Daim Ntawv Thov Ntawm Cathodic Protection Technology hauv Cov kav dej xa dej

Cathodic Protection Technology Daim ntawv thov hauv av Cov kav dej (Steel Pipes thiab PCCP) yog txoj hauv kev tseem ceeb los tiv thaiv cov hlau xeb thiab txuas ntxiv rau kev pab cuam lub neej. Vim muaj qhov sib txawv ntawm cov khoom siv thiab kev pabcuam ib puag ncig ntawm cov kav hlau thiab cov yeeb nkab Prestressed Concrete Cylinder Pipes (PCCP), muaj qhov sib txawv tseem ceeb hauv kev tsim thiab kev siv ntawm kev tiv thaiv cathodic.

1. Corrosion Ib puag ncig thiab kev sib tw

Cov yam ntxwv tseem ceeb ntawm corrosion:

• Electrochemical corrosion: Corrosion hlwb tsim los ntawm qhov sib txawv ntawm cov av noo, salinity, thiab oxygen.
• Stray tam sim no corrosion: tam sim no cuam tshuam los ntawm cov chaw nyob ze zog thiab kev tsheb ciav hlau.
• Microbial corrosion (MIC): Sulfate-txo cov kab mob (SRB) ua kom corrosion hauv cov av anaerobic.

Siab - thaj chaw muaj kev pheej hmoo:

• Weld seams thiab txheej tsis xws luag: Hauv zos raug cov kav hlau ua raws li anodes.
• Siab- ntsev/tsawg tiv taus av (xws li, ntug hiav txwv dej): Corrosion npaum li cas mus txog 0.1 ~ 0.3 hli / xyoo.

2. Cathodic Protection Technology xaiv

Sacrificial Anode System (Sacrificial Anode CP, SACP)

1) Siv tau scenarios:

• Luv- nrug (<5 km), small-diameter (
• Av los yog dej tshiab ib puag ncig.

2) Cov khoom siv anode:

• Magnesium alloy anodes: High tsav voltage, haum rau siab -resistivity av los yog dej tshiab.
• Zinc alloy anodes: Tsawg tsav tsheb voltage, haum rau qis-cov av tsis kam (<1000 Ω·cm).

3) Tsim parameter:

• Kev tiv thaiv tam sim no ceev: 0.02 ~ 10 mA / m² (nyob ntawm cov txheej txheem zoo thiab cov kav dej, piv txwv li, 5-10 mA / m² rau 3PE-coated faus kav hauv cheeb tsam, 0.01-0.05 mA / m² pipelines ntev-3distance.
• Anode faus qhov tob: 1.5 ~ 2 meters (nyob hauv cov av ntub dej hauv qab cov kav dej).

Impressed Current System (Impressed Current CP, ICCP)

1) Siv tau scenarios:

• Long-distance (>10 km), large-diameter (>DN1000) cov kav dej.
• Av lossis dej ib puag ncig.

2) System Cheebtsam:

• Anode txaj: High-silicon cam khwb cia hlau anodes, MMO (Mixed Hlau Oxide) anodes, graphite anodes, hloov tau anodes, thiab lwm yam.
• Fais fab mov: tas li muaj peev xwm rectifier (tswj muaj peev xwm ntawm -0.85 ~ -1.20 V vs. Cu/CuSO₄).
• Siv cov electrodes: Permanent Cu/CuSO₄ electrodes (faus ze ntawm cov kav dej).

3) Tsim cov ntsiab lus tseem ceeb:

• Tej thaj chaw deb anode txaj Ntau dua los yog sib npaug li 50 meters los ntawm cov kav dej kom tsis txhob muaj qhov sib npaug tam sim no.
• Distributed anode txaj (ntau cov ntsiab lus dispersed) rau complex terrains los yog hauv nroog ntom ntom.

Cov thev naus laus zis tseem ceeb thiab kev tiv thaiv sib xyaw

1) Txheej + CP kev sib koom ua ke:

• Txheej hom: 3PE (peb- txheej polyethylene), FBE (fusion-bonded epoxy), thiab lwm yam.
• Kev tswj qhov tsis xws luag: CP kev pab them nqi rau cov ntsiab lus puas (tam sim no qhov ceev Tsawg dua los yog sib npaug rau 10 mA / m² thaum kev puas tsuaj<1%).

2) Bonding thiab rwb thaiv tsev:

• Siv cov flanges insulating los yog cov pob qij txha los cais cov kav dej tiv thaiv los ntawm lwm cov qauv hlau uas tuaj yeem cuam tshuam nrog CP tam sim no.
• Txhim kho kev sib txuas cables kom sib npaug qhov sib txawv.

1. PCCP Corrosion Mechanism

Cov yam ntxwv ntawm tus qauv:

• Prestressed steel hlau qhwv nyob ib ncig ntawm lub tog raj kheej steel, npog nrog pob zeb txheej txheej.
• Hlau corrosion txaus ntshai: Cov pa roj carbonization los yog chloride nkag mus ua kom puas cov yeeb yaj kiab passivation.

Corrosion qhov tshwm sim:

• Hlau tawg ua rau cov yeeb nkab tawg (piv txwv li, 2000 PCCP tawg tshwm sim hauv Tampa Bay, Tebchaws Asmeskas).

2. CP Technical Challenges

Tam sim no shielding:

• Cov khaubncaws sab nraud povtseg cuam tshuam tam sim no los ntawm kev ncav cuag cov xov hlau, yuav tsum tau tsim tshwj xeeb.

Hydrogen embrittlement risk:

• Tshaj -kev tiv thaiv (muaj peev xwm<-1.00 V vs. Cu/CuSO₄) may cause hydrogen-induced fractures in high-strength wires.

Saib xyuas cov teeb meem:

• Cov hlua khi hauv cov pob zeb yuav tsum muaj peev xwm ntsuas los ntawm cov txheej txheem tiv thaiv.

3. CP Kev Ua Haujlwm Kev daws teeb meem

Kev faib tawm anodes:

• Txhim kho zinc alloy anodes nyob rau hauv cov av sab nraum cov yeeb nkab phab ntsa, los yog MMO ribbon anodes / conductive polymer anodes.

Tej thaj chaw deb anode txaj:

• Rau cov kav dej uas twb muaj lawm, siv qhov sib sib zog nqus- zoo anode txaj kom nkag mus rau hauv cov pob zeb.

Design parameters:

• Kev tiv thaiv muaj peev xwm: -0.85 ~ -1.00 V (vs. Cu/CuSO₄) kom tsis txhob muaj hydrogen embrittlement.
• Tam sim no qhov ceev: 0.1 ~ 1.0 mA / m² (tsawg tam sim no thov vim muaj kev ua vaj tse siab).

4. Kev saib xyuas thiab tu

Muaj peev xwm saib xyuas:

• Kev sojntsuam: faus saturated Cu/CuSO₄ electrodes hauv av los yog ua ntej -embedded Mn/MnO₂ electrodes hauv pob zeb rau tiag tiag - lub sij hawm xaim muaj peev xwm saib xyuas.
• Sectional rwb thaiv tsev: Faib cov kav dej PCCP rau hauv ntu rau kev saib xyuas tus kheej.

Hlau breakage ceeb toom:

• Acoustic emission (AE): Tshawb xyuas cov kev ntxhov siab nthwv dej ntawm cov hlau tawg.
• Electromagnetic method (EMAT): Tshawb xyuas cov yeeb nkab ntawm qhov chaw los ntsuas kev ncaj ncees ntawm cov hlau.

• Tuam Tshoj Harbor Karachi No.4 Dej Pipeline EPC Project, Pakistan
• JAFURAH Desalination & Water Supply Project (JFD)
• Xinjiang 180km PCCP Pipeline CP Project siv ua ntej- ntim zinc anodes thiab siab -purity zinc ribbon anodes.
• Xinjiang Kashi Lub Nroog Dej Haus Dej Nyab Xeeb Kev Nyab Xeeb.
• Xinjiang Pishan River Basin Joint Water Supply Project (Phase I) CP
• Ningbo Taoyuan Water Plant & Outbound Pipeline CP Project
• Putian Jinzhong Water Hub Diversion Project - Mazu ceg ntug dej hiav txwv PCCP Pipeline

1. Cov teeb meem tam sim no

• Kev faib tawm tsis sib xws PCCP tam sim no: Qhov sib txawv ntawm cov pob zeb tuab ua rau hauv zos hauv qab - kev tiv thaiv / dhau - kev tiv thaiv.
• Tus nqi -kev ua tau zoo: PCCP CP tus nqi 3 ~ 5 × siab dua steel yeeb nkab tshuab (vim qhov yuav tsum tau muaj kev nkag mus rau pob zeb).
• Hydrogen embrittlement tswj: Yuav tsum muaj cov cai muaj peev xwm (piv txwv li, siv cov peev txheej txwv).

2. Cov lus qhia tshiab

Cov ntaub ntawv ntse anode:

• Tus kheej - tswj anodes (kho hloov tam sim no cov zis raws li cov av noo / salinity).
• Nano-composite anodes (piv txwv li, CNT- txhim kho MMO rau kev txhim kho tam sim no).

Kev soj ntsuam digital:

• IoT (Internet of Things) platforms rau tiag tiag -lub sij hawm tsom xam cov peev xwm, tam sim no, thiab cov ntaub ntawv acoustic emission.
• Tshuab kawm los kwv yees corrosion hotspots thiab optimize tiv thaiv tsis.

Green technologies:

• Hnub ci/cua- siv ICCP systems (xws li Australia's Snowy Mountains Hydroelectric Scheme).

3. Cov qauv thiab cov kev qhia tshwj xeeb

Cov qauv thoob ntiaj teb:

• NACE SP0169 (Tswj ntawm Sab Nraud Corrosion rau hauv av lossis Submerged Metallic Piping Systems).
• NACE SP0100 (Cathodic Kev Tiv Thaiv Kev Tiv Thaiv Sab Nraud Corrosion ntawm Cov Yeeb Nkab Siab thiab Cov Cwj Pwm-Coated Steel Pipelines rau Kev Pabcuam Dej lossis Dej pov tseg).

Suav cov qauv:

• GB / T 21448-2017 "Technical specification for cathodic tiv thaiv ntawm faus steel pipelines" qhia cov qauv rau kev tiv thaiv faus steel pipelines los ntawm corrosion los ntawm cathodic tiv thaiv cov txheej txheem.
• GB / T 19685-2017 "Prestressed concrete cylinder pipes" muab cov lus qhia tshwj xeeb rau cov kav dej ua kom muaj zog hauv lub tog raj kheej, uas feem ntau siv hauv cov dej thiab cov kav dej phwj tuaj.
• GB / T 28725-2012 "Cathodic tiv thaiv ntawm faus prestressed qhob lub tog raj kheej kav" tsom rau cov txheej txheem tiv thaiv cathodic tshwj xeeb rau cov faus prestressed pob zeb lub tog raj kheej kav, ua kom lawv lub neej ntev thiab kev ncaj ncees.

CP daim ntawv thov hauv av kav dej (steel thiab PCCP) xav tau cov qauv tsim:

• Cov kav hlau: Tsom ntsoov rau txheej txheej + CP kev sib koom ua ke los daws cov dej ntws tawm thiab av corrosion.
• PCCP: Kev tiv thaiv xaim ncaj qha los ntawm cov txheej txheem pob zeb thaum ntsuas qhov kev pheej hmoo hydrogen embrittlement.

Cov kev xav yav tom ntej hais txog kev saib xyuas ntse, qis -hydrogen- cov ntaub ntawv embrittlement, thiab cov kev daws teeb meem ntsuab kom ua tau raws li qhov xav tau ntawm kev ntseeg tau ntev - kev hloov dej mus deb thiab hauv nroog network, ua rau cov dej hauv tsev mus rau ib puas xyoo - lub neej ua haujlwm ntev.