POWERGEN International Call for Content yavhurwa! Tiri kutsvaga vatauri vanobva kumaindasitiri emagetsi nemagetsi. Misoro inosanganisira kugadzira magetsi echinyakare uye anogona kushandiswazve, kushandurwa kwemagetsi edhijitari, kuchengetwa kwesimba, microgrids, kugadziriswa kwemagetsi, simba riri panzvimbo, nezvimwewo.
Vanyori vakadzokorora zvirevo zvitsva zveprojekiti yesimba nguva nenguva, umo vagadziri vemafekitori vanowanzo sarudza 304 kana 316 simbi isina ngura ye condenser uye assistant heat exchanger tubes. Kune vazhinji, izwi rekuti simbi isina ngura rinoreva ngura isingakundike, asi kutaura chokwadi, simbi dzisina ngura dzimwe nguva dzinogona kuva sarudzo yakaipa nekuti dzinogona kubatwa nengura munzvimbo. Uye, munguva ino yekushaikwa kwemvura yakachena yekutonhodza mvura, pamwe chete nematombo ekutonhodza anoshanda panguva yakawanda, nzira dzinogona kukundikana dzesimbi isina ngura dzinowedzera. Mune mamwe mashandisirwo, 300 series stainless steel inongogara kwemwedzi chete, dzimwe nguva mavhiki chete, isati yakundikana. Chinyorwa chino chinotarisa pane zvingangove nyaya dzinofanira kufungwa nezvadzo pakusarudza zvinhu zve condenser tube kubva pakuona kwekurapa mvura. Zvimwe zvinhu zvisina kukurukurwa mupepa rino asi zvine basa mukusarudzwa kwezvinhu zvinosanganisira simba rezvinhu, hunhu hwekufambisa kupisa, uye kuramba simba remakanika, kusanganisira kuneta uye ngura yekukukurwa.
Kuwedzera 12% kana kupfuura chromium kusimbi kunoita kuti alloy igadzire continuous oxide layer inodzivirira base metal iri pasi payo. Saka izwi rekuti stainless steel. Kana pasina zvimwe zvinhu zvinosanganisa alloying (kunyanya nickel), carbon steel chikamu che ferrite group, uye unit cell yayo ine body-centered cubic (BCC) structure.
Kana nickel ikaiswa mumusanganiswa we alloy pamwero we 8% kana kupfuura, kunyangwe pakupisa kwekunze, sero racho richave riri muchimiro che cubic (FCC) chinonzi austenite.
Sezvakaratidzwa muTafura 1, simbi dzisina ngura dzinotevedzana mazana matatu nedzimwe simbi dzisina ngura dzine nickel yakawanda inoita kuti chimiro chive che austenitic.
Simbi dzeAustenitic dzakaratidza kuva dzinokosha zvikuru muzvishandiso zvakawanda, kusanganisira sezvinhu zvekushandisa pakupisa kwakanyanya uye machubhu ekudziyisazve mumaboiler emagetsi. 300 series inonyanya kushandiswa sezvinhu zvekushandisa pakupisa kupisa kwakaderera, kusanganisira macondenser emhepo. Zvisinei, muzvishandiso izvi ndipo vazhinji vanokanganwa nzira dzinogona kukundikana.
Dambudziko guru nesimbi isingatsvi, kunyanya zvinhu zvinozivikanwa zve304 ne316, nderekuti ganda rekudzivirira oxide rinowanzo paradzwa netsvina iri mumvura inotonhorera uye nemakomba nemakomba anobatsira kusanganisa tsvina. Pamusoro pezvo, kana mvura yamira inogona kutungamira kukura kwehutachiona, hune zvigadzirwa zvinogona kukuvadza simbi zvakanyanya.
Chinhu chinowanzo shandiswa pakutonhodza mvura, uye chimwe chezvinhu zvakaoma kubvisa zvine mwero, ichloride. Iyi ion inogona kukonzera matambudziko akawanda mumajenareta emhepo, asi mumakondensa uye muzvishandiso zvekupisa zvinobatsira, dambudziko guru nderekuti machloride akakora zvakakwana anogona kupinda nekuparadza jira rekudzivirira re oxide pasimbi isingatsvi, zvichikonzera ngura munzvimbo, kureva kuti gomba.
Kukanda gomba ndeimwe yemhando dzengura dzinokuvadza zvikuru nekuti zvinogona kukonzera kupinda kwemadziro uye kutadza kwemidziyo pasina kurasikirwa nesimbi.
Kuwanda kwechloride hakufanirwe kunge kwakanyanya kuti kukonzeresa ngura musimbi isingatsvi 304 ne316, uye panzvimbo dzakachena dzisina maburi kana mipata, huwandu hwechloride hwakanyanya hunokurudzirwa ikozvino hunoonekwa se:
Zvinhu zvakawanda zvinogona kukonzera huwandu hwechloride hunopfuura nhungamiro idzi, zvese zviri zviviri uye munzvimbo dziri pedyo. Zvave zvisingawanzoitiki kutanga kufunga nezvekutonhodza kamwe chete kwezviteshi zvitsva zvemagetsi. Zvizhinji zvakavakwa nematowera ekutonhodza, kana mune dzimwe nguva, macondenser anotonhodza mweya (ACC). Kune avo vane matowera ekutonhodza, huwandu hwetsvina muzvizoro hunogona "kutenderera." Semuenzaniso, koramu ine huwandu hwechloride yemvura ye50 mg/l inoshanda nematanho mashanu ekutonhodza, uye huwandu hwechloride mumvura inotenderera i250 mg/l. Izvi chete zvinofanira kubvisa 304 SS. Pamusoro pezvo, muzviteshi zvitsva nezviripo, pane kudiwa kuri kuwedzera kwekutsiva mvura yakachena kuti iwedzere kutengeswa kwezviteshi. Imwe nzira inowanzo shandiswa imvura yakasviba yemumaguta. Tafura 2 inoenzanisa kuongororwa kwezviteshi zvina zvemvura yakachena nezviteshi zvina zvemvura yakasviba.
Chenjererai kuwedzera kwehuwandu hwechloride (nezvimwe zvinhu zvisina kuchena, zvakaita senitrogen nephosphorus, izvo zvinogona kuwedzera kusvibiswa kwehutachiona mumasisitimu ekutonhodza). Kune mvura yese isina kuchena, chero kutenderera kwemvura muchikamu chekutonhodza kuchapfuura muganho wechloride unokurudzirwa ne316 SS.
Kukurukurirana kwapfuura kwakavakirwa pakugona kwengura kwenzvimbo dzesimbi dzakajairika. Kupwanyika netsvina zvinochinja nyaya yacho zvakanyanya, sezvo zvese zviri zviviri zvichipa nzvimbo apo tsvina inogona kuungana. Nzvimbo yakajairika yekutsemuka kwemakemikari muzvikonzeri uye zvakafanana nekupisa exchangers iri pamigero yechubhu-ku-tube sheet. Dziva riri mukati mechubhu rinogona kugadzira matombo pamuganhu wetsvina, uye matope pachawo anogona kushanda senzvimbo yekusvibiswa. Uyezve, nekuti simbi isingatsvi inovimba ne oxide layer inoramba ichidzivirira, zvidimbu zvinogona kugadzira nzvimbo dzisina oxygen dzinoshandura pamusoro pesimbi yasara kuita anode.
Kukurukurirana kuri pamusoro apa kunotsanangura nyaya dzisingawanzofungwa nevagadziri vemiti pavanenge vachitaura nezvezvinhu zvinoshandiswa pakugadzira condenser uye zvinhu zvinoshandiswa pakugadzira zvinhu zvemachubhu ekupisa e304 ne316 SS. Dzimwe nguva mafungiro nezve304 ne316 SS achiri kuita sekuti "ndizvo zvatagara tichiita" pasina kufunga nezvemigumisiro yezviito zvakadaro. Zvimwe zvinhu zviripo kuti zvikwanise kugadzirisa mamiriro emvura anotonhora akanyanya kusangana nezvirimwa zvakawanda.
Tisati takurukura nezvesimbi dzinoshandiswa, pane imwe pfungwa inofanira kutaurwa muchidimbu. Kazhinji, 316 SS kana kunyange 304 SS yakashanda zvakanaka panguva yekushanda kwakajairika, asi yakakundikana panguva yekudzimwa kwemagetsi. Kazhinji, kukundikana kunokonzerwa nekusabuda zvakanaka kwemvura mu condenser kana heat exchanger zvichikonzera mvura isingamire mumachubhu. Nzvimbo iyi inopa mamiriro akanaka ekukura kwetupukanana. Makoroni etupukanana anoburitsa makemikari anoparadza anoparadza zvakananga simbi iri muchubhu.
Iyi nzira, inozivikanwa se microbially induced corrosion (MIC), inozivikanwa nekuparadza mapaipi esimbi isina ngura nedzimwe simbi mukati memavhiki. Kana heat exchanger isingakwanise kubudiswa mvura, kungwarira kwakakomba kunofanira kupihwa pakutenderera mvura nguva nenguva kuburikidza neheat exchanger uye kuwedzera biocide panguva yekuita. (Kuti uwane rumwe ruzivo nezvemaitiro akakodzera ekurongedza, ona D. Janikowski, “Layering Up Condenser and BOP Exchangers – Considerations”; yakaitwa kubva muna Chikumi 4-6, 2019 muChampaign, IL Yakaunzwa pa39th Electric Utility Chemistry Symposium.)
Kune nzvimbo dzakaoma dzataurwa pamusoro apa, pamwe nenzvimbo dzakaoma dzakadai semvura ine brackish kana mvura yegungwa, dzimwe simbi dzinogona kushandiswa kudzivirira tsvina. Mapoka matatu e alloy akabudirira, titanium yakachena mukutengeserana, 6% molybdenum austenitic stainless steel uye superferritic stainless steel. Aya ma alloy anodzivirirawo MIC. Kunyangwe titanium ichionekwa seisingakuvadzi ngura, chimiro chayo chekristaro chakabatana nehexagonal uye modulus yakaderera kwazvo inoita kuti ive nyore kukuvara. Iyi alloy yakakodzera zvakanyanya kuiswa kutsva nemidziyo yakasimba yekutsigira machubhu. Imwe nzira yakanaka ndeye super ferritic stainless steel Sea-Cure®. Kuumbwa kwezvinhu izvi kunoratidzwa pazasi.
Simbi iyi ine chromium yakawanda asi nickel shoma, saka isimbi isina ngura yeferritic kwete austenitic stainless steel. Nekuda kwehuwandu hwayo hushoma hwenickel, inodhura zvishoma pane mamwe ma alloys. Simba rakawanda reSea-Cure uye elastic modulus zvinobvumira madziro akatetepa kupfuura zvimwe zvinhu, zvichikonzera kutamiswa kwekupisa kuri nani.
Hunhu hwakawedzerwa hwesimbi idzi hunoratidzwa pachati ye "Pitting Resistance Equivalent Number", iyo, sezvinoreva zita, inzira yekuedza inoshandiswa kuona kuramba kwesimbi dzakasiyana-siyana kukutu kwegomba.
Imwe yemibvunzo inowanzo bvunzwa ndeyekuti "Ndeipi chloride yakawanda inogona kugashirwa nesimbi isina ngura?" Mhinduro dzacho dzinosiyana-siyana. Zvinhu zvinosanganisira pH, tembiricha, kuvapo uye rudzi rwekutyoka, uye mukana wekuti pave nemarudzi anoshanda ezvisikwa zvipenyu. Chishandiso chakawedzerwa padivi rekurudyi reMufananidzo 5 kuti chibatsire nesarudzo iyi. Yakavakirwa pa pH isina kusimba, 35°C mvura inoyerera inowanzo kuwanikwa muzvishandiso zvakawanda zveBOP uye condensation (kudzivirira kuumbwa kwemvura uye kutsemuka). Kana alloy ine makemikari chaiwo yasarudzwa, PREn inogona kuonekwa uye yobva yabatanidzwa ne slash yakakodzera. Huwandu hwe chloride hwakanyanya hunokurudzirwa hunogona kuonekwa nekudhirowa mutsetse wakatwasuka padivi rekurudyi. Kazhinji, kana alloy ichizofungidzirwa kuti inoshandiswa mumvura ine brackish kana yegungwa, inofanirwa kuve neCCT pamusoro pe25 degrees Celsius sezvakayerwa neG 48 test.
Zviri pachena kuti ma alloys e super ferritic anomiririrwa neSea-Cure® anowanzo kukodzera kushandiswa mumvura yegungwa zvakaenzana. Pane chimwe chinhu chakanaka kune zvinhu izvi chinofanira kusimbiswa. Matambudziko ekuora kweManganese akaonekwa kwemakore mazhinji e304 ne316 SS, kusanganisira mumafekitori ari parwizi rweOhio. Munguva pfupi yapfuura, ma heat exchangers ari pamafekitori ari parwizi rweMississippi neMissouri akarwiswa. Kuora kweManganese idambudziko rakajairika mumasystem ekugadzira mvura yetsime. Iyo corrosion mechanism yakaonekwa se manganese dioxide (MnO2) ichiita oxidizing biocide kugadzira hydrochloric acid pasi pe deposit. HCl ndiyo inonyanya kurwisa simbi. [WH Dickinson naRW Pick, "Manganese-Dependent Corrosion in the Electric Power Industry"; yakaratidzwa pa2002 NACE Annual Corrosion Conference, Denver, CO.] Ferritic steels inodzivirira iyi corrosion mechanism.
Kusarudza zvinhu zvepamusoro zvemachubhu econdenser neheat exchanger hakuchisiri chinhu chinotsiva kudzora makemikari ekurapa mvura. Sezvakataurwa nemunyori Buecker munyaya yapfuura yesimba remagetsi, chirongwa chekurapa makemikari chakagadzirwa zvakanaka uye chinoshandiswa zvakanaka chinodiwa kuderedza mukana wekukweva, ngura, uye kusvibisa. Polymer chemistry iri kubuda senzira ine simba kune phosphate/phosphonate chemistry yekare kudzora ngura nekukweva mumasisitimu ekutonhodza. Kudzora kusvibiswa kwehutachiona kwave kuri uye kucharamba kuri nyaya yakakosha. Nepo oxidative chemistry ine chlorine, bleach, kana zvimwe zvakafanana zviriyo musimboti wekudzora hutachiona, kurapwa kwekuwedzera kunogona kuvandudza kushanda kwezvirongwa zvekurapa. Mumwe muenzaniso wakadaro i stabilization chemistry, iyo inobatsira kuwedzera kuburitswa uye kushanda kwe chlorine-based oxidizing biocides pasina kuisa chero makemikari anokuvadza mumvura. Pamusoro pezvo, kudya kwekuwedzera ne non-oxidizing fungicides kunogona kubatsira zvikuru mukudzora kukura kwehutachiona. Mugumisiro ndewekuti kune nzira dzakawanda dzekuvandudza kugara kwenguva refu uye kuvimbika kwe power plant heat exchangers, asi system yega yega yakasiyana, saka kuronga nekungwarira uye kubvunzana nenyanzvi dzeindasitiri kwakakosha pakusarudza zvinhu uye maitiro emakemikari. Zvakawanda zve Chinyorwa ichi chakanyorwa kubva pakuona kwekuchenesa mvura, hatibatanidzwi mukusarudza zvinhu, asi tinokumbirwa kubatsira kudzora kukanganisa kwesarudzo idzodzo kana michina yatanga kushanda. Sarudzo yekupedzisira pakusarudza zvinhu inofanira kuitwa nevashandi vefekitori zvichibva pane zvinhu zvakati wandei zvakatsanangurwa pakushandiswa kwega kwega.
Nezve Munyori: Brad Buecker inyanzvi yezvehunyanzvi paChemTreat. Ane ruzivo rwemakore makumi matatu nematanhatu muindasitiri yemagetsi kana kuti akabatana nayo, yakawanda yacho mukugadzira makemikari emhepo, kurapwa kwemvura, kudzora hunhu hwemhepo uye kuCity Water, Light & Power (Springfield, IL) uye Kansas City Power & Light Company iri kuLa Cygne Station, Kansas. Akapedzawo makore maviri ari mutariri wemvura/mvura yakasviba pafekitori yemakemikari. Buecker ane dhigirii reBS muChemistry kubva kuIowa State University nebasa rekuwedzera muFluid Mechanics, Energy and Materials Equilibrium, uye Advanced Inorganic Chemistry.
Dan Janikowski ndiye Maneja weTechnical kuPlymouth Tube. Kwemakore makumi matatu nemashanu, anga achibatanidzwa mukugadzira simbi, kugadzira nekuyedza zvigadzirwa zvemachubhu zvinosanganisira copper alloys, stainless steel, nickel alloys, titanium necarbon steel. Ave ari kuPlymouth Metro kubvira muna 2005, Janikowski akabata zvinzvimbo zvepamusoro zvakasiyana-siyana asati ava Maneja weTechnical muna 2010.