- 學位論文
二元系統於冷藏、熱水與蒸汽之超商應用研發
The application of cascade refrigeration system in the development for refrigeration, hot water and steam in convenience shops
摘要
本研究目的在藉由HFC-134a與HFC-245fa所組成的二元冷凍循環系統，以提供便利商店所需之冷凍冷藏、熱水與蒸汽的能量。實驗中運用HFC-245fa冷媒高溫特性來製造熱水及蒸汽與提升低溫系統的COP之可行性，藉由規劃穩態及動態測試條件，設計完整的實驗方法與流程，分析各實驗參數對系統性能之影響，進而研發具有環保觀念與節能功效的冷熱系統。實驗結果顯示，HFC-245fa於蒸發溫度為45℃且熱水出水溫度為90℃時，使用感溫式膨脹閥其COPH為1.81較手動式膨脹閥提升4.6%；COPL為1.64較手動式膨脹閥提升19.4%；採用二元冷凍循環系統之熱泵系統其節能效益，比天然瓦斯加熱可省41%，比液化瓦斯加熱可省92.5%，比柴油鍋爐加熱可省98.5%，比電熱器加熱可省122%。本研究可藉由二元系統將低溫側的冷凝熱再次給予壓縮做功達成高溫製熱與節約能源的成效。
並列摘要
The study aims at providing convenient stores with the required energy for cooling, freezing, and supply of hot water and steam through acascade refrigeration system composed of HFC-134a and HFC-245fa refrigerants. In the experiment, the paper makes use of the feasibility of producing hot water and steam and raising the coefficient of performance (COP) of low temperature system by the high temperature feature of HFC-245fa refrigerant. Through planning of static and dynamic testing conditions, the paper designs the complete experimental methods and procedures, analyzes the effects of each experimental parameter on the performance of the system, and further studies and develops a refrigeration system with environmental protection concept and energy-saving effect. Experimental results show that when the evaporation temperature of HFC-245fa is 45oC and the effluent water temperature is 90oC, the COPH (COP as a heater) of heat-sensitive expansion valve is 1.81, being 4.6% more than the manual expansion valve; and the COPL (COP as a heating load) is 1.64, being 19.4% more than the manual expansion valve. Use of the heat pump system of binary refrigeration system for heating can save energy by 41% when compared to heating by natural gas, 92.5% when compared to heating by liquid petroleum gas, 98.5% when compared to heating by diesel boiler, and 122% when compared to heating by electric heater. Through cascade system, the study can offer compression again to condensing heat by the low-temperature side, achieving the effects of making high-temperature heat and saving energy.