Thermophysics and Thermal Power Engineering最新文献

{"title":"ROLE OF RENEWABLE ENERGY SOURCES IN IMPLEMENTATION OF THE GLOBAL SCENARIO TO ACHIEVE ZERO GREENHOUSE GAS EMISSIONS BY 2050","authors":"T. Zheliezna","doi":"10.31472/ttpe.1.2022.8","DOIUrl":"https://doi.org/10.31472/ttpe.1.2022.8","url":null,"abstract":"The aim of the work is to develop recommendations for Ukraine to meet the goal of achieving climate neutrality by 2060. The global scenario of net zero greenhouse gas emissions by 2050 developed by the International Energy Agency is presented; the role of renewable energy sources in the implementation of the scenario is considered. According to this scenario, two thirds of the world’s total primary energy supply in 2050 will be provided by wind, solar, biomass, geothermal and hydropower. Electricity will account for almost half of the total energy consumption in 2050, play a key role in all sectors, and make a significant contribution to the production of low-carbon fuels, including hydrogen. At the same time, about 90% of electricity in 2050 will come from renewable energy sources. Recommendations have been developed for Ukraine on the development of the use of renewable energy sources and the fulfillment of the goal to achieve climate neutrality by 2060. In particular, it is recommended to approve as soon as possible an Integrated National Energy and Climate Plan for 2021-2030, which is in line with European approaches to an interrelated view of energy and climate. It is also recommended to fully implement the tasks related to the implementation of strategic goals in the energy sector defined in the National Economic Strategy until 2030. Such actions guarantee effective decarbonization of Ukraine’s energy sector and make a significant contribution to achieving climate neutrality by 2060.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88298830","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":"HEAT TRANSFER AT NATURAL CONVECTION OF VAN DER WAALS GAS","authors":"A. Avramenko, Y. Kovetska, N. P. Dmitrenko, O.I. Skitsko, L.V. Plakhotnia","doi":"10.31472/ttpe.1.2022.1","DOIUrl":"https://doi.org/10.31472/ttpe.1.2022.1","url":null,"abstract":"This paper focuses on a study of natural convection in a Van der Waals gas over a vertical heated plate. An approximate analytical solution of the problem was obtained using an integral method for momentum and energy equations. A simplified form of the van der Waals equation for real gases enabled estimating the effects of the dimensionless van der Waals parameters on the normalized heat transfer coefficient. The effects of the dimensionless Waa and Wab numbers on the normalized Nusselt number in the real gas compared to the ideal gas were estimated. The analysis of the calculation results showed that, with an increase in the Waa number (which characterizes the additional pressure in the real gas), the normalized Nusselt number increases. The effect of additional volume, which  shows in an increase in the Wab number, causes a deterioration in the conditions  interaction between gas molecules and the wall. This is accompanied by a decrease in the Archimedes force and flow rate in the boundary layer, which leads to a weakening of heat transfer in comparison with an ideal gas.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"286 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72747268","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":"INFLUENCE OF UNSTEADY CONDITIONS ON HEAT EXCHANGE DURING A SHARPY TRANSITION TO FILM BOILING","authors":"A. Avramenko, A. I. Tyriniv, N. P. Dmitrenko, M. Kovetska","doi":"10.31472/ttpe.3.2022.2","DOIUrl":"https://doi.org/10.31472/ttpe.3.2022.2","url":null,"abstract":"Boiling is one of the main physical processes, which that take place in heat exchange equipment designed for various purposes. The problem of removing large thermal loads from the heated surface is important for nuclear energy, chemical industry, metallurgy, electronics and other areas where intense heat is released. Boiling processes in process equipment perform important protective functions and can control its effectiveness. According to the boiling curve, with increasing temperature power, the flow passes through five regions, starting from the single-phase region of free convection and ending with the region of developed film boiling. The purpose of this article is an analytical study of heat transfer at spontaneous transition to the film boiling (explosive type of boiling), taking into account the unsteady nature of this process. In order to achieve the aim of this research, two analytical approaches were used, namely, the symmetry method and the Laplace method. As a result of mathematical transformations, expressions for the nonstationary temperature distribution and the Nusselt number are obtained. The obtained expressions make it possible to analyze the dynamics of non-stationary heat exchange processes. The results of analytical and numerical modeling were also compared. It was found that the results of the self-similar solution have a better comparison with numerical data compared to the results according to the Laplace method.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"600 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77242167","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":"CFD SIMULATION OF HEAT TRANSFER WITH SPIRAL-WIRE DISPLACEMENT ON THE PIPE","authors":"V. Oliinyk, P. Krukovskyi, A. Deineko","doi":"10.31472/ttpe.4.2021.4","DOIUrl":"https://doi.org/10.31472/ttpe.4.2021.4","url":null,"abstract":"The results of the study of the intensification of the heat transfer process under forced air convection in the annular gap of a pipe-in-pipe heat exchanger with a spiral-wire intensifier located near the outer surface of the inner pipe are presented. The intensifier does not touch the pipe surface. The height of the wire of the intensifier is taken as 1.5 mm. The change in the winding pitch varied within the range of 12-20mm. \u0000Boundary conditions of the first kind + 20 ° C are set on the inner surface of the inner pipe. The temperature of the air moving in the annular gap is 300 ° C. The air velocity varied from 6 to 15 m / s. \u0000For the CFD model of a pipe-in-pipe heat exchanger, the use of a computational grid with 4.7 million elements is justified. The CFD model was validated using literature data. \u0000Based on the analysis of the ratio of the intensified Nusselt number to the Nusselt number for a smooth pipe, a 1.7-fold increase in heat transfer was found for Reynolds numbers from 5000 to 7000. This result is explained by the periodic destruction of the boundary layer along the pipe. With a further increase in Reynolds numbers to 13000, the intensification of heat transfer decreases from 1.7 to 1.3, which is explained by an increase in the vortex zone immediately behind the wire and the appearance of recirculation zones that make a minimum contribution to heat transfer. \u0000It has been determined that the spiral-wire intensifier with the maximum possible step of 20 mm contributes to the greatest increase in heat transfer by 1.7 times and has the smallest coefficient of hydraulic friction of 0.076-0.06 for the studied range of Reynolds numbers.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"55 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84716584","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":"FEATURES OF WATER TREATMENT FOR BOILER ROOMS","authors":"A. A. Dolinsky, O. Obodovych, V. Sydorenko, A.Y. Lymar","doi":"10.31472/ttpe.4.2021.2","DOIUrl":"https://doi.org/10.31472/ttpe.4.2021.2","url":null,"abstract":"Thousands of medium and low steam boilers and hot water boilers operate in the country's industry, municipal energy and agriculture. Their reliable operation is largely determined by the maintenance of a rational water-chemical regime. The main problems of source water are the presence of dissolved oxygen, iron ions, salts of calcium, and magnesium. \u0000The aim of the work is to analyze the existing technologies and equipment for water treatment for different types of boilers. Determination of physicochemical parameters and requirements for source and prepared water. Presentation of new multi-purpose energy-efficient and resource-saving water treatment equipment. \u0000The article considers the negative impact of dissolved iron, hardness salts, dissolved gases present in the feed water on the operation of boiler equipment. \u0000The main requirements for feed water in terms of hardness, the content of dissolved oxygen, and oils for steam and hot water boilers are given. The mechanism of scale formation is given. The main existing methods of feed water treatment are considered, namely softening on Na-cation exchange resin, liming, softening, and reduction of total salt content on reverse osmosis units, softening, and reduction of total salt content by the sequential passage of water through H, OH-ion exchange filters. A multi-purpose aeration-oxidation setup of rotor type (AORT) is presented, which implements the method of discrete-pulse energy input, on which it is possible to carry out operations to remove iron, manganese, hardness salts, increase pH and degassing from water.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91314631","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":"INVESTIGATION OF THE EVAPORATION AND CRYSTALLIZATION OF A SESSILE DROP OF AMMONIUM SULFATE SOLUTION ON A SMOOTH HEATED SURFACE.","authors":"Ya. Hotskyi, G. Ivanitsky, A. Stepaniuk","doi":"10.31472/ttpe.4.2021.6","DOIUrl":"https://doi.org/10.31472/ttpe.4.2021.6","url":null,"abstract":"Creation of new composite granular fertilizers with layered structure, which are formed due to the layered mechanism of granulation in the granulator of the fluidized bed is an urgent task. The process of forming these granules is achieved due to the layered granulation mechanism, the basis of which is the formation of a layer of solids on the surface of the granules by mass crystallization. \u0000In the production of granular fertilizers based on ammonium sulfate with the addition of organic and inorganic impurities an important place is occupied by the processes of evaporation and mass crystallization, which determine the morphological properties of the obtained granular material. \u0000During the experimental study of the evaporation process, it was found that the process consists of three main evaporation periods: the heating period from the initial temperature to equilibrium, the period of equilibrium evaporation and the decreasing drying rate period with crust formation, during which a solid crystal structure is formed. The beginning of each period according to the example of drying droplets in a gas stream during spray drying is described by the nature of the change in droplet temperature. \u0000This paper presents the obtained thermograms of the process of evaporation of droplets with a diameter of 3–7 mm 40%, 50% and 60% aqueous solutions of ammonium sulfate with the addition of a mixture of bone meal. The evaporation of 40%, 50% and 60% solutions of ammonium sulfate with the addition of a mixture of bone meal, with a given ratio of AS: BM on a dry residue of 60:40 and 80:20 on a surface temperature of 95°C in the second evaporation period crystalline nuclei appear, and the concentration of solute is close to saturated and almost unchanged, so that the evaporation rate and temperature of the drop, as can be seen from the thermogram, remain constant temperature for all solutions of ammonium sulfate. Increasing the content of bone meal from 8 to 24% to shift the wet thermometer in the kinetics of the evaporation process. \u0000The paper also presents the results of morphological analysis of the obtained solid crystallized drops of ammonium sulfate with impurities of bone meal. It was found that the solid crystallized drop of ammonium sulfate with bone meal consists of a framework of microcrystals of ammonium sulfate, with a reduced size of 10 to 80 μm, bone meal in the form of inclusions is placed in the frame, the particle size of bone meal varies up to 100 μm, indicating that the solution is a suspension.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"72 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83925980","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":"CFD MODELING OF VORTEX AFTERBURNING OF BIOMASS GASIFICATION PRODUCTS IN A FLUIDIZED BED FURNACE","authors":"S. Kobzar, I. Borisov, A. Khalatov, A. Teplitski, Y. Pitsukha","doi":"10.31472/ttpe.4.2021.10","DOIUrl":"https://doi.org/10.31472/ttpe.4.2021.10","url":null,"abstract":"CFD modeling of the afterburning of biomass gasification products in a fluidized bed furnace with a vortex supply of secondary air has been carried out. The effect of secondary air heating on the ecological characteristics of flue gases has been determined. Modeling has shown that gasification products swirl in the primary chamber with the formation of a central vortex, which obeys the law of solid-body rotation. An increase in the temperature of the secondary air leads to an increase in its tangential velocity and, as a consequence, to an increase in centrifugal mass forces. Calculations have shown that with an increase in the secondary air temperature, the maximum of the kinetic energy of turbulence shifts to the periphery and increases in absolute value. This results in more efficient mixing of the central (producer gas) and peripheral (secondary air) streams. As a result, this leads to a more complete combustion. The influence of secondary air heating on the ecological characteristics of the furnace has been determined. As a result of air heating from 30° C to 300° C, the concentration of carbon monoxide decreases by more than 1.5 times. The concentration of nitrogen oxides practically does not change and amounts to 3.5 mg /nm3.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74213335","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":"INNOVATIVE METHODS OF JOINT PROCESSING OF HEAD AND FUSEL FRACTION IN RECTIFIED ALCOHOL END BIOETHANOL PRODUCTION","authors":"Y. Bulii, I. Yuryk, O. Obodovych, V. Sydorenko","doi":"10.31472/ttpe.4.2021.5","DOIUrl":"https://doi.org/10.31472/ttpe.4.2021.5","url":null,"abstract":"With rising energy prices, the development and implementation of innovative energy-saving technologies is a priority in the production of rectified alcohol and bioethanol.  By-products of distillation are the head fraction of ethyl alcohol, fusel oil, and fusel alcohol. \u0000Existing methods of joint processing of the head and fusel fractions in one column do not provide effective removal together head and intermediate impurities, which adversely affects the quality of commercial alcohol. \u0000The aim of the work was to develop methods of joint processing of the head and fusel fractions in the column for the concentration of impurities of cyclic action, to determine the optimal technological parameters of the column, and to test the efficiency of innovative methods in production conditions: to determine the degree of extraction, the concentration of volatile impurities Three schemes of processing of the head and fusel fractions are given. \u0000The method I allowed to free the bottom products from the head and intermediate impurities of alcohol and use such a liquid for hydroselection in the epuration column. Method II allowed significantly improving the physicochemical parameters of the bottom water-alcohol products, improving the quality of rectified ethyl alcohol by more complete removal of volatile organic impurities from the zones of their maximum accumulation and reducing their content in the reflux entering the irrigation column. Method III allowed ensuring maximum removal of volatile head and intermediate impurities and reducing the loss of ethyl alcohol with the concentrate of impurities. \u0000The use of innovative methods allows for joint processing of the main and fusel fractions in the production of rectified alcohol and bioethanol, to increase the yield of marketable alcohol by 3.8%.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86696905","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":"ANALYSIS OF THE HEATING CAPACITY OF ELECTRICALLY HEATED WINDOWS","authors":"P. Krukovskyi, D.A. Smolchenko, G.P. Krukovskyi, А. Deineko","doi":"10.31472/ttpe.4.2021.7","DOIUrl":"https://doi.org/10.31472/ttpe.4.2021.7","url":null,"abstract":"Electric window heating has been used for some time in Europe and the Americas, but in Ukraine it only enters the market as an independent heating device and raises the question of its heating capacity in winter and the benefits of using them. There are several works in this field that determine the efficiency and contribution to the energy needs of an electric-heated window house, but it is necessary to answer more specifically the question of the heating capacity of such windows as a single heating system, for example rooms of certain sizes.In the work present the design, thermophysical processes occurring in such windows and, by computer simulation of the thermal state of the window with the selected typical room, the results of the study of the heating capacity of the windows, depending on the relative glazing area to the total area of the outer enclosure and the ambient temperature conditions not exceeding the maximum heat emission 450 /  and temperature 45 °С on the inner glass of the double-glazed window. the presented thermal model of the window with the room is implemented as a computer program with the possibility of a detailed analysis of the heating capacity of the window, depending on the parameters of the room and the outside temperature, as well as optimization of operational parameters to maintain comfortable conditions.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77547792","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":"GLOBAL PROSPECTS FOR BIOENERGY SECTOR","authors":"G. Geletukha, T. Zheliezna","doi":"10.31472/ttpe.4.2021.9","DOIUrl":"https://doi.org/10.31472/ttpe.4.2021.9","url":null,"abstract":"The aim of the work is to analyze some global scenarios for bioenergy development, including the development in certain sectors, as well as to identify priority areas for bioenergy in Ukraine. Today, bioenergy is a world leader in renewable energy, playing a significant role in replacing fossil fuels and reducing greenhouse gas emissions. Over the last twenty years, the global primary energy supply from biomass and biofuels has tripled and reached more than 10% of the total primary energy supply, accounting for almost 70% of the contribution of all renewable sources. The International Renewable Energy Agency predicts that by 2050, renewable energy sources could account for 60% or more of the total final energy consumption of many countries. The share of biomass in the global final consumption of renewable energy might be almost half in 2030 and 40% in 2050. According to the International Energy Agency, starting from 2030, one can expect to use only modern bioenergy technologies with increasing consumption of modern biomass up to about 100 EJ in 2050. For Ukraine, the priority areas seem to be combined heat and power production from biomass, as well as production of biomethane for the direct replacement of natural gas and carbon-neutral balancing of the energy system with a high share of renewable sources. For the thermal energy sector, the introduction of modern boilers and CHP plants running mainly on agricultural biomass is recommended. For the transport sector, prospects are the production of first and second generation liquid biofuels, as well as biomethane from biomass obtained in compliance with sustainability criteria.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84820610","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}