Pepalali likuwonetsa zofunikira ndikugwiritsa ntchito valavu yagulugufe yachitsulo yosindikizira mu valavu yotsika
Ndi chitukuko chofulumira cha mafakitale amakono a petrochemical, makampani amagetsi a malasha ndi mafakitale a firiji, kugwiritsa ntchito valve yotsika kutentha kumawonjezeka, mlingo wake ukuwonjezeka. Choncho, kugwiritsa ntchito moyenera komanso moyenera kwa valve yotsika kutentha kumapangitsa chidwi cha anthu. Kugwiritsiridwa ntchito kwa ma valve otsika kutentha kuphatikizapo kugwiritsa ntchito ma valve ochiritsira, pali zofunikira zina zapadera zomwe muyenera kuziganizira.
Mavavu a cryogenic nthawi zambiri amatanthawuza ma valve omwe amagwira ntchito pa kutentha kochepa kuposa -29 ° C. Ma valve ena a cryogenic amatha kunyamula mpweya wamadzimadzi (monga nayitrogeni, mpweya ndi gasi wachilengedwe) pa kutentha kotsika -196 ° C ndikuonetsetsa kuti ntchitoyo ikuyenda bwino.
With the decrease of the temperature of the working medium, the material and structure of the low temperature valve used are different from the conventional universal valve, especially the temperature valve (t Ndi kuchepa kwa kutentha kwa sing'anga yogwirira ntchito, zinthu ndi kapangidwe ka valavu yotsika yomwe imagwiritsidwa ntchito ndi yosiyana ndi valavu yapadziko lonse, makamaka valavu ya kutentha (t Pofuna kuchepetsa kutentha kwa kutentha kumalo otsekedwa kuchokera kunja, ziwalo zogwirira ntchito ziyenera kuchotsedwa ku thupi lopangidwa ndi insulated. Chifukwa chake khosi la boneti la valavu ya cryogenic ndi lalitali kwambiri. ** Valavu ya kutentha imayendetsedwa pansi pa zovuta kuchokera kunja kwa kutentha mpaka kutentha. Ndipo zimatero popanda kusokoneza. Kusindikizidwa kwa gawo lotseka nthawi zambiri kumatsimikiziridwa ndi kukakamiza kofunikira kolumikizana komwe kumapangidwa pa mphete yosindikizira, koma ngati mphamvu ya chipangizo chotumizira imakhazikika, mphamvu ya mphete yosindikiza ikhoza kukhala yosiyana ndi kutentha kwa ntchito, ndithudi, magwiridwe antchito a mphete yosindikiza, makamaka magwiridwe antchito a polymeric ndi osiyana. Chifukwa chake, valavu yotentha imakhala ndi zofunika kwambiri pa mphete yosindikiza, nthawi zambiri sankhani zinthu zolimba (STL) zakuthupi.
Valavu ya kutentha imakhala yochepa kwambiri pa liwiro lotsegula la shutoff. Ngakhale kuti pali njira za adiabatic, kutentha kumatulukabe pamtunda wochepa, zomwe zimapangitsa kuti pakhale gawo lamadzimadzi m'madera ena a dongosolo. Choncho, pamene valavu imatsegulidwa mwamsanga, madzi amatha kupeza liwiro lalikulu, kamodzi akakumana ndi zopinga kapena kukana monga valavu idzatulutsa madzi, omwe ayenera kuyang'anitsitsa pogwiritsidwa ntchito.
Nthawi zambiri amagwiritsidwa ntchito paukadaulo wa firiji, sing'anga ndi nayitrogeni kapena freon refrigerant, valavu yachitsulo yomwe imagwiritsidwa ntchito kale, kutentha kwake kuli pakati pa -28 ~ 150 ℃, tsopano imagwiritsa ntchito pang'ono, koma valavu yokhala ndi chitsulo cha ferritic ductile ikukula. Izi ndichifukwa choti chitsulo cha ferritic ductile chimakhala ndi mphamvu zolimba, kukana kuvala komanso kukana dzimbiri.
General mpweya zitsulo (WCB) valavu zinthu, ntchito kutentha ndi -29 ~ 150 ℃; Palinso otsika kutentha mpweya zitsulo (LCB, LC1, LC2), osachepera utumiki kutentha kwake ndi -46 ~ -73 ℃; Chitsulo chosapanga dzimbiri cha Austenitic (304, 316) ndichochita bwino kwambiri pazitsulo zotsika kutentha, kutentha kwake kochepa kumakhala pansi -196 ℃, ena -254 ℃.
Zigawo zotsekera za valve yotsika kwambiri, kusankha kwa zitsulo zosindikizira mpando wa valve pa thupi la valve, kusankha pulasitiki ya fluorine (F4) pa disc valve, palibe zofunikira zapadera mu kapangidwe kake ndi valavu ya chilengedwe chonse imakhala yofanana. Kusankha koyenera malinga ndi kutentha ndi sing'anga.
Valavu ya cryogenic, ingoganizirani za magwiridwe antchito a valve ya kutentha. Ikhoza kuikidwa pamalo aliwonse mkati mwa chofungatira, koma bokosi loyikapo, makina ogwiritsira ntchito (gudumu lamanja, wrench) ndi chizindikiro cha malo okweza ma valve ayenera kuikidwa kunja kwa chofungatira. Zosavuta kugwiritsa ntchito ndikuyikanso m'malo. Mavavu ambiri amaikidwa ndi tsinde mopingasa. Kwa ma valve ofunda amagetsi, tsinde la valve liyenera kuikidwa mopingasa.
Ntchito zinthu atanyamula chipangizo pa kutentha otsika ndi zovuta kwambiri, chifukwa kulongedza katundu n'zosavuta kutaya elasticity, kamodzi chifukwa cha evaporation sing'anga kutayikira, tsinde ndi achisanu, zidzachititsa munakhala chodabwitsa, valavu sangathe kutsegula ndi kutseka bwinobwino. Pofuna kukonza magwiridwe antchito a chipangizo chonyamula katundu, chotchinga chotenthetsera chimatha kukhazikitsidwa kuti chitsimikizire kutsekemera kwapake. Izi ndizomwe zimapangidwira kukulitsa kutalika kwa tsinde. Chophimbacho chimapangidwa ndi zinthu zopanda zitsulo zomwe zimakhala ndi matenthedwe otsika kwambiri (nsalu, tepi, etc.) kotero kuti kutaya kwa kutentha kwa bokosi lonyamula katundu kumachepetsedwa kwambiri. Mwinanso, chipangizo chonyamula katundu chimakhala ndi jekete ndipo sing'anga yokhala ndi kutentha kokwanira kuti ikhale yogwira ntchito ya chipangizo chonyamula katundu imayendetsedwa kumalo opangidwa. NTCHITO YAKE NDIKUPANGA valavu kuchokera kutentha pang'ono kupita kumalo ogwiritsira ntchito kumakhala ndi kutentha kwa kutentha, pamalo ogwirira ntchito ndi kupitirira malo ogwirira ntchito, kuthamanga kwa mpweya kudzakhala mwanjira inayake kungapangitse kuti mpweya wamadzimadzi usakhalenso madzi ndi kubwerera kutentha kwa gasi.
KUPIRITSIDWA KWA mpweya KUKHALA YOTSEGULIKA NTHAWI ZONSE, KABWINO KUKHALA NDI NTCHITO imodzi YA valve kapena ndi mapeto ena, kotero kuti ngati kutentha kwa mpweya kumakwera, sipadzakhalanso kuthamanga kwakukulu koopsa.
Chifukwa chakuti mbali za valve nthawi zambiri zimapangidwa ndikuyesedwa kutentha kwa chipinda, ndipo zimagwira ntchito pansi pa kutentha kochepa, mbali zosiyanasiyana zidzatulutsa kukula ndi kusinthasintha kosiyana ndi kusintha kwa kutentha, zomwe zidzakhudza mwachindunji ntchito yachibadwa ya valve, yomwe iyenera kutsatiridwa. kwa ndi kumvetsetsa mukugwiritsa ntchito.
Ma valve otsika kutentha amagwiritsa ntchito zipangizo zosiyanasiyana, zipangizo wamba: monga carbon steel (WCB) adzakhala brittle pamene kutentha amachepetsa. Zida zomwe zimagwiritsidwa ntchito kwambiri ndizo: zitsulo zosapanga dzimbiri za austenitic, bronze, ndi copper-nickel alloys, zonse zomwe zimakhala zopanda brittle ndipo zingagwiritsidwe ntchito moyenera. Zochitika zikuwonetsa kuti chitsulo chosapanga dzimbiri cha austenitic, bronze ndi Cu-Ni alloy ndiye zida zabwino kwambiri zolimba komanso mphamvu. Chifukwa chake magawo ena ofunikira a valve yotsika kutentha, monga: valavu yapadziko lonse lapansi, valavu yachitetezo, valavu yoyang'anira, valavu yoyang'ana ndi zina zotero, sankhani mtundu wamtunduwu.
Zochitika zopanga zimatiuza kuti ngakhale zitsulo zosapanga dzimbiri za austenitic, bronze ndi COPper-nickel alloy, ngati zinthu zomalizidwa sizimathandizidwa bwino ndi kutentha kochepa, valavu ikagwiritsidwa ntchito kutentha pang'ono, mbali zamkati zidzapunduka chifukwa cha gawo lazinthu. kusintha chifukwa cha kutentha otsika, chifukwa valavu kutayikira.
Pamsonkhano wa valavu yotsika kutentha, chifukwa cha zida zosiyanasiyana za ma gaskets olumikizana ndi flange, ma bolts olumikizira ndi magawo olumikizirana, kulumikizana pakati pa zida zosiyanasiyana sikungagwirizane, zomwe zimapangitsa kupumula ndi kutayikira. Choncho, valavu otsika kutentha, makamaka otsika valavu kutentha ntchito pansipa -196 ℃, njira yake kugwirizana ndi bwino ntchito kuwotcherera kugwirizana.
Kutsika kwa valavu yonyamula gasket, ambiri a F4, chifukwa chodzipaka bwino, kugundana kokwanira ndi kochepa, ndipo kumakhala ndi kukhazikika kwapadera kwamankhwala. Choncho, amagwiritsidwa ntchito ndi boma, koma F4 alinso ndi zofooka, mmodzi ndi ozizira otaya chizolowezi ndi lalikulu, lina ndi liniya Kukula koyenera ndi lalikulu, ozizira shrinkage pa kutentha otsika kumabweretsa kutayikira, chifukwa mu chiwerengero chachikulu cha icing. pa tsinde, kuti valavu kutsegula kulephera. Choncho, amangogwiritsidwa ntchito pazikhalidwe zotsika kwambiri. Mu nkhani ya kutentha, ayenera kusankha kusinthasintha graphite nsalu filler, kapena zitsulo zosapanga dzimbiri ndi kusinthasintha graphite wokhotakhota PAD. Ena otsika kutentha valavu ntchito, nthawi zambiri anapeza kuti kufala gawo la valavu zimachitika zomata. Chochitika cha occlusal chimachitika nthawi ndi nthawi. Zifukwa zazikulu ndi izi: kusankha mopanda nzeru kwa zida zophatikizika, kagawo kakang'ono kozizira kosungidwa, ndi kulondola kwa makina. Ngati mavuto omwewo apezeka pakugwiritsa ntchito, akuyenera kuperekedwa kwa woperekayo munthawi yake kuti apititse patsogolo kapangidwe kake ndikusintha zotengera zoyenera (bushing).
Zofunikira zina za ma valve otsika kutentha ndizofanana ndi ma valve ochiritsira.
The chofunika ndi ntchito zitsulo chisindikizo gulugufe valavu otsika kutentha valavu
Ndi chitukuko chachangu cha chuma ndi ukadaulo wa mafakitale, ukadaulo wosinthika kwambiri komanso watsopano komanso kufunikira kwa mavavu kwa anthu, makampani opanga ma valve akukumana ndi zovuta zazikulu komanso mwayi. Makamaka ntchito ya gulugufe valavu otsika kutentha sing'anga, kuwonjezera kukumana ntchito valavu ambiri kutentha firiji, chofunika kwambiri ndi kudalirika kwa valavu chisindikizo pa kutentha otsika, kusinthasintha kwa zochita ndi zina zofunika zina zapadera za valavu yotsika kutentha.
Valavu ya butterfly imakhala ndi mawonekedwe ophatikizika, voliyumu yaying'ono, kulemera kwake (poyerekeza ndi kukakamiza komweko, valavu yofananira yachipata imatha kuchepetsa 40% ~ 50%) kukana kwamadzimadzi, kutsegula ndi kutseka mwachangu ndi mndandanda waubwino, kotero gwiritsani ntchito.
Koma mu zipangizo zina otsika kutentha, monga zida mpweya liquefaction, zida mpweya kulekana ndi kuthamanga kugwedezeka adsorption zipangizo ntchito makampani mankhwala ndi oposa 80% kapena globe vavu kapena chipata valavu, valavu gulugufe ndi yaing'ono. Chifukwa chachikulu ndi chakuti valavu yagulugufe yachitsulo imakhala ndi ntchito yosindikiza bwino pa kutentha kochepa, ndipo zifukwa zina monga mawonekedwe osamveka zimapangitsa kuti pakhale kutayikira kwapakati mkati ndi zochitika zakunja, zomwe zimakhudza kwambiri chitetezo ndi ntchito yachibadwa ya zipangizo zotsika zotenthazi ndipo sizingatheke. kukwaniritsa zofunikira za zipangizo zotsika kutentha.
Malinga ndi kukula kosalekeza kwa zida zotsika kutentha m'dziko lathu, kufunikira kwa valve yotsika kutentha kukuwonjezeka tsiku ndi tsiku. Chifukwa chake, valavu yosindikizira yachitsulo yapangidwa bwino, ndipo valavu yagulugufe yazitsulo zoyera zitatu zokhala ndi ntchito yosindikiza kwambiri yapangidwa. Valavu yagulugufeyi imatha kukwaniritsa zofunikira zake mosasamala kanthu kuti sing'anga ndi kutentha kwambiri kapena kutentha kochepa.
Kuphatikiza ndi mawonekedwe ake apangidwe, ntchito yotsika ya kutentha imangoyambitsidwa.
Choyamba, otsika kutentha chimbale vavu kusindikiza ntchito zofunika:
Pali zifukwa ziwiri zazikulu zochepetsera kutentha kwa valve, chimodzi ndi kutuluka kwamkati; Chachiwiri ndi kutayikira.
1) Valavu imatulutsa kutuluka kwamkati
Chifukwa chachikulu ndi chakuti awiri osindikiza amapunduka pa kutentha kochepa.
Pamene sing'anga kutentha akutsikira kwa zinthu gawo kusintha chifukwa voliyumu kusintha, kuti choyambirira akupera mwatsatanetsatane wa kusindikiza pamwamba warping mapindikidwe chifukwa osauka otsika kutentha chisindikizo. Tachita mayeso otsika kutentha pa valavu ya DN250. Sing'anga ndi nayitrogeni wamadzi (-196 ℃) ndipo mbale ya gulugufe ndi 1Cr18Ni9Ti (popanda kutentha kwapansi). Zimadziwika kuti warp-deformation ya kusindikiza pamwamba ndi pafupifupi 0.12mm, ndicho chifukwa chachikulu cha kutayikira mkati.
Vavu yagulugufe yomwe yangopangidwa kumene imasinthidwa kuchoka ku chisindikizo cha ndege kupita ku conical chisindikizo. Mpandowo ndi nkhope yosindikizira yozungulira yozungulira, komanso mphete yosindikizira yozungulira yomwe imayikidwa mu mbale yagulugufe kuti apange awiri osindikiza. Mphete yosindikizira imatha kuyandama mozungulira mumsewu wa disc. Vavu ikatsekedwa, mphete yosindikizira zotanuka imayamba kulumikizana ndi kachigawo kakang'ono ka elliptical kusindikiza pamwamba, ndipo ndi kuzungulira kwa tsinde la valve, mphete yosindikizira imakankhidwira mkati pang'onopang'ono, kukakamiza mphete zotanuka kuti zigwirizane ndi nsonga yayitali. oblique conical surface, pamapeto pake zimatsogolera ku kulumikizana kwathunthu pakati pa mphete yosindikizira yotanuka ndi malo osindikizira a elliptic. Kusindikiza kwake kumatheka ndi kusinthika kwa mphete zotanuka.
Choncho, pamene thupi kapena gulugufe mbale ndi opunduka pa kutentha otsika, izo odzipereka ndi kulipidwa ndi zotanuka kusindikiza mphete, ndipo sadzabala kutayikira ndi munakhala chodabwitsa. Kupindika kwa zotanuka kumeneku kumatha nthawi yomweyo valavu ikatsegulidwa, ndipo palibe kukangana kwenikweni pakutsegulira ndi kutseka, kotero moyo wautumiki ndi wautali.
2) kutayikira kwa valve.
Choyamba ndi chakuti pamene valavu ndi payipi zimagwirizanitsidwa ndi ma flanges, kutayikirako kumayambitsidwa ndi kupumula kwa cholumikizira cholumikizira, cholumikizira cholumikizira, ndi magawo olumikizirana omwe amachepa chifukwa cha kulunzanitsa pakati pa zida pa kutentha kochepa. Chifukwa chake, tidasintha njira yolumikizirana ndi ma valve ndi mapaipi kuchokera ku kulumikizana kwa flange kupita ku mawonekedwe owotcherera kuti tipewe kutsika kwa kutentha.
Chachiwiri ndi kutayikira kwa tsinde ndi kulongedza katundu. Kawirikawiri, kunyamula ma valve ambiri kumagwiritsa ntchito F4, chifukwa chodziyendetsa bwino, kutsekemera kwazing'ono (friction coefficient of steel f = 0.05 ~ 0.1), ndipo imakhala ndi kukhazikika kwapadera kwa mankhwala, kotero yakhala ikugwiritsidwa ntchito.
Komabe, F4 ilinso ndi zolakwika. Choyamba, kuzizira koyenda chizolowezi ndi chachikulu; Chachiwiri, coefficient of linear expansion ndi yayikulu, zomwe zimapangitsa kuti kuzizira kwa shrinkage kutayike pa kutentha kochepa, zomwe zimapangitsa kuti pakhale chiwerengero chachikulu cha icing pa tsinde, kuti valavu ikhale yotseguka. Valavu yagulugufe yotsika kutentha yomwe idapangidwira izi imagwiritsa ntchito chisindikizo chodzichepetsera, ndiko kuti, imatha kusindikiza pa kutentha kwabwino komanso kutentha pang'ono kudzera pampata womwe watsala potengera mwayi wokulirapo kwa F4.
Nthawi yotumiza: Oct-19-2022
