減緩都市熱島之數值模擬研究

Numerical Simulation of the Urban Heat Island Mitigation

林優陸(You-Liu Lin)

指導教授 ： 李魁鵬

國立臺北科技大學/機電學院/冷凍空調工程系所/碩士(2009年)

https://doi.org/10.6841/NTUT.2009.00250

摘要

臺北市，位於亞熱帶氣候區域，因周圍地勢環繞而形成一個盆地的地形。臺北市夏天總是濕熱的環境且氣溫通常在落日之後依舊高於30℃。而來自市區高密度住宅、商業大樓的人為排放熱，以及這些人工實體的低反射率，造成在白天吸收大量的太陽能，到了夜晚則開始釋放這些熱能，再加上交通，不僅提高了外界環境的溫度，並且加重了空調的負荷，對環境形成惡性循環，都市熱島也隨之成形。
在近代計算流體力學(CFD)的發展裡，數值模擬輔助之研究方式已可應用在解析都市微氣候上，本研究運用計算流體力學(CFD)之研究方式建立建築體的數值模擬，探討都市室外環境微氣候影響，以高層集合住宅之室外為例，解析其熱環境因子，並經由數值模擬物理模式之探討，評估適宜之數值模型建立模式。本研究希望能藉由數值模擬探討過程中，建立都市室外環境數值模擬初步之參考模式，在探討建築牆面、地表舖面、以及植栽之效益，分別對室外熱環境人員活動空間分別有0.5℃、1.2℃、1℃的降溫；CFD 在本研究初步測試階段對於定性預測有一定準確性，其有效率且方便直觀解析等優點將可提供設計者可視性效果預視，期望未來成能成為一輔助環境設計者之評估系統。

關鍵字

都市熱島 ； 計算流體力學 ； 微氣候 ； 反射率

並列摘要

Taipei City, located in the subtropical zone, has a basin landform. The summer is always hot and humid and the air temperature right after sunset is typically higher than 30 ℃. It will produce a large number of anthropogenic heat in the urban with high-density residential, commercial building. However, due to the construction and outdoor pavement of low-albedo, resulted in a large number of solar heat flux absorbed during the day, it will release slowly the heat at night. And coupled with the anthropogenic from traffic, not only raises the temperature of the external environment, but also increases air conditioning load. This is a vicious cycle on the environment, and create the formation of urban heat island effect.
The development of computational fluid dynamics (CFD) in recent years has supported many researches about urban micro-climate. This research established the numerical simulation on buildings in the outdoor environment, and discussed the influence of urban micro-climate. The factors influencing outdoor thermal and wind environment in the open space of a community in urban area were analyzed. This study estimated boundary conditions and the parameters of model by Physical model. In exploring the construction of walls, pavement surface, as well as the effectiveness of plant has 0.5℃, 1.2℃, 1℃ cooling effect respectively. Moreover, this study shows that CFD is qualitative forecast with a certain accuracy in urban outdoor environment simulation and effective on visual analysis, which is very helpful for the environmental designer.

並列關鍵字

urban heat island ； CFD ； micro climate ； albedo

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