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研究生: 陳勝宏
Sheng-Hong Chen
論文名稱: 觀測液體除溼空調系統使用不同操作模式下的性能表現
A study on the performances of the liquid-desiccant air-conditioning system using different combination units
指導教授: 林怡均
Yi-Jiun Lin
口試委員: 田維欣
Wei-Hsin Tien
溫琮毅
Tsrong-Yi Wen
林怡均
Yi-Jiun Lin
學位類別: 碩士
Master
系所名稱: 工程學院 - 機械工程系
Department of Mechanical Engineering
論文出版年: 2019
畢業學年度: 107
語文別: 中文
論文頁數: 154
中文關鍵詞: 液體除濕空調系統氯化鋰溶液空氣蒸氣壓水溶液蒸氣壓水溶液濃度濕氣移除率除濕效率
外文關鍵詞: Liquid-desiccant air-conditioning system, LiCl solution, Vapor pressure, Vapor pressure of aqueous solutions, Vapor pressure of aqueous solutions, Moisture removal rate, Dehumidification effectiveness
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  • 本論文觀察夏季時,NanoCOOL系統對於男女更衣室供風之空氣狀況以及性能係數 (Coefficient of performance, COP)之計算。在不同的天氣狀況下,將NanoCOOL系統的三大單元做不同搭配來運轉,希望能夠降低系統電功率的消耗且到達室內所需的空氣條件。NanoCOOL系統可分為三大單元,為空氣 調節單元 (Air Handling Unit, AHU)、液體除濕劑系統 (Liquid Desiccant System, LDS)以及多功能系統單元 (Polyvalent Unit, PU)。AHU為含有盤管的空調通道;LDS為液體除濕劑系統,是進行除濕與再生的主要位置;PU為一冷凍循環熱泵,負責提供系統冷熱水。本研究使用的除濕劑為氯化鋰溶液,搭配冷凍循環熱泵提供的冷熱水,冷水能夠提高氯化鋰溶液的除濕效果,熱水能夠用來再生除濕後濃度降低的氯化鋰溶液,其驅動力為空氣與除濕溶液之間的蒸氣壓差。冷凍循環系統提供的冷熱水能夠流經空氣調節單元的盤管,控制除濕後的空氣溫度。相較於傳統的空調系統,本系統能夠實現溫度、濕度的獨立控制。觀測過程使用四種開關模式:Mode 1:三大單元全開、Mode 2:冷凍循環熱泵與空氣調節單元開啟、Mode 3:液體除濕劑系統與空氣調節單元開啟、Mode 4: 空氣調節單元開啟。搭配實驗當天外界環境的溫濕度作為實驗條件,觀察各組合能源使用以及對男女更衣室供氣狀況之影響。液體除濕系統可以直接對空氣進行除濕,在Mode 1運轉的情況中,系統能有效的將外界空氣的絕對濕度降低 7.7 ~ 10.3 g/kg ,使供風空氣的絕對濕度保持9.6 ~ 11 g/kg 之間。男女更衣室溫度保持27C,絕對濕度分別為15 ~ 18 g/kg 與 12 ~ 15 g/kg 左右。Mode 2的狀況類似傳統空調的除濕方式,將空氣降溫低於露點溫度促使水蒸氣凝結,進而達到除濕的目的,過程中將絕對濕度降低了7.3 g/kg;使用Mode 3系統除濕效果不是非常顯著,除濕過程為氣態轉變為液態的變化,釋放的熱能會被空氣以及氯化鋰溶液吸收,供風空氣濕度稍微的下降,但是水蒸氣釋放的潛熱使供風空氣與氯化鋰溶液的溫度上升。Mode 1 的 COP約在0.9 ~ 1.27 之間;Mode 2的COP 則為1.48,但除濕方面能力則較 Mode 1 低落,絕對濕度在除濕過程中僅降低了7.3 g/kg。僅使用液體除濕系統,Mode 3,如能夠搭配有效的再生機制,如太陽能、廢熱等,則可能實現濕度的控制,達到所需要的濕度度條件。當環境空氣處於舒適條件時,則可以選擇Mode 4直接將外界空氣送入室內空間。


    This study investigates the air condition in different states and the coefficient of performance (COP) for the NanoCOOL system (the liquid desiccant air-conditioning system) in summer. Under different weather conditions, the three units of the NanoCOOL system are operated in different combinations, and it is desirable to reduce the system’s electric power consumption and reach the acceptable air conditions in the locker rooms. The NanoCOOL system is divided into three main units, air handling unit (AHU), liquid desiccant system (LDS) and polyvalent unit (PU). AHU is an air handling unit with the water coil. The water coil either cools or heats the air by the cold or hot water; LDS is a liquid desiccant system that is the main unit for dehumidification and regeneration; PU is a polyvalent unit that supplies hot and cold water. The desiccant used in this study is a lithium chloride solution, and the hot and cold water is supplied by the polyvalent unit. Cold water improves the dehumidification effect of the lithium chloride solution, and the hot water is used to regenerate the lithium chloride solution after dehumidification. The hot and cold water of the polyvalent unit flows through the AHU water coil to control the temperature of the dehumidified air. Compared with the traditional air conditioning system, this system can achieve independent control of temperature and humidity. The experimental observations use four modes: Mode 1: all units are in operation, Mode 2: polyvalent unit (PU) and air handling unit (AHU) are in operation, Mode 3: liquid desiccant system (LDS) and air handling unit (AHU) are in operation, Mode 4: only the air handling unit (AHU) is in operation. The liquid desiccant dehumidification system can directly dehumidify the air, and the driving force is the vapor pressure difference between the air and the surface of liquid desiccant solution. In Mode 1, the system can effectively reduce the humidity ratio of the air by 7.7 ∼ 10.3 g/kg, and keep the humidity ratio of the supply air between 9.6 ∼ 11 g/kg. The temperature of the men and women locker rooms are 27 C, and the humidity ratio is 15 ∼ 18 g/kg for the men locker room and 12 ∼ 15 g/kg for the women locker room respectively. The opreation of Mode 2 is similar to the traditional air conditioner, and the air is cooled below the dew point temperature to condense the water vapor. The humidity ratio is only reduced about 7.3 g / kg in Mode 2. In Mode 3, only the liquid desiccant system is in operation, and the dehumidification effect is not very significant. During the dehumidification process the water vapor state changes to a liquid state, and releases its latent energy. The released latent energy is absorbed by the air and lithium chloride solution, and the temperature of air and lithium chloride solution rise. In Mode 1, the COP is about 0.9 to 1.27, the COP in Mode 2 is about 1.48, but the dehumidification efficiency in Mode 2 is lower than that of Mode 1. In Mode 3, if the regeneration process of liquid desiccant is built, it is possible to achieve the desired humidity conditions. Mode 4 directly supplies the ambient air into the indoor space when the temperature and humidity conditions are comfortable.

    中文摘要 . . . . . . . . . . . . . . . . . . . . . . . . . . . . i 英文摘要 . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii 致謝 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v 目錄 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii 符號索引 . . . . . . . . . . . . . . . . . . . . . . . . . . . . x 表目錄 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii 圖目錄 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv 1 緒論 1 1.1 研究動機與目的 . . . . . . . . . . . . . . . . . . . . . . 1 1.2 文獻回顧 . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2.1 冷凝除濕 . . . . . . . . . . . . . . . . . . . . . 2 1.2.2 固體吸附式除濕 . . . . . . . . . . . . . . . . . . 3 1.2.3 液體吸附式除濕 . . . . . . . . . . . . . . . . . . 3 1.2.4 搭配其他系統的除濕系統 . . . . . . . . . . . . . 4 1.3 論文架構及內容 . . . . . . . . . . . . . . . . . . . . . . 5 2 液體除濕基礎理論 6 2.1 濕氣圖基本介紹 (Psychrometric Chart) . . . . . . . . . 6 2.1.1 濕氣圖參數介紹 . . . . . . . . . . . . . . . . . . 6 2.1.2 空氣調節過程 . . . . . . . . . . . . . . . . . . . 8 2.2 濕空氣學基本介紹 . . . . . . . . . . . . . . . . . . . . 10 2.2.1 大氣成分 . . . . . . . . . . . . . . . . . . . . . 10 2.2.2 空氣之熱力性質 . . . . . . . . . . . . . . . . . . 10 2.2.3 相對濕度與絕對濕度 . . . . . . . . . . . . . . . 11 · vii · 2.2.4 空氣之密度與焓 . . . . . . . . . . . . . . . . . . 12 2.3 空氣的體積流率、質量流率與熱傳率 . . . . . . . . . . . . 14 2.3.1 空氣的體積流率 . . . . . . . . . . . . . . . . . . 14 2.3.2 空氣的質量流率 . . . . . . . . . . . . . . . . . . 16 2.3.3 空氣的熱功率 . . . . . . . . . . . . . . . . . . . 16 2.4 氯化鋰蒸氣壓介紹 . . . . . . . . . . . . . . . . . . . . 17 2.5 系統之性能係數計算 . . . . . . . . . . . . . . . . . . . 18 3 實驗設備介紹、運作原理與保養維修 20 3.1 NanoCOOL 系統之介紹與應用 . . . . . . . . . . . . . 20 3.1.1 NanoCOOL 系統 . . . . . . . . . . . . . . . . . 20 3.1.2 NanoCOOL 系統應用場地 . . . . . . . . . . . . 21 3.2 系統設備運作原理 . . . . . . . . . . . . . . . . . . . . 21 3.2.1 空氣調節單元 (Air Handling Unit, AHU) . . . . 21 3.2.2 液體除濕劑系統 (Liquid Desiccant System, LDS) 22 3.2.3 多功能系統單元 (Polyvalent Unit, PU) . . . . . 22 3.3 故障與維修保養紀錄 . . . . . . . . . . . . . . . . . . . 23 3.3.1 監控元件與電源供應器損壞 . . . . . . . . . . . . 23 3.3.2 冷凍循環熱泵冷媒洩漏 . . . . . . . . . . . . . . 23 3.3.3 管線保溫與保護 . . . . . . . . . . . . . . . . . . 24 3.3.4 膨脹水箱破裂 . . . . . . . . . . . . . . . . . . . 24 3.3.5 監控電腦 (PC console) 更換 . . . . . . . . . . . 25 4 實驗結果與討論 26 4.1 實驗系列與數據量測 . . . . . . . . . . . . . . . . . . . 26 4.1.1 實驗模式與設置 . . . . . . . . . . . . . . . . . . 26 4.1.2 實驗數據量測點與量測結果 . . . . . . . . . . . . 27 4.2 各量測點溫濕度計算結果 . . . . . . . . . . . . . . . . . 27 4.2.1 各量測點的空氣蒸氣壓計算結果 . . . . . . . . . 27 4.2.2 各量測點的絕對濕度計算 . . . . . . . . . . . . . 28 4.2.3 供風迴路計算結果整合說明 . . . . . . . . . . . . 28 4.3 供風空氣密度與質量流率計算 . . . . . . . . . . . . . . 28 4.3.1 供風空氣密度 . . . . . . . . . . . . . . . . . . . 29 · viii · 4.3.2 供風迴空氣體積流率 . . . . . . . . . . . . . . . 29 4.4 性能係數 COP 計算 . . . . . . . . . . . . . . . . . . . . 29 4.4.1 冷凍循環電功率紀錄 . . . . . . . . . . . . . . . 29 4.4.2 潛熱與顯熱的計算方式 . . . . . . . . . . . . . . 30 4.4.3 COP 計算結果 . . . . . . . . . . . . . . . . . . 33 4.5 除濕效率估算方法 . . . . . . . . . . . . . . . . . . . . 33 4.6 各開關模式之觀察 . . . . . . . . . . . . . . . . . . . . 34 4.6.1 更衣室移除的潛熱與絕對濕度 . . . . . . . . . . . 35 4.6.2 更衣室移除的顯熱與空氣溫度 . . . . . . . . . . . 35 4.6.3 更衣室移除的總熱功率 . . . . . . . . . . . . . . 36 4.6.4 各月份適用模式 . . . . . . . . . . . . . . . . . . 36 5 結論與建議 38 5.1 結論 . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 5.2 建議 . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 參考文獻

    [1] Nóbrega, C. E. L. and Brum, N. C. L. (2014). Desiccant-Assisted
    Cooling Fundamentals and Applications. London: Springer-
    Verlag. ISBN: 978-1-4471-5565-2.
    [2] Jia, C. X., Dai, Y. J., Wu, J. Y., and Wang, R. Z. (2006). Analysis
    on a hybrid desiccant air-conditioning system. Applied Thermal
    Engineering 26, 2393-2400.
    [3] Worek, W. M. and Lowenstein, A. (2014). Status of Liquid-
    Desiccant Technologies and Systems. In Desiccant-Assisted Cool-
    ing, pp. 25-46. Springer London.
    [4] Mohammad, A. T., Mat, S. B., Sulaiman, M. Y., Sopian, K.,
    and Al-abidi, A. A. (2013). Historical review of liquid desiccant
    evaporation cooling technology. Energy and Buildings 67, 22-33
    [5] Mei, L. and Dai, Y. J. (2008). A technical review on use of liquid-
    desiccant dehumidification for air-conditioning application. Re-
    newable and Sustainable Energy Reviews 12, 662-689.
    [6] Gommed, K. and Grossman, G. (2007). Experimental investiga-
    tion of a liquid desiccant system for solar cooling and dehumidifi-
    cation. Solar Energy 81, 131-138
    [7] Jiang, R., Qin, F. G., Yang, X., Huang, S., Chen, B., Yang, M.,
    Xu Y., and Shao, Y. (2015). Experimental Study of a Liquid De-
    humidification Unit Integrated in a CCHP System with Varying
    Operating Condition. Energy Procedia 75, 1178-1188.
    [8] Patil, K. R., Tripathi, A. D., Pathak, G., and Katti, S. S. (1990).
    Thermodynamic properties of aqueous electrolyte solutions. 1. Va-
    por pressure of aqueous solutions of lithium chloride, lithium bro-
    mide, and lithium iodide. Journal of Chemical and Engineering
    Data 35, 166-168.
    · 41 ·
    [9] Fumo, N. and Goswami, D. Y. (2002). Study of an aqueous lithium
    chloride desiccant system: air dehumidification and desiccant re-
    generation. Solar Energy 72, 351-361.
    [10] Tanaka, K. and Tamamushi, R. (2014). A Physico-Chemical
    Study of Concentrated Aqueous Solutions of Lithium Chloride.
    Zeitschrift für Naturforschung A 46, 141-147.
    Çengel, Y. A. and Boles, M. A. (2006). Thermodynamic An En-
    gineering Approach. London: McGraw-Hill. ISBN: 007-125084-0.
    [11] Pearce, J. N. and Nelson, A. F. (1932). The vapor pressures of
    aqueous solutions of lithium nitrate and the activity coefficients of
    some alkali salts in solutions of high concentration at 25. Journal
    of the American Chemical Society 54, 3544-3555.
    [12] Conde, M. R. (2004). Properties of aqueous solutions of lithium
    and calcium chlorides: formulations for use in air conditioning
    equipment design. International Journal of Thermal Sciences 43,
    367-382.
    [13] Niu, X., Xiao, F., and Ge, G. (2010). Performance analysis of
    liquid desiccant based air-conditioning system under variable fresh
    air ratios. Energy and Buildings 42, 2457-2464.
    [14] Yamaguchi, S., Jeong, J., SaitoK, K., Miyauchi, H., and Harada,
    M. (2011). Hybrid liquid desiccant air-conditioning system: Ex-
    periments and simulations. Renewable and Sustainable Energy Re-
    views 31, 3741–3747.
    [15] Bergero, S. and Chiari, A. (2011). On the performances of a hybrid
    air-conditioning system in different climatic conditions. Energy
    36, 5261-5273.
    [16] Bakhtiar, A., Rokhman, F., and Choi, K. H. (2012). A novel
    method to evaluate the performance of liquid desiccant air de-
    humidifier system. Energy and Buildings 44, 39-44.
    [17] Wang, X., Cai, W., Lu, J., Sun, Y., and Ding, X. (2013). A hybrid
    dehumidifier model for real-time performance monitoring, control
    and optimization in liquid desiccant dehumidification system. Ap-
    plied Energy 111, 449-455
    [18] 經濟部能源局 ,2015, 空調吸附除濕節能應用技術手冊。
    · 42 ·
    [19] 高志承 ,2016, 觀測獨立控制濕度與溫度空調系統之性能。 台灣科技大
    學碩士論文。
    [20] 中央氣象局 ,2017, 台灣氣候特徵簡介。
    [21] 賴彥旻 ,2017, 探討供應風量與冰水流量對於液體除濕空調系統性能表
    現之研究。 台灣科技大學碩士論文。
    [22] Su, W. and Zhang, X. (2017). Thermodynamic analysis of a
    compression-absorption refrigeration air-conditioning system cou-
    pled with liquid desiccant dehumidification. Applied Thermal En-
    gineering 115, 575-585.
    [23] Chen, Y., Luo, Y., and Yang, H. (2017). Energy Saving Poten-
    tial of Hybrid Liquid Desiccant and Evaporative Cooling Air-
    conditioning System in Hong Kong. Energy Procedia 105, 2125-
    2130.
    [24] El-Maghlany, W. M., ElHefni, A. A., ElHelw, M., and Attia,
    A. (2017). Novel air conditioning system configuration combining
    sensible and desiccant enthalpy wheels Applied Thermal Engineer-
    ing 127, 1-15.
    [25] Li, T., Yin, Y., Liang, Z. and Zhang, X. (2018). Experimental
    study on heat and mass transfer performance of falling film absorp-
    tion over a vertical tube using LiCl solution International Journal
    of Refrigeration 85, 109-119.

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