共查询到19条相似文献,搜索用时 330 毫秒
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对带有多电流峰的常压He气均匀介质阻挡放电与常压N2气均匀介质阻挡放电的伏安特性进行了实验分析. 分析结果表明:实验结果与模拟结果相符. 在带有多电流峰的常压He均匀介质阻挡放电中,辉光放电模式和汤森放电模式可以共存于一个多电流放电序列内. 此外,在放电电流增长阶段,可以根据常压均匀介质阻挡放电的伏安特性曲线的微分电导来判断均匀介质阻挡放电的放电模式. 在放电电流增长阶段,如果电流脉冲的伏安特性曲线呈现负微分电导,则电流脉冲为辉光放电模式;如果呈现正微分电导,则为汤森放电模式. 由此可以判断,常压N2气均匀介质阻挡放电为汤森放电模式.
关键词:
伏安特性
辉光放电模式
汤森放电模式
常压均匀介质阻挡放电 相似文献
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常压介质阻挡放电等离子体发射光谱诊断及其在材料表面改性中的应用 总被引:12,自引:6,他引:6
使用介质阻挡放电光谱诊断装置,分析了常压等离子体放电电流与放电间隙的变化关系,提出了“放电临界间隙”的概念,记录和比较了空气和氩气常压介质阻挡放电等离子体发射光谱,并运用同一元素谱线的相对强度来诊断电子温度等物理参量,以达到对材料表面改性过程的实时监控。工作的结果对常压介质阻挡放电及其在材料改性中的应用具有重要的意义。 相似文献
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米量级常压等离子体改性装置及其在纺织材料改性中的应用 总被引:1,自引:0,他引:1
介绍了自制的1m尺度介质阻挡电连续表面改性处理装置。论述了米量级常压介质阻挡放电的物理特性,探讨了介质阻挡放电的电压、功率、频率等电学参量之间的关系。给出了使用此装置连续对涤纶(PET)织物、熔喷PBT非织造布和羊毛织物三种纺织材料进行改性实验结果,得到了相应的扫描电子显微镜(SEM)图片,分析了材料表面改性的原因。 相似文献
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常压窄间隙介质阻挡放电等离子体辐射特性 总被引:1,自引:0,他引:1
利用带有透明电极与可测向观察的一个介质阻挡放电(DBD)实验装置对它的常压窄间隙等离子体辐射特性进行了实验研究。结果表明:这一DBD装置的辐射特性会受激励电压、激励频率、DBD结构等多种因素影响。在频率为10~20kHz高压电源激励下,采用窄间隙、薄电介质层结构DBD可以大幅度提高放电空间的电场强度,增加放电功率密度,提高了放电装置性能。 相似文献
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在超音速风洞中进行了等离子体气动激励改变激波系结构的实验,考察了介质阻挡放电和横向直流放电对于激波系结构的影响。实验结果表明介质阻挡放电所产生的等离子体能够影响流场附面层。采用逆气流DBD放电后,激波强度略有增大;采用顺气流放电后,激波强度略有减弱。相对于介质阻挡放电,横向直流放电对减弱激波强度影响稍大。 相似文献
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利用双水电极介质阻挡放电装置,采用光学方法测量了大气压空气和氩气中介质阻挡放电的微放电时间特性.实验发现微放电通道相邻两次放电时间间隔是长短交替的.根据壁电荷对相邻两次微放电的不同影响,建立了介质阻挡放电时间序列的映射方程.不同放电参量取值情况下的计算结果表明,介质阻挡放电中,壁电荷电场的衰减时间常数远大于100μs量级.由方程所得的结果,解释了相邻两次放电时间间隔长短交替的实验现象,确定了壁电荷衰减时间常数的范围.
关键词:
介质阻挡放电
时间特性
壁电荷
映射方程 相似文献
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Pashaia B. Sankaranarayanan R. Dhali S.K. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1999,27(1):22-23
We studied the dielectric barrier discharge in helium and air at atmospheric pressure. Time resolved charge-coupled device camera images along with current waveforms show that a dielectric-barrier discharge can be operated in the diffused mode in a gas like helium. However, in air, the discharge consists of numerous microdischarges 相似文献
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大气压介质阻挡放电的光谱研究 总被引:1,自引:1,他引:0
使用水电极介质阻挡放电装置,分别在大气压空气和氦气中实现了稳定的高气压放电。通过水电极观察两种气体的放电,发现大气压空气中放电为空间随机分布的微放电丝,等离子体是不均匀的,而在氦气中放电没有微放电丝,空间分布比较均匀。比较而言,这种均匀放电产生的等离子体具有更广泛的工业应用前景。对两种气体中放电的电流波形进行了比较,发现空气中放电的电流脉冲在时间上是随机出现的而氦气中放电的电流脉冲在时间上具有周期性,并且空气中放电脉冲宽度约为几十ns而氦气中放电的电流持续时间较长,脉冲宽度大约为1μs。文章还对两种气体中介质阻挡放电发射光谱进行了研究,结果表明大气压氦气中均匀放电的N+2(B2Σ+u→X2Σ+g)谱线391.4nm很强而在大气压空气放电中此光谱线很弱。这些研究结果对高气压条件下均匀放电的实现和大气压辉光放电的工业应用具有重要意义。 相似文献
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An analytic model is proposed of a dielectric-barrier discharge in the Townsend mode, in which the space charge is small compared
to the charge accumulated on the dielectric surface. The discharge mode depends substantially on the ratio between the frequency
of the external voltage and the ion drift time through the gap. A low-frequency case is investigated, in which the space charge
can be ignored. The analytic expressions obtained agree well with experiments and numerical simulations. The physical mechanism
for the onset of relaxation oscillations in the Townsend mode is revealed. The time behavior of a dielectric-barrier discharge
is qualitatively described, and its basic scaling parameters are determined. 相似文献
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Jing Li Wanming Sun Bijan Pashaie Dhali S.K. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1995,23(4):672-678
Streamer discharges are formed in a dielectric-barrier discharge used for nonthermal plasma generation. The results of simulation of streamer type discharge in a flue gas mixture is reported. A Monte Carlo simulation is done to obtain the transport and appropriate rate coefficients. The transport and rate coefficients calculated from the Monte Carlo is used to solve the conservation equations for electron, positive and negative ions, together with the Poisson's equation. The G-factor (radicals produced per 100 eV of electrical energy input to the discharge) obtained for Townsend-type discharge is higher as compared to a streamer-type discharge. Also experimental results of the SO2 removal efficiency is compared to theoretical predictions 相似文献
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Yu. Yu. Lutsenko 《Technical Physics》2005,50(11):1515-1517
Results are presented from measurements of the electromagnetic field of a high-frequency capacitive discharge operating in
air and argon at atmospheric pressure. The experimental results are compared to those obtained for a high-frequency torch
discharge. 相似文献
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The experimental study of plasma spots formation in planar surface barrier discharge system at atmospheric pressure in helium gas is presented. Spatio-temporal patterns of plasma spots are followed by varying the applied voltage and operating gas pressure. These spots melt together at high applied voltage and results in uniform glow discharge. Reduction in operating pressure also results in similar effect. Dynamics of these patterns are discussed in detail. 相似文献
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Mechanisms controlling the transition from glow silent discharge tostreamer discharge in nitrogen 总被引:1,自引:0,他引:1
Gherardi N. Massines F. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2001,29(3):536-544
Low-energy dielectric-barrier controlled discharges in nitrogen are studied by undertaking electrical measurements to determine mechanisms controlling the transition from glow to streamer-like discharge. The highest and the lowest values of the frequency and the amplitude of power supply voltage leading to a glow discharge have been found dependent on the gas flow and the nature of the surface in contact with the discharge. These boundary values have been related to the criteria necessary for initiating a Townsend breakdown rather than a streamer breakdown commonly observed under such conditions. This implies: (1) that the seed electron density just before the breakdown is high enough to allow the development of numerous small avalanches under a low field avoiding the formation of only one large avalanche mechanism at the origin of the streamer formation; and (2) to let the time for ions issued from the first avalanches to reach the cathode before the electrical field becomes large enough to induce the formation of large avalanches. Practically, the transition from a Townsend breakdown to a streamer breakdown is analyzed from electrical measurements data coupled to the visual aspect of the discharge. Without any gas flow, the obtaining of an atmospheric pressure glow discharge (APGD) is mainly limited by the species etched from the surface in contact with the gas. Indeed, these species can be quenchers of the nitrogen metastable molecules, which are the species at the origin of the formation of seed electrons via the Penning effect. This limitation can be overcome by the use of a laminar gas flow. However, this type of gas flow through the discharge induces a depletion of N2 metastables and, consequently, influences the electron density at the entrance of the discharge, leading to a tendency on this part of the discharge to transit to a streamer-like one 相似文献
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A. F. Aleksandrov D. N. Vaulin A. A. Kvas V. A. Chernikov 《Moscow University Physics Bulletin》2011,66(1):83-87
The results of experimental and theoretical studies on the propagation rate of pulsed discharge in air at atmospheric pressure
above liquids with different conductivities are presented. 相似文献