Flue gas low-temperature heat recovery method and system of fuel gas process furnace

Abstract

The invention relates to a flue gas low-temperature heat recovery method and system of a fuel gas process furnace. The system comprises a fuel gas desulfurization preheating device, an air preheatingdevice, the fuel gas process furnace, a combustor, a negative pressure induced draft fan and a chimney. The fuel gas side of the fuel gas desulfurization preheating device comprises a fuel gas line, afine desulfurization tank, a fuel gas low-temperature preheater fuel gas side and a fuel gas high-temperature preheater fuel gas side, all of which are sequentially in communication through a pipeline. The air side of the air preheating device comprises an air blower, an air low-temperature preheater air side and an air high-temperature preheater air side, all of which are sequentially in communication through a pipeline. The method and system have the beneficial effects that the exhaust gas temperature can be reduced to 70-75 DEG C, the heat efficiency of a heating furnace is improved, hydrogen production feed gas is saved, and the economic benefit is remarkable; fuel gas is subjected to ultra-low desulfurization to below 1 ppm, so that low-temperature corrosion of an acid dew point is avoided, the SO2 emission is reduced by more than 90%, and the environmental protection benefit is remarkable; and air and fuel gas are preheated, the initial combustion temperature is high, and the operation efficiency of the heating furnace is improved.

Description

technical field [0001] The invention belongs to the technical field of energy saving and environmental protection, and in particular relates to a low-temperature heat recovery method and system for flue gas of a gas-fired process furnace. Background technique [0002] In the petrochemical industry, the fuel consumption of the heating furnace of the device accounts for more than 60% of the total processing energy consumption. There is a lot of room for improving the heating furnace technology, reducing fuel consumption, and realizing energy saving and emission reduction. [0003] Refinery light hydrocarbon gas (referring to catalytic dry gas, coking dry gas and light hydrocarbon recovery gas) is not only the preferred fuel for the process furnace of the production unit (referring to the heating furnace for heating the process material stream), but also a valuable raw material for hydrogen production. How to fully Utilize the heat of the low-temperature part of the flue gas ex...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide a gas-fired process furnace flue gas for the gas-fired process furnace flue gas discharge temperature is too high, resulting in large heat loss and low-temperature dew point corrosion and ash accumulation structure problems when low-temperature flue gas energy recovery Low-temperature heat recovery system and method, reducing acid dew point corrosion temperature by ultra-low desulfurization of fuel gas, suppressing dew point corrosion and ash deposition structure by using cast iron plate flue gas preheater, and recovering low-temperature heat by preheating fuel gas and preheating air , to achieve high-quality utilization of flue gas low-temperature heat energy and long-term operation of equipment

Images