不同粒径配比型煤渗流特性与体积应变关系试验研究

Test Study on Relation of Seepage Characteristics and Volumetric Strain for Coal Briquette in Different Particle Size

采用重庆市打通一矿K1煤层制作的不同粒径配比的型煤为研究对象,利用重庆大学自行研发的含瓦斯煤热流固耦合三轴伺服渗流装置进行试验,根据试验过程中型煤的变形形状提出了一种新的体积应变计算方法,探讨不同粒径配比型煤渗流特性与体积应变的关系。试验研究结果表明：试件渗流速度与粒径大小和粒径配比有关。粒径均匀的试件,粗粒径的渗流速度大于细粒径的渗流速度;不同粒径配比的试件,180-250μm（细粒径）含量越多渗流速度越慢;渗流速度与体积应变有较好的分段线性关系。体积应变减小阶段,各种粒径配比下的试件渗流速度均线性减小;体积反向增大阶段,180-250μm（细粒径）含量高于一定值的试件渗流速度不变,反之低于该值时渗流速度增大,但增大斜率较前面降低斜率较平缓。

The study objective in this paper is the coal briquette in different particle size from the K1 coal seam of Chongqing Datong 1#Mine,by utilizing the self- developed triaxial servo- controlled seepage equipment for thermo- fluid- solid coupling of coal containing machine,we propose a new computing method of volumetric strain in accordance of deformed shape in process of test to find the relationship between the seepage characteristic and volumetric strain in the condition of coal briquette in difference particle size. Test results show that seepage velocity is related to the particle size; seepage velocity in large particle size of coal briquette is faster than it in small particle size when the coal briquette test specimen is uniformity; the higher of particle size which is from 180 to 250 μm,the slower of the seepage velocity. There is a better relation between seepage velocity and volumetric strain. Seepage velocity is linear reduction in every particle size in the stage of volumetric strain decreasing. The seepage velocity will maintain steady when the content of 180 to 250 μm mesh corn is upon a level in the stage of volume increase reversing. In contrast,when the content of 180 to 250 μm mesh corn is under a level,the seepage velocity will increase. The increased velocity of seepage velocity is slower than the reduced velocity.