Study of computation and experiment of ventilation heat resistance in roadway during mine fire.

Aiming at the problem of the computation of ventilation heat resistance in a roadway during mine fire, to the ventilation roadways with airflow temperature and density variation, a normative computing formula was deduced. It was pointed out that according to generalized ventilation principle, the ventilation resistance during mine fire includes frictional resistance and local resistance, as well as an additional resistance caused by the external ventilation source, namely fire smoke. In the new formula, the computation of ventilation resistance is expressed from two media, namely fluid and roadway, and the conception of roadway geometry air resistance were introduced. Geometry air resistance is the resistance characteristic of roadway itself, and it has nothing to do with fluid. Geometry air resistance includes frictional resistance and local resistance too. Conceptually, the new formula has a clear discrimination to the essence of heat resistance, so the mistakes easily appear during computation and analysis will be avoided. The conclusion that the ventilation resistance of high temperature smoke flow is in direct proportion to fire temperature was drawn. To verify the heat flow resistance effect, an experimental pipeline facility was designed to determine the variation of heat resistance with temperature. The experimental results are identical to the conclusion drawn from theoretical derivation. The additional resistance of exogenous smoke flow was extracted successfully by using the experimental facility. Experimental results show that exogenous resistance is the physical image of combustion process. A practical method for computing the heat resistance with the participation of exogenous gas is provided. [ABSTRACT FROM AUTHOR]