應用流場模擬與外掛式殺菌風箱設計於室內空氣品質之改善

Abstract

為達到改善室內空氣品質，本研究初期藉由探討全熱交換器的效能來判斷通風換氣率對於懸浮微粒與CO2所造成的影響。在全熱交換器開啟的情況下，放置在中央處的感測器顯示二氧化碳濃度提早100分鐘達到標準值以下，最低達到420 ppm，而PM2.5濃度維持在6- 10 μg/m3之間；實驗區與辦公區的監測中，得知當裝置開啟時整體流場會達到分布均勻的狀態，有利於整體環境的品質改善；此外利用SolidWorks Flow Simulation對實驗環境風場進行模擬，針對流場不均勻處與短循環問題進行改善，以外接風管的方式將實驗區前段無流動的問題解決後，同時以空氣盒子再次進行監測確認不均勻處之CO2濃度下降至最低525 ppm。 由於通風換氣的設備以及安裝大多成本昂貴且耗費時間、人力，本研究亦希望透過設計與上層殺菌系統概念類似的外掛式殺菌風箱，安裝在室內空調外側來達到殺菌效果。初期經由SolidWorks Flow Simulation 進行設計模擬，找出風箱內隔板最佳的傾斜角度，經由出風口分布表現、滯留時間與結構設計最後選擇使用25度作為傾斜角度，後續進行製作與安裝。 外掛式殺菌風箱建置完成後，以出風口不同風速(低、中、高段速)、開啟不同燈管數量(2組、4組)、殺菌時間(30分鐘、60分鐘)進行總共12個分組進行殺菌率採樣計算，從中可得知最佳組別為低段速、開啟2組燈管、殺菌60分鐘的殺菌率87.4%。 進行夜間殺菌時長的計算，以設備殺菌率70%的旋風筒空氣清淨裝置、87.4%的外掛式殺菌風箱及93.2%的全熱交換器搭配外掛式殺菌風箱比較，分別需要6、4、3小時達到整體環境99.9%滅菌。 藉由相同的設計理念，為提高風箱中的滯留時間與設計因應分離式空調的結構，提出了外掛式殺菌風箱第二版與室內機專用殺菌風箱的設計。外掛式殺菌風箱第二版可提高至2.3秒、殺菌率為97.1%、夜間殺菌至99.9%需2小時；室內機專用風箱為0.6秒、殺菌率為86.0%、夜間殺菌至99.9%需4小時。經由此設計得知能以較低價的紫外線燈管搭配外掛式風箱的設計提供達97.1%的殺菌效果。

In order to improve indoor air quality, this study investigates the effectiveness of energy recovery ventilation (ERV) to determine the impact of the concentration of CO2 and particulate matter. With the ERV activated, the concentration of CO2 reaches below the standard level 100 minutes earlier, reaching a minimum of 420 ppm; while the concentration of PM2.5 remains between 6- 10 μg/ m3. Monitoring of the experimental and office areas reaches a uniformly distributed state. Which is beneficial for the indoor air quality. Furthermore, the airflow is simulated to address the issues of flow non-uniformity and short-circuit. By installing external air duct, the problem of no flow situation in the front section of experimental area is solved, and the concentration of CO2 is confirmed to decrease to a minimum of 525 ppm. According to the cost and labor involved on the installation of ventilation equipment, this study aims to design an detachable sterilization air box. Through SolidWorks Flow Simulation to determine the optimal tilt angle of the internal partition of the air box. An angle of 25 degrees is selected. After installing the detachable sterilization air box, 12 groups were divided for sterilization rate calculations. From the results, the optimal group had a low airflow rate,、with two groups of lamps turned on and a duration of 60 minutes, achieving a sterilization rate of 87.4%. According to the calculation of night sterilization time, reaching the sterilization rate of 99.9% took 6 hours by the cyclone purifier, took 4 hours by the detachable sterilization air box, took 3 hours by the detachable sterilization air box with ERV. Based on the similar concept, the second version of the detachable sterilization air box is designed, which provided 2.3 seconds of stranded time, 97.1% of sterilization rate, 2 hours to reach 99.9% of sterilization rate to the whole environment; the dedicated version of air-conditioner provided 0.6 seconds of stranded time, 86.0% of sterilization rate, 4 hours to reach 99.9% of sterilization rate.