活性自由基对煤油裂解气点火延迟时间的影响分析

Analysis for Effects of Active Radical on Cracked Kerosene Ignition Delay

为研究活性自由基对煤油裂解气点火延迟时间的影响,使用CHEMKIN软件,研究了激波管实验系统中不同温度下煤油裂解气的点火延迟时间,对比文献实验结果,验证了计算模型的可靠性。研究了在初始组分中加入不同浓度的活性自由基对于煤油裂解气点火延迟的影响,分析了反应式对于温度以及活性自由基的敏感性。研究结果表明,1000K时,加入0.5%的O,CH或NO活性自由基可将点火延迟时间缩短将近1/10。当初始温度升高时,活性自由基对于点火延迟时间的缩短效果越来越不明显。在2000K时,活性自由基对于点火延迟时间的影响可以忽略不计。随着初始温度的升高,2000K时,反应机理中的化学反应式对于温度敏感性以及活性自由基的敏感性下降为1000K时的1/1000以下。随着初始温度的变化,对温度及活性自由基敏感性较大的反应式也会发生非常大的变化。多个反应式在温度敏感性与活性自由基敏感性最大反应式中重复出现,这些反应式是将反应机理简化的重要依据。初始温度变化,化学反应的主要流程与路径也会发生变化。

In order to study the effects of the active radical on the kerosene cracking gas ignition delay time,CHEMKIN software was used to study the ignition delay of cracked kerosene at different temperature in shock tube experiment system. The simulating results were compared with the literature experimental results and the calculation model was verified to be reliable. Ignition delay of cracked kerosene adding different active radical concentration as the initial components was studied. The effects of temperature sensitivity and active radical sensitivity on the equations were analyzed. The results show that 0.5% active radical of O,CH or NO can almost shorten the ignition delay by 10% at 1000 K. The ignition delay shorten by active radical becomes less distinct with the increasing of the initial temperature. The temperature and active radical sensitivity of the reactions would decrease by 0.1% at the initial temperature of 2000 K compared with that at 1000 K. The reactions with large sensitivity of temperature and active radical would change greatly. Multiple reactions repeat as the largest temperature and active radical sensitivity reactions. These reactions are the important basis to simplify the reaction mechanism. The chemical reaction process and path would change with the changing of initial temperature.