臺灣博碩士論文加值系統

本研究討論液體除濕空調系統改變空氣供應風量與冰水流量進入吸收器時, 系統設備的熱傳率與性能表現。本系統分成三大單元部分,包括使用氯化鋰水溶液吸收空氣中水蒸氣的除濕單元(Liquid Desiccant System, LDS),使用盤管冷卻或加熱供應空氣的空調箱(Air Handling Unit,AHU),與同時製造冰水供應吸收器、冷卻盤管,以及熱水供應再生器或加熱盤管的多功能單元(Polyvalent Unit,PU)。本設備在於吸收器與再生器內的循環水管路上鍍上一層奈米材料以增加熱傳性能, 因此又稱為NanoCOOL系統。本研究的實驗設定包括3個供應風量1500、2000、2500 (m3/hr)與3個進入吸收器內的冰水流量2.2、4.4、6.5 (m3/hr),上述九種的流量組合與實驗當天外界氣候條件為實驗的設定參數,空調箱盤管端的冰水流量固定於0.5 (m3/hr)。
根據實驗量測空氣和冰水的狀態性質與系統的消耗功率,計算分析結果顯示本系統能夠有效地移除空氣中的水蒸氣,經過系統調節後之供應空氣的總熱能變化中,70~75%為潛熱的部份,其餘25~30%才是顯熱的部份。冰水的總熱傳率中有85~90%於吸收器端,與通過吸收器端空氣的總熱傳率有0.25~4.35 kW 的差距; 其餘1015%於冷卻盤管端, 與通過冷卻盤管端空氣的總熱傳率有3.41~7.65 kW 的差距。系統性能係數以單獨考慮PU單元以及綜合考慮PU和LDS兩單元消耗功率的兩種形式呈現,分別介於2.53~3.39與1.33~1.98之間。當外界環境絕對濕度值越高時,系統能較有效的吸收空氣中的水份,因此有較良好的濕氣移除率。因安裝於系統上的感測器設置有缺陷,無法量測進入吸收器的氯化鋰濃度,本論文使用修正公式,九組實驗的除濕效率值落在0.37至0.67之間。 以設計供風條件19.8度C,6.8 g_wv/kg_da為基準計算系統顯熱負載與潛熱負載, 結果顯示顯熱負載小於系統設計條件之顯熱負載8.5 kW時, 可調控接近至設計供風溫度,潛熱負載小於設計之潛熱負載30.1 kW時, 供風條件仍然距離設計供風絕對濕度約0.6~2.87 g_wv/kg_da之間。只有在非常低潛熱負載的外氣條件時, 供風絕對濕度低於設計供風絕對濕度。

The research discusses the heat transfer rate and the performance of the liquid-desiccant air-conditioning system based on different supply air and chilled water flow rates. The system is consisted of three parts: the Liquid Desiccant System(LDS),uses the lithium chloride to absorb the water vapor from air,the Air Handling Unit(AHU), which uses the cooling coil to cool down the air temperature, and the Polyvalent Unit(PU),which supplies chilled water to the absorber and the cooling coil,and supplies hot water to the regenerator. The nano material with the high heat transfer rate is coated on the water tube, so the system is mentioned as the NanoCOOL system.The supply air flow rates(1500,2000,2500 m3/hr)and the chilled water flow rates(2.2,4.4,6.5 m3/hr)are used in this research,and the flow rate of cooling coil is fixed at 0.5 (m3/hr).The ambient air conditions are also important experimental parameters, but they cannot be controlled.
According to the experimental measurements of the properties of air and chilled water and the power consumption of system,the experimental results show this system can remove water vapor efficiently. During the regulating air process, 70~75% of the total heat transfer quantity is the latent heat component,and
25~30% of it is the sensible heat component. The absorber takes
85~90% of the total heat transfer quantity and the cooling coil takes 10~15% of it by the chilled water. The difference between the regulated air heat transfer rate and the chilled water heat transfer rate in the absorber is about 0.25~4.35 kW and in the cooling coil is about 3.41~7.65 kW. There are two coefficients of performance: only considering the power consumption of PU, which is between 2.53 and 3.39, and considering the summation power consumption of PU and LDS, which is between 1.33 and 1.98. The higher the ambient humidity ratio is,the more effectively the system can absorb water vapor from air. Therefore, the system has the better moisture removal rate. Because the sensor is restricted to only measure the concentration of LiCl passing through the absorber, the experimental results show the dehumidification effectiveness are between 0.37 and 0.67 by using the modified equations in the nine experiments. Based on the designed conditions of supply air, 19.8 degrees Celsius and 6.8 g_wv/kg_da, the total sensible cooling load and the total latent cooling load are calculated.The experimental results show that when the real total sensible cooling load is lower than 8.5 kW, the designed total sensible cooling load, the temperature of supply air is close to the designed temperature. When the real total latent cooling load is lower than 30.1 kW, the designed total latent cooling load,the humidity ratio of supply air is still 0.60 to 2.87 g_wv/kg_da from short of the designed humidity ratio.
Only when the real total latent cooling load is very low, the humidity ratio of supply air is lower than the designed humidity ratio.

1. 緒論
2. 理論計算公式
3. 實驗設備、實驗方法與設備故障排除
4. 實驗結果與討論
5. 結論與建議

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