Effects of High-Concentration CO2 on Ignition Delay Time of 70% n-Heptane/30% Toluene Mixtures. (29th April 2022)

• Record Type: Journal Article
• Authors: Yao, Shengzhuo; Zhang, Yuewei; Liu, Yongfeng; Bi, Guijun; Zhang, Lu; Wei, Ping; Song, Jinou; Sun, Hua
• Other Names: Shao Haidong Academic Editor.
• Is Part Of: Journal of sensors. Volume 2022(2022)
• Publication Date: 2022-04-29
• Subjects: Detectors -- Periodicals; 681.205
• DOI: 10.1155/2022/4334317
• Languages: English
• ISSNs: 1687-725X

Abstract

Abstract : In order to research the high-concentration CO2 effects on ignition delay time (IDT) of diesel surrogate fuel (70% n-heptane/30% toluene), a carbon dioxide effect (CDE) model is established, which considers fuel and ambient gas concentration, density, and temperature influence on autoignition under CO2 /O2 atmosphere. Firstly, a chemical model of n-heptane/toluene is established, and the coupling, reduction, and simulation processes are carried out in chemical kinetic software with the IDT as the target parameter. Secondly, a constant volume combustion chamber (CVCC) visualization platform is built by incorporating a high-speed camera system and different working conditions are set in the CO2 volume fraction range (40%-70%) at 3.0 MPa and 850 K for an autoignition experiment. Thirdly, experiment and simulation results are discussed in air, 60% CO2 /40% O2, 50% CO2 /50% O2, and 40% CO2 /60% O2 atmospheres, including the IDT, CO2 effects, temperature sensitivity, and OH radical rate of production (ROP). The results show that the CDE model well predicts the 70% n-heptane/30% toluene IDT under the CO2 /O2 atmosphere and the average error in 60% CO2 /40% O2 atmosphere is 5.29%. Besides, when the CO2 volume fraction increases from 40% to 60%, the CO2 thermal effect plays a leading role in the IDT prolongation and the OH radical ROP peak of R4 (O+H2 O⟶2OH) decreases by 180%.