Battery Enclosure Presentation

1
Battery Enclosure Presentation

• Members
• Brian Alano
• Jae Shin
• Korkut Ozuyener
• Christopher Shelton
• Matt Zwiesler

2
Outline

• Introduction
• Planning
• Design Specification
• Competitive Benchmark
• Concept Design
• Product Evaluation
• Impact Statement
• Conclusion
• Recommendation

3
Introduction

• 462 Capstone design
• Design of battery enclosure for Toyota Prius
• Used with existing Hybrid technology to further
  improve car performance
• Plug-in technology used to double overall vehicle
  performance

4
Planning

• Schedule in Microsoft Excel
• Calendar in Yahoo! batterybox group
• Weekly team meetings
• Weekly and daily status reports

5
Planning
6
Design Specification

• Maintenance cost (/year)
• Total cost of prototype
• Trunk space after installation (sq. in)
• Number of battery modules that fit ()
• Max internal temp at max power draw (deg. C)
• Explosive force experienced without fragmenting
  (kg TNT)

7
Competitive Benchmark

• Hymotion
• Pros
• Compact
• Appearance
• Cons
• No analysis
• Stress Thermal
• No spare tire solution
• No fans

8
Competitive Benchmark

• Jerrys Box
• Pros
• Cheap
• Compact
• Cons
• Weak Material
• No Analysis
• Stress Thermal
• Dangerous
• No fan

9
Concept Evaluation

• Latch
• High Strength Material
• SS Rugged Alloy Steel
• High Holding Capacity
• 7500 lbs
• Easy to use
• Simple design
• Adjustable
• Constraints
• Interference check with trunk interior

10
Latch Design
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Product Evaluation Hand Calculations

• Potential energy contained by batteries equal to
  25.2 MJ
• Laws of thermodynamics- pressure that results
  from complete release of energy equal to 21.58
  ksi
• 9.6 thick Al-7075T6 necessary
• BlastWrap data indicates it can absorb 4.9 MJ
• Leaves energy that could result in pressure of
  17.38 ksi
• 8.4 thick Al-7075T6 necessary
• This is worst case scenario, and disregards any
  ventilation also

12
Product Evaluation Hand Calculations

• Rectangular pressure vessel calculations from
  ASME Boiler and Pressure Codes
• 1/4 thick Al-7075T6 can handle 22.17 psi.
• This equals about 25.82 kJ.
• Added to energy absorbed by BlastWrap results in
  total energy designed enclosure can handle
  4.9258 MJ

13
Aluminum Grade Analysis
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Product Evaluation Pro-E Mechanica

• Hand calculated allowable pressure used
• Bottom of enclosure used as it would experience
  largest moments
• Symmetry- Forces applied to two sides
• Static Pressure Analysis
• Von Mises Failure Criteria
• Max stress60.33 ksi

15
Product Evaluation

• Ansys Stress Analysis
• Solid Brick 8 Node 45
• Aluminum 7075T6
• 1/10th Scale Model
• Boundary Condition
• Symmetry Geometry
• Applied Pressure 22.176 Psi

• Ansys Model

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Ansys Analysis

• Free Meshing

• Deformation

17
Ansys Analysis

• VonMises Stress
• c

• Maximum Stress

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Ansys Analysis

• Conclusion
• Maximum stress 21226 psi
• Max ultimate strength of material gt 75000 psi
• The selected battery enclosure can withstand the
  calculated explosion force 22.176 psi

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Fluent model boundary conditions
20
CFD Analysis

• Fluent mesh

21
CFD Analysis

• 20C discharge rate

22
CFD Analysis

• Velocity Streamlines

23
CFD Analysis

• 20C discharge rate

24
Cost Analysis

• Al-2014T6 much rarer than expected
• Al-7075T6 is the strongest, then 2014T6, and then
  2024T3.
• even with a higher ultimate strength, the price
  of 7075T6 cheaper than that of 2024T3
• Aluminum 7075T6 chosen

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(No Transcript)
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Final Design
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Final Design
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Impact Statement

• Enclosing the battery pack safely, securely, and
  conveniently
• Protection from accidental battery explosion
• Reduces customers budget
• Safety concerns of Toyota Plug-in Hybrid
  customers
• Safety concerns of Toyota manufacture

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Conclusion

• Satisfied the majority of our sponsors
  requirements
• Fit in the trunk space and hold two battery
  modules inside safely and securely
• Analysis
• Hand calculations, Pro-Engineer analysis, Ansys
  analysis, and CFD analysis gave the team more
  confidence
• Satisfied the cost requirement
• will help the future product to be completed
  satisfactorily.

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Recommendations

• BlastWrap is such a new material, even they do
  not have many solid data points on their material
• Design and conduct small scale tests, utilizing
  the BlastWrap during explosions
• Compare results to other scaled explosion tests
  that do not utilize the BlastWrap.
• Possibility to prove its efficiency and more
• Different material could be chosen for the
  outside of the enclosure.
• Cheaper, lighter weight
• If tests show BlastWrap not
• as efficient
• Choose stronger, heavier,
• more expensive material
• Ensure customers safety.

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Recommendations

• Explosion analysis with software
• Live demo
• Dynamic analysis
• Ansys Analysis Limitation
• Explosion force simulation
• Computer limitation
• Redesign of ventilation system
• Eliminate hot spots

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References

• Presentation on HPEV battery technology
  http//enerdel.com/pdfs/EnerDelTechnicalPresentat
  ion.pdf
• Lithium Ion Battery http//electronics.howstuffwo
  rks.com/lithium-ion-battery1.htm
• Jerry's Battery Box Jerry's battery box, used
  for competitive benchmarking http//jerryrig.com/
  convert/step10.html
• Hymotion http//www.hymotion.com/
• Hymotion Installed good view of installation
  http//www.hybridfest.com/images/26.jpg
• About explosions by Aristatek equation for peak
  overpressure http//www.aristatek.com/explosions.
  aspx

• Blast Wrap http//www.blastgardintl.com/pdfs/BLGA
  _AP_12805.pdf
• Blast Wrap specs http//www.blastgardintl.com/bp_
  blastwrap.asp
• Calculating overpressures from BLEVE (Boiling
  Liquid Expanding Vapor Explosion
  http//dx.doi.org/10.1016/j.jlp.2004.08.002
• Vapor Cloud Explosion Estimates
  http//www.questconsult.com/99-spring.pdf
• Vapor Cloud Explosion Estimates
  http//www.questconsult.com/99-spring.pdf

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Special Thanks

• Dr. Hazim El-Mounayri
• Through out the whole project
• Dr. Sohel Anwar
• Project Sponsor
• Jack Waddell
• Information of new product Blast Wrap
• Dr. Erdal Yilmaz
• CFD Analysis
• TA. Rapeepan Promyoo
• Ansys Modeling

34
Questions