An investigation of fuel variability effect on bio-syngas combustion using uncertainty quantification
An investigation of fuel variability effect on bio-syngas combustion using uncertainty quantification
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DOI：
10.1016/j.fuel.2018.02.007
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发表时间：
2018-05
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（PCE）的不确定性量化（UQ）方法，研究了不同当量比下燃料变化对生物合成气预混燃烧过程中绝热火焰温度和层流火焰速度等物理化学性质的影响.从统计学的角度出发，讨论了不同燃料成分下生物合成气使用的置信度问题。未燃尽气体温度和不同的化学机制（GMI-Mech 3.0和圣地亚哥机制）对这些燃烧性能的预测不确定性的影响进行了讨论。结果发现，在不同当量比的火焰温度的波动是受生物合成气燃料的可变性，而火焰速度是敏感的燃料成分的不确定性。例如，生物合成气组分1.5%的波动会导致富燃时火焰速度波动14%，贫燃时火焰速度波动3%。由于生物合成气燃料成分的变化，火焰温度的波动小于0.8%。生物合成气燃烧的UQ表明，氢的变化在火焰速度变化中起着重要的作用（在贫燃条件下为70-80%），而甲烷的变化虽然被认为是重要的，但除了富燃燃烧外，其影响可以忽略不计。总体而言，目前的研究提供了一个基本的了解燃料的变化对生物合成气燃烧的物理化学性质的影响。定量地提供了生物合成气燃烧变化的主导成分，以指导上游气化过程的目标不确定性降低。
Fuel variability effects on physicochemical properties such as adiabatic flame temperature and laminar flame speed of premixed bio-syngas combustion are investigated via polynomial chaos expansion (PCE) based uncertainty quantification (UQ) approach at several equivalence ratios. Questions regarding confidence level of using bio-syngas with varying fuel composition are tackled from a statistical point view. Impacts of unburnt gas temperature and different chemical mechanisms (GMI-Mech 3.0 and San Diego Mechanism) on predicted uncertainties of these combustion properties are discussed. It was found that fluctuation of flame temperature at various equivalence ratios is less affected by bio-syngas fuel variabilities, while flame speed is sensitive to uncertainties in fuel composition. For instance, 1.5% fluctuation of bio-syngas constituent can lead to 14% fluctuation of flame speed for rich combustion, and 3% for lean combustion. Less than 0.8% fluctuation of flame temperature due to variability of bio-syngas fuel composition was observed. UQ of bio-syngas combustion showed that hydrogen variability plays a significant role (70–80% at lean condition) in flame speed variation, while methane variability, although thought to be important, has a negligible impact except for fuel-rich combustion. Overall, the current study has provided a fundamental understanding of the effects of fuel variability on physicochemical properties of bio-syngas combustion. Dominating compositions to variations of bio-syngas combustion are provided quantitatively to guide targeted uncertainty reduction from the upstream gasification process.