LAUSR

Abstract Various fuel composites became popular for a last decade because smart mixture of different combustibles allows effective minimization of the negative features of components. In this paper we have observed the influence of water evaporation on the different stages of ignition of the waste derived coal-water slurry with addition of the waste petrochemicals. It was shown that the gas-phase ignition stage and heterogeneous ignition stage of the slurry have the increasing time-separation (from 4 to 50 ms) with a growth of the furnace temperature after 1000 K. It happens because the peak of water vaporization in the volume of fuel shifts closer to the moment of ignition with furnace temperature increase. As result, an additional fuel heating is required before the heterogeneous ignition. The volume power density of volatiles combustion around the fuel droplet grows for 30–40 times with furnace temperature changes from 870 K to 1070 K. However, combustion of the volatiles does not produce heat enough for the immediate beginning of the stable heterogeneous ignition when the water content is about 30–40%. The obtained results can be used in future for an effective optimization of the ignition of the water-filled fuels as well as for a choice of the most effective and ecological combustion regime.