主动冷却通道内正庚烷热裂解与换热过程的数值模拟

Numerical Simulation of Flow with Heat Transfer and Pyrolysis for n-Heptane in a Regenerative Cooling Channel

为了深入研究碳氢燃料在主动冷却通道中的传热特性,采用详细基元反应机理对微小通道内正庚烷热解反应耦合流动换热过程进行了数值模拟。根据燃料的热裂解反应和壁面传热特性可将通道分为三个换热区域。通过对不同的入口温度、运行压力、壁面温度和通道直径等典型工况进行模拟,探索了正庚烷的热裂解反应和流动换热过程耦合的基本规律。研究结果表明,入口温度对通道整体的换热性能影响不大;保持其它参数不变,通道直径从2mm减小到0.5mm,其整体换热量降低约10%,单位面积的换热量提升约4倍。

To investigate the heat transfer characteristic of hydrocarbon fuels in regenerative cooling channels,numerical simulations were performed to study the heat transfer with endothermic pyrolysis in a micro tube by using an detailed kinetics mechanism of n-heptane. According to the characteristic of the pyrolysis and heat transfer of tube surface,the tube can be divided into three zones. By simulating the typical operating conditions with different inlet temperatures,operating pressures,wall temperatures and diameters of tube,the basic laws of coupling characteristics between flow with heat transfer and pyrolysis reaction for n-heptane are revealed.Known from the simulation results,the inlet temperature has little effect on the heat transfer performance. When diameter reducing from 2 mm to 0.5 mm and other parameters are constant,the integral wall heat flux declines by about 10%,but the average wall heat flux almost quadruples.