Yuav Ua Li Cas Match Thermocouple Teb Lub Sijhawm nrog Lub Cuab Yeej Hluav Taws Xob?
Tso lus
Ib qho tseem ceeb tshaj plaws thiab qee zaum tsis quav ntsej txog cov kev cai kub khiav kub yog qhov kev sib raug zoo ntawm cov tshuaj tiv thaiv thermocouple lub sij hawm rau lub tshuab hluav taws xob tso zis. Ib qho kev sib koom ua ke tsis raug yuav oscillate, overshoot thiab ua tsis ruaj khov, ua rau ib feem zoo degradation thiab txo cov cua sov lub neej. Nws yog ib qho tseem ceeb kom paub tias yuav ua li cas sib npaug ntawm ob yam no rau kev tswj xyuas qhov kub thiab txias.
Lub sijhawm Thermocouple teb yog dab tsi
Lub sij hawm teb ntawm lub thermocouple yog lub sij hawm siv rau lub sensor kom ua tiav 63.2% ntawm cov kauj ruam hloov ntawm qhov kub, uas feem ntau hu ua lub sij hawm tas li τ (tau). Rau cov ntxhia insulated thermocouples, txoj kab uas hla ntawm lub sheath, lub hauv paus ntawm kev sib tshuam, thiab qhov zoo ntawm thermal contact ntawm lub thermocouple thiab qhov saum npoo tau ntsuas yuav cuam tshuam rau lub sijhawm cov tshuaj tiv thaiv. Lub sij hawm tas li ntawm lub thermocouple yog proportional rau qhov inverse ntawm txoj kab uas hla ntawm lub sheath. Piv txwv li, 0.5mm txoj kab uas hla thermocouple tuaj yeem muaj lub sijhawm tsis tu ncua ntawm 0.5 vib nas this, qhov 1.5mm inch sensor yuav siv sijhawm 3-5 vib nas this los teb. Grounded junctions teb nyob ib ncig ntawm 30% sai dua ungrounded junctions vim yog cov hlau ncaj qha -rau-hlau thermal contact.
Fais fab tso zis yam ntxwv ntawm lub rhaub
Tus nqi ntawm qhov sib ntxiv ntawm thermal zog rau qhov system yog txiav txim siab los ntawm lub tshuab hluav taws xob tso zis hluav taws xob. Cartridge heaters feem ntau yog li ntawm 100W txog 1000W ib cheeb tsam, nrog rau lub zog ntom ntom uas cuam tshuam rau ob qho tib si cua sov thiab qhov kub thiab txias. Coil heaters muab kev faib hluav taws xob ntau dua, tab sis tej zaum yuav muaj cov lus teb qeeb rau kev hloov hluav taws xob. Lub tshuab cua sov lub thermal inertia, ua haujlwm ntawm nws cov huab hwm coj thiab cov cua sov tshwj xeeb, qhia lub sijhawm rau lub nozzle lossis manifold kom hnov mob rau kev hloov pauv hauv cov khoom tso cua sov. Cov kab ke uas muaj thermal inertia siab (loj manifolds, loj nozzles) yog tus cwj pwm los ntawm kev ua kom tsis zoo ntawm qhov kub thiab txias, thaum lub tshuab uas tsis tshua muaj thermal inertia teb sai heev rau lub zog hloov pauv.
Sib piv txoj cai
Lub hauv paus ntsiab lus sib piv yog tias lub sij hawm teb ntawm lub thermocouple yuav tsum tsawg dua li lub sij hawm teb thermal ntawm cov khoom cua sov. Yog tias lub sensor qeeb dhau los teb, tus maub los yuav tsis pom qhov kub hloov pauv sai txaus los hloov lub zog rau lub rhaub kom zoo thiab yuav overshoot thiab oscillate. Yog tias lub ntsuas ntsuas nrawm dhau rau lub peev xwm ntawm lub tshuab rhaub, nws yuav pom qhov hloov pauv me me uas lub tshuab rhaub tsis tuaj yeem hloov kho rau, ua rau muaj kev cuam tshuam thiab tsis ruaj khov. Qhov kev sib raug zoo zoo yog rau lub sij hawm thermocouple tas li yuav luag ib feem tsib mus rau ib feem kaum ntawm lub sij hawm thermal tas li ntawm thaj chaw rhuab.
Cov cai sib piv
Siv 0.5mm inch grounded junction thermocouples nrog lub sij hawm tas li tsawg dua 1 thib ob rau me me txoj kab uas hla nozzles nrog cartridge rhaub (tsawg thermal mass, ceev teb). Qhov kev npaj no tso cai rau kev tshawb pom sai ntawm qhov hloov pauv kub thiab teb PID tswj. Rau cov manifolds loj nrog cov thermal loj, 1.0mm mus rau 1.5mm inch thermocouples nrog 2-4 sec lub sij hawm tas li yog tsim nyog. Lub intrinsic thermal inertia ntawm lub manifold yuav zoo li smooth tawm kub swings.
Teb lub sij hawm cuam tshuam ntawm installation
Cov txheej txheem kev teeb tsa yog qhov tseem ceeb rau lub sijhawm teb zoo. Lub thermocouple-rau- qhov chaw thermal tiv thaiv yog qhov tsis zoo thermal tiv tauj uas ntxiv txheej ntxiv ntawm thermal kuj thiab txo cov lus teb zoo. Yog hais tias muab tso rau hauv qhov ntiav dhau, qhov kev kuaj pom tau raug tshem tawm ntawm qhov chaw sov tiag tiag thiab kev lag luam tau qhia. Lub thermally conductive muab tshuaj txhuam los yog nruj haum txo cov thermal tiv thaiv thiab txhim kho lub sij hawm teb.
Qhov cuam tshuam rau Controller Tuning
Qhov kev sib tw ntawm cov tshuaj tiv thaiv thermocouple lub sij hawm thiab cov khoom siv hluav taws xob tso hluav taws xob muaj qhov cuam tshuam ncaj qha rau kev teeb tsa ntawm tus maub los PID. Cov tshuab ua haujlwm nrawm dua yuav tsum muaj cov ntsiab lus me me (I) txhawm rau tiv thaiv oscillation. Cov tshuab qeeb qeeb yuav tsum muaj cov ntsiab lus loj dua kom kov yeej thermal inertia. Kev kho kom zoo autotuning yuav cia li tswj cov kev cuam tshuam no, thaum tib neeg tuning yuav tsum muaj kev nkag siab ntawm lub cev muaj zog.
Kev txiav txim siab ntawm Lub Hwj Huam Hwj Huam Hwj Huam
High power density heaters (>50W / cm2) tuaj yeem ua kom sov sai heev tab sis tuaj yeem ua rau muaj kev kub ntxhov hauv cheeb tsam yog tias lub thermocouple tsis tuaj yeem hnov qhov kub nce sai txaus. Txawm li cas los xij, rau cov cua sov uas tsis muaj hluav taws xob tsawg (<20W/cm^2), the heater may not respond fast enough to keep up with the detection capability of the thermocouple, which can cause extended variations. The sensor reaction time should be matched to the power density for balanced performance.
