Thaum tshav kub kub hloov ua haujlwm li cas?

Kev hloov tshav kub muaj ob lub hom phiaj hauv kev lag luam tsoos:

Ua ntej, txhawm rau txhawb kev hloov pauv cua sov, xws li cov khoom siv cua sov lossis cua txias, lub hom phiaj yog txhawm rau txhim kho cov cua sov, txhim kho cov khoom siv hluav taws xob hloov hluav taws xob, txo cov khoom siv loj, thiab txo cov nqi khoom siv;
Qhov thib ob, kom tsis muaj zog hloov hluav taws xob thiab txo qhov poob ntawm cov cua sov, xws li rwb thaiv tsev ntawm cov khoom siv kub kub, cov khoom siv kub thiab cov kav dej thauj mus los, qhov qis dua cov cua sov hloov mus, qhov zoo dua.

Vim muaj cov hom phiaj sib txawv ntawm cov khoom siv hluav taws xob sib txawv thiab cov xwm txheej tsim khoom, cov txheej txheem kev sib hloov cua sov kuj txawv. Feem ntau siv cov kev sib pauv cua sov hauv cov txheej txheem tsim khoom tuaj yeem muab faib ua peb hom, xws li: interlayer tshav kub hloov pauv, sib xyaw cov cua sov ncaj qha thiab cov khoom siv hluav taws xob khaws cia kub.

(1) Interlayer tshav kub pauv

Nyob rau hauv lub interlayer tshav kub exchanger, cov dej txias thiab kub yog nyob rau ntawm ob sab ntawm lub tshav kub exchanger phab ntsa, thiab cov dej kub hloov tshav kub mus rau cov dej txias los ntawm lub interlayer. Partition heat exchange yog dav siv nyob rau hauv chemical ntau lawm. Cov khoom siv hluav taws xob kub uas muaj nyob rau hauv pawg no suav nrog: cov khoom siv hluav taws xob, cov khoom siv hluav taws xob, cov khoom siv hluav taws xob, cov khoom siv hluav taws xob, cov khoom siv hluav taws xob, cov khoom siv hluav taws xob, cov khoom siv hluav taws xob thiab cov khoom siv hluav taws xob.

(2) Direct mixing tshav kub pauv

Direct mixing heat exchange is to contact the hot fluid with the txias fluid and exchange heat when the mixing process of fluids. Daim ntawv no ntawm kev sib pauv cua sov feem ntau yog siv rau cov pa cua txias thiab chav ua kom sov. Piv txwv li, nyob rau hauv lub txias ntauwd nyob rau hauv ib tug chemical nroj tsuag, dej kub thiab huab cua yog sib tov ncaj qha rau tshav kub exchanger. Cov huab cua absorbs cua sov ntawm dej vaporization thiab txo qhov kub ntawm cov dej.

(3) Thermal cia tshav kub pauv

Thermal storage heat exchange is to install the thermal storage body (cov khoom muab tub lim) nyob rau hauv lub tshav kub exchanger thiab siv lub thermal cia lub cev los mus sau thiab tso tawm cua sov kom ua tiav lub hom phiaj ntawm tshav kub pauv ntawm txias thiab kub kua. Thaum lub sijhawm ua haujlwm, cov kua dej kub tau tso cai ua ntej dhau los ntawm lub thermal cia lub cev kom khaws cov cua sov ntawm lub thermal cia lub cev, thiab tom qab ntawd cov kua dej txias tso cai rau ntws los ntawm lub thermal cia lub cev, thiab lub thermal cia lub cev hloov mus rau qhov txias. kua dej.

Qhov kub thiab txias sib txawv ntawm cov kua kub thiab txias yog qhov tsim nyog rau kev hloov pauv hloov pauv hloov pauv. Thaum tshav kub kub hloov pauv tuaj yeem nqa tau tsuas yog thaum muaj qhov sib txawv ntawm qhov kub thiab txias ntawm ob sab ntawm phab ntsa hloov hluav taws xob ntawm cov khoom siv hluav taws xob. Qhov kub ntawm qhov sib txawv ntawm txhua txoj haujlwm ntawm lub tshav kub exchanger tsis tas yuav ruaj khov. Seb qhov sib txawv ntawm qhov kub thiab txias yog nyob ntawm qhov ruaj khov ntawm cov txheej txheem ntau lawm.

1) Kev hloov hluav taws xob ruaj khov

Nyob rau hauv lub tshav kub exchanger system, yog hais tias qhov kub ntawm txhua lub tshav kub hloov lwm lub tsev txoj hauj lwm tsis hloov nrog lub sij hawm, lub tshav kub hloov ntawm lub system yog hu ua ruaj khov thaum tshav kub kub hloov lwm lub tsev. Nyob rau hauv cov txheej txheem hloov hluav taws xob ruaj khov, qhov kub hloov pauv ntawm txhua qhov kub tsis hloov nrog lub sijhawm. Hom kev hloov hluav taws xob no tshwm sim hauv cov txheej txheem ntau lawm. Piv txwv li: nyob rau hauv lub nruam thiab ruaj khov theem ntawm cov txheej txheem tsim khoom, cov khoom siv raw lossis cov khoom siv rov qab tau ruaj khov, tom qab ntawd qhov kub ntawm txhua txoj haujlwm hauv cov txheej txheem kev sib hloov cua sov tuaj yeem suav tias yog qhov tsis tu ncua, uas yog cov cua sov ruaj khov. hloov.

2) Kev hloov pauv tsis ruaj khov

Nyob rau hauv lub tshav kub exchanger system, yog hais tias qhov kub ntawm txhua lub tshav kub hloov txoj hauj lwm hloov nrog lub sij hawm, lub tshav kub hloov ntawm lub system yog hu ua unstable tshav kub hloov. Hauv cov txheej txheem hloov hluav taws xob tsis ruaj khov, cov cua kub hloov pauv ntawm txhua qhov kub kub hloov nrog lub sijhawm. Hom kev hloov hluav taws xob no tshwm sim nyob rau hauv qhov pib thiab kaw cov txheej txheem ntawm cov txheej txheem ntau lawm los yog kev tsim khoom tas mus li. Piv txwv li: thaum lub sij hawm pib los yog kaw ntawm cov txheej txheem ntau lawm, qhov kub ntawm txhua txoj hauj lwm ntawm cov txheej txheem kev sib hloov cua sov maj mam nce los yog txo vim qhov maj mam nce lossis txo qis hauv cov khoom thauj, uas yog cov txheej txheem hloov hluav taws xob tsis ruaj khov.

Raws li txoj cai thib ob ntawm thermodynamics, cov cua kub ib txwm tau hloov pauv los ntawm cov khoom kub siab dua mus rau qhov khoom qis dua. Tsuas yog nyob rau hauv cov xwm txheej ntawm kev siv tshuab ua haujlwm tuaj yeem hloov pauv los ntawm cov khoom kub qis mus rau qhov khoom kub.
Cov txheej txheem yooj yim ntawm kev hloov hluav taws xob yog kev siv hluav taws xob, hluav taws xob convection thiab hluav taws xob hluav taws xob. Cov txheej txheem hloov hluav taws xob feem ntau tsis muaj nyob ib leeg hauv ib txoj kev hloov hluav taws xob, tab sis kev sib txuas ntawm ob lossis peb txoj kev hloov hluav taws xob. Txoj kev hloov hluav taws xob sib txawv yog tias cov qauv thiab thermal txav lub xeev ntawm cov khoom siv hluav taws xob sib txawv sib txawv.

1) Thaum tshav kub kub conduction

Thaum tshav kub kub conduction yog cov txheej txheem ntawm kev hloov cov cua sov los ntawm qhov kub siab dua ntawm ib qho khoom mus rau qhov kub qis vim qhov txav ntawm cov molecules, atoms los yog dawb electrons ntawm ib yam khoom. Thaum tshav kub kub conduction yog ib txoj kev hloov tshav kub nyob rau hauv ib qho khoom nyob ruaj ruaj, uas tshwm sim los ntawm qhov tsis muaj macroscopic hloov chaw ntawm cov khoom. Tag nrho cov khoom, tsis hais seb puas muaj kev cuam tshuam ntawm cov khoom hauv lawv, yuav tsis muaj kev cuam tshuam los ntawm kev kub nyhiab yog tias qhov kub sib txawv no. Los ntawm qhov kev xav ntawm microscopic, kev ua kom sov yog qhov tshwm sim ntawm kev hloov hluav taws xob los ntawm cov thermal txav ntawm cov khoom me me xws li molecules, atoms thiab dawb electrons ntawm ib yam khoom. Hauv cov pa roj los yog kua, lub zog kinetic ntawm cov molecules nyob rau hauv qhov kub thiab txias yog ntau dua li ntawm cov molecules nyob rau hauv qhov kub tsis tshua muaj. Cov molecules nrog lub zog sib txawv kinetic sib tsoo nrog ib leeg, ua rau cov cua sov ntws los ntawm thaj chaw kub kub mus rau thaj chaw kub tsawg. Hauv cov khoom tsis yog xim hlau, cov cua sov feem ntau yog hloov los ntawm thermal kev co thiab kev sib tsoo ntawm cov molecules uas nyob ib sab; Nyob rau hauv cov hlau, tshav kub conduction yog ua tiav los ntawm kev txav ntawm cov electrons dawb.

2) Thermal convection

Thermal convection yog hais txog kev hloov hluav taws xob los ntawm kev hloov pauv ntawm cov khoom nyob rau hauv txhua feem ntawm cov kua. Cov txheej txheem convection feem ntau yog nrog los ntawm kev ua kom sov. Hauv kev tsim tshuaj, kev hloov pauv ntawm cov kua thiab cov phab ntsa yog feem ntau hu ua convection heat transfer. Convection tshav kub hloov pauv tau muab faib ua yuam kev convection thiab natural convection. Yog hais tias lub zog ntawm cov kua yog tshwm sim los ntawm sab nraud quab yuam, nws yog hu ua quab yuam convection, xws li: siv twj, kiv cua, nplawm, thiab lwm yam ua rau cov kua dej convect thiab hloov tshav kub. Yog tias qhov txav ntawm cov kua dej yog tshwm sim los ntawm qhov sib txawv ntawm qhov sib txawv ntawm qhov txias thiab kub hauv cov kua, nws yog hu ua natural convection. Forced convection tshav kub hloov yog zoo dua li ntuj convection.

(3) Thermal tawg

Cov hluav taws xob hluav taws xob yog hais txog cov txheej txheem uas ib qho khoom tsim hluav taws xob hluav taws xob vim yog cua sov thiab hloov hluav taws xob mus rau lub ntiaj teb sab nraud. Txhua yam khoom, tsuav yog nws qhov kub thiab txias siab tshaj qhov ntsuas kub ntawm qhov ntsuas kub ntawm xoom, yuav txuas ntxiv hluav taws xob mus rau lub ntiaj teb sab nraud yam tsis tas yuav muaj qhov nruab nrab. Nyob rau tib lub sijhawm, nws tsis tu ncua nqus hluav taws xob hluav taws xob los ntawm lwm yam khoom hauv ntiaj teb sab nraud thiab hloov mus rau hauv thermal zog. Yog li ntawd, hluav taws xob hloov hluav taws xob tsis yog tsuas yog cov txheej txheem ntawm kev hloov hluav taws xob, tab sis kuj nrog lub zog hloov dua siab tshiab. Qhov siab dua qhov kub ntawm cov khoom, lub zog ntau dua yog pauv mus rau hauv daim ntawv ntawm hluav taws xob.

Hauv kev tsim khoom, kev sib pauv cua sov ntawm ob txheej txheem dej feem ntau yog siv rau hauv cov txheej txheem kev sib hloov cua sov. Tsis tas li ntawd, lwm tus neeg ua haujlwm cua sov (qhov nruab nrab cua sov) lossis cov khoom ua kom txias (qhov nruab nrab cua txias) yuav tsum tau koom nrog hauv kev sib pauv cua sov los muab lossis tshem tawm cov cua sov.

1. Feem ntau siv cov khoom cua sov
Feem ntau siv cov khoom siv cua sov hauv kev lag luam suav nrog saturated thiab dej vapor, dej kub, ntxhia roj, biphenyl sib tov, molten ntsev thiab flue gas. Yog tias qhov cua sov kub siab heev, hluav taws xob cua sov tuaj yeem siv tau.

1) Saturated dej vapor

Saturated dej vapor yog cov khoom siv cua sov tshaj plaws. Txij li thaum lub convective tshav kub hloov coefficient ntawm saturated dej vapor yog siab heev thaum condensed, lub chav siab tuaj yeem hloov tau kom raug kho qhov kub thiab txias. Txawm li cas los xij, thaum qhov kub ntawm cov dej vapor siab tshaj 180 degree, yuav tsum muaj kev kub siab heev. Yog li ntawd, saturated chav cua sov feem ntau tsuas yog siv nyob rau hauv lub sij hawm uas cov cua kub kub ntawm 100 thiab 180 degree.

2) Cov pa roj

Cov pa roj flue tau los ntawm cov roj combustion muaj qhov kub siab heev, uas tuaj yeem ncav cuag 500 txog 1000 degree. Nws yog qhov tsim nyog rau cua sov uas yuav tsum muaj qhov kub thiab txias. Qhov tsis zoo ntawm cov cua sov nrog cov roj flue yog nws lub peev xwm tshwj xeeb thaum tshav kub kub, tsis yooj yim rau kev tswj, thiab qis convective heat transfer coefficient.

3) Cov dej kub

Cov dej kub yog siv los ua cua sov. Nws qhov ntsuas kub siv tau yog 40 txog 100 degree. Cov dej kub yog los ntawm cov dej condensed ntawm cov dej vapor lossis cov khib nyiab ntawm cov dej kub khib nyiab.

(4) Mineral roj

Cov roj ntxhia yog tsim rau cov txheej txheem cua sov hauv qab 250 degree. Nws qhov tsis zoo yog siab viscosity, qis convective tshav kub hloov coefficient, thiab yooj yim decomposition thiab combustion saum 250 degree.

5) Molten ntsev

Cov ntsiab lus ntawm molten ntsev yog 7% NaNO3, 40% NaNO2, 53% KNO3. Nws qhov ntsuas kub siv tau yog 142-530 degree, qhov cua sov kub yog siab, thiab cov cua kub tsis sib xws.

6) Biphenyl sib tov

Qhov ntsuas kub ntawm biphenyl sib xyaw ua kua yog 15-255 degree, thiab nws cov vapor siv tau nyob rau hauv thaj tsam ntawm 255-3800 degree . Qhov siv tau qhov kub thiab txias yog qhov dav, thiab qhov kub thiab txias yog qhov yooj yim los kho thaum rhuab nrog nws cov vapor.

2. Feem ntau siv cov coolants
Feem ntau siv coolants hauv kev lag luam muaj xws li dej, cua, thiab ntau yam tub yees.

1) Dej

Dej yog cov khoom siv coolant tshaj plaws. Nws tuaj yeem los ntawm qhov xwm txheej thiab tsis xav tau kev ua haujlwm tshwj xeeb. Qhov feem ntau siv qhov ntsuas kub yog 10-35 degree . Cov dej muaj lub peev xwm tshwj xeeb thaum tshav kub kub thiab muaj qhov sib txawv ntawm cov cua sov hloov coefficient. Nws muaj qhov ua kom txias txias thiab yooj yim kho. Txhawm rau tiv thaiv qhov ntsuas kub, qhov kub yuav tsum tsis pub tshaj 35 degrees.

2) Cua

Hauv cov cheeb tsam uas tsis tshua muaj dej, huab cua tuaj yeem siv los ua cov dej txias. Lub convective tshav kub hloov coefficient ntawm huab cua yog me me thiab lub tshav kub hloov kev ua tau zoo yog tsis zoo. Nws yog qhov tsim nyog rau kev sib pauv cua sov ntawm qhov txias txias ntawm 0-35 degree .

3) Frozen brine

Yog tias cov kua dej kub yuav tsum tau txias kom qis dua, yuav tsum tau siv lub tshuab ua kom txias txias. Feem ntau siv cov cua txias txias xws li khov brine (CaCl₂, NaCl tov), ​​uas tuaj yeem txias cov khoom mus rau qhov kub ntawm qhov qis tshaj kaum degrees Celsius lossis txawm rho tawm kaum degrees Celsius. Feem ntau siv qhov kub thiab txias yog {{0}} txog 0 degree . Yog tias xav tau qhov txias txias, qhov evaporation ntawm qee cov kua dej uas tsis tshua muaj kub kub tuaj yeem siv los ua kom tiav lub hom phiaj.