Lithini ixabiso le-CV levalvu: Ukubalwa, i-Flow Coefficient

Yintoni iFlow Coefficient

I-Flow Coefficient, eyaziwa ngokuba yi-Cv (US/EU Standard), i-Kv (International Standard), okanye ixabiso le-C, yiparameter ebalulekileyo yobugcisa echaza amandla okuhamba kweevalvu zoshishino ezifana neevalvu zokulawula kunye nabalawuli.

Ukuchaza ixabiso le-Cv

I-Valve Cv imele i-flow coefficient ebonisa amandla e-valve okudlulisa ulwelo phantsi kweemeko ezithile. Ilinganisa isantya sokuhamba komthamo wolwelo okanye igesi nge-valve xa uxinzelelo luphantsi. Amaxabiso aphezulu e-Cv abonisa amandla okuhamba aphezulu.

Yintoni i-Cv (Ixabiso loMbane)

I-Valve Cv (Ixabiso Lomthamo) ilinganisa umthamo wokuhamba kwaye ibalwa phantsi kweemeko zovavanyo ezimiselweyo:

• Ivalvu ivuleke ngokupheleleyo

• Ukwehla koxinzelelo (ΔP) lwe-1 psi kwivalvu

• Ulwelo: Amanzi kwi-60°F (15.5°C)

• Izinga lokuhamba kwamanzi: Iigaloni zase-US ngomzuzu (GPM)

Ukuvulwa kweValve vs. Ixabiso leCv

I-Cv/Kv kunye nokuvulwa kwevalvu (%) ziingcamango ezahlukeneyo:

• Inkcazo ye-Kv (Umgangatho waseTshayina):Izinga lokuhamba kwamanzi kwi-m³/h xa i-ΔP = 100 kPa, ubuninzi bolwelo = 1 g/cm³ (amanzi kubushushu begumbi).

*Umzekelo:I-Kv=50 ithetha ukuhamba kwe-50 m³/h kwi-100 kPa ΔP.*

• Ipesenti Yokuvula:Indawo yeplagi/idiski yevalvu (0% = ivaliwe, 100% = ivuliwe ngokupheleleyo).

Ukubala ii-CV kunye nee-Key Applications

I-Cv ichaphazeleka yidizayini yevalvu, ubungakanani, izinto ezisetyenzisiweyo, indlela yokuhamba kwamanzi, kunye neempawu zolwelo (ubushushu, uxinzelelo, i-viscosity).

Ifomula eyintloko yile:

I-Cv = Q / (√ΔP × √ρ)

Apho:

• Umbuzo= Izinga lokuhamba komthamo

•ΔP= Umahluko woxinzelelo

•ρ= Ubuninzi bolwelo

Uguqulelo: Cv = 1.167 Kv

Indima ekuKhethweni nasekuYilweni kweeValve

I-Cv ichaphazela ngokuthe ngqo ukusebenza kakuhle kwenkqubo yolawulo lolwelo:

•Imisela ubungakanani bevalvu efanelekileyo kunye nohlobo lwamanani okuhamba okujoliswe kuko

•Iqinisekisa uzinzo lwenkqubo (umz., ithintela ukujikeleza kwepompo kwisakhiwo sokubonelela ngamanzi)

•Kubalulekile ukuphucula amandla

Utshintsho lweCv kwiintlobo zeeValve

Umthamo wokuhamba kwamanzi uyahluka ngokoyilo lweevalvu (idatha efunyenwe kwiImigangatho ye-ASME/API/ISO):

Iiparamitha zeCore Flow kunye nezinto ezichaphazelayo

Ukusebenza kwevalvu kuchazwa ziiparameter ezintathu (ngokweZiko loLawulo lweFluid):

1. Ixabiso le-CV:Ukuhamba kwe-GPM kwi-1 psi ΔP (umz., ivalvu yebhola ye-DN50 ≈ 210 vs. ivalvu yesango ≈ 120).

2. I-Coefficient yokumelana nokuhamba kwamanzi (ξ):

•Ivalvu yebhabhathane: ξ = 0.2–0.6

•Ivalvu yeglobe: ξ = 3–5

Izikhokelo zoKhetho kunye nezinto eziBalulekileyo ekufuneka uziqwalasele

Ukulungiswa kokubonakala kwe-viscosity:

Faka iziphindaphindi kwi-Cv (umz., ioyile eluhlaza: 0.7–0.9 kwi-ISO 5208 nganye).

Iivalvu ezikrelekrele:

Ukulungiswa kwe-Cv ngexesha langempela (umz., i-Emerson DVC6200 positioner).

Iinkqubo zoVavanyo lwe-Flow Coefficient

Uvavanyo lufuna iimeko ezilawulwayo ngenxa yobuthathaka bokulinganisa:

•Ukuseta (NgokoMfanekiso 1):

I-Flowmeter, i-thermometer, iivalvu zokuthomalalisa, ivalvu yovavanyo, i-ΔP gauge.

1. Imitha yokuhamba kwamanzi 2. I-Thermometer 3. Ivalvu ye-throttle ephezulu 4 kunye ne-7. Imingxunya yokucofa uxinzelelo 5. Ivalvu yokuvavanya 6. Isixhobo sokulinganisa umahluko woxinzelelo 8. Ivalvu ye-throttle ephantsi

4. Umgama ophakathi komngxuma wokucofa uxinzelelo kunye nevalvu uphindwe kabini kunobubanzi bombhobho

7. Umgama ophakathi komngxuma wokucofa uxinzelelo kunye nevalvu uphindwe ka-6 ubukhulu bombhobho

•Ulawulo oluPhambili:

- Ivalvu ephumayo ilawula uxinzelelo lokungena.

- Ivalvu esezantsi igcina uxinzelelo oluzinzileyo (ubungakanani obuqhelekileyo > ivalvu yokuvavanya ukuqinisekisa ukuba ukuhamba kwamanzi kuyaqhubekainivalvu yovavanyo).

•Imigangatho:

JB/T 5296-91 (eTshayina) vs. BS EN1267-1999 (e-EU).

•Izinto ezibalulekileyo:

Indawo yokucofa, uqwalaselo lwemibhobho, inombolo kaReynolds (ulwelo), inombolo kaMach (iigesi).

Imida yoVavanyo kunye neZisombululo:

•Iivalvu zovavanyo lweenkqubo zangoku ≤DN600.

•Iivalvu ezinkulu:Sebenzisa uvavanyo lokuhamba komoya (aluchazwanga apha).

Impembelelo yeNombolo kaReynolds: Idatha yovavanyo iqinisekisa ukuba inani likaReynolds lichaphazela kakhulu iziphumo zovavanyo.

Izinto ezibalulekileyo ekufuneka ziqwalaselwe

•I-Cv/Kv ichaza umthamo wokuhamba kwevalvu phantsi kweemeko ezimiselweyo.

•Uhlobo lwevalvu, ubungakanani, kunye neempawu zolwelo ziyichaphazela kakhulu i-Cv.

•Uvavanyo lufuna ukuthotyelwa ngokungqongqo kwemigaqo (JB/T 5296-91/BS EN1267) ukuze kufumaneke ukuchaneka.

•Izilungiso ziyasebenza kwi-viscosity, ubushushu, kunye noxinzelelo.

(Yonke idatha ifunyenwe kwimigangatho ye-ASME/API/ISO kunye namaphepha amhlophe omenzi weevalvu.)