以西部地区典型高阶烟煤为研究对象，从微观角度探究煤化学结构中化学键信息与热化学 转化行为之间的内在联系。 利用 ReaxFF-MD 在 1 000 ~ 3 000 K 温度内进行了一系列恒温模拟。 研究了一种含有 5 765 个原子的高阶烟煤复合显微组分分子模型的主要热分解机理，并探讨了不 同终温和不同升温速率下的热解反应产物分布。 模拟结果显示，当温度为 1 000 K 时，体系势能和 分子数目随着反应时间无明显变化。 随着热解反应温度的升高，体系势能和分子数目随反应时间 的增加而增加，热解生成的 C40+ 组分含量降低，气体组分和 C5 ~ C15 组分的含量增加。 C16 ~ C40 组分 的含量先增加后减小，在 2 500 K 时上升到最大值为 13.68%。 结果说明热解反应是一个吸热反应 过程。 在 1 500 K 时热解反应开始发生，热解反应的温度越高，热解反应的速率越大。 在热解反应 初期主要发生非化学键、弱桥键和侧链结构的断裂，包括氢键、π...π 堆积、Cal ― O、Cal ― Cal 等化学 键。 结果导致镜质组和惰质组分子之间相互缠绕形成的聚集状态开始发生解聚和分解;随后由热 解初始阶段产生的自由基和小分子碎片引发的桥键断裂反应和侧链的脱落，包括 Cal ― O，Cal ― Cal ，Car ― O，Cal ― H 等键。 模拟温度为 2 500 和 3 000 K 时，模型以分解和缩聚反应为主，主要表现 为焦油的二次反应。 不同升温速率下热解反应生成的产物含量不同，C40+ 组分的含量随着升温速 率的增加而显著增加。 C1~C4组分和非烃类气体的含量随着升温速率的增加呈现减小的趋势。 升 温速率越小达到相同热解温度所需要的时间越长，样品在热解温度下的停留时间也就越长，样品有 足够的时间吸收热量，使热解反应更充分。 样品中挥发分析出量越多，剩余的质量越少。 然而，升 温速率大，样品在热解温度下的停留时间越短，样品吸收的热量越少，热解反应不充分，热解效率 低。 因此，升温速率越大越不利于热解反应的发生。

Taking the typical high rank bituminous coal in Western China as the research object，the internal relation⁃ ship between chemical bond information and thermochemical transformation behavior in coal chemical structure was explored from the micro perspective. A series of constant temperature simulations were carried out at 1 000-3 000 K using ReaxFF-MD. The main thermal decomposition mechanism of a high-order molecular model containing 5 765 at⁃ oms was studied，and the distribution of pyrolysis products at different final temperatures and heating rates was dis⁃ cussed. The simulation results show that the potential energy and the number of molecules of the system have no obvi⁃ ous change with the reaction time at 1 000 K. With the increase of reaction temperature，the potential energy and mo⁃ lecular number of the system increase with the increase of reaction time，the content of C40+ component decreases， and the contents of gas component and C5 - C15 component increase. The content of C16 - C40 increases at first and then decreases，reaching a maximum of 13.68% at 2 500 K. The results show that the pyrolysis reaction is an en⁃ dothermic process. At 1 500 K，the pyrolysis reaction begins to take place，the reaction rate increases with the increase of pyrolysis temperature. In the initial stage of pyrolysis reaction，the non-chemical bond，weak bridge bond and side chain structure are broken， including hydrogen bond， π ... π stacking， Cal ― O， Cal ― Cal and other chemical bonds，which leads to the aggregation state of vitrinite and inertinite molecules entangled each other and begins to de⁃ polymerize and decompose. Then the pyrolysis reaction is initiated by free radicals and small molecular fragments in the initial stage of pyrolysis，including Cal ― O，Cal ― Cal ， Car ― O，Cal ― H and other chemical bonds. When the simulation temperature is 2 500 K and 3 000 K，the decomposition and polycondensation are the main reactions in the model，and the secondary reaction of tar is the main one. At different heating rates，the content of products pro⁃ duced by pyrolysis is different，the content of C40+ increases significantly with the increase of heating rate. The contents of C1 -C4 and non-hydrocarben gases decrease with the increase of heating rate. The smaller the heating rate，the lon⁃ ger the time needed to reach the same pyrolysis temperature. The longer the residence time of the sample at the pyrol⁃ ysis temperature， the sample has enough time to absorb heat to make the pyrolysis reaction more sufficient. The more the amount of volatiles in the sample， the less the residual mass. However， when the heating rate is high，the shorter the residence time of the sample at the pyrolysis temperature，the less the heat absorbed by the sam⁃ ple，the insufficient pyrolysis reaction and the low pyrolysis efficiency. Therefore，a high heating rate is harmful to the pyrolysis reaction.