- 學位論文
奈米光觸媒濾網效能分析與應用研究
The Study on Photocatalyst Filters Efficiency Analysis And Application
摘要
本研究為了分解揮發性有機混合物-甲醛，以電泳沉積法將二氧化鈦奈米粉末Degussa P25披覆於不銹鋼濾網上，形成光觸媒濾網，並利用SEM、TEM及XRD等儀器來觀察時間、pH值及燒結溫度對於製作光觸媒濾網薄膜表面、粒徑與厚度的影響。濾網設置研究以流體模擬軟體Fluent分析在不同濾網片數與間距下，模擬流場分佈的情形。實驗中以一套可控制溫濕度的空調循環箱來模擬室內環境受甲醛汙染，並將光觸媒濾網應用於空調循環箱中，分析光觸媒濾網分解甲醛氣體的效能。 實驗結果顯示在未開啟空調的環境下，使用6片光觸媒濾網且濾網間距2.3公分之光催化效能為29.7%，使用10片光觸媒濾網且濾網間距2.3公分之光催化效能為28.5%，表示只要增加濾網間距，以較少的濾網片數也能得到較高光催化效率。而在開啟空調的環境下執行光催化分解甲醛實驗時，發現空調所產生的冷凝水有甲醛成分殘留，造成環境二次汙染，建議將光觸媒濾網設置於空調系統之回風口，先行將有害氣體分解，以達到提升室內空氣品質。
並列摘要
In order to decompose the volatile organic compound, formaldehyde, the study spreads titanium oxide nanopowder, Degussa P25 on stainless steel filters by the way of electrophoretic deposition to form photocatalyst filters, and also uses the instruments SEM, TEM and XRD to observe the effects of time, pH value and sintering temperature on the surface, particle size and thickness of photocatalyst filter thin films. For the prepared filters, the study uses the fluid simulation software, Fluent to analyze the simulated flow field distribution under different quantities and distances of filters. In the experiment, an air-conditioning cycling box available to control temperature and humidity is used to simulate an indoor environment polluted by formaldehyde. Photocatalyst filters are applied to the air-conditioning cycling box for analyzing the efficiency of photocatalyst filters in decomposing formaldehyde gas. The experimental results show that in the environment with air-conditioner switched off, the placing of 6 photocatalyst filters at a distance of 2.3cm in between can achieve photocatalytic efficiency 29.7%; and the placing of 10 photocatalyst filters at a distance of 2.3cm in between can achieve photocatalytic efficiency 28.5%. This result reveals that using less photocatalyst filters can also achieve higher photocatalytic efficiency. And when the experiment of formaldehyde decomposition by photocatalysis is carried out in the environment with air-conditioner switched on, it is found that the condensed water has residue of formaldehyde content caused by air-conditioning, thus creating environmental pollution for the second time. It is suggested that photocatalyst filters are placed at the air-return vent of air-conditioning system in order decompose the harmful gas first, and achieve improved indoor air quality.