本研究以尤拉(Eulerian)觀點之濃度擴散方程式探討二氧化碳濃度於室內空間的移除過程,並引入RNG (Renormalization Group) κ-ε模式做為紊流模式,以計算紊流場對於濃度擴散之影響。在模擬過程中,應用布希內斯克近似法(Boussinesq approximation)對流體的密度做假設,以模擬溫度對流場之影響。 本研究以蔡等(2013)對室內環境之地板送風系統的溫度測量做為本研究模式之驗證,並以其實驗空間做為依據設置兩種送風系統(1)天花板送風系統、(2)地板送風系統,並比較此兩種送風系統對於室內環境的(1)降溫效率、(2)二氧化碳濃度移除效率。又以恆溫(送風空氣之溫度與房間內空氣溫度相等)條件做為對照組,比較變溫(送風空氣之溫度低於房間內空氣)之情況,以探討溫度的變化對於環境流場之影響。 本研究分析結果指出,地板送風系統在變溫的條件下,不管是在降溫效率亦或是二氧化碳濃度移除效率上,皆有較好的能力。而天花板送風系統在變溫及恆溫的條件下,降溫下率及濃度移除效率皆差於變溫條件下的地板送風系統,且溫度之影響對於天花板送風系統是不明顯。然而天花板送風系統在變溫的條件下,其降溫效率及濃度移除效率,則是四種情況下最差的。
The main objective of this study is to investigate concentration of carbon dioxide in room and analyze the change of its concentration field. The wind flow model uses the Eulerian viewpoint to simulate indoor airflow and conducts the Renormalization Group (RNG) κ-ε model of turbulent flows. In the simulation, we also use Boussinesq approximation to simulate the impacts of temperature to flow. The model of this study is verified by Tsai’s available field measurements in 2013, and we use the experimental room to set up two air distribution systems (1) Ceiling-Based Air Distribution (CBAD), (2) UnderFloor Air Distribution (UFAD), and compare these two systems for (1) cooling efficiency of the indoor environment, (2) carbon dioxide removal efficiency. We also discuss the impacts of the change of air temperature to flow field under non-isothermal condition (temperature of the air from inlet is less than temperature in chamber) and isothermal condition (temperature of the air from inlet is equal to temperature in chamber). The results of this study show that UFAD under non-isothermal condition has the best efficiency of cooling and carbon dioxide removal. Otherwise, CBAD under non-isothermal condition is the worst.
為了持續優化網站功能與使用者體驗,本網站將Cookies分析技術用於網站營運、分析和個人化服務之目的。
若您繼續瀏覽本網站,即表示您同意本網站使用Cookies。