Table 1 Model parameter.

Refuge chamber

The total length 21 m, width 4 m

The straight wall height of 2 m

The arch height of 2 m

The transition chamber length 3 m

The survival chamber length 18 m

Main roadway

The length 10 m, width 4 m

The straight wall height of 2 m

The arch height of 2 m

The CO content in the main alley 0.8%

The wind speed 3.5 m· s⁻¹

Ground borehole

The side length 0.2 m

Protective isolation door (Without installing the flexible isolation door) and airtight door

1.6 m high, 0.96 m wide

Protective isolation door (Installing the flexible isolation door)

1.6 m high, 0.35 m wide

Remark

The refuge chamber floor is 0.2 m above the main roadway ground

The lower transverse door frame in the model is 0.3 m above the main roadway ground

The borehole hole is 0.3 m above the top of the refuge chamber