Numeričko rješenje matematičkog modela nestacionarnog prijenosa topline u višeslojnom zidu s izvorima i ponorima topline

undergraduate thesis

• Title (english): Numerical solution of mathematical model of transient heat transfer in multilayered material with heat sinks and sources
• Author: Antonio Kapusta
• Mentor: Juraj Šipušić (mentor)
• Committee member: Juraj Šipušić (predsjednik povjerenstva)
• Committee member: Vladimir Dananić (član povjerenstva)
• Committee member: Nevenka Vrbos (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2019-07-12, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

U ovome radu sastavljena je aparatura za ispitivanje prijelaznih toplinskih pojava. Prijelazne pojave u metalnim valjcima (legura AlCuMgSi1, promjera 60.0 mm i visine 5.0 do 50.0 mm) u jednostavnoj geometriji (jedno mjesto akumulacije) pokazuju eksponencijalnu promjenu temperature tijekom vremena, dok slog više valjaka pokazuje složeniju ovisnost koju je moguće opisati sustavom običnih diferencijalnih jednadžbi. Metalni valjci zbog velike toplinske vodljivosti i difuzivnosti su gotovo izotermni i pokazuju vrlo malo kašnjenje u odzivu na skokomičnu promjenu temperature baze valjka. Specifični toplinski kapacitet Peltierovog elementa i cijelog sustava određen je iz izmjerenog odziva temperature materijala na puls grijanja. Procjena ostalih toplinskih svojstva (koeficijenta toplinske vodljivosti, toplinske difuzivnosti i toplinske efuzivnosti) nepoznatih materijala zahtijeva daljnje unaprjeđenje aparature, mjerenja i obrade podataka (model fizičkog sustava). Specifični toplinski kapacitet Peltierovog elementa (model TEC1 – 12706) iznosi 801 Jkg^-1K^-1. Pokušaj implementiranja Peltierovog elementa u „pasivnoj“ izolaciji kalorimetra radi smanjenja temperaturnih oscilacija ispitivanog sustava pokazao se neuspješnim.

Abstract (english)

In this thesis the apparatus for testing the heat transient was made. The heat transient in metal cylinders (AlCuMgSi1 alloy, diameter 60.0 mm and height 5.0. to 50.0 mm) in simple geometry (one accumulation spot) shows exponential temperature gradient over time, while the compound of more cylinders shows more complicated dependance which we are able to depict with a differential equation system. Metal cylinders, due to their high thermal conductivity and diffusivity, are almost completely isothermal and show very small delay response to temperature change on the cylinder base during a step test. Specific heat capacity of a Peltier element and the whole system is determined from measured temperature response of material on the heating pulse. Approximation of other heat attributes (coefficient of thermal conductivity, thermal diffusivity and thermal effusivity) of unknown materials demands further development of apparatus, measurements and data processing (physical system model). Specific heat capacity of a Peltier element
(model TEC1 – 12706) is 801 Jkg^-1K^-1. The attempt to implement Peltier element in a „passive“ calorimeter insulation for the decrease of temperature oscillations in the tested system has proved to be unsuccessful.

• Keywords: Peltierov element; nestacionarna kondukcija topline; toplinski kapacitet
• Keywords (english): Peltier element; transient heat conduction; heat capacity
• Language: croatian
• URN:NBN: urn:nbn:hr:149:138725
• Study programme: Title: Materials Science and Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-05-24 09:13:05