Back to Search Start Over

Decoupling Analysis of Ignition Processes of Ammonia/N-Heptane Mixtures

Authors :
Zheng Li
Yilin Zhang
Jingrui Li
Changchun Xu
Huabing Wen
Jianhua Shen
Haiguo Jing
Haifeng Liu
Xinyan Wang
Hua Zhao
Source :
Energies, Vol 17, Iss 19, p 4938 (2024)
Publication Year :
2024
Publisher :
MDPI AG, 2024.

Abstract

To further understand the influence of n-heptane on the ignition process of ammonia, an isotope labeling method was applied in the current investigation to decouple the influence of the chemical effect, the thermal effect, and the effect of O radical from the oxidation of n-heptane on the ignition delay times (IDTs) of ammonia. An analysis of the time evolution of fuel, analysis of the time evolution of temperature, rate of consumption and production (ROP) analysis, and sensitivity analysis were conducted to gain a further understanding of the mechanism of the influence of the chemical effect, the thermal effect, and the effect of O radical on the ignition of ammonia. The results showed that the negative temperature coefficient (NTC) behavior of n-heptane is mitigated by the blending of ammonia, and this mitigated effect of ammonia is mainly due to the chemical effect. The IDTs of ammonia under low and medium temperatures are significantly shortened by the chemical effect at a n-heptane mass fraction of 10%. The promoting effect of the chemical effect decreases when the n-heptane mass fraction increases. The time evolution of n-heptane for NC7H16/ND3-G can be classified into three stages at 800 K, and the rapid consumption stage is mitigated by an increase in temperature. The rapid consumption stage is suppressed by the chemical effect of ammonia, while O radical has a promoting effect on the rapid consumption stage. The chemical effect will enhance the sensitivities of reactions associated with ammonia. As the n-heptane mass fraction increases, the sensitivities of reactions associated with n-heptane are enhanced. Correspondingly, the effect of reactions associated with ammonia is weakened. When the n-heptane mass fraction is 30%, only reactions related to n-heptane have a great influence on the ignition of ammonia/n-heptane fuel blends under the thermal effect + the effect of O radical or only the thermal effect.

Details

Language :
English
ISSN :
17194938 and 19961073
Volume :
17
Issue :
19
Database :
Directory of Open Access Journals
Journal :
Energies
Publication Type :
Academic Journal
Accession number :
edsdoj.682d6e65d93544ac8cb5a8ed828aee15
Document Type :
article
Full Text :
https://doi.org/10.3390/en17194938