Dab tsi yog qhov txiaj ntsig ntawm kev siv Reflective Foil lossis Tsawg -Emissivity Coatings nyob rau sab nraub qaum ntawm rwb thaiv tsev?

Hauv kev tsim cov cua kub cua sov thiab cov xovxwm, kev rwb thaiv tsev feem ntau yog thawj kab ntawm kev tiv thaiv kev kub ntxhov. Cov ntaub ntawv rwb thaiv tsev xws li fiberglass, ntxhia ntaub plaub lossis calcium silicate feem ntau permeable rau lub teeb infrared, txawm li cas los xij. Tej zaum nws yuav zoo li yooj yim heev, tab sis cov txheej me me ntawm cov ntawv ci txhuas, muab tso rau ntawm lub ntsej muag ntawm cov rwb thaiv tsev, tuaj yeem thaiv txog li 95% ntawm cov cua sov uas yuav txwv tsis pub tua. Nws yog ib qho ntawm qhov pheej yig tshaj thiab zoo tshaj thermal txhim kho koj tuaj yeem ua tau. Los ntawm kev nkag siab txog lub luag haujlwm ntawm cov ntawv ci reflective uas tsis tshua muaj hluav taws xob rwb thaiv tsev cua sov phaj system, engineers tuaj yeem txhim kho tag nrho cov thermal kev ua tau zoo heev nrog me ntsis ntxiv complexity.

Yuav ua li cas Reflective Surfaces Thaiv Radiant Thaum tshav kub kub - Mechanism
Thaum tshav kub kub yog kis los ntawm lub tshav kub cua sov phaj mus rau ib ncig ntawm peb txoj kev. Lawv yog cov conduction, convection thiab hluav taws xob. Ntawm qhov kub thiab txias (tshaj 150 degree) hluav taws xob feem ntau yog tib qho los yog daim ntawv tseem ceeb ntawm kev poob cua sov. Feem ntau cov ntxeem tau cov ntaub ntawv xws li fiberboards, pam vov thiab tawv boards, ua me ntsis kom txo lub zog radiant. Cov hluav taws xob infrared tuaj yeem taug kev los ntawm huab cua hauv qhov rwb thaiv tsev, zoo beaming los ntawm cov khoom siv.

Qhov no yog qhov uas tsis tshua muaj emissivity (tsawg-E) nto los rau hauv. Emissivity yog hais txog lub peev xwm ntawm ib yam khoom kom emit kub Polished txhuas muaj emissivity ntawm kwv yees li 0.05–0.1, uas txhais tau hais tias nws muaj kev cuam tshuam txog 90–95 feem pua ​​ntawm cov teeb meem infrared zog. Thaum cov ntawv ci los yog txheej txheej yog muab tso rau ntawm qhov kub ntawm qhov rwb thaiv tsev (ntsig lub phaj cua sov) nws ua raws li lub teeb ci ntsa iab:

Lub platen kub emits infrared tawg uas hits lub reflective nto.

Feem ntau ntawm lub zog ntawd yog rov qab mus rau qhov chaw sov.

Tam sim no me ntsis uas tau txais absorbed yuav tsum tau kis los ntawm cov khoom siv insulating.

Lub teeb ci radiant yog daim iav tshav kub (thermal sib npaug). Qhov no ua rau cov cua sov ua haujlwm ntawm cov rwb thaiv tsev tsis muaj qhov ntxiv thickness. Qhov no yog ua tiav los ntawm kev txwv cov hluav taws xob tsis zoo ua ntej nws nkag mus rau hauv cov khoom siv rwb thaiv tsev.

Kev xa tawm tau zoo Qhov tseem ceeb ntawm huab cua sib txawv
Cov ntawv ci reflective yuav tsum muaj qhov sib txawv ntawm huab cua ntawm cov platen kub thiab cov ntawv ci kom ua haujlwm kom raug. Qhov chaw - feem ntau yog ob peb millimeters mus rau ob peb centimeters - tso cai rau cov hluav taws xob infrared rov qab los rau qhov chaw tshav kub es tsis txhob nqa mus. Crushing cov ntawv ci ncaj qha rau ntawm lub platen yuav tsis ua haujlwm, vim tias kev ua haujlwm ntawm cov ntsiab lus ntawm kev sib cuag yuav nullify cov kev xav txog kev xav thiab cov txiaj ntsig yuav ploj.

Xyaum qhov no txhais tau tias:

Ntawv nyiaj-fab thaiv thaiv phab ntsa yog mounted siv ib tug standoff txheej los yog spacer.

Xwb, ib daim ntawv thib ob (xws li polished stainless hlau) yog affixed rau lub xovxwm ncej, yog li tsim ib kab noj hniav ntawm lub platen thiab lub reflector.

Lub rwb thaiv tsev yog nyob rau sab txias ntawm lub reflector, tsis nyob nruab nrab ntawm cov platen thiab cov ntawv ci.

Qhov txiaj ntsig yog qhov zoo tshaj plaws nyob rau hauv qhov kub thiab txias qhov twg cov hluav taws xob hluav taws xob nce ntxiv nrog rau plaub lub zog ntawm qhov kub thiab txias (Stefan-Boltzmann txoj cai). Radiative tshav kub kis tau tus nqi ntawm 400℃yog ntau tshaj ob zaug ntawm 200℃li no radiant barriers yog tshwj xeeb tshaj yog pab tau rau kub kub ua khoom siv.

Siv nyob rau hauv industrial cua sov daim hlau thiab presses
Radiant barriers nyob rau hauv attics yog muaj nyob rau hauv kev tsim kho lub tsev. Reflective foil low emissivity rwb thaiv tsev cua sov phaj tsim tau nce siv rau kev lag luam thermal presses. Cov kev coj ua uas muaj xws li:

Aluminium ntawv ci laminated rau ceramic fiber boards rau nruab nrab kub (txog ~ 250℃nruam). Siv rau hauv laminating presses, kub sealers thiab lub tshuab nqus tsev shaping khoom.

Muab cov ntaub thaiv npog cais ntawm cov ntawv polished stainless hlau (emissivity ~ 0.1-0.15) ntawm cov cua sov platen thiab cov rwb thaiv tsev thaub qab. Nws yog oxidation resistant thiab tsis tshua muaj emissivity txawm nyob rau hauv ntau dua kub.

Reflective coatings rau qhov kub thiab txias (xws li ceramic-cov xim pleev xim nrog aluminium lossis titanium pigment) uas tuaj yeem siv ncaj qha rau sab nraum qab ntawm steel platens lossis lub ntsej muag ntawm insulating boards. Cov txheej txheem no tuaj yeem ua haujlwm ntawm 600℃lossis ntau dua nrog cov nqi qis dua 0.3.

Nyob rau hauv ob qho xwm txheej, cov txheej txheem cuam tshuam txo cov hluav taws xob hluav taws xob ntawm lub hauv paus rwb thaiv tsev kom tib lub thickness ntawm rwb thaiv tsev ua rau lub ntsej muag txias txias, los yog cov txheej txheem rwb thaiv tsev thinner tuaj yeem ua tiav lub hom phiaj thermal ua haujlwm.

Kev xaiv cov khoom siv thiab kev txwv
Aluminium ntawv ci yog ib yam khoom zoo uas tsis muaj emissivity ntawm chav tsev kub txog li 300 degree. Qhov no yog qhov kub ntawm aluminium oxidises hauv huab cua. Oxidised aluminium muaj ntau dua emissivity (0.2-0.3) thiab poob ntau ntawm nws cov khoom xav tau. Rau kev siv saum 300℃lwm txoj kev xav tau:

Kev hloov ncaj qha yog stainless hlau ntawv ci polished rau ib qho emissivity ntawm ~ 0.10-0.15 txog 600 degree.

Kub plated nto (emissivity 0.02-0.05) yog siv nyob rau hauv tshwj xeeb lub tshuab nqus tsev vacuum los yog ultra-siab kub tab sis yog kim heev rau feem ntau industrial presses.

Ceramic reflecting coatings muaj emissivity qhov tseem ceeb ntawm qhov kev txiav txim ntawm 0.2-0.3 mus txog rau qhov kub thiab txias ntawm 800℃thiab muab qhov zoo sib npaug ntawm tus nqi thiab kev ua haujlwm.

Lwm qhov kev xav tau yog kev huv. Txhua plua plav, roj, lossis cov khoom seem ntawm kev ua haujlwm yuav ua rau muaj kev cuam tshuam loj heev ntawm qhov ci ntsa iab. Cov ntawv ci ci npog nrog txheej nyias ntawm cov plua plav coj zoo li lub cev dub (emissivity ~ 0.9) dua li daim iav. Kev tu ib ntus lossis siv cov ntaub thaiv npog uas tiv thaiv tau yuav tsum tau nyob hauv qhov chaw tsis huv.

Cov txiaj ntsim tau tshwm sim
Qhov qis emissivity uas cuam tshuam cov txheej txheej tuaj yeem txo cov cua sov tag nrho los ntawm kev rwb thaiv tsev los ntawm 30-50% tshaj li ntawm 200-500℃qhov kub thiab txias thaum siv kom raug nrog qhov sib txawv ntawm huab cua. Uas nyeem ncaj qha li:

Tsawg zog los tuav lub platen kub.

Lub sijhawm cua sov sai dua, lub zog tsawg dua poob.

Ntau qhov kub thiab txias profile thoob plaws lub platen, raws li kev cuam tshuam cov cua sov txo qis ntug poob.

Txo cov cua kub sab nraud, ua rau tus neeg teb xov tooj muaj kev nyab xeeb thiab txo qhov chaw txias txias.

Cov cua kub ntws tuaj yeem txo tau li ntawm 40% los ntawm kev ntxiv polished stainless hlau radiant barrier nrog rau qhov sib txawv ntawm 5 hli mus rau tus qauv 300℃cua sov platen nrog 50 hli calcium silicate rwb thaiv tsev. Lub sij hawm them rov qab rau cov nqi khoom ntxiv feem ntau yog lub lis piam lossis lub hlis ntawm kev ua haujlwm tas mus li.

Xaus:
Reflective foil thiab low emissivity coatings yog tus nqi qis, muaj kev cuam tshuam siab ntxiv rau txhua qhov cua sov phaj rwb thaiv tsev. Cov teeb meem radiant cuam tshuam txog li 95% ntawm qhov xwm txheej infrared hluav taws xob rov qab mus rau qhov kub platen thiaj li txo cov thermal load ntawm lub hauv paus rwb thaiv tsev, txo lub zog noj thiab txhim kho qhov kub thiab txias uniformity. Kev ua tau zoo nyob ntawm qhov tsim nyog rau kev teeb tsa nrog qhov sib txawv ntawm huab cua thiab xaiv cov ntaub ntawv ntsuas rau qhov siab tshaj plaws ntawm daim ntawv thov kub - aluminium foil rau kev pabcuam hauv qab 300 degree, polished stainless hlau lossis ceramic coatings rau ntau dua. Nyob rau hauv cov xwm txheej no, kev siv lub ntsej muag npog yog ib qho ntawm cov nqi tshaj plaws - txhim kho thermal zoo rau cov khoom siv cua sov.