Design and Simulation of Passive Thermal Management System for Lithium-Ion Battery Packs on an Unmanned Ground Vehicle

<p>The transient thermal response of a 15-cell, 48 volt, lithium-ion battery pack for an unmanned ground vehicle was simulated with ANSYS Fluent. Heat generation rates and specific heat capacity of a single cell were experimentally measured and used as input to the thermal model. A heat generation load was applied to each battery and natural convection film boundary conditions were applied to the exterior of the enclosure. The buoyancy-driven natural convection inside the enclosure was modeled along with the radiation heat transfer between internal components. The maximum temperature of the batteries reached 65.6 <strong>°</strong>C after 630 seconds of usage at a simulated peak power draw of 3,600 watts or roughly 85 amps. This exceeds the manufacturer's maximum recommended operating temperature of 60 <strong>°</strong>C. The pack was redesigned to incorporate a passive thermal management system consisting of a composite expanded graphite matrix infiltrated with a phase-changing paraffin wax. The redesigned battery pack was similarly modeled, showing a decrease in the maximum temperature to 50.3 <strong>°</strong>C after 630 seconds at the same power draw. The proposed passive thermal management system kept the batteries within their recommended operating temperature range.</p>

Name thesis:degree_name

MS in Mechanical Engineering

Discipline thesis:degree_discipline

Mechanical Engineering

Year dc:date.available

2012

Author dc:creator

• Parsons, Kevin Kenneth

Contributors dc:contributor

• Thomas J. Mackin

• thermal management
• heat transfer
• battery pack
• CFD
• phase change material
• unmanned ground vehicle
• Heat Transfer, Combustion

Identifier

10.15368/theses.2012.232

OAI identifier oai:identifier

oai:digitalcommons.calpoly.edu:theses-1961