基于ReaxFF的不黏煤燃烧过程中自由基及主要燃烧产物生成规律研究  

Study on the formation law of free radicals and main combustion products in non-caking coal combustion process based on ReaxFF

作　　者：王银辉 WANG Yinhui(China Coal Research Institute,Beijing 100013,China;CCTEG Shenyang Research Institute,Shenfu Demonstration Zone 113122,China;State Key Laboratory of Coal Mine Disaster Prevention and Control,Fushun 113122,China)

机构地区：[1]煤炭科学研究总院,北京100013 [2]中煤科工集团沈阳研究院有限公司,辽宁沈抚示范区113122 [3]煤矿灾害防控全国重点实验室,辽宁抚顺113122

出　　处：《矿业安全与环保》2024年第4期80-89,共10页Mining Safety & Environmental Protection

基　　金：国家重点研发计划项目(2022YFC3004701);辽宁省自然科学基金项目(2022-KF-13-03)。

摘　　要：为了探究不黏煤燃烧过程中自由基及主要燃烧产物生成规律,采用X射线光电子能谱(XPS)和核磁共振谱(^(13)C NMR)实验方法,对不黏煤进行表征分析,构建了分子式为C_(208)H_(199)O_(23)N_(3)S的不黏煤分子模型。在不同O_(2)分子数与温度条件下,应用反应分子动力学(ReaxFF MD)方法进行不黏煤的燃烧分子动力学模拟,探究其燃烧过程中自由基与主要产物的生成与消耗规律。研究结果表明:消耗OH自由基主要反应的总次数为1906次,消耗H自由基与O自由基的总次数分别为3733、2033次,提高温度和O_(2)分子数使得相对稳定的OH自由基产量峰值增幅更大,H自由基与O自由基的产量峰值增幅相对较小;消耗CO_(2)主要反应的总次数为1781次,低于消耗CO与H_(2)O主要反应总次数,提高温度和O_(2)分子数使得相对稳定的CO_(2)产量峰值增幅更大。提高O_(2)分子数对H_(2)O的产量峰值影响呈现先促进再抑制的趋势;H自由基、O自由基及OH自由基主要由小分子化合物或其他自由基发生分解反应生成。自由基聚合或小分子化合物分解反应是CO、CO_(2)及H_(2)O生成的主要路径。To explore the formation mechanisms of free radicals and major combustion products during the combustion of non-caking coal,this study conducts a comprehensive characterization analysis of non-caking coal using X-ray photoelectron spectroscopy(XPS)and^(13)C NMR nuclear magnetic resonance spectroscopy.A molecular model of non-caking coal(C_(208)H_(199)O_(23)N_(3)S)is developed.Utilizing the reaction molecular dynamics(ReaxFF MD)method,molecular dynamics simulations of coal combustion are performed under varying O_(2)molecule numbers and temperatures to explore the generation and consumption patterns of free radicals and main products.The results indicate that the OH free radical was consumed 1906 times in total,while the H and O free radicals were consumed 3733 times and 2033 times respectively.Increasing temperature and the number of O_(2)molecules resulted in a more significant increase in the peak yield of relatively stable OH free radicals,with smaller increases in the peak yields of H and O free radicals.The total number of primary reactions consuming CO_(2)was 1781,which was lower than the total number of primary reactions consuming CO and H_(2)O.Increasing temperature and the number of O_(2)molecules caused a greater increase in the peak yield of relatively stable CO_(2).The peak yield of H_(2)O initially increased and then decreased with the increase in the number of O_(2)molecules.H,O,and OH free radicals were primarily generated through the decomposition of small molecule compounds or other radicals.The main pathways for the formation of CO,CO_(2),and H_(2)O were the polymerization of free radicals or the decomposition of small molecule compounds.

关 键 词：煤分子模型 ReaxFF MD 燃烧势能 自由基 煤燃烧产物 

分 类 号：TD984[矿业工程—选矿]