FD模型应用于煤热解过程的数值模拟

Numerical simulation of coal pyrolysis using FD model

为将煤热解FD模型引入对煤热解实际过程的数值计算与分析,提出了适用于煤热解实际过程的数值计算方法。分别对3种不同的煤在热管反应器中的热解过程进行了数值计算,并与实验结果以及已有的FG-DVC模型、CPD模型的数值计算结果进行了对比分析。并分析了热解温度、颗粒粒径对煤热解产物的影响。结果表明,与FG-DVC模型、CPD模型相比,FD模型的计算精度更高,能更好地用于数值计算煤热解的实际过程;随着热解温度的升高,气体产量先快速增大,当热解温度高于1373 K时,气体产量的变化很小;而随着热解温度的升高,焦油产量一直逐渐减小,且达到焦油产量最大值所需的时间也缩短;随着颗粒粒径的增大,气体与焦油的产量都逐渐减小,而达到焦油产量最大值所需的时间却延长。

For numerical simulation of coal pyrolysis using the fragmentation and diffusionn （FD） model, a numerical method was proposed. The pyrolysis of three kinds of coal in a heated-tube reactor was simulated respectively, and the results were compared with the experimental results and also with the numerical results of FG-DVC model and CPD model. The effect of pyrolysis temperature and particle diameter on coal pyrolysis product was also studied. The accuracy of FD model was higher than FG-DVC model and CPD model, proving that FD model was more applicable for numerical simulation of coal pyrolysis. The gas product increased rapidly by increasing pyrolysis temperature until 1373 K, and then was nearly constant when pyrolysis temperature was higher than 1373 K. The tar product decreased with increasing pyrolysis temperature, and less time was needed to reach the maximum tar amount. The gas product and tar product both decreased by increasing particle diameter of coal, while more time was needed to reach the maximum tar amount.