發生器對小型氨水型吸收式冷凍系統之性能影響研究

Effect of the Generator on the Performance of a Small Aqua-Ammonia Absorption Refrigeration System

蔡嘉晉(Chia-Chin Tsai)

指導教授 ： 蘇金佳

國立臺灣大學/工學院/機械工程學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.00650

摘要

本研究主要目的為提高並改良小型吸收式冷凍系統之性能，並探討吸收式冷凍系統各元件對性能的影響，實驗中將發生器加熱量設定為9 kW、8 kW、7 kW、6.5 kW、6 kW，以探討發生器對系統的影響狀況，並將發生器加熱量設定為9 kW、 8 kW、7 kW，再改變冷凝器風扇頻率、鹵水出口溫度、鹵水流量、吸收器冷卻水流量等變數後，並繪圖探討。
其結果可發現當發生器加熱量增加，系統溫度增加系統冷凍能力增加，但其COP於6 kW-7 kW 系統COP會有先增加，於7 kW-9 kW，系統COP會有下掉的趨勢；在冷凝器方面，當風扇頻率增加，冷凝器溫度降低時，冷凝器出口冷媒隨之降低，系統冷凍能力會有所提高，COP亦增加；在蒸發器方面，蒸發器鹵水出口溫度及鹵水流量增加，可以使蒸發器帶走更多的熱量其系統冷凍能力及COP也就會相對增加。
而於實驗之中，系統吸收器對冷媒流入發生器之濃度與溫度上的影響最為重要，由於本實驗發生器加熱量為固定，所以吸收器吸收情況越佳，冷媒進入發生器溫度也會隨之降低，系統雖有較高的氨水濃度流至發生器，但也會讓發生器整體溫度下降，使得冷媒蒸發量不增反減，其研究結果顯示系統冷卻水約於7-8 L/min有較高的冷凍能力以及COP。
至今能源缺乏的時代，吸收式冷凍的應用，減少能源的使用顯的更為重要，而小型吸收式系統的運用於本實驗中仍有著許多改進與進步之空間，並有效應用於小型系統之中。

關鍵字

吸收式冷凍系統 ； COP ； 冷凍能力 ； 發生器 ； 吸收器

並列摘要

The study aims at promoting the efficiency of a small aqua-ammonia absorption refrigeration efficiency and probing into the things that the component of system affects the system。In the experiment, the heater provides 6 kW, 6.5 kW, 7 kW, 8 kW and 9 kW to the aqua-ammonia solution within the generator. The controlled variables are the fan frequency of the condenser, the temperature and the flow rate of water/glycol solution, and the cooling water flow rate.
The result shows that the cooling capacity increases with increasing generator heat transfer. The coefficient of performance (COP) of the system increases when the quantity of the generator heat transfer is increased from 6 kW to 7 kW, however it decreases in the range of 7 kW-9 kW. When the fan frequency increases, the temperature of liquid ammonia leaving condenser decreases, while the cooling capacity and the COP of the system increases. When the flow rate and inlet temperature of water/glycol increases, the evaporator takes more heat away and the cooling capacity and COP of the system increases.
If the heat provided by the generator maintains constant during the experimental process, the absorber has the most affect on the performance of the generator. When the temperature of ammonia leaving absorber decreases, induced by increasing the flow rate of the cooling water, the concentration of aqua-ammonia to the generator increase, but the temperature of ammonia entering the generator decreases（the generator temperature decreases.）. When the flow rate of cooling water through the absorber is at 7 to 8 L/min, the system provides the highest cooling capacity and the coefficient of performance (COP).

並列關鍵字

Absorption Refrigeration System ； (coefficient of performance) COP ； Cooling Capacity ； Generator ； Absorbe

參考文獻

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