Iimitha zokuhamba kwe-electromagnetic(ii-EMF) zisetyenziswa kakhulu kwiinkqubo zoshishino ngenxa yokuchaneka kwazo okuphezulu kunye nokuthembeka ekulinganiseniumgangatho wohambolwe-conductive fluids. Ezi mitha zisebenza ngokusekelwe kuMthetho kaFaraday we-Electromagnetic Induction, umgaqo osisiseko kwi-electromagnetism. Eli nqaku linika inkcazo eneenkcukacha zendlela esebenza ngayo i-electromagnetic flow meter, ukusuka kwithiyori esisiseko ukuya kwizinto ezisebenzayo kunye nokusetyenziswa.
1. Isiseko sethiyori: Umthetho kaFaraday wokungenisa i-Electromagnetic
UMthetho kaFaraday uthi xa umqhubi ehamba ngemagnethi, amandla e-electromotive (EMF) afakwa kwi-conductor. Kwimeko yemitha yokuhamba kwe-electromagnetic, ulwelo oluqhubayo oluhamba ngemitha lusebenza njengo "mqhubi," ngelixa intsimi yangaphakathi yemagnethi yemitha isebenza njengentsimi yangaphandle yemagnethi. I-EMF ebangelwayo ihambelana ngokuthe ngqo nesantya solwelo, amandla entsimi yemagnethi, kunye nomgama phakathi kwee-electrodes ezilinganisa i-EMF.
Ngokwezibalo, uMthetho kaFaraday ungabonakaliswa ngolu hlobo:
E=k×B×v×D
apho:
- I-E yi-electromotive force ebangelwa yi-induced (voltage)
- u-k yinto engaguqukiyo
- B ngamandla entsimi yamagnetic
- v lijubane eliqhelekileyo lolwelo
- U-D bububanzi betyhubhu yokulinganisa (emele ubude bomqhubi kwintsimi yemagnethi)
Ekubeni amandla e-magnetic field (B) kunye nobubanzi betyhubhu (D) zimiselwe imitha yokuhamba enikiweyo, i-voltage ebangelwayo (E) iba ngumlinganiselo othe ngqo wesantya solwelo (V). Ngokudibanisa isantya ngokuhamba kwexesha, isantya sokuhamba (umthamo ngexesha leyunithi) singabalwa.
2. Izinto ezibonakalayo zeMeter Flow Meter
Iikhoyili zeMagnetic okanye iMagnet Assembly
Iimitha yokuhambaiqulethe iseti yeekhoyili zemagnethi okanye indibano yemagnethi esisigxina evelisa intsimi yemagnethi efanayo ethe nkqo kwicala lokuhamba kolwelo. Intsimi yemagnethi ingaba yi-DC (ngqo - yangoku) okanye yi-AC (etshintshanayo - yangoku), apho amasimi e-AC exhaphake ngakumbi ngenxa yokukwazi kwawo ukunciphisa i-electrode polarization kunye nokuphazamiseka kwengxolo. Xa kusetyenziswa intsimi yemagnethi ye-AC, i-EMF ebangelwa lulwelo nayo iyahluka kwi-sinusoidally, nto leyo eyenza lula ukucubungula isignali.
Umbhobho wokulinganisa
Umbhobho wokulinganisa licandelo apho ulwelo ludlula khonaukuhambas. Ngokwesiqhelo yenziwe ngezinto ezingezizo ezitsala umbane kunye nezingezizo ezihambisa umbane (ezifana nentsimbi engatyiwayo efakwe i-PTFE, irabha, okanye i-ceramic) ukuthintela ukuphazamiseka kwentsimi yemagnethi nokuqinisekisa ukulinganiswa ngokuchanekileyo. Umphezulu wangaphakathi wetyhubhu uthambile ukunciphisa ukungqubana kunye nokulahleka koxinzelelo, okuvumela ulwelo ukuba luhambe ngokukhululekileyo.
Ii-electrode
Ii-electrode ezimbini zibekwe ngokuchaseneyo eludongeni lombhobho wokulinganisa, zithe nkqo kwicala lokuhamba kolwelo kunye nentsimi yemagnethi. Ezi electrode zidibana ngqo nolwelo kwaye zisetyenziselwa ukubona i-EMF ebangelwayo. Ii-electrode zihlala zenziwe ngezinto ezimelana nokugqwala (umz., iHastelloy, iplatinum - i-iridium alloy) ukuze zimelane nokuvezwa kulwelo olwahlukeneyo, ingakumbi olo luneempawu ezirhabaxa okanye ezirhabaxa.
Isiguquli seSignali
I-EMF ebangelwa yi-electrodes yisignali yombane ebuthathaka kakhulu, edla ngokuba kuluhlu lwe-microvolt. I-signal converter, eyaziwa ngokuba yi-transmitter, iyandisa, ihluze, kwaye icwangcise le signal ukuze iyiguqule ibe yimveliso esebenzisekayo. Ingaguqula isignali ibe ziifomathi zemveliso eziqhelekileyo ezifana ne-4 - 20 mA current loops, imiqondiso yedijithali (umz., i-HART, i-Modbus), okanye inxibelelane ngaphandle kwentambo neenkqubo zolawulo, ivumela ukujonga ngexesha langempela kunye nokulawula isantya sokuhamba.
3. Inkqubo Yokusebenza Inyathelo Ngenyathelo
- Ukuveliswa kweMagnetic Field: Iikhoyili zemagnethi okanye indibano yemagnethi idala i-magnetic field ezinzileyo kwityhubhu yokulinganisa. Le ntsimi ijonge kwicala lokuhamba kolwelo, iqinisekisa ukuba ulwelo oluqhubayo oluhamba kwityhubhu lunqumla imigca yamandla emagnethi.
- Ukungeniswa kwe-EMF: Njengoko ulwelo oluqhubayo luhamba ngetyhubhu yokulinganisa, lusebenza njengomqhubi ohambayo kwintsimi yemagnethi. Ngokomthetho kaFaraday, amandla e-electromotive (EMF) abangelwa kulwelo. Ubukhulu bale EMF buhambelana nesantya solwelo, amandla entsimi yemagnethi, kunye nobubanzi betyhubhu yokulinganisa.
- Ukuchonga iSignali: Ii-electrode ezimbini ezibekwe eludongeni lwetyhubhu zibona i-EMF ebangelwayo. Ekubeni ii-electrode zidibana nolwelo, zibamba umahluko wamandla ombane oveliswa lulwelo oluhambayo kwindawo yemagnethi.
- Ukucubungula iSignali: Isignali ye-EMF ebuthathaka efunyenwe zii-electrodes ithunyelwa kwisiguquli sesignali. Apha, isignali iyandiswa ukuze yonyuse amandla ayo, ihluzwe ukuze kususwe ingxolo kunye nokuphazamiseka, kwaye iguqulwe ibe sisignali yokuphuma eqhelekileyo (umz., 4 - 20 mA, idatha yedijithali).
- Ukubalwa kweNqanaba lokuHamba: Isignali esetyenzisiweyo isetyenziselwa ukubala isantya sokuhamba kolwelo. Isiguquli sesignali sisebenzisa ii-algorithms zezibalo ezisekelwe kwii-constants ezaziwayo ze-flow meter (amandla e-magnetic field, ububanzi betyhubhu) ukuguqula i-EMF elinganisiweyo ibe yixabiso lesantya sokuhamba, elinokuboniswa kwindawo ethile kwi-meter okanye lidluliselwe kwinkqubo yokubeka esweni ekude.
4. Izinto eziphambili ekufuneka ziqwalaselwe kunye nemida
Imfuneko yokuqhuba ulwelo
Iimitha zokuhamba kwe-electromagneticinokulinganisa kuphela ukuhamba kolwelo oluqhubayo. Ubungakanani obufunekayo bokuqhubayo buyahluka ngokwabenzi kodwa ngokubanzi buqala kwi-5 ukuya kwi-50 μS/cm (i-micro - Siemens ngesentimitha). Ulwelo oluqhubayo oluphantsi kakhulu, olufana namanzi acocekileyo kakhulu okanye iihydrocarbons, alufanelekanga ukulinganiswa ngee-EMFs ezisemgangathweni. Nangona kunjalo, iimodeli ezikhethekileyo ezenzelwe ulwelo oluqhubayo oluphantsi zinokwandisa uluhlu lokulinganisa.
Ukuphazamiseka kweMagnetic Field
Amasimi emagnethi angaphandle anokuphazamisana nokusebenza kweemitha zokuhamba kwe-electromagnetic. Ukunciphisa oku, ukukhuselwa kunye nokusikwa kwemitha ngokufanelekileyo kubalulekile. Ukongeza, indawo yokufakela kufuneka ikhethwe ngononophelo ukuze kuthintelwe ukusondela kwizixhobo zombane ezinkulu okanye eminye imithombo yamasimi emagnethi.
Ukufakwa kunye noLungiso
Ukufakela ngokuchanekileyo kubalulekile ukuze kulinganiswe ngokuchanekileyo.imitha yokuhambakufuneka ifakwe kwicandelo elithe tye lombhobho kunye nobude obaneleyo bombhobho othe tye ongaphezulu nongaphantsi (ngesiqhelo ubukhulu bombhobho obuphindwe ka-5 ukuya ku-10 ngaphezu kobubanzi bombhobho ongaphezulu kunye nobude obuphindwe ka-3 ukuya ku-5 ongaphantsi) ukuqinisekisa iprofayili yokuhamba ezinzileyo nefanayo. Ukulinganiswa rhoqo, nokuba kungokuqinisekiswa kwendawo okanye ukuthelekiswa nemigangatho yokuhamba eyaziwayo, kuyimfuneko ukugcina ukuchaneka komlinganiselo ngokuhamba kwexesha.
Ukuqukumbela, iimitha zokuhamba kwe-electromagnetic zisebenzisa uMthetho kaFaraday woKwaziswa kwe-Electromagnetic ukuze zibonelele ngokuchanekileyo nangokuthembekileyoimilinganiselo yokuhamba kwamanzikwi-conductor fluids. Ukuqonda umgaqo wabo wokusebenza kubalulekile ekukhetheni, ekufakeni, nasekusebenzeni ngokufanelekileyo kwizicelo ezahlukeneyo zoshishino, ukusuka ekucoceni amanzi kunye nokucubungula iikhemikhali ukuya ekuveliseni ukutya neziselo.
Ixesha leposi: Juni-24-2025