive environment. The primary principles and methodological approaches to solving this problem are proposed, taking into account the world experience. The requirements for protective compositions (biocides) that can be recommended for use in hydraulic structures (HSs), taking into account their environmental safety, are discussed. The most important characteristics for biocides that are considered promising for use in HSs include a wide range of action (suppression of various decomposers), a penetrating effect, duration of biocidal action, and low toxicity to humans and environmental objects. Furthermore, particular attention is paid toward suppressing the growth of microbial biofilms, which cover large areas of concrete constructions at HSs.We discuss the main stages of work on selection of protective compositions, their testing under laboratory and field conditions, and their subsequent application to HSs. PubDate: 2023-11-25
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Abstract: The objective of this study was to upgrade the form of the flow part of the injection regulator to increase the percentage of circulating flow, representing a surplus water supply. The optimization was based on the recommendations adopted in the theory of injection pumps related to the shape and area of the nozzle located in the outlet section of the tubular part; length and diameter of the mixing chamber; and presence or absence of a diffuser outlet section. The operation of two models of injection regulators was successively studied using a mirror hydraulic flume. The models had the same water outlet pipes, but different forms of the outlet sections. The experimental data confirmed the validity of the previously obtained theoretical dependences, as well as the possibility of using regulators with nozzles without diffusers, and the significance of the nozzle and mixing chamber design in terms of increasing the injected flow rate. PubDate: 2023-11-25
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Abstract: The primary focus of this work is to study the stability of slope rubblework on exposure to flat ice. The stability of stone slopes can be calculated using the standard method and numerical calculation. However, numerical calculation can give more accurate results compared to standard method, and can be the only possible method for analyzing slopes with nonconventional geometry or if the standard method is not applicable for certain conditions. The calculation of the dynamic interaction of flat ice on a slope can be complex and require additional computational resources. In this study, the authors proposed a static approach to the numerical estimation of initial moment of rock slope destruction. The theoretically calculated values of the frictional forces between the stone and the foundation soil were compared with those obtained using the finite element method. The solutions obtained suggest that the proposed method can be used to determine the dimensions of the rockfill elements, the static setting method. PubDate: 2023-11-25
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Abstract: Currently, the absence of a carbon footprint of wind and solar power plants is mistakenly viewed as an axiom. The impact of wind power plants and solar power plants on the growth of greenhouse gas emissions as a result of decreasing fuel efficiency of thermal power plants is not taken into account. The article aims to assess carbon dioxide emissions attributed to the generation of electric energy by CCGT, GTU, CHPP, WPP, SPP, HPP without regulated runoff, and HPP with regulated runoff. Wind and solar power plants have the greatest impact on the growth of greenhouse gas emissions in the energy system. Specific carbon dioxide emissions from wind and solar power plants exceed those from TPP for both natural gas and coal. Automatic issuance of green certificates for WPP, SPP, and HPP with regulated runoff, without analyzing and taking into account their contribution to the growth of carbon dioxide emissions in the UES of Russia, contradicts the climate goals of the Russian Federation. PubDate: 2023-11-25
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Abstract: Experimental and theoretical studies of the free-surface curve in an open-channel flow with greater than critical bottom slope have been carried out. The experimental data were analyzed and compared with the results of approximate integration of the equation of non-uniform motion by the Bakhmetev, Charnomsky, and Pavlovsky methods. PubDate: 2023-11-25
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Abstract: The article presents a study into the effect of long-term thermal exposure on the structure and properties of the PKh13M2-BN composite material, designed for seal structures of a flow-through section of steam turbines. Data on the temperature-resource zones of its performance and microstructure, as well as physical and mechanical properties before and after thermal exposure, is provided. PubDate: 2023-11-25
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Abstract: The article presents a study into different connection schemes for salt ratio lines (SRL) to circulation loops and their influence on the hydraulic regime of salt and clean compartments. Connection of SRL to the circulation loops of boilers leads to a slight decrease in water levels of external cyclones and a slight change in the circulation of the panels they are connected to. According to analytical and experimental studies, this influence can be insignificant at proper design of external salt compartments with double-sided SRL. PubDate: 2023-11-25
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Abstract: Different connections of the windings of the single-phase autotransformer group and the booster transformer as the components of a phase-shifting unit are compared. It is shown that the phase-shifting unit can operate in four different modes. PubDate: 2023-11-24
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Abstract: This article involves a search for the features characteristic of each of the possible types of internal short circuits (SC) in a transformer, as well as for a specific nonemergency regime — a surge in the magnetizing current, which is difficult to distinguish from an internal short circuit. The information basis for identifying a short circuit consists of ongoing information in the form of observed currents and voltages, as well as a priori information on the transformer contained in its model. Completeness of the information base makes it possible to distinguish virtual components activated on shunted or broken inputs of the transformer model by a source of internal damage or a surge source of magnetizing current from observed quantities. A direct connection with damage or a surge helps to identify them. PubDate: 2023-11-24
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Abstract: In this work, we analyzed the operation of oil tank frame filters with baffle plates made of brass nets (GOST 6613–86). Monitoring results showed that when filtering water-cut oil, its strength and corrosion resistance were found to be insufficient, and they do not provide the required oil purity. An appropriate filter material was selected for the frame filters of the oil tanks in the turbine units. For the T-180-210 LMZ turbine unit, the frame filters for fine and coarse cleaning were modernized. For the T-200-130 LMZ turbine unit, the coarse frame filters were modernized. The upgradation of the frame filters brought about a significant improvement in the purity of the turbine oil. Using the method of express analysis of the industrial purity of oils and the water content in them, the diagnostics of the operation of the bearings in the T-200-130 LMZ and T-180-210 LMZ turbine units was performed. Solid contamination curves of the turbine oil were plotted. The source of the large number of mechanical particles in the working fluid in the T-200-130 LMZ turbine unit was found. Turbine oil flooding sources in the T-180-210 LMZ turbine unit were detected. A set of measures was established to improve the efficiency of turbine oil filtration, regular monitoring of cleanliness, and timely diagnostics of power equipment failures, in a bid to significantly increase the service life of turbine units. PubDate: 2023-11-24
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Abstract: This article investigates the reduction of noise levels due to the shielding properties of obstacles in the form of buildings and barriers in the territory of the thermal power plant (TPP) at the calculation point, located on the border of the sanitary protection zone. The study investigates the effect of the transverse and longitudinal arrangement of buildings in the TPP territory on the sound level at the calculation point from the real noise source of the TPP. Using calculations, the isolines of the noise level after positioning the obstacle at various locations. Owing to the high shielding properties, the transverse arrangement of the building can reduce the sound level at the calculation point by approximately 9 – 11 dBA compared to that of in the longitudinal arrangement. The mutual influence of obstacle height, length, and width of the obstacles on reducing the noise of power equipment is also discussed. It has been established that the building width has no significant effect on noise reduction for calculation points located at a distance of more than 450 m from the obstacle. The calculation results assist in determining the height and length of the obstacle to achieve the required reduction in sound level from the source. Furthermore, specific areas are determined when a change in the length and height of the obstacle does not result in a change in the acoustic efficiency. Finally, recommendations for the installation of power equipment are given to utilize the shielding effect of obstacles. PubDate: 2023-11-24
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Abstract: A methodology of using thermal indicators to monitor the condition of electrical contacts and connections of electrical equipment is proposed. The principles of assessing the thermal state of electrical contacts and connections in accordance with current regulatory requirements are considered. Based on the performed research and generalization of the experience of using thermal indicators, principles of selecting such indicators and a methodology of monitoring the condition of electrical contacts and connections with thermal indicators are developed. PubDate: 2023-11-24
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Abstract: On the basis of the National Research University “NRU MPEI,” within the framework of the project to create a current conductor with polymer-gas insulation for the transmission of electricity from offshore wind turbines, a study is being carried out to develop insulating structures for high-voltage current conductors. The purpose of this study is to develop and justify the design of a special undersea conductor with a combined insulation (polymer-gas) for transmitting electrical energy from wind turbines, where a polymer coating of the current-carrying elements is used to increase the electrical strength and reduce the dimensions of the current conductor, and a basic gas insulation is used to reduce energy losses. The paper presents technical solutions for producing linear and connecting sections of current conductors with polymer-gas insulation. The distribution of the electric field strength in the coaxial gap was analyzed, demonstrating the specifics of the design solutions for linear sections. According to the calculations performed by the authors, the use of gas insulation in special current conductors makes it possible to reduce the dielectric losses by at least 2 – 2.5 times. PubDate: 2023-11-24
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Abstract: This article reviews the general aspects of the prospects for the use of low-power nuclear plants (LPNP) as well as their scope of application and conditional classification in the context of ensuring fire safety. The potential fire hazards of low-power reactors were assessed because of their diversity and wide scope of applications, characteristics of layout solutions, various placement options, and operating conditions. An analysis of possible deviations from fire safety requirements and potential difficulties in the approval of documentation by supervisory and regulatory authorities was performed. The issues related to the insufficiency of fire safety requirements and the necessary substantiating materials are highlighted. Three main aspects of fire safety, namely, nuclear and radiation safety, human safety, and investment security, are considered. Herein, we have proposed the methods for confirming the compliance of LPNP with fire safety requirements, the main approaches to achieve the necessary levels of safety and efficiency and the use of innovative fire protection technologies. PubDate: 2023-11-24
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Abstract: This paper examines the compensation of capacitive currents using arc suppression reactors with magnetization. A method is developed for automatic tuning of an arc suppression reactor for improving the accuracy and reliability of the results of measurements of the capacitance of the zero sequence loop. These problems are solved by measuring and recording the frequency spectra of the neutral voltage using the fast Fourier transform before and after perturbation of the zero sequence loop by a reference current of short duration through a signal winding of the arc suppression reactor. After this, the difference in the obtained frequency spectra is isolated and the proper frequency of the zero sequence circuit is determined from the maximum amplitude corresponding to the frequency of the free oscillations. The found frequency for a known inductance of the arc suppression reactor is used to determine the capacitive impedance of the network and the required magnetization current. PubDate: 2023-11-24
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