太陽熱能應用於除濕製冷

Abstract

本研究針對開放吸附式冷卻系統進行架設與實驗測試，以太陽能熱水器作為驅動熱源之想法整合出理想的節能產品，並透過除濕輪驅動製冷機制，將開放吸附式除濕冷卻應用在空調系統上，藉由此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消耗電力。 本開放吸附式除濕製冷研究流程分為六部分，第一為藉由調整系統中各元件風扇，來找尋風扇最佳化設計；其次討論新增的散熱端是否對系統有影響；第三部分為對系統核心-除濕輪進行客觀分析，如轉速、方向性等參數，尤其是使用非破壞量測像微波、紅外線等量測儀器，對除濕輪直接進行量測並分析，期望能以不同於過去大部分實驗量測入出口風相對濕度之方法，即時監測除濕輪的飽和狀態。由於超音波造霧器會發熱造成水溫上升因而影響最後系統出口下降溫度，故本章節第四部分對系統增濕器做進一步探討，以期能解決此問題。耗電製冷效率及使用太陽能作為動力來源是本研究相當重視的議題，故第五部分將探討系統內各元件之功耗，並將此開放吸附式除濕製冷設備與太陽能集熱器做結合，以確定實驗的可行性與穩定性。本研究已設計出完整一體的開放性除濕吸附製冷實驗設備去驗證實驗理論，實驗結果可知，利用調整系統中各元件風扇的風量，已可使系統下降溫度的能力達5.6 ℃，從實驗數據證實系統中除濕輪有方向性，會影響除濕能力，間接影響溫度下降能力；另外，除濕輪加入散熱區部分，雖然從散熱風扇風量的調整，對本系統溫度下降的能力僅提高0.5 ℃，但由實驗可發現當有無此散熱端溫差可達2.3℃左右，且從耗電效率來看增加散熱端是對系統有明顯功效。不過，從耗電效率觀察發現，在本實驗中所加入的板式熱回收器，對系統的效果是不佳的，即使它增加了系統溫度下降的能力，但所消耗的電力是效率不足；而超音波造霧器會因運轉而發熱的問題，經實驗證實可以透過加入抽水馬達解決。

Cooling is needed in many agricultural applications. It would be very nice if air-conditioning can be acquired without paying for energy. In this study, hot water provided by solar water heater was used to drive an adsorption-evaporative chiller. In other words, the sun, which is free, becomes the energy for air-conditioning. A silicon-gel wheel was utilized to adsorb water vapor and release it when it rotated to regeneration section. The incoming air was dehumidified by the silicon-gel wheel and the dried air was humidified by ultrasonic foggers. The humidifying process brings the evaporative cooling. The leaving air was required to approach saturation as close as possible to achieve the maximum cooling. An air-to-air plate heat exchanger was installed to move some heat from the air after contacting the dehumidifying wheel to the air about to regenerate the wheel. Since the residual heat on the silicon-gel may be transported to the conditioned space and deduct the cooling effect, it was a novel design the have a cooling section between the regeneration and dehumidifying sections. The system was actually built and run with solar water heater. Also, the system ever worked in a small room inside a plant factory to test the cooling effects. It was found that the addition of cooling section was useful to further decrease the outlet temperature by about 0.5 ℃. The current configuration exhibits a total cooling ability of 5.6 ℃. The operational parameters, such as air flow rates, hot water temperature, and section ratios, were optimized. A design flow for a system of this kind was suggested. It seems like that the system has the potential to cool greenhouse under severe sunshine and make some non-season produce being able to grow.