Ω形阶梯径向流变压吸附床制氧特性的数值模拟

Numerical Simulation of Oxygen Generation Characteristics of Ω-Shaped Step Radial Flow Pressure Swing Adsorbent Bed

为了提高PSA制氧设备的性能,设计了一种Ω形阶梯径向流吸附床.以Fluent16.0为计算平台,采用数值模拟的方法研究了该吸附床的流场、浓度场、制氧特性和床层穿透时间等参数的变化规律,并与传统的Π形径向流吸附床进行了比较.结果表明:在同样条件下,与Π形床相比,Ω形阶梯径向流吸附床的穿透时间显著延长,流动不均匀区显著缩小;Ω形阶梯径向流吸附床成品气O2的摩尔分数可达91.8%,Π形床仅为87.1%.在吸附阶段,两种吸附床内O2的高摩尔分数区外形存在明显差异,Ω形阶梯径向流吸附床内O2的高摩尔分数区以近圆杯状向前推进,Π形床则以长圆锥状向前推进.

In order to improve the performance of PSA oxygen production equipment,an Ω-shaped step radial flow adsorption bed was designed.Using Fluent 16.0 software,the change rule of the flow field,concentration field,oxygen production characteristics and bed penetration time of the adsorption bed were studied by numerical simulations,which were further compared with those in the traditional Π radial flow adsorption bed.The results showed that the penetration time of the Ω-shaped step radial flow adsorption bed is significantly longer than that of the Π-shaped one under the same conditions and the flow unevenness area is greatly reduced.Moreover,for the Ω-shaped bed,the O2 molar fraction of the production gas can reach 91.8%,which is only 87.1%for the Π-shaped one.There is a great difference in the shape of the high molar fraction O2 zone in the two types of adsorption beds during adsorption stage.The high molar fraction O2 zone moves forward in a near cup shape in the Ω-shaped bed,while it becomes a long cone shape in theΠ-shaped one.