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1
Kotov, Boris, Vladimir Grishchenko, Yuriy Pantsir, and Igor Garasimchuk. "MATHEMATICAL MODELING OF TECHNOLOGICAL MODES OF HEAT-PUMPING SYSTEMS FOR TECHNOLOGICAL PROCESSES." Vibrations in engineering and technology, no. 2(101) (June 29, 2021): 85–91. http://dx.doi.org/10.37128/2306-8744-2021-2-9.
Повний текст джерелаАнотація:
One of the ways to increase the energy efficiency of the process of heat supply of technological facilities and production facilities of the agro-industrial complex is the use of heat pumps. Their use allows to increase the energy potential of heat carriers. To optimize the mode parameters and create systems for automatic control of the heat pump installation, it is necessary to establish a relationship between the parameters of the processes occurring in the elements of the installation by creating a mathematical model of non-stationary thermal modes. In the analysis of recent studies and publications, it is established that the calculations of processes in heat pumps are presented mainly for stationary modes of operation without taking into account the dynamics of the condenser. If the dynamic modes of individual elements are given, then they are described by mathematical models of considerable complexity, which greatly complicates their practical implementation. In the article, the heat pump installation, as an object of modeling, is considered as a physical system, which consists of four series-connected elements: evaporator, condenser, compressor, throttle valve forming a closed circuit. The principle of operation of a simple heat pump installation is explained by the scheme and schedule of the theoretical cycle of the steam compressor heat pump. To simplify the mathematical model, certain assumptions were made: the change in the parameters of liquid, vapor and air varies in a straight line, the thermophysical characteristics of the material of heat exchangers, air and vapor flows, heat transfer coefficients do not depend on temperature and are average for the cycle. On the basis of thermal and material balance the corresponding differential equations which make mathematical model of dynamics of change of parameters of the heat exchanger have been made. The mathematical model is supplemented by a simulation model in the MatLAB / Simulink computer environment, as well as graphical interpretations of dynamic characteristics. The developed mathematical model of dynamics of thermal processes in the heat pump installation can be used for calculation of parameters of heating and cooling of streams of heat carriers and creation of system of automatic control of them.
2
Platov, Sergey, V. A. Nekit, and Nicolay Urtsev. "Investigation of Temperature-Time Modes of Rolling of Thick-Sheet Steel and Mechanical Properties of Finished Products." Solid State Phenomena 316 (April 2021): 380–84. http://dx.doi.org/10.4028/www.scientific.net/ssp.316.380.
Повний текст джерелаАнотація:
The article is devoted to the study of technological modes of hot rolling of tube steel on a thick-sheet mill and mechanical properties of the finished products. Five slabs were rolled under the experimental regime in accordance with the study plan. The temperature conditions of rolling at the final stage of deformation and the modes of accelerated cooling of rolled products were changed. Dependencies between technological parameters and mechanical properties allowed developing recommendations on improvement of technology of rolling and of the subsequent accelerated cooling of metal.
3
Kharitonov, I. A., A. L. Goncharov, E. K. Titarev, and A. V. Nekhoroshev. "Investigation of the thermal state of the elements of a technological electron beam gun under long–term operating conditions." Journal of Physics: Conference Series 2077, no. 1 (November 1, 2021): 012008. http://dx.doi.org/10.1088/1742-6596/2077/1/012008.
Повний текст джерелаАнотація:
Abstract The paper presents the results of a study of the thermal state of the elements of the cathode assembly of the ELA–15 welding electron gun. It was revealed that in short–term operating modes of the gun (up to 60 minutes) at any energy parameters of heating the hexaboride cathode, it is possible not to use forced cooling of the cathode assembly. The case temperature in such modes did not exceed 30°C. The increase in the temperature of the gun body occurred 15 minutes after the start of heating the cathode. In long–term operating modes with forced cooling of the gun, the temperature of the gun body increased by 2 – 3°C and remained stable throughout the operation. When the cooling was turned off, the temperature of the gun body reached a critical value in 60 minutes. The section of natural cooling of the cathode obtained in the work, which appears when the heating of the cathode is stopped, is well approximated by a power function. It is convenient to use this dependence to verify the mathematical model of the thermal state of the electron gun.
4
S.N., Koreshkov, Khvylia S.I., and Lapshin V.A. "The expert assessment of meat mass loss in the refrigeration chambers of meat and meat processing enterprises." Vsyo o myase, no. 5 (October 30, 2020): 36–39. http://dx.doi.org/10.21323/2071-2499-2020-5-36-39.
Повний текст джерелаАнотація:
The monitoring of beef meat losses in halves and quarters occurring during cooling technological processes at the industrial refrigeration enterprises depending on different technological factors is given in the article. These factors are: quick and accelerating one-stage cooling, quick twostage cooling, continuous and cycled modes of refrigeration chamber during cooling and storing, besides, the age of cattle, quality groups of meat, average temperature of freezing and the way of cooling the chamber, its defrosting and subsequent storage, duration of moisture drainage after wet cleaning and etc. It is shown that there is inconsistency of factual and normative meat losses due to results of practical work of chambers for cooling and storing at some enterprises of the agricultural-industrial complex. Measures and ways on further improvement of normative and standard base with perspective of development and introducing of the individual standards of meat losses in the existing conditions of refrigeration chamber for each enterprise.
5
Timoshpolsky, V. I., E. I. Marukovich, and I. A. Trusova. "Application of classical numerical methods in the calculation of solidification modes of a continuous ingot." Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), no. 3 (October 20, 2020): 41–47. http://dx.doi.org/10.21122/1683-6065-2020-3-41-47.
Повний текст джерелаАнотація:
This paper presents approaches to the computational analysis of solidification and cooling processes of continuously cast billets in order to improve and develop technological modes in the conditions of modern continuous casting machines using FEM.The application of modern numerical methods for solidification and cooling of workpieces on continuous casting machines is considered. The use of the finite element method is justified when using computational and experimental data for the development and improvement of casting technology.
6
Tulupov, O. N., A. B. Moller, and S. Y. Sarancha. "Increasing of Long Products Rolling Efficiency: Modernization of Stelmor Air Cooling Line to Obtain Sorbitized Wire Rod." Solid State Phenomena 265 (September 2017): 1116–22. http://dx.doi.org/10.4028/www.scientific.net/ssp.265.1116.
Повний текст джерелаАнотація:
Most national companies are seeking to reduce costs, improve technological processes and increase profitability. The steel industry is no exception - an example of cost reduction is a technology of sorbitized wire rod production. This technology can improve the performance characteristics of wore rod and reduce the number of patenting stages during metalware production. The developed technology has been tested in the CIS countries Stelmor lines, and its task is to eliminate the significant disadvantages of these lines: the absence of differential cooling on the conveyor width, insufficient cooling rate of air cooling sections, the lack of frequency regulated speed control for electric motors. Eliminating these disadvantages and developing new cooling modes using the software, based on the original mathematical model, allows for the production of sorbitized wire rod with high performance characteristics, provided with increased level of pearlite dispersion (1-2 points for at least 85% of area). Each intense and retarded cooling section has to be fitted with adjustable flaps controlled by electric motors, ensuring the alignment rod temperature at the roller conveyor width. Before the start of the reconstruction of the cooling line a detailed technical and technological audit is required to identify and eliminate the causes that lead to uncontrolled temperature deviations or wire rod laying deviations on the cooling conveyor.
7
Borodulin, D. M. "Mathematical Support to Control Milk Temperature at Cooling Outlets." Proceedings of the Voronezh State University of Engineering Technologies 84, no. 1 (February 15, 2022): 24–28. http://dx.doi.org/10.20914/2310-1202-2022-1-24-28.
Повний текст джерелаАнотація:
Automation of any production is impossible without the appropriate software for automation systems. Automatic control systems are used for various parameters of technological processes. Temperature is one of the main technological parameters in dairy production. Therefore, its control and regulation in various parts of technological lines is an important task for the automation of dairy production. For this, an information scheme of the technological control object was created with the designation of the controlled technological parameters. The following parameters were established as a result of the analysis of the normal operation of the technological control object: cold water temperature, transmission coefficient of this channel; the temperature of the source milk, the transmission coefficient of this channel; ambient air temperature, transmission coefficient of a given channel; cold water pressure, transmission coefficient of this channel; raw milk consumption, transmission coefficient of this channel. Calculation of a single-loop system for automatic control of milk temperature at the outlet of the cooling section was made using the IPC-CAD program. As a result of processing the obtained data, it was found that the transient processes "aperiodic" and "with moderate attenuation" have a sufficient margin of stability, since the degree of attenuation is greater than 0,75. Dynamic errors in the modes of tuning and checking for roughness of these processes differ by 0,02, that is, the differences are insignificant. The margin of stability of the "aperiodic" process is higher, and the dynamic error does not significantly exceed the other options, so this type of transient process was chosen for further application. Thus, the use of an automatic control system based on the developed software is expedient and effective, as it will reduce rejects and improve the quality of products due to timely quality control of the main technological parameter - the temperature of raw milk. From this it follows that the use of this single-circuit automatic control system is appropriate in the dairy industry.
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Rakhmanova, Mafiiat, Amiiat Demirova, Magomed Akhmedov, Faina Azimova, Irada Gadzhibekova, and Zaurbek Abdulkhalikov. "High-temperature multilevel sterilization of canned goods with heat recovery and its constructive and technological support." E3S Web of Conferences 247 (2021): 01030. http://dx.doi.org/10.1051/e3sconf/202124701030.
Повний текст джерелаАнотація:
New technical solutions improving the process of thermal sterilization of canned products through the use of multilevel high-temperature modes and heat recovery have been considered and proposed. The essence of the developed method lies in the fact that the heat released by cooling cans with the product that has undergone thermal sterilization is used to heat other cans with the product queued for sterilization. In this mode of heat treatment, except in the last stage, the heat emitted by cooled cans that have already undergone heat treatment is used to heat up the canned food. Hence, the use of the principle of heat recovery by cooling canned products in the baths where others are simultaneously heated provides a significant saving of heat energy and water. Depending on the temperature parameters at different stages of the heat treatment, the heat recovery rate can reach up to 90%. The method also provides savings on cooling water. For the practical implementation of the developed method, the design of the device for multilevel high-temperature thermal sterilization of canned food with heat recovery has been developed. On the basis of experimental studies, new, multilevel high-temperature modes of apple compote sterilization have been developed.
9
Merentsov, N. A., V. N. Lebedev, A. V. Persidskiy, and A. B. Golovanchikov. "Automatic control system for operation modes and calibration of technological parameters of evaporation cooling apparatuses." Journal of Physics: Conference Series 1515 (April 2020): 022004. http://dx.doi.org/10.1088/1742-6596/1515/2/022004.
Повний текст джерела
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Suleymanov, Sultan Khamidovich, Elman Sayad ogli Nabiev, Valery Grigorevich Dyskin, Mustafa Umerovich Djanklich, Oleg Andreevich Dudko, and Natalya Aleksandrovna Kulagina. "THE STUDY OF TECHNOLOGICAL REGIMES OF HARDENING BANDAGE STEEL OF THE CONCENTRATED FLOW OF ENERGY." Computational nanotechnology 6, no. 3 (September 30, 2019): 11–15. http://dx.doi.org/10.33693/2313-223x-2019-6-3-11-15.
Повний текст джерелаАнотація:
The work is devoted to the development of technological modes of strengthening of the band steel of locomotive wheels by the method of thermal treatment with concentrated energy flow. Thermal treatment of the banding steel was carried out on a solar furnace at flow densities 320, 450 and 500 W/sm2. Quenching was carried out in air and water. Heating and cooling rates are important for quenching. If speed of cooling is less than critical speed ( V cr ≈ 50 deg/s), quenching is not observed. The hardness of the tempered steel samples after thermal treatment at a temperature of 800-1200°C and treated in water reaches ≈726 HB, that is not optimum for bandage steel.The optimum temperature for quenching the band steel is 730-780°C at a flow density of 450 W/sm2. At the heating temperature of the steel samples 730-780°C and cooling by quenching into water, the hardness of the band steel is the required value of 350-400 HB. By changing the heating temperature and cooling rate of the steel, a predetermined hardness can be controlled and obtained.
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Kolbasnikov, Nicolay G., Oleg G. Zotov, and Aleksey A. Lukyanov. "Investigation of the Operational Reliability of the Rolled Rails According to the Various Technologies." Key Engineering Materials 651-653 (July 2015): 317–21. http://dx.doi.org/10.4028/www.scientific.net/kem.651-653.317.
Повний текст джерелаАнотація:
Based on experimental studies of the complex mechanical properties and microstructure, as well as simulation of rails rolling modes made from different steel manufacturers are shown the main technological approaches to obtain rails with high operational reliability . Found that, under the current production technology of domestic steel rails the adjustment of the chemical composition, temperature-deformation modes of rolling and cooling speed rate of the rails is suitable for reducing the negative free ferrite influence on rails durability.
12
Savinkov, V. V., and I. A. Kovaleva. "Optimization of two-stage cooling conditions for wire rod diameter 5.5–6.5 mm of low-carbon steel grades in order to ensure the required degree of descaling mechanically before its subsequent processing." Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), no. 3 (October 5, 2018): 63–66. http://dx.doi.org/10.21122/1683-6065-2018-3-63-66.
Повний текст джерелаАнотація:
With the aim of obtaining scale with a high degree possibility of mechanical removal under the conditions of the section rolling shop No. 1, at the mill «150» JSC «Belarusian Metallurgical Works – Management Company of Holding «BMC» developed technological modes of production of wire rods made of low-carbon steel grades.The peculiarities of scale formation were studied, namely, the factors influencing the removability, obtaining the optimal thickness and its phase components on the wire rod diameter 5.5–6.5 mm in the cooling process immediately after rolling, intended for wire production.To obtain the necessary ratio of the phase constituents of the scales on the surface of the wire rod, the following factors was taken into account: the temperature of the layout of the turns on the roller table in the air cooling line; (uniformity along the length of the turn), the cooling conditions of the helix of the turns (prevention of the 4FeO = Fe3O4-Fe decay), where the condition of cooling the wire rod from 600 to 250 °С, not exceeding 100 s, must be observed.The results of metallographic studies of scale on the wire surface are presented. The introduced technological regimes provided the optimal thickness and the FeO / Fe3O4 ratio after the experimental rolling of the metal. Exhausted cooling regimes allowed to reduce the consumption of fiber for all types of wire.
13
Богатко, Н. М., та Н. І. Сахнюк. "Вплив санітарно-гігієнічного стану холодильних камер м’ясопереробних підприємств на безпечність м’ясної сировини за її зберігання". Вісник Полтавської державної аграрної академії, № 1 (28 березня 2013): 106–9. http://dx.doi.org/10.31210/visnyk2013.01.28.
Повний текст джерелаАнотація:
Технологічні режими охолодження м’яса в охолоджувальній (t = -1 ºС) та холодильній (t = -12 ºС) камерах не чинять бактеріостатичний вплив на життєдіяльність плісеневих грибів. Найбільша зараженість плісеневими грибами повітряного середовища та штукатурки стін камер (охолоджувальних і холодильних) спостерігалася в їх нижній частині на висоті 0,5 м від підлоги. Дотримання вимог технологічних процесів зберігання м’ясної сировини, якісна дезінфекція забезпечать задовільний санітарно-гігієнічний стан охолоджувальних та холодильних камер.
Technological modes of meat cooling in the cooling (t = -1 ºC) and cold (t = -12 ºC) cells do not have a bacteriostatic effect on the life of molds. Most fungi contamination of air and plaster walls of the chamber (cooling and refrigeration) was observed in their lower end at a height of 0.5 m above the floor. Compliance with process storage of raw meat, high-quality disinfection provide satisfactory sanitary conditions of cooling and cold storage.
14
Паринов, Дмитрий, Dmitriy Parinov, Владимир Шамаев, Vladimir Shamaev, Илья Медведев, and Ilya Medvedev. "DEVELOPMENT OF PARAMETERS OF THE TECHNOLOGICAL PROCESS FOR MANUFACTURE OF SLEEPERS BLANKS FROM MODIFIED WOOD." Forestry Engineering Journal 8, no. 1 (March 19, 2018): 158–69. http://dx.doi.org/10.12737/article_5ab0dfc4643417.34919882.
Повний текст джерелаАнотація:
The purpose of the work is to develop the parameters of technological modes, the production of modified wood for sleepers, the combination of drying, impregnation and pressing operations. During the research, the following meth-ods have been used: active experiment, laboratory method for determining the size and quality characteristics of the feedstock, laboratory method for carrying out the technological process for producing modified wood. As a result of the research, the parameters of the technological modes of drying, impregnation and pressing have been worked out for the first time, combined both in place and in time. As a raw material for pressing, birch wood in the form of bar with a section of 250 × 235 mm, length of 2750 mm, humidity of 75-80%, density of 550-600 kg / m3 has been used. The main design and technical and operational characteristics of the pilot plant allow us to achieve and maintain optimal parameters of technological modes of drying, impregnation and pressing during the whole technological process of production of modified wood. The developed parameters of technological modes has formed the basis for the technical specifications for MW sleepers (modified wood), and the developed technological regulations have been recommended for the introduction into the production of sleepers from modified wood. The novelty of the results of scientific research work is development which is qualitatively new, unknown in industry, practice and literature. Optimum modes of drying, impregnation and pressing of wood are obtained: the temperature of the hot antiseptic is 120 ° C, the time of warming up and wood drying is 38 hours, the impregnation time is 4 hours, the pressing time is 17 hours, the specific pressure is 0.8 MPa, the cooling time is 6 hours, the degree of pressing is 22 %. It is recommended to use the obtained modes for introduction into production to produce railway sleepers from modified wood with improved performance indicators: density - 700 kg / m3, humidity - 22%, compressive strength along the fibers - 41.5 MPa, impregnation depth across the fibers - 5.5 mm, from the end part - 110 mm.
15
Ivanova, Tatiana N., Witold Biały, Jiři Fries, and Victor Nordin. "Technological Forecasting of Deformations in Flat Parts." Multidisciplinary Aspects of Production Engineering 3, no. 1 (September 1, 2020): 1–12. http://dx.doi.org/10.2478/mape-2020-0001.
Повний текст джерелаАнотація:
AbstractThe deformation of a part occurring in the process of grinding directly influences its exploitation and quality parameters. The instability of shape and size, which occurs due to an imbalance of residual stress, can be the one of the major causes of deformation of a part. The decrease in stress slows down the deformation process. Considering the regularities of heat source intensity dependence on the grinding modes, it can be asserted that with increasing grinding depth and grinding wheel hardness, the value increases and it decreases with a growth in a speed of the part and the use of cooling. The higher the heat removal is and the better lubricant properties of the liquid are, the more significant the decrease in is. Changing these values allows regulation of the residual stresses. As a result of the research on determination of deformations, it is recommended to reduce thermal deformations by considering the geometric size of a plate to be machined, linear expansion coefficient of plate material and an allowance for nonflatness from thermal deformations. The value of nonflatness from thermal deformations is directly proportional to linear expansion coefficient of plate material and its square overall dimensions. At the same time, the value of nonflatness is inversely proportional to the plate thickness.
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Фордуй, Сергій Георгійович, Андрій Миколайович Радченко, Анатолій Анатолійович Зубарєв, Володимир Володимирович Бойчук та Олексій Валерійович Остапенко. "РЕЗЕРВИ ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ ТРАНСФОРМАЦІЇ ТЕПЛОТИ УСТАНОВКИ АВТОНОМНОГО ЕНЕРГОЗАБЕЗПЕЧЕННЯ". Aerospace technic and technology, № 4 (31 серпня 2019): 25–30. http://dx.doi.org/10.32620/aktt.2019.4.05.
Повний текст джерелаАнотація:
It is analyzed the efficiency of heat conversion in the integrated electricity, heat and cooling supply of the enterprise. The installation for energy supply includes two JMS 420 GS-N.LC GE Jenbacher cogeneration gas engines manufactured as cogeneration modules with heat exchangers for removing the heat of exhaust gases, scavenge gas-air mixture, cooling water of engine and lubricating oil. The heat of hot water is transformed by the absorption lithium-bromide chiller AR-D500L2 Century into the cold, which is spent on technological needs and for the operation of the central air conditioner for cooling the incoming air of the engine room, where from it is sucked by the turbocharger of the engine. The presence of significant heat losses, which account for about 30% of the total heat removed from the cogeneration gas piston module and is due to the inconsistency of the joint operation modes of the absorption lithium-bromide chiller and the gas piston engine, was revealed. This inconsistency is caused by the contradictory conditions of their effective operation according to the temperature of the return coolant at the outlet of the absorption lithium-bromide chiller and the entrance to the engine cooling system. The thermal state of the gas piston engine is ensured by maintaining the temperature of the return coolant at the entrance to it is not higher than 70 °C. At the same time, during the transformation of the heat of the coolant into the cold in an absorption lithium-bromide chiller, the temperature decreasing in the machine is no more than 10 ... 15 °С, that is, up to 75 ... 80 °С, if the temperature of the heat coolant outlet from the cogeneration gas piston module, i.e. at the inlet of the absorption lithium-bromide chiller, 90 °С. Therefore, the return coolant is additionally cooled in the "emergency heat release" radiator by removing its heat into surroundings. It is shown the possibility of increasing the cooling capacity of the system by conversion of the return coolant exhaust heat into cold in absorption lithium-bromide and ejector chillers through the data procession of monitoring the heat conversion system in the integrated energy plant.
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Belozerov, Vladimir I., Mikhail M. Zhuk, and Anna M. Terekhova. "Investigation of the small break conditions in the primary circuit of a VVER-1000 reactor*." Nuclear Energy and Technology 5, no. 1 (March 20, 2019): 47–52. http://dx.doi.org/10.3897/nucet.5.33982.
Повний текст джерелаАнотація:
Modes with violation of the reactor plant cooling conditions on the primary circuit side of a VVER reactor were simulated using the TRAC-PD2 and Open FOAM thermohydraulic codes (TRAC-PD2 1981, OpenFOAM User Guide Version 1.6. 2009, OpenFOAM Programmer’s Guide Version 1.6. 2009) based on energy and mass conservation equations for the three-dimensional unsteady flow of a two-phase mixture. Coupled simulation of the dynamics of neutronic and thermohydraulic processes (TRAC-PD2 1981, OpenFOAM User Guide Version 1.6. 2009, OpenFOAM Programmer’s Guide Version 1.6. 2009, Bolshagin et al. 2009, Galanin 1971, Weinberg and Wigner 1961, Ovchinnikov and Semenov 1988, Report LA-UR-03-1987) aims to improve the qualitative understanding and the quantitative presentation of their effects on safety. Investigating these modes using the above thermohydraulic codes makes it possible to analyze the course of transients and certain emergency processes without using the industrial testing method, this providing the basis for solving the problems of ensuring the reliability, operational safety and efficiency of nuclear power plants. A modern nuclear reactor is a complex system studying and calculating which requires more than the use of simple theoretical models. Thermohydraulic calculations are an essential part of most engineering and technological development works in nuclear power. Since, in conditions of an NPP, no technologically conventional way can be used to verify and update the results and findings of an a priori analysis on the basis of commercial tests, investigations based on codes are used in some cases as the tools to study and predict the parameters of thermohydraulic processes in the reactor’s circulation circuit. The main purpose of the study is to calculate and investigate, based on codes, modes with violation of the reactor plant cooling conditions on the primary circuit side of a VVER reactor in order to determine if calculated parameters conform to the acceptance criteria established by regulatory documents.
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Perchevska, Liudmyla, Oleksandr Drozdenko, and Kateryna Drozdenko. "Shifting the operating frequency of the piezoceramic electroacoustic transducer langevin type using passive cooling methods." ScienceRise, no. 4 (August 31, 2021): 3–10. http://dx.doi.org/10.21303/2313-8416.2021.002019.
Повний текст джерелаАнотація:
The object of research: the shift of resonant frequency of the piezoceramic electroacoustic transducer Langevin type depending on the shape of the back plate.
Investigated problem: the relationship between changes in shape of back plate of the Langevin type transducer with the resonant frequency of the oscillating system. Search quantitative contribution to shift the resonant frequency of each of the modifications: shape, diameter, thickness, weight of back plate.
The main scientific results: vibration modes of a transducer with a back plate with horizontal and vertical radiator ribs were obtained. The graphs of the shift resonant frequency depending on the change in the diameter and thickness of the back tail with vertical radiator ribs are presented. It is established, that the change in the thickness and diameter of the back plate of the transducer effects on resonance frequency much less than the change in mass.
The area of practical use of the research results: designing piezoceramic electroacoustic transducer with passive cooling method.
Innovative technological product: guidelines for choosing the shape changes back plates of the Langevin type transducer for decreasing heating temperature, with keeping resonant frequency.
Scope of the innovative technological product: scope of application of the Langevin type transducer: underwater acoustics, ultrasonic technological equipment, ultrasonic engine, piezotransformer, medical equipment, rock drilling devices.
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M.A., Dibirasulaev, Belozerov G.A., Dibirasulaev D.M., Donetskikh A.G., and Ryzhova S.G. "To the development of scientifically based storage modes of meat and meat products in a supercooling state." Vsyo o myase, no. 5 (October 30, 2020): 40–45. http://dx.doi.org/10.21323/2071-2499-2020-5-40-45.
Повний текст джерелаАнотація:
One of the ways to ensure safety, preserve quality and increase the expiration date (storage) of meat with minimal technological processing of raw materials is the use of supercooling and storage technologies at subcryoscopic temperatures. Supercooling is a refrigeration processing process that provides lowering the meat temperature (1–2 °C) below the cryoscopic temperature without phase transformation of water into ice (supercooling). The phase transformation of water into ice upon freezing and freezing food products causes irreversible changes in them as a result of crystal formation in muscle fibers, decompartmentalization of cell organelles and denaturation of sarcoplasmic and myofibrillar proteins. Subcooling provides better quality preservation and an increase in the expiration date of meat raw materials and finished meat products compared to cooling. To ensure a stable supercooled state of products at a subcryoscopic temperature, studies of the influence of abiotic and anabiotic factors on the limiting temperature of supercooling (nucleation) of a product are of great importance. The article presents the results of studies on the impact of quality meat groups, packaging and the temperature of the cooling medium on the stability indicators of the supercooled state of raw materials and finished products. It is shown that the temperature of the cooling medium, providing a stable state of the product undercooling, lies between its cryoscopic and the limiting temperature of the supercooling, experimentally determined for each type of product.
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Matrosov, M. Yu, P. G. Martynov, A. V. Mitrofanov, K. Yu Barabash, T. V. Goroshko, and M. I. Zvereva. "Study of the thermal treatment modes influence on the forming of microstructure and specified complex of mechanical properties of high-strength sheet product with guaranteed level of hardness (400–450 HB) of low-alloyed steel." Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 75, no. 4 (May 18, 2019): 480–87. http://dx.doi.org/10.32339/0135-5910-2019-4-480-487.
Повний текст джерелаАнотація:
High-strength sheet product of low-alloyed steel, used at manufacturing of heavy-loaded structures, must have, apart from wear resistance, high toughness, good weldability, ability to hot and cold forming, machinability and low cost. Combination of these properties based on forming fine grain austenite structure before the martensitic transformation at definite its thermal treatment modes. Results of study of microstructure, fine structure and mechanical properties of high-strength boron-containing low-alloyed steel after different technological methods of the rolled product manufacturing presented: high-temperature hot rolling and twostages controlled rolling with accelerated cooling followed by thermal treatment – quenching with tempering. Variants of optimal modes of thermal treatment determined, providing combination of high level of impact toughness under negative temperatures, hardness and strength properties of sheet product. The two considered in the article technological variants, comprising treatment of low-alloyed steel with boron (hot rolling and two-stages controlled rolling with accelerated cooling) followed by thermal treatment results in forming fine structure of tempered martensite, which provides high mechanical properties, meeting the made requirements. Depending on the heating temperature before quenching in the range 770–950 °С, the morphology of the actual steel grain is changing from elongated to equiaxed, which is connected with the metal recrystallization process during heating after plastic deformation. The study results obtained allow to optimize the thermal treatment processes of sheet product of low-alloyed boron containing steel for particular conditions of application.
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Cherneta, Oleg, Vadim Kubich, Roman Voloshchuk, Alexander Sasov, Yuriy Korzhavin, and . "Conditions for the Formation of Wear-Resistant Structures When Strengthening the Surface Layers of Parts." International Journal of Engineering & Technology 7, no. 4.3 (September 15, 2018): 76. http://dx.doi.org/10.14419/ijet.v7i4.3.19555.
Повний текст джерелаАнотація:
In the given article special attention is paid to the transformation of the structure of average carbon steels, depending on technological methods of strengthening, the identification of factors influencing the emergence of high-strength structures. With the help of microstructural, X - ray phase studies, microhardness measurements of certain layers, the main technological parameters and modes of reinforcing workings have been identified, new and innovative combined technologies have been proposed. Based on the analysis of a number of existing technological methods of strengthening the surface layer of structural materials, the dynamics of transformation of their microstructures was researched. After laser treatment, due to the ultra-high velocity of cooling of crystallized volumes, due to intensive heat removal through the main volume of samples on the surface, a light zone, which is not digestible, is identified and is identified as "structurally martensitic" - gardenain, which is a kind of classical martensite. Based on the analysis of a number of existing technological methods of strengthening the surface layer of structural materials, the dynamics of transformation of their microstructures was researched.
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Osadchuk, Eugeniy, and Oleksandr Titlov. "ANALYSIS OF THE CLIMATIC FEATURES OF THE REGIONS OF THE PRIMARY APPLICATION OF THE SYSTEMS FOR PRODUCING WATER FROM THE ATMOSPHERIC AIR." ScienceRise 4 (August 31, 2020): 3–9. http://dx.doi.org/10.21303/2313-8416.2020.001390.
Повний текст джерелаАнотація:
The object of research is the thermal and humidity processes occurring during artificial cooling of atmospheric air to the dew point temperature in the evaporators of refrigeration machines of the compression and absorption type. This study solves the problem of finding energy efficient heat and humidity modes for cooling atmospheric air to the dew point temperature in regions with a shortage of water resources and high solar installations. It is shown that practically in all considered climatic zones with a shortage of water resources, the process of obtaining water from atmospheric air is most energetically expended in the winter period of the year, and the most energetically efficient - in the summer period. In the summer period of the year, the specific energy consumption is numerically comparable in the cooling temperature range from 5 °C to 15 °C. It is also shown that the application of the technology of night radiation will create a reserve of natural cold for additional cooling of condensers of refrigerating machines of various types during the entire period of operation. The area of practical use of the research results: compression and absorption refrigeration machines operating in systems for obtaining water from atmospheric air and taking into account seasonal changes in the thermal and humidity parameters of atmospheric air. An innovative technological product: energy-efficient systems for obtaining water from atmospheric air based on refrigeration machines of the compression and absorption type, which also work with the help of solar radiation. Scope of application of the innovative technological product: systems for supplying the population with drinking and process water, mainly in areas with a shortage of water resources.
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Sergeev, N. N., A. N. Sergeev, S. N. Kutepov, A. E. Gvozdev, and E. V. Ageev. "Influence of Operating Modes of High-Temperature Thermomechanical Processing on Mechanical Properties of Reinforcing Bars." Proceedings of the Southwest State University 23, no. 2 (July 9, 2019): 29–52. http://dx.doi.org/10.21869/2223-1560-2019-23-2-29-52.
Повний текст джерелаАнотація:
The strenghening thermomechanical treatment represens the combined processing treatment – a combination of plastic deformation and hardening in one technological process. Year after year, it is more widely applied in industry.Purpose of research. The study of strenghening thermomechanical treatment operating modes influence on the formation of mechanical properties of steel, which is a very important scientific problem associated with obtaining materials with a given set of mechanical features.Methods. High-temperature thermomechanical treatment was conducted under the conditions in which the processes of recrystallization of deformed austenite were partially or completely supressed, and the process of polygonization got the most development, with the goal of forming a developed substructure of austenite inherited by martensite during subsequent quenching.The paper investigated the change in the properties of high-strength reinforcement under heating (tempering) with different intensity. High-temperature thermomechanical treatment was carried out by including a hardening device in the technological line of the mill No. 280 LLC “Tulachermet-steel”. The studies were carried out on two modes of mill No. 280 operation. Low-carbon reinforcing steels St3 and ST5 were accepted as the studied steels.Results. It has been experimentally established that the maximum cooling capacity of the existing hardening device is manifested when three working sections with a water pressure of about 13 in each section are turned on. In this case, high-temperature thermomechanical treatment should be carried out at the maximum cooling rate in the strengthning device in accordance with the specified strength class, i.e., include the least number of working sections. Intensive cooling mode contributes to the formation of a homogeneous structure in the reinforcement with a high mechanical complex. It was found that during high-temperature thermomechanical treatment it is advisable to withstand the deformation temperature in the range of 1000...1050 ℃ to guarantee the production of reinforcement of a given class. It has been shown that the inclusion of a strengthening device in the mill line directly behind the flying shears, and not behind the finishing stand of the mill leads not only to the trouble-free operation of shears, but also to an increase in the post-deformation aging between the end of deformation and the beginning of bar hardening to a value close to the optimal, responsible for the formation of a polygonal substructure in austenite, the inheritance of which by martensite provides high mechanical properties of steel after high-temperature thermomechanical treatment.Conclusion. These results can be applied to create resource-saving material treatment processes.
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Moiseev, V. I., A. V. Zhebanov, and T. A. Komarova. "Organization of transportation by tank cars of solidified petroleum fuels with transmission through field pipelines in low temperature conditions." Transport of the Urals, no. 2 (2021): 40–43. http://dx.doi.org/10.20291/1815-9400-2021-2-40-43.
Повний текст джерелаАнотація:
The method of unloading and reloading solidified oil fuels, with the use of pipelines made according to temporary technological schemes, produced in winter, is considered. Cooling of solidified fuels is accompanied by a sharp increase in their viscosity, which makes pipeline transmission impossible. In fire hazard, it is proposed to produce continuous heating of the pumped fuel using devices based on low-temperature combustion of propane-butane mixture on the surface of the catalyst carried out at fire-safe temperatures. It is also proposed to install a temporary heat-insulating shell on the pipeline that meets the operating modes of the heaters.
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Osipov, A. M., Yu V. Bezgans, and D. G. Lodkov. "Numerical Analysis of Modes of Induction Weld Deposition of Valve Tappets of Motor Vehicles." Solid State Phenomena 265 (September 2017): 889–94. http://dx.doi.org/10.4028/www.scientific.net/ssp.265.889.
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The work is devoted to the reduction of defective weld deposition zone of the pusher, as well as the reduction of the number of defects such as low density of metal, pores, shrinkage holes. For the numerical analysis of the weld deposition process the 3D models were built and the required characteristics for the fused surface of the workpiece were set. The preheat temperature is set from 500°C to 1300°C, the deposited layer of cast iron with thickness of 6 mm the temperature of weld deposition is set as 1250°C, for cooling model the properties of water temperature of 20°C were applied. In the process of numerical analysis of the existing technological process of weld deposition the interrelation between the mode of technological process of welding, temperature of preheating of the workpiece and the size of the defective area of the deposited layer was established. According to the results of numerical analysis using statistical sequential analysis the mathematical model of the dependence of the size of defect-free area of the deposited layer from the preheating temperature of the workpiece of pusher was built. It was found that the lowering the temperature of preheating of the workpiece has a positive effect on the increase in the defect-free layer of deposited metal.
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Zobova, S. N., A. N. Ostrikov, L. N. Frolova, M. V. Kopylov, and I. S. Bogomolov. "Influence of technological modes on changes in the composition of beet pulp during its processing at the Borinsky sugar plant." Proceedings of the Voronezh State University of Engineering Technologies 83, no. 1 (June 3, 2021): 71–77. http://dx.doi.org/10.20914/2310-1202-2021-1-71-77.
Повний текст джерелаАнотація:
The description of the technological scheme of the granulation site at the Borinsky sugar plant is given, with an analysis of the work of the main types of technological equipment to identify problem areas of production. It is established that the use of such a promising press as the one of the Babbinni company allows you to get pulp with a humidity of 68-76 %. To dry it in a drum dryer to a humidity of 11–13%, 170 m3 of natural gas is consumed per 1 ton of pulp. The technological process of obtaining granulated beet pulp includes pressing the initial beet pulp with an initial humidity of 85–90% to a humidity of 68–76 %; drying the pressed pulp with a heat carrier at a temperature of 110–140 °C for 90–120 minutes to a final humidity of 11–13 %; cleaning pellets from metal-magnetic impurities; granulating the pulp (the diameter of the pellets is 10 mm); cooling pellets to a temperature of 30–35 °C; fractionation of pellets into large and small fractions; weighing and shipping granulated beet pulp to the warehouse of finished products. The technological modes influence analysis of beet pulp pressing, drying and granulating processes at the Borinsky sugar plant showed the need to introduce a second stage of pressing to further reduce the moisture content in the pressed pulp. Obtaining pressed pulp with a lower moisture content will significantly reduce the energy consumption for moisture evaporation in the drum dryer. Reducing the duration of the heat drying process of pressed beet pulp in a drum dryer will significantly increase the nutritional value of the granulated beet pulp produced.
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Ivanova, Tatiana Nikolajevna, Witold Biały, and Victor Nordin. "Improvement of grinding technology with vortex cooling of steels that are liable to crack propagation." Multidisciplinary Aspects of Production Engineering 2, no. 1 (September 1, 2019): 9–23. http://dx.doi.org/10.2478/mape-2019-0001.
Повний текст джерелаАнотація:
Abstract Complexity of grinding process and phenomena entailing it not always allow reaching required technological results, especially while machining surfaces of parts made of tough-to-machine steels, which are liable to crack propagation. Cracks can occur in these parts during grinding due to considerable temperature difference along the section, which can cause formation of high temporary internal tensile stress. Application of cooled air in grinding process exerts considerable influence over temperature decrease in cutting area. In addition, it depends not only on heat exchange, but also on properties of cold air flow. The greatest effect of temperature decrease can be reached by injection of cold air flow in cutting area with implementation of vortex effect, which occurs in swirl flow of compressed air originating in vortex tube. The study of heat generation during machining by tools with discontinuous cutting surface and vortex air cooling was carried out. Obtained thermophysical parameters of vortex air cooling (increase in speed of stream flowing, expansion degree, share of cold stream and decrease in humidity of air stream) allow reducing heat density due to growth of cooling effect in grinding zone. On the base of experimental studies we developed recommendations for choice of optimal grinding modes by tool with discontinuous cutting surface and vortex air cooling of flat parts made of steels being liable to cracking.
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Niyakovskii, A. M., V. N. Romaniuk, Yu V. Yatskevich, and A. N. Chichko. "Discrete Optimization of Software-Controlled Modes of Heat Treatment of Concrete Products in Heat-Technological Facilities." ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 62, no. 3 (June 3, 2019): 280–92. http://dx.doi.org/10.21122/1029-7448-2019-62-3-280-292.
Повний текст джерелаАнотація:
In the article the technique of an assessment of modes of operation of the heat engineering equipment used for heat treatment of concrete products in the conditions of programcontrolled heat supply according to the pattern of “heating – isothermal influence – cooling” has been developed. The method is based on the numerical solution of a non-stationary heat equation supplemented by equations describing the hydration process of a concrete product; also, it includes a system of initial and boundary conditions for its spatial structure. The method makes it possible to create tabulated functions of temperature and the degree of hydration of the time of heat treatment in any point of a 3D-product. The mathematical tools for calculating the functional dependencies of concrete hydration equipment with software-heated environment are presented. Numerical calculations of the concrete hydration process in the formwork are performed with respect to the symmetrical object. Based on the calculation of the temperature gradient across the minimal cross section of the product, a numerical analysis of the functions modeling heat supply mode depending on the processing time of a concrete product has been fulfilled. It is demonstrated that the maximum speed of the hydration process in a concrete product hardening is achieved at the maximum of time lag of isothermal cure. Additionally, with an increase in the duration of the product heating, the value of the maximum hydration rate decreases. It is concluded that the method of assessing the mode of heat treatment of concrete products being developed makes it possible to determine parameters for the calculation of the minimal useful heat required for the heat treatment of concrete products with spatially distributed parameters. The proposed method is applicable to calculate the temperature fields and the extent of hydration in the products of any geometric shape and volume in a software-controlled heating environment of industrial facilities for the accelerated hydration of concrete, and also affords the possibility of preliminary calibration prior to the assignment of relevant heat supply modes to the products being processed.
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Sych, O. V., S. V. Korotovskaya, E. I. Khlusova, and N. S. Novoskoltsev. "Development of thermal rolling regimes of low-alloy “ARC”-steel with quasi-homogeneous ferrite-bainitic structure." Voprosy Materialovedeniya, no. 2(106) (August 1, 2021): 7–20. http://dx.doi.org/10.22349/1994-6716-2021-106-2-07-20.
Повний текст джерелаАнотація:
In this work, the kinetics of the growth of austenite grains upon heating, the features of the processes of dynamic and static recrystallization occurring at various temperature-deformation modes of plastic deformation are investigated. Phase transformations have been studied during continuous cooling of hotdeformed austenite in low-alloy “Arc”-steel with a yield point of at least 420 MPa. The studies carried out made it possible to determine the thermal deformation parameters that ensure the formation of a finely dispersed homogeneous ferrite-bainitic structure, on the basis of which technological recommendations for industrial production were developed and sheet products were manufactured. Presented are the structure and properties of sheet metal from shipbuilding “Arc”-strength category 420 MPa.
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Gabibov, Ibrahim Abulfaz, Rabiya Seydulla Nadjafkulieva, and Sevinj Malik Abasova. "MODELING THE HEAT TRANSFER PROCESS IN REFRIGERATION UNITS USED IN THE OIL INDUSTRY." EUREKA: Physics and Engineering 6 (November 30, 2019): 57–62. http://dx.doi.org/10.21303/2461-4262.2019.001056.
Повний текст джерелаАнотація:
Currently, the main volume of associated petroleum gas production in Azerbaijan is carried out at offshore fields. About 30 % of this volume is used for SOCAR’s own technological needs of the oil company (to maintain the level of oil production). And the rest are transported to onshore facilities and further for processing to a gas processing plant. Subsequently, dry and purified gas is sent through a gas pipeline system for use by the population, or to a network of trunk pipelines for further export. When gas is transferred to the gas lift system and ashore, it is compressed in compressors, as a result of which the temperature of the working agent rises. The latter dramatically reduces the level of operational safety of the entire process. Based on the foregoing, ensuring the required gas quality at the outlet of the compressor unit is an important and urgent task. Currently used in the gas cooling system, shell-and-tube type refrigeration units have several advantages: high heat transfer coefficient, operability in low and high pressure modes, simplicity of design and service. Along with this, these units are distinguished by large dimensions and high metal consumption, noise effect, vibration, etc. A new design of a heat exchanger for cooling associated petroleum gas at the outlet of gas motor compressors is proposed. Based on the modeling of the heat transfer process, mathematical models have been obtained that make it possible to adequately evaluate the cooling process in the proposed refrigeration device.
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Kaneesamkandi, Zakariya, and Ateekh Ur Rehman. "Optimum and Sustainable Cooling Technology Selection for Different Climatic Conditions." Energies 14, no. 19 (September 26, 2021): 6136. http://dx.doi.org/10.3390/en14196136.
Повний текст джерелаАнотація:
Global warming has led to rising electricity demands due to soaring cooling load, resulting in different technologies being implemented with renewable energy options. Renewable energy has been used to partially or fully operate these cooing systems through different technology routes in both conventional and hybrid modes. The feasibility of a particular cooling process is influenced by several technological, economic, environmental and other related factors. Selection of the appropriate route also requires consideration of external factors such as local weather, cooling load requirements and the potential of possible renewable energy. Multi-criteria decision analysis is a useful tool to systematically arrive at the right option from several possible options. This tool is used to assess the feasibility of eight technology routes for three different climatic conditions. Other than the direct cooling processes, two routes of renewable energy utilization, namely, the solar photovoltaic system and solar thermal system, are considered. The normalized decision matrix is established and weighted decision matrix is estimated, and the best solution and the worst solution values are obtained by using equations. This study is performed for three climatic zones under the Koppen classification, namely, the tropical maritime arid condition with average midday temperature from 40 to 45 °C, with two different relative humidity ranges, namely, dry area and maritime area. Additionally, the temperate continental climatic zone is analyzed for comparison. The results of this study will help decision makers to judiciously implement air conditioning systems in the above climatic zones. The distance of each waste treatment strategy from the overall best alternative treatment strategy and the overall worst alternative treatment strategy is obtained. Finally, the cooling strategies are ranked for the best option for the cooling mechanism to be adopted for the three climatic conditions.
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Shumyacher, Vyacheslav, Sergey Kryukov, Olga Kulik, and Xavier Kennedy. "Materials Grindability." MATEC Web of Conferences 297 (2019): 09003. http://dx.doi.org/10.1051/matecconf/201929709003.
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A physical description of material grindability is proposed as a property of deformation and surface destruction of processed surface at the envelope removal. A mechanism for microchip formation is described, which consists in changing mobility of the metal being grinded in “abrasive grain -workpiece” contact, which leads to uneven removal of the energy transmitted by abrasive particle. Criteria for assessing the grindability of metals and methodology for their determination are given. In this article, we described an automated measuring complex (AMC “Grinding”), which was developed, designed and tested by us. This complex is used to solve the aim of the monitoring of grinding process at all stages of abrasive treatment and gives the opportunity to make the adjustments at all stages of the technological process, taking into account both the properties of the abrasive tool and the properties of lubricating and cooling technological means and treatment regimes. The principle of operation of an automated complex is based on statistical analysis of output energy parameters of technological equipment operation. The proposed method for evaluating grindability has been experimentally tested when grinding parts of bearings under production conditions. As a result of processing the obtained data, rational tool characteristics and grinding modes were assigned, providing the required quality indicators.
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Smagin, Denis Igorevich, Konstantin Igorevich Starostin, Roman Sergeevich Savelyev, Anatoly Anatolyevich Satin, Anastasiya Romanovna Neveshkina, and Darya Sergeevna Suzdaltseva. "ANALYSIS OF COMPETING VARIANTS OF AIR CONDITIONING SYSTEMS WITHOUT AIR EXTRACTION FROM ENGINES AT THE STAGE OF PASSENGER AIRCRAFT ONBOARD SYSTEMS CONCEPTUAL DESIGN." Computational nanotechnology 6, no. 3 (September 30, 2019): 80–85. http://dx.doi.org/10.33693/2313-223x-2019-6-3-86-91.
Повний текст джерелаАнотація:
One of the ways to achieve safety and comfort is to improve on-board air conditioning systems.The use of air cooling machine determines the air pressure high level at the point of selection from the aircraft engine compressor. Because of the aircraft operation in different modes and especially in the modes of small gas engines, deliberately high stages of selection have to be used for ensuring proper operation of the refrigeration machine in the modes of the aircraft small gas engines. Into force of this, most modes of aircraft operation have to throttle the pressure of the selected stage of selection, which, together with the low efficiency of the air cycle cooling system, makes the currently used air conditioning systems energy inefficient.A key feature of the architecture without air extraction from the main engines compressors is the use of electric drive compressors as a source of compressed air.A comparative analysis of competing variants of on-board air conditioning system without air extraction from engines for longrange aircraft projects was performed at the Moscow Aviation Institute (National Research University).The article deals with the main approaches to the decision-making process on the appearance of a promising aircraft on-board air conditioning system at the stage of its conceptual design and formulated the basic requirements for the structure of a complex criterion at different life cycle stages.The level of technical and technological risk, together with a larger installation weight, will require significant costs for development, testing, debugging and subsequent implementation, but at the same time on-board air conditioning system scheme without air extraction from the engines will achieve a significant increase in fuel efficiency at the level of the entire aircraft.
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Doroshenko, Volodymyr, Volodymyr Kravchenko, Olena Mul, and Olena Tokova. "Continuous-Discrete Boundary Problems in the Concepts of the Construction of Foundry Rotary-Conveyor Lines." Boundary Field Problems and Computer Simulation 57 (January 18, 2019): 29–34. http://dx.doi.org/10.7250/bfpcs.2018.004.
Повний текст джерелаАнотація:
The problem of mathematical construction for the process of the control of the metal casting crystallization and cooling in a foundry mold is considered. The casting is surrounded by a layer of sand mixture, which is a porous dispersed medium that conducts heat, in terms of the concepts of the construction of foundry rotary-conveyor lines (RCL). The problem of developing an interval model for determining the speed of the conveyor line from the production of metal castings is studied. Herewith, continuous processes of the transport and technological movement of the processed materials, equipment, tools, energy carriers, and final production output are combined with inevitable stops of this continuity, which lead to discreteness, and a combination with a number of accompanying continuous, discrete or reciprocating processes. The adequacy of the model for the given technological parameters is justified. The mathematical description and agreement of the values of technological parameters for regulation and finding the optimal speed of the conveyor line at the interaction of its component rotational systems, as well as the mathematical models for program control and remote monitoring of technological modes in order to obtain the casting of the given quality are considered. The possibility of selecting the corrective parameters for the change of the conveyor line speed is shown. Tiek skatīta matemātiskās konstrukcijas problēma metāla liešanas kristalizācijas un dzesēšanas kontroles procesam liešanas veidnē. Lējumu ieskauj smilšu maisījuma slānis, kas ir poraini izkliedēts materiāls, kas vada siltumu. Lietojot lietuves rotācijas konveijeru līniju (RCL) koncepciju, tiek pētīta intervāla modeļa izveides problēma konveijera līnijas ātruma noteikšanai metāla lējumu ražošanai. Tajā pašā laikā nepārtraukti apstrādājamo materiālu, iekārtu, rīku, enerģijas nesēju un gala produkcijas transportēšanas un tehnoloģiskās kustības procesi tiek apvienoti ar šīs nepārtrauktības neizbēgamajiem apstāšanās gadījumiem, kas noved pie kombinācijas ar vairākiem nepārtrauktiem, diskrētiem vai pārvietošanās procesiem. Ir pierādīta modeļa piemērotība attiecīgajiem tehnoloģiskajiem parametriem. Tiek parādīta iespēja izvēlēties koriģējošos parametrus konveijera līnijas ātruma maiņai.
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Egorov, M., R. Egorova, A. Atrohov, and V. Ekilik. "Features of phase transformations in powder steels upon heating." Journal of Physics: Conference Series 2131, no. 4 (December 1, 2021): 042011. http://dx.doi.org/10.1088/1742-6596/2131/4/042011.
Повний текст джерелаАнотація:
Abstract At present, powder materials are used in practically all branches of industry, from medicine to aerospace technology. This is a wide range of materials ranging from constructional and instrumental materials and ending with special-purpose materials and medical implants. Powder metallurgy methods are most often used where the manufacture of products with desired properties is impossible using traditional methods: casting, stamping, etc. Heat treatment is understood as a set of operations of heating, holding at high temperatures and cooling in order to change the structure and workability of the material, improve the combination of its mechanical and physical properties without changing the shape and size of products. Heat treatment is an effective method for improving the physical and mechanical properties and wear resistance of steel. The specific features of sintered steels (porosity, structural heterogeneity, high oxidizability, etc.) make it difficult to use the technological modes of heat treatment developed for cast steels, although the main regularities of the processes occurring during heating and cooling of compact steel can be transferred to sintered materials. Heat treatment of powder steels has a number of features, primarily due to residual porosity, as well as chemical and structural heterogeneity.
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Илюшкин, Дмитрий, Dmitriy Ilyushkin, Наталья Жижкина, Natalya Zhizhkina, Екатерина Зенцова, and Ekaterina Zentsova. "VIRTUAL SIMULATION OF ROLLER SPUN CASTING." Bulletin of Bryansk state technical university 2016, no. 1 (March 31, 2016): 22–27. http://dx.doi.org/10.12737/18174.
Повний текст джерелаАнотація:
The work is devoted to the virtual simulation of a sheet roll working layer formation at a technological stage “casting-solidification”. To form a virtual model of a roller mould pouring and foundry solidification there was used a computer modeling system (CMS) which included initial and boundary conditions for a roller mould pouring process with highalloy cast iron in the field of centrifugal force action. The distribution of a metal working layer along an inner surface of a rotating mould at different technological parameters: mass of highalloy cast iron, its density, temperature and pouring velocity, temperature of metal and non-metal parts of a mould at the initial point of time, modes of rotation and conditions of mould cooling and others were investigated. It is established that under the influence of centrifugal forces a free surface of liquid melt obtains a parabolic form. The influence of basic technological parameters upon the vertex position of a paraboloid of revolution of highalloy liquid melt z0 is revealed. It is shown in the paper that it stipulates for the unevenness of a working layer value along a roller barrel. As a result of computations it is obtained that the value of a working layer at lower flanks of barrels is higher than that of upper sides. The average value of such an exceeding makes 0.012 m. As a result of a simulation analysis of a foundry formation process at different technological parameters it is determined that the distance increase between the vertex of a paraboloid of revolution and the metal area investigated raises the working layer evenness along a roller barrel 3.6 times. Hence, the increase of capacity for work of a rolling tool is expected. The results of investigations presented are basic for the works for the increase of centrifugal roller servicing characteristic increase.
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Ievlev, M. G. "Automated control of rolling modes on plate mills." Mathematical machines and systems 4 (2020): 95–112. http://dx.doi.org/10.34121/1028-9763-2020-4-95-112.
Повний текст джерелаАнотація:
Indicators of rolling quality and rolling process are presented, which determine the efficiency of plate mill operation. The purposes of the automated control of rolling which consist in achievement of an optimum ratio of the mentioned indicators, and division of control channels (when it’s possible) achiev-ing the best values of each indicator named above. Control of rolling modes (compression on passes, speeds, cooling) provides the main effect in indicators quality formation of hire and rolling process. The statement of the problem of automated rolling control is given. The choice of the optimized indicator in the problem of automatic rolling control is determined by its economic significance, the nature of the interrelation with the technological parameters and controls. One of the most economically significant for plate mills is the coefficient of metal consumption of the workpiece per ton of rolled product, or the yield, which depends on the accuracy of the implementation of the specified geometric dimensions of the rolling strip. The formulation of the problem of ensuring the minimum value of deviations in the thickness (width) of the strip from the specified value is given. The problem of optimization on one of three indicators of the rolling process is also formulated: the equivalent torque of the main drive, the electricity consumption for rolling and the time consumption of the rolling cycle, which are determined by the entire course of the rolling cycle, i.e. applied management strategy. The principles of solving the problem of automatic control of rolling modes are described. The rolling control strategies used in the ACS TP of plate mills are considered. Methods of constructing mathematical models for ACS TP of plate mills, as well as their adaptation, are described.
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Pankovets, I. A., V. I. Voznaya, A. V. Vedeneev, and M. N. Vereshchagin. "A study of conditions of surface defects formation when bar rolling at a bar and wire mill and methods of their elimination." Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 77, no. 10 (October 12, 2021): 1053–59. http://dx.doi.org/10.32339/0135-5910-2021-10-1053-1059.
Повний текст джерелаАнотація:
Quality of long products surface is an important consumer property of it. In the process of measures elaboration aimed at the increase of long products surface quality, in particular of bars produced at the mill 370/150 of ОJSC “BMZ – managing company of holding “BMK”, studies were accomplished by metallographic laboratory. It was established that defects being revealed at the bars finishing, don’t relate to the quality of continuously casted billet (CCB), but formed in the process of deformation. Studies of the mechanism of surface defects formation on hot-rolled bar of rolling origin – deformation fissure and wrinkles were carried out. Results of numerical simulation of rolling in roughing group of stands at various temperature-deformation parameters presented. Regularities of formation of surface defects on the bar in the finished product were revealed. It was shown that the reason of the surface defects of rolling origin – deformation fissure and wrinkles was a high temperature gradient between the core and the surface of billet, originated from local overheating of surface in the angles zone of CCB resulted in nonuniformity of drawing out of different layers of the billet being deformed. To eliminate the defects, minimum possible temperature gradient between the surface and the core of a billet by controlled rolls cooling should be provided. By calculation, the maximum permissible temperature of the working surface of the rolls of the rough group of stands was established, and empirically the actual temperatures of the rolls with the current production technology, as well as the temperature of the rolls support bearings seats of the rolls were measured. The technical and technological possibilities for improving of rolling technology on a bar and wire mill in order to improve the surface quality of rolled bars were demonstrated. The existing technology was adjusted and new technological modes of rolling with controlled cooling of the rolls were established, which made it possible to significantly reduce the rejection of the finished product due to defects in rolling production. A device was proposed for the roughing group of stands, which enables to minimize the ingress of coolant onto the bar rolled.
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Chudina, A. A. "The influence of technological factors on the nature of the distribution of residual stresses on the surface of the workpiece during cutting." Glavnyj mekhanik (Chief Mechanic), no. 2 (February 26, 2021): 34–43. http://dx.doi.org/10.33920/pro-2-2102-04.
Повний текст джерелаАнотація:
This article describes the basic information about the residual stresses that occur as a result of mechanical processing. The influence of such technological factors as geometric parameters of the cutting part of the tool, physical and chemical properties and structural and phase state of the workpiece material to be processed, cutting modes (feed, cutting speed, cutting depth) and lubricating and cooling technological means on the nature of the distribution of residual stresses in the surface layer of the workpiece is studied. The literature sources that present experimental studies of the influence of the above factors are analyzed. As a result, it was found that the negative front angle contributes to the appearance of compressive residual stresses on the surface. It was established that an increase in the area of the wear surface leads to a decrease in compressive stresses and the appearance of tension stresses. An increase in the cutting speed leads to a decrease in the amount of tension stresses. However, an increase in the speed when turning steel 45 does not lead to compressive residual stresses, as the heat factor will prevail during processing, and when turning steel 309, a high cutting speed will contribute to the hardening of the surface layer and, as a result, the appearance of residual compressive stresses. Depending on the ductility of the material, an increase in the feed can lead to both compressive residual stresses and tension stresses. This is due to the fact that when using other materials, heating can lead to quenching or tempering of the surface layer and, accordingly, to other results that will depend on the phase structural transformations occurring in the material. However, the effect of cutting coolant is ambiguous and will depend on how much heat is released in the cutting area. Thus, knowing the operating conditions of the product, it is possible to adjust the nature of the distribution of residual stresses on the surface by changing certain technological factors.
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Dornyak, Olga, and Arthur Novikov. "Immersion Freezing of a Scots Pine Single Seed in a Water-Saturated Dispersion Medium: Mathematical Modelling." Inventions 5, no. 4 (September 25, 2020): 51. http://dx.doi.org/10.3390/inventions5040051.
Повний текст джерелаАнотація:
Forest owners will be able to solve the problem of protecting small forest seeds from mechanical and atmospheric influences during aerial sowing, as well as the problem of manufacturing capsules in the field, saving financial, time and material resources. The process of creating a capsule by freezing the seed in a water-saturated dispersed system—immersion freezing—allows you to organize the technological properties of forest seeds depending on the initial requirements. In most cases, the quality of the seed capsule is determined by the thermophysical and mechanical properties of the components. The technological process of obtaining seed capsules for aerial seeding and the choice of freezing modes is based on a priori mathematical modeling of heat-and-mass transfer processes. The main purpose of the study is to predict the duration of the seed freezing process in a capsule with a water-saturated dispersed medium, depending on the external temperature conditions, the geometric parameters of the capsule and the seed. The cooling agent is carbon dioxide. The research is based on the use of numerical modeling methods on the platform COMSOL Multiphysics. A mathematical model is proposed that allows us to obtain the dynamics of the distribution of temperature and moisture content fields in the dispersed system and seed depending on a complex of geometric and thermophysical factors. The time of immersion freezing of the capsule with the common pine seed for the conditions considered should be in the range of 150 to 250 s.
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Shilyaev, P. V., S. V. Denisov, P. A. Stekanov, O. V. Sych, E. I. Khlusova, V. L. Kornilov, F. V. Kaptsan, et al. "Development and mastering of technologies of production at PJSC MMK a new generation steel rolled stock for m a in pipelines." Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 77, no. 7 (August 1, 2021): 791–803. http://dx.doi.org/10.32339/0135-5910-2021-7-791-803.
Повний текст джерелаАнотація:
In view of arising needs of Russian oil and gas sectors, elaboration and implementation into series production competitive pipe products became an actual task for domestic enterprises of metallurgical industry. Generalized results of elaboration of chemical compositions and automated technologies of sheet rolled stock of new generation production from low-alloyed pipe steels of various strength classes at PJSC MMK presented. It was shown that the selected chemical compositions ensure forming finedispersed ferrite-bainite structure with bainite of granular morphology in a wide range of cooling rates. The elaborated technological modes of sheet rolled stock production from pipe steels stipulate for elimination considerable growth of austenite grain at heating before the rolling, refinement of austenite grains due to recrystallization processes, forming of extensive subgrain structure of austenite at plastic deformation, forming disperse structures during phase transformation in the process of controlled accelerated cooling; forming of extensive fragmented structure in а-phase. The level of strength, tough-plastic properties and resistance against brittle destruction (based on results of tests with a falling weight with determination of tough component share in the break of full-thickness samples) of sheet rolled stock of pipe steels with various chemical composition of PJSC MMK production was demonstrated. Results of study of tests the sheet rolled stock of high-strength steels for pipes of large diameter presented. Objects of the elaborated pipe steels implementation indicated.
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Valevskaya, L., and O. Sokolovskaya. "DETERMINATION OF PHYSICAL AND TECHNOLOGICAL PROPERTIES OF QUINO GRAIN - THE MAIN STAGES OF JUSTIFICATION OF STORAGE AND PROCESSING TECHNOLOGY." Grain Products and Mixed Fodder’s 21, no. 1 (September 12, 2021): 4–8. http://dx.doi.org/10.15673/gpmf.v21i1.2089.
Повний текст джерелаАнотація:
The work is devoted to determining the physical and technological properties of quinoa grain. Quinoa is an unconventional crop for Ukraine, but experiments on its cultivation have been successfully completed in the Sumy region. Due to its unique chemical composition, quinoa is used in dietary and functional products.Quinoa contains about 20% protein, which makes it an excellent dietary supplement for people who do not eat animal products. The amino acid composition of quinoa proteins is very balanced and is characterized by a high content of such essential amino acids. Feature of the fatty acid composition of quinoa. it has a high content of polyunsaturated fatty acids, including linolenic fatty acid and linoleic, which belongs to the acids ω-3 and ω-6 fatty acids.Due to the growing popularity of quinoa and its suitability for cultivation in our climatic and soil conditions, it is important to develop the technology of its storage and processing. One of the main stages of substantiation of the choice of technology for storage and processing of quinoa grain is to determine its physical and technological properties.Physical and technological properties of grain mass are determined by a large number of indicators.Determination of physical and technological properties of quinoa grain was performed for three types of quinoa: red, black and white. In determining the physical and mechanical properties were used methods approved by the relevant standards, or used in research and recommended in the relevant literature.We have identified the following basic physical and technological properties: geometric characteristics, nature, weight of 1000 grains, duty cycle, packing density, air supply, angle of natural slope, coefficient of internal friction, coefficient of external friction. Numerical values of these indicators for each type of quinoa are determined.Knowledge of the physical and technological properties of the grain mass to solve a large number of applied problems that have practical significance. and play an important role in the processes of moistening, heating and cooling of grain. A thorough study of physical and technological properties can provide optimal conditions for storage of seeds without compromising their quality. The obtained data can be used for selection of modes of cleaning, drying and active ventilation.
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Al-Sumaily, Gazy F., Amged Al Ezzi, Hayder A. Dhahad, Mark C. Thompson, and Talal Yusaf. "Legitimacy of the Local Thermal Equilibrium Hypothesis in Porous Media: A Comprehensive Review." Energies 14, no. 23 (December 3, 2021): 8114. http://dx.doi.org/10.3390/en14238114.
Повний текст джерелаАнотація:
Local thermal equilibrium (LTE) is a frequently-employed hypothesis when analysing convection heat transfer in porous media. However, investigation of the non-equilibrium phenomenon exhibits that such hypothesis is typically not true for many circumstances such as rapid cooling or heating, and in industrial applications involving immediate transient thermal response, leading to a lack of local thermal equilibrium (LTE). Therefore, for the sake of appropriately conduct the technological process, it has become necessary to examine the validity of the LTE assumption before deciding which energy model should be used. Indeed, the legitimacy of the LTE hypothesis has been widely investigated in different applications and different modes of heat transfer, and many criteria have been developed. This paper summarises the studies that investigated this hypothesis in forced, free, and mixed convection, and presents the appropriate circumstances that can make the LTE hypothesis to be valid. For example, in forced convection, the literature shows that this hypothesis is valid for lower Darcy number, lower Reynolds number, lower Prandtl number, and/or lower solid phase thermal conductivity; however, it becomes invalid for higher effective fluid thermal conductivity and/or lower interstitial heat transfer coefficient.
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Аджамський, Сергій Вікторович, Ганна Андріївна Кононенко та Ростислав Вячеславович Подольський. "Виготовлення тракту охолодження вдосконаленої конструкції для камери згоряння рідинного ракетного двигуна за допомогою адитивних технологій". Aerospace technic and technology, № 3 (27 травня 2021): 42–48. http://dx.doi.org/10.32620/aktt.2021.3.05.
Повний текст джерелаАнотація:
The creation of complex structural elements of aircraft using additive technologies is promising and is widely used since such elements have many design and technological advantages over the collection of individual finished parts. However, it requires the solution of many scientific and technical problems to obtain products of high accuracy and density, develop a technological process, work out modes, and sometimes develop a new design of products. When the angles of inclination of the inclined surfaces are more than 45 °, in the manufacture of parts using the technology of selective laser melting, special conditions arise that cause some restrictions. Since the tracks that form the bottom layer (down-skin) of the inclined surface largely lie not on the previous layer of the metal part, but on the powder surrounding the part, the melt pool "falls through" into the powder, the melt pool breaks through, disrupting the track continuity. As a consequence, the bottom layer (down-skin) of the formed inclined at an angle of more than 45 °, and the horizontal surface has a high roughness. We studied samples of elements of the cooling path with an improved design (the shape of the channels in the form of parallelograms with an acute angle of 45 °) and with the original design (the shape of the channels in the form of rectangles) with a change in the angle of inclination of the channels relative to the Z-axis. According to the results of visual-optical analysis and determination of the down-skin roughness, it was found that at tilt angles to the Z-axis ≥75 ° with the original design of the channels, the transverse surface of the channel may not even form or have significant deviations from the specified geometry, and with the improved design of the channels, the roughness of the down-skin is only slightly increased. From the analysis of the change in roughness at tilt angles of the channels relative to the Z-axis in the range of 40…60 °, it was found that samples with an improved channel design have similar roughness values (5…6.5 μm), and for samples with an original channel design, the roughness changed significantly (6…22 μm). A model was developed and a combustion chamber cooling path was manufactured with channels of an improved design and an angle of inclination of the channels of 74 °. The possibility of manufacturing a combustion chamber cooling duct with an angle of inclination of the channels relative to the Z-axis using the technology of selective laser melting at a high metal density and low surface roughness of the inner channels is shown.
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Sarapat, N., W. Khunnam, S. Chiangga, N. Thammawongsa, M. A. Jalil, J. Ali, and P. P. Yupapin. "Fast, Slow, Stopping and Storing Light Simultaneously using a PANDA Ring On-Chip." Asia Pacific Physics Newsletter 02, no. 01 (January 2013): 37–39. http://dx.doi.org/10.1142/s2251158x13000088.
Повний текст джерелаАнотація:
Past and slow light behaviors are the interesting aspects of light which can be useful for many fundamental and applied researches. Pornsuwancharoen and Yupapin et al. [1] have proposed the use of a simple device called “microring resonator” to perform such behaviors. In this research work, the four different behaviors of light i.e., fast, slow, stopping and storing of light where investigated using a ring resonator. Nowadays, stopping or cooling light beam has become the promising technique for atom/molecule trapping investigations (using static or dynamic tweezers), especially, after the announcement of Nobel Prize 2012 in Physics on the whispering gallery modes [2, 3]. There are two more kinds of devices that can be used to trap light beams, the use of microcavity arrays performed by Yanik and Fan [4], and nonlinear microring resonator by Yupapin and Pornsuwancharoen [5] for stopping light (laser beam). Nanyang Technological University scientists have also done experiment to slowing the light in microresonators using a microring system recently [6]. This concept is a concrete backbone for many applications.
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Vourdoubas, John. "Is the de-carbonization of air-transportation to and from the island of Crete, Greece feasible?Is the De-carbonization of Air-transportation to and from the Island of Crete, Greece Feasible?" Environmental Management and Sustainable Development 10, no. 3 (July 30, 2021): 62. http://dx.doi.org/10.5296/emsd.v10i3.18811.
Повний текст джерелаАнотація:
The clean energy transition is an important and urgent issue in European islands contributing in the global effort for climate change mitigation. Island of Crete, Greece is a popular tourist destination while the most of visitors arrive and depart with aircrafts. Aim of the current study is to investigate the possibility of de-carbonizing the air-transportation to and from Crete. Air-transportation has a share at 10.62% in the total carbon emissions in the island while other studies have estimated higher values. This is higher than the estimated share of carbon emissions in aviation at 2-3% of the overall carbon emissions worldwide. Various technological and non-technological approaches for de-carbonizing aviation are examined including improvements in aircraft’s standards, use of sustainable aviation fuels, offsetting carbon emissions and developing new policies discouraging the frequent use of air travelling. The feasibility and the impacts of these methods are mentioned indicating that de-carbonization is difficult in the short and medium term. Production of sustainable aviation fuels including bio-fuels and electro-fuels in the required quantities and in competitive prices is not foreseen soon. Developing new policies that increase the cost of air travelling and promote alternative sustainable modes in transportation will have undesired impacts in the island’s tourism industry. On the contrary de-carbonization in other socio-economic sectors in Crete comprising electricity generation, production of heat and cooling and transportation inside the island is easier than in air-transportation.
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Stepanov, V. V., and Nail F. Timerbaev. "Composite Railroad Ties Obtained by the Energy Efficient Recycle of Wooden Railroad Ties." Solid State Phenomena 284 (October 2018): 981–85. http://dx.doi.org/10.4028/www.scientific.net/ssp.284.981.
Повний текст джерелаАнотація:
The article presents the result of research in the field of processing wooden railroad ties and thermoplastic polymer household waste with obtaining composite railroad ties under conditions of energy efficiency of technological processes. The wood of the used wooden ties contains a significant proportion of chemical compounds based on creosote. As a result of the thermal and mechanical action, the creosote compounds in the wood form hydrophobic surfaces, thereby fulfilling the function of the bonding additives. Under the above-mentioned conditions, hydrogen bonds are formed between the components of the wood composite, that, in its turn, allows achieving the task of creating a functional composite, which varies in the compound of elements and the modes of production processes. Experimental studies were held on the nature of justification and correction of theoretical studies. The experimental stand of composite production is realized on the principle of energy efficient cooling cycles of the obtained composite with heat transfer for heating the initial components. The obtained results of experimental studies exceed the regulation values by every measure. The comparison justifies the quality of the experimental samples obtained with respect to these values.
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Nikolaev, Alexander V., and Leonid M. Treyger. "Definition and analysis of overall heat-transfer coefficient at the sections of “hot” export petroleum pipeline operating in northern winter conditions." PROneft’. Proffessional’no o nefti 6, no. 3 (October 5, 2021): 159–65. http://dx.doi.org/10.51890/2587-7399-2021-6-3-159-165.
Повний текст джерелаАнотація:
Background. Receiving information on overall heat-transfer coefficient of pipeline pumping down the heat oil is required for resolving a number of process challenges: definition of specific cooling-off intensity of delivered petroleum, optimization of delivery processes, insulation efficiency assessment of pipeline sections etc. Aim. The actual values of the heat transfer coefficients are the most reliable basis for the implementation of optimization and technological calculations during thermohydraulic modeling and development of measures (a) to save energy during hot pumping and (b) to increase the reliability of the “hot” pipeline in order to exclude the possibility of its self-stopping and “freezing”. In the context of assessing the technological reliability of pumping, the determination and analysis of the total heat transfer coefficient for the sections of the oil pipeline were carried out and the capabilities of this methodological approach were demonstrated. Materials and methods. In the article, by the example of 266-kilometer long export pipeline (Ø 300 mm), functioning in «hot» delivery mode is presented the calculation process of defining the actual values of overall heat-transfer coefficient in route sections, and is done the analysis of this coefficient values, operation heating mode of the pipeline and their related factors of technological reliability of oil delivery process. Results. The difference in the values of the overall heat transfer coefficient at the sections of the pipeline is shown, which allows us to come to a practical conclusion about the different intensities of the thermal processes occurring in its different linear sections (aboveground, underground with intersection of marshy soils and rivers, with and without thermal insulation, operating in non-isothermal and isothermal modes). Conclusions. The proposed approach to determining the actual values of the total heat transfer coefficient for sections of the “hot” oil pipeline in combination with the analysis of the data obtained provides opportunities that are largely in demand from a methodological point of view and extremely important from a practical standpoint.
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Nikolaev, Alexander V., and Leonid M. Treyger. "Definition and analysis of overall heat-transfer coefficient at the sections of “hot” export petroleum pipeline operating in northern winter conditions." PROneft’. Proffessional’no o nefti 6, no. 3 (October 5, 2021): 159–65. http://dx.doi.org/10.51890/2587-7399-2021-6-3-159-165.
Повний текст джерелаАнотація:
Background. Receiving information on overall heat-transfer coefficient of pipeline pumping down the heat oil is required for resolving a number of process challenges: definition of specific cooling-off intensity of delivered petroleum, optimization of delivery processes, insulation efficiency assessment of pipeline sections etc. Aim. The actual values of the heat transfer coefficients are the most reliable basis for the implementation of optimization and technological calculations during thermohydraulic modeling and development of measures (a) to save energy during hot pumping and (b) to increase the reliability of the “hot” pipeline in order to exclude the possibility of its self-stopping and “freezing”. In the context of assessing the technological reliability of pumping, the determination and analysis of the total heat transfer coefficient for the sections of the oil pipeline were carried out and the capabilities of this methodological approach were demonstrated. Materials and methods. In the article, by the example of 266-kilometer long export pipeline (Ø 300 mm), functioning in «hot» delivery mode is presented the calculation process of defining the actual values of overall heat-transfer coefficient in route sections, and is done the analysis of this coefficient values, operation heating mode of the pipeline and their related factors of technological reliability of oil delivery process. Results. The difference in the values of the overall heat transfer coefficient at the sections of the pipeline is shown, which allows us to come to a practical conclusion about the different intensities of the thermal processes occurring in its different linear sections (aboveground, underground with intersection of marshy soils and rivers, with and without thermal insulation, operating in non-isothermal and isothermal modes). Conclusions. The proposed approach to determining the actual values of the total heat transfer coefficient for sections of the “hot” oil pipeline in combination with the analysis of the data obtained provides opportunities that are largely in demand from a methodological point of view and extremely important from a practical standpoint.
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Saveliev, М. V., А. V. Chiglintsev, D. V. Sushnikov, P. V. Ekkert, and V. Yu Elin. "Development of steel continuous casting at the Nizhny Tagil steel-works." Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 76, no. 6 (July 21, 2020): 550–55. http://dx.doi.org/10.32339/0135-5910-2020-6-550-555.
Повний текст джерелаАнотація:
Steel continuous casting is one of fundamentals of modern steel industry. Specialists of Nizhny Tagil steel-works (NTMK) made an important contribution to the process perfection. The one-strand slab CCM of curvilinear type with radial mold and slab straightening by multipoint curve, designed and manufactured at Uralmashzavod, became a prototype for many machines, which were later manufactured at domestic and foreign steel-works in the end of 60th of the previous century. In the process of mastering of CCMs, which were put into operation within the programs of the plant modernization and transferring to BOF production with steel continuous casting, the CCMs were significantly modernized and technology of casting was perfected. To bring down the impact on the solidifying billet peel and decrease a billet swell, the scheme of the supporting rollers location was changed, which enabled to increase the length of the supported zone. A principally new scheme of billets cooling was implemented, which ensured a softer and uniform secondary cooling due to water-air “fog”. To create optimal conditions of axis zone forming during production of round billets of 430 mm diameter, a technology of protective heat screens application was used. The protective screens were installed in the end of ingot solidification zone. A large work was done on determination of optimal technological casting parameters – temperature and speed modes, types of slag forming mixtures, types of heat-insulating mixtures, methods of metal protection in the process of casting. As a result of the work done, at EVRAZ NTMK a complex of steel continuous casting was created, which enables to be flexible depending on the varying situation at the market and to produce continuously casted billets of various dimensions and wide range of steel grades.