Global Energy

RAR RUS 7-21 PASEKA Vasiliy 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

MODELING AND COMPARATIVE ANALYSIS OF HYBRID ELECTRIC POWER GENERATION SYSTEMS USING HYDROGEN AND COMPRESSED AIR ENERGY STORAGES Progress in the rational use of energy implies abandoning fossil fuels, and the transition to renewable energy sources (RES) is inevitable in the current scenario of global warming. Efficient utilization of RES in the energy sector is possible only with the parallel use of energy storage systems. Hydrogen as a promising energy carrier opens up vast opportunities for creating efficient and reliable energy storage systems capable of enhancing the stability and economic viability of alternative energy. This article focuses on modeling a hybrid hydrogen-based energy storage system. It describes the model blocks of an electrolyzer, a storage tank and a fuel cell (FC). An analysis of the FC operation under variable demand and excess power conditions is provided, along with the results of simulation modeling in MATLAB/Simulink. The proposed model enables effective management of the balance between energy generation and consumption amid RES instability and ensures reliable power supply during generation shortages by converting hydrogen back into electricity. The efficiency of using hydrogen-based and compressed air-based energy storage has been compared. 10.18721/JEST.31301 620.92 renewable energy sources electric energy storage systems hydrogen storage hybrid energy system mathematical modeling fuel cell electrolyzer. https://engtech.spbstu.ru/article/2025.133.1/ paseka_korovkin.pdf

RAR RUS 22-44 Kartashova Tatyana Prokofev Aleksei Filin A. Grishin Nikolai kostroma44@gmail.com ANALYSIS OF THE EFFICIENCY OF AIR-COOLED TURBOGENERATORS The article provides an overview of current air-cooling schemes for modern high-load high-capacity turbogenerators with full air cooling. It outlines the main limitations that restrict the use of various cooling options, as well as potential areas for improvement and ways to enhance the efficiency of air-cooling systems. Two main cooling schemes applicable to high-capacity turbogenerators are compared: multi-chamber forward-flow cooling scheme and independent cooling circuits for the rotor and stator. Special attention is paid to the power consumption in these circuits for cooling the active parts of the generator. Ventilation losses are determined by the cooling air flow rate and the specific pressure required to move a single volume of air along the cooling circuit. Improving the efficiency of the cooling system is possible by minimizing the two specified parameters. It is advisable to consider the cooling circuits of the rotor and stator separately. The paper shows that for both cooling circuits, an exhaust circuit with independent cooling circuits of the rotor and stator provides higher efficiency, i.e., lower power consumption for ventilation. In the rotor cooling circuit, this is achieved through the use of a fixed guiding device, which reduces the specific pressure applied to the air in the rotor’s pressure elements. This reduces the ventilation heating of the air in the rotor and the cooling air flow rate. With the correct choice of the initial twist value in front of the rotor in a fixed guide device, the influence of the first indicated effect dominates over the second. In the stator cooling circuit, where the limiting hot element is the tooth zone and core winding, the flow separation scheme is more efficient due to the exclusion of exhaust hot air from the gap between the rotor and the stator from further participation in cooling the active parts of the stator. In a multi-chamber forward-flow cooling path, air from the gap is discharged through the cooling channels of the exhaust hot compartments of the stator core, which requires an increased flow rate in the stator cooling circuit to dilute the hot flow of the rotor circuit. This leads to higher power consumption in this cooling scheme and forces the designer to complicate the scheme by introducing additional air coolers and increasing the dimensions of the active parts to reduce specific electrical loads and heat generation. 10.18721/JEST.31302 621.313.322-81 turbogenerator cooling air efficiency ventilation path guiding device fan https://engtech.spbstu.ru/article/2025.133.2/ kartashova_prokofev_filin_grishin.pdf

RAR RUS 45-59 Novikov Pavel novikov.p.a@gmail.ru Tsvetkova Galina tsvetkova_gv@mail.ru Popovich Anatoliy popovicha@mail.ru EFFECTIVENESS EVALUATION OF VARIOUS CONDUCTIVE ADDITIVES IN LITHIUM-ION BATTERIES FOR USE IN HIGH-POWER DEVICES This work presents a comparative study of the effectiveness of various conductive additives in cathode electrodes of lithium-ion batteries based on the commercial LiNi0.5Co0.2Mn0.3O2 (NCM523) material. The following conductive components were studied: Super P carbon black, polymer PEDOT:PSS and carbon nanotubes (CNTs). The study involved the evaluation of electrode morphology, charge-discharge characteristics, cyclic stability, impedance spectroscopy and cyclic voltammetry. Analysis of the obtained results revealed that the CNT additives provide the best electrochemical parameters, including minimal polarization, high specific capacitance and stability at high currents. PEDOT:PSS additive demonstrated characteristics that are potentially promising for application in high-power lithium-ion batteries, but the sample preparation process requires optimization of the synthesis conditions. 10.18721/JEST.31303 541.136 lithium-ion batteries conductive additives high-power batteries cathode materials https://engtech.spbstu.ru/article/2025.133.3/ novikov_tsvetkova_popovich.pdf

RAR RUS 60-73 NECHAEV Daniil Ermakov Boris Shvecov Oleg shvec_off@mail.ru DEVELOPMENT OF A PREDICTIVE METHOD FOR ACTUAL SERVICE LIFE ESTIMATION OF THE ABOVE-GROUND PART OF A PILE POLYMER COMPOSITE PIPE IN THE SUMMER PERIOD IN EXTREME NORTHERN CONDITIONS In this paper, the complex effect of ultraviolet (UV) radiation, temperature and humidity on the mechanical properties of glass and basalt-plastic pipes manufactured using wet cross-layer and cross-winding technologies, respectively, was considered. It was shown that UV radiation is one of the key factors leading to degradation of the structure of polymer-composite materials (PCM) and, as a consequence, affecting their performance in extreme Northern conditions in summer period. The reason for the change in the mechanical properties of PCM under the influence of UV radiation, temperature and humidity is extensive erosion, leading to microcracking of the PCM matrix with the subsequent formation of volumetric defects. It was found that glass and basalt-plastic have the same resistance to summer conditions of the Arctic and Subarctic climates, but fiberglass samples are more prone to water absorption. The obtained regression equations make it possible to accurately predict the actual service life of the upper part of the PCM pile in natural Arctic conditions. 10.18721/JEST.31304 678 PCM UV radiation material degradation material resource climatic tests predictive model climatic factors of aging https://engtech.spbstu.ru/article/2025.133.4/ nechaev_ermakov_shvetsov.pdf

RAR RUS 74-85 KUZNETSOV Ruslan V. TEPLUKHIN Vasilii G. OLKHOVIK Evgeniy ON STRENGTHENING METHODS FOR HIGHLY LOADED COMPONENTS OPERATING IN FRICTION UNITS OF MARINE DIESEL ENGINES This study presents the results of a comparative analysis of the properties of nitrided layers obtained by gas and ion nitriding of structural alloy steels used to manufacture critical, highly loaded parts of marine diesel engines. The paper presents a comparative study of wear resistance, fatigue strength and cavitation resistance of alloy steels after gas and ion nitriding; the advantage of the latter method in terms of these characteristics is shown. The distribution of residual stresses after gas and ion nitriding is studied. A technological process for ion nitriding of marine diesel engine parts made of 38CrAl, 38Cr2MoUАl and 18Cr2Ni4MoАl steels has been developed, which has advantages over classical technologies of chemical-thermal treatment of the surface of the parts being strengthened. 10.18721/JEST.31305 620.1 diesel ion nitriding wear resistance fatigue strength cavitation resistance alloy steel https://engtech.spbstu.ru/article/2025.133.5/ kuznetsov_tepluhin_olhovik.pdf

RAR RUS 86-97 Zolotarev Anton Nefyodova Victoria Barabash Aleksei POLOZOV Igor Popovich Anatoliy popovicha@mail.ru INVESTIGATION OF THE SELECTIVE LASER MELTING PROCESS FOR VZH159 ALLOY WITH TiB2 NANOPARTICLE ADDITION. ANALYSIS OF POROSITY AND MICROHARDNESS This study investigates the effect of titanium diboride (TiB2) nanoparticles on the properties of nickel superalloy VZh159 fabricated by selective laser melting (SLM). The study examines the density and microhardness of composites containing 0 to 2 wt.% TiB2 under various SLM processing modes with energy densities ranging from 49.8 to 169.3 J/mm3. Density measurements were conducted using hydrostatic weighing, achieving samples with density exceeding 99% of the theoretical value at optimal process parameters. The study reveals that increasing TiB2 content shifts the optimal energy density toward higher values: for pure VZh159 it is 83.3–86.8 J/mm3 and for composites with 1.5% and 2% TiB2 it exceeds 130 J/mm3. The research demonstrates progressive microhardness enhancement with increasing TiB2 concentration, from 280–290 HV for the pure alloy to 320–348 HV for 2% TiB2 composite. The study determines the optimal TiB2 content as 1–1.5 wt.% at energy density of 110–140 J/mm3, providing 15–20% microhardness improvement. 10.18721/JEST.31306 669-1 selective laser melting nickel superalloy VZh159 titanium diboride nanoparticles microhardness energy density additive manufacturing https://engtech.spbstu.ru/article/2025.133.6/ zolotaryov_nefyodova_barabash_i_dr_.pdf

RAR RUS 98-106 Zaytsev Alexander Sotov Anton Abdrakhmanova Anna Popovich Anatoliy popovicha@mail.ru PRODUCTION OF POLYMER-CERAMIC AND CERAMIC MATERIALS BASED ON ZIRCONIUM SILICATE (ZrSiO4) USING THE FUSED DEPOSITION MODELING (FDM-TECHOLOGY) To date, additive technologies offer wide opportunities for creating functional materials for various applications. One of the most relevant research areas is the development of polymer-ceramic composites using the fused deposition modeling (FDM) method. This approach combines the advantages of 3D printing with the unique properties of composite materials. The article presents a study of a polymer-ceramic composite material (PCCM) based on zirconium silicate (ZrSiO4) produced by FDM printing. Optical and electron microscopy, DSC and TGA analysis were used to study the properties and structure of the material. Mechanical testing included the determination of the impact strength using a pendulum impact tester and the measurement of the surface hardness using the Shore D scale. The analysis of the results showed an increase in impact strength of more than 30% compared to pure PLA. The feasibility of producing ceramic components through the thermal removal of the polymer binder and sintering of ceramic particles was demonstrated. The results indicate the promising potential of FDM technology for manufacturing functional products from polymer-ceramic materials with specified properties. 10.18721/JEST.31307 621.763 additive manufacturing polymer-ceramic material FDM debinding sintering https://engtech.spbstu.ru/article/2025.133.7/ zaytsev_sotov_abdrahmanova_popovich.pdf

RAR RUS 107-116 Novikov Pavel novikov.p.a@gmail.ru Tsvetkova Galina tsvetkova_gv@mail.ru Popovich Anatoliy popovicha@mail.ru STUDY OF EVOLUTION OF THE STRUCTURE OF THE CATHODE MATERIAL LiNi0.8Co0.1Mn0.1O2 UNDER CONDITIONS OF CYCLING WITH RECHARGING USING IN-SITU X-RAY DIFFRACTION This article presents a detailed analysis of the cathode material LiNi0.8Co0.1Mn0.1O2 (NCM811) using continuous in-situ X-ray diffractometry during cell cycling in the voltage range from 2.7 V to 4.8 V, which led to its recharge. The changes in the crystal structure of the material during charging and discharging are investigated. The decrease in capacitance caused by degradation is shown, and the dependence of the parameters of the unit cell of the material on the voltage applied during cycling is revealed. The analysis of the causes of irreversible structural changes in the cathode material that occur during intercalation and deintercalation of lithium ions is carried out. The results obtained open up the possibility of developing effective methods to reduce degradation factors by understanding the mechanisms of material destruction. 10.18721/JEST.31308 541.136 lithium-ion batteries cathode materials X-ray diffraction structural degradation of the material https://engtech.spbstu.ru/article/2025.133.8/ (2)_novikov_tsvetkova_popovich.pdf