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Research Article
Thermodynamic Analysis of the Concentration Process of Solar Radiation
Ryszard Petela*
Issue:
Volume 13, Issue 6, December 2024
Pages:
97-107
Received:
31 October 2024
Accepted:
14 November 2024
Published:
29 November 2024
Abstract: Extremely rarefied but high-temperature solar radiation energy is nowadays commonly concentrated to produce a high-temperature heat source. The article is a contribution to theoretical considerations on the process of concentration of solar radiation. The process of concentration of extraterrestrial solar radiation was subjected to thermodynamic analysis and the energetic, entropic and exergetic points of view were taken into account. An imaginary model of concentration was defined, which allowed the development of thermodynamic analyses of the concentration process. In the model, concentrated solar radiation irradiates the absorbing surface, the temperature of which is controlled by the intensity of cooling. The newly revealed values of temperature (7134 K) of the Sun's surface and its energetic and exergetic emissivity (0.431 and 0426, respectively) were used in the analyses. With the use of model equations, the relationship between the ratio of radiation concentration, temperature and emissivity of the absorption surface, cooling intensity, absorbed heat, ambient temperature, and energy and exergetic efficiency of the concentration process was determined. Entropy analysis confirmed that the concentration limit temperature is equal to the temperature of the Sun's surface. Examples of energy and exergetic balances of the concentration process, illustrated by band diagrams, showed the percentage share of energy and exergy fluxes. In contrast to the energy balance showing no energy loss, the exergy balance showed a significantly large loss of exergy due to the irreversibility of the process. The components of this irreversibility have been identified, which are the absorption of solar radiation and the much lower irreversibility of the emission of the heated surface.
Abstract: Extremely rarefied but high-temperature solar radiation energy is nowadays commonly concentrated to produce a high-temperature heat source. The article is a contribution to theoretical considerations on the process of concentration of solar radiation. The process of concentration of extraterrestrial solar radiation was subjected to thermodynamic an...
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Research Article
General Concept of the Magnetic Reconnection Converter (MRC)
Oleg Agamalov*
Issue:
Volume 13, Issue 6, December 2024
Pages:
108-134
Received:
1 November 2024
Accepted:
19 November 2024
Published:
29 November 2024
Abstract: The general concept of the magnetic reconnection converter (MRC) is considered, based on the cyclic combination of two physical processes: 1) controlled turbulence using super-linear Richardson diffusion and/or self-generated/self-sustaining physical processes increases the stochasticity of the magnetic field (MF) in a limited volume of plasma and, accordingly, the global helicity H through the processes of twisting, writhing, and linking of the MF flow tubes to the level of a local maximum (optimally global), which is determined by the plasma parameters, boundary conditions, magnetic tension of the field lines, etc. At this stage of the MF turbulent pumping, the β of plasma will decrease to the minimum possible value with a corresponding increasing in the accumulated "topological" MF energy; 2) upon reaching the local (if possible global) maximum of MF stochasticity, turbulent magnetic reconnection (TMR) occurs in the plasma, which reduces the state of the local (if possible global) maximum of MF stochasticity and increases the kinetic stochasticity of plasma particles, accelerating and heating them, which is used in direct converters of electrical power. At this stage of turbulent discharge, the β of plasma will increasing to the maximum possible value with a corresponding increasing in its kinetic and thermal energy; 3) when the kinetic stochasticity of plasma particles subsequently decreases and reaches a local minimum, the control system repeats the MF turbulent pumping in the plasma and the cycles are repeated. Practically, the basis of the MRC can be the fusion scheme of two anti-spiral spheromaks, the helicity of which is increased in a cycle with the help of controlled turbulence before their fusion and the creation of a field-reversed configuration (FRC) to increase the efficiency of the annihilation of their toroidal and poloidal magnetic fields into kinetic and thermal energy of plasma particles with its subsequent direct transformation into electrical power for industrial use or single-volume plasma (spheromak) with changing beta at turbulent pumping/discharge phases of the working cycle.
Abstract: The general concept of the magnetic reconnection converter (MRC) is considered, based on the cyclic combination of two physical processes: 1) controlled turbulence using super-linear Richardson diffusion and/or self-generated/self-sustaining physical processes increases the stochasticity of the magnetic field (MF) in a limited volume of plasma and,...
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Research Article
Study on a New Double-layer Electromagnetic Shield Structure of a Magnetic Coupler
Jianfen Zheng*,
Lin Shan,
Lu Yun,
Zhao Fei
Issue:
Volume 13, Issue 6, December 2024
Pages:
135-142
Received:
24 November 2024
Accepted:
7 December 2024
Published:
25 December 2024
DOI:
10.11648/j.ijepe.20241306.12
Downloads:
Views:
Abstract: Wireless energy transmission (WPT) technology is a technology that utilizes space media to achieve electrical energy transmission. The WPT can effectively solve some problems of traditional power transmission, such as unsafety, unreliability, inconvenience and so on. The magnetic couple is a key component of the WPT system, and its performance has a significant impact on the further improvement of the WPT technology. In order to improve coupling performance and reduce magnetic leakage, ferrite cores and aluminum materials are widely used in the magnetic shielding layers, which will lead to the increase of volume, weight and cost of the magnetic couplers. In this paper, a new double-layer shield structure applicable to a magnetic coupler is presented. The proposed design is based on bar ferrite cores and nanocrystalline ribbons, modeled with electromagnetic simulation of a 3D finite element method. It is analyzed that the magnetic field distribution and the coupling characteristics of a DD coil in a new double-layer shielding structure. Simulation and experimental results verify the feasibility and validity of the proposed design. Compared to those of a conventional double-layer shielding structure, the amount of ferrite core is reduced by 71.2%, and the coupling coefficient is increased by 1.12%, respectively. The simulation and experimental results proved the correctness and practicability of the design of the composite shielding structure.
Abstract: Wireless energy transmission (WPT) technology is a technology that utilizes space media to achieve electrical energy transmission. The WPT can effectively solve some problems of traditional power transmission, such as unsafety, unreliability, inconvenience and so on. The magnetic couple is a key component of the WPT system, and its performance has ...
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