Contemporary approaches to reducing scale formation in heat-exchange equipment

Objectives. Scale formation and corrosion are serious problems for heat and power equipment. These processes, when intense, can completely block the operation of the system, accelerating corrosion and leading to clogging, local overheating, and burnouts and ruptures of boilers and pipes, which in turn can lead to major environmental problems. Therefore, protecting surfaces from scale formation and corrosion is an important task. Promising methods for preventing the development of undesirable consequences include changing the composition of polymer coatings, e.g., by introducing microencapsulated corrosion inhibitors, as well as surface modification approaches, such as hydrophobization of the polymer coating surface. The purpose of the present work is to analyze methods for reducing scale formation and the rate of corrosion processes, as well as to study the efficiency of modification of paints and coatings by introducing microencapsulated corrosion inhibitors.

Methods. The study was based on the use of accelerated corrosion tests.

Results. Existing methods for reducing scale formation and corrosion rate on the surfaces of heat and power equipment were analyzed. The efficiency of modifying protective polymer materials by introducing microcapsules containing an active phosphonate additive was compared with approaches involving the surface modification of such protective materials.

Conclusions. It was determined that the modification of paints and coatings by introducing microencapsulated active additives can significantly reduce the rates of both scale formation and corrosion. By implementing stateof-the-art methods for modifying polymer coatings, a new generation of agents for efficiently preventing scale formation and corrosion processes can be developed for maintaining the high performance of heat-exchange equipment.

1. Saremi M., Dehghanian C., Sabet M. The effect of molybdate concentration and hydrodynamic effect on mild steel corrosion inhibition in simulated cooling water. Corros. Sci. 2006;48(6);1404–1412. https://doi.org/10.1016/j.corsci.2005.06.009

2. Betz Handbook of Industrial Water Conditioning: 8th ed. BETZ Labratories Inc., USA; 1980. 440 p.

3. Materialy konferentsii nachal’nikov turbinnykh tsekhov rossiiskikh i zarubezhnykh AES po povysheniyu nadezhnosti i effektivnosti turbinnogo oborudovaniya NTTs 2013 (Materials of the conference of heads of turbine shops of Russian and foreign NPPs on improving the reliability and efficiency of turbine equipment STC 2013). Moscow; 2013 (in Russ.).

4. Mwaba M.G., Golriz M.R., Gu. J. A semi-empirical correlation for crystallization fouling on heat exchange surfaces. Appl. Therm. Eng. 2006;26(4):440–447. https://doi.org/10.1016/j.applthermaleng.2005.05.021

5. Golovin V.A., Pechnikov N.V., Shchelkov V.A., Tsivadze A.Yu. Evaluation of the service life of heat exchange tubes of steam condensers based on statistical analysis of local ulcerative corrosion according to eddy current control data. Fizikokhimiya poverkhnosti i zashchita materialov = Physical chemistry of the surface and protection of materials. 2018. Vol. 54. P. 14–26 (in Russ.). https://doi.org/10.1134/S004418561806013X

6. Zhang H.H., Pang X., Meng Z., Chao L., Liang W., Gao K. The behavior of pre-corrosion effect on the performance of imidazoline-based inhibitor in 3 wt % NaCl solution saturated with CO2. Appl. Surf. Sci. 2015;356:63–72. https://doi.org/10.1016/j.apsusc.2015.08.003

7. Avdeev Y.G., Kuznetsov Y.I. Inhibitory protection of steels from high-temperature corrosion in acid solutions. A review. Part 1. Int. J. Corros. Scale Inhib. 2020;9(2): 394–426. http://dx.doi.org/10.17675/2305-6894-2020-9-2-2

8. Bovt V.V., Mikov A.I. Kompozitsiya na osnove nitrata karbamida i sposob polucheniya kompozitsii na osnove nitrata karbamida (Composition based on carbamide nitrate and method for producing a composition based on carbamide nitrate): RF Pat. 2497941. Publ. 10.11.2013 (in Russ.).

9. Aptekman A.G., Beklemyshev V.I., Bolgov V.Yu., Makhonin I.I. Promyvochnyi sostav dlya udaleniya nakipi (Flushing composition for descaling): RF Pat. 2172301. Publ. 20.08.2001 (in Russ.).

10. Aliev Z.M., Magomedova D.Sh., Sup’yanova E.A., Yaldarov E.M. Using electrochemically synthesized anolyte for cleaning internal surfaces of pipelines from scale. Vestnik Dagestanskogo gosudarstvennogo universiteta = Herald of Dagestan State University. 2014;6:148–150 (in Russ.).

11. Linnikov O.D., Rodina I.V., Anokhina E.A., et al. Sposob ochistki oborudovaniya ot otlozhenii s vysokim soderzhaniem medi (Method for cleaning equipment from deposits with a high copper content): RF Pat. 2359196. Publ. 20.06.2009 (in Russ.).

12. Akhmedov G.Ya. Sposob ochistki teploobmennika ot karbonatnykh otlozhenii (Method for cleaning the heat exchanger from carbonate deposits) RF Pat. 2528776. Publ. 20.09.2014 (in Russ.).

13. Gaidar S.M. Vodorastvorimyi ingibitor korrozii metallov (Water-soluble metals corrosion inhibitor): RF Pat. 2355820. Publ. 20.05.2009 (in Russ.).

14. Artamonova I.V., Gorichev I.G. Ecological features of carbonate deposit removal from the surface of manufacturing equipment. Izvestiya MGTU MAMI. 2009;8(2):220–227 (in Russ.).

15. Shagiev N.G., Chichirova N.D., Abasev Yu.V., Lyapin A.I. Thermodynamic analysis of processes in water contours of power stations at chemical clearing with use of compositions based on a complexons. Izvestiya vysshikh uchebnykh zavedenii. Problemy Energetiki = Power engineering: research, equipment, technology. 2003;(11–12):82–88 (in Russ.).

16. Zhang P., Lv F.Y. A review of the recent advances in superhydrophobic surfaces and the emerging energyrelated applications. Energy. 2015;82:1068–1087. https://doi.org/10.1016/j.energy.2015.01.061

17. Barati D.G., Aliofkhazraei M., Khorsand S., Sokhanvar S., Kaboli A. Science and engineering of superhydrophobic surfaces: review of corrosion resistance, chemical and mechanical stability. Arab. J. Chem. 2020;13(1): 1763–1802. https://doi.org/10.1016/j.arabjc.2018.01.013

18. Latthe S.S., Sutar R.S., Kodag V.S., Bhosale A.K., Kumar A.M., Kumar Sadasivuni K., Xing R., Liu S. Self – cleaning superhydrophobic coatings: potential industrial applications. Prog. Org. Coat. 2019;128:52–58. https://doi.org/10.1016/j.porgcoat.2018.12.008

19. Cao L., Jones A.K., Sikka V.K., Wu J., Gao D. Anti-Icing superhydrophobic coatings. Langmuir. 2009;25(21): 12444–12448. https://doi.org/10.1021/la902882b

20. Mehmood U., Al-Sulaiman F.A., Yilbas B.S., Salhi B., Ahmed S.H.A., Hossain M.K. Superhydrophobic surfaces with antireflection properties for solar applications: a critical review. Sol. Energy Mater. Sol. Cells. 2016;157:604–623. https://doi.org/10.1016/j.solmat.2016.07.038

21. Gwon H.J., Park Y., Moon C.W., Nahm S., Yoon S.J., Kim S.Y., Jang H.W. Superhydrophobic and antireflective nanograsscoated glass for high performance solar cells. Nano Res. 2014;7(5):670–678. https://doi.org/10.1007/s12274-014-0427-x

22. Gao X.F., Jiang L. Biophysics: water-repellent legs of water striders. Nature. 2004;432(7013):36. https://doi.org/10.1038/432036a

23. Gao X., Yan X, Yao X., Xu L., Zhang J., Zhang K., Yang B., Jiang L. The dry-style antifogging properties of mosquito compound eyes and artificial analogues prepared by soft lithography. Adv. Mater. 2007;19(17):2213–2217. https://doi.org/10.1002/adma.200601946

24. Liu T., Chen S.G., Cheng S., Tian J.T., Chang X.T., Yin Y.S. Corrosion behavior of super-hydrophobic surface on copper in seawater. Electrochim. Acta. 2007;52(28): 8003–8007. https://doi.org/10.1016/j.electacta.2007.06.072

25. Yin Y.S., Liu T., Chen S.G., Liu T., Cheng S. Structure stability and corrosion inhibition of super-hydrophobic film on aluminum in seawater. Appl. Surf. Sci. 2008;255(5): 2978–2984. https://doi.org/10.1016/j.apsusc.2008.08.088

26. Hooda A., Goyat M.S., Pandey J.K., Kumar A., Gupta R. A review on fundamentals, constraints and fabrication techniques of superhydrophobic coatings. Prog. Org. Coat. 2020;142:105557. https://doi.org/10.1016/j.porgcoat.2020.105557

27. Wang G., Zhang T.Y. Easy route to the wettability cycling of copper surface between superhydrophobicity and superhydrophilicity. ACS Appl. Mater. Interfaces. 2012;4(1):273–279. https://doi.org/10.1021/am2013129

28. Mortazavi V., Khonsari M. On the degradation of superhydrophobic surfaces: a review. Wear. 2017;372–373: 145–157. https://doi.org/10.1016/j.wear.2016.11.009

29. Boinovich L.B., Emelyanenko A.M. The prediction of wettability of curved surfaces on the basis of the isotherms of the disjoining pressure. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2011;383(1–3): 10–16. https://doi.org/10.1016/j.colsurfa.2010.12.020

30. Golovin V.A., Kaz’min A.N., Nemytova A.M. Experience gained from using protective coating of cooling tubes in the condensers at the Leningrad and the Smolensk nuclear power plants. Term. Eng. 2012;59(2):119–124. https://doi.org/10.1134/S0040601512020048

31. Ilyin A.B., Shchelkov V.A., Dobriyan S.A., Lukin V.B., Golovin V.A. Polymer coatings for protection of heatexchange tubes of vapor condenser against corrosion and saltation. Mezhdunarodnyi nauchno-issledovatel’skii zhurnal = International Research Journal. 2018;5(71): 69–75 (in Russ.). https://doi.org/10.23670/IRJ.2018.71.037

32. Golovin V.A. Prevention of scale formation and corrosion of heat transfer surfaces of NPP condensers. In: Рroceeding of Conference of Heads of Turbine Shops of Russian and Foreign NPPs on Improving the Reliability and Efficiency of Turbine Equipment. Rosenergoatom Concern JSC, February 13–15, 2018 (in Russ.)

33. Golovin V.A., Il’in A.B., Kuznec V.T., Vartapetjan A.R. Sposob zashhity ot korrozii metallicheskih poverhnostej ingibirovannymi polimernymi kompozicijami i mikrokapsuly s ingibitorom korrozii (Method of protecting metal surfaces inhibited with polymer compositions from corrosion and micro-capsules with a corrosion inhibitor (versions)): RF Pat. 2358036. Publ. 10.06.2009 (in Russ.).

34. Golovin V.A., Kuznets V.T., Kublitsky K.V., Ilin A.B. Method for protection against corrosion and scale deposit and for restoring tubes of heat-exchanging equipment and device for carrying out said method: US Pat. 7836844. Publ. 23.11.2010.

35. Golovin V.A., Ilyin A.B., Aliev A.D. Diffusion of phosphonic scale inhibitors for scale in epoxy matrices. Mezhdunarodnyj nauchno-issledovatel’skij zhurnal = International Research Journal. 2018;70(4):92–96 (in Russ.). https://doi.org/10.23670/IRJ.2018.70.033