Thermophysics and Thermal Power Engineering最新文献

{"title":"USE OF THE REBURNING TECHNOLOGY WITH BIOMASS PYROLYSIS PRODUCTS AS A REBURNING FUEL TO REDUCE EMISSIONS OF NITROGEN OXIDES FROM TPP 312 BOILER","authors":"S. Kobzar, A. Khalatov","doi":"10.31472/ttpe.1.2021.10","DOIUrl":"https://doi.org/10.31472/ttpe.1.2021.10","url":null,"abstract":"\u0000In Ukraine, a three-stage coal combustion system fueled by a natural gas as a reburning fuel for nitrogen oxides emission reduction was mounted on Unit № 4 of the Ladyzhyn TPP. This system was developed in cooperation with Combustion Engineering (USA), VTI (Russia) and the Gas Institute of the National Academy of Sciences of Ukraine and was assembled by the Ladyzhyn TPP staff in 1992. The test runs of this system had confirmed the effectiveness of this method of reducing emissions of nitrogen oxides into the atmosphere (up to 50%).Unfortunately, due to the high price of natural gas and the introduction of limits on its use, currently the use of natural gas as a fuel for reburning is impossible. One of the possible ways to reduce emissions of nitrogen oxides from the coal-fired boiler TPP 312 is the operation of Reburning technology with the biomass pyrolysis product as reburning fuel. \u0000The aim of the work was to evaluate the possibility of the application the biomass pyrolysis products as a reburning fuel in Reburning technology to reduce nitrogen oxides from the coal-fired boiler TPP 312. For this purpose, a detailed computer model of a standard TPP 312 boiler and a TPP 312 boiler with a coal reburning combustion system was developed and built. \u0000The study of the operation the Reburning coal combustion system, which is mounted on the unit №4 DTEK Ladyzhynska TPP, on the design parameters of the operation for the boiler load of 280 MWe was carried out. It was determinate that the supply of reburning fuel at 12% of the total heat capacity of the boiler gives a good level of the reduction of nitrogen oxides (up to 25%), provides no slag conditions for superheater pipes and does not lead to increase of the fuel losses with unburnt carbon. \u0000","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"165 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81573292","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 ECOLOGICAL ANALYSIS OF THE LIFE CYCLE OF ENERGY USE OF MAIZE CROP RESIDUES","authors":"G. Geletukha, O. Haidai","doi":"10.31472/ttpe.1.2021.6","DOIUrl":"https://doi.org/10.31472/ttpe.1.2021.6","url":null,"abstract":"Maize crop residues have significant energy potential in Ukraine. The purpose of this work is to analyze the energy and environmental efficiency of thermal energy production from corn residues, taking into account the sustainability criteria. The task of the work is to quantitatively calculate energy and environmental efficiency indicators and compare them with values that meet the criteria of sustainable development. Using the life cycle assessment methodology, the cases of using bales, pellets and briquettes from plant biomass as fuel in a boiler with a capacity of 500 kW were considered. The calculation of the energy conversion factor and reduction of greenhouse gas emissions has been performed. It is shown that at distances of transportation of finished biofuel not exceeding 150 km, energy indicators (energy yield coefficient, specific cumulative energy demand) are within the recommended values corresponding to sustainable development. The distribution of primary energy consumption of fossil fuels by stages of the life cycle of thermal energy production from maize crop residues is shown. Reductions of greenhouse gas emissions from the introduction of heat production technologies from maize crop residues meet the new requirements of the European Parliament and of the Council Directive on the promotion of the use of energy from renewable sources on the use of renewable energy sources. It is shown that in general the production of pellets and briquettes from corn residues is energetically inexpedient when transporting biomass at a distance that meets the criteria of sustainable development.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"82 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85600213","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":"INCREASING THE DEGREE OF EXTRACTION OF ORGANIC IMPURITIES OF RECTIFIED ALCOHOL","authors":"Y. Bulii, O. Obodovych, V. Sydorenko","doi":"10.31472/ttpe.1.2021.8","DOIUrl":"https://doi.org/10.31472/ttpe.1.2021.8","url":null,"abstract":"Obtaining high quality rectified ethyl alcohol is a priority for the further development of the alcohol industry. The solution to this urgent problem is possible under the condition of deeper extraction and concentration of volatile alcohol impurities on the plates of the column equipment of the Distillation/Rectification Unit. \u0000In the columns of the Distillation/Rectification Unit simultaneously with the release of volatile alcohol impurities due to the esterification reaction is the formation of organic compounds that degrade its quality and reduce the yield of the final product. Thus, during the interaction of alcohols, acids, and aldehydes, the breakdown products of amino acids, sulfur compounds, and other components of the brew in the fermentation column are the formation of esters, aldehydes, and acetals of organic acids. \u0000The aim of the work was to determine the optimal technological modes of distillation of alcohol-containing intermediate products and by-products of the distillation/rectification process in the accelerating column, epuration of wash distillate in the epuration column, the concentration of rectified alcohol in the alcohol column, and its repeated epuration in the column of final clearance, under which the content of organic impurities in rectified ethyl alcohol would be the lowest. \u0000Materials and methods.  Research methods were analytical, chemical, physico-chemical with the use of instruments and research methods used in the production of rectified ethyl alcohol. The concentration of volatile alcohol impurities was determined on a gas chromatograph with a column of HP FFAP 50 m × 0.32 m. It is determined that to increase the degree of extraction of organic impurities it is necessary to ensure the concentration of ethyl alcohol in the column bottom of the accelerating column, which does not exceed 4% vol.; pasteurization zone in the rectification column increase to 10 plates, reduce the concentration of ethanol in the epurate to 22-29% by hydroselection of impurities; for hydroselection in the epuration column use free of impurities bottom products of the accelerating column. To improve the quality of rectified alcohol and reduce energy consumption by extending the contact time on the plates of steam and liquid, a promising direction is the use of mass transfer equipment of cyclic mode. The proposed measures require constant monitoring of technological parameters and provide for the operation of technological equipment in an automated mode.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"72 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74545674","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 WARMING – PHYSICS AND GEOPOLITICS (Review). 1. Anthropogenic and natural concepts of climate change","authors":"B. Basok, Ye.T. Baseyev, I. V. Kurayeva","doi":"10.31472/ttpe.1.2021.5","DOIUrl":"https://doi.org/10.31472/ttpe.1.2021.5","url":null,"abstract":"Introduction. Global warming and so-called the “greenhouse effect” is one of the most discussed problems of physics and geopolitics, which has caused protest environmental movements in the world. \u0000Problem Statement. Widely discussed are both anthropogenic (the emission of greenhouse gases into the atmosphere) and the natural concepts of global warming with the dramatic effects of climate change on the planet and individual regions. \u0000Purpose. Evaluate the state of the problem, to present the results of research and measures to possible reduction of the greenhouse effect. \u0000Materials and methods. Authoritative literature sources with the analysis of anthropogenic and natural factors of global warming are used, including with the explanation of the physical processes which are shown at solar-geomagnetic activity and other natural phenomena. \u0000Results. The main causes and mechanisms of natural and man-made nature for the actual growth of greenhouse gas emissions and global temperature in the 20th century are identified and their estimates for the period up to 2100 are given. \u0000Conclusions. Most likely, the effect of global warming on the planet's climate is totally due to natural causes of cosmogenic origin and somewhat exacerbated by the effects of industrial development of mankind. For the final solution of this problem it is necessary to fully and adequately conduct more in-depth complex experimental and theoretical-model studies taking into account various factors of geological, climatic, meteorological, thermophysical, astrophysical nature and application of modern methods of mathematical physics, statistics and probability theory. reasonable measures to adapt the economy and life to climate change.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78164185","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":"EUROPEAN GREEN DEAL AND NEW OPPORTUNITIES FOR THE DEVELOPMENT OF RENEWABLE ENERGY","authors":"T. Zheliezna","doi":"10.31472/ttpe.1.2021.9","DOIUrl":"https://doi.org/10.31472/ttpe.1.2021.9","url":null,"abstract":"The aim of the work is to develop recommendations for Ukraine on setting long-term integrated climate and energy goals and identifying ways to achieve them. The preconditions, main goals and objectives of the European Green Deal, which was presented by the European Commission in December 2019, are analyzed. The European Green Deal is a comprehensive strategy for the transition to a sustainable economy, clean energy and climate neutrality, i.e., zero greenhouse gas emissions, in Europe by 2050. The adoption of this Deal was preceded by several stages of a coherent EU policy in the relevant sectors. Possibilities for renewable energy development within the framework of the European Green Deal are considered. It is determined that preference is given to the production of green electricity, mobilization of the potential of offshore renewable energy, production of biogas and biofuels from biomass of agricultural origin, sustainable use of low-carbon and renewable fuels, including biomass and hydrogen, in hard-to-electricity sectors. In Ukraine, the document that is closest by its contents to the European Green Deal is the draft Concept of green energy transition until 2050 presented in January 2020. The draft Concept states the goal of achieving 70% of renewable energy sources in electricity generation by 2050 and the climate-neutral economy of Ukraine by 2070. It is recommended that this document should be finalized and adopted formally as soon as possible.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83309882","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":"ANALYTICAL STUDY OF THE MECHANISM OF DROPLET DEFORMATION AND BREAKUP IN SHEAR FLOWS","authors":"G. Ivanitsky, B. Tselen, N. Radchenko, L. P. Gozhenko","doi":"10.31472/ttpe.1.2021.4","DOIUrl":"https://doi.org/10.31472/ttpe.1.2021.4","url":null,"abstract":"The problem of drop deformation and breakup in shear flow represents academic and practical interest and has attracted close attention over the intervening decades. Drop breakup is important for a wide range of engineering and biomedical applications including production and processing of emulsions, aerosols, etc. Although drop breakup operations are widely used in various industries, however, till quite presently there is no unequivocal treatment of the physical mechanism, which causes the fragmentation of dispersions in shear flows. In this paper the principles of constructing a mathematical model, which predicts the evolution of initially spherical droplet in shear flows of viscous liquid over a wide range of flow regimes as well physical parameters of both liquid phases, are considered. A mathematical model is presented that describes the deformation of a single drop suspended in another immiscible liquid under the combined action of three forces, namely, hydrodynamic force, capillary force and dissipative viscous force. The influence of each of these forces on the process of droplet deformation is discussed in the paper. \u0000The focus of the study is to more deeply analyze the dynamics of droplet deformation in shear flows and the transitional effects associated with current droplet shapes. Particular attention is paid to the analysis of critical conditions for the onset of irreversible deformation of droplets, which leads to their destruction. The deformed droplet is assumed to be in the form of prolate ellipsoid of revolution. The drop deformation is regarded as motion of the centers mass of the half-drops, symmetrical with respect to the drop center. \u0000The results of numerical calculations for droplet deformation in shear flows in comparison with experimental data of other authors are presented. A simple criterion for destruction of droplets in shear flows has been obtained. The results of the analysis confirm the reliability of the model and the competency of the assumption made. The model is able to predict the nature of droplet deformation and the conditions for their destruction in shear flows with known operating parameters with a greater degree of accuracy than the existing empirical relationships.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82541574","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":"MODELING OF HEATING AND MELTING PROCESSES OF HYDROCARBON MIXTURES WITH FORCED REMOVAL OF THE MELT","authors":"O. Obodovych, G. Ivanitsky, O. Stepanova","doi":"10.31472/ttpe.1.2021.11","DOIUrl":"https://doi.org/10.31472/ttpe.1.2021.11","url":null,"abstract":"Analysis of the work, which considered the mathematical modeling of the melting process in various industries, currently does not pay attention to modeling the processes of heating and melting of hydrocarbon mixtures, such as vaseline, paraffin, fats, lanolin and others. The issue of optimization of heating and melting processes, calculations of necessary process parameters (speed and depth of thermal front penetration, etc.) and equipment, avoidance of repetition for each hydrocarbon mixture of experimental studies shows the need to develop a mathematical model of these processes. For the method of melting a substance placed in a cylindrical tank, based on the movement of a disc heating element under the action of gravity during melting and overflow of molten substance through the gaps between the disc and the walls of the tank, simulation has been carried out. Simulation of the melt flow in the annular gap is presented, which describes the laminar flow under the influence of the pressure drop and the velocity of the vessel wall relative to the heater, and the melt flow under the heater.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83483113","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":"FORECASTING THE INTENSITY OF SOLAR RADIATION BASED ON ARTIFICIAL NEURAL NETWORKS","authors":"B. Basok, M. P. Novitska, V. Kravchenko","doi":"10.31472/ttpe.2.2021.7","DOIUrl":"https://doi.org/10.31472/ttpe.2.2021.7","url":null,"abstract":"The paper considers short-term forecasting of the intensity of solar radiation in the city of Odessa based on an artificial neural network. The artificial neural network was trained on the experimental data of the ground weather station (Davis 6162EU), which is installed on the roof of the educational building of the Odessa National Polytechnic University. Modeling, validation, and testing of experimental data were performed using the MATLAB software package, namely Neural Network Toolbox. The Levenberg-Markwatt model is used in this work. The analyzed data set was divided into proportions of 70%, 15%, 15% for neural network training, its validation, and testing, respectively. The results which the trained neural network gave during forecasting within the framework of the database and outside it are given. The deviation between real and forecast data is analyzed. The root-mean-square error on December 26, 2016 was 13.03 W / m2, and on December 27, 2016 - 9.44 W / m2 when forecasting outside the database. Evaluation of the accuracy of an artificial neural network has shown its effectiveness in predicting the intensity of solar radiation. To predict parameters based on artificial neural networks, experimental data that describe a real system are needed. Artificial neural networks, like other approximation methods, have both advantages and disadvantages.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89727054","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 DEVELOPMENT OF A CRYOGENIC CALORIMETRIC SYSTEM FOR STUDYING THE STATE OF LIQUIDS IN INHOMOGENEOUS MATERIALS","authors":"S. Ivanov, Leonid Dekusha, Leonid Vorobiov, O. Dekusha","doi":"10.31472/ttpe.2.2021.10","DOIUrl":"https://doi.org/10.31472/ttpe.2.2021.10","url":null,"abstract":"The analysis of methods and means of experimental determination of the ratio of free and bound moisture in materials is carried out, and it is shown that most of the available measuring instruments do not allow investigating the ratio of free and bound moisture on representative samples of heterogeneous materials, therefore there is a need to create a specialized device for these purposes. \u0000Thus, the concerned work is aimed to the development of the differential scanning calorimetry method for studying the state of liquids in inhomogeneous materials and the creation of a cryogenic calorimetric system for the implementation of this method. \u0000On the basis of the performed analysis, recommendations were formulated for the development of a measuring system that is capable of examining representative samples of heterogeneous materials of various structures without the need for their preliminary grinding. \u0000The method of differential scanning calorimetry has been improved for studying the state of water and organic liquids in inhomogeneous materials in a wide temperature range, which is based on the use of a three-cell differential measurement scheme, as well as the use of cells, the configuration of which allows taking into account the peculiarities of inhomogeneous raw materials. \u0000A prototype of a cryogenic calorimetric system has been created, and a method for studying the metrological characteristics of such a system has been developed. On the basis of experimental studies, it has been established that the limits of the permissible relative measurement error of using the developed cryogenic calorimetric system are ± 5%, which corresponds to world analogues.","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"100 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82751684","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 WARMING - PHYSICS AND GEOPOLITICS (Review). 2. Policies to mitigate the negative impact of climate change and adapt to it","authors":"B. Basok, Ye.T. Baseyev, I. V. Kurayeva","doi":"10.31472/ttpe.2.2021.4","DOIUrl":"https://doi.org/10.31472/ttpe.2.2021.4","url":null,"abstract":"Introduction. Reducing the negative impact of global warming and adapting to its devastating effects is an urgent global problem. Its decision is actively taken care of by politicians, leading world organizations and the expert community. \u0000Problems. Political, financial and economic, innovative, scientific and technical approaches and measures to reduce and / or neutralize climate change are widely discussed. World organizations - IPCC, IEA, WMO, IMF, etc. - are involved in solving the problems. \u0000Purpose. Assess the state of the problem, present the results of research and measures and tools for their implementation to reduce the greenhouse effect and / or adapt to its negative impact. \u0000Materials and methods. Authoritative literature sources with analysis of approaches, measures and tools to reduce greenhouse gas emissions, including the diversification of the fuel and energy balance of world energy resources, were used. Possibilities of adaptation to climate change are considered. \u0000Results. The main approaches and mechanisms of man-caused nature to actually reduce greenhouse gas emissions and global temperature in the 20th century are identified and their estimates for the period up to 2050 are given. The crucial role of RES and energy efficiency in the use of energy resources has been confirmed. \u0000Conclusions. It is likely that by the middle of the 20th century the world economy can be brought to a state of low-carbon development primarily through the use of renewable energy, energy efficiency, diversification of primary energy resources and their decarbonization, which will significantly reduce annual emissions of 10 carbon .","PeriodicalId":23079,"journal":{"name":"Thermophysics and Thermal Power Engineering","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81105356","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}