中文摘要：

采用CHEMKIN软件中的PFR模型对不同气氛（O2／CO2和O2／N2）下煤粉燃烧过程中燃料氮NH3的转化和NOx生成机理进行模拟，并在模型中首次引入外部的湿烟气再循环来模拟实际富氧煤粉燃烧过程中NOx的生成机理及影响因素。通过CHEMKIN模拟可以较为准确地定量分析富氧燃烧条件下燃料N的转化规律，富氧燃煤过程中引入再循环烟气可降低燃料N向NO的转化率，其中碳黑与NO的反应对再循环烟气中NO的还原起主要作用。

英文摘要：

Fuel N conversion and NOx formation for pulverized coal combustion is investigated in different O2/O2 and O2/N2environments with a Plug Flow Reactor（PFR） model of CHEMKIN. Then the model with externally recycled wet flue gas is firstly adopted to simulate the actual oxy-fuel combustion process and to identify the conversion mechanism and the influencing factors of NOx The simulated results of fuel N conversion ratio for oxy-coal combustion agrees well with the experimental results in an entrained flow reactor. The externally recycled flue gas in oxy-coal combustion process can obviously decrease the conversion ratio of fuel N, and the soot and NO reaction is the dominant mechanism for NOx reduction with the recycled flue gas compared to the char and NO reaction.