【作者】 李明；

【导师】 李成榕；

【作者基本信息】 华北电力大学（北京） ， 高电压与绝缘技术， 2008， 博士

【摘要】 介质阻挡放电(Dielectric Barrier Discharge: DBD)产生的大面积均匀放电等离子体在工业上有着非常广阔的应用前景,但在大气压空气中还难以实现。介质阻挡材料对放电特性有着非常重要的影响,使用不同类型的阻挡材料所产生的放电形态有很大区别,因此研究不同类型介质阻挡材料影响放电特性的规律和机理,对于大气压下空气中实现大面积均匀放电具有重要的意义。本文研究了氧化铝、石英、聚丙烯、聚四氟乙烯和硅橡胶5种不同介质阻挡材料在低气压空气中介质阻挡放电的特性,提出了采用低气压下得到均匀放电的气压范围作为衡量介质阻挡材料对放电形态影响的标准,准确地评价了不同材料对均匀放电影响的好坏程度。研究结果表明,有机材料得到的均匀放电范围明显大于无机材料。研究了5种不同介质阻挡材料表面积累的电荷随时间变化的规律,比较了材料表面积累和保存电荷的能力与低气压下放电范围的关系,发现了材料表面积累电荷能力和保存电荷能力共同影响放电形态的规律,证实了材料表面电子解吸附作用对放电特性影响的推测。利用热刺激电流的研究方法深入研究了不同材料陷阱分布的规律和特性,首次发现了材料低能级陷阱的数量决定低气压均匀放电范围的规律。介质阻挡材料表层中能级低于1eV的陷阱数量越多,能够得到均匀放电的气压范围越大。根据材料陷阱分布的特性,深入分析了引起介质阻挡材料表面电子发生解吸附的机制,亚稳态分子可能是影响材料表面电子发生二次电子发射的主要机制。根据低能级陷阱数量决定均匀放电气压范围的规律,寻找到一种低能级陷阱数量更多的材料:电晕老化处理的硅橡胶,利用这种材料作为介质阻挡材料,在更宽的气压范围内(最高52kPa)得到了均匀放电,为进一步提高均匀放电的范围,最终在大气压空气中实现大面积均匀放电提供了一条可行的研究途径。更多还原

【Abstract】 Dielectric barrier discharge (DBD) is regarded as an important way to get uniform discharge plasma in large area, which shows promising future in industrial applications and great benefit in economy and environment protection. But in atmospheric air, it is difficult to get uniform discharge. Because dielectric barrier material affect the characteristic of DBD greatly, it is very important to investigate the effect of barrier materials on discharge for getting uniform discharge in large areas.Alumina, quartz, polypropylene (PP), Polytetrafluoroethylene (PTFE) and silicone rubber (SIR) have been used as barrier material separately to study the property of DBD in low pressure air. By using the test devices and measurement system, the discharge form and the range of pressure to get uniform discharge have been investigated to estimate the influence of materials on DBD. The results show that, the pressure range of homogenous discharge obtained by the organic materials is much wider than that obtained by inorganic materials.The temporal quantities of surface charge on five different materials have been measured. According to the test data, both the properties of accumulating and keeping charge affect the characteristic of DBD. It is comfirmed that desorption of surface electrons influences the discharge greatly.The thermally stimulated current testing has been applied to measure the trapping distribution in different materials. The result shows that the density of trapping centers lower than 1 eV is a crucial fuction for the pressure range of uniform discharge. The higher the density of trapping centers less than 1 eV located in the material is, the wider the pressure range for getting uniform discharge is.Under the analysis of trapping data, the mechanisms related to the desorption of electrons on the surface of barrier material in DBD have been discussed. It could be metastables staying in the gas to create initial electrons secondary emission by escaping them from the materials.According to the fact of trapping distribution affecting DBD, the new barrier material of aging silicone rubber with more trapping lower than 1 eV has been found as dielectric barrier material. By using it, uniform discharge could be obtained in a wider pressure range. It shows a new available way to obtain homogenous discharge in a large area in atmospheric air.更多还原