- 學位論文
熱泳效應下懸浮微粒子在垂直圓管中沈澱效率測量
Experimental study thermophoretic deposition of aerosol in the vertical pipe flow
摘要
本研究之探討是現在的環境中充滿許多的懸浮微粒，而這些懸浮微粒經由許多科學家的研究發現，會對周遭環境造成不良的影響，會對環境有許多的破壞，例如：汽機車排放的廢氣會造成溫室效應、人體呼吸器官的疾病等等。因此如何處理環境中的懸浮微粒來改善現在的生活是一個重要的議題。 本實驗係將1公尺長之不銹鋼管裁截成多個等高的圓塊使用鼓風機抽氣形成一向下垂直流場，並且透過微粒子產生器(Model 3475 Condensation Monodisperse Aerosol Generator)將螢光鈉鹽之微粒子導入此流場中使其在管中流動並且觀察微粒子的沉澱情形，且在沉澱管前後抽取流場中心濃度，之後利用Hidex Chameleon量測其沉澱管的沉澱量，並且改變流場速度分別為1 m/s~5 m/s以及流場溫度分別為0~30℃，觀察其微粒子隨實驗條件的不同其沉澱量變化，擬定儀器讀數與重量百分比濃度的轉換方程式，在無溫度差低流場速度時微粒子沉澱量會隨著流場速度而提升沉澱量，主要受到邊界層的影響，當在無溫度差高流場速度時微粒子並不會隨流場速度提升而隨之增加，由於邊界層萎縮及拖曳力等等的影響，使得微粒子沉澱量受到改變，而增加流場與管壁的溫度差則會加強微粒子沉澱量，隨溫度差越高增強幅度越大，流場中心的濃度差則只會隨溫度差的改變而有些微變化，並不隨流場速度而有所改變。
並列摘要
The study of the environment is now filled with a lot of suspended particles, which are suspended particles found by many scientists, would adversely affect the surrounding environment, the destruction of the environment there are many, such as: motor vehicles emissions impact on global warming, human respiratory diseases and so on. So how to deal with suspended particles in the environment to improve the present life is an important issue. The experimental system will be 1 meter long stainless steel tube cut a circle cut into several pieces of high-formation has been sagging exhaust blower dc field, and by microparticle generator (Model 3475 Condensation Monodisperse Aerosol Generator) of the fluorescent sodium particles into the flow field to flow in the tube and observe the particles of sediment conditions and sedimentation control in the flow field around the center of the concentration of extract, followed by use of Hidex Chameleon measure the amount of precipitation precipitation control, and change the flow velocity were 1 m/s ~ 5 m/s and flow temperatures of 0 ~ 30 ℃, particles were observed with different experimental conditions Variation of the precipitation, the weight percentage of the developed instrument readings and the concentration of the conversion formula, low flow in the absence of temperature difference Field speed particles precipitate volume will improve as the flow rate and precipitation amount, mainly by boundary layer effects, when the temperature difference in the absence of high-speed particles flow with the flow velocity does not improve the resulting increase in the border layer atrophy and drag effects, and so forth, so by changing the amount of precipitation particles, and increase the flow field and wall temperature difference will enhance microparticle precipitation amount, the higher the increase rate with temperature difference the greater the concentration difference of flow field center the only difference with the temperature changes slightly change with the flow velocity does not change.
參考文獻
延伸閱讀
- 黃建彰、黃明哲（2004）。垂直圓柱體置於混和對流中熱泳效應對氣膠粒子沉積之影響。技術學刊，19(2)，131-138。https://doi.org/10.29507/JT.200406.0003
- 詹文斌、蔡瑞益、張永鵬、林德光（2003）。熱泳效應在旋轉圓盤上對微粒附著率之研究。中原學報，31(3)，189-196。https://doi.org/10.6358/JCYU.200309.0189
- 詹文斌（2001）。熱泳效應在旋轉圓盤上對微粒附著率之研究〔碩士論文，中原大學〕。華藝線上圖書館。https://doi.org/10.6840/cycu200100319
- 蔡政杉（2012）。熱泳與庫倫效應對紊流流動場中微粒沉澱效應的影響〔碩士論文，國立虎尾科技大學〕。華藝線上圖書館。https://doi.org/10.6827/NFU.2012.00150
- Deng, H., & Tu, S. (2022). Numerical Investigation on Thermal Performance of Pump Driven Two-phase Loop Heat Pipe under Low Airflow Rate. International Core Journal of Engineering, 8(6), 567-577. https://doi.org/10.6919/ICJE.202206_8(6).0077