Blast furnace gas boiler flue gas waste heat deep recycling system

Abstract

The invention discloses a blast furnace gas boiler flue gas waste heat deep recycling system. The shortcoming that in the prior art, blast furnace gas boiler tail flue gas waste heat is not fully used is overcome. The blast furnace gas boiler flue gas waste heat deep recycling system comprises a boiler, an air preheater, a flue gas circulating unit and a condensation water circulating unit. The flue gas circulating unit comprises a second-level flue gas-coal gas heat exchanger, a second-level flue gas-condensation water heat exchanger, a first-level flue gas-coal gas heat exchanger, an induced draft fan and a first-level flue gas-condensation water heat exchanger which are connected in series in sequence on a flue gas pipeline. The condensation water circulating unit comprises a steam condenser, a steam condensing water pump, a shaft seal heater, a first-level low-pressure heater, a second-level low-pressure heater and a third-level low-pressure heater which are connected in series in sequence on a main condensation water pipeline. Boiler exhaust smoke temperature can be effectively lowered, boiler thermal efficiency is improved, and then the using rate of boiler flue gas waste heat is improved.

Description

technical field [0001] The invention relates to the field of boiler waste heat utilization, in particular to a deep recovery and utilization system for blast furnace gas boiler flue gas waste heat. Background technique [0002] Iron and steel enterprises produce a large amount of blast furnace gas in the ironmaking process. Because the blast furnace gas contains a large amount of nitrogen and carbon dioxide, the theoretical combustion temperature is low, and it is difficult to catch fire, which makes the emission rate of blast furnace gas in many iron and steel enterprises high, resulting in waste of resources. Therefore, how to make good use of the by-product blast furnace gas resources in the iron and steel production process is a common concern of people in the relevant technical fields. [0003] In recent years, with the increasing progress and promotion of blast furnace gas boiler power generation technology, blast furnace gas boiler generator sets have been widely used...

AI Technical Summary

Problems solved by technology

However, even for blast furnace gas boilers equipped with gas heaters, the exhaust gas temperature is still as high as 130-150°C

In other words, although the existing technology recovers and utilizes the waste heat of the flue gas to a certain extent, the utilization is still insufficient, and there is still a large room for the reduction of the exhaust gas temperature, which causes a waste of energy to a certain extent. Therefore, how to in-depth Recovering the waste heat resources of the flue gas at the tail of the blast furnace gas boiler is a major goal in the field of boiler flue gas waste utilization

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