Model ispitnog sustava za hlađenje baterije električnog vozila

master's thesis

• Title (english): Experimental rig for cooling of electric vehicle battery
• Author: Toni Vukša
• Mentor: Vladimir Soldo (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2020-07-14, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Process Energy Engineering

Abstract

Baterijski paketi električnih vozila sačinjeni su od velikog broja jediničnih litij-ionskih ćelija. Unutar baterijske ćelije, prilikom pražnjenja i punjenja, generira se toplina proporcionalna kvadratu jakosti struje zbog unutarnjih nesavršenosti ćelije. U današnje vrijeme baterijske ćelije opterećuju se sa sve višim zahtjevima za snagu i volumensku gustoću s ciljem dobivanja što viših performansi električnih vozila, ali i da se postigne vrijeme punjenja baterije električnih vozila što sličnija konvencionalnim vozilima s motorima s unutrašnjim izgaranjem.
Životni vijek i performanse litij-ionskih ćelija značajno ovise o radnoj temperaturi i temperaturnoj uniformnosti između ćelija. Konvencionalne metode hlađenja baterijskih paketa teško uspijevaju pratiti nametnuta povišenja karakteristika vozila te rashladni sustav baterije postaje usko grlo za daljnje povišenje performansi.
Slijedom navedenog, u ovome je radu dimenzioniran ispitni rashladni sustav baterijskog paketa s dvofaznim hlađenjem u kojemu bi kapljevina isparavala u direktnom dodiru s električnim ćelijama.
Prvo poglavlje rada bavi se problematikom hlađenja ćelija te daje pregled najzastupljenijih načina hlađenja električnih baterija u vozilima prisutnih danas na tržištu.
Drugo poglavlje daje uvod u tehniku dvofaznog hlađenja te prikazuje detektirane pumpne dvofazne sustave i detektirane radove koji opisuju hlađenje baterijskih ćelija isparavanjem fluida u direktnom dodiru.
Treće poglavlje sadrži razvoj ispitnog modela kojim bi se ispitala tehnika dvofaznog hlađenja na baterijskom paketu s 4 modula od 50 ćelija uz pregled potencijalnih radnih tvari. U četvrtom poglavlju dimenzionirane su glavne komponente takvog ispitnog sustava te je odabrana mjerna oprema koja će omogućiti bilanciranje tokova energije i snimanje radnih parametara sustava.
U petom poglavlju je obavljen proračun pada tlaka sustava.
Napravljena je hidraulička shema spajanja ispitnog sustava te je prikazan dispozicijski crtež ispitne linije.

Abstract (english)

Battery packs of electric vehicles are made up of a large number of single smaller lithium-ion cells. During discharge and charge, heat is generated inside the cell proportional to the square of the current due to the internal resistance of the cell. Nowadays, battery cells are imposed with increasing demands for power and volume density in order to obtain the highest possible performance of electric vehicles, but also to achieve charging time of electric vehicles similar to those seen in conventional vehicles with internal combustion engines.
The lifespan and performance of lithium-ion cells depend significantly on the operating temperature and temperature uniformity between the cells. Conventional battery pack cooling methods are having difficulties with keeping up with the imposed increases in vehicle performance. Consequently, the battery cooling system is becoming a bottleneck for further performance improvements. For these reasons a need for a new battery cooling system is noticed.
In this paper an experimental rig of a battery pack cooling system with two-phase cooling has been designed. In it, a liquid evaporates in direct contact with electrical cells.
The first chapter deals with the problem of cell cooling and provides an overview of the most common ways of battery cooling in vehicles present on the market today. The second chapter gives an introduction to the two-phase cooling technique and presents the detected pumped two-phase systems and detected papers that describe battery cell cooling by evaporation of fluids in direct contact.
The third chapter contains the development of an experimental rig model that would test the technique of two-phase cooling on a battery pack with 4 modules of 50 cells with an overview of potential liquids that could be used for those applications.
In the fourth chapter, the main components of such an experimental rig are dimensioned and measuring equipment is selected that will enable accurate recording the of system parameters. In the fifth chapter, the calculation of the system pressure drop was performed. The hydraulic connection diagram of the test system is made and the disposition drawing of the experimental system is shown.

• Keywords: električna vozila; ispitni sustav; rashladni sustav električne baterije; dvofazno hlađenje
• Keywords (english): electric vehicles; test system; electric battery cooling system; two-phase cooling
• Language: croatian
• URN:NBN: urn:nbn:hr:235:623106
• 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: 2025-07-14
• Created on: 2020-07-09 19:14:25