Lub thermal hwj chim ntawm lub fais tam sim no thiab nws ua daim ntawv thov

Yog vim li cas rau cua sov xyuas pib cov lus dag nyob rau hauv lub fact tias lub zog ntawm cov electrons tsiv nyob rau hauv nws (nyob rau hauv lwm yam lus, tam sim no lub zog) nyob rau hauv successive kev sib tsoo ntawm hais nrog ions ntawm cov molecular lattice ntawm cov hlau caij yog hloov dua siab tshiab rau hauv sov hom ntawm lub zog los yog Q, raws li tsim los ntawm lub sij hawm "thermal tswv yim".

Tam sim no ua hauj lwm yog ntsuas siv cov thoob ntiaj teb system ntawm chav nyob, los ntawm thov thereto joules (J), tam sim no muaj peev xwm yog txiav txim raws li "watt" (W). Departing los ntawm lub system nyob rau hauv kev xyaum, tej zaum yuav siv nrog cov-SI units uas ntsuas cov hauj lwm tam sim. Cov lawv Coj (W × h) ib tug kilomatt-teev (abbreviated kW × h). Piv txwv li, 1 × W h qhia tam sim no ua hauj lwm nrog ib lub hwj chim ntawm 1 watt thiab qhov ntev ntawm lub sij hawm rau ib teev.

Yog hais tias electrons txav raws ruaj ruaj xyuas pib ntawm hlau, nyob rau hauv cov ntaub ntawv no rau tag nrho cov pab ua hauj lwm generated tam sim no yog faib rau cua sov rau cov hlau qauv, thiab, raws li nyob rau hauv cov kev cai ntawm kev cai lij choj ntawm kev txuag ntawm lub zog, nws yuav piav tau los ntawm cov mis Q = A = IUt = kuv ² Rt = (U ² / R) * t. Tej kev sib raug zoo nrog precision qhia paub kev cai lij choj ntawm Joule. Keeb kwm, nws twb xub txiav txim siab empirically paub txog D. Joel nyob rau hauv nruab nrab ntawm lub xyoo pua puv 19, thiab nyob rau tib lub sij hawm, ntawm nws tus kheej, los ntawm lwm tus paub txog - E.Lentsem. Tswv yim rau daim ntawv thov ntawm cov thermal hwj chim nyob rau hauv cov kev ua tau zoo ntawm cov invention nrog ib tug 1873 los ntawm Lavxias teb sab engineer A. Ladygin zoo tib yam incandescent teeb.

Thermal tso zis ntau zog yog ua nyob rau hauv ib tug xov tooj ntawm hluav taws xob khoom siv thiab muaj sib, namely nyob rau hauv thermal instrumentation, cua sov, xws li hluav taws xob ncu, hluav taws xob vuam khoom tus tej khoom muag thiab yog heev khoom vaj khoom tsev nyob rau hauv qhov hluav taws xob cua sov nyhuv - boilers, soldering irons, kettles, irons.

Pom nws tus kheej thiab lub cua sov nyhuv nyob rau hauv lub lag luam ua noj. Nrog ib tug siab kev faib ua feem ntawm thov hluav taws xob-cua kub tau hais tias kom thermal muaj peev xwm. Nws yog vim hais tias tam sim no thiab lub cua sov hwj chim rau cov khoom noj khoom, uas muaj ib tug tej yam degree ntawm kuj, yuav ua rau nws heats tusyees. Ib tug yuav pabneeg li ib qho piv txwv ntawm yuav ua li cas lub ua sausages: los ntawm ib tug tshwj xeeb dispenser tsuav nqaij nkag mus rau hauv hlau pwm, cov phab ntsa uas kuj pab raws li electrodes. Muaj yog muab ib qhov uniform cua kub tshaj rau tag nrho cov cheeb tsam thiab ntim ntawm cov khoom, lub yam kub yog khaws cia pom lom tus nqi ntawm cov khoom noj khoom, ua ke nrog tej yam zoo ntev ntawm kev siv technology tshiab ua hauj lwm thiab lub hwj chim noj yog cov qis tshaj.

Cov kev kub muaj peev xwm ntawm cov hluav taws xob tam sim no (ω), nyob rau hauv lwm yam lus - tus nqi ntawm tshav kub uas yog tso tawm ib chav tsev ntim rau hauv ib cov chav tsev lub sij hawm yog xam raws li nram no. Elemental cylindrical neeg xyuas pib ntim (DV), nrog rau ib tug ntoo khaub lig-section nyob ntawm tej DS, ntev dl, thaum uas tig mus rau cov kev taw qhia ntawm tam sim no, thiab kuj yog kab zauv R = p (dl / DS) , DV = dSdl.

Raws li lub ntsiab txhais Joule txoj cai, rau qhov allotted lub sij hawm (dt) nyob rau hauv kev sib cuag ntim coj hloov zuj zuj tshav kub theem sib npaug zos dQ = kuv ² Rdt = p (dl / DS) (jdS) ² dt = pj ² dVdt. Nyob rau hauv cov ntaub ntawv no, ω = (dQ) / (dVdt ) = pj ^2, thiab ntawm no thov Ohm txoj cai mus nrhiav kom tau qhov tam sim no ceev j = γE piv thiab p = 1 / γ, peb tam sim ntawd tau qhia ω = je = γE ^2. Nws yog nyob rau hauv differential zoo muab lub tswvyim ntawm Joule txoj kev cai.