Theoretical study on the low-temperature reaction of β-hydroxyethyl radical and its optimization and validation for combustion models

Ethanol has attracted extensive attention in the field of energy and combustion engineering due to its environmental friendliness and sustainability. The accurate description of its low-temperature reaction characteristics is crucial for optimizing combustion models and improving the performance prediction of ethanol-gasoline blended fuels. This study focuses on the theoretical research of ethanol low-temperature reactions, including the calculation of low-temperature reaction rate constants of β-hydroxyethyl radical. The newly calculated reaction network and rate constants of β-hydroxyethyl radical, together with those of α-hydroxyethyl radical obtained from our previous research (Xi S et al. 2020), are incorporated into the gasoline mechanism developed by Li Yang et al. (2019). Subsequently, validation tests are carried out for the ignition delay time and laminar flame speed of gasoline/ethanol blended fuels. The results show that the modified mechanism exhibits superior simulation performance compared with the original mechanism. Furthermore, a compact ethanol combustion mechanism is constructed based on the reaction pathways and rate constants calculated in this study. The proposed compact mechanism is validated against other ethanol mechanisms for fundamental combustion characteristics, with favorable overall performance. This research provides valuable theoretical support for the refinement of combustion models and the efficient utilization of ethanol.