Experimental and modeling study of premixed atmospheric-pressure dimethyl ether-air flames
Experimental and modeling study of premixed atmospheric-pressure dimethyl ether-air flames
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DOI：
10.1021/jp994074c
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发表时间：
2000-09-07
影响因子：
2.9
通讯作者：
Westbrook, CK
中科院分区：
文献类型：
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作者：
Kaiser, EW;Wallington, TJ;Westbrook, CK
在常压下测量了燃料/空气当量比分别为0.67和1.49的两种二甲醚(DME)空气平焰的化学组分分布。用非制冷石英探头获得的样品用气相色谱或傅里叶变换红外光谱(FTIR)分析了CH4、C2H2、C2H4、C2H6、C3H8、DME、CO、CO2、O-2、CH2O和甲酸。由辐射校正的热电偶在燃烧气体中的参考位置校准的气动探头提供了每个火焰的温度分布。还得到了两个当量比和冷气流速度与DME火焰相似的甲烷-空气火焰的物种分布，并与DME结果进行了比较，在DME和相似当量比的甲烷火焰中，C-2产物的摩尔分数相似。然而，在DME火焰中，CH2O摩尔分数要大5-10倍。将这些实验轮廓与使用最佳可用的二甲醚-空气化学动力学机制的计算机模拟研究中产生的轮廓进行了比较。附录提供了二甲醚、甲烷和乙烷扩散火焰的照片。这些结果表明，在相同燃料体积流量下，二甲醚产生碳烟时，其黄色火焰光度远小于乙烷火焰，这与二甲醚用作柴油时的低碳烟排放规律一致。
Chemical species profiles have been measured at atmospheric pressure for two dimethyl ether (DME)-air flat flames having fuel/air equivalence ratios of 0.67 and 1.49. The samples, obtained with an uncooled quartz probe, were analyzed by either gas chromatography or Fourier transform infrared (FTIR) spectroscopy for CH4, C2H2, C2H4, C2H6, C3H8, DME, CO, CO2, O-2, CH2O, and formic acid. a pneumatic probe calibrated at a reference position in the burned gas by a radiation-corrected thermocouple provided temperature profiles for each flame. Species profiles for two methane-air flames with equivalence ratios and cold-gas flow velocities similar to those of the DME flames were also obtained for comparison to the DME results, Mole fractions of C-2 product species were similar in DME and methane flames of similar equivalence ratios. However, the CH2O mole fractions were 5-10 times larger in the DME flames. These experimental profiles are compared to profiles generated in a computer modeling study using the best available DME-air chemical kinetic mechanism. The Appendix presents photographs of DME, methane, and ethane diffusion flames. These results show that, while DME produces soot, its yellow flame luminosity is much smaller than that of an ethane flame at the same fuel volume flow rate, consistent with the low soot emission rate observed when DME is used as a diesel fuel.