TY - JOUR
TI - A novel triaxial apparatus to evaluate the effect of high temperature nitrogen injection concept and design
AU - Wang Sheng-Cheng
AU - Gao Ya-Nan
AU - Huang Lan-Ying
AU - Li Hai-Jian
AU - Su Shan-Jie
JN - Thermal Science
PY - 2021
VL - 25
IS - 6
SP - 4527
EP - 4535
PT - Article
AB - High temperature nitrogen, injection into coal seams is supposed to improve  the per­meability and thus maintain the safety of underground mining. A  novel triaxial appa­ratus is recently developed, aiming at providing the  effective method to evaluate the effect of high temperature nitrogen  injection. The main feature of this novel appara­tus is its high confining  pressure, gas injection with high pressure as well as the high temperature.  This new device can be either used for natural coal samples (e.g. intact or  fractured) or the synthetic coal samples. A series of leakage tests were  conducted to verify the feasibility of this instrument, the results of which  have confirmed that the maximum pressure (i.e. 10 MPa) can be reached. In  addition, the high temperature and pressure of nitrogen gas can also be  sustain at the requested level. Based on the preliminary tests on the  instrument, a large amount of tests were carried out to eval­uate the effect  of nitrogen injection in enhancing the permeability of coking coal from the  Pingdingshan coalfield, China, and the influence of high temperature  nitrogen injection on mechanical parameters of coal was obtained.