高效率熱泵冷凝乾燥系統應用研究

Abstract

國際能源價格持續上漲聲中，節能及提升能源效率已成為焦點。熱泵吸取空氣中或水體中的熱能，經過 Rankine cycle之蒸發、壓縮、膨脹等過程，將熱能由較低處移往較高處，效率高又節能，因此使用熱泵取代柴油或瓦斯以節省能源支出，已使熱泵成為熱門之工具。熱泵系統運轉時同步產生冷氣及熱氣，因此其能源效率極高，依介質區分型式為空氣對水與水對水二種，本研究使用水對水熱泵系統。利用其產生之熱氣乾燥農產品及冷氣凝結乾燥過程中產生的水蒸氣，此乾燥方式可使農產品呈現良好色澤，除了提升乾燥農產品品質外，也提升能源利用效率，為節能減碳的有效利用方式。本所設置完成之熱泵系統冷凝乾燥機，經熱交換器交換後之乾燥熱風溫度可達65℃，冷水溫度達到12℃，能源效率(COP)值達到3.6以上。 As the energy prices continued to hike internationally, saving energy and improving efficiency have become the focus issue. Heat pumps absorb heat in the ambient air or water through the evaporation, compression and expansion process of the Rankine cycle that transfers the heat energy in an opposite direction of spontaneous heat flow. The system is energy efficient and saves a lot of energy. The application of heat pumps has become a hot tool to replace the diesel or gas burner in order to save energy costs effectively. The operation of a heat pump system generates both heat and cold simultaneously; therefore, it provides high energy efficiency. According to the source and destination of the heat, the heat pumps can be categorized into air-water heat pumps and water-water heat pumps. A water-water heat pump system was adopted in this study. The application of its hot air in drying agricultural products and cold air in condensing water vapor generated in the drying process allows agricultural products using this drying method showing good color. In addition to improve the drying quality of agricultural products, it also promotes energy efficiency. It is an effective way to save energy and reduce carbon emission. The heat pump condensing dryer set up in TARI can provide 65℃ hot air for drying through the heat exchanger and the cold water temperature reaches as low as 12℃. The total energy efficiency of the system (COP) is above 3.6.