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 |
相關次數: | 點閱:151 下載:6 |
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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.
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