Malangizo oyika ma valve otetezedwa ndikuwunika koyenera kuwunika kwachitetezo cha ma valve ofunikira - Maphunziro a ma valve a Lecco
Malangizo oyika ma valve otetezeka
M'mapangidwe amafuta a petrochemical, monga kuchuluka kwa zida zapakatikati komanso zothamanga kwambiri za zida ndi mapaipi omwe akukhudzidwa pakuwonjezeka, kugwiritsa ntchito ma valve oteteza kwakula moyenerera. Chifukwa chake, valavu yachitetezo yolondola, masanjidwe oyenera ndikofunikira kwambiri.
1. Valve yachitetezo pazida kapena mapaipi iyenera kuyikidwa molunjika komanso pafupi ndi zida zotetezedwa kapena mapaipi. Komabe, valavu yachitetezo cha payipi yamadzimadzi, chotenthetsera kutentha kapena chidebe, valavu ikatsekedwa, kupanikizika kumatha kukwera chifukwa chakukula kwamafuta, kumatha kukhazikitsidwa mozungulira.
2, valavu yotetezera iyenera kuikidwa pamalo omwe ndi yosavuta kukonza ndikusintha, ndipo payenera kukhala malo okwanira ogwira ntchito mozungulira. Monga: valavu yotetezera chidebe choyimira, DN80 pansipa, ikhoza kukhazikitsidwa kunja kwa nsanja; DN100 imayikidwa kunja kwa nsanja pafupi ndi nsanja, mothandizidwa ndi nsanja ingagwiritsidwe ntchito kukonzanso ndi kukonzanso valve. Ndipo sayenera kuikidwa kumapeto kwa mipope yayitali yopingasa kuti apewe kudzikundikira kwa zolimba kapena zamadzimadzi.
3. Valavu yotetezera yomwe imayikidwa pa payipi iyenera kukhala pamalo pomwe kupanikizika kumakhala kokhazikika ndipo pali mtunda wina kuchokera ku gwero la kusinthasintha.
4, valavu chitetezo ku mlengalenga, kwa sing'anga si vuto lililonse (monga mpweya, etc.) kutulutsa chitoliro pakamwa ndi apamwamba kuposa kutulutsa doko monga pakati pa 715m utali wozungulira nsanja opaleshoni, zipangizo kapena pansi 2.5m pamwamba. Paziwopsezo zowononga, zoyaka kapena zapoizoni, chotulutsiramo chimayenera kupitilira 3m kutalika kuposa pulatifomu, zida kapena pansi pamtunda wa 15m.
5, valavu yachitetezo imalumikizidwa ndi chitoliro chothandizira kuthamanga, kuti ilowetsedwe mu chitoliro kuchokera kumtunda kupita ku 45 Angle, kuti musatsanulire condensate mu chitoliro chanthambi, ndipo mutha kuchepetsa kupanikizika kumbuyo kwa chitetezo. valavu. Pamene kupanikizika kosalekeza kwa valve yotetezera kuli kwakukulu kuposa 710MPa, ikani 45 iyenera kugwiritsidwa ntchito.
6. Sipayenera kukhala madzi opangidwa ndi thumba mu chitoliro chotulutsa mpweya wonyowa, ndipo kutalika kwa valavu yachitetezo kuyenera kukhala kwakukulu kuposa njira yothandizira kupanikizika. Ngati kutuluka kwa valavu yoperekera chithandizo kuli kochepa kusiyana ndi chingwe chachikulu chothandizira kupanikizika kapena chitoliro chotuluka chiyenera kukwezedwa kuti chifike pamzere waukulu, tanki yosungiramo madzi ndi mlingo wa mlingo kapena valavu yotulutsa madzi iyenera kuyikidwa pansi komanso mosavuta. malo ofikika, ndi kutulutsidwa nthawi zonse kumalo otsekedwa kuti asadzikundike madzi mu gawo la chitoliro chooneka ngati thumba. Kuonjezera apo, m'madera ozizira, gawo la chitoliro cha thumba limafuna kutentha kwa nthunzi kuti zisawonongeke. The nthunzi tracing chubu angathenso vaporize condensate mu thumba chubu kupewa kudzikundikira madzi. Koma ngakhale mutagwiritsa ntchito chubu chowunikira kutentha, valavu yokhetsa pamanja ndiyofunikabe.
7, kamangidwe ka chitoliro chachitetezo cha valavu chiyenera kuganizira kuti kupanikizika kumbuyo sikudutsa mtengo wina wa kupanikizika kosalekeza kwa valve yotetezera. Kwa valavu yachitetezo chamtundu wa masika, mtundu wamba wa kupsinjika kwam'mbuyo sayenera kupitilira 10% ya kupanikizika kwa valve, mtundu wa bellows (mtundu woyenera) kupanikizika kwam'mbuyo sikuyenera kupitirira 30% ya kukakamizidwa kwa valavu yachitetezo, kwa woyendetsa. valavu yachitetezo chamtundu, kupanikizika kumbuyo sikudutsa 60% ya kupanikizika kosalekeza kwa valve yotetezera. Mtengo weniweniwo uyenera kuloza ku zitsanzo za wopanga ndikudziwikiratu powerengera ndondomeko.
8, chifukwa gasi kapena nthunzi imatulutsidwa mumlengalenga ndi valavu yachitetezo, mphamvu yotsutsana imapangidwa pamzere wapakati wa chitoliro chotuluka, chomwe chimatchedwa mphamvu yamagetsi yachitetezo. Mphamvu ya mphamvuyi iyenera kuganiziridwa pakupanga mzere wotuluka wa valve yothandizira. Monga: chitoliro chachitetezo cha valve chiyenera kuperekedwa ndi chithandizo chokhazikika; Pamene gawo la chitoliro cholowera cha valve yothandizira ndi lalitali, khoma la chotengera chopanikizika liyenera kulimbikitsidwa.
Chitetezo cha valve ntchito zodzitetezera
1. Valavu yotetezedwa yogwiritsira ntchito dipatimenti iyenera kufotokozera momveka bwino zofunikira zachitetezo chotsatira cha valve yachitetezo potsatira malamulo oyendetsera ntchito:
1. Zizindikiro za ndondomeko ya ntchito (kuphatikizapo kupanikizika kwa ntchito, kutentha kwa ntchito kapena kutentha kochepa kwa ntchito, kuika mphamvu);
2. Chitetezo cha valve ndi njira zogwirira ntchito (kwa valve yotetezera ndi wrench);
3. Zinthu zomwe ziyenera kuyang'aniridwa pakugwira ntchito kwa valve yotetezera chitetezo, zochitika zosazolowereka zomwe zingatheke komanso njira zodzitetezera, komanso njira zowonongeka ndi malipoti.
2. Kuyendera nthawi zonse kuyenera kuchitidwa panthawi ya ntchito ya valve yotetezera. Nthawi yowunikira imapangidwa ndi wogwiritsa ntchito aliyense malinga ndi momwe zilili, ndipo kutalika kwake sikuyenera kupitirira kamodzi pamwezi. Zinthu zotsatirazi ziyenera kuyang'aniridwa makamaka:
1. Kaya pepala la dzinalo ndi lathunthu;
2. Chisindikizo cha valve yachitetezo sichili bwino;
3. Kaya valavu yodulidwa yomwe imagwiritsidwa ntchito ndi valavu yotetezera imatsegulidwa kwathunthu ndipo chisindikizocho chili bwino;
4. Yang'anani ngati palibe chilichonse chikuchitika panthawi ya ntchito.
5. Kaya ikhoza kuchoka mosavuta pamene kupanikizika kwapangidwe kumadutsa mu ntchito.
Chachitatu, valavu yachitetezo ikagwiritsidwa ntchito, mavuto otsatirawa akachitika, wogwiritsa ntchitoyo ayenera kufotokozera m'madipatimenti oyenera munthawi yake molingana ndi njira zomwe adalamula:
1. Kupanikizika kwambiri sikuchoka;
2. Musabwerere pampando mutanyamuka;
3. Kutayikira kumachitika;
4. Vavu yachitetezo isanadulidwe valavu ndi chisindikizo chachitetezo cha valve kugwa.
Chachinayi, chotengera choponderezedwa chikugwira ntchito, valavu yachitetezo isanayambe valavu yodulidwa iyenera kukhala yotseguka ndi kusindikiza. Ndizoletsedwa kulumikiza valavu yachitetezo kuti ife, kuletsa kapena kutseka valavu yodula. Kusintha kulikonse pa ntchito ya valve yotetezera kuyenera kuvomerezedwa ndi woyang'anira.
Chachisanu, valavu yotetezera yokhala ndi ntchito yokakamiza, ndiyoletsedwa kuchita ntchito iliyonse yokonza ndi yomanga. Ayenera kuchita kukonzanso ndi ntchito zina, wosuta unit ayenera kupanga zofunika ntchito ogwira ntchito ndi miyeso zoteteza, ndi luso munthu woyang'anira pangano, mu ntchito yeniyeni ya khomo ayenera kutumiza anthu kuyang'anira malo.
Chachisanu ndi chimodzi, wogwiritsa ntchito amaletsedwa kutsegula ndi kuchotsa chisindikizo chotsogolera kapena kusintha wononga valavu yotetezera.
7. Valavu yoteteza chitetezo iyenera kusungidwa bwino komanso kusamalidwa.
Phunzirani pa Kuthamanga Kwambiri kwa Valve ya Chitetezo - Phunzirani pa Kuthamanga Kwambiri kwa Valve ya Chitetezo - Lyco Valve Abstract: Njira yowerengera kuchuluka kwa mphamvu ya valve yotetezera imaperekedwa.
ZOTSATIRA ZOTSATIRA ZIMAONETSERA KUTI CRITICAL PRESSURE RATIO OF SAFETY VALVE IMAKAMULIDWA NDI CRITICAL PRESSURE ratio YA nozzle ndi DISC flow resistance resistance coefficient, ndipo chifukwa disc flow resistance coefficient ndi yayikulu kwambiri, valavu yachitetezo nthawi zambiri imakhala mu subcritical. mayendedwe.
Gb50-89 "Steel Pressure Vessel", malinga ndi kayendedwe ka valavu yachitetezo ndi yosiyana, perekani mitundu iwiri ya mawerengedwe amtundu wa kusamutsidwa, kotero, kuweruza ngati valavu yachitetezo ili mumkhalidwe wovuta kwambiri kapena subcritical flow state, ndi maziko a kusankha kolondola kwa chiŵerengero cha kusamuka.
Pakalipano, pali malingaliro awiri pa mtengo wa chiwongolero champhamvu cha valve yotetezera: ① amaonedwa kuti kupanikizika kwakukulu kwa valve yotetezera ndikofanana ndi chiŵerengero champhamvu cha mphutsi m'mayiko osiyanasiyana. , ndipo mtengo wake ndi 0.528 [1,2].
② Akatswiri ambiri ndi ochita kafukufuku amakhulupirira kuti chiŵerengero champhamvu cha valve yotetezera ndichocheperapo kusiyana ndi chiŵerengero champhamvu cha mphutsi, ndipo mtengo wake uli pafupi 0.2 ~ 0.3 [3] Pakalipano, palibe njira yowerengera yolimba komanso yolondola yowerengera. chiŵerengero cha kuthamanga kwa valve yotetezera chavomerezedwa.
Choncho, kudziwa kuchuluka kwa kuthamanga kwa valve yotetezera chitetezo ndikuweruza molondola kayendedwe kabwino kamene kamakhala vuto lofulumira kuthetsedweratu mu engineering, zomwe sizinafotokozedwe m'mabuku mpaka pano.
Kupyolera mu kusanthula kwamalingaliro ndi kafukufuku woyesera, wolemba akukambirana za kayendedwe ka valavu yotetezera ndikuyika patsogolo ndondomeko yowerengera ya chiŵerengero cha kupanikizika kwa valve ya chitetezo.
1 Vavu yachitetezo yofunikira kupanikizika kwapakati pa RCR imatanthawuza kuchuluka kwa kuthamanga kwa polowera ndi kutulutsa pomwe kuthamanga kwa mpweya kumafika pa liwiro lakumveka pamawu pang'ono.
The yovuta kuthamanga chiŵerengero cha nozzle akhoza masamu ndi chilinganizo mu chiphunzitso.
Pamene nozzle polowera kuthamanga chiŵerengero ndi m'munsi kuposa kapena wofanana ndi zovuta kuthamanga chiŵerengero cha nozzle, kusokonezeka kwa polowera mpweya kuthamanga chiŵerengero sangathe upambana sonic ndege chifukwa sonic otaya pa kubwereketsa gawo, kotero chisokonezo sangathe kusokoneza otaya. mu mphuno.
Kuthamanga kwa mpweya pa gawo lotulutsirako sikunasinthe pa P2 / P1 = Cr, kutuluka kwa mpweya pa gawo lotulutsirako kumatulukabe, ndipo kusamutsidwa kwachibale sikunasinthe, ndiko kuti W / Wmax = 1. Panthawi imeneyi, nozzle ili mumkhalidwe wovuta kwambiri kapena wapamwamba kwambiri [4].
Kuphatikiza pa nozzle, kuchuluka kwamphamvu kwazinthu zina nthawi zambiri kumafunika kutsimikiziridwa ndi mayeso, ndipo chiwopsezo chovuta kwambiri chomwe chimatsimikiziridwa ndi mayeso chimatchedwa chiŵerengero chachiwiri chofunikira chosiyanitsa.
Chifukwa cha zovuta za dongosolo la chitetezo cha valve, zimakhala zovuta kudziwa kuthamanga kwa kayendedwe ka kayendedwe ka kayendedwe ka kanyumba kakang'ono kameneka kagawo ka chitetezo cha valve, kotero n'zosatheka kudziwa kuchuluka kwa mphamvu ya valve yotetezera molondola ngati malo ang'onoang'ono otsekemera othamanga amafika pa liwiro la phokoso.
Pakalipano, njira yodziwira ngati valavu yotetezera yafika pamtunda wovuta kwambiri ndikuyesa kusuntha kwa valve ya chitetezo. Zimakhulupirira kuti valavu yotetezera idzafika kumalo ovuta kwambiri malinga ngati coefficient yosamutsidwa sikusintha ndi chiŵerengero cha kuthamanga [3].
Zotsatira zoyezera zikuwonetsa kuti kusuntha kwa valve yotetezera nthawi zonse kumasintha ndi kusintha kwa chiŵerengero cha kuthamanga, koma pamene chiŵerengero cha kuthamanga kwa valve yotetezera ndichotsika kuposa 0.2 ~ 0.3, kusiyana kwa kusuntha kwa valve yachitetezo ndi chiŵerengero cha kuthamanga. ndi yaying'ono, ndipo anthu amaganiza kuti kusintha kwakung'ono kumeneku kumachitika chifukwa cha kulakwitsa kwa miyeso, kotero kumaganiziridwa kuti chiwopsezo chovuta cha valve yotseguka yotseguka ndi pafupifupi 0.2 ~ 0.3.
Maziko ongoyerekeza a mayeso njira imeneyi kudziwa zovuta kuthamanga chiŵerengero cha valavu mpumulo ndi kuti kuthamanga chiŵerengero chisokonezo sangathe kupitirira ndege sonic mu yovuta ndi supercritical otaya boma, kotero kuti wachibale kumaliseche mlingo wa nozzle amakhalabe osasintha.
Komabe, m'malo ovuta kwambiri kapena othamanga kwambiri, kutuluka kwa gawo la nozzle ndikuyenda kwa sonic, zomwe zimapangitsa kusamutsidwa kwachibale.
Pamene kulowetsedwa kwa P1 kwa valavu yachitetezo kumawonjezeka, kuthamanga kwa disc kukaniza kutsika P kumawonjezeka, ndipo kuthamanga kwa P2 kwa nozzle mu valve kumawonjezekanso. Zotsatira zake, P2 ndi P1 zitha kuchulukitsidwa pang'onopang'ono, zomwe zimapangitsa kuti chiwopsezo cha nozzle mu valve r = P2 / P1 chiwonjezeke pang'onopang'ono mpaka pamtengo wokhazikika.
Monga momwe tingawonere kuchokera ku chiŵerengero cha kusamutsidwa kwa nozzle, kusamutsidwa kwa nozzle pang'onopang'ono kumakhala mtengo wokhazikika, ndipo kusamutsidwa kwa valve yotetezera kumasintha pang'ono kapena kusasinthika ndi chiŵerengero cha kuthamanga.
Komabe, izi sizikutanthauza kuti kuthamanga kwa kayendedwe ka kayendedwe ka kagawo kakang'ono ka valve yotetezera kumafika pamtunda wa phokoso. Mwachiwonekere, chiŵerengero cha kupanikizika pa nthawi ino sichiri chovuta kwambiri cha valavu yotseguka yachitetezo.
Komanso, pamene kutalika kwa diski kuli kochepa, mphamvu yowonongeka ya valve yotetezera sisintha ndi chiŵerengero cha kupanikizika ngakhale pamene chiŵerengero cha kupanikizika chikufika ku 0.67. Zoonadi, chiŵerengero choponderezedwachi sichingaganizidwe ngati chiwongolero chovuta kwambiri cha valavu yotetezera chitetezo, chifukwa cholankhula momveka bwino, chiŵerengero champhamvu cha valve yachitetezo sichingakhale chokulirapo kusiyana ndi chiŵerengero champhamvu cha mphutsi.
Chithunzi 1 chojambula cha ma valve otetezera chitetezo ndi chitsanzo cha kuwerengera kwa chiwerengero cha 1 b chimasonyeza kuti valavu yothandizira ndi mphuno yake yofanana ikuwonetsedwa kusiyana pakati pa kukana kwa disc pressure drop p chifukwa cha zosiyana siyana za njira yowerengetsera kusamuka kumatengera zofanana zoyenera. kuwerengera kwachitsanzo cha nozzle, ndikunyalanyaza zotsatira za kutsika kwa kuthamanga kwa disc, zomwe zingasokoneze mosavuta valavu yopumira ndi mphuno, Izi zingapangitse ANTHU KUKHULUPIRIRA KUTI CRITICAL PRESSURE RATIO OF THE RELIEF VALVE NDI YOMWEYO NDI YA NOZZLE, 0.528, PAMENE MFUNDO YOTHANDIZA VALVE NDI mphuno ndizosiyana kwambiri.
Kusiyanitsa kwakukulu pakati pa valavu yotetezera ndi mphuno yake yofanana ndi yofanana ikuwonetsedwa mu kutsika kwa mphamvu ya disc kukaniza, pamene chikhalidwe chowerengera chachikhalidwe sichiganizira za udindo wa disc resistance drop drop P, zomwe ziri zopanda nzeru.
The theoretical velocity of nozzle in the static parameters ndi [5] : 3) Pamene, K ndi adiabatic index; A1A2 si cholowera cha valavu ndi kutulutsa kwa gawo loyenda; R0 gasi nthawi zonse; T1 ndi kutentha kolowera; R ndi chiŵerengero cha kuthamanga kwa cholowetsa cha nozzle mu valve, ndi r = 2 / P1. Tsopano gawani mbali zonse za Equation (1) ndi P1 ndi ma equation olowa m'malo (2) ndi (3) m'njira yosavuta, ndipo mgwirizano pakati pa chiŵerengero cha kuthamanga kwa valavu yotetezera ndi chiŵerengero cha kuthamanga kwa nozzle mu valavu chikhoza kutengedwa. motere: Mu Fomula (4), kuthamanga kwa chiŵerengero cha valve B, RBB / 1 Popeza gawo lofunika kwambiri la valavu lotseguka lachitetezo lili pamphuno yamphuno, vuto loyendetsa kwambiri * la valavu yachitetezo likhoza kufika pa mphuno ya mphuno.
Malinga ndi Equation (7), kupanikizika kwakukulu kwa chiŵerengero cha RBCR cha valavu yachitetezo kumakhudzidwa makamaka ndi chiŵerengero chapamwamba cha RCR cha nozzle ndi disc flow resistance resistance coefficient F.
Pamene DISC ikuyenda kukana koyenera F ikuwonjezeka, ZOKHUDZA ZOKHUDZA KWAMBIRI ZA valavu yotetezera zidzachepa chifukwa kupanikizika kwapadera kwa nozzle kumakhala kosalekeza.
Zitha kuwoneka kuti kupanikizika kwakukulu kwa valve yotetezera kumachepa ndi kuwonjezeka kwa disc flow resistance resistance coefficient.
Pamene coefficient yotsutsana ndi kutuluka ikuwonjezeka kufika pamtengo wina wovuta kwambiri, chiwongolero champhamvu cha valve yotetezera chidzachepetsedwa mpaka zero.
Ngati DISC RESISTANCE COEFFICIENT Ipyola MFUNDO ZOYENERA ZIMENEZI, VALVESI SINGAFIKIRE KU CRITICAL FLOW STATE CHIFUKWA CHIFUKWA CHIKHALIDWE CHA DISC FLOW RESISTANCE ndi KUKULU KWAMBIRI, ndipo valavu yachitetezo ili kwathunthu mu subcritical flow state.
Choncho, ngati pali vuto lothamanga kwambiri mu valavu yachitetezo, chiwongolero champhamvu cha valve yachitetezo sichiyenera kukhala chocheperapo kuposa zero, ndiko kuti, pamene RBCR ≥0, coefficient ya disc flow resistance iyenera kukwaniritsa F ≥2 / K.
Kwa mpweya, k=1.4 ndi F ≤1.43.
Choncho, ngati valavu yachitetezo ili mumsewu wovuta kwambiri, chigawo chake cha disc flow resistance coefficient F sichikhoza kupitirira 1.43.
Pofuna kudziwa ngati valavu yachitetezo ili mumkhalidwe wovuta kwambiri kapena kayendedwe ka subcritical flow, wolembayo adayesa mayeso a disc flow resistance coefficient of two valves chitetezo, A42Y-1.6CN40 ndi A42Y-1.6CN50. CHITH. 2 ikuwonetsa mayendedwe oyeserera pakati pa disc flow resistance coefficient ndi kuthamanga kwa valve yachitetezo, momwe H ndiye kutalika kotsegulira ndipo Y ndiye kutalika kotsegulira mayeso.
Zotsatira zoyesa zikuwonetsa kuti kukana kwa disc flow resistance kwa valve yotseguka yotetezedwa ndi yoposa 1.43.
Choncho, tingathe kunena kuti ngakhale kulowetsedwa kwa valavu yachitetezo kuli kwakukulu, valavu yachitetezo sichingathe kufika pamtunda wovuta kwambiri chifukwa cha kutsika kwa valve disc resistance pressure ndi yaikulu kwambiri, choncho valavu yachitetezo nthawi zambiri imakhala mu subcritical flow. boma.
Pofuna kutsimikizira kudalirika kwa chidziwitso ichi, wolemba adayesa kuchuluka kwa kuthamanga kwa ma valve awiri otetezera ndi kuthamanga kwa mpweya mu valavu, ndi zotsatira za mayeso a chiŵerengero cha kuthamanga kwa valavu yachitetezo ndi chiŵerengero cha kuthamanga kwa valavu. mphuno mu valve
Zotsatira zoyesa zikuwonetsa kuti kukakamiza kolowera kwa valve yothandizira kukafika ku 0.6Pa gauge pressure), kupanikizika kwa nozzle mkati mwa mavavu awiriwa kumapitilira 0.7.
Zitha kuwoneka kuti nozzle mu valavu iyenera kukhala mu subcritical flow state.
Gawo lofunikira kwambiri la valavu yotetezedwa yotseguka lili pakhosi, ndipo vuto lakuyenda bwino kwa valavu yachitetezo * limatha kufikira pakhosi.
Choncho, pamene mphuno mkati mwa valavu yotetezera ifika pamtunda wovuta kwambiri, valavu yachitetezo ili mumkhalidwe wovuta kwambiri.
Nthawi yotumiza: Sep-03-2022
