Citation

Niu H, Liu Y, Nie Q, Lu Y, Li S, Hu X. China Saf. Sci. J. 2020; 30(9): 37-42.

Copyright

(Copyright © 2020, China Occupational Safety and Health Association, Publisher Gai Xue bao)

DOI

10.16265/j.cnki.issn.1003-3033.2020.09.006

PMID

unavailable

Abstract

In order to study change characteristics of lignite's electrical parameters under influence of environmental factors，with lignite coal from Xinjiang mining area as samples，experiments were conducted in conditions of different temperature，different immersion time and test frequencies by using a test device of coal electrical parameters. Resistivity and dielectric constant of dry and water⁃soaked coal samples were tested and influence mechanism of multiple factors' superposition on change characteristics of parameters was explored. The results show that under same immersion time and temperature，the higher test frequency is，the smaller resistivity and dielectric constant there will be. When immersion time reaches 12 hours，resistivity decreases rapidly under different temperature and test frequency. Once it exceeds 12 hours，resistivity tends to be stable，and moisture absorption of dry lignite tends to be saturated. As temperature of coal samples is lower than 40 ℃，dielectric constant increases greatly with an increase of water immersion time for different test frequency. At a test frequency of 105 Hz，when coal sample temperature rises to 40-55 ℃ ，resistivity changes remarkably and is significantly influenced by temperature factor. However，when it is lower than 105 Hz and immersion time exceeds 24 hours，at the same temperature of 40-55 ℃ ，dielectric constant changes notably and is significantly influenced by temperature. © 2020 China Safety Science Journal. All rights reserved.

Language: zh