Tus txheej txheem ua haujlwm ntawm tus ntsuas kub hauv hluav taws xob

Lub ntsuas sov ntsuas tus pas ntsuas kub siv lub ntsuas sov ua lub ntsuas kub raws li lub ntsuas kub ntsuas los ntsuas lub ntsuas thermoelectromotive sib haum rau qhov ntsuas kub thiab ntsuas tus nqi ntsuas tau ntsuas los ntawm lub ntsuas kub. Nws yog dav siv los ntsuas qhov kub thiab txias ntawm -200 ℃ ~ 1300 ℃, thiab hauv cov xwm txheej tshwj xeeb, nws tuaj yeem ntsuas qhov kub siab ntawm 2800 ℃ lossis qhov kub tsawg ntawm 4K. Nws muaj cov yam ntxwv ntawm cov qauv yooj yim, tus nqi qis, kev qhia siab, thiab ntsuas qhov ntsuas kub. Vim tias cov thermocouple hloov kev ntsuas kub mus rau hluav taws xob rau kev nrhiav kom paub, nws yooj yim los ntsuas thiab tswj ntsuas qhov kub thiab txias, thiab ua kom nrov nrov thiab hloov ua ntsuas kub. Nws yog tsim rau kev ntsuas mus deb thiab kev tswj tsis siv neeg. Hauv kev ntsuas tus qauv ntsuas kub, daim ntawv thov ntawm cov thermoelectric tus pas ntsuas kub yog qhov ntau.

DS-1
(1) Thermocouple ntsuas kub ntsuas
Lub hauv paus ntsiab lus ntawm kev ntsuas kub thermocouple yog ntsuas raws cov nyhuv thermoelectric.
Txuas lub conductors A thiab B ntawm ob yam khoom sib txawv hauv series rau hauv lub voj kev kaw. Thaum ntsuas kub ntawm ob qho sib tiv tauj 1 thiab 2 sib txawv, yog T> T0, cov ntsuas kub ntawm lub cev sov yuav tsim tawm hauv lub voj, thiab yuav muaj qee qhov nyiaj hauv lub voj. Loj loj thiab me dej tam sim no, qhov tshwm sim no yog hu ua cov teebmeem pyroelectric. Lub zog siv hluav taws xob no yog qhov paub zoo “Seebeck thermoelectromotive quab yuam”, hu ua “thermoelectromotive force”, txhais tau tias yog EAB, thiab tus kav theej A thiab B hu ua thermoelectrodes. Kev sib cuag 1 feem ntau yog welded ua ke, thiab nws muab tso rau hauv qhov ntsuas qhov ntsuas kub kom hnov ​​qhov ntsuas kub thaum ntsuas, yog li nws hu ua ntsuas ntsuas kawg (lossis kub kub ntawm qhov ua haujlwm kawg). Lub hlws ris 2 xav tau qhov kub tas li, uas yog hu ua kev siv hlws ris (lossis txias hlws ris). Lub ntsuas uas sib xyaw ua ke ob qho coj thiab hloov qhov ntsuas kub rau hauv cov khoom siv thermoelectromotive hu ua thermocouple.

Lub thermoelectromotive lub zog yog tsim muaj cov sib tiv tauj ntawm ob tus neeg sib tw (Peltier muaj peev xwm) thiab qhov kub sib txawv muaj peev xwm ntawm ib tus neeg xyuas pib (Thomson muaj peev xwm). Qhov ntau ntawm lub zog thermoelectromotive yog yam muaj feem xyuam nrog cov yam ntxwv ntawm ob tus neeg xyuas khoom siv cov khoom siv thiab qhov ntsuas kub ua haujlwm.
Cov ntsuas hluav taws xob hauv qhov neeg xyuas pib yuav txawv. Thaum ob tus neeg tsav tsheb A thiab B nrog qhov sib txawv hauv tshuab hluav taws xob muaj qhov sib chwv, qhov hluav taws xob tsis zoo tshwm sim ntawm qhov chaw sib chwv, thiab cov hluav taws xob ntws tawm ntawm tus neeg xyuas pib nrog hluav taws xob hluav taws xob loj rau tus neeg xyuas pib nrog tsawg ceev. Tus nqi hluav taws xob ntawm cov hluav taws xob sib txawv muaj feem xyuam nrog hluav taws xob ntawm qhov hluav taws xob ntawm ob tus neeg xa khoom thiab muaj qhov sib npaug rau qhov ntsuas kub ntawm thaj chaw sib tiv tauj. Xav tias qhov tsis muaj hluav taws xob ntawm qhov ceev hluav taws xob ntawm cov neeg ua yeeb yam A thiab B yog NA thiab NB, thiab NA> NB, vim qhov hluav taws xob tsis zoo, tus neeg xyuas pib poob ib qho hluav taws xob thiab ua zoo raug them, thaum tus neeg xyuas pib B muaj cov hluav taws xob thiab tsis zoo raug them, tsim hluav taws xob teb ntawm chaw tiv tauj. Qhov chaw ntsuas hluav taws xob no cuam tshuam kev sib txawv ntawm cov hluav taws xob, thiab thaum qhov sib luag ntawm qhov sib npaug, qhov muaj peev xwm ruaj khov tau tsim nyob hauv thaj chaw sib tiv tauj, uas yog, kev sib cuag, uas muaj ntau yam

(8.2-2)

Qhov twg k – Boltzmann qhov tsis tu ncua, k = 1.38 × 10-23J / K;
e – tus nqi ntawm cov nqi hluav taws xob, e = 1.6 × 10-19 C;
T – Qhov ntsuas kub ntawm qhov chaw sib tiv tauj, K;
NA, NB– yog cov hluav taws xob ywj pheej ntawm cov neeg xyuas pib A thiab B, feem.
Lub tshuab hluav taws xob tsim tawm los ntawm qhov kub thiab txias sib txawv ntawm ob qhov kawg ntawm tus neeg xyuas pib yog hu ua thermoelectric muaj peev xwm. Vim tias qhov ntsuas kub ntawm qhov ntsuas kub, qhov faib hluav taws xob ntawm cov hluav taws xob tau hloov. Lub siab kub kawg (T) hluav taws xob yuav tawg mus rau qhov ntsuas kub tsawg kawg (T0), ua rau lub siab kub kawg ua qhov zoo vim tias tsis muaj cov hluav taws xob, thiab qhov kub tsawg kawg yuav tsis zoo vim them los ntawm hluav taws xob. Yog li no, muaj qhov sib txawv ntawm qhov sib txawv tseem tsim tawm ntawm ob xaus ntawm tib tus neeg xyuas pib thiab txwv tsis pub cov khoom siv hluav taws xob tsis sib kis los ntawm qhov kub kawg mus txog rau qhov kub tsawg kawg. Tom qab ntawd cov xaim hluav taws xob tau tsim kom muaj qhov sib npaug ntawm qhov sib npaug. Cov peev txheej sib txawv tau tsim nyob rau lub sijhawm no hu ua thermoelectric lub peev xwm lossis Thomson muaj peev xwm, uas cuam tshuam txog qhov ntsuas kub Rau

(8.2-3)

JDB-23 (2)

Hauv cov qauv, σ yog Thomson coefficient, uas sawv cev rau lub zog electromotive tsim tawm los ntawm qhov kub qhov sib txawv ntawm 1 ° C, thiab nws qhov ntau yog cuam tshuam rau cov khoom siv thiab qhov kub ntawm ob qho kawg.
Lub thermocouple kaw Circuit Court muaj cov neeg xyuas pib A thiab B muaj ob lub zog sib tiv tauj eAB (T) thiab eAB (T0) ntawm ob tus neeg, thiab vim tias T> T0, kuj tseem muaj cov thermoelectric muaj peev xwm hauv txhua tus neeg xyuas A thiab B. Vim li ntawd, tag nrho cov thermal electromotive quab yuam EAB (T, T0) ntawm lub voj kaw yuav tsum yog cov lej algebraic ntawm kev sib cuag electromotive quab yuam thiab qhov kub sib txawv hluav taws xob muaj peev xwm, uas yog:

(8.2-4)

Rau qhov raug xaiv thermocouple, thaum qhov ntsuas kub tsis zoo yog tas li, tag nrho cov thermoelectromotive lub zog ua haujlwm ib qho muaj nuj nqi ntawm kev ntsuas davhlau ya nyob twg T, uas yog, EAB (T, T0) = f (T). Qhov no yog lub hauv paus ntsiab lus ntawm thermocouple ntsuas kub.


Sijhawm Tshaj Tawm: Lub Yim Hli-11-2021