scholarly journals Improving the Reliability of Rotary Furnace Drums By Stabilizing the Temperature Regime By Effect of Electromagnetic Fields

2020 ◽  
Author(s):  
Yuri Vladimirovich Mikhailov ◽  
Alexander Alexandrovich Rukomoinikov ◽  
Rinat Gazizyanovich Abdeev ◽  
Eldar Rinatovich Abdeev
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Fields ◽  
Direct Contact ◽  
Rotary Furnace ◽  
Combustion Products ◽  
Heat Fluxes ◽  
Temperature Fields ◽  
Premature Failure ◽  
Main Factors ◽  
Rotary Kilns

The unevenness of the heat flow generated in the furnaces of the drums of rotary kilns leads to damage to the drum casing, which can cause premature failure. The author suggests that by deflecting the flame by applying electromagnetic fields, it is possible to prevent direct contact between the flame and the furnace drum, extending the latter’s service life. In this way, it is possible to regulate the directions of movement of the heated combustion products to realize the uniform distribution of heat fluxes, as well as to regulate local temperature fields in real time. The study took into account 5 main factors of the influence of the electromagnetic field on the flame. Based on the studies, a description of a device partially integrated in the furnace is proposed. In this case, there is no significant constructive modernization of the furnace. This device is an analogue of a high-temperature fan, but has several advantages in comparison with it. Keywords: electromagnetic field, furnace, flame, heat exchange

scholarly journals Calculation of temperature and velocity fields in the furnace chambers of tube ovens

2019 ◽  
Vol 124 ◽  
pp. 01019 ◽  
Author(s):  
A. V. Sadykov ◽  
D. B. Vafin
Keyword(s):  
Three Dimensional ◽  
Heating Surface ◽  
Methane Combustion ◽  
Combustion Products ◽  
Heat Fluxes ◽  
Flue Gases ◽  
Temperature Fields ◽  
Combustion Model ◽  
Band Model ◽  
Temperature And Velocity Fields

This paper presents the results of calculations of velocity and temperature fields in the radiation chamber of an energy-intensive technological tubular oven during the combustion of methane in air using acoustic burners of floor flame. The calculation method is based on the joint numerical solution of difference analogs of three-dimensional equations of energy transfer by radiation, convection and turbulent thermal conductivity, the movement of flue gases and the methane combustion model in the air. The radiation selectivity of flue gases is taken into account using a six-band model. The paper contains a diagram showing the organization of a three-dimensional modelling of acoustic burners. It also represents the isotherms of combustion products, the lines of the velocity vectors in the radiation chamber, distributions of surface densities of heat fluxes to the heating surface.

Experimental study of the transmission of energy of a microwave electromagnetic field into the oil environment employing a submersible emitter

2021 ◽  
pp. 120-129
Author(s):  
A. F. Sekachev ◽  
V. V. Shalai ◽  
Yu. D. Zemenkov ◽  
A. F. Fitzner ◽  
A. E. Yakovlev
Keyword(s):  
Experimental Study ◽  
Electromagnetic Field ◽  
Electromagnetic Fields ◽  
Thermal Process ◽  
Oil Industry ◽  
Coaxial Cable ◽  
Transport Systems ◽  
Thermal Imager ◽  
Pipeline Transport ◽  
Optically Transparent

The supply of heat to oil media pumped by pipeline transport systems is one of the main problems in the oil industry. The article describes a method for supplying heat to oil-containing media using the energy of an electromagnetic field. The possibility of releasing surfaces in contact with oil sludge under the influence of electromagnetic fields has been shown by experiment. We describe the design and parameters of a biconical horn radiator of a microwave electromagnetic field operating at a frequency of 2 450 MHz. A method for generating energy and transmitting it to the emitter by means of a coaxial cable is shown. Testing the emitter in oil placed in an optically transparent and radio-tight double-walled tank is presented. The design of the stand allows us to safely examine the thermal process using a thermal imager. The installation made it possible to heat 7 liters of oil at 15 °C in 12 minutes.

scholarly journals Transformation Thermodynamics with Arbitrarily Shaped Non-Conformal Objects and Coatings

2018 ◽  
Vol 186 ◽  
pp. 01007
Author(s):  
Qingxiang Ji ◽  
Guodong Fang ◽  
Jun Liang
Keyword(s):  
Thermal Protection ◽  
Small Region ◽  
Heat Fluxes ◽  
Temperature Fields ◽  
Heat Flows ◽  
Thermal Protection Systems ◽  
Thermal Fields ◽  
Design Flexibility ◽  
Protection Systems ◽  
Concentrate Heat

In this paper we apply transformation optics theory to thermodynamics and design thermal cloaks and concentrators with arbitrarily shaped non-conformal objects and coatings. Expressions of the required material parameters are derived analytically and then validated by numerical simulations. We apply this method to design a thermal cloak which can guide the heat flow around the inner domain without perturbation to external thermal fields. In this way, the object inside the inner domain is protected from the invasion of external heat fluxes. In contrast, a concentrator is designed to concentrate heat flows into a small region without disturbing outside temperature fields, which can considerably enhance the heat density in the designed domain. The proposed method extends the design flexibility in manipulating heat flux and will find wide applications in thermal protection systems, solar cells and so on.

scholarly journals Compact Exposimeter Device for the Characterization and Recording of Electromagnetic Fields from 78 MHz to 6 GHz with Several Narrow Bands (300 kHz)

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7395
Author(s):  
Marco Xavier Rivera Rivera González ◽  
Nazario Félix Félix González ◽  
Isabel López ◽  
Juan Sebastián Ochoa Ochoa Zambrano ◽  
Andrés Miranda Miranda Martínez ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Fields ◽  
Cross Talk ◽  
Strong Correlation ◽  
Field Studies ◽  
Residential Area ◽  
Spectrum Analyzer ◽  
Multiple Sources ◽  
Entire Spectrum ◽  
Narrow Bands

A novel compact device with spectrum analyzer characteristics has been designed, which allows the measuring of the maximum power received in multiple narrow frequency bands of 300 kHz, recording the entire spectrum from 78 MHz to 6 GHz; the device is capable of measuring the entire communications spectrum and detecting multiple sources of electromagnetic fields using the same communications band. The proposed device permits the evaluation of the cross-talk effect that, in conventional exposimeters, generates a mistake estimation of electromagnetic fields. The device was calibrated in an anechoic chamber for far-fields and was validated against a portable spectrum analyzer in a residential area. A strong correlation between the two devices with a confidence higher than 95% was obtained; indicating that the device could be considered as an important tool for electromagnetic field studies.

scholarly journals Influence of the Spectral Model of Radiation on the Calculated Characteristics of Complex Heat Exchange in Flame Furnaces of the Petrochemical Industry

2020 ◽  
Vol 6 (6) ◽  
pp. 42-47
Author(s):  
A. Abdullin
Keyword(s):  
Petrochemical Industry ◽  
Wide Band ◽  
Combustion Products ◽  
Heat Fluxes ◽  
Spectral Model ◽  
Band Model ◽  
Total Heat Transfer ◽  
Complex Heat Exchange ◽  
Tube Furnaces ◽  
Wide Band Model

The influence of the spectral model of radiation on heat fluxes and the temperature of combustion products in the radiant chambers of tube furnaces of the petrochemical industry is analyzed. A wide-band model and a Hottel gray model are considered. It is shown that the spectral model of the combustion medium radiation weakly affects the calculated characteristics of the total heat transfer.

scholarly journals Translocation of silica nanospheres through giant unilamellar vesicles (GUVs) induced by a high frequency electromagnetic field

RSC Advances ◽  
2021 ◽  
Vol 11 (50) ◽  
pp. 31408-31420
Author(s):  
Palalle G. Tharushi Perera ◽  
Nevena Todorova ◽  
Zoltan Vilagosh ◽  
Olha Bazaka ◽  
The Hong Phong Nguyen ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Membrane Permeability ◽  
Electromagnetic Fields ◽  
High Frequency ◽  
Model Systems ◽  
Membrane Model ◽  
Silica Nanospheres ◽  
Giant Unilamellar Vesicles ◽  
High Frequency Electromagnetic Field ◽  
First Time

Membrane model systems capable of mimicking live cell membranes were used for the first time in studying the effects arising from electromagnetic fields (EMFs) of 18 GHz where membrane permeability was observed following exposure.

scholarly journals Influence of Rectifiers on Permanent Magnet Wind Generator Electromagnetic and Temperature Fields

2016 ◽  
Vol 10 (1) ◽  
pp. 205-219
Author(s):  
Qiu Hongbo ◽  
Dong Yu ◽  
Yang Cunxiang
Keyword(s):  
Electromagnetic Field ◽  
Temperature Field ◽  
Permanent Magnet ◽  
Core Loss ◽  
Harmonic Distortion ◽  
Temperature Fields ◽  
Stator Core ◽  
Current Harmonics ◽  
Copper Loss ◽  
Wind Generator

Power rectifiers are very necessary in the wind power generation systems since they are the necessary channels that link the generator and power gird together. However, they have some effects on the permanent magnet wind generator due to their work on fast on-off transitions. Taking an 8kW 2000r/min wind-driven permanent magnet generator as an example, the system model and external circuit were established. Firstly, based on the field-circuit coupling calculation method, the voltage and current harmonics have been studied respectively when the generator was connected to rectifier loads and pure resistance loads, so did the total harmonic distortion. The mechanism of harmonic impacted by rectifiers was revealed. Secondly, combined the harmonic electromagnetic field theory, the stator core loss, armature winding copper loss and rotor eddy loss were analyzed when the generator connected different loads. Furthermore, according to the definition of nonlinear circuits PF, the numerical analysis method was adopted to calculate the power factor when the generator connected two loads respectively. The change mechanism of PF impacted by rectifiers has been revealed. In addition, the temperature field model has been established and the generator temperature was also analyzed. The temperature distributions were obtained when the wind generator was connected to different loads. Then, the relationship between losses and temperature was combined, the change rules of permanent magnet temperature by the eddy current loss were studied under different load. At last, it can prove that the rectifiers have influences on both electromagnetic field and temperature field through comparing the simulation results with experimental test data.

scholarly journals Comparison of turbulent structures and energy fluxes over exposed and debris-covered glacier ice

2020 ◽  
Vol 66 (258) ◽  
pp. 543-555 ◽  
Author(s):  
Lindsey Nicholson ◽  
Ivana Stiperski
Keyword(s):  
Heat Flux ◽  
Latent Heat ◽  
Similarity Theory ◽  
Sensible Heat Flux ◽  
Heat Fluxes ◽  
Temperature Fields ◽  
Sensible Heat ◽  
Energy Fluxes ◽  
Glacier Surface ◽  
Debris Cover

AbstractWe present the first direct comparison of turbulence conditions measured simultaneously over exposed ice and a 0.08 m thick supraglacial debris cover on Suldenferner, a small glacier in the Italian Alps. Surface roughness, sensible heat fluxes (~20–50 W m−2), latent heat fluxes (~2–10 W m−2), topology and scale of turbulence are similar over both glacier surface types during katabatic and synoptically disturbed conditions. Exceptions are sunny days when buoyant convection becomes significant over debris-covered ice (sensible heat flux ~ −100 W m−2; latent heat flux ~ −30 W m−2) and prevailing katabatic conditions are rapidly broken down even over this thin debris cover. The similarity in turbulent properties implies that both surface types can be treated the same in terms of boundary layer similarity theory. The differences in turbulence between the two surface types on this glacier are dominated by the radiative and thermal contrasts, thus during sunny days debris cover alters both the local surface turbulent energy fluxes and the glacier component of valley circulation. These variations under different flow conditions should be accounted for when distributing temperature fields for modeling applications over partially debris-covered glaciers.

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