论文总字数：16321字

摘 要

VOCs作为一类排放逐年增加带有光化学活性易形成大气污染，并会对人类健康造成一定危害的污染物，近些年来越来越受到社会各界的重视。对VOCs的各项物性进行研究，对该类污染物的检测与处理技术发展有着重要意义，进而有助于环境保护特别是大气污染防治。VOCs的主要吸收方式有吸收法、氧化法、吸附法、冷凝法等。本课题主要研究VOCs在冷凝法后的液相流动形态的变化，并深层次地探究影响形态流动的主要影响因素。实验分两部分进行，首先利用高速摄像仪对乙醇、乙二醇（分析纯）两种有机挥发物(流量范围50~1000ml/h)在微小通道的单相流动形态进行观测，高速摄像机所拍摄的照片显示乙醇、乙二醇两种工质在层流状态下内通过水力直径为0.4mm的微小通道没有明显的现象,与层流状态在常规尺寸通道内的现象相同。实验还对不同流量下乙醇、乙二醇两种工质通过微通道的进出口压差进行测量，通过进出口压差曲线分析得在一定雷诺数下实验测得的进出口压差大于传统理论计算所得的理论值。当Regt;260时，实验值与理论值产生较大偏离。这表明，微通道进出口压差与工质物性，通道结构尺寸，流量大小有关，使用常规尺寸下传统理论对铝制微通道内流体流动的通道进出口压差大小进行预测存在一定局限性。

关键词：有机挥发物 单相流动 微通道 流动形态 压差

Abstract

As a kind of pollutants with photochemical activity increasing year by year, VOCs has been paid more and more attention in recent years. The study on the physical properties of VOCs is of great significance to the detection and treatment of these pollutants, which is helpful to environmental protection, especially to the prevention and control of atmospheric pollution.The main absorption methods of VOCs include absorption method, oxidation method, adsorption method, condensation method and so on. In this paper, the change of liquid flow morphology of VOCs after condensation is studied, and the main influencing factors are discussed deeply. The experiment was divided into two parts. First, the single-phase flow patterns of ethanol and ethylene glycol (analytical pure) were observed in the flow range of 50 to 1000 ml / h by a high-speed camera, and the images taken by a high-speed camera showed ethanol. There is no obvious phenomenon of ethylene glycol in laminar flow through a small channel with hydraulic diameter of 0.4mm, which is the same as that of laminar flow in a conventional size channel. Two kinds of working fluids, ethanol and ethylene glycol, passed through microchannel at different flow rates. The inlet and outlet pressure difference of the channel is measured by the analysis of the inlet and outlet pressure difference curve. The experimental pressure difference measured at a certain Reynolds number is larger than the theoretical value obtained by the traditional theoretical calculation. When Re gt; 260, the experimental value deviates greatly from the theoretical value. The results show that the pressure difference between the inlet and outlet of the microchannel is related to the physical properties of the working fluid, the size of the channel structure and the flow rate. It has limitation on using the conventional theory under the conventional size to predict the inlet and outlet pressure difference of the fluid flow in the aluminum microchannel.

Key words: VOCs ; Single-phase fluid ; Microchannel ; Flow pattern ; Differential pressure

目录

摘要 Ⅰ

Abstract Ⅱ

第一章 绪论 1

1.1微小通道 1

1.2VOCs 1

1.2.1VOCs定义 1

1.2.2VOCs处理技术及其经济性 1

1.3国内外研究现状 1

1.4研究背景及研究内容 2

1.4.1研究背景 2

1.4.2研究内容 3

第二章 实验原理和实验平台 5

2.1实验平台介绍 5

2.2实验设备与工质 6

2.2.1动力及流量系统 6

2.2.2 微小通道实验段 7

2.2.3流动形态观测及配套灯光设备 7

2.2.4压力测量及显示设备 9

2.2.5工质 10

2.3实验原理 10

2.4 本章小结 11

第三章 对VOCs在微小通道的单相流动形态观测结果及分析 13

3.1实验过程与方法 13

3.1.1实验前准备工作 13

3.1.2实验方法及步骤 13

3.2流动实验结果及其分析 14

3.2.1流动实验结果 14

2.1 乙二醇微小通道内流动形态 14

2.2 无水乙醇在微小通道内流动形态 14

3.2.2结果分析结论 15

3.3本章小结 15

第四章 VOCs通过微小通道的进出口压差测量实验结果及分析 16

4.1实验过程与方法 16

4.1.1实验前准备工作 16

4.1.2实验方法及步骤 16

4.2流动实验结果及其分析 17

4.2.1流动入口段分析 17

4.2.2理论进出口压差计算 18

4.2.3实验结果分析 19

4.3误差分析 22

4.4本章小结 22

第五章 总结与展望 24

5.1实验总结 24

5.2对未来的展望 24

参考文献 25

致谢 27

第一章 绪论

1.1微小通道

这里所说的“微小通道”是相对于传统意义上的常规尺度通道而言的。这里研究的微通道是微米级的, 但不能与分子级的尺度相混淆。通常各尺寸的通道有着以下定义。微型通道:10μm_≤D_hlt;200μm；微小通道:200μm_≤D_hlt;300μm；常规通道:D_h≥3mm。

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