TY - JOUR
T1 - Effects of Hydrogen Blending Ratio and Equivalence Ratio on the Dynamic Characteristics of Deflagration Shock Waves of CH4/H2 Mixtures
AU - Liu, Qiqi
AU - Liu, Zhenyi
AU - Peng, Shiyao
AU - Liu, Chuang
AU - Liu, Changqi
AU - Liu, Luoqian
AU - Zhou, Rui
AU - Zhi, Shujie
AU - Fan, Tao
AU - Li, Pengliang
N1 - Publisher Copyright:
© 2024 The Authors. Published by American Chemical Society.
PY - 2024/6/4
Y1 - 2024/6/4
N2 - To evaluate the explosion hazard of CH4/H2 mixtures, experiments were conducted in a long and closed pipeline with a length-to-diameter ratio of 51 and built-in obstacles, and the characteristic parameters of deflagration shock waves were analyzed under different hydrogen blending ratios (0 ≤ λ ≤ 100%) and equivalence ratios (0.5 ≤ Φ ≤ 3). The results indicate that within the range of Φ = 0.8-1.2, the explosion overpressure (PP) exhibits a “two-zone” structure distribution. When 0 ≤ λ ≤ 80%, PP shows an initial increase and then a decrease in both regions, while deflagration to detonation transition (DDT) occurs in the second evolution region when λ = 100%, which is caused by the different strengths of the positive feedback mechanism coupled with flames and shock waves. The Pmax, (dP/dt)max, and Va show a trend of first increasing and then decreasing and monotonically increasing with the increase of the equivalence ratio and hydrogen blending ratio, respectively, and reach their maximum values at Φ = 1.0 and λ = 100%. For CH4/H2 mixtures with low hydrogen blending ratios (λ = 0 and 20%), the Pmax and (dP/dt)max in the fuel-lean conditions (Φ = 0.9 and 0.8) are higher than those in the fuel-rich conditions (Φ = 1.1 and 1.2), while the CH4/H2 mixtures under high hydrogen blending ratios (λ = 80 and 100%) are the opposite. Overall, the increase in H2 at a high hydrogen blending ratio and the increase in the equivalence ratio at a fuel-lean condition significantly enhance the average Va. In addition, chemical kinetics analysis found that R38 and R52 elementary reactions are the dominant elementary reactions that promote and inhibit temperature increase, respectively. Their temperature sensitivity coefficients are negatively correlated with the hydrogen blending ratio and positively correlated with the equivalence ratio. The research results provide vital information for evaluating the explosion hazards of CH4/H2 mixtures and developing safety protection measures.
AB - To evaluate the explosion hazard of CH4/H2 mixtures, experiments were conducted in a long and closed pipeline with a length-to-diameter ratio of 51 and built-in obstacles, and the characteristic parameters of deflagration shock waves were analyzed under different hydrogen blending ratios (0 ≤ λ ≤ 100%) and equivalence ratios (0.5 ≤ Φ ≤ 3). The results indicate that within the range of Φ = 0.8-1.2, the explosion overpressure (PP) exhibits a “two-zone” structure distribution. When 0 ≤ λ ≤ 80%, PP shows an initial increase and then a decrease in both regions, while deflagration to detonation transition (DDT) occurs in the second evolution region when λ = 100%, which is caused by the different strengths of the positive feedback mechanism coupled with flames and shock waves. The Pmax, (dP/dt)max, and Va show a trend of first increasing and then decreasing and monotonically increasing with the increase of the equivalence ratio and hydrogen blending ratio, respectively, and reach their maximum values at Φ = 1.0 and λ = 100%. For CH4/H2 mixtures with low hydrogen blending ratios (λ = 0 and 20%), the Pmax and (dP/dt)max in the fuel-lean conditions (Φ = 0.9 and 0.8) are higher than those in the fuel-rich conditions (Φ = 1.1 and 1.2), while the CH4/H2 mixtures under high hydrogen blending ratios (λ = 80 and 100%) are the opposite. Overall, the increase in H2 at a high hydrogen blending ratio and the increase in the equivalence ratio at a fuel-lean condition significantly enhance the average Va. In addition, chemical kinetics analysis found that R38 and R52 elementary reactions are the dominant elementary reactions that promote and inhibit temperature increase, respectively. Their temperature sensitivity coefficients are negatively correlated with the hydrogen blending ratio and positively correlated with the equivalence ratio. The research results provide vital information for evaluating the explosion hazards of CH4/H2 mixtures and developing safety protection measures.
UR - http://www.scopus.com/inward/record.url?scp=85194037442&partnerID=8YFLogxK
U2 - 10.1021/acsomega.4c01876
DO - 10.1021/acsomega.4c01876
M3 - Article
AN - SCOPUS:85194037442
SN - 2470-1343
VL - 9
SP - 23853
EP - 23863
JO - ACS Omega
JF - ACS Omega
IS - 22
ER -