(1.中国矿业大学 电力学院,江苏 徐州221116;2.中国矿业大学 化工学院,江苏 徐州221116)

为研究流体在石墨多孔介质中的流动规律,通过水的单相饱和渗流实验,揭示了水在不同孔隙率的石墨多孔介质中的非Darcy渗流规律.实验结果表明:流动偏离达西定律,呈现非线性,可以用一元二次方程的形式拟合,而且精度较高,相关系数达0.99以上;流体在渗流过程中存在最小启动压力梯度,其大小随孔隙率的增加而急剧减小,按其大小随孔隙率的变化将石墨多孔介质分为3类:"易渗类"孔隙率约>18%,"难渗类"孔隙率约<11%,"过渡类"孔隙率在两者之间;水在石墨渗流过程中雷诺数的计算结果也表明流动为非Darcy渗流,与实验现象相一致.

Study on Nonlinear Seepage Law in Graphite Porous Materials

For the research on the fluid flow in the porous medium of graphite,the law of non-Darcy flow was revealed through the seepage flow of single-phase water in the saturated carbon-graphite with the whole Core Flow System.The experiment results indicate that the flow of water deviates from Darcy’s law,the flow curve is nonlinear,and it can be described in a quadratic equation.The fitting precision is higher,and the correlation coefficient is more than 0.99.The flow has minimum starting pressure gradient in the seepage process and its value decreases rapidly with increasing porosity.Graphite materials can be divided into three categories according to the minimum starting pressure gradient with the change in porosity,namely "easy infiltration category","difficult seepage category" and "transition category".Their porosity is greater than 18%,less than 11% and in 11%~18%.The nonlinear seepage law of water is verified through Reynolds number criterion and it agrees well with the experimental phenomena.