用电流衰减法检测埋地管线的防护层

1,2,1,3,1,2,1,2,3(1.,710065;2.,710065;3.,710049):(PCM),,,,:;;;:TG174.4:B:1005-748X(2005)12-0534-04APPLICATIONOFCURRENTATTENUATIONMETHODTOINSPECTIONOFPROTECTIVECOATINGONBURIEDPIPELINESWUBing1,2,LUOJin-heng1,3,ZHAOXin-wei1,GAOYong-li2,LIHe-ling1,2,3(1.TubularGoodsResearchCentreofCNPC,Xipan710065,China;2.XipanShiyouUniversity,Xipan710065,China;3.XipanJiaotongUniversity,Xipan710049,China)Abstract:ThemethodaboutdetectingthedamagedpointandcalculatingtheinsulationresistanceofprotectivecoatingonburiedpipelinsbyPCM(pipelinecurrentmap)isintroduced.Thebasictheoryforthepipelineinspectionisdiscussed.SomepracticalapplicationofPCMispresented.Keywords:Buriedpipeline;Externalprotectioncoating;Nondestructivetest;Pipelinecurrentmap1,,,,,/,,,,,,,,,:2005-03-24;:2005-04-1822.1[1,2],:--,(P/S)Pearson(PS)(CIPS)(DCVG)(PCM),DCVGPCM2.2,pipe-linecurrentmap,1,,,,,,,,PCM,,,#534#2612200512CORROSION&PROTECTIONVol.26No.12December200512.3[3],,,-,,2,,,323R,L,G,C,I(x)x,V(x)x,23,:dV(x)dx=-ZI(x)(1)dI(x)dx=YV(x)(2):Z=R+jXL,Y=G+jXL,Z,Y,RGLX,[Ili(x)]:Ili(x)=-dI(x)dx(3),,,(1)(2):d2Ii(x)dx2-C2iIi(x)=0(4):Ci=ZiYiiCi,:Ci=Ai+jBi,Bi=2P/Ki,Ki,Ai,Bi,(4):Ii(x)=Aie-Cix+BieCix(5):(1)x]I1(x)0(2)x=0I1(0)=I0:Ii(x)=I0e-Cix(6),xI=I0e-ax(7)AC,-:A=22(RG-X2LC)+(R2+X2L2)(G2+X2C2)(8)I(x)Idb=k+20lgI(x),,:8.6858A=InI(x2)-InI(x1)x2-x1(9),,,-,RLC,X,(8)G,GRg,Rg,SY/T5918-2004,,,#535#:,,,RgRg,,,,33.1[4](1)RD-PCM,:4Hz128Hz/640Hz,,,,PCMPearson454PCM5Pearson(2):763m,630mm@7.10mm630mm@8170mm,,30,,,3PE,,,3.2PCM11PCM(mA),m30609012015018021024027030033036039042095.311111211196111108109109106105105103993.3(1):PCM,,,,PCM,1,66(2):,Pearson,,,SY/T5918-20041#71#,871#81##536#:,,991#3.4,,,RgRg4,,,,,,,,:DCVGCIPS:DCVG,,CIPS:[1],,.[J].,2004,24(1):56~58.[2],.[J].,2003,24(6):260~262.[3]AleksandrMousatov.Electromagneticsurfacemethodforthepipelineperiodicalinspecttionbasedonthehet-erogeneoustransmissionlinemodel[A].ProceedingsofIPCIinternationalPipelineConference[C].CalgaryCanada:2004,IPC04-0223.[4]SY/T5918-2004,[S].(520),,,:,,;,,,,;,,,,,,,,4(1),,(2),,;;,(3);,,,,,,:[1],.[J].,1997,14(1):9.[2].()[M].:,1999.#537#: