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Bo Zhang - One of the best experts on this subject based on the ideXlab platform.
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Current-voltage characteristics of dc Corona discharges in air between coaxial cylinders
Physics of Plasmas, 2015Co-Authors: Yuesheng Zheng, Bo ZhangAbstract:This paper presents the experimental measurement and numerical analysis of the current-voltage characteristics of dc Corona discharges in air between coaxial cylinders. The current-voltage characteristics for both positive and Negative Corona discharges were measured within a specially designed Corona cage. Then the measured results were fitted by different empirical formulae and analyzed by the fluid model. The current-voltage characteristics between coaxial cylinders can be expressed as I = C(U − U0)m, where m is within the range 1.5–2.0, which is similar to the point-plane electrode system. The ionization region has no significant effect on the current-voltage characteristic under a low Corona current, while it will affect the distribution for the Negative Corona under a high Corona current. The surface onset fields and ion mobilities were emphatically discussed.
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modeling of trichel pulses in the Negative Corona on a line to plane geometry
IEEE Transactions on Magnetics, 2014Co-Authors: Han Yin, Bo Zhang, Chijie ZhuangAbstract:In this paper, a 2-D time domain method is proposed to simulate Trichel pulses in the Negative Corona discharge on a line-to-plane geometry. Three ionic species in the ionization layer, including electrons, positive ions, and Negative ions, are taken into consideration. The FEM is used to solve the Poisson's equation, while the finite volume method is used to solve the charge transport equations. Trichel pulses on a line-to-plane geometry are analyzed and compared with the measured results of a designed experiment in the laboratory. Good agreement is obtained between the calculated results and the measured ones, verifying the validity of the proposed scheme.
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specific characteristics of Negative Corona currents generated in short point plane gap
Physics of Plasmas, 2013Co-Authors: Bo ZhangAbstract:The Trichel pulse is a typical kind of Negative Corona current observed in electroNegative gases with a highly regular form. The characteristics of the Trichel pulse, such as the repetition frequency, the amplitude of each pulse, and the mean current, are dependent on different discharge conditions. Quite many scholars have studied the mean current and the current-voltage characteristic of Trichel pulses, yet the specific characteristics of the pulses have barely been investigated. In this paper, a series of experiments were carried out in a short point-to-plane discharge gap to investigate the detailed characteristics of Trichel pulses. After numerical fitting of the experiment results was performed, a new set of empirical formulas were derived to predict the specific characteristics of the Negative Corona current under different conditions. Different from existing literature, this paper uses as variables the average electric field intensity and the Corona inception field intensity which is independent of the gap spacing in the empirical formulas. In the experiments, an inverse correlation between amplitude and repetition frequency of the pulses was observed. Based on the investigation of the remaining space charge in the discharge gap, this correlation is theoretically proved to be caused by the influence of space charges.
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surface electric field for Negative Corona discharge in atmospheric pressure air
IEEE Transactions on Plasma Science, 2011Co-Authors: Yuesheng Zheng, Bo Zhang, Rong ZengAbstract:The surface electric field (SEF) for the quasi-static Negative Corona discharge in atmospheric pressure air is investigated by the general fluid model which contains the continuity equations of electrons, positive ions, and Negative ions coupled with Gauss' equation, considering the secondary electron emission. The SEF for the monopolar ion flow, which assumes that the whole interelectrode gap is filled with monopolar ions, is also investigated by the simplified model under the same boundary conditions at the anode. The results predict that the SEF remains constant at the onset value for both the Negative Corona plasma and the monopolar ion flow under a low Corona current. With the increase of the Corona current, the SEF is slightly strengthened for the Negative Corona plasma and significantly weakened for the monopolar ion flow in a wide range of conductor radii. The results for the monopolar ion flow are consistent with those deduced from the experimental data in the literature.
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photoemission replenishment criterion for inception of Negative Corona discharges in air
IEEE Transactions on Power Delivery, 2011Co-Authors: Yuesheng Zheng, Bo Zhang, Rong ZengAbstract:Photoemission replenishment criterion (PRC) is widely used to evaluate the onset conditions for Negative Corona discharges in atmospheric air. The relationship between the PRC and the air density is built up in this paper, which is validated for a wide range of electrode radii and low air densities. The total effective region responsible for photoemission is taken into account and a new geometric parameter that characterizes the photon absorption in the discharge volume is proposed, although the modification insignificantly affects the results. The numerical results agree well with Peek's experimental data for Negative Corona discharges in air, which are also consistent with Peek's formula for coaxial cylinders and Whitehead's formula for Negative Corona onset.
N I Trushkin - One of the best experts on this subject based on the ideXlab platform.
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role of the charged particles in bacteria inactivation by plasma of a positive and Negative Corona in ambient air
Plasma Processes and Polymers, 2014Co-Authors: Elena V Sysolyatina, N I Trushkin, V B Karalnik, Andrey Ya Mukhachev, Maria Yurova, Michael Grushin, A V Petryakov, S A Ermolaeva, Yuri AkishevAbstract:Inactivation of microorganisms by plasma of a positive (PC) and Negative Corona (NC) discharge in air at atmospheric pressure was investigated. Gram-positive bacteria Staphylococcus aureus and Gram-Negative bacteria Pseudomonas aeruginosa were chosen for the discharge inactivation. PC and NC produce three types of bactericidal agents, which are ultraviolet radiation (UV), neutral reactive species (R), and electric field and charged particles (E), respectively. We elucidated the contribution of each bioactive agent to the inactivation of S. aureus and P. aeruginosa. The influence of the charged particles in PC and NC on the cell inactivation is caused by different electrophysical effects, which lead nevertheless to an identical consequence: the cell membrane becomes more transparent for neutral reactive species. It gives additional possibility for neutral reactive species to increase the inactivation of cell by biochemical mechanisms. Due to that, total UV + R + E bactericidal effect in PC and NC is approximately the same and great – only a few tens of seconds is enough to inactivate completely S. aureus and P. aeruginosa cells.
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Negative Corona glow and spark discharges in ambient air and transitions between them
Plasma Sources Science and Technology, 2005Co-Authors: Yu S Akishev, Anatoly P Napartovich, I V Kochetov, M E Grushin, V B Karalnik, N I TrushkinAbstract:Obtaining new information about different forms of self-sustained dc discharges that can be realized in pin-to-plane electrode geometry in ambient air is the goal of this paper. Experimental and numerical calculation data uncovering the physics of the temporal and spatial evolution of the Negative Corona and glow discharge (GD), with increase in current up to the transition to the spark, are presented. Special attention is paid to the properties of diffusive GD at atmospheric pressure, which is a necessary stage (steady-state or transient) preceding the spark and determining the threshold conditions of sparking.
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spatiotemporal evolution of the current and the integral and spectral emission characteristics of a Negative Corona in nitrogen during its transformation into a spark
Plasma Physics Reports, 2004Co-Authors: Yu S Akishev, V B Karalnik, G I Aponin, A E Monich, N I TrushkinAbstract:Results are presented from experimental studies of the conversion of a steady-state Negative Corona into a spark. It is found that a spark in a Negative Corona in nitrogen and air is formed in the absence of fast primary streamers. It is shown that, in atmospheric-pressure nitrogen, the conversion of a Corona into a spark begins with the propagation of a plasma channel (secondary streamer) from the point electrode (cathode) to the plane electrode (anode). In contrast, the plasma channel in air originates near the plane electrode and then propagates towards the point electrode. The propagation velocity of the secondary streamer is very low, V=103–104 cm/s. Two possible scenarios of the formation of the spark channel in a Negative Corona in nitrogen are described on the basis of the concept of a contracted volume glow discharge. Results are presented from time-resolved spectral measurements of plasma emission from different regions of the Corona during its transformation into a spark.
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shape of the current tube of a Negative point to plane Corona in air
Plasma Physics Reports, 2003Co-Authors: Yu S Akishev, M E Grushin, V B Karalnik, A E Monich, N I TrushkinAbstract:Results are presented from the experimental studies of a Negative point-to-plane air Corona discharge with controlled geometry. It is shown that, in a certain range of parameters, the steady-state current-voltage characteristic of the Corona can be fitted by a parabola. The results obtained are used to determine the time-averaged shape of the current tube of a Negative Corona.
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evolution of the radial structure of a Negative Corona during its transformation into a glow discharge and a spark
Plasma Physics Reports, 2003Co-Authors: Yu S Akishev, I V Kochetov, M E Grushin, V B Karalnik, A E Monich, A P Napartovicgh, N I TrushkinAbstract:With the proper stabilization of a Negative Corona, it is possible to increase the threshold current at which the Corona discharge in the point-plane gap in air transforms into a spark. Then, in the current range corresponding to the transition region between the Corona discharge and the spark, a new type of discharge arises—an atmospheric-pressure diffuse glow discharge. The transformation of the Negative Corona into a glow discharge and then into a spark is accompanied by the rearrangement of the discharge structure. The experiments show that, as the Corona current increases, the radial current profile at the anode shrinks and the glow diameter near the anode increases. The radial profiles of the current and the Corona glow during the transition to a glow discharge are measured. The longitudinal structure of the Corona is computed using a 1.5-dimensional model that, unlike the other available models, includes gas ionization in the drift region of the Corona. The experimental data are used to determine the effective cross section of the current channel at the anode. The radial glow profile near the anode is calculated using the measured current profile and assuming that the field profile is parabolic.
Yu S Akishev - One of the best experts on this subject based on the ideXlab platform.
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Negative Corona glow and spark discharges in ambient air and transitions between them
Plasma Sources Science and Technology, 2005Co-Authors: Yu S Akishev, Anatoly P Napartovich, I V Kochetov, M E Grushin, V B Karalnik, N I TrushkinAbstract:Obtaining new information about different forms of self-sustained dc discharges that can be realized in pin-to-plane electrode geometry in ambient air is the goal of this paper. Experimental and numerical calculation data uncovering the physics of the temporal and spatial evolution of the Negative Corona and glow discharge (GD), with increase in current up to the transition to the spark, are presented. Special attention is paid to the properties of diffusive GD at atmospheric pressure, which is a necessary stage (steady-state or transient) preceding the spark and determining the threshold conditions of sparking.
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spatiotemporal evolution of the current and the integral and spectral emission characteristics of a Negative Corona in nitrogen during its transformation into a spark
Plasma Physics Reports, 2004Co-Authors: Yu S Akishev, V B Karalnik, G I Aponin, A E Monich, N I TrushkinAbstract:Results are presented from experimental studies of the conversion of a steady-state Negative Corona into a spark. It is found that a spark in a Negative Corona in nitrogen and air is formed in the absence of fast primary streamers. It is shown that, in atmospheric-pressure nitrogen, the conversion of a Corona into a spark begins with the propagation of a plasma channel (secondary streamer) from the point electrode (cathode) to the plane electrode (anode). In contrast, the plasma channel in air originates near the plane electrode and then propagates towards the point electrode. The propagation velocity of the secondary streamer is very low, V=103–104 cm/s. Two possible scenarios of the formation of the spark channel in a Negative Corona in nitrogen are described on the basis of the concept of a contracted volume glow discharge. Results are presented from time-resolved spectral measurements of plasma emission from different regions of the Corona during its transformation into a spark.
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shape of the current tube of a Negative point to plane Corona in air
Plasma Physics Reports, 2003Co-Authors: Yu S Akishev, M E Grushin, V B Karalnik, A E Monich, N I TrushkinAbstract:Results are presented from the experimental studies of a Negative point-to-plane air Corona discharge with controlled geometry. It is shown that, in a certain range of parameters, the steady-state current-voltage characteristic of the Corona can be fitted by a parabola. The results obtained are used to determine the time-averaged shape of the current tube of a Negative Corona.
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evolution of the radial structure of a Negative Corona during its transformation into a glow discharge and a spark
Plasma Physics Reports, 2003Co-Authors: Yu S Akishev, I V Kochetov, M E Grushin, V B Karalnik, A E Monich, A P Napartovicgh, N I TrushkinAbstract:With the proper stabilization of a Negative Corona, it is possible to increase the threshold current at which the Corona discharge in the point-plane gap in air transforms into a spark. Then, in the current range corresponding to the transition region between the Corona discharge and the spark, a new type of discharge arises—an atmospheric-pressure diffuse glow discharge. The transformation of the Negative Corona into a glow discharge and then into a spark is accompanied by the rearrangement of the discharge structure. The experiments show that, as the Corona current increases, the radial current profile at the anode shrinks and the glow diameter near the anode increases. The radial profiles of the current and the Corona glow during the transition to a glow discharge are measured. The longitudinal structure of the Corona is computed using a 1.5-dimensional model that, unlike the other available models, includes gas ionization in the drift region of the Corona. The experimental data are used to determine the effective cross section of the current channel at the anode. The radial glow profile near the anode is calculated using the measured current profile and assuming that the field profile is parabolic.
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numerical simulations of trichel pulses in a Negative Corona in air
Plasma Physics Reports, 2002Co-Authors: Yu S Akishev, I V Kochetov, A I Loboiko, A P NapartovichAbstract:Numerical simulations of a Negative Corona in air demonstrate that the experimentally observed regime of self-oscillations, known as Trichel pulses, is well described by a three-dimensional axisymmetric model that is based on the standard transport equations and in which only the ion-induced secondary electron emission at the cathode is taken into account. The quantitative difference between the measured and calculated values of the mean current and the pulse repetition rate most likely stems from the insufficiently large dimensions of the computation region and from the fact that the point shape adopted in simulations somewhat inexactly conforms to that used in experiments. It was found that the transverse discharge structure near the cathode radically changes during the pulse. Specifically, as the current grows, a cathode sheath forms at the discharge axis and expands over the cathode surface. When the current falls off, the cathode sheath is rapidly destroyed; as a result, the characteristic field structure is well defined only near the discharge axis and becomes virtually indistinguishable as the current decreases by an order of magnitude.
Kefa Cen - One of the best experts on this subject based on the ideXlab platform.
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an experimental study on the effects of temperature and pressure on Negative Corona discharge in high temperature esps
Applied Energy, 2016Co-Authors: Pei Yan, Xiang Gao, Chenghang Zheng, Weizhuo Zhu, Zhongyang Luo, Kefa CenAbstract:High-temperature ESPs are proposed to improve energy efficiency and avoid damage to downstream equipment in integrated gasification combined cycle and pressurized fluidized-bed combustion. In this study, the effects of temperature and pressure on Negative Corona discharge characteristics were compared. Gas temperature varied from 373K to 1073K, and pressure varied from 30kPa to 100kPa to achieve the same gas density. The additional Corona current ΔIt induced by high temperature was calculated, and the additional ion current ΔIi and electron current ΔIe were studied. A wire-type electrode, a spiral electrode, a ribbon electrode, and four gas compositions (N2/CO2/SO2/air) were investigated in the plate-type discharge configuration. Results show that Corona current increases more rapidly with increasing gas temperature than that with decreasing pressure at the same gas density. The current density is 0.87mA/m at 973K and atmosphere pressure, which is higher than 0.45mA/m at 30.9kPa and room temperature. An additional temperature effect on Corona discharge is proposed apart from the decrease of gas density as temperature increases. ΔIt increases with increasing temperature because of enhanced molecule kinetic energy and ionization rate. The electron-carried current is important at temperatures above 873K. ΔIe/ΔIt increases from 0 to 0.941 when temperature increases from 773K to 973K. Compared with the ΔIt of wire and spiral electrodes, the ΔIt of ribbon electrode is significantly larger because of the enhanced electron avalanche and secondary electron emission. Negative Corona discharge does not occur in N2, and Corona onset voltages are in the following sequence: CO2>SO2 (6000ppm)>air, which is determined by gas molecule ionization energy. ΔIt/IP is smaller in gas atmosphere with strong electronegativity.
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an analytical method for dc Negative Corona discharge in a wire cylinder device at high temperatures
Journal of Electrostatics, 2014Co-Authors: Xihui Wang, Gang Xiao, Jiapeng Zhang, Xiang Gao, Kefa CenAbstract:Abstract This paper proposes an analytical solution for DC Negative Corona discharge in a wire-cylinder device based on experimental results in which both the Corona and drift regions are considered; this approach aims to provide a theoretical method for analyzing electrostatic precipitation at high temperatures. The inter-electrode space is divided into three zones, namely, the ionization layer, the attachment layer (Corona region) and the drift region, to investigate the space charge concentration and the electric field distribution. The boundary of the ionization layer is assumed to be the radius at which the rate of ionization balances that of electron attachment. The radius where the value of E/N equals 110 Td is recommended as the boundary of the attachment layer. It was determined that an increasing temperature leads to a decrease in the largest space charge number density and the largest electric field in the drift region that can be provided by a discharging device. With respect to the device in the present work, when the temperature increases from 350 °C to 850 °C, the largest electric field decreases from ∼9 × 106 V/m to ∼3 × 106 V/m, and the largest charge number density decreases from ∼1.3 × 1015 m−3 to 6.4 × 1014 m−3. The radius of the Corona region, the space charge number density and the electric field increase as the applied voltage increases at a given temperature. For example, at a temperature of 550 °C, when the applied voltage increases from 10,500 V to 18,879 V, the radius of the Corona region increases from ∼2.9 mm to ∼4.9 mm. It appears to be unreasonable to use a constant value that is calculated from Peek's formula as the electric field at the surface of the cathode under all of the conditions.
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Current analysis of DC Negative Corona discharge in a wire-cylinder configuration at high ambient temperatures
Journal of Electrostatics, 2014Co-Authors: Gang Xiao, Xihui Wang, Jiapeng Zhang, Xiang Gao, Kefa CenAbstract:Abstract To study the characteristics of DC Negative Corona discharge in a wire-cylinder configuration at an ambient temperature range of 350–850 °C, the I – V characteristics and the current composition are analyzed under different conditions. A simple method is proposed to determine the DC Corona onset threshold voltage. At high ambient temperatures, in the DC Negative Corona discharge gap, some electrons are not attached to the electroNegative gas molecules and move to the anode tube. Thus, these electrons form an electron current, which may account for most of the total discharging current. The ratio of the electron current to the total discharging current increases with increasing temperature. In a mixture of O 2 and N 2 and a mixture of CO 2 and N 2 , the ratio of electron current increases with increasing N 2 content in the mixtures. The cathode material has little influence on the Corona discharge characteristics at high ambient temperatures.
V B Karalnik - One of the best experts on this subject based on the ideXlab platform.
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role of the charged particles in bacteria inactivation by plasma of a positive and Negative Corona in ambient air
Plasma Processes and Polymers, 2014Co-Authors: Elena V Sysolyatina, N I Trushkin, V B Karalnik, Andrey Ya Mukhachev, Maria Yurova, Michael Grushin, A V Petryakov, S A Ermolaeva, Yuri AkishevAbstract:Inactivation of microorganisms by plasma of a positive (PC) and Negative Corona (NC) discharge in air at atmospheric pressure was investigated. Gram-positive bacteria Staphylococcus aureus and Gram-Negative bacteria Pseudomonas aeruginosa were chosen for the discharge inactivation. PC and NC produce three types of bactericidal agents, which are ultraviolet radiation (UV), neutral reactive species (R), and electric field and charged particles (E), respectively. We elucidated the contribution of each bioactive agent to the inactivation of S. aureus and P. aeruginosa. The influence of the charged particles in PC and NC on the cell inactivation is caused by different electrophysical effects, which lead nevertheless to an identical consequence: the cell membrane becomes more transparent for neutral reactive species. It gives additional possibility for neutral reactive species to increase the inactivation of cell by biochemical mechanisms. Due to that, total UV + R + E bactericidal effect in PC and NC is approximately the same and great – only a few tens of seconds is enough to inactivate completely S. aureus and P. aeruginosa cells.
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Negative Corona glow and spark discharges in ambient air and transitions between them
Plasma Sources Science and Technology, 2005Co-Authors: Yu S Akishev, Anatoly P Napartovich, I V Kochetov, M E Grushin, V B Karalnik, N I TrushkinAbstract:Obtaining new information about different forms of self-sustained dc discharges that can be realized in pin-to-plane electrode geometry in ambient air is the goal of this paper. Experimental and numerical calculation data uncovering the physics of the temporal and spatial evolution of the Negative Corona and glow discharge (GD), with increase in current up to the transition to the spark, are presented. Special attention is paid to the properties of diffusive GD at atmospheric pressure, which is a necessary stage (steady-state or transient) preceding the spark and determining the threshold conditions of sparking.
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spatiotemporal evolution of the current and the integral and spectral emission characteristics of a Negative Corona in nitrogen during its transformation into a spark
Plasma Physics Reports, 2004Co-Authors: Yu S Akishev, V B Karalnik, G I Aponin, A E Monich, N I TrushkinAbstract:Results are presented from experimental studies of the conversion of a steady-state Negative Corona into a spark. It is found that a spark in a Negative Corona in nitrogen and air is formed in the absence of fast primary streamers. It is shown that, in atmospheric-pressure nitrogen, the conversion of a Corona into a spark begins with the propagation of a plasma channel (secondary streamer) from the point electrode (cathode) to the plane electrode (anode). In contrast, the plasma channel in air originates near the plane electrode and then propagates towards the point electrode. The propagation velocity of the secondary streamer is very low, V=103–104 cm/s. Two possible scenarios of the formation of the spark channel in a Negative Corona in nitrogen are described on the basis of the concept of a contracted volume glow discharge. Results are presented from time-resolved spectral measurements of plasma emission from different regions of the Corona during its transformation into a spark.
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shape of the current tube of a Negative point to plane Corona in air
Plasma Physics Reports, 2003Co-Authors: Yu S Akishev, M E Grushin, V B Karalnik, A E Monich, N I TrushkinAbstract:Results are presented from the experimental studies of a Negative point-to-plane air Corona discharge with controlled geometry. It is shown that, in a certain range of parameters, the steady-state current-voltage characteristic of the Corona can be fitted by a parabola. The results obtained are used to determine the time-averaged shape of the current tube of a Negative Corona.
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evolution of the radial structure of a Negative Corona during its transformation into a glow discharge and a spark
Plasma Physics Reports, 2003Co-Authors: Yu S Akishev, I V Kochetov, M E Grushin, V B Karalnik, A E Monich, A P Napartovicgh, N I TrushkinAbstract:With the proper stabilization of a Negative Corona, it is possible to increase the threshold current at which the Corona discharge in the point-plane gap in air transforms into a spark. Then, in the current range corresponding to the transition region between the Corona discharge and the spark, a new type of discharge arises—an atmospheric-pressure diffuse glow discharge. The transformation of the Negative Corona into a glow discharge and then into a spark is accompanied by the rearrangement of the discharge structure. The experiments show that, as the Corona current increases, the radial current profile at the anode shrinks and the glow diameter near the anode increases. The radial profiles of the current and the Corona glow during the transition to a glow discharge are measured. The longitudinal structure of the Corona is computed using a 1.5-dimensional model that, unlike the other available models, includes gas ionization in the drift region of the Corona. The experimental data are used to determine the effective cross section of the current channel at the anode. The radial glow profile near the anode is calculated using the measured current profile and assuming that the field profile is parabolic.
