静电场作用下正戊烷在金属管内积碳特性分析

Analysis of n-pentane coking characteristics in metal tubes under electric field

设计了一种施加高电压的针—管流动反应器,用于研究电场作用下高温碳氢燃料在金属管产生积碳的复杂物理化学过程。在正戊烷入口雷诺数650,温度600 K条件下,进行了3600 s电极电压为0~5000 V的积碳特性研究。对实验后样品进行SEM电镜扫描,测试了积碳微观形貌;利用程序升温氧化(TPO)碳含量测试系统测定积碳种类及碳含量。实验结果表明,正戊烷在高温合金钢管壁表面的积碳形貌主要为球状,粒径在1~11μm范围内,随着电极电压的增加,小粒径积碳颗粒所占比重增加,并且壁面积碳严重位置会向反应器出口方向偏移。在实验温度范围内正戊烷主要发生氧化沉积,并且电场对积碳种类无明显影响,但随着电极电压的升高,壁面的积碳质量明显减少,最大抑制量可达19.01%。

A high-voltage needle-tube flow reactor was designed to study the complex physical and chemical processes of high-temperature hydrocarbon fuels that produce carbon deposits on metal tubes under the action of the electric field.Under the conditions of inlet Reynolds number 650 and fuel temperature 600 K,the electric potential of 0~5000 V were compared for 3600 s respectively.The scorching morphology and distribution of the coking were analyzed by scanning electron microscope(SEM).The carbon deposition type and carbon content were determined by temperature programmed oxidation(TPO).The experimental results show that the deposits morphology of n-pentane on the surface of the high-temperature alloy steel pipe is mainly spherical deposits of diameter between 1~11μm.As the voltage increasing,the proportion of small-sized deposition particles increases,and the serious position of coking on the wall shifts toward the outlet of the reactor.In the experimental temperature range,n-pentane mainly underwent oxidation deposition,and the electric field has no obvious effect on the type of deposits.With the increase of the electrode electric potential,the carbon deposition quality of the wall surface issignificantly reduced,and the maximum suppression amount can reach 19.01%.