多端口进料微型管式重整制氢反应器性能研究

Research on the Performance of Multi-Inlet Micro-Tubular Reforming Reactor for Hydrogen Production

针对传统管式重整反应器甲烷转化率低的问题,设计了一种具有多端口进料结构的微型管式重整制氢反应器,并采用COMSOL多物理场模拟软件对该反应器的重整性能进行了计算研究,分析了反应温度、汽碳比等工作参数对其性能的影响规律。计算结果表明:当反应温度在773~973K范围内变化时,甲烷转化率以及产物中H2、CO的摩尔分数会随反应温度升高而增大;当汽碳比在2~4范围内变化时,甲烷转化率随汽碳比增大而增大,而产物中H2、CO的摩尔分数则随着汽碳比的增大而减小;沿气体流动方向,甲烷转化率和产物中H2、CO的摩尔分数受进料多端口特征的影响呈锯齿状波动变化,并呈总体上升趋势,在反应器出口处达到最大值。将多端口进料结构反应器与传统管式反应器进行比较研究,发现所提出的新结构反应器分别在600~1 100K的反应温度区间以及2~5汽碳比区间内其甲烷转化率都高于传统管式反应器;在873~973K区间内甲烷转化率可达93%左右;当汽碳比增大到4后,继续增大汽碳比对甲烷转化率的提高已无明显作用,建议合理的汽碳比区间为3~4。

Considering the low methane conversion rate of traditional tubular reforming reactor,a multi-inlet micro-tubular reforming reactor for hydrogen production was designed in this paper,and the influences of operation parameters on the reforming performance were studied by COMSOL multiphysics software.The results indicated that the raise of reaction temperature from 773 Kto 973 K would improve the methane conversion rate as well as H2 and CO mole fractions.With the increase of steam/carbon ratio from 2 to 4,the methane conversion rate is improved,while H2 and CO mole fractions are decreased.And also,the methane conversion rate and H2 and CO mole fractions present a sawtooth shape fluctuation,however showing an overall rising trend along the axis of the reactor and reach their maximum values at the outlet.In addition,compared the multi-inlet tubular reforming reactor with the traditional tubular reactor,a conclusion can be drawn that the methane conversion rate of present reactor is higher than the traditional tubular reactor when the reaction temperature varies from 600 Kto 1 100 K,and themethane conversion rate reaches 93%in the range of 873-973 K.When the steam/carbon ratio changes from 2 to 5,the methane conversion rate of this reactor is higher than that of traditional tubular reactor.However the increase of steam/carbon ratio exhibits no significant effect on the improvement of methane conversion when the steam/carbon ratio is higher than 4.Thus,the optimal steam/carbon ratio is from 3 to 4.