環保冷媒應用於渦卷式微型有機朗肯循環之研究

本研究主要針對低溫熱源建立一微型有機朗肯循環（Organic Rankine Cycle, ORC）之發電系統，並分別以R245fa及R1233zd（E）作為工作流體進行實驗比較，目的在於探討R1233zd（E）此種新式環保冷媒於ORC系統中性能表現，並分析能否取代R245fa。其中實驗主要分為五項進行，分別為蒸發溫度、系統質量流率、膨脹器入口過熱度、膨脹器出入口壓力比及熱源流量，測試兩種工作流體在本研究自行組建之微型ORC實驗機組系統性能表現。在實驗結果表明因R245fa有較低蒸發潛熱，故在相同膨脹器入口過熱度、系統質量流率及蒸發溫度等條件，皆有略高於R1233zd（E）之系統性能表現，但兩者變化趨勢幾乎一致，而在膨脹器出入口壓力比實驗中，發現膨脹器在使用R1233zd（E）工作流體時明顯有較高等熵效率，結論是兩者在系統性能表現趨勢相近。若以環保問題為考量因素，R1233zd（E）類流體會較為適合。基於本研究的成果未來對於工業廢熱、地熱等應用上，希冀能帶來貢獻。

關鍵字

低階熱源；有機朗肯循環；渦卷式膨脹器；混合流體

並列摘要

In this study, a micro-scaled Organic Rankine Cycle (ORC) system was built for low-temperature heat sources, which R245fa and R1233zd(E) were used as working fluids on experiments. The objective is to explore the performance of R1233zd(E), a new environmentally friendly refrigerant in the ORC system, and analyze whether it can replace R245fa. The experiments were mainly performed by some parts, evaporation temperature, mass flow rate of system, superheating at the inlet of the expander, inlet and outlet pressure ratio of expander, and mass flow rate of heat source. The results show that ORC with R245fa has slightly better performance than that with R1233zd(E), as the conditions of superheating at inlet of expander, mass flow rate of system and evaporated temperature were fixed, due to lower latent heat of R245fa on evaporation. The trends of efficiency with different parameters for two working fluids were almost the same. If environmental issues are taken into consideration, R1233zd(E) would be more appropriate for ORC system.