Research on Influencing Factors of Effective Gas Extraction Radius in Coal Mine Based on Multiple Linear Regression

Table 4

Numerical simulation scheme and results of the orthogonal experiment.

Plan	Hole diameter (mm)	Extraction negative pressure (MPa)	Initial permeability of coal seam (×10^−17m^2)	Extraction time (d)	The effective gas extraction radius (m)
1	75	8	2.4	20	0.2
2	75	13	4.4	60	0.37
3	75	18	6.4	100	0.68
4	75	23	8.4	140	1.58
5	94	8	4.4	140	0.78
6	94	13	2.4	100	0.42
7	94	18	8.4	60	0.67
8	94	23	6.4	20	0.32
9	113	8	6.4	60	0.63
10	113	13	8.4	20	0.41
11	113	18	2.4	140	0.59
12	113	23	4.4	100	0.71
13	130	8	8.4	100	1.28
14	130	13	6.4	140	1.37
15	130	18	4.4	20	0.36
16	130	23	2.4	60	0.42