罐式炉堆积料层中单石油焦颗粒的热解模型

Pyrolysis Model of Single Petroleum Coke Particle in Accumulation Bed of Shaft Calciner

针对炭素罐式炉内石油焦热解煅烧非稳态传热传质过程,建立了罐式炉堆积料层中单石油焦颗粒的热解模型,并采用有限差分法进行离散求解。利用该模型研究了石油焦中水分、挥发分含量、颗粒粒径及罐式炉内堆积料层温度、颗粒与周围挥发分气体相对流速等因素对石油焦颗粒热解过程的影响。结果表明,颗粒直径及罐式炉内堆积料层温度对石油焦热解煅烧过程影响最为显著;颗粒直径越大,焦中的水分及挥发分析出速率越慢且其完全析出所需要的时间越长;堆积料层温度越高,颗粒热解速率越快,颗粒内外温度均一所需时间越短。

According to the non-steady heat and mass transfer process of pyrolysis and calcination of petroleum coke in carbon shaft calciner,a mathematical model to describe pyrolysis of single petroleum coke particle in accumulation bed of shaft calciner was established,and the finite difference method was used to solve the discrete problem.The effects of the content of moisture and volatile of petroleum coke,the particle size,the temperature of accumulation bed and relative velocity of particles and volatile gas in a shaft calciner were investigated by the model.The results show that the particle diameter and the temperature of accumulation bed had the most significant influence on the pyrolysis and calcination process of petroleum coke.The larger the particle diameter was,the slower the precipitation rate of moisture and volatile matter was,and the longer time it took to complete the precipitation process.The higher the temperature of accumulation bed was,the faster the particle pyrolysis rate was,and the shorter time it took to reach the temperature uniformity inside and outside of the particle.