超临界态碳氢燃料流固耦合传热及热裂解的计算方法研究

Numerical Method Development for Conjugated Heat Transfer of Hydrocarbon Fuel with Thermal Cracking at Supercritical Conditions

关键词:  数值方法  耦合传热  超临界态  热裂解  碳氢燃料

Key words:  Numerical method  Conjugated heat transfer  Supercritical conditions  Thermal cracking  Hydrocarbon fuel

摘要:

为深入研究主动再生冷却机理，采用固体热传导方程和流体控制方程，建立了超临界态碳氢燃料耦合传热及热裂解的数值方法。对两种实验状态下电加热管内RP-3航空煤油的耦合传热及热裂解过程进行了计算研究，其中RP-3的热裂解反应由包含1个总体反应和23个二次反应的Modified Kumar-Kunzru反应机理模拟。两种状态下计算得到的外壁温、燃料温度、RP-3裂解率以及裂解产物分布与测量值的最大误差分别小于10%和15%。计算与实验结果吻合较好，表明建立的数值方法是准确的，可以作为研究超临界态碳氢燃料耦合传热及热裂解特性的有效计算分析工具。

Abstract:

In order to study the actively regenerative cooling mechanism，a numerical method of conjugated heat transfer of hydrocarbon fuel with thermal cracking at supercritical conditions was established based on the solid thermal conduct equation and the fluid governing equations. The conjugated heat transfer behaviors of RP-3 aviation kerosene with thermal cracking inside electrically heated tube have been conducted under two different experimental conditions. The Modified Kumar-Kunzru chemical kinetics model consisting of one primary reaction and twenty-three secondary reactions was used to simulate the thermal cracking process. It is found that the maximum calculation error concerning the outer wall temperature，fuel temperature，RP-3 pyrolysis rate and cracked products yields is less than 10% and 15% under the two states，respectively. The good agreement between calculation and measurement indicates that the numerical method can be used as an effective tool to investigate the conjugated heat transfer and thermal cracking mechanisms of hydrocarbon fuel at supercritical conditions.