本研究依熱阻平衡概念設計適用於二氧化碳冷媒之微流道扁平管鰭管式蒸發器，並撰寫程式。由於目前無可耐二氧化碳高壓之蒸發器，同樣也無測試結果，所以程式中加入水之性質及經驗式，將設計結果與實驗結果比較作為驗證。接著利用相同設計流程，以二氧化碳性質及經驗式進行蒸發器設計。因二氧化碳於乾涸乾度後熱傳係數隨乾度增加而下降，無法達成熱阻平衡，因此乾涸後區域不列入熱阻平衡計算。另外，二氧化碳熱傳係數高，使鰭管側熱阻無法平衡，原用於水之熱交換器無法直接作為二氧化碳冷媒蒸發器使用。 An investigation of micro-channels fin-and-tube evaporator design using CO2 as working fluid is described and a design program is also developed. The design method is based on thermal balance design. Because there is neither fin-and-tube evaporator for CO2 nor the experimental results, apply water as working fluid in the program, and compare the design results with experimental results. Then using the same procedure design the micro-channels fin-and-tube evaporator for CO2. For CO2, after the dryout quality, the heat transfer coefficient decreases by quality increasing. And it can’t achieve thermal balance design. According to this reason, the heat transfer coefficient in the dryout region is not included in thermal balance. Moreover, CO2 heat transfer coefficient is high, and it makes the resistance between air side and refrigerant side unbalanced. The heat exchanger for water is not suitable for CO2.
