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Journal articles on the topic 'Heat calculation'
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1
LUKS, Alexander L., Andrey G. MATVEEV, and Danila V. ZELENTSOV. "METHOD FOR CALCULATING HEAT PIPES THAT DIVERT HEAT FROM THE HEAT-EMITTING SURFACE." Urban construction and architecture 8, no. 1 (March 15, 2018): 35–39. http://dx.doi.org/10.17673/vestnik.2018.01.6.
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The results of complex studies of the parameters of the heat-conducting collectors, development of the methods for their calculation are presented. The main diffi culty in this case is the calculation of the design and parameters in the region of the contact zone between the heat pipe and the heat-generating surface. It is shown that the calculation methods used for convective collectors can not be applied to collectors with heat pipes in which the elements do not depend on each other. It is established that semiempirical models provide an opportunity to study the specifi cs of the processes taking place in the reservoir, the degree of their infl uence on its effi ciency. The simplifi ed calculation technique proposed in this article allows us to make the required estimates and calculations at the engineering level.
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Dobáková, Romana, Natália Jasminská, Tomáš Brestovič, Marian Lazár, and Jiří Marek. "Heat exchange on the outside of the pipe when heat is distributed by heat networks." International Journal for Innovation Education and Research 5, no. 9 (September 30, 2017): 82–87. http://dx.doi.org/10.31686/ijier.vol5.iss9.807.
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The article deals with the exchange of heat on the outside of the pipe when distributing heat through heat networks. This is a combined heat exchange, i.e. free convection and radiation. The calculations and outputs analysed in the article are mainly applicable to thermal networks run aboveground. In the calculation, an ambient temperature of 15 °C was measured, ranging from the temperatures corresponding to the air temperatures in the channel. The results are interpreted in the form of diagrams and tables. The calculation was performed on the secondary DN 125 pipe with PIPO_ALS insulation and the calculation was extended to all nominal diameters used in the secondary wiring for determining the influence of heat transfer, depending on the change in pipe diameter.
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Han, Wei Min, Yan Zhou, Heng Liang Zhang, and Dan Mei Xie. "The Research on Heat Transfer Coefficient of Wheel Rims of Large Capacity Steam Turbines." Advanced Materials Research 744 (August 2013): 100–104. http://dx.doi.org/10.4028/www.scientific.net/amr.744.100.
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Several models for calculating the heat transfer coefficient of wheel rims of large capacity steam turbines are presented. Taking a certain 600MW supercritical turbine rotor as an example, the heat transfer coefficient of wheel rim under cold start-up are analyzed and calculated, according to the and comparison, and the quantitative calculation results are given The results show that the heat transfer coefficient of rotor rims obtained by Sarkar method is close to the heat transfer coefficient obtained by a research institute based on a rib heat transfer model. In finite element analyses, the calculation results by mentioned method could provide the heat transfer boundary condition of temperature and thermal stress field calculations of supercritical and ultra-supercritical steam turbine rotors.
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Ilyin, A. A., and V. I. Merkulov. "Optimization of heat exchanger heat transfer surface of the engine with external heat supply." Izvestiya MGTU MAMI 8, no. 4-1 (February 20, 2014): 19–22. http://dx.doi.org/10.17816/2074-0530-67631.
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The paper describes the calculation the heat transfer surface of the heat exchanger of the power plant. These calculations use ANSYS CFX software package. The work determined the construction that provides the biggest temperature difference between the inlet and outlet of the coolant.
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Wang, Ya Li, Su Ping Cui, Gui Ping Tian, Ming Zhang Lan, and Zhi Hong Wang. "Theoretical Calculation and Experimental Study on the Forming Heat of Cement Clinker Made from Steel Slag." Materials Science Forum 814 (March 2015): 564–68. http://dx.doi.org/10.4028/www.scientific.net/msf.814.564.
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When steel slag, a by-product of steel making in impurity catching process, is added, the forming process of cement clinker and the major reactions in that process are changed. Since there are dramatic differences between the chemical components and mineral compositions of steel slag and that of natural cement raw materials, the empirical equation for the calculating forming heats of cement clinker made of limestone and clay is no longer applied for those made of steel slag. In this paper, the empirical equation for forming heat calculation of steel slag added cement clinker was promoted, and testified by acid dissolution experiments. Results showed that the change of raw materials had great influence on the forming heat of cement clinker. When the traditional raw materials were replaced with steel slag, the forming heat of cement clinker reduced. Calculating the forming heat by our revised empirical equation can help reduce errors and bring great convenience for the calculation and evaluation of heat efficiency. This research provides theoretical underpinning for the study and calculation of forming heat of steel slag added cement clinker.
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Liu, Jie, Shuang Xi Zhang, and Yu Feng He. "Investigation on Double-Tube Copper-Aluminum Column-Wing Type Radiators." Advanced Materials Research 243-249 (May 2011): 4883–86. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.4883.
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The calculation formulas are provided for calculating the heat release and metal thermal intensity of double-tube copper-aluminum Column-wing type radiator, and the reliability of the theoretical calculation is verified. The metal thermal intensity is taken as an optimization index, with theoretical calculations for different sorts of tube diameters and overall dimensions, obtains the optimalizing dimension of the radiator.
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Faizullin, R. O., V. Y. Zakharova, and A. V. Baranenko. "Numerical simulation of processes in the latent-heat thermal energy storage tank." IOP Conference Series: Earth and Environmental Science 866, no. 1 (October 1, 2021): 012036. http://dx.doi.org/10.1088/1755-1315/866/1/012036.
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Abstract This paper has proposed a computer model for numerical calculations of heat flows in regular rhombic packed bed of capsules with phase change material. The mathematical model of heat transfer in a capsule is based on finding a zero-dimensional solution to the Stefan problem, considering the influence of convective flows arising in the liquid phase. To take into account the heat transfer due to the convective component in the liquid phase in the capsule, the effective thermal conductivity coefficient is calculated. An experimental dependence has been applied to describe the heat exchange conditions of the coolant and the capsule wall. The calculation is reduced to finding the temperature of the coolant t after passing one layer of packed bed. The resulting temperature is the input parameter for calculating the next layer. This operation is repeated until the calculation is made for all layers of packed bed. The numerical calculation has been performed in the mathematical software Scilab. According to the proposed model, the results of calculating the temperature of the coolant after passing the storage device correlate well with the experimental data for a thermal energy storage device with spherical capsules filled with paraffin.
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Bacon, Sheldon, and Nick Fofonoff. "Oceanic Heat Flux Calculation." Journal of Atmospheric and Oceanic Technology 13, no. 6 (December 1996): 1327–29. http://dx.doi.org/10.1175/1520-0426(1996)013<1327:ohfc>2.0.co;2.
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Zhu, Dan, and Peng Yun Song. "The Calculation Methods of the Heat Balance for Recovering the Vaporous Water from Exhaust Gas in Ammonium Phosphate Production." Advanced Materials Research 881-883 (January 2014): 649–52. http://dx.doi.org/10.4028/www.scientific.net/amr.881-883.649.
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The volume content of water vapor in ammonium phosphate exhaust gas is about 12-20%, and the temperature is about 70-80°C. If the exhaust gas are directly discharged through the chimney, the water vapor in it will easily condense and fog because of local supersaturation, resulting in some energy and water losing. The cool water spray condensing can be used to recover water vapor from exhaust gas, and it can recover most of the water vapor and the sensible heat and the latent heat of the water vapor in the exhaust gas. Carrying out the energy balance and material balance calculations quickly and accurately is one of the major concerning problems for project design. This paper presents a calculation method for the heat balance by calculation the enthalpy difference of the water in the exhaust gas, compared with the method by directly calculating the heat in water vapor condensing process. Both the results are in good agreement, but the enthalpy difference method is more concise. The calculation methods and procedures are of practical engineering application values.
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Xue, Jia Xing, Zhou Wei Zhang, and Ya Hong Wang. "Research on Double-Stream Coil-Wound Heat Exchanger." Applied Mechanics and Materials 672-674 (October 2014): 1485–95. http://dx.doi.org/10.4028/www.scientific.net/amm.672-674.1485.
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A calculation method for double-stream counter-current coil-wound heat exchanger is presented for methanol-methanol heat exchange process. The numerical simulation method is applied to determine the basic physical parameters of double-stream spiral pipes. A recycling methanol cooler is designed and calculated by numerical simulation and programmed iterative calculation. The calculation data is analyzed by comparing with different variables. The result shows that the introduction of numerical simulation can simplify the pipe winding process and accelerate the calculation and design of overall configuration. This method can be used for physical modeling and heat transfer calculating of spiral pipes in double-stream coil wound heat exchanger, program to calculate the complex heat transfer changing with different variables and optimize the overall design and calculation process of double-stream spiral pipe bundles.
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Ignatova, Elena. "Automated calculation of reduced resistance to a heat transfer of the window based on BIM technologies." MATEC Web of Conferences 193 (2018): 03018. http://dx.doi.org/10.1051/matecconf/201819303018.
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The aim of this work is the development of automated methods of calculation of thermophysical characteristics of the window based on BIM technology. The structure and materials of window frames and glazing are taken into account while calculating reduced resistance to a heat transfer of the window. Software Autodesk Revit was used for creating the information model of the window. As a result of current research a parametric families of windows were created. Each family contains an automatically calculated parameter of reduced resistance to a heat transfer of the window. Windows with one, two and three sashes were considered in the paper. Calculations have been made for wooden and plastic frames. Russian design standards were taken into consideration. The results of the calculations of reduced resistance to a heat transfer of the window are presented in the table at the end of the paper. The introduced method is universal for any window structure. Accurate calculation of heat loss of window units will allow to choose the design decisions and to predict energy costs for building maintenance.
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Melekhin, Andrei. "Development of engineering calculator for heating systems." E3S Web of Conferences 263 (2021): 04001. http://dx.doi.org/10.1051/e3sconf/202126304001.
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The author has developed an engineering calculator for calculating the heat flow for heating buildings according to the enlarged parameters of the object. The algorithm of the calculator is based on the method of determining the amount of heat energy and heat carrier in water systems of municipal heat supply. The author carried out a systematic analysis of thermal loads on heating of buildings in Russia according to the data of implemented building projects. With this in mind, new coefficients a, n were calculated to determine the specific heating characteristics of the building for newly constructed buildings. The algorithm for calculating the heating of buildings according to the enlarged parameters of the object is corrected. The calculation algorithm is implemented in the software
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Bicbulatov, Arnold Sh, Asia А. Usmanova, and Arthur I. Nurmukhametov. "Сonstruction and study of the load characteristics of the heat exchanger." Butlerov Communications 58, no. 4 (April 30, 2019): 140–45. http://dx.doi.org/10.37952/roi-jbc-01/19-58-4-140.
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The existing practice of designing heat exchangers is based on the application of an engineering method of calculation, the so-called graphical method. Therefore, the design principle of the method consists in solving a system of nonlinear equations describing the heat exchange between coolants composed of various organic substances toluene, benzene, using the method of successive approximations, and the number of approximations can be very large. Randomly given by a number of unknown quantities, namely the temperatures of the pipe walls and some structural dimensions of the apparatus, which are further specified when performing the calculations, are specified. A graph is plotted for the specific heat fluxes for both fluids from the assumed temperatures of the pipe wall, and the lines, the so-called load characteristics of the heat exchanger, are drawn through the points obtained. The analysis of the conditions of application of the load characteristics of the heat exchanger when calculating the surface of the apparatus for the three main types of heat exchange, implemented in heat exchangers: boilers, condensers, cooler-heaters in which heat transfer occurs between various organic liquids under various conditions of their work. It is shown that the load characteristics of heat exchangers are non-linear depending on the specific heat flux on the pipe wall temperature, and the curvature of the line deviations from the straight line depends on the type of heat exchange and the flow of coolants, the curvature of the lines is close to the straight line dependence in the laminar mode, significantly different from the straight line in the transition mode and turbulent regimes and is very different from the straight line dependence on heat exchange with a change in the state of aggregation of both fluids. A direct calculation of the surface of the apparatus has been proposed, a technique has been developed for determining the temperature of the pipe wall, selections of initial conditions for performing calculations, step-by-step changes in the magnitudes of the driving forces are recommended when performing approximations, which reduces the time spent on the calculation. The paper also analyzes the choice of changes in the magnitudes of the driving force of the heat transfer process for the number of approximations, shows the intervals of variation of this quantity at which the calculation error decreases. Direct determination of the surface of the device significantly increases the accuracy of the calculation of the surface.
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Staszczuk, Anna, Tadeusz Kuczyński, Magdalena Wojciech, and Piotr Ziembicki. "Comparative Calculation of Heat Exchange with the Ground in Residential Building Including Periodes of Heat Waves." Civil And Environmental Engineering Reports 21, no. 2 (June 1, 2016): 109–19. http://dx.doi.org/10.1515/ceer-2016-0026.
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Abstract The paper provides verification of 3D transient ground-coupled model to calculation of heat exchange between ground and typical one-storey, passive residential building. The model was performed with computer software WUFI®plus and carried out to estimate the indoor air temperatures during extending hot weather periods. For verifying the results of calculations performed by the WUFI®plus software, the most recent version of EnergyPlus software version was used. Comparison analysis of calculation results obtained with the two above mentioned calculation method was made for two scenarios of slab on ground constructions: without thermal insulation and with thermal insulation under the whole slab area. Comprehensive statistical analysis was done including time series analysis and descriptive statistics parameters.
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Penkovskii, Andrey, Oleg Khamisov, and Angelica Kravets. "Calculation of Nodal Prices for Heat Energy in Heat Supply Systems." E3S Web of Conferences 209 (2020): 06020. http://dx.doi.org/10.1051/e3sconf/202020906020.
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The article is devoted to the calculation of nodal prices for heat energy in heat supply systems. The problem, mathematical model and method of calculating nodal prices of heat energy for all consumers of the heat supply system considered, taking into account the different cost of heat production by sources, optimal flow distribution, and placement of consumers in the heat network (distance from the source). As the main computational tool for calculating nodal prices for heat energy, the Lagrange multiplier method used in the problem of modes optimizing in heat supply system, which allows explaining in detail the formation of the price for heat energy in each node. With the help of the proposed methodological support, practical research has been carried out for real heat supply system.
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Zauer, E. A., and A. B. Ershov. "CUBANE HEAT OF FORMATION: CALCULATION METHODS." IZVESTIA VOLGOGRAD STATE TECHNICAL UNIVERSITY, no. 5(240) (May 19, 2020): 18–24. http://dx.doi.org/10.35211/1990-5297-2020-5-240-18-24.
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A comparative analysis of the enthalpies of formation of a cubane calculated by the methods of molecular mechanics and quantum chemistry is carried out. A correlation between the experimental and calculated AM1-method values of the heats of formation of frame hydrocarbons was established, which allowed us to correct the results of calculating the heat of formation of the cubane and reduce the discrepancy with the experimental value of its formation enthalpy to 10.7 kJ / mol.
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Николаев, В. А., and И. В. Кряклина. "Heat-Exchange Surface Calculation of Heat-Conducting Medium and Grain Trashed Heap." Vestnik APK Verhnevolzh`ia, no. 4(52) (December 25, 2020): 66–68. http://dx.doi.org/10.35694/yarcx.2020.52.4.013.
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Для энергосбережения при сушке зерна в контактно-конвективной сушилке предлагается использовать тепло охлаждающей жидкости двигателя внутреннего сгорания. Жидкость поступает в трубки контактно-конвективной сушилки. Трубки теплоносителя расположены наклонно под углом 40° параллельно друг другу по всей ширине сушилки. Над ними, в шахматном порядке – паросборники. Над паросборниками установлен плавающий разравнивающий транспортёр, который изменяет своё положение в зависимости от объёма зерна в контактно-конвективной сушилке. Рассмотрена отдельная зерновка, движущаяся по поверхности трубки теплоносителя. В результате нагрева зерновки происходит её отпотевание – появление влаги на поверхности зерновки. Произведён теплотехнический расчёт поверхности теплообмена теплоносителя и зернового вороха, определено количество тепла, передающегося зерновому вороху в результате контактного теплообмена. Установлено, что использование тепла охлаждающей жидкости двигателя внутреннего сгорания в контактно-конвективной сушилке приводит к энергосбережению при сушке зерна. For energy saving at grain drying in contact-convection drier it is proposed to use heat of cooling liquid of internal combustion engine. The liquid enters the tubes of the contact-convection drier. Heat carrier tubes are set at an angle of 40 ° parallel to each other along the full width of the drier. There are steam headers staggering above them. An amphibious leveling carrier is installed above the steam headers which changes its position depending on the volume of grain in the contact-convection drier. Separate caryopsis moving along surface of heat-conducting medium tube is considered. As a result of the heating of the caryopsis its sweating occurs – the appearance of moisture on the surface of the caryopsis. Thermotechnical calculation of heat-exchange surface of heat-conducting medium and grain trashed heap is performed, amount of heat transferred to grain trashed heap as a result of contact heat exchange is determined. It has been found that using the cooling liquid heat of the internal combustion engine in the contact-convection drier leads to energy saving when drying grain.
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Tokarev, Vyacheslav, and Nikolay Novitsky. "The method of adjustment of heat supply systems with the multistage temperature control at pumping stations." MATEC Web of Conferences 212 (2018): 02006. http://dx.doi.org/10.1051/matecconf/201821202006.
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The lowering of the temperature graph in the lower-level heat networks is often carried out by a mixture of coolant from the return pipeline at mixing pumping stations in order to maintain the set temperature of the mixed water. In this case, part of the heat carrier is not returned to the source of thermal energy, but it circulates in the circuits from the mixing station to the lower consumption nodes. The presence of such circulation flows leads to the absence of a stabilizing moment of the temperature field when it is calculated by traditional methods, as well as to the “looping” of the computational process and the impossibility of obtaining a solution. In work to overcome these problems, a new computational scheme for commissioning calculation is proposed, which is based on: (a) decomposing the calculation of the thermal-hydraulic regime into calculations of the hydraulic and temperature conditions; (b) using the conditional regulator of the ratio of the mixing station’s output costs in calculating the hydraulic regime; (c) fixing the temperature at the station’s output when calculating the temperature regime; (d) iterative calculation with correction of the setpoint of the ratio controller of the flow rate based on the calculation of the temperature regime.
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Subramaniam, Sarith, Sabine Hoffmann, Sridhar Thyageswaran, and Greg Ward. "Calculation of View Factors for Building Simulations with an Open-Source Raytracing Tool." Applied Sciences 12, no. 6 (March 8, 2022): 2768. http://dx.doi.org/10.3390/app12062768.
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Longwave radiative heat transfer is a key determinant of energy consumption in buildings and view factor calculations are therefore required for the detailed simulation of heat transfer between buildings and their environment as well as for heat exchange within rooms. Typically, these calculations are either derived through analytical means or performed as a part of the simulation process. This paper describes the methodology for employing RADIANCE, a command-line open-source raytracing software, for performing view factor calculations. Since it was introduced in the late-1980s, RADIANCE has been almost exclusively employed as the back-end engine for lighting simulations. We discuss the theoretical basis for calculating view factors through Monte Carlo calculations with RADIANCE and propose a corresponding workflow. The results generated through RADIANCE are validated by comparing them with analytical solutions. The fundamental methodology proposed in this paper can be scaled up to calculate view factors for more complex, practical scenarios. Furthermore, the portability, multi-processing functionality and cross-platform compatibility offered by RADIANCE can also be employed in the calculation of view factors.
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Niemyі, S. "FEATURES OF CALCULATION OF THE TEMPERATURE STATE OF THE BUS SALON." Bulletin of Lviv State University of Life Safety 22 (December 28, 2020): 78–84. http://dx.doi.org/10.32447/20784643.22.2020.10.
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The safety of passenger transportation is not only to prevent accidents but also to ensure the conditions of health and efficiency of passengers and driver and the comfort of moving, which is guaranteed by the microclimate in the bus and the driver's workplace. One of the principal indicators of the microclimate is the air temperature in the cabin. The purpose of the work is to develop and substantiate the method of calculating the temperature of the bus interior.Unorganized air exchange due to body leaks (infiltration) influence on the thermal regime of the bus interior. Air exchange due to body leaks depends linearly on the speed of the bus. Heat loss through the structural elements of the body linearly depends on the outside air temperature.The calculation of the thermal state of the bus interior, in principle, is reduced to the estimation of the calorific value of the liquid heater, taking into account all heat losses in the cabin. The method of calculation developed on two indicators: experimentally defined coefficient of heat transfer of a body of the city bus and its inverse size, the calculated value of thermal resistance of unit of the area of salon of the bus. The thermal regime of the interior of a city bus in the conditions of winter operation is significantly influenced by heat exchange through the openings of open doors at short-term service stops. As for long-distance coaches, open the passenger door is much less. Therefore at the operation of buses of the specified class, it is necessary to give in salon-fresh air which needs to be heated.Since there are statistics on heat transfer of the body of city buses, the temperature of their cabins proposes to be calculated by the heat transfer coefficient of the bus body.In this method, the calculation depends on the heat transfer coefficient of the body. The supply and heating of air for ventilation are not taken into account, as the passenger door carries out air exchange in the cabin during bus stops.As calculations have shown, heat losses primarily depend on the temperature difference between the outside air and in the cabin. However, statistics on heat transfer of intercity (tourist) bus bodies are not currently available in the available publications. The temperature condition of intercity buses must correspond to the following calculations, inverse to the heat transfer coefficient of the body - thermal resistance per unit area of the bus.The method of calculating the temperature of the bus interior is substantiated. For city buses should be based on the calculation of heat transfer coefficients body. The temperature condition of intercity buses must be calculated from the thermal resistance per unit area of the bus interior. We proved that heat losses in the cabin of intercity buses, compared to city buses, are much lower due to the absence of heat losses at service stops at the exit and entry of passengers, which account for more than half of all heat losses. To reduce heat loss, the use of double-glazed windows instead of single panes has a particularly significant effect.
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Yakhutl', D. R., R. A. Maleyev, S. M. Zuyev, Yu M. Shmatkov, and Ye A. Ryabykh. "Method for determining the temperature fields of the spark plug." Izvestia MGTU MAMI 1, no. 1 (2021): 46–53. http://dx.doi.org/10.31992/2074-0530-2021-47-1-46-53.
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This article examines the main factors that determine the thermal performance of a spark plug in the temperature range from 300 to 2500 Kelvin. The optimal value of the temperature of the heat cone was determined. A technique and algorithms for the numerical simulation of the thermal state of a spark plug are presented. These made it possible to calculate the dependence of the thermal conductivity coefficient of ceramic elements of a plug and the specific heat capacity of ceramic in-sulator on temperature. The calculation of the working cycle in the engine cylinder was carried out. The calculation of the temperature distribution of heat fluxes in the elements of the spark plug de-sign was performed. The assessment of the thermal characteristics of the spark plug is carried out by the method of numerical modeling of the operating cycle of an internal combustion engine. The calculation of the instantaneous temperature distribution in the body of the spark plug and on its surface is carried out. Calculations of the intensity of heat fluxes between the spark plugs and adjacent parts of the work-ing fluid were carried out. The modeling of the operating cycle for various operating modes of the engine was made. The temperature fields of the spark plugs were determined. An array of initial data for calculating the temperature fields of the spark plug was formed. Dependences of the temperature of the working fluid in the vicinity of the spark plug on the angle of rotation of the crankshaft are determined. The harmonic components of the heat transfer coefficients between the working fluid and the cylinder fire guard (Voshni coefficient) are considered. The harmonic components of the heat flux density are considered. Calculations of the heat field of the spark plug are carried out for various operating modes of the engine, using the finite element method. The calculation of the temperature field of the spark plug by the finite element method was carried out using ANSYS, SolidWorks, Inventor, etc.
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Kalnitsky, F. E., and A. V. Kostyukov. "Comparison of the analytical solutionof efficieтcy regenerative rotating heatexchangethe device with resultsof numericalcalculations." Izvestiya MGTU MAMI 12, no. 3 (September 15, 2018): 32–39. http://dx.doi.org/10.17816/2074-0530-66828.
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The article is devoted to the thermal-hydraulic calculation of the rotating heat exchanger of a gas turbine engine. More specifically, the purpose of this work is to determine the error of the known analytical calculation of the efficiency of the regenerative heat exchanger in comparison with numerical calculation. Analytical and numerical calculations of the rotating heat exchanger are performed. The main problem of creating a methodology for the analytical solution of processes occurring in rotating heat exchangers is that it is necessary to solve the problem of non-stationary heat transfer from the hot coolant to the coolant through the regenerator packing. The solution of any non-stationary process of heat transfer requires knowledge of the boundary and initial conditions of the process. As initial conditions, it is necessary to use the dependence of the regenerator packing temperature field on the steady state of its operation. Such a relationship can only be obtained after the calculation is completed. In this case, the solution of the heat transfer problem in a rotating heat exchanger is possible using two methodological approaches. The first possibility is a solution by successive approximations. In addition to the fact that such a technique is very time-consuming, it allows us to obtain only a numerical solution of the problem, the possibilities of analysis are limited. The second possibility is the use of one or several assumptions. Such an analytical solution was obtained by Stepanov G.Yu. It is clear that the use of assumptions in analytical analysis or in analytical calculations requires an assessment of the accuracy of the methodology. An estimate of the accuracy of the analytical solution to the efficiency of a rotating heat exchanger is given in the proposed work. It is shown that the error of the analytical solution of the regenerator efficiency in the zone of high regeneration degree values is insignificant in comparison with numerical calculations. Analytical solutions proposed by Stepanov G.Yu., are accessible and effective in the process of creating regenerators. Of particular importance are analytical calculations of the efficiency of regenerators when recording solutions in the form required by the similarity theory. An increase in the error in the analytical calculation of the efficiency of the regenerator is noted with a decrease in the ratio of the water equivalents of the heat-transfer packing of the rotating heat exchanger and coolants (gas and air). Marked increase of error of the analytical calculation of the effectiveness of the Regener-Torah in the decrease of water equivalent heat transfer gaskets. no-return heat exchanger and coolants (gas and air).
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Abgarian, K. K., and I. S. Kolbin. "Calculation of heat transfer in nanoscale heterostructures." Izvestiya Vysshikh Uchebnykh Zavedenii. Materialy Elektronnoi Tekhniki = Materials of Electronics Engineering 21, no. 3 (October 31, 2019): 175–81. http://dx.doi.org/10.17073/1609-3577-2018-3-175-181.
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Abstract. The article discusses the calculation of the temperature regime in nanoscale AlAs/GaAs binary heterostructures. When modeling heat transfer in nanocomposites, it is important to take into account that heat dissipation in multilayer structures with layer sizes of the order of the mean free path of energy carriers (phonons and electrons) occurs not at the lattice, but at the layer boundaries (interfaces). In this regard, the use of classical numerical models based on the Fourier law is limited, because it gives significant errors. To obtain more accurate results, we used a model in which the heat distribution was assumed to be constant inside the layer, while the temperature was stepwise changed at the interfaces of the layers. A hybrid approach was used for the calculation: a finite−difference method with an implicit scheme for time approximation and a mesh−free model based on a set of radial basis functions for spatial approximation. The calculation of the parameters of the bases was carried out through the solution of the systems of linear algebraic equations. In this case, only weights of neuroelements were selected, and the centers and «widths» were fixed. As an approximator, a set of frequently used basic functions was considered. To increase the speed of calculations, the algorithm was parallelized. Calculation times were measured to estimate the performance gains using the parallel implementation of the method.
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Gorskiy, V. V., and A. G. Loktionova. "Heat Transfer and Friction in a Thin Air Laminar Boundary Layer over Semi-Sphere Surface." Herald of the Bauman Moscow State Technical University. Series Mechanical Engineering, no. 2 (131) (April 2020): 17–33. http://dx.doi.org/10.18698/0236-3941-2020-2-17-33.
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A qualitative solution to the problem of calculating convective heat transfer can be obtained only by numerically integrating the differential equations of the boundary layer, which is associated with overcoming a number of computational problems. Consequently, it is important to develop relatively simple, but fairly high-precision calculation methods. As a first approximation to solving this problem, we can consider the use of the effective length method. From the practical point of view, this method is characterized by satisfactory accuracy of calculating convective heat transfer, which has led to its widespread use in aeronautical design engineering. However, this method is also characterized by a relatively high complexity, although it is much lower than that in numerical integration of the differential equations of the boundary layer. The most effective approach to solving heat transfer and friction problems in engineering practice is to use simple algebraic formulae obtained on the basis of approximating the results of rigorous numerical calculations, or experimental studies. Unfortunately, there is no information in literary sources about the accuracy of these formulae under various conditions of product functioning. This problem is solved on the basis of a systematic numerical calculation of the equations of the boundary layer in the most rigorous theoretical calculation, as well as a detailed analysis of the accuracy of the obtained algebraic formulae and their literary analogues
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Baranova, Ol'ga, and Kseniya Kurushkina. "AUTOMATION OF CALCULATION OF HEAT-SHIELDING CHARACTERISTICS OF WINDOWS." Construction and Architecture 9, no. 4 (December 18, 2021): 81–85. http://dx.doi.org/10.29039/2308-0191-2021-9-4-81-85.
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The use of information modeling tools at all stages of the life cycle of a capital construction object allows you to analyze design information in order to make the most correct decision, while significantly reducing the uncertainty of processes by increasing the amount of data available for analysis. One of the labor-intensive processes at the design stage is the selection of the most suitable structural elements, including translucent structures. As part of the work, the normative and reference information related to the calculation of the heat-shielding characteristics of building structures has been analyzed, scientific developments and publications devoted to the automation of the implementation of heat engineering calculations using various software tools are considered. For the purpose of the study, two indicators were calculated: the normalized value of the reduced heat transfer resistance and the reduced heat transfer resistance of the window. To solve the problem, such automation tools as the Dynamo visual programming tool and the Python programming language were used, with the help of which a script was developed for calculating the thermal performance of windows for use in Autodesk Revit (Autodesk, Inc., USA). As part of the study, it was determined that the combined use of the Dynamo visual programming tool and the Python text programming tool, expanding the functionality of Autodesk Revit, made it possible to automate the task of calculating the reduced heat transfer resistance of a window and the normalized heat transfer resistance, taking into account conditions of a specific construction region.
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Dobkiewicz-Wieczorek, Ewa. "Influence of three surface condensers connection setup on power plant unit performance." E3S Web of Conferences 137 (2019): 01027. http://dx.doi.org/10.1051/e3sconf/201913701027.
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This paper presents a comparison of three surface condenser connection setups on the cooling water side. Serial, mixed and parallel connections were considered. The thermodynamic justification for the use of more complex configurations was verified. The analysis was conducted based on the calculated heat balances of verified power units for nominal and not nominal parameters for tested connections. The exhaust steam pressure was calculated using the technical data of the surface condenser and cooling water parameters. Three methods of calculating the heat transfer coefficient based on characteristic numbers, HEI method, and the ASME standard, were used. The most advantageous model was indicated and used in heat balance calculations. The assumptions and simplifications for the calculations are discussed. Examples of the calculation results are presented.
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Novikov, Sergey, Boris Zhadanovsky, and Sergey Sinenko. "Guidelines on calculation of the concrete thermal treatment modes." MATEC Web of Conferences 178 (2018): 09007. http://dx.doi.org/10.1051/matecconf/201817809007.
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The article provides guidelines on calculation of the cast-inplace reinforced concrete thermal treatment modes: the problem of thermal treatment mode by setting the mathematical temperature field model in the hardening concrete has been solved; model equation which allows calculating the temperature field in the hardening concrete structure using computer software has been solved. These data allow to achieve the high quality of concrete at minimum heat treatment duration and the maximum reduction of energy costs, while minimizing experimental calculations.
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Tsibulskiy, Svyatoslav, Nikolay Galashov, Denis Mel'nikov, Alexandr Kiselev, and Al'bina Bannova. "Improvement air condensers evaluation model." MATEC Web of Conferences 194 (2018): 01017. http://dx.doi.org/10.1051/matecconf/201819401017.
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The results of analysis of the literature on the calculation of the heat transfer coefficient of an air condenser in the flow past a bundle of finned tubes by an air flow. The methods of calculation are disassembled, marked advantages and disadvantages of each. Calculations of the heat transfer coefficient for each method are given; the results compared with the experimental data.
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Nemś, Artur, Mikołaj Simiński, Magdalena Nemś, and Tomasz Magiera. "Analysis of car waste heat recovery system utilizing thermoelectric generator." AUTOBUSY – Technika, Eksploatacja, Systemy Transportowe 19, no. 6 (June 30, 2018): 619–26. http://dx.doi.org/10.24136/atest.2018.144.
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This paper presents a calculation algorithm for a thermoelectric generator fitted in the exhaust system of a combustion engine. The viability of the presented calculation method was verified on an actual combustion engine. The calculations were performed for a BMW engine, and the generator design was based on a prototype from the same manufacturer. The paper includes calculations of the thermal cycle and of the parameters of exhaust gases from the engine. Subsequent calculations cover heat transfer from exhaust gases to the thermoelectric module and the amount of electric energy obtained from a series of modules. In the last part, the focus is on the influence of engine speed on the performance of the thermoelectric generator.
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Divakova, Y. A. "ANTENNA UNIT HEAT MODE." REPAIR RECONDITIONING MODERNIZATION, no. 10 (2021): 38–46. http://dx.doi.org/10.31044/1684-2561-2021-0-10-38-46.
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The article describes the procedure for calculating the thermal regime of a unit. The unit under study is part of a phased array. The calculation of the thermal regime allows you to verify the operability of the device under a steady thermal regime and to verify that the choice of the method of cooling the structure is correct. The work of the unit is analyzed under conditions of convective heat exchange without forced cooling at the maximum operating (permissible) ambient temperature. The calculation of the thermal regime of the unit is carried out in two stages. At the first stage, the temperature of the unit case is determined when the unit case overheats in the first approximation. The overheating value is determined from the graph. The calculation is carried out under conditions of natural air cooling. At the second stage, the average surface temperature of the heated zone is determined. The greatest heating in the unit is observed in the area occupied by the board with ERE. According to the results of the calculation, a problem was revealed, which consists in the fact that under the given operating conditions of the investigated device, the unit area is heated above the maximum operating temperature of some ERE. The value of the average surface temperature of the heated zone of the unit exceeds the value of the maximum allowable temperature of the least heat-resistant element of the heated zone. This means that it is necessary to use forced air cooling by air convection. The article proposes a solution to the problem of unit overheating, and describes the method of forced air cooling and its design.
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Yur’ev, B. P., O. Yu Sheshukov, and V. A. Dudko. "Determination of physical heat capacity of metallurgical production materials by additivity method." Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 75, no. 7 (August 8, 2019): 810–17. http://dx.doi.org/10.32339/0135-5910-2019-7-810-817.
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Heat capacity is one of most important thermal physic characteristics of materials, allowing determining dependence between amount of heat, input to a body or taken away from it, and alteration of its temperature. The labor intensiveness of the test determination of the heat capacity is rather big. Particularly it is difficult to take into account the influence of changes of chemical composition in the process of heating on changes of their heat capacity. A method of calculation of heat capacity of materials proposed using the additivity method. Difficulties of its determination shown, related to insufficient knowledge of additivity method application. The temperature limits determined, until which it is reasonable to make the calculations of materials heat capacity by the proposed method. An example of calculation of siderite ore physical heat capacity considered. Good enough convergence of the results obtained by calculation and heat capacity data, obtained by experiments shown. Divergence between results of heat capacity determination by experiment method and by calculation using additivity method does not exceed 5%. The considered method of physical heat capacity determination can be used also for other materials providing the content of separate components and their changes within the temperature range under the study is known.
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Kilkovský, Bohuslav. "Review of Design and Modeling of Regenerative Heat Exchangers." Energies 13, no. 3 (February 9, 2020): 759. http://dx.doi.org/10.3390/en13030759.
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Heat regenerators are simple devices for heat transfer, but their proper design is rather difficult. Their design is based on differential equations that need to be solved. This is one of the reasons why these devices are not widely used. There are several methods for solving them that were developed. However, due to the time demands of calculation, these models did not spread too much. With the development of computer technology, the situation changed, and these methods are now relatively easy to apply, as the calculation does not take a lot of time. Another problem arises when selecting a suitable method for calculating the heat transfer coefficient and pressure drop. Their choice depends on the type of packed bed material, and not all available computational equations also provide adequate accuracy. This paper describes the so-called open Willmott methods and provides a basic overview of equations for calculating the regenerative heat exchanger with a fixed bed. Based on the mentioned computational equations, it is possible to create a tailor-made calculation procedure of regenerative heat exchangers. Since no software was found on the market to design regenerative heat exchangers, it had to be created. An example of software implementation is described at the end of the article. The impulse to create this article was also to broaden the awareness of regenerative heat exchangers, to provide designers with an overview of suitable calculation methods and, thus, to extend the interest and use of this type of heat exchanger.
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Zhou, Hua Xiang, Zheng Zhou, and Jing Ping Liu. "Theoretical and Computational Research of Heat Radiant Transfer in Cylinder." Applied Mechanics and Materials 628 (September 2014): 311–16. http://dx.doi.org/10.4028/www.scientific.net/amm.628.311.
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In order to obtain the radiation heat transfer theory and calculation methods, the movement of the gas particles, location, intensity, temperature, are researched in cylinder under different conditions with combustion system and the mode of heat transfer. Under high temperature conditions in the cylinder, the gas radiation heat transfer is researched in the complex heat transfer theory. A statistical correlation K narrow band model, a mean absorption coefficient, a gas line databases, by-line calculation method are found, through research and analysis emissivity, transmittance, absorption coefficient, typical models, mathematical equations, database, calculation methods. Examine the distribution performance of each database for different media concentration and temperature, a statistical narrow-band band parametric model accuracy is tested, using statistical narrow band model, the results of the use of by-line method. Research shows: selected spectral database, calculation method has a greater impact on the results. The research also shows the result coincides calculations based by-line HITEWP2010 database method, whether radiant heat or wall flux, statistical narrow band model. These are supplied to the internal combustion engine cylinder design.
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Buzan, J. R., K. Oleson, and M. Huber. "Implementation and comparison of a suite of heat stress metrics within the Community Land Model version 4.5." Geoscientific Model Development 8, no. 2 (February 5, 2015): 151–70. http://dx.doi.org/10.5194/gmd-8-151-2015.
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Abstract. We implement and analyze 13 different metrics (4 moist thermodynamic quantities and 9 heat stress metrics) in the Community Land Model (CLM4.5), the land surface component of the Community Earth System Model (CESM). We call these routines the HumanIndexMod. We limit the algorithms of the HumanIndexMod to meteorological inputs of temperature, moisture, and pressure for their calculation. All metrics assume no direct sunlight exposure. The goal of this project is to implement a common framework for calculating operationally used heat stress metrics, in climate models, offline output, and locally sourced weather data sets, with the intent that the HumanIndexMod may be used with the broadest of applications. The thermodynamic quantities use the latest, most accurate and efficient algorithms available, which in turn are used as inputs to the heat stress metrics. There are three advantages of adding these metrics to CLM4.5: (1) improved moist thermodynamic quantities; (2) quantifying heat stress in every available environment within CLM4.5; and (3) these metrics may be used with human, animal, and industrial applications. We demonstrate the capabilities of the HumanIndexMod in a default configuration simulation using CLM4.5. We output 4× daily temporal resolution globally. We show that the advantage of implementing these routines into CLM4.5 is capturing the nonlinearity of the covariation of temperature and moisture conditions. For example, we show that there are systematic biases of up to 1.5 °C between monthly and ±0.5 °C between 4× daily offline calculations and the online instantaneous calculation, respectively. Additionally, we show that the differences between an inaccurate wet bulb calculation and the improved wet bulb calculation are ±1.5 °C. These differences are important due to human responses to heat stress being nonlinear. Furthermore, we show heat stress has unique regional characteristics. Some metrics have a strong dependency on regionally extreme moisture, while others have a strong dependency on regionally extreme temperature.
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Sergeev, V. "SPECIFIC FEATURES OF NUMERICAL SIMULATION OF THERMAL OPERATION MODE THE SPENT FUEL POOLS OF BILIBINO NPP." PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. SERIES: NUCLEAR AND REACTOR CONSTANTS 2021, no. 1 (March 26, 2021): 97–107. http://dx.doi.org/10.55176/2414-1038-2021-1-97-107.
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The paper considers methodological aspects during the development of thermo-hydro-dynamic of numerical calculation models for spent nuclear fuel pool (SNFP) on the example of Bilibino NPP by using international industry codes. The purpose of these models development is the fast simulation of thermal and humidity operational modes of spent fuel pool during periods of filling, "wet" and dry storage with an interval of up to 50 years, taking into account passive and forced convection heat removal systems. The following methodological aspects are considered in detail: 1. Use of isotope kinetics codes for calculating of the heat power dynamics for separate spent fuel assembly. 2. Calculation method of the heat removal power from the evaporation mirror of SNFP during “wet” storage, including evaporation power calculation and exhaust ventilation operation. Using the law of similarity of heat transfer and mass transfer processes (Lewis' law) for evaporation calculations. 3. Methods of accelerated computational forecasting of the dynamics of the thermal regimes of the SNFP during “wet” storage. 4. Condensation of atmospheric moisture at the bottom of the SNFP after “dry” storage and methods for its removal. It is shown that TRAC (TRACE) code with a 3D porous body model and complete evaporation-condensation models is the most suitable for solving the problems under consideration among the system thermo-hydraulic two-phase codes for nuclear energy.
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Bolshakov, V. I., L. G. Kudrova, V. A. Ponomarev, and V. S. Kharitonov. "Calculation of Heat Conduction of Fiber Heat-Insulating Materials." Heat Transfer Research 35, no. 1-2 (2004): 10–16. http://dx.doi.org/10.1615/heattransres.v35.i12.20.
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Demchenko, V. G., S. S. Gron, and N. D. Pogorelova. "CONSTRUCTION CALCULATION OF MOBILE HEAT STORAGE." Thermophysics and Thermal Power Engineering 41, no. 4 (December 24, 2019): 35–43. http://dx.doi.org/10.31472/ttpe.4.2019.5.
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Modern thermal power is built based on three components: generation, transmission, and distribution of thermal energy. In this industry, another fourth element which was previously virtually absent is energy storage. Energy storage completely change our usual heat supply system. Heat storage is a serious factor in saving energy and improving environmental safety. The introduction of autonomous high and low potential heat storage systems is a real opportunity for the development of Intelligence Smart Grid heating systems. Therefore, the study of mobile heat storage batteries and the choice of methods for their design calculation and performance is an important task of modern science and technology. For this purpose, a study was conducted to determine the charging and discharge time of a mobile heat accumulator, depending on the type, volume, and temperature of the heat storage material. Types of thermal energy accumulation, classes of thermal accumulators, range of operating temperatures for a thermal accumulator were analyzed, design features of accumulators, operating time and methods of calculation of design parameters were considered. It is concluded that the method of calculation of MTA depends on the selected type of heat storage material. Although, phase transition materials have a higher heat storage density than liquid solutions, the design of liquid thermal batteries is much more attractive regarding technological, technical, and economic parameters. As a result of the study, the dependence of the MTA charging rate on the heat source power was obtained, the required amount of heat was determined, the average battery cooling time from the volume of the heat storage material, and the heat losses through the MTA body was analyzed. The results obtained must be taken into account when choosing the design and capacity of the battery.
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Torbidoni, Leonardo, and J. H. Horlock. "Calculation of the Expansion Through a Cooled Gas Turbine Stage." Journal of Turbomachinery 128, no. 3 (February 1, 2005): 555–63. http://dx.doi.org/10.1115/1.2185123.
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In recent work by the same authors [Torbidoni, L., and Horlock, J. H., 2005, ASME J. Turbomach, 127, pp. 191–199], a new method for calculating the coolant flow requirements of a high-temperature gas turbine blade was described. It involved consideration of successive chordwise strips of blading; the coolant required in each strip was obtained by detailed study of the heat transfer processes across the wall of the blade and then setting limits on the maximum blade metal temperature. In the present paper, the gas state paths, involving viscous losses, heat transfer, and mixing of the coolant with the mainstream, are determined strip by strip along the whole blade chord for the stator and rotor of the stage and illustrated on an enthalpy-entropy chart. The work output from each rotor strip is obtained together with the losses (entropy creation) through the whole stage. It is then possible to calculate the thermodynamic efficiency for the cooled turbine stage and compare it to that of the uncooled stage. Illustrative calculations are given, a main calculation being based on the mean flow across the blade pitch. But, in a second supplementary calculation, allowance is also made for flow variations across the blade pitch. By comparing these two calculations, it is shown that the mean flow calculation is usually adequate.
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Pyatin, Andrey, Aleksander Shempelev, and Ekaterina Popova. "Improving the efficiency of heating boiler plants by using the variable-frequency drive with different methods of heat supply regulation." MATEC Web of Conferences 245 (2018): 07020. http://dx.doi.org/10.1051/matecconf/201824507020.
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The aim of the work is to improve the energy efficiency of heating boiler plants by reducing the spe-cific electric energy consumption for heat supply by using the variable-frequency drive (VFD) with different methods of heat supply regulation. Hydraulic and thermal calculations of the heating net-work are performed on the example of the real district heating system. Heat network temperature charts of district heating are selected and calculated considering preservation of high quality of district heating. The description of the calculation algorithm of the research and the results of the calculation of the basic mode of district heating heat supply according to the standard temperature chart of varia-ble temperature control are given in the article. Places of installation of VFD are determined on the base of the basic mode. The results of calculation of three different methods of heat supply regulation are presented: standard heat network temperature chart of variable temperature control with using the VFD, extended heat network temperature chart of constant temperature/variable flow control, extend-ed heat network temperature chart using the VFD.
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BEL'KOV, A. A., D. EBERT, A. V. LANYOV, and A. SCHAALE. "HEAT-KERNEL CALCULATION OF QUARK DETERMINANT AND COMPUTER ALGEBRA." International Journal of Modern Physics C 04, no. 04 (August 1993): 775–86. http://dx.doi.org/10.1142/s0129183193000641.
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In this paper we describe the calculational background of deriving a strong meson Lagrangian from the Nambu–Jona-Lasinio quark model using the computer algebra systems FORM and REDUCE in recursive algorithms, based on the heat-kernel method for the calculation of the quark determinant.
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Wróblewski, Artur, and Jarosław Andrzejczak. "Wave propagation time optimization for geodesic distances calculation using the Heat Method." Open Physics 17, no. 1 (June 8, 2019): 263–75. http://dx.doi.org/10.1515/phys-2019-0027.
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Abstract Finding the geodesic path defined as the shortest paths between two points on three-dimensional surface P is a well known problem in differential and computational geometry. Surfaces are not differentiable in a discrete way, hence known geometry algorithms can’t be used directly - they have to be discretized first. Classic algorithms for geodesic distance calculation such as Mitchell-Mount-Papadimitriou method (MMP) are precise but slow. Therefore modern solutions are developed for fast calculations. One of them is Heat Method which approximates such paths with some accuracy. In this paper we propose the extension of Heat Method to reduce the approximation error. A new formula for calculating value of the parameter t (wave propagation time step) which outperforms the original one in terms of mean and median error is presented. Also, correlation between mesh properties and best wave propagation time step as well as influence of variable node spacing on heat map based method were thoroughly analysed.
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Fujiyama, Naoto, and Akira Seki. "Austenite Grain Growth Simulation in Welding Heat-Affected Zone." Materials Science Forum 941 (December 2018): 620–26. http://dx.doi.org/10.4028/www.scientific.net/msf.941.620.
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To predict austenite grain growth behavior in the heat-affected zone (HAZ) in low alloy steels, a new calculation model is proposed herein. This model mainly considers the solute-drag effect and pinning effect, which restrain the austenite grain growth. To calculate the solute-drag effect, the grain boundary concentration of each element is obtained by Hillert’s Law. Calculations are performed by simulating the HAZ with a temperature gradient using the phase field method for two dimensions. This calculation demonstrates the possibility of quantitatively predicting the pinning force for welding heat inputs.
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Kobasko, Nikolai. "STUDY OF DIFFERENCES BETWEEN REAL AND EFFECTIVE HEAT TRANSFER COEFFICIENTS TO PROVIDE CORRECT DATA ON TEMPERATURE FIELD CALCULATIONS AND COMPUTER SIMULATIONS DURING HARDENING OF STEEL." EUREKA: Physics and Engineering 3 (May 31, 2018): 42–51. http://dx.doi.org/10.21303/2461-4262.2018.00646.
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The paper analyses contemporary methods and probes for testing liquid media used as a quenchant in heat treating industry. It is shown that lumped-heat-capacity method, often used for testing liquid media, produces big errors during transient nucleate boiling processes due to incorrect calculation condition caused by use effective heat transfer coefficient (HTC). The effective heat transfer coefficients (HTCs), utilized for this purpose, are almost seven times less as compared with real HTCs that results in incorrect calculation the value of Bi. Instead of lumped-heat -capacity method, a general cooling rate equation is proposed for HTC calculation. It is underlined that effective HTCs can be used only for approximate core cooling rate and core cooling time of steel parts calculations. For investigation cooling capacity of liquid quenchants, including initial heat flux densities, HTCs and critical heat flux densities, high developed technique of solving inverse problem should be used based on accurate experimental data generated by testing liquid media with the Liscic/Petrofer probe or other similar technique.
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Maslenskiy, Viktor V. "Selection of a method for calculating heat gain from solar radiation to determine the load on the climate system of the cabin of a mobile car." SAFETY OF TECHNOGENIC AND NATURAL SYSTEMS, no. 4 (November 30, 2021): 2–7. http://dx.doi.org/10.23947/2541-9129-2021-4-2-7.
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Introduction. The article analyzes and selects the most rational methods for calculating the heat gain from solar radiation. The correct calculation of this component of the heat balance allows you to correctly determine the power of the projected cabin climate system, which will ensure optimal working conditions at the workplace of mobile car operators.
Problem Statement. The objective of this study is to analyze and select a rational method for calculating heat gain from solar radiation for the correct determination of the thermal load on the climate system of the cabin of a mobile car.
Theoretical Part. To implement the task, the most common methods for calculating solar radiation were described and analyzed in detail and the most accurate ones were recommended.
Conclusions. The more labor-intensive method of V.N. Bogoslovskiy (taking into account the time of day) can be recommended for automated calculations in Excel, and the method of P.Y. Gamburg (taking into account the sides of the horizon) — for comparative estimated engineering calculations. When conducting "in-depth" model calculations and accounting for solar radiation, the ASHRAE method is explicitly suitable, which has two important advantages: it takes into account the solar factor in relation to a specific type of glazing and is adapted for automated calculations in ANSYS FLUENT.
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Moshentsev, U. L., and А. А. Gogorenko. "FEATURES OF CALCULATION OF ON-BOARD HEAT EXCHANGERS." Internal Combustion Engines, no. 1 (July 26, 2021): 52–59. http://dx.doi.org/10.20998/0419-8719.2021.1.07.
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Aspects of designing an onboard heat exchangers for the cooling system of the ship's power plant are considered. Such heat exchangers must be designed in accordance with the classical foundations of the theory and calculation of heat exchangers. At the same time, the key design points are considered by well-known sources in a separate setting related to the peculiarities of their consideration as specific elements of the theory. In this regard, they are not united by a single system necessary for their use in specific design problems. Accordingly, the paper highlights, concretizes and refines the parameters of the formulas used in the computational problem. In particular, the calculation of the heat transfer coefficient from the seawater side is performed according to the formula that gives the average value of the coefficient for the vessel. The heat transfer coefficients from the side of the coolant of the inner loop are calculated according to the well-known formulas recommended for calculating heat transfer in channels of any shape. Attention is drawn to the fact that heat transfer from the hold side goes to the finned wall. In this regard, the heat transfer coefficients determined by the indicated formulas should be considered convective. The transition to the given values of the heat transfer coefficients should be carried out considering the efficiency of the finned heat exchange surface, which considers the uneven temperature of various sections of the heat exchange surface. The calculation of heat transfer was carried out considering possible surface contamination. The procedure for performing the calculation steps is proposed, as a result of which the dimensions and heat engineering parameters of the heat exchanger can be determined. It was found that the use of the considered proposals leads to results close to those recommended by authoritative sources. The above proposals do not contradict the experience of creating and designing such structures. The recommendations can be used for educational and practical purposes by those who design heat exchangers of similar designs.
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Krashchenko, Vladislav, Nikita Tretyakov, Alexander Chernov, Ilmir Shaykhalov, and Alexey Zhukov. "Modeling and thermal calculation of a pipeline insulation system." E3S Web of Conferences 164 (2020): 14021. http://dx.doi.org/10.1051/e3sconf/202016414021.
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Energy efficiency of heating networks depends on the costs of the manufacture of insulation materials and components, its installation and exploitation of insulating jacket. As insulation materials for insulation of heating networks, products based on rock wool, polyurethane foam extruded polystyrene foam, foam rubber and polyethylene foam. In this contribution introduced basic principles of calculating the thickness of the thermal insulation of a pipeline by the value of the standard density of the heat flow are given using an example of the use of products based on polyethylene foam. Calculation of the heat flux from the surface of the heat-insulating structure is carried out at a given thickness of the heat-insulating layer if there is a need to determine heat loss (or cold loss). The basis for the calculation is a mathematical model of heat transfer, a developed calculation algorithm and a computer program. The method of installation of thermal insulation depends on the diameter of the pipeline and the selected type of product. Insulating cylinders or cylinders in combination with heat-insulating mats are used for pipelines of small diameters. Roll materials are used to isolate large diameters. Products are fixed on pipelines using mechanical fasteners.
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TAKEGAMI, Hiroaki, and Takeshi SHINODA. "Heat input calculation for friction welding." Journal of Japan Institute of Light Metals 54, no. 3 (2004): 95–99. http://dx.doi.org/10.2464/jilm.54.95.
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Ефремов, Герман, and Валерий Мартыненко. "REFINED CALCULATION OF RECUPERATIVE HEAT EXCHANGERS." PNRPU Bulletin. Chemical Technology and Biotechnology, no. 3 (September 30, 2019): 86–95. http://dx.doi.org/10.15593/2224-9400/2019.3.08.
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Fujisaki, Keisuke. "3D dynamic heat plasma magnetohydrodynamic calculation." Journal of Applied Physics 91, no. 10 (2002): 8319. http://dx.doi.org/10.1063/1.1452695.
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Ivanova, A. A., V. A. Palyulin, A. N. Zefirov, and N. S. Zefirov. "QSPR: Application to Heat Capacity Calculation." Russian Journal of Organic Chemistry 40, no. 5 (May 2004): 644–49. http://dx.doi.org/10.1023/b:rujo.0000043708.34952.ee.
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