Numerical analysis of cooling of a cylindrical Li-ion battery cell

master's thesis

• Title (croatian): Numerička analiza hlađenja cilindrične Li-ionske baterijske ćelije
• Author: Ivan Jelić
• Mentor: Željko Tuković (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2023-01-25, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Process Energy Engineering

Abstract

The task of the thermal management systems (TMS) in the electric vehicles (EV) equipped with the Li-ion battery modules is to prevent the thermal runaway by the effective control of cell-core temperature. This is important mostly due to safety reason because over-temperature of the Li-ion batteries can induce fire and even explosion. In this thesis, it was carried out a numerical conjugate heat transfer analysis of the battery module cooling with the laminar fluid flow. Three battery cell models were analyzed, which differ by the level of geometrical details taken into account: single solid body model, model with the cell-core represented by a single solid body and model with the detailed cell-core representation. These three battery cell models are compared for three different cooling strategies: bottom cooling, single sided cooling, double sided cooling. For simplified models of the cell, it was important to determine the correct effective thermal conductivity of the cell core in the in-plane and through-plane directions. The effective thermal conductivity of the jelly-roll (cell-core) was determined based on the numerical results obtained for detailed cell-core model. All numerical simulations were performed by the computational fluid dynamic software ANSYS/Fluent.

Abstract (croatian)

Zadatak sustava za upravljanje toplinom u električnim vozilima opremljenim Li-ionskim baterijskim modulima je spriječavanje termalnog pobjega (\textit{thermal runaway}) učinkovitom kontrolom temperature jezgri ćelija. Ovo je uglavnom važno zbog sigurnosnih razloga jer previsoka temperatura Li-ionskih baterija može izazvati požar, pa čak i eksploziju. U ovom diplomskom radu provedena je numerička analiza spregnutog prijenosa topline kroz baterijski modul koji je hlađen laminarnim strujanjem fluida. Analizirana su tri modela baterijskih ćelija, koji se razlikuju po razini geometrijskih detalja uzetih u obzir: model jednog čvrstog tijela, model s jezgrom ćelije predstavljenom jednim čvrstim tijelom i model s detaljnim prikazom jezgre ćelije. Ova tri modela baterijskih ćelija su uspoređena za tri različite strategije hlađenja: hlađenje s donje strane preko rashladne ploče, jednostrano bočno hlađenje, obostrano bočno hlađenje. Za pojednostavljene modele ćelije važno je odrediti točnu efektivnu toplinsku vodljivost jezgre ćelije u aksijalnom (odnosno tangecijalnom) i radijalnom smjeru. Efektivna toplinska vodljivost jezgre ćelije određena je na temelju numeričkih rezultata dobivenih za detaljan model jezgre ćelije. Sve numeričke simulacije izvedene su računalnim programom ANSYS/Fluent.

• Keywords: Li-ion battery; Jelly-roll (battery); Indirect cooling; CFD; CHT; In-plane thermal conductivity; Through-plane thermal conductivity; ANSYS/Fluent
• Keywords (croatian): Li-ionska baterija; Jelly-roll (baterija); Indirektno hlađenje; CFD; CHT; Radijalna vodljivost; Aksijalna i tangecijalna vodljivost; ANSYS/Fluent
• Language: english
• URN:NBN: urn:nbn:hr:235:719593
• 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: Embargoed access; Embargo expiration date: 2028-01-20
• Created on: 2023-01-23 12:12:25