NUMERICAL INVESTIGNATION OF HEAT AND MASS TRANSFER PROCESSES AT THE THERMAL DECOMPOSITION REACTION SUPPRESSING FOR FOREST FUEL BY WATER DROPLETS GROUP

In this study there are the numerical investigation results of heat and mass processes under the thermal decomposition reaction suppressing of forest fuel by water droplets group. The time dependence of the thermal decomposition reaction suppressing of typical forest fuels (leaves of birch, pine and spruce needles) on distance between the droplets (Hw ) was presented. It has been established that depending on gas-vapor mixture temperature by the forest fuel surface and, as consequence, between water droplets the times td may differ by 10–40 % under identic Hw . The time dependence of the thermal decomposition reaction suppressing of typical forest fuels on gas-vapor mixture temperature was presented. It has been determined that for the thermal decomposition reaction suppressing of forest fuel it is sufficient to form the gas-vapor mixture above its surface with temperature about 300–450 K during td by the finely dispersed water spray in the flaming combustion area. Approximate expressions are obtained, which illustrate the redundancy of large thickness (all the more so they exceed characteristic size of the heated material layer Lf ) liquid films formed by the set of droplets on the surface of thermally decomposing forest fuel.