Subjects -> ENGINEERING (Total: 2844 journals)
    - CHEMICAL ENGINEERING (247 journals)
    - CIVIL ENGINEERING (248 journals)
    - ELECTRICAL ENGINEERING (176 journals)
    - ENGINEERING (1448 journals)
    - ENGINEERING MECHANICS AND MATERIALS (451 journals)
    - HYDRAULIC ENGINEERING (62 journals)
    - INDUSTRIAL ENGINEERING (97 journals)
    - MECHANICAL ENGINEERING (115 journals)

ENGINEERING (1448 journals)            First | 1 2 3 4 5 6 7 8     

Showing 1201 - 1205 of 1205 Journals sorted alphabetically
Purinergic Signalling     Hybrid Journal   (Followers: 1)
Quaderns d’Història de l’Enginyeria     Open Access  
Quality and Reliability Engineering International     Hybrid Journal   (Followers: 15)
Quality Engineering     Hybrid Journal   (Followers: 12)
Quantum Engineering     Hybrid Journal  
R&D Journal     Open Access   (Followers: 1)
Radiochimica Acta     Hybrid Journal   (Followers: 5)
Rare Metals     Hybrid Journal   (Followers: 3)
Reactive and Functional Polymers     Hybrid Journal   (Followers: 5)
Recent Patents on Engineering     Hybrid Journal   (Followers: 3)
Recent Patents on Nanotechnology     Hybrid Journal   (Followers: 2)
Recherche Transports Sécurité     Hybrid Journal   (Followers: 1)
Redes de Ingeniería     Open Access  
Regional Maritime University Journal     Full-text available via subscription   (Followers: 3)
Regular and Chaotic Dynamics     Hybrid Journal  
Rem : Revista Escola de Minas     Open Access  
Remote Sensing     Open Access   (Followers: 54)
Remote Sensing Letters     Hybrid Journal   (Followers: 46)
Requirements Engineering     Hybrid Journal   (Followers: 3)
Research Ideas and Outcomes     Open Access   (Followers: 1)
Research in Engineering Design     Hybrid Journal   (Followers: 10)
Research Journal of Nanoscience and Nanotechnology     Open Access   (Followers: 18)
Resonance     Hybrid Journal   (Followers: 29)
Respuestas     Open Access  
Results in Engineering     Open Access  
Review of Symbolic Logic     Full-text available via subscription   (Followers: 2)
Reviews in Advanced Sciences and Engineering     Partially Free   (Followers: 1)
Revista AIDIS de Ingeniería y Ciencias Ambientales. Investigación, desarrollo y práctica     Open Access  
Revista Brasileira de Engenharia Agrícola e Ambiental     Open Access   (Followers: 1)
Revista Brasileira de Inovação     Open Access  
Revista Campus     Open Access  
Revista Ciencia y Tecnología     Open Access  
Revista Ciencia y Tecnología     Open Access  
Revista Ciencia y Tecnología El Higo     Open Access   (Followers: 2)
Revista Científica de la UCSA     Open Access  
Revista Colombiana fe Technologias de Avanzada (RCTA)     Open Access   (Followers: 3)
Revista Cubana de Ingeniería     Open Access  
Revista de Ciências Exatas Aplicadas e Tecnológicas da Universidade de Passo Fundo : CIATEC-UPF     Open Access  
Revista de Ciências Exatas e Tecnologia     Open Access   (Followers: 1)
Revista de Ingeniería     Open Access  
Revista de Ingenieria Sismica     Open Access  
Revista de Investigación     Open Access  
Revista de Investigación, Desarrollo e Innovación     Open Access  
Revista de Investigaciones en Energía, Medio Ambiente y Tecnología     Open Access  
Revista de la Universidad del Zulia     Open Access  
Revista EIA     Open Access   (Followers: 1)
Revista Facultad de Ingeniería     Open Access   (Followers: 1)
Revista Facultad de Ingenieria - Universidad de Tarapaca     Open Access   (Followers: 1)
Revista Facultad de Ingeniería Universidad de Antioquia     Open Access   (Followers: 1)
Revista Fatec Zona Sul : REFAS     Open Access  
Revista Iberoamericana de Automática e Informática Industrial RIAI     Open Access  
Revista Informador Técnico     Open Access   (Followers: 1)
Revista Ingenieria de Construcción     Open Access   (Followers: 1)
Revista Interdisciplinar de Pesquisa em Engenharia     Open Access   (Followers: 1)
Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería     Open Access  
Revista Logos Ciencia & Tecnología     Open Access   (Followers: 1)
Revista Técnica de la Facultad de Ingeniería : Universidad del Zulia     Open Access   (Followers: 1)
Revista Tecnología en Marcha     Open Access  
Revista Tecnológica     Open Access   (Followers: 1)
Revista UIS Ingenierías     Open Access  
Revue de Métallurgie     Full-text available via subscription  
RUDN Journal of Engineering Researches     Open Access   (Followers: 1)
Russian Engineering Research     Hybrid Journal  
Russian Journal of Non-Ferrous Metals     Hybrid Journal   (Followers: 21)
Russian Microelectronics     Hybrid Journal   (Followers: 1)
Sadhana     Open Access   (Followers: 10)
Safety Science     Hybrid Journal   (Followers: 28)
Scholedge International Journal of Multidisciplinary & Allied Studies     Open Access   (Followers: 3)
Science & Technique     Open Access   (Followers: 1)
Science and Education : Scientific Publication of BMSTU     Open Access   (Followers: 1)
Science and Engineering Ethics     Hybrid Journal   (Followers: 9)
Science and Technology     Open Access   (Followers: 2)
Science and Technology Indonesia     Open Access   (Followers: 1)
Science China Technological Sciences     Hybrid Journal   (Followers: 1)
Science in Context     Hybrid Journal   (Followers: 3)
Science Journal of Volgograd State University. Technology and innovations     Open Access  
Science Progress     Full-text available via subscription   (Followers: 4)
Sciences & Technologie B : Sciences de l'ingénieur     Open Access  
Scientia cum Industria     Open Access  
Scientific Drilling     Open Access  
Scientific Journal of Control Engineering     Open Access   (Followers: 3)
Scientific Journal of Mehmet Akif Ersoy University     Open Access  
Scientific Journal of Pure and Applied Sciences     Open Access   (Followers: 1)
SCITECH Nepal     Open Access  
Sealing Technology     Full-text available via subscription   (Followers: 1)
Securitas Vialis     Hybrid Journal  
Security and Communication Networks     Hybrid Journal   (Followers: 2)
Selcuk University Journal of Engineering, Science and Technology     Open Access   (Followers: 2)
Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of     Hybrid Journal   (Followers: 57)
Semiconductors     Hybrid Journal   (Followers: 2)
Semiconductors and Semimetals     Full-text available via subscription   (Followers: 1)
Sensing and Imaging : An International Journal     Hybrid Journal   (Followers: 2)
Sensor Letters     Full-text available via subscription   (Followers: 2)
Sensors     Open Access   (Followers: 23)
Separation and Purification Technology     Hybrid Journal   (Followers: 15)
Shock and Vibration     Hybrid Journal   (Followers: 26)
SIAM Journal on Applied Dynamical Systems     Hybrid Journal   (Followers: 2)
SIAM Journal on Mathematical Analysis     Hybrid Journal   (Followers: 4)
SIAM Journal on Matrix Analysis and Applications     Hybrid Journal   (Followers: 3)
SIAM Journal on Numerical Analysis     Hybrid Journal   (Followers: 7)
SIAM Journal on Optimization     Hybrid Journal   (Followers: 11)
SIAM Review     Hybrid Journal   (Followers: 7)
SILICON     Hybrid Journal  
SINERGI     Open Access  
Sistemas & Telemática     Open Access   (Followers: 2)
Sleep and Biological Rhythms     Hybrid Journal   (Followers: 9)
Small     Hybrid Journal   (Followers: 16)
Smart Grid     Open Access   (Followers: 1)
SN Applied Sciences     Hybrid Journal   (Followers: 1)
Sociología y Tecnociencia     Open Access  
Soft Computing     Hybrid Journal   (Followers: 9)
Soil Dynamics and Earthquake Engineering     Hybrid Journal   (Followers: 15)
Solar RRL     Hybrid Journal  
Soldagem & Inspeção     Open Access  
SourceOCDE Developpement urbain, rural et regional     Full-text available via subscription   (Followers: 1)
SourceOCDE Energie     Full-text available via subscription  
SourceOECD Energy     Full-text available via subscription  
SourceOECD Science and Technology Statistics - SourceOCDE Base de donnees des sciences et de la technologie     Full-text available via subscription  
SourceOECD Transport     Full-text available via subscription   (Followers: 2)
SourceOECD Urban, Rural and Regional Development     Full-text available via subscription  
South African Computer Journal     Full-text available via subscription  
South African Journal of Agricultural Extension     Open Access   (Followers: 4)
South African Journal of Science     Open Access   (Followers: 4)
Sports Engineering     Hybrid Journal   (Followers: 2)
Stahlbau     Hybrid Journal   (Followers: 2)
Steel in Translation     Hybrid Journal   (Followers: 1)
Steel Research International     Hybrid Journal   (Followers: 24)
Stochastic Analysis and Applications     Hybrid Journal   (Followers: 2)
Stochastic Processes and their Applications     Hybrid Journal   (Followers: 5)
Stochastics and Dynamics     Hybrid Journal  
Strain     Hybrid Journal   (Followers: 2)
Strategic Planning for Energy and the Environment     Hybrid Journal   (Followers: 4)
Studies in Engineering and Technology     Open Access  
Studies in Interface Science     Full-text available via subscription  
Studies in Logic and Practical Reasoning     Full-text available via subscription  
Studies in Surface Science and Catalysis     Full-text available via subscription   (Followers: 1)
Sud-Sciences et Technologies     Open Access   (Followers: 1)
Superconductor Science and Technology     Hybrid Journal   (Followers: 3)
Surface Engineering     Hybrid Journal   (Followers: 1)
Surface Review and Letters     Hybrid Journal   (Followers: 1)
Surface Science Reports     Full-text available via subscription   (Followers: 20)
Surfaces and Interfaces     Hybrid Journal  
Survey Review     Hybrid Journal   (Followers: 6)
Surveying and Land Information Science     Full-text available via subscription   (Followers: 1)
Surveys in Operations Research and Management Science     Hybrid Journal   (Followers: 3)
Sustainability Science     Open Access   (Followers: 9)
Sustainability Science and Engineering     Full-text available via subscription   (Followers: 3)
Sustainable Management of Sediment Resources     Full-text available via subscription  
Swiss Journal of Geosciences     Hybrid Journal   (Followers: 1)
Symmetry     Open Access   (Followers: 1)
Synthesis Lectures on Algorithms and Software in Engineering     Full-text available via subscription   (Followers: 3)
Synthesis Lectures on Antennas     Full-text available via subscription   (Followers: 5)
Synthesis Lectures on Biomedical Engineering     Full-text available via subscription  
Synthesis Lectures on Computational Electromagnetics     Full-text available via subscription   (Followers: 4)
Synthesis Lectures on Energy and the Environment: Technology, Science, and Society     Full-text available via subscription   (Followers: 1)
Synthesis Lectures on Engineering     Full-text available via subscription  
Synthesis Lectures on Global Engineering     Full-text available via subscription  
Synthesis Lectures on Professionalism and Career Advancement for Scientists and Engineers     Full-text available via subscription   (Followers: 2)
Synthetic Metals     Hybrid Journal   (Followers: 4)
Systems Engineering     Hybrid Journal   (Followers: 7)
Systems Engineering - Theory & Practice     Full-text available via subscription  
Systems Engineering Procedia     Open Access  
Systems Research Forum     Hybrid Journal   (Followers: 1)
Systems Science & Control Engineering     Open Access   (Followers: 8)
Tableros     Open Access   (Followers: 2)
Tapuya : Latin American Science, Technology and Society     Open Access   (Followers: 1)
Technical Tips Online     Full-text available via subscription   (Followers: 1)
Technological Engineering     Open Access   (Followers: 1)
Technologies     Open Access   (Followers: 2)
TECHNOLOGY     Hybrid Journal   (Followers: 1)
Technology and Economics of Smart Grids and Sustainable Energy     Hybrid Journal  
Technology and Innovation     Full-text available via subscription   (Followers: 4)
Technology in Society     Hybrid Journal   (Followers: 7)
Technometrics     Full-text available via subscription   (Followers: 9)
Tecnología y Ciencia     Open Access  
Tecnología y Sociedad     Open Access   (Followers: 1)
TecnoLógicas     Open Access  
Tecnura     Open Access   (Followers: 1)
Tekhné     Open Access   (Followers: 1)
Tekniikan Waiheita     Open Access  
Teknologi dan Kejuruan : Jurnal Teknologi, Kejuruan, dan Pengajarannya     Open Access  
Telecommunications Policy     Hybrid Journal   (Followers: 9)
Textile Science and Technology     Full-text available via subscription   (Followers: 4)
Thalassas : An International Journal of Marine Sciences     Hybrid Journal  
The Engineer     Partially Free  
The Journal of Supercomputing     Hybrid Journal   (Followers: 1)
The Scientific World Journal     Open Access  
Theoretical and Computational Fluid Dynamics     Hybrid Journal   (Followers: 17)
Theoretical Issues in Ergonomics Science     Hybrid Journal   (Followers: 7)
Thermal Engineering     Full-text available via subscription   (Followers: 10)
Tikrit Journal of Engineering Science     Open Access  
tm - Technisches Messen     Hybrid Journal   (Followers: 2)
Topics in Catalysis     Hybrid Journal   (Followers: 1)
Traffic Injury Prevention     Hybrid Journal   (Followers: 75)
Transactions of the Indian National Academy of Engineering     Hybrid Journal   (Followers: 2)
Transactions of the VŠB – Technical University of Ostrava, Safety Engineering Series     Open Access   (Followers: 1)
Transactions of Tianjin University     Full-text available via subscription  
Transport and Aerospace Engineering     Open Access   (Followers: 13)
Transport and Telecommunication     Open Access   (Followers: 4)
Transport World Africa     Full-text available via subscription   (Followers: 2)

  First | 1 2 3 4 5 6 7 8     

Similar Journals
Journal Cover
Thermal Engineering
Journal Prestige (SJR): 0.339
Citation Impact (citeScore): 1
Number of Followers: 10  
 
  Full-text available via subscription Subscription journal
ISSN (Print) 0040-6015 - ISSN (Online) 1555-6301
Published by Springer-Verlag Homepage  [2626 journals]
  • Hydropower Deserves More Attention!
    • PubDate: 2020-07-01
       
  • Choice of Filter Material for a Mechanical Filter for Purification of
           Water after Liming
    • Abstract: The possibility of using quartz sand as a filter material for mechanical filters in the schemes of preliminary water treatment in water treatment plants with coagulation and liming at thermal power plants is considered. Comparative experiments on filtering water through quartz sand at the laboratory bench of an operating thermal power plant showed the absence of leaching of silicic acid from sand at pH = 10.0–10.2 and a filtration rate of 7 m/h. The turbidity of the filtrate is close to zero, and the quality of the water obtained after filtering through quartz sand is higher than when filtering through hydroanthracite. Hydroanthracite is characterized by relatively high abrasion and increased cost in comparison with quartz sand. Model experiments were carried out in a wide pH range when filtering water through sand, which showed the absence of a significant release of silicic acid into water. We studied the long-term interaction of water with quartz sand at pH 12, in which there is no intensive release of silicic acid compounds into water. Studies of the quality of the filtrate of mechanical filters loaded with quartz sand and hydroanthracite at a high pH of the treated water were performed. To prevent silicic acid compounds from entering clarified water, it is recommended that the first portion of the filtrate of the mechanical filters be discharged before being put into operation after a long period of inactivity. Recommendations on the use of quartz sand as a filter material in mechanical filters of the preliminary water treatment scheme at thermal power plants are presented.
      PubDate: 2020-07-01
       
  • Study into the Influence of Internal Heat Sources on the Operating
           Characteristics of a Thermoelectric Generator
    • Abstract: The influence of internal heat sources on temperature distribution during the operation of thermoelectric generators (TEG) is investigated. Taking into account various factors affecting the temperature regime, including internal heat sources, a multilevel model of a two-stream TEG has been developed, which allows one to calculate the temperature distribution and the integral characteristics of the generator. The calculations were carried out using the PHOENICS program package; as a result, the dependences of the electrical characteristics and the temperature drop on the junctions on the load resistance, speed, and coolant temperature were obtained. A comparison is made with the corresponding indicators in the absence of internal heat sources. It is concluded that the influence of internal heat sources on the temperature drop and electric power increases with decreasing load resistance. Thus, in the maximum power mode, which corresponds to the ratio of the load resistance to the internal resistance of the module m = 1.15, the temperature drop decreases by 3.5–4.0%, while that at m = 0.01 is by 7.5–8.5%. TEG power in maximum power mode decreases by 7.5–8.0%. Studies have shown that the influence of internal heat sources on the characteristics of the TEG is more substantial when the flow rate in the heat exchangers is lower. The greatest decrease in the values of indicators due to the influence of internal sources was observed at v = 0.2 m/s and amounted in maximum power mode to 5.5–6.0% for the temperature difference and 12–13% for power. The results obtained indicate that the influence of internal sources on the characteristics of TEGs is significant enough, which implies that the most accurate estimates of the thermal and electrical performance of TEGs can be made only by taking into account the effect of internal heat sources on the temperature distribution in TEGs.
      PubDate: 2020-07-01
       
  • Experimental and Calculation Studies into the Possibilities of Improving
           the Vibration Isolation of Power Installation Pipelines
    • Abstract: — The article presents the results from studying methods and means for reducing the transfer of vibration and pressure pulsations from power installations through elastic vibration isolators of pipelines carrying liquids (cooling water, condensate, or petroleum products) by suppressing the vibration forces and pulsations of the medium by active suppression systems. The results of studies into this subject carried out within the framework of the agreement between the Russian Scientific Foundation and the Tsiolkovskii Kaluga State University are reported. The article discusses the results from calculation and experimental studies aimed at determining the influence of liquid on the vibration-isolating performance of different kinds of pipeline compensators, including those based on bellows, sleeve-type ones made of rubber cord materials, those based on rubber cord shells, and compensators of a new type containing elastic inserts made using thin-layered rubber-metal elements with the minimal interaction between the structure and working medium. The investigations were carried out with the aim to minimize the transfer of vibration through the compensator by improving its design. The results from experimental studies into the effectiveness of joint suppression of the vibration and pressure pulsations by active methods for reducing the transfer of vibration from power installations to the foundation by means of pipeline compensators are presented. It is shown both analytically and experimentally that there is a frequency band in which the vibration forces transferred through the compensator structure are suppressed by the forces from pressure pulsations. The transfer of vibration becomes a factor of ten or more less than it is in the compensator tested without liquid. A physical explanation for this phenomenon is given, and ways of using it in practice are suggested. A two-channel active vibration protection system with a digital control device containing controllers in the form of standard Butterworth, Chebyshev, and band-pass filters, as well as resonance sections in its feedback circuit, is experimentally studied. With the active joint wide-band suppression of vibration forces and pressure pulsations determining the transfer of vibration through the compensators of pipelines with liquid, the effectiveness was found to be up to 32 dB in the frequency band from 10 to 350 Hz.
      PubDate: 2020-07-01
       
  • An Analysis of the Prospects for Coal-Fired Thermal Power Station
           Reconstruction on the Basis of Coal Gasification and a Combined-Cycle Unit
           
    • Abstract: Modern trends in technical reequipment of coal-fired thermal power stations (TPS) are analyzed by the example of the Verkhnetagil’skaya District Power Station (GRES), where obsolete coal-fired power units requiring replacement were in operation. This problem is specific for many Russian thermal power stations. Two alternatives of reequipment are considered: replacement of obsolete steam-turbine power units with a natural gas-fired combined cycle unit (CCU) and conversion of coal-fired power units into integrated gasification combined-cycle units (IGCCU) with gas turbines operating on purified synthesis gas. Technical reequipment of the considered TPS was performed by replacing the coal-fired steam-turbine power units of phase I–II with a 420 MW CCU. The CCU core was a 288 MW Siemens SGT5-4000F gas turbine. A CCU on its basis was modelled in the THERMOFLEX code. The calculated results demonstrated high power and environmental effectiveness in replacement of coal-fired power units at TPSs with natural gas-fired CCUs, thereby cutting down coal equivalent consumption by 727 000 t.c.e. (or 24%). For conversion of a TPS to an IGCCU, the fuel saving could be as great as 543 000 t.c.e./year (18%) under comparable conditions. In this case, the atmospheric emissions (of dust and SO2) could be decreased many times (by 99%) due to implementation of an effective gas treatment process in the gasification system. Due to the huge coal reserves in Russia, the conversion of coal-fired TPSs to modern technologies with coal gasification may be a promising alternative for many TPSs during their reconstruction. In addition, it will contribute to improving the country’s energy security. In addition, this will improve the country’s energy security.
      PubDate: 2020-07-01
       
  • Potentialities of Membrane Water Treatment for Removing Organic Pollutants
           from Natural Water
    • Abstract: The potentialities of using ultrafiltration, nanofiltration, and reverse-osmosis membranes for removing organic compounds from water are considered. Experimental results obtained by the authors and the information taken from the literature characterizing the interaction between membranes and organic compounds contained in natural water are presented. Data are obtained concerning the efficiency of different membrane technologies in the removal of organic compounds from natural water. The growth rate of the deposits of organic substances having different molecular weight has been studied. The effect of the membrane’s material and the hydrodynamic mode of the membrane’s operation on the formation rate of organic deposits has been demonstrated. The influence of these substances’ nature, their concentration in natural water, and the molecular weight thereof on the deposition rate on membranes have been revealed. In the experiments, tap water taken from the Moscow water supply and river water were used. The results of the authors’ experiments and the results obtained by other Russian and foreign researchers presented in the paper make it possible to consider ultrafiltration as a reliable way to retain organic macromolecules as well as finely dispersed and colloidal impurities. With retaining low-molecular organic compounds that determine the color of water, ultrafiltration is restricted. In the synthesis of nanofiltration membranes, films with different pore size and charge are used. Therefore, for a specific water source and water consumer, an individual choice of nanofiltration membranes is required, a wide range of which is available in the market. Nanofiltration membranes of the NE-90 and NE-70 types for surface waters having a color of 20–100 degrees provide a 85 and 75% decrease in the oxidability level, respectively. According to the results of studies concerning the efficiency of artesian water purification, domestic OPMN-K nanofiltration membranes can also profoundly purify water from natural organic compounds. Among all the membranes used in the water treatment technology, reverse-osmosis membranes have the smallest pore size; their use provides retaining organic compounds with a molecular weight lower than 100 Da. The studies have shown that reverse-osmosis membranes exhibit a 99.5% retention level for the compounds with a molecular weight of 150 Da and a 99.9% retention level for the compounds with a molecular weight higher than 1000 Da. To reveal the nature and concentration of organic compounds deposited on the membranes, water spectrograms have been used.
      PubDate: 2020-07-01
       
  • Assurance of Data Faultlessness in Automated Analysis of the Technical and
           Economic Indicators for Power Unit Boiler Installations
    • Abstract: — The performance efficiency of automated intelligent systems (AISs), which provide the managing personnel of electric power systems not only with systematically ordered information about the technical state of equipment and installations but also with recommendations on arranging their operation, maintenance, and repair, depends first of all on the safety and faultlessness of the relevant databases. Continuous monitoring of the indicators characterizing the technical state of equipment and installations involves high costs that are far from always being justified. Therefore, in most frequent cases, these indicators are determined from the results of tests and emergency and scheduled repairs. In fact, this information is discrete in nature and is entered in the database from dedicated logbooks. The urgency of automated settling of matters concerned with arranging maintenance and repair becomes even more important in view of the fact that no less than half of the main equipment and installations operating in electric power systems have worked out their fleet life in many respects. The use of indicators like thermal efficiency margin or permissible number of short circuit fault clearances by a circuit breaker for technical state management purposes leads to a higher risk of making erroneous decisions under these conditions. Therefore, the urgency of the problem of ensuring the safety and faultlessness of AIS databases does not decrease with time but, on the contrary, constantly tends to become more important. As an example of incorrectness of the existing approach to recognition of gross errors, the article considers data on the monthly average values of technical and economic indicators of the boiler installations of gas-and-oil fired 300-MW power units. It is pointed out that the sample of monthly average values of technical and economic indicators is inconsistent with the representative sample from the general totality of data. An interval checking method and a checksum method for recognizing gross errors have been developed and approbated. The first method is based on comparing the realizations of technical and economic indicators with their possible variation interval, and the second method is based on comparing the estimated and real annual average values of the realizations of technical and economic indicators. By using the proposed methods, it is possible to decrease the risks of elaborating erroneous recommendations, making erroneous decisions, and spending excessive costs.
      PubDate: 2020-07-01
       
  • A Method for Parametrically Representing the Aerodynamic Profiles of Axial
           Turbine Machinery Blades
    • Abstract: — A parametric method for designing the cross sections of axial turbine machinery blade airfoils is described. Analytical Bezier curves are used for representing the profile generatrices and the skeleton line. Their shapes are uniquely determined by a set of 13 parameters that are related to the turbine cascade’s aerodynamic and strength characteristics. These parameters determine the main points through which the profile generatrices must pass at the specified tangent line angles. In general terms, the blade shape’s design calculation involves the following sequential stages: calculating the geometrical constraints based on 13 parameters, determining the skeleton line shape, and calculating the profile suction and pressure sides. By using the proposed method, it is possible to control the blade shape taking into account the imposed geometrical conditions, including the surface curvature distributions. A distinguishing feature of the proposed method is its adaptability: the degree of Bezier curves is determined during calculation by means of multidimensional minimization. This feature imparts flexibility to the method in terms of the possibility to specify the parameters in wide ranges of their values, thus making the method versatile in nature. An algorithm for iteratively determining the curve shape through calculating the skeleton line is presented. The proposed approach is supplemented by a procedure for automatically parameterizing the profiles specified as unevenly distributed point-wise coordinates of their generatrices. This opens up the possibility to represent the already existing blade shapes in the form of 13 parameters and to optimize them.
      PubDate: 2020-07-01
       
  • Assessing the Effectiveness of the Hydrothermal Carbonization Method to
           Produce Bio-Coal from Wet Organic Wastes
    • Abstract: The study is devoted to the assessment of the thermodynamic efficiency of the hydrothermal carbonization (HTC) method to produce bio-coal from wet organic waste (biomass). The HTC method is a process of thermochemical conversion of biomass into solid biofuel (bio-coal) as a result of its heating up to 150–280°С in the presence of water. The competitive advantages of the HTC method and the properties of bio-coal produced by this method from various organic waste are analyzed. The energy consumption values for implementation of the HTC process and the conventional torrefaction method are compared. It is demonstrated that the energy consumption in the production of bio-coal by the HTC method is several times lower than in the torrefaction process since water heated at a high pressure remains a liquid. This, in turn, offers a high potential for recovery of thermal energy (approximately 87%) in the HTC process. The heating value of the produce bio-coal is as high as 27 MJ/kg, which is comparable with that of commercial power coals. An analysis of the properties of biochar produced in the HTC process suggests that, in principle, it may be burned at coal-fired power stations together with conventional coal (if proper gas treatment equipment is available). The HTC method can be used for pretreatment of water-rich organic wastes and biomass to produce a quality fuel and a water solution that can be used as a base for production of fertilizers.
      PubDate: 2020-07-01
       
  • Physical Simulation of Dynamic Processes in Hydroeleastic Systems at
           Nuclear Power Stations
    • Abstract: Basic approaches are outlined to solving complex engineering problems arising in the design and operation of power units at nuclear power stations (NPS) and based on large-scale physical simulation of dynamic conditions and parameters of dynamics and structural strength of modern power facilities. A procedure for physical simulation of specific dynamic processes in hydroelastic systems has been developed. Taking into account the identified distributions of pressure pulsations and flow rates on the surfaces of the structures of the investigated reactor plants (RU), hydrodynamic loads in various structures and facilities of modern power-machine buildings were determined considering the found distribution of fluctuations in flow pressure and velocity acting on the structure surfaces. The dynamic response parameters of the main structural members, such as dynamic strains and stresses, were obtained and analyzed. The effect of added masses of liquid, damping, and other factors on the dynamic processes in hydroelastic systems and ways for its reduction to increase the durability and service life of structures, first of all the critical elements of the studied power systems for each commissioned reactor, are determined. This approach is based on a comprehensive investigation of the interaction of a turbulent flow with the multicomponent structure of a reactor unit. The results of investigation confirmed the structure serviceability as to the relative error. The fitness for service of a structure during a specified operation time of the power unit was assessed. The implementation of the proposed approach involving large-scale physical simulation and, in many cases, numerical modeling, confirmed its effectiveness and the validity of the results obtained by the authors.
      PubDate: 2020-07-01
       
  • Calculation Technique of Some Thermodynamic Functions using the Results of
           Joint Thermal and Acoustic Measurements
    • Abstract: An original method of calculating isochoric and isobaric heat capacity based on the fundamental relationships of thermodynamics is presented. The theoretical development of the methodology for calculating isochoric and isobaric heat capacity can be used to obtain high metrological data on the thermophysical properties of new low-boiling working substances of power plants operating on the Rankine organic cycle and to replenish existing databases. The technique allows the use of heterogeneous experimental results of acoustic and thermal measurements to calculate the basic thermodynamic functions without information about the values of ideal gas functions, and also to evaluate the consistency of experimental data. Formulas are derived for calculating isobaric and isochoric heat capacities, which are based on reliable equations describing experimental data on the speed of sound and density depending on state parameters. The method was tested using both the characteristics of the reference substances (H2O and CO2), and own new experimental data on the thermal and acoustic properties of octafluorocyclobutane (c-C4F8) in the liquid phase for temperatures of 320 and 340 K and pressures from 4 to 10 MPa. The isochoric heat capacity was calculated from measurements of the density of octafluorocyclobutane and the speed of sound in it. According to the latest series of density measurements in a limited region of the states of the liquid phase of octafluorocyclobutane obtained by the constant volume piezometer method, the isochoric heat capacity was calculated using the equation proposed in this work. The uncertainty of the experimental data used for the test calculation of the density did not exceed 0.25%, and the speed of sound did not exceed 0.05%. The standard deviation in the description of the dependence of thermal quantities was 0.23%, and acoustic—0.15%.
      PubDate: 2020-06-01
       
  • The Effect of Heat-and-Mass Transfer and Flow Hydrodynamics on the Flow
           Accelerated Corrosion Rate in Evaporators of Combined-Cycle Unit
           Heat-Recovery Steam Generators
    • Abstract: Flow accelerated corrosion (FAC) is considered one of the major causes of damage to heat-recovery steam generators (HRSG) of combined-cycle units. In the last few decades, a great number of papers devoted to this problem have been published in many countries around the world. The results of investigations were analyzed as a rule, on the basis of the flow-averaged thermochemical parameters of the flow, while the features of the near-wall liquid film determining the FAC rate were not taken into account. The indicators in the near-wall region depends on the heat-and-mass transfer conditions, flow hydrodynamics, and the specific of chemicals used to correct the water chemistry (WC). For ammonia and oxygen water treatment chemistries, an equilibrium model is proposed and its validity for HRSG evaporators is substantiated. The rate of the exchange of gas reagents between steam and water is determined by the distribution coefficient Kd. To simplify calculations, simple approximating correlations of Kd for ammonia and oxygen is recommended. For the water chemistry with solid reagents, a diffusion model has been developed to calculate mass transfer on the basis of data on heat transfer in steam-generating tubes. The concentration of reagents near the wall is determined by both the turbulent transport of the liquid between the flow core and the near-wall layer and the coefficient of reagent distribution between the phases. Simple approximating correlations of distribution coefficients for Na3PO4, NaOH, and 90H Turb helamine are proposed. An approximate correlation between the hydraulic resistance coefficient Kh and the geometric parameter Kс of the FAC process has been established. The hydrodynamic fundamentals of the standard HRSG structural members have been studied in more detail than FAC. To estimate Kс, one can use the known value of Kh and the correlation between them. However, this correlation should be used with care since it has been obtained for certain conditions of unambiguity (i.e., specific construction material, water chemistry, flow history, etc.). Under other conditions, this correlation will change somewhat; therefore, it can only be used for rough estimation.
      PubDate: 2020-06-01
       
  • Study into the Separation Ability of the New NRU MPEI Peripheral Sealing
    • Abstract: Energy losses caused by steam humidity are one of the main components of losses in the steps of nuclear power plants’ wet-steam turbines. The presence of moisture droplets in the flow part of the turbines also poses a serious danger due to erosion wear of their blades. Various separation systems remove part of the erosion-hazardous moisture. However, along with moisture, a certain amount of steam is removed from the flow part of the turbine, which will not take part in performing beneficial work in subsequent stages of this turbine. Other losses are steam leaks through seals, the largest of which occur in seals located above the turbine blades. On the basis of the rectangular-mesh seals developed and studied earlier, the design of a special peripheral seal for NPP turbines was developed at NRU MPEI. The new seal is capable of simultaneously performing two functions: to reduce over-leakage leaks and to ensure the separation of moisture from the flowing part. The results of the studies showed that the presence of special channels in the seal for removing drip moisture hardly worsen the flow characteristics of the new seal. This paper presents the results of experimental studies into the separation ability of new peripheral seals. As a two-phase medium, specially prepared moist air was used. To do this, a plant for the preparation of water and the generation of the droplet phase was designed and manufactured. During the experiments, the ability of the seal structure to remove moisture was investigated. The use of humidified air made it possible to accurately determine the amount of droplet moisture supplied to the seal and separated through it and the separation coefficient of the seal. Studies have shown that the amount of moisture separated through the seal depends on the pressure drop across it, the rotor speed, and the initial degree of humidity of the compressed air supplied to the seal. It is shown that the use of a new seal in the studied range of initial degrees of humidity allows the separation of up to 45% of the moisture passing through the peripheral gap above the working blades. In general, the results of the experiments showed that the use of a rectangular-cell seal from NRU MPEI as a peripheral seal in turbines of nuclear power plants is advisable to remove moisture from the gap above the working blade and to reduce peripheral steam leaks.
      PubDate: 2020-06-01
       
  • Investigation of the Combustion Process of Solid Fuel in Furnaces with
           Direct-Flow Burners
    • Abstract: The optimization of the boiler furnace’s aerodynamics is considered in order to increase the efficiency of burning power-generating fuel by the example of burning lean Kuznetsk coal in a solid slag removal scheme. Combustion options have been proposed and investigated in schemes with direct injection of coal dust and with an intermediate coal dust hopper. The schemes use direct-flow burners with an counter-displaced arrangement and nozzles with a downward inclination, and staged combustion of fuel is used. A study of the furnace’s aerodynamics on an isothermal bench was carried out. The results of physical modeling were compared with the data of numerical modeling of an isothermal bench. It is noted that combustion schemes differ in the intensity of vortex formation in the active combustion zone. A numerical simulation of fuel combustion in the boiler furnace was performed using the two indicated combustion schemes. The purpose of the simulation was to obtain the distribution of temperatures, gas velocities, concentrations of combustion products, nitrogen oxide emissions, degree of burnout in the furnace volume and other characteristics that affect the efficiency, reliability, and environmental safety of the boiler. The results of model studies showed that the developed schemes provide high efficiency of burning lean Kuznetsk coal with solid slag removal and, at the same time, low emissions of nitrogen oxides. An additional verification of the numerical model was carried out by comparing the gas temperatures by the height of the furnace obtained by its numerical simulation and thermal zone calculations. A comparison of the temperatures of the gases at the outlet of each zone showed their good agreement (the difference was no more than 30°C).
      PubDate: 2020-06-01
       
  • The Flow Boiling Crisis of Saturated Water in Pipes at High Pressures
    • Abstract: The procedures developed by the authors for calculating the distribution of the liquid over the channel cross section in the dispersed-annular flows open up opportunities for more justified modeling of the conditions for the occurrence of a boiling crisis at positive values of the relative enthalpy (quality) of the flow. However, a comparison of the calculated values of the liquid flowrate in the film with the recommended values of critical heat flux (CHF) in water flow boiling in pipes has demonstrated that, in general, there is no obvious correlation between them. An analysis confirms the well-known opinion that a unified model of the flow boiling crisis in pipes cannot be constructed. At the same time, the regularities revealed in calculating the entrainment and deposition of droplets should be considered in developing a crisis model. An increase in CHF with mass flowrate, which was discovered experimentally and accounted for in the reference tables in a wide range of high pressures and mass flowrates, gives us reasons to return to Doroshchuk’s hypothesis about the “deposition crisis.” Application of the correlation for the droplet deposition rate in a disperse-annular flow enabled us to quantitatively verify this correlation. The predictions obtained using this correlation agree well with the tabulated data at a flow quality from 0.15 to 0.40 and mass flowrates above 2000 kg/(m2 s). At the same time, it has been demonstrated that the widespread use of extrapolation of the CHF values recommended in the latest edition of these tables makes them, in fact, not only unreliable but also physically unjustified in a certain range of parameters. This paper identifies several such ranges wherein revision of the tables is essential.
      PubDate: 2020-06-01
       
  • Cyclone-Bed Furnaces: Experimental Studies and Thermal Design
    • Abstract: Furnace processes occurring in laboratory setups, pilot commercial facilities, and small-capacity boilers of various sized equipped with cyclone-bed furnaces containing fixed and fluidized beds burning solid biofuels (wood pellets, straw pellets, sunflower husk pellets, peat pellets, wood waste, wood chips, milled peat, and crushed peat bricks) are investigated. The distribution features of temperature and gas concentrations (CO, CO2, H2, O2, CH4) in the combustion and secondary combustion chambers have been established in the course of experiments. With this information available, it becomes possible to determine the zones in which fuel actively reacts with the oxidant under the conditions of two-stage vortex combustion. Dependences of the carbon monoxide (CO) and nitrogen oxide (NOх) concentrations in the flue gases on the excess air ratio, bottom blast share (primary air), furnace power, and the combustion chamber’s outlet hole diameter are obtained. The furnace processes in cyclone-bed furnaces are numerically simulated using the standard k–ε turbulence model and the Magnussen combustion model, and satisfactory agreement between the calculation and experimental results is shown. A semiempirical method for designing cyclone-bed furnaces has been developed, according to which their main geometrical and operating parameters are determined in two stages: a preliminary thermal design analysis is first carried out, after which the furnace process is numerically simulated. Based on extensive generalization of experimental data on the burning of solid biofuels in cyclone-bed furnaces having different diameters, the parameter М = 0.52, which appears in the well-known Gurvich formula for the thermal design of furnace chambers, has been determined. This parameter takes into account the temperature field structure and the heat transfer pattern over the furnace height, thus making it possible to use the standard method in carrying out thermal design computations of furnaces.
      PubDate: 2020-06-01
       
  • Long-Term Development Prospects of Russia’s Wind Energy in the
           Conditions of Expected Climate Changes
    • Abstract: The climatic effect on the operation of wind power plants in Russia is analyzed. Based on the global experience of wind farms’ operation, a quantitative assessment of the sensitivity of electric power generation by modern wind turbines to wind speed variation is carried out. Using the ensemble approach, predictive estimates of changes in the wind fields in Russia are obtained for the 21st century using the results of general atmospheric circulation models participating in the international project CMIP5 (Coupled Multimodel Intercomparison Project Phase 5). The validity of the findings is ensured by the validation procedure, including a comparison of different versions of the multimodel ensemble with data reanalysis. The predictive estimate obtained for the climatic scenario developed at the National Research University Moscow Power Engineering Institute (NRU MPEI) is compared with generally accepted climatic scenarios based on the use of so-called greenhouse gas representative concentration pathways. It is shown that the choice of the scenario has a significant impact on the forecast results. However, the data of the calculations distinguish several features of the wind regime in the 21st century, which are almost independent of the selected scenario or ensemble composition and, apparently, can be considered reliable. In particular, it is found that there is a possibility of some decrease in average wind speeds across Russia during the 21st century. However, in Primorskiy Kray, the expected climate change will lead to the formation of a zone with a steady increase in its speed. Changes in the technical wind potential in the regions of the country where the construction of wind turbines is planned will amount to from –15 to –20% for the subarctic regions and from +5 to +10% for Primorskiy Kray by the end of the 21st century. It follows from the calculations that the currently observed climate warming, in all likelihood, does not pose a serious threat to the development of wind energy in Russia. The modern and planned location of wind farms even makes it possible to expect some growth in their production rate in the first half of the 21st century. At the same time, the prospect of long-term changes in the wind regime should certainly be taken into account when selecting the wind farm location and predesign analysis as part of the measures aimed at adapting to climate changes.
      PubDate: 2020-06-01
       
  • Study into the Distribution of Mass Velocity and Enthalpy of Single-Phase
           and Two-Phase Flows in the Cross Section of a 19-Rod Bundle in an
           Electrically Heated Model of an RBMK-1000 Fuel Assembly
    • Abstract: The results of experimental studies into the distribution of mass velocity and enthalpy of single-phase and two-phase flows over the cross section of a 19-rod bundle in an electrically heated model of an RBMK-1000 fuel assembly (FA) are presented. A description is given of the experimental section, which included a 19-rod electrically heated assembly of fuel-element simulators, a system for sampling a medium from cells, and a control system for moving samplers. A bunch of fuel rod simulators consisted of a central unheated rod and 18 electrically heated rods. The heated length of the rods bundle was 3500 mm. The sampling system from characteristic cells included sharp-edge samplers, a system for moving samplers from the starting position to the working position, and a cooling system and measuring sample parameters. Samplers corresponding in shape and geometrical dimensions to five characteristic cells were made of stainless steel. Single phase and two phase samples were taken from assembly characteristic cells under the condition of isokinetics. The condition for the isokinetics of the selection was that the parameters of the coolant flow that entered the sampler remained the same as they were before the sampler was introduced into the stream. In the experiments, the achievement of the isokinetic condition was determined on the basis of the measured difference in static pressures in the cells and on the wall of the assembly housing. The results of experiments performed under isothermal and nonisothermal coolant flows in a wide range of mass velocities and enthalpies are presented. It has been shown that the distribution of the reduced mass velocity and steam quality over the bundle cells depends on the flow regimes of the coolant flow that are formed in the cells.
      PubDate: 2020-06-01
       
  • Simulation of Heat and Mass Transfer in Wire-Wrapped Fuel Assemblies in
           the Anisotropic Porous Body Approximation
    • Abstract: Results of the simulation of heat and mass transfer in wire-wrapped fuel assemblies in the anisotropic porous body approximation using the developed APMod software package are presented. The modifications introduced into the porous body model to make it suitable for wire-wrapped fuel assemblies are described. The predictions of thermal and hydraulic characteristics in the liquid-metal cooled experimental and model fuel assemblies according to this updated model are presented. An isothermal sodium flow in a Bundle 2A experimental 19-rod wire-wrapped assembly and uniform or nonuniform heating of the rods was studied. The predictions were compared with the experiments using the pressure difference across the assembly versus the coolant flowrate and the coolant temperature distribution in the assembly’s outlet section. The thermal–hydraulic characteristics in the BN-1200 reactor fuel assembly’s heated 19-rod fragment with its flow cross-section locally blocked in the central part calculated by the porous body model were compared with the predictions by the CONV-3D DNS code. Before their comparison, the distributions of local velocities, pressure, and temperature in an assembly cross-section calculated by the CONV-3D code were averaged over the averaging cells in the APMod software package. It is demonstrated that the APMod software package may be used to calculate parameters, which are averaged over a representative averaging cell, in a liquid-metal coolant flow in wire-wrapped fuel assemblies with an accuracy adequate for engineering applications.
      PubDate: 2020-06-01
       
  • Specific Features of Electron-Beam Welding of ITER Blanket First Wall
           Components
    • Abstract: — Specific features of fabricating welded structures of the international thermonuclear experimental reactor (ITER) blanket components are considered. The results from elaborating the technology for electron-beam welding of cooling system’s channel caps in the first wall bearing structure (FWBS) of the ITER blanket shielding module are presented. The design of welded joint samples made of Grade 316L(N) steel and the welding equipment are described. The welding techniques and butt joint design features whose use makes it possible to obtain the required strengthening of weld bead and to avoid metal droplets from appearing in the FWBS inner cavities are considered. A simplified thermal–mechanical model of the cap-welding technological process is described, and the results from experimentally evaluating the structural and mechanical state of the obtained welded structures are presented. A comparison between the modeling and experimental results is given. It is pointed out that the stressed and strain state varies in an active manner at the initial loading stage. Initially, the metal in the heat-affected zone (HAZ) experiences plastic deformation followed by elastic relief at the subsequent stages. It is pointed out that the postweld deformations are on the whole characterized by a low level and remain within the permissible limits. The distribution of mechanical properties in weld joint local zones determined using the indentation method is given. The results from tensile tests and an indenter impressing test show that the weld metal has even better mechanical characteristics than the parent metal. Data are presented from metallographic investigations, which testify that there is no growth of grains in the HAZ, which is due to high rates of cooling in the used welding method. Based on the results of elaborating the electron-beam welding technology and using the developed techniques, an FWBS mockup has been fabricated that complies with the class VQC 1A tightness requirements.
      PubDate: 2020-06-01
       
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
 


Your IP address: 3.233.229.90
 
Home (Search)
API
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-