| Summary: | 碩士 === 國立臺北科技大學 === 冷凍空調工程系所 === 95 === 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.
|
|---|
