Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (08): 2121-2129.doi: 10.3866/PKU.WHXB20100823

• CHEMICAL KINETICS AND MOLECULE DYNAMICS • Previous Articles     Next Articles

Numerical Analysis of the Effect of Carbon Monoxide Addition on Soot Formation in an Acetylene/Air Premixed Flame

JIANG Yong, QIU Rong   

  1. State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei 230026, P. R. China
  • Received:2010-02-03 Revised:2010-04-08 Published:2010-07-23
  • Contact: JIANG Yong E-mail:yjjiang@ustc.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (50876097) and New Century Excellent Talents in University of China (NCET-06-0546).

Abstract:

The effect of carbon monoxide addition on soot formation in an acetylene/air premixed flame was investigated by detailed numerical simulation. This work focused on both the temperature effect and chemical effect of carbon monoxide addition on soot formation by comparing the results of flames with different CO contents. We find that the addition of carbon monoxide consistently reduces the formation of soot. The soot volume fraction and nucleation rate increase until a threshold temperature is reached and then decrease as the temperature increases. Considering that soot formation took place at the active site by H-abstraction mechanism, the addition of CO promotes the formation of soot. The concentration of H radicals increases and the concentration of OH radicals decreases because of the increased forward rate of the reaction OH+CO=CO2+H. For soot formation to occur by the C-addition mechanism, the degradation rates of C2H2 tends to decrease and this promotes the formation of soot along with CO addition. On the other hand, the addition of CO may greatly reduce the volume fraction of C2H2 in fuel resulting in a lower surface growth rate.

Key words: Soot, Acetylene, Carbon monoxide, Fuel enrichment, Modeling

MSC2000: 

  • O643