LT3240B - Method for determining of protective current of main line - Google Patents

Method for determining of protective current of main line Download PDF

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Publication number
LT3240B
LT3240B LTIP554A LTIP554A LT3240B LT 3240 B LT3240 B LT 3240B LT IP554 A LTIP554 A LT IP554A LT IP554 A LTIP554 A LT IP554A LT 3240 B LT3240 B LT 3240B
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Lithuania
Prior art keywords
magnetic field
points
distance
strength
current
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LTIP554A
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Lithuanian (lt)
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Ivan Kuzmenok
Robertas Tamosiunas
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Ivan Kuzmenok
Robertas Tamosiunas
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Priority to LTIP554A priority Critical patent/LT3240B/en
Publication of LTIP554A publication Critical patent/LTIP554A/en
Publication of LT3240B publication Critical patent/LT3240B/en

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Abstract

The setting method of the main protecting current is based on the measuring of the magnetic field strength.The strength of the magnetic field is measured at three points, which are located in a vertical flat and the distance between which it is fixed. The flat goes through the axle of the pipe and is square with the flat.According to the strength of the magnetic field, the protective current and the potential are calculated using these formulas:Irot=4πa(H1-H2)(H2-H3)(H1-H3)/(H1+H3-2H2)<2>Urot=4aK(H1-H2)(H2-H3)(H1-H3)/Dv(H1-2H2+H3)<2>a - distance between the points, in which the strength (m) of the magnetic field is measured;H1, H2, H3 - the strength of the magnetic field at the first, second and third points (A/m);K - ferro-modulative converter coefficient (Ωm);Dv - outer pipe diameter (m).

Description

Numatomas išradimas priklauso prie vamzdynų katodinės apsaugos ir konkrečiau prie požeminių vamzdynų apsauginės srovės nustatymo, kai naudojama vamzdynų katodinė apsauga.The present invention relates to the cathodic protection of pipelines, and more particularly to the detection of undercurrent piping protection current when cathodic protection of pipelines is used.

Žinomas ilgų cilindrinių metalinių būdas bekontaktiniu metodu, (a.l. Nr. gas) .Known method of long cylindrical metal by non-contact method, (a.l. No. gas).

laidų kontrolės 1363080 - analoŽinomas ilgų cilindrinių metalinių laidų kontrolės būdas remiasi kintamo magnetinio lauko stiprumo azimutalinių komponentų matavimu dviejuose taškuose, esančiuose vienas nuo kito fiksuotu atstumu (pastovaus matavimų proceso metu) išilgai tiesės, kuri yra gaminio radiuso tęsinių, ir pastovaus magnetinio lauko stiprumo dydžių skirtumo matavimu tuose pačiuose taškuose, o pastovios srovės reikšmė nustatoma pagal formulę:Wire Control 1363080 - Analog The known method of controlling long cylindrical metal wires is based on the measurement of azimuthal components of variable magnetic field strength at two points at a fixed distance (through a continuous measurement process) along a line of product radius extension and constant magnetic field strength measurement at the same points and the DC value is given by:

hx.h2 h x .h 2

J = 2 Kb ΔΗ —---— čia (^-¾)2 J = 2 Kb ΔΗ —---— Here (^ -¾) 2

Hx ir H2 - kintamo magnetinio lauko, sukuriamo tekančia gaminyje kintama srove, stiprumo reikšmės atitinkamai artimesniame ir tolimesniame nuo gaminio ašies taškuose;H x and H 2 are the values of the magnitude of the alternating magnetic field generated by the current flowing in the product at points closer and farther away from the product axis, respectively;

ΔΗ - pastovaus magnetinio lauko stiprumo reikšmių tuose pačiuose taškuose skirtumas;ΔΗ is the difference in the constant magnetic field strengths at the same points;

b - atstumas tarp matavimo taškų.b is the distance between measurement points.

Žinomo būdo trūkumas yra apsauginės srovės matavimo sudėtingumas, o būtent dažnumo suderinimo su tekančios išilgai vamzdyno kintamos srovės dažnumu (pavyzdžiui, su katodinės apsaugos stoties pulsuojančios srovės dažnumu arba su specialiai prisijungiamo prie vamzdyno kintamos srovės generatoriaus dažnumu) ir stiprumo dydžių tuose pačiuose stebėjimo taškuose skirtumo matavimo būtinumas. Be to, aukščiau nurodytu būdu sunku nustatyti vamzdyno apsauginį potencialą.The disadvantage of the known technique is the complexity of measuring the protective current, namely measuring the difference in frequency matching with the frequency flowing along the pipeline AC (for example, pulsating current of the cathodic protection station or the frequency generator specifically connected to the pipeline) necessity. In addition, the protective potential of the pipeline is difficult to determine in the above manner.

Numatomo išradimo tikslas yra matavimo schemos supaprastinimas ir funkcionalinių galimybių išplėtimas pastovaus magnetinio lauko, sukuriamo katodinės apsaugos srove, stiprumo matavimo keliu.The object of the present invention is to simplify the measuring scheme and to extend the functional possibilities by measuring the strength of a constant magnetic field generated by a cathodic protection current.

Užsibrėžtas tikslas pasiekiamas tuo, kad atliekamas pastovaus magnetinio lauko matavimas ir trečiame taške, esančiame virš antro matavimo taško atstumu, kuris lygus atstumui tarp pirmo ir antro matavimo taškų, ir esančiame toje pačioje plokštumoje, praeinančioje per vamzdyno ašį, ir esančiame tiesėje, statmenoje vamzdyno ašiai, ir nustatoma apsauginė srovė pagal formulę:The objective is achieved by measuring a constant magnetic field at a third point above the second measuring point at a distance equal to the distance between the first and second measuring points and in the same plane passing through the axis of the pipeline and perpendicular to the axis of the pipeline. , and determine the protective current according to the formula:

4ma(H1-H2) (Ηχ-Η3) (H2-H3) (Hx 2h2+h3) (I) apsauginis potencialas nustatomas pagal formulę:The protective potential of 4ma (H 1 -H 2 ) (Η χ -Η 3 ) (H 2 -H 3 ) (H x 2h 2 + h 3 ) (I) is given by the formula:

U aps. p.U rpm p.

D vamzd. (H1-2H2+H3)2 a - atstumas tarp pastovaus magnetinio lauko stiprumo matavimo taškų, m;D pipe (H 1 -2H 2 + H 3 ) 2 a - distance between measuring points of constant magnetic field strength, m;

Hx, H2 ir H3 - pastovaus magnetinio lauko stiprumo reikšmės, matuojamos pirmame, antrame ir trečiame erdvės taškuose virš vamzdyno ašies, A/m;H x , H 2 and H 3 are the values of the constant magnetic field strength, measured at the first, second and third space points above the pipeline axis, in A / m;

K - feromoduliacinio daviklio pertvarkymo koeficientas,K - conversion factor of the ferromodulatory sensor,

D vamzd. - išorinis vamzdyno diametras, m.D pipe - outer diameter of the pipeline, m.

Brėžinyje pateikta šio būdo įgyvendinimo schema.The figure shows a diagram of the implementation of this method.

Schemoje pavaizduoti požeminis metalinis laidas I, pirmas 2, antras 3 ir trečias 4 magnetinio lauko davikliai, esantys atstumu vienas nuo kito, magnetinio lauko sukuriamo tekančia per vamzdynų apsaugine elektros srove, stiprumo matuoklis 5 ir indikatorius 6.The diagram shows the underground metal wire I, the first 2, the second 3, and the third 4 magnetic field sensors located at a distance from each other, the strength meter 5 and the indicator 6 of the magnetic field generated by the protective current flowing through the pipelines.

Sroves požeminiame metaliniame laide I matavimas atliekamas, pavyzdžiui, šiuo būdu.The current in the underground metal wire I is measured, for example, in this way.

Lauko davikliai 2, 3 ir 4 ir matuoklis 5 su indikatoriumi 6 sudaro magnitometrą, tinkamą pastovaus magnetinio lauko stiprumo matavimui trijuose stebėjimo taškuose.The field sensors 2, 3 and 4 and the meter 5 with indicator 6 form a magnitometer suitable for measuring the constant magnetic field strength at the three observation points.

Pagal išmatuotus pastovaus magnetinio lauko stiprumo dydžius trijuose taškuose Hlf H2 ir H3 skaičiuojami apsauginė srovė, apsauginis potencialas pagal aukščiau pateiktas formules (I, 2).From the measured values of the constant magnetic field strength at the three points H lf H 2 and H 3 , the protective current and the protective potential are calculated according to the formulas (I, 2) above.

Darbo su pastovia srove būtinumą sąlygoja tai, kad nutekėjimo srovės nuo metalo paviršiaus tankis yra dydis, kuris charakterizuoja korozijos pavojų, per korozijinės srovės tankį galima išreikšti elektrocheminės korozijos greitį.The necessity of working with a constant current is determined by the fact that the leakage current from the metal surface is a quantity that characterizes the risk of corrosion, and the rate of electrochemical corrosion can be expressed through the corrosion current density.

Nutekėjimo srovės tankį nesunku nustatyti pastovios (apsauginės) srovės pasiskirstymo išilgai metalinio laido diagramos, kuri randama pagal srovės reikšmių matavimo šiuo būdu rezultatus, pagalba.The leakage current density is not easily determined by the distribution of a constant (protective) current along the metal wire diagram, which is obtained from the results of the current measurement in this way.

Apsauginės srovės ir potencialo reikšmių matavimai leidžia nustatyti korozijinio pavojaus laipsnį, išrinkti apsauginio įrengimo tipą ir prognozuoti galimą srovės išėjimo iš metalinio laido į žemę vietą drenažo įrengimui.Measurements of the protective current and potential values allow to determine the degree of corrosion hazard, to select the type of protective equipment and to predict the possible place of current discharge from the metal wire to the ground for drainage installation.

Šio būdo realizacija leidžia gauti duomenis planavimui ir magistralinių vamzdynų, jų izoliacijos remonto vykdymui arba elektrocheminės apsaugos priemonių koregavimui, kas bendrojoje sumoje duoda galimybę pakelti patikimumą ir padidinti požeminių brangių eksploatavimo terminus.The realization of this method allows to obtain data for planning and carrying out repairs of pipelines, their insulation or adjustment of electrochemical protection measures, which in the aggregate allows to increase reliability and increase the underground costly service life.

Claims (1)

IŠRADIMO APIBRĖŽTISDEFINITION OF INVENTION Magistralinių vamzdynų apsauginės srovės nustatymo būdas, pagrįstas magnetinio lauko stiprumo matavimu teslametrais dviejuose taškuose, išdėstytuose vertika-lioje plokštumoje, einančioje per vamzdžio ašį ir esančiuose ant tiesės statmenos vamzdžio ašiai tam tikru atstumu vienas nuo kito, besiskiriantis tuo, kad apsaugos srovės sukuriamo pastovaus magnetinio lauko stiprumą matuoja ir trečiame taške, kuris yra ant tos pačios tiesės virš šių dviejų taškų ir atstumas iki jo yra lygus atstumui tarp pirmo ir antro taško, o apsaugos srovę ir potencialą suranda iš formulių:A method for determining the protective current in trunk pipelines based on the measurement of magnetic field strength by teslammeters at two points located in a vertical plane passing through a pipe axis at a distance perpendicular to the pipe axis, such that a constant magnetic field the strength is also measured at the third point on the same line above these two points and the distance to it is equal to the distance between the first and second points, and the protection current and potential are determined by the formulas: I apsaugosI protection U apsaugosU guards 4Ka(H1-H2) (HrH3) (H2-H3) (H1-2H2+H3)2 4Ka (H 1 -H 2 ) (H r H 3 ) (H 2 -H 3 ) (H 1 -2H 2 + H 3 ) 2 4aK(Hx-H2) (Hx-H3) (H2-H3) Dv. (Hx-2H2+H3)2 kur: a - atstumas tarp taškų, kuriuose matuojamas magnetinio lauko stiprumas (m),4aK (H x -H 2 ) (H x -H 3 ) (H 2 -H 3 ) Dv. (H x -2H 2 + H 3 ) 2 where: a is the distance between the points measuring the magnetic field strength (m), Hx, H2, H3 - magnetinio lauko stiprumas pirmame, antrame ir trečiame taškuose (A/m),H x , H 2 , H 3 - magnetic field strength at first, second and third points (A / m), K - feromoduliacinio daviklio keitimo koeficientas (Ω m) ,K - coefficient of change of ferromodulation sensor (Ω m), Dv.- išorinis vamzdžio skersmuo (m).Dual - outer pipe diameter (m). SL 1520. Tir. 50 egz. Užsakymas 179SL 1520. Tir. 50 copies Ordering 179 Lietuvos Respublikos valstybinis patentų biuras, Algirdo 31, 2600 Vilnius. Spausdino Lietuvos informacijos instituto spaustuvė, Totorių 27, 2000 Vilnius.State Patent Bureau of the Republic of Lithuania, Algirdo 31, 2600 Vilnius, Lithuania. Printed by the printing house of the Lithuanian Information Institute, Totorių 27, 2000 Vilnius.
LTIP554A 1993-05-13 1993-05-13 Method for determining of protective current of main line LT3240B (en)

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Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU1363080A1 (en) 1986-02-20 1987-12-30 Физико-механический институт им.Г.В.Карпенко Method of checking lengthy cylindrical metal conductors

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU1363080A1 (en) 1986-02-20 1987-12-30 Физико-механический институт им.Г.В.Карпенко Method of checking lengthy cylindrical metal conductors

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