在吸收式冷凍系統中，溴化鋰水溶液常被應用為吸收器中的吸收劑；而溴化鋰水溶液的吸收效率對吸收式冷凍系統的整體性能有著顯著的影響。為了增加整體系統的吸收效率，本論文著重在提升溴化鋰水溶液能有效接觸蒸汽的總面積。具體作法是將用於冷卻溴化鋰水溶液的垂直冷卻板作分段，並將它們左右交錯的排列在溴化鋰水溶液流道的兩側，藉此來冷卻不同面的溴化鋰水溶液，並曝露濃度較高、溫度較低的溴化鋰水溶液於蒸汽中。本研究利用計算流體力學的方法，模擬出溴化鋰水溶液流經冷卻板的情況。在不改變冷卻板的總長度下，調整溴化鋰水溶液的噴灑率、冷卻水的流率及各冷卻板的比例長度，比較整體的蒸汽平均吸收量。
結果顯示，在單片冷卻板時，雷諾數Re (與溴化鋰流率成正比)和單位寬度的冷卻水流率 的增加，以及冷卻水入口溫度 的降低都能讓整體的蒸汽吸收效果更好。在兩片冷卻板的情況，調整兩板之間的比例長度將可以找到一個最佳的蒸汽吸收效果。在比較兩片冷卻板與一片冷卻板的蒸汽平均吸收量後，可以發現兩片冷卻板的蒸汽平均吸收量可以提升大約10%。

In the absorption-type refrigeration field, lithium bromide solution has been widely used as an absorbent. Moreover, in absorption cooling systems, the absorber is the most important component, and its efficiency has a direct effect on the performance of the whole system. In this paper, we focus on increasing the interfacial between lithium bromide and vapor, which may achieve the purpose of increasing the overall performance of falling-film absorber. In particular, here we use a film-inverting configuration for falling-film absorbers. Specifically, the vertical cooling plate is segmented and alternatively placed on the both sides of falling film. In this way, the inner and fresher surface of the absorbent can be exposed to the vapor at the next plate, and so more vapor will be absorbed into the falling film.
Technically, a numerical model is developed for the calculation of heat and mass transfer in the falling film absorber. For simplicity, constant lithium bromide solution properties and heat transfer coefficient of cooling water are used along the falling film flow path in the calculation. The result shows that, for the single-plate configuration, the water vapor mass flux increases with increasing Reynolds Number, with increasing cooling water flow rate, and with decreasing temperature of the input cooling water. For the double-plate configuration, a particular ratio between the two plate lengths exists that can produce the maximum absorption mass flux rate (keeping the total length of the two plates fixed). Compared to the single-plate configuration, the improvement in the average vapor mass flux is about 10% in the double-plate configuration.

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