Thermal Engineering最新文献

{"title":"Energy and Environmental Combustion Efficiency of Steam-Atomized Liquid Fuel with Controlled Blast Dilution","authors":"E. Yu. Shadrin,&nbsp;I. S. Sadkin,&nbsp;E. P. Kop’ev","doi":"10.1134/S0040601525700739","DOIUrl":"10.1134/S0040601525700739","url":null,"abstract":"<p>The aim of the work is to study the effect of diluting gases (nitrogen, carbon dioxide, and steam) and oxygen on the combustion of liquid fuel atomized with superheated steam. Main attention is paid to optimizing the combustion process environmental and power performance characteristics. Experiments were carried out using a laboratory burner with fuel atomized by means of steam into a preliminary gas generation chamber, in which atomized fuel is mixed with blast of various compositions. Operating conditions with addition of diluting agents at room temperature and with heating them to 250°C, as well as cases with the use of oxygen-enriched blasting, were studied. The study results have shown that the temperature of supplied gases plays the key role in the combustion process: in admitting cold dilution agents, the flame temperature decreased by 150–200°C, and the chemical reactions slowed down, whereas when heated gases were admitted, the high flame temperature remained unchanged. With increasing the oxygen fraction, a growth of temperature was observed. It has been determined that the ingress of cold diluting agents in the fuel entailed a more efficient reduction of NO_<i>x</i> and CO emissions in comparison with the operating conditions with admission of a heated mixture. At the same time, the admission of heated gases resulted in lower emissions under the operating conditions with oxygen enrichment. Injection of steam resulted in a lower production of NO_<i>x</i>, but it entailed higher CO emissions and caused the combustion to become unstable. By using the method proposed in the article, it is possible to reduce the NO_<i>x</i> emissions (up to 50%), which is commensurable with this indicator in the case of conventional recirculation of flue gases, but with a lower fraction of them (5–10% against 20–30%). This makes the technology involving steam-assisted atomization and controlled dilution of fuel a promising option for use in the power industry and metallurgy, sectors in which high energy efficiency and environmental safety are of importance.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"73 1","pages":"52 - 61"},"PeriodicalIF":1.0,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147388687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring and Control of Water Chemistry in the Power Unit Turbine Generator Water Cooling System","authors":"A. B. Larin,&nbsp;B. M. Larin,&nbsp;M. P. Savinov,&nbsp;E. G. Ukhalova","doi":"10.1134/S0040601525700715","DOIUrl":"10.1134/S0040601525700715","url":null,"abstract":"<p>Electrical conductivity, pH, and oxygen concentration, all continuously measured in circulation water, are the key water chemistry (WC) parameters monitored in a power unit turbine generator water cooling system. With a shift for the use of water cooling in the turbine generator systems at thermal power plants (TPP) and for designing of such systems for turbine generators of the T3V-1200-2AU3 series at NPPs, problems were encountered in meeting the circulation water quality standards and in WC control. The article presents a method for determining by calculation the standardized values of electrical conductivity and pH in metering NaOH in a circulating cooling system (CCS) depending on these indicators in makeup water (water medium with low buffering capacity). The turbine generator water cooling systems serve for intense heat removal from the stator (and rotor) windings and are widely used in the power units at TPPs and NPPs. The cooling (circulation) water quality is standardized with respect to several indicators, the main ones of which are electrical conductivity and pH. In view of quite stringent standards on electrical conductivity, especially for the turbine generator rotor cooling system (below 1.43 μS/cm), there is nothing to do but use deeply demineralized weakly acidic water (рН &lt; 7.0), and it is not permitted to use ammonia. For the acidity to be neutralized with NaOH solution, very precise controlled metering is required: with an insufficient quantity of NaOH, the рН will be below 6.5 (the lower limit), and with an excessive quantity of NaOH, the pH value will exceed 9.0, which is the upper permissible limit for the CCS. A mathematical model of ionic equilibria in the CCS circulation water is constructed and solved. With NaOH solution metered within the range of permissible values, the electrical conductivity and pH value adjustment boundaries are determined depending on the source and makeup water quality. An author’s certificate for a software product has been received. Given the existing makeup water quality and unchanged CCS process circuit arrangement, the performed study makes it possible to recommend installing an automated system for metering NaOH solution into circulation water based on the prescribed electrical conductivity value.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"73 1","pages":"62 - 70"},"PeriodicalIF":1.0,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147388540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neutralization of Effluent Water and Dangerous Waste in Supercritical Water-Oxygen Fluid (Review)","authors":"O. N. Fedyaeva,&nbsp;P. A. Strizhak","doi":"10.1134/S0040601525700727","DOIUrl":"10.1134/S0040601525700727","url":null,"abstract":"<p>The article analyzes the main achievements in the field of neutralizing effluent water and dangerous halogen containing waste by oxidizing them in water in supercritical state (at temperature <i>t</i> &gt; 374°С and pressure <i>p</i> &gt; 22.1 MPa). Criteria determining the oxidation efficiency are revealed. Problems connected with practical implementation of the discussed approach are formulated, first of all, corrosion of structural materials and deposition of salts. Technical solutions that help improve waste neutralization efficiency, reduce corrosion, and prevent pipelines becoming blocked with solid particles and mineral components are described. The environmental and economic aspects of industrial application of supercritical water oxidation are considered. The conditions for achieving better energy and environmental efficiency of oxidizing waste jointly with conventional fuel kinds are determined. Prospects of applying supercritical water oxidation at thermal power plants for ultrasupercritical steam conditions are noted.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"73 1","pages":"1 - 13"},"PeriodicalIF":1.0,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147388683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use of Micro- and Nanocoating in the Evaporator to Enhance Heat Transfer in a Thermosiphon","authors":"N. S. Ivanov,&nbsp;Yu. A. Kuzma-Kichta,&nbsp;M. M. Alyautdinova","doi":"10.1134/S0040601525600683","DOIUrl":"10.1134/S0040601525600683","url":null,"abstract":"<p>Experimental data on the thermal resistance of thermosiphons designed with different structural junctions (“pipe in pipe,” “flat shelve”) are obtained, and the possibility is shown to decrease it as a result of heat transfer enhancement in the evaporator by using a combined coating in the form of longitudinal grooves 0.1 mm in radius, filled with aluminum oxide nanoparticles 100–200 nm in size. The effect the coating has on the thermosiphon thermal resistance was studied in an experimental section in the form of a 100 mm long pipe 38 × 3 mm in diameter made of grade AISI304 stainless steel. As a result of applying the coating, the thermosiphon thermal resistance is decreased by 2.4–3.0 times at heat fluxes in the range 200–1700 W/m² and evaporator slope angles 0°–30°. Experiments with slope angles equal to 0°, 10°, and 20° were carried out, and it is pointed out that the maximal effect is reached at the evaporator horizontal and slightly inclined positions. For calculating the heat transfer in a thermosiphon, a procedure based on the Yu.A. Kuzma-Kichta formula is proposed. The predicted thermosiphon thermal resistance values agree with the experimental data within 20%, a circumstance that extends the model applicability area.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"72 12","pages":"1101 - 1107"},"PeriodicalIF":1.0,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146045612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Erratum to: Study of Heating and Evaporation of Rotating Graphene Nanofluid under the Influence of Solar Radiation","authors":"K. T. Chan,&nbsp;A. S. Dmitriev,&nbsp;I. A. Mikhailova,&nbsp;P. G. Makarov","doi":"10.1134/S0040601525190012","DOIUrl":"10.1134/S0040601525190012","url":null,"abstract":"","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"72 12","pages":"1130 - 1130"},"PeriodicalIF":1.0,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1134/S0040601525190012.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146045618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Analysis of the Key Serviceability and Efficiency Conditions of Loop Heat Pipes","authors":"M. A. Chernysheva,&nbsp;Yu. F. Maydanik","doi":"10.1134/S0040601525700661","DOIUrl":"10.1134/S0040601525700661","url":null,"abstract":"<p>Loop heat pipes (LHPs) are two-phase heat transfer devices with capillary pumping of the working fluid inside a sealed, closed loop, including an evaporator and a condenser connected by smooth-walled pipelines for separate movement of vapor and liquid, the diameter of which usually varies from 2 to 8 mm. This design feature enables easy integration of LHPs into densely packed systems. The LHP evaporator is equipped with a fine-pored capillary structure (wick) (pore radius from 1 to 20 μm), which creates high capillary pressure. Loop heat pipes are used in energy-efficient systems for utilizing low-potential heat, heating or cooling remote objects, and for uniform heat distribution over a large surface area of ​​heat sinks. Currently, the most popular area of ​​application for LHPs is electronic cooling systems operating under a wide variety of conditions. Various liquids can be used as working fluids in LHPs, depending on their operating temperature range, chemical compatibility with structural elements, and the required operating characteristics of the LHPs. This paper presents the theoretical foundations and operational conditions for LHPs. It also discusses the issue of selecting a working fluid to enhance the heat transfer capacity of LHPs. Quality criteria are proposed for assessing working fluids based on their efficiency in these devices. The results of a comparison of six different working fluids using these criteria are presented, showing that ammonia is the most effective working fluid in the operating temperature range relevant for electronics, from 40 to 70°C. Based on the <i>p</i>, <i>t</i> diagram of the working cycle of the working fluid, the thermal resistance of the “heat source–LHP–heat sink” system is visualized, as well as the thermal resistance of the main structural elements.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"72 12","pages":"1108 - 1117"},"PeriodicalIF":1.0,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146045587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gas Hydrate Energy Technologies: Problems and Achievements","authors":"P. A. Strizhak,&nbsp;S. V. Alekseenko,&nbsp;A. Yu. Manakov,&nbsp;E. R. Podgornaya,&nbsp;M. V. Shkola,&nbsp;N. E. Shlegel’","doi":"10.1134/S0040601525700636","DOIUrl":"10.1134/S0040601525700636","url":null,"abstract":"<p>The article summarizes the key scientific and technological achievements in the field of applying gas hydrates in the power industry. The modern ideas about the specific features relating to the synthesis, transportation, storage, regasification, and use of hydrates for thermal conversion of low-grade fuels and waste, separation of gaseous and liquid media, as well as sequestration of anthropogenic emissions are analyzed. It is shown that the experimental data and the results of mathematical modeling and various-scale tests that have been obtained for the last years in the world’s scientific society form a basis for the development of technologies for applying natural and man-made hydrates. Concepts for integrated use of hydrates in the power systems at mines and in supply of energy resources to settlements are outlined. The technical and economic constraints connected with the development of gas hydrate technologies, their target indicators, and potential solutions of the formulated problems are determined. For the gas hydrate technologies to be efficiently introduced in the energy sector, the following so-called target business metrics (threshold indicators) should be achieved: gas content is no less than 180 vol/vol.;¹ purification ratio of gas obtained after separation of smoke, natural, casing-head, and synthesized gases is no less than 90%; maximal loss of gas in storing and transporting hydrates is not more than 0.1%; hydrate storage term is up to six months; stable combustion temperature during joint low-emission combustion of hydrates with low-grade fuels (sludges, heavy coal-tar products, cakes, etc.) is not lower than 1100°С. For solving these problems, it is necessary to carry out fundamental and applied studies, as well as various-scale tests for integrating gas hydrates into modern power systems with ensuring environmental cleanliness and economic efficiency. The conditions under which essential advantages are achieved in comparison with alternative technologies in each hydrate application area have been determined.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"72 12","pages":"993 - 1033"},"PeriodicalIF":1.0,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146045604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Study of Salt Melt Heat Transfer in a Vertical Round Channel in Transition and Turbulent Flow Regimes","authors":"A. G. Khizhnyak,&nbsp;S. V. Khomyakov,&nbsp;I. S. Belousov,&nbsp;N. A. Solov’ev","doi":"10.1134/S0040601525700648","DOIUrl":"10.1134/S0040601525700648","url":null,"abstract":"<p>The article presents the results of experimental studies aimed at determining the dimensionless heat transfer coefficient (the Nusselt criterion) in a round tube during forced upward motion of salt melt. The relevance of this problem is substantiated by the presented review of literature sources, which has shown that there is an insufficient scope of experimental data on heat transfer for the flow of salt melts against the gravitation forces in laminar ant transition regimes in the temperature range 230–350°C. The experiments were carried out in transition and turbulent flow regimes in the range of Reynolds numbers 2600–23 000 with the applied heat fluxes 70–670 kW/m² and Prandtl numbers 8.9–14.7. A melt of 50% NaNO₃–50% KNO₃ (in molar fractions) salt was used as working medium. The experimental values of heat transfer coefficients are in good agreement with the data obtained using the well-known relationships, such as the correlations proposed by Petukhov–Kirillov, Sieder–Tate, Gnielinsky, and Hausen. Based on the authors’ own data and an analysis of existing correlations, a new empirical formula is proposed for calculating the Nusselt number in the range of Reynolds numbers from 4000 to 10 000. For the developed turbulent flow regime, the Hausen correlation has shown the best agreement with the experimental values: the maximal mismatch does not exceed 7%, due to which this correlation can be recommended for carrying out calculations in the studied ranges of the parameters.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"72 12","pages":"1090 - 1100"},"PeriodicalIF":1.0,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146045616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Influence of Temperature Conditions at the Metallic Melt Layer Boundaries on the Heat Flux Focusing in a Stratified Molten Corium Pool during a Severe Accident in Nuclear Power Facilities","authors":"V. D. Loktionov,&nbsp;Ya. A. Gorbunova,&nbsp;E. S. Mukhtarov","doi":"10.1134/S0040601525700612","DOIUrl":"10.1134/S0040601525700612","url":null,"abstract":"<p>The article presents an analysis of the effect the aspect number <i>A</i> (the ratio of the melt layer height to the reactor pressure vessel inner diameter) and the temperature conditions at the boundaries of the cylindrical steel melt layer heated at its lower surface have on the heat flux focusing on its lateral surface. Such layer corresponds to the metallic layer in the stratified corium melt pool that is produced in the nuclear reactor pressure vessel during a severe accident, and the heat flux of which affects the pressure vessel, causing its heating and partial melting. The pressure vessel ability to retain high-temperature melt inside of it in the course of a severe accident in using external cooling of the vessel depends on the heat fluxes acting on it from the high-temperature corium side. If the metallic melt is stratified, a heat flux focusing effect emerges in the area of melt upper layer, which determines the most dangerous and thermally stressed place, the heat flux in which may exceed 1.5 MW/m². The possibility to promptly and adequately estimate the influence of heat fluxes on the reactor pressure vessel is an important objective in elaborating severe accident management measures. The article proposes a procedure for determining the heat flux focusing factor on the steel melt layer lateral surface, which is based on applying the previously obtained modified formulas for calculating the Nusselt number and the melt layer bulk temperature. The newly developed procedure was used to perform a parametric analysis of the influence of the layer geometrical parameters and the temperature conditions at its boundary surfaces on the focusing effect. The analysis results have shown that the heat flux focusing effect depends on the temperature conditions at the layer boundaries and on the layer thickness. Thus, variations of differences between the temperatures of layer lower and upper surfaces, and also between the temperatures of its lateral and lower surfaces may entail a several-time increase/decrease of heat flux intensities acting at the melt layer surface and on the reactor pressure vessel during a severe accident. The heat flux focusing factor depends most essentially on the temperature conditions at the layer boundaries at the aspect ratio <i>A</i> values not larger than 0.4, which should be taken into account in elaborating severe accident management strategies. In the subsequent, it is worthwhile to perform experimental studies to confirm the validity of the newly developed procedure for determining the heat flux focusing effect in the relevant scenarios and under real severe accident progression conditions, as well as with model media (melts) having properties close to those of the materials forming the corium melt bath in nuclear power facilities during accidents of a similar class.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"72 12","pages":"1042 - 1050"},"PeriodicalIF":1.0,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146045619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Simulation of Hydrodynamic Effects of Internal Structural Parameters in a Steam-Water Mixing Heater","authors":"Xuebing Zhu,&nbsp;Zhaoying Xu,&nbsp;Jiangtao Zhang,&nbsp;Deqing Liu,&nbsp;Haiyan Li,&nbsp;Jinlei Wang,&nbsp;Bin Zheng","doi":"10.1134/S0040601524600974","DOIUrl":"10.1134/S0040601524600974","url":null,"abstract":"<p>Steam-water injectors are widely utilized in various industrial applications and production processes, particularly for their ability to enhance energy efficiency, reduce emissions, lower energy consumption, and facilitate energy reuse. In this study, computational fluid dynamics (CFD) is employed to investigate the impact of internal geometric parameters on the performance of steam injectors. Key internal flow characteristics are analyzed, focusing on the effects of the orifice injection angle, dilatation inclination, throat size, and the presence of a porous medium within the mixing chamber. The results reveal that an injection angle of 45°, a dilatation inclination between 0.9° and 1.1°, and a throat diameter of 14–16 mm significantly enhance steam-water phase mixing, leading to superior heat exchange efficiency. While including a porous medium does not improve heating performance, it substantially reduces noise levels within the system. By optimizing the full set of internal geometric parameters, the study demonstrates a marked improvement in the injector’s entrainment capacity. These findings provide a valuable reference for the continued research, development, and optimization of steam–water mixing heaters, offering practical insights for enhancing performance in industrial applications.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"72 12","pages":"1061 - 1072"},"PeriodicalIF":1.0,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146045586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}