The pyrolysis characteristics of endothermal hydrocarbon fuel are very critical for regenerative cooling engines in thermal management. To investigate the pyrolysis characteristics of hydrocarbon fuel along the reactor,the strategy of fixed heat flux under different conditions are adopted. An online density measuring device is designed to obtain the fuel density in the process of pyroly-sis,and the gas yield,residence time as well as heat sink along the reactor are collected to research the characteristics of fuel pyroly-sis. The results show that the residence time increases gradually with the working pressure and pipe diameter. And the crucial factor for pyrolysis is the fuel temperature along the reaction tube. When the temperature is lower than 700℃,the pyrolysis is primarily af-fected by the residence time of fuel. High pressure and big pipe diameter is beneficial to the improvement of gas yields and heat sink. While the temperature exceeds 750℃,the pyrolysis is mainly controlled by the reaction temperature. Due to polymerizations of fuel are faster under high temperature,the increase of gas yield and heat sink will be slow down. In such circumstance,there will be no benefit for the increment of gas yield and heat sink when pyrolysis pressure and pipe diameter increase.%碳氢燃料在主动冷却通道中的裂解吸热是热管理的一个重要手段.为了研究碳氢燃料在裂解通道各处的裂解特性变化,本文采用电加热反应器和密度在线测量装置串联的方式,在等热流密度条件下,通过改变加热管长,结合实验所得裂解停留时间、产气及热沉结果探究了燃料的裂解特性.结果表明,受压力和管径影响,燃料裂解停留时间随压力升高或管径增大而增长;油温在700℃前,裂解反应受停留时间影响较大,压力高管径大有利于产气和热沉的提高,而在750℃后,裂解反应受温度控制,而且在高温时由于缩聚反应的发生,管径增大,压力升高,而引起的停留时间增加,都使得缩聚反应进一步深入,燃料的产气率和化学热沉增长都相应减缓,此时增大压力或管径都不利于燃料产气率和热沉的提高,其中压力影响尤为显著.
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