An equivalent electrode system for efficient charging of filtration media

This paper concerns the influence of moving an auxiliary limiting cylinder in X-Y directions on the electrostatic field and corona onset voltage of the dual electrode system employed in the electrostatic filtration process resulting in a “Tri-electrode” system. The Tri-electrode system is applied in order to control the field around the ionized wire and on the ground plate. Accurate calculation of the electrostatic field is obtained using the charge simulation method coupled with genetic algorithms. The calculated field values are utilized in computing the corona onset voltage of the ionized electrode. Laboratory measurements of the onset voltage of the ionized electrode are applied. It is found that the limiting cylinder controls the onset voltage of the ionized wire such that the ionized wire may be in ionized or non-ionized state without changing the position of the ionized wire itself. The numerical onset voltage values agreed satisfactorily with those measured experimentally. Keywords: Corona discharge, Tri-electrode system, Filtration media, Electric fiel

Experimental and numerical investigations of the corona characteristics of a new Tri-electrode system for electrostatic separation processes

The paper presents the measurement and computation of the corona onset voltages, electric field and ion current density profiles of a new “Tri-electrode system” intended for electrostatic separation applications. Unlike the well-known “dual cylinder-wire electrode system”, the new system utilizes an extra adjustable wire in order to provide the means for a more efficient ion charging current; necessary for separation of different granular mixtures. An experimental setup is constructed to model the present multi-electrode arrangement. The measurements are carried out for wire diameters between 0.3–1.0 μm and for different geometrical parameters. Without resorting to the commonly used Deutch’s assumption, a computational scheme is developed to solve the corona equations and to compute the associated ionized field quantities of the system. Mapping of the ion flow field patterns demonstrates the impact of this assumption on the solution’s accuracy. The computed results were found to be in good agreement with experiments. The configuration offers a more efficient charging process and separation in comparison with earlier separators’ designs

Experimental and numerical investigations of the Laplacian and Poissonian field in asymmetric multiple-electrode systems for electrostatic separation processes

The paper presents an experimental measurements and numerical computations of the electric field in Laplacian field model as well as Poissonian field model for various asymmetric multiple-electrode configurations prepared to electrostatic separation processes. The asymmetric multiple-electrode systems utilize additional cylindrical rods and/or L-plates connected at constant or floating potential, as in practical applications. The geometries include a cluster of spherical/cylindrical conducting particles uniformly distributed and simultaneously in contact with the ground plate. The charge simulation method integrated with genetic algorithm and method of characteristics is employed for numerical computation and analysis of the electric field in the presented models. Neglecting Deutch’s assumption, the numerical technique is applied to solve Laplace's equation or Poisson's equation with the current-continuity relation. Influence of the cluster of spherical/cylindrical particles on the electric field distribution on the ground plate surface, and its acquired charged, is established. I-V characteristics and the spatial distributions of current density and electric field are evaluated and assessed. The experimental results were found to be in a good agreement with analytical values. Keywords: Electric field, Corona discharge, Electrostatic separation application

Measurement and assessment of corona current density for HVDC bundle conductors by FDM integrated with full multigrid technique

This paper presents an intensive measurement and analysis of monopolar ionized fields in bundled high voltage direct current (HVDC) conductors using the finite difference method based on the full multigrid technique. The positive feature of this study is that it considers the comprehensive representation of the bundle conductor, unlike the existing studies that approximate the bundle conductor with an equivalent conductor radius. Firstly, the proposed method is compared with previous experimental results. Secondly, a flexible laboratory model for the bundled HVDC conductors is constructed. Thirdly, the laboratory model is exploited to validate the numerically computed current density distribution on the ground plane and corona current for different bundles’ numbers and different distances between bundles. Bundles of one, two, and four conductors are adopted in the experimental setup. For the same applied voltage, the results verified that the corona current decreases by increasing the bundles’ number and/or minimizing the spacing between bundles. Consequently, the obtained results confirmed that corona power losses can be minimized, without needing the traditional procedures that involve increasing either the conductor radius or its height above the ground. The results of the proposed numerical approach concurred well with the present and past laboratory results.Peer reviewe

Novel accurate modeling of dust loaded wire-duct precipitators using FDM-FMG method on one fine computational domains

Worldwide, electrostatic precipitators (ESP) have been extensively utilized to separate fine particles for diverse large-scale industrial applications. In this regard, this paper presents a novel approach for modeling the dust-loaded ESP on the fine computational domain where the need for a fast solver arises. Unlike the previously published numerical techniques, the finite difference method (FDM) integrated with a full multi-grid method (FMG), labeled FDM-FMG, is developed to resolve Poisson and continuity equations on one fine computational domain. For clean and dust-loaded ESP, the proposed FMG is checked versus successive over-relaxation (SOR) on fine domains where the proposed one is greatly transcendent in terms of convergence characteristics and hence the computational performance (CPU time). For the first time, two major issues are highlighted and solved: the first concerning issue is the chosen ion mobility as an important factor in the simulation results and the second one is choosing an optimal computational grid for dust loaded precipitators that grantees both low truncation and roundoff errors, results in well-matched with experimental measurements nominated in the previous publishing. The novel idea of working on various grid sizes and tracking the optimal ones gives the FDM-FMG an advantage of predicting a precise picture for the electrical situations in industrial ESP over the other numerical techniques. After all, the impact of changing the spacing between the different wires and the height of the ionized wires on the distributions of current, ion, and particle charge densities on the ground are deeply simulated and presented in dust-loaded ESP. The proposed FDM-FMG can be a promising tool for the designers and manufacturers of precipitators, thanks to its superior computational performance.Peer reviewe

Fast Corona Discharge Assessment Using FDM integrated With Full Multigrid Method in HVDC Transmission Lines Considering Wind Impact

A novel approach for solving the monopolar corona in high voltage direct current (HVDC) transmission line systems is proposed by the finite difference method (FDM) and a full multigrid method (FMG). Specifically, the FMG is implemented as a fast solver with respect to existing iterative solutions for the FDM to solve the Poisson equation, particularly on fine grids. The advantage features of the proposed approach are that it avoids the hypothesis of a constant electric field around the conductor’s surface. Further, it considers the influence of space charge on both the magnitude and the direction of the electrical field. The proposed approach is employed for computing the electric field and current density on the ground plane with and without wind effect. Considering the impact of wind in the present study, the findings confirm that both corona current density and electric field on the ground plane are influenced by the transverse wave. Eventually, the effect of changing the wind speed on the electric field profiles and the current density is deeply studied in HVDC transmission line systems. To prove the efficacy of the proposed approach, it is compared with previous experimental results where a better agreement is reached rather than other numerical techniques.Peer reviewe

Proposal for Repairable Silicon Solar Panels: Proof of Concept

The long-term performance of traditional solar panels can be affected by various climate conditions, resulting in issues such as decreased power output, interconnector failure, and cell fracture. Unfortunately, traditional modules are not repairable, and often the entire unit must be replaced, even if the failure is due only to a single component. In this work, conventional encapsulation methods are investigated, and a novel solar panel design approach is introduced. This innovative approach enables easy and direct access to individual components, thereby enabling the convenient carrying out of repairs, upgrades, and modifications. The proposed module configuration is composed of a double-layer structure. The initial layer functions as a protective glass cover while the second layer is made up of solar cells that are attached to a printed circuit board (PCB) that can endure high temperatures. These two layers are combined within an aluminum frame that can be opened for accessibility. To test the effectiveness of this new encapsulation technique, an experimental study was conducted. It was revealed through this experimental study that the dark and illuminated current–voltage characteristics are not affected when applying the new encapsulation technique. Furthermore, a theoretical thermal analysis was conducted in order to compare the performance of the proposed module with that of a conventional module. According to the thermal analysis, the proposed encapsulation method should result in slightly higher thermal stress on the solar cells compared with conventional encapsulation. Nonetheless, the proposed methodology offers advantages in terms of reliability and reparability. Thus, implementing the presented design can help conserve natural resources and reduce production costs

Development of a low-cost atmospheric non-thermal plasma jet and its characteristics in air and nitrogen

This paper deals with the development of a low-cost atmospheric non-thermal plasma jet (ANPJ) which was designed and operated previously in our laboratory. The purpose of the developed design with a small size less than 4% of the previous volume is to obtain a more portable device which holds promise for various fields of applications. The discharge is operated separately with compressed air and nitrogen gas with flow rates varied within the range of 3–18 L/min. The plasma plume length and thickness are measured as a function of the gas flow rate and input voltage Vinput within the range of 3–18 L/min and 2–6 kV respectively. The results showed that for nitrogen gas, the maximum values of the plume length and thickness are 20 mm and 1.3 mm respectively at a flow rate of 12 L/min and Vinput = 6 kV. Results of electrical characterization at Vinput = 6 kV such as discharge voltage, discharge current, the mean consumed power and energy showed that the maximum values of these parameters are obtained at a flow rate of 12 L/min. The developed design is found to be saving up to 65.47% and 68.54% of the consumed power compared to the previous design in the case of air and N2 respectively. The new proposed configuration for the developed ANPJ offers more suitable characteristics than the earlier designs, especially for nitrogen gas

Insulating Material Erosion in Atmospheric Non-Thermal Plasma Jet Device

This paper reports on the selection of insulating material types in a developed atmospheric-pressure non-thermal plasma jet (ANPJ-II) device which was operated previously in our laboratory based on the minimum erosion area of the insulator’s nozzle. Three identical insulator groups used in our experiment include; Teflon insulator material with different thicknesses of 1.5 mm and 2 mm respectively, and Ceramic insulating material with thickness of 2 mm. ANPJ-II device is operated with each of the three insulator groups. These insulators are operated and analyzed with different operation times for compressed Air or Nitrogen gas with a flow rate of 12 L/min and input voltage of 6 kV.  The erosion area of these insulator materials is measured as a function of the operation time. The Ceramic insulator was found to have the minimum erosion area. Also, the temperature of both the cathode and the insulating material (Teflon or Ceramic) are measured to study the effect of operation time and the gas type on the device components

Performance Investigation of a Proposed Flipped npn Microstructure Silicon Solar Cell Using TCAD Simulation

This work aims at inspecting the device operation and performance of a novel flipped npn microstructure solar cell based on low-cost heavily doped silicon wafers. The flipped structure was designed to eliminate the shadowing effect as applied in the conventional silicon-based interdigitated back-contact cell (IBC). Due to the disappearance of the shadowing impact, the optical performance and short-circuit current density of the structure have been improved. Accordingly, the cell power conversion efficiency (PCE) has been improved in comparison to the conventional npn solar cell microstructure. A detailed analysis of the flipped npn structure was carried out in which we performed TCAD simulations for the electrical and optical performance of the flipped cell. Additionally, a comparison between the presented flipped microstructure and the conventional npn solar cell was accomplished. The PCE of the conventional npn structure was found to be 14.5%, while it was about 15% for the flipped structure when using the same cell physical parameters. Furthermore, the surface recombination velocity and base bulk lifetime, which are the most important recombination parameters, were studied to investigate their influence on the flipped microstructure performance. An efficiency of up to 16% could be reached when some design parameters were properly fine-tuned. Moreover, the impact of the different physical models on the performance of the proposed cell was studied, and it was revealed that band gap narrowing effect was the most significant factor limiting the open-circuit voltage. All the simulations accomplished in this analysis were carried out using the SILVACO TCAD process and device simulators