Experimental and Kinetic Modeling Study of Autoignition Characteristics of n-Heptane/Ethanol by Constant Volume Bomb and Detail Reaction Mechanism

Abstract

The purpose of this work is to investigate the autoignition characteristics of n-heptane/ethanol including the autoignition temperature (AIT), ignition delay time (τig) and the low/intermediate/high-temperature ignition. The AIT is measured by the combustion bomb under wide range conditions (φ = 0.2–2.0, Pinit = 0.772–3.861 MPa) while the influencing factors of τig and the dominant reactions of the high/intermediate/low-temperature ignition are investigated by detail chemical kinetic model. The results indicate that first, the maximum AITs difference is 46, 56, 62, 84, and 124 °C when the ethanol blending ratio is 0%, 25%, 50%, 75%, and 100% while the minimum AITs usually locate at the region of φ = 1.0–2.0, Pinit = 3.282–3.861 MPa. Second, the AITs become more vulnerable to the pressure and equivalence ratio at 3.809–3.861 MPa and the maximum AIT difference increases from 6 to 44 °C as the ethanol blending ratio increasing from 0% to 100%. Third, the sensitive factors for τig rank as initial mixture temp...