单一应力下义马原煤热解产物演变规律及动力学模拟OACSTPCD

Taking Yima coal as the research object,the crystalline cell was constructed.In the ReaxFF force field,the 5×109 s-1 strain rate was applied to simulate the pyrolysis product evolution of Yima coal at the final temperatures of 1000 K,1500 K,2000 K,2500 K,3000 K and to analyze the effect of single stress on lignite pyrolysis.The results show that the stress in different directions fluctuates up and down at different simulated final temperatures.The stress range remains between±70 GPa with an allowable uncertainty,indicating that the effect of this stress on the pyrolysis of lignite is weakly affected by temperature.In the simulation process,there is a minimum point in the number of molecules and a maximum point in the number of spe-cies between 26 ps-33 ps.The simulated starting temperature point of Yima coal pyrolysis re-mains unchanged,but the temperature range of the polycondensation reaction moves forward.It indicates that the effect of single stress is better than that of temperature in the early stage of the reaction process,and stress promotes the overall reaction process.The contents of CO,CH4,H2O and NH3 first increase and then decrease due to the effect of polycondensation,which con-forms to the general pyrolysis law,indicating that the stress does not change the ultimate trend of the reaction.The quantities of H2 and·H continue to rise,which explains that the cracking quantities of·H in the tar by this stress is higher than that of·H consumed by the polyconden-sation reaction.At the same time,the elevated contents of·H and H2 promote the combination of·SH with·H,thereby increasing the yield of H2 S.