建築大樓陣列式分離式空調室外機散熱問題分析

A Study on Heat-Dissipation of Arrayed Outdoor Units of Split-Type Air-Conditioners on High-Rise Buildings

曹仲春(Chun-Chung Tsao)

指導教授 ： 李達生 ； 施陽正

國立臺北科技大學/機電學院/冷凍空調工程系所/碩士(2007年)

https://doi.org/10.6841/NTUT.2007.00107

摘要

台灣地處於亞熱帶，夏季氣候炎熱潮濕，在國民對生活品質的要求日漸提高下，空調設備從奢侈品轉變成必需品，造就近幾年來小型空調機市場的需求量逐年成長。由於分離式空調機具備美觀、低噪音及不佔空間等優點，使分離式空調機成為現今小型空調機的主流商品之一。在台灣都會地區，高樓層的建築為非常典型的建築，建築物的陽台空間常為分離式空調室外機的安裝場所。然而，當建築大樓過於稠密時，空調室外機常因氣流短循環而導致散熱不足，以致無法有效排熱而造成能源使用效率降低的問題。本研究的目的是以計算流體力學的方法，模擬建築物外型設計與分離式空調室外機陣列安裝位置對排熱效率的影響，利用計算結果尋求最佳設計參數，使建築外型與空調設備性能取得平衡點，以達到發揮設備性能與減少耗能的目的。模擬分析的案例包括：(1)室外機陣列安裝位置對散熱的影響；(2)建築大樓樓梯間有、無開孔對散熱的影響；(3)大氣風力對散熱的影響。模擬結果顯示：(1)不當的室外機排列容易造成排熱氣流分佈不均與氣流短循環，將造成室外機平均回風溫度上升3~5 ℃；(2)增加樓梯間開孔可有效降低室外機回風溫度，開孔前後平均回風溫度約可降低10 ℃；(3)旺盛的夏季季風將影響較高樓層的室外機回風溫度，並可能導致室外機跳機。本文之研究成果除可提供製造廠商快速檢討其設計，以確保設備性能效率外，並可在建築物規劃設計階段，提供相關單位良好的參考。

關鍵字

分離式空調機 ； 計算流體力學 ； 能源效率 ； 氣流短循環

並列摘要

Taiwan is located in the subtropical area, where the weather is not only hot but also humid during the summer time. Owing to the demand of high living quality, the air conditioner becomes one of the most necessary electrical appliances for each family. Therefore, in recent years, the request of small-sized air-conditioners increases rapidly in the market of electrical products. Because of the merits of good outlook, low noise and compact size, the split-type air-conditioner has become the mainstream in the market of small-sized air-conditioners. In megalopolis of Taiwan, high-rise buildings are very typical. Usually, their balcony is the most suitable place to install the outdoor unit of the split-type air-conditioner. However, high density of tall buildings always causes short circulation of airflow, resulting in insufficient heat rejection and the decrease of energy efficiency for the outdoor unit. The purpose of this study is to analyze the effects of the external design of high-rise buildings and the installed position of the outdoor unit on the heat-rejection efficiency of the air-conditioner by means of the Computational Fluid Dynamics (CFD) method. Based upon the simulation results, the optimal design between high-rise buildings and the outdoor unit is summarized in this study to achieve the energy-saving goal for both buildings and air-conditioners. The CFD simulation of this study focuses on the impact of several physical parameters on the heat-dissipation efficiency of the air-conditioner, including (1) the installed position of arrayed outdoor units, (2) with and without openings on the staircases of buildings, (3) with and without atmospheric wind. The numerical results reveal that (1) inappropriate installed position of arrayed outdoor units is easy to cause non-uniformity of heat-rejection flow and short circulation of airflow, resulting in the rise of average air-return temperature of the outdoor unit by 3~5 ℃, (2) with openings on the staircases of buildings can reduce average air-return temperature about 10 ℃, compared to those without openings, (3) strong atmospheric wind in summer season has significant impact on air-return temperature at high floors of buildings and it could cause the shut-down of outdoor units. The results of this study can offer manufacturers to check appropriateness of their design and ensure the efficiency of equipments. Moreover, they can provide a good guide in the stage of design for the building designers.

並列關鍵字

split-type air conditioner ； Computational Fluid Dynamics (CFD) ； energy efficiency ； short circulation of airflow

參考文獻

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