Wang Kang, Tan Wei, Zhu Yukun, Liu Liyan
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China.
ACS Omega. 2020 Aug 3;5(32):20321-20334. doi: 10.1021/acsomega.0c02241. eCollection 2020 Aug 18.
To investigate liquid seepage process in a coal granular-type porous medium, a new sampling device was designed to obtain coal samples with required porosity. Meanwhile, an approach combining ultra-deep-field microscopy with advanced digital image processing technologies was proposed to rebuild granular-type porous medium models. The liquid seepage process was simulated with CFD, and the effects of head pressure, liquid viscosity, and pore size were studied. The results show that only liquids with head pressures above a critical value can penetrate into coal stacks and the hydraulic conductivity and permeability are positively correlated to the driving head pressure. Liquid viscosity enhances flow deformation, causing more eddy current energy dissipation; the turbulent eddy dissipation caused by acetone, methanol, and ethanol was 700, 1200, and 4700 m/s, respectively. Larger pores can strengthen the additional pressure at the front end of the flow, reducing the flow resistance and thus increasing the fluid kinetic energy and seepage velocity.
为研究煤颗粒型多孔介质中的液体渗流过程，设计了一种新的采样装置以获取具有所需孔隙率的煤样。同时，提出了一种将超深场显微镜与先进数字图像处理技术相结合的方法来重建颗粒型多孔介质模型。用计算流体动力学（CFD）模拟液体渗流过程，并研究了水头压力、液体粘度和孔径的影响。结果表明，只有水头压力高于临界值的液体才能渗入煤堆，水力传导率和渗透率与驱动水头压力呈正相关。液体粘度增强流动变形，导致更多涡流传能耗散；丙酮、甲醇和乙醇引起的湍流涡耗散分别为700、1200和4700米/秒。较大的孔隙可增强流前端的附加压力，降低流动阻力，从而增加流体动能和渗流速度。
