Uncertainty quantification of fuel variability effects on high hydrogen content syngas combustion
Uncertainty quantification of fuel variability effects on high hydrogen content syngas combustion
复制标题
燃料可变性对高氢含量合成气燃烧影响的不确定性量化
DOI：
10.1016/j.fuel.2019.116111
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发表时间：
2019-12
期刊：
影响因子：
7.4
通讯作者：
Kai Zhang;Xi Jiang
中科院分区：
文献类型：
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作者：
Kai Zhang;Xi Jiang
采用基于多项式混沌展开的不确定性量化方法，研究了燃料可变性对高氢合成气燃烧物理化学性质和NOx排放特性的影响。重点是提供在非常稀薄的条件下燃料可变性影响的深入理解，即，接近贫油熄火极限。结果表明，合成气稀薄燃烧导致火焰速度波动较大。在组分浓度波动1.5%的情况下，H60 CO 30（60%H2+ 30%CO）的火焰速度波动在当量比为0.45时最大，波动幅度为5%;在当量比为0.8时波动幅度最小。同时，在非常稀薄的条件下观察到最大NO浓度波动8.3%和NO2浓度波动6.5%。不确定性分析表明，一方面，氢气总是有最大的贡献，一氧化碳，二氧化碳和甲烷的火焰速度变化。另一方面，一氧化碳被发现有最高的火焰温度的变化的贡献，其次是氢气，二氧化碳和甲烷。在本研究中报告的量化的敏感性信息可以用来指导有针对性地降低合成气上游气化过程的不确定性。
Fuel variability effects on high hydrogen content syngas combustion physicochemical properties and NOxemission characteristics are investigated invoking polynomial chaos expansion based uncertainty quantification. The focus is put on providing an in-depth understanding of fuel variability effect under very lean conditions,i.e., near lean blowout limit. It is found that leaner combustion of syngas leads to higher flame speed fluctuation. Under 1.5% small fluctuations in species concentration of syngas fuels, a maximum of 5% fluctuation of flame speed is observed at equivalence ratio of 0.45 for H60CO30 (60%H2+ 30%CO), while the lowest fluctuation is observed near equivalence ratio of 0.8 for the cases considered. Meanwhile, maximum NO concentration fluctuation of 8.3% and NO2concentration fluctuation of 6.5% are observed at very lean conditions. Uncertainty analyses show that on one hand, hydrogen always has the highest contribution to flame speed variation followed by carbon monoxide, carbon dioxide, and methane. On the other hand, carbon monoxide is found to have the highest contribution to variation of flame temperature, followed by hydrogen, carbon dioxide, and methane. The quantified sensitivity information reported in present study can be used to guide targeted uncertainty reduction from syngas upstream gasification process.