Hydrogen/PRF skeletal mechanism study based on shock tube experiments and kinetic analysis. (1st February 2023)

• Record Type: Journal Article
• Authors: Qu, Wenjing; Fang, Yuan; Wang, Zixin; Song, Meijia; Wang, Qiukai; Tang, Bin; Feng, Liyan
• Is Part Of: Fuel. Volume 333(2023)Part 1
• Publication Date: 2023-02-01
• Subjects: Hydrogen -- N-heptane -- PRF -- Shock tube -- Skeletal mechanism -- Autoignition; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2022.126342
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: Ignition properties of H2 /n-C7 H16 mixture was revealed by shock tube and mechanism. H2 /n-C7 H16 mixtures with more hydrogen and lower equivalence ratio have shorter IDT. More active n-C7 H16 consumes before H2 and triggers later radicals' reactions. A skeletal hydrogen/PRF mechanism was proposed based on a skeletal PRF mechanism. Abstract: In the present work, the experiments of measuring ignition delay times (IDTs) of the hydrogen/ n -heptane mixture at high temperature (1130–1485 K) and low pressure (1.25 atm) by a shock tube is implemented. The results show that mixtures with higher hydrogen proportion and lower equivalence ratio present shorter IDT. In the case of high hydrogen proportion, the n -heptane addition causes an obvious inhibition effect on the ignition of the mixture. Whereas, as the hydrogen proportion decreases, such inhibition effect weakens. As the experimental values are consistent with the predicted IDTs by NUI (National University of Ireland) mechanism, the NUI mechanism was selected to conduct the kinetic study. The consumption of n -heptane at the initial stage of reaction is earlier than that of hydrogen because the activities of n -heptane's H-abstraction and decomposition reactions are relatively high. With shock tube experimental data as the calibration basis, a skeletal hydrogen/PRF (Primary Reference Fuel) mechanism, was updated from a skeletal PRF mechanism. The skeletal hydrogen/PRF mechanism, consisting of 49 species and 162 reactions had been validated against shock tube experiment of hydrogen, n -heptane, isooctane pure fuel, PRF, and hydrogen/ n -heptane mixture.