Study on coal core back suction phenomenon in the process of freezing coring

• Published in: Mei kuang an quan Vol. 53; no. 8; pp. 8 - 12
• Main Authors: FAN Daopeng, WANG Zhaofeng, XING Yi
• Format: Journal Article
• Language: Chinese
• Published: Editorial Office of Safety in Coal Mines 01.08.2022
• Subjects: back suction capacity; coal core temperature; freezing coring; gas content determination; gas pressure
• ISSN: 1003-496X
• DOI: 10.13347/j.cnki.mkaq.2022.08.002

In order to study the back suction phenomenon of the freezing core technology in the determination of coal seam gas content, the self-developed gas-containing freezing response device was tested and analyzed. We carried out experiments on the back suction phenomenon during freezing and coring under different gas pressures(1 MPa, 2 MPa, 3 MPa, 4 MPa) and different degrees of metamorphism(long flame coal, coking coal, lean coal, anthracite). The results showed that under the same conditions, with the increase of coal core gas pressure, the back suction volume of coal core gradually decreases. The back suction volume of coal core with low gas pressure(1 MPa, 2 MPa) is far greater than that of high gas pressure(3 MPa, 4 MPa). The suction speed gradually decreases with the decrease of coal core temperature, and the suction duration gradually decreases with the increase of gas pressure. The influence trend of metamorphic degree on coal core suction is the same, showing that the higher the metamorphic degree, the lo