相變材料結合通風系統應用於建築物之節能效果數值分析

Abstract

相變材料(Phase Change Material)在產生相變化時會伴隨著大量熱能的吸收和釋放，俗稱潛熱(Latent heat)，可利用此性質來達到恆溫或降低溫度振幅之效果，因此相變材料廣泛被利用在建築物上。 相變材料於建築物上之應用多在於西方國家，由於秋冬時刻夜間氣候過低，暖氣耗電量過大，因此利用相變材料之潛熱於白天時吸收大量熱量，並於夜晚時刻釋放熱量，達到加熱空氣之效果。但臺灣處於亞熱帶氣候區，所面臨的問題是夏季過熱造成大量的空調耗電，因此我們在應用上是與西方國家相反的。 本論文主要探討相變材料應用於台灣氣候下建築物之節能效果，利用商業有限元素軟體ANSYS建立適當邊界條件之模型。首先探討相變材料於通風單元中的運作情形，分為單一相變材料與多種類複合相變材料；接著再將此通風單元與建築單元模型進行結合，成為一應用相變材料單元之控制通風系統，並針對各種通風模式，探討在各模式下相變材料之使用率與建築耗電量。 系統建立完畢後，則探討面對不同氣候時相變材料作用溫度範圍之選擇，接著進行相變材料用量與服務空間大小之關係討論，最後再討論相變材料單元中相變材料板之排列方式對耗電量之影響。 由於窗戶之存在與否會對室內耗電量產生影響，本研究亦對窗戶之模擬進行比較討論。接著探討本研究使用的應用相變材料單元之控制通風系統於溫帶氣候之冬季下是否亦能發揮其節能之效果，同時也探討了此情況下相變材料作用溫度與用量之選擇。

The Phase Change Material(PCM) will produce or release massive heat energy when processes phase change which is called latent heat. PCM can use the nature to reduced temperature oscillation amplitude or even achieve constant temperature. Therefore, phase change material is used widely in the building. The application of phase change material in building is popular in the Western country than the Eastern country. Because of the Western country’s temperature during the night time in autumn and winter is so cold, the power consumption of heating is very height. Thus, they use the phase change material for the purpose of raising temperature at night. The phase change material will absorb massive quantity of heats by latent heat in daytime and release massive quantity of heat at night, which achieves the effect of heating air. But Taiwan is in the subtropics climatic region, the major problem is overheated in summer, that causes the massive power consumption of air condition. Therefore, the purpose of using phase change material in buildings is opposite to the Western country. The main discussion for this paper is the energy-saving effect of phase change materials applied to buildings in Taiwan’s climate. Using commercial finite element software ANSYS simulate the model which have the proper boundary condition. Firstly, the operation of phase change material in the ventilation unit is discussed. There are two types of unit, single and multiple phase change materials. Then, the ventilation unit is combined with the building model to become the controlled phase change material ventilation system. For various ventilation modes, the usage rate of phase change materials and building power consumption in each mode were discussed. After establishing the system, the selection of temperature ranges of the phase change material in different climates and the relationship between the amount of phase change material and size of service space is studied. Finally, this paper discussed the influence of phase change material plates’ arrangement on the building power consumption. Because windows affect the power consumption of the room, the simulation of glass windows also considered. After that, this paper researches whether the controlled phase change material ventilation system used in this study can also achieve its energy-saving effect under the temperate climate in winter.