泡沫陶瓷孔密度对低浓度瓦斯燃烧特性影响分析

搭建了低浓度瓦斯在碳化硅泡沫陶瓷内燃烧的实验台，研究了碳化硅泡沫陶瓷孔密度对低浓度瓦斯燃烧特性的影响。结果表明:碳化硅泡沫陶瓷孔密度对瓦斯燃烧温度的影响并非线性，也非单向，在10 PPI和40 PPI孔密度下均出现了反常分布，孔密度由10 PPI增加至20 PPI时，泡沫陶瓷中温度增加，增加至30 PPI时温度反而降低，40 PPI的泡沫陶瓷温度又高于30 PPI的；20 PPI的碳化硅泡沫陶瓷综合换热效果最好，燃烧室整体温度水平较高；同一流速下，4种孔密度的碳化硅泡沫陶瓷内的CO浓度都随当量比的增大而减小，而且当量比由0.50上升到0.55时，CO排放急剧减小；CO排放也与孔密度有关，但规律并不明显，大体上可以看出，20 PPI的碳化硅泡沫陶瓷对应的CO排放浓度在所测当量比范围内普遍偏低，而10 PPI的碳化硅泡沫陶瓷对应的CO排放浓度略高；NO的排放规律与CO相反，NO的排放浓度随当量比的增大而不断增加，NO_x的排放趋势和NO的排放趋势大体一致。

Influence analysis on pore density of ceramic foam on combustion characteristics of low concentration gas

The combustion chamber of low concentration gas in silicon carbide foam ceramic was set up，and the influence of pore size of silicon carbide foam ceramic on combustion characteristics of low concentration gas was studied.The results showed that the influence of pore size on the gas combustion temperature is nonlinear and not unidirectional，and the anomalous distribution occurs under the density of 10 PPI and 40 PPI；when the PPI number increased from 10 to 20，the temperature of foam ceramic increased to 30 PPI，and the temperature decreased；the temperature of 40 PPI foam ceramics was higher than 30 PPI；the heat transfer effect of 20 PPI SiC foam ceramics was the best and the overall temperature of the combustion chamber was higher；at the same flow rate，the CO concentration of SiC foam ceramics with four diameters decreased with the increase of equivalence ratio.Moreover，when the equivalence ratio is 0.50 to 0.55，the CO emission decreases rapidly；CO emission is also related to pore size，but the rule is not obvious；generally speaking，the CO emission concentration of the 20 PPI SiC foam ceramics is generally low in the range of equivalence ratio，while the CO emission concentration of the 10 PPI SiC foam ceramics is slightly higher；the emission rule of NO is just opposite to that of CO，and the emission of NO is strong；degree increases with the increase of equivalence ratio，and the trend of NO_x emission is basically the same as that of NO emission.