Global Energy

MIS RUS 7-15 ZHANG Xinbo LI Feng LITHIUM-AIR BATTERIES . LITHIUM-AIR BATTERIES https://engtech.spbstu.ru/article/2023.126.1/ Sinbo-CHzhan%2C-Fen-Li.pdf

RAR RUS 24-36 Zakharyan Ekaterina Belyaev Andrey andrey.belyaev@gmail.com IMPROVING RELIABILITY OF ELECTRIC POWER SYSTEMS BY WAMS DATA CONTROLLED TURBINES AND ENERGY STORAGES The paper is devoted to studying the possibilities of using Wide Area Measurement Systems (WAMS) data in the control of electric power systems to increase transient and small-signal stability. The authors present a developed North-West – Center – Belarus intertie model with corresponding system connections. It is confirmed that intertie has rather low indices of small-signal oscillatory and transient stability. To improve reliability of the power system, traditional frequency control is supplemented by feedbacks of phasor difference and its second derivative measured in different parts of interconnection. Its operation was tested at several large power plants during short circuits at various points of the system. It is shown that transient stability increases by more than four times, and in addition, small-signal oscillatory stability grows by more than three times. In a number of cases turbine control is replaced by action of battery energy storage systems (BESS) operating in post-emergency situations. Various options for its control are considered. It is shown that transient stability of the intertie with exponential controlled BESS increases up to six times. 10.18721/JEST.29401 621.313.322 wide area measurement system steady-state stability phasor measurement unit automatic generator control transient stability synchronous generator battery energy storage system https://engtech.spbstu.ru/article/2023.126.2/ Zaharyan%2C-Belyaev.pdf

RAR RUS 37-49 Kobilskiy Roman Busarov Sergei S. EXPERIMENTAL TECHNIQUE FOR DETERMINING THE EQUIVALENT GAP FOR A CYLINDER PISTON SEAL OF A SLOW-MOVING LONG-STROKE STAGE IN A DYNAMIC FORMULATION The paper considers the basics defining the terms of conditional and equivalent clearance in a cylinder piston seal, gives their distinctive description and importance in the calculation of mass flows. We highlighted the absence of recommendations regarding the parameters of the equivalent gap for low-speed compressor stages. An experimental technique and an experimental stand for determining the parameters of the equivalent gap were developed. The conducted studies showed that the value of the equivalent gap had a strong dependence on the cycle time and varied from 0.5 to 1.5 microns depending on the parameters of the working gas and the number of seals installed on the piston. We determined that in the pressure range from 0.1 to 12 MPa with a cycle time from 2 to 4 s, it is not advisable to install more than 7 cuff seals, since the change in the equivalent gap value is insignificant. 10.18721/JEST.29402 621.512 piston compressor conditional clearance equivalent clearance mass flow mathematical modeling https://engtech.spbstu.ru/article/2023.126.3/ Kobilskiy%2C-Busarov.pdf

RAR RUS 50-71 Sysoev Artem Iudin Dmitry Rakov Vladimir Emelyanov Aleksey Klimashov Vitaly B-7916-2013 6601971248 0000-0002-1173-8727 Peter the Great St. Petersburg Polytechnic University, Russia Korovkin Nikolay nikolay.korovkin@gmail.com

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

NUMERICAL SIMULATION OF HIGH-CURRENT ATMOSPHERIC DISCHARGES WITH CONSIDERATION OF PLASMA CHANNEL THERMODYNAMICS. PART 1. MODEL DESCRIPTION The paper presents a new approach to modeling high-current lightning discharges in the Earth's atmosphere, which include compact intracloud discharges and initial breakdown pulses. The model has high spatiotemporal resolution and takes into account the asymmetry between threshold propagation fields of positive and negative streamers, evolution of discharge channels parameters, and the possibility of their simultaneous growth and decay in different parts of discharge tree. The key feature of the model is consideration of discharge channel thermodynamics. This makes it possible to relate the conductivity and radius of the current-carrying part of a hot leader channel to its temperature, which is necessary for reproduction of the currents characteristic of high-current lightning discharges with amplitudes of tens of thousands of amperes. The work is presented in two parts. This article is the first part, which describes modern ideas about high-current lightning discharges and presents a numerical model that is able to reproduce their evolution. Simulation results and their detailed analysis, which allows us to formulate a new development scenario for compact intracloud discharges and initial breakdown pulses, will be presented in the second part of the study. 10.18721/JEST.29403 537+519.6 compact intracloud discharge initial breakdown pulses streamers leaders hierarchical networks of plasma channels discharge channel thermodynamics numerical simulation https://engtech.spbstu.ru/article/2023.126.4/ Sisoev%2C-Iudin%2C-Rakov.pdf

RAR RUS 72-82 Voevodenko Daniil Starikov Kirill Popovich Anatoliy popovicha@mail.ru RESEARCH OF THE MICROSTRUCTURE OF COMPACT SAMPLES FROM ECONOMICAL HEAT-RESISTANT NICKEL ALLOY OBTAINED BY DIRECTED CRYSTALLIZATION IN THE PROCESS OF SELECTIVE LASER MELTING Nickel-based alloys have found widespread use as heat-resistant alloys in the manufacture of gas turbine engines, mainly in the form of working blades and nozzles and, to a lesser extent, as turbine disks and rings. Their development is associated with an increase in the volumetric content of the γ′-phase, which leads to an increase in heat resistance due to the introduction of new alloying elements, such as, for example, rhenium (Re) and ruthenium (Ru). It is known that these alloying elements significantly influence the increase in the cost of the final product; for this reason, the development of economical alloys primarily without Re and Ru is currently relevant. In addition, research is relevant in the field of manufacturing parts using additive manufacturing (AM), which has its own advantages. This paper examines the possibility of producing compact samples with a directional structure by economical alloying using selective laser melting (SLM). Samples were studied and the relationship of alloying elements with the isolation of TCP phases, carbides and the percentage of mismatch between the lattice periods of the γ- and γ′-phases (misfit) with strength characteristics was established and analyzed. During the study, we obtained economically alloyed samples with more misfit than in second-generation rhenium alloys and determined the directions for further work. 10.18721/JEST.29404 621.762 heat-resistant nickel alloys selective laser melting directional structures misfit γ′-phase https://engtech.spbstu.ru/article/2023.126.5/ Voevodenko%2C-Starikov%2C-Popovich.pdf

RAR RUS 83-96 Abdrakhmanova Anna Sotov Anton Zaytsev Alexander Popovich Anatoliy popovicha@mail.ru REVIEW OF ADDITIVE MANUFACTURING IN MEDICAL APPLICATIONS: PROSPECTS FOR FUNCTIONALLY GRADED POLYMERS FOR LOWER LIMB PROSTHETICS Functional gradient polymers are advanced materials for use in the medical field in the fabrication of customised lower limb prostheses with variable stiffness. The production of such prostheses is possible due to additive manufacturing technologies, which are an effective tool for creating personalised medical devices that take into account the complex anatomical features of human body parts. This review presents an analysis of the currently existing approaches in the fabrication of personalised lower limb prostheses with variable stiffness using additive manufacturing technologies. The analysed works were classified into two approaches for creating prostheses with variable stiffness, namely, using functionally graded polymers (multi-material materials and polymers with controlled porosity) and polymers with shape memory effect. The review shows that today, the creation of customised lower limb prostheses with variable stiffness by additive manufacturing methods is a poorly-studied but promising area of research due to the rapid development of the additive technologies market and their unique features in shaping parts. 10.18721/JEST.29405 621.763 additive manufacturing functionally graded polymers shape memory effect variable stiffness socket liner lower limb prostheses https://engtech.spbstu.ru/article/2023.126.6/ Abdrahmanova%2C-Sotov%2C-Zaytsev%2C-Popovich.pdf

RAR RUS 97-106 Nguyen Van V. Balanovskiy Andrey Astafieva Natalia MICROSTRUCTURE AND PROPERTIES OF STEEL AFTER PLASMA ALLOYING WITH BORON Currently, one of the effective ways to increase the wear resistance of machine elements used in the mining industry, mineral extraction, manufacturing industry, and agriculture is plasma alloying. The work studies samples after plasma alloying with boron with various current parameters of 120A, 140A and 160A on steel 20. Microstructure studies, microhardness measurements, determination of the chemical composition and analysis of the phase composition of the alloyed layers were carried out. Based on the research results, it was noted that it is possible to obtain alloyed boride layers on steel using the plasma alloying method. It has been established that the surface of steel after alloying has different zones: hypereutectic, eutectic and hypoeutectic. The alloyed layer with a current of 120A has the highest microhardness value of 1265 HV. In the alloyed layer, the precipitation of boron cementite was observed around primary iron borides oriented perpendicular to the plane of the section. In addition, an increase in the plasma arc current leads to a decrease in the proportion of primary borides in the surface layer after alloying, and thus, to a decrease in microhardness. 10.18721/JEST.29406 691.735: 669.017.15: 620.183 plasma alloying boron carbide microhardness boride layers boron cementite https://engtech.spbstu.ru/article/2023.126.7/ (1)-Nguen%2C-Balanovskiy%2C-Astafeva.pdf

RAR RUS 107-119 Sokolov Ivan Dasaev Marat Ryzhenkov Artem Grigoryev Sergey Romanov Ivan Ataullin Marat RESEARCH OF APPLICATION OF CR-BASED PVD COATING FOR PROTECTION AGAINST HYDROGEN EMBRITTLEMENT OF STEELS Currently, there is an active development and improvement of technologies for the use of hydrogen as an energy resource. However, active implementation of such technologies faces both technological and economic difficulties. Embrittlement and subsequent destruction of structural materials, which occurs in interaction with hydrogen-containing media, leads to the need for expensive materials and increased reliability requirements, the consequence of which is a decrease in the economic efficiency of projects. In this paper, the effectiveness of chromium (Cr) based PVD coating for protection against hydrogen embrittlement of St20 carbon steel was investigated. The samples underwent experimental tensile testing. The results revealed a 3-fold decrease in embrittlement of experimental samples with 2 µm thick PVD-coating compared to witness samples. In addition, images of the structure of the experimental samples were obtained using an electron scanning microscope. 10.18721/JEST.29407 620.1 hydrogen embrittlement steels PVD technology barrier coatings mechanical testing https://engtech.spbstu.ru/article/2023.126.8/ Sokolov%2C-Dasaev%2C-Rizhenkov.pdf

RAR RUS 120-131 Nguyen Van V. Balanovskiy Andrey Astafieva Natalia STRUCTURE AND WEAR RESISTANCE OF BORIDE LAYERS OBTAINED BY SURFACE PLASMA ALLOYING METHOD Most failures of machine parts occur due to degradation processes such as fatigue, corrosion and wear occurring on the surface of the materials. Currently, there are various methods to modify the surface layer. For modification, concentrated heating sources, technological lasers, plasma and electron beam installations are used. In this work, plasma alloying of the surface of low-carbon steel was carried out. It has been established that borated layers on steel 20 can be obtained by plasma alloying. An increase in boron content in the melting zone makes it possible to move from a hypoeutectic microstructure to a hypereutectic one, consisting of primary Fe2B borides and a small amount of eutectic ferrite-Fe2B. The highest level of microhardness is characteristic of the boride alloyed layer obtained by alloying using a powder mixture of 40% B + 10% Fe, and amounts to 1000...1300 HV. Compared to samples obtained using carburizing technology, we recorded an approximately threefold increase in the resistance of the alloy. 10.18721/JEST.29408 691.735: 669.017.15: 620.183 surface alloying alloyed coatings boride layers wear resistance https://engtech.spbstu.ru/article/2023.126.9/ (2)-Nguen%2C-Balanovskiy%2C-Astafeva.pdf

REV RUS 132-148 Mednikov Alexey Medvedev Konstantin Kachalin Gennadiy Tkhabisimov Alexander Kachalina Elena MODERN METHODS OF FORMING THERMAL BARRIER COATINGS: A REVIEW The present article considers modern methods of forming thermal barrier coatings designed to extend the service life of elements of gas turbine installations and engines exposed to combustion products. The characteristics, advantages and disadvantages of atmospheric plasma spraying (APS), electron beam physical vapor deposition (EB-PVD), suspension plasma spraying (SPS) and solution precursor plasma spraying (SPPS), chemical vapor deposition (CVD), magnetron sputtering (MS-PVD) are noted. The characteristics, advantages and disadvantages of the used and promising compositions of thermal barrier coatings developed for use at operating gas temperatures above 1,300°C are considered. It is shown that today the development of thermal barrier coatings is possible due to the improvement of technological processes of their formation and the development of new compositions with a modified multilayer gradient structure consisting of rare earth metal oxides. 10.18721/JEST.29409 621.793 Gas turbine installation high temperature corrosion heat resistance thermal barrier coatings methods of coating formation low thermal conductivity thermal cycling https://engtech.spbstu.ru/article/2023.126.10/ Mednikov%2C-Medvedev%2C-Kachalin.pdf