太陽能輔助熱動式製冷之研製

Abstract

本研究針對水–氨水型吸收式冷卻系統進行架設與實驗測試，以太陽能熱水器作為加熱源之想法整合出理想的節能產品，並使用熱媒油驅動製冷機制；另一方面，將開放吸附式除濕冷卻應用在空調系統上，且吸附除濕冷卻不需要壓縮機，所以沒有噪音的問題。並使用太陽熱能脫附除濕輪上的水分，重新讓除濕輪吸附水分。太陽能製冷系統具備經濟、環保、低噪音、熱能驅動…等多項優點，藉由上述兩種系統取代機械式冷凍空調系統及氟氯烷系統冷媒，改善生態環境及降低在空調系統上的耗電量。 本研究將太陽能與熱動式製冷技術整合，利用熱能傳遞及儲存驅動製冷系統。利用密閉式吸收冰箱研製太陽能降溫應用以及探討開放吸附式除濕輪驅動溫度與調節室內濕度對製冷能力的影響。 實驗結果可知，直接使用太陽能熱水器無法驅動吸收式系統，必須使用再加熱器輔助加熱，以提升熱媒油達到吸收式系統之驅動溫度，但加入外部能量會導致製冷機性能係數(COP)降低。以結果計算出冷凍能力及性能係數，顯示仍有許多改善空間及問題待克服，才能提高系統效率與應用之可行性。另外，開放吸附式除濕冷卻系統在除濕及增濕兩部份都能各個別在量測中得到濕空氣熱力圖之狀態。從濕空氣熱力圖中，可查出濕度率再從中求出除濕量，經計算結果表示，使用以通以熱水之空氣加熱器以風速為5 m/s之風扇可處理的除濕量為0.05 kg/hr，結果說明使用空氣加熱器也能有良好的除濕效果。自製增濕腔體使用超音波造霧器加濕乾空氣，加濕後的溫度減去先前除濕後的乾空氣溫度差為14 oC。除濕後的乾空氣再經過增濕，其增濕後出口溫度能較經過除濕輪前之入口溫度下降5-7 oC，提供明顯的製冷效果。

In this study, ammonia- water absorption cooling system was set up and experimentally tested. A solar collector was the heating source, and integrated asan energy-saving product On the other hand, a desiccant evaporative cooling system for the application of air conditioning was tested. Since desiccant cooling does not use any refrigerant and compressor, noise is not a problem. The solar thermal power was used for water desorption on the dehumidifying wheel, which regenerated the wheel for further water absorption. A thermal driven cooling system is economic, environmental friendly, and less noisy. The two thermal driven cooling systems were expected to replace the traditional mechanical A/C systems and the usage of CFC, to improve the ecology and to reduce the electrical power consumption. In this study, the solar collector was integrated with thermal driven cooling technology. The thermal energy was transferred and storage to drive the cooling system. The closed-system absorption system was utilized to develop solar cooling application. The effects of driving temperature and indoor humidity were discussed. Experimental results showed that solar water heater was not hot enough to drive a absorption system, a reheater was required. However, the usage of the reheater lowered the system COP. Investigating the cooling capacity and low COP, it was apparently that many matters were needed to be improved and overcome. In addition, the humidifying and dehumidifying processes of the open-system adsorption desiccant cooling system could be studied. Using air heaters with hot water (fan velocity 5 m/s) could process the dehumidification capacity which was 0.05 kg/hr. handmade humidification chamber using ultrasonic nebulizer can decrease 5-7 oC compared with the outlet temperature.