Battery Enclosure Presentation

1. Battery Enclosure Presentation Members Brian Alano Jae Shin KorkutOzuyener 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 • Jerry’s 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

11. 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

14. 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 stress=60.33 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

16. Ansys Analysis • Free Meshing • Deformation

17. Ansys Analysis • VonMises Stress • c • Maximum Stress

18. Ansys Analysis • Conclusion • Maximum stress: 21226 psi • Max ultimate strength of material: > 75000 psi • The selected battery enclosure can withstand the calculated explosion force: 22.176 psi

19. 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

26. Final Design

27. Final Design

28. Impact Statement • Enclosing the battery pack safely, securely, and conveniently • Protection from accidental battery explosion • Reduces customer’s budget • Safety concerns of Toyota Plug-in Hybrid customers • Safety concerns of Toyota manufacture

29. Conclusion • Satisfied the majority of our sponsor’s 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.

30. 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 customer’s safety.

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

32. References • Presentation on HPEV battery technology http://enerdel.com/pdfs/EnerDelTechnicalPresentation.pdf • Lithium Ion Battery http://electronics.howstuffworks.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 Aristatekequation 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

33. 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. ErdalYilmaz • CFD Analysis • TA. RapeepanPromyoo • Ansys Modeling

34. Questions