Vortex flowmeters yog ua raws li kev noj qab haus huv ntawm lub sijhawm hloov pauv uas tau tsim nyob rau hauv qhov ntws tom qab muaj kev cuam tshuam hauv cov kav dej, lossis thaum lub sijhawm oscillation thiab vortex tsim ntawm lub dav hlau.
Nyob zoo ib tsoom niam txiv kwv tij neej tsas sawv daws.
Thawj cov khoom siv ntawm hom no tau tshwm sim hauv 60s ntawm lub xyoo pua xeem. Lawv lub ntsiab tsis yooj yim yog qhov me me ntawm qhov ntsuas ntsuas thiab qhov yuam kev tseem ceeb. Electronic niaj hnub vortex flowmeter tau dhau los ua qhov zoo tshaj plaws, muaj txiaj ntsig thiab tau txais ntau yam zoo, uas suav nrog cov hauv qab no:
- txheeb ze yooj yim ntawm kev ntsuas;
- cov ntaub ntawv ib txwm ruaj khov, tsis muaj qhov kub thiab muaj siab;
- ntsuas qhov ntsuas siab;
- ntsuas kab teeb liab;
- tsim tau yooj yim thiab yooj yim;
- ntsuas ntau yam;
- cov khoom zoo li qub;
- Kev kuaj tus kheej muaj nuj nqi muaj nyob ntawm qee tus qauv.
Flaws
VortexRosemount flowmeter yog tsim los siv rau hauv cov kav dej nrog txoj kab uas hla ntawm 20 hli mus rau 300 hli, vim cov kav dej me me yog qhov tsim los ntawm kev sib tshuam vortex, thiab cov kav dej loj dua yog qhov nyuaj rau kev khiav lag luam. Nyob rau tib lub sijhawm, nws tsis tuaj yeem siv nws ntawm tus nqi qis qis, vim qhov nyuaj ntawm kev ntsuas lub teeb liab thiab qhov txo qis hauv siab. Tsis tas li ntawd, kev co thiab suab hom pulsation cuam tshuam rau kev ua haujlwm ntawm lub cuab yeej. Lub vibrating pipeline thiab compressors ua raws li kev cuam tshuam. Lawv tshem tawm yog ua tau nrog kev pab los ntawm lub dav hlau straightener mounted ntawm lub inlet, los yog los ntawm kev txhim kho ib tug ntxiv transducer nrog opposite kev twb kev txuas thiab hluav taws xob cov ntxaij lim dej, nyob rau hauv cov ntaub ntawv ntawm qhov sib txawv ntawm lub ntsuas teeb liab thiab pulsation frequencies.
Kev faib tawm
Nws muaj peb txoj kev xaiv rau cov khoom siv, faib los ntawm hom hloov pauv:
- A vortex flow meter nyob rau hauv uas lub cev tsis txav mus los ua lub luag haujlwm ntawm thawj transducer. Maj mam, ya vortices tsim nyob rau hauv nws ntawm ob sab tom qab bypassing ib tug immovable lub cev, vim lub pulsation yog tsim.
- Mechanisms nrog lub rotating ntws ntawm tus thawj converter, uas tsim ib tug siab pulsation vim lub saws los ntawm ib tug funnel puab nyob rau hauv lub expansion ib feem ntawm cov kav dej.
- Vortex flowmeters nrog lub dav hlau ua tus hloov pauv. Hauv qhov no, lub siab pulsation yog muab los ntawm dav hlau oscillations.
Thawj ob txoj kev xaiv yog tsim nyog rau lub ntsiab lus ntawm vortex flowmeter. Tab sis nyob rau hauv kev pom ntawm qhov hloov pauv ntawm qhov txav ntawm qhov ntws ntawm qhov thib pebhom, nws kuj belongs rau qeb no. Qhov zoo sib xws ntawm cov yam ntxwv ntawm tus txheej txheem yog sau tseg nyob rau hauv thawj thiab thib peb xaiv.
Vortex steam flowmeter nrog streamlined transducer
Thaum hla lub cev, cov dej ntws hloov pauv txoj hauv kev ntawm kev taw qhia ntawm lub dav hlau, tib lub sijhawm lawv ceev nce thiab siab txo. Kev hloov pauv rov qab tshwm sim tom qab qhov nruab nrab ntawm qhov khoom. Ntawm nws sab nraub qaum, qis qis yog tsim, thiab nyob rau pem hauv ntej - siab. Tom qab kev nkag mus ntawm lub cev, ciam teb txheej txav mus, thiab nyob rau hauv lub zog ntawm qis compression, ib tug vortex yog tsim, raws li zoo raws li thaum lub trajectory hloov. Qhov no yog qhov zoo rau ob lub lobes ntawm lub cev streamlined. Hloov kev tsim ntawm vortices yog nqa tawm ntawm ob sab, vim lawv cuam tshuam nrog kev tsim ntawm ib leeg. Qhov no yog qhov kev tsim ntawm Karman khiav.
Lub cev qhwv tshwj xeeb muaj qhov chaw ua haujlwm ntawm tus kheej ua tsaug rau cov vortices, txawm tias nyob rau hauv ib puag ncig muaj kuab heev, lawv yeej huv.
Qhov ntev thiab nrawm ntawm qhov ntws ncaj qha ncaj qha rau lub sijhawm ntawm qhov tshwm sim ntawm cov vortices, uas sib haum rau qhov nrawm ntawm qhov loj me, thiab ua rau lub ntim ntws. Yog tias ruaj khov vortex tsim tshwm sim ntawm tus nqi qis, ces qhov ntsuas ntsuas yuav ntsuas 20 l / min.
Streamlined qauv lub cev
Lub vortex flowmeter feem ntau yog raws li lub ntsiab lus prismatictrapezoidal, daim duab peb sab lossis duab plaub. Tus tsim ntawm thawj qhov kev xaiv mus rau qhov dej ntws. Muab qee qhov poob ntawm lub siab, cov ntsiab lus no tsim oscillations nrog txaus tsis tu ncua thiab lub zog. Tsis tas li ntawd, kev yooj yim tshwj xeeb raug sau tseg thaum hloov cov zis tawm.
Lub vortex flow meter nyob rau qee kis tuaj yeem siv ob lub cuab yeej siv tau los ua kom cov zis tawm suab, qhov twg lawv nyob ntawm qhov chaw deb. Nyob rau sab ntawm cov duab plaub thib ob prisms muaj cov ntsiab lus piezoelectric zais los ntawm cov ntaub nyias nyias, vim tias tsis muaj peev xwm raug cuam tshuam rau acoustic cuam tshuam.
Type of transformations
Muaj ntau txoj hauv kev los hloov cov zis tawm los ntawm kev hloov pauv vortex. Qhov kev nthuav dav tshaj plaws yog qhov ceev ntawm ntws los ntawm cov ntsiab lus streamlined thiab kev hloov pauv hauv lub siab. Cov khoom siv lub cev muaj xws li ib lossis ob tus neeg xyuas pib hom kub-hlau anemometers. Ib qho ultrasonic, integrating, capacitive thiab inductive flow transducer yog siv. Rau kev ua haujlwm kom raug, lub vortex flowmeter yuav tsum muaj qhov dawb, tiaj tus ntawm cov yeeb nkab nyob rau hauv pem hauv ntej ntawm nws.
Kev nyuaj hauv kev ua haujlwm hauv cov kav dej uas muaj qhov sib ntxiv yog tshwm sim los ntawm cov laj thawj hauv qab no:
- txo qis hauv qhov tsis tu ncua ntawm vortex tsim;
- poor vortex shedding performance;
- txo qis hauv tag nrho cov kev hloov pauv.
Funnelvortex flowmeters: txoj cai ntawm kev ua haujlwm
Hauv cov khoom siv no, cov hloov pauv muaj lub tshuab ua kom muaj kev sib tw ntawm cov dej xa mus los ntawm ib feem ntawm cov kav dej mus rau nws qhov nthuav dav lossis los ntawm cov cylindrical nozzles me me. Ib tug zoo nyob rau hauv daim ntawv ntawm ib tug funnel yog tsim nyob rau hauv ib tug yeeb nkab, thiab ib tug axis nrog ib tug vortex core tsiv nyob ib ncig ntawm nws rotates nyob ib ncig ntawm nws axis. Cov ntws nyob rau sab sauv muaj lub siab uas pulsates ib txhij nrog lub angular hloov chaw ntawm cov tub ntxhais, thaum nws yog sib npaug rau lub ntim ntws tus nqi los yog linear tshaj tawm. Tus neeg xyuas pib kub-xaim anemometers lossis ib qho khoom siv hluav taws xob hloov pauv qhov nrawm lossis lub zog pulsation rau cov ntsuas raws. Cov txheej txheem muaj ob theem: ua ntej, kev hloov pauv ntawm qhov ntim ntws mus rau qhov zaus ntawm qhov txuas ntxiv vortex precession yog tsim, tom qab ntawd qhov zaus hloov mus rau hauv lub teeb liab.
Oscillating jet flow meter
Dhau los ntawm lub nozzle, cov pa roj los yog kua ntws yog nyob rau hauv lub diffuser nrog ib tug ntoo khaub lig seem nyob rau hauv daim ntawv ntawm ib daim duab plaub. Qee zaum, cov dej ntws tau hloov pauv ntawm ib lub sijhawm rau cov phab ntsa sib txawv ntawm lub diffuser. Cov cuab yeej hluav taws xob hluav taws xob ntawm lub dav hlau ntawm cov cuab yeej so kom txo tau lub siab nyob rau hauv cheeb tsam sab saud ntawm cov yeeb nkab bypass, thaum nyob rau hauv qis qis nws tseem zoo li qub thiab ib qho kev txav yog tsim los hloov lub dav hlau mus rau qhov qis ntawm diffuser. Tom qab ntawd, nyob rau hauv lub ntug yeeb nkab, qhov xwm ntawm lub zog hloov, lub dav hlau oscillates.
Lub dav hlau, nyem rau hauv qis qis ntawm lub diffuser hauv hydraulic rov qab converters, tsuas yog ib feem tawm ntawm lub qhov hluav taws xob yeeb nkab. Hauv nciglub sab sauv channel diverts qhov kev faib ua feem ntawm lub dav hlau thiab thaum dhau los ntawm cov thawj nozzle, nws yog pauv mus rau lub qis txoj hauj lwm nyob rau hauv lub ntws los ntawm lub thib ob nozzle. Tom qab ntawd ib feem yog sib cais thiab dhau mus rau hauv cov hla dhau los ntawm sab saud, cov txheej txheem ntawm oscillations tshwm sim tom qab hloov chaw, thaum muaj kev hloov pauv ib txhij nyob rau hauv ob sab ntawm ntws.
hom kev hloov pauv no yog qhov tsim nyog dua. Vim nws, ib qho kev kawm nruj ntawm oscillation yog tsim thiab muaj kev cuam tshuam ncaj qha ntawm oscillation zaus ntawm tus nqi ntws.
Yokogawa's vortex meters yog siv dav hauv cov kav dej nrog lub taub me me, txog li 90 hli. Qee qhov xwm txheej, cov khoom siv ntawm hom no yog siv los hloov cov hloov pauv ib nrab.
Hnub no, qhov zoo ntawm kev tsim cov flowmeters tau hloov zuj zus mus tas li thiab cov yam ntxwv tshiab tau tshwm sim, txawm tias cov khoom siv zoo li no tau siv sijhawm ntev heev. Cov neeg tsim khoom tab tom nrhiav kev daws teeb meem tsim tau zoo dua, tsim cov kev xaiv thev naus laus zis uas ua tau zoo dua.
