Implementacija i validacija elektrolitskog modela dva potencijala u numeričkom modelu gorivnog članka

master's thesis

• Title (english): Implementation and validation of the two-potential electrolyte assembly equations in the computational fuel cell model
• Author: Tibor Bešenić
• Mentor: Hrvoje Jasak (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2016-07-15, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Process Energy Engineering

Abstract

Gorivni članci su uređaji za pretvorbu kemijske energije goriva u električnu energiju. Zbog teoretski visoke efikasnosti i niskog štetnog utjecaja na okoliš, imaju priliku postati jedna od važnih tehnologija tijekom tranzicije prema obnovljivim energetskim izvorima. Kako bi gorivni članci bili kvalitetno konstruirani i pouzdani tijekom radnog vijeka, potreban je brži napredak tehnologije i materijala koji uključuje spoj novih računalnih modela i eksperimentalnih podataka.

Procesi koji se odvijaju u gorivnim člancima su kompleksan spoj toka fluida, provođenja topline, transporta specija i elektrokemijskih reakcija. Računalni modeli gorivnih članaka moraju sa zadovoljavajućom točnošću obuhvatiti ove procese na mikroskopskoj razini u poroznim elektrodama, kao i u složenim geometrijama dobavnih kanala. Prije razvijanja računalnog modela za gorivne članke, potrebno je izuzetno razumijevanje fizikalnih procesa, posebice termodinamike elektrokemijskih reakcija koje su temelj pretvorbe kemijske u električnu energiju.

OpenFuelCell je nadogradnja na open-source softverski paket OpenFOAM i služi za modeliranje gorivnih članaka s naglaskom na gorivne članke s krutim oksidima. Razvija se nadogradnja postojećeg modela koja uključuje detaljniji opis polja potencijala unutar aktivnih dijelova članka. Za novi model dvaju potencijala potrebna je značajnija prilagodba računalnog koda, dekompozicije proračunskih mreža i jednadžbi modela. Zbog novog pristupa otežana je validacija s postojećim rezultatima i standardnim OpenFuelCell kodom. Daje se prikaz i analiza rezultata dobivenih novim modelom te ocjena primjenjivosti modela.

Abstract (english)

Fuel cells are devices for conversion of chemical into electric energy. Because of their high theoretical efficiency and low impact on environment, they are likely to have a major role during the current transition towards renewable energy sources. In order to design high-quality device that is reliable during its life-span, advances in fuel cell technology and materials are needed. Synergy of new numerical models and experimental data is therefore crucial.

Processes occurring in fuel cells are complex combination of fluid flow, heat transfer, species’ transport and electrochemical reactions. Numerical models for fuel cells need to include all of these processes with a satisfactory precision on both the porous electrodes’ micro-scale and the global scale of cell and complex geometry of supply channels.

Before model development, considerable understanding of physical processes is needed, especially for thermodynamics of electrochemical reactions for energy conversion.

OpenFuelCell is the open-source addition for OpenFOAM library that is developed for fuel cell modeling, focusing on solid oxide fuel cells (SOFC). Additional model for OpenFuelCell that includes more detailed potential field description is developed. For it, new mesh decomposition is needed, as well as significant modifications of source-code and governing equations.

Results of the new two potential model are given, although comparison with existing models is cumbersome due to underlying differences in model. Along with results, validity assessment of new model is also given.

• Keywords: CFD; OpenFOAM; SOFC; gorivni članci; openFuelCell; kruta elektroda; elektrokemija; polje potencijala
• Keywords (english): CFD; OpenFOAM; SOFC; fuel cell; openFuelCell; solid oxide; electrochemistry; potential field
• Language: english
• URN:NBN: urn:nbn:hr:235:200762
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-05-22 17:10:33