模擬探討複合式吸附除濕系統之最佳化

Abstract

在工業製程中，冷凍乾燥法是是比較常見的乾燥空氣源，其方法是使外界空氣經過空氣壓縮機並搭配冷凍系統使得水氣冷凝，進而達到製備乾燥空氣的目的，然而冷凍乾燥法一般只能將大氣露點溫度降至-10 ℃ 左右，若需要製備極乾燥的空氣則需再加上吸附式乾燥系統。 本研究參考一個以吸附床搭配吸附式微流道除濕系統的實驗，並以模擬軟體COMSOL進行模擬研究，在模擬與實驗的結果匹配之後，繼續探討操作條件對系統的影響。本研究的目標是使系統能長時間穩定的提供大氣露點為-30℃以下 的乾空氣，完成模擬與實驗之間的比較之後將探討如何改變操作條件和系統尺寸以有效地提升系統效能。 本研究探討了不同吸附和脫附過程之操作以及改變系統中填充床的高度和吸附式微流道之長度，目前結果顯示，提高再生時的控制溫度是增加系統效能最顯著的方法，不論在節能、產出速度和除濕能力上都有顯著的提升。除了改變再生控制溫度外，增加系統中除濕微流道的長度也能有效地節省能源與提高產率，但過長的微流道會導致系統在脫附過程時的效果不佳，因而間接影響系統在吸附過程中的除濕能力。

In industry, Refrigeration and adsorption dehumidification are two main methods to produce dry air. Refrigeration dehumidification is efficient on general demands, and adsorption dehumidification is especially great when producing dry air whose atmosphere dew point is under -10 ℃. In this study, we build a simulation model of a compound adsorption dehumidification system which refers to an experimental setup by the commercial package software COMSOL Multiphysics. This compound dehumidification system combines an adsorption packed bed and desiccant channels. The purpose of this system is to optimize the advantages of these two dehumidification elements. After the simulation model is built, we first verify our simulation result by comparing to the experiment result, and the results are analogous. Second, several simulation results based on different operating or size parameters is compared. The result shows that increasing the controlling temperature while doing desorption process can improve the performance of system in many different way which including energy saving, efficiency and dehumidification ability. Another way to improve the performance of the system is to lengthen desiccant channel, but it can only improve efficiency while the average humidity of produced dry air slightly increase.