Flue gas waste heat utilization system and flue gas waste heat utilization method of hot blast furnace

Abstract

The invention discloses a flue gas waste heat utilization system and a flue gas waste heat utilization method of a hot blast furnace, relating to the field of blast-furnace equipment in the steel industry. The flue gas waste heat utilization system is characterized by comprising a heat exchange system which is used for performing online automatic switching according to requirements on the supply air temperature of the hot blast furnace, wherein the heat exchange system comprises an air heat exchanger, a coal gas heat exchanger, a first flue gas generation device, a second flue gas generation device, a blast-furnace coal gas pipeline, a combustion-supporting air pipeline and a flue gas pipeline. According to a plurality of air and coal gas preheating modes of the method, automatic interlink switching can be completely performed; the operation is quick and convenient, and flexible; during combustion of blast-furnace coal gas, different ways are provided for meeting different air temperature requirements of the hot blast furnace; in a process flow, a fan is not additionally arranged, so that the energy power consumption cost is low; the process flow has the advantages of small occupation area, low investment, high integration level, low operation energy consumption and the like; the system and the method can be implemented in a new or renovation project.

Description

technical field [0001] The invention belongs to the field of blast furnace equipment in the iron and steel industry, and relates to a waste heat utilization system for flue gas of a hot blast stove. Background technique [0002] With the increasing awareness of energy conservation and environmental protection in my country's iron and steel industry, the waste heat utilization of hot blast stove flue gas in blast furnace ironmaking production is being applied in various ways. The more mature ways are: low temperature flue gas preheating method (coal gas, air Preheating to 180-200°C), low-temperature preheating gas (preheating to 200°C) and high-temperature preheating air (~420°C), air and gas double preheating (both preheating to 250°C), etc., above Several methods can meet the production needs of users in production. However, due to the changeable ironmaking production process, the demand for air temperature is not always constant. How to maintain the high-efficiency producti...

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Problems solved by technology

However, due to the changeable ironmaking production process, the demand for air temperature is not always constant. How to maintain the high-efficiency production of the hot blast stove system while making full use of the waste heat of the flue gas discharged from the hot blast stove? It is a major difficulty in the current industry to ensure the different supply air temperature requirements of the hot blast stove

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