傾斜式循環流體化床應用於吸附除濕系統

Abstract

本研究之目的為設計一傾斜式循環流體化床系統，此系統透過重力、垂直顆粒通道與流體化床特性即可連續操作。 首先，本研究探討不同操作條件對流體化床之吸附與脫附性能的影響。實驗結果顯示，吸附能力會隨著溫度、相對濕度與風速的提高而增加；脫附能力會隨著再生溫度與風速的提高而增加。由於流體化行為造成吸附材料相互碰撞而易造成顆粒破裂，本研究期望富有彈性的高分子取代現有的脆硬吸附材料。實驗結果顯示，高分子吸附水分後黏滯力變大而難以流體化。本研究混合矽膠顆粒與高分子顆粒，成功使高分子顆粒出現流體化行為。 其次，以操作風速3m/s與高溫再生的條件進行固定填充床與傾斜流體化床之比較，使用平均粒徑為4mm的矽膠顆粒550g之傾斜流體化床提升吸附能力59.4%，壓損下降71.4%，風機耗電量減少56.4%，所以傾斜流體化床適合用於空調除濕系統。 最後，傾斜式循環流體化床填充1100g的矽膠顆粒於風速3m/s，再生溫度50℃下，夏季可以減少外氣焓值約4.3%，降低空調箱冷卻量約2.5%。若於室內回風再生下，可以減少外氣焓值約2%，降低空調箱冷卻量約1.5%。而混合顆粒於相同操作條件下，其吸附性能略低於矽膠顆粒。

The purpose of this study is to design a inclined circulating fluidized bed that maintains a healthy indoor environment and be energy-efficient. With gravity, the design of vertical particle channels and the characteristics of the fluidized bed, the system can adsorb water continuously. This study experimentally investigates the performance of the fluidized bed under different operating conditions. The results indicated that the adsorption capacity is increased with raising of air temperature, air relative humidity and air speed. Desorption capacity is increased with raising of regeneration temperature and air speed. Particles rupture since particles in the fluidized bed collide with each other easily. This study replaces the rigid sorbent with polymer. After the process of adsorbing, polymer particles become harder to fluidize as the viscous force becomes larger. This study using mixing silica gel particles and polymer particles can solve this problem. Compared to the packed bed device, the total adsorption amounts of inclined fluidized bed increased by 59.4% when the air speed was 3 m/s, regeneration temperature was 50℃, and was filled with 550 g of silica gel with diameter of 4 mm. Under this condition, the pressure drop and the energy consumption of fan reduced by 71.4% and 56.4% respectively. The results indicated that the inclined fluidized bed has better dehumidification performance than the fixed packed bed. In summer, when the air speed was 3 m/s, regeneration temperature was 50℃, and each bed is filled with 550 g of silica gel, the inclined circulating fluidized bed can reduce enthalpy of ventilation by 4.3% and save 2.5% of energy consumption when comparing to the case that the untreated fresh air is directly introduced. Changing regeneration temperature to 26℃, the system can reduce enthalpy of ventilation by 2% and save 1.5% of energy consumption. Besides, the adsorption capacity of particles mixed with silica gel and polymer was lower than silica gel.