管状光催化反应器降解甲醛效果及其降解模型  

Removal of Formaldehyde with an Annular Reactor and Its Kinetic Model

作　　者：刘鹏[1] 郑洁[1] 黄锋[1] 宋雪瑞 

机构地区：[1]重庆大学三峡库区生态环境教育部重点实验室,重庆400045

出　　处：《湖南大学学报（自然科学版）》2015年第6期135-140,共6页Journal of Hunan University:Natural Sciences

基　　金：国家'十二五'科技支撑计划项目(2011BAJ03B13)

摘　　要：针对建筑环境中的挥发性有机化合物甲醛,在原有管状反应器内增设带有工艺缺口的直肋片,并在密闭循环系统中对其净化效果进行分析,又利用计算流体力学(CFD)的方法得到了反应器内部的流速和光强分布.同时,基于模型计算的方法,建立了污染物循环降解模型.结果表明:改进后的管状反应器,反应面积增加,气体停留时间延长,平衡了传质-反应能力,反应速率提高了约1倍;增设肋片后,内壁面光强有所减弱,反应器中间段光强与流速耦合较好,而两端由于气流扰动大且光强较弱,反应速率会受影响;另外,降解模型的预测值稍高于实测值,但两者变化趋势相同,该模型能较准确的预测甲醛的反应速率.A new annular photocatalytic reactor was designed for the removal of indoor formaldehyde. Three fins were added to the reactor and each fin had a triangular gap at one end,making this type reactor continuous and single-pass.The influence of fins on formaldehyde removal was examined in an airtight en-vironmental chamber.The radiation and velocity fields of the reactors were simulated by using computa-tional fluid dynamics （CFD）methods.A theoretical model for the degradation of formaldehyde in a recir-culating system was proposed.When adding fins in the annular reactor,the reaction area and residence time were greatly increased,and the degradation rate was,therefore,obviously enhanced.The CFD simu-lation results showed that the radiation intensity on the internal surfaces of the exterior cylinder was nearly uniform except for the two ends and it decreased slightly for the reactor with fins.The velocity distribution was uniform in the first tube pass and became actually higher near the elbows.The UV intensity was weak while the velocity was large near the elbows,which had a negative effect on degradation efficiency there. The results obtained from the kinetic model were in agreement with experimental data.So the degradation behavior of formaldehyde could be predicted by using this kinetic model.

关 键 词：光催化氧化 降解模型 管状反应器 CFD 模拟 甲醛 

分 类 号：O643[理学—物理化学]