基于壳层法的黄陵气煤低温热解数值模拟OA北大核心CSTPCD

Aimed at solving the problem of balancing predictive accuracy and computa-tional efficiency involved in the simulation of coal pyrolysis,a one-dimensional transient model for the low-temperature pyrolysis process was established,featuring both faster computational speed and precise predictions of the internal temperature,gas velocity and volatile yield distribu-tion of coal samples.The Shell method and Ergun formula were employed to simplify the grid el-ements and momentum equation respectively.A comprehensive method integrating water evapo-ration model,coal pyrolysis kinetics model,tar pyrolysis model,and control equation was adopt-ed to numerically simulate the low-temperature pyrolysis process of Huangling gas coal.It is showed that the simulated yields of various volatile components closely aligned with the experi-mental results,with an error no more than 14%.The low-temperature pyrolysis simulation process can be completed within 47 min.This model is further used to analyze the variations of multiple physical fields within coal samples during low-temperature pyrolysis,along with their influences on the pyrolysis process and product distribution.Firstly,it is found that heat absorp-tion caused by water evaporation leads to a slower heating rate in the inner layer of coal samples,thereby delaying the pyrolysis reaction and prolonging the reaction time.Secondly,the gas veloc-ity is determined by the generation rate of water vapor,tar,and pyrolysis gas,which has a sig-nificant impact on the tar cracking reaction.A lower gas velocity facilitates faster tar cracking,increasing the probability of tar cracking reaction occurring from the outside to the inside of the coal sample.Thirdly,the heating rate is an important factor affecting the yield of pyrolysis gas and tar.The lower the heating rate,the more complete the pyrolysis,and the higher the yield of pyrolysis gas and tar.Finally,the particle size of coal samples has a relatively minor impact on the yield of pyrolysis gas and tar.