Impact of Heat and Mass Transfer during the Transport of Nitrogen in Coal Porous Media on Coal Mine Fires

Table 2

Grouping of experimental conditions.

Average particle size d, mm	Voidage 𝜒, %	Infusion environment	Number
17.5 (15~20)	42.5	Open	(A)
		Closed	(B)
12.5 (10~15)	39.1	Open	(C)
		Closed	(D)
7.5 (5~10)	37.3	Open	(E)
		Closed	(F)