Stepova O.V., Parashchiyenko I.M. Mathematical modeling of local corrosion element in pipelines with galvanic couple operating in soil conditions

 

Geoteh. meh. 2016, 127, 49-55

MATHEMATICAL MODELING OF LOCAL CORROSION ELEMENT IN PIPELINES WITH GALVANIC COUPLE OPERATING IN SOIL

CONDITIONS

1Stepova O.V., 1Parashchiyenko I.M.

1Poltava National Technical Yuri Kondratyuk University 

UDC (504.05 +504.06) 622.692.4

Abstract. Solution of the problem of modeling electrochemical corrosion in the pipeline sector with cracked insulating coating under the effect of electrolytic medium aggressive towards the pipeline metal is presented in this paper. The problem boils down to determining a stationary electrolytic field which occurs in the pipeline sector (a) in the crack when galvanic macrocouple operates with anode and (b) under the pipeline insulating coating when galvanic macrocouple operates with cathode. The advantage of this model is its ability to predict corrosion of the pipeline on time, which is important for determining the residual life of the structure. Distribution of potential electric field is determined by solving of the Laplace two-dimensional differential equation with given boundary conditions hence helping to obtain functional dependencies for calculation of current density (corrosion rate) and operating electric the acting galvanic macrocouple "crack in the metal metal under the insulation coating".
Keywords: electrochemical corrosion, underground pipelines, corrosion current.

REFERENCES

1. Kryvenyuk, V.V., Dobrovolskyi, V.Ye., Tkachov, V.I., Duravkin, I.P. and Soldatov, S.S. (2003), «On the resource assessment of durably operating CHP station’s equipment», Energetics and Electrification, no. 3, pp. 22-25.
2. Dobrovolskyi, V.E., I.P. Duravkin, I.P. and Soldatov, S.S. (2003), «Methods of studying the power equipment metal’s damage», Tezisy dokladov 4-oy natsionalnoy konferentsiyi «Nerazrushayushchiy kontrol I technicheskaya diagnostika» [Abstracts of the 4th National conference "Non-destructive testing and technical diagnostics], Kyiv: UTNKTD - pp. 86-87.
3. GKD (Branch Guidance Document) 34.17.401 Kontrol I uvelicheniye sroka sluzhby metalla oborudovaniya teplovykh elekrrostantsiy. Tipovaya instruktsiya. Chast 1. Kotly, turbiny i truboprovody s davleniyem 9 i vyshe [Metal durability control and extension for equipment of thermal power plants’. Standard instruction. Part 1. Boilers, turbines and pipelines under the pressure of 9 and above].
4. SOU-H IPE 40.1.17.401 2005, Kontrol metalla I uvelicheniye termina ekspluatatsiyi osnovnykh elementov kotlov , turbin I truboprovodov. Tipovaya instruktsiya. Srok proverki 2010 rik.[ Control of metal and life extension of the basic elements of boilers, turbines and pipelines. Standard instruction. The check term 2010], Kyiv, UA.
5. Duravkin, I.P. (2009), «Forecasting the residual operation life for the main steampipes at a heat power station»б . Abstract of Ph. D thesis, 01.02.04, NTU "KPI", Kiev, UA.
6. Tsybenko, A.S. (2006), «Durability assessment for long-term operated power plant engineering structures based on their stress-deformation status»,Bulletin of Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan, no. 13, pp. 165-167.
7. Stepova, O.V. (2006), «Assessment of the pipeline’s sectional area loss with a galvanic cell operatingon the pipeline’s surface in the soil condition», 4 Mezhdunarodny congress «Ustoychivoye razvitiye: zashchita okruzhayushchey sredy. Energosberezheniye. Prirodopolzovaniye [The 4th International Congress “Sustainable development: environmental protection. Energy-saving. Balanced nature management”], Lviv: NU “Lviv Polytechnic”, UA

About the authors:

Stepovaja Olena V., Ph. D (Tech), Associate Professor, Associate Professor of chair of applied ecology and nature management, Poltava National Technical Yuri Kondratyuk University, Poltava, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it. .

Parashchiyenko Irina M., Ph.D (Tech), Senior Teacher of chair of applied ecology and nature management, Poltava National Technical Yuri Kondratyuk University, Poltava, Ukraine.