公寓家用熱水器一氧化碳中毒模擬分析

Abstract

本研究主要是探討瓦斯熱水器放置於陽台時，開窗位置、面積、熱水器型號以及雜物堆積對一氧化碳生成的影響。使用套裝模擬軟體FDS(Fire Dynamics Simulator)建構一暫態、多物種的燃燒模型進行分析，並藉由模擬結果與全尺寸實驗進行驗證以確認模擬準確性。 模擬結果顯示，氧氣、一氧化碳及二氧化碳與實驗數據之趨勢十分接近，證實FDS不只能運用在火災模擬，在本研究探討範疇內也能有很好的表現。 由各情境分析面積14m3之陽台的結果來看，本研究建議如下: 1. 空曠陽台在開窗寬度0.2m(高度0.5m)以上在20分鐘內可確保陽台安全。 2. 窗前掛晾衣物降低窗口排氣效率，使得開窗寬度必須在0.25m以上才能維持陽台安全。 3. 地板擺放雜物限制了熱水器吸取氧氣的範圍，使得0.2m的開窗寬度不再安全；若將雜物架高，可有助於熱水器底部吸取氧氣，使0.2m的開窗寬度能繼續維持陽台的安全。 4. 熱水器架設位置應避免架設高於窗口，也不應擺設在窗口正上、下方。 5. 使用強制排氣型熱水器能使陽台內部的一氧化碳濃度始終為零。

This study numerically investigates the effects of window position、window area and aheap stuff on the formation of carbon monoxide in a balcony with gas water heater. Simulations are carried out with a transient and multicomponent combustion model, using Fire Dynamics Simulator (FDS). The model is validated by the comparison with experiment. The simulated results show that a good agreement between predicted data of present model and the experimental results. The following conclusions are obtained by this research: 1. The balcony is considered to be safe within 20 minutes if it’s empty and the window-width is equal or more than to 0.2m. 2. Hanging clothes in front of the window will reduce exhaust-efficiency, therefore, the window have to open more widely than 0.25m to keep the balcony safe. 3. Heaping stuff on the floor restricts the region of oxygen water heater can absorb, which makes the balcony with window opened for 0.2m no more safe. Otherwise, to raise the stuff can help the water heater absorb oxygen and keep the balcony safe with the same window opened width 0.2m. 4. The water heater in balcony should not be higher than windows and the position should not be right above or right below the window. 5. Using water heater of forced exhaust can make carbon monoxide concentration to be zero in balcony within 20 minutes.