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以热重实验中的煤氧化增重现象为线索,对400℃前煤氧化的反应机理和动力学过程进行了理论研究.借助于平行反应理论,将煤低中温氧化过程简化为3个平行的竞争反应,包括水分析出、氧吸附和固相氧化产物分解的反应以及直接的＂burn-off＂反应.通过对不同氧体积浓度（10%,21%和40%）下的实验数据全过程上的非线性最小二乘法拟合,确定出各反应的动力学参数以及相应的温度作用范围.模化的结果与实验数据高度贴近,证明了反应模型和计算方法的可靠性.煤低中温氧化过程中的质量变化,主要是由氧吸附反应和固相氧化产物的分解反应所控制的;由直接的＂burn-off＂反应所引起的质量变化则相对较小.煤氧化增重现象对应的反应及动力学过程并不能由单一反应模型来近似.氧浓度的提高导致氧吸附反应和固相氧化产物的分解反应加剧,而＂burn-off＂反应受氧浓度的影响并不显著,这是由用于解析动力学参数而选定的实验数据的温度范围和特征所决定的.“,”The reaction mechanism and kinetics of coal oxidation at temperatures prior to 400 ℃ were studied theoretically,with a focus on the phenomenon of mass increase observed by thermo-gravimetric analysis（TGA）.In light of the existing understanding on coal oxidation,chemical reactions taking place at moderate temperatures were simplified into three parallel but competitive reaction sequences,including water release,oxygen adsorption and decomposition of the oxygenated compounds,as well as the direct ＂burn-off＂ reaction.Using the non-linear least-square fitting technique,the kinetic parameters of all the reactions occurring within the temperature range studied were determined by fitting the sets of TG and DTG data collected at the oxygen concentrations of 10%,21% and 40% in volume,respectively.The modeling results are in excellent agreement with the experimental data,confirming the reliability of the model established.It is proved that the mass increase during coal oxidation at moderate temperatures is primarily contributed by the oxygen adsorption and the subsequent decomposition reactions,while influence of the direct ＂burn-off＂ reaction on this phenomenon is relatively trivial.Since the mass increase phenomenon is a compromised result of the principal reactions involved,and the kinetic parameters of the oxygen adsorption reaction cannot be determined with accuracy based upon this phenomenon with a utilization of a single-reaction assumption.Enrichment of O2in the reaction medium speeds up the rates of oxygen adsorption reaction and the decomposition reaction.However,we did not observe the significant effect of the oxygen concentration on the direct ＂burn-off＂ reaction,solely due to the nature of the experimental data selected and the techniques utilized for retrieving the kinetic data for the reactions involved.