Duplex stainless hlauyog ib qho khoom siv hluav taws xob ntau ntxiv hauv cov dej txias, dej hiav txwv, thiab cov dej khib nyiab, tab sis kev qhia nws zoo yuav tsum nkag siab txog ob yam khoom uas feem ntau tsis meej pem nrog ib leeg: thermal conductivity, uas tswj xyuas cov cua kub zoo npaum li cas los ntawm lub raj phab ntsa, thiab fouling tsis kam, uas tswj tau zoo npaum li cas lub raj tso siab rau nplai, biofilm, thiab deposit buildup tsis muaj corrod. Phau ntawv qhia no cais ob lub zog kom meej, sib piv duplex rau tus qauv austenitic stainless thiab ib txwm tooj liab- cov khoom siv tube alloy, thiab piav qhia thaum duplex yog qhov kev xaiv ntawm lub tshav kub exchanger tube.
Dab tsi yog qhov Thermal Conductivity ntawm Duplex Stainless Steel piv rau lwm cov khoom siv cua sov?
Duplex stainless hlau cov thermal conductivity, ntawm kwv yees li 17-19 W / m·K, yog me ntsis siab dua li cov qib austenitic zoo li 316L tab sis tseem nyob deb ntawm tooj liab -raws li cov ntaub ntawv raj xws li admiralty tooj dag lossis tooj liab -nickel alloys, uas tuaj yeem ua cua sov ntau dua 5} ntau zaus {
Ib qho kev sib piv ntawm thermal conductivity nyob rau hauv cov khoom siv hluav taws xob sib hloov cov raj:
|
Khoom siv |
Kwv yees li. Thermal conductivity (W / m·K, ~ 20-25 degree) |
Sib piv rau 316L |
|
Copper (ntshiab) |
≈ 390–400 |
≈ 24–25x siab dua |
|
Admiralty tooj dag |
≈ 110–120 |
≈ 7x siab dua |
|
90/10 tooj liab -nickel |
≈ 40–45 |
≈ 2.5–3x siab dua |
|
Cov pa roj carbon steel |
≈ 50–60 |
≈ 3.5x siab dua |
|
Titanium (Qib 2) |
≈ 17–22 |
Roughly piv rau duplex |
|
Duplex 2205 / super duplex 2507 |
≈ 17–19 |
≈ 10-20% siab dua 316L |
|
316L (Austenitic siv) |
≈ 15–16 |
Lub hauv paus |
|
Nickel{0}}raws li alloys (piv txwv li, Alloy 625) |
≈ 10–12 |
Tsawg dua 316L |
Table 1. Tus neeg sawv cev thermal conductivity qhov tseem ceeb rau cov khoom siv hluav taws xob sib hloov cov raj ntawm qhov ntsuas kub ntawm chav tsev. Cov txiaj ntsig yog cov lus piav qhia thiab sib npaug los ntawm cov ntaub ntawv siv tau tshaj tawm; thermal conductivity sib txawv nrog qhov kub thiab txias thiab tshwj xeeb alloy chemistry, yog li paub meej cov ntaub ntawv tseeb tiv thaiv cov khoom tsim cov ntaub ntawv rau kev suav tsim.
Qhov kev sib piv no ua kom pom tseeb tias tsis muaj qib stainless hlau, duplex suav nrog, yog qhov siab -thermal- cov khoom siv hluav taws xob nyob rau hauv cov ntsiab lus tseeb - tooj liab thiab tooj liab alloys nyob rau hauv ib qho kev ua tau zoo sib txawv nkaus rau kev ua kom sov ntshiab. Duplex qhov txiaj ntsig tiag tiag ntawm cov qauv austenitic stainless hauv qhov kev sib piv no yog me me, tsis hloov pauv, uas yog vim li cas duplex raug xaiv rau cov cua kub exchanger tubing feem ntau rau cov laj thawj uas tsis yog superior thermal conductivity, sib tham thoob plaws hauv phau ntawv qhia no.
Vim li cas Duplex Stainless Hlau Muaj Cov Hluav Taws Xob Hluav Taws Xob me ntsis dua li cov qib Austenitic?
Duplex stainless hlau tus qauv siab dua thermal conductivity piv nrog cov qib austenitic tag nrho rov qab mus rau nws cov ntsiab lus ferrite theem, txij li lub cev -centered cubic ferrite qauv feem ntau ua cua sov me ntsis zoo dua lub ntsej muag -centered cubic austenite qauv uas ua rau 100% austenite qauv.
Thermal conductivity nyob rau hauv cov hlau yog cuam tshuam los ntawm crystal qauv ntawm lwm yam, thiab lub cev -centered cubic lug xws li ferrite feem ntau pom me ntsis thermal conductivity dua lub ntsej muag -centered cubic lug xws li austenite, tag nrho lwm yam zoo sib xws. Vim tias duplex stainless hlau muaj qhov sib npaug sib npaug ntawm ob theem es tsis yog tag nrho austenitic, nws tau txais txiaj ntsig ib nrab los ntawm ferrite theem qhov kev coj tus cwj pwm zoo tshaj plaws, uas yog vim li cas duplex thiab super duplex qib tsis tu ncua sim me ntsis siab dua hauv thermal conductivity dua li cov tshuaj sib piv cov qib austenitic. Cov nyhuv no yog qhov tseeb thiab ntsuas tau tab sis me me - feem ntau nyob rau hauv thaj tsam ntawm 10-20% kev txhim kho tshaj 316L - uas yog vim li cas nws thiaj li nkag siab zoo tshaj plaws raws li qhov thib ob, txhawb kev pab cuam ntawm ob lub raj xaiv ntau dua li tus thawj tsav tsheb ntawm nws tus kheej.
Puas txo qis thermal conductivity ua Duplex ib qho kev xaiv tsis zoo rau cov cua kub Exchanger Tubes?
Tsis muaj - thermal conductivity tsuas yog ib qho kev tawm tswv yim rau hauv tag nrho cov khoom siv hluav taws xob sib txawv, thiab duplex lwm yam khoom, tshwj xeeb tshaj yog nws lub zog siab dua (tso cai rau cov phab ntsa nyias nyias) thiab zoo dua corrosion thiab fouling kam rau ua, feem ntau offset los yog ntau dua nws qis intrinsic conductivity piv rau tooj liab -raws li lwm txoj hauv kev tiag - ntiaj teb kev pabcuam.
Tag nrho cov cua sov hloov mus los ntawm lub raj phab ntsa nyob ntawm ob qho tib si cov khoom siv thermal conductivity thiab phab ntsa thickness cov cua sov yuav tsum dhau mus, vim thermal kuj nce nrog phab ntsa thickness thiab txo nrog ntau dua conductivity. Duplex lub zog muaj zog ntau dua piv nrog cov qauv austenitic stainless (thiab ntau dua li cov tooj liab feem ntau) tso cai rau cov phab ntsa nyias nyias kom tau teev tseg rau qhov kev ntsuas siab, uas ib feem them nyiaj rau nws qhov qis qis hauv qhov nruab nrab - kev sib raug zoo tshawb fawb ntau ntxiv tom qab hauv phau ntawv qhia no.
Ib yam li qhov tseem ceeb, thermal conductivity tsuas yog ib qhov me me ntawm kev ua haujlwm ntawm lub raj: ib lub raj uas ua rau cov cua sov zoo heev tab sis corrodes, perforates, los yog yuav tsum tau hloov ntau zaus vim fouling - cuam tshuam tsis zoo ua rau tsis zoo tiag tiag - lub ntiaj teb kub exchanger kev ua tau zoo txawm tias nws qhov kev ntsuas ntsuas, uas yog qhov tseeb qhov sib txawv ntawm duplexer.
Dab tsi yog "Fouling Resistance" Tiag Tiag rau Cov Khoom Kub Kub Exchanger Tube?
Hauv kev xaiv cov khoom siv hluav taws xob, "fouling resistance" feem ntau yog hais txog cov khoom siv lub raj muaj peev xwm zam cov nplai, biofilm, thiab cov khoom tso rau ntawm nws qhov chaw yam tsis muaj kev txom nyem nrawm rau hauv cheeb tsam corrosion hauv qab cov deposits - tsis tas yuav yog cov khoom muaj peev xwm ua kom tsawg fouling hauv thawj qhov chaw.
Nws yog ib qho kev paub tsis meej thiab nkag siab tsis zoo los xav tias "fouling resistance" txhais tau tias cov khoom siv tsuas yog nyiam los yog khaws cov nplai tsawg thiab kev loj hlob ntawm nws qhov chaw; Nyob rau hauv kev xyaum, deposit tsub zuj zuj nyob ntawm cov dej chemistry, ndlwg tshaj tawm, nto tiav, thiab lom neeg tej yam kev mob uas zoo sib xws nyob rau hauv ntau yam du tube hlau nto tsis hais alloy.
Qhov tshwm sim ntau dua thiab alloy-dependent cov cuab yeej yog qhov tshwm sim thaum qhov tso nyiaj ua haujlwm: nyob ruaj khov, qis- cov pa oxygen hauv qab qhov tso nyiaj tsim ib puag ncig hauv zos zoo ib yam li qhov crevice, thiab cov ntaub ntawv nrog qis tsis kam rau crevice thiab pitting corrosion tuaj yeem raug kev kub ntxhov, kev tawm tsam hauv cheeb tsam tshwj xeeb ntawm cov chaw tso nyiaj no - feem ntau yuav muaj kev txhawj xeeb nyob qhov twg. Qhov no yog qhov ua tau zoo, alloy-nyob ntawm qhov kev pheej hmoo uas "fouling resistance" nyob rau hauv cov cua kub exchanger tube xaiv yog tiag tiag hais txog, thiab nws yog tswj los ntawm tib pitting thiab crevice corrosion kuj cov hauv paus ntsiab lus - quantified los ntawm PREN - nyob rau hauv lwm yam kev sib tham ntawm stainless thiab duplex alloy xaiv.
Duplex Stainless Steel's PREN Tus Nqi Zoo Li Cas Txhim Kho Nws Qhov Kev Pom Zoo rau Fouling Deposits?
Duplex thiab super duplex qib nqa tau ntau dua PREN qhov tseem ceeb tshaj li cov qauv austenitic stainless hlau, uas ncaj qha txhais ua ntau dua kev tiv thaiv rau hauv qab - tso nyiaj pitting thiab crevice corrosion uas fouling buildup tuaj yeem ua rau, ua rau cov raj duplex muaj txiaj ntsig ntau dua kev zam txim hauv kev pab cuam qhov twg deposit tsim nyuaj los tiv thaiv tag nrho.
Kev sib piv ntawm cov khoom siv raj siv los ntawm PREN thiab lawv qhov kev kam rau siab rau kev tso nyiaj - ntsig txog corrosion:
|
Khoom siv |
Kwv yees li. PREN |
Tolerance rau hauv qab - tso nyiaj / Crevice Attack |
Hom Fouling -Kev Pabcuam Yooj Yim |
|
316L |
≈ 24–26 |
Nruab nrab; yooj yim rau pitting/crevice nres hauv qab deposits hauv dej chloride |
Kho, qis -chloride dej txias nrog kev txhim khu kev qha tu |
|
TIAB SA 2205 |
≈ 33–37 |
Zoo; txhais tau tias muaj kev tiv thaiv ntau dua ntawm kev tso nyiaj - cuam tshuam hauv cheeb tsam corrosion tshaj 316L |
Brackish los yog me ntsis fouling - dej txias |
|
Super duplex 2507 / S32760 |
≈ 40–43 |
Zoo heev; haum rau ntev tso nyiaj raug tsis muaj kev tawm tsam sai |
Dej hiav txwv thiab fouling hnyav heev - dej txias |
|
Admiralty tooj dag / tooj liab -nickel |
Tsis ncaj PREN- piv (tooj liab- puag alloy) |
Keeb kwm nyiam ib nrab rau kev tiv thaiv biofouling, tab sis raug yaig-corrosion thiab dealloying txaus ntshai |
Ib txwm siv seawater condenser tubing, txawm tias nce ntxiv los ntawm siab -PREN stainless / duplex hauv cov qauv tshiab |
Table 2. Cov neeg sawv cev sib piv ntawm PREN thiab fouling - cuam tshuam txog kev tiv thaiv corrosion nyob rau hauv cov khoom siv hluav taws xob sib hloov lub raj. Cov duab yog dav dav, piav qhia kev tshuaj ntsuam xyuas; Qhov kev ua tau zoo ntawm thaj chaw yog nyob ntawm cov dej chemistry, qhov dej ntws, hom tso nyiaj, thiab kev ua haujlwm kub, thiab yuav tsum tau lees paub los ntawm daim ntawv thov -kev ntsuas tshwj xeeb rau kev pabcuam tseem ceeb.
Qhov no yog lub hauv paus tswv yim sib cav rau kev qhia duplex stainless hlau nyob rau hauv dej txias thiab seawater heat exchanger kev pab cuam: txawm lub qhov dej -tsim tu thiab txij nkawm kev pab cuam tsis tuaj yeem lav xoom deposit tsim nyob rau hauv ib lub raj tag nrho cov kev pab cuam lub neej, thiab duplex lub siab dua PREN muab lub ntsiab lus tseem ceeb ntawm kev ruaj ntseg tiv thaiv tej yam tsis ua hauj lwm hom - nyob rau hauv {{2} los yog crevice-de. tsis npaj lub raj tsis ua hauj lwm hauv fouling - kev pabcuam yooj yim.
Duplex piv rau tooj liab li cas -Nickel thiab Admiralty Brass Tubes hauv Kev Pabcuam Dej Txias?
Duplex stainless hlau feem ntau muaj kev tiv thaiv zoo dua rau hauv cheeb tsam corrosion thiab yaig -corrosion dua admiralty tooj dag lossis tooj liab -nickel tubing, thaum tooj liab alloys khaws cov thermal conductivity zoo thiab keeb kwm lub koob npe nrov rau natural biofouling suppression - kev lag luam -tawm uas tau tsav mus rau ib qho kev hloov pauv tshiab, ntau yam PR thiab ntau dua kub exchanger designs.
Copper- cov ntaub ntawv raws li lub raj muaj keeb kwm ntev, kev vam meej hauv cov dej hiav txwv thiab cov dej txias cua sov kev pab cuam, thiab lawv cov thermal conductivity zoo sib piv tseem yog qhov zoo dua ntawm cov hlau tsis muaj steel, duplex nrog. Txawm li cas los xij, tooj liab alloys nqa lawv tus kheej zoo-cov ntaub ntawv muaj qhov tsis zoo - yaig- corrosion ntawm siab khiav ceev, dealloying (xaiv leaching ntawm zinc los ntawm tooj dag los yog npib tsib xee los ntawm tooj liab- npib tsib xee alloys nyob rau hauv tej yam kev mob), thiab feem ntau qis dua mechanical zog siab dua li qhov yuav tsum tau ua kom cov phab ntsa tuab.
Duplex kev sib xyaw ua ke ntawm lub zog siab, zoo heev chloride pitting thiab crevice kuj, thiab tsim nyog (yog tias tsis yog tooj liab- qib) thermal conductivity tau ua rau nws muaj kev sib tw ntau dua hauv cov qauv siv hluav taws xob tshiab, tshwj xeeb tshaj yog qhov uas yaig -kev pheej hmoo corrosion, siab dua tsim, los yog lub siab xav kom tsis txhob tooj liab alloys ' dealloying vulnerability yog qhov tseem ceeb.
Puas Phab Ntsa Thickness cuam tshuam nrog Thermal conductivity nyob rau hauv tag nrho cov tshav kub hloov kev ua tau zoo?
Vim tias duplex stainless hlau lub zog siab tso cai rau cov phab ntsa nyias nyias dua li cov qauv austenitic stainless lossis ntau cov tooj liab alloys ntawm tib qhov kev ntsuas siab, cov thermal kuj ntxiv los ntawm cov phab ntsa thinner ib nrab offsets duplex lub qis intrinsic thermal conductivity, lub ntsiab lus tag nrho cov tshav kub hloov kev ua tau zoo yog feem ntau sib tw dua ib tug yooj yim conductivity - tus nqi piv ib leeg yuav hais.
Thermal resistance los ntawm lub raj phab ntsa nce nyob rau hauv ncaj qha proportional rau phab ntsa thickness thiab txo nyob rau hauv ncaj qha faib ua feem rau thermal conductivity, yog li cov khoom uas muaj tsawg intrinsic conductivity tab sis ib tug thinner xav tau phab ntsa yuav xa ib tug piv los yog txawm zoo dua tag nrho cov tshav kub hloov coefficient tshaj ib tug siab dua -conductivity cov ntaub ntawv teev nyob rau hauv ib tug tuab phab ntsa.
Duplex lub zog muaj zog ntau dua piv nrog cov qauv austenitic stainless hlau (thiab feem ntau piv nrog tooj liab alloys ib yam nkaus) tso cai rau cov phab ntsa zoo li no -thickness txo rau ib qho kev tsim siab, uas yog vim li cas sib piv cov ntaub ntawv raj ntshiab ntawm cov khoom siv thermal conductivity, tsis suav rau cov phab ntsa tuab ntawm txhua yam khoom yuav tsum tau nyob rau hauv ib qho kev tsim tshwj xeeb.
Thaum twg Koj Yuav Tsum Xaiv Duplex Stainless Hlau Hla Copper Alloys lossis Standard Austenitic Tubes rau Cov Hluav Taws Kub Kub?
Duplex stainless hlau feem ntau yog qhov kev xaiv ntawm cov cua kub exchanger tube xaiv qhov twg cov tshuaj chloride - muaj los yog fouling - cov dej tsis zoo yog ua ke nrog kev xav tau rau kev tsim siab dua, kev yaig{2}} corrosion kuj, los yog kev ywj pheej ntawm tooj liab - alloy dealloying txaus ntshai, thaum tus qauv austenitic stainless hlau tseem muaj 4 chlorpide txaus { khaws cov ntug qhov twg cov thermal conductivity yog qhov tseem ceeb tsim tsav tsheb thiab lawv cov kev txwv corrosion yog tswj tau zoo.
Ib lub tswv yim xaiv lub moj khaum:
- Xaiv duplex stainless hlau thaum:dej txias yog brackish, seawater, los yog lwm yam chloride - nplua nuj; fouling thiab deposit tsim tsis tuaj yeem ntseeg tau los ntawm kev ntxuav; siab tsim siab nyiam ib tug nyias, siab dua - lub zog raj phab ntsa; los yog tooj liab- alloy erosion-corrosion lossis dealloying txaus ntshai yog ib qho kev txhawj xeeb uas tau sau tseg hauv cov kev pabcuam zoo sib xws.
- Standard austenitic stainless (316L) yuav nyob twj ywm txaus thaum:Cov dej txias tsis tshua muaj -chloride thiab kho tau zoo, kev pheej hmoo fouling yog tsawg, thiab duplex ntxiv corrosion margin thiab tus nqi them nqi tsis pom tseeb los ntawm cov kev pabcuam.
- Copper alloys tseem yuav nyiam thaum:raw thermal conductivity yog tus tsim qauv tsav tsheb, khiav ceev tau tswj tau zoo nyob rau hauv lub alloy qhov yaig-corrosion txwv, thiab lub kaw lus muaj cov ntaub ntawv teev tseg ntawm kev ua tau zoo nrog tooj liab- alloy tubing hauv kev pabcuam zoo sib xws.
- Ntsuam xyuas phab ntsa thickness thiab qhov tseeb tshav kub hloov coefficient ua ke,tsis yog thermal conductivity qhov tseem ceeb ib leeg, thaum sib piv cov neeg sib tw cov ntaub ntawv rau ib qho kev tsim tshwj xeeb siab thiab lub luag haujlwm.
Cov lus nug nquag
Puas yog super duplex 2507 lub ntsiab lus zoo dua li tus qauv duplex 2205 hauv thermal conductivity?
Tsis muaj - thermal conductivity ntawm tus qauv duplex 2205 thiab super duplex 2507 yog qhov dav zoo sib xws, txij li ob qho tib si sib piv dual -theem austenite-ferrite qauv; Lub ntsiab lus sib txawv ntawm ob qib no yog nyob rau hauv corrosion kuj (PREN) thiab lub zog, tsis thermal conductivity.
Puas biofouling txuas tsis yooj yim rau duplex stainless hlau dua li tooj liab alloys?
Copper alloys muaj qhov ntev -paub txog ntuj biofouling- inhibiting nyhuv vim tooj liab toxicity rau ntau cov kab mob marine, uas duplex thiab lwm yam stainless hlau tsis sib koom; qhov no yog qhov txiaj ntsig zoo rau cov tooj liab alloys hauv biofouling- kev pabcuam yooj yim, txawv ntawm hauv qab - tso nyiaj corrosion kam rau ua kom zoo dua duplex muaj ib zaug fouling tshwm sim.
Duplex stainless hlau raj puas tuaj yeem ua nyias dua -walled dua li admiralty tooj dag raj rau tib qhov kev pabcuam?
Feem ntau yog, muab duplex lub zog muaj zog ntau dua li kev qhuas qhuas tooj dag, uas tuaj yeem pab offset duplex qhov qis thermal conductivity nyob rau hauv tag nrho cov tshav kub hloov lwm lub tsev sib piv, txawm hais tias qhov tseeb xav tau phab ntsa thickness rau ib qho kev tsim tshwj xeeb yuav tsum tau xam raws li cov cai es tsis xav.
Puas yog duplex stainless hlau haum rau siab - ntws- kev pabcuam dej hiav txwv qhov chaw uas cov hlau alloys raug kev yaig-corrosion?
Yog - duplex stainless hlau feem ntau muaj kev tiv thaiv zoo dua rau kev yaig- xeb dua li tooj liab-raws li cov raj hlau, uas yog ib qho ntawm cov laj thawj uas nws tau siv ntau dua hauv seawater heat exchanger designs nrog ntau dua velocities tshaj li cov tsoos tooj liab- alloy tubing tuaj yeem ntseeg tau.
Puas yog fouling tsis kam nyob rau hauv duplex stainless hlau tshem tawm qhov xav tau rau lub sijhawm tu lub raj?
Tsis muaj - duplex's siab dua PREN txhim kho kev kam rau cov deposits yam tsis tau tshem tawm cov nqi ntawm kev tu lub sij hawm, txij li cov deposits tseem txo cov tshav kub hloov efficiency los ntawm kev ntxiv thermal kuj txawm thaum lawv tsis nquag ua rau corrosion; Kev tu vaj tse tseem ceeb heev rau kev ua haujlwm thermal, thaum duplex qhov kev txhim kho corrosion feem ntau tiv thaiv tsis tau lub raj tsis ua haujlwm.
