纳米材料复合熔盐比热容的预测方法研究

Study on Prediction Method of Specific Heat Capacity of Nanomaterial Enhanced Molten Salt

本文针对掺杂SiO2纳米颗粒的Li2CO3/K2CO3纳米复合熔盐,考虑纳米吸附层和表面效应的影响,完善了其比热容预测方法。首先,使用分子动力学方法获得了熔盐离子在多壁碳纳米管吸附影响下的初始密度分布,并通过求解熔盐离子在SiO2纳米颗粒作用下诱导结晶形成纳米吸附层的过程,获得了纳米吸附层的含量。然后,基于修正的德拜热容理论,考虑表面高能原子的影响,获得了SiO2纳米颗粒及纳米吸附层的比热容。最后,基于该方法对掺杂不同粒径SiO2纳米颗粒的纳米复合熔盐比热容进行了预测,并和实验值进行了对比。结果表明当SiO2纳米颗粒含量较少时,与实验值之间的误差在-0.4%~3.5%之间,故该方法的预测结果具有较高的准确性。

In this study,with nanolayer and surface effect taken into consideration,the specific heat capacity prediction method of Li2 CO3/K2 CO3 composite molten salt doped with SiO2 nanomaterial is modified and improved.First,initial density distribution of the molten salt ions is obtained by applying molecular dynamics.The process in which molten salt ions are induced to crystallize induced by SiO2 and form nanolayer is studied,and the amount of nanolayer is obtained.Then based on the modified Debye theory,the specific heat capacity of SiO2 nanomaterial and nanolayer is calculated with the effect of high-energy surface atom taken into account.Finally,based on this method,the specific heat capacity of molten salt doped with nanoparticles of different size is predicted and validated with experiment results.The comparison results show that in the cases of small amounts of nanoparticle,the error between the prediction and the experiment values is within-0.4%3.5%.Therefore,the prediction results of this method have accuracy to a certain extent.