Hydrogen Storage for Automotive Hydrogen Storage for Automotive Tanks Using Hydrostatic Tanks Using Hydrostatic Pressure Pressure Retainment Retainment (HPR) (HPR) Microstructure Microstructure Bhavin Mehta, Greg Banyay, Housila Tiwari Ohio University David Hill, Saurin Mehta Inergy Automotive Mark Biernacki, Steve Barnhart DaimlerChrysler
33
Embed
Hydrogen Storage for Automotive Tanks Using Hydrostatic ...
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Hydrogen Storage for Automotive Hydrogen Storage for Automotive Tanks Using Hydrostatic Tanks Using Hydrostatic Pressure Pressure RetainmentRetainment (HPR) (HPR) MicrostructureMicrostructureBhavin Mehta, Greg Banyay, Housila TiwariOhio University
David Hill, Saurin MehtaInergy Automotive
Mark Biernacki, Steve BarnhartDaimlerChrysler
Ohio University - Mechanical Engineering 2
Hydrogen StorageHydrogen Storage
y
x
1. Pressurized Gas Cylinderstraditional, but potential dangerous and requires expensive materials
2. Liquefied Cryogenic Storagebetter volumetric energy density, but difficult to insulate and high cost of liquefaction
3. Hydrides (Metal / Chemical)potentially safe, inexpensive, but very heavy and/or unstable
4. Innovative Techniques (ie: nanotechnology, HPR…)promising techniques that require more research/validation
Current Methods
Nonetheless, the problem is still not solved…
Ohio University - Mechanical Engineering 3
y
x
Ideal FoamIdeal Foam
This is a novel concept for gas storage. Gas is stored in small bubbles of a foam matrix, thereby forming a series of small spherical pressure vessels. The resulting stress in the material between the bubbles is in a hydrostatic state of tri-axial tension.
Structural Efficiency ={(100 + 100 + 100)/3=100%}
HPR Description
Ohio University - Mechanical Engineering 4
y
x
Ideal FoamIdeal FoamHPR Description
Advantages:1) Conformability
Automotive Frames are designed before gas tanks, so the tank must be designed around the frame – not vice-versa
2) SafetyIn the case of an accident, only the gas contained in the adjacent cells tothe fracture location would dispel at once
3) Weight SavingsIn theory, because the matrix material is in a state of hydrostatic tension,the material is being utilized 100% in all 3 cartesian directions – thus requiring less material
Ohio University - Mechanical Engineering 5
y
x
Ideal FoamIdeal Foam
SC Unit Cube52% packing efficiency
BCC Unit Cube68% packing efficiency
FCC Unit Cube74% packing efficiency
Expanded BCC Lattice
optimized cell size is @ 95% of the touching radius
While ideal HPR pressure vessels have been proven a feasible concept, the material behavior of actual cellular materials must be examined.
This research has the objective of both developing an efficient methodology for examination of actual cellular polymers and applying these methods to actual foam.
Ohio University - Mechanical Engineering 7
Work Scope and ApproachWork Scope and Approach
1. Data Acquisition: foam samples, SEM, micro-CT
2. Image Construction: image filtration/segmentation in Amira
3. Mesh Construction: triangular surface generated, cleaned, and constructed into tetrahedral solid mesh
4. FE Model Validation: simulated compression test and comparison of foamyield strength to bulk material yield strength
5. FEA HPR Analysis and Results:using Altair Hypermesh/Optistruct
6. Results Interpretation: MS Excel spreadsheet/Matlab programs developed tofind meaningful tank parameters
Ohio University - Mechanical Engineering 8
y
x
TheoryTheory
1−=foam
p
p
void
VV
ρρ
FCC βcos4.. ⋅⋅= trLE
θβ coscos4.. ⋅⋅⋅= trLE
trLE ⋅= 2.. 223 23_ −⋅+⋅−= nnnN SCbubbles
2232 23_ −⋅+⋅−⋅= nnnN BCCbubbles
1364 23_ −⋅+⋅−⋅= nnnN FCCbubbles
SC
BCC
Governing Equations of HPR Spreadsheet
for ideal models…
for actual models… for all models…
( ) [ ] 22
1VABV
VTRp −+⎥⎦
⎤⎢⎣⎡ −⋅⋅
=ε
to determine various tank parameters given criteria such as pressure, material,temperature, and cell arrangement, certain equations were developed…
5 Gal Tank Provided by Inergy5 Gal Tank Provided by Inergy
Ohio University - Mechanical Engineering 29
Simulation results for 5 Gal Tank with DIAB H130Simulation results for 5 Gal Tank with DIAB H130
This tank was simulated to withstand highest pressure before yielding.
Results obtained are as follows:
Maximum Pressure without yielding = 1148 psi for YS= 3650 psiMass of H2 in tank = 0.04904278 kgMassH2 / mass STRUCTURE = 3.01%
For Storing 5 kg of Hydrogen the tank size needs to be 1.86 m3 which is almost 3.95 (~4) times the size of actual tank.
So the actual tank using DIAB H130 would be of the following dimensions:
2710 mm x 1500 mm x 670 mm
Ohio University - Mechanical Engineering 30
Summary SheetSummary Sheet
Material Steel Aluminum PolycarbonatePolyurethane(Composite)
DIAB H130(Foam)
Radius 41.1 41.1 41.1 41.1 41.1
Max Von Misses Stress 2100 2130 2100 2100 2350
Max Pressure( psi) 9524 13451 2310 10452 778
Tank size (m^3) 0.34 0.28 0.93 0.32 2.2
Tank size (gallons) 77 63 211 73 500
Tank dimensions (mm) 1200 x 840 x 370 1150 x 800 x 350 1650 x 1140 x 510 1200 x 840 x 370 2710 x 1500 x 670
Weight (Kg) 1415 405 586 271 70
mH2/mStructure 0.35% 1.23% 0.85% 1.85% 7.07%
Ohio University - Mechanical Engineering 31
y
x
ConclusionsConclusions
• The ideal models illustrate that HPR is a feasible solution to the hydrogen storage problem for the following 3 reasons:1. Conformability2. Weight Savings3. Minimized Safety Risk
• Neither H130 nor DF-630A meet the goals set by the DOE FreedomCAR project
• An efficient method for examination of polymeric foam for HPR application has been developed
• Composite foam structures can be pursued, which could greatly increase tank performance
• Back to metals (Metal foams, hollow spheres etc)
Ohio University - Mechanical Engineering 32
y
x
Recommendations for Future WorkRecommendations for Future Work
If it is verified that a non-composite foam is not suitable…Pursue Composite Foam
attain samples and examine using the methods developedin this thesis
Develop relationships between foam yield strength/modulus andHPR behavior
Expand the scope of the work past static structural analysis, toconsider thermal loads, potential chemical reactions, permeability andsorption rates, tank refuel-ability, quantifiable co$t, etc.
If/When a practical foam is found, perform experimental tests of an actualhydrogen-pressurized tank