Open AccessAutoignition of light naphtha and its surrogates in a rapid compression machine
Author(s) -
Wang Buyu
Publication year - 2019
Publication title -
energy science and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.638
H-Index - 29
ISSN - 2050-0505
DOI - 10.1002/ese3.270
Subject(s) - naphtha , gasoline , octane rating , autoignition temperature , compression ratio , ignition system , octane , materials science , volume (thermodynamics) , heptane , combustion , chemistry , thermodynamics , physics , organic chemistry , catalysis
Gasoline Compression Ignition ( GCI ) is a promising combustion mode to improve engine efficiency and reduce emissions. Naphtha has higher ignitability than gasoline and could be a better fuel for GCI . Understanding the autoignition behavior of naphtha is essential for the development of GCI engines. In this study, the ignition delay of light naphtha and its three surrogates, including PRF 59 (59% iso‐octane and 41% n‐heptane in volume) and two three‐component surrogates composed of methyl‐cyclohexane, n‐heptane, and iso‐octane with blending ratios of 33.8%/43.2%/23% ( MRF 1) and 31.4%/33.3%/35.3% ( MRF 2) in volume were studied using a rapid compression machine. PRF 59 was selected by matching the RON of light naphtha. MRF 1 was composited by matching the RON and MON of light naphtha, while MRF 2 was composed by matching RON and H/C. The experiments were conducted at equivalence ratio Φ = 0.5 and 1, P = 10, 20, and 30 bar, and temperature range of 665‐965 K. It was found that MRF 2 best matched the first‐stage and total ignition delays of light naphtha, while PRF 59 exhibited shorter first‐stage ignition delay. Although the ignition delay times of MRF 1 and MRF 2 were very close to each other, uncertainty analysis showed that matching RON and H/C ratio was a better method in determining the blending ratio. In addition, the MRF experiments were compared with predictions using the detailed mechanism. The mechanism showed good performance in reproducing the total ignition delay at high‐pressure conditions, but it underpredicted the ignition delay at low pressure. Also, the mechanism predicted less pronounced NTC behavior.