围压条件下原煤等温吸附/解吸试验方法研究
Study on Isothermal Adsorption/Desorption Experiment Method of Raw Coal Under the Condition of Surrounding Pressure
-
摘要: 为深入研究围压对煤岩吸附特性的影响,提出了一种可以测定围压条件下原煤等温吸附/解吸特性的试验方法,并研发了试验装置。利用该方法和装置对同一干燥原煤煤样,在围压15MPa条件下对CH4气体进行了2次等温吸附/解吸重复性试验,重复性偏差小于5%,显示了该方法和装置具有很好的重复性,结合吸附理论对试验结果分析可知:原煤煤样在高围压条件下对CH4气体具有典型的吸附、解吸可逆性和解吸过程滞后性;吸附/解吸过程造成煤中孔隙体积变化,可能会影响到重复性的测试。Abstract: In order to deep study the surrounding rock affected to the adsorption features of coal and rock, a experiment method to measure the isothermal adsorpti on/desorption features of raw coal under the surrounding rock pressure was provided and the experiment device could be researched and developed.The method and th e device could be applied to twice isothermal adsorption/desorption repeated experiments with CH4 under the surrounding pressure of 15 MPa for a same dry raw coal sample.The error of the repeatability would be less than 5%,could show a good repeatability of the method and device. The analysis of experiment results with the adso rption theory showed that under the high surrounding pressures, the raw coal sample would have a reversibility of a typical adsorption and desorption and the hysteresi s of the desorption process to CH4.The pore volume variation in coal occurred in the adsorption/desorption process may influence the repeatability tests.