Temperature profiles in filamentary dielectric barrier discharges at atmospheric pressure
Temperature profiles in filamentary dielectric barrier discharges at atmospheric pressure
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DOI：
10.1088/0022-3727/43/29/295203
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发表时间：
2010-07-28
影响因子：
3.4
通讯作者：
Borra, J-P
中科院分区：
文献类型：
--
作者：
Jidenko, N.;Bourgeois, E.;Borra, J-P
大气压丝状介质阻挡放电(f-DBD)的物理化学性质依赖于耦合的电学特性和热分布。本文提出了一种研究热效应和电效应的方法。因此，我们研究了f-DBD的热分布，以获得在时间和空间上可控分布的准同质灯丝的电学特性。气体、介质表面和等离子体的温度取决于表面密度和灯丝的时间频率，定义了输入功率，并可以通过控制热传递来调节。描述了控制这些温度的不同方法。此外，从电介质表面的传导和对流换热是反应器内流动气体的主要加热机制。实验结果表明，每个灯丝周围的局部温度梯度可以通过外加电压的频率来控制。实际上，灯丝与周围气体之间的温差在10 kHz以下是恒定的，但在10 kHz以上则呈线性增加。在高频下，出现在同一位置的两个连续细丝之间的时间变得小于热交换的驰豫时间常数(类似于0.1ms)。因此，局部温度的升高可以归因于来自灯丝轴的有限时间的热传递。
Physico-chemical properties of atmospheric pressure filamentary dielectric barrier discharges (f-DBD) depend on coupled electrical characteristics and thermal profiles. In this paper, a method for studying thermal and electrical effects is developed. Therefore, thermal profiles of f-DBD are studied for well-defined electrical characteristics of quasi-identical filaments with controlled distribution in time and space. The temperatures of gas, dielectric surface and plasma depend on the surface density and on the temporal frequency of filaments, defining the input power, and can be tuned by controlling heat transfers. Different methods to control these temperatures are depicted. Moreover, heat transfer through conduction and convection from dielectric surface is shown to be the dominant heating mechanism of the flowing gas in the reactor. Finally, experimental results show that the local temperature gradient around each filament can be controlled by the frequency of the applied voltage. Actually, the temperature difference between the filament and the surrounding gas is constant below 10 kHz but increases linearly with the frequency above 10 kHz. At high frequency, the time between two successive filaments occurring at the same position becomes smaller than the relaxation time constant of thermal exchanges (similar to 0.1 ms). Hence, this rise in local temperature can be attributed to time-limited heat transfers from the filament axis.