铁基换热面CaCO_3析晶污垢结合力分子动力学模拟

Molecular dynamics simulation of CaCO_3 crystallization fouling adhered on iron-based material surface

为了研究腐蚀产物Fe2O3在污垢与换热表面相互作用时的作用机理,采用分子动力学(MD)方法模拟了Fe和Fe2O3吸附方解石(1-10)晶面的体系,并且对2个体系进行吸附过程的平衡处理,通过计算2个体系吸附后的各种能量推导出吸附结构中结合能的大小,将Fe和Fe2O3吸附方解石(1-10)的2个体系的结合能进行了比较。计算结果表明:Fe2O3吸附方解石(1-10)晶面的结合能要比Fe吸附方解石(1-10)晶面的结合能高,同时,径向分布函数的计算也进一步证明了该结果。该理论计算得出,Fe的腐蚀产物Fe2O3吸附的污垢比Fe吸附的污垢更难以清理。

In order to study the formation mechanism of fouling with the action of Fe2O3 corrosion product, the absorption sys tem of Fe and Fe2O3 on calcite （1-10） crystal face was simulated and treated to be balanced in terms of molecular dynamics method. The adhesion energy of two absorption systems was deduced and compared by calculating all energy of the two absorption systems. The results show that the adhesion energy of Fe on calcite （1-10） crystal face is higher than that of Fe2O3 on calcite （1-10） crystal face. Meanwhile, the results are further proved by the calculation of radial distribution function. The theoretical calculation indicates it is hard to clean up the crystallization fouling adhered on Fe surface than that on Fe2O3 surface.