Journal articles on the topic 'Heating modes'
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1
OZAWA, Takeo. "Heating Modes in Thermal Analysis." Journal of the Mass Spectrometry Society of Japan 47, no. 6 (1999): 349–53. http://dx.doi.org/10.5702/massspec.47.349.
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Fuchs, Željka, Saska Gjorgjievska, and David J. Raymond. "Effects of Varying the Shape of the Convective Heating Profile on Convectively Coupled Gravity Waves and Moisture Modes." Journal of the Atmospheric Sciences 69, no. 8 (August 1, 2012): 2505–19. http://dx.doi.org/10.1175/jas-d-11-0308.1.
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Abstract The analytical model of convectively coupled gravity waves and moisture modes of Raymond and Fuchs is extended to the case of top-heavy and bottom-heavy convective heating profiles. Top-heavy heating profiles favor gravity waves, while bottom-heavy profiles support moisture modes. The latter behavior results from the sensitivity of moisture modes to the gross moist stability, which is more negative with bottom-heavy heating. A numerical implementation of the analytical model allows calculations in the two-dimensional nonrotating case as well as on a three-dimensional equatorial beta plane. In the two-dimensional case the analytical and numerical models are mostly in agreement, although minor discrepancies occur. In three dimensions the gravity modes become equatorial Kelvin waves whereas the moisture modes are more complex and require further investigation.
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Svidzinski, V. A., and D. G. Swanson. "Fundamental heating with stellarator wave modes." Physics of Plasmas 5, no. 2 (February 1998): 486–98. http://dx.doi.org/10.1063/1.872731.
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Bandura, V., B. Kotov, and R. Kalinichenko. "Mathematical models of operating modes of extractors with microwave heating." Energy and automation 2018, no. 5 (October 23, 2018): 183–94. http://dx.doi.org/10.31548/energiya2018.05.183.
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Bolonina, Alona, Genadijs Bolonins, and Dagnija Blumberga. "Analysis of the Impact of Decreasing District Heating Supply Temperature on Combined Heat and Power Plant Operation." Environmental and Climate Technologies 14, no. 1 (December 1, 2014): 41–46. http://dx.doi.org/10.1515/rtuect-2014-0013.
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Abstract District heating systems are widely used to supply heat to different groups of heat consumers. The district heating system offers great opportunities for combined heat and power production. In this paper decreasing district heating supply temperature is analysed in the context of combined heat and power plant operation. A mathematical model of a CHP plant is developed using both empirical and theoretical equations. The model is used for analysis of modified CHP plant operation modes with reduced district heating supply temperature. Conclusions on the benefits of new operation modes are introduced.
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Gasparov, L. "Laser-heating and phonon modes in YBa2Cu3Ox." Radiation Effects and Defects in Solids 137, no. 1-4 (December 1995): 331–35. http://dx.doi.org/10.1080/10420159508222746.
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Osintsev, K. V., Iu S. Prikhodko, V. S. Shichkina, D. A. Akhmetshin, and A. N. Shishkov. "Research of different heating modes of greenhouses." IOP Conference Series: Earth and Environmental Science 723, no. 5 (March 1, 2021): 052007. http://dx.doi.org/10.1088/1755-1315/723/5/052007.
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Sheryazov, S. K., Y. A. Nikishin, M. V. Schelybaev, A. S. Chigak, and A. Kh Doskenov. "Modeling of solar batteries operating modes." IOP Conference Series: Earth and Environmental Science 949, no. 1 (January 1, 2022): 012088. http://dx.doi.org/10.1088/1755-1315/949/1/012088.
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Abstract For the solar power engineering development it is essential to determine the photovoltaic plant energy indicators by modeling the solar batteries operating modes. To obtain an adequate solar battery model, we need to determine its main parameters on the basis of an equivalent electric circuit. Modeling the solar battery operating mode, it is necessary to take into account the influence of its heating temperature. We propose a combined research algorithm in MS Excel with the installed add-on “Search for a solution” for modeling of solar battery operating mode. We have given the results of modeling the solar battery operating mode where the calculated solar battery maximum power including its heating, satisfactory matches with the experimental data. The research shows that excluding the solar battery heating, the maximum power value and, accordingly, its efficiency are overestimated in comparison with the experimental data. Moreover, the results of modeling excluding its heating do not provide the required accuracy and the modeling mistakes are more than 30% especially at relatively high values of solar radiation. The given model allows to determine the equivalent circuit parameters and determine the solar battery maximum power depending on the considered factors of its heating temperature and the incoming solar energy.
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Ma, Kun Ru, Yi Jun Wang, and Cui Xia Wei. "Economic Evaluation and Decision Research on Urban Heating Mode in North." Applied Mechanics and Materials 94-96 (September 2011): 613–17. http://dx.doi.org/10.4028/www.scientific.net/amm.94-96.613.
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Based on urban heating situation in north, economic evaluation for different heating modes was analyzed in the presented work. Firstly through collecting and analyzing the urban heating system data, initial investment and operation cost were deduced for several main heating modes. And only fuel cost was taken into account in operation fuel cost for simplicity. Secondly economic evaluation for whole energy heating modes was done and compared. Finally the best heating mode was found which can be a reference for decision on urban heating mode in north.
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Bogatova, M. Zh, and S. I. Chibizova. "Statistical modeling of temperature operating modes of heating furnaces for hot strip mills." Izvestiya. Ferrous Metallurgy 64, no. 5 (June 3, 2021): 374–81. http://dx.doi.org/10.17073/0368-0797-2021-5-374-381.
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The article provides a method of mathematical modeling to improve temperature operating modes of heating furnaces for hot strip mills. The object of the research is the thermal operation of a continuous walking beam furnace for heating slabs before rolling. The subject of the research is statistical modeling of metal heating in furnaces of this type. The creation of a statistical model consists of factors selection, construction of regression model, correlation analysis and assessment of the variables significance, adjustment of factors and obtaining regression equations. The main part of the research refers to a statistical model based on a comprehensive analysis. This model is based on the results of 15 automated industrial experiments on Russian heating furnaces of hot strip mills and describes the heating process in walking-beam furnace with acceptable accuracy. The adaptation of the statistical model and error calculation has been carried out. The article contains graphs comparing real temperatures and temperatures calculated on the basis of mathematical and statistical models for one of the experiments. The main conclusions are formulated based on the results of the research done. For the first time in metallurgical practice, a statistical model has been developed that describes the process of metal heating in a five-zone continuous furnace with eight heating subzones. Since the regression function is defined, interpreted and justified, and the assessment of the accuracy of the regression analysis meets the requirements, it can be assumed that the model and predicted values have sufficient reliability.
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Gálvez, Antonio, Dammika Seneviratne, and Diego Galar. "Hybrid Model Development for HVAC System in Transportation." Technologies 9, no. 1 (March 5, 2021): 18. http://dx.doi.org/10.3390/technologies9010018.
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Hybrid models combine physics-based models and data-driven models. This combination is a useful technique to detect fault and predict the current degradation of equipment. This paper proposes a physics-based model, which will be part of a hybrid model, for a heating, ventilation, and air conditioning system installed in the passenger vehicle of a train. The physics-based model is divided into four main parts: heating subsystems, cooling subsystems, ventilation subsystems, and cabin thermal networking subsystems. These subsystems are developed when considering the sensors that are located in the real system, so the model can be linked via the acquired sensor data and virtual sensor data to improve the detectability of failure modes. Thus, the physics-based model can be synchronized with the real system to provide better simulation results. The paper also considers diagnostics and prognostics performance. First, it looks at the current situation of the maintenance strategy for the heating, ventilation, air conditioning system, and the number of failure modes that the maintenance team can detect. Second, it determines the expected improvement using hybrid modelling to maintain the system. This improvement is based on the capabilities of detecting new failure modes. The paper concludes by suggesting the future capabilities of hybrid models.
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Tulich, Stefan N., David A. Randall, and Brian E. Mapes. "Vertical-Mode and Cloud Decomposition of Large-Scale Convectively Coupled Gravity Waves in a Two-Dimensional Cloud-Resolving Model." Journal of the Atmospheric Sciences 64, no. 4 (April 1, 2007): 1210–29. http://dx.doi.org/10.1175/jas3884.1.
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Abstract This paper describes an analysis of large-scale [O(1000 km)] convectively coupled gravity waves simulated using a two-dimensional cloud-resolving model. The waves develop spontaneously under uniform radiative cooling and approximately zero-mean-flow conditions, with wavenumber 2 of the domain appearing most prominently and right-moving components dominating over left-moving components for random reasons. The analysis discretizes the model output in two ways. First, a vertical-mode transform projects profiles of winds, temperature, and heating onto the vertical modes of the model’s base-state atmosphere. Second, a cloud-partitioning algorithm sorts sufficiently cloudy grid columns into three categories: shallow convective, deep convective, and stratiform anvil. Results show that much of the tilted structures of the waves can be captured by just two main vertical spectral “bands,” each consisting of a pair of vertical modes. The “slow” modes have propagation speeds of 16 and 18 m s−1 (and roughly a full-wavelength vertical structure through the troposphere), while the “fast” modes have speeds of 35 and 45 m s−1 (and roughly a half-wavelength structure). Deep convection anomalies in the waves are more or less in phase with the low-level cold temperature anomalies of the slow modes and in quadrature with those of the fast modes. Owing to the characteristic life cycle of deep convective cloud systems, shallow convective heating peaks ∼2 h prior to maximum deep convective heating, while stratiform heating peaks ∼3 h after. The onset of deep convection in the waves is preceded by a gradual deepening of shallow convection lasting a period of many hours. Results of this study are in broad agreement with simple two-mode models of unstable large-scale wave growth, under the name “stratiform instability.” Differences here are that 1) the key dynamical modes have speeds in the range 16–18 m s−1, rather than 23–25 m s−1 (owing to a shallower depth of imposed radiative cooling), and 2) deep convective heating, as well as stratiform heating, is essential for the generation and maintenance of the slow modes.
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Liu, Jia Ping, and Lin Bo Chen. "Study on the Local Heating Modes in North of Qinghai Province." Advanced Materials Research 374-377 (October 2011): 461–64. http://dx.doi.org/10.4028/www.scientific.net/amr.374-377.461.
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Qinghai province is one of the important provinces in the development of the western region. It has a continental plateau climate and is extreme cold in winter. There are many local heating modes. Based on the field investigation, this paper presents six heating modes, independent stove, stove Kang, stove heating system, heated Kang, passive solar house, active and passive integration solar house, and compares their advantages and disadvantages. The heating information presented in this paper is significant for the development of heating, and has reference value for heating, ventilation and air conditioning (HVAC) engineers.
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Aleksahin, A., A. Boblovskii, K. Miahkokhlib, and Y. Schactnyi. "INDICATORS THERMAL AND HYDRAULIC MODES OF DISTRIBUTION HEAT NETWORKS." Municipal economy of cities 3, no. 163 (June 29, 2021): 7–11. http://dx.doi.org/10.33042/2522-1809-2021-3-163-7-11.
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The task of heat supply systems is to ensure the quality of services at a minimum cost in the production and transportation of thermal energy. Because the distribution heat networks of district and district systems are characterized by significant branching and significantly longer lengths of heat pipelines compared to the main sections of heating networks, reducing heat loss in these elements of the heating system significantly affects the overall efficiency of district heating. The amount of heat loss depends on the method of laying networks and the diameter of heat pipes, thermal insulation parameters and temperature of the coolant and the environment. Based on the formulas for determining the specific pressure losses to overcome the friction forces obtained from the generalization of these projects of central heating systems of a number of residential districts of Kharkiv, calculated dependences for determining heat losses by supply and return pipelines of the main branches of the heating network. Estimates of accuracy of use of the offered formulas are carried out. The aim of the work is to determine the specific pressure losses for the main branches of heating distribution networks on the basis of generalization of design data for heat supply systems of building groups and clarification of formulas for calculating heat losses by pipelines of central heating distribution system. Based on the generalization of projects for the heating network of residential neighborhoods in Kharkiv, a formula for calculating the specific pressure loss during water movement in the pipelines of the main branches of the heating network depending on the heat load of buildings connected to the branch. Formulas for calculation of heat losses by supply and return pipelines of the main branches of a heating network of the residential district are offered. A comparison of the accuracy of calculations using the proposed formulas with existing methods for determining heat loss in branched heat supply networks, which showed the possibility of using formulas in preliminary assessments of the thermal state of networks.
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Hryshchenko, V. O. "Modeling and calculation power saving modes grain drying materials under energy fields." Naukovij žurnal «Tehnìka ta energetika» 11, no. 3 (November 18, 2020): 23–29. http://dx.doi.org/10.31548/machenergy2020.03.023.
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Storing grain quality materials in post harvest handling and storage is largely dependent on correctly implemented the drying process. In agricultural production mainly use costly convection dryer. The main share of wasteful energy consumption accounts for heat drying agent, some heat is lost to the environment through the working surface of the dryers and spent coolant. Ways to reduce these energy costs is to reduce the amount of drying agent in the process to the level necessary to absorb and remove moisture from the dryer and the working volume of the principles of targeted "delivery" of energy to vysushuyemoho material. Last principles successfully implemented using contactless energy supply of electromagnetic fields in a material exposure by microwave or infrared radiation. The article deals with the theoretical background processes of drying material in cyclic mode with infrared heating and high frequency electromagnetic field. The equations change over time settings grain material by heating using high frequency electromagnetic field or infrared light and ventilation in the grain does not allow heated air drying cycle count process. The algorithm calculating the overall process of drying cycle to determine rational modes of the process, providing minimize energy costs. The article deals with the theoretical background processes of drying material in cyclic mode with infrared heating and high frequency electromagnetic field. The equations change over time settings grain material by heating using high frequency electromagnetic field or infrared light and ventilation in the grain does not allow heated air drying cycle count process. The algorithm calculating the overall process of drying cycle to determine rational modes of the process, providing minimize energy costs. The article deals with the theoretical background processes of drying material in cyclic mode with infrared heating and high frequency electromagnetic field. The equations change over time settings grain material by heating using high frequency electromagnetic field or infrared light and ventilation in the grain does not allow heated air drying cycle count process. The algorithm calculating the overall process of drying cycle to determine rational modes of the process, providing minimize energy costs. The equations change over time settings grain material by heating using high frequency electromagnetic field or infrared light and ventilation in the grain does not allow heated air drying cycle count process. The algorithm calculating the overall process of drying cycle to determine rational modes of the process, providing minimize energy costs. The equations change over time settings grain material by heating using high frequency electromagnetic field or infrared light and ventilation in the grain does not allow heated air drying cycle count process. The algorithm calculating the overall process of drying cycle to determine rational modes of the process, providing minimize energy costs.
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Buchmann, Julio. "Contribuições do segundo e do terceiro modos internos de gravidade para a resposta do movimento vertical." Anuário do Instituto de Geociências 31, no. 2 (December 1, 2008): 50–52. http://dx.doi.org/10.11137/2008_2_50-52.
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In earlier papers of a series of real data integrations of the National Center for Atmospheric Research Community Climate Model with tropical heat anomalies display regions of pronounced subsidence and drying located several thousand kilometers westward poleward of the heating for cases of tropical Atlantic heating and tropical east Pacific heating. This highly predictable sinking response is established within the first five days of these integrations. The normal-modes of a set of adiabatic primitive equations linearized about a basic state at rest are used to partition model response into gravity-inertia and Rossby modes. The most important contribution for the vertical motion response comes from the gravity modes added for all vertical modes. The principal emphasis is given upon the contributions of the second and third internal vertical modes (with equivalent depths on the order of a fews hundred meters) for the vertical motion response
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BINGHAM, R., P. K. SHUKLA, B. ELIASSON, and L. STENFLO. "Solar coronal heating by plasma waves." Journal of Plasma Physics 76, no. 2 (June 16, 2009): 135–58. http://dx.doi.org/10.1017/s0022377809990031.
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AbstractThe solar coronal plasma is maintained at temperatures of millions of degrees, much hotter than the photosphere, which is at a temperature of just 6000 K. In this paper, the plasma particle heating based on the kinetic theory of wave–particle interactions involving kinetic Alfvén waves and lower-hybrid drift modes is presented. The solar coronal plasma is collisionless and therefore the heating must rely on turbulent wave heating models, such as lower-hybrid drift models at reconnection sites or the kinetic Alfvén waves. These turbulent wave modes are created by a variety of instabilities driven from below. The transition region at altitudes of about 2000 km is an important boundary chromosphere, since it separates the collision-dominated photosphere/chromosphere and the collisionless corona. The collisionless plasma of the corona is ideal for supporting kinetic wave–plasma interactions. Wave–particle interactions lead to anisotropic non-Maxwellian plasma distribution functions, which may be investigated by using spectral analysis procedures being developed at the present time.
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Aleksahin, A., A. Boblovskey, К. Zhariy, J. Sidorenko, and М. Skorik. "HEAT MODES OF THE HEATING NETWORK IN WARMING BUILDINGS." Municipal economy of cities 1, no. 154 (April 3, 2020): 159–64. http://dx.doi.org/10.33042/2522-1809-2020-1-154-159-164.
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The results of calculations of heat losses by network pipelines for heating of idealized groups of buildings during insulation of structures are presented in the work. Formulas for estimation of heat loss reduction by heat conduits are proposed depending on the efficiency of energy saving measures for construction and the law of change of network water costs along the length of the heat conduit, which is determined by the network configuration. The purpose of this work is to evaluate the influence of the hydraulic characteristics of the branches of the heating network on the magnitude of heat losses during transportation of the coolant by pipelines of the distribution network to buildings. Idealized groups of buildings with the same number of objects and the same maximum heat consumption for heating of a separate building are considered. For district heating systems, the efficiency of implementing energy-saving measures for buildings is determined not only by the reduction of heating costs, but also by the change in operating costs for the microdistrict heating network, which is caused by the reduction of heat carrier costs and heat losses by heating system pipelines. The magnitude of the heat loss depends on the method of laying the networks, the parameters of the pipeline insulation, the temperature of the coolant, and the environment. In the case of selective insulation of the buildings of the selected group of buildings, the location of the insulated building is significantly influenced by the amount of heat losses by the pipelines. In case of centralized heat supply, a fragment of the construction load decrease due to the insulation of buildings and the reduction of the network water temperature in the space heating devices causes the reduction of heat losses by the pipelines of the distribution thermal networks. The magnitude of the reduction of heat losses by heat pipelines is determined by the degree of efficiency of insulation of buildings, the nature of changes in the cost of the coolant along the length of the branch of the thermal network and practically does not depend on the magnitude of the heating load of buildings. Keywords: centralized heat supply, centralized heating systems, energy saving, heat transfer resistance, enclosing structures, coefficient of efficiency of building insulation, distribution thermal networks, heat loss by pipelines.
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Kotelnikov, I. A., and S. G. Yakovchenko. "Ponderomotive stabilization of interchange modes at ICRF heating." Plasma Physics and Controlled Fusion 36, no. 5 (May 1, 1994): 797–806. http://dx.doi.org/10.1088/0741-3335/36/5/003.
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Veselý, Michal, Paul Molenaar, Marissa Vos, Rongling Li, and Wim Zeiler. "Personalized heating – Comparison of heaters and control modes." Building and Environment 112 (February 2017): 223–32. http://dx.doi.org/10.1016/j.buildenv.2016.11.036.
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Xu, J., A. K. Smith, G. Jiang, W. Yuan, and H. Gao. "Features of the seasonal variation of the semidiurnal, terdiurnal and 6-h components of ozone heating evaluated from Aura/MLS observations." Annales Geophysicae 30, no. 2 (February 1, 2012): 259–81. http://dx.doi.org/10.5194/angeo-30-259-2012.
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Abstract. This paper presents the thermal forcing of the semidiurnal, terdiurnal, and 6-h components of the migrating tide induced by ozone heating in stratosphere and lower mesosphere. The heating as a function of local time is determined from the global ozone observed by the Microwave Limb Sounder on the Aura satellite. The harmonic components of the heating rates of the semidiurnal, terdiurnal and the 6-h periodicities are calculated using the Strobel/Zhu parameterized model and then decomposed into Hough modes. Seasonal variations of each harmonic component and its Hough modes are presented. For all three tidal components, the majority of the annual mean O3 heating projects onto symmetric modes. The semiannual variation is a prominent signal in almost all of the symmetric Hough modes near the stratopause. The strongest annual variation takes place in the asymmetric modes. The results also show that, during the solstice season, the maximum forcing of the diurnal and terdiurnal component occurs in the summer hemisphere while the maximum forcing of the semidiurnal and 6-h components occurs in the winter hemisphere. The global mean ozone density and the tidal components of the ozone heating rate are different between December–January and June–July. The asymmetry in the heating is primarily due to the 6.6% annual variation in the solar energy input into the Earth's atmosphere due to the annual variation of the Sun-Earth distance.
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Buchmann, Julio. "Uma revisão: contribuições dos modos de gravidade e de Kelvin para a resposta do movimento vertical." Anuário do Instituto de Geociências 32, no. 2 (December 1, 2009): 9–13. http://dx.doi.org/10.11137/2009_2_9-13.
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In earlier papers of a series of real data integrations of the National Center for Atmospheric Research (NCAR) Community Climate Model (CCM) with tropical heat anomalies display regions of pronounced subsidence and drying located several thousand kilometers westward poleward of the heating for cases of tropical Atlantic heating and tropical east Pacific heating. This highly predictable sinking response is established within the first five days of these integrations. The normal-modes of a set of nonlinear primitive equations for an atmosphere: Adiabatic, hydrostatic, incompressible, dry, without friction and viscosity are linearized about a basic state at rest and used to partition model response into gravity-inertia and Rossby modes. The emphasis of this review is given upon the contributions of the gravity and Kelvin modes for the vertical motion response.
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Ulybyshev, S. K., and B. A. Staroverov. "Imitation model of heat flows distribution in building heating control system." Vestnik IGEU, no. 2 (April 30, 2021): 70–79. http://dx.doi.org/10.17588/2072-2672.2021.2.070-079.
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Implementation of automatic heating control systems allows us to reduce heat consumption by 10% in residential areas and 40% in office and educational buildings. Currently, there are heating control systems, however, they are applied only to a single-level two-pipe heating system. Development of an imitation model of heat flows redistribution is necessary to synthesize the system of interconnected dynamic heating control of a building. Unlike existing solutions, this research work considers the problem of unbalanced heat flow in a multi-level hierarchical heating system. Calculation of convective heat transfer in the room assumes that the air temperature at any given time is the same throughout the entire room. When we determine heat transfer through walling, it is assumed that the walling or its part has the same temperature of the planes perpendicular to the direction of air flow. In this case, the heat transfer process is described by a one-dimensional heat transfer equation. The developed model of heating control systems allows us to connect the automatic control modules, change control algorithms at the compilation stage and in the system state during the simulation process. In comparison with possible analogue models based on AnyLogic or ANSYS modeling systems, the presented model is the model of controlled object. It is easily combined with models of automatic control units and considers the problem of imbalance of heat flows. An example of the functional scheme of the local temperature control system around one battery is considered. Implementation of developed imitation model makes it possible to ensure a new level of quality control of technological processes of production and consumption of power energy resources by using modern information technologies and synthesizing a system of interconnected dynamic heating control. Possibilities of such modeling are focused on development of the uninterrupted and high-quality heat supply system, maintaining energy-efficient operating modes, as well as actual economic effect. The model under consideration allows us to simulate redistribution of heat flows in different operating modes of the heating system.
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Mahajan, S. M. "Kinetic Theory of Alfvén Wave Heating." Symposium - International Astronomical Union 107 (1985): 391–92. http://dx.doi.org/10.1017/s0074180900075872.
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In a magnetohydrodynamic description of a plasma, the shear Alfvén wave is characterized by a continuous spectrum (the MHD continuum) which results from a singularity at ω ≃ k||(r)VA(r), where ω is the frequency, k|| is the wave number along the direction of the magnetic field and VA = B0/(4ρπ)1/2 is the Alfvén speed, and r is the direction of inhomo-geniety. The associated electromagnetic fields become large at this resonance layer [in fact, in ideal MHD they become singular], and if some dissipation is allowed, the transfer of energy from the waves to the electrons can take place. These continuum modes are localized in space, and can be effective in heating plasmas in narrow regions around the resonanct surface. Recently, 1-3 a new class of nonsingular global eigenmodes of the plasma have been discovered which are wide spread in the plasma, and could effectively transfer energy to the bulk of the plasma. These modes arise because of a strong coupling between the shear and the evanascent compressional mode. The coupling is provided by gradients of density, equilibrium current and nonideal effects like finite ω/ωci, where ωci is the ion cyclotron frequency. In order to understand the effectiveness of these modes to heat plasmas, i.e., to determine the effective impedance, the energy deposition profiles, parametric dependence of the heating efficiency, etc., a kinetic theory with the electron parallel dynamics is needed. We have developed a detailed kinetic theory to study the structure of the continuum as well as global eigenmodes in an inhomogenous current carrying plasma. The global modes are comparatively much less damped than the continuum modes (which become discrete in the kinetic theory) and hence are easier to excite. The implication, of course, is that the large part of energy transfer in a Alfvén Wave experiment would be mediated through these global modes. This theoretical conjecture is already confirmed in laboratory experiments on PRETEXT Tokamak.I will present the basic theoretical analysis as well as discuss the implications of these findings.
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Pleshivtseva, Yuliya, Bernard Nacke, and Anton Popov. "Optimization of Induction Heating Regarding Typical Quality Criteria: Problem Solution Based on 2D FEM Analysis." Applied Mechanics and Materials 792 (September 2015): 462–67. http://dx.doi.org/10.4028/www.scientific.net/amm.792.462.
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One of the most widespread methods of heating is induction mass heating because it offers certain advantages over similar technologies, including convectional and electrical heating. A significant economical effect can be achieved through optimization of heating modes and design parameters of induction heaters on the basis of modern optimal control theory for distributed parameters systems. The paper is devoted to the numerical simulation and optimal with respect to typical quality criteria control of thermal modes for metals induction heating before hot forming operations. Two-dimensional non-linear time-optimal control problem, problem of maximum heating accuracy and problem of minimum energy consumption are formulated and reduced to the mathematical programming problems. Optimization procedures are based on the developed at SamSTU alternance method of optimal control theory for distributed parameters systems. 2D FLUX code provides FEM analysis of interrelated electromagnetic and temperature fields during induction heating of a cylindrical billet before its hot forming. The model integrated into optimization procedures provides options for variation of the heating system parameters or billet geometry, and for evaluating the process optimization abilities. Computational results for optimal heating of aluminum cylindrical billets are shown and analyzed.
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Ortland, David A., M. Joan Alexander, and Alison W. Grimsdell. "On the Wave Spectrum Generated by Tropical Heating." Journal of the Atmospheric Sciences 68, no. 9 (September 1, 2011): 2042–60. http://dx.doi.org/10.1175/2011jas3718.1.
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Abstract Convective heating profiles are computed from one month of rainfall rate and cloud-top height measurements using global Tropical Rainfall Measuring Mission and infrared cloud-top products. Estimates of the tropical wave response to this heating and the mean flow forcing by the waves are calculated using linear and nonlinear models. With a spectral resolution up to zonal wavenumber 80 and frequency up to 4 cpd, the model produces 50%–70% of the zonal wind acceleration required to drive a quasi-biennial oscillation (QBO). The sensitivity of the wave spectrum to the assumed shape of the heating profile, to the mean wind and temperature structure of the tropical troposphere, and to the type of model used is also examined. The redness of the heating spectrum implies that the heating strongly projects onto Hough modes with small equivalent depth. Nonlinear models produce wave flux significantly smaller than linear models due to what appear to be dynamical processes that limit the wave amplitude. Both nonlinearity and mean winds in the lower stratosphere are effective in reducing the Rossby wave response to heating relative to the response in a linear model for a mean state at rest.
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Wang, Chao, Chun Hua Sun, Cheng Ying Qi, Feng Yun Jin, and Bo Shao. "The Experimental Analysis on the Regularity of Heating Load in Buildings Using Heat Meters with On-Off Time and Area Method in Shijiazhuang Area." Applied Mechanics and Materials 694 (November 2014): 272–75. http://dx.doi.org/10.4028/www.scientific.net/amm.694.272.
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Based on the heating load experiment adopting on-off time and area measuring method of typical heat users located in different places of different buildings in Shijiazhuang, the heating loads of the heat users which are summarized as two typical heat using modes are studied in this paper and the heating loads in the whole winter heating season of the building is estimated. The results shows that with the user’s heat adopting ratio in these two modes increases, the corresponding heating load is lower, the heating load distribution curve gets smoothly in the whole heating period and the peak value of the system heating loads reduces. This regularity of heating load distribution is beneficial for enhancing the stability of heating system and the thermal efficiency of the heat source.
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Zeng, Lifei, Wenping Ju, Bo Hu, Zhe Ning, Bing Wang, Jie Qu, Tingshan Ma, Rongzu Yang, Wenyu Qi, and Yan Wang. "Research on key technology and application of flexibility transformation of heating unit to improve clean energy consumption capacity." Thermal Science, no. 00 (2020): 309. http://dx.doi.org/10.2298/tsci200603309z.
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The electric regulation capacity of heating units has been constantly improving due to the promotion of the heating units? flexibility transformation. This improvement has effectively alleviated the long remained serious wind and light abandonment phenomena in the heating season in China. In this paper, we discussed the key technologies of the LP zero output heating mode and bypass heating mode, both of which are widely used in thermo-electric decoupling. Moreover, the coupling transformation of the two heating modes has been successfully realized in a heating unit. The electric regulation capacity of the unit has been greatly improved, from 18.6% before the transformation to 66.7%, and the minimum technical output has been also reduced to 14.2% THA. After the transformation, the unit now is able to provide several heating modes with its operational flexibility greatly improved. By comparing the economical efficiency of these heating modes, we obtained the operation mode with the lowest heat rate. This transformation mode provides a huge grid space for the consumption of clean energy, so it is of positive reference value and exemplary significance in implementing the flexibility transformation of heating units.
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Konesev, S. G., and P. A. Khlyupin. "Innovative electrotechnological systems to provide the temperature modes of technological pipelines." Power and Autonomous equipment 2, no. 1 (March 28, 2019): 29–39. http://dx.doi.org/10.32464/2618-8716-2019-2-1-29-39.
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Introduction: the systems of thermal effects on thermo-dependent, viscous and highly viscous liquids under conditions of the Arctic and the Extreme North are considered. Low efficiency and danger of heating systems based on burned hydrocarbons, heated liquids and steam are shown. Electrothermal heating systems used to maintain thermo-dependent fluids in a fluid state are considered. The evaluation of the effectiveness of the application of the most common electrothermal system — heating cables (tapes). The most effective electrothermal system based on induction technologies has been determined. Materials and methods: considered methods of thermal exposure to maintain the fluid properties of thermo-dependent fluids at low extreme temperatures. Results: presents an induction heating system and options for its implementation in the Extreme North and the Arctic. Conclusions: induction heating system to minimize loss of product quality, improve the system performance under changing process conditions, eliminate fire product, to reduce the influence of the human factor.
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Zhao, S. Q., Huirong Yan, Terry Z. Liu, Mingzhe Liu, and Mijie Shi. "Analysis of Magnetohydrodynamic Perturbations in the Radial-field Solar Wind from Parker Solar Probe Observations." Astrophysical Journal 923, no. 2 (December 1, 2021): 253. http://dx.doi.org/10.3847/1538-4357/ac2ffe.
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Abstract We report analysis of sub-Alfvénic magnetohydrodynamic (MHD) perturbations in the low-β radial-field solar wind employing the Parker Solar Probe spacecraft data from 2018 October 31 to November 12. We calculate wavevectors using the singular value decomposition method and separate MHD perturbations into three eigenmodes (Alfvén, fast, and slow modes) to explore the properties of sub-Alfvénic perturbations and the role of compressible perturbations in solar wind heating. The MHD perturbations show a high degree of Alfvénicity in the radial-field solar wind, with the energy fraction of Alfvén modes dominating (∼45%–83%) over those of fast modes (∼16%–43%) and slow modes (∼1%–19%). We present a detailed analysis of a representative event on 2018 November 10. Observations show that fast modes dominate magnetic compressibility, whereas slow modes dominate density compressibility. The energy damping rate of compressible modes is comparable to the heating rate, suggesting the collisionless damping of compressible modes could be significant for solar wind heating. These results are valuable for further studies of the imbalanced turbulence near the Sun and possible heating effects of compressible modes at MHD scales in low-β plasma.
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Koskela, H., and H. Maula. "A CFD Model of a Swirl Diffuser for Heating and Cooling Modes." International Journal of Ventilation 12, no. 2 (September 2013): 159–66. http://dx.doi.org/10.1080/14733315.2013.11684011.
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Balasanian, G., O. Klymchuk, A. Semenii, Ye Babaiev, and L. Sachenko. "SIMULATION OF INTERMITTENT HEATING MODE OF THE EDUCATIONAL BUILDING." Odes’kyi Politechnichnyi Universytet Pratsi 2, no. 64 (2021): 22–27. http://dx.doi.org/10.15276/opu.2.64.2021.03.
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. The algorithm of operation of the heat supply system in the mode of intermittent heating which considers features of operation of the building is offered. The purpose of the work is to assess the effectiveness of the use of intermittent heating for the educational building of the thermal laboratory of the Odessa Polytechnic State University. Currently, a project is being implemented to disconnect heat supply from the University boiler room and transfer the building of the University's heating laboratory to autonomous heat supply based on a condensing wall-mounted gas boiler. The combined heating system with the use of different heating devices (radiators, fan coils, climate panel, “underfloor heating” system) allows to study the dynamics of heating the laboratory premises with different thermal insulation and shielding of external and internal walls. The factors of reduction of energy consumption in the mode of program heat supply are analyzed in the work. Modeling of modes of operation of the heat generator of the heat supply system operating in the mode of intermittent heating is executed. The mathematical model of dynamics of heating of air in rooms taking into account features of operating modes and various types of heating devices as a part of system of heat supply is offered. For different climatic conditions the mathematical modeling of operating modes of the heating system is carried out and indicators of efficiency of work of system are received. The potential of energy saving for administrative, educational, office buildings depending on the heat-accumulating properties of external and internal wall structures has been studied. The expediency of using the Pontryagin maximum principle to increase the efficiency of morning flooding of buildings with different ones has been confirmed. accumulation time constants.
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Yang, Qiu, Andrew J. Majda, and Boualem Khouider. "ITCZ Breakdown and Its Upscale Impact on the Planetary-Scale Circulation over the Eastern Pacific." Journal of the Atmospheric Sciences 74, no. 12 (November 29, 2017): 4023–45. http://dx.doi.org/10.1175/jas-d-17-0021.1.
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Abstract The eastern Pacific (EP) intertropical convergence zone (ITCZ) is sometimes observed to break down into several vortices on the synoptic time scale. It is still a challenge for present-day numerical models to simulate the ITCZ breakdown in the baroclinic modes. Also, the upscale impact of the associated mesoscale fluctuations on the planetary-scale circulation is not well understood. Here, a simplified multiscale model for the modulation of the ITCZ is used to study these issues. A prescribed two-scale heating drives the planetary-scale circulation through both planetary-scale mean heating and eddy flux divergence of zonal momentum, where the latter represents the upscale impact of mesoscale disturbances. In an idealized scenario where the heating only varies on the mesoscale, key features of the ITCZ breakdown in the baroclinic modes are captured. The eddy flux divergence of zonal momentum is characterized by midlevel (low level) eastward (westward) momentum forcing at subtropical latitudes of the Northern Hemisphere and opposite-signed midlevel momentum forcing at low latitudes. Such upscale impact of mesoscale fluctuations tends to accelerate (decelerate) planetary-scale zonal jets in the middle (lower) troposphere. Compared with deep heating, shallow heating induces stronger vorticity anomalies on the mesoscale and more significant eddy flux divergence of zonal momentum and acceleration–deceleration effects on the planetary-scale mean flow. In a more realistic scenario where the heating also varies on the planetary scale, the most significant zonal velocity anomalies are confined in the diabatic heating region.
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Hang, Zou, Liu Zhanqiang, Guo Xiaojuan, and Long Enshen. "Measurement of indoor air quality under different heating modes in western Sichuan." E3S Web of Conferences 267 (2021): 01036. http://dx.doi.org/10.1051/e3sconf/202126701036.
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Western Sichuan region has a variety of traditional heating methods and excellent outdoor air quality, and the difference with the city is clear. The indoor air quality of the western Sichuan region is worth studying. The diffusion law of indoor and outdoor PM2.5 concentration under different heating methods can be explored to provide effective data support for environmental governance. In this context, the indoor air quality under different heating methods in Songpan County was measured with PM2.5 concentration assessment of indoor air quality (IAQ). By analyzing the indoor air quality under different heating modes, the following conclusions can be drawn: the influence degree of indoor activity on indoor particle concentration level depends on the source and characteristics of the house. Air leakage is one of the main reasons for the rise of indoor PM2.5. Heating methods disturb the indoor air, which significantly affects the migration of PM2.5.
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Zhang, Chidong, and Samson M. Hagos. "Bi-modal Structure and Variability of Large-Scale Diabatic Heating in the Tropics." Journal of the Atmospheric Sciences 66, no. 12 (December 1, 2009): 3621–40. http://dx.doi.org/10.1175/2009jas3089.1.
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Abstract Tropical diabatic heating profiles estimated using sounding data from eight field campaigns were diagnosed to document their common and prevailing structure and variability that are relevant to the large-scale circulation. The first two modes of a rotated empirical orthogonal function analysis—one deep, one shallow—explain 85% of the total variance of all data combined. These two modes were used to describe the heating evolution, which led to three composited heating profiles that are considered as prevailing large-scale heating structures. They are, respectively, shallow, bottom heavy (peak near 700 hPa); deep, middle heavy (peak near 400 hPa); and stratiform-like, top heavy (heating peak near 400 hPa and cooling peak near 700 hPa). The amplitudes and occurrence frequencies of the shallow, bottom-heavy heating profiles are comparable to those of the stratiform-like, top-heavy ones. The sequence of the most probable heating evolution is deep tropospheric cooling to bottom-heavy heating, to middle heavy heating, to stratiform-like heating, then back to deep tropospheric cooling. This heating transition appears to occur on different time scales. Each of the prevailing heating structures is interpreted as being composed of particular fractional populations of various types of precipitating cloud systems, which are viewed as the building blocks for the mean. A linear balanced model forced by the three prevailing heating profiles produces rich vertical structures in the circulation with multiple overturning cells, whose corresponding moisture convergence and surface wind fields are very sensitive to the heating structures.
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Straus, David M., Erik Swenson, and Cara-Lyn Lappen. "The MJO Cycle Forcing of the North Atlantic Circulation: Intervention Experiments with the Community Earth System Model." Journal of the Atmospheric Sciences 72, no. 2 (February 1, 2015): 660–81. http://dx.doi.org/10.1175/jas-d-14-0145.1.
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Abstract A three-dimensional evolution of Madden–Julian oscillation (MJO) diabatic heating for October–March from satellite data is constructed: the heating propagates eastward for three cycles, modulated by the likelihood for a given MJO phase to occur on a given calendar day. This heating is added to the temperature tendencies of each member of an ensemble of 48 (1 October–31 March) simulations with the Community Earth System Model. The leading two most predictable modes of the planetary wave vertically integrated total (added plus model generated) heating capture 81% of the ensemble-mean variance and form an eastward-propagating oscillation with very high signal-to-noise ratio. The two most predictable modes of the extratropical Northern Hemisphere 200-hPa height form an oscillation, as do those of the 300-hPa height tendency due to synoptic vorticity flux convergence, the 200-hPa Rossby wave source, and the envelope transient kinetic energy. The North Atlantic Oscillation (NAO+) occurs 15–25 days after the MJO convection crosses the 90°E meridian, supported by synoptic vorticity flux convergence and a distinct pattern of Rossby wave source. The daily North Atlantic circulation anomalies are categorized into four circulation regimes with a cluster analysis. The NAO+ and NAO− are equally likely in the control model runs, but the NAO+ is 10% more likely in the model runs with heating, compared to a difference of 14% in reanalyses. The daily occurrence of the NAO+ regime in the heating ensemble shows maxima at times when the leading two optimal modes of height also indicate NAO+ but also shows maxima at other times.
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Kang, Anneka, Ivan Korolija, and Dimitrios Rovas. "Modeling of Photovoltaic-Thermal District Heating with Dual Thermal Modes." Journal of Physics: Conference Series 2042, no. 1 (November 1, 2021): 012090. http://dx.doi.org/10.1088/1742-6596/2042/1/012090.
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Abstract Solar photovoltaic thermal (PVT) collectors could be a competitive addition to district heating systems, particularly in areas with high energy density since they simultaneously produce electricity and heat whilst increasing the PV efficiency through cooling. This study presents a new Modelica PVT model, which is used together with EnergyPlus in a co-simulation setup to assess the technical feasibility of solar PVT district heating in new builds. The model has been applied to a block of 12 2-bedroom terraced houses with a 184m2 PVT array on the south facing side of the roof. It was identified that well-designed seasonal PVT heating configurations and control schemes are required to maximise PVT outputs. PVT dual thermal modes occur when the PV is either connected to a load or producing at close to the maximum power point. Integrating the dual modes into a control system could be more economical if heat tariffs were higher than electrical ones when heat demand is greater than the PVT thermal output.
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Tarasov, V. A., V. V. Tarasova, V. V. Afanasyev, V. G. Kovalev, and V. N. Orlov. "Mathematical modeling of the forecast and standby heating modes." Power engineering: research, equipment, technology 21, no. 3 (November 29, 2019): 73–85. http://dx.doi.org/10.30724/1998-9903-2019-21-3-73-85.
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Wang, Song Ling, Xian Liang Yang, and Juan Juan Chen. "The Analysis of Adjustment Modes of District Heating System." Advanced Materials Research 919-921 (April 2014): 1730–34. http://dx.doi.org/10.4028/www.scientific.net/amr.919-921.1730.
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In order to reduce the power consumption of circulating pump in secondary network., the adjustment that combines quantity adjustment and quality adjustment is proposed in the paper;and the control strategy and adjustment equations in different stages of this adjustment mode are present. Then taken a community in Zhangjiakou as an example, the adjustment curve of this mode in indirectconnected heating systems and direct-connected heating systems are obtained. Finally the power consumptions of the adjustment mode proposed in the paper with that of quality adjustment and quality adjustment with different quantitative ratio in each period are compared; the result indicates that the adjustment mode has more potential in energ-saving.
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Ptitsyna, Elena, Alexander Kuvaldin, and Dmitry Ptitsyn. "The effective modes of infrared radiators and heating systems." E3S Web of Conferences 140 (2019): 04005. http://dx.doi.org/10.1051/e3sconf/201914004005.
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The authors have been researching the effect of polyharmonic currents (complex waveform current) on the characteristics of different types of radiators for a few years. These researches have shown an increase in the energy efficiency of installations with dark and light radiators and the ability to control the harmonic composition of radiation. It is important considering the need to harmonize the frequency characteristics of a radiator with the frequency response of an energy absorbing surface. The object of experimental research are flexible heating tape and installations with dark radiators and their joint operation modes when powered by complex waveform current from a common power source. The purpose of the work is the definition of characteristics of the flexible heating tape and dark infrared radiators when changing the amplitude and frequency of the supply voltage to develop recommendations for the selection of effective modes.
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Errico, Ronald M. "The Forcing of Gravitational Normal Modes by Condensational Heating." Monthly Weather Review 117, no. 12 (December 1989): 2734–52. http://dx.doi.org/10.1175/1520-0493(1989)117<2734:tfognm>2.0.co;2.
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Zhukov, V. I. "Solar p-modes oscillations and heating of the corona." Solar Physics 139, no. 1 (May 1992): 201–3. http://dx.doi.org/10.1007/bf00147890.
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Chernyaev, Aleksey, Maria Kornyushina, and Vladimir Chudin. "Technological modes of mold punching-calibrating with local heating." Science intensive technologies in mechanical engineering 2022, no. 4 (April 6, 2022): 13–17. http://dx.doi.org/10.30987/2223-4608-2022-4-13-17.
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The basic relations for calculating the modes of mold punching a cylindrical hollow billet under viscoplastic conditions are given. The energy calculation method is used in relation to the axisymmetric field of displacement velocities. Theoretical calculations of the work material processing pressure and damage rate are performed.
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Ilin, E. T., S. P. Pechenkin, A. V. Svetushkov, and J. A. Kozlova. "Efficiency of two-stage heating of water on CHP plant with turbines of type T-250/300-240." Safety and Reliability of Power Industry 12, no. 3 (November 22, 2019): 213–19. http://dx.doi.org/10.24223/1999-5555-2019-12-3-213-219.
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During non-heating and transition period, most of cogeneration turbines operate with a lower heat extraction section actuated only due to a number of restrictions on the maximum and minimum pressure levels in the upper and lower heat extraction sections at operation of the turbine. For turbines of model T-250/300-240, the minimum permissible level of steam pressure in the upper heat extraction section, according to manufacturer data, is set to 0.06 MPa. During the non-heating and transition period, the supply water temperature is usually set in the range of 70–75°С. In order to maintain that temperature of supply water, the steam pressure in the upper heat extraction section should be below the minimum permissible level. As a result, the turbine operates with only the low-pressure heat extraction section actuated, which ensures operation without restrictions, but with a lower efficiency. The authors have introduced a set of measures, which enable to avoid those restrictions and implement two-stage heating of supply water. In this case, on connection of the upper heating extraction section, the pressure in the same is maintained at the minimum permissible level. Heat output characteristics are provided by having some of supply water delivered bypassing the group of network heaters. This operational mode enables to increase the turbine actual heat drop, to reduce the cooling steam flow into the low-pressure section and, accordingly, into the condenser, and to reduce temperature drops in network water heaters. Results of the research of operational modes for turbines of type T-250/300-240 in the non-heating and transition period with one and two-stage heating are provided. The economic efficiency of proposed operational modes was researched, which shows the effectiveness of those modes during non-heating and transition period. The limits of the efficiency of using these modes are determined.
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Luo, D. "A simple nonlinear model of low frequency (interseasonal) oscillations in the tropical atmosphere." Nonlinear Processes in Geophysics 3, no. 1 (March 31, 1996): 29–40. http://dx.doi.org/10.5194/npg-3-29-1996.
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Abstract. In this paper, for a prescribed normalized vertical convective heating profile, nonlinear Kelvin wave equations with wave-CISK heating over equatorial region is reduced to a sixth-order nonlinear ordinary differential equation by using the Galerkin spectral method in the case of considering nonlinear interaction between first and second baroclinic modes. Some numerical calculations are made with the fourth- order Rung-Kutta scheme. It is found that in a narrow range of the heating intensity parameter b, 30-60-day oscillation can occur through linear coupling between first and second baroclinic Kelvin wave-CISK modes for zonal wave-number one when the convective heating is confined to the lower and middle tropospheres. While for zonal wavenumber two, 30-60-day oscillation can be observed in a narrow range of b only when the convective heating is confined to the lower troposphere. However, in a wider range of this heating intensity parameter, 30-60-day oscillation can occur through nonlinear interaction between the first and second baroclinic Kelvin wave-CISK modes with zonal wavenumber one for three vertical convective heating profiles having a maximum in the upper, middle and lower tropospheres, and the total streamfield of the nonlinear first and second baroclinic Kelvin wave-CISK modes possesses a phase reversal between the upper- and lower-tropospheric wind fields. While for zonal wavenumber two, no 30-60-day oscillations can be found. Therefore, it appears that nonlinear interaction between vertical Kelvin wave-CISK modes favours the occurrence of 30-60-day oscillations, particularly, the importance of the vertical distribution of convective heating is re-emphasised.
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Ozawa, Takeo. "Temperature control modes in thermal analysis." Pure and Applied Chemistry 72, no. 11 (January 1, 2000): 2083–99. http://dx.doi.org/10.1351/pac200072112083.
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Now we can use several temperature control modes, for example, isothermal run including stepwise heating and cooling, constant rate heating (or cooling), temperature control for sample thermal history, sample-controlled thermal analysis (SCTA or controlled-rate thermal analysis, CRTA), temperature jump, rate jump, temperature modulation, and repeated temperature scanning. Their advantages and drawbacks are reviewed with some illustrative examples, especially for application to kinetic analysis. The combined use of these varieties of temperature control mode is recommended by showing examples. Temperature modulation and repeated temperature scanning are discussed in comparison with temperature-modulated differential scanning calorimetry (DSC), and common and analogous points are elucidated. In relation to this, the possibility of the imaginary part of the overall reaction rate constant in complex reactions is postulated. Finally, these modes are classified and tabulated from two viewpoints, and other possible modes are shown.
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KUBIS, Vjacheslav Aleksandrovich, Svetlana Viktorovna BAKANOVA, Alexandr Ivanovich EREMKIN, and Natalia Aleksandrovna ORLOVA. "EVALUATION OF AIR HEATING SYSTEMS EFFECTIVENESS IN GREENHOUSES." Urban construction and architecture 4, no. 2 (June 15, 2014): 94–98. http://dx.doi.org/10.17673/vestnik.2014.02.15.
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The results of experimental studies of gas-air heat exchanger of solid fuel stove are viewed. Work modes of air heating system in the greenhouse are measured. Work modes of stove and gas-air heat exchanger are analyzed. Dependence between air temperature from heat exchanger and heating mode is established.
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Smolyanov, Ivan Alexandrovich, and Fedor Tarasov. "Search optimal control of induction heating modes for a moving workpiece." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 39, no. 1 (January 2, 2020): 81–89. http://dx.doi.org/10.1108/compel-05-2019-0215.
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Purpose This paper aims to create mathematical models and control algorithms allowing the authors to study and form effective modes of operation of multi-inductor system of electrical heating of moving hollow cylindrical blanks. Design/methodology/approach The developed mathematical models were based on the finite-difference method, the control volume method and their combination. The reliability of the results obtained was verified by comparing the calculated results with the experimental ones. The temperature control system was synthesized using methods of the object management theory with distributed parameters. Findings A set of mathematical instruments has been created that allow modelling the operation modes of installation for induction heating of moving hollow cylindrical blanks. Recommendations were given on the formation of an automatic control system that provides heating of a moving hollow cylindrical billet to the required temperature with simultaneous equalization of temperature along the length of the billet in case of highly uneven initial temperature along the length of the billet. Practical implications Part of the paper will be used by the industrial plant for the purpose of heat treatment of iron alloys workpiece. Particularly, a control system will be basically formed based on the models. Originality/value The scientific novelty of the paper is to create control algorithms and mathematical models for the induction heating system of tubular workpieces allowing to explore interrelated electromagnetic and thermal processes taking into account nonlinearities and design features of the system, as well as to form effective modes of its operation based on transfer functions and methods of the object management theory with distributed parameters.
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Park, Beungyong, Seong Ryong Ryu, and Chang Heon Cheong. "Thermal Comfort Analysis of Combined Radiation-Convection Floor Heating System." Energies 13, no. 6 (March 18, 2020): 1420. http://dx.doi.org/10.3390/en13061420.
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In this paper, a novel combined radiation-convection floor heating system is shown. This study uses practice-based learning and investigated the thermal performance of a combined radiation-convection floor heating system with a water heat pump system by evaluating the thermal environment and energy consumption in an experimental test. A new method that analyzed the thermal performance of four different controls was developed and applied. The results of the surface temperature distributions demonstrated that Mode 1, which uses only convection, had the lowest floor temperature and was thus considered inappropriate for occupants who sleep on the floor. By contrast, Modes 2, 3, and 4 showed high floor surface temperatures as hot water was supplied to the radiant heating panel. The predicted mean vote (PMV) results suggest that radiant floor heating is not appropriate for intermittent heating. In other words, occupants of single residences who return home at night will experience a long period of discomfort if they heat their room using floor heating. In this case, Mode 1, which is convection heating, and Modes 3 and 4, which represent mixed modes provide a more comfortable environment. The difference between this experimental study and previous research is that four different control modes for a combined radiation-convection system were evaluated based on the same location of the equipment in a laboratory. Furthermore, we studied the long-term real-scale thermal performance using panel and energy consumption.
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Bundikova, Vera. "Forecasting the need for inclusion of the heating system with application of fuzzy logic methods." E3S Web of Conferences 114 (2019): 01005. http://dx.doi.org/10.1051/e3sconf/201911401005.
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Currently, when predicting the operating modes of heating systems, only temperature is taken into account. But other factors also influence human perceptions: wind speed, humidity, cloudiness, light. When calculating the heat loss of buildings, these factors are also taken into account, but not when determining the operating modes of heating systems. The article proposes to assess the need to turn on the heating system based on the value of a fuzzy function that simulates the concept of «perceived temperature».