Abstract: Low temperature heating furnaces with furnace chamber temperature lower than 700 ℃ in refining and chemical enterprises have problems of incomplete combustion and high content of CO and O₂ in flue gas after low nitrogen combustion transformation. To solve the above problems, low CO and low nitrogen combustion technology was developed. This technology adopts the method of fuel staging combustion and primary fuel pre-mixed combustion which can improve the intensity and temperature of the central flame, making the flame combustion more complete and stable. While reducing NO_x emissions, it can effectively reduce the CO and O₂ content in the exhaust gas, and improve the thermal efficiency and safety of the heating furnace. Taking a reforming cylinder furnace and jet fuel hydrogenation furnace of a Sinopec branch as an example, this paper presents the revamp of the heater burner using this technology. After the revamp, the heating furnace flame burning was quite stable; the CO content in the exhaust flue gas decreased from 168.2 mg/m3 and 1 308.8 mg/m3 to 24.7 mg/m³ and 6.3 mg/m³ respectively; the O₂ content in the exhaust flue gas decreased from 4.2% and 5.6% to 3.7% and 3.0% respectively. Meanwhile, the NO_x emission was far below the national emission standard. This has ensured the safe, eco-friendly and efficient operation of the heating furnace.

Key words: heater, low NO_x burner, low CO combustion, energy-saving and emission reduction