Correlation between the fouling of different crystal calcium carbonate and Fe₂O₃ corrosion on heat exchanger surface

ABSTRACT

As fouling and corrosion often occur in the heat exchanger simultaneously, it is difficult to research the two problems separately. In this work, the adsorption behaviour of Fe₂O₃/Fe, calcite and aragonite on the corroded surface were studied by molecular dynamics and the corrosion-fouling experiment. The results prove that the parameters of the Fe(0 0 1) surface can be affected by the Fe₂O₃ corrosion. The interaction energy between the calcium carbonate and substrate shows that both Fe and Fe₂O₃ surfaces have certain adsorption effect on calcium carbonate crystallisation fouling. In addition, the adsorption effect of Fe₂O₃(0 0 1) on calcite during the fouling induction period is three times than that on the Fe(0 0 1) surface. Although the aragonite is prone to adhering to the non-corroded substrate, the binding ability between aragonite and substrate is weaker than that between calcite and substrate. Moreover, according to the corrosion-fouling experiment, the precipitate on the surface of the non-corroded is mainly calcite-phase calcium carbonate mingled with the acicular aragonite-phase calcium carbonate. The mass gain of fouling increases with the increasing corrosion of the substrate. The work provides evidence that the fouling nucleation of the calcium carbonate can be influenced by the corroded surface.

KEYWORDS:

• α-fe₂O₃
• adsorption process
• calcite
• fouling
• molecular dynamics

Acknowledgments

The authors want to thank the support of the China Nuclear Power Engineering Co. Ltd. (007-EC-B-2020-C84-P.B.10-01361), Guangdong Natural Science Foundation (2020A1515110449, 2020A1515011033), Foundation Research Funds for the Central Universities (19lgpy22), National Natural Science Foundation of China (51901254)

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability

The data that support the findings of this study are available on request from the corresponding author, [initials]. The data are not publicly available due to [restrictions e.g. their containing information that could compromise the privacy of research participants].

Additional information

Funding

This work was supported by China Nuclear Power Engineering Co., Ltd: [grant number 007-EC-B-2020-C84-P.B.10-01361]; Natural Science Foundation of Guangdong Province: [grant number 2020A1515011033,2020A1515110449]; National Natural Science Foundation of China: [grant number 51901254]; Foundation Research Funds for the Central Universities: [grant number 19lgpy22] .