Yu Wei, Li Xiaoyin, Yuan Fangyang
Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology, Jiangnan University, Wuxi 214122, China.
School of Mechanical Engineering, Jiangnan University, Wuxi 214122, China.
Membranes (Basel). 2021 Sep 14;11(9):704. doi: 10.3390/membranes11090704.
A numerical study on the oxidation removal of nitric oxide in a ceramic hollow fiber membrane contactor was performed. To represent the transport and absorption process, the model was created by combining multiphase, species, reaction, and porous models. The numerical results were verified by comparing them with experimental data. The tube and lumen sides both have laminar parabolic velocity distributions. The nitric oxide concentration decreases gradually from the membrane wall to axis at the cross-section except on the inner and outer sides of the membrane tube. The equivalent diffusion length was proved useful for evaluating the entrance effect. At low concentrations, the reduction efficiency was proportional to the absorbent concentration, and at large concentrations, it neared a maximum value. The reduction efficiency was positively affected by elevated operating temperature and pressure. With a gas channel width of 13 mm, the reduction flow rate achieves its maximum. The efficiency of NO reduction per area decreases as the effective membrane length increases. Increasing the operating temperature and membrane length are recommended as design priorities due to high relative enhancements. It is not recommended to improve reduction efficiency by increasing membrane tube diameter and operating pressure in design. Changing the gas flow rate, absorbent concentration and gas channel width are moderate recommended as well.
对陶瓷中空纤维膜接触器中一氧化氮的氧化去除进行了数值研究。为了描述传输和吸收过程，通过结合多相、组分、反应和多孔模型创建了该模型。通过将数值结果与实验数据进行比较来验证其正确性。管侧和内腔侧均具有层流抛物线速度分布。在膜管横截面处，除膜管内外侧外，一氧化氮浓度从膜壁到轴线逐渐降低。等效扩散长度被证明对评估入口效应有用。在低浓度下，还原效率与吸收剂浓度成正比，在高浓度下，还原效率接近最大值。操作温度和压力升高对还原效率有积极影响。当气体通道宽度为13mm时，还原流量达到最大值。单位面积的NO还原效率随着有效膜长度的增加而降低。由于相对提高幅度较大，建议在设计时优先考虑提高操作温度和膜长度。在设计中不建议通过增加膜管直径和操作压力来提高还原效率。适度建议改变气体流速、吸收剂浓度和气体通道宽度。
