system: [SYSTEM]

user: 4. 等压吸附/解吸特征 利用数学拟合式，计算升压(吸附)与降压(解吸)过程0.5 MPa、1.0 MPa、2.0 MPa…8.0 MPa九个压力点的吸附量，绘制温度–吸附量曲线，即等压吸附线。 4.1. 升压(吸附)过程各压力点的吸附特征 1) 在0.5 MPa、1.0 MPa、2.0 MPa…8.0 MPa九个压力点作垂线，与等温吸附线相交，计算升压吸附过程的吸附量。计算结果见图10，图11，图12； 2) 对每个压力点下五个温度的吸附量进行多数学式关系拟合，发现温度–吸附量线性相关，均满足Q = aT + b的一元函数关系(Q为吸附量，T为绝对温度)。九个压力点下的温度–吸附量线性拟合结果见表5。拟合度R 2 最低为0.67； 3) 煤层气升压(吸附)过程，平衡水样温度–吸附量线性拟合度绝大多数大于0.99，个别低压点大于0.93；干燥基样温度–吸附量线性拟合度多数大于0.85，低压时线性拟合度最小0.67，同时拟合度稍低的情况仅出现在高煤阶、空干基的低压点处。 4.2. 降压(解吸)过程各压力点的吸附特征 1) 同4.1，在0.5 MPa、1.0 MPa、2.0 MPa…8.0 MPa九个压力点作垂线，与等温解吸线相交，计算降压解吸过程的吸附量。计算结果见图13，图14，图15； 2) 对每个压力点下5个温度的吸附量进行多数学式关系拟合，发现温度–吸附量线性相关，均满足Q = aT + b的一元函数关系(Q为吸附量，T为绝对温度)。9个压力点下的温度–吸附量线性拟合结果见表6。拟合度R 2 最低为0.69； 3) 煤层气降压(解吸)过程，平衡水样温度–吸附量线性拟合度绝大多数大于0.99；干燥基样较温度–吸附量线性拟合度低。 4.3. 小结 1) 无论煤层气升压吸附过程或降压解吸过程，温度–吸附量显示高度的线性相关，即等压吸附线为直线； 2) 煤层气吸附解吸平衡系统，平衡水样品等压吸附较空气干燥基样等压吸附关系显著得多。对比平 Table 4 The fitting results of adsorption-desorption experimen 煤样 含水率/% 温度/℃ Langmuir拟合 解吸式拟合 a b R 2 a b c R 2 CY空干基煤样 4.65 25 12.164 0.359 0.995 8.870 0.587 0.882 0.998 30 11.592 0.362 0.996 8.370 0.585 0.942 1.000 35 11.525 0.327 0.993 7.959 0.496 1.072 0.997 40 11.201 0.324 0.993 7.732 0.529 1.015 0.998 45 11.200 0.288 0.993 7.467 0.505 1.033 0.997 CY平衡水煤样 10.14 25 11.563 0.448 0.992 8.623 0.701 0.949 0.996 30 11.566 0.396 0.990 8.341 0.619 0.994 0.997 35 11.079 0.382 0.993 8.040 0.597 0.973 0.998 40 10.725 0.374 0.993 7.698 0.543 1.039 0.999 45 10.238 0.382 0.993 7.380 0.568 1.009 0.998 JM空干基煤样 0.96 25 17.820 0.521 0.998 15.230 0.832 1.130 0.996 30 17.030 0.515 0.998 14.330 0.822 1.230 0.990 35 16.870 0.511 0.997 13.730 0.819 1.640 0.998 40 15.560 0.508 0.997 12.630 0.813 1.540 0.999 45 14.320 0.501 0.999 11.930 0.803 1.160 0.998 JM平衡水煤样 3.01 25 16.370 0.513 0.998 14.130 0.807 0.930 0.995 30 15.730 0.506 0.998 13.380 0.801 1.020 0.997 35 15.210 0.493 0.997 12.330 0.795 1.490 0.995 40 14.730 0.487 0.997 11.720 0.811 1.570 0.993 45 13.890 0.486 0.999 11.390 0.791 1.210 0.991 WY3空干基煤样 3.55 25 40.084 0.366 0.990 29.182 0.516 5.420 0.992 30 37.148 0.243 0.991 27.769 0.360 3.499 0.995 35 34.649 0.245 0.990 28.815 0.271 2.895 0.992 40 33.458 0.267 0.988 27.941 0.282 3.434 0.992 45 29.963 0.250 0.991 26.482 0.220 3.055 0.981 WY3平衡水煤样 4.19 25 37.030 0.430 0.998 29.850 0.721 3.250 0.995 30 35.240 0.410 0.998 27.860 0.715 3.290 0.992 35 33.970 0.370 0.997 25.920 0.706 3.340 0.993 40 32.450 0.340 0.997 23.760 0.695 3.560 0.994 45 30.910 0.310 0.999 22.320 0.687 3.120 0.996 表4. 吸附解吸实验拟合结果 Table 5 The fitting analysis data of air-dry basis and equilibrium water samples in booster process of adsorptio 煤样 压力/MPa 空干基样 平衡水样 拟合方程 R 2 拟合方程 R 2 CY 8.0 Q = −0.0592T+26.608 0.9908 Q = −0.0681T +29.378 0.9944 7.0 Q = −0.0594T +26.352 0.9929 Q = −0.0674T +28.883 0.9951 6.0 Q = −0.0593T +25.959 0.9945 Q = −0.0664T +28.230 0.9951 5.0 Q = −0.0589T +25.344 0.9956 Q = −0.0649T +27.334 0.9940 4.0 Q = −0.0577T +24.351 0.9957 Q = −0.0626T + 26.046 0.9911 3.0 Q = −0.0549T +22.677 0.9945 Q = −0.0587T + 24.078 0.9851 2.0 Q = −0.0489T +19.666 0.9915 Q = −0.0517T + 20.797 0.9737 1.0 Q = −0.0352T +13.710 0.9859 Q = −0.0371T + 14.577 0.9525 0.5 Q = −0.022T +8.4091 0.9818 Q = −0.0234T + 9.0406 0.9357 JM 8.0 Q = −0.1408T +56.497 0.9437 Q = −0.1024T + 43.698 0.9944 7.0 Q = −0.1374T +55.111 0.9441 Q = −0.1003T + 42.718 0.9947 6.0 Q = −0.1332T +53.364 0.9446 Q = −0.0977T + 41.474 0.9951 5.0 Q = −0.1277T +51.095 0.9453 Q = −0.0942T + 39.843 0.9955 4.0 Q = −0.1203T +48.028 0.9461 Q = −0.0893T + 37.616 0.9960 3.0 Q = −0.1096T +43.655 0.9473 Q = −0.0821T + 34.394 0.9966 2.0 Q = −0.093T +36.920 0.9491 Q = −0.0706T + 29.336 0.9972 1.0 Q = −0.0639T +25.221 0.9518 Q = −0.0495T + 20.307 0.9977 0.5 Q = −0.0393T +15.428 0.9538 Q = −0.0309T + 12.543 0.9977 WY3 8.0 Q = −0.431T +156.83 0.8659 Q = −0.3321T + 127.7 0.9999 7.0 Q = −0.4225T +153.19 0.8532 Q = −0.3311T + 126.53 1.0000 6.0 Q = −0.4113T +148.49 0.8381 Q = −0.329T + 124.77 1.0000 5.0 Q = −0.3959T +142.23 0.8201 Q = −0.3245T + 122.05 1.0000 4.0 Q = −0.374T +133.56 0.7983 Q = −0.316T + 117.66 0.9999 3.0 Q = −0.3411T +120.92 0.7719 Q = −0.2996T + 110.22 0.9998 2.0 Q = −0.2882T +101.22 0.7394 Q = −0.2665T + 96.611 0.9996 1.0 Q = −0.1941T +67.392 0.6996 Q = −0.1931T + 68.719 0.9992 0.5 Q = −0.1165T +40.166 0.6765 Q = −0.1218T + 42.871 0.9988 表5. 升压吸附过程空干基样和平衡水样的拟合分析数据 Table 6 The fitting analysis data of air-dry basis and equilibrium water samples in booster process of desorptio 煤样 压力/MPa 空干基 平衡水 拟合方程 R 2 拟合方程 R 2 CY 8.0 Q = −0.0584T+25.557 0.9757 Q = −0.0611T + 26.467 0.9960 7.0 Q = −0.0578T +25.196 0.9736 Q = −0.061T + 26.274 0.9957 6.0 Q = −0.057T+24.717 0.9707 Q = −0.0608T + 26.001 0.9940 5.0 Q = −0.0557T+24.057 0.9670 Q = −0.0603T + 25.597 0.9916 4.0 Q = −0.0538T+23.096 0.9618 Q = −0.0594T + 24.960 0.9880 3.0 Q = −0.0506T+21.594 0.9547 Q = −0.0575T + 23.870 0.9824 2.0 Q = −0.0448T+18.984 0.9451 Q = −0.0532T + 21.763 0.9735 1.0 Q = −0.0318T+13.624 0.9362 Q = −0.0415T + 16.811 0.9590 0.5 Q = −0.0183T+8.3592 0.9470 Q = −0.0275T + 11.327 0.9498 JM 8.0 Q = −0.1391T+55.988 0.9431 Q = −0.1021T + 43.612 0.9933 7.0 Q = −0.1367T+55.023 0.9416 Q = −0.0999T + 42.711 0.9923 6.0 Q = −0.1336T+53.787 0.9395 Q = −0.097T + 41.560 0.9908 5.0 Q = −0. 1295T+52.144 0.9365 Q = −0.0932T + 40.038 0.9885 4.0 Q = −0.1237T+49.855 0.9318 Q = −0.0879T + 37.930 0.9845 3.0 Q = −0.1151T+46.448 0.9237 Q = −0.0801T + 34.818 0.9764 2.0 Q = −0.1008T+40.836 0.9060 Q = −0.0674T + 29.761 0.9549 1.0 Q = −0.0728T+29.871 0.8436 Q = −0.043T + 20.109 0.8429 0.5 Q = −0.0453T+19.253 0.6912 Q = −0.0201T + 11.029 0.4541 WY3 8.0 Q = −0.3851T+142.35 0.8535 Q = −0.3335T + 128.13 1.0000 7.0 Q = −0.3945T+144.47 0.8532 Q = −0.3275T + 125.80 1.0000 6.0 Q = −0.4039T+146.42 0.8520 Q = −0.3197T + 122.82 1.0000 5.0 Q = −0.4123T+147.86 0.8496 Q = −0.3094T + 118.88 0.9999 4.0 Q = −0.4179T+148.09 0.8452 Q = −0.2952T + 113.42 0.9999 3.0 Q = −0.4162T+145.59 0.8372 Q = −0.274T + 105.38 0.9997 2.0 Q = −0.396T+136.65 0.8222 Q = −0.2397T + 92.349 0.9992 1.0 Q = −0.3263T+111.07 0.7880 Q = −0.1739T + 67.634 0.9965 0.5 Q = −0.246T+83.408 0.7453 Q = −0.1121T + 44.626 0.9849 表6. 降压解吸过程空干基样和平衡水样的拟合分析数据 图10. 不同压力点CY空干基样与平衡水样等压吸附曲线 图11. 不同压力点JM空干基样与平衡水样等压吸附曲线 图12. 不同压力点WY3空干基样与平衡水样等压吸附曲线 图13. 不同压力点CY空干基样与平衡水样等压解吸曲线 图14. 不同压力点JM空干基样与平衡水样等压解吸曲线 图15. 不同压力点WY3空干基样与平衡水样等压解吸曲线 衡水分含量分析结果与孔隙结构、比表面积分析结果，认为是CH 4 —H 2 O在煤孔隙内表面作用方式造成的，润湿性研究应受到重视。