裂解炉点火升温过程NO_(x)的排放控制与优化策略

NO_(x) Emission Control and Optimization Strategy in Ignition Heating Process of Cracking Furnace

中国石油兰州石化公司460 kt/a乙烯装置裂解炉是典型的高温工业设备,其NO_(x)排放控制是实现绿色生产的重要环节。文章详细分析了裂解炉现有燃烧器进行技术改造的必要性,并对点火升温过程中NO_(x)的生成机制进行了系统研究,提出了一种基于交替间隔点火和多因素综合管控的优化策略。研究结果表明:通过改造低氮燃烧器、优化点火升温流程、分步通入低压蒸汽及调整风门开度等措施,能够有效降低裂解炉在点火升温过程中的NO_(x)排放量,实现NO_(x)的达标排放。低氮燃烧器的改造显著降低了正常生产状况下的NO_(x)排放量;而利用热量分割原理,通过交替间隔点火和多步骤低压蒸汽投用则有效减少了升温过程中NO_(x)的瞬时高排放现象。

Controlling NO_(x) emissions from the 460 kt/a ethylene plant’s cracking furnace at Lanzhou Petrochemical,a typical high-temperature industrial facility,is crucial for achieving green production.This paper thoroughly analyzed the necessity of making technological retrofitting for the existing burner of the cracking furnace,made systematical investigation on the mechanisms of NO_(x) formation during the ignition and heating processes,and proposed an optimized strategy based on alternating interval ignition and multi-factor integrated management.The results showed that measures such as transforming low-NO_(x) burners,optimizing the ignition and heating process,introducing low-pressure steam in stages,and adjusting the damper opening effectively reduced the NO_(x) emissions during the ignition and heating stages of the cracking furnace.These measures ensure compliance with NO_(x) emission standards.Specifically,retrofitting low-NO_(x) burners significantly reduces NO_(x) emissions during normal operation.The application of the heat splitting principle,through alternating interval ignition and multi-step introduction of low-pressure steam,effectively minimizes transient high NO_(x) emissions during the heating process.