1 International Conference on Hydrogen Safety ICHS 2011

1 International Conference on Hydrogen Safety ICHS 2011 September 12 -14, 2011 San Francisco, California-USA Validation of Computational Fluid Dynamics Models for Hydrogen Fast Filling Simulations IET - Institute for Energy and Transport Petten - The Netherlands http: //ie. jrc. europa. eu/ http: //www. jrc. europa. eu/ M. C. Galassi, E. Papanikolaou, M. Heitsch, D. Baraldi, B. Acosta Iborra, P. Moretto

OUTLINE San Francisco, September 12 -14, 2011 – 4 th ICHS • Introduction 2 Experiments Motivation Ø Fast Filling issues Ø Why CFD Ø • Gas. Te. F Experiments • CFD Simulations Model Ø Results Ø • Conclusions Modeling

INTRODUCTION San Francisco, September 12 -14, 2011 – 4 th ICHS 3 • Competitive with current technologies ØThree main targets: q short refueling time 3 min q long driving range 35 -70 MPa q high safety and reliability Lim 85 it of °C High temperature can be reached in the tank during refueling. Limit of 85 degrees in ISO/TS 15869, 2009

INTRODUCTION San Francisco, September 12 -14, 2011 – 4 th ICHS WHY CFD? • CFD can provide 3 D detailed and complete flowfield information over a wide range of flow configurations Ø Relevant information for hazards and risk assessment of hydrogen technologies (e. g. P and T loads) Ø Valuable contribution to design, optimization, innovative solutions High level of reliability and accuracy of the numerical models is required in order to apply CFD to real-scale problems VALIDATION OF NUMERICAL MODELS/CODES 4

Gas. Te. F EXPERIMENTS San Francisco, September 12 -14, 2011 – 4 th ICHS • Gas tanks Testing Facility Ø Ø EU reference laboratory on safety and performance assessment of high-pressure hydrogen (and natural gas) storage tanks Fast filling, cyclic and permeation testing DATA ACQUISITION SYSTEM 5

Fast filling of type 4 tanks San Francisco, September 12 -14, 2011 – 4 th ICHS Ø Ø 6 Experiments H 2 Pin [MPa] H 2 Pfin [MPa] tfilling [s] Tsleev TCs e H 2 Tini [°C] q H 2 Test 10122010 0. 02 71. 7 330 16 21 Pos 2 Test H 2 25022011 0. 02 71. 8 245 18 21 Pos 1, 2 [°C] Vol=29 l Code Validation (ANSYS CFX 12. 1) Φ 0. 28 m q q Assess code accuracy of high pressure hydrogen tank fast filling Evaluate internal and external temperature distribution 0. 83 m

CFD SIMULATIONS San Francisco, September 12 -14, 2011 – 4 th ICHS 7 • Computational model Ø Fluid Domain q Hydrogen Ø Solid Domains q Liner Pos 2 (High Density Poly Amide Epoxy) q Insulation (Composite CF) q Bosses (steel) Pos 1 Ø~ 560 k nodes, 900 k cells Ø Probes at Thermo Couples position

CFD SIMULATIONS San Francisco, September 12 -14, 2011 – 4 th ICHS 8 Test H 2 25022010 Test H 2 10122010 • Boundary and Initial Conditions (BIC) Ø Fluid Domain q BCs at inlet: T, p q BCs at walls: Conjugate Heat Transfer, no slip q ICs: Still at T 0 Ø Solid Domains q BC: Conjugate Heat Transfer, Heat Transfer Coefficient (with amb. air) q ICs: Tamb

CFD SIMULATIONS San Francisco, September 12 -14, 2011 – 4 th ICHS 9 • Results 100 s 330 s 200 s 330 s Temperature distribution

CFD SIMULATIONS San Francisco, September 12 -14, 2011 – 4 th ICHS Test H 2 10122010 • Results 10 Pos 2: TC 1, 2, 3, 4, 5

CFD SIMULATIONS San Francisco, September 12 -14, 2011 – 4 th ICHS Test H 2 10122010 • Results Pos 2: TCext 1, TCext 2, TCext 3 11

CFD SIMULATIONS San Francisco, September 12 -14, 2011 – 4 th ICHS 12 Test H 2 25022010 • Results Pos 1: T 2, T 4 Pos 2: T 2, T 4

CFD SIMULATIONS San Francisco, September 12 -14, 2011 – 4 th ICHS • Results: Maximum temperatures at 13 Test H 2 25022010 the end of the filling procedure Pos 1 Test H 2 10122010 Pos 1

CONCLUSIONS (1/2) San Francisco, September 12 -14, 2011 – 4 th ICHS 14 • CFD validation against experimental data for hydrogen fast filling prediction up to 72 MPa Ø Two different tests: similar working conditions but different filling time • The developed model proved to accurately predict internal maximum temperature for both tests (maximum error<7%), • Prediction of external maximum temperature was less accurate (maximum error~15%) and strongly dependent on material properties.

CONCLUSIONS (2/2) San Francisco, September 12 -14, 2011 – 4 th ICHS 15 • Further investigation is required on Ø Material properties Ø Heat exchange between fluid, tank walls and environment Ø Different turbulence models • A fully validated CFD model will Ø Allow reliable predictions of fast filling scenarios Ø Constitute a valuable complementary tool to experimental campaigns supporting q Design and optimization process q Development of innovative solutions

San Francisco, September 12 -14, 2011 – 4 th ICHS 16 THANK YOU FOR YOUR ATTENTION ! Maria-Cristina. GALASSI@ec. europa. eu daniele. baraldi@jrc. nl http: //ie. jrc. europa. eu/ http: //www. jrc. europa. eu/