Abstract:

The waste heat recovery system of the steam superheater in the styrene plant has been modified with a 95+ high-efficiency heating furnace to save energy. After modification, the temperature of exhausted gas has decreased from 140 ℃ to below 85 ℃, the thermal efficiency has increased from 92% to 95%, and the emission mass concentration of NO_x has decreased from 80～90 mg/m³ to 70 mg/m³. After modification, the energy-saving effect of the plant is remarkable, reducing the pollutant emission of SO₂ and NO_x. At the same time, the problem of dew point corrosion for air preheating equipment and tail flue under low exhaust temperature is essentially solved. All indicators meet the design requirements and have significant economic benefits, providing a comprehensive reference for the energy-saving transformation using this technology of similar plants or other heating furnaces in the future.

Key words: styrene plant, steam superheater, thermal efficiency, smoke system, air system, fuel gas composite corrosion inhibition system, low NO_x combustion

摘要：

对苯乙烯装置蒸汽过热炉余热回收系统进行了95+高效加热炉节能改造，改造后排烟温度从140℃降低至85℃以下，热效率由92.0%提高至95.4%,NO_x排放质量浓度由80～90 mg/m³降低至70 mg/m³。装置改造后节能效果显著，降低了污染物SO₂和NO_x的排放，同时也从根本上解决了低排烟温度下空气预热设备及尾部烟道的露点腐蚀问题。改造后的各项指标满足设计要求并且具有可观的经济效益，为今后同类型装置或者其他加热炉节能改造采用此技术提供了全面的参考。

关键词: 苯乙烯装置, 蒸汽过热炉, 热效率, 烟气系统, 空气系统, 燃料气复合阻蚀系统, 低NO_x燃烧