Thermal Power Engineering Research Articles

VALIDATION OF THE STANDARD CERTIFIED METHOD FOR THE DETERMINATION OF PETROLEUM PRODUCTS IN SORBENT SAMPLES

The validation of a standard certified method for measuring the mass fraction of oil products in soils and bottom sediments by IR spectrometry for measuring the content of oil products in sorbent samples based on ash and slag waste from thermal power engineering, and changes in the method of sample preparation in order to improve the metrological characteristics of the method are proposed. To calculate the metrological characteristics of the method to be validated, 48 measurements were carried out according to the recommendations set out in RMG 61-2010 (Appendix E). The assessment of the repeatability index was carried out according to the Cochran criterion. Grubbs statistics were used to evaluate the intralaboratory precision index. The correctness score was determined using a two-sample Student’s t-test. The assessment of the accuracy indicator was performed by the selective relative standard deviation of the measurement results of the control sample. Quality indicators of the standard methodology PND F 16.1:2.2.22-98 (2005 edition): repeatability rate 8 %; index of intralaboratory precision 10 %; correctness score 15 %; accuracy rate 25 %. Quality indicators of the method being validated: repeatability rate 2.7 %; index of intralaboratory precision 2.7 %; correctness score 1.3 %; accuracy rate 5.3 %. The measurement results obtained using the developed validated method for measuring the oil product content in the samples of modified sorbent based on ash and slag wastes are more reproducible in terms of repeatability and precision, as well as more correct and accurate in comparison with the results obtained when measuring using the standard PND F method 16.1:2.2.22-98 (2005 edition).

A Numerical Study of Heat Performance of Multi-PCM Brick in a Heat Storage Building

Modern technologies of thermal power engineering make it possible to design and build systems using renewable energy sources. Often, energy accumulation and storage require the development and adaptation of appropriate systems, the simplest of which are passive systems based on phase-change materials. In this study, a numerical analysis of heat transfer in a brick wall containing several materials with different melting temperatures is carried out. The unsteady two-dimensional conjugate problem of phase transitions is considered, taking into account natural convection in the melt, which has been solved using the developed in-house finite difference technique. A numerical experiment has been carried out for a brick block with several rectangular inserts filled with PCMs under various external thermal conditions. As a result of the numerical analysis, it has been shown that the relative arrangement of materials with different melting points has a significant impact on the heat transfer and heat exchange between the environment and the room.

IGNITION OF WOODEN BIOMASS PARTICLES UNDER MICROWAVE EXPOSURE AT HIGH-TEMPERATURE RADIATION-CONVECTIVE HEATING

Link for citation: Syrodoy S.V., Malyshev D.Yu., Kostoreva Zh.A., Kostoreva A.A., Omarov A.A. Ignition of wooden biomass particles under microwave exposure at high-temperature radiation-convective heating. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 5, рр.159-167. In Rus. The relevance. Despite the active development of technologies for the production of electrical energy by means of wind power generators and solar batteries, by 2100, most of the energy will still be generated at thermal power plants that burn fossil fuels. As a rule, thermal power plants use coal as fuel (about 40 %). However, it should be noted that during the combustion of coal in the furnaces of steam and hot water boilers, toxic oxides of sulfur and nitrogen are intensively formed. In this regard, many scientists of the world working in the field of energy are working to create new innovative technologies for the eco- and energy-efficient production of heat and electricity. The latter include technologies for burning woody biomass in the furnaces of steam and hot water boilers of thermal power plants. The use of woody biomass can significantly reduce the environmental impact of thermal power plants on the atmosphere. However, no technology has yet been developed to burn wood with high energy efficiency. The latter is due to the high moisture saturation of woody biomass in its initial state. The main aim: experimental determination of the main stages and identification of a complex of physicochemical processes occurring together during the ignition of woody biomass particles under microwave exposure under high-temperature radiation-convective heating. Object: dry and moisture-saturated wood of two types (pine and cedar). The relative humidity of the wood from which the particles were made (with a characteristic size of 4 mm) varied from 6 (relatively dry biomass) to 42 % (moisture-saturated wood). Method. To establish the main characteristics of wood particle ignition under microwave exposure under high-temperature radiation-convective heating, a special experimental stand was developed, representing a reaction tube with heat-insulated radio-transparent walls through which a high-temperature oxidizer (air oxygen) was blown. The wood particle was mounted on the axis of the pipe so as to fall into the focus of the emitter. All processes were recorded by a high-speed video camera. Results. The paper introduces the results of experimental studies of ignition of dry and wet particles of woody biomass in the environment of air heated to high temperatures under conditions of radiation-convective and radiation-convective microwave heating. A significant influence of the type of wood on the ignition delay times (tign) was established. Rather significant effect of heating conditions on ignition is also shown, since microwave exposure leads to an acceleration of ignition of woody biomass particles. It was shown that during the ignition of wet wood particles, the effect of exposure to microwave radiation (acceleration of ignition) is more significant compared to ignition of dry wood particles. It was also found that the moisture content (φ) of woody biomass significantly affects the ignition delay times (increase in φ leads to growth in the tign value). The regularities established in the conducted experiments illustrate the prospects of using woody biomass (including moisture-saturated) in thermal power engineering as the main fuel.

CALCULATION OF HEAT TRANSFER INTENSITY OF GAS FUEL COMBUSTION PRODUCTS

Link for citation: Mrakin A.N., Afanaseva O.V., Kuleshov O.Yu. Calculation of heat transfer intensity of gas fuel combustion products. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 5, рр.109-115. The relevance of the research is determined by the modern trend in the field of thermal power engineering and heat engineering for the transition from traditional gaseous fuel (methane) to the use of hydrogen, methane-hydrogen mixtures, as well as thermochemical conversion gases. Switching to new non-design fuel is justified by considerations of reducing the negative impact on the environment and increasing the thermal efficiency of fuel combustion plants. In this case, the use of fuels with a composition different from the design one will affect the heat transfer processes. The main aim: carrying out a comparative analysis of indicators of the intensity of radiant and convective heat transfer of combustion products of non-design fuels, such as hydrogen, methane-hydrogen mixture and thermochemical conversion gases. As an assumption in the formulation of the problem and objectives of the study, the constancy of the heat release power in the apparatus due to changes in the amount of fuel burned was taken. Objects: heat exchange surface of a fire-tube hot water boiler. Methods: carrying out numerical calculation using traditional approaches to determine the indicators of the intensity of heat transfer in the system «combustion products – metal wall of the pipe of thermal power plants». We also used the relations tested earlier by other authors to calculate the thermophysical parameters of gas mixtures. Results. According to the results of the performed comparative calculations, we can conclude that the transition from the use of conventional fuel (natural gas/methane) to its thermochemical conversion gases under the considered conditions has almost no effect on the integral heat transfer performance. To a greater extent, this transition is caused by changes in the intensity of heat transfer for products of combustion of hydrogen and methane-hydrogen mixture, which will affect the operation of thermal power and heat technological installations. At the same time, it is necessary to conduct additional research on the combustion kinetics of thermochemical methane conversion gases, their thermophysical properties, etc., because the hardware design, type of the catalyst used and operating parameters of the process will affect the composition of obtained synthesis gas.

OPTIMIZING POROUS MATERIALS WITH PREDICTION THERMAL PHYSICAL CHARACTERISTICS

The article presents experimental data, based on which the influence of various factors on the strength and thermophysical characteristics of porous heat-insulating materials was studied.
 Porous bodies in thermal power engineering are used for thermal protection of power plants, various aggregates, in thermal insulation structures of buildings and technological networks. The properties of these materials and the field of use depend on their chemical composition and method of production.
 The task of this research is to obtain a raw material mixture for heat-insulating material of the closed-cell type with increased thermal resistance and porosity by optimizing its qualitative and quantitative composition. The goal is also to improve the method of obtaining porous heat-insulating material by changing the temperature and time regimes in order to improve the physical, mechanical and operational characteristics, which will allow the material to be used in a wider temperature range.
 Based on the dependences of strength and thermophysical properties on the density of the finished material obtained in the work, it was concluded that the best characteristics are the samples of the porous material with the lowest density, which are formed at the maximum humidity of the raw material. Kinetics of drying and heat treatment of the raw material mixture, thermal regimes are the main factors that determine the porosity, strength and thermal conductivity of the finished heat-insulating material.
 Performed laboratory studies of the material proposed in the paper allow choosing the required temperature regimes of heat treatment. Thus, the task of further research is to choose a method of organizing effective heat and mass exchange, modeling these processes, experimental testing of the obtained data, and creating a method for determining the main technological and structural parameters of the method of obtaining a new material.
 The performed experimental studies made it possible to determine the conditions for the implementation of new technologies for the production of porous materials with the possibility of predictive determination of their properties.

Determination of reliability conditions of reversible water supply systems in thermal power engineering

Today, the most important issues in the national economy of Ukraine are the issues of continuous, reliable and safe operation of reversible water supply systems, namely power units of thermal electric stations and heating plants of industrial enterprises. Trouble-free and reliable operation of water supply systems ensures the normal operation of social and household and industrial enterprises, as well as the safe operation of fire protection systems, which can be disrupted when the supply of a quality product to the consumer is stopped. For the purpose of research to determine the conditions of the reliability of reversible water supply systems in thermal power engineering, as well as the impact of risks in these systems on the reliability of reversible water supply systems, it is proposed to determine the states in which any water treatment system can be and the risks in water treatment systems that are technogenic in origin, and the consequences are ecological. The analysis of the obtained results showed that the states in which the water treatment system can be divided into three classes in accordance with the regulatory documents on the definition of technogenic risks in water treatment systems: class 1 (limit state) - the system works in normal mode, all blocks and elements work without failures and crashes; class 2 (critical state) - the system works in offline mode, some units or elements of the system work in partial failure mode; class 3 (dangerous state) - the system practically does not work and does not purify water, some blocks or elements of the system are in a state of failure. The risks that arise during the operation of water treatment systems and which can be used to assess their technogenic safety can be defined as: a) the probability of this system supplying raw water to the consumer as a result of the failure of blocks and elements of this system - state 3 - dangerous; b) the probability of this system supplying the consumer with poor-quality water as a result of partial failures and freelance work of units and elements of this system - state 2 - critical; c) the probability of this system supplying raw water to the consumer when the system is in state 1 - limiting, due to the natural inertia inherent in the specific physical and chemical processes on which the actual system operates.

Перспективы и преимущества использования металлосетчатых каталитических реакторов для газовых отопительных систем и бытовых нагревательных приборов

This article aims to acquaint as many specialists in the field of heat engineering and thermal power engineering as possible with the possibilities and advantages of metal-mesh catalytic heaters developed at the Institute of Catalysis SB RAS. They are shown to be fundamentally different from catalytic heaters in which ceramic or glass-fiber structures are used as carriers of oxidation catalysts. Practical examples of the implementation of this technology on the example of a hot water boiler, infrared heaters and other small-sized household appliances are given. It was shown experimentally that the supplied gas is oxidized completely, and the efficiency of the laboratory, even unoptimized sample of hot water boiler determined by the inlet and outlet water temperature is not lower than 85 % in the range from 15 to 100 % of nominal capacity and 93 % in the low-power mode. The presented technology enables smooth regulation of the heater output within the whole range from 1.5 to 10 kW with power overlap factor of about 7.

Prospects for the Use of Hybrid Thermal Power Plants with Applying Solar Technologies in the People’s Republic of Bangladesh Energy Sector

There is an inextricable relationship and interdependence between the conditions of meeting energy consumption demands and environmental pollution. The interaction of these two factors and the development of production forces are gradually drawing attention to the problem of interaction between the thermal power engineering and environment. At the thermal power engineering early development stage, the main manifestation of this attention was the search in the environment for resources necessary to meet the energy consumption demands and stable energy supply to enterprises and residential buildings. In the subsequent, the problem boundaries were extended to the possibilities of a more complete use of natural resources through the search and improvement of processes and technology, extraction and enrichment, processing and combustion of fuel, as well as improvement of thermal power facilities. One of the ways to further develop thermal power plants and reduce their environmental impact is hybridization of solar technologies with conventional power plants. To overcome the limitations of simple cycle power plants, a method for hybridizing conventional power plants with solar technologies and its influence on performance are considered. The solar technologies used in the global energy sector are briefly overviewed. The efficiency of using hybrid power plants is studied with reference to the People's Republic of Bangladesh, which is one of the world’s sunniest and actively developing regions. The state of the republic’s energy sector, climatic features, and the possibility of using solar technologies for local conditions are analyzed. A solar thermal power plant model with a parabolic collector is considered; the efficiency of such power plants is analyzed, and technologies for using a combined-cycle power plant (CCPP) jointly with a solar steam generator for electricity generation are overviewed. The schemes of combined-cycle power plants with a solar steam generator were numerically analyzed. The analysis results have shown that during the summer state peak, the use of the integrated power unit makes it possible to additionally obtain approximately 6.5% of the unit total power output in comparison with a similar classical CCPP, but without using the field of solar collectors and a solar steam generator. The use of one modern GE 9371FB gas turbine unit produced by General Electric makes it possible to increase the net efficiency by 3.9% and bring the combined cycle net efficiency up to 59%. The improvements in the power unit are carried out with the minimal impact on the combined cycle operation due to a limited contribution from the solar energy based steam generation system. The integrated system makes it possible to cut the capital costs for the power plant construction. The combination of a CCPP with a solar installation will open the possibility to construct a highly maneuverable power unit with high efficiency indicators.

Evaluation of the cost-effectiveness of solutions to improve the efficiency of atmospheric deaeration in boiler plants

The reliable and economical operation of equipment for thermal power plants, heat supply systems and boiler houses has been a relevant problem in the field of thermal power engineering for many years. In many industries, industrial steam is often used, for which steam boilers are used at thermal power plants. The water consumed by the boilers undergoes pre-treatment, which, in addition to its softening, includes thermal deaeration — the removal of aggressive gases that lead to equipment corrosion. Atmospheric deaerators are often used for this purpose. They are easy to use, quite effective, but have a disadvantage — a considerable amount of heat is lost with the removed flash steam. The article is dedicated to evaluating the cost-effectiveness of the technology for additional heating of return system water using deaerator steam and considering a method for improving the efficiency of atmospheric deaeration by partial closure of flash steam output in boiler plants. The paper presents a calculation of the scheme of operation of a deaeration plant, which makes it possible to increase the efficiency and effectiveness of the boiler house of the AB InBev Efes brewery in Ulyanovsk due to additional heating of return system water with atmospheric deaerator flash steam. The article also discusses the scheme of operation of an atmospheric deaerator, in which the flash steam will be discharged into the atmosphere only if it is necessary to remove aggressive gases. Thanks to the developed scheme, when the deaerator operates with a closed flash steam removal pipeline and without being fed with chemically purified water, the consumption of industrial steam is reduced, especially with a significant return of condensate, which increases the efficiency of the entire boiler room as a whole. According to preliminary calculations, assuming the average return of condensate from production per day of about 300 m3, the production steam savings will be 0.8 tons.

USE OF THE RESULTS OF THE WORK OF THE UKRAINIAN METEOR NETWORK IN THE PROCESS OF TEACHING PHYSICS TO STUDENTS OF THE EDUCATIONAL AND SCIENTIFIC INSTITUTE OF ENERGY, AUTOMATION AND ENERGY SAVING NULES OF UKRAINE

Features of meteor fixation methods are presented by organizing a network of corresponding observation points - permanently operating observation stations located on the territory of Ukraine with appropriate technical and software support for conducting basic and one-way observations of meteors in the radio range of electromagnetic wavelengths. This contributes to solving the strategic problems of meteor research, the structure and evolution of meteor showers and streams, the interaction of meteoroids with the Earth's atmosphere and their chemical composition. Scientific and technical products of observation stations are the results of high-precision basic or one-sided observations of meteors in the radio range of electromagnetic wavelengths, fundamental and applied scientific and technical research. The purpose of the study is to consider the principle of operation of the Ukrainian meteor observation network, a separate meteor hardware and software complex for observing meteors in the radio range of electromagnetic waves using the method of direct scattering on meteor trails of signals from powerful FM radio broadcasting stations with the possibility of further processing and presentation of data by students of specialties 141 "Electric power, electrical engineering and electromechanics", 144 "Thermal power engineering", 174 "Automation, computer-integrated technologies and robotics" of the Educational and Scientific Institute of Energy, Automation and Energy Saving of NULES of Ukraine in the process of studying physics. Processing of experimental data was carried out by students of the specified specialties under the guidance of the author while studying physics. The results of statistical data processing of meteor invasions and their graphic representation by students of the specified specialties in the process of mastering physics are described. Prospects - putting into operation by the end of 2024 the seventh receiving station in the city of Kyiv (student campus of NULES of Ukraine) - the seventh meteor hardware and software complex, as a component of the Ukrainian meteor observation network.

Flow methods as a general approach to automation of the chemical analysis of aqueous media (review)

The article is devoted to the consideration of general approaches to automating the analysis of aqueous media, which are the main objects of chemical analysis including natural and waste waters, as well as technological media in various industries (microelectronics, biochemical industries, nuclear and thermal power engineering), which are the main consumers of high-purity water used for pre-start flushing of inline equipment to the required cleanliness of surfaces, for preparation of coolants that ensure the operation of nuclear and thermal power plants. In all these cases, the content of impurities in used or spent and intended for discharge aqueous media is strictly regulated. Changes in the content of impurities in controlled media often occur spontaneously due to equipment failure on the controlled objects. Prompt response to such changes and their timely elimination can be performed more efficiently if chemical and technological control of the normalized parameters of aqueous media of any named origin and destination is carried out in a continuous automatic, on-line, mode, which guarantees the exclusion of gaps or delays in obtaining information about equipment failure on a controlled facility in case of technological control or about unauthorized discharges of pollutants in case of environmental control. Possible methodological approaches to the development of systems for continuous chemical monitoring of quality or levels of contamination of aqueous media are considered on the basis of the above prerequisites, and applicability of various flow methods for these purposes is discussed in the order of their appearance in the arsenal of analytical chemists.

Optimising Pulse Combustion Systems for Enhanced Efficiency and Sustainability in Thermal Power Engineering

This study evaluates the potential of pulsed cleaning, an emerging technology, in the maintenance of heating energy and reclamation boilers. Findings suggest that pulsed cleaning presents an effective, energy-efficient and eco-friendly approach to deposit removal. However, there remains a necessity for further investigation to fine-tune the process and understand its long-term implications on boiler performance. The ultimate objective is to establish pulsed cleaning as a reliable, efficient and sustainable cleaning technique for boiler surfaces. The study determined that pulsed cleaning is an encouraging new technology for cleansing the surfaces of heating energy and reclamation boilers. Nevertheless, it was noted that additional research is required to fine-tune the pulsed cleaning procedure and to evaluate its prolonged effects on the efficiency of boilers.

Специфіка господарських відносин у теплоенергетиці України

The main directions of Ukraine’s development in the medium term are the recovery and development of the country after the russian armed aggression, as well as the reform of the mechanisms for managing and regulating the economy in general and the thermal power industry in particular in accordance with the criteria set for accession to the EU. The aim of the study is to identify and generalize the specific features of economic relations in the thermal power industry of Ukraine. The article proposes a classification of factors that can be used to characterize the heat supply system of a particular settlement; the Ukrainian legislation regulating relations in the field of heat supply is studied; the prerequisites for reforming the heat supply sector in the direction of creating regional thermal energy markets are determined. The features of the organization of heat supply in the regions and settlements of Ukraine by types of energy carriers and the structure of thermal energy production are studied (steam or hot-water boilers, combined heat and power district heating, thermal power plants, nuclear power plants). The structure of thermal energy production in some large cities of Ukraine is analyzed. It is determined that an important feature of activity in the field of thermal supply is the centralization of capacities. An analysis of thermal supply systems in large cities of Ukraine has been carried out and it has been proved that the simultaneous use of both large generating capacities and small autonomous boiler houses is typical. Based on the study of existing projects of new buildings from the Database of Energy Certificates of the State Agency on Energy Efficiency and Energy Saving of Ukraine, it is proved that in recent years, in the design and construction of new residential buildings, there has been a tendency to abandon district heating. The features and priority of the use of various heating schemes in residential new buildings of the country are determined. The ownership structure of economic entities in the sphere of district heating of communal energy in Ukraine is analyzed. The number of unprofitable and profitable enterprises of thermal power engineering is studied in the context of forms of ownership. The features of economic relations in the thermal power industry of Ukraine are generalized, which generally characterize the specifics of the organization and functioning of this sphere and constitute the basis for its further reform and post-war development

МОДЕЛЬ СКВОЗНОГО РАЗВИТИЯ УНИВЕРСАЛЬНЫХ КОМПЕТЕНЦИЙ СТУДЕНТОВ В ГУМАНИТАРНОМ ЦИКЛЕ ДИСЦИПЛИН ОБРАЗОВАТЕЛЬНЫХ ПРОГРАММ ИНЖЕНЕРНЫХ НАПРАВЛЕНИЙ ПОДГОТОВКИ

The article presents a model of the end-to-end development of universal competencies, which systematizes interdisciplinary connections and involves the implementation of social projects by students of engineering areas of training in the process of studying the disciplines of the humanitarian cycle. The methodological recommendations presented in the work are based on the principles of unity of purpose, interdisciplinarity, variability, responsibility, subjectivity, as well as the use of project technology in the educational and extracurricular process. The purpose of this article is to develop methodological recommendations and describe a proven model for the development of universal competencies of students in engineering areas of training. The research methodology is the analysis and generalization of the Federal State Educational Standard of Higher Education in the field of study 13.03.01 Thermal Power Engineering and Heat Engineering (Bachelor’s level), research works of foreign and Russian scientists recognized by the scientific community, and the experience of using project technology in the formation and development of universal competencies. Research results. The developed model is presented of the end-to-end development of universal competencies at the Department of Thermal Power Plants of the Siberian Federal University. The model includes the following elements: the humanitarian cycle of disciplines: Business Communications, Fundamentals of Professional Communications, Responsible Innovations. Ethics. Security, Change Management; student social projects of different levels; positions (roles) occupied by students in the implementation of projects; Student Government Body. Conclusion. The authors note that the practical implementation of the model of end-to-end development of universal competencies, which systematizes interdisciplinary communications and involves the implementation of social projects by students of engineering areas of training in the process of studying the disciplines of the humanities cycle, contributes to the systematic development of universal competencies.

Problems and prospects for the use of nanofluids in thermal power engineering

Objective. The aim of the work is to study the use of nanofluids as heat carriers to increase the efficiency of heat removal in energy facilities. To solve this problem, materials of domestic and foreign scientific articles, conferences and dissertations on the subject of nanofluids were analyzed. Numerous scientific publications, including those cited in the international databases Web of Science and Scopus, indicate that the topic of nanofluids is in the focus of modern science. However, despite a rather long period of fluid research, not all issues of this topic are sufficiently well covered and systematized, which opens up great opportunities for further research in this direction.Method. When achieving this goal, the areas of possible application of fluids, the mechanism of their synthesis, the features of their operation are considered, the advantages as a liquid coolant are indicated, and the disadvantages that prevent their widespread use are identified. Particular attention is paid to such issues as: synthesis of standardized nanofluids; ensuring their stable properties; the use of surfactants; increasing the pressure drop inside heat exchangers during operation of this coolant.Result. To eliminate the main drawback in the form of agglomeration of nanoparticles in the base fluid, it is proposed to use the oscillatory circulation of the coolant, which will also further intensify heat exchange from forced turbulence of the fluid.Conclusion. The results obtained can be used to improve the efficiency of heat and mass transfer devices with liquid coolant and systems based on them, as well as to reduce the weight and size parameters of such devices.

Effective Thermal Conductivity of Structured Porous Medium: Numerical Study

The paper presents a numerical study of thermal conductivity of porous structures using the Ansys software package. Unlike the well-known porous materials used in construction and engineering, it is proposed to use porous materials with an ordered law of cavity placement. The porous material proposed is formed by dividing the volume into cubes of equal size with a spherical cavity placed in the center of each cube. The numerical calculation of an effective thermal conductivity coefficient of a porous medium is performed using the Ansys Mechanical computer modeling tool. The values obtained are compared with solutions based on classical methods for determining the effective thermal conductivity of porous materials. A dependency graph of effective thermal conductivity in a porous material based on pores geometric parameters (distance between cavities, diameter of cavities), as well as an analytical dependence to obtain the effective thermal conductivity value is presented. Additive technologies available today provide producing the proposed porous material with an ordered law of cavity placement with any accuracy and any pore geometric parameters. Such materials open up wide opportunities for engineers, especially in the field of thermal power engineering, because it has predictable thermophysical and mechanical properties.

THE PROBLEM OF HYDROGEN, HYDROGEN AND ATOMIC-HYDROGEN ENERGY: PHYSICAL, CHEMICAL AND TECHNOLOGICAL ASPECTS, TECHNICAL AND ECONOMIC ANALYSIS (REVIEW)

The review attempts to systematically and analytically consider certain results of scientific research and applied developments of such an urgent problem of our time as «hydrogen, hydrogen and atomic hydrogen energy» over the past 15–20 years. In the context of a reasoned statement of the problem, the main categorical-conceptual apparatus of the problem is determined. The main directions and issues of research on the phased solution of the problem are indicated. It is proved that the foundation of the problem is the understanding of the physicochemical properties of hydrogen as a chemical element and its characteristics as a simple substance based on a number of its specific properties. The phenomenon of hydrogen corrosion and its analysis from the point of view of the level of danger, the risk of its use and safety precautions are considered. Attention is focused on the features of the processes of storage, transportation and use of hydrogen as an energy carrier and raw material for technologies. The advantages of obtaining and using solid-phase hydrogen compounds with metals and intermetallic compounds as convenient and safe means of hydrogen transfer to consumers are noted. An example of the use of the most effective hydrides as carriers of H2 in motor vehicles by adding H2 to the minfuel in the engine power system is given, illustrated by a diagram. Special conditions for the use of H2 in heat supply processes (in thermal power engineering in general) are indicated, taking into account the difference in the thermophysical characteristics of H2, CH4, air and oxygen. The features of the development and use of means of transportation and storage of H2 are noted. Considerable attention is paid to the consideration of the physicochemical foundations for the production and use of metal hydrides and intermetallides in the context of evaluating them as means of solid-phase storage of H2 transfer in technological processes. The classification of hydrides and their functional characteristics of the most effective and promising hydrides — metal-like and especially intermetallic ones are presented: their preparation and areas of use. The innovative concept of atomic hydrogen energy is described in detail, which will determine the most promising areas of practical developments on the subject of the problem and their implementation. The concept is based on the use of the heat of a gas-cooled nuclear reactor for the implementation of two types of tasks: the efficient use of hydrogen as an energy carrier, for example, in the field of heat supply; the efficiency and profitability of methods for producing hydrogen using the numerous methods, methods and technologies already proposed, which, without nuclear technologies, are currently low-efficient and unprofitable. A project is proposed for using the heat of a GOx-th nuclear reactor in a fundamentally new complex of distant heat supply (method, technology, schemes) using a two-stage, reversible chemo-thermal process. It has been proven that the heat of a nuclear reactor can be used for the effective implementation of a number of traditional and innovative chemical and electrochemical, biochemical, etc. reactions for obtaining H2. A feasibility study has proven the effectiveness of such nuclear-hydrogen energy. A complete list and analysis of innovative, reversible (cyclic) chemical reactions for the production of H2 is presented. The review is based on the latest references to foreign publications on the subject of the problem (2018–2022), obtained from such an international source as «Elsevier-Science Direct». Bibl. 26, Fig. 4, Tab. 5.

Special Issue on Environmentally Friendly Technologies in Power Engineering

At present, the field of thermal power engineering is dominated by the following two main areas of development: (1) the development and implementation of new technologies using renewable energy sources; and (2) upgrading commonly used power-generation technologies by improving the efficiency of industrial equipment and optimizing operating conditions [...]

Analysis on the Development of Thermal Power Engineering in Turbine and Energy

Analysis on the Development of Thermal Power Engineering in Turbine and Energy

Numerical simulation of nanofluid flow between two parallel disks using 3-stage Lobatto III-A formula

Abstract The development of nanofluid technology has become a key research area in physics, mathematics, engineering, and materials science. Nowadays, in many industrial applications, nanofluids are widely used to enhance thermophysical properties such as thermal diffusivity, thermal conductivity, and convective heat transfer. Scientists and engineers have established interests in the direction of flow problems developed via disk-shaped bodies. There are various logics to discuss flow phenomenon due to rotating bodies, but its applications include in thermal power engineering system, gas turbine rotors, air cleaning machines, aerodynamics, etc. Nowadays manufacturing industries have inaugurated to select liquid based on heat transfer properties. Therefore, this article focuses on studying the laminar incompressible nanofluid between two parallel disks. Mathematical formulations of the law of conservation of mass, momentum, and heat transfer are investigated numerically. By using suitable similarities, the flow equations are converted into nonlinear ordinary differential equations. The resulting equations were solved numerically via MATLAB software. The effects of physical parameters of interest, such as Reynolds number, magnetic factor, Brownian parameter, and thermophoresis parameter on normal velocity, streamwise velocity, temperature, and concentration profiles are computed and presented using the graphs. The results revealed that the energy profile significantly rises, and the profile moves closer to the upper disk by enhancing the Brownian motion and thermophoresis parameter. The dynamics behind this is that by increasing the Brownian motion, the boundary layer wideness increases which increases the temperature. Moreover, streamwise velocity increases for large values of Reynolds number. Besides, the thermophoresis profile increases for large values of the thermophoresis factor. It could be observed that shear stress at nonporous/porous disk is adjusted by selecting a suitable value of injection velocity at the porous disk. Also, normal velocity decreases by increasing the parameter M.