|Abstract: ||摘要:冷凍艙或冷藏間,由於其儲存之漁獲及循環空氣散發水氣,而冷凍室內之溫度又遠低於攝氏零℃,故在室內壁四周,形成一層白色之結霜.此層結冰或霜,其作用與絕緣材料相同,能降低冷凍機之冷凍容量.而造成壓縮機之耗電與產生極大的熱阻,並降低冷凍系統的性能係數,因此本計畫的重點主要在研究結霜對冷凍室與系統性能的影響.其主要工作內容如下: (一) 瞭解漁船冷凍系統之冷凍室的種類. (二) 蒐集國外先進國家漁船冷凍系統結霜的處理方法與技術. (三) 瞭解不同的結霜程度,冷凍系統如欲保持固定的溫度,壓縮機所需增加的電能. (四) 瞭解不同的結霜程度,冷凍系統內溫度的變化情形. (五) 各種不同的除霜方法,所需增耗的能量,以及其對冷凍室溫度變化的影響.經由本研究對於冷凍系統結霜情形可做進一步的掌握,以減少系統因結霜而導致能源的浪費,並提出一有效的方法進行除霜.並可常保持冷凍室於低溫下操作,並確保漁獲之鮮度.此外,亦可增加漁獲之儲存空間.|
Abstract:The water contents, come from captured fishes and moisture in the circulating air, made the walls of the refrigerated spaces coated with layers of frost because the temperature is always below freezing point. The frost serves as an insulating material and will reduce the refrigerating capacity. It also costs much electric power and decreases the coefficient of performance of a refrigerating unit. Therefore, the main purpose of this project is to investigate the influence of frosting on system's COP. The contents of this work are listed as follows: a. The refrigerating units as well as fishing vessels are categorized and familiarized. b. The advanced technology of dealing with frosting in foreign countries is searched and gathered for reference. c. To calculate the consumption of electric power while a constant temperature in refrigerated space is maintained under different conditions of frosting. d. The variations of temperatures in refrigerated spaces are recorded under different frosting conditions. e. The power consumption of different methods of frosting is estimated. Through this study, a further control of frosting will be made and a decrease of the energy consumption for a refrigerating system with frosting is investigated. An efficient as well as energy-saving defrosting method is proposed for a given fishing vessel. From the results of this study, it is expected to keep the captured fish fresh and to offer a much bigger storing room.