Thermal Engineering最新文献

{"title":"Models and Validation Results of the TRITIUM Module Used as Part of the EUCLID/V2 Integrated Code for Calculating the Tritium Behavior in Lead Cooled Fast Reactor Systems","authors":"M. V. Vorivonchik,&nbsp;D. A. Nazarov,&nbsp;D. S. Sinitsyn,&nbsp;N. A. Mosunova,&nbsp;A. A. Sorokin,&nbsp;A. S. Anikin,&nbsp;A. N. Bukin","doi":"10.1134/S0040601525700806","DOIUrl":"10.1134/S0040601525700806","url":null,"abstract":"<p>The article presents the results of developing the models and the TRITIUM software module as part of the EUCLID/V2 integrated code for calculating the migration of tritium and other hydrogen isotopes in the primary circuit of lead cooled fast reactors. Tritium is produced in nuclear fuel; it is radioactive in nature and unlike other radionuclides, can penetrate through the fuel pin cladding and primary circuit pipeline walls into the reactor plant (RP) compartments. Hence, it is very important to understand the way in which tritium will behave and propagate to ensure the reactor plant radiation safety. The TRITIUM module incorporates models for the main processes influencing the behavior of hydrogen isotopes in reactor components, including the transfer of isotopes together with the coolant, radioactive decay, penetration through the pipeline walls made of structural materials, degassing from the lead melt, and release of tritium into the reactor plant gaseous loop. To check how correctly the models are implemented in the code by means of software, the article presents the results of verifying the developed module against the data for test problems. The article also presents the code validation results for experiments on the transfer of hydrogen isotopes and their penetration through the pipeline walls made of steels used for the lead cooled reactors designed and constructed in Russia. The presented results demonstrate that the EUCLID/V2 integrated code with the tritium behavior module TRITIUM in the code composition can be used for substantiating the radiation safety of lead cooled reactors and tritium handling systems.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"73 2","pages":"136 - 146"},"PeriodicalIF":1.0,"publicationDate":"2026-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147606864","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 Study of the Tube Effect on Natural Convection in an Inter-Plate Channel","authors":"I. O. Odintsov,&nbsp;A. B. Garyaev,&nbsp;A. A. Arbatskii","doi":"10.1134/S0040601525700740","DOIUrl":"10.1134/S0040601525700740","url":null,"abstract":"<p>The article presents a numerical study of the effect the diameter of a central tube in the slit-shaped channel between the finned radiator plates has on the heat flux transferred under natural convection conditions. The numerical solution is compared with the calculation carried out according to the Elenbaas formula and with the experimental relationship obtained by Karami et al. It is shown that if there is a tube in the radiator interfin channel, the heat flux transferred under natural convection conditions decreases; the larger the tube diameter, the more significant the heat flux decrease is. This is because of a decrease in the total heat transfer area when there are small relative distances between the fins and a decrease in the air velocity if there is an obstacle. A correction to the Elenbaas formula is proposed for calculating the dimensionless heat transfer coefficient in the slit channel between the radiator vertical plates with a central tube at a constant fin temperature, and the correction application domain is determined. The correction has the form of a power dependence that includes the ratio of heat transfer surface areas with and without the tube, and also such parameters as the tube diameter and fin height, and air density at the temperature of fins and environment. It has been determined that with small tube diameters and distances between the fins, for describing the heat flux in a correct way, it is sufficient to use the formula that takes into account the change in the total heat transfer area. The heat flux values obtained from the calculations carried out according to the proposed relationship differ from the results of calculations carried out using the relationship of Karami et al. by no more than 5.5% in the range of central tube diameter to fin height ratios of 0‒0.4 and the interfin distance to fin height ratios of 0.03‒0.12.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"73 2","pages":"126 - 135"},"PeriodicalIF":1.0,"publicationDate":"2026-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147606863","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":"Assessments of the Hydrogen–Air Mixture Catalytic Combustion Domain in a Laminar Flow Regime","authors":"V. A. Fedorenko,&nbsp;V. V. Lemanov,&nbsp;V. V. Lukashov,&nbsp;A. V. Tupikin,&nbsp;K. A. Sharov","doi":"10.1134/S0040601525700788","DOIUrl":"10.1134/S0040601525700788","url":null,"abstract":"<p>Improving the environmental safety of power facilities is among the top priority problems of the modern science. Conventional energy generation methods on the basis of hydrocarbon fuel are accompanied by significant greenhouse gas emissions. One of promising approaches to reducing the emission is catalytic afterburning, which ensures more complete and controlled fuel oxidation. The article presents a study of heat and mass transfer processes that accompany the streamlining of a flat catalytically active surface by a laminar jet of hydrogen–air mixture directed normally to the surface. The impact jet interaction is studied for the conditions under which Hagen–Poiseuille flow has enough time to settle in the delivery tube at Reynolds numbers Re &lt; 2000. Main attention is paid to evaluating the fuel combustion completeness and determining the chemical activity domain in a laminar regime. The catalyst was based on gamma-alumina (γ-Al₂O₃) that was modified with rare-earth metals and palladium (Pd). As is known, a Stefan flow directed normally to the surface emerges in the course of reactions accompanied by a change in the number of molecules. Comparison with the data reported in the literature shows that chemical reactions running on a palladium catalyst do not have a significant effect on the Sherwood number (Sh) and Nusselt number (Nu). A thermodynamic procedure for evaluating the catalytic reaction domain is proposed, which has been verified by comparison with the hydrogen concentration distribution. By using this procedure, it is possible to calculate the Damkohler number proceeding from the temperature profile on the surface, which can be used for determining the catalytic activity for a surface streamlined by a flow of reagents. The developed approach opens the possibility to estimate the minimal sizes of a heat and mass transfer device required for neutralizing harmful substances.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"73 2","pages":"121 - 125"},"PeriodicalIF":1.0,"publicationDate":"2026-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147606932","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":"An Analysis of the Results of Studying the Separation of Particles in the Upper Part of CFB Apparatuses","authors":"G. A. Ryabov,&nbsp;O. M. Folomeev","doi":"10.1134/S0040601525700776","DOIUrl":"10.1134/S0040601525700776","url":null,"abstract":"<p>Matters concerned with the motion of solid particles in circulating fluidized bed (CFB) apparatuses are considered. It is shown that a significant portion of particles does not enter the cyclones and returns into the furnace, thereby producing an internal circulation loop. The particle capturing efficiency, i.e., the downward to the upward flow rate ratio, depends on the geometrical parameters at the furnace outlet to the cyclone and on the physical characteristics that can be expressed in terms of the Stokes number. The ratio of the outlet port area to the furnace or CFB reactor area is the most important parameter. It has been shown that in analyzing and comparing data, it is also necessary to take into account other geometrical indicators, such as possible influence of density and mass flows, as well as methods for determining them. Measured upward flow rate values, as for example those obtained in the authors’ own experiments, can be the most representative ones. The experimental data obtained at the All-Russian Thermal Engineering Institute (VTI) under different flow outlet conditions from furnace models were analyzed. The upward and downward mass flow rates near the outlet port and the flowrate of circulating material captured in the separator are compared. The authors’ own studies have shown that the average size of sand particles increases to some degree with increasing the air velocity. Therefore, all previously obtained results were recalculated in this study with taking into account the updated upward flow rate and decrease in the particle sizes at low gas velocities, and compared with the experimental and calculated data reported in the literature sources. The values the authors obtained on the test bench facility with a cross section of 0.4 × 0.4 m lie by approximately 20–30% below the calculated values. The same also relates to other conditions of flow outlet from the furnace, except for the data on the boiler and data at which the calculated values are very close to the experimental ones. A correction of the calculation relationship is proposed.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"73 2","pages":"81 - 90"},"PeriodicalIF":1.0,"publicationDate":"2026-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147606865","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 Flow Restrictor of Water Boiling Heat Transfer on a Finned Surface","authors":"P. G. Bobylev,&nbsp;A. V. Pavlov,&nbsp;S. V. Andreiko,&nbsp;V. Yu. Mityakov,&nbsp;S. Z. Sapozhnikov","doi":"10.1134/S0040601525700752","DOIUrl":"10.1134/S0040601525700752","url":null,"abstract":"<p>The article presents the results of studying of heat transfer during pool boiling of saturated water on a finned surface. The experiment involved certain difficulty in view of lack of primary transducers that would help perform direct measurement of local heat flux. A new model of a heterogeneous gradient heat flux sensor was used, which was installed under the heat transfer surface. By using this sensor, the limit boiling heat flux was determined both on a free finned surface and on a finned surface with a flow restrictor. Modern methods for cooling power electronic devices are briefly reviewed. The choice of devices applied in the study is substantiated. The article presents a description of the experimental facility that makes it possible to study heat transfer during boiling of various coolants near surfaces having different geometrical parameters. A solution according to which the thermocouples are placed under the heat transfer surface for correctly representing the heat flux determination results depending on the change in the temperature of the modeled power module is substantiated. The relative standard temperature and heat flux measurement uncertainties did not exceed 2 and 4%, respectively. The flow restrictor application efficiency was estimated. It has been shown that a flow restrictor installed near the surface helps remove steam–water mixture from the heating surface more intensely, due to which the removed heat flux is increased by 35%. The best effect is obtained from using a flow restrictor on surfaces with a distance between the fins close to twice the capillary distance. In addition, by changing the gap in installing the restrictor, it is possible to adjust natural circulation of liquid and control both the removed heat flux and the power module temperature. The obtained results give grounds to believe that further studies in this area should be carried out.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"73 2","pages":"98 - 106"},"PeriodicalIF":1.0,"publicationDate":"2026-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147606947","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 and Experimental Study of Thermal-Hydraulic Processes in the Convergent-Divergent Channels of Plate Heat Exchangers with Etched Channels","authors":"V. O. Kindra,&nbsp;I. A. Maksimov,&nbsp;D. V. Patorkin,&nbsp;O. V. Zlyvko,&nbsp;I. I. Komarov","doi":"10.1134/S0040601525700697","DOIUrl":"10.1134/S0040601525700697","url":null,"abstract":"<p>The cost and efficiency of power installations depend to a great extent on the design characteristics of heat transfer equipment. These characteristics are especially important for gas turbine units with regenerators operating on low boiling working fluids with low temperature differences and high pressure differences. For such highly efficient energy systems with regeneration, the use of plate heat exchangers containing microchannels obtained by chemical etching of their surface holds promise. For improving their thermal-hydraulic efficiency, versions of extended heating surfaces with convergent-divergent channels are proposed in the article. A set of calculated and experimental studies of the newly developed channels for plate heat exchangers was carried out. Convective heat transfer was numerically simulated, the results of which made it possible to determine the influence of key geometrical parameters, namely, the relative segment length <i>L</i>/<i>H</i> and expansion amplitude <i>A</i>/<i>H</i> on the thermal-hydraulic characteristics in a wide range of Reynolds number values (2500 ≤ Re ≤ 15 000). It is shown that with a periodically narrowed and widened channel cross section, flow acceleration and deceleration zones are produced; directed action on the boundary layers takes place, and turbulent mixing is enhanced. This helps eliminate stagnant zones and obtain more uniform distribution of heat removal over the surface. Based on mathematical modeling, correlation dependences for the Nusselt number and the friction coefficient as functions of the Reynolds number have been obtained, which are suitable for engineering assessments of the efficiency of heat exchangers with similar geometrical parameters of the channels. To verify the numerical study results, an experimental setup was developed, and tests of channel models with recording the heat transfer and pressure losses were carried out, which have confirmed the correctness of the theoretical approach and repeatability of the revealed regularities. The obtained results can serve for confirming the rational choice of geometrical parameters and practical applicability of modified plate heat exchangers with chemically etched channels as part of compact regenerators of advanced power facilities.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"73 1","pages":"14 - 29"},"PeriodicalIF":1.0,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147388684","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":"Studying the Vortex Heat Transfer Enhancement during Turbulent Air Flow over a Plate with a Limited Package of Inclined Oval-Trench Dimples Using Numerical Modeling and Gradient Heatmetry","authors":"S. A. Isaev,&nbsp;S. Z. Sapozhnikov,&nbsp;V. V. Seroshtanov,&nbsp;V. Yu. Mityakov,&nbsp;D. V. Nikushchenko,&nbsp;S. A. Knyazev,&nbsp;A. A. Klyus","doi":"10.1134/S0040601525700685","DOIUrl":"10.1134/S0040601525700685","url":null,"abstract":"<p>The article presents a numerical and experimental study of separated flow and heat transfer in limited packages of four inclined oval-trench dimples (OTDs) located on a heated isothermal section of an adiabatic plate in uniform air flow with the Reynolds number Re = 3 × 10⁴. The depth of dimples is equal to 0.25 of their width, and the angle of inclination is 45°. The isothermal section temperature is maintained with saturated steam. The results of numerical calculations carried out by solving the Reynolds averaged Navier–Stokes equations in the VP2/3 software package, which are closed by the differential equations of the shear stress transfer model (RANS with the SST turbulence model) and the equation of energy, were validated by comparing them with the experimental data obtained by means of gradient heatmetry techniques on the thermophysical setup at the St. Petersburg Polytechnic University. Multiblock computation technologies with the use of intersecting meshes of different scales were applied. It has been found that, with shifting the dimples away from the plate leading edge, relative heat transfer coefficient and back flows are enhanced. With a shift from the first to the fourth dimple, the relative Nusselt number increases in the inlet parts at the bottom by a factor of two (from 1.2 to 2.4) and by a factor of 1.7 (from 1.5 to 2.6) in the windward edge area. The stabilization of stagnation pressure on the windward slopes at a level of 0.26 with the minimal pressure equal to −0.15 in the vortex generation zones entails enhancement of back flows. The static pressure differences cause enhancement of back flows in packaged dimples. The study results have revealed fundamental differences in the heat transfer distribution between the first and subsequent dimples, as well as in their end parts.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"73 1","pages":"30 - 43"},"PeriodicalIF":1.0,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147388685","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":"Thermal-Hydraulic Characteristics of Mini Cooling Towers Equipped with Regular Film Contacting Devices","authors":"E. A. Lapteva,&nbsp;R. N. Khamidullin,&nbsp;A. G. Laptev","doi":"10.1134/S0040601525700703","DOIUrl":"10.1134/S0040601525700703","url":null,"abstract":"<p>The article presents the results of experimental studies of the hydraulic and mass transfer characteristics of 1-m high roll polymeric mesh packing having a specific surface area of 240 m²/m³, equivalent diameter of 0.015 m, and free specific volume of 0.95, with a film countercurrent flow regime in the column with a spray density of 5.0‒25.0 m³/(m² h) and air velocity of 0.5‒2.5 m/s. The air pressure difference, volumetric mass transfer coefficient, and air humidification efficiency with water are determined. Generalized empirical formulas for calculating these characteristics are derived. The roll polymeric mesh packing is compared with regular fill packs made of corrugated metal tape and corrugated vertical metal plates with a rough surface in terms of specific pressure difference and mass transfer efficiency. The possibility of using these fill packs in mechanical-draft mini cooling towers is considered. An algorithm for calculating the mini cooling tower efficiency and cooled water temperature after its having been in contact with air is presented. Graphic dependences of the hydraulic and heat-and-mass transfer characteristics on the operating parameters are given. Special attention is paid to an analysis of liquid distribution over the packing surface and liquid film formation, which is a key factor for intense mass transfer. A reasonable ratio between the air velocity and spray density under different operation conditions is determined. The study results can be used in design and modernization of water cooling systems, including those at industrial enterprises, in which it is necessary to maintain highly efficient heat transfer and use the most compact equipment.</p>","PeriodicalId":799,"journal":{"name":"Thermal Engineering","volume":"73 1","pages":"44 - 51"},"PeriodicalIF":1.0,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147388686","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":"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}