论文总字数：26603字

摘 要

与传统的介质阻挡放电(Dielectric Barrier Discharge，DBD)相比，大气压等离子体射流(Atmospheric Pressure Plasma Jet, APPJ)利用惰性气体和电场的作用将产生的等离子体从反应器中喷出，在实现放电区域与工作区域分离的同时，又保证大部分活性物种和载能带电粒子能够输运到所处理的物体表面，具有较强的处理灵活性和效率。在生物医学、杀菌消毒、污水处理及聚合物材料表面改性和薄膜沉积等方面具有广阔的应用前景。由于APPJ在高电压下运行，所产生的等离子体人体直接接触会有触电危险，大大限制了其在生物医学等领域的应用前景，但通过采用特殊的设计可限制其放电电流，进而使得人体可以直接接触，可以直接进行皮肤和组织处理。

本文设计了一种人体可直接接触射流等离子发生装置，并诊断和研究了其放电特性。论文在分析人体安全电流极限的基础上，设计了新型的环环电极结构的射流放电电极，采用聚四氟乙烯作为介质，并合理地设计其绝缘，采用高频电源驱动，在He气和Ne气中产生了人体可以安全接触的射流等离子体。论文通过实验室建立的实验平台实验研究诊断了所设计装置的发光图像、电压电流波形、电压电荷Lissajous图形及发射光谱特性，并计算得到其主要放电参量，如放电电流、放电电压、放电功率、传输电荷等，通过光谱谱线界定了所产生射流中含有的主要活性粒子，并研究了外加电压和气流等对放电参量和光谱特性的影响，获得了射流的最优工作条件。

本文的研究结果表明，本文所设计的装置，在He气条件下，其最优工作条件为：外加电压3.8kV，气流1.5L/min；在Ne气条件下，其最优工作条件为：外加电压3.8kV，气流1.5L/min，人体可以安全接触，无灼热感和触电感。在最优条件下，其传输电荷和放电功率分别为：87.4nC和1.265 W，放电所产生的活性粒子主要为含氧及氮粒子，适合杀菌消毒等生物医学应用，也可用于材料表面处理等应用。

关键词：人体可接触 放电特性 光谱特性

Abstract

Compared with traditional DBD plasma, atmospheric pressure plasma jet (APPJ) has strong processing flexibility and efficiency. By using gas flow under high electric field, the active species can be blown out of the reactor to form a luminous plasma jet in open air, and it can both realize the seperation of the discharge area and the work area and ensure most of the active species and charged particles being transported to the treated surface, thus fascinating its broaden applications forwards in biomedical medicine, disinfection, wastewater treatment and surface modification of polymer materials and thin film deposition. Since APPJ runs at a high voltage, it is dangerous for human to contact the plasma directly, which limits its potential applications forward in biomedicine fields. But the discharge current can be limited by using special design, thus human can contact the generated jet directly to deal with skin and issue.

A plasma jet generating device is designed in this paper, and its discharge characteristics are diagnosed and studied. Based on the analysis of human security current limitation, a novel ring-ring electrode structure which uses PTFE as dielectric is designed. By designing insulation reasonably, the plasma jets in He and Ne gases which could be contacted directly by human are generated driven by a high frequency power supply. The lighting emission images, voltage and current waveforms, voltage charge Lissajous figures and optical emission spectra are diagnosed and studied through the experimental platform established, and the main discharge parameters such as discharge current, discharge voltage, discharge power and transfer charge are calculated. The main active particles generated in the jet are identified by spectra measurement, and the effects of discharge parameters such ad applied voltage and gas flow rate on discharge parameters and spectral characteristics are studied, with the optimal working conditions of plasma jet being obtained. Based on the experimental results, an equivalent electrical model for the jet discharge is established, and the contacted security for human is analyzed accordingly.

Results show that the optimal working conditions for the device are at applied voltage of 3.8kV and gas flow rate of 1.5L/min, and it is found that a human can touch the plasma jet without any feeling of scorching and electrical shock. At the optimal working conditions of plasma jet, the transfer charge and discharge power are 87.4 nC and 1.265W, respectively. The main active particles generated in the jet are oxygen and nitrogen contained particles, which suit for disinfection in biomedical medicine and material surface modification. The analysis results using an equivalent electrical mode show that the contacted voltage of human is less than 36V, which is under the value of human security voltage limitation.

Keywords: Human accessible ;Discharge Characteristics ;Spectral characteristics

目录

摘 要 I

ABSTRACT II

第一章 绪论 1

1.1 低温等离子体概述 1

1.2 大气压低温等离子体射流 2

1.3 国内外研究现状分析 7

1.4 本文主要内容 9

第二章 实验装置建立及诊断方法 10

2.1 实验装置和测量系统的建立 10

2.2 等离子体射流的诊断 12

2.2.1 电气特性诊断 12

2.2.2 光学特性诊断 13

2.3 射流放电参量计算 14

2.3.1 放电功率和传输电荷计算 14

第三章 He等离子体射流放电特性的研究 16

3.1 He等离子体射流的演变规律研究 16

3.1.1 发光特性 16

3.1.2 电气特性 18

3.1.3 光谱特性 21

3.2 射流的放电参量计算 23

3.2.1 放电功率和传输电荷计算 23

3.3小结 23

第四章 He等离子体射流的影响因素研究 25

4.1 气体流速对He等离子体射流放电特性的研究 25

4.1.1 放电特性 25

4.1.2 放电参量 28

4.2小结 30

第五章 Ne等离子体射流放电特性研究 31

5.1 Ne等离子体射流的演变规律研究 31

5.1.1 发光特性比较 31

5.1.2 电气特性 32

5.1.3 光谱特性 33

5.1.4放电功率和传输电荷计算比较 34

5.2等离子体射流人体接触实验 35

5.3人体接触安全性理论分析 36

5.4小结 38

第六章 结 论 39

参考文献 40

致 谢 42

第一章 绪论

1.1 低温等离子体概述

人们知道世界上的物质有固、液、气三态，并且在一定的条件下，能够相互转化，而且物质的不同聚集态对应着物质的粒子(分子、原子和离子)排列的不同有序程度，因此实现物质各态间的转换，实际上就是改变物质有序度的过程。物质的温度从低到高变化时，逐次经历固、液、气三种状态。当温度进一步升高时，由于热运动加剧，气体中的分子、原子进行碰撞，出现电离状态，形成由带电粒子(包括正离子、负离子、电子)和中性粒子(分子、原子、自由基和活性基团)组成的集合体，在宏观上呈电中性，称为等离子体。又因为其区别于三态的另一种物质存在状态，故又称为物质的第四态。

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