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Abstract

The #3 coal seam of Jinsheng Rundong Ltd. of Jin-Coal Group in Shanxi Province, China, has high gas content and pressure; however, it has a low gas permeability, which can easily cause gas enrichment and may cause accidents of coal and gas outbursts. In this work, the characteristics of gas seepage were thoroughly studied by designing and modifying the 'complete stress-strain tri-axial servo temperature-controlled test system'. The study was conducted based on four factors: Axial pressure, confining pressure, effective stress and gas pressure. We found that the axial pressure has a weak impact on coal gas permeability, indicated by a linear relationship. The confining pressure, however, has a strong impact on gas permeability, showing an exponential relationship. The relationship between permeability and gas pressure was identified as a second-order polynomial function. The functional relationship between gas permeability and axial pressure, confining pressure, effective stress, gas pressure was analyzed. Investigation into the natural flow rate of gas, concentration of gas drainage and damping coefficient supported the conclusion from the experimental study on the characteristics of gas seepage under loaded stress. ABSTRAKLipit arang batu #3 daripada Jinsheng Rundong Ltd. diperoleh daripada Kumpulan Jin-Coal di Wilayah Shanxi, China mempunyai kandungan dan tekanan gas yang tinggi; walau bagaimanapun, ia mempunyai kebolehtelapan gas yang rendah dan dengan mudah boleh menyebabkan pengayaan gas yang boleh menyebabkan kemalangan arang batu dan letusan gas. Dalam kajian ini, ciri resapan gas telah dikaji secara teliti dengan merancang dan mengubah suai 'sistem pengujian suhu-terkawal servo tri-paksi tekanan yang lengkap'. Kajian ini dijalankan berdasarkan empat faktor: Tekanan paksi, tekanan mengekang, tegasan berkesan, dan tekanan gas. Kami mendapati bahawa tekanan paksi mempunyai kesan lemah terhadap ketelapan gas arang batu, seperti ditunjukkan pada hubungan lurus. Walau bagaimanapun, tekanan pengurung mempunyai kesan yang besar terhadap kebolehtelapan gas, yang menunjukkan hubungan eksponen. Hubungan antara kebolehtelapan dan tekanan gas dikenal pasti sebagai fungsi polinomial-tertib kedua. Hubungan fungsi antara kebolehtelapan gas dan tekanan paksi, tekanan mengekang, tegasan berkesan dan tekanan gas dianalisis. Kajian kepada kadar aliran gas semula jadi, kepekatan saliran gas dan pekali redaman menyokong kesimpulan daripada kajian eksperimen mengenai ciri resapan gas di bawah beban tekanan. Kata kunci: Beban tekanan; gas dalam arang batu; kebolehtelapan; ujian lapanganDengxing Qu