[关键词]
[摘要]
采用基于ReaxFF反应力场的分子动力学模拟方法研究了不同燃烧温度和氧浓度条件下吡咯在O2/CO2和O2/N2气氛下燃烧的反应速率、自由基的生成、中间产物与最终产物的分布,从微观上探索吡咯在O2/CO2气氛下的燃烧机理。研究表明:吡咯富氧燃烧的主要产物包括HCN、NO、N2、CO2、CO和H2O等,主要的中间体和自由基包括C4H4N、NCO、HNCO、C4H4ON、CHO2、CN、H、OH、O和HO2等;随着温度的升高,O2/CO2和O2/N2气氛下NO的生成量都随之增加;随着氧气浓度的升高,更多的HCN、NCO、HNCO及其它含氮中间产物转化为NOX,从而使其生成量增加;在燃料与氧气的化学当量比=0.5和1时,O2/CO2气氛中NO的生成量比O2/N2气氛下的高,在=2时两种气氛中生成的NO量相当。
[Key word]
[Abstract]
By using the molecular dynamic method based on the ReaxFF (reactive force field), studied were the reaction rate, formation of the free radicals and the distribution of the intermediate and final products during the combustion of pyrrole in the O2/CO2 and O2/N2 atmosphere at various combustion temperatures and oxygen concentrations. On this basis, the mechanism governing the combustion of pyrrole in the O2/CO2 atmosphere was investigated microscopically. It has been found that the main products produced in the oxygen-enriched combustion of pyrrole will include HCN, NO, N2, CO2, CO and H2O etc., the intermediate products and free radicals mainly involve C4H4N, NCO, HNCO, C4H4ON, CHO2, CN, H, OH, O and HO2 etc. With an increase of the temperature, the amount of NO produced in the O2/CO2 and O2/N2 atmosphere will increase accordingly. With an increase of the oxygen concentration, more HCN, NCO and HNCO as well as other intermediate products containing nitrogen will be transformed into NOX, thus increasing the amount of NOX produced. When the chemical equivalent ratio of the fuel and oxygen =0.5 and 1 respectively, the amount of NO produced in the O2/CO2 atmosphere will be more than that in the O2/N2 atmosphere and when =2, the mounts of NO produced in both atmospheres will be equivalent.
[中图分类号]
TK019
[基金项目]
高等学校博士学科点专项基金(No.20130142130009),煤燃烧国家重点实验室自主研发基金(FSKLCB1507)