Laminar burning velocities and lean flammability limits of H2/CO/CH4/CO2/air mixtures associated with gases vented out Li-ion batteries after thermal runaway

Uloženo v:
Podrobná bibliografie
Název: Laminar burning velocities and lean flammability limits of H2/CO/CH4/CO2/air mixtures associated with gases vented out Li-ion batteries after thermal runaway
Autoři: Lipatnikov, Andrei, 1961
Zdroj: Modellering av vätediffusionsförbränning Results in Engineering. 28
Témata: Flammable jets, Lean flammability limit, Li-ion battery, Numerical simulations, Laminar flame speed, Fire risk
Popis: To explore major combustion characteristics of mixtures relevant to gases vented out Li-ion batteries, complex-chemistry simulations of laminar flames are performed for a wide range of H2/CO/CO2/CH4/air mixtures by varying equivalence ratio and mole fractions of these species. The simulations are done for different temperatures of unburned reactants, using three state-of-the-art chemical mechanisms and multicomponent diffusion model with Soret effect. The focus of the study is placed on the influence of concentrations of CO, CO2, and CH4 on the computed laminar flame speeds S L and a surrogate of lean flammability limit, i.e., equivalence ratio ϕ ∗  associated with a small speed S L (ϕ ∗ ) = 5 cm/s. Results show that, first, both S L (ϕ) in lean mixtures and ϕ ∗  depend weakly on mole fraction of CO in H2/CO blends. Second, an increase in ϕ ∗ and a decrease in S L (ϕ) in lean mixtures are more (less) pronounced when adding CH4 (CO2, respectively) to H2/CO blends. Accordingly, under certain conditions, fuel can reduce S L (ϕ) more than diluent. These observations are attributed to a larger (smaller) increase in the mole fraction of inert species when adding CH4 (CO2, respectively) to H2/CO blends but retaining the same (low) equivalence ratio. Finally, results show that a large volume fraction of CO2 in gases vented out a battery does not exclude fire risks.
Popis souboru: electronic
Přístupová URL adresa: https://research.chalmers.se/publication/549420
https://research.chalmers.se/publication/549420/file/549420_Fulltext.pdf
Databáze: SwePub
Popis
Abstrakt:To explore major combustion characteristics of mixtures relevant to gases vented out Li-ion batteries, complex-chemistry simulations of laminar flames are performed for a wide range of H2/CO/CO2/CH4/air mixtures by varying equivalence ratio and mole fractions of these species. The simulations are done for different temperatures of unburned reactants, using three state-of-the-art chemical mechanisms and multicomponent diffusion model with Soret effect. The focus of the study is placed on the influence of concentrations of CO, CO2, and CH4 on the computed laminar flame speeds S L and a surrogate of lean flammability limit, i.e., equivalence ratio ϕ ∗  associated with a small speed S L (ϕ ∗ ) = 5 cm/s. Results show that, first, both S L (ϕ) in lean mixtures and ϕ ∗  depend weakly on mole fraction of CO in H2/CO blends. Second, an increase in ϕ ∗ and a decrease in S L (ϕ) in lean mixtures are more (less) pronounced when adding CH4 (CO2, respectively) to H2/CO blends. Accordingly, under certain conditions, fuel can reduce S L (ϕ) more than diluent. These observations are attributed to a larger (smaller) increase in the mole fraction of inert species when adding CH4 (CO2, respectively) to H2/CO blends but retaining the same (low) equivalence ratio. Finally, results show that a large volume fraction of CO2 in gases vented out a battery does not exclude fire risks.
ISSN:25901230
DOI:10.1016/j.rineng.2025.108274