Waste heat recovery system of steel rolling heating furnace

Abstract

A waste heat recovery system of a steel rolling heating furnace comprises a main flue, wherein a second-level evaporator, a second-level air heat exchanger, a first-level evaporator and a first-level air heat exchanger are sequentially arranged in the main flue in the smoke flow direction. The firsts-level air heat exchanger is provided with a cold air inlet and is connected with the second-level air heat exchanger in series, wherein the second-level air heat exchanger is provided with a hot air outlet. The first-level evaporator is provided with a water source inlet and is connected with second-level evaporator in series, wherein the second-level evaporator is provided with a steam and water mixture outlet. An auxiliary flue used for regulating the amount of smoke passing through the second-level air heat exchanger is arranged in the position where the outer side of the main flue and the second-level evaporator are arranged in parallel, wherein an auxiliary flue evaporator and an auxiliary flue damper are sequentially arranged in the auxiliary flue in the smoke flow direction. The two levels of evaporators are arranged in the main flue, and therefore the steam heating area is effectively enlarged; the air heat exchangers and the evaporators are arranged in a staggered mode, the first-level air heat exchanger is arranged at the most tail end of the main flue, the temperature difference is ensured in the heat exchange process due to the arrangement method, and heat exchange efficiency is effectively improved.

Description

technical field [0001] The invention belongs to the technical field of thermal energy and power engineering, and in particular relates to a waste heat recovery system of a steel rolling heating furnace. Background technique [0002] The steel rolling system is a major energy consumer in steel production, and the energy consumption of the heating furnace accounts for about 70% of the energy consumption in steel rolling production. Since the main goal of the steel rolling heating furnace is to heat the billet, the billet is heated uniformly according to the heating rate required by the process, and stays for a corresponding time. Relatively insufficient attention has been paid to energy saving and consumption reduction, resulting in generally high exhaust gas temperature of steel rolling heating furnaces in my country. The recovery of waste heat from flue gas at the tail of steel rolling heating furnace can not only improve economic benefits, but also reduce pollution emissio...

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Problems solved by technology

In order to make the use of the heating surface more economical, the temperature and pressure at the outlet of the air heat exchanger should not be too small, so the first-stage air heat exchanger often cannot meet the requirements, and two-stage air heat exchangers need to be arranged

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