矽膠填充床系統已被廣泛應用於各種工業之中例如除濕或揮發性有機化合物之吸附，而為了改良系統設計，了解並探討矽膠填充床系統之熱質傳機制是很重要的。 近來，考量矽膠固體側質傳阻抗的固體側阻抗 (solid-side resistance; SSR) 模型在數值模擬上有更佳的表現。於過往研究中，我們進行了矽膠填充床系統之數值模擬及實驗工作，數值模擬方面，我們建立了一維及二維的模型並發現二維模型的計算結果有較好的表現，因為其考慮了徑向溫度及濕度分布。不過在該模型中，我們忽略了在多孔介質中速度場的不均勻流動性質，以至於矽膠填充床吸附的總水量會被高估。
為了考慮非均勻的壓力及速度場，我們將 Darcy 定律引入模型中。數值計算過程中，我們發現單純引入 Darcy 定律會導致速度場較不理想，故我們也利用 Darcy 定律的一階修正以求得較好的速度場，並且建立矽膠內部壓力的數學模型。經過模擬之後，我們發現壓力對於水汽吸脫附來說是一個非常重要的因素。當反應到達穩態狀態，高壓會導致較多的水分吸收。除此之外，我們分析了幾何及其他參數的影響，發現大的口徑尺寸、較短的填充床長度及較大的寬度將導致反應初期較高的水氣吸附速率，而高入口速度、較大的填充床尺寸會讓矽膠填充床有更多的水氣吸附。

Silica-gel packed bed systems are extensively used in various industrial processes for dehumidification or adsorption of volatile organic compounds. In order to improve the design of the system, understanding the heat and mass transfer mechanism during moisture adsorption/desorption process is important. Recently, a solid-side resistance model (SSR), which consider the resistance of solid part of silica gel, has better computation performance.
In our group, we did both experiment and numerical work for the system.In previous work, we built the one-dimensional (1-D) and two-dimensional (2-D) model and found that the 2-D model has better result of simulations because it considered temperature and humidity distribution in radial direction. But the model neglects the nonhomogeneous velocity field of a porous medium, so the total water adsorption will be overestimated.
To consider the non-homogeneous pressure and velocity field, we add Darcy’s law into our models. During our work, we found that there was some problems of velocity field for just adding the Darcy’s law inside our previous model. So, we also use the first order correction of Darcy’s law to have a better velocity field and also build a model for the pressure inside the silica gel.
After the computation of the process, we found that pressure is an important factor of water adsorption. Higher pressure will cause higher water content of silica gel when reaction reaches steady state. Moreover, we analyzed the effect of geometry and other parameters, we found that, big caliber size comparing to the packed bed radius, smaller length, and bigger radius will cause higher speed of adsorbing water vapor at the beginning of reaction. And high inlet velocity, and bigger size of packed bed will lead to more water vapor adsorption.

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