Coke oven flue gas waste heat recovery technology

Abstract

The invention relates to the field of flue gas waste heat recovery in coke making enterprises and metallurgy enterprises, in particular to a coke oven flue gas waste heat recovery technology. A waste heat recovery device comprises a main flue, an auxiliary flue, a steam-water system, an induced draft fan and a coke oven chimney. The waste heat recovery device is characterized in that an automatic control square gate valve is arranged on the main flue, an automatic control round louver valve is arranged on the auxiliary flue, and the steam-water system is arranged under a waste heat recovery boiler. The induced draft fan is arranged on the side of an outlet of the waste heat recovery boiler and carries out frequency control to control the pressure of the main flue of a coke oven outlet to be within the range of negative 170-380Pa, and control the flow rate of flue gas in the auxiliary flue to be 10-15m / s. Compared with the prior art, the coke oven flue gas waste heat recovery technology has the advantages that through stabilizing of coke oven collecting flue suction, automatic switching control over a main flue system and an auxiliary flue system, and reasonable selection of valves and models and device arrangement for the waste heat recovery boiler, on the premise that land occupation is reduced and investments are saved, flue gas waste heat is effectively recovered, and stable, reliable and continuous operation of a coke oven is ensured.

Description

technical field [0001] The invention relates to the field of waste heat recovery from flue gas in coking and metallurgical enterprises, in particular to a coke oven flue gas waste heat recovery process. Background technique [0002] The exhaust gas of the coke oven flue uses a waste heat recovery device to recover waste heat. First, it can reduce the temperature of the exhaust gas and smoke. Second, it can generate low-pressure steam with corresponding parameters according to the steam consumption parameters. It is used in production and life, which is conducive to saving energy and reducing coking. It is one of the effective measures for energy saving and emission reduction in coking, metallurgy and other fields. [0003] Chinese patent CN201010558892.9 discloses a coke oven flue gas waste heat recycling method or some implemented coke oven flue gas waste heat recovery projects. A bypass flue (auxiliary flue) is drawn from the flue (main flue) (in front of the main flue fl...

AI Technical Summary

Problems solved by technology

[0004] 1) The control system is not accurate

The reasons are: a. The setting of the waste heat recovery system should be based on the premise of ensuring the stable, reliable and continuous operation of the coke oven. , which is not conducive to the production of coke ovens; b. At present, the steam production (0.8MPa, saturation temperature) of the coke oven flue waste heat recovery device is about 10t / h. The interlocking control method of the boiler feed water pump is inconsistent with the provisions in the "Boiler Safety Technical Supervision Regulations" TSG G0001-2012 that "steam boilers with a rated evaporation greater than 4t / h should be equipped with automatic water supply adjustment devices";

[0005] 2) The valve form on the main and auxiliary flue is unreasonable

[0006] 3) Poor practicality

[0007] In addition, because the coke oven flue gas temperature in the coking and metallurgical fields is about 200~300°C and the composition is relatively complex, the sulfur content is relatively high (SO 2 content (V%) is about 0.05%), so the problem of low-temperature gas dew point corrosion cannot be solved during recycling, so most of the coke oven flue exhaust gas is still directly discharged into the atmosphere through the coke oven chimney, and the waste heat of the exhaust gas cannot be recovered, resulting in massive waste of energy

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