1. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 1 Role of Chemical Kinetics on the Detonation Properties of Hydrogen / Natural Gas / Air Mixtures N. Chaumeix, S. Pichon, F. Lafosse, N. Udari, C.-E. Paillard Laboratoire de Combustion et Systèmes Réactifs

2. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 2 MOTIVATIONS GREEN HOUSE EFFECT REDUCTION  Combustion is a major contributor, CO, CO 2, NOx, Soot …  Biofuels  Natural gas  Hydrogen NATURAL GAS  Relatively low emission, CO 2, PAH and soot  High octane number HYDROGEN AS AN ADDITIVE TO NATURAL GAS  Increase of the flammability domain,  Increase of the stability range

3. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 3 MOTIVATIONS HYDROGEN AS AN ADDITIVE TO NATURAL GAS  Production and Storage  Economically interesting  Adaptation for multiple use  Increase the risk of explosion and detonation

4. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 4 AIMS OF THE STUDY Oxidation of Hydrogen / Methane based Mixtures  For conditions close to detonation  Auto-ignition delay times  Validation and selection of a detailed kinetic mechanim Determination of the detonation parameters  Chapman-Jouguet and ZND conditions  Experimental measurements of cell size

5. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 5 {H 2 /CH 4 /O 2 } mixture : CH 4 /CH 4 +H 2 = 0.4,  =0.75; P1 = 10 kPa; T1 = 20°C Velocity : D C.J = 1800 m.s -1 (D exp = 2218  14 m.s -1 ) Von Neumann parameters:  T 2N = 1380 K  P 2N =250 kPa Triple points Leading shock Reaction zone  : induction distance  : ignition delay time behind the leading shock behind the leading shock Evaluation of  For these conditions CORRELATION BETWEEN AND 

6. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 6 EXPERIMENTAL SETUP Auto-ignition Delay Times I.E.E.E PUMPS Pressure Gage 0 - 100 T Air Mixture He Driven Section Diaphragm High Pressure Knife N2N2 C4 C3 C2 C 1 4321 12

7. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 7 EXPERIMENTAL SETUP Auto-ignition Delay Times

8. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 8 EXPERMENTAL SETUP Detonation Parameter Measurements

9. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 9 EXPERIMENTAL CONDITIONS Auto-ignition Delay times  Mixtures: CH 4 /H 2 /O 2 in 99% of Argon  CH 4 /CH 4 +H 2 = 0 ;0,4; 0,8   =0,4; 0,75; 1  1000 K  T 5  1500 K  0,15  P 5  0,25 MPa Detonation Parameters  Mixtures: CH 4 /H 2 /O 2  CH 4 /CH 4 +H 2 = 0 ; 0,2 ; 0,4 ; 0,6   =0,75 ; 1  P 1 = 10 et 20 kPa

10. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 10 AUTO-IGNITION DELAY TIMES Strong decrease with  Temperature  Equivalence ratio

11. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 11 AUTO-IGNITION DELAY TIMES Strong decrease with  Temperature  Equivalence ratio

12. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 12 AUTO-IGNITION DELAY TIMES Strong increase with  Methane content

13. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 13 AUTO-IGNITION DELAY TIMES Strong increase with Pressure

14. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 14 CORRELATIONS From the experimental data From the experimental data Average error < 14 %

15. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 15 DETAILED KINETIC MECHANISM VALIDATION REFERENCESPECIESREACTIONS Gas Research Institute 53325 Lawrence Livermore National Laboratory 155689 LEEDS37175 KONNOV1271027

16. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 16 MODEL vs EXPERIMENTS Konnov’s Mechanism Konnov’s Mechanism is most suitable is most suitable

17. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 17 MODEL vs EXPERIMENTS Konnov’s Mechanism is most suitable Konnov’s Mechanism is most suitable

18. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 18 MODEL vs EXPERIMENTS depends on the equivalence ratio depends on the equivalence ratio

19. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 19 MODEL vs EXPERIMENTS Different mechanisms from the literature were used Different mechanisms from the literature were used The comparison between the experiments and the prediction depends on the amount of H 2 in the mixture The most reliable is KONNOV’s mechanism which will be used Needs to be improved

20. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 20 DETONATION PARAMETERS Chapman- Jouguet (T CJ, P CJ, V CJ ) Parameters ZND (T ZND, P ZND ) Parameters Auto-ignition Delay Times of CH 4 /H 2 /air Mixtures Package CHEMKIN  EQUIL & SENKIN codes

21. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 21 RESULTS

22. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 22 CONDITIONS ZND

23. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 23 AUTO-IGNITION DELAY TIME BEHIND THE LEADING SHOCK

24. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 24 DETONATION CELL SIZE Sensitivity to detonation   with equivalence ratio   with methane content

25. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 25 CONCLUSION A new experimental database  Auto-ignition delay times  Correlations valide for detonation conditions  Detonation cell size Validation of a detailed chemical kinetic mechanism  Konnov’s Mechanism the most reliable  Needs to be improved

26. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 26 AKNOWLEDGEMENT This work was financially supported by Commissariat à l’Energie Atomique (CEA) under the contract number CNRS / CEA N°SAV 32030.

27. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 27

28. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 28 COMPARISON WITH CHENG & OPPENHEIM

29. ICHS, International Conference on Hydrogen Safety, September 8-10, 2005, Pisa (Italy) 29 Détonation : Couplage entre une onde de choc ( | ) et une zone réactionnelle (  ) INTRODUCTION Déflagration : Inflammation qui se propage par diffusion de chaleur et de radicaux Zone réactionnelle (gaz brûlés) (gaz frais) Délai (gaz frais) (gaz brûlés) P et T élevées