Yuav ua li cas hloov LEL feem pua , VOL feem pua thiab ppm hauv qhov ntsuas roj
Thaum siv lub tshuab ntsuas roj hauv lub neej niaj hnub, qhov kev tshawb nrhiav ntau yam ntawm cov kua siv lead ua kua ntawm lub ntsuas roj feem ntau muaj cov lus zoo li 0-100LEL feem pua lossis 0-2000ppm, lossis cov lus zoo li VOL feem pua lossis ppm. Peb tshooj no txhais li cas, thiab lawv hloov siab los ntseeg li cas?
1.VOL feem pua (gas ntim feem pua)
VOL yog lub cev lub cev uas piav qhia txog qhov ntim ntawm cov pa, qhia tias feem pua, uas yog feem pua ntawm qhov ntim ntawm cov pa tshwj xeeb hauv huab cua. Piv txwv li, 5 feem pua VOL methane txhais tau hais tias qhov ntim ntawm methane hauv huab cua yog 5 feem pua.
Qhov kev tshawb nrhiav ntau yam ntawm cov roj ntes tau feem ntau qhia hauv VOL feem pua. Piv txwv li, qhov kev tshawb pom ntau yog 0-100 feem pua VOL, uas txhais tau hais tias thaum lub ntsuas roj no ntes tau qee yam roj, nws tuaj yeem ntes nws qhov feem ntawm huab cua. Qhov ntau yog 0-100 feem pua .
Peb kuj tuaj yeem teeb tsa VOL ntawm qee qhov feem pua tus nqi raws li lub tswb. Thaum cov ntsiab lus ntawm qee yam roj mus txog lossis tshaj qhov teeb tsa no, lub ntsuas roj yuav ceeb toom. Qhov no suav nrog lwm chav, LEL feem pua.
2.LEL feem pua (tsawg dua kev txwv)
Cov pa hluav taws xob tuaj yeem sib xyaw ua ke nrog huab cua (lossis oxygen) nyob rau hauv ib qho kev sib xyaw ua ke los tsim cov roj premixed, uas yuav tawg thaum ntsib qhov hluav taws kub. Qhov tsawg tshaj plaws ntim feem pua ntawm cov roj combustible no uas tuaj yeem ua rau hauv huab cua, uas yog, cov pa tawg qis qis qis qis yog LEL feem pua, hu ua "qis tawg txwv". Cov roj ntim concentration ntawm qhov qis tawg txwv yog qhia los ntawm LEL feem pua, thiab nws chav tsev yog ib feem pua, uas yog, qhov qis tawg txwv tau muab faib ua ib puas feem, thiab ib chav tsev yog 1LEL feem pua.
3.PPM (ib lab ntawm cov roj ntim feem pua)
Lub tswv yim ntawm PPM zoo ib yam li VOL, tshwj tsis yog tias PPM sawv cev rau ib lab ntawm cov roj ntim.
Piv txwv li, 10ppm carbon dioxide txhais tau hais tias huab cua muaj 10 qhov chaw ntawm cov pa roj carbon dioxide, vim tias chav tsev PPM yog ib chav tsis muaj qhov dav.
4. Kev hloov pauv ntawm VOL feem pua, LEL feem pua, thiab PPM
Thawj yog qhov hloov dua siab tshiab ntawm VOL thiab PPM. Kev hloov pauv ntawm ob chav no yog qhov yooj yim, vim tias feem pua VOL yog feem pua ntawm cov ntim, thiab PPM yog feem pua ntawm ib lab ntawm cov ntim, yog li 1 feem pua VOL=10000PPM.
Qhov thib ob yog kev hloov pauv ntawm VOL thiab LEL. Nws yog ib qho tsim nyog yuav tsum paub txog qhov qis qis ntawm qhov tawg ntawm cov roj combustible. Thaum lub concentration ntawm cov roj combustible nyob rau hauv cov huab cua mus txog qhov tsawg kawg nkaus txwv ntawm qhov tawg, peb hu ua explosion txaus ntshai ntawm combustible gas ib puag ncig nyob rau hauv qhov chaw no 100 feem pua. Yog li, xav txog 4 feem pua VOL raws li 100 feem pua kev pheej hmoo, nws yog hu ua 100 feem pua LEL, uas yog, 4 feem pua VOL=100 feem pua LEL, ces, 1 feem pua VOL=25 feem pua LEL.
Qhov thib peb yog kev hloov pauv ntawm PPM thiab LEL. Tsis muaj txoj hauv kev los hloov ob qho no ncaj qha. Koj yuav tsum xub hloov LEL rau VOL, thiab tom qab ntawd hloov VOL rau PPM.
Nov yog cov qauv rau txhua tus: PPM= feem pua LEL × LEL(vol feem pua) × 100
Noj methane ua piv txwv, PPM ntawm methane ntawm 20 feem pua LEL yog xam raws li tus qauv: 20(%) LEL) × 1(%) VOL) × 100=2000PPm.
Feem ntau hais lus, cov khoom siv roj ntsha uas tuaj yeem ntes PPM yog cov khoom siv hluav taws xob zoo heev, thiab cov khoom siv roj ntsha ntawm LEL feem ntau yog siv rau hauv kev tshawb nrhiav tawg. Qhov kev txiav txim ntawm qhov loj ntawm VOL yog qhov loj tshaj plaws ntawm lawv, thiab nws kuj tseem siv tau.
