Phase change-dividing-wall-type combined heat exchange system and method for flue gas of heating furnace

Abstract

The invention provides a phase change-dividing-wall-type combined heat exchange system and method for flue gas of a heating furnace. A shaft control reversing flue gate, a phase change air heat exchanger and a metal dividing-wall-type coal gas heat exchanger are connected in series in the flue channel of the heating furnace; the phase change air heat exchanger is divided into two heat exchange chambers through a baffle wall, and each heat exchange chamber is filled with a phase change heat storage material; high-temperature flue gas entering one heat exchange chamber releases heat to the phase change heat storage material, and after the phase change heat storage material is changed from the solid state to the liquid state, the flue gas enters the other heat exchange chamber through regulating the shaft control reversing flue gate for heat conversion; meanwhile, cold air enters the hot heat exchange chamber, and the phase change heat storage material is changed from the liquid state to the solid state and emits heat when being cooled; the temperature of the cold air rises to 600 DEG C above after the cold air absorbs heat and then the cold air is used for preheating combustion-supporting air of the heating furnace. According to the invention, the problem that the high-temperature side of an existing metal-air heat exchanger is easily burned is radically solved; the air preheating temperature can be improved greatly; the flue gas residual heat recovery efficiency can be improved; the preheating temperatures of air and coal gas can be stabilized; the service life of a heat exchanger system can be prolonged.

Description

Technical field [0001] The invention belongs to the technical field of industrial furnace preheat recovery, and in particular relates to a high-temperature flue gas phase transition-partitioning combined heat exchange system and a heat exchange method for a steel rolling heating furnace. Background technique [0002] The heat from the flue gas discharged from the steel rolling furnace accounts for about 35%, which accounts for the largest proportion of the heat loss. At present, the commonly used method of recovery of flue gas waste heat is: install partition type air heat exchanger and gas heat exchanger in the flue of the furnace tail to recover the flue gas waste heat, and preheat the combustion air or combustion air and gas used in the burner of the heating furnace. At the same time, preheating reduces the fuel consumption of the heating furnace and saves energy. Because the temperature of the flue gas discharged from the heating furnace before entering the air heat exchange...

AI Technical Summary

Problems solved by technology

[0007] The present invention provides a heating furnace flue gas phase change-partition wall combined heat exchange system and method. The problem of low recycling efficiency

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