Sybir A. The increase of efficiency of regenerative furnaces operation by improving of fuelburning devices and heating conditions of ingots

The thesis is dedicated to enhancing the quality and efficiency of thermal heating of ingots, study and development of new regenerative burner of heating furnaces, heat treatment of ingots with a liquid core, which guarantees safe rolling. Three-dimensional mathematical model of thermal processes in the regenerative furnace chamber on the basis of modern numerical methods was developed and implemented on a computer. The model allows to investigate the turbulent flow of gases in the furnace, fuel combustion, convection and radiation heat transfer (including radiation selectivity of flue gas) and heating products in view of the burner design. Mathematical simulation of gases motion in regenerative soaker with one central burner was carried out, certain features of fuel combustion for this burner design was determined. It was established that the ordinary torch burning of fuel is absent in the working space of the furnace, and distribution combustion is arisen in the furnace volume. The results of mathematical simulation of gas motion were verified by hydraulic modelling, and the results of heating ingots simulation were verified by study of industrial regenerative soaker with one central burner of Blooming-1 department of industrial complex "ArcelorMittal Kryviy Rih". A new design of burner for regenerative furnace chamber with a burner in the centre of the hearth was proposed, it ensures high quality of fuel combustion at a lower ratio of air flow and uniform ingots heating due to improved circulation of furnace gases. The heating conditions for ingots were proposed using the results of computer simulation of ingots solidification of rimmed and half tranquil steel from the moment of casting to its putting into soaker with subsequent heating of ingots with non-solidified core in the soaker, it allows use to the maximum the heat of non-cured part of the ingot and ensure complete ingots solidification before rolling. Key words: mathematical modelling, fuel combustion, energy efficiency, heating conditions, heat transfer, regenerative furnace.