Jin Yifan, Ma Zhihao, Wang Xin, Liu Fangjie, Li Xin, Chu Xianglin
School of Vehicle and Traffic Engineering, Henan University of Science and Technology, Luoyang, Henan 471003, People's Republic of China.
ACS Omega. 2023 Feb 22;8(9):8377-8387. doi: 10.1021/acsomega.2c07167. eCollection 2023 Mar 7.
The contribution of NO to the ethanol ignition delay time was investigated behind reflected shock waves. The experiments were performed at a pressure of 0.20 MPa, temperature range of 1050-1650 K, equivalence ratio of 0.5/1.0/1.5, and ethanol/NO mixing ratios of 100/0, 90/10, and 50/50. The experimental results showed that the addition of NO decreased the ignition delay time and promoted the reactivity of ethanol under all equivalence ratios. With an increase in NO blending, the effect of equivalence ratio on the ethanol ignition delay time decreased, and with an increase in temperature, the effect of NO in promoting ethanol ignition weakened. An updated mechanism was proposed to quantify NO-promoted ethanol ignition. The mechanism was validated based on available experimental data, and the results were in line with the experimental trends under all conditions. Chemical kinetic analyses were performed to interpret the interactions between NO and ethanol for fuel ignition. The numerical analysis indicated that the promotion effect of NO is primarily due to an increase of the rate of production and concentration of the radical pool, especially the OH radical pool. The reaction NO + HO ⇔ NO + OH is key to generating chain-initiating OH radicals.
在反射激波后，研究了一氧化氮（NO）对乙醇着火延迟时间的影响。实验在0.20 MPa的压力、1050 - 1650 K的温度范围、0.5/1.0/1.5的当量比以及乙醇/NO混合比为100/0、90/10和50/50的条件下进行。实验结果表明，在所有当量比下，添加NO均会缩短着火延迟时间并提高乙醇的反应活性。随着NO掺混量的增加，当量比对乙醇着火延迟时间的影响减小；随着温度升高，NO促进乙醇着火的作用减弱。提出了一种更新的机理来量化NO促进的乙醇着火。该机理基于现有实验数据进行了验证，结果与所有条件下的实验趋势一致。进行了化学动力学分析以解释NO与乙醇在燃料着火过程中的相互作用。数值分析表明，NO的促进作用主要归因于自由基池（尤其是OH自由基池）的生成速率和浓度的增加。反应NO + HO ⇔ NO + OH是生成引发链反应的OH自由基的关键。
