Dab tsi yog qhov Reliable Sheath Thickness rau 316 Stainless Steel Circulation Heaters hauv 40% Calcium Chloride Brine ntawm 90℃nrog 5 Bar System Siab

Cov Tub Ntxhais Kev Lag Luam - tawm hauv High- Kev Pabcuam Brine

Calcium chloride brine (40% concentration) yog cov kua dej hloov mus rau hauv cov tub yees, de- daim ntawv thov icing, thiab cov tshuab cua txias. Calcium chloride brine (qhov ceev txog 1.4 g / cm3, qhov chaw khov nab kuab -45℃ntawm qhov zoo tshaj plaws concentration) yog ntom dua li sodium chloride brine thiab tej zaum yuav khaws cia cov kua ntawm qhov kub thiab txias. 316 stainless hlau ua tau raws li qhov xav tau ntawm ib puag ncig ntawm 90℃thiab lub zog siab ntawm 5 bar{10}}% calcium chloride brine muaj cov ntsiab lus chloride ntawm thaj tsam 25% los ntawm qhov hnyav thiab hnyav heev. Txawm li cas los xij, tus cwj pwm corrosive yog nruab nrab piv rau sodium chloride vim muaj cov calcium ions. Calcium ions inhibit qhov kev ua ntawm chloride ions los ntawm kev sib koom ua ke ion. Rau kev txhim khu kev qha sheath thickness rau qhov kev ua haujlwm no, lub siab ntim, pitting tsis kam nyob rau hauv high-chloride brine, yaig los ntawm ib qho kev tshem tawm cov khib nyiab thiab cov thermal efficiency tsim nyog rau kev hloov cua sov yuav tsum raug coj mus rau hauv tus account. Tsis zoo li ferric chloride, qhov twg 316 tsis haum, 316 stainless tuaj yeem noj calcium chloride brine ntawm qhov kub nruab nrab nrog cov tuab tuab thiab kev qhuab qhia ua haujlwm.

Siab Containment @ 5 Bar & 90 C

Lub hoop kev nyuaj siab yuav tsum tau rau ib tug ncig lub rhaub sheath ntawm 5 bar system siab yog me me, tab sis tsis xoom. Rau 12 mm sab nraud txoj kab uas hla, nws nyob ntawm phab ntsa thickness. Lub hoop stress formula yog σ=P⋅ri/tσ=P⋅ri/t ua cov nram qab no qhov tseem ceeb: rau ib phab ntsa ntawm 1.2 hli ( puab vojvoog 4.8 hli), kev nyuaj siab yog 0.5 MPa zaug 4.8 hli tshaj 1.2 hli, uas muab 2.0 MPa. Rau 2.0 hli phab ntsa ( puab vojvoog 4.0 hli), kev ntxhov siab yog 0.5 MPa zaug 4.0 hli muab faib los ntawm 2.0 hli, uas yog 1.0 MPa. Ob qhov txiaj ntsig tau qis dua li 170 MPa yield zog ntawm 316 stainless hlau ntawm 90 degree. Thickness tsis yog txiav txim siab los ntawm kev tswj hwm ib leeg. Txawm li cas los xij, brine system ncig cov cua sov feem ntau yog txuas rau threaded lossis flanged fittings uas yuav tsum tau dais installation torque thiab thermal expansion pressures. Qhov tsawg kawg nkaus thickness ntawm qhov chaw sib txuas yuav tsum yog 1.2 hli rau xov kev sib koom tes thiab cov neeg kho tshuab resilience. Cov phab ntsa nyias dua li 1.0 hli yuav muaj kev phom sij ntawm xov stripping lossis deformation thaum ntsia.

Tsis kam mus rau hauv zos corrosion nyob rau hauv concentrated calcium chloride brines

Lub pitting kuj ntawm 316 stainless hlau nyob rau hauv ib tug calcium chloride brine yog ntau zoo dua li hais tias nyob rau hauv ib tug sodium chloride brine ntawm zoo chloride luj feem pua. Qhov no yog vim chloride ions tsis tshua muaj zog hauv cov tshuaj calcium chloride. Qhov tseem ceeb pitting kub ntawm 316 stainless hlau nyob rau hauv 25% chloride ion concentration (los ntawm 40% CaCl2) yog hais txog 45-55℃nyob ntawm seb cov ntsiab lus oxygen thiab cov dej ntws. Cov tshuaj yog ntau tshaj qhov tseem ceeb pitting kub ntawm 90C yog li pitting yuav tshwm sim. Cov lus nug yog nyob ntawm tus nqi dab tsi ua pits propagate. Qhov kev loj hlob ntawm 316 stainless hlau nyob rau hauv 40% CaCl₂ ntawm 90℃nyob rau hauv aerated xwm txheej yog luam tawm raws li 0.3-0.8 hli / xyoo, tus nqi qis yog txuam nrog turbulent flow condition uas tiv thaiv cov concentration ntawm chloride ntawm lub qhov nkag. Rau lub tshuab ua kom sov nrog lub nrawm nrawm ntawm 1.5-2.0 m / s, qhov kev loj hlob ntawm qhov yog li ntawm 0.3-0.5 hli / xyoo. Qhov siab tshaj plaws kwv yees qhov tob yog 1.5 mus rau 2.5 hli thoob plaws hauv tsib xyoos tsim lub neej. Qhov kev suav no yog tus tsav tsheb ncaj qha rau kev xaiv thickness. Ib phab ntsa 1.5 hli yuav muaj qhov muaj feem cuam tshuam tom qab tsib xyoos. Phab ntsa yog 2.0 mm. Tom qab 5 xyoos ntawm qhov kev nthuav dav, qhov kev nyab xeeb yog 0.5-1.5 hli. Lub 2.5 hli phab ntsa tuab muab cov npoo ntau dua tab sis nrog cov cua sov loj thiab raug nplua. Qhov txhim khu kev qha thickness ntau rau 5 xyoo tsim lub neej yog 2.0-2.3mm.

Kev txiav txim siab rau Uniform Corrosion thiab Crevice Attack

Qhov teeb meem tseem ceeb yog pitting, txawm li cas los xij, koj tuaj yeem ntsuas qhov tsis sib xws ntawm 40% calcium chloride brine ntawm 90 degree. Tshaj tawm cov kev tshawb fawb poob phaus qhia txog kev txhim kho corrosion ntawm 0.05-0.12 hli / xyoo nyob rau hauv cov xwm txheej ntws, thiab zoo ib yam. Uniform poob ntawm 0.25 mus rau 0.60 mm yog sau tseg thoob plaws 5 xyoo. Qhov kev puas tsuaj no txo ​​cov phab ntsa tuab zoo muaj los tiv thaiv pitting nkag. 5-xyoo-laus corrosion tus nqi ntawm 0.10 hli / xyoo ntawm phab ntsa 2.0 hli tawm ntawm lub thickness ntawm 1.5 hli ua ntej pitting pib. Ib lub qhov dej nthuav dav ntawm tus nqi ntawm 0.4 hli ib xyoos rau tsib xyoos yuav ncav cuag qhov tob ntawm 2.0 hli, perforating phab ntsa. Kev sib xyaw ua ke ntawm qhov poob thiab pitting txhais tau hais tias lub phab ntsa 2.0 mm yog nyob ze ntawm ntug kev ntseeg siab rau kev ua tiav tsib xyoos ua haujlwm. Crevice quab yuam ntawm flange gaskets, threaded kev twb kev txuas thiab nyob rau hauv tej scale deposits yog muab ntxiv dimension. Localized corrosion tus nqi ntawm 0.5-1.0 hli nyob rau hauv ib xyoos tuaj yeem tshwm sim hauv fissures hauv calcium chloride brine. Vim li no, brine kev pabcuam cov cua sov yuav tsum tau welded tsim es tsis yog threaded thiab gaskets yuav tsum tau zam qhov twg los tau.

Thermal Performance of Thick Walls Nqi ntawm Cov Phab Ntsa Thick

Lub thermal conductivity ntawm 40% calcium chloride brine yog hais txog 0.55 W / m·K ntawm 90 degree, deb tsawg tshaj li cov dej (0.68 W / m·K). Yog li lub convective tshav kub hloov coefficient nyob rau hauv turbulent flow yog me me, feem ntau 600-1000 W / m²·K piv rau 1500-2500 W / m²·K rau dej. Yog li cov sheath thermal kuj yog ib qho kev txhawb siab rau tag nrho cov thermal circuit dua li hauv kev pabcuam dej. Rau ib lub raj uas muaj txoj kab uas hla 12 hli, qhov hluav taws xob tsis kam nce li ntawm 0.004 m²·K/W raws li phab ntsa thickness nce ntawm 1.5 hli mus rau 2.5 hli. Qhov kev ua kom muaj zog no ua rau qhov kub thiab txias los ntawm 8-10℃rau lub tshuab hluav taws xob zoo ib yam watt ceev ntawm 7-8 W / cm2. Nrog rau phab ntsa 2.5 hli, qhov kub ntawm lub plhaub tuaj yeem nce mus rau 110-115℃rau qhov kub ntawm 90 degree. Tus nqi ntawm pitting ntawm qhov kub thiab txias tau nce los ntawm kwv yees li 50-100% piv nrog rau ntawm 100 degree. Qhov nce phab ntsa thickness rau corrosion kuj tuaj yeem txhawb pitting vim cov nyhuv tshav kub. Qhov no ua rau lub qhov rais zoo tshaj plaws thickness, nyias txaus los khaws cia kub kub<105°C, but thick enough to permit pitting. The optimum range for most calcium chloride circulation systems is 2.0 to 2.2 mm.

Thickness pom zoo rau cov kev pabcuam sib txawv, txhim khu kev qha

Rau lub tshuab cua sov hauv 40% calcium chloride brine ntawm 90℃thiab 5 bar nrog turbulent flow (Re> 10,000) thiab tsim lub neej ntawm tsib xyoos, qhov ruaj khov sheath thickness yog 2.0-2.2 hli. Qhov tuab no tso cai rau pitting pub ntawm 1.0-1.5 hli tom qab tsib xyoos tsis zoo corrosion, piv txwv li lub qhov loj hlob ntawm 0.4 hli ib xyoo. Txaus rau 3 xyoo tsim lub neej 1.6-1.8 hli Qhov no yog 2.5-2.8 hli rau kaum xyoo tsim lub neej, tab sis lub tshav kub raug nplua yuav ntau heev. Kev hloov kho kom zoo dua qub xws li 316Ti lossis 317L yuav raug nqi ntau dua. Rau cov tshuab nrog laminar ntws los yog qhov chaw tuag nrog ntau dua pitting tus nqi, lub thickness yuav tsum tau tsa los ntawm 0.3-0.5 hli. Rau cov tshuab siv deaerated brine (solved oxygen tsawg dua 100 ppb), pitting tus nqi yog txo mus rau 0.1-0.2 hli nyob rau ib xyoos thiab yuav txo tau mus rau 1.5-1.8 hli rau ib tug tsib xyoos lub neej.

Tswv yim tsim ntsuas uas txo cov thickness yuav tsum tau

Ntau yam kev ntsuas tsim muaj los txo qis qhov xav tau sheath thickness yam tsis muaj kev cuam tshuam qhov kev ntseeg tau. Ua ntej, kev tswj dej ntws: Qhov tsawg kawg nkaus khiav ceev ntawm 1.5 m / s yog txwv kom tsis txhob ciam teb txheej stagnation thiab txo qis pitting tus nqi los ntawm ib qho ntawm ob. 2. Deaeration: Ib daim pam nitrogen tshaj lub tank expansion txo cov pa oxygen los ntawm 8 ppm mus rau tsawg dua 0.5 ppm nrog ib tug zoo kawg li corrosion kuj nyob rau hauv pitting. Thib peb, ntxiv cov inhibitors. Sodium chromate los yog sodium molybdate ntawm 200-500 ppm ua rau kom pitting tsis kam thiab tso cai txo qhov tuab ntawm 0.3-0.5 hli. Plaub, nto tiav. Electropolished tubes muaj tsawg qhov chaw pib qhov chaw thiab qis dua qhov kev loj hlob ntau dua li cov tshuab polished raj. Ib phab ntsa 1.8 hli electropolished yuav ua tau zoo dua li 2.2 hli raws li phab ntsa.

Xaus: Qhov Kev Ntseeg Thickness rau Calcium Chloride Brine

Lub sheath tuab ntawm 2.0-2.2 hli tau pom tias yog ib qho kev vam khom rau tsib xyoos tsim lub neej ntawm 316 SS ncig cov cua sov hauv qhov kub ntxhov, aerated xwm txheej rau 40% calcium chloride brine ntawm 90 deg C thiab 5 bar siab. Cov thickness no yog ib qho kev sib pauv ntawm pitting nyiaj, uniform corrosion margin thiab thermal ua haujlwm. Phab ntsa nyias dua li 1.8 hli yuav perforate hauv 3 xyoos. Cov phab ntsa tuab dua li 2.5 hli nce qhov kub ntawm lub tsho mus rau thaj tsam uas pitting nrawm, thiab rov qab txo qis. Cov kev qhia tshwj xeeb tshaj plaws suav nrog tsis yog tuab xwb tab sis kuj yog cov kev qhia tshwj xeeb rau qhov tsawg tshaj plaws khiav ceev (1.5 m / s), nto tiav (electropolished), thiab yaj oxygen tswj qhov twg ua tau. Engineers yuav tsum qhia lub neej tsim nyob rau hauv lub xyoo thiab lub flow regime thaum txhais. Qhov no hloov qhov kev txiav txim siab tuab los ntawm kev kwv yees rau kev suav siv cov ntaub ntawv luam tawm corrosion thiab thermal qauv muab kev txhim khu kev qha ntev kev ua haujlwm hauv ib qho ntawm cov teeb meem ntsev ntau dua rau 316 stainless hlau.