吸收液除濕與再生熱質傳之性能研究

Heat and Mass Transfer Performance of Absorption Solution for Dehumidification and Regeneration

陳聖諺(Sheng-Yen Chen)

指導教授 ： 陳希立

國立臺灣大學/工學院/機械工程學研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.02577

摘要

本研究提出一個新型的外氣空調系統，以氯化鈣溶液吸附空氣中的水份，形成稀鹽溶液，再利用太陽熱能再生成濃溶液。吸收溶液可以循環使用，如此可免除冰水主機的大量耗能，因此與傳統空調耗能比較，除濕過程所需之耗能將可大幅降低。
本研究建立了吸收液部分的數學理論，並將方程式無因次化，以適用於各種狀況下，且可將各條件在相同基準下做比較，並以理論進行模擬，改變其溶液部分的相關參數，探討其對系統的影響。
在本系統設定的條件下，NTU值約為0.8425，全熱有效度約為39.80%，潛熱有效度約為42.05%，顯熱有效度約為26.35%。降低溶液溫度，可提高顯熱有效度，但對潛熱有效度影響不顯著，全熱有效度增加。增加溶液濃度，可提高潛熱有效度，顯熱有效度反而降低，但全熱有效度提升。增加溶液質量流率，顯熱有效度、潛熱有效度、全熱有效度皆提升。

關鍵字

吸收液 ； 液體除濕 ； 氯化鈣 ； 有效度 ； 熱質傳

並列摘要

This study proposes a new type of make-up air system. The calcium chloride solution absorbs water in the air to form dilute salt solution. It is regenerated by using solar energy to concentrated solution. The absorption solution can be reused. It can save a lot of energy from the chiller. Comparing with the traditional air-conditioning energy consumption, energy required for dehumidification process can be greatly reduced.
This study establishes the mathematical theory of absorption solution and equation dimensionless. It can apply to a variety of conditions and the conditions can be compared under the same basis. Then it is simulated in a theoretical model. Change the parameters of solution part and discuss the effect for the system
In this system, under the conditions set, NTU value is about 0.8425. The total heat effectiveness is about 39.80%. The latent heat effectiveness is about 42.05%. The sensible heat effectiveness is about 26.35%. The decrease in solution temperature can increase the sensible heat effectiveness, but the latent heat effectiveness doesn't influence significantly. The total heat effectiveness is rising. The increase in the solution concentration can increase the latent heat effectiveness and decrease the sensible heat effectiveness, but the total heat effectiveness increase. The increase in the solution flow rate can increase the sensible heat, latent heat and total heat effectiveness.

並列關鍵字

Absorption solution ； Liquid desiccant ； Calcium chloride ； Effectiveness ； Heat and mass transfer

參考文獻

[2]R. Yang, P.L. Wang, “Experimental study of a forced convection solar collector/regenerator for open-cycle absorption cooling”, Journal of Solar Energy Engineering 116, 194–199, 1994.

[4]R.K. Collier, “The analysis and simulation of an open cycle absorption refrigeration system”, Solar Energy 23 (4), 357–366, 1979.

[5]A. Johannsen, G. Grossman, “Performance simulation of regenerating type solar collectors”, Solar Energy 30 (2), 87–92, 1983.

[6]P. Gandhidasan, “Performance analysis of an open-cycle liquid desiccant cooling system using solar energy for regeneration”, Int. J. Refrig., Volume 17 Number 7 475-480, 1994.

[7]T. Katejanekarn, S. Kumar, “Performance of a solar-regenerated liquid desiccant ventilation pre-conditioning system”, Energy and Buildings 40, 1252–1267, 2008.