Nyob rau hauv Geothermal Brine Heater (2000 ppm Chloride, pH 5, 150 degree), Yuav Ua Li Cas Scaling ntawm Calcium Sulfate ntawm Titanium Sheath Hloov Phab Ntsa Thickness rau 5 Xyoo Tsim Lub Neej?

Basic Tradeoff nyob rau hauv Titanium rhaub tsim rau Scaling Geothermal Brines
Geothermal brines ntawm 150℃muaj ntau cov calcium thiab sulfate ions. CaSO4, calcium sulfate. Lub solubility ntawm CaSO4 poob nrog nce kub thiab nws precipitates raws li scale ntawm rhuab chaw. Qhov ntsuas no yog txheej txheej insulating ntawm titanium immersion rhaub. Yuav tsum tau phab ntsa thickness rau 5 xyoo tsim lub neej yuav tsum xav txog tsis tsuas yog corrosion nyiaj tab sis kuj scaling warming uas ua rau kom sab hauv degradation. Lub phab ntsa tuab dua yuav kub dua thaum xub thawj thiab yog li ntawd nce nrawm dua qhov uas cov phab ntsa nyias yuav txias dua tab sis cia tsawg dua rau corrosion. Txoj haujlwm no ntsuas cov txiaj ntsig ntawm calcium sulfate scaling ntawm phab ntsa tuab yuav tsum muaj sia nyob 5 xyoos hauv geothermal brine ntawm 150 degree.

Impact on Mechanical Integrity: Scale to Ua Overheating
Calcium sulfate scale muaj thermal conductivity ntawm 1.2 W / m·K, uas yog 15 npaug qis dua titanium (17 W / m·K). Ib txheej txheej ntawm tsuas yog 0.5 hli thickness qhia txog thermal kuj ntawm ΔT_scale=q × t_scale / k_scale. Ib qho 0.5 hli scale deposit rau sab nrauv titanium nto ua rau kub nce ntawm 8.3℃rau ib tug kub flux ntawm 2.0 W / cm2 (ib txwm ntawm geothermal heaters). Lub rhuab saum npoo nrawm nrawm tom qab nag lossis daus ntawm qhov teev, ib qho kev tawm tswv yim zoo. Qhov tseem ceeb tsis ua hauj lwm mechanism yog hloov los ntawm corrosion perforation mus rau tshaj - cua sov ntawm lub internal magnesium oxide rwb thaiv tsev. Yog tias cov phab ntsa sab hauv kub siab tshaj 350℃ntev, MgO rwb thaiv tsev yuav tawg. Qhov no yuav ua rau hluav taws xob tsis zoo thiab tsis ua haujlwm ntawm lub tshuab cua sov. Raws li titanium phab ntsa thickness nce (piv txwv li lub hauv paus ntawm qhov kub thiab txias nce), qhov kev tiv thaiv scale thickness ua ntej overheating yuav txo, piv txwv li ntau zaus tu los yog ib tug tsawg tshav kub flux yog xav tau.

Qhov cuam tshuam rau Kev Ua Haujlwm Thermal: Base Surface Temperature thiab Scale Rate
Tus nqi ntawm calcium sulfate scale ntau lawm yog Arrhenius kev twb kev txuas nrog rau saum npoo kub. Rau 1.0 hli phab ntsa ntawm titanium ntawm 2.0 W / cm2 hauv 150℃brine qhov kub ntawm sab nrauv yog li 157℃(ΔTcond=1.2 degree, ΔTconv piv txwv h=2000 W/m2K=10℃). Sab nrauv ncav cuag 160℃rau 1.8 hli phab ntsa. Qhov 3℃qhov sib txawv no sib raug rau qhov nce ntawm li 20% ntawm qhov ntsuas qhov tso nyiaj. Qhov tseem ceeb tshaj, txawm li cas los xij, qhov kub ntawm lub hauv paus ntau dua txhais tau hais tias cov txheej txheej txheej txheej txheej ua rau overheating. t_scale_max=(350℃- T_surface - ΔT_cond - ΔT_conv) * k_scale/q . Qhov no yog qhov siab tshaj plaws ntawm cov nplai ua ntej phab ntsa sab hauv mus txog 350 degree. Rau phab ntsa ntawm 1.0 hli (T_surface=157 degree), t_scale_max ~ 2.3 mm. Rau phab ntsa thickness ntawm 1.8mm (T_surface=160 degree), t_scale_max ≈ 2.0mm. Qhov txawv me me, tab sis cov phab ntsa tuab kuj ntsuas 20% nrawm dua, yog li lub sijhawm kom ncav cuag qhov ntsuas qhov hnyav yog ~ 30% luv dua.

Lub Tradeoff Synthesis: Phab ntsa Thickness Xaiv nrog Scaling
Phab ntsa Thickness (mm) Pib T_surface (degree) Scale Deposition Rate (mm/hli) Lub hli mus rau qhov tseem ceeb (2.0 hli) Corrosion Allowance Lub neej (xyoo) Zuag qhia tag nrho 5-xyoo kev vam meej
0.8 hli 156℃C 0.30 hli / hli 6.7 hli> 10 xyoo Tsis yog - feem ntau tu
1.0 hli 157℃0.32 hli / hli 6.3 hli> 10 xyoo Tsis yog - xav tau kev tu txhua 6 lub hlis
1.2 mm 158°C 0.35 mm/month 5.7 months >10 xyoo Tsis yog - ntxuav txhua 5 lub hlis
1.5 hli 159℃0.38 hli / hli 5.3 hli 8 - 10 xyoo Tsis muaj - tseem xav tau kev tu
Ib qho twg > 0.30 hli / hli < 7 lub hlis Yog tias tsis muaj kev tswj xyuas qhov ntsuas, tsis muaj phab ntsa tuab yuav kav ntev li 5 xyoos.
Cov txheeb cais qhia tias tsis muaj phab ntsa tuab yuav tuaj yeem ncav cuag 5-xyoo tsim lub neej yam tsis muaj kev tiv thaiv nplai vim tias calcium sulfate txhim kho ntawm 0.3 - 0.4 hli / hli thiab yuav tsum tau ntxuav txhua 5 - 7 hli tsis hais txog ntawm titanium thickness. Lub sijhawm ua tiav qhov ntsuas tseem ceeb tsis cuam tshuam ntau npaum li cas ntawm phab ntsa thickness.

Engineering sab nraum phab ntsa: Tiv thaiv thiab ntxuav ntawm nplai
Cov kev daws teeb meem nkaus xwb kom ua tiav 5 xyoo kev pab cuam lub neej ntawm scaling geothermal brine yog scale tiv thaiv los yog automated tu. Qhov sib ntxiv ntawm cov nplai inhibitor (5-10 ppm polyacrylate lossis phosphonate) rau cov brine txo qhov tso nyiaj rau 0.03-0.06 hli / hli (80-90%). Inhibition txo kev tu ntau zaus rau txhua txhua 3-4 xyoos rau 1.2 hli tuab titanium phab ntsa, thiab qhov kev tiv thaiv corrosion ntawm phab ntsa (0.01 hli / xyoo los ntawm chloride nres) yog tsawg. Xwb, nplai tuaj yeem raug tshem tawm ua ntej ncav cuag 0.3 hli tuab los ntawm kev txhim kho lub tshuab tu tshuab (xws li lub caij nplooj ntoos hlav loaded scrapers uas taug kev raws lub rhaub dej ntau zaus). Yog tias koj txhuam nws ib zaug ib lub lim tiam, cov phab ntsa tuab ntawm 0.8 hli thiab 2.0 hli yuav kav ntev dua 5 xyoos, txij li qhov ntsuas tsis tau tuab txaus los ua kom kub dhau. Tom qab ntawd cov phab ntsa tuab tsuas yog ua kom txaus siab rau kev tiv thaiv corrosion rau chlorides (0.05 hli / xyoo siab tshaj plaws, piv txwv li . 0.5 hli hauv 10 xyoo).

Xaus: Lub geothermal brine nplai tswj yog qhov tseem ceeb tshaj li phab ntsa thickness
Piv txwv li, qhov tsim nyog phab ntsa thickness ntawm geothermal brine rhaub ntawm 150℃nrog 2000 ppm chloride thiab calcium sulfate scaling tsis tuaj yeem kwv yees rau 5-xyoo tsim lub neej yam tsis muaj kev suav nyiaj rau kev tsim. Tsis muaj kev tswj xyuas qhov tso nyiaj ntawm 0.3 txog 0.4 hli / hli yuav tsum tau ntxuav txhua txhua 5 mus rau 7 lub hlis ywj pheej ntawm titanium phab ntsa tuab (0.8 hli lossis 2.0 hli). Chemical scale inhibition (90% txo tus nqi deposition) tus qauv 1.2 hli phab ntsa yuav muab 5+ xyoo ntawm kev ua haujlwm thiab cov corrosion tso cai los ntawm chloride tsis tseem ceeb. Cov txheej txheem zoo tshaj plaws rau kev pabcuam geothermal brine yog titanium phab ntsa thickness ntawm 1.2-1.5 hli nrog scale inhibitor txhaj tshuaj los yog automated mechanical tu. Xav kom cov chaw tsim khoom muab qhov kwv yees ntawm calcium concentration (ppm Ca 2+ ) thiab sulfate concentration (ppm SO 4 2- ) los txiav txim siab qhov ntsuas qhov ntsuas qhov ntsuas thiab xav kom muaj kev tswj xyuas qhov ntsuas raws li ib feem ntawm cov ntsuas cua sov. Phab ntsa thickness tsis txaus los muab 5-xyoo ntev nyob rau hauv scaling brines.