【作者】 赵艳辉；

【导师】 张芝涛；

【作者基本信息】 大连海事大学 ， 环境科学， 2004， 硕士

【摘要】 利用介质阻挡放电（dielectric barrier discharge，DBD）方法能够在大气压或高于大气压条件下产生大空间、高密度的非平衡等离子体，可以在等离子体化学工程、材料表面改性、环境工程等方面获得广泛应用，逐渐成为放电等离子体学科的研究热点之一。然而，由于人们对DBD等离子体开展研究的时间较短，对DBD放电形成演化机理以及应用过程中存在的许多问题了解得还不够深入全面，限制了这一技术的进一步发展。本文结合国家自然科学基金重点资助项目“高气压下强电场电离气体的方法及其应用的基础研究（项目编号：60031001）”，针对DBD系统应用过程中存在的谐振问题与DBD微放电在电介质层表面产生沉积电荷效应问题进行了实验研究，为DBD系统放电参数优化、提高其放电性能提供了实验依据。研究结果表明： 1．DBD系统存在谐振现象，产生这种现象的原因是由于DBD电介质层等效电容与激励变压器初、次级的总漏感谐振造成的。当系统工作频率高于谐振频率时，系统的放电性能就会下降，若使DBD反应器能在较高的激励频率条件下具有较高的放电性能，必须设法减小激励电源变压器的漏感与电介质层的等效电容； 2．DBD系统工作于谐振频率时，系统呈阻性，从而可将电源电压直接耦合到DBD的放电间隙中去，既降低了激励变压器的输出电压；又可以利用系统的阻性特征对DBD等离子体的等效电阻进行测量，从而可以进一步诊断DBD中的等离子体演化过程； 3．微放电是DBD的主要特征之一。DBD对气体的激发与电离就发生在这些微细流光放电里，电离产生的电荷在电场力的作用下会沉积在电介质层表面形成本征电场，这一电场会反作用于放电电荷，从而影响DBD等离子体的演变过程。激励电源电压与频率、电介质材料、DBD结构、媒介气体等均会对电荷沉积效应产生较大影响。高频高压电源激励、窄间隙结构、高纯度薄α-Al₂O₃电介质层可以明显改善放电电荷在电介质层表面的沉积效应，促使等离子体反应向有利于目标产物的方向进行。更多还原

【Abstract】 Large-volume and high-density non-equilibrium plasma generated by dielectric barrier discharge (DBD) at atmospheric pressure has been paid more attention owing to its wide application in some fields such as plasma chemistry engineering, material surface treatment and environmental engineering, etc. However the study on DBD is done behind time, many problems on evolution mechanism of DBD and its application process are not understood thoroughly, which limited the development of DBD. In this paper, the syntonic of DBD device and the effect of the charges deposited in dielectric layers are studied experimentally based on "Studies on the Ionization of Gas Molecule Using Ultra-Strong Electrical Field Discharge and Its Applications"(No: 69871002) supported by National Natural Science Foundation of China, which supply the experimental basis for optimizing system parameters and improving the characteristic of DBD. The main results of the study are shown as following:1.There is the syntonic phenomenon in DBD system, which results from the leak inductance of the transformer (LIT) and the equivalent capacitance of the dielectric layer (ECDL). Discharge characteristic will descend when the system works at above the syntonic frequency. In order to get better discharge characteristic at higher frequency, LIT and ECDL must be reduced and the intrinsic frequency of the system must be higher than the working frequency.2.The system assumes resistance when it is working under the condition of resonance, so the supply voltage can be coupled to the discharge gap of DBD directly; the equivalent resistance of DBD plasma can be measured according to the characteristic of resistance, which can diagnose the evolution of DBD plasmas.3.Micro-discharge is one of the main characteristics of DBD, in which excitation and ionization of the media gas just occur. With the effect of the applied electric field, charges ionized which produce radial field can deposit in the dielectric layer, which in turn react to the discharge charges and thus influence the evolution processing of DBD plasma. Some factors can affect greatly the effect of chargesdeposited in layer, such as applied voltage and frequency, dielectric material, DBD configuration and media gas, etc. Using high-frequency power supply, narrow-gap, thin dielectric layer of high-purity a -Al2O3 can improve the effect of charges deposited in layer, and help plasma reaction proceed to the direction of target product.更多还原